Alshaaer, M.; Alanazi, A.O.S.; Absa, I.M.I. Use of Sulfur Waste in the Production of Metakaolin-Based Geopolymers. Sustainability2023, 15, 13608.
Alshaaer, M.; Alanazi, A.O.S.; Absa, I.M.I. Use of Sulfur Waste in the Production of Metakaolin-Based Geopolymers. Sustainability 2023, 15, 13608.
Alshaaer, M.; Alanazi, A.O.S.; Absa, I.M.I. Use of Sulfur Waste in the Production of Metakaolin-Based Geopolymers. Sustainability2023, 15, 13608.
Alshaaer, M.; Alanazi, A.O.S.; Absa, I.M.I. Use of Sulfur Waste in the Production of Metakaolin-Based Geopolymers. Sustainability 2023, 15, 13608.
Abstract
This preliminary study introduces the incorporation and chemical stabilization of sulfur waste into geopolymers matrix and explores the concept of material production for further environmental and engineering solutions. Geopolymers were synthesized by dissolving sulfur in the alkaline activator of sodium hydroxide and sodium silicate in different proportions. The Alkaline solution was then mixed with metakaolin to synthesize the geopolymer matrix. Adding sulfur from 0 wt.% to 5 wt.%, compared with metakaolin, was found to lead to an increase in the compressive strength of the geopolymer from 22.5 MPa to 29.9MPa. When sulfur is between 5 wt.% and 15 wt.%, a decrease in compressive strength was observed to 15.7 MPa, which can be explained by defects and voids in the geopolymer microstructure through the solubility of excess sulfur and thus the formation of defects and voids in the geopolymer microstructure. Because of the incorporation of sulfur into the geo-polymer, a compact and dense microstructure is formed as reported in the SEM analysis. XRD analysis shows that besides quartz and Analcime, a new phase, Al2·H10·O17·S3, is also formed as a result of sulfur dissolution in alkaline activator of geopolymer.
Keywords
sulfur; geopolymers; metakaolin, XRD
Subject
Chemistry and Materials Science, Materials Science and Technology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
