Heteropoly acid is a kind of acid, which has been acidified, condensed and dehydrated by two or more than two kinds of inorganic oxyacid ions. It is a new type of acid catalyst and oxidation-reduction catalyst, which has been widely studied and developed in recent years.

Pressure leaching and water leaching are two mature methods for industrial leaching of tungsten from tungsten ore. The leachate obtained by the above two leaching methods is a mixed solution of sodium tungstate and sodium carbonate, which usually contains a small amount of impurities such as P, As, Si, etc. and this solution is a soda leaching solution containing a tungsten material.

Tungsten oxide limonite is a multi metal component, containing tungsten oxide 0.3%-0.6%, iron 26%-31% and other elements such as silicon, aluminum and calcium. It is difficult to be separated and enriched by traditional ore dressing method, it can not be enriched in high grade like other tungsten ores. At present, the ore can only be used as the raw material for cement production. A large amount of precious metal tungsten is irreversibly disappearing in building materials.

Tungsten is a very important non-ferrous metal. It has a series of properties such as high density and high strength. It is commonly used in counterweight materials, shielding materials, military firing materials, semiconductor materials, etc.