抄録
A study of quantitative spectrographic analysis of metallic impurities in high-purity tantalum metal and its compounds has become increasingly important because of the availability of such metal for the electrolytic condenser and the atomic engineering materials. In order to use a medium quartz spectrograph which is unsuitable for the analysis of such an element of complex spectrum as tantalum because of its poor resolving power, an attempt was successfully made to overcome its disadvantage by selecting the optimum condition and using an intermittent AC-arc source unit. The experiments were carried out to select the optimum conditions of excitation, the mixing ratio of carbon powder added as buffer, the formula of relative intensity and the analytical line pairs, and to find the sources of serious errors. This method in which a sample is converted to oxide, can be applied to metallic tantalum of powder or ingot form and its compounds where the concentrations of impurities are greater than 0.03% for W, 0.01% for Ti, 0.005% for Mo, V, 0.003% for Cr, Fe, Nb, Ni, 0.001% for Si, Mn, and 0.0003% for Mg. The coefficient of variation for the analytical result is about 7%. This method is also applicable to the analysis of condenser-grade tantalum powder as well as tantalum for ordinary industrial use.
