A study was made of the preparation of a uranium - 10 w/O niobium alloy by the bomb reduction of a suitable form of niobium and uranium tetrafluoride with calcium. A compound with a probable formula of Na2NbOF5 proved to be most satisfactory as the source of niobium. High yields and good metal-slag separations were obtained. Chemical analysis and density determinations showed the composition to be 10 ℗± 0.5 w/o niobium. Fifteen pounds of alloy were melted in BeO and cast into a graphite mold.

The niobium-uranium alloy is dissolved in hydrofluoric nitric acids and the fluoride removed by fuming sulfuric acid. The niobium is hydrolyzed in an acid-sulfur dioxide medium and converted to niobic oxide by ignition at 900 deg C. The method covers the determination of niobium in niobium-uranium alloys having a niobium content of 8 to 12%. Metals which hydrolyze readily in dilute acid solutions interfere with the determination. (auth).