污酸浸出锌窑渣过程中铜的浸出行为及动力学研究

Research of leaching behavior and kinetics of copper during process of leaching zinc waelz slag by waste acid

基于湿法炼锌窑渣中含有大量未经利用的有价金属资源,锌冶炼行业产出的污酸酸度高,含有大量的砷及重金属离子,将窑渣与污酸进行联合处理,利用污酸浸出窑酸中的有价资源实现窑渣的资源化和污酸的清洁化处理;采用单因素浸出实验研究污酸浸出锌窑渣过程中铜的浸出行为规律,探讨液固比、反应温度、窑渣粒度、搅拌转速、氧分压等参数对铜浸出行为的影响。研究结果表明:在液固比为10 mL/g,温度为90℃,窑渣粒度为75~53μm,搅拌转速为400 r/min,氧分压为0.5 MPa条件下反应3 h,铜的浸出率达95.05%;铜的浸出过程符合固体膜层内扩散与界面化学反应混合控制的收缩核模型,浸出反应的表观活化能为32.82 kJ/mol。

Considering that there are a large amount of unutilized valuable metal resources in zinc waelz slag,and the waste acid which is produced by zinc refinery smelting industry contains lots of arsenic and heavy metal ions,the resource utilization of zinc waelz slag and clean treatment of wasted acid were realized using leaching valuable metals in zinc waelz by waste acid for their physicochemical properties.The leaching behavior of copper was studied by single factor leaching experiment,and the effects of liquid-solid ratio,reaction temperature,slag particle size,stirring speed and oxygen partial pressure on copper leaching behavior were investigated.The results show that the copper extraction is 95.05%after leaching for 3 h in the conditions of liquid-solid ratio of 10 mL/g,temperature of 90℃,stirring speed of 400 r/min,slag particle size of 75−53μm and oxygen pressure of 0.5 MPa.The leaching process of copper is fitted to the shrinkage core model which is jointly controlled by the diffusion of steam through the product layer and chemical reaction at the interface,and the apparent activation energy calculated is 32.82 kJ/mol.