The Effects of Combined Water-Bearing Minerals on the X-Ray Fluorescence Analysis of Iron Ores

Abstract

An investigation was made of the influence of minerals having water of crystallization on X-ray fluorescence analysis of iron ores using a briquetting technique. An electron microscope, a derivatograph, an infrared spectrometer and an X-ray diffractometer were used together with a fluorescent X-ray spectrometer in this investigation. The results obtained are summarized as follows: (1) The weight of iron ore is considerably decreased by grinding for about 10 min. The weight loss gives a considerable influence on the fluorescent X-ray intensity of iron in iron ore. The analytical precision can be greatly improved by correcting the fluorescent X-ray intensity with the weight loss. (2) The minerals having water of crystallization like goethite (α-Fe₂O₃·H₂O) and kaolinite (Al₂O₃·2SiO₂·2H₂O) are dehydrated by grinding iron ores for about 10 min. (3) Against the dehydration, cobalt (Co₂O₃) is fairly effective as an internal standard for the X-ray fluorescence analysis of iron in iron ores. The internal standard material (Co₂O₃) must be added to iron ores before grinding for its better performance.