The invalidation modes of tungsten carbide rock drilling button include the phenomenon of thermal fatigue and the detachment of the button. 

Ammonium paratungstate is an important tungsten intermediate chemical products, mainly white crystals, there are two kinds of flake or needle, used to make tungsten trioxide or blue tungsten oxide metal tungsten powder, also used to make ammonium metatungstate and other tungsten compounds.

Nitrogen oxide (NOx) is one of the sources of air pollution and poses a great threat to human health. Thermal power plant is one of the main sources of NOx emission. At present, the main dry flue gas denitrification method is selective catalytic reduction (SCR), the key part of which is catalyst.

The existing scheelite is mainly recovered by two methods: one is the "Petrov method" with flotation as the main method, in which sodium carbonate is used as adjusting agent, sodium silicate as inhibitor and fatty acid as collector for normal temperature flotation to obtain high-grade (about 2%) tungsten crude concentrate, the other is the concentrated slurry heating concentrate. Gravity separation is mainly a combined process of gravity and flotation. According to the uneven distribution of scheelite particle size, the method adopts the principle of "stage grinding - stage separation" to carry out gravity separation and recovery, the obtained tungsten fine mud is recovered by flotation.

Metal tungstates are a kind of important inorganic materials. They have good application prospects in optical fibers, scintillation materials, photoluminescent materials, humidity sensors, magnetic devices, microwave applications, catalysts and corrosion inhibitors. Among them, zinc tungstate nanometer material is a good photoluminescence, photocatalytic and gas sensitive material. However, pure zinc tungstate nanomaterials are less sensitive to hydrogen.