Scheelite is a troublesome raw material in tungsten smelting. After the popularization of alkaline pressure leaching technology in the last century, the smelting capacity and scale of scheelite have been greatly improved, and the technology and process have been further mature. Due to the use of excessive alkali process, although a large part of alkali is consumed in the leaching process, the amount of residual alkali in the crude sodium tungstate solution is still very high after the reaction.

In recent years, with the development of industrialization and the rapid improvement of people's living standards, environmental pollution has become the main problem facing human beings, especially water pollution, which has attracted more and more attention. Industrial waste water accounts for a large part of the water pollution sources. Because of its dark color and strong toxicity, it is difficult to treat.

Tungsten oxide is a kind of transition metal oxide, which belongs to n-type semiconductor. At present, a large number of researches have found that w-based oxides not only act as catalytic, electrochromic, solar energy absorbing and invisible materials, but also have the characteristics of semiconductor functional materials such as heat sensitive, pressure-sensitive and gas sensitive.

To produce tungsten powder from ammonium paratungstate, it is usually necessary to first burn tungsten oxide in a weak reducing atmosphere, and then carry out hydrogen reduction to produce tungsten powder. Most of the tungsten powders prepared by this process are very regular polycrystalline, which are the main raw materials for the preparation of tungsten alloy and tungsten carbide.