Mineral formation process and environmental benefits of belite-ye’elimite cement clinker from industrial solid wastes

To optimize resource utilization of bulk industrial solid waste and promote low-carbon production in the cement industry, the belite-ye’elimite cement (BSAC) clinker was prepared entirely from solid waste materials (carbide ash, coal gangue, steel slag, desulfurization gypsum). The mineral formation process of the clinker was systematically analyzed. Findings reveal that within the temperature range of 700-1100 ºC, the clinker primarily comprises transition minerals such as aluminosilicate, aluminate, calcium sulphosilicate. At 1100-1200 ºC, these phases gradually convert to dicalcium silicate (C2S) and ye’elimite (C4A3Š). Above 1200 ºC, changes in the minerals correlate to the structural and morphological evolution of C2S and C4A3Š crystals. However, beyond 1320 ºC, C2S exhibit an irregular morphology, and C4A3Š decomposes. BSAC prepared at 1260 °C met the mechanical requirements for 52.5 grade sulphoaluminate cement. Environmentally, BSAC clinker reduces energy consumption by 18% and carbon emissions by 65% compared to traditional Portland cement.