SO2-H2SO4体系中锌浸渣还原浸出锌和铟

以锌浸出渣为对象,研究了在硫酸—二氧化硫体系还原浸出锌浸渣过程中反应温度、转速、液固比、初始硫酸浓度、SO2分压对锌和铟浸出行为及浸出率的影响。结果表明:采用SO2对锌浸渣进行还原浸出能够大幅提高锌和铟的浸出率,在SO2-H2SO4体系下锌浸渣还原过程中的锌和铟的浸出行为及动力学特性符合二级反应方程,浸出过程受到化学反应控制,表观活化能分别为21.72和39.16kJ/mol,提高温度能够显著提高锌和铟的浸出速率,提高液固比和初始硫酸浓度对锌和铟浸出速率影响较小,在一定范围内提高二氧化硫分压对锌和铟浸出速率影响较为显著。在反应温度105℃、转速500r/min、液固比8、初始硫酸浓度120g/L、SO2分压200kPa的条件下反应150min,锌浸出率达到96%以上、铟浸出率达到95%以上。

Reduction Leaching of Zn and In from Zinc Leaching Residue in SO2-H2SO4 System

Reducing leaching behavior of zinc and indium from zinc leaching residue in SO2-H2SO4 system was studied.Effects of reaction temperature,rotational speed,L/S,initial sulfuric acid concentration,and SO2 partial pressure on leaching behavior and leaching rate of zinc and indium were investigated.The results show that SO2 can be used for reducing leaching of zinc leach residues,which can effectively improve leaching rate of zinc and indium.Leaching behavior and kinetics of zinc and indium during reduction leaching of zinc leaching residue are in accordance with second-order reaction equation and controlled by chemical reaction with apparent activation energy of 21.72 and 39.16 kJ/mol respectively.Leaching rate of zinc and indium can be enhanced by increasing initial sulfuric acid concentration,enhancing L/S and initial sulfuric acid concentration has little effect on leaching rate of zinc and indium,while enhancing partial pressure of sulfur dioxide has a significant effect on leaching rate of zinc within a certain range.Over 96% of zinc and 95% of indium in zinc leaching residue are leached under the conditions of reaction temperature of 105 ℃,stirring speed of 500 r/min,L/S of 8,initial sulfuric acid concentration of 120 g/L,SO2 partial pressure of 200 kPa,and reaction time of 150 min.