Mineralogical characterization of uranium ore to evaluate in-situ leaching prospects

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · SPEJ, Soc. Pet. Eng. J.; (United States)

DOI:https://doi.org/10.2118/11045-PA· OSTI ID:6136557

Tsui, T F

Mineralogical studies of ore samples from Mobil uranium properties in Grants mineral belt (NM) revealed a correlation between certain mineralogical characteristics of the ore and its leaching behavior in the laboratory. Mild alkaline carbonate solutions containing dissolved oxygen gas or hydrogen peroxide were used to leach ore samples. Leaching effects of the uranium minerals and reactive gangue material were investigated by comparing the mineralogical characteristics between pre- and postleach samples. Analyses were made by using the X-ray diffraction method, petrographic microscopic, and scanning electron microscopic (SEM) examinations. In one ore trend where uraninite was the principal uranium mineral, studies showed that (1) the majority of uranium minerals was readily accessible to the leachate on a microscopic scale, (2) the predominant, 1-micron (1-..mu..m) size uraninite crystals were dissolved rapidly during leaching, (3) the minor but locally abundant uranium vandate species was insoluble in mild alkaline carbonate leachate, and (4) pyrite crystals, with dimensions 10 times greater than the uraninite crystallites, showed some surface etchings. These results indicate that the solubility and microscopic occurrence of uraninite are favorable for high and rapid uranium recovery, while the fraction of uranium contained in the insoluble uranium vanadate phase cannot be recovered under mild leaching conditions. The uraninite apparently dissolved at a much faster rate than pyrite, indicating a favorable initial selectivity of leachate for uranium. Mineralogical studies of the preand postleach ore samples correlate well with the laboratory leach tests, which showed 80 to 90% uranium recovery as well as low vanadium and sulfate levels in the effluents.

• Research Organization: Mobil R and D Corp.
• OSTI ID: 6136557
• Journal Information: SPEJ, Soc. Pet. Eng. J.; (United States), Journal Name: SPEJ, Soc. Pet. Eng. J.; (United States) Vol. 24:5; ISSN SSPJD
• Country of Publication: United States
• Language: English

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