Effects of Ultrafine and Calcining Treatment on the Hiding Power of Kaolin

Coal-measure kaolinite is a very important non-metallic mineral. The kaolin obtained by crushing, grinding and calcining has a series of excellent properties and has been widely used in many industries, especially the paint industry.

At present, the price of comon calcined kaolin products is relatively low, but its application in high-grade coatings is limited due to its unsatisfactory covering power. The effects of ultra-fine and calcination treatments on the covering power of kaolin were studied, and the results showed that:

(1) With the increase of particle size, the covering power of calcined kaolin gradually increases. The main reason is that the finer the kaolin particles, the greater the covering power.

(2) When the calcination temperature is higher than 850 °C, with the increase of the calcination temperature, the fine particles are sintered to form larger particles, which reduces the covering power of kaolin.

(3) The coal-measure kaolin is crushed, ground, and ultra-fine, calcined at 850 °C, and then disintegrated and depolymerized for a second time to obtain calcined kaolin with high covering power, which provides practicality for the application and deep processing of coal-measure kaolin. reference basis.