Tungsten slag is produced in tungsten smelting process, that is, tungsten ore and waste tungsten carbide raw materials are decomposed by wet method in high temperature or aqueous solution to obtain primary tungsten products (sodium tungstate, ammonium paratungstate) and solid waste slag (i.e. tungsten slag).

Q-switched laser technology is a technology that compresses the general output continuous laser energy into a very narrow pulse to emit, so that the peak power of the light source can be increased by several orders of magnitude. Because Q-switched lasers can obtain high peak power and narrow pulse width, they are widely used in industrial processing and scientific research fields, such as the manufacture of ultrafine semiconductors, terahertz wave equipment and so on.

Tungsten metal has excellent physical and chemical properties, such as high melting point (3410 ℃), high density (19.35g/cm³), high conductivity/thermal conductivity, excellent high temperature strength and hardness, low work escape, very low thermal expansion coefficient and vapor pressure, and good corrosion resistance, which makes tungsten an important functional material and high temperature structural material.

Non-noble metal sulfides are layered materials with graphene-like structure, which have good applications in catalysis, microelectronics, semiconductor and other fields. Tungsten sulfide and molybdenum sulfide catalysts have been used as hydrogenation catalysts in petroleum processing. They are widely used in hydrodesulfurization, hydrodenitrification, hydrodearomatization, hydrodeoxygenation and hydrodemetallization.

As the main transition metal selenide, tungsten diselenide (WSe₂) is a kind of engineering material and functional material with many special properties. WSe₂ crystal has a hexagonal sandwich structure similar to MoS₂. Each WSe₂ molecule layer is composed of two Se atom layers with a W atom layer. The W atom layer and Se atom layer are covalently bonded, while the adjacent WSe2 layers are separated by Se layer with a long distance and a weak van der waals force.

In order to ensure the uniformity of the dispersion of the composite particles and to improve the properties of the materials to the greatest extent, it is often required that the doped phase particles be coated on the surface of the matrix particles to form a coating to achieve the best mixing degree.

Suspension bed hydrogenation is an advanced technology for preparing liquid fuel oil from heavy unconventional oil. Suspension bed hydrogenation process requires catalyst with high activity, high dispersibility, high stability and good economy. Tungsten sulfide and molybdenum sulfide catalysts have been used as hydrogenation catalysts in petroleum processing. They are widely used in hydrodesulfurization, hydrodenitrification and other reactions. They are very promising catalysts for heavy oil hydrogenation in suspension bed process to produce clean fuel.

In recent years, more and more studies have been carried out on the properties of Er-doped materials, including infrared-visible up-conversion, optical and electrical properties of Er, as well as the progress and development of laser diodes, which have attracted unprecedented attention to Er-doping and luminescence.

Under the existing technical system, a large amount of sodium silicate (sodium silicate) is usually added to the flotation process of scheelite to form a very stable colloidal dispersion system of fine particles in the pulp, which is conducive to flotation. However, a large amount of water glass wastewater has also been produced after flotation.

The traditional preparation methods of sintered W-Co cemented carbides are usually composed of WC-TiC compound carbides and WC powder, Co powder through proportioning, ball milling, drying, mixing of forming agents, pressing and sintering. The toughness and flexural strength of the tungsten-cobalt-titanium cemented carbides prepared by this method have been improved, but the density and hardness of the materials are low, and the high temperature resistance is poor, so they can not be used as high-speed cutting tools. Tools can only be used for rough or semi-finish machining.