|
Owner of data set CEMEX Polska Sp. z o.o. |
Technical purpose Cement is a hydraulic binder, which means, a finelyground inorganic material which, when mixed with water,forms a mass, which sets and hardens as a resultof the reactions and hydration processes, maintainingstrength and durability even under water after hardening.The cement according to the EN 197-1 standard is calledCEM cement, properly measured and mixed with theaggregate and water, it should form concrete or mortarthat retains workability for a sufficiently long time,and after a specified time should obtain a certain levelof strength, and should maintain long-term stability ofthe volume.The CEM cements are made of different materials, butare statistically homogeneous in composition by qualityassurance in the production and material handlingprocesses.One of the main components of the cement is the Portlandclinker. For its production, calcareous materials(for example, limestone, chalk) and other natural orwaste materials are used, correcting the proportion ofthe 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 introducedinto a rotary kiln where they are sintered at1450°C.In Cemex Poland the clinker is produced in two plants(Chelm, Rudniki). The main fuels used in the clinker firingprocess are alternative waste-derived fuels. Yearby year, the share of the alternative fuels is graduallyincreasing, while the use of fossil fuels is decreasing.Among alternative fuels, there is the biomass for whichthe carbon footprint is zero.The amount of the CO2 calculated in accordance withthe European regulations for monitoring the productionof the CO2 for the plant in Rudniki in connectionwith the production of the clinker is 722 kg of the CO2/Mg of clinker, and in Chelm 725 kg of the CO2/Mg ofclinker.Cement is produced by the joint grinding of the mainconstituents 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 followingprocesses/modules were taken into account in theLCA analysis:
A1 – the production of raw materials: fuel extraction,raw material extraction, electricity production, alternativefuel production,
A2 – the transport: transport of raw materials,
A3 – the production of a product: production of rawmeal, fuel consumption for firing, consumption of theelectricity for grinding.The figure below (Figure 1) shows the cement manufacturingprocess from the quarry to the shipment (productionphase) in a schematic way. - |
