Lightweight glass-ceramics using coal gangue as main raw material for adsorption removal of phosphorus

To promote the comprehensive utilization of coal gangue, this study employed a direct sintering method to fabricate glass-ceramics using coal gangue as the primary raw material, supplemented by asbestos tailings and copper tailings as additives. The effects of material composition, sintering temperature, and holding time on the physicochemical properties of the ceramics were systematically investigated to determine optimal preparation conditions. Furthermore, the phosphorus adsorption performance of the resulting ceramic was evaluated. The optimal composition was identified as 55 % coal gangue, 35 % asbestos tailings, 5 % copper tailings, and 5 % ammonium bicarbonate. Sintered at 1,200 °C for 30 min, the resulting ceramic exhibited a mass loss rate of 37.28 %, a bulk density of 0.16 g/cm 3 , a water absorption rate of 18.54 %, and a linear expansion rate of 7.89 %, with magnetic intensity remaining below 0.2 mT. Under these optimized conditions, the ceramic demonstrated remarkable phosphorus removal efficiency. Specifically, at an initial pH of 5.0–11.0, a reaction time of 90 min, and a dosage of 10.0 g/L, the phosphorus removal efficiency reached 93.56 %. These findings highlight the significant potential of coal gangue-based ceramics for the treatment of phosphorus-containing wastewater and the valorization of solid waste.