博文

目前显示的是 二月, 2017的博文

Ammonium Metatungstate Preparing Composite Cobalt - Tungsten Oxide Powder

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Composite cobalt - tungsten oxide powder is the main raw material for manufacturing cemented carbide powder, the finished product cemented carbide has been widely used in machinery manufacturing, oil exploration, military industry, aerospace and other fields because of its high hardness and density, wear-resisting and other special performance.  Common methods for manufacturing composite cobalt - tungsten oxide powder by using the ammonium metatungstate (AMT) or metatungstate as raw material are like following: 1. Make a certain concentration of ammonium metatungstate solution, then add a certain amount of cobalt carbonate powder (CoCO 3 ) with heating, stirring for full reaction, and then cooling, filtering the compound salt solution; drying the compound salt solution to get the powder, get the compound powder heated in fluidized bed to finally get composite cobalt - tungsten oxide powder. In this method, the reaction of AMT and cobalt carbonate is really slow and di

Ammonium Metatungstate (AMT) Preparing Hollow Porous Tungsten Oxide Sphere by Spray Drying Method

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Compared with the ordinary tungsten oxide , hollow porous tungsten oxide sphere because of the larger specific surface area, thus to has the significant size, surface, quantum size and macroscopic quantum tunneling effect, and thereby to expand the application areas, which can be used as a solar absorption, stealth and photocatalytic materials and gas sensitive materials of NO x , H 2 S and NH 3  etc. Ammonium metatungstate (AMT) is an important intermediate compound in tungsten production industry, the excellent raw material for manufacturing tungsten oxide, tungsten powder, tungsten carbide powder and other tungsten products.  A study was taking the ammonium metatungstate solution or a mixture of AMT and ammonium tungstate solution as raw material, to produce hollow porous tungsten oxide sphere through a combination of spray drying method and heat treatment, its technological process is: Preparing ammonium metatungstate solution or a mixture solution of AMT and ammonium tung

Ammonium Metatungstate (AMT) Preparing Hexagonal Tungsten Oxide Ball

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Hexagonal tungsten oxide ball (hex-WO 3 ), which is the tungsten oxide ball with hexagonal crystal structure. Since the single crystal hexagonal tungsten oxide has an empty hexagonal space tunnel structure, the W contained compound will exit mixed valence states of W 6+ , W 5+  and W 4+  and so on, thus to make the overall compound in a balance charge state. This special structure and valence is making hexagonal tungsten oxide ball has well electro-optic effect and excellent electrical properties, thus it has widely been used in laser frequency doubling, optical signal processing, superconducting material, solid fuel cell and other fields. A study was taking glucose and ammonium metatungstate (AMT) as the raw materials to prepare hexagonal tungsten oxide ball by solid - phase thermal decomposition method, which is controlling the crystal morphology of tungsten oxide ball by adjusting the temperature in the reaction process. The manufacture steps are as follow: 1. Weight th

Waste Tungsten Oxide Recovering Ammonium Metatungstate (AMT)

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Waste tungsten oxide , including the scrapped, the not qualified which must be reworked to improve the quality indicators of tungsten trioxide, blue tungsten oxide and others. During the production, using process, or in the case of large inventories, tungsten oxide may not reach a certain specific standards due to various reasons, or directly scrapped. However, these waste tungsten oxide still contains a high content of tungsten, since the tungsten is a rare metal element, thus a more effective approach to reuse waste the tungsten is turning waste into treasure. Ammonium metatungstate (AMT) is an important raw material in tungsten smelting industry, catalyst for petrochemical industry and other fields. The ways of waste tungsten oxide as raw materials to produce ammonium metatungstate are many; however, since tungsten trioxide and blue tungsten oxide are not soluble or slightly soluble in ammonia water, which only soluble in caustic soda or soda ash. Therefore, the traditional

Ammonium Metatungstate Preparing Nano Tungsten Oxide Aqueous Solution

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Nano tungsten oxide can not soluble in water itself, the so called nano tungsten oxide aqueous solution is the dispersion which nano tungsten oxide particles are uniformly distributed in water, to play the roles of oxidization and reunion of tungsten oxide. Tungsten oxide is the typical transition metal oxides, while the nano tungsten oxide is a new type of functional material, and because of its excellent discoloration performance, it can be widely used in many fields, such as intelligent window, large area flat panel display, gas sensor, dye-sensitized solar cell, automatic mirror, energy storage. Ammonium metatungstate (AMT) is the important intermediate compound of tungsten metallurgy, and being the important raw material for manufacturing tungsten oxide, tungsten and tungsten carbide powder and other tungsten products. An invention has proposed one method to prepare nano tungsten oxide aqueous solution from the raw material of ammonium metatungstate and sodium borohydrid

Ammonium Metatungstate Preparing Violet Tungsten Oxide Whisker

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Ammonium metatungstate (AMT) is an important compound in tungsten metallurgy industry, an important raw material for preparing tungsten oxide, such as tungsten trioxide (YTO, WO 3 ), violet tungsten oxide (VTO, WO 2.72  or W 18 O 49 ). Violet tungsten oxide whisker is the micro-nano-short fibers which are generated by the high purity violet tungsten oxide, with the mechanical strength equal to the strength of adjacent atoms between the intensity. The highly oriented structure of W 18 O 49  whisker has not only making itself of high strength, modulus and elongation, but also of the properties of electrical, optical, magnetism, dielectricity, conductivity and superconductivity. It is pointed out that a process for producing violet tungsten oxide whiskers by coaxial electrostatic spinning method with ammonium metatungstate as a raw material is as follows: 1. Mix 2ml saturated ammonium metatungstate solution and 12% PVA solution in a certain proportion, to prepare spinning solu