Cement is made by extracting and processing raw materials such as limestone and clay, heating them to around 1,450ยฐC to produce clinker, and then grinding the clinker into a fine powder.ย The result is the cement used to make concrete for roads, bridges, buildings and infrastructure around the world.
In this episode ofย EXPLAINED by Lion, we take a closer look at how cement is made and the engineering behind the cement manufacturing process.
What is cement made from?
Cement production starts in a quarry, where raw materials are extracted from the earth.
The main ingredient isย limestone, which contains calcium carbonate. Materials such asย clay or shaleย are added to provide silica, aluminium and iron, all important components in the production of cement.
After extraction, the rock is transported to the processing plant, where it is crushed and ground into a fine powder known asย raw meal.
How does the cement manufacturing process work?
Once the raw meal is prepared, it enters a large rotating kiln.
Inside the kiln, temperatures reach approximatelyย 1,450ยฐC. At this extreme heat, the raw materials undergo chemical reactions that fundamentally change their composition.
As the material moves through the kiln, carbon dioxide is released from the limestone, and the remaining components react with minerals from the clay or shale.
The result isย clinker: small, dark, rock-like nodules that form the basis of cement.
How does clinker become cement?
Clinker is not yet the finished product.
After leaving the kiln, it is cooled and ground into an extremely fine powder. During this final grinding stage, a small amount ofย gypsumย is added.
Gypsum helps control how quickly cement sets when mixed with water. Without it, cement would harden too quickly for practical use.
The final fine grey powder is the cement used as a key ingredient in concrete.
Why is cement production an important industrial process?
Cement may look like a simple grey powder, but producing it requiresย raw material processing, extreme temperatures, chemical transformation and precision engineering.
It forms the basis of concrete and plays an essential role in the construction of buildings, roads, bridges and infrastructure worldwide.
Watch How Cement Is Made | EXPLAINED by Lion
See how limestone and other raw materials are transformed into cement in this episode ofย EXPLAINED by Lion.
