PURIFICATION OF CHLOR-ALKALI MEMBRANE CELL BRINE

摘要

This invention relates to methods and systems for purifying brine for electrolysis in chloralkali cells, especially membrane cells by reducing the sulfate ion concentration, while at the same time minimizing the concentration of other undesirable ions such as calcium and chlorate. The methods and systems employed are unique combinations of refrigeration and crystallization, and brine recirculation techniques in the systems for electrolyzing brine.