还原焙烧红土矿的硫酸浸出动力学

Sulphuric acid leaching kinetics of pre-reduced laterite ores

研究了选择性还原焙烧红土矿的硫酸浸出动力学．实验考察了浸出温度（30℃～70℃）和硫酸浓度（0．01～0．5mol·l^-1）对Ni、Fe浸出率的影响．结果表明：红土矿的选择性还原焙烧可增快Ni的浸出而抑止Fe的溶解．Ni的浸出动力学可用Avrami方程描述，其浸出反应的表观活化能为（15．40±0．18）kJ·moL^-1．Fe的浸出受内扩散过程控制，浸出的表观活化能为（55．16±1．37）kJ·moL^-1．

The laterite ore with high iron content can be treated by acid leaching method to extract nickel. To speed up the nickel extraction rate and minimize the acid consumption, reduction is a feasible pretreatment, hi this paper the sulphuric acid leaching kinetics of pre-reduced laterite ore was invested. The effects of leaching temperature （30- 70 ℃ ） and H2SO4 concentration （0.01 -0.5 mol·L^-1） on the extraction rate of nickel and iron were examined.The result indicated selective reduction could speed up the nickel extraction and obstructed the iron dissolution. The nickel extraction followed Avrami equation and the apparent activation energy was （ 15.40 ± 0.18） kJ· mol^- 1. The dissolutionrate of iron was inner-diffusion controlled and the apparent activation energy was （55.16 ± 1.37） kJ·mol^- 1.