Calcination process of kaolin

1、 Calcination Process of Liaoning Kaolin

During the calcination of kaolin, due to different calcination temperatures, different phases and characteristics of calcined products, the application directions and fields are also different. Therefore, calcination temperature is the key factor to produce different kaolin products.

Calcined at low temperature (600-1000 ℃), its kaolin products have high activity and are used to synthesize molecular sieves, aluminum salt chemicals and functional materials of plastics and rubber.

Calcined at medium temperature (1000 ℃ - 1200 ℃), its kaolin products have high whiteness and good opacity, and can be used in paper making and coating industries to replace titanium dioxide as structural pigment. It can increase the pore volume and loose thickness of paper coating, and reduce the loss of brightness and opacity during calendering.

Calcined at high temperature (above 1200 ℃), its kaolin products are mullite and cordierite, which are used to produce mullite grain dense casting molding sand, advanced refractories and special ceramics.

According to the different calcination temperature, the calcination of kaolin can be divided into incomplete calcination and complete calcination.

Calcination of incomplete kaolin: Calcination temperature is 650-750 ℃, dehydroxylation, density 2.4-2.5g/cm ³， It can be used as paper filler and coating.

Complete calcination of kaolin: the calcination temperature is 1000-1050 ℃, a small amount of mullite crystals have appeared under the electron microscope, and the density is about 2.7g/cm ³， The whiteness is above 90%. The good properties of fully calcined kaolin are very important for the production of coated paper, especially for low weight coated paper, and its use in high-grade paperboard coatings is also expanding.