Halotungstate is a kind of tungstate which is mainly composed of oxyhalide, it is a new type of visible light response photocatalyst.

Tungstate is an important inorganic functional material, which has broad application prospects and development potential. It can be used as scintillation crystal, luminescent matrix material, photoluminescent material, gas sensitive material, catalyst, etc. Tungstate is a typical self activating luminescent material. Its luminescent source is WO₄^2- complex ion. Under the excitation of X-ray, ultraviolet light and cathode ray, they can emit high-efficiency fluorescence. According to the different structure, tungstate can be divided into two types: scheelite type and wolframite type. In tungstate, calcium tungstate, lead tungstate, zinc tungstate, cadmium tungstate and barium tungstate are important inorganic materials.

Barium tungstate (BaWO₄) is one of the divalent metal tungstate, which is an important photoelectric functional material. Barium tungstate crystal is a promising Raman laser crystal due to its stimulated Raman scattering. Barium tungstate crystal can be used in all solid state lasers, and it is possible to design it to emit radiation in special spectral region. Barium tungstate crystal has important application value in many fields, such as photoelectricity, medicine, spectroscopy, because of its special characteristics of photoluminescence, thermoluminescence and stimulated Raman scattering.

Thermal expansion and cold shrinkage of materials is a common phenomenon in nature, but some materials are contrary to this. The coefficient of thermal expansion is negative, that is, the volume decreases with the increase of temperature, which is called negative thermal expansion material (NTE) or thermal shrinkage material. ZrW₂O₈ is a recently discovered material with large isotropic negative thermal expansion in a wide temperature range (0.3k to 1050k). The simple cubic ZrW₂O₈ was first synthesized in 1959 and found to have NTE effect. At that time, it was known that its crystal was cubic structure, but the atomic position was not determined, and its unique NTE performance did not attract attention. Until 1996, the a w sight research group of Oregon State University reported the crystal structure type of the material in science, and the research on ZrW₂O₈ started. It's the beginning of attention.

Zirconium tungstate has a formula of Zr(WO₄)₂ and a molecular weight of 586.9. It is a negative thermal expansion material with excellent performance. It has negative thermal expansion performance in the temperature range of 0.3-1050.0k.

The low-grade tungsten concentrate produced by some tungsten concentrators can not meet the quality standard, the grade of WO3 is 5-30%, and the content of other impurities is also relatively high. It is mainly low-grade tungsten slime concentrate, tungsten tin medium ore, tungsten bearing iron sand and other refractory tungsten containing intermediate products. These products are sold in the form of sodium tungstate or scheelite, ammonium paratungstate, tungstic acid or tungsten trioxide through chemical beneficiation, and other useful components are comprehensively recovered from the leaching slag. The principle process of chemical beneficiation of low-grade tungsten mineral raw materials can be divided into material preparation, etc.

With the rapid development of petroleum processing industry, the research and development of tungsten catalysts have been paid more and more attention. The active component of the catalyst, tungsten trioxide, is used as catalyst carrier, such as spherical silicon and aluminum oxide, which are made by leaching and pyrolysis of ammonium metatungstate. This is the direct driving force to promote the development of AMT in recent years. There are many processes for AMT production. Nanofiltration technology is a membrane separation technology separated from reverse osmosis technology, which is the continuation and development branch of ultra-low pressure reverse osmosis technology.

Ammonium paratungstate is the main raw material of tungsten industry. In a sense, it is a kind of purified tungsten concentrate, that is to say, the tungsten concentrate containing 60% bustard is purified to the intermediate products containing more than 88.5% tungsten oxide. In the final application products of tungsten, more than 70% are made of apt as the main raw material, while the rest are made of ferrotungsten, metatungsten, tungstic acid and waste tungsten.

Tungsten trioxide is an important intermediate product in the process of tungsten extraction and gold treatment. It is the main raw material for the production of tungsten powder and tungsten related products. It is usually obtained by calcining ammonium paratungstate. The traditional production process of tungsten trioxide is to place the powdered ammonium paratungstate in a fixed furnace or a rotary furnace for calcination. 

Ammonium paratungstate is a kind of chemical substance, mainly white crystal, with two kinds of flake or needle, which is used to produce tungsten trioxide or blue tungsten oxide to make tungsten powder. It is also used to manufacture ammonium metatungstate and other tungsten compounds, and used as additives in petrochemical industry.