Chromium powder, also known as basic chromium sulfate, molecular formula Cr (OH) nSO40.5 (3-n), relative molecular weight 165.07, salinity 33%. The main components are hydrated basic chromium sulfate and sodium sulfate complex, green powder, easy to absorb moisture and dissolve.Several ways of calling chromium powder: chromium powder, basic chromium sulfate, chrome tanning agent, basic chromium sulfate, chromium salts, are referring to a product with different appellations in different regions.
Basic chromium sulfate is mainly used for tanning leather. It is the raw material for producing chromium hydroxide. The dyestuff industry is used to produce reactive black dyes. The printing and dyeing industry is used as mordant.
The main production methods of basic chromium sulfate are organic matter reduction method and sulfur dioxide reduction method. Sodium dichromate mother liquor was acidified by sodium bisulfate solution (40-42 degrees B) or sulfuric acid in a lead-lined or glass-lined stirred reactor by organic reduction method. Sucrose/glucose reductant was slowly added under stirring to reduce hexavalent chromium and keep the solution boiling at the end of the reaction, which was conducive to complete reaction.The reaction product is syrupy viscous liquid. First, it is cooled naturally, then frozen in the cooling crystallizer to below 10 degrees C. Some sodium sulfate is crystallized into mirabilite. After centrifugal separation, the liquid basic chromium sulfate product is prepared. Then, the solid basic chromium sulfate product is concentrated and dried.