Abstract:
Production of kaolin clay of very high purity, brightness and whiteness was undertaken in this study for the purpose of developing an economic pro cessing technique for working any local kaolin clay deposit. Clay materials were collected from locations such as Akure, Ifon and Ijero. The chemical analysis of Akure clay was carried out using the wet-leach technique while that of Ifon was obtained from a previous work by Delta Steel Company, Aladja and the various compositions showed that iron was responsible for colouration. Ijero clay was not analysed. Classification and jigging technique were employed at the primary pro cessing stage to separate the coarse impurities from the clay; and an oxide reductive bleaching technique was used in a secondary processing to remove colour. A greyish-white product was obtained from the initial red samples. The purity of this final product was determined by measuring the iron content with an atomic absorption spectrophotometer. Results showed that an integration of a multi-stage classification process and the oxide reductive bleaching process gave a good product; while jigging produces an unsatisfactory result. The results further indicated that the reductive bleaching process can be employed to remove the colour induced by iron from any kaolin clay and that the whiteness and purity of the final product can meet most industrial specifications.
