Microwave-thermal-assisted curing method on geopolymer preparation from Panzhihua high-titanium slag by alkali activation

Abstract

This paper emphasizes the feasibility of using microwave-thermal-assisted treatment to promote the rapid geopolymerzation and early strength improvement of Panzhihua high-titanium slag (HTS)-based geopolymers. The results reveal that the microwave radiation promotes the geopolymerzation reaction of the HTS during the alkaline activation reaction with a remarkable early compressive strength improvement of 623% only in 20 min. Since the dispersed CaTiO3 particles in the HTS serve as local thermal hot spots and nucleation elements, they will rapidly elevate the temperature in a short time and facilitate the hydration products growing to form a gel network structure. Moreover, due to more water evaporation and accelerating effects of the endothermic reaction in the dissolution-polycondensation stage, the optimum process of microwave-thermal-assisted treatment has further advanced the hydration process, which endowed the highest geopolymerization degree, the lowest residue water, the densest microstructures of geopolymeric network and a desirable mechanical performance (54 MPa) of the HTS-based geopolymer.