Potassium fluorottanate (K2TaF7) is an inorganic compound that usually exists as a white crystalline powder. It is slightly soluble in cold water, hydrofluoric acid, but soluble in hot water. 

The main uses of potassium fluorottanate include the preparation of tantalum metal and other tantalum compounds, as well as as catalysts and reagents. The preparation of this compound usually involves crushing tantalum and niobium ore and mixing it with hydrofluoric acid and sulfuric acid to obtain potassium fluorotanate after a series of chemical treatments.

Uses of Potassium Fluorottanate 

1. Preparation of tantalum metal: Potassium fluorottanate is an important intermediate in the production of tantalum metal. Tantalum metal has an extremely high melting point, excellent corrosion resistance and good electronic properties, so it is widely used in aerospace, chemical, electronic and other high-tech fields.

2. Catalysts and reagents: In chemical synthesis, potassium fluorottanate can be used as a catalyst and reagent, especially in organic synthesis. It is also used in the production of other tantalum compounds, which have important applications in the catalytic, electronics, and ceramics industries.

3. Nuclear industry: Potassium fluorottanate also has certain applications in the nuclear industry, such as in the manufacture of fuel rods for nuclear reactors.

4. Other applications: In addition to the above applications, potassium fluorottanate may also be used in the production of optical glass, electronic ceramics, and other advanced materials.