PROCESS FOR PRECIPITATING AMMONIUM CHLORIDE

摘要

A process for precipitating ammonium chloride in ammonia-soda process wherein ammonium chloride and sodium bicarbonate are alternately precipitated by using sodium chloride, carbon dioxide gas and ammonia as raw materials, which comprises introducing a liquid cooling medium directly into an ammonium chloride precipitation solution in a precipitation tank to cool the solution by the heat of vaporization of the medium and thereby precipitate ammonium chloride to form a slurry containing solid ammonium chloride thus precipitated, wherein a part of the slurry is subjected to a solid concentrator and concentrated by the removal of a part of liquid therefrom, and the resulting concentrated slurry is returned to the precipitation solution to increase the solid ammonium chloride concentration in the precipitation solution and thus promote the grain growth of the solid ammonium chloride.