冶炼污酸蒸发浓缩处理的实验研究

Study on Treatment of Smelting Contaminated Acid by Evaporation Condensing Process

铜冶炼的工艺烟气制酸环节产生污酸，其特点是舍高浓度的氟、氯、砷，以及铜、锌、铅、镉等多种金属。目前采用的硫化沉淀一石灰中和的处理方法，存在产生大量难以处理的危险废物且处理成本高、出水水质难以达到回用要求等不足。本文针对该类污酸的特性，探讨采用蒸发浓缩法处理并回收砷．并后续回收硫酸以及其中有价金属的可行性。在常压加热蒸发条件下。实验研究考察了不同温度、浓缩比时污酸中氟、氯、硫酸根、砷在浓缩液及冷凝液中的走向及分布．以及不同蒸发比条件下浓缩液冷却结晶析出三氧化二砷的去除率。实验结果表明，污酸蒸发浓缩对砷、氟、氯均具有较好的去除率，蒸发温度在130℃、浓缩比6-7时，砷、氟、氯的去除率达到62％、88％、77％。蒸发浓缩处理实验研究表明，蒸发浓缩法处理污酸具有较好的应用前景。

Copper smelting gas producing sulfuric acid process produces contaminated acid which contains high concentration of fluorine, chlorine, arsenic and copper, zinc, lead, cadmium and other metals. The sulfide precipitation and lime neutralization methods have been used at present. Those methods have some deficiencies as which produces a lot of hazardous and unwieldy solid wastes, spends huge process cost, reuse difficultly the water after treatment. In this paper, according to characteristics of this kind of smelting con- taminated acid, studied evaporation condensing process and the feasibility of recycling arsenic, sulfuric acid and valuable metals. Under the condition of atmospheric heating evaporation, this study explored the distri- bution characteristics of fluorine, chlorine, sulfate radical, arsenic in condensate and in concentrate and the crystallization removal rates of arsenic trioxide in concentrate at different temperatures and different enrichment ratios. The results show arsenic, fluorine and chloride have good removal rates from contaminated acid by evaporation condensing process. Temperature at 130℃, enrichment ratio in 6-7, the removal rate of arsenic, fluorine and chlorine reached 62%, 88%, 77%. The results also show evaporation condensing process has good application prospects to treat smelting contaminated acid.