MODELING THE TEMPERATURE DEPENDENCE OF SELECTED VARIABLES RELEVANT TO THE OPERATION OF A COPPER ELECTROWINNING CELL BASED ON REACTIVE ELECTRODIALYSIS

摘要

The temperature dependence of: a) electrolyte density, viscosity and electrical conductivity and b) the equilibrium constants of formation for all relevant species have been determined as part of an effort to model the operation of a copper electrowinning cell based on reactive electrodialysis. The studied ranges were: 1.01 to 1.25 g/cm~3 for density, 4.9 X 10~(-4) to 16.4 X 10~(-4) kg m~(-1) s~(-1) for viscosity and 0.02 to 86.0 OMEGA~(-1) m~(-1) for electrical conductivity. Density and the electrical conductivity of the catholyte increased linearly with temperature whereas the viscosity increase was exponential. The main effect of ionic speciation was to decrease the electrical conductivity with increasing metal concentration due to ion association (mainly the formation of bisulphate ion) which lowered the concentration of protons (the most mobile species) in solution. This effect was specially noticeable in the anolyte. Mathematical relationships with correlation coefficients between 0.959 and 1.000 have been found for all the studied variables.