The main difference between white cement and grey Portland cement is their color and fineness. White cement gets its color from the raw materials used and the manufacturing process. The process of manufacturing white cement is similar to that of grey Portland cement. The article focuses on various aspects of white cement such as its manufacture, properties, uses, and differences.
Manufacture of White Cement
The process of producing white cement is similar to that of grey cement, but the choice of raw materials plays a crucial role in the manufacturing process. The presence of oxides such as chromium, manganese, iron, copper, vanadium, nickel, and titanium gives the grey colour to cement. However, when it comes to white cement, these raw materials are utilized in minimal amounts.
Limestone and clay are the primary raw materials used in the production of white cement. The manufacturing process is identical to that of Ordinary Portland Cement (OPC); the only difference is that the raw materials must be burned at a higher temperature, and the resulting product must be ground to a finer texture.
In conclusion, while the process of producing white cement is similar to grey cement, the key difference lies in the selection of raw materials. By minimizing the oxides that impart the grey colour, manufacturers can achieve the desired white colour in the final product. The production process itself is identical, although additional heat and increased fineness are necessary to create the high-quality white cement that is commonly used in construction and decoration.
Fig 1: Concrete made of White cement.
Following Raw material are used to make white cement
Limestone is a type of sedimentary rock that is characterized by its high carbonate content and low iron content. It is commonly used in construction and as a raw material for cement production due to its ability to harden when mixed with water.
Clay, on the other hand, is a type of soil that contains high levels of alumina and low levels of iron. It is commonly used in the production of ceramics, bricks, and cement due to its ability to harden when fired at high temperatures.
Oil, pet coke, and rubber are all materials commonly used as fuels in various industrial processes. Oil is a fossil fuel that is extracted from the earth and refined into various products such as gasoline, diesel fuel, and heating oil. Pet coke, short for petroleum coke, is a byproduct of the oil refining process that is often used as a fuel source in industrial processes. Rubber, on the other hand, is a natural material that is commonly used in the production of tires, hoses, and other industrial products.
Gypsum and Salenile are both mineral compounds that are commonly used in construction and building materials. Gypsum is a soft mineral that is commonly used to make plasterboard and other construction materials due to its ability to harden when mixed with water. Salenile is a type of rock that is commonly used as a building stone due to its durability and resistance to weathering.
Properties of White Cement
Table 1: Properties of white cement and their values.
| Properties | Value |
| Fineness | 395 m2/kg |
| Setting Time | 100 min |
| Compressive Strength | |
| 1 day | 21 MPa |
| 2 day | 38 MPa |
| 7 day | 61 MPa |
| 28 day | 74 MPa |
| Compact Density | 3150 kg/m3 |
| Bulk Density | 1100 kg/m3 |
| Brightness | 87% |
Uses of White Cement
White cement is a specialized type of cement used in prestigious construction projects and decorative works. One of its unique features is its ability to produce brightly colored concrete and mortars by incorporating inorganic pigments. This makes it highly suitable for use in architectural beauty, interior and exterior decorations, floorings, and ornamental concrete products such as idols. In contrast, grey cement is mostly used for construction purposes.
The whiteness of white cement makes it highly reflective, which is why it is commonly used in roads to improve visibility in highway medians. In addition, it is frequently used to manufacture precast members, such as cast stones of appealing appearance. However, white cement is relatively costly compared to other types of cement, which means that it is used selectively.
Overall, white cement is an excellent option for producing aesthetically pleasing and high-quality construction products. Its unique properties make it a popular choice for various decorative applications, but its cost means that it is not always the most practical option for every project.
Fig 2: Building constructed using white cement.
Differences between White Cement and Grey Cement
Table 2: Difference between grey and white cement.
| Properties | Grey Cement | White Cement |
| Raw Materials | Raw materials contain a high amount of Iron Oxide and Manganese Oxide. | Raw materials contain a very little amount of Iron Oxide and Manganese Oxide. |
| Fineness | Usually less fine than white cement. | Usually finer than gray cement. |
| Kiln Fuel | Coal, petroleum coke, fuel oil, natural gas. | Oil is used to avoid contamination by coal ash. |
| Energy Consumption | Low. | High. |
| Cost | Less expensive. | Expensive than gray cement. |