含砷冶炼烟尘选择性脱砷与铜锌回收研究

Research on Selective Dearsenic and Copper and Zinc Recovery from Arsenic-Bearing Smelting Dust

含砷冶炼烟尘是有色金属冶炼中产生的一类重要二次资源,但砷具有剧毒性,限制其清洁化利用。根据含砷烟尘中砷物相特征,采用水浸-氧化酸浸梯次脱砷,利用溶剂萃取回收铜锌,实现烟尘资源的综合利用。对于易溶相As_(2)O_(3),在液固比4∶1、温度95℃和时间3 h的条件下进行水浸,砷浸出率为52.85%,水浸液在120℃温度下蒸发结晶回收砷。对于难溶相Pb5(AsO4)3Cl,在温度45℃、液固比3∶1、硫酸浓度1.5 mol/L、H_(2)O_(2)浓度3.0%和反应时间4 h的条件下进行氧化酸浸,砷、铜和锌的浸出率分别为99.16%、99.67%和98.64%,酸浸渣可作为炼铅原料。浸出液中,铜和锌分别采用萃取剂N902和P204进行回收,其萃取率分别为96.42%和96.38%。含砷冶炼烟尘选择性脱砷和铜锌萃取组合工艺具有脱砷效率高、成本低、安全环保等优点,适用于含砷物料资源化清洁利用。

Arsenic-bearing smelting dust is an important secondary resource generated in non-ferrous metal smelting,but arsenic is highly toxic,limiting its clean utilization.Based on the phase characteristics of arsenic in arsenic containing smoke and dust,water immersion oxidation acid leaching is used for stepwise arsenic removal,and solvent extraction is used to recover copper and zinc,achieving comprehensive utilization of smoke and dust resources.For the easily soluble phase As_(2)O_(3),water leaching is carried out under the conditions of liquid-solid ratio of 4∶1,temperature 95℃,and time 3 h,and the arsenic leaching rate is 52.85%,and the water leaching solution evaporates and crystallizes at a temperature of 120℃to recover arsenic.For the insoluble phase Pb5(AsO4)3Cl,oxidation acid leaching is carried out under the conditions of temperature 45℃,liquidsolid ratio 3∶1,sulfuric acid concentration 1.5 mol/L,H_(2)O_(2)concentration 3.0%,and reaction time 4 h,the leaching rates of arsenic,copper,and zinc are 99.16%,99.67%,and 98.64%,respectively,and the acid leaching residue can be used as a lead smelting raw material.In the leaching solution,copper and zinc are recovered using extractants N902 and P204,with extraction rates of 96.42%and 96.38%,respectively.The combined process of selective dearsenic and copper and zinc extraction from arsenic-bearing smelting dust has the advantages of high arsenic removal efficiency,low cost,safety and environmental protection,and is suitable for the resource utilization and clean utilization of arsenic containing materials.