Experimental Study Of Ion-exchange Membrance Electrolysis For Desalination Of Baking Soda Mother Liquor

The baking soda is produced by trona as the main method of production of baking soda. When the trone mining is exploited by dissolve mining methods, Mine will produce a large number of filtration, centrifugation mother liquor (spent caustic). When the filtration, centrifugation mother liquor recycling, due to the continuous accumulation of sodium chloride, this will result in the salt content of mother liquor increases, and thus directly affect the recovery rate and utilization of alkaline mineral. This will also enable the production decline in the quality of baking soda. A lot of sodium carbonate, sodium bicarbonate with the filtration, centrifugation mother liquor is drained. This is not only a waste of resources, but also caused environmental pollution.This paper preliminarily studies on the feasibility of the ion-exchange membrane electrolysis technique to desalination and explores new salt separation technology. The salt will be removed by ion-exchange membrane electrolysis from filtration, centrifugation mother liquor, and sodium carbonate, sodium bicarbonate will be recovered, through the anion and cation membrane electrolysis experiment, anion-exchange membrane electrolysis technique is adopted for the mother liquor desalination. For the anion-exchange membrane electrolysis technique, dicussing the influence of different anion membrane different current densities and different anode electrolyte on current efficiency and electrolysis energy consumption of desalination. The results of experiment showed that AMI homogeneous anion membrane is very well in chemical stability, mechanical strength and selectivity for chloride. The optimum current density is 2500-3000A/m2. The optimum anode electrolyte and its concentration is 25% sodium chloride solution or 25% sodium hydroxide solution.Trona mother liquid which is treated by ion-exchange membrane electrolysis can be used for the injection and well washing. This could protect the trone low concentration in sodium chloride and achieve recycling, clean production. In principle, with salt mines for the rational development and utilization of natural resources, we can find a more satisfactory process.