Abstract: In order to overcome the harsh decomposition of chromite ore by sulfuric acid, both mechanical activation and oxidant were used as a new method to intensify the decomposition process by sulfuric acid. The effects of ratio of liquid to solid, concentration of H2SO4, mechanical activation, oxidant addition and leaching temperature on the leaching rate of Cr from chromite ore originated in South Africa were examined, and the leaching kinetics of Cr was analyzed. The results showed that the optimum leaching conditions were the ratio of sulfuric acid to solid 2.4 mL/g, H2SO4 concentration 80%(w), mechanical activation time 20 min, oxidant addition 13%(w), leaching temperature 120℃ and leaching time 5 h. Under the optimum conditions, the leaching rate of Cr reached 92.36%. The leaching process of Cr was in line with the unreacted shrinking core model.

Key words: chromite ore, Cr, sulfuric acid, mechanical activation, leaching, kinetics

摘要： 针对铬铁矿硫酸酸解条件苛刻的难题，提出机械活化和氧化剂相结合强化铬铁矿硫酸酸解过程的新方法. 以南非铬铁矿为原料，考察了液固比、硫酸浓度、机械活化、氧化剂加入量、温度等参数对铬浸出过程的影响，对铬铁矿硫酸酸解过程铬的浸出动力学进行了研究. 结果表明，最佳浸出条件为：液固比2.4 mL/g，硫酸浓度80%(w)，机械活化时间20 min，氧化剂加入量13%(w)，温度120℃，浸出时间5 h，该条件下铬浸出率达92.36%. 浸出过程符合未反应收缩核模型.

关键词: 铬铁矿, 铬, 硫酸, 机械活化, 浸出, 动力学