X-Ray Spectrogralphic Determination of Zirconium, Tungsten, Vanadiijm, Iron, Titanium, Tantalum, and Niobium Oxildes Application of the Coirrection Factor Method B E l l Y J. MITCHELL Resea& and Development Analyiical Lab,oratory, Technology Department, Union Carbide Metals Co., Division of Union Carbide Corp., Niogon2 Falls, N. Y. ,,
b A multichannel x-ray spectrograph has been applied to the d6termination of the combined oxides of zirconium, tungsten, vanadium, iron, titonium, tantalum, and niobium. Simultaneous measurement of mmbinationr of from two to seven elements varying in concentration range from 0.1 to 99.9% requires less than 2 minuter; total x-ray analyikal time averages less than 15 minutes per oxide sample. An instrumental precision of better than &OS% of the quantity being measured is possible for high percentage components. The effects of interelement absorption are corrected by an arithmetic foctar methad.
I .: '
t l ~ u m ZkCOniUm, , tantalum mobium, tungsten, and vanadium can be determined simultaneously in ores, liquids, high-purity metals, alloys, or oxides whenever it is feasible to prepare a combined oxide sample. The method, based on one developed for use with a Norelco x-ray spectrographic unit (s),employs an x-ray industrial Quantometer, the X I Q (Applied Research Laboratories). When present, additional elements such as tin, molybdenum, or thorium are determined on the scanning equipment. This paper describes the calibration and computational procedure employed with the RON
Table I.
Element Iron Zirconium TantslUm Niobium Tungsten
Titanium Vanadium
1652
e
X I Q for the analysis of combinations of the seven elements-iron, titanium, zirconium, tantalum, niobium, tungsten, and vanadium+ oxides. The interelement effects occurring in combinations of iron, titanium, tantalum, and niobium oxides have heen evaluated (2). The existimg correction method for fonr-element mixtures is extended to include zirconium, tungsten, and vanadium. EQUIPMENT
The x-rav industrial Quantometer
tector outputs are fed to capacitors which simultaneously integrate the fluorescent intensities over a period of time determined hy the intensity of an external standard. Element intensities are then read sequentially as the ratio of the charge on each capacitor to that of the external (or internal) standard capacitor. Because Multitron senhitivity varies directly with the voltage applied, the proper choice of voltage is necessary to obtain linear response for trace, medium, or high concentrations. The integration-readout console is a standard Applied Research Laboratories Model No. 9650. Instrumental operating conditions are listed in Table
Opera
Radius, Detector Voltage Inches Analysis Line Detector Multitron (Argon) 1400 bigl1 % range 4 Fe K a at 1.937 A. 1600 meclium % ' range 11 Zr Ka s t 0.788 A. Same 89 for iron Same as lor iron 4 Ta La, at 1.522 A. 11 Nb K a at 0.748 A. Same as for iron Multitron ( h i o n j 1600 biglI % range 4 W La, at 1.476 A. 1800 me
