Comprehensive Comparison of Washed Kaolin and Calcined Kaolin

Comprehensive Comparison of Washed Kaolin and Calcined Kaolin

In the field of inorganic non - metallic materials, kaolin plays a vital role. Among various types of kaolin, washed kaolin and calcined kaolin each have unique characteristics. Below is a detailed comparison of their properties and applications.

1. Depolymerization Performance

Calcined kaolin undergoes a depolymerization process during calcination. This depolymerization significantly enhances its performance, making it particularly suitable for applications requiring high reactivity. On the other hand, washed kaolin maintains a relatively stable structure after washing and does not exhibit obvious depolymerization characteristics, thus performing differently in certain chemical reactions.

2. Whiteness

Whiteness is a critical parameter in many industrial applications. Calcined kaolin demonstrates a significant improvement in whiteness after calcination, meeting the demands of industries with high whiteness requirements, such as papermaking and coatings. It can impart a bright white appearance to products, enhancing their visual appeal. In contrast, the whiteness of washed kaolin does not increase significantly and is more suitable for fields with relatively low whiteness requirements.

3. Physical Properties

Calcined kaolin boasts a range of superior physical properties. It has high oil absorption, which allows it to effectively absorb oils and other liquids. Its high opacity makes it an excellent choice for applications requiring light blocking and covering. The porosity of calcined kaolin provides good adsorption capabilities, while its high hardness ensures durability and stability in use. Additionally, calcined kaolin offers superior insulation and thermal stability, enabling it to function well in high - temperature and electrically insulating environments. In comparison, washed kaolin has relatively lower physical properties. However, it still serves as a basic filler, providing certain filling and supporting functions.

4. Applications

Calcined kaolin is widely used in high - end fields. In the papermaking industry, it serves as an additive, improving paper quality and performance. As a functional filler, it is used in coatings to enhance coating properties, such as adhesion and weather resistance. It also finds applications in refractory materials and other high - end fields. Washed kaolin is primarily used in basic applications. In the papermaking industry, it functions as a filler, providing certain filling and covering effects. It is also used as a binder for refractory materials, leveraging the adhesiveness of the original soil to bond refractory materials.

5. Cost

The cost of calcined kaolin is relatively high due to its complex processing methods. These methods involve multiple steps and require advanced equipment and technology. However, the excellent performance of calcined kaolin often justifies its higher cost. Washed kaolin, with its simpler processing method, has a relatively lower cost. This makes it more cost - effective in applications with relatively low requirements.

6. Application Fields

Washed kaolin excels as a papermaking filler. Its strong covering power effectively covers paper fibers, improving paper appearance and performance. Its uniform particle size ensures even distribution in paper products, enhancing paper quality. In the refractory materials field, washed kaolin serves as a binder. It utilizes the adhesiveness of the original soil to bond refractory materials, ensuring the stability and durability of refractory products. Calcined kaolin is widely used in high - end paper and coatings. Its high whiteness and high dispersion provide excellent covering and coloring effects for high - end paper products. In coatings, it improves coating performance, such as adhesion and weather resistance. As a reinforcing filler for rubber and plastic, calcined kaolin leverages its amorphous structure to enhance the strength of rubber and plastic products, meeting the performance requirements of high - end rubber and plastic applications.

In summary, washed kaolin and calcined kaolin each have their advantages and suitable application fields. The choice between them should be based on specific application requirements, cost considerations, and performance expectations. Our company offers high - quality washed kaolin and calcined kaolin products to meet the diverse needs of customers in different industries.