湿法炼锌浸出渣减量化浸出工艺研究

以常规湿法炼锌工艺锌浸渣为研究对象，对比研究常压酸浸和加压酸浸条件下锌浸渣的酸性浸出减量化效果，以及渣中锌、铜和铟等有价金属的浸出率。结果表明，在常压酸浸条件下，渣量可减少65%以上，渣中锌含量可降至3%左右，锌、铜和铟的浸出率均在91%以上；在加压酸浸条件下，渣量可减少40%以上，渣中锌含量可将至2%以下，锌和铜的浸出率达到95%左右，但铟浸出率仅为70%左右，相对较低。常压酸浸过程锌浸渣中的铁绝大部分浸出，有利于铟的浸出；加压酸浸过程锌浸渣中的铁大量以铅铁矾的形式留在渣中，阻碍了铟的浸出。常压浸出液中铁含量较高，达到25 g/L以上；加压浸出液中铁含量较低，小于2 g/L，有利于后续浸出液中铜、铟的回收。常压浸出渣量少，有利于渣中铅、银的富集，可单独销售；加压浸出由于铁沉淀入渣，致使渣中铅、银富集比低，适合于铅锌联合企业返回铅熔炼炉。

Decrement Leaching Process of Zinc Leaching Residue

Taking zinc leaching residue of conventional zinc hydrometallurgy process as research object, leaching behavior of zinc, copper and indium in zinc leaching residue and decrement of zinc leaching residue were comparative studied in the process of atmospheric and pressure system. The results show that under the condition of atmospheric acid leaching, the residue amount can be reduced by more than 65%, zinc content in residue can be reduced to about 3%, and leaching efficiency of zinc, copper and indium are all above 91%. The residue amount can be reduced by more than 40%, and zinc content in residue can be below 2% in the process of pressure acid leaching. Leaching efficiency of zinc and copper can reach about 95%, but leaching efficiency of indium is only about 70%, which is relatively low. The vast majority of iron in zinc leaching residue is leached during atmospheric acid leaching, which is conducive to leaching of indium. A large number of iron in zinc leaching residue remains in the form of plumbojarosite during pressure acid leaching process, which hinders leaching of indium. Iron content in atmospheric leachate is higher, reaching more than 25 g/L, while iron content in pressurized leachate is 2 g/L below, which is beneficial to recovery of copper and indium in subsequent leachate. The amount of atmospheric leaching residue is small, which is beneficial to enrichment of lead and silver in the residue, and can be sold separately. Due to iron precipitation into residue during pressure leaching, resulting in low enrichment ratio of lead and silver in the residue, it is suitable for lead-zinc joint enterprise back to lead smelting furnace.