Preparation of glass-ceramics via co-sintering of coal fly ash and metastable slag

Coal fly ash (CFA) was used as the main object of study to prepare ash microcrystalline glass by co-sintering with metastable slag (MS) using its strong crystallization ability and sintering activity at low and medium temperatures. The effects of different material ratios on the crystalline phase composition and properties of the microcrystalline glass were discussed using various physical and chemical analysis methods in combination with mechanical properties tests. The results show that the compressive strength, density, chemical resistance and sintering densities of ash microcrystalline glass gradually increase with the increase of sintering temperature and the proportion of metastable slag. The compressive strength of the prepared ash microcrystalline glass can meet the requirements of GB/T19766–2016 “Natural Marble Building Panel” (≥50 MPa) when the addition amount of fly ash is 10–40% and the sintering temperature is 850–1085°C; among them, the chemical corrosion resistance of the prepared product meets the industrial requirements when the addition amount of fly ash is 10–30% and the sintering temperature is 940°C (acid loss rate ≤ 96%, alkali loss rate ≤ 98%).