"The effects of oxidation on the floation of chromite and olivine were studied in an effort to improve chromite recovery from domestic sources. The flotation behavior of pure chromite, pure olivine, and a chromite gravity concentrate were investigated. Freshly prepared chromite floated well between pH 2.2 and pH 4.5, but floated poorly at pH greater than 5. Oxidation at 150 deg. C increased chromite floatability above pH 5 to about 30%. In contrast, oxidation did not measurably affect olivine flotation. This suggested that controlled oxidation may improve selectivity in the flotation of chromite from olivine. This concept was tested using a chromite gravity concentrate. Both flotation recovery and Cr2O3 grade increased slightly following oxidation of the concentrate. Although the benefit from oxidation was small, this result shows some promise for improving flotation selectivity using oxidation." - NIOSHTIC-2

NIOSHTIC no. 19950101

National Institute for Occupational Safety and Health