As an important new natural environmental pigment, kaolin has been widely used in paper making and occupies a more and more important position. It can not only improve the quality of paper, increase the added value of the product, but also meet the requirements of excellent quality and special paper products. In a long period of time, kaolin will be an ideal choice for high-grade coated paper pigment.
With the higher demand of the downstream users on the quality of kaolin products, it has greatly promoted the development of Kaolin mineral processing and purification, ultrafine grinding, calcination, surface modification, dehydration and other related technologies and mechanical equipment.
The main coloring matter in kaolin is iron, titanium and organic matter. Iron and titanium mostly exist in hematite, goethite, pyrite, pyrite, siderite, limonite, anatase and ilmenite.
The traditional methods for improving the whiteness of kaolin include physical and chemical methods. The main physical methods are magnetic separation, flotation and selective flocculation, and chemical methods include oxidation, reduction, oxidation reduction, acid leaching, chelating agent strengthening and microbial leaching.