采用锌冶炼窑渣处理污酸回收铜铁技术

Recovery of Copper and Iron from Zinc Waelz Slag by Waste Acid

针对锌冶炼系统产生的污酸成分复杂、酸度高,砷及重金属浓度高的特点,利用湿法炼锌过程中产生的含有大量有价金属的回转窑渣对其进行处理。提出了“污酸浸出锌窑渣—常压臭葱石合成法沉砷—铁粉置换沉淀铜、砷—中和水解—赤铁矿法沉铁”的主体工艺,在实现污酸无害化处理的同时有效利用窑渣中的有价金属资源。结果表明,经二段逆流浸出后,铜、铁、锌的浸出率均在90%以上,砷的沉淀率高于95%,沉砷渣为晶型良好的臭葱石。溶液中铜的沉淀率超过99%,实验得到的赤铁矿渣含铁量达64.42%,可作为炼铁或制作铁红的原料。

Based on the characteristics of complex composition,high acidity,arsenic and other heavy metal ions in the waste acid produced by the zinc smelting system,zinc waelz slag produced by zinc hydrometallurgy,which containing a large amount of valuable metals was used to treat the waste acid.This paper puts forward the main process of"Leaching waelz slag by waste acid-Arsenic-Iron co-precipitation-Copper-arsenic cementation-Neutralization and hydroxide-Hematite precipitation process".While realizing the harmless treatment of waste acid,the valuable metal resources in zinc waelz slag are effectively used.The results showed that the leaching rate of copper,iron and zinc was above 90%in the conditions of two stages cross-current leaching,the precipitation rate of arsenic was above 95%and the precipitation residue was crystalline scorodite.The copper precipitating rate from the solution was over 99%and the iron content of hematite precipitation was up to 64.42%which can be the raw materials of iron and iron red making processes.