Hydrothermal barite is a typical low-temperature mineral formed during the mixing of hydrothermal fluid and seawater.Because of its extremely low solubility,barite behaves as a close system after crystallization and p...Hydrothermal barite is a typical low-temperature mineral formed during the mixing of hydrothermal fluid and seawater.Because of its extremely low solubility,barite behaves as a close system after crystallization and preserves the geochemical fingerprint of hydrothermal fluid.In this study,the elemental contents and Sr isotope compositions of hydrothermal barites from the Yonaguni IV were determined using electron microprobe and LA-MC-ICP-MS respectively.On these bases,the fluid/sediment interaction during the hydrothermal circulation and physicochemical condition of barite crystallization were discussed.Results show that the 87 Sr/86 Sr values of hydrothermal barites from the Yonaguni IV are apparently higher than those of the seawater and associated volcanic rocks,indicating the sufficient interaction between the hydrothermal fluid and overlying sediment.Monomineral Sr abundance shows large variations,reflecting the changes in barite growth rate during the fluid mixing.The mineralization condition in the Yonaguni IV was unstable.During the crystallization of barite,hydrothermal fluid and seawater mixed in varying degrees,with the pro-portions of hydrothermal fluid varied from 36%to 72%.The calculated crystallization temperatures range from 109 to 220℃.Sediment plays a critical role during the mineralization process in the Yonaguni IV and incorporation of sediment component into hydrothermal system was prior to barite crystallization and sulfide mineralization.展开更多
1 Introduction Crystallization is one of important unit operations in the chemical production process,which requires not only the crystal product with high purity and yield,but also the available particle size of the ...1 Introduction Crystallization is one of important unit operations in the chemical production process,which requires not only the crystal product with high purity and yield,but also the available particle size of the crystal products to ensure product quality.Crystallization process is affected by展开更多
The crystalline precipitate of rare earth carbonates has been produced by the ammonium bicar- bonate precipitation method in the recovery of RE from the ammonium sulfate leaching liquor of the weath- ered leach-deposi...The crystalline precipitate of rare earth carbonates has been produced by the ammonium bicar- bonate precipitation method in the recovery of RE from the ammonium sulfate leaching liquor of the weath- ered leach-deposited rare earth ore.Various influencing factors such as time,temperature and reagent con- centration have been studied.And chemical analysis,XRD,SEM,IR spectrography,TGA and DTA have been used to analyze and examine the crystalline RE carbonates.Good results were obtained.展开更多
Two metal-organic coordination complexes, [Zn(2,6-ndc)(1,2-bix)]n(1) and [Zn(2,6-ndc)(1,3-bix)]n(2)(2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene and 1,3-...Two metal-organic coordination complexes, [Zn(2,6-ndc)(1,2-bix)]n(1) and [Zn(2,6-ndc)(1,3-bix)]n(2)(2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene and 1,3-bix = 1,3-bis(imidazole-1-ylmethyl)-benzene) have been synthesized by the hydrothermal method. Though the two complexes both crystallize in a triclinic system, space group P1 and show similar two-dimensional structures, weak intermolecular interactions(π-π packing interactions) only exist in complex 2. They are characterized by single-crystal X-ray diffraction analysis, fluorescence measurement, IR spectroscopy and TGA. Moreover, the solid-state fluorescence spectra of two complexes show maximal emission peaks at 365(λ(ex) = 329 nm) and 367 nm(λex = 344 nm), respectively.展开更多
基金financially supported by the National Basic Research Program of China(No.2013CB429702)
文摘Hydrothermal barite is a typical low-temperature mineral formed during the mixing of hydrothermal fluid and seawater.Because of its extremely low solubility,barite behaves as a close system after crystallization and preserves the geochemical fingerprint of hydrothermal fluid.In this study,the elemental contents and Sr isotope compositions of hydrothermal barites from the Yonaguni IV were determined using electron microprobe and LA-MC-ICP-MS respectively.On these bases,the fluid/sediment interaction during the hydrothermal circulation and physicochemical condition of barite crystallization were discussed.Results show that the 87 Sr/86 Sr values of hydrothermal barites from the Yonaguni IV are apparently higher than those of the seawater and associated volcanic rocks,indicating the sufficient interaction between the hydrothermal fluid and overlying sediment.Monomineral Sr abundance shows large variations,reflecting the changes in barite growth rate during the fluid mixing.The mineralization condition in the Yonaguni IV was unstable.During the crystallization of barite,hydrothermal fluid and seawater mixed in varying degrees,with the pro-portions of hydrothermal fluid varied from 36%to 72%.The calculated crystallization temperatures range from 109 to 220℃.Sediment plays a critical role during the mineralization process in the Yonaguni IV and incorporation of sediment component into hydrothermal system was prior to barite crystallization and sulfide mineralization.
基金financial support of National Nature Science Foundation (21376178)TIDA giant growth plan (2011-XJR13020)Tianjin Science and technology support program (12ZCDZSF06900)
文摘1 Introduction Crystallization is one of important unit operations in the chemical production process,which requires not only the crystal product with high purity and yield,but also the available particle size of the crystal products to ensure product quality.Crystallization process is affected by
基金The project supported by National Natural Science Foundation of China
文摘The crystalline precipitate of rare earth carbonates has been produced by the ammonium bicar- bonate precipitation method in the recovery of RE from the ammonium sulfate leaching liquor of the weath- ered leach-deposited rare earth ore.Various influencing factors such as time,temperature and reagent con- centration have been studied.And chemical analysis,XRD,SEM,IR spectrography,TGA and DTA have been used to analyze and examine the crystalline RE carbonates.Good results were obtained.
基金Supported by the National Natural Science Foundation of China for Young Scholars(No.21201087)Natural Science Foundation of Jiangsu Province(No.BK20131244)+1 种基金Jiangsu Overseas Research & Training Program for University Prominent Young & Middle-aged Teachers and Presidents,a start-up grant from Jiangsu University of Science and Technology,and Jiangsu Innovation Program for Graduate Student(No.KYZZ15-0300)Innovation Program for Graduate Student from Jiangsu University of Science and Technology,China
文摘Two metal-organic coordination complexes, [Zn(2,6-ndc)(1,2-bix)]n(1) and [Zn(2,6-ndc)(1,3-bix)]n(2)(2,6-H2ndc = 2,6-naphthalenedicarboxylic acid, 1,2-bix = 1,2-bis(imidazole-1-ylmethyl)-benzene and 1,3-bix = 1,3-bis(imidazole-1-ylmethyl)-benzene) have been synthesized by the hydrothermal method. Though the two complexes both crystallize in a triclinic system, space group P1 and show similar two-dimensional structures, weak intermolecular interactions(π-π packing interactions) only exist in complex 2. They are characterized by single-crystal X-ray diffraction analysis, fluorescence measurement, IR spectroscopy and TGA. Moreover, the solid-state fluorescence spectra of two complexes show maximal emission peaks at 365(λ(ex) = 329 nm) and 367 nm(λex = 344 nm), respectively.