Uranium mobility during interaction of rhyolitic obsidian, perlite and felsite with alkaline carbonate solution: T = 120° C, P = 210 kg/cm 2

Robert A. Zielinski

doi:10.1016/0009-2541(79)90103-7

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Uranium mobility during interaction of rhyolitic obsidian, perlite and felsite with alkaline carbonate solution: T = 120° C, P = 210 kg/cm 2

Robert A. Zielinski

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Abstract

Well-characterized samples of rhyolitic obsidian, perlite and felsite from a single lava flow are leached of U by alkaline oxidizing solutions under open-system conditions. Pressure, temperature, flow rate and solution composition are held constant in order to evaluate the relative importance of differences in surface area and crystallinity. Under the experimental conditions U removal from crushed glassy samples proceeds by a mechanism of glass dissolution in which U and silica are dissolved in approximately equal weight fractions. The rate of U removal from crushed glassy samples increases with decreasing average grain size (surface area). Initial rapid loss of a small component (≈ 2.5%) of the total U from crushed felsite. followed by much slower U loss, reflects variable rates of attack of numerous uranium sites. The fractions of U removed during the experiment ranged from 3.2% (felsite) to 27% (perlite). An empirical method for evaluating the relative rate of U loss from contemporaneous volcanic rocks is presented which incorporates leaching results and rock permeability data.

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Robert A. Zielinski. 1979. Uranium mobility during interaction of rhyolitic obsidian, perlite and felsite with alkaline carbonate solution: T = 120° C, P = 210 kg/cm 2. https://doi.org/10.1016/0009-2541(79)90103-7

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