We see cement daily by simply walking on the sidewalk, but what is cement made of? And how is it made?
Cement goes through a six-step manufacturing process.
The first step is separating and extracting raw cement ingredients. The ingredients required to make cement are primarily limestone, sand, and clay. These products are then quarried and crushed.
The second step is grinding, proportioning, and blending. Once the raw materials are crushed, they are taken to a kiln to be combined with additives. Cement is generally proportioned into 80% limestone and 20% clay. Any raw materials are dried and then blended into a fine powder to be stored in silos and fed into a kiln.
The third step is the preheating of raw materials. This consists of utilizing hot gasses produced by the kiln, reducing energy consumption and making the cement-making process more environmentally friendly.
The fourth step is the most important step of the cement-making process. Here the clinker is produced from raw mix created between a chemical reaction of calcium and silicon dioxide compounds. For the clinker production to be successful, it has to follow the following sequence.
1) Evaporation of free water
2) Dehydration and formation of oxidized silicon, aluminum, and iron
3) CaO evolves, and CaO is produced through calcination
4) Cement clinker forms
This entire process will take approximately 20-30 minutes.
The fifth stage is cooling and final grading. After exiting the kiln, the clinker will cool down rapidly. This is the time when all the different additives are combined in order to create cement. Gypsum is added and ground to the clinker, which regulates the setting time and gives cement its most important property. Sometimes organic additives such as Triethanolamine are added as a grinding aid to avoid powder agglomeration.
After this process is the final grinding process. After being cooled, the materials are transferred to a rotating drum and ground into a fine powder that each pound contains 150 billion grains and is the final product, cement.
Cement is then packed and shipped off to retailers such as Unicon. We have an ample supply of cement currently in stock at all our locations.