KINETICS STUDY OF IRON LEACHING FROM KAOLINITIC CLAY USING OXALIC ACID

Abstract

The kinetics study of iron leaching from kaolin clay from the County of Agua Blanca (Mexico) was carried out using solutions of oxalic acid for iron dissolution. The effects of acid concentration and temperature were studied to determinate kinetics parameters during iron leaching in oxalic acid media. It was found that iron dissolution rate increased with increasing of concentration and temperature, respectively. Leaching results showed that iron dissolution from the kaolin clay could be due to a chemical reaction control. The energy of activation calculated in this work was of 50.32 kJ • mol-1, for the interval of temperatures from 273 to 333 K; which is characteristic of a process controlled by chemical reaction. According to the results shown above, iron removal is possible, and this can improve the economic value for this kind of kaolin clay, being possible its use in the ceramic and paper industries as raw material of high quality.