This study investigates the effects of coal-based solid waste/ground granulated blast furnace slag mass ratios (90/10,70/30,50/50) and water glass modulus (1.0, 1.2, 1.5) on geopolymer fluidity, setting time, and compressive strength. Fly ash (FA), coal gangue (CGP; 20% of coal-derived solid waste), and finely ground g...