Determination of niobium in niobium containing multi-metal ore by X-ray fluorescence spectrometry with powder pressed pellet
LIANG Zu-shun1,LI Xiao-li*2, LIU Feng3,LI Guo-hui4
1.209 Geological Survey and Exploration Team of Yunnan Nuclear Industry,Kunming 650607,China; 2.Tianjin Institute of Geology and Mineral, Tianjin 300170,China;3.Armed Police Golden 2 Team Laboratory,Hohhot 010010,China; 4. Institute of Geophysical and Geochemical Exploration,Chinese Academy of GeologicalSciences, Langfang 065000,China
Abstract：A method for the determination of niobium in niobium containing multi-metal ore by X-ray fluorescence spectrometer(XRF) with powder pressed pellet was studied. Since there are quite few niobium containing multi-metal ore and the content of niobium is quite low, tantalum ore certified reference materials, representative samples in ore area calculated by chemical method ,and calibration samples prepared by soil, rock, multi-metallic minerals certified reference materials and ore samples were selected to prepare calibration sample series with 5.9-2 700 μg/g niobium. The correlation coefficient of calibration curve was 0.998 6. Empirical coefficients and Compton scattering line internal standard method were applied to correct matrix effect. Omnian software for approximate quantitative analysis, chemical analysis and rock and mineral identification were used to determine the highest allowable amount of SiO2, Al2O3, CaO, MgO, K2O, Pb, Zn, Cu, Fe, Zr, Mo, Rb, Hf, Th, U, Ti, Ga and rare earth in the ore. By considering the influence of matrix to the detection limit of niobium, the average detection limit of 8 certified reference materials was 1.62 μg/g. The precision of rock certified reference material was investigated with the RSD (n=12) of 2.2%. Standard sample and practical ore sample were analyzed. Tested value and certified value, the tested value by other methods of internal laboratory and the tested value by other laboratories were consistent with each other, meeting the requirement of Quality Management Practices of Geology and Mineral Resources Laboratory.
