Chemical characteristics of the waters of a uranium mineralized zone in NW Spain

摘要

In Sageras-Mina Fe there are more than 100 boreholes drilled to investigate the mineral resources of the deposit. 35 boreholes were selected in order to analyze the chemical composition of groundwaters based on their depth and situation around the uranium ore. Groundwater samples come from 50 to 150 m depth. The waters are classified as calcium-bicarbonate type waters, with a redox potential that indicates they are slightly reduced (values vary between 50 to -350 mV). The TOC varies between ＜0.1 and 4.0 mgC/L and the dissolved uranium has a maximum value of 7.7 mg/L.The tritium contents in the groundwaters vary between 1.5 and 7.3 T.U. Considering that the mean value of tritium in rainwater from the studied area has a value of 4 T.U., the residence times of the groundwaters are relatively short, not longer than 50 years in the oldest case.