With the development of tungsten ore raw materials towards low quality and high impurity, various companies have recovered and decomposed tungsten ore in different ways, resulting in high hetero tungsten in the market than sodium tungstate / tungsten ore. China's tungsten smelting is the mainstream of ion exchange. The biggest characteristic of ion exchange is strict demand for impurity content in the precursor fluid. Therefore, we must purify high hetero tungsten than sodium tungstate before exchanging, so as to get qualified pre liquid.

Most domestic tungsten smelters in China use "pressure cook - ion exchange - evaporation crystallization" process to produce ammonium tungstate. The advantages of ion-exchange process are stable product quality and easy operation. However, the major drawback of the process is that the water consumption is very large. The appointment of APT for 1 tons per ton produces 100~120 tons of wastewater.

At present, the preparation method of tungstate is through calcium tungstate to add inorganic acid to obtain required tungstic acid, then the ammonia will dissolve into the solution of coarse tungsten tungstate, ammonium tungstate. Due to the increase of pH value, acid decomposition process without washing clean iron and manganese and soluble impurities can be hydrolyzed and precipitation, metasilicate H₂SiO₄ insoluble in alkaline medium into slag and no decomposition of mineral particles and removal.

The tungsten hexafluoride gas used in the microelectronic industry VLSI requires high purity, generally not less than 99.999%. The purity of industrial synthesis of tungsten hexafluoride is relatively low, does not meet the needs of electronic products, therefore, the industrial synthesis of primary tungsten hexafluoride must be purified.

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.