高含砷冶炼污酸单级硫化脱砷试验

硫化法是目前冶炼污酸除砷应用最广泛的方法。常规硫化法采用阶梯式硫化、多级硫化、高效硫化反应器等工艺,或产出大量危废渣且后液不能回用只能排放,或成本高、流程长,或对高含砷污酸处理效果不理想。对含砷16 060 mg/L、铜28.04 mg/L、铅9.80 mg/L的高含砷污酸的除杂工艺进行研究,考察了硫化钠（Na2S?9H2O）加入量、加入方式及时间、反应温度等因素对除杂效果的影响,确定了“硫化+絮凝”的工艺,通过优化药剂加入方式从而减少药剂加入量,探索出了最佳工艺控制条件,达到“流程短、加药精准、污染小”的目的。结果表明,污酸中的砷可降至0.23 mg/L甚至<0.1 mg/L,铅、铜分别降至<0.1 mg/L,远低于工业硫酸一级品的限值。

High Arsenic Content Smelting Waste Acid Single Stage Sulfidation Test for Arsenic Removal

The sulfurization method is currently the most widely used method for removing arsenic from smelting waste acid. The conventional sulfurization method adopts stepped sulfurization, multistage sulfurization, and high-efficiency sulfurization reactor, which may produces a large amount of hazardous waste residue and the effluent cannot be reused and can only be discharged, or the cost is high, the process is long, or the treatment effect of high arsenic content waste acid is not ideal. The impurity removal process of high arsenic content waste acid containing 16 060 mg/L arsenic, 28.04 mg/L copper, and 9.80 mg/L lead was studied. The effects of the addition amount and method of Na2S?9H2O, reaction time and temperature on impurity removal effect were investigated. The process of "vulcanization + flocculation" was determined. By optimizing the method of adding agents to reduce the amount of adding agents, the optimal process conditions were explored to achieve the purpose of "short process, precise dosing and small pollution". The results show that arsenic in the waste acid can be reduced to 0.23 mg/L or even <0.1 mg/L, while lead and copper can be reduced to <0.1mg/L respectively, far below the limit of industrial sulfuric acid Grade 1.