Preliminary Study on Treatment of Soil Enriched in Chromite Ore Processing Residue by Electrokinetics

Abstract

The effectiveness of the electrokinetic (EK) process in treating soil enriched in chromite ore processing residue (Cr–soil) was investigated. An electric gradient of 1.2 V/cm was applied to induce the movement of electrolyte solution in the soil cell for 17–43 days. Simulated rainwater was used as EK processing fluid. Results show low removal efficiency of total Cr (2–7%) because the insoluble form of chromite dominates in the Cr–soil. However, more than 95% of leachable Cr(VI) can be removed by controlling the pH of the processing fluid at 9.0 during experiments. The removal of Cr from Cr–soil was characterized by the high Cr(VI) concentration collected at the anode, and the presence of Cr precipitates collected at cathode. The electric energy requirement under all experimental conditions varied from 1.3 to 5.8 kW h/m