Gypsum mine

The late 60s, early 70s, due to the introduction of new building materials and development, the state attaches great importance to the basis of gypsum industry - gypsum mine construction, a large number of investment, Nanjing gypsum mine, Dawenkou gypsum mine, Pingyi gypsum mine For the gypsum mine, Jingmen gypsum mine, Lingshi gypsum mine and other large and medium-sized gypsum mines have been put into operation. These large-scale gypsum mine, mechanization process is higher, China's gypsum ore production accounted for about 40% of the total. In 1995 the national gypsum production 17.8 million tons, 2000, about 18 million tons. But compared with the foreign industrial countries, there is a big gap. Due to management problems, the development of deep processing of products, market competition and mechanisms and other reasons, the mine is not good, or even bankruptcy. With the reform of state-owned enterprises, mechanism conversion, asset restructuring and new product development and a series of changes, the gypsum mine is expected to develop.

2. Building plaster.

Production scale from an annual output of thousands of tons to 10 to 20 million tons of large-scale high degree of automation of the production line, from a simple β-hemihydrate gypsum to dozens of different properties, a variety of uses of gypsum cement. At present, has been able to replace some of the imported models of gypsum powder, self-leveling materials, adhesives and other high-grade materials, domestic powder gypsum has been in Beijing, Shanghai and other places to be applied. Building gypsum powder has greatly improved the quality of products, building gypsum, model gypsum national or industry standards developed and carried out several amendments.

Production process from the early to burn (dehydration) grinding process after the development of grinding to burn and dehydration grinding the integration of new technology, production equipment from the soil frying pan, small rotary kiln development to large-scale integration of dehydration grinding Vertical mill, cement production in the advanced cyclone preheater in Shandong Province Taihe Group has been a very good application, energy saving and efficient from the mill, vertical fine grinding machine and oil boiler and other advanced equipment is also a number of enterprises to promote the use of .

3. Gypsum board.

In 2000, the production of paper gypsum to the country has exceeded 100 million square meters. According to incomplete statistics, coupled with foreign joint ventures or gypsum board total production capacity will reach 400 million square meters. Product quality, variety and function increased, has gradually open up the domestic market and bulk exports. The cost of plaster board plummeted, about the surface and the composite application of gypsum board technology has made great progress in market competitiveness and share greatly increased.

It is worth mentioning that, Taihe Group in Shandong Province take full advantage of the advantages of joint-stock enterprises and staff enthusiasm, relying entirely on their own strength to transform three annual output of 10 million square meters of plaster board production line, expansion of a paper production line, With an annual output of 200,000 tons of phosphogypsum production line, has its own modified powder plant, foam agent plant, glass fiber processing plants. They try to use the domestic advanced new technology, new technologies, new equipment, greatly reducing the investment, improve the yield and quality, reduce energy consumption and cost, product competitiveness. 2000 sales of 40 million square meters of gypsum board, profits of 20 million yuan, has become China's largest gypsum board manufacturers, accounting for 1/3 of the domestic market last year, nearly one million square meters of plaster board Export to the United States.

4. Gypsum block, strip and other new wall materials.

At present, both domestic units with an annual output of 10,000 square meters of soil block equipment, but also the introduction and domestic production of 20 to 60 million square meters of mechanized production lines. It is understood that public Shandong Province has been built or ready to build 20 to 600,000 square meters of block production line 4 to 6, Linyi Red Chemical Group reported the introduction of modern gypsum block production line of the project, Tai'an, Jinan, Qingdao and other places There are a number of different sizes of block production line, and will be the main raw material of phosphogypsum. Therefore, Shandong Province, China is not only a large plaster board production, gypsum block is also an important new production base of the wall. In addition, Jiangsu, Hubei, Sichuan, Shanxi and Guangdong and Guangxi provinces gypsum block and strip have a certain development, is expected in 2010 domestic total output of about 20 million square meters.

5. Gypsum decorative materials.

Gypsum variety of decorative materials, colorful, large amount of wide. Guangdong wide gypsum company, Zhuzhou Taiwan Joint Corporation, Beijing, Shanghai, Dalian and many large and medium-sized cities or the country can produce and develop a variety of plaster decoration materials. After a number of Pijian improve, a mechanism for reporting, all kinds of high-strength, moisture, fire and has a green function of the plaster decorative panels, plaster lines, lamp panels, door posts, arch door public security office and other decorative products continue to emerge. In addition, with sound-absorbing, radiation protection, fire-resistant decorative gypsum board is or will be applied. 2010, the total output of gypsum decorative materials will be around 300,000 tons.

6. Anhydrite.

China's hard stone resources are very rich, geological reserves of hundreds of billions of tons in the past exploitation of small. To the Nanjing gypsum mine as the representative of the development of a single anhydrite deposits for 30 years, the development and utilization of anhydrite has made great progress. Early with the same dihydrate gypsum, only as a cement retarder. With the development of the cement industry, due to the competition of the natural chemical dihydrate gypsum, the production value and the benefit of the mine are very low, only in the east, northeast and southwest areas. Not nearly 30 years, anhydrite in concrete expansive agent and special cement, anhydrite cement products and other aspects of the celebration with a great development. Under the care and guidance of Academician Wu Zhongwei, China's "expansive concrete", "concrete structure waterproofing" and inorganic waterproof material has been greatly developed, with an annual output of 400,000 tons of concrete expansion agent as the main raw material of anhydrite , Is expected to reach 1 million tons in 2010.

Recently, Hubei Daye Lingxiang Hongxing gypsum mine put into operation. The grade of anhydrite in the mine more than 90%, 1/3 in more than 95%, more than 90% whiteness, is the world may also be the best anhydrite ores. It can produce a good whiteness of the surface layer of whitewashed anhydrite, self-leveling material =, caulking joint materials and a series of decoration, decoration materials and walls; to produce high-quality high-performance concrete expansive agent and white cement; poultry, livestock , Aquatic feed good additives, but also edible fungi, soybeans, rape, fruit and other crops important culture medium; grinding fine anhydrite to replace the calcined gypsum point tofu; after ultra-fine, purified, especially the double 90 (2 (Including 90% micron, 90% whiteness) of quality products can replace light calcium, calcined kaolin, lithopone and some titanium dioxide used as rubber, plastics, coatings (including paint) and red functional filler.

7. Chemical gypsum.

Chemical gypsum is produced in the production and environmental management of waste emissions from the process, mainly include: the exclusion of phosphate production of phosphate gypsum, the production process of fluoride acid fluoride gypsum, citric acid production of lemon gypsum emissions, the manufacture of salt By-product of the gypsum, the treatment of flue gas in the toxic gases - sulfur dioxide and the discharge of gypsum and so on.

Shandong, Wudi, Zaozhuang, Qingdao and Sichuan, Guizhou and other places to establish a multi-application of chemical gypsum production of sulfuric acid, by-product of the cement plant, the Ministry of Chemical Industry plans to promote the 100 sets of "four or six projects" set (annual output of 40,000 tons Sulfuric acid, by-product 60,000 tons of cement). Copper Group, the introduction of Australia's technology and equipment, installation of an annual processing 300,000 tons of phosphogypsum production line, processed gypsum supply to Wuhu, Shanghai and other gypsum plaster factory, part of the production of building gypsum and products, Retarding agent and high water agent filling material. Chongqing Luohuang Power Plant introduced a set of flue gas desulfurization equipment in Japan, the annual row desulfurization gypsum 300,000 tons, as the region building gypsum powder, gypsum block, strip and gypsum decorative products, the main raw material (Beijing Thermal Power Plant also installed a set Desulfurization unit); Shandong Hongri Chemical Group successfully used phosphogypsum with local rich coal gangue residue production of sintered bricks. Shandong Taihe Group gypsum board in the paper into 30% of dehydrated phosphogypsum, paper also mixed with a small amount of phosphogypsum, in ensuring the quality of the premise, reducing costs for enterprises and the community brought a very good Of the benefits.

Gypsum new trend of high - tech products

1. Ultrafine, purified, modified anhydrous calcium sulfate.

At present, the domestic experts have dihydrate gypsum after not off, superfine, purification and modification of a series of processing, manufacturing into a high-end products known as Kay powder. It can replace lithopone, ultrafine calcined kaolin, talc, heavy calcium carbonate (or light calcium), can replace some of the titanium dioxide used as rubber, plastics, paint filler. As the water in my work after the affinity of calcium sulfate and organic materials, can be a large number of incorporation, the amount of light mixed with calcium or light calcium into the amount of more than 2 times the product strength, rigidity, surface hardness, acid resistance, Weatherability, thermal stability have increased, while the cost per ton of products that is down more than 200 yuan. According to their results, in Shanxi Jincheng has built processing plants for mass production. Kay powder has been in Jiangsu, Shanghai, Hainan and other places to promote the application.

According to the experimental data, gypsum professional committee of experts prepared in Hubei Daye Ling Township with high-quality hard gypsum processing micron-grade calcium sulfate for rubber, plastics and coatings, and kai color as will be very good application. The excellent anhydrite without calcination, but also can simplify some of the processing plant process, save energy, reduce costs, improve product competitiveness in the market, is expected to develop in large numbers.

2. Gypsum whisker (fiber calcium sulfate).

In the early 1990s, the Shanghai Academy of Building Sciences developed a gypsum whisker (up to 100), the main method of the ratio of gypsum whisker, using hydrothermal autoclave process, but the father is the laboratory results, did not stick to it, then do not understand it The role and importance. After that, Northeastern University and Shenyang Anglixin Material Company produced hydrothermal method to produce about 20 gypsum whiskers as the reinforcing material of nylon, and achieved certain results, and established an annual production capacity of 600 tons. Wugongda has also developed a patented technology for manufacturing gypsum whiskers. Shanxi, the event Yang some experts have also been studied. In Nanjing, Shandong, with the principle of atmospheric pressure recrystallization, chemical gypsum, natural dihydrate gypsum test, the manufacture of some dihydrate fiber calcium sulfate, due to process, equipment is not perfect, fiber length to diameter ratio of only 20 to 30, Mostly for the fiber bundle, also experimented with several dry, reborn water method, has not yet found a perfect process and equipment. The use of these fiber calcium sulphate in paper mills did not achieve satisfactory results.

According to the information: the international trade name of the gypsum whisker "ONODA-GPF", basically made by hydrothermal method, there are several semi-water and anhydrous. Gypsum whisker is mainly used in resin, rubber, paint, paper, reinforcing agent or functional filler, but also can be used for friction materials, building materials, sealing materials, insulation and flame retardant materials. Gypsum whisker has excellent performance, as enhancer can improve product strength of about 30%. The current international market price of 30,000 yuan per ton. We forecast the price of less than 10,000 yuan per ton. Gypsum whiskers is a harmless or harm to the human body is very small mineral fibers, only one trial production, the market is basically a blank, most people do not understand, will not use, always thought that the price is higher than the average filler Not dare to use. In fact, gypsum whisker (fiber calcium sulfate) is a good performance, low price (than silicon carbide, titanium dioxide and other fiber is much lower), but also green materials should be vigorously developed.

3. Lightweight, high strength, water, insulation plaster composite wall.

For a long time, many domestic units have developed a number of gypsum composite wall, such as light steel keel gypsum board sandwich plate composite wall, fiber gypsum board or gypsum particle board and keel composite wall, aerated (or foam ) Gypsum insulation board or block composite wall, gypsum and polystyrene foam board, straw board, honeycomb paper core, wheat straw core board, such as composite of large panels. In particular, fiber reinforced low alkaline main cement (GRC board) or anhydrite cement pressure plate and a variety of organic and inorganic core composite wall, both can do internal walls can also do the external walls. Conditional areas and factories, and architectural design, construction and construction units in close cooperation with the organization of the production of various assembly gypsum composite wall panels, roof and even the door between the boxes. This factory production of building components, and then on-site assembly, can improve the construction speed and quality, reduce costs, reduce labor intensity and environmental pollution, is the new building materials development direction.