【Know Tungsten】What Is Violet Tungsten Oxide?

Violet tungsten oxide, named for its violet appearance, is a violet or blue-violet fine crystal-like powder.

Violet tungsten oxide is usually produced by controlling certain reduction conditions using ammonium paratungstate, tungstic acid or tungsten trioxide as raw materials. The preparation methods of violet tungsten usually include APT wet hydrogen direct reduction method, hydrogen tungstate reduction method, APT mild reduction method, etc.

Due to the special needle-like or fine columnar crystal structure of violet tungsten oxide, and its more abundant cracks than other tungsten oxide particles (all tungsten oxide particles have abundant cracks inside), this structure has large gaps, making Its bulk density is low, which is beneficial to reduction or other reactions. The uses of violet tungsten oxide are as follows:

1. Preparation of tungsten powder, especially the preparation of nanometer, submicron or ultra-fine tungsten powder;

2. Used in gas sensors, showing good gas sensitivity to nitrogen dioxide (NO2) at room temperature;

3. Preparation of tungsten carbide powder and ultrafine WC-Co powder.

4. Raw materials for the production of glass thermal insulation coating dispersions.

5. Additives for lithium battery cathode materials.

【Know Tungsten】What Is Blue Tungsten Oxide?

Blue tungsten oxide is the product of the interaction between reducing agent and tungsten compound, usually called blue tungsten. The composition of blue tungsten is very complex, and there are also intermediate oxides such as WO2 and W4. If the composition of blue tungsten is calculated as WO, the tungsten content is 82.13%, while the tungsten content in WO is 79.30%. That is to say, the tungsten content in blue tungsten oxide is greater than tungsten trioxide. According to the blue tungsten oxide product standard requirements, its purity is 99.95%, and the tungsten content should reach 80%~80.8%.

The preparation methods of blue tungsten oxide include: APT sealed calcination method, APT hydrogen mild reduction method, intrinsic reduction method, ion exchange method, etc. Among them, the ion exchange method is the most common and economical preparation method.

Blue tungsten oxide can be used to produce tungsten powder, and then produce tungsten products such as cemented carbide, pure tungsten and tungsten alloy products. In recent years, blue tungsten oxide has been used in emerging industries such as lubricants, catalysts, thin film substrates for semiconductor equipment, radiation protection products, electronic components, raw materials for glass thermal insulation coating dispersions, etc.

【Know Tungsten】Tungsten Wire Mesh

tungsten wire mesh video image

Tungsten wire mesh is woven by tungsten wire with purity over 99.95%, and is also called tungsten shielding wire mesh, filter tungsten wire mesh, and high temperature tungsten wire mesh.

tungsten wire mesh video image

 

【Know Tungsten】What is Ammonium Metatungstate?

Ammonium metatungstate is an important intermediate compound in the tungsten wet smelting process. It appears as a white slightly yellow crystalline powder. Soluble in water, at 25℃, the solubility is greater than 300grams in 100ml water.

The main preparation methods are: acid neutralization method, thermal separation method, electrodialysis method, ion exchange method, solvent extraction method and preparation method using ammonium paratungstate as raw material. Among them, the acid neutralization method is the main process, which can use organic acids (formic acid, acetic acid, citric acid, lactic acid, etc.) or inorganic acids (tungstic acid, nitric acid, etc.). Organic acids are mild in acidity and easy to operate, but they are more expensive and affecting costs is a major drawback. Among inorganic acids, nitric acid is easy to obtain and cheap. The nitric acid neutralization method for preparing ammonium metatungstate has simple process and equipment, which has attracted people's attention and has been widely used in industrial production.

The purity of ammonium metatungstate provided by Chinatungsten Online is generally above 90.00% or 91.00%. 

 

【Know Tungsten】Tungsten Oxide Inspection Equipment

Tungsten Oxide Inspection Equipment

1. Laser Particle Size Analyzer
Laser particle size analyzer is used for testing the particle size distribution for tungsten oxide.
Size range: 0.1~1000 micron
Acuracy: better than 1%
Repeatability: better than 1%
Voltage: 220+/-2V

Read more: 【Know Tungsten】Tungsten Oxide Inspection Equipment

 

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