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US 6,171,363 B2Granted
Method for producing tantallum/niobium metal powders by the reduction of their oxides with gaseous magnesium
AssigneeH. C. Starck GmbH
InventorsLeonid N. Shekhter, Terrance B. Tripp, Leonid L. Lanin
Life of this patent
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Abstract
Metal powder from the group Ta, Nb, Ti, Mo, W, V, Zr, Hf preferrably Ta or Nb, is made in a fine powder form by reduction of metal oxide by contact with a gaseous reducing agent, preferrably an alkaline earth metal, to near complete reduction, leaching, further deoxidation and agglomeration, the powder so produced being sinterable to capacitor anode form and processable to other usages.
Claims11
Process for production of capacitor or metallurgical or chemical grade metal powder selected from the class consisting of tantalum and niobium, comprising the steps of:
- (a) providing an oxide or mixed oxides of the metal(s), the oxide or mixed oxides being in a form, that is traversable by gas,
- (b) generating a mixture of gaseous reducing agent and inert diluent gas and passing the gas mixture through the mass at an elevated temperature, effective to gradually reduce the oxide(s),
- (c) selecting the reactants, porosity of the oxide, temperature and time of the reduction reaction for substantially complete reduction of the oxide(s) to free the metal portion(s) thereof, the residual oxide of reducing agent formed in the reaction being easily removable,
- whereby a high surface area, flowable primary metal powder of tantalum and/or niobium is formed in a process that essentially avoids use of molten state reducing agent in production of primary powder.
1 more element
Dependencies are inferred from the claim text.