Kaolin is a kind of rock with kaolinite minerals as the main component and reaching useful content, which can be soil or stone. China has many types of kaolin deposits, which are widely distributed and rich in resources, ranking second in the world (figure 1- 1). According to the data of the Ministry of Land and Resources, by the end of 2006, there were 3 18 non-coal kaolin deposits in China, with a basic reserve of 636 million t and a reserve of 2.31000, and a proven resource reserve of191400 million t [5]. Guangdong is the largest non-coal kaolin resource in China. Among them, the reserve of kaolin in Maoming Basin in western Guangdong ranks first in the country, and the reserve of basic kaolin reaches 280 million t, especially in the southern part of Maoming Basin, where the proven kaolin resources exceed 470 million t ... Shaanxi is close behind, followed by Fujian, Guangxi, Jiangxi, Hunan and Jiangsu.
Coal series kaolin is a unique kaolin resource in China, which is rich in resources. The proven prospective reserves and calculated reserves are 654.38+08.05 billion t, ranking first in the world [5]. It mainly exists independently in coal seam, roof and floor or independent coal seam in the form of gangue. Kaolin from China coal measures is widely distributed in vertical direction (geological age), and it is distributed in all major coal measures strata from Late Paleozoic to Cenozoic. The distribution law in the horizontal direction (geographical area) is also obvious. Late Paleozoic coal-series kaolin is mainly distributed in North China, Mesozoic coal-series kaolin is mainly distributed in North China, Northeast China, Inner Mongolia and Xinjiang, and Cenozoic coal-series kaolin is mainly distributed in Guangdong, Guangxi, Yunnan, Tibet and Taiwan Province Province in the south, with a small amount in Northeast China and Shandong. Among them, the late Paleozoic Carboniferous-Permian coal-series kaolin is widely distributed, with large thickness, many horizons and good quality, which has great development and utilization value, followed by Mesozoic and Cenozoic coal-series kaolin.
Figure 1- 1 Schematic Diagram of Kaolin Deposit and Occurrence in China [4]
Ⅰ —— Kaolinite clay rock types in non-coal bearing strata; Ⅱ —— Types of kaolinite clay rocks in coal-bearing strata
Second, the production status of kaolin
At present, there are more than 0/00 kaolin production enterprises at or above the county level and more than 700 township enterprises in China. In 2006, the annual production capacity of kaolin mines in China exceeded 6 million tons, and the concentrate output was about 3.6 million tons, of which mechanical soil selection was about10.8 million tons, mainly concentrated in Suzhou, Jiangsu, Maoming, Guangdong, Zhanjiang and Longyan, Fujian.
According to the data of 2004 [5], the main manufacturers in China are:
1) Guangdong Maoming Kaolin Technology Co., Ltd.: 1997 was completed and put into operation, mainly producing three series of products: paper coating, paint coating and ceramic glaze. At present, the annual production capacity of deep processing enterprises has reached 900 thousand t, and the actual output is 250 thousand t.
Other enterprises in Maoming include: Maoming Shan Ge Porcelain Clay Company, a joint venture established in 1997, with an annual mining capacity of 500,000 t; Maoming Petrochemical Mining Company was completed and put into operation on 1996, with an annual production capacity of 300,000 t, and the actual output in 2006 was130,000 t.
2) China Kaolin Company in Suzhou, Jiangsu Province, located in Yangshan, Suzhou, was completed and put into operation on 1975, with an annual output of 250,000 tons. In 2006, the actual output was 200,000 tons, part of which was soil washing.
3) Fujian Longyan Kaolin Co., Ltd., with an annual output of 600,000 tons of kaolin ore and more than 500,000 tons of concentrate; Mainly produces high-quality ceramic raw materials. After processing and modification, it can also be used in papermaking, rubber, paint, coating and so on.
4) Guangxi Yankuang Beihai Kaolin Co., Ltd., a large state-owned mining enterprise, was established in 200 1, with an annual production capacity of 550,000 t, and the actual output in 2006 was about 300,000 t, mainly used for ceramic production.
5) Guangxi Hepu Jinhai Kaolin Co., Ltd., with an estimated annual production capacity of 400,000 t (under construction).
6) The output of Chaozhou Feitianyan porcelain clay mine in 2006 was 6.5438+500,000 t..
Among them, kaolin from Suzhou, Zhanjiang and Longyan can be used as coating-grade papermaking raw materials and high-grade ceramic raw materials.
In addition, enterprises with an annual output of less than 65,438+10,000 t include Zhangzhou Weiya Kaolin Company (20,000 t), Guangdong Gaozhou Welfare Factory (40,000 t), Yunnan Lincang, Anhui Xuena Non-mineral Materials Co., Ltd. (30,000 t) and Zhanjiang Xindongcheng Mining Co., Ltd.; As well as Hepu in Guangxi, jiepai in Hunan, Hengshan, Songyang in Zhejiang, Jiaozuo in Henan, Shahe in Hebei, Xu Shui in Shanxi, Datong and other places, there are small manufacturers producing kaolin.
Coal-series kaolin: Some coal-series kaolin contains kaolinite with high purity and complete crystal form, which can be used to produce ultrafine calcined kaolin. Calcined kaolin in China started in 1990s, but it developed rapidly. By 2005, there were nearly 45 calcined kaolin enterprises of different scales in China, with a total production capacity of over 300,000 t and a production capacity of over 1 10,000 t. Most of them were small processing plants, with an annual output of several hundred to several thousand tons, mainly producing middle and low-grade products.
The main manufacturer is Huaibei Jin Yan Kaolin Development Company, with an annual production and processing capacity of 200,000 tons. In 2006, it produced 300,000 tons of raw ore, and the main product was calcined kaolin. Other enterprises with an annual output of 50,000 ~ 6,543,800 tons include Guangxi Beihai and Hepu. Jiepai and Hengshan in Hunan; Zhejiang Songyang; Shahe, Hebei, Xu Shui, Shanxi, Datong (table 1- 1).
Table 1- 1 Domestic Major Coal-series Calcined Kaolin Manufacturers [5]
Three. Import and export of kaolin
See table 1-2 for the import and export of kaolin in China. From the point of view of import and export, there are two characteristics: first, the price ratio of import and export is about 4 ~12; Another feature is that the volume of imported kaolin products has increased sharply in recent years, and the import trade volume far exceeds the export trade volume. This shows that with the development of industrial production and science and technology in China, the demand for high-grade kaolin for deep processing is increasing year by year. On the other hand, it also shows that a large number of kaolin products exported from China are low-grade products that are initially processed, while imported products are high-grade products.
The development and production capacity of deep-processed high-grade products in China is far from meeting the domestic market demand, and there is a big gap with foreign countries. In order to get rid of this backward situation, we must develop new materials with high added value, especially coal-series kaolin with unique characteristics and the largest reserves in China, so as to give full play to its resource advantages and improve economic benefits. According to the statistics of China Customs, the main export flows of China kaolin products are Hongkong, China, Taiwan Province Province, China, China, Japan, South Korea, Philippines, Thailand, India, Italy, Vietnam, Netherlands, United Arab Emirates and Indonesia. Imports mainly come from the United States, Brazil, Britain, Malaysia, Japan, North Korea and Indonesia. Kaolin produced in mainland China is mainly used in China, Taiwan Province Province and Japan, and is sold back to Chinese mainland at a high price after reprocessing.
Table 1-2 1996-2006 China Kaolin Import and Export Situation [5 ~ 6]
Note: China, Hongkong and Taiwan Province Province of China are the main exporters, followed by Japanese, Malaysian, Philippine and Korean. Imports mainly come from the United States and Britain, followed by Taiwan Province Province of China.