用含硫化砷废渣制备砷酸铜

以湖北省某化工企业含砷废水处理过程中产生的含硫化砷废渣为研究对象，采用氧化碱浸—沉淀工艺制备砷酸铜。考察了沉淀反应液pH、沉淀反应温度、搅拌转速对砷沉淀效果的影响。采用XRD和SEM技术对砷酸铜的物相及形貌进行了表征。实验结果表明：废渣在氧化碱浸过程的砷浸出率为96.53%；沉淀反应时间为30 min时，沉淀步骤的最佳工艺条件为沉淀反应液pH 5.0、搅拌转速500 r/min、沉淀反应温度50 ℃。验证实验结果表明，在该工艺条件下，砷沉淀率均达93.96%以上。SEM表征结果显示，砷酸铜产品为颗粒状，粒径约为500 nm。XRD表征结果显示，砷酸铜产品中主要含有Cu₃As₂O₈，Cu₄O（AsO₄）₂，Cu₄（As₂O₇）O₂。该方法工艺简单、无二次污染，为废渣的综合利用提供了一种新的技术路线。

Preparation of Copper Arsenate from Arsenic Sulfide Residue

The arsenic sulfide residue produced in the treatment of arsenic-containing wastewater from a chemical factory in Hubei province is used to prepare copper arsenate by the process of oxidation and alkaline leaching - precipitation. The factors affecting the arsenic precipitation were studied. The phase structure and morphology of the product were characterized by XRD and TEM. The arsenic leaching rate is 96.53%. The optimum process conditions for precipitation are as follows：precipitation time 30 min,precipitation solution pH 5.0,stirring speed 500 r/min and precipitation temperature 50℃. Under these conditions,the arsenic precipitation rate is over 93.96%. The SEM characterization results show that the copper arsenate product is particles with about 500 nm of particle size. The XRD characterization results show that the copper arsenate product mainly contains Cu₃As₂O₈,Cu₄O(AsO₄)₂ and Cu₄(As₂O₇)O₂. This process is simple and without secondary pollution,and it provides a new technologic route for comprehensive utilization of residue.