Used for mordant, analytical reagent, catalyst, water treatment agent, manufacture of fireproof and waterproof materials, and phosphotungstate, boron tungstate, etc. They are used as catalysts for cracking hydrocarbons and in the dehydrogenation of olefines, in textiles as a mordant, and in the making of plastics (7). Tungstic acid glue has also been suggested as an India rubber substitute
Tungsten is rather resistant to attack by acids, except for mixtures of concentrated nitric and hydrofluoric acids, and it can be attacked rapidly by alkaline oxidizing melts, such as fused mixtures of potassium nitrate and sodium hydroxide or sodium peroxide; aqueous alkalies, however, are without effect. It is inert to oxygen at normal temperature but combines with it readily at red heat, to give the trioxides, and is attacked by fluorine at room temperature, to give the hexafluorides.