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Composite samples of high-grade ore samples from the Doris and Johnny M mines were leached under controlled laboratory conditions to determine which elements are more mobile in the presence of organic acids. The samples selected consisted of -2-µ composites of kaolinite + mixed layer smectite/illite + U-mineral + accessory organic matter and sulfides; and chlorite + mixed layer smectite/illite + U-minerals + accessory organic matter and sulfides. These samples were leached with 0.01 molar tartaric acids in tightly sealed Erlenmeyer flasks, with constant agitation, for 100 hours and the leachates and insoluble residues were analyzed by neutron activation analysis. Uranium, Th, and the REE (rare earth element) were strongly leached and presumably form chelates with the tartaric acid; Na, K, and Ba were also leached but Rb and Cs were either not leached or else fixed on the outer armor of the insoluble residue. Fe and Hf were also leached but Cr, Co, Sb, and Ta concentrated in the insoluble residues. The distribution patterns for the REE for leached and untreated samples are parallel, but the amount of REE leached is proportional to U leached, thus suggesting that organic transport of the REE with U (and Th?) may account for the high REE contents common in many uranium deposits of the Grants mineral belt. The source for the REE and for at least some of the U may have been the Brushy Basin Member (Morrison Formation) for deposits in the underlying Westwater Canyon Member.
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