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Owner of data set CEMEX Polska Sp. z o.o. |
Technical purpose Cement is a hydraulic binder, which means, a finely ground inorganic material which, when mixed with water, forms a mass, which sets and hardens as a result of the reactions and hydration processes, maintaining strength and durability even under water after hardening.
The cement according to the EN 197-1 standard is called CEM cement, properly measured and mixed with the aggregate and water, it should form concrete or mortar that retains workability for a sufficiently long time, and after a specified time should obtain a certain level of strength, and should maintain long-term stability of the volume.
The CEM cements are made of different materials, but are statistically homogeneous in composition by quality assurance in the production and material handling processes.
One of the main components of the cement is the Portland clinker. For its production, calcareous materials (for example, limestone, chalk) and other natural or waste materials are used, correcting the proportion of the silicates and aluminates, such as: clay, sand, fly ash, iron-bearing additives or slag from the steel industry. All of these materials are crushed, homogenised and introduced into a rotary kiln where they are sintered at 1450°C.
In Cemex Poland the clinker is produced in two plants (Chelm, Rudniki). The main fuels used in the clinker firing process are alternative waste-derived fuels. Year by year, the share of the alternative fuels is gradually increasing, while the use of fossil fuels is decreasing. Among alternative fuels, there is the biomass for which the carbon footprint is zero.
The amount of the CO2 calculated in accordance with the European regulations for monitoring the production of the CO2 for the plant in Rudniki in connection with the production of the clinker is 711 kg of the CO2/Mg of clinker, and in Chelm 718 kg of the CO2/Mg of clinker.
Cement is produced by the joint grinding of the main constituents of the cement (for example, clinker, fly ash, blast furnace slag) with minor additional constituents, setting time adjuster and other additives.
Cemex Poland produces cement in three plants (Chelm, Gdynia, Rudniki).
The product phase (A1-A3, see Table 3) and the following processes/modules were taken into account in the LCA analysis:
• A1 – the production of raw materials: fuel extraction, raw material extraction, electricity production, alternative fuel production,
• A2 – the transport: transport of raw materials;
• A3 – the production of a product: production of raw meal, fuel consumption for firing, consumption of the electricity for grinding.
The figure below (Figure 1) shows the cement manufacturing process from the quarry to the shipment (production phase) in a schematic way. |
