低含铟浸出渣中铟的氧压酸浸实验及动力学研究

Experimental and kinetic study on oxygen pressure acid leaching of indium from low-content indium-containing leaching residue

采用氧压酸浸的方法浸出低含铟浸出渣中的铟,研究铟的氧压酸浸过程及动力学;研究搅拌速率、浸出温度、初始硫酸浓度、氧分压、物料粒度对铟浸出率的影响。研究结果表明:在浸出温度为220℃,物料粒度为75~80μm,硫酸浓度为1.53 mol/L,转速为650 r/min,氧分压为0.60 MPa时,铟、锌和铜的浸出率分别为99.5%,95.36%和95.94%;铟的浸出过程符合未反应收缩核模型,前期受化学反应控制,然后转为混合控制,后期受固体产物层扩散控制;化学反应控制和固体产物层扩散控制过程的表观活化能分别为46.09 k J/mol和11.62 k J/mol。

Low indium-containing leaching residue was treated by oxygen pressure acid leaching,and dissolution kinetics and behavior of indium extraction from indium-containing leaching residue were investigated.Effects of stirring speed,temperature,sulfuric acid concentration,oxygen partial pressure and particle size on extraction rate of indium were studied.The results show that leaching rates of In,Zn and Cu are 99.5%,95.36%and 95.94%respectively when leaching temperature is 220℃,particle size is 75-80μm,initial sulfuric acid concentration is 1.53 mol/L,stirring speed is 650 r/min and oxygen partial pressure is 0.60 MPa.The indium leaching process is conformed to shrinking ore model.It is controlled by chemical reaction in its early stage,then switches to mix-controlled stage,and finally to the stage in which diffusion is controlled by the solid product layer.Activation energy is 46.09 kJ/mol in chemical reaction control stage and 11.62 kJ/mol in the later product layer diffusion control.