PURIFICATION OF AQUEOUS ALKALI METAL CHLORATE SOLUTIONS

摘要

A process for removing alkaline earth metal impurities (e.g. calcium and magnesium ions) from an aqueous alkali metal chlorate solution (1) which includes adding sufficient alkali metal carbonate (3) or hydroxide (4) or both to the impure solution (1) to raise the pH to above 9 and form alkaline earth metal precipitates which are then removed from the pH-adjusted solution (e.g. by microfiltration) (12, 14). This process can lower the level of these impurities from about 1-20 ppm to less than about 0.3 ppm or less.