The invention discloses a method for preparing
chromium chloride hexahydrate by using
sodium chromate. The method comprises the following processes: dissolving
sodium chromate into a certain amount ofhydrochloric acid A; heating to boil, acidifying, filtering undissolved
sodium chloride, and pumping
hydrochloric acid B and a
reducing agent which are uniformly mixed according to a certain proportion while stirring the filtrate; after the reaction is completed, carrying out
evaporation concentration, concentrating to Baume degree A; and carrying out secondary
filtration to remove precipitated sodium
chloride, supplementing water to Baume degree B, cooling to a temperature A, crystallizing, precipitating
chromium chloride hexahydrate crystals, and centrifuging to obtain a
chromium chloride hexahydrate finished product. According to the method,
hydrochloric acid is used for acidification, so that generation of a byproduct
mirabilite in a traditional
chromic anhydride process is avoided; compared with
mirabilite, the byproduct sodium chloride of the method has larger
crystal particles and chromium is easy to wash, and in addition, an alkaline substance is not required to be added to adjust the pH to prepare chromium
hydroxide, so that the alkaline substance is not required to be consumed and washed, the comprehensive
recovery value is realized, and the production cost of productionenterprises is reduced.