Cement is a fine powder which contains sand, limestone, clay and iron ores. It is the chemical composition of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite and gypsum.

Cement, when mixed with water, it becomes a paste and used as a binding material in the construction process. Cement is the main ingredient in concrete. Concrete is used to make hard stone-like structures which are formed by mixing aggregates and paste. A paste is the mixture of cement and water while aggregates are gravel and sand. The strength and durability of concrete are also determined by the quality of paste of cement and water. Concrete is often reinforced with steel rebar to maintain its structural integrity. Cement is also used in mortars, which is a thick mixture of water, sand, and cement. It is used to bind building materials, such as brick or stone together.

Cement production is an energy-intensive process which emits a huge amount of carbon dioxide. It is the third largest sector in terms of consumption of energy and production of carbon dioxide. For producing one tonne of cement, almost one tonne of carbon dioxide is generated.

There are different types of process for cement manufacturing, depending on technology. The processes are dry, semi-dry, wet and semi-wet. The dry processes are usually more efficient and use less amount of energy as compared to wet processes. In dry processes, dry raw materials are used in the mill without the inclusion of water, which are usually hard and strong and converted to a powdered form. On the other hand, wet processes use water for mixing raw materials in the mill. Increasing pollution and environmental regulations are encouraging the use of dry cement plants, and phasing out wet processing plants.