Cement is manufactured through a closely controlled chemical combination of calcium, silicon, aluminum, iron and other ingredients.
Common materials used to manufacture cement include limestone, shells, and chalk or marl combined with shale, clay, slate, blast furnace slag, silica sand, and iron ore.
- Limestone (supplies the bulk of the lime)
- Clay, marl or shale (supplies the bulk of the silica, alumina and ferric oxide)
- Other supplementary materials such as sand, fly ash/pulverised fuel ash (PFA), or ironstone to achieve the desired bulk composition.
Composition of Cement
There are eight major ingredients of cement. The general percentage of these ingredients in cement is given below:
Percentage in cement