Coal gangue‐based ceramics foams by water spray granulation and post particle stacking method

Abstract

Foamed ceramics were prepared by the water spray granulation and post particle stacking method using coal gangue as the main raw material. The effects of raw material weight ratio (i.e., raw material composition by varying the content of dolomite and talc), calcination temperature, time, and heating rate on the pore structure and properties of the samples were investigated and the foaming mechanism of foamed ceramics was revealed. The crystalline phase of foamed ceramics mainly consisted of quartz, anorthite, and enstatite. The decrease of dolomite content and the increase of talc content in the raw materials led to the initial decrease and then increase of the pore size dispersion coefficient, while the apparent porosity and water absorption of the samples gradually decreased, and the apparent density increased. The sample with a composition of gangue:waste glass:dolomite:albite:talc of 65:5:10:10:10 and calcined at 1200°C for 10 min with a heating rate of 1°C/min has the optimized uniform pore structure. This study provides a high value‐added utilization of coal gangue, and the experimental basis for the preparation of low‐cost foamed ceramics.