Exploratory Study On The Separation Of Chromium And Iron In Multicomponent Acid Solution System

Hexavalent chromium Cr(VI) is produced in traditional oxidizing roasting process and Cr(VI) in chromium slag will cause serious environmental pollution. As a new process for producing chromium salt, sulfuric acid leaching process of chromite does not produce toxic Cr(VI), solving the problem of Cr(VI) pollution from the source. However the quality of chromium salt is poor because the chemical properties of Fe3+ and Cr3+ in sulfuric acid leaching solution are too similar to separate.The separation effect of precipitation behavior by jarosite process and goethite process is studied in this paper, and two-step process of jarosite-goethite is proposed to remove iron. The research results will provide sulfuric acid leaching process of theoretical guidance for further development. Under the condition of this experiment, we get the following conclusions:When the initial concentration of Fe3+ solution was 5.60g·L-1, at pH 2.4, temperature 90?, Fe3+ in solution precipitated in the form of crystal jarosite. Accompanied by a decline in Fe3+ concentration, the recipitate transformed from crystal jarosite to amorphous precipitate, and the precipitate was filtered deteriorated.Well-developed goethite seed was prepared by Fe(OH)3 precursor at 120? for 8h. Precursor was generated by adding mineralizer to Fe2(SO4)3 solution. When the concentration of Fe3+ in Sulfuric acid leaching solution was diluted to 1 g·L-1 and goethite seed was added into the solution, Fe3+ precipitated in the form of goethite at proper time, pH and aging time.