含镁三元系锰电解液理化性能研究

Physical-Chemical Properties of Ternary Mg-containing Manganese Electrolyte

研究了MgSO4-MnSO4-(NH4)2SO4三元系锰电解液的理化性能。选取电解锰合格液作为研究对象,研究了温度、溶液成分对锰电解液密度、电导率和缓冲能力的影响。结果表明,锰电解液密度随溶液温度降低、硫酸铵浓度和镁离子浓度升高而增加;镁离子对电解液密度影响较大,镁离子浓度从0增至30 g/L,40℃下锰电解液密度从1.133 g/mL增至1.263 g/mL。电导率随溶液温度、硫酸铵浓度升高而增加,随镁离子浓度升高而降低;硫酸铵浓度从70 g/L增至100 g/L时,溶液电导率增幅超过27%;镁离子浓度从0增至30 g/L时,溶液电导率降幅将近14%。硫酸铵能显著增加锰电解液的缓冲能力,镁离子浓度对缓冲容量影响不大,但是镁离子浓度超过25 g/L后会降低锰电解液对pH值的调节能力。

The research on physical-chemical properties of MgSO4-MnSO4-(NH4)2SO4 ternary electrolyte is presented here, which can provide some reference for the industrial production of electrolytic manganese. A kind of qualified manganese electrolyte solution was chosen for investigating the effects of temperature and solution compositions on the density, conductivity and buffer capacity of manganese electrolyte. Results showed that the density of electrolyte increased with the fall in the solution temperature, as well as the increase in ammonium sulfate concentration and magnesium concentration. With magnesium ion concentration increasing from 0 g/L to 30 g/L, the density of manganese electrolyte increased from 1.133 g/mL to 1.263 g/mL at 40 ℃, indicating that magnesium ion brought significant influence on the electrolyte density. The conductivity increased with the increasing of the solution temperature and the ammonium sulfate concentration, but decreased with the increasing of magnesium ion concentration. With the concentration of ammonium sulfate increasing from 70 g/L to 100 g/L, the conductivity of electrolyte increased by more than 27%, while with the concentration of magnesium ion increasing from 0 g/L to 30 g/L, the conductivity of electrolyte decreased by nearly 14%. Ammonium sulfate can significantly improve the buffer capacity of manganese electrolyte, while the concentration of magnesium ion shows little effect on the buffer capacity. However, after the magnesium ion concentration exceeds 25 g/L, manganese electrolyte becomes less capable of adjusting the pH value.