Batch ion-exchange membrane electrodialysis of mother liquid discharged from a salt-manufacturing process. Experiment and simulation

摘要

Mother liquid discharged from a salt manufacturing plant was electrodialyzed in the batch process incorporated with SO42- ion low-permeable anion-exchange membranes for decreasing Na2SO4 concentration and recovering NaCl. Energy consumption of the electrodialysis was compared with that of the cooling method to precipitate Na2SO4 as Na2SO4 center dot 10H(2)O. Energy consumption of cooling method depends largely on cooling energy for decreasing temperature. If the temperature of the discharged mother liquid cannot be cooled under 31 degrees C in the atmosphere, the cooling method needs much cooling energy, so the electrodialysis is advantageous. If the temperature can be decreased to lower than 31 degrees C in the atmosphere, cooling method is possible.