难处理复杂氧化锌烟尘碱洗渣浸出试验研究

Experimental Study on Alkaline Leaching Residues of Zinc Oxide Dusts from Lead Smelting by Neutral Leaching Then Acid Leaching

对铅冶炼难处理复杂氧化锌烟尘碱洗渣进行了“中性浸出—酸浸”工艺试验研究。结果表明,碱洗渣中性浸出时,锌、镉的浸出率先随浸出温度、液固比、搅拌速度和时间的增加而提高,后增速变缓;中浸渣酸浸时,液固比对锌、铟的浸出率无明显影响。锌、铟的浸出率随初始酸度、浸出温度和时间的增加先增加后变缓。中性浸出最佳条件为:温度338 K、液固比5∶1、搅拌速度400 r/min、浸出时间1h,此条件下,锌、镉的浸出率分别为80.3%和76.3%。中浸渣酸浸最佳条件为:初始酸度100 g/L、浸出时间2 h、浸出温度363 K、液固比5∶1,在该条件下,锌、铟的浸出率分别为97.1%和85.5%。

The technological experiments of neutral leaching-acid leaching on alkaline leaching residues of zinc oxide dusts from lead smelting were studied systematically.The results show that the leaching rate of zinc and cadmium from alkaline residues increases first with the increase of leaching temperature, liquid-solid ratio, agitation speed and time, and then slows down. The liquid-solid ratio has no significant effect on the leaching rate of zinc and indium during acid leaching.The leaching rate of zinc and indium increases first and then decreases with the increase of initial acid concentration, leaching temperature, and time. The optimum conditions for neutral leaching are: the temperature 338 K, liquid-solid ratio 5∶1, the stirring speed 400 r/min,and the leaching time 1 h. Under this condition, the leaching rates of zinc and cadmium are 80.3% and 76.3%, respectively. The optimum conditions for acid leaching of neutral leaching residue are: the initial sulfuric acid concentration 100 g/L, the leaching time 2 h, the leaching temperature 363 K, and the liquid-solid ratio 5∶1. Under this condition, the leaching rates of zinc and indium are 97.1% and 85.5%.