Raw material mapping in selected areas of Rajasthan and West Bengal and their suitability for use in low carbon cement production

Abstract

Low carbon cement is a ternary blended Portland cement with clinker factor as low as 0. 40. It uses the synergetic hydration of clinker, calcined clay and crushed limestone to achieve comparable properties of commercial cements. One of the major components of low carbon cement is calcined china clay having a kaolinite content as low as 20%. The present report discusses the availability of required clays in two surveyed areas of Rajasthan and West Bengal. Characterization of clays have been performed through various techniques and their suitability established from thermo-gravimetric analysis supplemented by mineral and chemical composition. Medium grade china clay (40-60% kaolinite) is abundantly available in Rajasthan, whereas very high grade (60-80% kaolinite) is commercially available in West Bengal. It was difficult to get low grade china clay under commercial terms and conditions although it is dumped as wastes in and around mine areas. All the various grades of china clay were found to be suitable for use in low carbon cement by replacing clinker.