Abstract: The conditions of roasting activation of coal fly ash with KF as assistant and extraction of aluminum by acid leaching were studied. The effects of conditions of roasting activation and acid leaching on the leaching rate of aluminum from coal fly ash were investigated, and the leaching kinetics studied. The results show that the optimal conditions of roasting activations were obtained as: under time 1 h, mass ratio of coal fly ash to KF 20:4, and temperature 800℃; and the optimal conditions of leaching temperature 90℃, leaching time 1 h, concentration of hydrochloric acid 4 mol/L, and liquid-to-solid ratio 4 mL/g, the leaching rate of aluminum reached 92.46%. The acid leaching process of roasted coal fly ash could be modeled with the shrinking core model. The apparent reaction progression was 0.3718, and the apparent activation energy 43.49 kJ/mol. The leaching rate was controlled by chemical reaction.

Key words: coal fly ash, roasting activation, extraction, kinetics

摘要： 对KF为助剂焙烧活化粉煤灰酸浸提铝过程进行了研究，考察了粉煤灰焙烧活化和盐酸浸出条件对粉煤灰中铝浸出率的影响及其浸出过程动力学. 结果表明，焙烧活化优化条件为：时间1 h、温度800℃、粉煤灰与KF质量比为20:4. 浸出温度90℃、浸出时间2 h、盐酸浓度4 mol/L、液固比4 mL/g的条件下，铝提取率达到92.46%. 粉煤灰烧结产物加热酸浸过程符合收缩未反应核模型，反应级数为0.3718，反应活化能为43.49 kJ/mol，过程速率为化学反应速率控制.

关键词: 粉煤灰, 焙烧活化, 提取, 动力学