高砷铜精矿浸出液制备砷酸铜及热力学研究

Research on the Thermodynamics and Preparation of Copper Arsenate from High Arsenic-bearing Copper Concentrate Leaching Liquor

高砷铜精矿浸出液中因含砷较高存在砷害问题,砷回收利用具有重要的意义。研究针对某高砷硫化铜精矿除杂后的浸出液,探讨了以砷酸铜形式综合利用砷的热力学及工艺参数。绘制了Cu-As-H2O系电位-pH图,进行了砷酸铜制备工艺过程的热力学分析,对净化后的某高砷硫化铜精矿浸出液,以氨水为中和剂,当pH=5.0-8.0,温度80-90℃时,制得了CuAs2O4、C4H6As6Cu4O16、Cu5As2O10.5H2O、Cu5As4O15.9H2O、Cu2AsO4OH.3H2O及Cu2AsO4OH 6种不同结构的砷酸铜,沉砷后溶液中砷含量为9.11-35.82 mg/L。

The arsenic in the high-arsenic copper sulfide concentrate leaching liquor is harmful to the quality of copper and pollutes the environment so that it is crucially important for the comprehensive utilization of arsenic.The Eh-pH diagram of Cu-As-H2O system and the thermodynamic of copper arsenate preparation from leaching liquor after removing Fe3＋ are investigated in the present study.The results of XRD analysis indicate that the forming process of copper arsenate is complicated and different molecular formulas are formed at a pH of 5.0～8.0 when the temperature is controlled at 80 ℃ to 90 ℃ with ammonia as neutralizer;And the molecular formulas of copper arsenate are CuAs2O4,Cu5As2O10·5H2O,C4H6As6Cu4O16,Cu5As4O15·9H2O,Cu2AsO4OH·3H2O and Cu2AsO4OH.Most of arsenic can be utilized in the form of copper arsenate and the arsenic content as low as 9.11～35.82 mg/L is achieved in solution after it is precipitated.