fossil fuel foundation - conf ff energy recovery …...(1) solid fuel-fired small boiler (2) liquid...

LEGISLATION APPLICABLE TO ENERGY RECOVERY FROM WASTE AND THE DISPOSAL OF ASH ARISING FROM

COAL / BIOMASS / WASTE COMBUSTION

22 July 2014

Theo Fischer -EScience Associates

LEGAL REQUIREMENTS FOR ENERGY RECOVERY

§ Legislation applicable to energy recovery and waste disposal

§ Fuels and combustion technologies

§ Ash characterisation with focus on coal ash

§ Waste Classification& Standard for Assessment of Waste for Landfill Disposal

§ Beneficial uses of ash: Cement and Concrete Masonry Units

FFF Boiler Optimisation Workshop

Legislation applicable to energy recovery and waste disposal


>50MW thermal GN 893 Licensed facility and emission limitsNew & Existing with different emission limitsSolid Fuel Category 1.1 Combustion

Liquid fuel Category 1.2 Combustion

Solid Biomass Category 1.3 Combustion

Gas Category 1.4 Combustion

Reciprocating engines (liquid) Category 1.5 Combustion

Reciprocating engines (gas) Category 1.5 Combustion

Waste co-feed Category 1.6 Combustion

Waste Category 8.1 Incineration

<50MW thermal GN 831 Controlled emitter and emission limitsNew & Existing with different emission limits(1) Solid fuel-fired small boiler(2) Liquid fuel-fired small boiler(3) Gaseous fuel-fired small boiler (using natural gas and liquefied petroleum gas)(4) Gaseous fuel-fired small boiler (using process gas)(6) Co-feedingWhere a small boiler is fired simultaneously with two or more fuels, emission standards for the main fuel shall be applicable.

FFF FBC Workshop

LEGAL REQUIREMENTS FOR ENERGY RECOVERY

NATIONAL ENVIRONEMNTAL MANAGEMENT: WASTE ACT (SCHEDULED ACTIVITIES THAT REQUIRE AUTHORISATION)

ª GN 636 National Environmental Management: Waste Act (59/2008): National norms and standards for disposal of waste to landfill§ Landfill prohibition:

FFF FBC Workshop

Waste Prohibited or Restricted in terms of Disposal Compliance Timeframe

(c) Flammable waste with a closed cup flashpoint lower than 61°Celsius. Immediate(j) Re-usable, recoverable or recyclable used lubricating mineral oils, as well as oil filters, but excluding other oil containing wastes. Four (4) years(o) Waste tyres: Whole. Immediate(p) Waste tyres: Quartered. Five (5) years(r) Hazardous waste with a calorific value of:

(i) > 25 MJ/kg. Four (4) years(ii) > 20 MJ/kg. Six (6) years(iii) > 10 MJ/kg. Twelve (12) years(iv) > 6% TOC. Fifteen (15) years

NATIONAL ENVIRONMENTAL MANAGEMENT WASTE ACT (NEMWA)

§ What is it the ash that I will be recovering or disposing? Waste? Or by-product?

“waste” means-(a) any substance, material or object, that is unwanted, rejected, abandoned,

discarded or disposed of, or that is intended or required to be discarded or disposed of, by the holder of that substance, material or object, whether or not such substance, material or object can be re-used, recycled or recovered and includes all wastes as defined in Schedule 3 to this Act; or(b) any other substance, material or object that is not included in Schedule 3 that may

be defined as a waste by the Minister by notice in the Gazette, but any waste or portion of waste, referred to in paragraphs (a) and (b), ceases to be

a waste-(i) once an application for its re-use, recycling or recovery has been approved or, after such

approval, once it is, or has been re-used, recycled or recovered;(ii) where approval is not required, once a waste is, or has been re-used, recycled or recovered;(iii) where the Minister has, in terms of section 74, exempted any waste or a portion of waste generated by a particular process from the definition of waste; or(iv) where the Minister has, in the prescribed manner, excluded any waste stream or a portion of a waste stream from the definition of waste.[Definition of “waste” substituted by s. 38 of Act 14/2013 and s. 1 of Act 26/2014]



§ What is it the ash that I will be recovering or disposing? Waste? Or by-product?

“recycle” means any process where waste is reclaimed for further use, which process involves the separation of waste from a waste stream for further use and the processing of that separated material as a product or raw material;“recovery” means the controlled extraction or retrieval of any substance, material or object from waste;“re-use” means to utilise the whole, a portion of or a specific part of any substance, material or object from the waste stream for a similar or different purpose without changing the form or properties of such substance, material or object;



§ When am I combusting waste and when am I combusting fuel (or recovered waste? § No clear cut answer§ Assume it is waste unless you pay for it

§ To address this legal lacunae the DEA published terms of reference to develop a Waste Derived Fuel Standard ("WDF Standard") and a Standard Operating Procedure ("SOP") for Blending Platforms.8

§ One of the primary objectives of the tender is the development of a WDF Standard based on International Best Practice and taking cognisance of existing South African law. This will enable the DEA to prescribe standards that ensure that WDF does not cause greater harm to human health and the environment than the use of any virgin product.

§ The Standard will also identify the point when the end of waste is reached. This is the point when the waste recovery operation has been completed and the waste streams become a product or material which can be used by businesses or industries or supplied to the market "without the need for a waste management licence".



§ When am I combusting waste and when am I combusting fuel (or recovered waste?

§ No clear cut answer§ 4.8 In EC Law, the definition of a by-product is subject to 4 requirements -

§ "(a) further use of the substance or object is certain;§ (b) the substance or object can be used directly without any further processing other

than normal industrial practice;§ (c) the substance or object is produced as an integral part of a production process;

and§ (d) further use is lawful, i.e. the substance or object fulfils all relevant product,

environmental and health protection requirements for the specific use and will not lead to overall adverse environmental or human health impacts."



ª Listed Waste Management Activities requiring a license: GN 921 National Environmental Management: Waste Act (59/2008): List of waste management activities that have, or are likely to have, a detrimental effect on the environment

ª Category A (Basic Assessment – 6months)

§ CATEGORY A: Reuse, recycling or recovery of waste§ (4) The recycling of hazardous waste in excess of 500kg but less than 1 ton

per day calculated as a monthly average, excluding recycling that takes place as an integral part of an internal manufacturing process within the same premises.

§ (5) The recovery of waste including the refining, utilisation, or co-processing of waste in excess of 10 tons but less than 100 tons of general waste per day or in excess of 500kg but less than 1 ton of hazardous waste per day, excluding recovery that takes place as an integral part of an internal manufacturing process within the same premises.




ª Category A (Basic Assessment – 6months)

§ CATEGORY A: Disposal of waste on land§ (9) The disposal of inert waste to land in excess of 25 tons but not exceeding

25 000 tons, excluding the disposal of such waste for the purposes of levelling and building which has been authorised by or under other legislation.

§ (10) The disposal of general waste to land covering an area of more than 50m2 but less than 200m2 and with a total capacity not exceeding 25 000 tons.




ª Category B (Scoping and EIA – 12 months):

§ CATEGORY B: Reuse, recycling or recovery of waste§ (2) The reuse or recycling of hazardous waste in excess of 1 ton per day,

excluding reuse or recycling that takes place as an integral part of an internal manufacturing process within the same premises.

§ (3) The recovery of waste including the refining, utilisation, or co-processing of the waste at a facility that processes in excess of 100 tons of general waste per day or in excess of 1 ton of hazardous waste per day, excluding recovery that takes place as an integral part of an internal manufacturing process within the same premises.




ª Category B (Scoping and EIA – 12 months):

§ CATEGORY B: Disposal of waste on land§ (7) The disposal of any quantity of hazardous waste to land.§ (8) The disposal of general waste to land covering an area in excess of 200m2

and with a total capacity exceeding 25 000 tons.§ (9) The disposal of inert waste to land in excess of 25 000 tons, excluding the

disposal of such waste for the purposes of levelling and building which has been authorised by or under other legislation.


Fuels and combustion technologies


FUELS


FUELS AND CONSIDERATION OF TECHNOLOGY

Application of the Technologies: Solid Fuel Boilers


Technology Gas LiquidChain grate BFB CFB Pyrolosis

Fuelcoal Gas Liquid Solid fuel Solid fuel Solid fuel Solid fueldiscard coal Solid fuel Solid fuel Solid fuel Solid fuelbiomass Biomass Biomass Biomass Biomass

coal + waste Liquid+Waste Solid+Waste Solid+Waste Solid+Waste Solid+Wasterefuse derived fuel +coal Solid+Waste Solid+Waste Solid+Waste Solid+Wastewaste Incinerator Incinerator Incinerator Incinerator

FUELS AND CONSIDERATION OF TECHNOLOGY

Application of the Technologies: Solid Fuel Boilers

IMPLICATIONS FOR BOILERS: NEMAQA

ª Adapted from: Economics of Lime and Limestone for Control of Sulphur Dioxide (DePriest and Gaikwad 2001)

CONFERENCE: Optimisation of Industrial Boilers

LSFO (Limestone forced oxidation)

MEL (magnesium enhanced lime)

LSD (Lime spray-dryer) (low sulphur)

CFB (Circulating fluidised bed) (low sulphur)

SO2 removal efficiencyCapital cost($) 64 451 000 54 665 000 61 291 999 66 914 000Fixed operating costs($/year) 3 929 000 3 574 000 2 539 000 271 000Variable operating costs($/year) 4 369 000 5 527 000 4 202 000 4 089 000

Reagent 2 059 000 3 847 000 2 769 000 2 670 000Disposal 0 0 1 071 000 1 057 000

Byproduct credit 0 0 0 0bag replacement 0 0 341 000 341 000

cage replacement 0 0 21 000 21 000Water 208 000 208 000 102 000 102 000Power 2 102 000 1 472 000 1 156 000 841 000

Levelised cost (cents/kWhr) 0.57 0.57 0.49 0.49

98% 95% (when used with baghouse after scrubber)

FGD system for 500MWWET FGD DRY FGD

Ash characterisation with focus on coal ash


CHEMISTRY OF ASH FORMATION

DIFFERENCES BETWEEN PC AND FB ASH

§ PC Ash§ PC Fly Ash: coal ash that exits a combustion chamber

in the flue gas and is captured by air pollution control equipment such as electrostatic precipitators, bag houses, and wet scrubbers.

§ PC Bottom ash: agglomerated ash particles formed in pulverized coal boilers that are too large to be carried in the flue gases. Bottom ash is typically grey to black in colour, is quite angular, and has a porous surface structure.

§ FB Ash§ FB Fly ash: the fly ash and bed ash produced by an

FBC boiler that exits bed toward air pollution abatement equipment.

§ FB Bed ash: the spent bed material that is produced by an FBC boiler. The bed ash usually collected separately but not equivalent to bottom ash in dry in PC furnace.



§ FB fly ash has a mean particle size is similar to pulverized coal fly ash (about 20-30 µm) and most of the particles are of an angular cubic or prismatic shape. The specific gravity of CFB fly ash varies from1.9 to 2.4 (Yoginder et al 2007).

§ FB ash is distinctly different from the residues of PC fired hard coal or brown coal boilers in terms of mineral composition and degree of crystallinity.

SEM of coal combustion waste materials Pulverised Fuel Boiler vs Fluidised bed (Werner 2004).FFF Boiler Optimisation Workshop

Waste Classification& Standard for Assessment of Waste for Landfill Disposal


Principlesª Classification: ª All waste that will be stored, handled, transported require classification of

waste in terms of SANS 10234 (GHS) – hazardous or not. Informs storage, handling, transport, reporting etc.

ª Assessment for landfill: ª Contaminant concentrations in waste now determine specific requirements

for disposal.ª Applicable to hazardous & general waste, but does not apply to –

• pre-classified non-hazardous waste,• business waste collected as part of municipal waste collection system, or• waste stored in lagoons.


Waste Classification Regulationª Classification of waste is a legal requirementª Waste Generators must ensure their waste is correctly classified (third party

handling, storage, transport and disposal)ª Classification in accordance with SANS 10234:2008 – Globally Harmonized

System of classification & labelling of chemicals (GHS)ª Waste Classification = Establishing i.t.o. SANS 10234 whether (i) a waste is

hazardous based on physical, health and environmental hazardous properties (hazard classes), and (ii) the degree or severity of hazard posed (hazard categories)


SANS 10234:2007 - GHS1. Physical Hazards 2. Health Hazards- Explosives- Flammable gases- Flammable aerosols- Oxidizing gases- Gases under pressure- Flammable liquids (up to 93ºC)- Flammable solids- Self-reactive substances and mixtures- Pyrophoric substances- Self-heating substances and mixtures- Substances and mixtures that, on contact

with water, emit flammable gases- Oxidizing substances and mixtures- Organic peroxides- Corrosive to metals

- Acute toxicity- Skin corrosion and skin irritation- Serious eye damage and eye irritation- Respiratory sensitization and skin sensitization- Germ cell mutagenicity- Carcinogenicity- Reproductive toxicity (Teratogenicity in MRHW)- Specific target organ toxicity – single exposure- Specific target organ toxicity – repeated

exposure- Aspiration hazards

3. Hazards to the Aquatic Environment- Acute aquatic toxicity- Chronic aquatic toxicity

KEY: SANS10234-GHS & SANS10228 & MRHCWSANS10234 & MRHCWSANS10234 Only (Also SABS0265 though)


Landfill Risk Category: Approach


Landfill Risk Category: Approachª Sampling & analysis of waste to determine the Leachable Concentration (LC)

and Total Concentration (TC) of specified contaminants in the waste.ª Compare the LC and TC values with corresponding threshold limits (LCT &

TCT values).ª Three levels of threshold limits for each – LCT0, LCT1 & LCT2, and TCT0,

TCT1 &TCT2, as well as LCTi & TCTi for inert waste.ª Based on LC or TC values exceeding the particular threshold values, a level of

risk associated with disposal to landfill is assigned to the waste, reflecting the degree of potential risk associated with disposal where waste could impact on groundwater.

ª Risk profiling designates five types (risk levels) of hazardous waste, each with specific landfill design requirements (management linked with the existing Minimum Requirements for Landfill).


Landfill Risk Category: Leach Testª Total Concentration determined by suitable local/international standard

extraction techniques & analysis – must provide accurate & precise resultª Leachable Concentration – Australian Standard Leaching Procedure (ASLP);

based on USEPA TCLP & Otherª ASLP allows for alternative leaching scenarios, with the leaching solution

depending on the waste or type of disposal:• Waste containing or disposed with putrescible waste: Standard ASLP

solution – acetic acid (pH 5.0 or 2.9 depending on acid neutralisation capacity of waste)

• Waste disposed with non-putrescible waste: Basic sodium tetraboratedecahydrate solution (pH 9.2), and acetic acid solution (pH 5.0 or 2.9)

• Non-putrescible waste disposed without other waste (Mono-disposal): Reagent water.

ª TC for all contaminants reasonably expected to be presentª LC only determined if TC > 20 X LCT0


LC & TC Threshold Valuesª Leachable concentration based on DWAF, SANS, WHO & USEPA drinking water

standards, multiplied by dilution attenuation factor (DAF) of 50, as Victoria EPA (NSW & USEPA – DAF of 100).

• DAF value of 50 for lowest or base level leachable concentration (LCT0) – on basis of precautionary principle.

• LCT1 = 2 x LCT0; LCT2 = 4 x LCT1.• Represents a conservative assessment of the decrease in risk achieved by the

increase in environmental protection provided by landfill construction and landfill operating requirements (Minimum Requirements = factor 5; attenuation due to liner & leachate management).

ª TCT values derived from Contaminated Land Standards, but consideration given to different risk exposure pathways.

ª LCT & TCT values are aligned with international standards (US, EU, Australia, UK, New Zealand etc.)


Waste Disposal Risk RatingContaminant

Concentration Criteria

Risk Level Description of Risk Level associated with the Disposal of Waste to

Landfill

LC > LCT2, or

TC > TCT2

Type 0: Very

High Risk

Considered very high risk waste with a very high potential for contaminant release. Requires very high level of control and ongoing management to protect health and the environment.

LCT1 < LC ≤ LCT2, or

TCT1 < TC ≤ TCT2

Type 1: High

Risk

Considered high risk waste with high potential for contaminant release. Requires high level of control and ongoing management to protect health and the environment.

LCT0 < LC ≤ LCT1 or

TC > TCT0

Type 2:

Moderate Risk

Considered moderate risk waste with some potential for contaminant release. Requires proper control and ongoing management to protect health and the environment.

TC < 20 x LCT0, or

LCTi < LC ≤ LCT0 and

TCTi < TC ≤ TCT0

Type 3: Low

RiskLow risk waste with low potential for contaminant release. Requires some level of control and ongoing management to protect health and the environment.

TC < 20 x LCTi, or

LC < LCTiType 4: Inert

Very low risk waste that–(a) does not undergo any significant physical, chemical or biological

transformation; (b) does not burn, react physically or chemically or otherwise affect any other

matter with which it may come into contact; and(c) does not impact negatively on the environment because of its very low

pollutant content and because the toxicity of its leachate is insignificant. Only basic control and management required.


FUELS


LCT & TCT Thresholds

Inorganics

Contaminants in Waste LCTimg/l

TCTimg/kg

LCT0 mg/l

TCT0 mg/kg

LCT1 mg/l

TCT1 mg/kg

LCT2 mg/l

TCT2 mg/kg

Metal Ion ContaminantsAs, Arsenic 0.01 5.8 0.5 500 1 500 4 2000B, Boron 0.5 150 25 15000 50 15000 200 60000Ba, Barium 0.7 62.5 35 6250 70 6250 280 25000Cd, Cadmium 0.005 7.5 0.25 260 0.5 260 2 1040Co, Cobalt 0.5 50 25 5000 50 5000 200 20000CrTotal, Chromium Total 0.1 46000 5.0 800000 10 800000 40 N/ACr(VI), Chromium (VI) 0.05 6.5 2.5 500 5 500 20 2000Cu, Copper 1.0 16 50 19500 100 19500 400 78000Hg, Mercury 0.001 0.93 0.05 160 0.1 160 0.4 640Mn, Manganese 0.4 1000 20 25000 40 25000 160 100000Mo, Molybdenum 0.07 40 3.5 1000 7 1000 28 4000Ni, Nickel 0.07 91 3.5 10600 7 10600 28 42400Pb, Lead 0.01 20 0.5 1900 1 1900 4 7600Sb, Antimony 0.01 10 0.5 75 1 75 4 300Se, Selenium 0.01 10 0.5 50 1 50 4 200V, Vanadium 0.1 150 5.0 2680 10 2680 40 10720Zn, Zinc 3.0 240 150 160000 300 160000 1200 640000Inorganic AnionsTDS 250 N/A 2500 N/A 5000 N/A 20000 N/AChloride 100 N/A 1000 N/A 2000 N/A 8000 N/ASulphate 200 N/A 2000 N/A 4000 N/A 16000 N/ANO3 as N, Nitrate-N 6.0 N/A 300 N/A 600 N/A 2400 N/AF, Fluoride 1.0 100 50 10000 100 10000 400 40000CN- (total), Cyanide Total 0.05 14 2.5 10500 5 10500 20 42000

LCT & TCT Thresholds - Organics Contaminants in Waste LCTi

mg/lTCTi

mg/kgLCT0 mg/l

TCT0 mg/kg

LCT1 mg/l

TCT1 mg/kg

LCT2 mg/l

TCT2 mg/kg

Organic Contaminants

Benzene N/A 0.05 0.01 10 0.02 10 0.08 40

Benzo(a)pyrene N/A 0.05 0.035 1.7 0.07 1.7 0.28 6.8

Carbon tetrachloride N/A 0.05 0.20 4 0.40 4 1.6 16

Chlorobenzene N/A 0.05 5.0 8800 10 8800 40 35200

Chloroform N/A 0.05 15 700 30 700 120 2800

2-Chlorophenol N/A 0.05 525 2100 30 2100 120 8400

Di (2 ethylhexyl) phthalate N/A 0.05 0.50 40 1 40 4 160

1,2-Dichlorobenzene N/A 0.05 50 31900 10 31900 40 127600

1,4-Dichlorobenzene N/A 0.05 15 18400 30 18400 120 73600

1,2-Dichloroethane N/A 0.05 1.5 3.7 3 3.7 12 14.8

1,1-Dichloroethylene N/A 0.05 0.35 150 0.7 150 2.8 600

1-2-Dichloroethylene N/A 0.05 2.5 3750 5 3750 20 15000

Dichloromethane N/A 0.05 0.25 16 0.5 16 2 64

2,4-Dichlorophenol N/A 0.05 10 800 20 800 80 3200

2,4-Dinitrotoluene N/A 0.05 0.065 5.2 0.13 5.2 0.52 20.8

Ethylbenzene N/A 0.05 3.5 540 7 540 28 2160

Formaldehyde N/A 0.05 25 2000 50 2000 200 8000

Hexachlorobutadiene N/A 0.05 0.03 2.8 0.06 2.8 0.24 5.4

LCT & TCT Thresholds

Organics

Contaminants in Waste LCTi mg/l

TCTi mg/kg

LCT0 mg/l

TCT0 mg/kg

LCT1 mg/l

TCT1 mg/kg

LCT2 mg/l

TCT2 mg/kg

Organic ContaminantsMethyl ethyl ketone N/A 0.05 100 8000 200 8000 800 32000MTBE (Methyl t-butyl ether) N/A 0.05 2.5 1435 5.0 1435 20.0 5740Nitrobenzene N/A 0.05 1 45 2 45 8 180PAHs (total) N/A 0.05 N/A 50 N/A 50 N/A 200Petroleum H/Cs, C6 to C9 N/A 0.05 N/A 325 N/A 650 N/A 2600

Petroleum H/Cs, C10 -C36 N/A 0.05 N/A 5000 N/A 10000 N/A 40000

Phenols (total, non-halogenated)

N/A 0.057 560 14 560 56 2240

Polychlorinated biphenyls N/A 0.05 0.025 3 0.05 3 0.2 12Styrene N/A 0.05 1.0 120 2 120 8 4801,1,1,2-Tetrachloroethane N/A 0.05 5 400 10 400 40 16001,1,2,2-Tetrachloroethane N/A 0.05 0.65 5.0 1.3 5.0 5.3 20Tetrachloroethylene N/A 0.05 0.25 200 0.5 200 2 800Toluene N/A 0.05 35 1150 70 1150 280 4600Trichlorobenzenes (total) N/A 0.05 3.5 3300 7 3300 28 132001,1,1-Trichloroethane N/A 0.05 15 1200 30 1200 120 48001,1,2-Trichloroethane N/A 0.05 0.6 48 1 48 4 192Trichloroethylene N/A 0.05 0.25 11600 2 11600 8 464002,4,6-Trichlorophenol N/A 0.05 10.0 1770 20 1770 80 7080Vinyl chloride N/A 0.05 0.015 1.5 0.03 1.5 0.12 6.0Xylenes (total) N/A 0.05 25 890 50 890 200 3560PesticidesAldrin + Dieldrin N/A 0.05 0.015 1.2 0.03 1.2 0.03 4.8DDT + DDD + DDE N/A 0.05 1 50 2 50 2 2002,4-D N/A 0.05 1.5 120 3 120 3 480Chlordane N/A 0.05 0.05 4 0.1 4 0.1 16Heptachlor N/A 0.05 0.015 1.2 0.03 1.2 0.03 4.8

Beneficial uses of ash: Cement and Concrete Masonry Units


BENEFICIAL USE OF ASH: CEMENT EXTENDER

§ Although most Western countries including US, Britain, SA have standards sulphate in concrete (ASTM C 618), sulphate in fly ash for use as a cement extender as (ASTM C 595 as well as EN 450 , SANS ).


BENEFICIAL USE OF ASH: CEMENT EXTENDER

§ When PC fly ash is used as a partial replacement for Portland cement in a concrete mixture, the fly ash spheres act as ball bearings within the concrete mix that can significantly lower the water requirements and improve the flowability and workability of the concrete.

§ This does not apply in FB ash where water requirements may increase due to nature of FB particles

SEM of coal combustion waste materials Pulverised Fuel Boiler vs Fluidised bed (Werner 2004).


§ Many countries including US, Britain, SA (and EU) have standards that limit the sulphate content of aggregates (fine and course eg EN 12620 – that specifies both acid soluble sulphates as well as total S – for concrete and EN 13139 for use in mortar and use in concrete masonry units) as well as sulphate in concrete (ASTM C 618)

BENEFICIAL USE OF ASH: CONCRETE MASONRY UNITS


§ SANS 1215: Concrete masonry units. Guidance in this regard is given in SANS 1215, which stipulates that well-burnt clinker, complying with the requirements of SANS 794: Aggregates of low density in respect of soundness, sulphate content and loss on ignition, should be used. Of particular importance is that:

(a) the clinker is free from quicklime nodules that may lead to “popping” on walls as a result of expansion when they hydrate, leading to brick and/or plaster damage.(b) the clinker does not contain excessive amounts of sulphate (SANS 794 limits the sulphate content as sulphur trioxide to 1%, by mass). Excessive amounts of soluble sulphate causes efflorescence on wall surfaces when it is transported by moisture in the wall and deposited when the water evaporates. The crystallisation of the salts could be responsible for severe plaster and mortar joint disintegration and paint failure.

§ Seemingly not the case in India where they use fly ash and gypsum to make masonry products without any qualms using (using fly ash, lime/cement and gypsum – so called FALG cement) used in manufacture of bricks.




Photo 1000984. Cracking and adhesion failure of plaster next to a movement joint in an inadequately water-proofed, exposed wall, caused by expanding clinker brickwork containing excessive amounts of sulphate

Photo DSC01139. An inadequately water-proofed,plastered wall build with clinker bricks, which containedundue amounts of sulphate. Note the excessive crazingand the efflorescence in and paint failure along thecracks as well as spalling of plaster from a column dueto expansion of the brickwork.

Late Dr Japie Krüger, Honorary Member of the SACAA: SANS 794: Aggregates of low density

EScience Associates research into FB ash in cement and concrete masonry uits


More work to done in SA-Willing and able!

Thank You

Escience Associates (Pty) Ltd

Theo Fischer [email protected]

FFF FBC Workshop

mailto:[email protected]

fossil fuel foundation - conf ff energy recovery …...(1) solid fuel-fired small boiler (2) liquid...

Documents