2019 Volume 105 Issue 5 Pages 560-565
An accurate quantitative analysis method including total iron had been proposed for the iron ore analysis by wavelength dispersive X-ray fluorescence spectrometry using fusion method and was accepted at ISO TC 102 meeting in 2010. The project has been proceeded in ISO TC 102/SC 2/WG54 as ISO/WD 9516-2 project. Number of covered elements is 19, and 14 elements among them including total iron are for referee analysis. The calibration discs are prepared only from reagents and the calibration equation includes coexisting component correction, overlap correction, flux/sample and oxidizer/sample mixing ratio corrections. The coexisting component correction method is based on the absorption/enhancement correction coefficients obtained by a FP (fundamental parameter) method so that LOI (loss on ignition) and GOI (gain on ignition) during fusion do not affect to analyzed results. In the verification experiments with 20 certified reference materials, the accuracy obtained by root mean square of the difference between certified values and analyzed values using proposed method was 0.14 mass%, which indicated analytical accuracy could be greatly improved compared with the existing method. For the other components, the values of accuracy obtained were almost same as the existing method. We are conducting final round-robin test in foreign laboratories and have a plan to set the method as an ISO standard.
