工业回水体系下硫化锌氧压浸出渣中硫磺和含银矿物分选回收试验研究

Flotation separation and recovery of sulfur and silver-containing minerals from a residue produced by oxygen pressure leaching process of zinc sulfide ore using industrial backwater

内蒙古某锌冶炼厂利用锌电解工业回水,浮选分离硫化锌氧压浸出渣中的硫磺和含银矿物。由于工业回水具有高酸、高杂质离子浓度的特点,生产指标较小型浮选探索试验(自来水调浆)差得多。基于对工业回水性质的测定,深入研究了高浓度的硫酸、锌离子和铁离子对浸出渣中硫磺和含银矿物分选回收的影响。根据研究结果,针对性地提出了浮选工艺优化思路,即在工业回水调浆条件下,对矿浆流体性质进行调控,提高矿浆分散性,并采用适应性较强的丁基铵黑药和煤油组合捕收剂代替原有黄药体系。在优化的条件下,对含硫、银分别为44.30%和193 g/t的浸出渣,小型闭路试验获得了硫精矿硫品位79.52%,S回收率91.06%;尾矿银品位446.4 g/t,Ag回收率81.82%。相比生产指标,硫精矿品位和回收率分别提升了约9个百分点和22个百分点,Ag回收率提升了约36个百分点。在工业回水条件下获得的良好分选指标,为生产指标的提升提供了有力的支撑,这对于提高企业经济和环境效益具有实际意义。

In a zinc smeltery of Inner Mongolia,flotation separation of sulfur and silver-containing minerals from the zinc sulfide oxygen pressure leaching residue were conducted using zinc electrolysis industrial backwater.Because of the industrial backwater characteristics of high acid and high impurity ion concentrations,the separation index in practice is much worse than that of the laboratory-scale flotation test,which has been performed by tap water slurrying.In this paper,based on the determination of the properties of industrial backwater,the effects of sulfuric acid,zinc ions and iron ions at high concentrations on floatation separation of sulfur and silver-containing minerals in leaching residue were studied.According to the results,an improvement of flotation separation for the residue was proposed.Under the condition of industrial backwater slurry adjustment,the pulp properties were regulated to improve its dispersion,and a combination of collectors,i.e.,ammonium dibutyl dithiophosphate and kerosene with strong adaptability was used to replace the original xanthate system.Periodic floatation test at laboratory-scale was performed for separation of the residue assaying 44.30%sulfur and 193 g/t silver.Under the optimized conditions,it produced a sulfur concentrate assaying 79.52%sulfur with 91.06%sulfur recovery,and tailings assayed 446.4 g/t silver with 81.82%silver recovery.Compared with the separation index from practice,the grade and recovery of sulfur concentrate from separation test increased by around 9 percentage points and 22 percentage points,respectively,and the recovery of silver increased by around 36 percentage points.The good sorting index obtained under the condition of industrial backwater provides a strong support for the improvement of production index,which has practical significance for improving the economic and environmental benefits of enterprises.