Kaolin, also known as white dry mud, pure kaolin with high whiteness, soft, easy to disperse suspended in water, good plasticity and high adhesion, excellent electrical insulation properties; with good acid solubility, very low cation exchange, good refractory and other physical and chemical properties. Therefore, kaolin has become a necessary mineral raw material for dozens of industries such as paper, ceramics, rubber, chemical, paint, medicine and national defense. It has been reported that kaolin is also used in Japan as a substitute for steel in the manufacture of cutting tools, lathe bits and internal combustion engine shells. Especially in recent years, the rapid development of modern science and technology, making kaolin more widely used, some high-tech fields began to use kaolin as a large number of new materials, and even atomic reactors, space shuttles and spaceships, high-temperature porcelain parts, also made of kaolin.　At present, the global total production of kaolin is about 40 million tons (the data belongs to the simple country and country production of the sum, which does not count the trade volume of raw ore, including more double counting), of which about 23.5 million tons of refined soil. The paper industry is the largest consumer of refined kaolin, accounting for about 60% of total kaolin consumption. According to the data provided by Temanex Consulting of Canada, the total global production of paper and paperboard in 2000 was about 319 million tons, and the total global use of kaolin for paper coating was about 13.6 million tons.　Kaolin in the paper industry has a wide range of applications. There are two main areas, one is the filler used in the papermaking (or paper copying) process, and the other is the pigment used in the surface coating process. For general cultural paper, the amount of filler accounts for 10-20% of the weight of the paper. For coated paper and paperboard (kaolin ore mainly includes lightweight coated paper, coated paper and coated paperboard), in addition to the need for filler, but also need pigment, filler, pigment with kaolin accounted for the proportion of the weight of the paper of 20-35%. Kaolin used in papermaking, can give the paper good covering properties and good coating gloss performance, but also increase the whiteness of paper, opacity, smoothness and printability, greatly improve the quality of paper. White dry clay is mainly sold to the production of ceramics.