Application of the fundamental parameter method to the assessment of major and trace elements in soil and sediments from Osamu Utsumi uranium mine by WDXRF

Abstract Wavelength dispersive X-ray fluorescence spectrometry (WDXRF) is a suitable technique for the characterization of contaminated mining sites, providing a quick and reliable screening for areas of significant contamination. This study established and validated a non-destructive methodology for quantitative simultaneous determination of major and minor constituents in soil and sediments by WDXRF, which was further applied to quantify soil and sediment samples from Osamu Utsumi uranium mine (Caldas, Minas Gerais, Brazil). Elements such as Ce, La, Nd, Mn and U were found in more concentrated levels in the calcium diuranate deposit (DUCA), whereas Fe and Al were found at higher levels in the soil samples corresponding to sites where accentuated leaching processes have occurred. Comparatively, the levels of U and rare-earth elements were found in significantly higher levels in the sediments retrieved from the mine’s pit as a result of acid mine drainage. These findings are believed to be useful as an initial environmental assessment for the decommissioning process of the mine.

摘要：波长色散X射线荧光光谱法（Wavelength dispersive X-ray fluorescence spectrometry，WDXRF）是一种适用于受污染矿区表征的可靠技术，可对存在显著污染的区域开展快速可靠的筛查。本研究建立并验证了一种基于WDXRF的无损分析方法，可同时定量测定土壤与沉积物中的常量及微量组分，并将该方法应用于巴西米纳斯吉拉斯州卡尔达斯市奥萨穆·乌祖米铀矿的土壤与沉积物样本分析。研究发现，重铀酸钙沉积物（DUCA）中铈（Ce）、镧（La）、钕（Nd）、锰（Mn）及铀（U）的浓度较高；而在发生显著淋滤作用的区域采集的土壤样本中，铁（Fe）与铝（Al）的含量更高。对比来看，受酸性矿山排水影响，矿井采坑沉积物中的铀与稀土元素含量显著更高。上述研究结果可作为该矿山退役流程的初始环境评估依据，具有重要的实用价值。