Production of high-purity niobium monoxide and capacitor production therefrom
View Patent ↗The present invention relates to high-purity niobium monoxide powder (NbO) produced by a process of combining a mixture of higher niobium oxides and niobium metal powder or granules; heating and reacting the compacted mixture under controlled atmosphere to achieve temperatures greater than about 1800° C., at which temperature the NbO is liquid; solidifying the liquid NbO to form a body of material; and fragmenting the body to form NbO particles suitable for application as e.g., capacitor anodes. The NbO product is unusually pure in composition and crystallography, highly dense, and can be used for capacitors and for other electronic applications. The method of production of the NbO is robust, does not require high-purity feedstock, and can reclaim value from waste streams associated with the processing of NbO electronic components.
1. A method of producing niobium monoxide (NbO) powder which comprises:
a) combining a mixture of (1) a niobium oxide selected from the group consisting of Nb 2 O 5 , NbO 2 and Nb 2 O 3 , and (2) metallic niobium, wherein the niobium oxide and metallic niobium are present in powder or granular form;
b) forming a compact of the mixture;
c) reacting the compact of the mixture with a heat source to a temperature greater than about 1800° C.;
d) solidifying the reacted mixture to form a body of material; and
e) fragmenting the body of material to form the NbO powder.
2. The method as recited in claim 1 , wherein the weight ratio of Nb 2 O 5 to metallic niobium in the mixture is about 1:1.
3. The method as recited in claim 1 , wherein the weight ratio of NbO 2 to metallic niobium in the mixture is about 1.3:1.
4. The method as recited in claim 1 , wherein the weight ratio of Nb 2 O 3 to metallic niobium in the mixture is about 2.5:1.
5. The method as recited in claim 1 , wherein the niobium oxide is Nb 2 O 5 .
6. The method as recited in claim 1 , wherein the heat source is an electron beam furnace.
7. The method as recited in claim 1 , wherein the heat source is a plasma-arc furnace.
8. The method as recited an claim 1 , wherein the heat source is an induction furnace.