Oxidation decomposition of chromite ore in molten potassium hydroxide

Oxidation decomposition of a Vietnamese chromite ore in molten KOH under atmospheric condition was investigated. The decomposition and the further leaching processes were briefly described, together with a discussion on the related thermodynamics and kinetics. During decomposition, the silica in the mineral was first destroyed, followed by the chromite spinel and the activation energy of this process is 35.53 kJ/mol. In addition, the effects of reaction temperature, oxygen partial pressure, weight ratio of KOH-to-chromite ore, chromite particle size on chromium extraction, and behaviors of chromium, aluminum, and silicon were examined.