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uraninite——An Economic Uranium Mineral in Metamorphic Uranium Deposit No.3075

Acta Geochimica 1984年第2期 172-186页

作者：曹淑德 Beijing Institute of Uranium Geology

uraninite from the metamorphic deposit investigated is divided into two groups on thebasis of its occurrence and physical and chemical *** of the first group occursas distorted crystals in the form of elongated cubes a{100};the second group occurs mainlyin the form of rhombo-dodecahedra d{100),all belonging to the GaF;type in the *** chemical formulae are 8UO;·UO;·PbO for the first group and 5UO;·UO;·PbO forthe *** dating yields 1,900 and 300 *** the formation time of uraninite inthis *** former value corresponds to the main mineralization period and the latterrepresents the reformation event. *** major economic uranium mineral in metamorphic uranium deposit No.3075is a typical *** account of the low content of Th,it is also called“Th-free’ uranini-te of pure uranium *** is obviously different from the eguivalent with high contentsof Th and rare earths present as accessory minerals in granite and pegmatite elsewhere *** crystal form of uraninite No.1 is simple,whereas that of No.2 is *** UO;/UO;ratio for No.1 is larger than that of uraninite *** No 1 hashigh values for some physical parameters,such as reflectance,cell size,weight gain and har-dness as-compared with uraninite *** two types of uraninite are formed in different geological environments anddifferent in *** No.1 occurring in two-mica quartz-schist in the *** at the base of the Lower Proterozoiic Liaohe Group is of dynamo-thermal meta-morphic origin,as evidenced by:（1）The uraninite occurs as elongated platy crystals andis arranged in a direction paralled with *** is due to directional stress that the crystals have been elongated to become distorted cubic crystals during crystallization;（2）The ore-bearing rocks are generally similar in lithology to the barren rocks,without the in-troduction of extraneous *** is due to the fact that the formation

关键词： Th uraninite An Economic Uranium Mineral in Metamorphic Uranium Deposit No.3075

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U-Blacks Mineralization in Sandstone Uranium Deposits

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Journal of Earth Science 2022年第2期33卷 308-316页

作者： Olga A.Doynikova Institute of Ore Deposits Geology PetrographyMineralogy and Geochemistry Russian Academy of ScienceMoscow 119017Russia

Ores of infiltration sandstone-hosted uranium deposits in the sedimentary cover are ubiquitous composed of dispersed soot powder mineralization of black,brownish-black *** studies of such loose U-ores by analytical transmission electron microscopy(ATEM)proved their polymineral *** blacks are composed by at least three different U-mineral forms:oxide(uraninite),silicate(coffinite)and phosphate(ningyoite)which are present in various proportions of ore *** high dispersed friable uranium formations are difficult to diagnose by traditional mineralogical methods(optical,XRD,IR and X-ray spectroscopy,etc.)which analyze total sample composition(phases mixture);their results characterize the dominant sample phase,omitting both sharply subordinate and X-ray amorphous *** research results are based on ATEM methods(SAED+EDS),which are optimal for crystallochemical diagnostics in the mineralogical study of such uranium *** article presents the diagnostic characteristics under electron microscope(EM)of uranous minerals from different sandstone deposits with their origin being discussed.

关键词： uranous minerals uraninite coffinite ningyoite biogenic nature U-deposit ore deposit geology

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Biomineralization of Uranium: A Simulated Experiment and Its Significance

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Acta Geologica Sinica(English Edition) 2005年第1期79卷 134-138页

作者： MINMaozhong HuifangXU L.L.BARTON WANGJinping PENGXinjian H.WIATROWSKI DepartmentofEarthSciences StateKey.LaboratoryofMineralDepositResearchNanjingUniversityNanjingJiangsu210093China DepartmentofEarthandPlanetarySciences UniversityofNewMexicoAlbuquerqueNM87131-1116USA DepartmentofBiology UniversityofNewMexicoAlbuquerqueNM87131-1116USA

A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were: 35°C, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments, might have participated in the biomineralization of this uranium deposit. There is an important difference in the order- disorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.

关键词： microbial biomineralization uraninite sulfate-reducing bacteria sandstone-hosted uranium deposit simulated experiment

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