Production method for coproduction of chromium chloride and chromic carbonate

Abstract

The invention discloses a production method for the coproduction of chromium chloride and chromic carbonate, and the production method is used for solving the problems that the chromic carbonate produced through the existing method is easy to age, and the solubility of the chromic carbonate in acidic aqueous solutions is greatly reduced after the chromic carbonate is subjected to long-term storage. According to the production method, an alkaline solution of sodium chromate is taken as a raw material, sulfur and alkali sulfide are taken as reducing agents to be subjected to redox reaction in a reaction tank so as to obtain chromic hydroxide, the obtained chromic hydroxide is filtered and washed and then reacts with hydrochloric acid to produce the chromium chloride, and the chromic carbonate is produced in a manner that the chromium chloride is subjected to the precipitation of a soda solution. The production method has the advantages that the process flow is short, the operation is simple, the redox reaction is complete, the chromium yield is high, and hexavalent chromium is not detected in the filtrate, so that the pollution to the environment cannot be caused.

Description

technical field

[0001] The invention relates to a production method for co-producing chromium chloride and chromium carbonate, which belongs to a new method of clean production in the field of chromium salt production. Background technique

[0002] Chromium chloride is a commonly used raw material for the preparation of other inorganic and organic chromium compounds. It is an intermediate for the production of chromium and carbon atoms directly bonded to Cr-C organic chromium, especially organic acid chromium, such as medical, food additives, feed additives, oil field The production of chromium compounds mostly uses chromium chloride as raw material. Chromium chloride is used to prepare catalysts, and is also directly used as organic synthesis catalysts, mordants, polymer adhesives and trivalent chromium plating.

[0003] Chromium carbonate is more soluble in acid than aged hydroxide, making chromium carbonate more suitable as a raw material for preparing other trivalent ch...