Method for producing high-purity niobium

摘要

A method for producing high-purity niobium involves refining crude niobium in an electrolyte comprising a melt of salts containing a complex niobium and potassium fluoride and an equimolar mixture of alkaline metal chlorides, said electrolyte further containing sodium fluoride in the amount of from 5 to 15 wt %, and subjecting the obtained cathode deposit to electron-beam melting in a vacuum free of oil vapors under a residual gas pressure of from 5*10-5 to 5*10-7 mm Hg, a melting rate of from 0.7 to 2 mm/min and a leakage into a melting chamber from 0.05 to 0.005 l .mum/s to produce an ingot of niobium. The method produces high-purity niobium having the total amount of impurities within the range of from 0.002 to 0.007 wt % which satisfies the requirements imposed on the materials used in microwave technology and microelectronics, with reduced losses of niobium in both of the refining stages and increased yield of high-purity niobium.