Uranium isotope variation within vein-type uranium ore deposits

Isotopic composition of uranium has previously been used to infer the depositional redox environment ore concentrates and also provide a potential signature inform nuclear forensic investigations. This study evaluates diagnostic power U isotope by investigating (1) heterogeneity compositions in samples collected from same mine and/or vein, (2) influence processing on 238U/235U 234U/238U ratios. These characteristics are explored via high precision mass spectrometric measurement vein type predominantly mines located central Portugal Southwest England. Samples exhibit ?238U values ?0.16 +0.03 (±0.04) ‰ ?1.6 ?64.7 (±0.4) for ?234U (±2SD). variations can be attributed redox-driven fractionation processes redistribution during localised leaching re-precipitation. Analyses residues leachates small-scale batch experiments designed simulate industrial procedures reveal significant positive negative changes leachate relative bulk material (up 0.21 ± 0.06‰ 62.0 0.6‰ ?234U). findings highlight possibility significantly different concentrate even if manufacturing remain unchanged.