Patent holder (s):
PJSC “State Research and Design Institute of Rare-Metal Industry “Giredmet”
L.I. Voronenko, A.V. Elyutin, K.S. Kovalyov, F.V. Kovalyov
The invention relates to refractory rare metal metallurgy area, particularly to niobium metallurgy, and can be used in producing high purity niobium and products made of it for microwave engineering and microelectronics. Technological effect of the invention is production of high purity niobium and products made from it, which have impurity total content of 0,002 - 0,007 mass.%, as well as increase of niobium yield and loss reduction. Process for producing high purity niobium includes crude niobium electrolytic refining in salt melt containing potassium fluocolumbate and potassium and sodium chloride equimolar mixture, and the following electron-beam melting of cathode deposition in vacuum. According to the invention, sodium fluoride is added into electrolyte in the capacity of 5-15 mass.%, and electron-beam melting of cathode deposition is performed in oil-free vacuum at residual gas pressure of 5·10-5 - 5·10-7 mm Hg, melting chamber leakage no more than 5·10-2 l.mcm/s and melting rate of 0,7 - 2 mm/min, produced niobium ingot is processed by pressure at temperature of 300 - 8000С, and undergoes thermal and chemical treatment while product manufacturing.