Tungsten hexafluoride is a binary compound of tungsten and fluorine with the chemical formula WF₆. Among the tungsten fluorides, tungsten hexafluoride (WF₆) is the only stable and industrially produced variety.

At present, some manufacturers in order to reduce the cost, improve the recycle rate of tungsten smelting, substandard ammonium paratungstate recycle as seeds to melted down, we can get rid of unqualified products while at the same time does not increase the cost, but after doping products for the quality of hard alloy production of tungsten powder, tungsten carbide and tungsten will affect the order of products. Some manufacturers directly dissolve unqualified products with strong alkali to turn them into sodium tungstate solution and return to the production of ammonium paratungstate, but this method is very expensive.

Tungsten smelting wastewater containing 3 ~ 7mg / L of arsenic as the main sludge factor, except for arsenic sludge is mainly generated in the process of wastewater arsenic removal. Arsenic removal process mainly includes calcium salt precipitation method, iron salt precipitation method or calcium salt - iron salt joint precipitation method. At present, the combined method of calcium salt and iron salt is the most stable method for arsenic removal from tungsten smelting wastewater, but it will produce more arsenic-removing sludge. The final destination is solid landfill, cement solidification or lime solidification treatment. These methods subsequent processing and potential hazards can be reduced. But in fact, the tungsten mud also contains other valuable metals, there is room for further processing.

The existing pressure cooker method to be abandoned tungsten slag alkaline secondary pressure cooker, tungsten extraction of tungsten in depth, and then the resulting low-tungsten high lye for pressure cook scheelite concentrate and tungsten ore. Finally, autoclaving combined process of black and white tungsten concentrate, the tungsten solution decreased and alkali concentration of tungsten concentration increases, can obtain very good depth extraction effect, not only make full use of the tungsten resources, but also solve the problem of caustic soda recycling.

Traditionally, the tungsten concentrate is mainly smelted by classical technology, extraction process and ion exchange process. Because sodium hydroxide and hydrochloric acid are used in these processes, sodium ions and chloride ions are very active in chemistry, so they cannot be separated from precipitates in an economical and effective way. It will produce acid and alkali waste liquid and pollute the environment.

The traditional method of reducing tungsten trioxide is to evaporate and crystallize the wet ammonium paratungstate to be dried and packaged by a dryer, join the rotary kiln for the production of tungsten trioxide, drying packaging process not only waste manpower, material and energy, but also increase the cost of production.

Tungsten in the smelting production process will produce ammonium paratungstate waste, tungsten oxide waste, and tungsten powder, tungsten carbide and tungsten carbide scrap and other substandard products.

Wolframite mainly adopts the classical process, extraction and ion exchange process for smelting. Because of the use of sodium hydroxide and hydrochloric acid in these processes, the chemical properties of sodium and chloride ions are active, the precipitation can not be separated by economic and effective methods. It is difficult to open the process in the process and will produce acid and alkali waste liquid and pollute the environment.

In practical applications, it was found that Na₂WO₄ solution could remove more than 90% of phosphorus by ion exchange without phosphorus removal by calcium salt, and the phosphorus concentration in the ammonium tungstate solution was also about 0-3 g/l. Therefore, calcium phosphorus removal has no substantial effect on phosphorus removal, and the process can be eliminated directly. In addition, the calcium salt removal process has many drawbacks, the content of phosphorus slag in WO₃ up to 30%, production must be returned to the boiler alkali recycling, which consumes a lot of raw materials, production costs increased significantly.

Preparation of tungstic acid products in two ways: First, wolframite as the raw material of the classic process; second is scheelite as the raw material of acid production process. Wolframite classic raw material for the process specific process: milling → alkaline boil → purification → scheelite → acidification → dehydration drying → packaging.