湿法炼锌酸性浸出条件优化及元素浸出行为研究

以国内某湿法炼锌厂的中性浓密机底流为原料,开展了酸性浸出条件优化及元素浸出行为研究,考察了温度、终酸对渣含锌、渣率、渣银品位以及元素浸出率的影响,对浸出渣进行了锌、银的物相分析。结果表明,试验的最佳条件为温度90℃,液固比7~9∶1,终酸40g/L,时间5h,此时锌的浸出率为75.97%,渣含锌为17.87%,渣率为37%,渣银品位为380g/t,浸出渣中除铁酸锌外,其它形态的锌基本被浸出完全,锌主要以铁酸锌形态存在,银以单质银和硫化银为主,通过强化浸出后,银品位得到了大幅度的提高。

Research on Optimization of Acid Leaching Conditions and Element Leaching Behavior in Zinc Hydrometallurgy

Using the underflow of the neutral thickener of a domestic hydro-zinc smeler as raw material,the acidleaching conditions were optimized and the elemental leaching behavior was studied.The effects of temperature andfinal acid on zinc content,slag yield,slag silver grade and elemental leaching rate were investigated.Tlhe phaseanalysis of zinc and silver in the leaching residue was carried out.The results show that the best conditions for theexperiment are temperature 90℃,liquid-solid ratio 7~9:1,final acid 40 g/L,anmd time 5 h.At this time,theleaching rale of zinc is 75.97%,the zrinc content of the slag is 17.77%,and the slag rate is 37%.The slag silvergrade is 380 g/t.Except for zinc ferrite,other forms of zinc in the leaching slag are basically leached completely.Zincmainly exists in the form of zinc ferrile,and silver is mainly composed of elemental silver and silver sulfide.Afterintensified leaching,the silver grade has been greatly improved.