Sodium Content in Tungsten Oxide

Sodium as an activator can affect the particle size of tungsten powder in the process of hydrogenation of tungsten oxide, which is of great importance to the variation of the particle size of the tungsten powder product caused by the fluctuation of the sodium content in the tungsten oxide; It is of considerable theoretical and practical significance.

In recent years, many research results on the physical properties of tungsten oxide have been released. The study on the variation of tungsten powder particle size caused by the difference of sodium contained in tungsten oxide during the hydrogen reduction process is a steady production of tungsten powder In the indispensable important part.

During the reduction of tungsten oxide to tungsten powder, the reaction process is usually carried out in stages, namely:

WO_2.90+0.18H₂→WO_2.72+0.12H₂O

WO_2.72+0.72H₂→WO₂+0.72H₂O

WO₂+2H₂→W+2H₂O

The above reaction process is mainly controlled by the temperature and time of reduction, the concentration of H2O / H2 and the partial pressure of WO2 (OH) 2, that is, the particle size of tungsten powder is affected by oxidation-reduction and volatilization-deposition. Sodium content in tungsten oxide reduction and carbonization process involved in the process are as follows:

WO_3-X→W→WC

Related researchers conducted a lot of in-depth studies based on this phenomenon. The range of influence on the grain size of the tungsten powder product caused by the different sodium contained in the tungsten oxide is as follows:

1. When the sodium contained in tungsten oxide is less than 0.0045%, the sodium impurities contained in the produced WC are few, which can meet the requirements of the international standard (<0.002%).
2.  The higher the vapor pressure of sodium contained in the tungsten oxide, the greater the impact on the hydrogen reduction process

With the gradual development of the tungsten industry, the tungsten industry has paid more and more attention to the principle and characteristics of the tungsten powder manufacturing process. The research on the tungsten physical and chemical reaction processes has also become more and more in-depth.

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