STUDY OF X-RAY-FLUORESCENCE SPECTROMETRY AND SPARK ABLATION INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY FOR CHROMIUM DETERMINATION IN FERROCHROMIUM FROM BULK METAL SAMPLES

A study of chromium determination in ferrochromium by X-ray fluorescence and spark ablation inductively coupled plasma atomic emission spectrometry was made. Bulk test samples were prepared by re-melting the ferroalloy diluted with iron in an induction furnace. Calibration samples were obtained from an industrial ferroalloy, using different FeCr+Fe dilution ratios, in order to cover the chromium concentration range that is probably present in these materials. A study is presented of the influence of the carbon contents on Cr Kalpha line intensities and on the amount of spark aerosol produced, as well methods of compensating for the effect. The total variance and the average instrumental variation were calculated from the values obtained for samples with the same chromium concentration and variable carbon contents. The criterion applied to test the agreement of the two methods showed that the difference between the results provided by both techniques can be explained by random errors. Accuracies were tested by analysing a series of ferrochromium reference materials.