The scheelite is often associated with sulfide ores such as copper-lead-zinc ore and calcium-containing gangue minerals such as calcite and fluorite. At present, it is common to separate the sulphide ores and then scheelite.

Currently, there are three industrial methods for purifying the Ammonium paratungstate (APT) solution from the sodium tungstate solution: chemical method, ion exchange method, and solvent extraction method. Wherein the classical chemical method consumes large energy and has low production, it has been less frequently used. Both ion exchange and solvent extraction have their own advantages and disadvantages.

In the field of microwave electric vacuum device, the preparation of tungsten sponge with uniform pore size is the key to achieve uniform emission of tantalum tungsten cathode current. The tungsten sponge is the main carrier of the impregnated ruthenium tungsten cathode and is made by powder metallurgy. The pores in the sponge are used to store the emitting material and at the same time serve as a transport channel for the emitting material.

Molybdenum is a strictly controlled impurity element in tungsten products. China's national standard GB10116-88 stipulates that molybdenum is not more than 20ppm in the 0 grade ammonium paratungstate. At the same time, tungsten is also a strictly controlled impurity element in molybdenum products. The national standard GB/T3480-2007 stipulates that MSA-0 grade molybdenum acid is not more than 150ppm in the product.