Experimental processing of some of the Indian clays for commercial purposes

India has vast resources of different types of clays, which find industrial applications, either directly or after simple processing, in ceramic, paper, cement industry as well as in foundaries. Washing, flotation, magnetic, separation, electrostatic separation are some of the important processes that could be normally employed for dressing the clays to meet the purity required for commercial applications. As appraisal has been made in this paper on the researches carried out at the National Metallurgical Laboratory, on beneficiation of some of the clay samples, with a widely divergent range of objectives such as: (i) recovering sulphur from sulphur bearing clays, (ii) reducing iron content in clay for cement making, (iii) improving the colour brightness of clay for use in paper industry and (iv) determining the bonding effect of betonite for pelletisation purposes. Some specifications for certain industrial applications of clay samples have also been included within the text of this paper.