Method of manufacturing niobium and/or tantalum powder
A method of manufacturing niobium and/or tantalum powder consisting of: a first-stage reduction process of reducing niobium and/or tantalum oxides with alkali metals and/or alkaline-earth metals to obtain low-grade oxide powder represented by (NbTa) Ox, where x=0.06 to 0.35, a process of removing the oxide of alkali metals and/or alkaline-earth metals generated in the first-stage reduction process, and a second-stage reduction process of reducing the low-grade oxide powder obtained in the first-stage reduction process, with a melt solution of alkali metals and alkaline-earth metals to obtain niobium and/or tantalum powder.
1. A method of manufacturing niobium and/or tantalum powder consisting of:
(1) a first-stage reduction process of reducing niobium and/or tantalum oxides with at least one member selected from the group of alkali metals and alkaline-earth metals to obtain low-grade oxide powder represented by (NbTa) Ox, where x=0.06 to 0.35, wherein the at least one member is turned to an oxide,
(2) a process of removing the oxide of at least one member generated in the first-stage reduction process, and
(3) a second-stage reduction process of reducing the low-grade oxide powder obtained in the first-stage reduction process, with a melt solution of at least one member selected from the group of alkali metals and alkaline-earth metals in a temperature range of 400 to 1200° C., to obtain niobium and/or tantalum powder.
2. The method of manufacturing niobium and/or tantalum powder according to claim 1 , wherein in the second-stage reduction process, when reducing the low-grade oxide powder obtained in the first-stage reduction process with the at least one member selected from the group of alkali metals and alkaline-earth metals, the quantity in mixture of the at least one member is adjusted to a chemical equivalent of 0.5 to 1.5 for the stoichiometry required for removing the oxygen remaining in the low-grade oxide powder, so that the remaining amount of the at least one member is up to 200 ppm in the niobium and/or tantalum powder.