Abstract: 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.
Thermodynamic analysis of copper arsenate preparation process
Abstract:
The thermodynamics of copper arsenate preparation from black copper sludge was analyzed by constructing potential—pH diagram of Cu As H 2O system, lg[Cu] T/[As] T—pH diagram at different concentration of arsenic, lg[Fe] T—pH diagram of Fe As (Ⅴ) H 2O 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: CuHAsO 4, Cu 2AsO 4OH and Cu 5H 2 (AsO 4) 4 can be formed. Under the technological conditions of copper arsenate preparation the molecular formula of copper arsenate prepared is Cu 5H 2 (AsO 4) 4. The result of thermodynamic analysis is consistent with XRD. [