Cement is the primary binding agent in concrete, which is the most widely used building material in the world. There are several ways to make cement depending on your needs and resources. In this article, we will discuss three different methods of producing cement: Portland cement making, Fly ash blended cement making, and Hydrophobic cement making.

1. Portland Cement Making

Portland cement is the most common type of cement produced worldwide. It was invented by Joseph Aspdin in 1824 and named because its color resembled the natural limestone found on the Isle of Portland in Dorset, England. Here are the steps involved in making Portland cement:

a. Raw material extraction: The primary raw materials required for Portland cement production are limestone (rich in calcium carbonate) and clay, or shale (rich in silica and alumina). These materials are extracted from quarries using blasting techniques.

b. Raw material preparation: In this stage, the materials are crushed into smaller chunks using crushers before mixing them with other ingredients like sand, iron ore, gypsum, and fly ash.

c. Clinker production: The mixture is heated to temperatures of up to 1450°C in a rotating kiln. During this process, calcium carbonate reacts with silica and alumina to form calcium silicates, aka clinker.

d. Cement grinding: Once cooled down, clinker is ground into fine powder together with small amounts of gypsum to control the setting time of the final product – cement. The grinding process may involve ball mills or vertical roller mills.

2. Fly Ash Blended Cement Making

Fly ash blended cement is gaining popularity due to its eco-friendly nature and increased durability compared to ordinary Portland cement. Fly ash – a by-product from coal combustion power plants – replaces a portion of clinker in the final mix. Here’s how it is made:

a. Raw material extraction and preparation: Just like Portland cement, limestone and clay are extracted and crushed to the desired size.

b. Fly ash: The fly ash content in blended cement ranges from 15% to 35%. It is stored separately before blending with the clinker and gypsum during the cement grinding process.

c. Clinker production: The process for producing clinker remains the same as Portland cement making, but it uses less limestone as a raw material due to fly ash addition.

d. Cement grinding: Finally, clinker, fly ash, and gypsum are ground together, resulting in a fine powder known as fly ash blended cement.

3. Hydrophobic Cement Making

Hydrophobic cement is designed to protect structures against water damage. A hydrophobic chemical called oleic acid is added during the grinding process. The steps involved in making hydrophobic cement are:

a. Raw material extraction and preparation: Follow the same procedure as for Portland cement and fly ash blended cement.

b. Clinker production: Similar to traditional Portland cement, calcium silicates are produced in this stage by heating the raw materials.

c. Cement grinding: During this stage, while clinker is being ground with gypsum to form a fine powder, a small quantity of oleic acid or another suitable hydrophobic agent is added to create hydrophobic cement.

In conclusion, depending on your specific needs and available resources, there are several ways you can make cement—be it traditional Portland cement, eco-friendly fly ash blended cement or with added water resistance properties like hydrophobic cement.