GB386351A - Improvements in the manufacture and production of potassium bicarbonate - Google Patents

Abstract

Potassium bicarbonate is obtained by the reaction of potassium chloride with carbon dioxide or compounds of carbon dioxide and ammonia in mixtures of ammonia and water containing at least sufficient water to hydrolyse the carbonate to bicarbonate, but more ammonia than can be dissolved in the water present at room temperature and atmospheric pressure, at temperatures at which potassium carbamate would be decomposed under the conditions of working. Temperatures between zero and 80 DEG C. may be employed depending in the amount of water present. The pressure should be preferably between 5 and 10 atmospheres. According to one example, liquid ammonia, water and powdered potassium chloride are placed in a pressure vessel to which carbon dioxide at 10 atmospheres and room temperature is introduced. The solid component consisting of potassium bicarbonate with some potassium chloride is separated from the mother liquor and is washed with a mixture of liquid ammonia and water. Ammonium chloride may be recovered from the mother liquor. According to a second example powdered potassium chloride and ammonium bicarbonate are placed in a pressure vessel and a mixture of liquid ammonia and water is led through at a pressure of 25 atmospheres at 60 DEG C. with stirring. Pure potassium bicarbonate and a mother liquor containing ammonium chloride are obtained. Other ammonia-carbon dioxide compounds such as ammonium carbonate or carbamate may also be used.