4.23.3.1 Availability and Consumption

(1) Supply

China's bentonite supply in 1997 was estimated at about two million tons (data from the Chinese Nonmetallic Minerals Industry Association).

(2) Consumption

Bentonite has very wide uses. The consumption in drill well muds, iron ore pellets and founding is greatest. The United States is the largest producer of bentonite in the world as well as the largest consumer. The proportions of the consumption are 23% for iron ore pellets, 22% for drill well muds, 17% for founding and 38% for others. In recent years, the consumption structure of bentonite in the United States has changed somewhat. The consumption in the environmental protection engineering works is increasing steadily, of which the bentonite used in the manufacture of concrete formwork and sewage treatment has increased by 10 to 20% in five years. The consumption of bentonite in Japan is 35% for the founding industry, 20.50% for civil construction, 6.5% for drill well muds, 3% for pesticide carriers and 35% for soil improvement. The changes of the general consumption structure of the world's bentonite in the seventies, eighties and nineties of the 20th century are shown in Table 4.23.2.

Table 4.23.2 Changes of the general consumption structure of the world's bentonite (%)

China's bentonite has been applied in 24 fields, of which founding accounts for 52%, drill well muds 24%, iron ore pellets 8%, and others (mainly including the petrochemical industry, light industry, agriculture and building) 16%. Although the bentonite used in the other fields is small in amount, it has high value and good economic returns. For example, it can replace part of starch used in dyes of the textile industry, can be used as mineral gel to replace all the starch gel, can be used as high-duty bentonite for the manufacture of coating material to replace part of polyvinyl alcohol, and can be used as the binder of non-woven fabrics and gypsum board grains, the emulsified asphalt of pavement and roofing, insecticide carriers, waterproof material and various kinds of filling.

In terms of quantity of bentonite produced now in China, the supply and demand are essentially in balance; but in terms of the commodities, the supply of Ca-base bentonite exceeds the demand, while the supply of Na-base bentonite falls short of the demand; the production of activated clay cannot satisfy the demand because the production development is restricted by the supply of sulfuric acid and affected by the treatment of "three wastes" (waste gas, waste water and industrial residue produced during the industrial production). The development of the production of organic bentonite has long been retarded by the low technological level, incomplete special-use equipment and unstable quality of the products in addition to the too high production cost. At present the organic bentonite for domestic uses still depends on exports.

(3) Foreign trade

In recent years there has been competition on the international bentonite markets. The yearly average trade volume is about 3 million tons. The main exporters are the United States, Greece, Bulgaria, Italy, Ugoslavia and Spain, and the main importers are Canada, Germany, Britain, Belgium, Australia and Japan. The United States is the first exporter of bentonite as well as an international bentonite trade center.

At present, there is a crossing situation in the production, exports and imports of many countries on the international markets. The main reasons are as follows: ¢ÙThe bentonite quality and production technical levels of these countries are different. For example, Western Europe is short of high-duty bentonite, but its production technology is advanced; so it imports raw bentonite and exports processed products abroad. ¢ÚThe application field of bentonite has been expanding continuously; so although many countries have abundant bentonite resources, they still need to import some bentonite products with special uses. ¢ÛThe industrial technical levels of various countries are unbalanced and economic crisis exerts influence on some applied bentonite industries.

In 1997 China's bentonite export volume was 65,200 tons, with earnings of US $ 4.95 million, and the import volume was 1679 tons, valued at US $ 1.0089 million.

Although in China the volumes of imports and exports of bentonite have increased somewhat in recent years, in most cases we export high-duty raw material and primary products at a low price and import manufactured goods at a high price. The bentonite is mainly exported to Japan, the Republic of Korea, Singapore, Thailand and Hong Kong. The main exported product is Ca-base bentonite, but as this product is of limited use (mainly used in animal and plant oil decoloring and liquid purification), the export volume is not large. China mainly imports intensively processed organic bentonite from the United States and other countries, which are used in the manufacture of oil-base mud for oil drilling, paint (anti-settling agent and rheological agent), printing oil (thixotropic agent for high-speed printing oil) and lubricant grease (thickening agent), as well as cosmetics. China's bentonite import and export volumes and earnings (expenses) of foreign currency in 1994~1997 are shown in Table 4.23.3.

Table 4.23.3 China's bentonite imports and exports in 1994~1997


4.23.3.2 Trends

In terms of the quantity of bentonite produced by China now, the supply and demand are largely in balance; in terms of the commodities, the supply of Ca-base bentonite exceeds the demand, while the supply of Na-base bentonite falls short of the demand. Restricted by the supply of the raw material sulfuric acid and influenced by the treatment of the "three wastes", the production of activated clay is inhibited and cannot yet meet the demands. The quality of the organic clay is not quite stable; so most of the organic clay used in China depends on imports. According to the prediction of the development strategy of the building materials industry, the demands for organic clay in 2000 will be 2.50 million tons.

Bentonite is one of the clay minerals with a relatively wide application range and relatively high economic value in the world.

Na-base bentonite is scarce in the world but consumed in vast amounts; therefore, all industrial countries pay great attention to prospecting for Na-base bentonite and strive to lower the minable grade, increase industrial reserves of the available mines and strengthen the applied studies of concentration and selection of low-grade raw material. In foreign countries the industries are capital- and technology-intensive, so joint bentonite ventures including exploration, mining, processing and production of series products of various grades are set up. For example, there are international joint bentonite ventures in the United States, Britain, Greece and Japan, and these joint ventures affect the world's bentonite industry. In the future development, the industrial countries will still focus on the total use of bentonite resources, dressing and purification, as well as intensive processing technology, while actively conducting the development of the application field of bentonite, especially researches on oil purification, the oil distillation catalyst agent, environmental protection, artificial Na-base bentonite, activated clay and organic bentonite.

The development in the application of bentonite in China started late, and up to now bentonite is only used in large amounts in machinery founding, metallurgical pellets and oil drilling. In recent years, a number of new products have been developed and their demand on the market has great potential. According to the prediction of departments concerned, China's demand for bentonite in 2000 will be 2.50 million tons and the market of its products will be expanded gradually. In addition to the traditional application fields, the year of 2000 will witness great development in fodder, environmental protection and decoloring by bentonite adsorption and catalyst agents. In the future, according to the demands of the domestic and overseas markets, China will regulate the structure of bentonite products, use the resources in a rational way, mainly develop such series products as artificially modified Na-base bentonite, organic bentonite and activated white clay, and change the situation of export at a low price and import at a high price.

China is endowed with abundant bentonite resources. It is predicted according to the available explored minable reserves that it can fully satisfy the demands for China's bentonite production in the 21st century.