Niobium powder and a process for the production of niobium and/or tantalum powders
AssigneeH. C. Starck GmbH
InventorsJosua Loffelholz, Frank Behrens
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Abstract
The process comprises the reduction of niobium and/or tantalum oxides by means of alkaline earth metals and/or rare earth metals, wherein the first reduction stage is carried out as far as an average composition corresponding to (Nb, Ta)O.sub.x where x=0.5 to 1.5 and before the second stage the reduction product from the first stage is freed from alkaline earth oxides and/or rare earth metal oxides which are formed (and optionally from excess alkaline earth metal and/or rare earth metal) by washing with mineral acids.
Claims11
A process for producing niobium and/or tantalum powders by the reduction of their corresponding niobium and/or tantalum oxides, wherein the reduction is carried out in two stages using a reducing agent selected from the group consisting of alkaline earth metals and rare earth metals, the process comprising:
- conducting the first reduction stage using said reducing agent until an average composition corresponding to (Nb,Ta)O.sub.x where x=0.5 to 1.5 is reached,
- washing the reduction product from the first reduction stage with one or more mineral acids to remove oxides of the reducing agent, and then
- conducting the second reducing stage with said reducing agent to produce powder of the metal.
Niobium powder agglomerates with a primary grain size of diameter 0.1 to 1 .mu.m and an agglomerate diameter distribution corresponding to a D50 of 100 to 300 pm as determined by Mastersizer.
Dependencies are inferred from the claim text.