Fabrication of green one-part geopolymer from silica-rich vanadium tailing via thermal activation and modification

The aim of this investigation was to prepare geopolymeric precursor from vanadium tailing (VT) by thermal activation and modification. For activation, a homogeneous blend of VT and sodium hydroxide was calcinated at an elevated temperature and then modified with metakaolin to produce a geopolymeric precursor. During the thermal activation, the VT was corroded by sodium hydroxide and then sodium silicate formed on the particle surfaces. After water was added, the sodium silicate coating dissolved to release silicon species, which created an alkaline solution environment. The metakaolin then dissolved in the alkaline environment to generate aluminum species, which was followed by geopolymerization. The VT particles were connected by a gel produced during geopolymerization, which yielded a geopolymer with excellent mechanical performance. This investigation not only improves the feasibility of using geopolymer technology for large-scale and in-situ applications, but also promotes the utilization of VT and other silica-rich solid wastes.