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Fine Particles Of Wo <sub> 3 </ Sub> Study On Preparation

Posted on:2011-09-07Degree:MasterType:Thesis
Country:ChinaCandidate:B Q ZhuFull Text:PDF
GTID:2191360305495150Subject:Non-ferrous metallurgy
Abstract/Summary:PDF Full Text Request
As is known to all, tungsten is an important kind of rare metals, with many outstanding physical properties, such as melting point, high strength, high elastic modulus, thermal expansion coefficient, low thermal conductivity and wear resistance, and chemical properties stable, good corrosion resistance. Because of excellent performance tungsten alloys has been widely used in all sectors of national economy. Especially plays an extremely important role in metallurgy, lighting, military, aviation, machinery, electronic telecommunication field and etc.APT, WO3 and tungsten are important intermediate products in industry field. Recently fine grain WO3 (especially the Fsss≤5μm tungsten oxide) is favoured by more and more customers. Tungsten powder as the downstream products of WO3, its size determined to a great extent by the size of the upstream WO3 products. That means the more small size of tungsten oxide, the more small size of tungsten powder can be got after hydrogen reduction from WO3. It has been proved that the smaller size of tungsten powder can greatly improve the performance of tungsten wire, or greatly enhance hardness and strength and toughness of the tungsten carbide.The main factors influence of crystal size has been studied combining industrial practice experience. Such as crystallization temperature and speed, vacuμm, inhibitor agent etc. The best condition is determined, stirring speed is 140rpm, the crystallization temperature is 60℃and the coefficient of inhibitors agent is 0.15%. Research focus on the factor such as calcinations temperature, furnace tube speed, air displacement, which has effections on particle size of WO3. The optima calcining temperature has been determined that is 600℃.
Keywords/Search Tags:fine grain, stirring speed, temperature, inhibitor agent
PDF Full Text Request
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