Green Chemical Technology
Project manager(s): 
Project manager(s): 
Dr. Alireza Salehi Rad
Financial supporter: 
Chemi Pakhsh Paykan Co.‎
Basic chromium sulfate is a chrome chemical mostly required as main tanning agent in chrome tanning process in leather industry and also to synthesize other chromic compounds. Because of the acute toxicity of Cr(VI)-bearing substances, the pollution problem caused by chromite process residue has become a worldwide concern. In the view of relevant studies, the technologies based on the alkali treatment cannot fundamentally resolve the pollution problem, because the oxidation of Cr(III) to Cr(VI) is unavoidable during chromite decomposition. In contrast, the oxidation of Cr(III) to Cr(VI) can be controlled by the sulfuric acid treatment of chromite, and the Cr(VI) pollution can be eliminated from the original source of production. In this research, a clean hydrometallurgical process without the generation of hexavalent chromium is demonstrated. The used approach includes the following steps: 1- chromite milling 2- chromite leaching by sulfuric acid solution in the presence of an oxidant 3- removal of iron from the acid solution as the precipitate of jarosite and 4- Finally, production of chromium sulfate by adjusting the basicity of the solution.‎
Iranian Research Organization for Science and Technology
Department of Chemical Technologies
Last updated on Aug - 16 2022
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