A Novel Technology For Rock-Mineral Identification:Application Of Micro-X-Ray Fluorescence Spectrometry In Analysis Of Nonferrous Metallic Ores

Using microscope to identify minerals and rocks by observing the physical properties of minerals, mineral structures, mineral symbiotic characteristics and the relationship between minerals, is the basic means of rock-mineral identification. But there are isomorphous in many natural minerals, such as tetrahedrite, tennantite, galena, clausthalite, ferberite, hubnerite and so on. It is difficult to distinguish these minerals with similar characteristics using microscope. The chemical composition and structure of these kinds of minerals can be obtained by using electron microscope, electron microprobe analysis, ion probe analysis, which is necessary for mineral identification, naming and research.In this thesis, a novel rock/mineral identification method has been established based on micro-X-ray fluorescence spectrometry to obtain micro-situ chemical composition of minerals, to solve the difficult microscope identification problems of isomorphism mineral, most of the uncommon sulfide and rare minerals, and to improve the naming accuracy of minerals. At the same time, this novel method can fully exploit the potential of such instruments, broaden the application field of the X-ray fluorescence analysis, improve the efficiency of the instrument, and supply and improve the micro-analysis technology. This thesis includes the following aspects:1. A total of60non-ferrous metallic ore samples including copper, lead, zinc, tungsten and molybdenum ore etc. have been collected. After making slices, plane processing, and polishing, the specimens were made to be identified. Ore samples were studied and identified using microscope coupled with electron microprobe analysis. The minerals have been named, the structural features described, and the various features explained by mineralogical means.2. Elemental distribution of the specified area of the ore samples have been analyzed under the optimum conditions. Two or three-dimensional elemental distribution maps have been drawn using the fluorescence intensity measured. And the model of X-ray fluorescence microanalysis qualitative identification of rock-mineral has been established.3. Spectrum overlapping of the possible interfere elements to the analysis elements in the ore samples has been studied. The best correction scheme of matrix effect and mineral effect on the results of quantitative analysis has been selected. At last, the model of X-ray fluorescence microanalysis quantitative identification of rock-mineral has been established. The quantitative identification results of this method have been verified with electron microprobe analysis and chemical analysis method. And the X-ray fluorescence micro-quantitative analysis technique has been further improved.4. All non-ferrous metallic ore samples have been analyzed using the models established in this thesis. The elemental distribution maps in the measurement region have been drawn. The minerals were named according to the principal component content, combined with the theoretical value of the mineral component content.