01_mt-dr process,snti, 09 august-dr amit_(71 slides)

8/13/2019 01_mt-Dr Process,Snti, 09 August-dr Amit_(71 Slides)

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ALTERNATE ROUTE OF IRONMAKING: DIRECREDUCTION

MT-SNTI, TATA STEEL, JAMSHEDPUR, 09 AUGUST, 200

Amit Chatterjee

Adviser to the MDTata Steel, Jamshedpur


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Fe-O PHASE DIAGRAM

2000 -

1800 -

1600 -

1400 -

1200 -

1000 -

800 -

0 -

0 10 20 30 40 50 60 70Atomic oxygen, %

Fe3O4 Fe2O3 F e 3

O 4

+ F e 2

O 3

58.02

Fe2O3 +

O2

Fe3O4

Fe3O4 + O2

Liq. oxide +O2

Liq.oxide

1596OC1424OC

54.57

51.26

( Fe) + Fe3O4

( Fe) + Wustite

570OC

1371OC

( Fe) + Wustite

912OC

( Fe) + Liq. oxide

( Fe) + Liq. oxide

Liq. metal 0.58 Liq. metal

+Liq. oxide

1538OC

1394OC

T e m p e r a

t u r e ,

O C

51.38


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States of Iron (Fe)

Fe=69.9%, O=30.1%

Fe=72.4%, O=27.6%

Fe=77.7%, O=22.3%

Fe=100%, O=0%Metallic IronFe

WustiteFeO

MagnetiteFe3O4

HematiteFe2O3

BASICS OF IRON ORE REDUCTION


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During direct reduction of iron oxide to DRI (direct reduced

iron), almost the entire amount of oxygen present in the ironoxide is removed.

As a result, the final product has a high degree of metallisation.

Metallisation is defined as, Metallic Fe in percentage/(Total Fe inpercentage x 100).

It exhibits a 'honeycomb structure unde r a mic roscope , because of which DRI is also often referred to as 'sponge' iron(solid porous iron pieces with many voids).

WHAT IS DIRECT REDUCTION?

For removing oxygen from iron oxide, coal or natural gas can beused


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MICROSTRUCTURE OF SPONGE IRON


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REACTIONS IN DRI PRODUCTIONTECHNOLOGIES

DRI production using reformed natural gas

CH 4 + CO 2 = 2CO + 2H 2

Fe 2O 3 + 3H 2 = 2Fe + 3H 2O

Fe 2O 3 + 3CO = 2Fe + 3CO 2

Coal based direct reduction

3Fe 2O 3 + CO = 2Fe 3O 4 + CO 2 Fe 3O 4 + CO = 3FeO + CO 2 FeO + CO = Fe + CO 2

C + CO 2 = 2CO


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Total metallics neededShortfall in metallics

Home scrap +

New scrap generatedAlternative iron units(DRI + SR hot metal)

Hot metal from blastfurnaces

Obsolete scrapavailable

IRON UNITS AND THEIR DEMAND


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0

10

20

30

40

50

60

70

8090

100

1960 1970 1980 1990 2000 2005 2010 2015 2020

EAF

BOF

OH

EVOLUTION OF GLOBAL STEEL PRODUCTIO

Year

S h a r e , %


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Iron source 1995 2000 2005 2010 Hot metal 58.9 57.2 55.0 52.5DRI and hotbriquetted iron(HBI)

3.4 5.2 6.6 8.1

Recirculatingscrap

12.8 9.6 8.80 8.0

Collectedscrap

24.9 28.0 29.5 31.4

SHARE OF DIFFERENT METALLICS AS APERCENTAGE OF THE TOTAL


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METHODS OF IRONMAKING

Reductant Oxide feed Process Product

Coke, Coal Lump ore, Sinter,Pellets

Blast furnace/MBFs Hot metal

Coal / NG Lump ore, Pellets Coal based /Gas based DR DRI (Spongeiron)

Coal andoxygen/ air

Lump ore, fines,pellets, wastes

Smeltingreduction

Synthetichot metal

Ironmaking involves total removal of oxygen. Reductantremoves oxygen; often also supplies heat, e.g. in BFs(still the most predominantly used process).In new ironmaking technologies, the two roles areseparated.

EVOLUTION OF DIRECT REDUCTION


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Time Main methodsdeveloped

Mainprocesses

Remark

1930 /1950

Saggers in tunnel kilnsSmall shaft furnacesRotary kilns

HoganasWibergKrupp

Based on coalBased on coalBased on coal

From endof 50s Static reactorsFluid bed reactors HyL IFior Based on gasBased on gasFrom endof 60s

Shaft furnaces(up to 14 processes)

Midrex andHyL

Based on gas

Current Rotary hearth furnacesImproved fluid bedprocessesSelf-reformingprocesses

Fastmet,InmetcoFinmetHyL III

Based on coal

Based on gasBased on gas

EVOLUTION OF DIRECT REDUCTIONTECHNOLOGIES


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Blast furnace ironmaking will continue to dominate but DR will

play an increasingly important role. BF technology has unchallenged superiority in bulk production

of hot metal. DR more suitable at smaller scale. World DRI production has increased from 1 Mt to 59.8 Mt over the

last 30 years handsome growth. Growth in India in this industryhas been the highest in the world.

India has high grade iron ore suitable for DR. Both coal andnatural gas now have equal shares in DRI production in India.

This is different from the rest of the world where virtually 90%DRI is based on gas.

PRESENT GLOBAL AND INDIAN SCENARIO

India is today the worlds largest producer of DRI and by2010 should be producing 30 Mtpa (world 85-90 Mtpa) at least 70% based on coal .


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30.67 33.2536.18 37.09 38.6

40.32 45

49.89

6075

0

10

20

30

40

50

60

70

80

P r o

d u c

t i o n

M t p a

1995 1996 1997 1998 1999 2001 2002 2003 2005 2010

Year

GROWTH IN GLOBAL DRI PRODUCTION

CAGR 6%

DRI production has increased at a satisfactory pace at atime when the steel industry in general has not alwaysprospered.


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0.21.3

2.3 4.25.4 5.3 6.5

7.18.1

10.0611.82

16.27

20.1

0

5

10

15

20

25

P r o

d u c t

i o n

( m t )

89-

90

91-

92

93-

94

95-

96

97-

98

99-

00

01-

02

02-

03

03-

04

04-

05

05-

06

06-

07

07-

08

Year

DRI PRODUCTION IN INDIA

Growth of DR industry till mid 1980s was slow because of restrictivelicencing.

After 1985, this industry has exploded from 0.2 mt in 89-90 to 20.1Mt in07-08.India is now the largest producer of DRI in the world


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1.9

2.91.95

3.3

1.55

3.61.75

3.41.93

3.4

2.03

3.453.24

3.26

3.28

3.623.9

4.19

5.6

4.5

7.5

4.3

11

5.3

14.2

5.9

1

35

7

9

11

13

15

17

P r o

d u c

t i o n , M

t

95-

96

96-

97

97-

98

98-

99

99-

00

00-

01

01-

02

02-

03

03-

04

04-

05

05-

06

06-

07

07-

08

Coal Gas

BREAK-UP OF INDIAS DRI PRODUCTION

Year

Today, DR production through Coal based has surpassedGas based.

Initially, gas based processes were adopted. Coal based DRI then became gradually become more popular.

TOP DRI PRODUCING COUNTRIES TODAY


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Country Production, Mtpa2004Production, Mtpa

2005Production, Mtpa

2006

India 9.37 11.1 14.7

Venezuela 7.83 8.95 8.6

Mexico 6.54 5.98 6.2

Iran 6.41 6.85 6.9Trinidad &Tobago 2.36 2.25 2.1

South Africa 1.63 1.78 1.8

Canada 1.09 0.59 0.5

Saudi Arabia 3.41 3.63 1.6

Russia 3.14 3.34 3.3

TOP DRI PRODUCING COUNTRIES TODAY


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NG

FIOR Circored Finmet

IronCarbide

Fine ore

MidrexHyL III

PelletisingLump ore Waste

oxidesCoal

Fine orePelletising

SL/RN Codir

Davy DRC Accar TDR

Jindal OSIL

Inmetco

DRI / Fe3C EAF

FastmetSidcometCircofer

Low metal.solid

SAFSynthetichot metal

Primus

DR TECHNOLOGIES

CHARACTERISTICS OF GAS BASED AND CO


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CHARACTERISTICS OF GAS BASED AND COBASED DR

Items Coal Based Gas BasedFe (t) 90-91 93-94Fe (M) 80-82 86-88Carbon 0.1-0.3 1-2Sulphur 0.03-0.050 0.008-0.010

Phosphorus 0.040-0.050 0.030-0.040

Chemical analysis,%

COAL VS GAS BASED DRI TECHNOLOGIES


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COAL VS GAS BASED DRI TECHNOLOGIES Gas based DR involves gas-solid reactions faster even at lowertemperatures.Cracking of natural gas produces both carbon mono oxide and

hydrogen hydrogen, is a better reductant, DRI then has highermetallisation.The nascent carbon available from the cracking combines with iron toform Fe3C and carbon contents between 1.0-2.5% can be obtained.Coal based DR irrespective of the operating conditions, the carboncontent is always between 0.15 to 0.20%.Higher carbon in DRI gives advantages in steelmaking lower meltingpoint, higher opening carbon in the bath, etc.Gas based DRI is produced at 950-980 oC -- porosity is greater,tendency towards re-oxidation and even self-ignition in extreme cases.Coal based DRI is produced at 1050-1080 oC -- an outer slaggy layerprotects the DRI from re-oxidation.Coal based DRI plants are smaller in size (maximum 500 tpd) -- lowertotal capital investment but specific investment/tpa is higher.Gas based technology is intrinsically cleaner; coal based DRI plantshave to contend with fine coal and extensive waste disposal.

TREND OF GROWTH OF COAL BASED VIS


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TREND OF GROWTH OF COAL BASED VIS--GAS BASED DR PRODUCTION

PROCESS WISEPRODUCTION OF DRI


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Process 2006,% 2005,% 2004, % 2003, %Midrex 59.7 62.4 64.1 64.6HyL (I&III) 18.4 19.8 20.8 19.7Finmet 2.2 2.4 2.9 5.2Other gas

0 0.4


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Year Installed capacity, (Mt) Production, (Mt)

Gas

based

Coal based Total Gas based Coal based Total

2004-05 6.1 6.0 12.1 4.6 5.5 10.1

2005-06 6.1 8.5 14.6 5.7 6.5 12.2

2006-07 7.1 11.0 18.1 7.0 8.5 15.5

2007-08 7.1 13.0 20.1 7.0 10.0 17.02008-09 7.1 15.0 22.1 7.0 11.0 18.0

2009-10 7.1 18.0 25.1 7.0 14.0 21.0

BREAK UP OF DRI PRODUCTION IN INDIA

Three large gas-based units (Essar Steel, Ispat Industries and

Vikram Ispat) have capacities of 3.60, 1.60, and 0.9 Mtpa. Large number of coal-based plants with capacities ranging from30- 400ktpa are in operation in Orissa, Chattisgarh, Jharkhand.India will further consolidate its position as the worldleader in DRI. EAFs and ISPs will then use DRI.

IRON ORE RESERVES IN INDIA AND OTHERS


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IRON ORE RESERVES IN INDIA AND OTHERS

Country Reserve (Mt) Average Fe%

Ukraine 30,000 30Russia 25,000 56

China 21,000 33

Australia 18,000 61

India 13,400 63

World recoverable iron ore reserve 150,000 Mt (47% Fe). Ukraine, Russia, China, Australia and India account for

about 72% of world iron ore. Indias iron ore far superior to that of China Fe 63%against 33% of China. Orissa and Jharkhand are major ironore centres.

TOTAL INDIAN COAL RESERVES


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TOTAL INDIAN COAL RESERVES

Coal type Reserve, billion tonnes

Total coking coal 32.0

Prime coking coal 5.31

Non-coking superior grade 55

Non-coking inferior grade 135

Total non-coking coal 190

Total coal available 222

UNIQUE FEATURE OF INDIAN DRI INDUSTRY


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In India, unlike in many other countries, both coal and naturalgas have been used.

First coal and then natural gas had been predominant -- todaythe shares are almost equal.

Installation of a large number of small coal based rotary kilnsplants is another distinctive feature .

These units often have induction furnaces capable of directlyusing DRI fines below 3mm.

India is the only country in the world using IFs on such a largescale to produce steel in the secondary sector.

Many mini-mills have shutdown their EAFs and installed IFs of 5to 20t capacity.

Melting has been optimised to produce low phosphorus and lowsulphur steel. Upto 30% DRI can be continuously charged in IFs without

changing the normal operating procedure; in some furnaces,upto 85% DRI has been used.

UNIQUE FEATURE OF INDIAN DRI INDUSTRY

FUTURE OF DRI PRODUCTION IN INDIA


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Gas price and gas availability would be critical for gas basedplants.

Availability of appropriate coal would decide the future of coalbased plants. Washing of non-coking coal will be necessary tocater to total DRI demand.

Import of non-coking coal from Australia, SA, etc willsupplement demand.

Large number of small coal based plants (50-100tpd) haveproliferated along with Induction Furnaces a unique Indiancontribution to world steel. This trend will continue.

Ecology in such plants has not always received attention;requires nation-wide focus to ensure sustainability.

Rotary kilns using coal and shaft furnaces using natural gas willbe supplemented by fluidised bed, multi-hearth and rotaryhearth furnaces to treat fine materials directly even in integratedplants.

FUTURE OF DRI PRODUCTION IN INDIA


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Coal-based DR Production using Rotary Kilns

FLOW SHEET OF ROTARY KILN PROCESS


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FLOW SHEET OF ROTARY KILN PROCESS


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IRON OXIDE SUITABLE FOR ROTARY KILN D


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Chemical Constituent Percentage Fe 62.0 min. SiO2 + Al2O3 7.0 max. CaO + MgO 2.0 max. S 0.030 P 0.080 max. Pb, Zn, Cu, Sn, Cr, As, etc. (combined total) 0.020 max.

Physical a) Size range, mm Percentage - 5 5 max. + 25 10 max.

Tolerable, % Preferable, % b) Tumbler index

+ 5 mm 80 92 - 28 mesh 10 5

c) Reducibility (dR / dt) 40 %, %per min. 0.5 0.6

d) Decrepitation - 5 mm 20.0 15.0 - 0.5 mm 5.0 3.0

IRON OXIDE SUITABLE FOR ROTARY KILN D

CHARACTERISTICS OF NON-COKING COALS


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Chemical analysis, %

Ash 24 4 VM 30 4 FC By difference

Sulphur 1.0 max. Inherent moisture 6.0 max. Other properties

IDT,C 1250 min.

Caking index Less than 5 Swelling index Less than 3

CHARACTERISTICS OF NON COKING COALSSUITABLE FOR ROTARY KILN DR

SALIENT FEATURES OF THE COAL BASED


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Waste heat recovery through steam generation, in some cases.

ROTARY KILN DR TECHNOLOGY

Flexibility with regard to the type of iron bearing materialswhich can be used such as lump ore, pellets, ilmenite, ironsands and steel plant wastes.

Use of a wide variety of solid fuels ranging from anthractieto lignite including charcoal.

Improved heating of the charge by submerged air injection inthe pre-heating zone of the kiln plants installed recently.

Optimised coal injection facilities.

Waste gas conditioning by controlled post-combustion.

MODES OF HEAT TRANSFER IN ROTARY KIL


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Conductive: From the lining (heated by the flame) to the charge during

rotation. From the inner surface of the refractory lining to the outer

shell.

Convective:

From the free-board gas to the charge (forced convection). From the free-board gas to the kiln refractories (forcedconvection)

From the outer shell of the kiln to the surroundings (naturalconvection).

Radiative: From the free-board gas to the charge. From the free-board gas to the refractories. From the outer shell of the kiln to the surroundings.

PROCESS

PROGRESS OF REDUCTION OF IRON OXIDE I


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ROTARY KILN ALONG THE LENGTH

DR PRODUCTION CAPACITY OF DIFFERENT


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Process 2000 2001 2002 2003 2004 2005 2006SL/RN 1.19 1.07 1.39 1.51 1.76 1.83 1.83Codir 0.20 0.25 0.33 0.39 0.44 0.56 0.52TDR 0.21 0.21 0.34 0.32 0.41 0.36 0.36DRC 0.40 0.49 0.55 0.67 0.75 0.63 0.63SIIL 0.29 0.29 0.37 0.39 0.44 0.35 0.38Jindal 0.59 0.62 0.98 1.10 1.20 1.37 1.37

COAL BASED ROTARY KILN PROCESSES

Total world DR production (59.8 Mt) through RotaryKiln was 11.53 Mt in 2006

QUALITY OF DRI PRODUCED AT TATA SPONG


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Fe (metallic), % 82-84 Fe (total), % 91-93Metallisation, % 91 2 Carbon, % 0.006-0.012

Sulphur, % 0.020-0.040 Phosphorus, % 0.050-0.080 Non-metallics in thesaleable product, %

1-2

Size of the primesaleable product, mm

3-20 (- 3 mm spongeiron is sold as fines)

QUALITY OF DRI PRODUCED AT TATA SPONG


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SOME NEW DR TECHNOLOGIES TO WATCH


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Inmetco is a RHF based process. Can use wastes in the feed a new trend in DR. Iron oxide feed mixed with non-coking coal, char, coke breeze

and then pelletised. Coal requirement is 700 kg/t DRI. Process coupled with SAF a trend to separate gangue.

Fastmet is another RHF based process.

Reduction time as short as 12 mins. High gangue bearing DRI melted in EAF( Fastmet).

Finmet is a fluidised bed process using reformed natural gas. Process works at 12 bar pressure to produce DRI as fines.

Primus uses a MHF to produce high quality. Ore fines charged along with coal fines without agglomeration.

PRINCIPLES OF CHARGE HEATING IN ROTARY


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HEARTH FURNACE

CONDITIONS PREVAILING AROUND THE PEL


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BED PLACED ON THE ROTARY HEARTH

EFFECT OF PELLET LAYERS ON PRDUCTIVITOF RHF


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Pellet radius, cm

P r o

d u c t i vi t y ,k

gDRI / m2 .h

OF RHF

FLOW SHEET OF FASTMET PROCESS


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Total world DR production (59.8 Mt) through RHF was0.24 Mt in 2006.

ROTARY HEARTH FURNACE IN THE FASTMETPROCESS


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PROCESS


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GAS-BASED DR PRODUCTION

CONSTITUENTS OF NATURAL GAS


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Compound Formula Heating value, kJ/Nm 3

Methane CH 4 28397-33617

Ethane C2H6 53405-59275

Propane C3H8 78625-85250

Butane C4H10 104044-112323

Pentane C5H12 129218-139157

Carbon dioxide CO 2 0

Nitrogen N2 0

Water vapour H2O 0

Sulphur compounds S combined with elements 0 (has to be removed)

WORLD RESERVES OF NATURAL GAS


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Country Proven reserves, trillioncubic feet

Percent of world total

World 6076 100.0

Top 20 countries 5449 89.7

Russia 1680 27.6

Iran 940 15.5

Qatar 910 15.0Saudi Arabia 231 3.8

United States 187 3.1

Venezuela 148 2.4

Iraq 110 1.8China 53 0.9

India 30 0.5

Bangladesh 18 0.3

RESERVES OF NATURAL GAS (Mt) IN INDIA


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Initialestimate

Ultimate reserves Recoverable reserves

ONGC 1688.32 942.28 523.01OIL 251.00 170.00 110.00Pvt/JV 933.59 511.76 466.94Total 2872.91 1624.04 1099.95

As of 2006, the total prognosticated reserves, ultimate

reserves and balance recoverable reserves of natural gas:

FEATURES OF GAS-BASED DR PROCESSES


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Parameter Midrex HYL I HYL IIIType of reductionreactor

CC shaft furnace Static beds (4 innumber)

CC shaft furnace

Raw materials Lump ore/pellets Lump ore/pellets Lump ore/pellets

Size range of ironoxide feed, mm

6-30(lump), 9-16(pellets)

12-50 (lump),9-16(pellets)

16-30 (lump),9-16(pellets)

Reductant used Reformed NG, COG,naphtha, LPG,heavy oil or coalgas, furnace off-gas

Reformed NG,COG, gasifiedcoal or tar

Reformed NG,COG, gasifiedcoal or tar

Reforming agent(catalyst)

Recycled top gas(Nickel)

Steam (Nickel) Steam(DRI)

GAS COMPOSITION AND ENERGYREQUIREMENTS OF DIFFERENT DR PROCESSE


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Parameter Midrex HYL I HYL IIIReducing gas analysis,

%CO2 2.0 8.0 -

%CO 10-20 14.0 -

%H2 80-90 75.0 70-87

%(N2 + CH4) 5.0 3.0 -

% H2O 5.0 - -

Energy, Gcal /t DRI 2.51-3.01 2.6-3.0 2.53-2.70

Electrical power, kWh 120-130 80 100 90

REQUIREMENTS OF DIFFERENT DR PROCESSE


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SHAFT FURNACE DIRECT REDUCTION ANDPLANT COMPONENTS


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PLANT COMPONENTS

ZONES IN REDUCTION SHAFT INCLUDING THMAIN INPUTS AND OUTPUTS


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MAIN INPUTS AND OUTPUTS

SCHEMATIC DIAGRAM OF THE REFORMERFURNACE


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FURNACE

HYL I PROCESS EMPLOYING CATALYTIC STEA


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REFORMING FOR GENERATING REDUCING GA

FLOW SHEET OF HYL III


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TYPICAL CHARACTERISTICS OF THE TWOTYPES OF HYL III DRI PRODUCED


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Weight % Low carbon variety High carbon variety

Metallisation 94.00 94.00

Total iron 93.14 91.05

Metallic iron 87.56 85.59

FeO 7.18 7.03

Carbon 1.80 4.00

Gangue 3.46 3.38

Fe3C 25.59 55.56Discharge DR temp, C 700 650

TYPES OF HYL III DRI PRODUCED

SPECIFIC CONSUMPTION FIGURES FOR THETWO TYPES OF HYL III DRI


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Item Unit Consumption per tonne of DRI

Low carbon variety High carbon variety

Iron ore tonne 1.45 1.45

Process natural gas Gcal 1.54 1.94Fuel Gcal 1.02 0.73

Total thermal energy Gcal 2.56 2.67

Electricity kWh 90 Slightly higher

Water m 3 1.80 1.80

Oxygen m 3 0 12.60

TWO TYPES OF HYL III DRI

FLOW DIAGRAM OF HYL WITH SELF REFORM


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MIDREX PROCESS FLOW SHEET


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ZONES AND UNIT OPERATIONS IN A MIDREXSHAFT FURNACE


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InsulatedUpperReductionZone

Un-insulatedCoolingZone

I n s u

l a t e

d U p p e r

R e d u c t

i o n

Z o n e

L e n g

t h =

2 x

U n - I n s u

l a t e d

C o o

l i n g

Z o

n e

L e n g

t h =

1 x

Reducing gas

s o

l i d

s

s o

l i d

s

s o

l i d s

s o

l i d

s

g a s e s

g a s e s

g a s e s

ReductionFurnaceOff gases

Iron OxideFeed

Material

DRI

CHEMICAL ANALYSIS OF MIDREX DRI


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Element Wt,%

Fe, (total) 91 93

Fe, (metallic) 83 88

Metallisation 92 95

Carbon 1.0-4.0

Sulphur 0.005-0.015

Phosphorus 0.02 0.04

SiO 2 2.0 3.5

Al2O3 0.5 1.5

CaO 0.2 1.6

MgO 0.005 0.015

Plant Location Capacity, No. of Start-upSOME MIDREX DR PLANTS (JANUARY 2005)


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Mpta modules year

Sidbec Dosco (Ispat) 2 Cantrecoeur, Quebec,Canada

0.60 1 '77

Sidor I & II Matanzas, Venezuela 1.64 2 '77/79

Caribbean Ispat Point Lisas, Trinidad &Tobago

2.20 3 80/82/99

Hadeed I Al-Jubail, S. Arabia 0.80 2 82/83

OEMK Stary Oskol, Russia 1.67 4 83/87

Khuzestan Steel Co. Ahwaz, Iran 1.84 4 85/01

LISCO Misurata, Libya 1.10 2 89/90

Essar Steel I, II,III & IV Hazira, India 2.32 4 90/92/04

Hadeed II Al-Jubail, S. Arabia 0.65 1 92

Mobarakeh Steel Mobarakeh, Iran 3.20 5 92/94

Ispat Industries Raigad, India 1.00 1 94

Comsigua Matanzas, Venezuela 1.00 1 98

Saldhana Steel Saldhana Bay, S. Africa 0.804 1 98

COMPARISON OF MIDREX, HYL III AND HYLWITH SELF-REFORMING


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Operationalparameters

Midrex HYL III HYL with self-reforming(HYL ZR)

Reduction reactorsize Bigger than HYL IIIand HYL ZR Smaller than Midrex Smaller than Midrex

Iron oxide feedstock used

Mixture of iron orepellets and lumps

Mixture of iron ore pelletsand lumps

Mixture of iron ore pellets andlumps

Reducing gasgeneration

CO 2 reforming. Catalytic gas reformingusing steam

Partial oxidation or in-situ gasreforming

Primary gasreformingreactions

CH 4 + CO 2 2CO

+2H 2 CH 4 + H 2

O CO + 3H2 CH 4 + H 2

O CO + 3H2 CH 4 +1/2 O 2 2H 2O

2H 2 + O 2 2H 2OCO + H 2O CO 2 + H 2

Operationalpressure

Ambient pressure 5 atm 5 atm

Reducing gastemperature

850-900C 920-980C 930- 1000C

High sulphur feedstocks

High sulphur feedstocks can not be useddue to catalystpoisoning

Can utilise high sulphurfeed stock

Can utilise high sulphur feedstock.

FINMET PROCESS FLOW SHEET


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It D t il

CHARACTERISTICS OF FINMET PROCESS


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Item Details

Iron oxide feed stock Progressive feed iron ore fines

Reduction reactor 4 fluidised bed reactors

Reducing agent Catalytic steam reforming and partial oxidation of heavy crude oil

Product characteristics 92 % metallization

Operating temperature Fluidised bed reaction temperature 550-800 C

Operating pressure 10.8-12.8 atm

CONCLUSIONS There is a world shortage of metallics. Hence several technologies

have been developed to produce DRI

(1)


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have been developed to produce DRI. Gas based technologies have some inherent advantages lower

temperature, higher metallisation , higher carbon content, etc. Main disadvantage is propensity towards re-oxidation of DRI as well as

higher total capital investment required in large capacity plants. Coal based DR plants are smaller in size, easy to build, require less

total capital, etc. Face problems of kiln availability, lower carboncontent in DRI and require extensive facilities for waste disposal.

India has high grade iron ore suitable for DRI. Both coal and naturalgas are now used. India has emerged as the worlds largest producerof DRI within a period of 20 years.

Future of DR industry in India appears bright. Gas price and gasavailability would be critical for gas based plants; availability ofappropriate coal would be the rate limiting step for coal based plants.

Large number of small coal based kilns (50-100tpd) have proliferatedalong with Induction Furnaces unique to India. Ecology in suchplants requires greater attention for long term sustainability.

CONCLUDING COMMENTS (2)


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DRI (sponge iron) made by reducing iron oxides by natural gasor non-coking coal has become a popular feed stock for EAFsteelmaking.

The future of the DRI-EAF route is bright. By 2020, this methodwill contribute 50% of the world steel production.

With scrap in increasingly short supply, sponge iron and hotmetal will be required to be part of the charge in all EAFs.

All efficiently run EAFs will use 50-60% DRI, 40- 50% hot metaland 0-10% re-circulating scrap in the charge.

DRI can also be used in BOFs (10-15%), IFs (upto 75%) andBFs (10%).

Future of this industry will thus be governed more by supplythan demand. Demand of upto 200 Mtpa by 2010 is likely.

The worlds sponge iron production has increased from 1 Mtpa to

CONCLUDING COMMENTS (3)


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The world s sponge iron production has increased from 1 Mtpa to58.9 Mtpa over the last 30 years.

India has gone far ahead of the world. CAGR has been + 45% insome periods; average of 8-9% over the last 15 years.

Future growth of DR would depend on sustained availability ofthe required raw materials (including iron ore).

Beneficiation of lower grade coals and / or import of low ash non-

coking coal is foreseen in the long run in India. India expected to reach 150-175 Mtpa steel production by 2015-

2020 to complement Chinas production of at least 500 -700 mtpaby that stage. China No. 1; India No. 2.

At least 30 Mtpa of DRI and 20 Mtpa of non-BF hot metal will beproduced in India by then.

Unless ecological factors prevent growth, a major wavein sponge iron production (70% coal based) is foreseen.


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01_mt-dr process,snti, 09 august-dr amit_(71 slides)

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