SULFATE REMOVAL FROM ALKALI METAL CHLORATE SOLUTIONS AND PRODUCTION OF ALKALI METAL CHLORATE INCLUDING SAID REMOVAL

摘要

A process for the removal of substantially chromium free sulfate from aqueous alkali metal solutions containing chromate and sulfate which includes mixing the solutions while having a pH of between about 2.5 and 4.5 with a calcium-containing material for a time and at a temperature sufficient to form a gypsum precipitate and separating that precipitate from the solutions; as well as a process for the production of alkali metal chlorate by electrolysis of alkali metal chloride including the removal of chromium free sulfate.