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Owner of data set Lafarge Cement S.A. |
Technical purpose The main component of cements according to EN 197-1 is clinker. It is produced from raw materials such as limestone and clay, silica or other waste materials which are crushed, homogenized and fed into a rotary kiln. The raw materials are sintered at a temperature of 1450°C to form new compounds. Clinker consists mainly of oxides of calcium, silicon, aluminum and iron. In a second phase calcium sulfates and possibly additional cementitious or inert materials are added to the clinker. All constituents are ground leading to a fine and homogenous powder. The natural raw materials for cement production are mainly calcareous materials such as limestone, sand and aluminacontaining materials such as clay or shale, which are widespread. Alternative raw materials, such as different type of ash, slag or other waste materials are used in the process as substitutes for natural ones. Raw resource is preheated using input gases and then fired in a rotary kiln at a temperature of approximately 1450°C. Currently one of the main fuels used in the process is alternative fuel that is derived from waste and its share is growing. Cement production through the use of alternative fuels, tries to reduce environmental impact, which is one of the basic strategic assumptions of the company. Clinker is ground together with setting time regulator and other additives. The LCA assessment encompassed the production phase (A1-A3, see Table 3) and the following processes/modules: A1 – raw material production: fuel mining, raw material mining, electricity generation, alternative fuel production; A2 – transport: raw material transport; A3 – production of the product: raw meal production, consumption of fuel for firing, electricity consumption for grinding. |
