Abstract Trace U species (i.e., ppm) found in the combined solid and liquid residues from uranium milling operations, known as tailings, are of scientific interest as tailings management facilities (TMFs) are designed to keep U species and other potentially harmful substances sequestered as solid species to limit exposure to the environment. Use of X-ray microprobe to study U within solid tailings is challenging due to overlapping U Mα1 and K Kα1 X-ray fluorescence (XRF) signals. This problem of overlapping XRF signals is worsened due to the K concentration in the tailings being much higher than that of U. Reported herein is a methodology for using X-ray microprobe and the U Mα1 XRF signal to determine the distribution of U in samples of U mill tailings from the TMF located at McClean Lake, SK. The reported methodology utilizes an excitation energy just above the U M5-edge to avoid excitation of the K K-edge or an excitation energy that is higher than the K K-edge with the resulting XRF spectra being fitted to deconvolute the overlapping U Mα1 and K Kα1 XRF signals. Also discussed is the use of U M5-edge micro X-ray absorption near edge spectroscopy (μ-XANES) to both verify the U X-ray microprobe map collection methodology and to obtain chemical information on the U species present in the tailings.

中文翻译：

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使用 X 射线微探针分析 U 磨尾矿中的低浓度 U 物质

摘要 铀研磨作业产生的固体和液体残留物（称为尾矿）中发现的痕量 U 物种（即 ppm）具有科学意义，因为尾矿管理设施 (TMF) 旨在将 U 物种和其他潜在有害物质隔离为固体物种以限制暴露于环境中。由于 U Mα1 和 K Kα1 X 射线荧光 (XRF) 信号重叠，因此使用 X 射线微探针研究固体尾矿中的 U 具有挑战性。由于尾矿中的 K 浓度远高于 U 的浓度，因此 XRF 信号重叠的问题变得更糟。 本文报告了一种使用 X 射线微探针和 U Mα1 XRF 信号来确定 U 在样品中的分布的方法。来自位于 SK 麦克林湖的 TMF 的 U 磨尾矿。报告的方法利用刚好在 U M5 边缘上方的激发能量来避免激发 K K 边缘或高于 K K 边缘的激发能量，得到的 XRF 光谱被拟合以去卷积重叠的 U Mα1 和K Kα1 XRF 信号。还讨论了使用 U M5 边缘微 X 射线吸收近边缘光谱 (μ-XANES) 来验证 U X 射线微探针图收集方法并获得尾矿中存在的 U 物质的化学信息。