Tungsten Oxide

Because the grain uniformity of hard alloy mainly depends on the particle size distribution of WC powder, the particle size distribution of WC powder is hereditary in tungsten powder . Therefore, the preparation technology of tungsten powder and tungsten carbide powder by submicron size and narrow size is very important. The key technical indexes of fine grain, submicron, ultrafine or nanocrystalline cemented carbide for WC powder are the purity, particle size and particle size distribution, and it is clearly stipulated that there is no type of type III coarse in WC powder. Some scholars have adopted the following technical schemes to prepare submicron tungsten powder or tungsten carbide powder, including the following steps: (1) Ammonium paratungstate (APT) is pyrolyzed to ammonium metatungstate (AMT) and dissolved in ammonia solution or deionized water and filtered to obtain ammonium tungstate solution, or using ammonium paratungstate (APT) production line after ion exchange or cryst...

At present, the general method of preparing tungsten oxide is liquid phase method. In the process of preparing tungstic acid in liquid phase, the tungstic acid particles are automatically coalesced because of the unstable thermodynamics. In addition, the free water molecules on the surface of the particles form hydrogen bonds with the free hydroxyl groups, and then form a hydrogen chain with the water molecules on the surface of the adjacent particles to produce a bridging action. Some scholars have proposed a method of adjusting the length of tungsten oxide nanorod by oxygen, with a surface functionalized carbon nanotube with a diameter of 2-200 nm and a layer of 1-30 layers as the carrier, tungsten metal salt as the tungsten source, the addition of hydrochloric acid in the carbon nanorod glycol suspension and tungsten metal salt system, and the principle of making the weak acid with strong acid to make tungstate granules. It directly forms on the surface of the carbon nanotubes and ...

The wolframite is brittle and easy to smash and produce fine slime, and most of them have fine embedded granularity and more useful metal minerals. The gangue minerals are closely related to tungsten minerals, and the separation is difficult. Many fine grain tungsten can not be recycled. Then it forms tailings. Some scholars have proposed a comprehensive mineral processing scheme for recycling wolframite from tailings, including the following steps: (1) Centrifuge gravity separation and tail preconcentration, after the wolframite tailings are adjusted to pulp, the centrifugal concentrator is used to preconcentration and discarding tailings, and the concentrate and tailings of centrifugal gravity separation are obtained. (2) The concentrate is floated by the first coarse second sweep process, and the flotation tailings and sulfide ore concentrate are obtained. (3) Magnetic separation of flotation tailings by magnetic separation is carried out, and magnetic separation concentrate and ma...

High purity tungsten, which means more than 99.995% of the purity of tungsten, is a key material for the formation of the diffusion barrier in the process of mass integrated circuit and PVD coating. High purity tungsten powder has become an indispensable raw material for the microelectronics industry. Some scholars have put forward the preparation method of high purity tungsten powder for scale integrated circuit, which aims to make the production of high purity tungsten powder with purity not less than 99.999%, and to ensure the controllability of the particle size and morphology of tungsten powder. The process is as follows: (1) Using the industrial 0 grade ammonium parotungstate in GB/T10116-2007 as raw material, the three band rotary tube air furnace is calcined to form yellow tungsten. The temperature of the three zone is 550 + 5°C, 600 + 5°C, 600 + 5°C.  The concentration of yellow tungsten is dissolved in 10% ammonia water at 50-60°C, the initial concentration of solution is...