Method of preparing sodium dichromate

TLDR: In this article, a method of preparing sodium dichromate, comprising the steps of (1), subjecting chromite and alkali solution to liquid oxidation, subjecting slurry to solid-liquid separation after reacting to obtain liquid phase A and solid phase B; (2), washing the solid phase A with circulatory alkali liquid, and returning the washing liquid to crystal dissolution; (3), preparing circulatory liquid with the liquid phase C and crystal-dissolved liquid, adding an acid solution to the remaining crystal-disolved liquid to adjust pH, and carrying

Abstract: The invention discloses a method of preparing sodium dichromate, comprising the steps of (1), subjecting chromite and alkali solution to liquid oxidation, subjecting slurry to solid-liquid separation after reacting to obtain liquid phase A and solid phase B; (2), washing the solid phase B with circulatory alkali liquid, subjecting post-washing slurry to solid-liquid separation to obtain liquid phase C and solid phase D; (3), crystal-dissolving the solid phase D with sodium chromate crystal with water and iron residue washing liquid, carrying out solid-liquid separation to obtain crystal-dissolved liquid and iron residue, washing the iron residue with water, and returning the washing liquid to crystal dissolution; (4), preparing circulatory alkali liquid with the liquid phase C and crystal-dissolved liquid, adding an acid solution to the remaining crystal-dissolved liquid to adjust pH, and carrying out aluminum-silicon removal, acidifying, crystallizing and separating to obtain sodium dichromate and sodium sulfate; preparing. The process of the invention is simple, the flow is short, and the method is highly operable, low in cost and free of wastewater and is an effective way of chromium salt industry to make recycle use and reduce pollution.