Desilication of fly ash and development of lightweight construction blocks from alkaline activated desilicated fly ash

T. Falayi, F.N. Okonta, F. Ntuli

Research output: Contribution to journalArticle

Abstract

Massive reserves of power plant fly ash dumps in South Africa have necessitated the development of different processes for effective remediation to achieve zero waste generation by secondary processes. Silica was leached from fly ash (FA) at the optimum conditions of a leaching time of 6 h, 3 M KOH, 500 rpm agitation speed, 25 liquid to solid ratio and a leaching temperature of 100°C. A lightweight construction block (LWCB) was developed from desilicated fly ash (DFA) and KOH. It was found that the optimum synthesis conditions were 10 M KOH, +0.075-0.300 mm DFA and a curing temperature of 40°C for 12 h, 80°C for 12 h and 100°C for 24 h. The development of strength was through the formation of Kalsilite. The LWCB met the minimum requirements for ASTM C34-13, C129-14a and South African standard (SANS227: 2007). © 2017 Inderscience Enterprises Ltd.
Original languageEnglish
Pages (from-to)233-253
Number of pages21
JournalInternational Journal of Environment and Waste Management
Volume20
Issue number3
DOIs
Publication statusPublished - 2017

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Fly ash
fly ash
Leaching
kalsilite
leaching
Remediation
Curing
power plant
Power plants
remediation
silica
temperature
Silica
Temperature
liquid
Liquids
Industry

Cite this

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abstract = "Massive reserves of power plant fly ash dumps in South Africa have necessitated the development of different processes for effective remediation to achieve zero waste generation by secondary processes. Silica was leached from fly ash (FA) at the optimum conditions of a leaching time of 6 h, 3 M KOH, 500 rpm agitation speed, 25 liquid to solid ratio and a leaching temperature of 100°C. A lightweight construction block (LWCB) was developed from desilicated fly ash (DFA) and KOH. It was found that the optimum synthesis conditions were 10 M KOH, +0.075-0.300 mm DFA and a curing temperature of 40°C for 12 h, 80°C for 12 h and 100°C for 24 h. The development of strength was through the formation of Kalsilite. The LWCB met the minimum requirements for ASTM C34-13, C129-14a and South African standard (SANS227: 2007). {\circledC} 2017 Inderscience Enterprises Ltd.",
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T1 - Desilication of fly ash and development of lightweight construction blocks from alkaline activated desilicated fly ash

AU - Falayi, T.

AU - Okonta, F.N.

AU - Ntuli, F.

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PY - 2017

Y1 - 2017

N2 - Massive reserves of power plant fly ash dumps in South Africa have necessitated the development of different processes for effective remediation to achieve zero waste generation by secondary processes. Silica was leached from fly ash (FA) at the optimum conditions of a leaching time of 6 h, 3 M KOH, 500 rpm agitation speed, 25 liquid to solid ratio and a leaching temperature of 100°C. A lightweight construction block (LWCB) was developed from desilicated fly ash (DFA) and KOH. It was found that the optimum synthesis conditions were 10 M KOH, +0.075-0.300 mm DFA and a curing temperature of 40°C for 12 h, 80°C for 12 h and 100°C for 24 h. The development of strength was through the formation of Kalsilite. The LWCB met the minimum requirements for ASTM C34-13, C129-14a and South African standard (SANS227: 2007). © 2017 Inderscience Enterprises Ltd.

AB - Massive reserves of power plant fly ash dumps in South Africa have necessitated the development of different processes for effective remediation to achieve zero waste generation by secondary processes. Silica was leached from fly ash (FA) at the optimum conditions of a leaching time of 6 h, 3 M KOH, 500 rpm agitation speed, 25 liquid to solid ratio and a leaching temperature of 100°C. A lightweight construction block (LWCB) was developed from desilicated fly ash (DFA) and KOH. It was found that the optimum synthesis conditions were 10 M KOH, +0.075-0.300 mm DFA and a curing temperature of 40°C for 12 h, 80°C for 12 h and 100°C for 24 h. The development of strength was through the formation of Kalsilite. The LWCB met the minimum requirements for ASTM C34-13, C129-14a and South African standard (SANS227: 2007). © 2017 Inderscience Enterprises Ltd.

U2 - 10.1504/IJEWM.2017.087152

DO - 10.1504/IJEWM.2017.087152

M3 - Article

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JO - International Journal of Environment and Waste Management

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