1 Please ments to evelien.******@ and wouter.******@ , Authors, and to io.******@ and Giancarlo Tosato (gct@), Project Co-ordinators ? IEA ETSAP - Technolo gy Brief I03 – June 2010 - .or g Cement Production HIGHLIGHTS ? PROCESSES AND T ECHNOLOGY STATUS – The manufacture of cement is a tw o-phase process. Clinker is first produced in a kiln system from calcareous (limestone, chal k or marl) and argillaceous (clay or shale) materials, with addition, in some cases, of small amo unts of corrective materials (sand, waste bauxite, iron ore). Various fossil fuels and waste fuels are used in this process to reach the reaction temperature of 1450 °C. Secondly, the clinker is ground with calcium sulphates and with industrial processes wastes such as blast furnace slag, limestone, natural pozzolana and industrial pozzolanic materials, . fly ash, silica fume and burnt shale. 90-150 kWh/t cement are used in the process. Two basic types of clinker production processes exist, depending on the way the row materials are prepared before entering the kiln system: in the wet method, water is added to form a wet thick slurry whereas the dry process is based on drying the bulk materials to form a dry powdered meal. T he choice of process depends on moisture content of the available raw material. When wet raw materials (moisture content over 20%) are
