Diatomite is a typical siliceous biosedimentary rock. Its chemical composition is mainly SiO2, and also contains impurities such as Al2O3, Fe2O3 and alkali metals. Biological remains such as spores such as freshwater sponge bone needles and endospores of golden algae are often accompanied in non marine diatomite, and siliceous biological remains such as silicon flagellates and radiolarians are often accompanied in marine diatomite. In addition, various clay minerals and clastic minerals are often involved. SiO2 in diatomite is different from SiO2 in minerals and rocks. It is usually called diatom silica, which is biogenic. The correct English word for diatomite is diatomite or diatom earth. China also has different names for diatomite, such as white mud, clay, mountain powder, diatomite and Guanyin soil.

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（1） Geological research and development

The study of diatomite abroad began in the 19th century. Diatomite was discovered in the southwest of Missouri in 1870. It was mined and utilized in 1872, and the American diatomite company was established.

The research on Diatomite in China began in the 1930s. In 1935, Professor Yang Zhongjian discovered diatomite deposit and carried out geological research while doing geological work in Linqu County, Shandong Province. Since the 1950s, especially in recent years, great progress has been made in the geological research and exploration of diatomite and its related fields.

The theoretical research on Fossil Diatoms related to diatomite in China began in 1962. It has systematically studied the flora combination, sedimentary environment, lithofacies paleogeography, ecology and structural structure of Fossil Diatoms. It has played an important role in geological exploration and deposit evaluation of diatomite resources, and achieved great results. Since the 1950s, the geological research of diatomite in China has been continuously carried out in the departments of geology, mining, chemical industry and metallurgy. A large number of diatomite resources have been found in 14 provinces (autonomous regions) in China, and there are 34 mining areas with proved reserves.

The development and application of diatomite resources in China began in the 1940s. Since Mr. Yang Zhongjian discovered diatomite in Linqu, Shandong Province in 1935, it has been at the primary level of producing and processing raw soil until the mid-1950s. It was not until the late 1950s that China's sulfuric acid industry urgently needed to solve the problem of shortage of catalyst support sources that the chemical industry began the test work of domestic diatomite, and successfully used the diatomite in Linqu County, Shandong Province to produce the first generation vanadium catalyst support. In the early 1960s, Tongji University successfully developed diatomite filter aid by using diatomite from Shengxian County, Zhejiang Province. In 1966, it was put into mass production by Ningbo Jiangbei mineral powder factory (now known as Ningbo dye chemical factory) and Tongji University, creating a new situation of localization of filter aid in China. In the early 1980s, the demand for diatomite and its products began to rise year by year, which greatly promoted the development of diatomite industry in China. The geological research, development and utilization and product serialization of diatomite have also made great progress.

（2） Resources and development and utilization

China is rich in diatomite resources. By the end of 2000, diatomite deposits (points) had been found in 14 provinces (autonomous regions) (Jilin, Heilongjiang, Hebei, Inner Mongolia, Shandong, Shanxi, Zhejiang, Jiangxi, Fujian, Guangdong, Hainan, Sichuan, Yunnan and Tibet), but they are mainly concentrated in the East and southwest, with an estimated resource of 2 billion tons, Among them, the proved diatomite reserves in Jilin province reach 180 million tons and the prospective reserves reach 300 million tons, ranking the first in China. According to relevant statistics, according to the retained reserves of diatomite in China, the reserves of diatomite in Jilin Province account for 55.06% of the national total, followed by Yunnan, accounting for 20.12% of the national total, Zhejiang, Hebei, 7.27% and Sichuan, about 3%. Other provinces (autonomous regions) are Inner Mongolia, Fujian, Shandong, Guangdong, Hainan and Tibet in turn. Super large and large deposits are mainly distributed in Yunnan, Guangdong, Zhejiang, Jilin, Heilongjiang, Hebei and other provinces. The distribution of diatomite resources in China not only has obvious regionality, but also has certain differences in metallogenic age.

The output of diatomite in China in 1995 was about 200000 tons, mainly in Zhejiang and Jilin. According to the statistics of mineral commodity summaries in 1995, the output of diatom soil in the world in 1995 was 1.5 million tons, including 670000 tons in the United States, 250000 tons in France, 120000 tons in the former Soviet Union, 95000 tons in Denmark, 70000 tons in South Korea, 50000 tons in Germany, 50000 tons in Mexico, 40000 tons in Spain and 160000 tons in other countries. The output of diatom soil in China accounts for about 14% of the world's total output, ranking the third in the world. According to relevant data, by 2000, the annual consumption of diatomite will increase to 300000 tons, which can meet the demand for hundreds of years according to China's proved reserves.

Diatomite, as a non-metallic mineral, has been used for a hundred years. Because of its excellent properties such as light weight, large porosity, strong adsorption, good thermal stability, high melting point and corrosion resistance, it is widely used as filter aid, filler, catalyst carrier, thermal insulation material, adsorbent and bleaching material.

Diatomite ore in China has good quality, easy dressing, shallow burial, thin overburden, gentle occurrence and stable ore bed, so it is generally dominated by open-pit mining. Through cleaning, the diatom in diatomite is more enriched, so as to improve the SiO2 content of diatomite and meet the requirements of industrial utilization.

The production of diatomite in China is mainly concentrated in Tengchong, Yunnan, Changbai, Jilin, Dunhua, Shengxian, Zhejiang, Sichuan and Hebei. Other diatomite resource provinces (cities and autonomous regions) have production, but the production capacity and scale are small. In 1995, China's total production capacity reached 350000 tons / year. The product of diatomite after crushing, mixing, grinding and drying is generally called diatomite powder. The refined diatomite purified by water separation, acid treatment and other processes is called refined soil. Selected diatomite products using roasting method are called roasted diatomite. The diatomite roasted with flux is called flux roasted diatomite. The products formed by these beneficiation processes have many characteristics and wide applications, and their products can reach more than 500 kinds. At present, it is mainly used in the production of filter aids, fillers, thermal insulation materials, chemical fertilizers and reagent carriers, industrial adsorbents, explosive density regulators, etc. The use of diatomite in China has been expanding in recent years. It is mainly used as filter aid, filler, building materials, adsorbent, coating, thermal insulation materials, diatomite carrier and vanadium catalyst carrier, and some of them are exported.

China began to import diatomite products in 1965. Since the 1990s, the export volume of diatomite has been increasing and the foreign trade volume has been expanding. In 1995, the export of diatomite powder was about 134300 tons, mainly exported to Japan, Italy, the Netherlands, France, Belgium, South Korea and the United States, while the import of diatomite was about 3800 tons, mainly from the United States, Japan, France and other countries. With the development of diatomite industry in China, its export trade will continue to expand and its import volume will decrease year by year.