Metallurgical grade chromic oxide prodn. - using oxidising agent addn. to obtain low sulphur@ content prod.

摘要

In chromium (III) oxide prodn. by firing a mixt. of sodium dechromate (dihydrate) in solid and/or aq. soln. or suspension form and ammonium sulphate in solid and/or aq. soln. or suspension form and then washing and drying, the novelty is that a chromium-free water-soluble inorganic oxidising agent is present during prodn. of the mixt. Pref. the oxidising agent is an alkali metal chlorate or hypochlorite. USE/ADVANTAGE - For prodn. of Cr metal or Cr-contg. alloys (claimed). A prod. with very low sulphur content (e.g. down to 16 ppm) is obtained in a simple manner in a single, relatively low temp. firing step