硫氧混合铅锌矿中锌的氧化氨浸动力学

常压低温条件下在NH3-(NH4)2 SO4体系中使用过硫酸铵作为氧化剂对硫氧混合铅锌矿中的锌进行浸出实验,系统研究了搅拌速度、浸出剂浓度、氧化剂浓度与温度对于锌浸出率的影响.结果表明,在最优条件下锌的浸出率可达93.2%,且浸出过程中几乎没有其他离子进入溶液,实现了锌的选择性高效浸出,从而简化了后续的浸出液净化与材料制备过程.动力学研究表明,硫氧混合铅锌矿中锌的氧化氨浸过程遵循固体产物层扩散控制的未反应核收缩模型,浸出反应的表观活化能为17.89 kJ·mol-1.

Oxidative ammonia leaching kinetics of zinc extracted from mixed sulfide-oxide lead and zinc ore

The leaching experiments of zinc from mixed sulfide-oxide lead and zinc ore were performed in NH3-( NH4 ) 2 SO4 solu-tion with ammonium persulfate as an oxidant under atmospheric pressure and relatively low temperature. The effects of stirring speed, lixiviants, oxidant concentration and reaction temperature on the leaching rate of zinc were studied. The results show that under the op-timal conditions, the leaching rate of zinc can reach 93. 2%, and nearly no other metal ions enter into lixivium during the leaching process, which shows that this ammoniacal leaching system has a high efficiency and selectivity. This is significant to simplify the fol-lowing purification process and product preparation process. Leaching kinetics indicates that the oxidative leaching of zinc could be re-presented by a shrinking core model with product layer diffusion and the activation energy for the dissolution reaction is calculated as 17. 89 kJ·mol-1 .