Method of making chromic oxide

摘要

Disclosed is a method of making hydrated chromic oxide of low sodium content by forming an aqueous solution of sodium bichromate, reducing the sodium bichromate to chromic oxide using sucrose or formaldehyde, which results in the precipitation of chromic oxide, filtering the hydrated chromic oxide, acid repulping and filtering or calcining the hydrated chromic oxide, followed by water repulp and filtering with displacement washing. The color of the particle can be controlled by the drying temperature. A composite particle of hydrated chromic oxide/carbon can be made by forming a slurry of the aqueous solution of sodium bichromate with powdered carbon. The composite particle can be heated to directly produce chrome metal.