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In This Chapter A Critical Overview On The Cement Production Followed By The ...

In this chapter a critical overview on the cement production followed by the production methods for lightweight aggregates is presented to the reader.
3.2: Cement Production
The main ingredient for the production of cement is limestone of varying chemical compositions that are freely available in the quarries as argued by Sarah Gaventa (2006). The lime stone is processed and further chemicals are added to gain the cement of the necessary strength and compressibility. The following explains the production process briefly
The raw limestone of varying chemical combinations is first collected to prepare the raw mix where the limestone is mixed with minerals of minerals containing calcium oxide, silicon oxide, aluminium oxide, ferric oxide, and magnesium oxide. This mixture is prepared to a fine mixture which forms the raw mix for a typical Portland cement. This is then blended to form the raw blend where the raw mix is formulated to a very tight chemical formulation to gain the desired strength from the finished produce of the cement as argued by Sarah Gaventa (2006).
The raw blending process is conducted in a fashion where the relative content of each oxide in the chemical composition is kept constant throughout the production process in order to ensure that the properties of the final product is not altered. It is also argued by Sarah Gaventa (2006) very small changes to the calcium content in the raw mix may lead to large changes in the ratio of alite to belite in the clinker, and to corresponding changes in the cement's strength-growth characteristics (Sarah Gaventa, 2006). This makes it clear that the effective control of the raw mix is critical for the production of consistent quality cement to meet the demands of the structural application.
The next stage is the formulation of the clinker where the blend raw mixture is put through a complex chemical reaction process in a large cement kiln with temperature increasing over the length of the cylinder as argued by Sarah Gaventa (2006). The final product of the process is called clinker which is the final product of the cement produced in the solid form at the desired chemical combination. This is then put through a cement grinding process where the clinker that is produced is mixed with small amounts of calcium sulphate to grind the cement to the desired granularity in order to support the structural application.
Sarah Gaventa (2006) further argues that the major components that decide on the strength and quality of cement include the following
Clinker
Gypsum
Limestone
Blast Furnace Slag
The Blast Furnace Slag is one of the critical elements in contributing to the stability of the chemical reaction in the cement kiln as argued by Sarah Gaventa (2006).


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