An Investigation on the Extraction of High-Carbon Ferrochrome with an Environmental Approach

The main minerals containing chromium are chromite mineral compounds. Ferrochrome is divided into three groups: high carbon, medium carbon and low carbon. Chromite mineral has a cubic lattice and belongs to spinel category. In the present study, Fe-Cr-C three-component diagrams are presented along with chemical compounds of ferrochromium. In the following, the extraction of high carbon ferrochromium is further investigated. Fe-Cr-C ternary diagrams confirm that Cr3C2 decomposition at temperatures below 1600°C in minerals with 60 wt% Cr and 8 wt% C results in Cr7C3 composition. Finally, a solution to reduce the most toxic chromium ion (Cr6+) in the leachate of the extraction process is presented. Cr6+ is the most toxic species among its different oxidation states. Cr6+ is also toxic to aquatic animals, plants, and bacteria. Cr3+ is 100 times less toxic than Cr6+. In humans and in small quantities, chromium is an essential nutrient required for sugar and lipid metabolism, but in excess it may cause cancer and allergic skin reactions.