Leaching kinetics for iron from partially laterised khondalite rocks by hydrochloric acid solution

Partially Lateritised Khondalite (PLK) rocks are the waste materials generated during the mining of bauxite. The major discolouring elemental impurity in the PLK rock is iron oxides; render it unsuitable for its use as a filler material. In this paper an attempt is made to remove iron by leaching using hydrochloric acid. The best condition found for the leaching study is 3 M acid concentration at 80°C temperature for 4 hours time period. The apparent activation energy calculated from the first order reaction kinetics is 40.72 kJ/ mol. The product is characterized by particle size analysis, surface morphology, mineral phases and brightness. The brightness of the product is found about 80%, which is suitable for filler industrial application.