rueddenklau snowman prevention

Snowman Formation and Prevention

Thesis

at the Institute of Non-Metallic Materials Cements and Building Materials

in cooperation with

HeidelbergCement AG

presented by cand. Ing. Thomas Rüddenklau

August 2006

HC-Tutor: Ulrich Mrowald First examiner: Prof. Dr. A. Wolter Second examiner: Prof. Dr. R. Weber

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I declare herewith that the presented thesis is made single-handed and that only the

mentioned sources and utilities were used.

Clausthal-Zellerfeld, 10.08.2006

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Table of contents

0. Abstract...............................................................................................................................7

1. Introduction ........................................................................................................................8

2. Principles ............................................................................................................................9

2.1. Clinker phases ............................................................................................................9

2.2. Calculations of the phase composition..................................................................10

2.3. Calculation of the melting phase ............................................................................11

2.4. Other important moduli............................................................................................11

2.4.1. Lime saturation factor (LSF)................................................................................11

2.4.2. Silica ratio (SR) ...................................................................................................12

2.4.3. Alumina ratio (AR)...............................................................................................12

2.4.4. Degree of sulfatization (DS) ................................................................................12

2.5. Burning process .......................................................................................................12

2.6. Vaporizable constituents and its recirculating system.........................................14

2.7. Operation control measurements ...........................................................................16

2.8. Clinker cooling..........................................................................................................17

2.9. Clinker cooler types .................................................................................................18

2.10. Principle design and process technology features of modern grate coolers ..20

2.10.1. Fixed inlet areas................................................................................................20

2.10.2. Grate plate development...................................................................................20

2.10.3. Side sealing.......................................................................................................20

2.10.4. Cooler drive.......................................................................................................20

2.10.5. Clinker crusher ..................................................................................................20

2.10.6. Improvement of thermal efficiency ....................................................................21

2.10.7. Material discharge system ................................................................................21

2.10.8. Grate support system........................................................................................21

2.10.9. Cooler control system .......................................................................................21

2.10.10. Cooling air fans ...............................................................................................22

2.11. Process interrelationships – trend curves ...........................................................22

2.12. Red River .................................................................................................................28

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2.13. Snowman.................................................................................................................29

3. Checklist ...........................................................................................................................31

3.1. Part 1 (Material data) ................................................................................................31

3.1.1. Chemical Compositions ......................................................................................31

3.1.2. Clinker Mineralogy ..............................................................................................31

3.1.3. Moduli .................................................................................................................31

3.1.4. Clinker .................................................................................................................31

3.2. Part 2 (Process data) ................................................................................................32

3.2.1. Feeding system...................................................................................................32

3.2.2. Kiln ......................................................................................................................32

3.2.3. Cooler .................................................................................................................32

3.3. Part 3 (Other data) ....................................................................................................33

3.3.1. Snowman type ....................................................................................................33

3.3.2. Visual checks ......................................................................................................33

4. The cement plant in Brevik, Norway...............................................................................34

4.1. Introduction...............................................................................................................34

4.2. Flow sheet .................................................................................................................34

4.3. Kiln system modification .........................................................................................35

4.4. Actual Cooler at Brevik ............................................................................................38

4.5. Kiln stop list caused by Snowmen..........................................................................39

4.6. Chemical Compositions...........................................................................................40

4.6.1. Raw meal (kiln feed) ...........................................................................................41

4.6.2. Clinker .................................................................................................................41

4.6.3. By-pass dust .......................................................................................................41

4.6.4. Secondary and primary fuels and ash.................................................................41

4.7. Clinker mineralogy ...................................................................................................42

4.8. Moduli ........................................................................................................................42

4.9. Clinker analyses .......................................................................................................42

4.10. Burning system (Process Data) ............................................................................42

4.10.1. Feeding system.................................................................................................43

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4.10.2. Kiln ....................................................................................................................44

4.10.3. Cooler ...............................................................................................................46

4.11. Snowman type ........................................................................................................51

4.12. Visual checks..........................................................................................................52

4.13. Other noticeable features ......................................................................................52

5. The cement plant Burglengenfeld in Germany..............................................................53

5.1. Introduction...............................................................................................................53

5.2. Collected Data...........................................................................................................53

5.3. The two different cooler systems in operation ......................................................53

5.4. Specific cooling air calculations .............................................................................54

5.5. Chemical analyses....................................................................................................54

5.5.1. Raw meal ............................................................................................................54

5.5.2. Clinker .................................................................................................................55

5.5.3. Bypass dust.........................................................................................................55

5.5.4. Clinker Mineralogy ..............................................................................................55

5.5.5. Moduli .................................................................................................................55

5.6. Process data .............................................................................................................56

5.7. CARDOX-procedure .................................................................................................56

6. Snowman-Analyses .........................................................................................................57

6.1. Introduction...............................................................................................................57

6.2. Analyses....................................................................................................................57

6.2.1. Preparation of the Snowman samples ................................................................57

6.2.2. XRF – free lime – water soluble salts..................................................................58

6.2.3. XRD – Rietveld....................................................................................................59

6.2.4. Water soluble salts..............................................................................................60

6.2.5. Reflected light microscopy ..................................................................................60

6.2.6. Hot stage microscopy..........................................................................................61

6.2.7. SEM ....................................................................................................................61

7. Conclusions......................................................................................................................63

7.1. Snowman...................................................................................................................63

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7.2. Hypothesis of Snowman formation ........................................................................63

7.3. Comparable natural phenomenon ..........................................................................65

7.4. Emphasis of the important items of the Checklist ................................................67

8. Outlook..............................................................................................................................68

8.1. In general...................................................................................................................68

8.2. Tasks of Brevik .........................................................................................................68

9. List of literature ................................................................................................................71

10. Table of figures...............................................................................................................72

11. List of tables ...................................................................................................................74

12. Appendix .........................................................................................................................76

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0. Abstract

The following thesis is the first step to approach the subject of Snowman formation. In

literature there cannot be found a lot of detailed analyses and coherences of those build-ups

at the static cooler inlet. In general build-ups in the cement production often cause kiln shut

downs with the result of additional cost. Fact is that every identification of a possible problem

leading to loss of production means a prevention to reduce cost. Along a developed checklist

a cement plant with Snowman formation was checked. Influences like e.g. the content of

melting phase of the clinker, the air distribution at the static cooler inlet or the steadiness of

raw meal and fuels feeding, which lead to this kind of production breakdown, are presented

and discussed. Additionally, some analyses of a Snowman are presented and the relevant

consequences for the checked plant have been drawn. These analyses show that the

investigated Snowman is built by fritted clinker dust. Besides this some preventions are

presented like a general chemical analysis of raw meal fed into the kiln, an improvement of

air distribution at the static cooler inlet as well as an additional independent control cycle with

a clinker-level measurement. These actions can help to improve the situation at the

investigated cement plant and other cement plants with Snowman formation problems.

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1. Introduction

Build ups are often the reason for kiln shut downs. Increased pressure losses or the different

chemical compositions of intermediate products, give first indications. Very often salt

compositions (e.g. alkali chlorides and sulfates) cause those undesired build ups, which can

be found from the kiln inlet up to the cyclones of the preheater tower. A bypass system

decreases those emissions by extracting parts of the gas streams from the kiln inlet. Those

extracted gas streams are cooled and dedusted separately.

Another disturbing build up can be found at the discontinuous operating connection between

kiln and cooler. There, especially at the static cooler inlet, build ups are formed which are

called Snowmen because of there design. Apparently the causes are not indicated in

sufficient time. These build ups cannot be predicted because of a lack of information about

the reasons of formation. On the one hand chemical and mineralogical composition, grain

size distribution and temperature of the burned material affect the physical clinker properties.

From this point of view some evidences are desired for the behaviour of clinker at the grate

coolers. On the other hand the cooler construction and the distribution of cooling air at the

cooler inlet affect the clinker transport.

In this thesis the cement plant in Brevik, Norway, which had great problems with Snowman

formations, was checked. For that, a useful checklist is developed and will be presented

along the found facts of this cement plant. It will be shown that several influences combined

with each other lead to Snowman formation. Luckily there was a chance to save a piece of

an indicated Snowman formation. This Snowman sample will be analysed and discussed in

detail. These information will show that this Snowman in particular is built by fritted clinker

dust. For comparable reasons another cement plant, which is located at Burglengenfeld,

Germany, was investigated. This cement plant is selected as one with almost no Snowman

formations. The specific cooling air quantities in particular give useful information for

comparisons.

This thesis is made at the HeidelbergCement Group in cooperation with the Clausthal

University of Technology. Special thanks applies to the people from the cement plant in

Brevik, Norway, the people from Heidelberg Technology Center (HTC-Germany) and the

cooler manufacturers IKN Neustadt and Claudius Peters.

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2. Principles

2.1. Clinker phases

Essentially cement clinker consists of tricalcium silicate (Alite), dicalcium silicate (Belite),

tricalcium aluminate (Aluminate) and calcium aluminoferrite (Aluminoferrite). It is produced

from a raw material mix which contains mainly calcium oxide (CaO), silicon dioxide (SiO2),

aluminium oxide (Al2O3) and iron oxide (Fe2O3). A summary of the potential phase

composition are shown in Table 1.

Table 1: Potential phase composition of German cement clinker [1].

Clinker phases Chemicalformula

Abbreviated formula

Content in % by mass

max 85

av 65 Tricalcium silicate Alite

3CaO*SiO2 C3S

min 52

max 27

av 13 Dicalcium silicate Belite

2Cao*SiO2 C2S

min 0.2

max 16

av 8 Calcium aluminoferrite (Aluminoferrite)

2CaO*(Al2O3,Fe2O3)

C2(A,F)

min 4

max 16

av 11 Tricalcium aluminate (Aluminate)

3CaO*Al2O3 C3A

min 7

max 5.6

av 1.2 Free CaO CaO

min 0.1

max 4.5

av 1.5 MgO, total MgO

min 0.7

The raw material mix is fed into the kiln (see chapter Burning process). By increasing the

temperature during the process the following reactions take place to form clinker phases

(Figure 1) [2]:

100°C Evaporation of free water

>500°C Evolution of combined water

>860°C CaCO3 CaO + CO2

>900°C Reactions between CaO and Al2O3, Fe2O3 and SiO2

>1200°C Melting phase formation

>1250°C Formation of C3S and finished reaction of CaO

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Figure 1: Clinker phases formation [3].

2.2. Calculations of the phase composition

The phase composition of a cement clinker can be calculated from the values of the chemical

analyses according to R.H. Bogue. For a cement clinker of usual composition, which

contains C3S, C2S, C3A and C4AF and has the AR >0.638, the following formulae can be

used:

C3S = 4.071*CaO – 7.600*SiO2 – 6.718*Al2O3 – 1.430*Fe2O3

C2S = 2.867*SiO2 – 0.754* C3S

C3A = 2.670*Al2O3 – 1.692*Fe2O3

C4AF = 3.043 Fe2O3

These calculations do not reflect the reality but give a potential composition, which is used in

practice. However the phase composition given by the calculation is only valid if the clinker

melt is always in thermodynamic equilibrium with the solid clinker phases Alite and Belite. In

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practice this precondition is never fulfilled. Therefore the calculation of Bogue always gives

too low values for the Alite and too high values for Belite content. But the difference between

the calculated and the actual clinker composition can be determined by quantitative

microscopic methods or by X-ray diffraction analysis. [1]

2.3. Calculation of the melting phase

The clinker contains 15 % to 25 % by mass of melt at the sintering temperature. The quantity

of melt (S) at 1400 °C can be calculated as follows [1]:

3232 2.295.2 OFeOAlS %mass

2.4. Other important moduli

The calculation of the Bogue potential clinker composition is descriptive but it does not give

any impression of the contents of CaO in the clinker. Therefore the raw material and the

clinker compositions are generally characterized by moduli in practice. These are called the

lime saturation factor (LSF), the silica ratio (SR) and the alumina ratio (AR). Additionally, the

degree of sulfatization (DS) is used. Table 2 shows potential values of German cement

clinker for those moduli. [1]

Table 2: Moduli of German cement clinker [1].

max av min

Lime saturation factor LSF 104 97 90

Silica ratio SR 4.1 2.5 1.6

Alumina ratio AR 3.7 2.3 1.4

Degree of sulfatization DS 109 77 35

2.4.1. Lime saturation factor (LSF)

The lime saturation factor shows the actual CaO content in the raw material mix or in cement

clinker relative to the maximum CaO amount, which can be combined with the SiO2, Al2O3

and Fe2O3 under industrial burning and cooling conditions. It can be calculated as follows [1]:

32322 65.018.180.2

100

OFeOAlSiO

CaOLSF

%

%

mass

mass

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2.4.2. Silica ratio (SR)

The silica ratio is the mass ratio of the silicon dioxide content relatively to the total of the

aluminum and iron oxide contents. It describes the solid/liquid ratio in the sintering zone of

the cement kiln. The following formula shows the mentioned relation [1]:

3232

2

OFeOAl

SiOSR

%

%

mass

mass

2.4.3. Alumina ratio (AR)

The alumina ratio gives information about the quantity of calcium aluminate to calcium

aluminoferrite. It reflects the behaviour of the clinker melt. The following formula can be used

for calculation [1]:

32

32

OFe

OAlAR

%

%

mass

mass

2.4.4. Degree of sulfatization (DS)

The degree of sulfatization shows the percentage of the alkalis, which are presented as alkali

sulfates. It can be calculated as follows:

ClONaOK

SODS

13.129.185.0

100

22

3

%

%

mass

mass

(* The chloride content will be considered if Cl (loI-free) is higher than 0.015 % by-mass.)[3]

A degree of sulfatization of 100 % means that all the alkalis in the clinker are totally

combined to alkali sulfate. If the degree of sulfatization is higher than 100 %, then there is a

sulfur excess, which forms Ca-langbeinite (K2SO4*2CaSO4) and/or anhydrite (CaSO4) [1].

2.5. Burning process

At present there are two different techniques of clinker manufacturing; one is the dry and the

other the wet process. For this thesis, only the dry process is relevant and will be described.

In the fifties and early sixties two types of external preheaters were developed; a preheater

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with Lepol grate and a suspension preheater. Progressively the suspension preheaters

predominate and are only important for this thesis [4].

Figure 2: Diagram of cyclone

preheater [1].

Figure 3: Diagram of cyclone preheater with

precalcination [1].

The suspension preheaters, also called cyclone preheaters, have a simple layout and

several designs. The first system of this type was developed by Klöckner-Humboldt-Deutz.

Several cyclones are arranged superposed and displaced sideways. They are connected

and form the preheater tower. The first one consists of four cyclone stages (Figure 2), but

newer kiln systems have up to six stages. The main task is to preheat the raw material. The

exhaust gases from the rotary kiln pass through the cyclones from bottom to top. The dry raw

material is added to the exhaust gases before the top cyclone stage, is separated from the

gas and then drops back into the gas flow before the next cyclone stage. This process is

repeated up to five times until the material is discharged from the last cyclone stage into the

kiln.

Since 1970 those kiln systems got a new development, which is called precalcination. This

means that the supply of fuel energy is divided into two firing systems. The new additional

firing system takes place at the preheater (Figure 3). This means that the calcium carbonate

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in the kiln feed is dissociated over 90 %, when it enters the kiln. The degree of dissociation of

the kiln feed is between 40 – 50 % at conventional burning processes.

Figure 4: Different combustion air supply systems for

precalcination [1].

In the precalcining process the combustion air required for the firing system can be taken

from two different ways (Figure 4). On the one hand, through the rotary kiln (a) and on the

other hand directly from the clinker cooler through a special duct, which is called tertiary air

duct (b). The connection of this duct can be located in two different positions. The first one is

on top of the kiln head (connection between kiln and cooler) and the second is directly after

the kiln head on top of the cooler enclosure.

2.6. Vaporizable constituents and its recirculating system

The hot kiln gas, which heats the kiln feed by counter-current flow, contains various gaseous

or vapour compounds. These are formed from vaporized or disassociated constituents of the

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kiln feed and the fuel. These are mostly alkali, sulphur and chloride compounds as well as

some trace elements like zinc, lead, chromium, cadmium, thallium, mercury and fluoride.

The vapour compounds condense in the cooler parts of the kiln or in the preheater or in the

downstream installations and deposit on the kiln feed and dust. If the fraction deposited on

the kiln feed passes the hot zone of the kiln again and vaporizes, then internal circulations

can be formed. The constituents are often carried out of the kiln and preheater area and

collected in the gas cleaning system. These constituents are added to the raw meal again

with the dust and go back to the kiln. This creates an external recirculating system (e.g. the

green line in Figure 5). The internal and external recirculation can be reduced by removing

part of the recirculating substances from the system e.g. by a bypass system.

Figure 5: Recirculating system [3].

The most important recirculating substances are alkali sulphates and alkali chlorides, which

can affect the operation of a cement kiln system. This recirculation system can be found at

the high temperature part of the kiln system (red line). They can form an additional melt in

the clinker, which influences the flow characteristics of the material in the kiln. [1]

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2.7. Operation control measurements

The kiln operation is mostly monitored by several measurements:

Production rate [t/h]

Operating hours

Involuntary downtime hours

Total fuel rate [t/h]

Specific heat consumption [kcal/kg]

Proportion of fuel to precalciner / riser [%]

Secondary air temperature [°C]

ID fan draft [mmH2O]

Preheater exhaust gas temperature [°C]

O2 Kiln feed-end and exhaust gas [Vol.-%]

Downcomer O2 [%]

Kiln feed-end material: - LoI [%]

- SO3 [%]

Kiln drive power [kW]

There are also numerous other process parameters which should be logged. Those data are

needed to observe trends, which may indicate problems and to provide necessary mean data

for process analyses. Those factors are [2]:

Primary air tip velocity [m/sec]

Specific kiln volume loading [%]

Gas velocity in burning zone [m/sec]

Specific heat loading of burning zone [kcal/h per m² of effective burning zone cross-

section area]

Cooler air [Nm³/h per m² grate area]

Cooler + primary air [Nm³ per kg clinker]

Temperature, pressure and oxygen profile of preheater

NOx and CO in the waste gas

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2.8. Clinker cooling

The cooling process influences the structure of the clinker, its mineralogical composition as

well as the grind ability and in consequence the quality of the produced cement.

The speed of clinker cooling has an influence on the ratio of crystalline and melting phases in

the clinker. During slow cooling almost all clinker components are formed of crystals,

whereas fast cooling delays the formation of crystals and avoids the generation of the

melting phase. A typical value of melting phase in clinkers from rotary kilns is in the range

from 20 – 25 mass-%. Additional fast cooling prevents the crystal growing and has also an

influence on the formation of the periclase crystals (MgOfree). The faster the cooling of clinker,

the smaller the periclase crystals grow, which emerge by crystallization of the melting phase.

A typical size of fast cooled clinker is in the range from 5 – 8 µm. Slow cooled ones have up

to 60 µm large crystals [5].

It is reported that the best clinker is obtained by cooling slowly to 1250 °C followed by rapid

cooling [4]. A summary of the effects of cooling rate on the clinker phase and their properties

can be seen in Figure 6.

Figure 6: Effect of cooling rate on cement properties and phases [4].

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2.9. Clinker cooler types

Clinker coolers can be found basically in three different types. They are built as grate, rotary

or planetary coolers (Figure 7). The coolers differ mainly in the type of heat transfer, the

length and the design of pre-cooling zone (see the dot and dash line in Figure 7), the clinker

inlet temperature and the controllability.

Figure 7: Conventional cooler types [6].

The rotary coolers (Rohrkühler) are the older ones. The heat transfer of the hot clinker to the

cooling air occurs by counter current flow. The pre-cooling zone is longer than the one from

the grate coolers (Rostkühler), which decreases the clinker inlet temperature (1400 –> 1200

°C). The rotary cooler has an independent adjustable rotation speed from the rotary kiln. A

summary of essential technology data of rotary coolers can be found in Table 3.

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Table 3: Essential technical data of rotary coolers [6].

Technical terms Unit Value

Throughputs t/d <2,000 – 4,500

L/D-relation - approx. 10:1

Rotation speed min-1 1 – 3

Incline % 3 – 5

Specific cooling air quantity m3N/kgCli. 0.8 – 1.1

Clinker inlet temperature °C 1,200 – 1,400

Clinker outlet temperature °C 200 – 400

Coolant efficiency ratio % 56 – 70

The planetary coolers (Satellitenkühler) consist of nine to eleven cooling tubes attached

around the perimeter of the kiln tube. The heat transfer also takes place by counter current

flow like the rotary coolers. This cooler cannot be adjusted. The specific cooling air quantity

is identical with the amount of combustion air. Caused by a longer pre-cooling zone the

clinker inlet temperature is lower compared to rotary coolers. Table 4 shows essential

technology data for this type of cooler.

Table 4: Essential technical data of planetary coolers [6].


Throughputs t/d <3,000 – 4,000

L/D-relation - 9 – 11

Specific cooling air quantity m3N/kgCli. 0.8 – 1.0




A grate cooler is nowadays the usual cooler type. In this cooler the clinker bed is transported

on a grate, which is cooled by transverse flow of air. This type of cooler requires more

cooling air than is needed for the combustion. The cooler exhaust air can be used e.g. for

drying the raw material. Table 5 presents the relevant information about the technology of

grate coolers.

Table 5: Essential technical data of grate coolers [6].


Throughputs t/d 700 – >10,000

Grate area loading t/m2d 26 – 55 (100)

Grate incline degree up to 10

Specific cooling air quantity m3N/kgCli. (1.4) 1.6 – 2.6




20

2.10. Principle design and process technology features of modern grate

coolers

2.10.1. Fixed inlet areas

The fixed inlet of a cooler is the most important interface between the rotary kiln discharge

and the clinker cooler. Almost all cooler manufacturers use a fixed inlet area with direct

aeration to improve the thermal efficiency of the cooler system and to increase the availability

of the grate plates in the hot zone. But the static inlet also increases the risk of the formation

of a “Snowman”, which is further strengthened by using more and more secondary fuels [7].

2.10.2. Grate plate development

Modern grate plates and their systems enhance the grate resistance for improving the air

distribution and its thermal efficiency of both aeration systems (air beam and chamber). The

new developed plates raise the service life of mechanical parts and minimize their wear.

Additionally they achieve a constant grate resistance over a longer operating time and

reduce the grate riddling by having constant, narrow gaps and slots [7].

2.10.3. Side sealing

New developments of grate seals minimize the gaps during thermal expansion of the grate

surface. Very long service lives are achieved by hardening the surface of the moving parts of

a plate. This prevents air channelling at the edges of a clinker cooler [7].

2.10.4. Cooler drive

The hydraulic cylinder drive is developed continuously. The stroke lengths and the cylinder

speeds are optimized to an effective conveying and minimization of wear (fewer thrusts) [7].

2.10.5. Clinker crusher

A modern cooler requires a roll crusher. This type of crusher is in fact more expensive than a

hammer crusher but the maintenance and spare-parts costs are very low. The dust load at

the end of a cooler is lower by using a roll crusher. This type of crusher deals with very large

pieces of coating from the kiln, which avoids unplanned kiln shut downs [7].

21

2.10.6. Improvement of thermal efficiency

By using a specific and controlled direct aeration of the static inlet, the efficiency of a cooler

can be improved significantly. The air and material distribution play a decisive role. The main

goals are that the clinker is optimally cooled down and gets the best heat recuperation. In

other words a good material distribution at the start of the grate, maintains a constant clinker

bed with a depth of about 500 to 900 mm over the entire grate area. This is achieved by a

static grate or special distribution grates for large widths. Additionally, a partition wall

between the recuperation zone and the cooling area minimizes the heat radiation loss and

assists the heat exchange [7].

2.10.7. Material discharge system

The discharge of grate riddling can be solved in different ways. One is the traditional hopper

arrangement with double flap valves or the other the level-controlled slides with a drag chain

to remove the material. Furthermore coolers with small gaps reduce the grate riddling.

The newest development is a cooler design without grate riddling. At this type of cooler,

known as a reciprocating beam cooler, the transport mechanism is separated from the

cooling mechanism. This means that the aeration base has no moving parts and is protected

by a stationary layer of clinker [7].

2.10.8. Grate support system

The internal roller or axle support systems are used for supporting the grate or moving frame.

The design and material of these systems is improved to reduce the wear [7].

2.10.9. Cooler control system

The following measuring and control loops can be used for an automatic process control of a

clinker cooler:

Cooling air volume flow

Chamber pressure / grate thrust rate

Kiln hood pressure

Grate plate temperature

Secondary / tertiary air temperature

Exhaust air temperature

22

Normally the grate speed is controlled by the pressure in the first air chamber or by a

combination of several initial air chambers. New developments like level radar, which

measures the clinker bed depth at the inlet of the cooler directly, can be very useful for the

control of the grate speed [7].

2.10.10. Cooling air fans

In general the cooling air comes from radial fans with double bearings. By using fans

operating at constant speed with small changes in air quantity the air volume is controlled by

a vane controller with an actuating mechanism. Only fans with large control reserves (e.g. at

the inlet area) are operating with frequency-controlled motors. The first fans indicate a

rotational speed of over 2000 rpm due to the high pressures of 80 – 130 mbar [7].

2.11. Process interrelationships – trend curves

The following trend curves show the qualitative coherence between the described process

parameters. The quantitative coherence and the wave shape are not taken into account. For

simplification all curves are drawn linear to get an impression for the existing

interdependency [8].

23

Table 6: Clinker capacity - clinker exit temperature - cooling air quantity [8].

Higher clinker capacity Higher clinker exit temperature

Constant: Thrust rate, cooling air quantity

Increasing the capacity means a rise of the specific grate area load (capacity / grate area). If the cooler is operating with the same cooling air quantity and thrust rate after an increase of capacity then the clinker exit temperature will rise.

Higher cooling air quantity Lower clinker exit temperature

Constant: Clinker capacity, thrust rate

It is significant, for the coherence between clinker exit temperature and cooling air quantity, that an enhanced air volume leads to a lower clinker exit temperature by constant capacity.

Lower thrust rate Lower clinker exit temperature

Constant: Clinker capacity, cooling air quantity

A lower thrust rate supports the heat transfer between cooling air and clinker and therewith it produces a lower clinker exit temperature.

Higher clinker capacity Higher cooling air quantity

Constant: Clinker exit temperature

The clinker exit temperature will be constant if the clinker capacity and the cooling air is increased at the same time and / or the thrust rate is dropped. The cooling air quantity and the thrust rate have to be adjusted to reach an optimum.

The main statement is that an optimal adjustment of cooling air quantity and thrust rate is

preconditioned for a low clinker exit temperature.

24

Table 7:Specific cooling air quantity - secondary air temperature - cooler efficiency [8].

Lower cooling air admission Higher secondary air temperature

Constant: --

A change from an conventional grate plate arrangement to a direct aeration in the first chamber enables the reducing of specific cooling air admission. A lower specific cooling air admission accords with a lower air speed and therewith an increasing of the air stay in the cooler. The result is a better heat transfer and a higher secondary air temperature.The specific cooling air admission at the beginning of the cooler has to be high enough to prevent clinker agglomeration.

Higher secondary air temperature Higher cooler efficiency

Constant: --

A higher secondary air temperature (higher heat content of the secondary air) increases the cooler efficiency.

Higher cooler efficiency Lower kiln heat requirement

Constant: --

A higher heat recuperation of the clinker accords with a reduction of fuel in the kiln. Therewith the kiln heat requirement and the production cost of the kiln system decrease.

The main statement is that the cooling air admission at the beginning of a cooler affects

essentially the recuperation efficiency of the cooler.

25

Table 8: Clinker bed level - thrust rate/time of stay - clinker exit temperature - wear [8].

Lower thrust rate Higher clinker bed level

Constant: Clinker capacity

If the pressure-set point for the thrust rate controlling is increased (higher clinker bed level) than the grate thrust rate will be lower and the time of stay of the clinker in the cooler will be enhanced.

Higher time of stay Lower clinker exit temperature


The time of stay of the clinker per row or rather chamber is higher with a lower speed of the clinker. This means that there is more time for heat transfer between hot clinker and cold air. The result is a lower clinker exit temperature at the end of the cooler.

Lower thrust rate Less wear


A decreasing of the thrust rate means a lower friction between the clinker and the grate plate surface. The result is a reducing of the wear.

The main statement is that a lower thrust rate affects a higher clinker bed level and a higher

time of stay of the clinker in the cooler. Furthermore the grate plate wear is lower by having a

lower thrust rate standard.

26

Table 9:Clinker bed level - clinker exit temperature - cooler efficiency - power requirement[8].

Higher clinker bed level Lower clinker exit temperature *

By increasing the clinker bed level the time of stay of cooling air in the clinker bed is enhanced. Therefore the heat transfer is better and leads to a lower clinker exit temperature. This is confirmed when the clinker bed level limit is not reached. At this limit the cooling air starts to blow through and causes a worser cooling with higher exit temperatures.

Higher clinker bed level Higher cooler efficiency *

A good heat transfer during a higher clinker bed level causes an increasing recuperation air temperature. This leads to an enhanced cooler efficiency. To pass the clinker bed level limit has the result of a worse heat transfer and efficiency.

Higher clinker bed level Higher fan pressure *

A high clinker bed level means a higher resistance, which has to be overcome by the fan. Until reaching the clinker bed level limit, the fan pressure will increase. After passing this limit the pressure will decrease because the air blows through. The available fan pressure (by definition of the cooling air quantity) limits the maximum of the clinker bed level.

Higher clinker bed level Higher power requirement

The rise of the clinker bed level and the fan pressure effect an increasing of the specific power requirement of the fans by reducing the kiln heat requirement.

* It is only essential until reaching the optimal clinker bed level.

The main statement is that clinker bed level optimizing decreases the operating expenses.

27

Table 10: Cooling air quantity - thrust rate - exhaust air quantity - exhaust air temperature [8].

Higher cooling air quantity Higher exhaust air quantity

If the cooling air quantity is increased in the cooler (especially at the after-cooling-zone) then the exhaust air quantity rises.

Higher thrust rate Higher exhaust air and clinker exit temperature

Constant: Clinker capacity, cooling air quantity

If the cooler operates with a higher thrust rate, then the time of recuperation will be lower to achieve a sufficient heat transfer. The result is that an enhanced amount of heat will be transferred to the after-cooling-zone. This leads to an increasing of the exhaust air and clinker exit temperature.

Lower cooling air quantity Higher exhaust air temperature

Constant: Amount of combustion air, clinker exit temperature

If the total cooling air quantity is reduced at constant combustion terms, then the amount of exhaust air will be decreased. The result is a higher exhaust air temperature.

Higher exhaust air temperature Higher potential heat recovery

An efficient heat recovery leads to a higher exhaust air temperature. This can be mainly found at stage coolers because of their intermediate cooling.

The main statement is that a higher thrust rate standard increases the heat losses of the

cooler, which means that clinker exit and cooler exhaust air temperature rises.

28

2.12. Red River

The “Red River” is a phenomenon in the cooler. Distinctive for it is a narrow stream of fine

clinker which appears far down in the cooler at higher temperatures than the neighboured

clinker. This narrow stream is often red hot (hence the name). Fine and coarse clinker will be

partly segregated in the kiln and fall separated to the right/left side of the static inlet. The fine

clinker falls on the kiln load side and the coarse clinker on the other one. If, additional to the

segregation, a clinker bed with unilateral or bilateral slope is formed on the static inlet, the

fine clinker slides down the slope to the side (Figure 8).

Figure 8: Formation of Red River [9].

The segregation and slope, not inclined in clinker flow direction, are the reasons for “Red

River”. Furthermore a “Red River” can be caused by a “Snowman” because of the

disturbance of aeration at the static inlet in the cooler. A fine clinker has a higher resistance

to the airflow than the coarse clinker, so the cooling air takes the path of least resistance,

which intensifies the “Red River” formation. Figure 9 shows the pressure losses of various

clinker sizes as a function of free air velocity. It can be seen that the particle size has a great

influence on air distribution, which can be described by pressure losses [10].

29

Figure 9: Pressure losses of various clinker sizes as a function of free air velocity [10].

2.13. Snowman

Another phenomenon in the cooler is the formation of a “Snowman”. A Snowman (SM) is a

type of build up formed in the static inlet. In general a snowman is caused by [9]:

fine and sticky clinker

fall of coating from the kiln.

A sticky clinker occurs when the content of the melting phase or the kiln temperature is too

high. In the one case the melting phase works as a binder and bonds the clinker together. In

the other case, fall of coating, a big lump stays in the cooler inlet without transport. The

surface of the big lump means an additional free area. Those formed platforms are the base

where a snowman can grow (Figure 10).

30

Figure 10: Formation of Snowman [9].

These big lumps cannot be cooled down. They store a lot of heat and disturb the aeration.

Figure 11 presents the non-steady state cooling of clinker for a number of different clinker

sizes as a function of time. It shows that it is physically impossible to cool large clinker

particles (> 100 mm) to an acceptable temperature within a reasonable retention time of 20

min, which is typical for grate coolers [10].

Figure 11: Effect of clinker size on needed retention time [10].

Clinker build ups at the static inlet of the cooler are mainly formed at clinker temperatures

over 1250 °C in the kiln outlet [11].

The following checklist was made before visiting the cement plant Brevik in Norway. It was

the first step to approach the Snowman phenomenon.

31

3. Checklist

This general checklist is written in keywords to shorten the thesis. A detailed explanation is

given with the example of the cement plant in Brevik, Norway. The checklist is divided into

three parts. The first one takes a look into the material data, the second one describes the

process data and the last one shows other available data. All data show possible reasons for

Snowman formation. Later on this checklist will be introduced by means of visiting the

cement plant in Brevik, Norway.

3.1. Part 1 (Material data)

3.1.1. Chemical Compositions

To be analyzed: a) Raw meal (kiln feed)

b) Clinker

c) By-pass dust

d) Secondary and primary fuels

e) Ash

Main components and in particular the contents of: sulfates; chlorides; alkalis

mineralizer like CaF2; SnO2

3.1.2. Clinker Mineralogy

Focusing on: liquid phase; CaOfree; MgOfree; oxidizing vs. reducing burning conditions,

homogeneity

3.1.3. Moduli

LSF; AR; SR; SD; Melt content; Sodium equivalent

3.1.4. Clinker

Grain size distribution (from cooler inlet; in front of the crusher)

Segregation of the falling clinker into the cooler inlet

(Stickiness-check)

Liter-weight / density / porosity

Mechanical properties

32

Size distribution

Hot stage microscope liquid phase vs. adhesion

3.2. Part 2 (Process data)

3.2.1. Feeding system

Dosages and amount of: - fuels (primary and secondary)

- kiln feed

- dust

Homogeneity / fineness

Steadiness of feed and fineness

3.2.2. Kiln

Type of fuels

Temperature of: - flame (especially peaks)

- secondary and tertiary air

Design of the flame

Coal fineness

NOx-values (Over-burning)

Zone length (especially pre-cooling and sintering zone)

Electrical power consumption (peaks?)

Rotary kiln speed

Places of Build-ups caused by dust

Dust content in the secondary air and handling system

Gas velocity at the kiln outlet

3.2.3. Cooler

Airflows: - amount

- distribution

- pressure losses

- reserves

Operation: - grate speed

- fan flows

- blasters

- pressures

33

- exhaust temperature

- intensity and frequency of control adjustments

Integrity: - plates

- aeration

- refractories

Clinker level at the inlet (especially free areas at plates and horse shoe)

Slope of the inlet module

Dust content in the air and handling system

Installed crusher type

“RedRiver”-formation

Temperatures of: - clinker (inlet & outlet)

- plates

3.3. Part 3 (Other data)

3.3.1. Snowman type

“mushroom”-formation (fast growing on a small area, not moveable)

“sugar loaf”-formation (fritted dust, moveable)

“bridges”-formation (connection between each side or corner of refractory walls)

3.3.2. Visual checks

- Glowing clinker after cooler outlet amount of crushed clinker (extreme grain sizes)

- “Bubbling” at the surface of the clinker bed in the cooler (“BlowThrough” indication at high

clinker levels)

- Surface colour of the clinker flow

34

4. The cement plant in Brevik, Norway

4.1. Introduction

The investigated cement plant in Brevik is one of two plants of Norcem AS. It has been part

of HeidelbergCement AG since 1999, in Norway. Three different types of clinker, a standard-

(OPC), a low alkali- (LA) and an oil well clinker (LA-SR) are produced in one rotary kiln and

seven types of cement are manufactured in three cement mills. The clinker and cement

production capacities are 1 million and 1.3 million tons per year.

At Brevik there are a lot of problems with snowman formation, which often occur after

changing the clinker type during the production. The first time of mentioning a snowman was

in February 2002 after the cooler modification in November 2001. Before that day no

snowman appeared. During the modification in November 2001 a moveable inlet was

changed to a static one.

The purpose of the visit was to collect data which could give some hints for snowman

formation and information about the kiln and cooler system.

4.2. Flow sheet

Figure 12: Simplified flow sheet of the clinker production at Brevik, Norway.

35

Bauxite, Iron ore, Oxiton, Quartz and limestone of two different qualities are the raw

materials for the production in Brevik. They are fed over a cross belt analyzer to the raw meal

production. The material is milled first with an aero fall mill followed by a roll mill and a

hammer mill. After this the coarse and fine material is separated in the separator. The

finished raw meal is stored in an 25,000 tons raw meal silo. This silo stores the material up to

100 hours. After that the raw meal is fed into the kiln at the second cyclone stage. It goes

through the cyclones of the preheater tower into the kiln and leaves the burning process at

the cooler end. The clinker is also stored in a silo. Typical mass flows can be found in Table

30 in the appendix.

The two red arrows, which can be seen in Figure 12 show the two regular checkpoints of raw

material and raw meal (see also paragraph “4.6 Chemical Compositions”).

4.3. Kiln system modification

A summary of the various tasks of the kiln system modification in Brevik during 2003 and

2004 and the purpose of each task can be found in Table 11.

Table 11: Overview of the kiln system modification items [12].

Part Item Purpose

Installation of a “hot-spot” combustion chamber (down-draft type) with high-temperature zone, high-O2 zone, increased residence time and increased turbulence level

Improve burnout of lumpy fuels in the calciner system

Installation of mixing chamber Mixing kiln gas and gas from the new combustion chamber

Installation of a KHD Pyrotop swirl chamber at the top of the loop duct of the calciner

Improve burnout of lumpy fuels fed to the calciner system

Installation of an orifice in the riser duct

Balance kiln gas and tertiary air, as well as ensure sufficient gas velocity in the riser duct to avoid drop-through of fuel fragments

Re-routing and extension of the tertiary air duct

Adapt the tertiary air duct to the new combustion chamber

Modification of lower cyclone stage on string 1

Make space for the new combustion chamber

Re-routing of meal pipes Make space for the new combustion chamber

Calciner/preheater system

Modification of the kiln inlet chamber Ensure sufficient inclination of the re-routed meal pipes

Installation of new 70 m³ cylindrical silo, equipped with a rotary discharge feeder

Provide intermediate storage and waste buffer, with a trouble-free discharge, in front of weigh feeder

Waste feeding system

Installation of weight feeder with a waste feeding capacity of 25 tph

Provide accurate and sufficient feeding of waste fuels to the new

36

combustion chamber

Extension of existing pocket conveyor and modification of screw conveying system for RDF and SHW

Convey RDF and SHW from reception bins to new waste silo and from new waste silo to new combustion chamber

Installation of mass flow measurement equipment based on gamma radiation; mounted outside screw conveyors

Control discharge rate and mixture of different waste fuel types from reception bins

Installation of air-cooled bypass quenching chamber, designed for 10 % kiln gas extraction

Relieve the kiln system of chlorine, and hence reduce or avoid chlorine related operational, environmental and quality challenges

Refurbishment of an existing ESP (previously used on another, closed kiln line)

Extraction of chlorine rich bypass dust from the bypass gas

Routing of the de-dusted bypass gas to the front part of the clinker, and re-use of the oxygen-rich (19 – 20 % O2) cooled bypass gas as combustion air in the rotary kiln and the precalciner

Avoid a new emission point, and hence avoid additional emissions of NOx, Sox and dust, and possible dioxins

Bypass system

Installation of fans and ductwork for the bypass gas, including re-use of two existing in-series arranged MRD blowers

Route the bypass gas from the kiln inlet, via the ESP to the cooler

In 2003 and 2004 the calciner/preheater modifications took place. The bypass installation

(Figure 14) was commissioned in June 2004, thus completing the new kiln system (Figure

13).

The latest modifications take place during the maintenance shut down in 2006. During this

production stop the kiln head is modified to a bigger one. The area is increased from 7.6 m²

to 12.8 m². The reason for this modification is the high gas velocity at the static cooler and

kiln outlet area. The calculations of the gas velocity before the reconstruction show values of

8 – 10 m/s. The calculation of the new kiln hood indicates a gas velocity of around 4 – 6 m/s,

which can be seen as a normal condition.

37

Figure 13: The modified kiln system [12].

These bypass installation features are an environmentally friendly concept for re-cycling the

bypass gas in the system and avoid new emissions. The hot gas is bled stream at the rotary

kiln inlet, cleaned by an ESP and taken back into the second and third chamber of grate

number one from the cooler.

Figure 14: The new bypass system [12].

38

The cleaning of the bypass gas is sometimes not good enough, which leads to a high dust

concentration in chamber two and three. This causes some problems like clogging of the

cooler grate plates, which reduces the cooler efficiency. Additionally, it is reported that

sometimes Snowman formation in front of the cooler can be seen. It is suggested that this

Snowman formation is caused by insufficient cooling. To prevent this effect, the bypass filter

system has to be improved. At the moment the hot bypass gas is rerouted to the exhaust air

stream of the cooler.

Some characteristics of the modified kiln system are given in the following Table 12.

Table 12: Kiln system characteristics [12].

Parameter Value Unit

Rotary kiln length 68 m

Rotary kiln (outer) diameter 4.4 m

Clinker production capacity 3,300 tpd

Typical specific fuel consumption 3,400 kJ/kgCli

Representative temperature interval in rotary kiln 1,100 – 2,000 °C

Representative temperature interval in the precaliner 840 – 1,300 °C

Typical gas residence time in the rotary kiln 5 s

Typical gas residence time in the precalciner 5 s

Typical O2 concentration in rotary kiln exhaust gas 3.5 %

Typical O2 concentration in precalciner exhaust gas 4 %

4.4. Actual Cooler at Brevik

The following cooler type is used in Brevik (Figure 15). It is a rebuilt Claudius Peters (CP)

cooler with a static inlet. The tertiary air is extracted from the cooler roof directly after the kiln

hood. A hammer crusher is located at the end. Additional this cooler has a so called

“Fishbone aeration” with stoppers, which intensify the cooling of fine clinker at side to prevent

the Red River formation [10].

39

Figure 15: The used clinker cooler system at Brevik, Norway.

4.5. Kiln stop list caused by Snowmen

The following stop list was made from the monthly reports of kiln operating control (1999 -

2006):

Table 13: Kiln stops caused by Snowman formation (1999 - 2006).

Year Dates CommentsClinker

type produced

Clinkertype

before

Date of type change

19.02.2002 Snowman in clinker crusher OPC LA-SR 09.02.2002; 11:00 2002

19.05.2002 Snowman before crusher LA OPC 13.05.2002; 13:00

25.01.2003 Snowman in cooler & grate 2 stopped

OPC LA-SR 24.01.2003; 13:00

18.08.2003 Snowman in cooler & grate 2 stopped

OPC LA 17.08.2003; 22:00

14.10.2003 Snowman in cooler (& shooting a ring)

LA OPC 11.10.2003; 15:00

05.11.2003 Snowman in cooler OPC LA-SR 04.11.2003; 0:00

04.12.2003 Snowman in cooler LA OPC 02.12.2003; 17:00

2003


40

07.08.2004 Snowman in cooler LA-SR LA 05.08.2004; 19:00

07.09.2004 Snowman in cooler OPC LA 28.08.2004; 1:00


2004

13.10.2004 Snowman before crusher LA OPC 08.10.2004; 20:00


24.04.2005 Snowman in cooler OPC LA-SR 22.04.2005; 15:00

23.05.2005 Snowman in cooler & welding after tire slap

OPC LA-SR 22.05.2005; 13:00

22.06.2005 Snowman removed with dynamite

LA OPC 19.05.2005; 2:00

23.06.2005 Snowman OPC LA 23.06.2005; 10:00


02.08.2005 Snowman in cooler & blocked grate from bypass dust

OPC LA 27.07.2005; 7:00

14.08.2005 Snowman OPC LA-SR 13.08.2005; 16:00

20.08.2005 Snowman LA OPC 19.08.2005; 22:00

22.08.2005 Snowman LA OPC 19.08.2005; 22:00

29.08.2005 Snowman & inlet plates LA OPC 27.08.2005; 19:00



2005

16.12.2005 Snowman in cooler & problems with ignition device of dynamite

LA LA-SR 14.12.2005; 21:00

21.02.2006 Snowman in cooler LA-SR OPC 20.02.2006; 6:00 2006

07.03.2006 Snowman almost every day/night until 11.03.06

LA OPC 06.03.2006; 10:00

In total there were 28 Snowman formations in the last five years which led to stops of the

clinker production. Especially in 2005 the Snowman formation became a general problem. In

that year 50 % of the Snowman formations occured and this tendency did not stop in 2006.

Furthermore it is conspicuous that almost all Snowman formations took place within 24 hours

after switching from one type of clinker to another. Unfortunately there is no tendency visible

which would show at what kind of clinker type switch the danger of Snowman formation is

highest. It is also shown that the change of bypass way on 25.08.2005 has no influence on

this kind of build up in the cooler inlet.

For the following investigation of the chemical and process data the last Snowmen (period:

06.03.06 – 11.03.06) will be observed. Other important data like calculated annual average

values can be found in the appendix.

4.6. Chemical Compositions

The following analyses are calculated from the laboratory data, which are averages of the

period from 06.03.06 to 11.03.06.

41

4.6.1. Raw meal (kiln feed)

The raw material is only analysed with the full stream analyzer in this viewed period. This

analyser is operating before the raw mill. There are no comparable analysed values for the

raw meal, which is fed into the kiln. See also part “4.13 Other noticeable features”.

Table 14 shows the raw meal analyses of the full stream analyser.

Table 14: Raw meal chemistry of LA-clinker (06.03.06 - 11.03.06) *FSA.

CaO SiO2 Al2O3 Fe2O3 Na2O K2O SO3 Alkali xSO3

66.10 21.84 4.26 3.28 0.44 0.40 0.80 0.68 1.21

It can be seen that a small content of alkalis and sulfates are coming from the raw mix into

the production process.

4.6.2. Clinker

The low alkali clinker chemistry can be seen in Table 15. Those values shall be the standard

values for the following observations.

Table 15: LA-Clinker chemistry (06.03.06 - 11.03.06).

CaO SiO2 Al2O3 Fe2O3 Na2O K2O MgO Alkali SO3

65.01 21.47 4.37 3.46 0.31 0.45 2.08 0.60 1.10

4.6.3. By-pass dust

For the considered period there are only two measurements of the By-pass dust. See the

Table 16.

Table 16: Bypass dust chemistry (06.03.06 - 11.03.06).

CaO SiO2 Al2O3 Fe2O3 Na2O K2O MgO Cl SO3

56.90 17.21 3.66 2.65 1.06 4.51 1.76 4.13 5.70

It can be found that alkali and sulfate rich bypass dust is extracted. Furthermore this dust

contains a lot of chlorides.

4.6.4. Secondary and primary fuels and ash

In Brevik there are no general analyses made during operation. Caused by this fact those

values are not comparable for the viewed period.

42

4.7. Clinker mineralogy

Table 17 shows the calculated values by Bogue. Furthermore it gives the content of the

melting phase, calculated by Lea and the average analyzed content of free lime.

Table 17: Clinker mineralogy calculated by Bogue and Lea (06.03.06 - 11.03.06).

C3S C2S C3A C4AF CaOfree (analyzed) Melting phase

67.16 10.93 5.81 10.52 1.30 20.49

Demonstrative is the value of melting phase. It stays by 20.49 %. This value can be seen as

having a very low content, which can be depicted as a preventive measure, suggested in a

dissertation by Dr. D. Optiz [11]. Besides this, the free lime lays at 1.3 and can be considered

as a middle value.

4.8. Moduli

In Table 18 the calculated moduli from the LA-clinker values (Table 15) can be found. The

most demonstrative value is the degree of sulfatization which lies over 100.

Table 18: Calculated Moduli (06.03.06 - 11.03.06).

LSF SR AR SD

96.27 2.74 1.26 141.15

4.9. Clinker analyses

No analyses of clinker are made at the cement plant in Brevik. Even the Liter-weight, which

is a very fast and easy way to check the density of a clinker, is not used.

To analyze the grain size distribution from the cooler inlet a lot of time is required and this

means an intervention into the process. Because of safety reasons the segregation analyses

of the falling clinker into the cooler inlet is impossible today. Maybe a system with a CCD-

Camera which is used for particle analyses can help to make this analysis possible in the

future.

4.10. Burning system (Process Data)

There are a lot of influences which can affect the measurement of the process data, and

which cause difficulties in analyzing such data. This has to be remembered by taking a look

into the process data. It must also been taken in consideration, that other problems also

43

occurred besides Snowman formation, during that period of time. So the given values should

be handled with care. They only give suggestions about what might be the reason of having

Snowman formations.

For the following observation of process data it shall be mentioned that only comparable data

of the Snowman analyses will be presented. The viewed period is marked with a red spotted

rectangle in the diagrams. Furthermore the rectangle with lines going from bottom left to top

right shows the period of the first kiln shut down caused by Snowman formation. The other

rectangle with lines going from top left to bottom right indicates the second kiln shut down

caused by Snowman formation. The measurements of process data end with the

maintenances shut down in the morning of March 11, 2006. It was reported that there was

another Snowman indicated.

4.10.1. Feeding system

Figure 16 shows the feed amount of the primary and secondary fuels of the main burner.

Figure 16: Diagram of fuels feeding (06.03.06 - 11.03.06).

The blue line presents the coal, the red one the oil, the green one the animal meal and the

yellow one the feeding of liquid hazardous waste. The first demonstrative subject is, that the

feeding of animal meal makes a lot of problems during the whole period. During the time

period when the second Snowman appeared (marked with the red rectangle), it can be seen,

that there is no measurement of animal meal amount. So it cannot be excluded that there is

44

a possible feeding of animal meal. Besides this there are some regulations of coal feeding,

which show that the operator regulates the heat in the kiln system. After the animal feeding is

shut down the amount of liquid hazardous waste and coal gets higher values to compensate

the missing animal meal. Overall there seems to be too much energy in the kiln system

which may lead to overburning.

Additionally, the feeding of secondary fuels to the calciner seem to be very unstable,

although the process measurements show a steady feeding. The secondary fuels, especially

the RDF contains big pieces of wood. These pieces are bigger than a fist, which also lead to

other problems at the bypass filter system. So it can be mentioned that the steadiness of

feed is affected.

4.10.2. Kiln

Figure 17 shows the temperatures of secondary air (blue line), tertiary air (red line), clinker

exit (yellow line) and the exhaust air from the cooler (green line). These measurements can

only show tendencies and do not represent the real values. The other important values of kiln

amp (red line) and raw meal feeding (blue line) can be found in Figure 18.

Figure 17: Diagram of temperatures (06.03.06 - 11.03.06).

It can be seen that the secondary air temperature contains two significant peaks. These

peaks are the results of the fuel feeding and underline the suggested overburning. The

45

tertiary air temperature indicates a tendency to a lower value which means a worse heat

recuperation. This fact correlates to a Snowman formation. If a Snowman is formed then the

clinker flow is disturbed in the cooler. Furthermore it can be seen that the measurement of

the clinker end temperature shows a high peak followed by a low value. This behavior also

stays in correlation with the clinker flow. A higher clinker end temperature means a higher

amount of clinker flow in the cooler. The best coherence of this correlation can be seen

before the first Snowman formation. There are three peaks in a short time period followed by

a result Snowman formation.

The measurement of the exhaust air temperature is affected by cooling with water and

cannot be used for finding hints of Snowmen formations.

In Figure 18 a sharp peak in the kiln amp can be found. This peak supports the thesis of a

possible fall of coating and underlines the Snowman formation during that time. Besides this

the raw meal feeding shows a regulation. This is explained in the paragraph about the cooler

findings.

Figure 18: Diagram of kiln amp and raw meal feeding (06.03.06 - 11.03.06).

Another interesting point can be seen in the following pictures. Figure 19 shows the used

burner pipe in new condition and Figure 20 directly after removal. The burner pipe is a low-

NOx burner and is built as followes. Twenty jet air openings (a) are arrange outside. Then

the installed opening for the pulverized coal and conveying air (b), followed by the swirl air

46

output (c). The output tubes of waste oil (d), liquid hazardous waste (e) and solid alternative

fuels (f) are arranged in the middle of the burner.

Figure 19: Burner in new condition. Figure 20: Burner in used condition.

The burning pipe in used condition seems to be in a bad shape. By taking a look at the end

of the burning pipe (Figure 20) a broken spacer can be found (see the arrow). The task of the

spacer is to secure a steady entrance gap for the coal. This refers to an uneven entry of

energy into the sintering zone of the kiln, which influences the nodulization of the clinker and

can lead to inhomogeneities in chemistry.

Additionally it should be mentioned that the dust content in the burning process is extremely

high. Especially burning the low-alkali clinker types the dust content is so high, that the flame

of the main burner can not be seen clearly. This is the reason why the flame temperature is

not measured by a pyrometer in Brevik and no statement about the design of the flame can

be made.

The gas velocity at the kiln outlet plays a separate role. As mentioned before the kiln head

enlarged to decrease the gas velocity at the cooler inlet. The calculated high gas velocity in

this area of the cooler can also lead to the high dust content in the process. Additionally, it is

reported that this modification also increases the clinker production.

4.10.3. Cooler

The speed of grate one (yellow line) and grate two (green line) can be seen in Figure 21.

There the two sharp peaks, especially from grate 2, are prominent. They underline the

Snowman formation. The Snowman disturb, is known as, the aeration which leads to

pressure losses. The control cycle which controls the grate speed by measuring the chamber

pressure reacts as seen in Figure 21. The operator notices those regulations of the system

47

and takes corrective action by regulating the raw meal dosage, which correspond to the peak

in Figure 18. The almost periodically grate 1 speed is accelerated significantly for short

periods. This behaviour cannot be explained.

Figure 21: Diagram of fuels feeding into kiln (06.03.06 - 11.03.06).

Table 19 shows the used cooling air volume. By checking the reserves of the operating fans,

it is conspicuous that the fan HE-2 is operating at almost maximum air flow. Furthermore this

fan is working with a steady amount of cooling air flow. There is no regulation module. The

task of this fan is to supply the twelve center plates of the static inlet with cooling air. This fan

in particular is operating in the potential area where a Snowman could be formed.

Table 19: The used cooling air volume calculated from process data (06.03.06 - 11.03.06).

Fan No. HE-1 HE-2 3 4 5 6 7 8 9 10

Process

data ( )[Bm³/h]

22000 10500 22000 29279 52398 4900 4900 30808 34698 75648

Process

data ( )[Nm³/h]

21223 10129 21223 28245 50548 4727 4727 29721 33474 72977

Installed air quantity[Nm³/h]

23300 10500 22900 38900 69100 12500 12500 36100 39300 92000

Workingload [%]

91.09 96.47 92.68 72.61 73.15 37.82 37.82 82.33 85.18 79.32

Reserves[%]

8.91 3.53 7.32 27.39 26.85 62.18 62.18 17.67 14.82 20.68

48

The calculation of specific cooling air quantity from the process data of the cooler fans can

be seen at Table 38 in the appendix. The calculated values show that the plates of the static

inlet are supported with a very high amount of cooling air (923 & 844 Nm³/h*plate). This fact

indicates a possible method to prevent a Snowman formation by better cooling.

The time cycle of the blaster seems to be in normal operation. At Brevik there are 12 Blasters

in operation. They are connected into three groups, which operate every 10 minutes. The

break between each group takes 8 seconds and each blaster is switched with a 0.8 second

break. It was reported that any change of the blaster arrangements and their control were not

successful to prevent a snowman.

Figure 22: Static cooler inlet after shut down.

The plates and the refractory in the static inlet are in bad shape. Figure 22 gives an

impression of the static inlet directly after cleaning the grate plates. During cleaning there

was no residue of a potential Snowman on the plates, although a snowman appeared 3

times over the viewed period (06.03.06 - 11.03.06) as mentioned before.

49

Figure 23: One plate of the second row. Figure 24: Plates of the first row.

Figure 23 shows the surface integrity of one plate of the second row on the right side. This

plate is located in the area, where the hot clinker is falling directly from the kiln into the

cooler. Some spotty wear and a blink surface can be detected. There could be several

reasons for it. On the one hand this plate does not get enough cooling air from fan HE-1,

which is supplying that area with cooling air. In the area of the static inlet there are a lot of

gaps between the plates. For example Figure 24 shows a ca. 1 cm gap between two plates,

a ca. 2 cm gap between the steel plate and the refractory-wall, where the air can go through

with the result of a handicapped distribution. On the other hand the pipe of one blaster (arrow

in Figure 22) points on that plate. This may also lead to spotty wear by blasting into the

clinker bed. The fine clinker particularly has an abrasive effect, which gets a great impact

from this blaster. Those two effects blasting and bad aeration lead to the bad shape of this

plate.

Figure 25: Plates 2 & 3 of row five. Figure 26: Plates 4 & 5 of row five.

50

Furthermore some other plates also show a bad surface. The plates 2; 3; 4 and 5 in row 5

(counted from left) indicate spotty wear, too (Figure 25 & Figure 26). These are in the cooling

area of fan HE-1 and HE-2. One reason may be the gaps, which lead to a bad cooling air

distribution.

Figure 27: Overview of the plates of row five on the left side.

Figure 27 shows these plates from a different position. It can be seen that additional to the

gaps at the sides the plates form some other gaps caused by plastic deformation. These

gaps disturb the aeration of the static inlet.

The measuring of four grate plate temperatures at Brevik does nor give the desired result.

The thermo elements, welded under four plates of grate one, are in a bad shape. So the

measurement probably provides wrong values and is not useful.

51

Figure 28: Cooler wall of one side.

Figure 28 shows one side of the refractory wall of the cooler. The clinker level during

operation can only be estimated. The value lies around 600 mm. There is no clinker-level

measurement installed, which would give independent important information for operation.

4.11. Snowman type

Figure 29: Piece of a collected Snowman (09.03.06).

52

During the visit of the plant, Snowmen could be indicated almost every night until the

maintenance shutdown. There was a chance to save a piece of one Snowman, which was

formed in the night from 9.3.06 to 10.3.06 (Figure 29). This piece of Snowman is analysed

(see chapter “6. Snowman-Analyses”).

It was reported that this Snowman was growing on a small area in the middle of the static

inlet, at which point a “mushroom”-formed. This type of a Snowman is built by fritted dust

(see chapter “6. Snowman-Analyses”).

4.12. Visual checks

During the stay in Brevik there could be no distinctive features indicated. “Bubbling” at the

surface of the clinker bed in the cooler could not be seen. Even the content of glowing clinker

after the cooler outlet, which could be seen, seems to be normal.

4.13. Other noticeable features

The main noticeable problem, which can be checked, is the way of carrying out raw meal

analyses at the plant. Samples are only taken before the 25,000 tons raw meal silo, which

contains raw meal for about 100 hours. There are no regular analyses of the raw meal, which

is fed to the kiln. The goal of production is to produce a steady raw meal quality, which is

realized with a full stream analyser (Crossbeltanalyser), located in front of the raw mill. This

arrangement is not acceptable and will be discussed in chapter 7 Conclusions.

Another noticeable thing is the small kiln head with the result of high gas velocities at the

cooler inlet area (see also chapter 4.3 Kiln system modification).

53

5. The cement plant Burglengenfeld in Germany

5.1. Introduction

The cement plant Burglengenfeld in Germany has almost no problems with Snowman

formations. For this reason it was chosen for comparative data collection. There are two

almost identical kiln lines working side by side. Both kiln lines (WT2 & WT3) operate with

three stations rotary kilns with a Preheater tower, but without a calciner. The daily outputs

add up to 2000 tons each system. The main difference are the installed cooler systems. One

cooler is from IKN and the other one from Claudius Peters. It is reported that there have

been no Snowmen indicated for the last two years. If a Snowman did form then it occurred

on kiln line 2, where the Claudius Peters cooler is in operation.

5.2. Collected Data

The following data are collected:

Drawings about the two different cooler systems

Chemical analyses from 2005 about: - Raw meal fed to the kiln

- Clinker

- Bypass dust

Current Process data

Information about the CARDOX-procedure

5.3. The two different cooler systems in operation

The IKN cooler operates at kiln line WT3. This cooler type is equipped with a roll crusher at

the cooler end. The static inlet of an IKN cooler is called KIDS. At this static inlet two fans

support the grate plates with cooling air. Fan No.1 supports the first three rows and fan No.2

the last four rows of the KIDS.

The Claudius Peters cooler operates at kiln line WT2. This cooler type is equipped with a

hammer crusher. Furthermore the aeration of the static inlet, so called HE-Module, has a

different configuration. There the first fan supports the first four rows and the second one

only the last two rows.

54

In total both operating systems for aeration of the static inlet differ to the configuration in

Brevik, Norway. But the calculations of the specific cooling air quantities are conspicuous, as

can be seen in the next chapter “5.4 Specific cooling air calculations”.

5.4. Specific cooling air calculations

For the calculations of the specific cooling air quantities the collected process data are used.

Table 39 and Table 40 show these calculations, which can be found in the appendix. Both

cooler systems (IKN & CP) operate in total with very high specific cooling air quantities. The

Claudius Peters cooler indicates a value of 2.35 Nm³/kgcli and the IKN cooler a value of 2.33

Nm³/kgcli. It is obvious, that the cooling air quantity per cooling plate is much lower at the

IKN cooler (291 & 244 Nm³/plate) than the one at the CP cooler (973 & 754 Nm³/plate).

Comparable values of the CP cooler can be also found at the cooler in Brevik, which is

mentioned in chapter “4.10.3 Cooler”. Maybe these adjustments are preventive actions as a

result from history, where Snowman formations appeared. It is reported that these

adjustment will be changed in the future.

5.5. Chemical analyses

The following analyses are calculated from the laboratory data, which are annual averages

from 2005. Several values are 0.00. Such values are not measured continuously.

5.5.1. Raw meal

Table 20: Raw meal chemistry from kiln WT2 (2005).

CaO SiO2 Al2O3 Fe2O3 K2O SO3 MgO Cl F Na2O MnO

44.08 13.32 3.58 1.99 0.56 0.21 0.00 0.00 0.00 0.00 0.00 63.73

Table 21: Raw meal chemistry from kiln WT3 (2005).


44.18 13.37 3.55 1.97 0.54 0.21 0.00 0.00 0.00 0.00 0.00 63.82

Table 20 and Table 21 shows the measured control analyses of the cement plant in

Burglengenfeld. The most obvious fact is that in Burglengenfeld the raw meal indicates a

much lower content of sulfates. Unfortunately the sodium oxide is not measured.

Furthermore these analyses show that the potassium oxide content is higher than at Brevik.

55

5.5.2. Clinker

Table 22: Clinker chemistry of both lines (WT2 & WT3) from 2005.

CaO SiO2 Al2O3 Fe2O3 MgO K2O SO3 Na2O MnO

WT2 67.46 21.32 5.57 3.26 1.21 0.40 0.28 0.00 0.00

WT3 67.41 21.15 5.62 3.31 1.19 0.38 0.25 0.00 0.00

Table 22 shows the measured Clinker chemistry from 2005. Here the content of sulfates is

very low. This fact can be also seen at the calculated moduli in Table 25.

5.5.3. Bypass dust

Table 23: Bypass chemistry of both lines (2005).


WT2 0.00 0.00 0.00 0.00 19.20 8.72 0.00 9.09 0.00 0.47 0.00

WT3 0.00 0.00 0.00 0.00 23.91 12.53 0.00 9.99 0.00 0.61 0.00

In Table 23 it can be seen that the bypass dust is rich on sulfates and chlorides. In addition it

can be found that only a low content of sodium oxide is in the production process. The

extracted bypass dust indicates a high content of potassium oxide.

5.5.4. Clinker Mineralogy

Table 24: Clinker mineralogy from laboratory data and calculated

melting phase (2005).

C3S C2S C3A C4AF CaOfree Melting phase

WT2 66.50 10.98 9.25 9.91 1.00 23.61

WT3 67.78 9.53 9.29 10.06 0.83 23.87

Table 24 shows the values of the clinker mineralogy of Burglengenfeld. It can be seen that

the content of the melting phase is higher than the value at Brevik. Furthermore, the free lime

content is lower, but it can also be seen as a middle value. It is conspicuous that the free

lime value of kiln WT3 is lower than the one of kiln WT2.

5.5.5. Moduli

Table 25: Calculated Moduli of clinker (2005).

LSF SR AR DS

WT2 98.65 2.41 1.71 82.31

WT3 99.13 2.37 1.70 76.63

56

An obvious fact of the calculated moduli, which are mentioned in Table 25, is that the clinker

from both kiln lines indicates a degree of sulfatization lower than 100. The main reason is the

low content of sulfates in the raw meal and fuels.

5.6. Process data

At Burglengenfeld the employed control system allows only to save data for one week. It is

impossible to see the process data digitally during the time period where a Snowman

formation is indicated. But the current process data is used to calculate the specific cooling

air quantities.

5.7. CARDOX-procedure

Besides the calculated specific cooling air quantities the procedure to destroy build ups at

refractory walls, is very interesting. This method, called CARDOX, is often used at rotary kiln

and at cyclones of the preheater tower (Figure 30 & Figure 31). This system is installed at

the inlet area of the CP cooler at Burglengenfeld.

Figure 30: CARDOX system at rotary kiln

[13].

Figure 31: CARDOX system at cyclones of the

preheater tower [13].

The mode of action is simple. A pressure pipe with different screwable tops is filled up with

CO2-gas. A priming charge and a pressure gas generator are also placed in the pipe. By

igniting the pressure gas generator produced additional 50 litres CO2 gas. This expansion

takes places at 20 milliseconds and has a around 15 tonnes of shear force. This shear force

moves to the top and breaks the build ups.

57

6. Snowman-Analyses

6.1. Introduction

The following samples are collected during the visit of the cement plant Brevik:

One piece of Snowman (from 09.03.06)

LA Clinker from the cooler after shut down

Clinker dust from the tertiary air pipe

The purpose of the analyses is to have the chemistry (main components; sulfates; chlorides;

alkalis; CaOfree; MgOfree), the content of mineral phases, the content of liquid phase and the

porosity. The Snowman sample will be compared to the LA clinker samples and especially to

the laboratory data from Brevik of clinker chemistry (2002-2006).

The Clinker dust from the tertiary air pipe shows a great LOI value (over 5%). This fact

shows that the collected tertiary air pipe dust is very old and cannot be used for comparable

analyses.

6.2. Analyses

The following analyses were made:

XRF (to get the chemistry) + free lime, water soluble salts

XRD + Rietveld (to get the composition and content of mineral phases)

Reflected light microscopy

Hot stage microscope (liquid phase)

SEM

6.2.1. Preparation of the Snowman samples

The piece of the Snowman is cut in the middle. One piece is served and stored under

vacuum. A plate is cut from the other one and from this piece five strips are analysed by XRF

& XRD (Figure 32). The samples for the hot stage microscope are also from these strips.

58

Figure 32: Prepared piece of the found Snowman.

The samples for the reflected light microscope and SEM are located inside of the cut plate. It

is important that these samples consist of different layers.

The last sample is taken from the surface of the Snowman and contains the indicated big

white particles (marked by the arrow in Figure 29), which are analysed in the SEM.

6.2.2. XRF – free lime – water soluble salts

In Table 26 the XRF analyses of the Snowman and the collected clinker can be found. Those

analyses are made with a Bruker-AXS S4 Pionier X-ray system.

Table 26: XRF & free lime analyses of the Snowman sample (rows 1 - 5) and the clinker.

Row 1 Row 2 Row 3 Row 4 Row 5 average Clinker

CaO 66.2 66.0 66.2 66.2 66.3 66.2 64.97

SiO2 22.0 22.4 22.3 21.6 21.7 22.0 20.92

Al2O3 4.39 4.29 4.36 4.45 4.38 4.37 4.55

Fe2O3 3.33 3.28 3.36 3.45 3.35 3.35 3.37

MgO 2.59 2.57 2.59 2.60 2.58 2.59 2.64

SO3 0.807 0.909 0.855 0.946 0.986 0.901 2.01

K2O 0.265 0.288 0.271 0.320 0.340 0.297 0.768

Na2O 0.0406 0.0611 0.0435 0.0611 0.0434 0.0499 0.160

TiO2 0.337 0.332 0.339 0.348 0.341 0.339 0.365

P2O5 0.0614 0.0599 0.0594 0.0615 0.0620 0.0608 0.0920

59

MnO 0.0987 0.0972 0.0992 0.1020 0.0989 0.0992 0.0848

SrO 0.0693 0.0693 0.0700 0.0708 0.0703 0.0699 0.0730

Cl 0.00 0.00 0.00 0.00 0.00 0.00 0.13

CaOfree 0.17 0.10 0.14 0.18 0.14 0.15 5.26

It is an obvious fact that the Snowman has a lower content of sulfates and alkalis than the

collected clinker samples. This coherence can also be found by comparing with the LA-

clinker chemistry from the laboratory data of the cement plant in Brevik. Furthermore this

Snowman indicates a very low free lime value and holds no chlorides.

The free lime value of the collected clinker shows an extreme value of 5.26 %. So this clinker

is burnt weakly. This fact is also underlined by the XRD analyses, see chapter 6.2.3 XRD –

Rietveld and appendix.

The XRF calculated moduli and melting phase value are shown in Table 27. Those are

calculated from values of Table 26. For detailed values of each row see Table 42 in the

appendix.

Table 27: Calculated values (LSF, SR, AR, DS, S).

LSF SR AR DS Melting phase

Snowman 96.01 2.85 1.30 285.01 20.28

Clinker 98.24 2.64 1.35 233.86 22.40

The most interesting fact is the very low content of melting phase of the Snowman. This

value lays at 20.28 % and is a surprise because it is in contradiction to the proposed

hypothesis, which assumed a high content of melt.

6.2.3. XRD – Rietveld

For the XRD analyses a Siemens D 5000 is used. This system operates with an CuK -

radiation. Table 28 shows the average data of the XRD-analyses. These values will be

compared to the calculated values of phases, which can be found in Table 17 in chapter “4.7

Clinker mineralogy”. For detailed values of each row see Table 43 in the appendix.

Table 28: XRD - Snowman sample corresponding to the LA-clinker.

C2S C3S C3A C4AF Anhydrite Periclase

Snowman [%-by mass] 15.0 67.5 2.6 14.1 0.2 0.7

The Snowman has high contents of the C2S and C4AF phases. Beside this the content of the

aluminates phase has quite low value.

The XRD analyses of the clinker sample can be found at Table 44 in the appendix. It shows

very low contents of C3S and C3A phases. Furthermore the C2S phase is increased. This fact

60

also indicates a weak burning. This piece of a clinker was collected directly after the shut

down of the kiln. The rotary kiln was emptied for maintenance. An explanation for this weak

burnt clinker is that some residual material in the kiln is burnt with insufficient sintering

temperature. This configuration leads to a weak burnt clinker.

6.2.4. Water soluble salts

The water soluble salts, tested by the DEV-S4-procedure (a leaching test), of the Snowman,

lay at 1.39 %. The composition of these can be seen in Table 29. These values indicate that

the salts exist mainly of sodium and potassium sulfates. The rest are carbonates, which

explain the content of calcium. The compositions are analysed with an Atom Absorbing

Spectrometer (AAS).

Table 29: Water soluble salts.

Weight[mg]

[%]

SO4 21 29.62

Na 10 14.10

K 16 22.57

Ca 6 8.46

Rest 17.9 25.25

Total 70.9 100.00

6.2.5. Reflected light microscopy

The reflected light microscopy from Axio Phot Zeiss, Germany is used to make the following

micrographs.

Figure 33: Clinker 2.5x polished surface. Figure 34: Snowman 2.5x polished surface.

61

Figure 33 and Figure 34 show the polished samples of one Snowman and one clinker. The

first visible feature is the porosity. The Snowman has a porosity of 46.28 % in contradiction to

the clinker with a porosity of 8.35 %. The calculations of the porosity are made with a particle

analysing program. The different layers of the Snowman (Figure 29), have different

porosities. The black layer has a higher porosity than the area between two of them. This can

be also seen at the SEM analyses (Figure 36).

Unfortunately the etching with hydrofluoric acid, which will make the different phases visual,

was not successful. Only parts of the samples are etch. But the SEM with the EDX-analyses

show the different clinker phases, which can be found in the appendix. It should be remarked

that the Snowman contains ordinary clinker phases, as analysed with XRD.

6.2.6. Hot stage microscopy

The hot stage microscope, which is used for the analyses, is a self-construction after DIN

51730 [14]. These analyses do not present the correlation, which can be found in literature

[15]. Because of the low content of liquid phase the temperature, which indicates the

softening point, is located at 1560 °C calculated from the following formula [15].

xTEB

1.171907

TEB: Temperature of the softening point X: Melting phase content in %

The temperature limit of the used hot stage microscope is 1450 °C. Because of this only a

slumping down of the samples can be seen.

6.2.7. SEM

The scanning electron microscope (SEM) CamScan CS4 is used for the following

micrographs. Additionally for the chemical compositions an EDX-detector from Tracor

Northern 5502 is used, which can be found at the appendix.

62

Figure 35: Snowman 20x polished surface. Figure 36: Snowman 20x fractured surface.

The two figures show SEM micrographs of the Snowman. One is a polished surface (Figure

35) the other a fractured surface (Figure 36). At the polished surface small clinker particles

and a high porosity are visible. These particles are smaller than 800 µm. The micrograph of

the fractured surface shows that there are differences in porosities of the Snowman. This is

correlated to the darker layers (marked with arrows in Figure 36), as mentioned before.

Figure 37: Snowman 2000x fractured surface. Figure 38: Snowman 2000x fractured surface.

Figure 37 and Figure 38 show the fractured surface with a higher magnification. Two different

criteria are obvious. On the one hand sintering necks (Figure 37) and on the other hand a

triple point (Figure 38) can be seen. Both are marked with arrows. This criteria is typical for

sintering processes.

Furthermore the analyses with an EDX detector shows that the Snowman is built by clinker.

Additionally the white particles on the surface of the Snowman consists of sodium and

potassium sulfates (appendix). The origin is unknown. Maybe those white particles are the

results of decomposition.

63

7. Conclusions

7.1. Snowman

The Snowman analyses show that the investigated Snowman of Brevik is built by fritted

clinker dust and small clinker particles < 800 µm. The clinker phases have no content of

chlorides and a low content of sulfates. This fact is caused by passing the sintering zone. In

the sintering zone the chlorides vaporize totally. The duration of dwell was not long enough

to vaporize the sulfates completely, so a lower content of sulfates can be found in the

Snowman than in the clinker. The very low free lime content shows that the material of the

Snowman is burnt under higher temperatures as usual. This fact is also underlined by the

measured secondary air temperature from the process data. It is found that the secondary air

temperature has two peaks to higher temperatures, caused by too much fuel feeding.

Furthermore the clinker phases of the Snowman have higher contents of C2S and C4AF and

also a lower content of the C3A phase. This fact can be the result of fluctuations in the raw

meal composition or caused by the uneven energy input which also leads to

inhomogeneities. Possible fluctuations in the raw meal chemistry cannot be checked. As

mentioned the two raw meal checkpoints for the plant analyses are both before the 25,000

tons raw meal silo. There are no general analyses of the kiln feed which can help to prevent

those potential fluctuations. Besides this the most surprising fact is that the content of liquid

phase is lower than expected. Because of a very high temperature in the process and a very

high dust content, which can be seen at the kiln head, this type of Snowman is formed. This

shows that a Snowman formation can be formed although the melting phase content is very

low. A possible formation of this type of Snowman is described in the next paragraph.

7.2. Hypothesis of Snowman formation

During the time period when the analysed Snowman occurred, there seemed to be a coating

fall according to examination of the process data. Big lumps fall from the kiln into the cooler

inlet and stay at the plates of the static part. As mentioned before this leads to a platform

where a Snowman can grow. In Figure 39 the proposed clinker dust cycle is shown.

64

Figure 39: Potential clinker dust circulation at the cooler inlet.

Dust from the cooler streams into the kiln with the secondary air, marked by yellow arrows.

This air is rich on clinker dust and streams under the flame. With additional clinker dust from

the kiln and the jet air pressure differences under the flame, the clinker dust air is deflected,

which is marked by the blue arrows. Furthermore this deflection is probably intensified by the

broken spacer of the burner pipe. The air under the flame streams back to the cooler, passes

the surface of the static inlet and streams back into the kiln with the secondary air. On the

free area as a result of coating fall, the clinker dust can deposit on this lump especially during

the deflection at the cooler inlet. With the indicated high temperature combined with the very

bad aeration in the area of the static inlet this Snowman is formed. Additionally, this type of

Snowman formation is also underlined by the fact that high gas velocities (8 m/s) exist at the

static inlet. These high gas velocities are caused by the small kiln head. Moreover the high

dust content in the secondary air comes from the high sulfate content. The calculation of the

moduli shows a degree of sulfatization over 100, which means a sulfur excess. Free sulfates

makes the clinker granules porous and brittle. These dust particles are easily carried away

from the clinker surface with the high gas velocity.

In addition those glowing dust clouds are well known from nature and can be compared to

the phenomenon at the cooler inlet (see the next paragraph “7.3 Comparable natural

phenomenon”).

65

7.3. Comparable natural phenomenon

In nature glowing dust clouds are called Ignimbrite. Geologists also call them pyroclastic flow

deposits. They are formed during volcanic eruptions. Generally, three different ways of

formations can be found in nature (Figure 40).

Figure 40: Some ways the pyroclastic flows can

originate [16].

The first one is a vertical eruption and column collapse, the second one a low pressure

boiling over and the third one a directed blast or dome collapse. All of them produce a lava

stream combined with glowing dust clouds. The glowing dust clouds consist of particles with

a size of < 2 mm. Those streams have high velocities from 14 up to 230 km/h under

temperatures around 500 - 650 °C and up to 850 °C. The dust content of those clouds varies

around 1 g/cm³. Figure 41 shows such an ignimbrite in detail.

66

Figure 41: Diagram showing development of block and ash flow [16].

It can be seen that the structure of a Ignimbrite is caused by dense segregation. The

particles with a higher density and a bigger size can be found after cooling down at the

bottom layers. In contrast to the particles with a lower density, they deposit more at the top of

the rock. This segregation leads to the typical structure of an Ignimbrite. Furthermore under

high temperatures a plastic deformation affects the structure. Some dust particles are welded

together which can be seen in Figure 42. Lines separate the different layers in this Ignimbrite

from Gran Canaria.

Figure 42: Strongly welded pantelleritic ignimbrite

from Gran Canaria [16].

The affinity to the investigated Snowman is obvious (see Figure 42).

67

7.4. Emphasis of the important items of the Checklist

At Brevik several influences are detected. The fuel feeding, especially of animal meal,

indicates some problems which leads to an uneven energy input. In addition the burner was

in bad shape because of a broken spacer and closed air jet pipes. The process data

indicates a periodical over heating of the kiln. Furthermore the fans of the static cooler inlet

operate almost on maximum air volume to prevent a potential Snowman formation, but with

an extremely disturbed distribution of cooling air this prevention has no effect. Some plates of

the static inlet are overheated and show plastic deformation. Possibly the high gas velocity

and the high dust content in the area of the kiln hood are the basic conditions of the

Snowman formation. The high content of sulfates from the raw meal leads to porous clinker.

Combined with the overheating and high gas velocity the recuperation air becomes rich on

dust. Finally, several influences make a Snowman formation possible. A suggested

emphasis of the important items of the developed checklist are mentioned below.

Figure 43: Emphasis of the important items of the checklist.

68

8. Outlook

8.1. In general

This thesis is a step to take a more systematic look at Snowman formations. It is known that

several Snowman types can be formed. This thesis deals with a mushroom type of a

Snowman. Because of high temperatures in the cooler inlet area it is very difficult to take

direct analyses at the point. Furthermore the measured temperatures and other process data

can only indicate tendencies. These are only indirect ones which give hints of a potential

Snowman formation scheme. Maybe in the future the measurement of the secondary air

temperature for example can be more exactly determined.

Generally, several items can be done to prevent Snowman formations. Besides checking the

chemistry and mineralogy of the produced clinker and its raw material, the aeration at the

static cooler inlet has to be investigated and improved. Furthermore the kiln shall be

operated at lower temperatures or the length of the pre-cooling zone can be increased to get

a lower clinker temperature at the kiln outlet. Additionally, an independent clinker-level

measurement can help to improve the situation of the cooler.

Some important indications can be also seen at the cement plant in Brevik, Norway. To solve

the problem of Snowman formation in Brevik, improvements have to be carried out.

The tasks to prevent Snowman formation in Brevik are presented in the next chapter.

8.2. Tasks of Brevik

The following tasks should be done at the cement plant in Brevik:

1. Chemical analysis of the kiln feed

2. Checking the cooler fans HE-1 & HE-2

3. Improving the air distribution

4. Improving the refractory arrangement at the cooler inlet

5. Improving the secondary fuels measuring and control

6. Saving always pieces of Snowmen

7. Increasing the length of the pre-cooling zone

8. Installing a clinker-level measurement

9. Changeover to the CARDOX system

69

The first point should be to analyze the kiln feed. It has been known for the elimination of

fluctuations in raw meal chemistry. Furthermore the cooler fans which supports the static

inlet with cooling air has to be checked to get reserves of air volume. This point can be

combined with an improvement of the air distribution. The goal should be to operate with a

lower cooling air quantity beside a better distribution. It should be clear that the gaps in the

plates should be repaired. An improvement of the refractory arrangement should also be

done. It was reported that in history very often a Snowman was formed on top of the

horseshoe. The people from Claudius Peters suggest the following refractory arrangement

(Figure 44).

Figure 44: Modification lining HE-Modul [17].

The aim must be to avoid platforms at the static inlet.

Another point should be to improve the secondary fuels situation by avoiding the use of big

pieces of wood. A better fineness will also help.

Saving pieces of Snowman should also always be a task. Snowmen formation is not well

described in the literature. Especially the liquid phase correlation seems to contradict the

shown results of this thesis.

Furthermore the pre-cooling zone can be increased to get a lower temperature of the falling

clinker.

The next point is to install a clinker-level measurement for the static inlet. This measurement

can be integrated in the process control system and will be another indicator to improve the

discontinuous operating connection between kiln and cooler.

70

Additionally, a changeover to the CARDOX system can be interesting for the cement plant in

Brevik. It is reported that this procedure has a very fast and easy handling. Maybe shut down

times of the kiln can be reduced. At Burglengenfeld there is good knowledge and experience

about this procedure, so the workers can be easily trained from members of the

HeidelbergCement group.

71

9. List of literature

[1] Locher, F.W.: Cement - Principles of Production and Use. Verlag Bau+Technik GmbH, Düsseldorf, 2006.

[2] Alsop, P.A.: Cement Plant Operations Handbook. International Cement Review, 1998, Second Edition.

[3] Wolter, A.: Vorlesungsunterlagen. 2005.

[4] Ghosh, S.N.: Advances in Cement Technology - Critical Reviews and Case Studies on Manufacturing, Quality Control, Optimisation and Use. Pergamon Press, 1983.

[5] Duda, W.H.: Cement Data Book - International Process Engineering in the Cement Industry. Bauverlag GmbH, 1985, 3rd. edition.

[6] Buzzi, S. and G. Sassone: Optimierung des Klinkerkühlerbetriebs. ZKG, 1993, Jahrg. 46, (Nr. 12), S. 755-760.

[7] Wallis, H.: Produktübersicht Klinkerkühler. ZKG International, 2004, Vol. 57, (No. 7), p. 40-49.

[8] ClaudiusPeters: Klinkerkühler Betriebsanleitung. 2002.

[9] IKN: Betriebsanleitung für den IKN-Pendelrostkühler. 2003.

[10] Bentsen, B. and B.P. Keefe: Der SF Cross-Bar Cooler - ein neuer Klinkerkühler mit innovativer Luftverteilung. ZKG International, 1999, Vol. 52, (No. 11), S.608-619.

[11] Opitz, D.: Die Ansatzringe in Zementdrehöfen. Schriftenreihe der Zementindustrie, Beton-Verlag GmbH, Düsseldorf, 1974, Heft 41.

[12] Tokheim, L.-A.: An Alternative Solution. World Cement, 2005, Vol. 11, p. 57-63.

[13] ATD-Abbausysteme: ATD-System: Druckgasverfahren Cardox. Düsseldorf.

[14] Görke, R. and K.J. Leers: Automatisierung eines Erhitzungsmikroskops mit Hilfe digitaler Bildverabeitung. Keramische Zeitschrift, 1996, 48, (No.4), S.300-305.

[15] Reich, R.: Zur Bestimmung der Ersthaftung von Klinker auf feuerfestem Material. Silikattechnik, 1985, Vol. 36, (Heft 9), p. 291-292.

[16] Fisher, R.V. and H.-U. Schmincke: Pyroclastic Rocks. Springer Verlag, Berlin, 1984.

[17] ClaudiusPeters: Information sheet of Claudius Peters. 2006.

72

10. Table of figures

Figure 1: Clinker phases formation [3]. ................................................................................... 10

Figure 2: Diagram of cyclone preheater [1]. ............................................................................ 13

Figure 3: Diagram of cyclone preheater with precalcination [1]. ............................................ 13

Figure 4: Different combustion air supply systems for precalcination [1]. ............................. 14

Figure 5: Recirculating system [3]. .......................................................................................... 15

Figure 6: Effect of cooling rate on cement properties and phases [4]...................................... 17

Figure 7: Conventional cooler types [6]................................................................................... 18

Figure 8: Formation of Red River [9]. ..................................................................................... 28

Figure 9: Pressure losses of various clinker sizes as a function of free air velocity [10]. ....... 29

Figure 10: Formation of Snowman [9]..................................................................................... 30

Figure 11: Effect of clinker size on needed retention time [10]............................................... 30

Figure 12: Simplified flow sheet of the clinker production at Brevik, Norway....................... 34

Figure 13: The modified kiln system [12]................................................................................ 37

Figure 14: The new bypass system [12]................................................................................... 37

Figure 15: The used clinker cooler system at Brevik, Norway. ............................................... 39

Figure 16: Diagram of fuels feeding (06.03.06 - 11.03.06). .................................................... 43

Figure 17: Diagram of temperatures (06.03.06 - 11.03.06). .................................................... 44

Figure 18: Diagram of kiln amp and raw meal feeding (06.03.06 - 11.03.06). ....................... 45

Figure 19: Burner in new condition. ........................................................................................ 46

Figure 20: Burner in used condition......................................................................................... 46

Figure 21: Diagram of fuels feeding into kiln (06.03.06 - 11.03.06)....................................... 47

Figure 22: Static cooler inlet after shut down. ......................................................................... 48

Figure 23: One plate of the second row. .................................................................................. 49

Figure 24: Plates of the first row.............................................................................................. 49

Figure 25: Plates 2 & 3 of row five. ......................................................................................... 49

Figure 26: Plates 4 & 5 of row five. ......................................................................................... 49

Figure 27: Overview of the plates of row five on the left side................................................. 50

Figure 28: Cooler wall of one side. .......................................................................................... 51

Figure 29: Piece of a collected Snowman (09.03.06). ............................................................. 51

Figure 30: CARDOX system at rotary kiln [13]. ..................................................................... 56

Figure 31: CARDOX system at cyclones of the preheater tower [13]..................................... 56

Figure 32: Prepared piece of the found Snowman. .................................................................. 58

Figure 33: Clinker 2.5x polished surface. ................................................................................ 60

Figure 34: Snowman 2.5x polished surface. ............................................................................ 60

Figure 35: Snowman 20x polished surface. ............................................................................. 62

Figure 36: Snowman 20x fractured surface. ............................................................................ 62

Figure 37: Snowman 2000x fractured surface. ........................................................................ 62

Figure 38: Snowman 2000x fractured surface. ........................................................................ 62

Figure 39: Potential clinker dust circulation at the cooler inlet. .............................................. 64

Figure 40: Some ways the pyroclastic flows can originate [16]. ............................................. 65

Figure 41: Diagram showing development of block and ash flow [16]................................... 66

Figure 42: Strongly welded pantelleritic ignimbrite from Gran Canaria [16]. ........................ 66

Figure 43: Emphasis of the important items of the checklist. .................................................. 67

Figure 44: Modification lining HE-Modul [17]. ...................................................................... 69

Figure 45: XRD - Snowman row 1. ......................................................................................... 82



73



Figure 50: XRD - LA-Clinker. ................................................................................................. 84

Figure 51: SM-fractured 1000x................................................................................................ 85

Figure 52: SM-fractured 100x.................................................................................................. 85

Figure 53: SM(a)-fractured 1000x. .......................................................................................... 85

Figure 54: SM(b)-fractured 1000x. .......................................................................................... 85

Figure 55: SM(c)-fractured 1000x. .......................................................................................... 86

Figure 56: SM(d)-fractured 1000x. .......................................................................................... 86

Figure 57: White particles 200x. .............................................................................................. 87

Figure 58: White particles 500x. .............................................................................................. 87

Figure 59: White particles 3000x. ............................................................................................ 87

Figure 60: SM-fractured 20x.................................................................................................... 89



Figure 63: SM-fractured 1000x................................................................................................ 89

Figure 64: SM(a)-fractured-neck 2000x. ................................................................................. 90

Figure 65: SM(b)-fractured-neck 2000x. ................................................................................. 90

Figure 66: SM(a)-fractured-crystals 2000x.............................................................................. 90

Figure 67: SM(b)-fractured-crystals 2000x.............................................................................. 91

Figure 68: SM(a)-fractured-inter phase 2000x......................................................................... 91

Figure 69: SM(b)-fractured-inter phase 2000x. ....................................................................... 92

Figure 70: SM-fractured 20x.................................................................................................... 92

Figure 71: SM(3)-polished 20x. ............................................................................................... 92

Figure 72: SM(1)-polished 100x. ............................................................................................. 93

Figure 73: SM(3)-polished 20x. ............................................................................................... 93



Figure 76: SM(3)-polished 1000x. ........................................................................................... 93




Figure 80: Clinker-polished 20x. ............................................................................................. 99

Figure 81: Clinker-polished 100x. ........................................................................................... 99



Figure 84: Clinker-polished 1000x. ......................................................................................... 99

Figure 85: Clinker(a)-polished 2000x. ..................................................................................... 99

Figure 86: Clinker(b)-polished 2000x...................................................................................... 99

Figure 87: Clinker-polished 500x. ......................................................................................... 100

Figure 88: Clinker(b)-polished 2000x.................................................................................... 102

74

11. List of tables

Table 1: Potential phase composition of German cement clinker [1]. ....................................... 9

Table 2: Moduli of German cement clinker [1]. ...................................................................... 11

Table 3: Essential technical data of rotary coolers [6]. ............................................................ 19

Table 4: Essential technical data of planetary coolers [6]........................................................ 19

Table 5: Essential technical data of grate coolers [6]............................................................... 19

Table 6: Clinker capacity - clinker exit temperature - cooling air quantity [8]. ...................... 23

Table 7:Specific cooling air quantity - secondary air temperature - cooler efficiency [8]. ..... 24

Table 8: Clinker bed level - thrust rate/time of stay - clinker exit temperature - wear [8]. ..... 25

Table 9:Clinker bed level - clinker exit temperature - cooler efficiency - power

requirement[8]............................................................................................................ 26

Table 10: Cooling air quantity - thrust rate - exhaust air quantity - exhaust air temperature [8].

.................................................................................................................................... 27

Table 11: Overview of the kiln system modification items [12].............................................. 35

Table 12: Kiln system characteristics [12]. .............................................................................. 38

Table 13: Kiln stops caused by Snowman formation (1999 - 2006)........................................ 39

Table 14: Raw meal chemistry of LA-clinker (06.03.06 - 11.03.06) *FSA. ........................... 41

Table 15: LA-Clinker chemistry (06.03.06 - 11.03.06). .......................................................... 41

Table 16: Bypass dust chemistry (06.03.06 - 11.03.06)........................................................... 41

Table 17: Clinker mineralogy calculated by Bogue and Lea (06.03.06 - 11.03.06). ............... 42

Table 18: Calculated Moduli (06.03.06 - 11.03.06)................................................................. 42

Table 19: The used cooling air volume calculated from process data (06.03.06 - 11.03.06). . 47

Table 20: Raw meal chemistry from kiln WT2 (2005). ........................................................... 54

Table 21: Raw meal chemistry from kiln WT3 (2005). ........................................................... 54

Table 22: Clinker chemistry of both lines (WT2 & WT3) from 2005. .................................... 55

Table 23: Bypass chemistry of both lines (2005)..................................................................... 55

Table 24: Clinker mineralogy from laboratory data and calculated melting phase (2005)...... 55

Table 25: Calculated Moduli of clinker (2005)........................................................................ 55

Table 26: XRF & free lime analyses of the Snowman sample (rows 1 - 5) and the clinker.... 58

Table 27: Calculated values (LSF, SR, AR, DS, S). ................................................................ 59

Table 28: XRD - Snowman sample corresponding to the LA-clinker. .................................... 59

Table 29: Water soluble salts. .................................................................................................. 60

Table 30: Typical mass flows of kiln 6 in Brevik. ................................................................... 76

Table 31: OPC-Raw meal chemistry 2004 - 2006. .................................................................. 76

Table 32: LA-Raw meal chemistry 2004 - 2006...................................................................... 76

Table 33: LA-SR-Raw meal chemistry 2004 - 2006................................................................ 76

Table 34: OPC-Clinker chemistry 2004 - 2006. ...................................................................... 77

Table 35: LA-Clinker chemistry 2004 - 2006. ......................................................................... 77

Table 36: LA-SR-Clinker chemistry 2004 - 2006.................................................................... 77

Table 37: Bypass dust chemistry 2004 - 2006. ........................................................................ 77

Table 38: Calculations of specific cooling air quantity, Brevik (Kiln 6). ................................ 78

Table 39: Calculations of specific cooling air quantity, Burglegenfeld (Kiln 2 - CP)............. 79

Table 40: Calculations of specific cooling air quantity, Burglengenfeld (Kiln 3 - IKN)......... 80

Table 41: XRF & free lime analyses of the Snowman sample (rows 1 - 5) and the clinker.... 81

Table 42: Calculated values (LSF, SR, AR, DS, S). ................................................................ 81

Table 43: XRD - Snowman (SM) sample (rows 1 - 5). ........................................................... 81

Table 44: XRD - LA-Clinker sample. ...................................................................................... 81

Table 45: EDX-analyses of SM(a)-fractured 1000x. ............................................................... 85

75

Table 46: EDX-analyses of SM(b)-fractured 1000x. ............................................................... 85

Table 47: EDX-analyses of SM(c)-fractured 1000x. ............................................................... 86

Table 48: EDX-analyses of SM(d)-fractured 1000x. ............................................................... 86

Table 49: EDX-analyses point 1 (left table) & 2 (right table) of White particles 3000x......... 87

Table 50: EDX-analyses point 3 (left table) & 4 (right table) of White particles 3000x......... 88

Table 51: EDX-analyses point 5 (left) & 6 (right) of White particles 3000x. ......................... 88

Table 52: EDX-analyses point 7 of White particles 3000x...................................................... 88

Table 53: EDX-analyses of SM-fractured 100x....................................................................... 89

Table 54: EDX-analyses point 1 of SM(a)-fractured-neck 2000x. .......................................... 90

Table 55: EDX-analyses of SM(a)-fractured-crystals 2000x................................................... 90

Table 56: EDX-analyses of SM(b)-fractured-crystals 2000x. ................................................. 91

Table 57: EDX-analyses of SM(a)-fractured-inter phase 2000x. ............................................ 91

Table 58: EDX-analyses point 1 (left table) & 2 (right table) of SM-fractured-inter phase

2000x.......................................................................................................................... 92

Table 59: EDX-analyses of SM(1)-polished 100x. .................................................................. 93

Table 60: EDX-analyses point 1(left table) & 2 (right table) of SM(1)-polished 500x........... 94

Table 61: EDX-analyses point 3 (left table) & 4 (right table) of SM(1)-polished 500x.......... 94




Table 65: EDX-analyses point 5 of SM(2)-polished 500x....................................................... 96

Table 66: EDX-analyses point 1 (left table) & 2 (right table of SM(3)-polished 500x. .......... 97


Table 68: EDX-analyses of point 5 of SM(3)-polished 500x. ................................................. 98

Table 69: EDX-analyses of Clinker-polished 20x. ................................................................ 100

Table 70: EDX-analyses point 1 (left table) & 2 (right table) of Clinker-polished 500x. ..... 100




Table 74: EDX-analyses point 1 (left table) & 2 (right table of Clinker(b)-polished 2000x. 102

Table 75: EDX-analyses point 3 (left table) & 4 (right table of Clinker(b)-polished 2000x. 102

76

12. Appendix

Table 30: Typical mass flows of kiln 6 in Brevik.

Parameter Value Unit Comment

Raw meal production 260 t/h Output from RM; going into raw meal silo

Apparent raw meal feed rate

220 t/h Kiln feed

Filter dust return 15 t/h Dust going out from cyclone tower; into kiln feed silo

Bypass dust extraction 1.6 t/h Cl rich dust extracted from kiln inlet

Clinker 135 t/h Output from cooler

Primary coal 5.5 t/h Rotary kiln fuel

Animal meal 1.5 t/h Rotary kiln fuel

Liquid hazardous waste 1.5 t/h Rotary kiln fuel

Secondary coal 2 t/h Calciner fuel

Refuse derived fuel 13 t/h Calciner fuel

Solid hazardous waste 2 t/h Calciner fuel

Raw meal (kiln feed)

Table 31: OPC-Raw meal chemistry 2004 - 2006.

Year CaO SiO2 Al2O3 Fe2O3 Na2O K2O MgO Alkali SO3

2004 64.64 21.30 4.79 3.29 0.51 1.23 2.93 1.32 1.58

2005 64.69 21.41 4.80 3.71 0.52 1.21 2.77 1.31 1.46

2006 64.10 21.87 5.03 3.66 0.56 1.25 2.96 1.38 1.39

64.48 21.52 4.87 3.55 0.53 1.23 2.88 1.34 1.47

Table 32: LA-Raw meal chemistry 2004 - 2006.


2004 66.58 21.84 4.50 3.44 0.25 0.47 2.06 0.56 0.77

2005 66.09 22.03 4.36 3.35 0.28 0.48 2.30 0.59 0.67

2006 65.84 22.26 4.23 3.24 0.26 0.58 1.95 0.64 0.70

66.17 22.04 4.36 3.34 0.26 0.51 2.11 0.60 0.71

Table 33: LA-SR-Raw meal chemistry 2004 - 2006.


2004 65.92 22.65 3.57 4.98 0.26 0.48 1.88 0.58 0.74

2005 65.46 22.79 3.46 4.90 0.25 0.48 1.85 0.56 0.65

2006 65.24 22.75 3.39 4.92 0.25 0.46 1.92 0.56 0.63

65.54 22.73 3.47 4.93 0.25 0.47 1.88 0.57 0.67

77

Clinker

Table 34: OPC-Clinker chemistry 2004 - 2006.

Year CaO SiO2 Al2O3 Fe2O3 Na2O K2O MgO Alkali SO3 CaOfree

2004 64.08 21.02 5.00 3.38 0.52 1.17 2.64 1.29 1.43 1.97

2005 64.29 20.95 4.86 3.64 0.51 1.09 2.61 1.23 1.34 1.92

2006 63.25 20.90 5.01 3.65 0.50 1.06 2.71 1.20 1.39 1.74

63.87 20.96 4.96 3.55 0.51 1.11 2.66 1.24 1.39 1.88

Table 35: LA-Clinker chemistry 2004 - 2006.


2004 65.25 21.74 4.54 3.55 0.28 0.46 1.95 0.59 0.91 1.96

2005 65.02 21.89 4.51 3.50 0.31 0.45 2.10 0.60 0.80 1.72

2006 64.77 22.14 4.59 3.37 0.30 0.53 1.95 0.65 0.89 1.56

65.01 21.93 4.55 3.47 0.30 0.48 2.00 0.61 0.87 1.74

Table 36: LA-SR-Clinker chemistry 2004 - 2006.


2004 64.59 22.54 3.68 5.03 0.28 0.46 1.77 0.59 0.89 1.30

2005 64.38 22.73 3.61 4.94 0.27 0.44 1.73 0.56 0.83 0.98

2006 64.26 22.63 3.65 4.96 0.26 0.41 1.67 0.53 0.79 0.92

64.41 22.64 3.64 4.98 0.27 0.44 1.72 0.56 0.84 1.07

By-pass dust

Table 37: Bypass dust chemistry 2004 - 2006.

Year CaO SiO2 Al2O3 Fe2O3 Na2O K2O MgO Cl LOI SO3(raw) CaOfree

2004 3.72 12.02 3.74 28.13

2005 55.43 18.62 4.07 3.04 0.83 4.51 2.20 3.89 5.58 4.91 29.37

2006 54.91 17.76 3.67 3.02 0.96 5.19 1.77 3.64 5.47 5.37 26.79

55.23 18.30 3.92 3.03 0.88 4.76 2.04 3.84 6.72 4.75 28.92

78

Table 38: Calculations of specific cooling air quantity, Brevik (Kiln 6).

Co

olin

g a

ir q

uan

tity

per

co

olin

g s

urf

ace

[Nm

³/m

²]

9,2

59

8,4

70

7,0

98

4,5

71

3,5

72

1,9

76

1,9

76

3,7

28

3,3

59

4,3

07

44,0

09

Co

olin

g s

urf

ace

[m²]

2.2

9

1.2

0

2.9

9

6.1

8

14.1

5

2.3

9

2.3

9

7.9

7

9.9

7

16.9

4

49.5

3

Co

olin

g a

ir q

uan

tity

per

co

olin

g p

late

[Nm

³/p

late

]

92

3

84

4

70

7

45

6

35

6

19

7

19

7

37

2

33

5

42

9

4,3

86

Ro

ws

6 4 8 17 8 10

17

53

Ae

rate

d

pla

tes

23

12

30

62

14

2

24

24

80

10

0

17

0

66

7

Sp

ecif

ic c

oo

lin

g

air

qu

an

tity

[Nm

³/kg

cli]

0.1

6

0.0

8

0.1

6

0.2

1

0.3

7

0.0

4

0.0

4

0.2

2

0.2

5

0.5

4

2.0

5

Am

bie

nt te

mp. [°

C] : 10

Co

olin

g a

ir

qu

an

tity

[Nm

³/h

]

21,2

23

10,1

29

21,2

23

28,2

45

50,5

48

4,7

27

4,7

27

29,7

21

33,4

74

72,9

77

276,9

94

Co

olin

g a

ir

qu

an

tity

[Bm

³/h

]

22,0

00

10,5

00

22,0

00

29,2

80

52,4

00

4,9

00

4,9

00

30,8

10

34,7

00

75,6

50

287,1

40

Ta

ble

38

: C

alc

ula

tio

ns o

f sp

ecific

coo

ling

air

qu

an

tity

, B

revik

(kiln

6).

Clin

ker

[t/d

]: 3

240

Fan

HE

-Mod

ul(1

)

HE

-Mod

ul(2

)

Ch

am

ber

2

Ch

am

ber

3

Ch

am

ber

4

Fis

hbo

ne

Fa

n6

Fis

hbo

ne

Fa

n7

Ch

am

ber

1

Ch

am

ber

2

Ch

am

ber

3

To

tal

79

Table 39: Calculations of specific cooling air quantity, Burglegenfeld (Kiln 2 - CP).

Co

olin

g a

ir q

uan

tity

per

co

olin

g s

urf

ace

[Nm

³/m

²]

9,7

60

7,5

68

8,0

45

3,7

09

2,5

24

1,8

46

1,7

21

35,1

74

Co

olin

g s

urf

ace

[m²]

2.3

9

1.5

9

3.1

9

10.3

6

11.1

6

12.7

6

13.5

5

55.0

1

Co

olin

g a

ir q

uan

tity

per

co

olin

g p

late

[Nm

³/p

late

]

97

3

75

4

80

2

37

0

25

2

18

4

17

2

3,5

05

Ro

ws

4 2 4 13

14

16

17

70

Ae

rate

d

pla

tes

24

16

32

10

4

11

2

12

8

13

6

55

2

Sp

ecif

ic c

oo

lin

g

air

qu

an

tity

[Nm

³/kg

cli]

0.3

1

0.1

6

0.3

5

0.5

2

0.3

8

0.3

2

0.3

1

2.3

5

Am

bie

nt te

mp. [°

C] : 20

Co

olin

g a

ir

qu

an

tity

[Nm

³/h

]

23,3

45

12,0

68

25,6

56

38,4

44

28,1

78

23,5

42

23,3

31

174,5

63

Co

olin

g a

ir

qu

an

tity

[Bm

³/h

]

25,0

55

12,9

52

27,5

36

41,2

60

30,2

42

25,2

67

25,0

40

187,3

52

Ta

ble

39

: C

alc

ula

tio

ns o

f sp

ecific

coo

ling

air

qu

an

tity

, B

urg

len

ge

nfe

ld (

Kiln

2 -

CP

).

Clin

ker

[t/d

]: 1

780

Fan

HE

-Mod

ul(1

)

HE

-Mod

ul(2

)

Ch

am

ber

1

Ch

am

ber

2

Ch

am

ber

3

Ch

am

ber

4

Ch

am

ber

5

To

tal

80

Table 40: Calculations of specific cooling air quantity, Burglengenfeld (Kiln 3 - IKN).

Co

olin

g a

ir q

uan

tity

per

co

olin

g s

urf

ace

[Nm

³/m

²]

5,2

66

4,4

20

4,2

91

3,5

08

3,2

74

2,9

36

23,6

95

Co

olin

g s

urf

ace

[m²]

1.7

9

3.3

8

8.3

0

11.0

0

11.0

0

12.9

0

48.3

7

Co

olin

g a

ir q

uan

tity

per

co

olin

g p

late

[Nm

³/p

late

]

29

1

24

4

28

3

23

0

21

4

19

3

1,4

55

Ro

ws

3 4 9 12

12

14

54

Ae

rate

d

pla

tes

32

61

12

6

16

8

16

8

19

6

75

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Sp

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oo

lin

g

air

qu

an

tity

[Nm

³/kg

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3

0.2

0

0.4

8

0.5

2

0.4

9

0.5

1

2.3

3

Am

bie

nt te

mp. [°

C] : 20

Co

olin

g a

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qu

an

tity

[Nm

³/h

]

9,4

26

14,9

40

35,6

13

38,5

87

36,0

15

37,8

81

172,4

61

Co

olin

g a

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an

tity

[Bm

³/h

]

10,1

17

16,0

34

38,2

22

41,4

14

38,6

53

40,6

56

185,0

96

Ta

ble

40

: C

alc

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ecific

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an

tity

, B

urg

len

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nfe

ld (

Kiln

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IK

N).

Clin

ker

[t/d

]: 1

780

Fan

Sta

t. G

rate

(1)

Sta

t. G

rate

(2)

Ch

am

ber

1

Ch

am

ber

2

Ch

am

ber

3

Ch

am

ber

4

To

tal

81

SEM-Analyses

Table 41: XRF & free lime analyses of the Snowman sample (rows 1 - 5) and the clinker.

Row 1 [m.-%]

Row 2 [m.-%]

Row 3 [m.-%]

Row 4 [m.-%]

Row 5 [m.-%]

Average[m.-%]

Clinker[m.-%]

CaO 66.2 66.0 66.2 66.2 66.3 66.2 64.97

SiO2 22.0 22.4 22.3 21.6 21.7 22.0 20.92

Al2O3 4.39 4.29 4.36 4.45 4.38 4.37 4.55

Fe2O3 3.33 3.28 3.36 3.45 3.35 3.35 3.37

MgO 2.59 2.57 2.59 2.60 2.58 2.59 2.64

SO3 0.807 0.909 0.855 0.946 0.986 0.901 2.01

K2O 0.265 0.288 0.271 0.320 0.340 0.297 0.768

Na2O 0.0406 0.0611 0.0435 0.0611 0.0434 0.0499 0.160

TiO2 0.337 0.332 0.339 0.348 0.341 0.339 0.365

P2O5 0.0614 0.0599 0.0594 0.0615 0.0620 0.0608 0.0920

MnO 0.0987 0.0972 0.0992 0.1020 0.0989 0.0992 0.0848

SrO 0.0693 0.0693 0.0700 0.0708 0.0703 0.0699 0.0730

Cl 0.00 0.00 0.00 0.00 0.00 0.00 0.13

CaOfree 0.17 0.10 0.14 0.18 0.14 0.15 5.26

Table 42: Calculated values (LSF, SR, AR, DS, S).

Row 1 Row 2 Row 3 Row 4 Row 5 average Clinker

LSF 96.02 94.40 94.88 97.39 97.35 96.01 98.24

SR 2.85 2.96 2.89 2.73 2.81 2.85 2.64

AR 1.32 1.31 1.30 1.29 1.31 1.30 1.35

DS 290.60 280.78 298.38 269.56 285.74 285.01 233.86

S [m.-%] 20.28 19.87 20.25 20.72 20.29 20.28 22.40

XRD – Rietveld

Table 43: XRD - Snowman (SM) sample (rows 1 - 5).

PhaseSM 1[wt.-%]

SM 2 [wt.-%]

SM 3 [wt.-%]

SM 4 [wt.-%]

SM 5 [wt.-%]

Average[wt.-%]

C2S 16.7 12.9 17.7 14.1 13.4 15.0

C3S 67.3 68.1 66.1 66.8 69.1 67.5

C3A 2.3 2.6 2.6 2.7 2.7 2.6

C4AF 12.6 16.1 12.7 16.0 13.0 14.1

Anhydrite 0.1 0.1 0.1 0.1 0.4 0.2

Periclase 1.0 0.2 0.9 0.2 1.4 0.7

Table 44: XRD - LA-Clinker sample.

Phase [wt.-%]

C2S 31.9

C3S 44.8

C3A 0.9

C4AF 13.6

Periclase 0.7

Lime 5.0

Portlandite 1.0

Rest 2.0

82

1600

1400

1200

1000

800

600

400

200

Snowman 1 RV

2500

2000

1500

1000

500

0

33-302 b-Ca2 Si O4

49-442 Ca3 Si O5

38-1429 Ca3 Al2 O6

30-226 Ca2 ( Al , Fe )2 O5

37-1496 Ca S O4

45-946 Mg O

Snowman 1

2-Theta (deg.)

Inte

snity (

cps)

10.0 20.0 30.0 40.0 50.0 60.0

Figure 45: XRD - Snowman row 1.

2500

2000

1500

1000

500

Snowman 2 RV

2500

2000

1500

1000

500

0

33-302 b-Ca2 Si O4

49-442 Ca3 Si O5

38-1429 Ca3 Al2 O6

30-226 Ca2 ( Al , Fe )2 O5

37-1496 Ca S O4

45-946 Mg O

Snowman 2

2-Theta (deg.)

Inte

snity (

cps)

10.0 20.0 30.0 40.0 50.0 60.0


83

1400

1200

1000

800

600

400

200

Snowman 3 RV

2500

2000

1500

1000

500

0

33-302 b-Ca2 Si O4

49-442 Ca3 Si O5

38-1429 Ca3 Al2 O6

30-226 Ca2 ( Al , Fe )2 O5

37-1496 Ca S O4

45-946 Mg O

Snowman 3

2-Theta (deg.)

Inte

snity (

cps)

10.0 20.0 30.0 40.0 50.0 60.0


1600

1400

1200

1000

800

600

400

200

Snowman 4 RV

2500

2000

1500

1000

500

0

33-302 b-Ca2 Si O4

49-442 Ca3 Si O5

38-1429 Ca3 Al2 O6

30-226 Ca2 ( Al , Fe )2 O5

37-1496 Ca S O4

45-946 Mg O

Snowman 4

2-Theta (deg.)

Inte

snity (

cps)

10.0 20.0 30.0 40.0 50.0 60.0


84

1400

1200

1000

800

600

400

200

Snowman 5 RV

2500

2000

1500

1000

500

0

33-302 b-Ca2 Si O4

49-442 Ca3 Si O5

38-1429 Ca3 Al2 O6

30-226 Ca2 ( Al , Fe )2 O5

37-1496 Ca S O4

45-946 Mg O

Snowman 5

2-Theta (deg.)

Inte

snity (

cps)

10.0 20.0 30.0 40.0 50.0 60.0


1200

1000

800

600

400

200

Rü_Klinker data

Background

2500

2000

1500

1000

500

0

49-442 Calcium Silicate

33-302 Larnite, syn

32-150 Calcium Aluminum Oxide

30-226 Brownmillerite, syn

37-1497 Lime, syn

Klinker (Anschliff )

2-Theta (deg.)

Inte

nsity (

cps)

10.0 20.0 30.0 40.0 50.0 60.0

Figure 50: XRD - LA-Clinker.

85

White particles of the sample snowman

Overview:

Figure 51: SM-fractured 1000x. Figure 52: SM-fractured 100x.

Table 45: EDX-analyses of SM(a)-fractured 1000x.

Element[wt.-%]

Oxide [wt.-%]

Na 2.3 Na2O 3.1

Mg 5.2 MgO 8.7

Al 4.2 Al2O3 7.9

Si 7.4 SiO2 15.9

K 0.4 K2O 0.5

Ca 43.0 CaO 10.2

Fe 2.5 FeO 3.3

O 34.5 --

Figure 53: SM(a)-fractured 1000x.

Table 46: EDX-analyses of SM(b)-fractured 1000x.

Element[wt.-%]

Oxide [wt.-%]

Na 2.6 Na2O 3.5

Mg 0.3 MgO 0.6

Al 6.3 Al2O3 11.9

Si 6.8 SiO2 14.7

K 0.6 K2O 0.7

Ca 42.8 CaO 59.9

Fe 6.5 FeO 8.4

O 33.7 --

Figure 54: SM(b)-fractured 1000x.

86

Table 47: EDX-analyses of SM(c)-fractured 1000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.2 Na2O 0.3

Mg 0.3 MgO 0.5

Al 1.0 Al2O3 1.9

Si 10.0 SiO2 21.4

K 0.2 K2O 0.4

Ca 52.9 CaO 74.1

Fe 0.9 FeO 1.2

O 34.1 --

Figure 55: SM(c)-fractured 1000x.

Table 48: EDX-analyses of SM(d)-fractured 1000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.8 Na2O 1.1

Mg 0.9 MgO 1.5

Al 1.2 Al2O3 2.2

Si 8.7 SiO2 18.7

K 0.4 K2O 0.5

Ca 50.2 CaO 70.3

Fe 2.7 FeO 3.5

S 0.7 SO3 1.8

O 34.0 --

Figure 56: SM(d)-fractured 1000x.

87

White particles separate from the snowman sample

Overview:

Figure 57: White particles 200x. Figure 58: White particles 500x.

Figure 59: White particles 3000x.

Table 49: EDX-analyses point 1 (left table) & 2 (right table) of White particles 3000x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 9.8 Na2O 13.2 Na 5.1 Na2O 6.9

Mg 0.0 MgO 0.0 Mg 0.2 MgO 0.3

Al 0.2 Al2O3 0.4 Al 0.3 Al2O3 0.6

Si 1.4 SiO2 2.9 Si 1.9 SiO2 4.2

K 26.3 K2O 31.7 K 26.0 K2O 31.4

Ca 4.7 CaO 6.6 Ca 8.6 CaO 12.0

Fe 0.0 FeO 0.0 Fe 0.0 FeO 0.0

S 18.0 SO3 44.9 S 17.7 SO3 44.4

O 39.4 -- O 39.8 --

88

Table 50: EDX-analyses point 3 (left table) & 4 (right table) of White particles 3000x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 7.6 Na2O 10.3 Na 0.6 Na2O 0.9

Mg 0.0 MgO 0.0 Mg 0.0 MgO 0.0

Al 0.1 Al2O3 0.2 Al 0.0 Al2O3 0.0

Si 1.0 SiO2 2.2 Si 15.6 SiO2 33.5

K 27.9 K2O 33.7 K 0.6 K2O 0.8

Ca 2.4 CaO 3.4 Ca 45.1 CaO 63.1

Fe 0.8 FeO 1.1 Fe 0.4 FeO 0.5

S 19.6 SO3 48.9 S 0.4 SO3 1.0

O 40.2 -- O 36.9 --

Table 51: EDX-analyses point 5 (left) & 6 (right) of White particles 3000x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 2.9 Na2O 3.9 Na 3.9 Na2O 5.3

Mg 0.0 MgO 0.0 Mg 0.9 MgO 1.5

Al 0.7 Al2O3 1.4 Al 0.2 Al2O3 0.4

Si 11.4 SiO2 24.4 Si 2.1 SiO2 4.6

K 5.7 K2O 6.8 K 24.8 K2O 29.9

Ca 36.3 CaO 50.8 Ca 9.0 CaO 12.7

Fe 0.0 FeO 0.0 Fe 0.7 FeO 0.9

S 4.9 SO3 12.4 S 17.8 SO3 44.5

O 37.8 -- O 40.2 --

Table 52: EDX-analyses point 7 of White particles 3000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.4 Na2O 0.5

Mg 0.2 MgO 0.4

Al 0.8 Al2O3 1.6

Si 11.5 SiO2 24.7

K 0.6 K2O 0.7

Ca 50.1 CaO 70.1

Fe 0.0 FeO 0.0

S 0.6 SO3 1.7

O 35.4 --

89

Fractured surface of the sample snowman

Figure 60: SM-fractured 20x.

Table 53: EDX-analyses of SM-fractured 100x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0

Mg 0.9 MgO 1.6

Al 0.9 Al2O3 1.7

Si 6.5 SiO2 13.9

K 0.5 K2O 0.6

Ca 55.0 CaO 76.9

Fe 3.1 FeO 4.0

S 0.4 SO3 1.0

O 32.4 --

Figure 61: SM-fractured 100x.

Figure 62: SM-fractured 500x Figure 63: SM-fractured 1000x

90

Table 54: EDX-analyses point 1 of SM(a)-fractured-neck 2000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0

Mg 0.9 MgO 1.6

Al 0.9 Al2O3 1.8

Si 8.9 SiO2 19.0

K 0.4 K2O 0.5

Ca 52.7 CaO 73.7

Fe 1.4 FeO 1.8

S 0.5 SO3 1.3

O 34.0 --

Figure 64: SM(a)-fractured-neck 2000x.

Figure 65: SM(b)-fractured-neck 2000x.

Table 55: EDX-analyses of SM(a)-fractured-crystals 2000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.4 Na2O 0.5

Mg 1.1 MgO 1.8

Al 3.0 Al2O3 5.7

Si 6.9 SiO2 14.9

K 0.1 K2O 0.2

Ca 49.4 CaO 69.1

Fe 5.2 FeO 6.8

S 0.3 SO3 0.7

O 33.2 --

Figure 66: SM(a)-fractured-crystals 2000x.

91

Table 56: EDX-analyses of SM(b)-fractured-crystals 2000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0

Mg 3.0 MgO 5.0

Al 1.4 Al2O3 2.7

Si 11.8 SiO2 25.3

K 0.7 K2O 0.8

Ca 42.4 CaO 59.3

Fe 4.0 FeO 5.2

S 0.6 SO3 1.4

O 35.9 --

Figure 67: SM(b)-fractured-crystals 2000x.

Table 57: EDX-analyses of SM(a)-fractured-inter phase 2000x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0

Mg 4.1 MgO 6.9

Al 8.1 Al2O3 15.3

Si 2.7 SiO2 5.7

K 0.1 K2O 0.2

Ca 42.4 CaO 59.3

Fe 8.7 FeO 11.2

S 0.4 SO3 1.1

O 33.1 --

Figure 68: SM(a)-fractured-inter phase

2000x.

92

Figure 69: SM(b)-fractured-inter phase 2000x.

Table 58: EDX-analyses point 1 (left table) & 2 (right table) of SM-fractured-inter phase

2000x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0 Na 0.9 Na2O 1.2

Mg 3.3 MgO 5.5 Mg 1.2 MgO 2.0

Al 8.9 Al2O3 16.8 Al 0.7 Al2O3 1.4

Si 3.3 SiO2 7.1 Si 10.4 SiO2 22.3

K 0.1 K2O 0.1 K 0.2 K2O 0.2

Ca 42.7 CaO 59.7 Ca 50.9 CaO 71.3

Fe 7.7 FeO 9.9 Fe 0.4 FeO 0.6

S 0.2 SO3 0.6 S 0.3 SO3 0.8

O 33.6 -- O 34.6 --

Figure 70: SM-fractured 20x. Figure 71: SM(3)-polished 20x.

93

Table 59: EDX-analyses of SM(1)-polished 100x.

Element[wt.-%]

Oxide [wt.-%]

Na 1.0 Na2O 1.4

Mg 1.8 MgO 3.0

Al 1.8 Al2O3 3.4

Si 8.9 SiO2 19.2

K 0.3 K2O 0.3

Ca 48.9 CaO 68.4

Fe 1.4 FeO 1.9

S 0.8 SO3 2.0

O 34.7 --

Figure 72: SM(1)-polished 100x.

Figure 73: SM(3)-polished 20x. Figure 74: SM(3)-polished 100x.

Figure 75: SM(3)-polished 500x. Figure 76: SM(3)-polished 1000x.

94


Table 60: EDX-analyses point 1(left table) & 2 (right table) of SM(1)-polished 500x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0 Na 0.0 Na2O 0.0

Mg 0.7 MgO 1.1 Mg 58.5 MgO 97.1

Al 0.7 Al2O3 1.3 Al 0.0 Al2O3 0.0

Si 10.1 SiO2 21.7 Si 0.1 SiO2 0.4

K 0.0 K2O 0.0 K 0.0 K2O 0.0

Ca 52.7 CaO 73.7 Ca 1.0 CaO 1.4

Fe 0.5 FeO 0.6 Fe 0.7 FeO 1.0

S 0.5 SO3 1.2 S 0.0 SO3 0.0

O 34.6 -- O 39.4 --

Table 61: EDX-analyses point 3 (left table) & 4 (right table) of SM(1)-polished 500x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.4 Na2O 0.5 Na 0.5 Na2O 0.7

Mg 0.4 MgO 0.6 Mg 0.9 MgO 1.5

Al 0.7 Al2O3 1.4 Al 0.7 Al2O3 1.4

Si 14.4 SiO2 30.8 Si 10.7 SiO2 22.9

K 0.2 K2O 0.2 K 0.2 K2O 0.2

Ca 45.4 CaO 63.5 Ca 51.4 CaO 72.0

Fe 0.7 FeO 0.9 Fe 0.4 FeO 0.5

S 0.7 SO3 1.8 S 0.2 SO3 0.5

O 36.9 -- O 34.7 --

95


Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.6 Na2O 0.9 Na 0.7 Na2O 0.9

Mg 0.9 MgO 1.5 Mg 0.8 MgO 1.3

Al 0.8 Al2O3 1.6 Al 11.6 Al2O3 22.0

Si 10.5 SiO2 22.4 Si 1.3 SiO2 2.8

K 0.0 K2O 0.0 K 0.1 K2O 0.1

Ca 50.6 CaO 70.8 Ca 36.3 CaO 50.8

Fe 0.7 FeO 0.9 Fe 16.2 FeO 20.9

S 0.6 SO3 1.6 S 0.3 SO3 0.8

O 34.9 -- O 32.3 --



Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0 Na 1.5 Na2O 2.1

Mg 0.6 MgO 1.0 Mg 1.2 MgO 1.0

Al 1.7 Al2O3 3.3 Al 11.8 Al2O3 22.3

Si 8.5 SiO2 18.3 Si 0.2 SiO2 0.5

K 0.0 K2O 0.0 K 0.1 K2O 0.2

Ca 54.0 CaO 75.6 Ca 35.5 CaO 49.7

Fe 0.6 FeO 0.8 Fe 17.6 FeO 22.6

S 0.3 SO3 0.8 S 0.1 SO3 0.3

O 34.0 -- O 31.6 --

96


Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0 Na 0.8 Na2O 1.1

Mg 59.2 MgO 98.2 Mg 0.4 MgO 0.7

Al 0.0 Al2O3 0.0 Al 2.2 Al2O3 4.2

Si 0.2 SiO2 0.6 Si 12.6 SiO2 27.0

K 0.0 K2O 0.0 K 0.2 K2O 0.3

Ca 0.0 CaO 0.0 Ca 46.3 CaO 64.8

Fe 0.8 FeO 1.1 Fe 0.4 FeO 0.5

S 0.0 SO3 0.0 S 0.4 SO3 1.0

O 39.5 -- O 36.3 --

Table 65: EDX-analyses point 5 of SM(2)-polished 500x.

Element[wt.-%]

Oxide [wt.-%]

Na 1.0 Na2O 1.4

Mg 1.8 MgO 3.0

Al 1.8 Al2O3 3.4

Si 8.9 SiO2 19.2

K 0.3 K2O 0.3

Ca 48.9 CaO 68.4

Fe 1.4 FeO 1.9

S 0.8 SO3 2.0

O 34.7 --

97


Table 66: EDX-analyses point 1 (left table) & 2 (right table of SM(3)-polished 500x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.9 Na2O 1.2 Na 1.2 Na2O 1.6

Mg 0.4 MgO 0.7 Mg 1.3 MgO 2.1

Al 1.2 Al2O3 2.3 Al 10.7 Al2O3 20.3

Si 13.9 SiO2 29.8 Si 0.3 SiO2 0.7

K 0.2 K2O 0.3 K 0.0 K2O 0.0

Ca 44.3 CaO 62.0 Ca 36.4 CaO 51.0

Fe 0.8 FeO 1.1 Fe 18.6 FeO 24.0

S 0.9 SO3 2.3 S 0.0 SO3 0.0

O 37.0 -- O 31.1 --


Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 1.1 Na2O 1.6 Na 0.7 Na2O 0.9

Mg 0.8 MgO 1.4 Mg 0.5 MgO 0.9

Al 12.6 Al2O3 23.9 Al 0.6 Al2O3 1.1

Si 0.5 SiO2 1.1 Si 10.3 SiO2 22.0

K 0.1 K2O 0.2 K 0.0 K2O 0.0

Ca 37.3 CaO 52.2 Ca 52.0 CaO 72.8

Fe 14.7 FeO 19.0 Fe 0.4 FeO 0.6

S 0.1 SO3 0.4 S 0.5 SO3 1.3

O 32.2 -- O 34.6 --

98

Table 68: EDX-analyses of point 5 of SM(3)-polished 500x.

Element[wt.-%]

Oxide[wt.-%]

Na 1.0 Na2O 1.4

Mg 1.8 MgO 3.0

Al 1.8 Al2O3 3.4

Si 8.9 SiO2 19.2

K 0.3 K2O 0.3

Ca 48.9 CaO 68.4

Fe 1.4 FeO 1.9

S 0.8 SO3 2.0

O 34.7 --

99

Figure 80: Clinker-polished 20x. Figure 81: Clinker-polished 100x.

Figure 82: Clinker-polished 200x. Figure 83: Clinker-polished 500x.

Figure 84: Clinker-polished 1000x. Figure 85: Clinker(a)-polished 2000x.

Figure 86: Clinker(b)-polished 2000x.

100

Table 69: EDX-analyses of Clinker-polished 20x.

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0

Mg 0.7 MgO 1.1

Al 0.7 Al2O3 1.3

Si 10.1 SiO2 21.7

K 0.0 K2O 0.0

Ca 52.7 CaO 73.7

Fe 0.5 FeO 0.6

S 0.5 SO3 1.2

O 34.6 --

Figure 87: Clinker-polished 500x.

Table 70: EDX-analyses point 1 (left table) & 2 (right table) of Clinker-polished 500x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.7 Na2O 0.9 Na 0.4 Na2O 0.5

Mg 0.6 MgO 0.9 Mg 0.4 MgO 0.8

Al 0.5 Al2O3 1.0 Al 0.5 Al2O3 1.0

Si 10.3 SiO2 22.1 Si 10.5 SiO2 22.6

K 0.0 K2O 0.0 K 0.1 K2O 0.1

Ca 52.4 CaO 73.3 Ca 52.1 CaO 72.9

Fe 0.6 FeO 0.8 Fe 0.7 FeO 1.0

S 0.3 SO3 0.7 S 0.3 SO3 0.8

O 34.4 -- O 34.5 --

101


Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.0 Na2O 0.0 Na 0.2 Na2O 0.3

Mg 0.2 MgO 0.3 Mg 0.7 MgO 1.2

Al 0.5 Al2O3 1.0 Al 0.3 Al2O3 0.5

Si 10.4 SiO2 22.3 Si 0.4 SiO2 0.9

K 0.1 K2O 0.1 K 0.1 K2O 0.2

Ca 52.7 CaO 73.8 Ca 68.3 CaO 95.5

Fe 1.1 FeO 1.4 Fe 0.5 FeO 0.7

S 0.3 SO3 0.8 S 0.1 SO3 0.3

O 34.4 -- O 29.0 --


Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.5 Na2O 0.7 Na 0.3 Na2O 0.4

Mg 0.4 MgO 0.7 Mg 1.6 MgO 2.7

Al 0.3 Al2O3 0.6 Al 10.1 Al2O3 19.2

Si 11.0 SiO2 23.6 Si 1.0 SiO2 2.1

K 0.0 K2O 0.0 K 0.1 K2O 0.1

Ca 52.3 CaO 73.1 Ca 38.1 CaO 53.3

Fe 0.4 FeO 0.6 Fe 16.4 FeO 21.1

S 0.2 SO3 0.5 S 0.3 SO3 0.7

O 34.6 -- O 31.8 --


Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 1.1 Na2O 1.5 Na 1.0 Na2O 1.3

Mg 0.8 MgO 1.4 Mg 1.6 MgO 2.8

Al 1.0 Al2O3 2.0 Al 10.1 Al2O3 19.1

Si 13.2 SiO2 28.4 Si 2.1 SiO2 4.6

K 0.4 K2O 0.5 K 0.0 K2O 0.0

Ca 44.9 CaO 62.8 Ca 39.0 CaO 54.6

Fe 1.0 FeO 1.2 Fe 13.2 FeO 17.0

S 0.7 SO3 1.9 S 0.1 SO3 0.2

O 36.5 -- O 32.5 --

102

Figure 88: Clinker(b)-polished 2000x.

Table 74: EDX-analyses point 1 (left table) & 2 (right table of Clinker(b)-polished 2000x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.5 Na2O 0.7 Na 0.8 Na2O 1.1

Mg 12.9 MgO 21.3 Mg 0.8 MgO 1.3

Al 10.9 Al2O3 20.6 Al 0.8 Al2O3 1.5

Si 1.2 SiO2 2.5 Si 10.5 SiO2 22.5

K 0.2 K2O 0.3 K 0.0 K2O 0.0

Ca 35.7 CaO 50.0 Ca 50.9 CaO 71.2

Fe 2.8 FeO 3.6 Fe 0.8 FeO 1.0

S 0.2 SO3 0.5 S 0.4 SO3 1.0

O 35.2 -- O 34.7 --

Table 75: EDX-analyses point 3 (left table) & 4 (right table of Clinker(b)-polished 2000x.

Element[wt.-%]

Oxide [wt.-%]

Element[wt.-%]

Oxide [wt.-%]

Na 0.8 Na2O 1.1 Na 0.7 Na2O 0.9

Mg 0.7 MgO 1.3 Mg 1.7 MgO 2.9

Al 0.6 Al2O3 1.1 Al 9.0 Al2O3 17.1

Si 10.4 SiO2 22.2 Si 1.7 SiO2 3.7

K 0.0 K2O 0.0 K 0.1 K2O 0.1

Ca 51.4 CaO 71.9 Ca 38.3 CaO 53.6

Fe 0.9 FeO 1.2 Fe 16.4 FeO 21.1

S 0.4 SO3 0.9 S 0.1 SO3 0.4

O 34.5 -- O 31.7 --

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