Sulfuric acid leaching of Turkish chromite concentrate

In this work a high grade chromite concentrate obtained from Pinarbasi–Kayseri district of Turkey was reacted with a solution of sulfuric acid and perchloric acid. The effect of sulfuric acid concentration, temperature, duration, and perchloric acid addition on leach recovery was studied. At the end of leach reaction chromium appeared in the solution as Cr3+ and it did not change to environmentally hazardous Cr6+. The final product in the solution was chromium(III) sulfate obtained with about 83% maximum recovery, under the optimum leaching conditions of 175 °C, 2 h, 70% H2SO4 and 1/2 perchloric acid/chromite ratio.