X-ray fluorescence determination of major and minor elements in ferrotitanium, ferroniobium and ferrovanadium from compressed pellets and fusion beads

Abstract

This paper describes the x-ray fluorescence determination of major and minor elements in ferrotitanium, ferroniobium and ferrovanadium. Samples preparation was accomplished using two different procedures: compressed pellets and fusion beads. Calibration graphs were prepared by mixing two ferroalloys of each of the considered types in different proportions. These ferroalloys were selected from industrial batches, providing the most varied composition available in order to cover as completely as possible the ranges of composition listed in ISO specifications. Total reproducibility tests, incorporating sample preparation and measurement,were performed using six samples preparedwith the ferroalloys having the highest alloying grade. The relative standard deviation (RSD) values referred to the major element in Fe–Ti, Fe–Nb and Fe–V were 0.20, 0.17 and 0.21%, respectively, when using compressed pellets, and 0.16, 0.14 and 0.13% when using fusion beads. As regards the minor elements, the RSD values were in all cases below 5% for compressed pellets and below 3% for fused beads. The criterion applied to test the agreement of the two methods showed that the difference between the results provided by both samples preparation systems may be explained in terms of random errors. Accuracy was checked by analysing Certified Reference Materials of each of the types of ferroalloys studied.