Influence of SiC Sludge on the Microstructure of Geopolymers

Kae-Long Lin; Kang-Wei Lo; Ta-Wui Cheng; Wei-Ting Lin; Ya-Wen Lin

doi:10.3390/ma13092203

Influence of SiC Sludge on the Microstructure of Geopolymers

Materials (Basel). 2020 May 11;13(9):2203. doi: 10.3390/ma13092203.

Authors

Kae-Long Lin¹, Kang-Wei Lo^{2

3}, Ta-Wui Cheng³, Wei-Ting Lin⁴, Ya-Wen Lin³

Affiliations

¹ Department of Environmental Engineering, National Ilan University, Ilan 260, Taiwan.
² Graduate Institute of Engineering Technology, National Taipei University of Technology, Taipei 106, Taiwan.
³ Institute of Mineral Resources Engineering, National Taipei University of Technology, Taipei 106, Taiwan.
⁴ Department of Civil Engineering, National Ilan University, Ilan 260, Taiwan.

Abstract

There are considerable resource reuse and environmental concerns regarding SiC sludge (SiCS) that results from cutting silicon ingots into wafers. In the current study, the effect of the Na₂SiO₃ solution/sodium hydroxide solution (NS/SS) mass ratio and SiCS amount on metakaolin geopolymers was found during geopolymerization system performance. The results indicate that while NS/SS ratio was relatively low, increasing the NaOH content resulted in a sufficient amount of OH^- in the system to increase the solubility and hinder polycondensation, as indicated by the bulk density and setting-time results; since the polycondensation was inhibited, the mechanical strength was reduced. This study demonstrated that a geopolymer can be formed from a substitution of 10% SiCS and with an NS/SS ratio of 1.6, and that this geopolymer is a feasible material.

Keywords: NASH gels; Na2SiO3 solution/ sodium hydroxide solution mass ratio; SiC sludge; alkaline-activator solutions.