oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Geochemical Soil Survey for the Exploration of Uranium ore Deposits, NE Vogelkop, Irian Jaya, Indonesia  [PDF]
Chaudry, M.A.,Donze, M,Tabrez, A. R,Inam, A
Journal of Applied Sciences , 2002,
Abstract: A local geochemical soil survey was carried out for the exploration of uranium deposits in the area of north – east Vogelkop Irian Jaya, Indonesia. The study explores the use of trace elements associations as an indicator for the possible presence of uranium deposits. This selective association of trace elements is useful since radon, helium or any other gaseous daughter product of uranium can not be used, as there are no known uranium deposits in the area. Hence no local ore samples are available to establish the inter-elemental association as a guide. To establish the trace elements association in ores, known uranium deposits from different parts of the world are investigated. Fifteen ore samples are analyzed by Instrumental Neutron Activation Analysis (INAA) for their total metal content. The comparative study of elemental association, established for these 15 ore samples with the elemental association shown by the soil is non-representative of the ore types that could be expected in such a geological environment. This study does not indicate the accurrence of local ore, however the geological set up in the area provides the environments in which granitic uranium deposits can occur.
Determination of specific activity of230Th in uranium ore samples
Yunlong Zhao,Dingxiang Gu,Ronghui Li,Gang Deng,Yutang Liang,Zhaohui Wu,Qiuhong Huang,Guiying Tian,Bin Wang,Caifang Chen
Chinese Science Bulletin , 2000, DOI: 10.1007/BF02884688
Abstract: A new method suitable for determining specific activity of230Th in uranium ore samples is built. The method is characterized by adding the230Th/232Th standard dilution agent with lower activity ratio (Its230Th/232Th activity ratio and230Th have been known) to the samples and using isotopic dilution analysis. The method can be applied to analyses of230Th specific activity in various230Th/232Th activity ratio samples. The precision can also be improved.
Determination of specific activity of 230Th in uranium ore samples

ZHAO Yunlong,GU Dingxiang,LI Ronghui,DENG Gang,LIANG Yutang,WU Zhaohui,HUANG Qiuhong,TIAN Guiying,WANG Bin,CHEN Caifang,

科学通报(英文版) , 2000,
Abstract: A new method suitable for determining specific activity of230Th in uranium ore samples is built. The method is characterized by adding the230Th/232Th standard dilution agent with lower activity ratio (Its230Th/232Th activity ratio and230Th have been known) to the samples and using isotopic dilution analysis. The method can be applied to analyses of230Th specific activity in various230Th/232Th activity ratio samples. The precision can also be improved.
A Study of the Formation Process and Ore-Prospecting Indicators of the Sandstone Type Uranium Deposits in the Light of Uranium Series Isotopes
从铀系列同位素角度探讨砂岩型铀矿的形成过程及找矿标志

LIU Jin-hui,SHI Wei-jun,SUN Zhan-xue,
刘金辉
,史维浚,孙占学

地球学报 , 2007,
Abstract: Based on a study of uranium series isotopes in uranium-bearing strata from different sectors of the No. 512 deposits, this paper deals with the formation process of sandstone type uranium deposits. According to distribution regularities of the compositions of uranium series isotopes in front of the ore roll and characteristics of isotope samples from different oxidation-reduction zones, the authors hold that the distribution of uranium series isotopes can not only be used to predict the location of the uranium ore body, but also be employed to study rolling mineralization of the roll in the process of the ore body formation. It is proper to name region A as the region of redox contradiction.
Solvent extraction studies on uranium using amine based extractants and recovery from low grade ore leach liquors
Kim, Chul-Joo;Kumar, Jyothi Rajesh;Kim, Joon-Soo;Lee, Jin-Young;Yoon, Ho-Sung;
Journal of the Brazilian Chemical Society , 2012, DOI: 10.1590/S0103-50532012000700009
Abstract: in this study, amine based extractants (alamine 336, alamine 308, alamine 304 and aliquat 336) diluted in kerosene were used as promising extractants for uranium extraction and separation from other associated elements. alamine 336 was the best extractant for uranium extraction process from sulfate solutions when compared with other amine based extractants, alamine 308, alamine 304 and aliquat 336. synergistic extraction behavior was studied with amines as extractants as well as synergists and organophosphorus reagents used as synergist mixed with amines. synergistic extraction studies with amines were not suitable with each other for better extraction efficiency. however, amines mixed with organophosphorus extractants gave positive synergetic behavior with the highest synergistic coefficient 0.567 calculated from results obtained. the developed methodology was applied to uranium low grade ore processing and 99.83% of uranium was recovered without the interferences of other metals.
Uranium in South America with Emphasis on the Brazilian Uranium Province (Summary) L'uranium en Amérique du Sud et plus particulièrement dans la province uranifère brésilienne (résumé)  [cached]
Forman J. M. A.
Oil & Gas Science and Technology , 2006, DOI: 10.2516/ogst:1980034
Abstract: The search for uranium hos been going on in South America for the last 30 years and has led to discoveries of deposits in the following countries: Brazil, Argentine, Venezuela, Peru, Chile, Colombia and Ecuador. - In addition to the already known deposits in Brazil at Pocas de Caldas (Minas Gerais), Figueira (Parana) and Quadrilatère Ferrifère (Minas Gerais), other deposits have been discovered at Itatiaia where the uranium is associated with phosphates, in the Lagoa Real region where the uranium is in microclinal gneiss, and in the Rio Preto region. Nearly 100 ore shows have been found in Lower Precarnbrian shales covered by Middle Precambrion quartzose sandstore. The industrial complexes of Pocas de Caldas and Fiqueira will start production respectively in 1980 and 1983. - In Argentina the mains deposits are in the Serra Pintada (Mendoza Province), at Los Adobes and Cerro Condor (Chubut Province) and at Don Otto in the northern part of the country. Reserves now known and those being developed are very promising for the future. Pendant les 30 dernières années la recherche de l'uranium s'est poursuivie en Amérique du Sud et a abouti à la découverte de gisements dans les pays suivants : Brésil, Argentine, Venezuela, Pérou, Chili, Colombie et équateur. . - Au Brésil, outre les gisements déjà connus de Po as de Caldas (Minas Gerais) de Figueira (Parana) et du Quadrilatère Ferrifère des Minas Gerais, d'autres gisements ont été découverts à Itatiaia où l'uranium est associé à des phosphates, dans la zone de Lagoa Real où l'uranium se trouve dans des gneiss à microcline et dans la région de Rio Preto. Près de 100 indices minéralisés sont reconnus dans les schistes du Précambrien inférieur recouverts par des grès quartzeux d'age précambrien moyen. Les complexes industriels de Pocas de Caldas et de Figueira entreront en production respectivement en 1980 et 1983. - En Argentine, les principaux gisements se trouvent dans la Serra Pintada (Province de Mendoza), à Los Adobes et Cerre Condor (Province de Chubut) et à Don Otto dans le nord du pays. Les réserves actuellement connues et celles en cours de développement sont très prometteuses pour l'avenir.
广东长排铀矿床成矿流体特征
Characteristics of Oreforming Fluids of the Changpai Uranium Deposit in Guangdong Province
 [PDF]

徐浩,张闯,庞雅庆,曹豪杰,刘佳林,刘文泉
XU Hao
,ZHANG Chuang,PANG Yaqing,CAO Haojie,LIU Jialin,LIU Wenquan

- , 2018,
Abstract: 摘要: 长排铀矿床位于广东长江铀矿田内,矿体主要赋存在北北西向硅化断裂带内及其两侧的蚀变花岗岩中。流体包裹体显微测温和激光拉曼光谱分析表明,成矿流体为中低温、中低盐度的含CO2、CH4和H2的流体。铀成矿期流体包裹体均一温度多集中于120~250 ℃,盐度为04%~102%。氢、氧同位素分析表明,成矿流体可能来源于深部,后期有大气降水的加入。成矿期方解石的δ13C值大多数集中于-91‰~-82‰,以深源碳为主。综合分析认为,长排铀矿床属于中低温热液脉型铀矿床。成矿流体经历了沸腾作用,使CO2等挥发分逃逸,这可能是长排铀矿床铀矿沉淀、富集的主要原因。
Abstract: The Changpai uranium deposit is located in the Changjiang ore field in northern Guangdong Province. The uranium orebodies are controlled by the NNW trending silicified fracture zones and hosted within both the fracture zones and adjacent altered granites. Microthermometric measurements and Laser Raman Spectrum analysis indicate that the oreforming fluids of the Changpai uranium deposit are of mediumlow temperature, mediumlow salinity and contain volatiles including CO2, CH4 and H2. The homogenization temperatures of the oreforming fluids range from 120 to 250 ℃ while the salinities range from 04% to 102%. Hydrogen and oxygen isotopic systems of quartz indicate that the oreforming fluids are mainly derived from magmatic water in the early stage but mixed with meteoric water in the late stage. The δ13C values of calcite from the mineralization stage are mostly from -91‰ to -82‰,signifying deepsourced carbon in this deposit. On the basis of the aforementioned analyses, it is suggested that the Changpai uranium deposit is a mediumlow temperature hydrothermal vein type uranium deposit. Fluid boiling of the oreforming fluids and consequent escape of the volatile (eg, CO2) components resulted in the precipitation of pitchblende and other uranium minerals
New discovery of uranium ore spot and prospecting discussion in north western Dayawan, Guangdong province.
广东大亚湾西北部新发现铀矿点及找矿远景讨论

WU Qifan,LU Fengxiang,FANG Yingyao,LU Jianzhong,XIONG Shengqing,FAN Zhengguo,ZHU Ba,
吴其反[
,] 路凤香 方迎尧 卢建忠 熊盛青 范正国 朱捌

岩石学报 , 2006,
Abstract: A volcanic rock-type uranium ore-spot was discovered with airborne gama-ray spectrometry in north-western Dayawan, Guangdong Province in 2003.The ore grade of mineralization zone is up to 0.459% in ditch sampling analyses.Uranium minerals of the ores are uraninite and altering uranium minerals.The Uraninite has high UO_2 (maximum about 94%),low Al_2O_3(<1%) and variable P_2O_5 contents.Two groups can be subdivided according to P_2O_5 contents,one ranges between 2.23% and 2.57% ,another between 17.96% and 19.95%.The altering uranium minerals contain UO_3 about 60%,1.6% to 3.0% in Al_2O_3 and 10% to 15% in P_2O_5.Ores-host rocks for ore spot have the characteristics as follows,they are mainly rhyolites and in the TAS diagram,similar to those in"Xiangshan Uranium Ore Field".Whole rocks composition between ores and wall rocks in this area does not show great distinction.The ores and wall rocks in ore spot have similar REE and traces elements,essentially the characteristics of geochemistry similar to those of calc-alkaline volcanic rocks.They have higher LREE/HREE ratios and slightly negative Eu anomalies.Although the scale of the uranium mineralization zone is not larger enough,the content of uranium ores is higher.Moreover,the tectonic background is similar to some deposits in"Xiangshan Uranium Ore Field".Thus,the discovery of uranium prospective area is significant for further exploration and research.
砂岩型铀矿的双重还原介质模型及其联合控矿机理:兼论大营和钱家店铀矿床
Model of Inner and Outer Reductive Media Within Uranium Reservoir Sandstone of Sandstone-Type Uranium Deposits and Its Ore-Controlling Mechanism: Case Studies in Daying and Qianjiadian Uranium Deposits
 [PDF]

焦养泉,吴立群,荣辉
Jiao Yangquan
, Wu Liqun, Rong Hui

地球科学(中国地质大学学报) , 2018, DOI: 10.3799/dqkx.2017.512
Abstract: 含铀岩系的还原介质可以依据与铀储层砂体的产出关系划分为内部还原介质和外部还原介质.铀储层砂体的双重还原介质对铀成矿同等重要.铀储层砂体中的层间氧化作用直接与内部还原介质相关,但是当叠加有外部还原介质时,外部还原介质将通过不同的方式大大增强铀储层砂体的整体还原能力,这种组合的出现有利于稳定的层间氧化带发育和持续的铀成矿.沉积期的古气候和沉积环境决定了含铀岩系还原介质的类型和丰度,以及铀储层砂体双重还原介质的组合规律,并从根本上决定了成矿期层间氧化带的发育规模.在进行砂岩型铀矿的勘查预测时,需要将双重还原介质模型评价与具体盆地的地质背景和成矿期控矿条件研究相结合,才能获得理想的结果.
The Daying and Qianjiadian uranium deposits, the reductive media within uranium-bearing series are divided into inner reductive media and outer reductive media according to its occurrence relationship with uranium reservoir sandstone. The assemblage of the inner and outer reductive media was in favor of the formation of the interlayer oxidation zone and continuous uranium mineralization. It is found that the interlayer oxidation within uranium reservoir sandstone was directly related with the inner reductive media and the reducibility of uranium reservoir sandstone was largely enhanced when the outer reductive media participated in the process of interlayer oxidation. The reductive media outside uranium reservoir sandstone was just as important to uranium mineralization as the reductive media inside uranium reservoir sandstone. Types and abundance of the reductive media inside and outside uranium reservoir sandstone and their spatial distribution were affected by the synsedimentary palaeoclimate and depositional environment of uranium-bearing series which basically constrained the scale of interlayer oxidation zone. The desired results will be achieved during prospecting prediction for the sandstone-type uranium deposit based on evaluation of the model of the double reductive media associated with the studies of geological background and ore-controlling conditions in the uranium mineralization stage
Effects of iron-ore particles on propagule release, growth and photosynthetic performance of Sargassum vulgare C. Agardh (Phaeophyta, Fucales)
ASSAR CRISTINA A.G.,LAVRADO HELENA P.,YONESHIGUE-VALENTIN YOCIE
Brazilian Journal of Botany , 2002,
Abstract: The effect of iron-ore particles on the propagule release and growth of Sargassum vulgare C. Agardh was tested under treatments with different concentrations of iron-ore particles: 0.1, 1.0, 10.0 g.L-1 and a solution of 10.0 g.L-1 of filtered iron-ore. Filtered seawater was used as control. Photosynthesis vs. irradiance (P-I) curves were calculated for S. vulgare in the presence of iron-ore and in seawater. There was no significant difference in the number of propagules released by the receptacles or in the percentage of zygote formation among the treatments. The released propagules acted like aggregation centers for the particles, those more heavily coated with iron (10.0 g.L-1) exhibiting the highest sinking velocity (32.6 ± 9.8 mm.s-1). No difference in the percentage of embryo survival was detected during the first week in culture. After four weeks the embryos grew in all treatments. Maximum frond development (5.3 ± 0.8 mm) was observed in treatment of seawater enriched with Provasoli's medium (PES) while initial filoids did not develop in three treatments without PES and with iron-ore (0.1 g.L-1, 1.0 g.L-1 and 10.0 g.L-1). The values for Pmax, alpha and respiration showed no significant differences between the P-I curves. The calculated value for I K was 106.26 μmol.m-2.s-1 to the control curve and 981.49 μmol.m-2.s-1 to the iron-ore curve. The results indicate that the iron-ore particles in high concentration reduce the growth of S. vulgare as they recovered the embryos, juveniles and young plants. In contrast, the presence of the particles did not affect the release of gametes, percentage of zygote formation or the percentage of embryo survival.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.