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basic information to define the nature of silicon, silicon smelting process uses silicon grinding process ultrapure silicon metal silicon classification silicon metal powder metal powder grinding industry pioneer - deep Xiang-chu-chu mill mill The structure of silica fume particle size column processing mill commenced Edit this paragraph constitutes basic information Chinese Name: silicon metal Chinese alias: crystalline silicon; industrial silicon; microsilica; fume; polysilicon; silicon; silicon optical window; silicon English name: Silicon English Synonyms: silicon coating quality balzers; silicium; silicon, containing by weight not less than 99.99% of silicon; SiliconpowderNmesh; Silicon Monocrystalline; SiliconchipsNmm; SiliconrandompiecesNcm; Silicon wafer orientation P-doped; Silicon wafer orientation; Silicon powder; Siliconwaferorientation; Siliconwafer ; Silicon (low oxygen); Silicon (3 oxygen levels); Silicon chips (99.9999%); Silicon random pieces (99.5%); Silicon solution 1000 ppm CAS :7440-21-3 [1] EINECS :231-130-8 Molecular formula: Si Molecular Weight: 28.0855 HS CODE: 2804.6900 Edit this paragraph defines "silicon metal" (also known as our industrial silicon) is the mid-1960s there has been a brand name. It appears on the rise of the semiconductor industry. At present, the international general practice is to commodity silicon into silicon metal and semiconductor silicon. Silicon metal is composed of quartz and coke in an electric smelting furnace into the product, the main component of silicon content of about 98% (in recent years, 99.99% Si content is also included within the silicon in the metal), the remaining impurities being iron, aluminum, , calcium. Semiconductor silicon for fabricating a semiconductor device of high-purity metallic silicon. Is polycrystalline, monocrystalline form sold, the former inexpensive, the latter price expensive. Because of their different purposes and is divided into a variety of specifications. According to statistics, in 1985 the world total consumption of about 500,000 tons of silicon metal, silicon metal alloy which is used about 60% for less than 30% of organic silicon for semiconductors, about 3%, the rest for iron and steel smelting and precision ceramics. Edit this paragraph the nature of silicon Silicon is one of semi-metallic, formerly known as "silicon." A melting point of 1420 ℃, density of 2.34 g / cm 3. Hard and brittle. At room temperature, insoluble in acids, soluble in alkali. The nature of the metal silicon germanium, lead, tin similar, with semiconductor properties. Silicon rich in natural resources in the crust, after oxygen, accounting for a quarter of the total weight of the crust is stronger in the form of silica or silicates. Purest silicon minerals are quartz or silica. Silicon has two allotropic forms: one is dark brown amorphous powder, lively nature, can burn in air; another way for the nature and stability of the crystal (crystalline silicon). General silica and quartz for glass and other building materials, for the production of high-quality quartz alloys, metal and crystal. Edit this paragraph the use of silicon into silicon is used extensively for smelting ferrosilicon alloy elements for the steel industry, in a variety of metal smelting as a reducing agent. Silicon or aluminum alloy good component, the vast majority of cast aluminum alloy contains silicon. Silicon is the electronics industry ultrapure silicon raw materials, ultra-pure silicon semiconductor electronic devices made with small size, light weight, good reliability and long lifetime. Specific trace impurity doped silicon single crystal made of high-power transistors, rectifiers and solar cells, made of germanium crystal than good. In recent years, amorphous silicon solar cell research progressed very quickly, the conversion rate of more than 8%. Molybdenum disilicide heating elements maximum temperature up to 1700 ℃, has not aging resistance and good oxidation resistance. Silicon produced trichlorosilane can be formulated hundreds of silicone lubricant and water compounds. In addition, silicon carbide can be used for abrasive, high-purity silica produced high-purity quartz tube lighting metal smelting and important material. Eighties paper - silicon silicon people called the "eighties paper." This is because the paper can only record information, and silicon can not only record information, but also processing of information processing in order to obtain new information. 1945 produced the world's first computer, equipped with 18,000 vacuum tubes, 70,000 resistors, 10,000 capacitors, the whole machine weighs 30 tons, covers an area of ​​170 square meters, equivalent to 10 house size. Today, the computer, due to technological progress and material improvement in a fingernail-sized silicon chip that can accommodate tens of thousands of transistors; and have input, output, computing, storage and control information and a series of functions. Microporous calcium silicate insulation materials microporous calcium silicate insulation material is an excellent insulation material. It has a small heat capacity, high mechanical strength, low thermal conductivity, non-burning, non-toxic, tasteless, can be cut, easy to transport and other characteristics, can be widely used in metallurgy, electric power, chemicals, shipbuilding and other heating equipment and piping. After testing, energy efficiency is better than asbestos, cement, perlite, vermiculite and cement and other insulation materials. Special calcium silicate material used as catalyst carriers, in petroleum refining, automobile exhaust, and many other widely used. Edit this paragraph silicon silicon metal smelting smelting process is energy-intensive production of silicon metal production has a long history, with the national energy policy tightening and carry out energy conservation and new energy advocates, silicon metal has become the primary smelting products and processes, many domestic enterprises to build new energy metal silicon, polycrystalline silicon, monocrystalline silicon, solar cells and a series of recycling industry chain, the next few years will inevitably affect China's entire energy sector development and new energy applications. Here are some of silicon metal smelting technology and processes. 1, the production of chemical industry need for silicon production of silicon metal (silicon content of 98.5% mainly), the original is mainly metallurgical silicon, chemicals with metal silicon (silicon content primarily 99.85%) of the production is mainly from the 90 Since the mid some development, in recent years, China's chemical use silicon production and exports grew rapidly. 1999 -2001, China's exports to Japan chemistry of silicon has reached 22,000 tons, 30,000 tons, 40,000 tons, in 2001 China's exports to Japan accounted for Japanese chemical chemistry of silicon silicon imports more than 40% . Now China has begun adding chemical production and supply of silicon ranks of the country, the production of chemical enterprises with increasing silicon. As Shanghai Guangji Silicon Materials Co., Ltd. in 2002, fully discloses the carbothermal reduction smelting process, resulting in China in 2002 to 2004, silicon metal production capacity rapidly from an annual output of 100,000 tons, rising to 1.2 million tons. As a result of comprehensive sanctions Development and Reform Commission, 2006, actual production of silicon metal and then down to 70 million tons. Total months in 2006, only Shanghai Guangji Silicon Materials Co., Ltd. Daigo silicon plant in the successful construction of the Xinjiang border tons of silicon metal plant Jingxin plant. Other and new silicon plant. Chemical means with silicon and polycrystalline silicon for the production of organic silicon metal. From a global perspective, and now the consumption of metallurgical silicon with silicon than chemical consumption, but with the continuous development of science and technology, chemistry of organic silicon and silicon for semiconductor manufacturing and other areas continue to expand, widely used in the production silicone monomers and silicone polymers, silicone rubber, silicone building corrosion, water and the like, they have a high temperature, electrical insulation, resistance to radiation, water and other unique properties. For electrical, aerospace, machinery, chemicals, pharmaceuticals, defense, construction and other sectors. As the core of the electronic components integrated circuit, more than 95% is made of silicon semiconductors, the semiconductor industry is the backbone of modern information. The "information highway" of the extensive use of optical fiber cables, but also as a raw material in the production of silicon metal. Now the United States and the EU chemical consumption of silicon metal silicon accounted for more than half of total consumption. Chemical use silicon as an important foundation for high-tech fields and industries have been widely used, its consumption is stabilized growth. Under normal circumstances in the international market, per ton of chemical metallurgical silicon with silicon than the high price of 300-400 dollars. Therefore, from the meet export and domestic demand, or to raise economic efficiency of enterprises silicon metal, improve product quality, to develop chemistry with silicon production are necessary. 2, chemical raw materials in the chemical silicon silicon production, the raw material is a prerequisite for achieving good job. Quartz rock for silicon metal production of chemical raw materials, low ash carbonaceous material as the reducing agent. Electric furnace production of chemical raw materials mainly silicon silica and carbon materials. Carbon-based materials Youyi petroleum coke, anthracite or charcoal with high quality, can also be mixed with part of the charge to increase the ratio of resistors. Demand for raw materials with the necessary purity, good ability to respond in order to achieve the product specifications; reducing agent has a different ability to respond in order to fully react with quartz Shifa Sheng; charge with different ingredients, and both different grain size, in order to adopt a proper fit, make a positive impact occurred furnace charge. 2.1, silica mineral extraction process of silicon metal without slag process, chemistry of silicon smelting more stringent selection of the silica, not less impurity content, also requires a high mechanical strength and sufficient thermal stability, a suitable grain size. Best use of chemical silicon melting silica. In its natural state or as independent silica quartz minerals exist, or is almost entirely of silicon oxide is integrated into the rocks - silica, or silica sand forms exist. Production of chemical silicon oxide containing silicon impurities and adhesion of mineral matter, and some in the smelting process is completely restored, and some portion is reduced, some with the silicon compound into the product form or generate slag. This not only increases energy consumption, lower product quality, and gave the smelting process difficult. Therefore, the chemical used in a silicon smelting silicon oxide-containing minerals demanding chemical composition. Requires SiO2 than 99%, Fe2O3 less than 0.15%, Al2O3 is not more than 0.2%, CaO less than 0.1% total impurities not more than 0.6%. The silica used in the smelting must be washed prior to, the surface cleaning. Silica into the furnace require a certain size. Smelting silica particle size is an important process factors. Suitable particle size silica by silica type, furnace, capacity, operating conditions, and the type and size reductant and other factors, according to the specific conditions to determine smelting. Generally, 6300KVA three-phase furnace (Daigo silicon plant built in 1983), requires the silica particle size 8-100mm, 3200KVA three phase electric furnace, the silica particle size required 8-80mm, and the middle of the proportion of grain size bigger. Particle size is too large, because it is not sticky materials, and the reaction furnace ramming speed to adapt easily the unreacted silicon silica into the liquid, resulting in increase in the amount of slag, baked difficulties silicon reduced recovery, energy consumption increases, causing the furnace bottom up, affecting the normal production. Particle size is too small, although the reducing agent can increase the contact surface is conducive to reduction reaction, but the reaction gas produced in the process can not be discharged smoothly, the reaction rate will slow down. Particle size is too small. Impurities introduced will increase, affect product quality. Generally less than 5mm in the production of silica should not be used. 2.2 silicon smelting carbonaceous reducing chemical reducing agent used mainly petroleum coke, bituminous coal, charcoal. To increase the resistance of the charge, increased chemical activity, but also with gas coal, silica, coke, charcoal blue, semi-coke, low-temperature coke, pieces of wood. Chemical composition of the carbonaceous reductant, the primary consideration should be fixed carbon, ash, volatile matter and moisture. General requirements for fixed carbon to be high, reducing the required amount by reducing the ash entrained impurities, a corresponding reduction in the amount of slag, power consumption is reduced, reducing impurities in silicon chemistry. Carbonaceous reducing to a large resistivity, the porosity is higher. Burden resistivity depends carbonaceous reducing agent. Carbonaceous reducing a large specific resistance, good chemical activity, high recovery rate of the silicon. Petroleum coke is used as a reducing agent in the production of silicon metal lowest ash content, ash-containing 0.17-0.6%, 90-95% fixed carbon, volatile no more than 3.5% -13%. A silicon smelting chemical reducing agent with petroleum coke, because it is a low ash content, help to improve the product quality. However, due to petroleum coke resistance is small,2013 Nike Mercurial Vapor Superfly III White Blue Volt Football Boots Indoor Soccer Cleats Shoes , poor response, graphite under high temperature, the amount is too large, resulting in poor control of furnace conditions, resulting in the charge does not sinter, thorn fire seriously, high power consumption, baked difficult. Charcoal having a high specific resistance and responsiveness, and the impurity content, is a silicon smelting industrial chemical reducing agent is preferable, but with a different type of wood and charcoal obtained by the method is very different in nature. The ash content of the charcoal peeled skin is usually higher than the low ash content of the charcoal half to one-third, bark ash content of the charcoal has a great influence. Charcoal main component is carbon, low ash, generally less than 10%. Resistivity greater chemical activity is good. Years of production practice has proved that the charcoal is to meet the needs of silicon smelting important chemical carbonaceous raw material, but the source of carbon is restricted, can no longer use charcoal reductant. Looking at the situation from abroad, most countries no longer use charcoal. Many domestic manufacturers in seeking and use charcoal substitutes has also done a lot of work. Practice has proved that, in a variety of carbonaceous reducing agent, from the response capacity and the size of the specific resistance of view, bituminous coal is charcoal than another ideal reductant. Bituminous coal is characterized by resistance, reaction ability, low ash bituminous coal is obtained after washing. Ash content of up to about 3%, Fe2O3 content of 0.2-0.3%, Al2O3 content of less than 1%. Now our reductant bituminous coal ash content more than 3%, while reducing foreign bituminous coal ash content of more than about 1%, the Soviet Union used chemical method selected bituminous coal, iron oxide content can be less than 0.1% of the coal . Bituminous charcoal smelting process on behalf of a patent by the Shanghai Guangji Silicon Materials Co., Ltd. and Erdos Electric Power Co., Ltd. jointly owned smelting. Wood's role is to increase the resistance of the material layer, the amount of size have an impact on the furnace conditions. Wood with excessive, loose material layer, furnace conditions deteriorate, electricity consumption rose wood as the ignition point, the carbon content is low, the actual minimal as the reducing agent. Carbon impurities in raw materials is mainly ash, all by oxide. In the chemical production, the ash must be reduced oxides, it is necessary to consume energy, but also consume carbon, and the impurities remain mixed with the reduced silicon solution, the lower the intensity of silicon. In the production practice, the charge for each additional 1% of the ash, the more power can be 100 degrees -120 degrees, therefore, requires carbon in the ash content of the raw material, the less the better. 2.3 Electrode Electrode is a chemical with the main production of silicon consumed materials. Chemistry of silicon smelting electrode, commonly used graphite electrodes and carbon electrodes, graphite electrodes currently used mainly. In the silicon smelting furnace, the electrode is the heart, is an important part of the conductive system. Current is input through the electrode arc furnace, for chemical silicon smelting. The electrode material requirements: (1) good electrical conductivity, low resistivity, in order to reduce energy losses. (2) melting points, high thermal expansion coefficient to be small, easily deformed; (3) a high temperature sufficient mechanical strength, low impurity content. Low ash content of graphite electrodes, conductivity, heat resistance and corrosion resistance are better, the chemistry of silicon smelting the best choice. 3, the chemical industry metallurgical silicon with silicon process technology, including chemical charge preparation, furnace melting, refining and casting of silicon, slag inclusions and for removing broken. Before the preparation of the charge, all the raw materials necessary treatment should be carried out. Silica in the jaw crusher broken into blocks of not more than 100mm, less than 5mm sieve out the pieces, and rinse clean. Because the upper part of the furnace furnace melting fragments, thereby reducing the permeability of the charge, so that the production process difficult. Petroleum coke has a higher conductivity, broken into pieces to be not greater than 10mm, but also control the amount of petroleum coke powder. Because of its direct combustion in the furnace mouth will cause reductant inadequate. Chemistry of silicon production, bituminous coal can replace charcoal, such as Hunan Zhuzhou sperm washing bituminous coal, up 77.19% fixed carbon, volatile divided into 19.4%, ash content 3.41%, Fe2O3 content of 0.22%, Al2O3 content of 0.99%, CaO content of 0.17% . The production practice, the use of such chemical bituminous coal smelting silicon is feasible. Silicon used in the production of chemical wood is cut timber and wood chips and wood chipper machine processing. Carbonaceous reducing agent in charge mainly petroleum coke and bituminous coal-based, wood and wood chips depending on the amount of furnace conditions to decide. Production without wood, but also more stable product quality. Charge ratio of the products upon request level to be. Petroleum coke and bituminous coal mines each batch of silicon by the ratio of the amount of carbon required to determine. Petroleum coke and bituminous coal ratio on the charge of operating resistance greater impact. After weighing the components after charge, the charge mixed until pound furnace, the charge concentration of the added mixing furnace. Material to maintain a certain height, uniform feeding. Chemical silicon production is carried out continuously. Furnace condition is not eternal. Chemical production of silicon in an electric furnace is to convert electrical energy into heat energy and then directly heat the material and the chemical reactions. Therefore, electrical characteristics of the furnace is very important to implement closed arc melting operation, to maintain high-temperature furnace, thermal efficiency, improved furnace efficiency, capacity is used in the study 3200KVA and 6300KVA furnace of a silicon metal. Melting adopt certain time stewing and regular operation of centralized feeding methods. Under normal circumstances the charge is difficult to automatically sink, sink materials generally should be compulsory. Furnace conditions easy to fluctuations difficult to control. Therefore, in production must be properly judged, timely manner. Once every four hours out of the furnace, scouring casting, slag crushing pick finishing storage. 4, chemical silicon smelting furnace operation is carried out in a submerged state. Constant for the production of homogeneous metal silicon furnace to implement the optimal operation of the smelting process. Main source of heat energy. Therefore, the current flow in the furnace route and the route path the amount of current distribution on the furnace temperature distribution within the district and throughout the conduct of the smelting process has important implications, should pay attention to three-phase power load balancing, so as to increase production, ensure quality and reduce power consumption. 4.1 pound furnace charging and silicon smelting furnace in order to make up the purpose of high-yield, in addition to demand good furnace parameters, sophisticated materials, a reasonable ratio, the method of operation is good or bad is a very important factor. Reasonable method for feeding material layer structure, the stability of the electrode in the furnace and heat fully utilized, plays a leading role. Production, is combined with feeding and ramming carried furnace. Smelting process according to the different circumstances and characteristics, timely completion of feeding, ramming furnace operation. In order to maintain a good ventilation furnace, the furnace required garish and pounding. Small pound furnace furnace conditions under which conducted a large pound furnace generally once every hour or so, going through to pound furnace, furnace pound out pound block of material into the reactor core, pound pound furnace hearth edge process can not add new material. A one electrode area electrode region furnace ramming operation is undesirable and must be centralized pound furnace, uniform feeding, so as to maintain a high melting temperature. Stable furnace operation of the most important factor is to maintain a constant temperature in the material layer distribution. If the furnace temperature distribution by [destroyed, stove operation may be severely disrupted. Production of particle size and uniformity of charge,2013 Football Boots Soccer Cleats Shoes Adidas 11Questra TRX Turf White Blue Black , as well as feeding and baked hearth material surface treatment will affect the electrode movement. Move the electrode is too large, too strong will cause the furnace ramming furnace unstable operation. 4.2 Closed arc operation closed arc operation is properly buried electrode charge, the charge for the impedance of a semi-molten body between the electrode and the molten charge arcing. To do closed arc operation, we must first consider the feeding method. Feeding method has a feeding method, sub-feeding method, repeatedly feeding method. In addition to the first feeding method is prescribed arc operation, other methods can be done closed arc operation. Chemical silicon production, we use sub-sub-feeding method, the material layer structural stability, low power consumption, long furnace. Operation handle several problems: First, a good choice for the electrical parameters of the electrode can be inserted into an appropriate depth of the material layer; Second, find a way to control the specific resistance of the charge; Third size on silicon smelting furnace charge has important influence on particle size is too high and too low on the furnace conditions are unfavorable. The advantage of closed arc operation are: ① material layer structure of the furnace to form a complete system, in order to sink charge; ② arc is not exposed, the material significantly reduced the surface radiation heat losses, to maintain a high furnace thermal efficiency, thereby increasing the yield, improve product quality and reduce power consumption. ③ electrode consumption can achieve balance and stability, to avoid thinking about breaking incidents. ④ material surface temperature is relatively low, so that the surface of the device by feeding hot corrosion lighter, longer equipment life, improve furnace equipment utilization. ⑤ less dust, can operate the furnace side have a better operating environment. Stove regardless of size, as long as appropriate measures are closed arc operation can be done, get a good production results. 4.3 arc distribution technology is the heat of arc occurrence means for heating. Silicon smelting process in the chemical, physical and chemical changes and electrical systems are closely linked. The quality of distribution operations for smelting efficiency has a very important impact. Mainly in the electric arc end, the cavity by the impact impulses of the arc, the leg on the material, the formation of the lamp shape. Smelting process, the furnace is controlled by electrical parameters distribution work done. Generally the control electrode is buried depth. Shallow depth electrodes, generally indicates excess reducing agent, the electrode is formed near the eyes of fire, arc sound loud, baked silicon temperature is low, a small number of high power consumption. Buried electrode, if the reducing agent in the charge is too small, the electrode will be in the lower position. Because the charge resistance as the reduction of carbon in the charge increases, the resistance increases so that the current load is decreased, the electrode consumption is increased, reduced productivity. Production, the buried depth of the electrode is determined according to the site operator. Adjust the depth of the electrode buried in the resistance value is to change the charge, which is the best means of regulating furnace conditions. When the furnace secondary voltage exceeds a certain value, the electrode will be affected by damage to the silicon evaporation losses increased, the upper chamber overheating, heat loss increases. Secondary current, by the electrode to allow the current density limitations, can not be arbitrarily increased. Current voltage ratio, is an important factor in the blast furnace operation. Current and voltage ratio is too small, the electrode Xiabu Qu Ming arc production difficult to operate. Current and voltage ratio is too large, too deep electrode insertion charge, production is not very satisfactory. Production, only to find the appropriate current and voltage ratio, current stability, balance and electrode materials even lift, in order to achieve the best production results. Adjust operating voltage is adjusted stove important means of productivity. Furnace operating voltage depends on two aspects: one is short network structure, requires higher electrical efficiency, power factor should be appropriate. On the other hand furnace conditions, including operation of the furnace structure and production, smelting work resistor is critical, it is easy to change, efforts should be made to stabilize and approaching the best value. In general, in order to ensure the normal material surface temperature, increase the voltage. The normal package material surface temperature about 600 ° C. Used in accordance with specifications of the raw materials, charge large size, the resistance is small, branch current, electrode easy depth. Edit this paragraph hyperpure silicon present, ultrapure silicon (per thousand atoms of impurities is not more than a few atoms) is the most important semiconductor material, widely used in computers, microwave communications, optical communications, solar power and so on. Semiconductor silicon materials developed rapidly, the annual amount of more than 2500 tons of monocrystalline silicon, silicon consumption 2.5 billion square inches. Our silicon materials research and production also has great development, a diameter of 3 inches below the crystal has reached the international level, and the establishment of cutting, grinding, polishing processes and equipment, but the overall level and internationally there is a certain gap. Therefore, the development of ultra-pure silicon great potential, long way to go. Why is the present era called silicon era? Crystalline silicon production at the Seventh International Conference, the scientists called silicon era to the present era. Why such a high position in the silicon mention it? This is because the world today is from the industrial age to the information age. In the industrial era, the leader of the steel, so the steel production capacity marks a country's economic and military strength. In the information age, the lead is a semiconductor material - silicon. Variety of semiconductor materials can be used for a lot number, but not many varieties of industrial production, mainly silicon, germanium, gallium arsenide and gallium phosphide, and wherein the silicon semiconductor material is present throughout the accounting for about 90% yield. This is what people called silicon era to the present era of reason. Edit this paragraph classification categories usually metallic silicon metal silicon component contained in the iron, aluminum, calcium impurities to three main categories. In accordance with the silicon metal iron, aluminum, calcium, silicon metal can be put into 553,441,411,421,3303,3305,2202,2502,1501,1101 other different grades. Industry, silicon metal in the furnace is typically made of carbon reduction of silica in the system. Chemical reaction equation: SiO2 + 2C → Si + 2CO thus obtained silicon purity of 97 ~ 98%, called silicon metal. It melted and then recrystallized to remove impurities with acid, with a purity of 99.7 to 99.8% of the metal silicon. Silicon metal mainly composed of silicon, and silicon so with similar properties. Amorphous silicon and amorphous silicon-silicon two kinds allotrope. Amorphous silicon is the gray-black powder, actually a kind of micro-crystals. Crystalline silicon having a diamond crystal structure and semiconductor properties, melting point 1410 ℃, boiling point 2355 ℃, density 2.32 ~ 2.34 g / cm 3, Mohs hardness 7, brittle. Amorphous silicon chemically active, intense burning in oxygen can. It is at an elevated temperature with a halogen, nitrogen, carbon and other non-metallic react also with magnesium, calcium, iron and other metals, generating silicide. Almost insoluble amorphous silica include hydrofluoric acid, including all inorganic and organic acids, but can be dissolved in a mixture of nitric acid and hydrofluoric acid. Concentrated sodium hydroxide solution to dissolve the amorphous silicon, hydrogen. Crystalline silicon is less active, nor even at high temperatures with oxygen compound, it is not soluble in any kind of inorganic and organic acids, but can be dissolved in nitric acid and hydrofluoric acid, and a mixture of concentrated sodium hydroxide solution. Edit this paragraph grinding machining of silicon metal silicon metal (also called industrial silicon) is 20 mid-1960s there has been a brand name. It appears on the rise of the semiconductor industry. International common practice is to put products into silicon metal and silicon semiconductor silicon. Metallic silicon (Si) is purified elemental silicon industry, mainly for the production of organic silicon, the production of high-purity semiconductor material and the formulation of special purpose alloys. China is the origin of the world's leading silicon metal, silicon metal in China in 2007 to 95-100 million tons, domestic silicon metal consumption amounted to 250,000 tons or more, and in recent years, domestic demand for silicon metal is also increasing, the domestic consumption in the proportion of total output is also rising. Chinese silicon metal production capacity is relatively large, the output mainly in Guizhou, Yunnan, Fujian, Guangxi, Sichuan, Hunan. Metallurgical grade silicon metal 553,441 which has a wider distribution area, mainly in Guizhou, Hunan, Sichuan, Yunnan, Guangxi, Inner Mongolia, Xinjiang and other places, which is the most important in Guizhou province silicon metal production, the country's total production output 15% -35%. In the next 5-10 years, silicon metal market demand will continue to increase steadily. With the car in popularity more and more places, aluminum industry silicon metal consumption will continue to increase. In addition, the chemical industry has also increased demand for silicon metal will become the main driving force. The next five years, the world demand for silicon metal will reach an annual average growth rate of 5%. With the global economic integration and the international division of labor in the economic development of China is rich in silica resources, small hydropower resources and cheap labor, Chinese silicon metal industry development prospects are bright. Silicon metal production way out is to develop high value-added products. Silicon metal powder, high purity silicon metal and other products sold in the market price is higher, and the country to encourage the production of high value-added products, the export tax rebate will be given, Chinese silicon metal industry to the development of deep processing is a trend. Metal fume According to the survey, the current domestic production capacity of about 250,000 tons of silica, mainly ordinary silica and silica purity ultrafine heavily dependent on imports. Our preliminary forecast 2005 demand for fine silica powder will reach 600 million tons. Among them, the rubber industry is the largest user, coatings industry is an important application areas have great potential, electronic plastic materials, silicon substrate materials and electronic appliances for purity ultrafine silica castable to rely on imports of raw materials, only the price of two ordinary spherical silica powder -3 million / ton, while the price of high purity ultrafine silica powder is as high as several hundred thousand dollars / ton. Not only did the metal fume excess production capacity and there are still gaps. From the Ministry of Science and Institute for Strategic Studies research report shows that although our silicon metal capacity expansion, but because of the construction period as well as the reasons for market volatility, silicon industry, there has been shortage. In 2008, China's output of 4,500 tons of silica fume links, silicon demand is more than 20,000 tons, which means that 3/4 or so have to rely on imports to meet demand. According to its estimates, in 2009 the domestic production of photovoltaic cells maintained in 2008 even though the level of 2300 megawatts, according to every megawatt photovoltaic cells need 12 tons of silica fume industry average calculation, but also need more than 28,000 tons of silica fume. It is estimated that more than 2009 domestic production of silicon powder may exceed 10,000 tons, which means that at least still need to import nearly 20,000 tons more silica,Football Boots Nike Mercurial Vapor Superfly III IC Blue Red Obsidian Indoor Soccer Cleats , in order to meet domestic production needs. Since the metal silicon is a brittle material in the grinding process Residue not well controlled, over-grinding caused serious fume waste, high production costs, product size is not standard, making the product not only on production do not, there is no competition. Currently grinding silica fume equipment mainly extrusion mill, disc mill, Raymond mill, jaw crusher, etc. These devices not only high energy consumption and low efficiency. Makes fume production falters, Changsha, Hunan General Machinery Co., Ltd. Shenzhen after years of research and experimentation, the successful production column mill, grind the silica fume problems successfully solved, the mill-45μm silica content of effective control within 5%. Silicon metal powder grinding industry pioneer - deep Xiang-chu-chu mill by mill Hunan General Machinery Co., Ltd. Changsha deep independent research, with completely independent intellectual property rights and access to national invention patent a new type of vertical mill. Adopted novel medium speed pulse, repeated low pressure continuous roll grinding principle and scientific design, so it also includes a high pressure roller press and the roller mill performance, but without its flaws. When the motor drive gear means to rotate the spindle, the spindle is mounted on a carriage and mounted on the stand in several lined conical rollers for rotation of the ring, the roller and the adjustable gap between the liner, when the material from the inlet into the mill, due to gravity and the upper pusher role, so that the material evenly from top to bottom through the liner four weeks, and was repeatedly rolling roller into powder, and finally from the lower part of the mill automatic nesting. As for the roller relative to the liner rules revolution and rotation, and with the material thickness and the particle size of the flexible material fluctuate between the liner and the roller wheel and no contact, thereby avoiding due between the impact on energy consumption and wear and tear, and the material being reasonable here, repeated many times rolling and grinding, plus grinding roller and the liner material is a good selection of domestic abrasion resistant multi-element alloy steel, thereby minimize the material during processing machinery for processing powders of iron contamination. The structure column mill 1) and the roller gap between the liner, according to the required fineness of grinding material adjustment; 2) the cartridge can be adjusted up and down to adjust the use of the material in the mill milling times and the material layer thickness, control of material discharging speed and milling degree; 3) spring pressure can be adjusted according to the material hardness. Column mill performance characteristics: 1) large capacity, high efficiency, suitable for mass powder processing 2) a large range of energy-saving, low production costs; column mill combination of domestic energy-saving grinding equipment Advantages over 50% energy saving ball mill, mill Bi Leimeng saving 30-40%. 3) minimal consumption of wearing parts, can reduce production costs, but also reduce the special requirements of iron contamination of materials (iron contamination can be reduced to two hundred thousandths); 4) fineness adjustable, can be strictly controlled according to user needs Product size range; 5) Small size, easy to install, stable mechanical properties, can save construction investment; 6) low noise, less dust, environmental effect; 7) good mechanical properties, simple operation, easy maintenance. Silica particle column mill processing materials into large particles constituting column mill, through the rollers and liner uneven teeth were rolling acetabular style crushing fine, transferred between the roller and the liner is formed material layer. Under the pressure of the spring means, the roller on the flexible material layer to make the material into powder extrusion. Plus dozens of repeated extrusion, grinding results are quite satisfactory.