Cr (Vi) Generation During Processing of Chromite Ore
Mining and processing of chromite ore has increased in recent years due to the ever-increasing demand of chromium containing products. Significant amounts of hexavalent chromium Cr (VI), an environmental pollutant, are unintentionally formed during processing of chromite ore. In this study, experiments were carried out in order to determine the factors that influence Cr(VI) generation during processing of chromite ore. These experiments include the effects of: dry and wet milling of chromite ore; heat treatment in a conventional and microwave oven at temperatures below 300oC and particle size. The data obtained in this study show that more Cr(VI) is generated during dry milling. Microwave heating of the chromite ore was found to produce more Cr(VI) than heating in a conventional oven. Cr(VI) generation was found to increase with decreasing particle size. From an environmental standpoint, the findings show that wet milling of chromite ore reduces hexavalent chromium release to the environment.
Keywords - Hexavalent Chromium, Chromite ore, Milling