Expanded Industrial Experiments of Free-alkali Recovery from Sodium Tungstate Solution by the Membrane Electrolysis Process

摘要

The expanded industrial experiments were conducted with practical industrial liquor to separate free alkali for sodium tungstate solution by electrolysis with cation-exchange membrane. Experimental results show that on the condition that the temperature is 50-55 deg. C and the current density is 1000 A/m~2, the single electrolysis cell is operated stably and 80/100 free-alkali in mass fraction is separated from the anode feed liquor of sodium tungstate, with electric ef- ficiency up to more than 88/100 and the unit energy consumption E lower than 1900 k Wh/t; while three electrolysis cells in series are operated, under the condition that the temperature is 60-65 deg. C and the current density is 1000 A/m~2, the elec- tric efficiency can reach higher than 88/100 and the unit energy consumption E can be lower than 2250 kWh/t.