Because the characteristics of whiteness , soft , easily dispersed suspension in water , with good acid -soluble , low cation exchange capacity , better fire resistance properties, high purity kaolin become an essential mineral raw materials in coating industry.
The mainly effect of kaolin in coating industry is filler and pigment alternatives.Adding a certain amount of the coating can improve the filling of the filler , grinding and mechanical strength of the coating layers.In coatings industry,kaolin is mainly to replace the white pigment,especially titanium dioxide.Different sizes and types of kaolin for different types of coating,coarse kaolin for need to dim the luster or flat paint,fine kaolin for producing high gloss paint,or for the manufacture of latex -like pigment, to make the coating has good opacity , corrosion resistance and anti-settling properties,to improve the hardness and quality of the film.The original kaolin production process was simply by air-drying and flotation,nowadays has been replaced by washing , strict control of particle size , calcined and surface treatment, thereby improving the quality of the product.In these reforms , the calcination is the most important step , so the scale is very large.Besides of the common kaolin’s characteristics,the calcined kaolin also has an irregular shape, having excellent optical properties , oil absorption and a high pigment volume concentration , not aging, abrasion and easily emulsified in water or an oil medium , with a high hiding power , etc., are widely used for coatings industry .
After filling the calcined kaolin in the paint,can be shielded UV radiation,to improve weatherability of the coating,to delay the chalking discoloration,enhance the mechanical properties of the coating and stain integrated self-cleaning,can bear acids,alkali and high temperature,to improve the heat and corrosion properties of the coating.Especially in interior and exterior paint , anti-corrosion coatings, powder coatings , heat resistant coating , insulation coatings, paint signs , waterproof coatings, paints and other specialty radiation functional coatings , the extensive use of high quality calcined kaolin.
The growth situation of the coating industry will undoubtedly promote the development of the upstream industry.Therefore , kaolin industry also need to constantly upgrade themselves,to meet the increasing market demand,to withstand the test from the market.