ELECTRON-BEAM MELTING AND REFINING OF NIOBIUM

With respect to the importance of remelting of the ATR-Nb for the future large scale production of niobium applied to corrosion resistance materials and superconducting magnets with Nb-Ti alloys, the electron beam melting and refining have been examined to the following items: 1) Process for the winning of niobium, 2) Thermochemical background for the melting and refining of niobium in vacuum, 3) Electron beam cold hearth remelting of niobium and 4) Purification of the ATR-Nb. In this process, the electron beam furnace can act not only as remelting but also as refining apparatus. The experimental results showed its feasibility for obtaining niobium ingot of more than 99.8 mass% purity from crude raw materials.