Thermodynamic oxygen isotope factors for uranium oxides have been calculated by means of the modified increment method. The sequence of 18 ̄O-enrichment in the uranium oxides with respect to the common rock-forming mi...Thermodynamic oxygen isotope factors for uranium oxides have been calculated by means of the modified increment method. The sequence of 18 ̄O-enrichment in the uranium oxides with respect to the common rock-forming minerals is predicted as follows: spinel < uraninite brannerite hematite < rutile < pitchblende <cassiterite uranium blacks coffinite sedovite UO3 < illite. Two sets of selfconsistent fractionation factors between the uranium oxides and water and between the uranium oxides and the other minerals have been obtained for 0~ 1200℃. The theoretical results are applicable to the isotopic geothermometry of uranium ores when pairing with other gangue minerals in hydrothermal uranium deposits.展开更多
文摘Thermodynamic oxygen isotope factors for uranium oxides have been calculated by means of the modified increment method. The sequence of 18 ̄O-enrichment in the uranium oxides with respect to the common rock-forming minerals is predicted as follows: spinel < uraninite brannerite hematite < rutile < pitchblende <cassiterite uranium blacks coffinite sedovite UO3 < illite. Two sets of selfconsistent fractionation factors between the uranium oxides and water and between the uranium oxides and the other minerals have been obtained for 0~ 1200℃. The theoretical results are applicable to the isotopic geothermometry of uranium ores when pairing with other gangue minerals in hydrothermal uranium deposits.