The determination of zirconium in its binary alloys with niobium and tantalum

A procedure is presented for the determination of zirconium in the presence of niobium or tantalum. The bulk of the niobium or tantalum is first removed by extracting with hexone from a 10M hyclrofluoric acid, 6M sulphuric acid solution of the sample. The zirconium is then. separated from any unextractcd earth, acid element by precipitation with ammonium hydroxide followed by the addition of hydrogen peroxide. Under these conditions, both the niobium and tantalum form soluble peroxy complexes whereas the zirconium is completely precipitated from solution. After the separation of the precipitate by filtration, it is re-dissolved in hydrochloric acid and the zirconium concentration is finally determined by titration with ethylenediaminetetraacetic acid.