The gold mine in Hunan is rich in resources, and the ore contains a small amount of ultra-low grade associated tungsten. The ore dressing method that the mine has been using for a long time is a single flotation. The only product is gold concentrate, and its flotation recovery rate is 80-90%. The associated tungsten grade in the ore is about 0.05%, which is much lower than the critical mining value of tungsten. The conventional beneficiation method has the problems of high cost and low recovery rate.

Tungsten carbide is an important raw material for the production of cemented carbide. The preparation technology of tungsten carbide is various, and the preparation of tungsten carbide powder from tungsten powder is the most widely used one.

Tungsten carbide belongs to the ceramic phase and has the advantages of high melting point, high hardness, high electrical and thermal conductivity, stable chemical properties, etc. It is an ideal material for preparing wear-resistant and corrosion-resistant coatings. However, due to the high melting point and high hardness of tungsten carbide (WC), the adhesion between the sprayed tungsten carbide particles and the substrate is poor, and oxidation occurs when air temperature raise. Therefore, the pure tungsten carbide powder is rarely used alone as a thermal spray powder material, and it is usually required to add a metal or alloy such as Co, Ni, Ni-Cr. The binder phase is used as a sintered powder or a coated powder for thermal spraying.

During the brazing of tungsten carbide mining button, the size of welding gap is the key factor that will affect the density and strength of weld line. If the gap is too narrow, it will hinder the inflow of the solder; if the gap is too wide, it will destroy capillary action so that the solder can not fill the gap. 

China is the world's largest producer of tungsten and a major producer of tin. Southern Yunnan and Western Yunnan of China are the main origin of tungsten-tin paragenic ore. Since it is difficult to apply the conventional methods (gravity concentration, froth flotation or magnetic separation) to separate the tungsten-tin ore, thousands of tons of them have been wasted. When tungsten exists as an impurity in tin concentrate, it is not only wasted, but also affects the cost of tin metallurgy and the quality of tin products; while tin exists in tungsten products as impurities, even if the amount is very small, the quality of tungsten products has been adversely affected.

In the pseudo-binary system Nb2O5/WO3, Nb8W9O47, crystallizing in a threefold superstructure of the tetragonal tungsten bronze (TTB) type, represents the most stable compound. The superstructure arises from a systematic occupation of a part of the pentagonal channels with metal-oxygen strings (see figure).

Tungsten carbide (WC) is an important raw material for the production of cemented carbide. The preparation processes of tungsten carbide are various, and the preparation of tungsten carbide powder from tungsten powder is the most widely used method.

At present, the common method for producing tungsten powder with high green strength is by: using ammonium paratungstate (APT) as raw material, APT is sintered to form tungsten oxide (WO3, WO2.9), and then tungsten oxide is reduced by hydrogen to form tungsten powder. Finally the high-green-strength tungsten powder is obtained by screening and removing impurities.

Due to the important position of tungsten resources and the scarcity of stocks, the recycling of tungsten waste is highly valued, especially in the United States, Japan, Germany and other countries. For example, about 35% of tungsten products in the United States use recycled tungsten. Compared with developed industrial countries, the recycling of tungsten waste in China possesses a later start point and there are fewer specialized techniques.

With the advent of nano-scale ceramic powders, related powder materials have also begun to be widely used as reinforcing phases of coatings. The use of nano-scale ceramic powder materials or carbon nanotubes helps to improve the mechanical properties of the coating, which has the effects of friction reduction and toughening have significant effects.