Abstract

The volume of cement production in the world has remained at the level of approxi mately 4.1 billion tons/year. The cement production process is energy intensive and is the world’s leading emitter of carbon dioxide. Therefore, the main activities cement plants are aimed at introducing technologies changes in production of clinkier.The construction industry is responsible for the majority of CO2 emissions to the atmosphere: the industry emits 30% of total CO2, building emits 28%, transportation is responsible for 22% of CO2, the production of building materials causes 11% of CO2 emissions, including the cement industry is responsible for around 7% of emissions CO2. Other industries are responsible for around 9% of CO2 emissions to the atmosphere. The process of burning raw materials for the production of clinker is the most important stage of the entire cement production process. Cement kiln dust (CKD) is waste generated during the production of clinker. The dust collected in the dust collectors is partly reused in the production process and some is stored. The storage method is not preferred due to its operations negative en vironmental impact. If the dust contains alkalis, chlorides, sulphates, or heavy metals, they cannot be recycled. Generally cement plants strive to reduce the formation of dust. About 1.5 tons of raw materials are used to produce 1 ton of clinker. After the extraction, grinding, and homogenization of raw materials, the process of calcination of calcium carbonate takes place. The source of calcium carbonate is naturally occurring limestone deposits, namely limestone, marl, or chalk. Then, to obtain clinker, calcium oxide is sintered with silica, aluminum oxide, and iron oxide at a temperature of 1450°C. Most often, clinker is fired using the dry or wet method in a long rotary kiln. After firing, the clinker is ground together with the binding regulator - gypsum and additives. To generate the heat needed to burn the clinker, fossil fuels such as petcoke, hard coal, lignite, and fuel oil or natural gas are used. Due to proecological activities, secondary solid fuels are used as alternative fuels as substitutes for fossil fuels. The amount of thermal energy obtained from their combustion currently accounts for about 85% of the total amount of thermal energy used in the clinker burning process. These changes lead to effective energy management through the efficient use of natural and alternative fuels.

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Authors (6)