GB791121A - Improvements in or relating to the production of niobium - Google Patents

Abstract

791,121. Producing niobium. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Dec. 9, 1955 [Nov. 18, 1954], No. 33386/54. Class 82(1) Niobium is produced by reduction of potassium niobium fluoride by means of sodium which is used in a small excess, e.g. 10 per cent, of that stoichiometrically required. The reactants are heated in an inert atmosphere such as argon to bring about initiation of the reaction and the reaction products are maintained at a temperature above the boiling point of sodium to distil any excess of sodium and any potassium which has been formed. As shown, the reactants are contained in crucible 2 in which they are placed in alternate layers, each being rammed down before addition of the next layer. The crucible is contained in reactor vessel 5 which is surmounted by a cooled condenser 6 for collection of any distilled sodium and is connected through pipe 7, valves 10 and 11 to expansion chamber 13 and to tube 14 through which evacuation and charging with argon is effected. Electric furnace 1 is energized to heat the crucible to 420‹C. at which temperature the reaction commences. At the conclusion of reaction the temperature is raised to 1100‹C. to distil off any sodium remaining. The reactor is allowed to cool to 600-700‹C., valves 10 and 11 are closed and the connection between them broken and the reactor is removed and cooled to room temperature in air. The products of reaction are removed, crushed and leached two or more times in water, the first leaching being carried out in a short period, e.g. 3 minutes, to minimize loss of niobium as niobate. The niobium may be then washed with de-mineralized water and dried.