Abstract:Based on mineral characteristics of high-alumina fly ash, effects of type and dosage of transforming agent, temperature, time and L/S on conversion behavior of calcium-bearing minerals in high-alumina fly ash were studied, and a new process to prepare Al-Si alloy from high-alumina fly ash was proposed. The results show that total content of Al2O3 and SiO2 in high-alumina fly ash is 70% above, and Ca element in fly ash mainly exists in forms of CaSO4 and 2CaO?Al2O3?SiO2. Transformation of calcium-containing minerals has almost no influence on loss rate of alumina in subsequent acid leaching process to remove impurities, but greatly improves calcium removing rate. Calcium removing rate is 90% above under the optimum conditions for phase conversion of calcium-containing minerals including dosage of conversion agent of Na2CO3 of twice theoretical amount, transformation temperature of 60 ℃, reaction time of 1.5 h, and L/S=4.