Utilization of graphite tailings and coal gangue in the preparation of foamed ceramics

Abstract To enhance the effective utilization of graphite tailings and coal gangue (CG), both considered typical industrial solid waste materials, we synthesized foamed ceramics incorporating these materials. The optimization process led to improvements in compressive strength, water absorption, and thermal conductivity by regulating critical parameters, including the proportions of SiC and Na 2 O, as well as the duration of ball milling. Employing techniques such as X‐ray diffraction, thermogravimetric analysis, and differential scanning calorimetry, we investigated the phase composition, high‐temperature reactions, and microstructural characteristics of the foamed ceramics. The incorporation of graphite tailings (GT) facilitated the formation of a rich network of pore structures and amorphous glass phases, which enhanced the lightweight nature, mechanical strength, and thermal insulation properties of the foamed ceramics. By analyzing the GT content as a variable, we determined that the G50C40 (GT:CG:potassium feldspar = 40:50:10) sample exhibited optimal performance overall. Under these experimental conditions, the foamed ceramic demonstrated a bulk density of 0.749 g/cm 3 , a compressive strength of 12.37 MPa, a thermal conductivity of 0.21 W/(m·K), and a water absorption rate of 0.79%. Therefore, it is posited that GT possesses considerable potential to broaden the application spectrum of foamed ceramics within the domain of building insulation materials.