Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers

Lithium slag is an industrial by-product obtained after lithium extraction from spodumene ore. The higher concentration of sulfate ions (SO4−2) in the form of gypsum/anhydrite makes it a chemically unviable binder. This research investigates the dilution of the sulphatic component in pore solution b...

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Main Authors: Javed, U., Shaikh, Faiz, Sarker, Prabir
Format: Journal Article
Language:English
Published: ELSEVIER SCI LTD 2022
Subjects:
Online Access:http://purl.org/au-research/grants/arc/DP200102784
http://hdl.handle.net/20.500.11937/91605
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author Javed, U.
Shaikh, Faiz
Sarker, Prabir
author_facet Javed, U.
Shaikh, Faiz
Sarker, Prabir
author_sort Javed, U.
building Curtin Institutional Repository
collection Online Access
description Lithium slag is an industrial by-product obtained after lithium extraction from spodumene ore. The higher concentration of sulfate ions (SO4−2) in the form of gypsum/anhydrite makes it a chemically unviable binder. This research investigates the dilution of the sulphatic component in pore solution by additive incorporation of silica fume and fly ash as chemical modifiers in the lithium slag geopolymer. The setting behavior, detailed microstructural properties, mineral phase quantitative analysis, and compressive strength of lithium slag geopolymer containing fly ash and silica fume were studied. The increasing silica to alumina ratios (Si/Al) by incorporating silica fume in sodium tetraborate added geopolymer resulted in the set retardation after the setting accelerated at Si/Al ratio of 3.5. Similarly, the set retardation was observed for all fly ash replaced lithium slag geopolymers marked by the lower dissolution of SO4−2 ions in pore solution. The fragmented and porous N-(C)-A-S-H gel in lithium slag geopolymer densified by additive incorporation of silica fume and fly ash due to suppressed formation of SO4−2 in pore solution, thus increasing the compressive strength. The main binding zeolite phases quantified in mineral and crystal phase analysis of fly ash replaced geopolymer were mordenite, anorthite, analcime, and calcium chabazite, whereas for silica fume incorporated geopolymer were mordenite, anorthite, analcime, and sodium clinoptilolite. Thus, the lithium slag can be a promising geopolymer precursor along with other supplementary cementitious materials. However, further research is suggested for its chemical viability as a sole geopolymer binder.
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spelling curtin-20.500.11937-916052024-11-12T02:36:01Z Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers Javed, U. Shaikh, Faiz Sarker, Prabir Science & Technology Technology Construction & Building Technology Materials Science, Composites Materials Science Lithium slag geopolymer Fly ash Silica fume Sulfates Rietveld quantitative analysis Zeolite phases N-(C)-A-S-H gel MECHANICAL-PROPERTIES DRYING SHRINKAGE LOCAL-STRUCTURE EARLY HYDRATION STRENGTH CONCRETE SPODUMENE TEMPERATURE RETARDERS CEMENT Lithium slag is an industrial by-product obtained after lithium extraction from spodumene ore. The higher concentration of sulfate ions (SO4−2) in the form of gypsum/anhydrite makes it a chemically unviable binder. This research investigates the dilution of the sulphatic component in pore solution by additive incorporation of silica fume and fly ash as chemical modifiers in the lithium slag geopolymer. The setting behavior, detailed microstructural properties, mineral phase quantitative analysis, and compressive strength of lithium slag geopolymer containing fly ash and silica fume were studied. The increasing silica to alumina ratios (Si/Al) by incorporating silica fume in sodium tetraborate added geopolymer resulted in the set retardation after the setting accelerated at Si/Al ratio of 3.5. Similarly, the set retardation was observed for all fly ash replaced lithium slag geopolymers marked by the lower dissolution of SO4−2 ions in pore solution. The fragmented and porous N-(C)-A-S-H gel in lithium slag geopolymer densified by additive incorporation of silica fume and fly ash due to suppressed formation of SO4−2 in pore solution, thus increasing the compressive strength. The main binding zeolite phases quantified in mineral and crystal phase analysis of fly ash replaced geopolymer were mordenite, anorthite, analcime, and calcium chabazite, whereas for silica fume incorporated geopolymer were mordenite, anorthite, analcime, and sodium clinoptilolite. Thus, the lithium slag can be a promising geopolymer precursor along with other supplementary cementitious materials. However, further research is suggested for its chemical viability as a sole geopolymer binder. 2022 Journal Article http://hdl.handle.net/20.500.11937/91605 10.1016/j.cemconcomp.2022.104736 English http://purl.org/au-research/grants/arc/DP200102784 ELSEVIER SCI LTD fulltext
spellingShingle Science & Technology
Technology
Construction & Building Technology
Materials Science, Composites
Materials Science
Lithium slag geopolymer
Fly ash
Silica fume
Sulfates
Rietveld quantitative analysis
Zeolite phases
N-(C)-A-S-H gel
MECHANICAL-PROPERTIES
DRYING SHRINKAGE
LOCAL-STRUCTURE
EARLY HYDRATION
STRENGTH
CONCRETE
SPODUMENE
TEMPERATURE
RETARDERS
CEMENT
Javed, U.
Shaikh, Faiz
Sarker, Prabir
Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
title Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
title_full Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
title_fullStr Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
title_full_unstemmed Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
title_short Microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
title_sort microstructural investigation of lithium slag geopolymer pastes containing silica fume and fly ash as additive chemical modifiers
topic Science & Technology
Technology
Construction & Building Technology
Materials Science, Composites
Materials Science
Lithium slag geopolymer
Fly ash
Silica fume
Sulfates
Rietveld quantitative analysis
Zeolite phases
N-(C)-A-S-H gel
MECHANICAL-PROPERTIES
DRYING SHRINKAGE
LOCAL-STRUCTURE
EARLY HYDRATION
STRENGTH
CONCRETE
SPODUMENE
TEMPERATURE
RETARDERS
CEMENT
url http://purl.org/au-research/grants/arc/DP200102784
http://hdl.handle.net/20.500.11937/91605