LABORATORY SIMULATION STUDIES OF URANIUM MOBILITY IN NATURAL-WATERS
LABORATORY SIMULATION STUDIES OF URANIUM MOBILITY IN NATURAL-WATERS
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DOI：
10.1016/0016-7037(81)90043-0
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发表时间：
1981-01-01
影响因子：
5
通讯作者：
SWAINE, DJ
中科院分区：
文献类型：
--
作者：
GIBLIN, AM;BATTS, BD;SWAINE, DJ
在三个自然水系统的模拟中，研究了pH和Eh的变化对25°C下铀水迁移率的影响。测试其对铀流动性的影响的组分是：1。(a)水合氧化铁表示响应于pH和Eh. 2的变化而沉淀或溶解的吸附性固体。(b)高岭石，代表尽管会因pH和Eh变化而改变的矿物质，但在天然水的pH-Eh范围内以固体形式存在。3. (c)碳酸盐，代表一个强大的铀络合物种。铀的流动性测量从每个模拟回归对pH值和Eh在一个范围内适当的天然沃茨。水合氧化铁和高岭石各自影响铀的流动性，但在单独的pH值-Eh域。含水碳酸盐增加了铀的流动性，而UO 2（CO 3）34−的吸附导致水合氧化铁的胶体分散，这可能解释了某些铀矿床中存在“热液赤铁矿”。增强铀的流动性观察到的pH-Eh域的不溶铀氧化物可以解释，如果氧化物是作为胶体。铀作为一个移动的物种，即使在还原后，仍然存在，这对铀矿的近地表成因有影响。
The effects of imposed variations of pH and Eh on aqueous uranium mobility at 25°C have been studied in three simulations of natural water systems. Constituents tested for their effect on uranium mobility were:1.(a) hydrous ferric oxide, to represent adsorptive solids which precipitate or dissolve in response to variations in pH and Eh.2.(b) kaolinite, representing minerals which, although modified by pH and Eh changes, are present as solids over the pH-Eh range of natural waters.3.(c) carbonate, to represent a strong uranium-complexing species.Uranium mobility measurements from each simulation were regressed against pH and Eh within a range appropriate to natural waters.Hydrous ferric oxide and kaolinite each affected uranium mobility, but in separate pH-Eh domains. Aqueous carbonate increased mobility of uranium, and adsorption of UO2(CO3)34−caused colloidal dispersion of hydrous ferric oxide, possibly explaining the presence of ‘hydrothermal hematite’ in some uranium deposits. Enhanced uranium mobility observed in the pH-Eh domains of thermodynamically insoluble uranium oxides could be explained if the oxides were present as colloids. Uranium persisting as a mobile species, even after reduction, has implications for the near surface genesis of uranium ores.