The surface effect means that when the tungsten oxide particles are in the small size range of 1-100 nm, as the diameter of the tungsten oxide particles becomes smaller, the number of atoms on the surface of the nano particles is rapidly increased.

Defective tungsten oxide nanomaterials have drawn wide attention in the tungsten products industry because of their unique structural properties and excellent properties. The use of traditional solvothermal method can be prepared with defective tungsten oxide nanomaterials. Defective tungsten oxide nanomaterials synthesis method is as follows:

Unlike the stoichiometric tungsten oxide color, the defective tungsten oxide nanomaterials are light green or blue with an extra broadband absorption between 400 and 700 nm. This increased absorption peak is due to the presence of oxygen vacancies leading to a new band in the conduction band.

In the prior art, the preparation of ammonium paratungstate industrial process from tungsten mineral raw materials by caustic soda or soda decomposition to obtain crude sodium tungstate solution; purification by solution ion exchange or solvent extraction transformation to obtain the pure ammonium tungstate solution; then through evaporation and crystallization, APT products.

Recovering tungsten from tungsten waste has become an important measure to alleviate the shortage of raw materials. At present, the main ways to treat tungsten waste at home and abroad include mechanical crushing, electrolysis, alkali leaching, sodium roasting and zinc melting. Among them, sodium roasting technology is more mature and has wide applicability to waste tungsten materials. Therefore, this method is generally used to recycle tungsten carbide and various kinds of tungsten.

Tungsten carbide is the main raw material for the production of hard alloy. The process of producing alloy powder in the tungsten production and processing enterprises is basically the combination of tungsten carbide powder and cobalt powder through mechanical mixing, and the uniformity of the alloy powder is not ideal. It has a great influence on the pressing of the subsequent cemented carbide. Some scholars have tried to pre - configure the alloy powder in the liquid state and then reduce the alloy powder.