1980 Volume 21 Issue 6 Pages 390-400
Based on Claisse’s model and considering the effects of the particle size and mixing rate, a theoretical formula expressing the intensity of the fluorescent X-rays emitted from heterogeneous systems has been established, by which the degree of homogeneity can be determined. The formula indicates that the effect of cobalt on the internal standard analysis of Fe content increases when the specimen and the element added thereto are pulverized to 2–3 μm or finer and thoroughly mixed. Insufficient mixing results in an apparent increase in the particle size. As microscopically confirmed, an iron ore sample, added with a briquetting binder and an internal standard, can be pulverized to 5 μm or finer by wet crushing for 3–5 min. This crushing also assures good mixing. This method almost fully cancels the influence of the matrix, and permits accurate determination of Fe content in various grades of iron and manganese ores and slags. The calibration curve is not necessarily linear over the wide Fe content range, probably because of the slight difference between the absorption coefficients of Fe and Co.
