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New Advances in Structural Studies of Barium Rare-Earth Fluor-Carbonate Minerals
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作者 Shen Jinchuan Mi JinxiaoChina University of Geosciences , Wuhan 430074 《Journal of Earth Science》 SCIE CAS CSCD 1992年第1期21-28,共8页
This paper summarizes the new developments in the study of barium rare-earth fluor-carbonate mineral structures .The second order superstructure of cebaite -(Ce ) was solved by using high power X-ray single crystal di... This paper summarizes the new developments in the study of barium rare-earth fluor-carbonate mineral structures .The second order superstructure of cebaite -(Ce ) was solved by using high power X-ray single crystal diffractometer . Five kinds of coordination forms were found . All atoms in the cell , including C and F , were properly located . In the process of study in a cordylite-(Ce ), a new mineral was discovered , whose chemical formula is (Ca0.5□0.5) BaCe2 (CO3)4F . It is isostructural with baiyuneboite - (Ce ), but different in composition (Na in baiyuneboite- (Ce ) is substituted by Ca disorderly ) . On the basis of the studies a proposal to re-define cordylite-(Ce )as a mineral group name is put forth by the authors . Finally a new type of twinning of huanghoite-(Ce ) was found on the systematical absence of diffraction data by means of a single crystal diffractometer . 展开更多
关键词 rare - earth mineral crystal structure cordylite -(Ce) cebaite - (Ce) baiyuneboite - (Ce) huanghoite - (Ce) X - ray analysis .
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Rare Earths, Niobium and Tantalum Minerals in Bayan Obo Ore Deposit and Discussion on Their Genesis 被引量:4
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作者 张培善 陶克捷 +2 位作者 杨主明 杨学明 宋仁奎 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第2期81-86,共6页
Bayan Obo ore deposit is endowed with and lie hidden in the Proterozoic strata. The localities and occurrences of the minerals in the ore deposit were described. It is obviously that some minerals are strata minerals ... Bayan Obo ore deposit is endowed with and lie hidden in the Proterozoic strata. The localities and occurrences of the minerals in the ore deposit were described. It is obviously that some minerals are strata minerals and some are post strata minerals. The rare earths, niobium and tantalum minerals are exactly the post strata minerals. In these minerals the hydrothermal metasomatic phenomena distinctly reveal their metallogenic characteristics. According to tectonic movement, magma activity, mineral paragenesis, hydrothermal metasomatism, geological age and lasting time scale of metallogenesis, and some other factors, it is supposed that genesis of rare earths, niobium and tantalum minerals in Bayan Obo ore deposit are closely related with hydrothermal metallogenic solution which is differentiated from silica acid and carbonic acid magma and derived from deep seated source, and then intruded into Proterozoic strata and metasomatized. It is recognized that the metallogenesis of Bayan Obo ore deposit is undergoing a long geological period and many episodes. 展开更多
关键词 rare earths niobium and tantalum mineral genesis Bayan Obo
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Flotation Separation on Rare Earth Minerals and Gangues 被引量:2
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作者 程建忠 侯运炳 车丽萍 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S1期62-66,共5页
The flotation process of native rare earth minerals such as bastnasite, monazite, mixed minerals of bastnasite and monazite, using the new effective collector Dh was studied, respectively, and the flotation properties... The flotation process of native rare earth minerals such as bastnasite, monazite, mixed minerals of bastnasite and monazite, using the new effective collector Dh was studied, respectively, and the flotation properties were described. The good qualities of the new collector Dh were revealed through comparing with other collector of rare earth minerals. The test results of different ore samples showed that at moderate pulp pH (8.5~9.5), rare earth minerals could be effectively separated from barium, calcium and silicon bearing intergrowth minerals (barite, calcite and silicate minerals) and high quality rare earth concentrates could be obtained successfully by the new collector Dh, acid silica gel, turpentine and reagents fitting together rationally. In order to determine optimum technical conditions, the effect of pulp pH, pulp temperature, pulp density and the effect of dosage of reagents (Dh and acid silica gel) on the flotation were investigated in the test. Simultaneously, the mechanism of the flotation of rare earth minerals from intergrowth minerals was explored. The infrared spectra for Dh and rare earth cation by analysis in theory showed that Dh formed chelate complex with rare earth cation and were adsorbed on the surfaces of rare earth minerals. The mechanism of the intergrowth minerals depressed by acid silica gel can be explained as gummy colloid hydrolyzed from acid silica gel which were selectively absorbed on the gangue minerals, making them hydrophilic and depressed, with pulp pH value of alkalescent. 展开更多
关键词 FLOTATION PROCESS RE minerals collector Dh gangues rare earths
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Kinetic of Dissolved Phosphorus from Calcination Products of Mixed Rare Earth Minerals 被引量:1
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作者 边雪 吴文远 +2 位作者 杨眉 孙树臣 涂赣峰 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第S1期120-124,共5页
The products of mixed rare earth minerals containing monazite and bastnaesite calcined by CaO-NaCl-CaCl2 contained calcium phosphate and phosphorite. In this paper, HCl-H3cit solution was used to wash the calcination ... The products of mixed rare earth minerals containing monazite and bastnaesite calcined by CaO-NaCl-CaCl2 contained calcium phosphate and phosphorite. In this paper, HCl-H3cit solution was used to wash the calcination products, and the kinetic character of dissolved phosphorus was studied. The results showed that the reaction rate control changed from chemical reaction control mode to mixed control mode and diffusion control mode with increasing temperature, and the activation energy were 7.36, 27.64 and 61.27 kJ·mol-1, respectively. The change of temperature, the reagent concentration and stirring speed were studied in order to increase the dissolution rate of phosphorus. Phosphorus and rare earth in the calcination products could be separated in this process applicable to the rare earth recovery in phosphorite containing the rare earth. 展开更多
关键词 mixed rare earth minerals HCl-H_3cit phosphorus removal KINETICS rare earths
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Progress of Flotation Reagents of Rare Earth Minerals in China 被引量:1
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作者 任俊 王文梅 +2 位作者 罗家柯 周高云 唐芳琼 《Journal of Rare Earths》 SCIE EI CAS CSCD 2003年第1期1-8,共8页
The development and application of several flot ation reagents of rare earth minerals in China since 1960s and their performance were described. Furthermore, the development trends of flotation reagents of ra re eart... The development and application of several flot ation reagents of rare earth minerals in China since 1960s and their performance were described. Furthermore, the development trends of flotation reagents of ra re earth minerals were discussed. 展开更多
关键词 mineral dressing engineering flotation rea gents FLOTATION rare earths
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Clay minerals and elemental composition of sediments on different sedimentary units in the northern East China Sea shelf:provenance tracing and genetic mechanism analysis
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作者 Xiaoyan Xu Yong Zhang +6 位作者 Yanguang Dou Jingyi Cong Beibei Mi Xiaohui Chen Xia Li Chengfen Xu Yongyu Ye 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第11期19-34,共16页
The composition,provenance,and genetic mechanism of sediment on different sedimentary units of the East China Sea(ECS)shelf are essential for understanding the depositional dynamics environment in the ECS.The sediment... The composition,provenance,and genetic mechanism of sediment on different sedimentary units of the East China Sea(ECS)shelf are essential for understanding the depositional dynamics environment in the ECS.The sediments in the northern ECS shelf are distributed in a ring-shaped distribution centered on the southwestern Cheju Island Mud.From the inside to the outside,the grain size goes from fine to coarse.Aside from the“grain size effect”,hydrodynamic sorting and mineral composition are important restrictions on the content of rare earth elements(REEs).Based on the grain size,REEs,and clay mineral composition of 300 surface sediments,as well as the sedimentary genesis,the northern ECS shelf is divided into three geochemical zones:southwestern Cheju Island Mud Area(ZoneⅠ),Changjiang Shoal Sand Ridges(ZoneⅡ-1),Sand Ridges of the East China Sea shelf(ZoneⅡ-2).The northern ECS shelf is mostly impacted by Chinese mainland rivers(the Changjiang River and Huanghe River),and the provenance and transport mechanism of sediments of different grain sizes is diverse.The bulk sediments come primarily from the Changjiang River,with some material from the Huanghe River carried by the Yellow Sea Coastal Current and the North Jiangsu Coastal Current,and less from Korean rivers.Among them,surface sediments in the southwestern Cheju Island Mud Area(ZoneⅠ)come mostly from the Changjiang River and partly from the Huanghe River.It was formed by the counterclockwise rotating cold eddies in the northern ECS shelf,which caused the sedimentation and accumulation of the fine-grained sediments of the Changjiang River and the Huanghe River.The Changjiang Shoal Sand Ridges(ZoneⅡ-1)were developed during the early-middle Holocene sea-level highstand.It is the modern tidal sand ridge sediment formed by intense hydrodynamic action under the influence of the Yellow Sea Coastal Current,North Jiangsu Coastal Current,and Changjiang Diluted Water.The surface sediments mainly originate from the Changjiang River and Huanghe River,with the Changjiang River dominating,and the Korean River(Hanjiang River)influencing just a few stations.Sand Ridges of the East China Sea shelf(ZoneⅡ-2)are the relict sediments of the paleo-Changjiang River created by sea invasion at the end of the Last Deglaciation in the Epipleistocene.The clay mineral composition of the surface sediments in the study area is just dominated by the Changjiang River,with the North Jiangsu Coastal Current and the Changjiang Diluted Water as the main transporting currents. 展开更多
关键词 the northern East China Sea shelf rare earth element clay mineral PROVENANCE genetic mechanism
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Syntactic Intergrowth Structure in the Calcium-Rare Earth Fluorocarbonate Minerals
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作者 吴秀玲 孟大维 +4 位作者 杨光明 潘兆橹 李斗星 戴吉岩 胡魁毅 《Journal of Rare Earths》 SCIE EI CAS CSCD 1998年第3期39-44,共6页
The microstructural characteristics of syntactic polycrystal in the calcium rare earth fluorocarbonate minerals from Southwest China have been studied by means of selected area electron diffraction and high resolutio... The microstructural characteristics of syntactic polycrystal in the calcium rare earth fluorocarbonate minerals from Southwest China have been studied by means of selected area electron diffraction and high resolution electron microscopy(HREM). The complication of the heterogeneous fabric of the minerals have been revealed by HREM. The results show that the crystal structure of the minerals was formed by a disorder stacking of the unit layers of bast naesite and synchisite in the calcium rare earth fluorocarbonate minerals along c direction. The stacking fault and other crystal defects in the syntactic polycrystal have been discussed. 展开更多
关键词 rare earths Calcium rare earth fluorocarbonate mineral Syntactic intergrowth High resolution electron microscopy
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Economical and Technical Indices of Decomposition Processes of Typical Rare Earth Minerals in China
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作者 Wang Weisheng Wang Songling +1 位作者 Jia Jiangtao Zhang Zhaobing 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第4期428-428,共1页
The typical treatment processes we of main rare earth resources in China, especially the economical and technical indices of the minerals decomposition of such as ionic adsorptive rare earth deposit ore, bastnasite an... The typical treatment processes we of main rare earth resources in China, especially the economical and technical indices of the minerals decomposition of such as ionic adsorptive rare earth deposit ore, bastnasite and mixed with monazite in Baotou, was presented. The dispersive ionic adsorptive rare earth deposit ore, which is enriched on valuable middle and heavy elements, concentrated by bicarbonate precipitation after exchanging with ammonium sulphate solution. Planting and waste liquid should be focused. Bastnasite and/or monazite, which is enriched light rare earth, centralized with high content and capacity,concentrated by gravimetric, magnetic, floating, then decomposed by calcinations and leaching. Waste liquid, gases and dregs should be treated properly. Investors interested in RE industry can find out the technical and economic characters and history of various RE minerals. Engineers and workers in RE industry can also find the differences of the plants, so as to make more efforts on improving management. However, solving environment protection problems for each process should be committed extraordinarily in order to make a sustainable development of RE industry. 展开更多
关键词 mineral decomposition economical and technique indices environment protection rare earths
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STUDY ON FLOTATION OF RARE EARTH MINERALS WITH P538 AND ITS MECHANISM
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作者 周高云 罗家珂 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第4期296-300,共5页
The properties and collecting ability of a new collector,monoalkyl ester phosphoric acid(P538),for the flotation of rare earth minerals are described in the paper.The mechanism of P538 adsorption on the surfaces of mo... The properties and collecting ability of a new collector,monoalkyl ester phosphoric acid(P538),for the flotation of rare earth minerals are described in the paper.The mechanism of P538 adsorption on the surfaces of monazite or bastnaesite is explored by modern measuring techniques,such as IR and ESCA,etc. 展开更多
关键词 ESCA STUDY ON FLOTATION OF rare EARTH minerals WITH P538 AND ITS MECHANISM
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Fractionation characteristics of rare earth elements(REEs) linked with secondary Fe, Mn, and Al minerals in soils 被引量:5
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作者 Chunying Chang Fangbai Li +3 位作者 Chengshuai Liu Jianfeng Gao Hui Tong Manjia Chen 《Acta Geochimica》 EI CAS CSCD 2016年第4期329-339,共11页
Soil secondary minerals are important scavengers of rare earth elements(REEs) in soils and thus affect geochemical behavior and occurrence of REEs. The fractionation of REEs is a common geochemical phenomenon in soils... Soil secondary minerals are important scavengers of rare earth elements(REEs) in soils and thus affect geochemical behavior and occurrence of REEs. The fractionation of REEs is a common geochemical phenomenon in soils but has received little attention, especially fractionation induced by secondary minerals. In this study, REEs(La to Lu and Y) associated with soil-abundant secondary minerals Fe-, Al-, and Mn-oxides in 196 soil samples were investigated to explore the fractionation and anomalies of REEs related to the minerals. The results show right-inclined chondrite-normalized REE patterns for La–Lu in soils subjected to total soil digestion and partial soil extraction. Light REEs(LREEs) enrichment features were negatively correlated with a Eu anomaly and positively correlated with a Ce anomaly. The fractionation between LREEs and heavy REEs(HREEs) was attributed to the high adsorption affinity of LREEs to secondary minerals and the preferred activation/leaching of HREEs.The substantial fractions of REEs in soils extracted byoxalate and Dithionite-Citrate-Bicarbonate buffer solutions were labile(10 %–30 %), which were similar to the mass fraction of Fe(10 %–20 %). Furthermore, Eu was found to be more mobile than the other REEs in the soils, whereas Ce was less mobile. These results add to our understanding of the distribution and geochemical behavior of REEs in soils, and also help to deduce the conditions of soil formation from REE fractionation. 展开更多
关键词 rare earth elements FRACTIONATION Secondary minerals Geochemical process - Europium anomaly Cerium anomaly
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Northern Minerals eyes globally significant role for Browns Range project amid heightened interest in rare earth elements
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《China Rare Earth Information》 2019年第9期7-8,共2页
Dysprosium is an essential ingredient in the production of NdDyFeB(dysprosium-neodymium-iron-boron)magnets which are used in clean energy and high-tech solutions.Northern Minerals Ltd(ASX:NTU)is progressing the staged... Dysprosium is an essential ingredient in the production of NdDyFeB(dysprosium-neodymium-iron-boron)magnets which are used in clean energy and high-tech solutions.Northern Minerals Ltd(ASX:NTU)is progressing the staged development of its Browns Range heavy rare earths project as global events create a unique moment in the rare earth metals industry. 展开更多
关键词 NORTHERN minerals Browns Range PROJECT rare earth elements
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Study of Adsorption Properties and Enriching RE on Clay Minerals by Ouantum Chemical Calculation 被引量:5
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作者 池汝安 王淀佐 《Journal of Rare Earths》 SCIE EI CAS CSCD 1993年第2期142-147,共6页
The order of adsorbability of three kinds of clay minerals and their selectivity of adsorption to common cations and RE ions have been studied by quantum chemical calculation.They are as follows: montmorilionite>ha... The order of adsorbability of three kinds of clay minerals and their selectivity of adsorption to common cations and RE ions have been studied by quantum chemical calculation.They are as follows: montmorilionite>halloysite>kaolinite,RE^(3+)>Al^(3+)>Ca^(2+)>Mg^(2+)>K^+>NH_4^+>Na^+,Sc^(3+)>La^(3+)> Ce^(3+)>Pr^(3+)>Nd^(3+)>Sm^(3+)>Eu^(3+)>Gd^(3+)>Tb^(3+)>Dy^(3+)>Ho^(3+)>Y^(3+)>Er^(3+)>Tm^(3+)>Yb^(3+)>Lu^(3+).Based on these orders,the facts that RE is preferentially adsorbed in weathered residual type of clay mineral and light RE and heavy RE are enriched at the upper layer and at the lower layer respectively in ore body have been explained. 展开更多
关键词 Quantum chemistry Clay mineral ADSORPTION rare earths
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Mineralogical and Petrological Studies on Carbonatite Dykes in Bayan Ebo,Nei Mongol,China and Their Implication to Rare Earth Mineralization 被引量:1
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作者 张培善 张任祜 杨主明 《Journal of Rare Earths》 SCIE EI CAS CSCD 1994年第4期299-302,共4页
Two carbonatite dykes separetely located on Dulahala Mountain and within Erdaowa Group strata in Bayan Ebo mineral deposit have been studied.For Dulahala carbonatite the content of RE2O3 is 23.9 wt%,higher than that i... Two carbonatite dykes separetely located on Dulahala Mountain and within Erdaowa Group strata in Bayan Ebo mineral deposit have been studied.For Dulahala carbonatite the content of RE2O3 is 23.9 wt%,higher than that in the rare earth ores of both Main Ore-body and Eastern Ore-body,the distribution patterns of rare earth elements and rare earth mineral assemblage are consistent with those in both Ore-bodies.The evidence indicates a material source for RE in Bayan Ebo deposit.Fenite occurring at the edge of the carbonatite in Erdaowa Group yields an isochron age of 343.26±7.33 Ma by Rb-Sr method.It implies the geological time of mineralization. 展开更多
关键词 Carbonatite dykes rare earth mineral deposit Bayan Ebo rare earth mineralization
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"Three Rare Mineral Resources" and Crystalline Graphite Have Become Prospecting Focuses in China 被引量:4
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作者 HAO Ziguo FEI Hongcai +1 位作者 HAO Qingqing LIU Lian 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第5期1905-1906,共2页
With the global rise of industries of the new-generation information technology, energy conservation and environmental protection, biotechnology, high-end manufacturing, new materials and clean-energy vehicles, tradit... With the global rise of industries of the new-generation information technology, energy conservation and environmental protection, biotechnology, high-end manufacturing, new materials and clean-energy vehicles, traditional metal materials cannot meet the functional requirements. Consequently, "three rare mineral resources", regarded as the best altemative for current and future new industries, have received much attention among industrial circles and have become a new focus during the present geological prospecting in China. 展开更多
关键词 Be and Crystalline Graphite Have Become Prospecting Focuses in China Three rare mineral Resources Graphite
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Geochemical Characteristics of Rare Earth Elements of Guidong Granitic Complex and Their Relationship with Uranium Mineralization 被引量:1
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作者 Zhang Zhanshi Hua Renmin +2 位作者 Liu Xiaodong Deng Ping Wu Lieqin 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第6期731-731,共1页
The Guidong granitic complex is constituted by Luxi pluton, Xiazhuang pluton, Maofeng pluton, Sundong pluton, Aizi pluton and Siqian pluton, which intruded in Indosinian and early Yanshanian Periods. These plutons var... The Guidong granitic complex is constituted by Luxi pluton, Xiazhuang pluton, Maofeng pluton, Sundong pluton, Aizi pluton and Siqian pluton, which intruded in Indosinian and early Yanshanian Periods. These plutons varies from each other not only in major element content, aluminium saturation index, but also in ∑REE, δEu, and LREE/HREE, (La/Yb)N, (La/Sm) N and (Gd/Yb) N ratios. Uranium mineralization is mainly hosted by strong peraluminous granites, which has undergone intense fluid-rock interaction, and their REE compositions are characterised by M-type tetrad effects and lower ∑REE, δEu value, LREE/HREE, (La/Yb) N, (La/Sm) N and (Gd/Yb) N ratios. 展开更多
关键词 Guidong granitic complex fluid-rock interaction tetrad effects uranium mineralization Maofeng pluton rare earths
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Sm-Nd dating and rare earth element geochemistry of the hydrothermal calcites from Guling carbonate-hosted talc mineralization in the central Guangxi province,South China 被引量:3
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作者 Yi Cai Qian Zhang +2 位作者 Yongbing Zhang Dapeng Wang Kaiwen Li 《Chinese Journal Of Geochemistry》 EI CAS CSCD 2015年第2期156-166,共11页
Many carbonate-hosted talc mineralization,which are widespread in South China,exclusively developed in Carboniferous dolomitic limestone with many siliceous bands and nodules,and cherts.One of those typical deposits i... Many carbonate-hosted talc mineralization,which are widespread in South China,exclusively developed in Carboniferous dolomitic limestone with many siliceous bands and nodules,and cherts.One of those typical deposits is the Guling talc deposit in Mashan County,central Guangxi province,with a talc reserve of1.51 million tons.Mineral associations in the deposit are sample,mainly including talc and calcite.In this paper,Sm-Nd isotopic system and rare earth elements and yttrium(REE + Y) for the hydrothermal calcite intergrown with talc are used to constrain the age and origin of the talc mineralization.The hydrothermal calcite samples from the deposit display Sm and Nd concentrations ranging from 0.18 to 0.85 and 0.85 to 4.56 ppm,respectively,and variable Sm/Nd ratios of 0.21-0.24.These calcites further yield an Sm-Nd isochron age of 232 ±19 Ma(2a)(MSWD = 0.47) with an concordant initial ^(143)Nd-^(144)Nd ratios of 0.511967 ± 0.000017,which should be interpreted as the mineralization age of the Guling talc deposit.In addition,the calcite samples are enriched in REE with the variable SREE contents ranging from 4.82 to21.50 ppm and display relatively consistent chondritenormalized REE + Y patterns with the LREE enrichment(LREE/HREE=2.00-3.60)and the obvious negative Eu(δEu=0.52-0.68)and Ce(δCe=0.16-0.33)anomalies.The Y/Ho ratios of seven calcites varies from 43.30 to59.34,with a mean value of 49.73.The available mineral associations and REE parameters(i.e.,REE patterns and Y/Ho ratios) of those calcites indicate that the ore-forming fluids of the talc mineralization be probably derived from the meteoric waters,in particular evolved ones in the Karst areas and the ore-forming materials(e.g.,Si and Mg) are likely to be originated from the ore-bearing dolostone in the Yanguan Formation(C_1y) and underlying siliceous rocks in the Liujiang Formation(D_3l).Furthermore,the talc mineralization could take place within a hydrothermal system with relative oxidizing environment and middle temperature,due to the obvious negative Eu and Ce anomalies in the calcites in the Guling deposit. 展开更多
关键词 稀土元素地球化学 SM-ND同位素 热液方解石 滑石矿床 中国南方 广西中部 碳酸盐 托管
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New Varieties of Na-Ca-Ba-RE Fluorocarbonate Series Minerals
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作者 杨主明 张培善 陶克捷 《Journal of Rare Earths》 SCIE EI CAS CSCD 1994年第3期207-211,共5页
The unnamed Sr-rich mineral and Ca-rich baiyuneboite-(Ce) were found in the Khibina alkali massif, Kola Peninsula, and the Baiyun Ebo Nb-Ta-REE deposits, Inner Mongolia, respectively. Their chemical formulas based on ... The unnamed Sr-rich mineral and Ca-rich baiyuneboite-(Ce) were found in the Khibina alkali massif, Kola Peninsula, and the Baiyun Ebo Nb-Ta-REE deposits, Inner Mongolia, respectively. Their chemical formulas based on electron microprobe analysis are (Ca0.46, Na0.28, 0.16)0.90Ba1.03 (CE0.82, Sr0.38, La0.35, Nd0.32, Pr0.09, Sm0.01)1.97 (CO3)4F and (Na0.44, Ca0.32, 0.24)1.00Ba1.07 (Ce1.03, La0.46, Nd0.26, Pr0.08, Sr0.08, Sm0.02)1.93 (CO3)4)F respectively. X-ray diffraction study yields the unit-cell parameters: a=0.5091 nm, c=2.302 nm for the unnamed Sr-rich mineral and a=0.5110 nm, c=2.333 nm for Ca-rich baiyuneboite-(Ce). Both minerals are the intermediate member of the isomorphous series minerals between the unnamed mineral (Ca0.5, 0.5) BaCe2(CO3)4F and baiyune- boite-(Ce) NaBaCe2 (CO3)4F. The ionic radius analysis and the bond valence calculation on the basis of the structure of baiyuneboite-(Ce) indicate that Sr2+ occupies the Ce site preferentially, while Ca2+ occupies the Na site preferentially. The charge balance is maintained by a combination of Na++RE3+ =Ca2++Sr2+ and 2Na+ =Ca2++. 展开更多
关键词 CRYSTALLOGRAPHY minerals rare earth elements STRONTIUM
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Domain Structure in Calcium Cerium Fluorocarbonate Minerals, Mianning County, Sichuan Province, China
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作者 吴秀玲 孟大维 +1 位作者 牟涛 潘兆橹 《Journal of Rare Earths》 SCIE EI CAS CSCD 2000年第2期144-147,共4页
The domain structures in calcium-cerium fluorocarbonate mineral series from a rare earth mineral deposit within an aegirine alkali granite massif in Mianning County, Sichuan Province, China, were studied by means of t... The domain structures in calcium-cerium fluorocarbonate mineral series from a rare earth mineral deposit within an aegirine alkali granite massif in Mianning County, Sichuan Province, China, were studied by means of transmission electron microscopy. Many categories of domain structures in this mineral series were observed and investigated, including the microtwin domains of parisite-6R(2) and B2S-6R, the antiphase domains of B2S-2H. The results show that the antiphase domains which are faults along crystal plane (0001) are formed by the displacement of crystal lattice in c * direction and the displacement is 0.471 nm. A new polytype (B4S2-3R) of regular mixed-layer structure with B4S2 type is found in the domain region of mixed-layer structure. 展开更多
关键词 rare earths Ca-Ce fluorocarbonate mineral domain structure POLYTYPE
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Study on Oxygen Isotope Fractionation in RE Oxide Minerals
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作者 方涛 裘愉卓 《Journal of Rare Earths》 SCIE EI CAS CSCD 1997年第3期69-72,共4页
The oxygen isotope fractionation equations are calculated for major rare earth oxide minerals by using an increment model. The effects of the variation of RE composition, the isomorphic replacement of Ti 4+ , Nb ... The oxygen isotope fractionation equations are calculated for major rare earth oxide minerals by using an increment model. The effects of the variation of RE composition, the isomorphic replacement of Ti 4+ , Nb 5+ , Ta 5+ , and Th 4+ and the metamictization on the oxygen isotope fractionation in minerals are also discussed. The rare earth oxides are not applicable for geothermometry due to their changeable oxygen isotope fractionation coefficients. 展开更多
关键词 rare earths Oxygen isotopes RE oxide minerals Fractionation coefficients
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Study on Visible Photoluminescence and Absorption Spectra of Fergusonite Group Minerals
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作者 薛理辉 贡伟亮 《Journal of Rare Earths》 SCIE EI CAS CSCD 2000年第1期9-13,共5页
Visible photoluminescence and absorption spectra of the metamict and annealing-recrystallized fergusonite and brocenite, found in Bayun Obo ore deposit in China, were determined and discussed. The results show that... Visible photoluminescence and absorption spectra of the metamict and annealing-recrystallized fergusonite and brocenite, found in Bayun Obo ore deposit in China, were determined and discussed. The results show that the glow centers of the fergusonite group minerals are Er3+ and Eu3 + when 488.0 and 514.5 nm lasers are used as excitation sources. The luminescence of fergusonites results mainly from Er3+, whereas that of brocenites is produced by Er3+ and Eu3+. The absorption spectra indicate that Nd3 + may be an important sensitizer to the luminescence of Er3 + and Eu3+. 展开更多
关键词 rare earths fergusonite group minerals luminescence spectra absorption spectra
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