机械活化铅锌烟尘强化硫酸浸出的工艺研究

Study on Effect of Mechanical Activation on Sulfuric Acid Leaching of Lead-Zinc Fume

以含铅锌烟尘为原料,采用机械活化-硫酸浸出的湿法冶炼工艺分离铅锌烟尘中的金属铅及锌。着重研究了机械活化前后不同的硫酸浓度、液固比、浸出温度、浸出时间等工艺条件对原料中Zn浸出率及Pb入渣率的影响。实验结果表明,机械活化前,H2SO4直接浸出铅锌烟尘的最佳工艺参数为H2SO4浓度175 g/L、液固比7∶1、浸出温度60℃、浸出时间60 min。在最佳工艺条件下,Zn浸出率达92.47%,Pb入渣率为90.30%。原料机械活化30min后,最佳工艺条件变为H2SO4溶液浓度150 g/L、液固比5∶1、浸出温度50℃、浸出时间40 min。此时Zn浸出率达91.52%及Pb入渣率为95.36%。机械活化后铅锌烟尘的Zn浸出率及Pb入渣率对H2SO4溶液浓度、液固比、浸出温度、浸出时间的依赖性明显降低。

An experimental study was conducted on recovering lead and zinc from lead-zinc fume by using the hydrometallurgical process consisting of mechanical activation and direct sulfuric acid leaching. The effect of sulfuric acid concentration, liquid-solid ratio, leaching temperature and leaching time before and after mechanical activation on the leaching rate of zinc as well as the content of lead into the leaching residue were studied. Results showed that the direct sulfuric acid leaching of lead-zinc fume without mechanical activation at the following optimum conditions with the concentration of H2SO4 at 175 g/L, the liquid-solid ratio of 7：1, at a temperature of 60 ℃ for about 60 mins, could result in the leaching rate of zinc up to 92.47% and 90.30% of lead into leach residue. However, after 30-min mechanical activation, the leaching process under the optimum conditions with H2SO4 concentration at 150 g/L, liquid- solid ratio at 5：1, at a temperature of 50 ℃ for around 40 rains, could lead to the leaching rate of zinc at 91.52% and 95.36% of lead into the leach residue. It is found that both zinc leaching rate and concentration of lead into the leach residue are less dependent on the sulfuric acid concentration, liquid-solid ratio, leaching temperature and leaching time after mechanical activation.