砷酸铜制备工艺过程热力学分析

绘制了Cu-As-H2O系电位－pH图、不同As浓度下lgCu]TAs]T)-pH图以及Fe-As(V)-H2O系lgFe]T-pH图等，分析了由墨铜渣制备胂酸铜过程的热力学。酸性氧化浸出可同时浸出Cu和As，pH＝2左右脱脱铁率可达99％以上。铜砷比和pH值的不同，可以得到不同形式的砷酸铜；CuHAsO4,Cu2AsO4OH，Cu5H2(AsO4)。在胂酸铜制备工艺条件下，所得砷酸铜分子式为Cu5H2(AsO4)4。热力学分析结果与XRD相一致。

Thermodynamic analysis of copper arsenate preparation process

The thermodynamics of copper arsenate preparation from black copper sludge was analyzed by constructing potential—pH diagram of Cu-As-H2O system， lg［Cu］T/［As］T—pH diagram at different concentration of arsenic， lg［Fe］T—pH diagram of Fe-As(Ⅴ)-H2O system. In acid oxidative leaching of the black copper sludge Cu and As can be leached simultaneously; in neutralization process of the mother liquor after copper sulfate crystallization Fe can be precipitated and its separation efficiency reaches more than 99% at pH=2. With the difference of ［Cu］T/［As］T ratio and pH, the different shape copper arsenate: CuHAsO4， Cu2AsO4OH and Cu5H2(AsO4)4 can be formed. Under the technological conditions of copper arsenate preparation the molecular formula of copper arsenate prepared is Cu5H2(AsO4)4.　The result of thermodynamic analysis is consistent with XRD.