Production of high-purity niobium monoxide and capacitor production therefrom

Abstract

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 high-purity niobium monoxide (NbO) powder, produced by a process comprising: 
 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 mixture with a heat source, so that a mixture temperature greater than about 1800° C. is reached;    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 niobium monoxide powder 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 niobium monoxide powder 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 niobium monoxide powder 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 niobium monoxide as recited in  claim 1 , wherein the niobium oxide is Nb 2 O 5 .  
   
   
       6 . The niobium monoxide as recited in  claim 1 , wherein the heat source is an electron beam furnace.  
   
   
       7 . The niobium monoxide as recited in  claim 1 , wherein the heat source is a plasma-arc furnace.  
   
   
       8 . The niobium monoxide as recited in  claim 1 , wherein the heat source is an induction furnace.  
   
   
       9 . The niobium monoxide as recited in  claim 1 , wherein the heat source is an electric resistance furnace.  
   
   
       10 . The niobium monoxide as recited in  claim 1 , wherein electronic valves are produced from the niobium monoxide powders.