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On the tungsten carbide world build China 's future
2017 National Entrepreneur Day and one of the important events of the annual meeting of Chinese entrepreneurs, "Tungsten Carbide Industry Summit and Production and Demand Cooperation Matchmaking" held in Zhuzhou City, Hunan Province, the top domestic tungsten carbide materials experts and entrepreneurs gathered together, To explore the application of tungsten carbide materials research and cooperation and cooperation for the "Made in China 2025" to seek "strong gluten bone bone" good policy. The Ministry of Industry and Industry Ministry of raw materials, deputy director of Miao Zhimin, Hunan Province, chairman of the letter by Xie Chaoying attended the meeting, Zhuzhou Municipal Committee, Municipal People's Congress Chairman Mao Tengfei speech.
Zhuzhou is China's production, research, sales and export as one of the largest carbide industry base, tungsten carbide is one of Zhuzhou five strategic industry one of the important pillars. At present, Zhuzhou City, there are 106 tungsten carbide production and processing enterprises, accounting for 226 of the country's 486, cemented carbide total of 9,000 tons, accounting for about 1/3, NC blade for 82 million, accounting for the country's production and sales Of the 68%. In recent years, with the "Made in China 2025" plan and "revitalize the real economic strategy" steady progress, Zhuzhou City, tungsten carbide industry ushered in a good opportunity for development.
Mao Tengfei said Zhuzhou municipal government put forward to speed up the completion of the "one valley three areas" to achieve the "two walk in the forefront of" strategic objectives, whether it is Zhuzhou China Power Valley three power industry development, or " The construction of the important logistics base in the south and south regions of the opening and development zone, or the layout of the modular construction industry in the urban and rural areas, and the need for the basic industry of tungsten carbide, which is called "industrial teeth". "China made 2025 'focus on the development of the top ten areas, new materials focus areas, tungsten carbide is the most important, the provincial government to the carbide as the representative of the new materials industry as a key province to create strong areas of development Zhuzhou as Minmetals the largest regional business units, have the best conditions, we have to seize the opportunity to make the tungsten carbide industry bigger and stronger.
Summit Forum, invited four academicians and experts for the purpose of the report. Among them, the Chinese Academy of Engineering Huang Boyun report on the theme of "tungsten carbide help" made in China 2025 '", Chinese Academy of Sciences Ge Changchun report theme" strategic emerging industries in some key material needs and research status ", Chinese Academy of Engineering Tan Jianrong report theme" Intelligent Manufacturing and Manufacturing Services: Key Technologies and Enterprise Applications ". In addition, 29 enterprises such as Tungsten High-tech Materials Co., Ltd., Zhuzhou Tungsten Carbide Group Co., Ltd., Yangquan Coal Group Huayue Machinery Co., Ltd., China Railway Construction Industry Co., Ltd. and China Southern Airlines Industrial Co., Ltd. signed 17 Production agreement.
Chinese Academy of Engineering Huang Baiyun in the meeting after the interview with the Red Net reporter. Huang Bo Yun said that tungsten carbide is the backbone of China's manufacturing industry, Zhuzhou tungsten carbide industry as China's leading carbide, the future of major responsibilities. At the same time, he has just passed the success of the C919 large aircraft and carbide combination, the interpretation of his field of hard alloy must be harder, higher, more refined understanding. Huang Zuyun said: "C919 has Hunan elements, such as landing gear and brake system, which are the core components of the aircraft, landing gear carbide material role can not be replaced.Zhuzhou tungsten carbide is the first batch of China's first alloy industry, 'Made in China 2025', all areas are inseparable from tungsten carbide, we must be stronger and bigger, this is our Chinese dream.
China Minmetals network structure of tungsten carbide complete sets of technology to enhance the international competitiveness of China's tungsten carbide
Tungsten carbide is an important category in new materials, is "China made 2025" delineated advantages and one of the strategic industries, China Minmetals Corporation owned Zhuzhou Tungsten Carbide Group Co., Ltd. (hereinafter referred to as "strain hard group") in the country to take the lead Network structure of tungsten carbide research, through the joint technical research in Central South University, successfully developed a network structure of tungsten carbide complete sets of technology, the Office of Science and Technology of Hunan Province reached the international leading level, changed the past 20 years, China's overall strengthening of tungsten carbide products technology development Slow and unfavorable situation for the development of high-end tungsten carbide products and traditional tungsten carbide product quality improvement provides a new technical means.
The research and application of tungsten carbide are of great significance to support the construction of major national projects, to promote the transformation and upgrading of traditional industries and to build new advantages of international competition in China's manufacturing industry. At present, China's conventional tungsten carbide products difficult to achieve advanced excavation technology and service environment changes in the requirements, seriously restricting the major projects and related downstream industry development. Mesh tungsten carbide is the new direction of international tungsten carbide research, compared with the existing technology, in the wear and tear requirements, especially supporting heavy duty drilling equipment and drilling hard rock layer has obvious advantages. Over the years, the world's tungsten carbide countries have attached great importance to the technology research, but did not make a breakthrough.
The company is the strongest in China's tungsten carbide field, the highest market share of the company, with China's well-known trademark "Diamond" trademark and Tungsten Carbium State Key Laboratory, its research and development of the network structure of tungsten carbide technology to composite materials As a means to improve the wear resistance of materials through high hardness, high toughness matrix effectively resist the crack propagation to ensure the overall toughness of the material, thereby significantly improving the coordination of the key mechanical properties of tungsten carbide, especially suitable for rock drilling and other wear and tear, High efficiency, high efficiency, environment-friendly, structurally controllable, easy to large-scale industrialization, and the existing equipment and process fit high degree of characteristics.
The rapid development of the solid-scale structure of tungsten carbide plant, the first in the world to achieve a large-scale industrial production, the establishment of the world's first and only an annual output of 200 tons of mesh alloy production line, developed a Better toughness and wear resistance matching drilling new materials, products in Australia, Brazil and large domestic mines, oil field field test shows that its service life exceeds the level of foreign advanced products, especially in iron ore, quartzite and other high hardness , Dense rock, product life than foreign high-end products increased by more than 1 times.
At present, the plant hard structure of the tungsten carbide has completed the cumulative output of 850 tons, more than 90% of related technology products directly or assembled into a diamond into the international market, the output value reached 400 million yuan, driven by the relevant industry added value reached 2 billion yuan, thus Significantly improve China's tungsten carbide products and supporting the international competitiveness of drilling tools, greatly improving the international image of China's drilling rig.
The world's top ten most hard materials, diamond even ranked 10th
In fact, it is difficult to determine what the hardest material in the world is. Depending on what type of strength we are discussing - tensile strength or shear toughness? Yield strength or hardness Therefore, the definition of strength is not unique, the following we will introduce ten kinds of materials, from different angles to analyze its strength.
10, diamonds: In terms of hardness, diamonds can be described as unparalleled, which is why it is basically impossible to be scratched. Diamonds are formed by the close together of carbon atoms, which are often used for drill bits, sandpaper and saws, etc., can be cut, grinding, polishing and so on. However, although diamonds are the hardest, but not the most powerful, when you hit it with a hammer, it will be broken into pieces.
09, spider silk: Spider silk has a very high tensile strength. It can withstand higher than the tensile strength of steel, but also can be stretched very long. The highest strength spider silk comes from Madagascar's Darwin bark spider, which makes one of the world's largest spider webs.
08, carbon / carbon composites: There are many kinds of carbon-carbon composites, but all the materials have good strength. They can resist the huge tension, can also absorb a lot of force before cracking. Because of its very light quality, so this complex can be used for aircraft engines, can also be used for space shuttle shells and intercontinental ballistic missile head cone.
07, osmium: Osmium is a platinum group of metal chemical elements, when the osmium monomer is obtained, it is a very hard metal, with blue, and is hexagonal crystal structure. It can be used for pens, electrical contact, etc., can also be used in areas requiring extreme durability and hardness.
06, martensitic aging steel: Maraging steel has high strength and toughness, and has good ductility, they can be used for aerospace and mold and so on. Martensite aging refers to the aging of martensite, hard tissue often appear in steel.
05, metal glass: This glass is made of palladium microalloy and has a chemical structure that, while maintaining its strength, can counteract the inherent brittleness of the glass. Its density is not high, and lighter than steel, and aluminum and titanium almost.
04, wurtzite type boron nitride: The structure of the wurtzite boron nitride is very similar to that of diamonds, but diamonds are formed by carbon at high pressure for a certain period of time while wurtzite boron nitride is formed at high temperature and high pressure conditions during volcanic eruptions. Hardness is 18% higher than diamonds. Similar to diamonds, wurtzite boron nitride can be used in areas where cutting tools and the like require very high hardness.
03, hexagonal diamond: This may be the hardest material of nature. It is similar to diamonds, is composed of carbon atoms, but its arrangement is not the same. The hardness of hexagonal diamond is 58% higher than that of diamond.
02, graphene: Graphene also has a single layer of carbon atoms, arranged in a honeycomb. In its crystalline form, graphene is the highest in the measured material. The manufacture of graphene is difficult, but scientists have been able to obtain a screen-sized graphene sheet by chemical vapor deposition in which graphene grows on a copper substrate. Its potential applications include for displaying screens and more.
01, vulcanized alkyne: Even if it is only a string of single atoms, but the vulcanized acetylene tensile strength is twice the graphene precursor, tensile stiffness is three times the diamond. It is stable at room temperature and can be predictably crosslinked with other chains when stored together. Although its structure is simple, but its strength is 200 times the steel.
Production of Tungsten Carbide by Thermo - reduction of Tungsten Concentraes
Abstract :A high quality tungsten carbide production technique by alumintherm reduction of tungsten concentrates was recommended. The tungsten carbide produced satisfied the requirements of Russian technical standard and can be used for manufacturing drilling instruments and hard metals.
Key words :tungsten concentrate ;thermo - reduction ;tungsten carbide
With the traditional process from the black tungsten concentrate or white tungsten concentrate production of tungsten carbide, usually have to undergo the production of ammonium paratungstate, tungsten powder preparation and carbonation and many other processes, high production costs, long process.
To reduce the production cost of tungsten carbide, a very intuitive way is to reduce the production process from the mineral raw materials to the production process. In recent years, in the tungsten carbide production process, people pay special attention to high temperature carbonation. High-quality tungsten carbide can be obtained due to the very complete carbonation at high temperatures, the reduction of free carbon content and lattice defects.
United States Kennametal Inc company developed Menstruum tungsten carbide production method. The method is based on the direct production of tungsten carbide from tungsten concentrates. A mixture of tungsten concentrates (white tungsten concentrates or black tungsten concentrates) and Fe3O4, Al, CaC2 or C is exothermic after ignition with an ignition agent. The reaction is self-° C to produce WC, Fe, CaO and Al2O3. Metal products WC, Fe and so the formation of the bottom phase, and a variety of oxide composition furnace Slag phase. The Menstruum process was carried out in a round kiln, and the entire carbonation process was completed in 60 min to obtain about 22 t tungsten carbide. The bottom phase contains about 65% of the tungsten carbide, the balance of Fe, Mn and excess reducing agent metal Al. After separation from the slag, the bottom phase is broken, the excess CaC2 is removed with water, and finally the base metal is dissolved with the mineral acid to obtain coarse particles of tungsten carbide. The tungsten carbide produced by the Menstruum process can be used to make surface hardened layers and high impact non-machining applications.
In recent years, the Russian Institute of Chemical Technology developed tungsten concentrate "furnace" aluminum thermal reduction method . Reliable autothermal reduction of tungsten directly from the concentrate at high temperatures and carbonization. Raw material tungsten concentrate contains 55% to 60% WO3. Aluminum thermal reduction is carried out in graphite, steel or steel crucibles. Reduction and carbonation process is very fast, only 3 ~ 5 min. The heat released by the reaction is sufficient to completely melt the reaction product and to allow the metal phase containing tungsten carbide to be well separated from the slag phase.
The metal phase obtained by the aluminum thermal reduction method is 55% to 75% of tungsten carbide, 15 to 20 percent of iron, 1 to 4 percent of excess reducing agent, and the remaining metal impurities (Mn, Ni, Cu, etc.) ) Less than 2%, and a small amount of slag inclusions. The slag phase is a mixture of CaO · 2Al2O3 and CaO · Al2O3. The metal phase was crushed to 150 m and the resulting powder was leached with hydrochloric acid to remove the acid-soluble product, i.e., the final product tungsten carbide was obtained.
X-ray diffraction analysis shows that the product contains only one phase of tungsten carbide. The chemical composition of tungsten carbide conforms to the Russian technical standards TY48-19 - 265 - 91. The quality of the product tungsten carbide is higher than that of the conventional process. The carbon content is reduced to 0101%, and the lattice defects are reduced, without W2C, Mo2C and Fe3W3C. The molybdenum in the scheelite enters the lattice of the tungsten carbide and does not produce a separate Mo2C phase. This is very important for the manufacture of cemented carbide. Products tungsten carbide impurities (including Fe) meet the requirements, Fisher's average particle size of 9μm. Russia's experience has shown that the product can be used for drilling tools and carbide production.
High quality products, simple process and low production cost is the basic characteristics of the production of tungsten carbide by the hot reduction of tungsten ore concentrate.