Laser Induced Breakdown Spectroscopic Technique And Its Application In Quantitative Elemental Analysis Of Ores

Metal and non-metallic elemental concentrations in ores are important indices of ore availability. Accurately measuring elemental concentrations will be helpful to classify ores and improve the efficiency of geological explorations. Among numerous exploration techniques, the hyperspectral remote sensing method, based on remote sensing image and spectroscopy, has been used to explore the earth surface layers. However, only physical and geological characters in the areas being explored can be recognized roughly. In order to obtain more accurate analytical results, some other quantitative analyzing means should be used to determine elemental concentrations of geological sample on surface or underground. Commonly used methods such as titration, spectrophotometry, X-ray fluorescence spectrometry, etc, all are complicated, time-consuming, unable to be used online and difficult to conduct multi-elemental analysis. The laser-induced breakdown spectroscopy (LIBS) technique was therefore proposed to quantitatively analyze and classify ores.In this article, the origin the LIBS technique, theoretical and application-oriented studies of LIBS were summarized; the basic principles and characteristics of LIBS were introduced, and quantitative analytical methods of LIBS were described; the experimental devices and samples were introduced, the classification of ore samples were researched. The experimental parameters which influence spectral characters of the ore samples were optimized, providing an experimental optimization basis for the study of quantitative ore analysis.Then the external standard method and the internal standard method for ores quantitative analysis were used to analyze 4 standard ore samples, calibration curves of analyzing elements were established. Concentrations of other ores were determined. Through comparing the actual content values with analytical results obtained by these two methods, feasibility for rapid elemental concentration measurement of ores by the LIBS technique was verified. Combining the two methods will be beneficial to reduce the measurement errors and this fact provides an experimental basis for geochemical exploration.Finally, a summarization of the article was put forwarded. Problems pertaining to quantitative measurements of ores by means of the LIBS technique were pointed out. Suggestions for further research were given.