Industrial wastes containing heavy metals such as copper, nickel, cobalt, manganese, tungsten, and other heavy metals are treated by proper methods, and the valuable components of the industrial waste can be recycled, the harmless and resource utilization of industrial waste can be realized. At present, the method of metal recycling for such industrial wastes is usually used by alkali leaching, using sodium hydroxide or sodium carbonate as leach agents. The tungsten is leached under normal pressure or pressure condition, and tungsten is separated from other metals, and the tungstate solution is obtained by ion exchange and enrichment in the next step, the alkali leaching residue is then soaked in acid. Removal of impurities, separation and purification of copper, nickel, cobalt and manganese products.

Nanocrystalline WC-Co cemented carbide has been widely used in cutting tools, impact tools and wear resistant parts, because of its high hardness and high strength. Nano tungsten powder with uniform particle size and good dispersibility is the key technology for the preparation of high performance nanocrystalline WC-Co cemented carbide.

The alkaline decomposition method of high calcium tungsten ore is first grinding with high calcium tungsten minerals (tungsten concentrates, wolwolwoltungsten medium ore, wolframite, high calcium tungsten fine mud, calcium containing 3%), and then the grinding high calcium tungsten minerals and high concentration alkali are added together in the ordinary stirred autoclave, at the temperature of 130-200°C and pressure 0.15-1.0MPa. Under the conditions of heat preservation and pressure cooking, after the pressure cooking is unloaded, the filtration and washing are carried out at a certain temperature and NaOH concentration, and the sodium tungstate solution is purified. The sodium tungstate solution contains WO₃ 80-300g/L and the free NaOH is 90-280g/L.

Tungsten carbide is black hexagonal crystal which has metallic luster, the hardness is closer to diamond. Since 1973, Levy R B firstly brought up the idea of catalytic effect of tungsten carbide like Pt, researchers started using it in multiphase catalytic and electro catalytic field to take place of precious metal catalyst.