Electron-beam melt refining of ferroniobium
AssigneeTeledyne Industries, Inc.
InventorsRichard S. Puopolo, John Roger Peterson, Richard Myers
Life of this patent
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Abstract
Niobium, Nb, is refined from FeNb by electron beam melt refining. The amount of the impurities in the FeNb which form suboxides with oxygen is optionally determined. Sufficient oxygen is added to form oxides with these impurities. The electron beam melt refining process is carried out at a sufficiently high temperature and under a sufficiently low vacuum so that the impurities are removed as oxides from the liquid Nb and the purified Nb is recovered. Preferably the oxygen is added as an oxygen-containing compound such as Nb.sub.2 O.sub.5. The recovered Nb can be subjected to additional electron beam melt refining cycles to obtain the desired purity.
Claims11
A process for separating and purifying metal values from master alloys of iron, magnesium, chromium, cobalt, nickel, vanadium or mixtures thereof in combination with other metal values selected from the group consisting of niobium, tantalum, tungsten, molybdenum, hafnium, zirconium, titanium and mixtures thereof, which alloys are prepared by ore or slag reduction techniques and contain impurities, said process comprising steps of:
- (a) adding sufficient oxygen to the master alloy to form oxides of impurities present;
- (b) conducting an electron beam melt refining process on the master alloy with added oxygen at a sufficient vacuum so that oxides of the impurities and master alloy metal to be removed from the other metal values are separated from the melt;
- and
- (c) recovering the metal values after the removal of the oxides and master alloy metal.
A process for refining Nb from FeNb containing impurities, where Nb in the FeNb can vary from 25% to 95% or more, by electron beam melt refining, comprising steps of:
- (a) adding sufficient oxygen to form oxides with the impurities;
- (b) conducting the electron beam melt refining process at a sufficiently high temperature and under a sufficient vacuum so that the impurities are removed from liquid Nb;
- and
- (c) recovering purified Nb.
Dependencies are inferred from the claim text.