低温酸浸高铁铝土矿中铁和铝的溶出规律研究

Study on the leaching rules of aluminum and ferrum from high iron bauxite by acid leaching at low temperature

采用低温酸浸法对广西高铁铝土矿中的铝和铁的溶出规律进行了研究,考察了硫酸浓度、浸出温度、浸出时间及液固比因素对铝土矿中铝和铁溶出率的影响。结果表明,最优浸出条件为浸出时间60min,浸出温度100℃,液固比5∶1,硫酸浓度20%。此条件下铁的浸出率为98.68%,铝的浸出率为3.02%,溶出比为32.68,可实现高铁铝土矿中铁和铝的分步溶出。对该浸出过程进行动力学分析研究表明,此条件下浸出过程属化学反应控制,其控制动力学方程为:lgk=3-1.83×10-31/T反应活化能Ea=35.11kJ/mol。

The rules of dissolved aluminum and ferrum from high iron bauxite from Guangxi province by acid leaching at low temperature were studied. The factors of sulfuric acid concentration, leaching temperature, leaching time and liquid-solid ratio were investigated. Results shows that ferrum and aluminum in bauxite are step- leached by sulfuric acid solution on the conditions of that the sulfuric acid concentration was 20%, leac- hing temperature was 100℃, leaching time was lh and liquid-solid ratio was 5 ： 1. On these conditions, the quantity of ferrum leached was 98.68M and that of aluminum was 3.02% ; its ratio was 32.68. The kinetic a- nalysis reveals that the leaching process is controlled by chemical reaction. The activation energy E, was35. llkJ/mol, and the leaching dynamic equation was as follow：