A spectrographic method for determining the hafnium-zirconium ratio in zircon

Abstract

To develop a rapid spectrographic method for the determination of hafnium, the hafnium-zirconium ratio, and percentage of zirconium in the mineral .zircon, the ratio was determined first by plotting the log of the intensity ratios against the log of the hafnium-zirconium ratio by weight of the standards, using -zirconium as an internal standard (zirconium 2761.911 A and hafnium 2641.406 A or zirconium 2761.911 A and hafnium 2820.224 A). Straight-line curves were produced when the line pairs zirconium 2538.405 A and hafnium 2641.406 A were used in a similar manner for the hafnium determinations. After the liafniumzirconium ratios and the hafnium percentages were determined, the zirconium percentages were determined arithmetically and some were checked by direct spectrographic analysis. When chemical methods were used to check the spectrographic hafnium and zirconium totals, an average spread of 0.14 was obeserved. The results indicated an average accuracy of 3 percent of the hafnium present in the range of 0.5 to 2.0 percent, and 0.6 percent for zirconium in the 43 to 58 percent range.