Limestone Calcined Clay Cement (LC3)

Low carbon cement or limestone calcined clay cement (LC3) 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. Low carbon cement blends use calcined clay as pozzolanic material lowering the clinker factor. The major raw material in the production of LC3 is kaolinitic clays. Clays with a kaolin content greater than 35 % has shown appreciable properties. It is a common myth that kaolinitic clays are not available abundantly. Studies and feasibility studies indicate massive deposits of kaolinitic clays or more than billion tons exists in Africa, Asia and other continents. There are also very suitable deposits in Russia and Commonwealth of Independent States of kaolinitic clays and can be used for production of LC3. No new greenfield plants are necessary to produce LC3. The entire production process can easily be integrated into the existing production system. The only additional requirement is a rotary calciner for calcination of clays. Production of LC3 saves upto 40 % of carbon emissions and uses around 45 % of non-commercial grade raw materials. Depending upon the production conditions, choice of equipment’s and distance of clay availability, production of LC3 can be more than 25 % cheaper than conventional cement production.

Author: S. Maity

Section: Science and production

Keywords: limestone calcined clay cement, kaolinitic clay, clinker factor, low carbon cement