Potassium fluorotantalate in solid, dissolved and molten conditions

Potassium fluorotantalate—K2TaF7 (K-salt) is used as an initial material for tantalum metal production. Current technology of tantalum metal powder is based on K-salt preparation from fluoric solutions in the form of small crystals and its reduction by sodium from the melt. The paper collects available data on K-salt preparation, structure and main properties of crystalline, dissolved and molten K-salt. The information could be useful for tantalum producers and researchers dealing with tantalum chemistry.