Before crystallization of ammonium para tungstate (APT), it is necessary to further remove molybdenum from the crystallization process of APT to obtain a more pure APT crystal product. The impurity removal rate in the crystallization process is directly related to the crystallization rate of APT. With the increase of the crystallization rate of APT, the precipitation rate of impurity increases rapidly. For the same concentration solution, when the crystallization rate of tungsten is increased from 60% to 80%, the crystallization rate of molybdenum will be increased by nearly 3 times. It is difficult to break through 80% of the crystallization rate.

As a solid waste, wolframite residue needs financial and material resources for harmless disposal.

The flotation of wolframite and scheelite is a difficult problem in the world. Because the composition and structure of the wolframite and scheelite are quite different, the conventional ore dressing method can not decompose the wolfram mixed ore perfectly.

Argon arc welding is an arc welding method using argon as protective gas, and the arc occurs between electrodes and weldments. Argon is formed around the arc to form a continuous closed air flow for protecting arc and molten pool.

Bismuth tungstate (Bi₂WO₆) is the most simple structure of Aurivillius type oxide. Its Bi₆s orbit and O₂p orbit are hybridized to form the valence band. The W5d orbit forms a guide band, and its band gap is narrower (about 2.7eV). It can absorb some visible light and be excited. Therefore, the Bi₂WO₆ photocatalytic material is in the field of environmental purification and new energy development. Potential application value.

Tungsten tailing is a solid waste produced after the selection of tungsten ore, which is used to recycle useful metals and non-metallic minerals, but the component of metal recycled group is less and still remains a large amount of tailings. It is used in the production of glass ceramics, non fired bricks and hollow bricks, with limited usage, high technological cost and limited application benefits.

The application of tungsten elements is very extensive. In order to improve the wear resistance of parts, the most fundamental method is to reduce the particle size of tungsten elements in the material to improve the wear resistance of super hard dies and bits.

The most common method for the production of ammonium para tungstate in tungsten smelting is ion exchange. Ammonium chloride is used as a desorption agent in almost all kinds of tungsten smelting. In order to prevent the production of ammonium para tungstate crystal during the process of desorption, a proper amount of ammonia water must be added to the desorption agent. Therefore, liquid ammonia is a necessary auxiliary material.

The super coarse tungsten powder is the main raw material for the production of coarse grain cemented carbide, and its downstream products are widely used in mining tools, stamping dies, oil drilling and hard surface materials and so on.

At present, the main equipments for producing tungsten powder are propulsion reduction furnace and rotary reduction furnace. The feeding way of a propelled reduction furnace is to place tungsten oxide in a boat, feed and discharge through the the push rod. The feeding mode of the rotary reduction furnace is to put tungsten oxide into the inlet of the reduction furnace and use its own gravity to flow itself into the furnace tube, which has a high requirement for the fluidity of tungsten oxide.