PROCESS FOR PURIFYING AQUEOUS SOLUTION OF ALKALI METAL HALIDE FOR ELECTROLYSIS

摘要

This invention relates to a process for purifying an aqueous solution of an alkali metal halide containing calcium ions for electrolysis which comprises adding phosphate ion to the solution with the amount of phosphate ion exceeding that which is consumed in the reaction of the phosphate ion with the calcium ions, adjusting the pH of the solution to the alkaline region to precipitate at least the calcium ions in the solution, and removing the precipitate. This process purifies the aqueous solution to a high degree of purity.