Research On Related Basis And Technology Of Separation Of Manganese And Magnesium From Metal Manganese Electrolyte

Magnesium sulfate exists in manganese electrolyte,which will be enriched continuously during the mother liquor recycling,thus affecting the electrolytic process and the quality of metal manganese products.In order to separate magnesium salt from manganese electrolyte,the solid-liquid phase equilibrium behaviors of MnSO4-MgSO4-(NH4)2SO4-H2O quaternary system were studied.The complete isothermal phase diagrams at three temperatures of 25?,50? and 100? were obtained.The results showed thatEach temperature phase diagram had 5 solid species,3 invariable liquid points,and 7 univariate curves.Ammonium sulfate prefered to form double-salts with manganese sulfate and magnesium sulfate,such as(MgSO4·(NH4)2SO4·6H2O)and(MnSO4-(NH4)2SO4-6H2O)were formed at 25?,and(MgSO4·(NH4)2SO4·6H2O)and(2MnSO4·(NH4)2SO4)were formed at 50? and 100?.The phase regions for double-salts changed significantly with temperature.For instance,the phase region of MgSO4.(NH4)2SO4·6H2O occupied the greatest part at 25?;with the temperature increases,the phase region of MgSO4·(NH4)2SO4·6H2O decreased gradually,and the phase region of 2MnSO4·(NH4)2SO4 increased by degrees;2MnSO4·(NH4)2SO4 occupied the largest phase region at 100?.According to the changed characteristics of the phase regions above mentioned,the scheme of high temperature evaporation separation of manganese ammonium sulfate double salt and cooling separation of magnesium ammonium sulfate double salt at low temperature were designed.The experimental results showed that the salt-forming behaviors during the evaporation and cooling process were consistent with the quaternary phase diagram obtained in this study.By controlling the temperature,manganese and magnesium salts can be separated from the metal manganese electrolyte via evaporation or crystallization process.