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).

A satisfactory procedure is described for the analysis of uranium-niobium alloys containing up to 25% niobium. It is based on the separation of the niobium from uranium by dissolving the cupferron complex of the former element into chloroform. After the evaporation of the solvent from the combined organic extracts, the niobium is ignited to the pentoxide. The uranium is afterwards precipitated from the remaining aqueous solution by the addition of ammonium hydroxide after the wet oxidation of organic matter. Absorptiometric procedures are included for the determination of the small amounts of uranium co-extracted with the niobium and the trace amounts of unextracted niobium. (auth).