Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that Korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than C...Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that Korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than Chinese river sediments (Changjiang, Huanghe and Yalujiang), shown by obvious enrichments of LREE (light rare earth element) relative to UCC (upper continental crust). Variations of source rock compositions in the drainage basins are responsible for the differences of REE compositions between the river sediments. REE fractionation parameters including (La/Yb)UCC and (Gd/Yb)UCC as well as the ratios of La/Sc and Th/Sc can be treated as proper proxies for identifying the Chinese river sediments from those Korean river matters, and furthermore, for studying the provenances and paleoenvironmental changes of the marginal seas of China.展开更多
Rare earth elements （REEs） have been proved ideal tracers for soil erosion and aggregation. REE tracer method （REETM） used to study soil erosion, as a new technique, has been developed in recent 20 yr. It is able ...Rare earth elements （REEs） have been proved ideal tracers for soil erosion and aggregation. REE tracer method （REETM） used to study soil erosion, as a new technique, has been developed in recent 20 yr. It is able to quantitatively monitor the temporal and spatial variation of erosion intensity, compared with traditional approaches. The applications of REETM in studying of sediment differentiation law, erosion process evolution, determination of sediment sources and sedimentation investigations, and determination of prediction parameters, were reviewed. Some application limitations were summarized.展开更多
For direct quantitative determination of rare earth elements（REE） in REE-rich minerals, a most acceptable reference material NIST 610 might be an alternative external calibration standard due to the lack of matrix-m...For direct quantitative determination of rare earth elements（REE） in REE-rich minerals, a most acceptable reference material NIST 610 might be an alternative external calibration standard due to the lack of matrix-matched reference materials. Here, we aimed to develop an analytical method for direct quantitative determination of REE concentrations in REE-rich minerals via laser ablation-inductively coupled plasma-mass spectrometry（LA-ICP-MS）. The results show that the REE concentrations measured via LA-ICP-MS using NIST 610 as an extemal standard are in good agreement with reference values with relative percentage difference（Dr） mainly less than 15%. Overall, these results demonstrate that our proposed analytical method is robust and accurate for direct quantitative determination of REE concentrations in REE-rich minerals.展开更多
Microfluidic solvent extraction （micro SX） of gadolinium was conducted using a mono- and diester mixture （MDEHPA） as the cationic extractant. A microfluidic Y-Y channel was fabricated using CO2- laser technique in...Microfluidic solvent extraction （micro SX） of gadolinium was conducted using a mono- and diester mixture （MDEHPA） as the cationic extractant. A microfluidic Y-Y channel was fabricated using CO2- laser technique in a glass microchip used as the extraction system. Compared with batch extraction, extraction kinetic is found fast, and extraction equilibrium is attained within 15 s. Stoichiometry of the extracted complex is found to be Gd（NOs）3-3MDEHPA using log-log plot method. Additionally, the operating parameters and overall volumetric mass transfer coefficient （kLα） were investigated to determine the mass transfer performance. Optimal condition of microextraction for gadolinium using response surface methodology was determined （feed solutions 31 mg/L adjusted to pH value 2.5, extractant concentration 2.9 vol% and extraction time 13.5 s）. In optimal condition, gadolinium extraction yield is obtained 95.5%. Findings of this study approve simplicity, portability, effectiveness, swiftness, and environmental friendliness microfluidic solvent extraction process and reveal that micro SX is useful in the field of extraction strategic metals present at low concentrations, which are otherwise not technically amenable or economically feasible to extract using current traditional methods.展开更多
Bayan Obo, a rare earth element (REE)-Fe-Nb ore deposit, located in central InnerMongolia, near the contact between the North China Platform and Inner MongoliaHercynian Geosyncline, is a unique deposit with a combinat...Bayan Obo, a rare earth element (REE)-Fe-Nb ore deposit, located in central InnerMongolia, near the contact between the North China Platform and Inner MongoliaHercynian Geosyncline, is a unique deposit with a combination of multi-sources, multi-stagesand multi-geneses. The orebodies occur comformably with the host rocks in stratoid,lenticular, lense and brush shapes within the dolomite of the Middle Proterozoic Bayan展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.4997601 6 and 40206008)the Korean Science and Engineering Foundation.
文摘Rare earth element (REE) compositions of the suspended sediments from the rivers around the Yellow Sea were different in that Korean river sediments (Han, Keum and Yeongsan Rivers) yield stronger fractionations than Chinese river sediments (Changjiang, Huanghe and Yalujiang), shown by obvious enrichments of LREE (light rare earth element) relative to UCC (upper continental crust). Variations of source rock compositions in the drainage basins are responsible for the differences of REE compositions between the river sediments. REE fractionation parameters including (La/Yb)UCC and (Gd/Yb)UCC as well as the ratios of La/Sc and Th/Sc can be treated as proper proxies for identifying the Chinese river sediments from those Korean river matters, and furthermore, for studying the provenances and paleoenvironmental changes of the marginal seas of China.
基金supported by the National Key Technology R&D Program of China(2006BAC10B020,2008BAD98B08)
文摘Rare earth elements （REEs） have been proved ideal tracers for soil erosion and aggregation. REE tracer method （REETM） used to study soil erosion, as a new technique, has been developed in recent 20 yr. It is able to quantitatively monitor the temporal and spatial variation of erosion intensity, compared with traditional approaches. The applications of REETM in studying of sediment differentiation law, erosion process evolution, determination of sediment sources and sedimentation investigations, and determination of prediction parameters, were reviewed. Some application limitations were summarized.
基金Supported by the National Natural Science Foundation of China（No.41603025）, the National Key Scientific Instrument and Equipment Development Projects of China（No.2015311007） and the China Postdoctoral Science Foundation（No.2016M602386）.
文摘For direct quantitative determination of rare earth elements（REE） in REE-rich minerals, a most acceptable reference material NIST 610 might be an alternative external calibration standard due to the lack of matrix-matched reference materials. Here, we aimed to develop an analytical method for direct quantitative determination of REE concentrations in REE-rich minerals via laser ablation-inductively coupled plasma-mass spectrometry（LA-ICP-MS）. The results show that the REE concentrations measured via LA-ICP-MS using NIST 610 as an extemal standard are in good agreement with reference values with relative percentage difference（Dr） mainly less than 15%. Overall, these results demonstrate that our proposed analytical method is robust and accurate for direct quantitative determination of REE concentrations in REE-rich minerals.
基金Project supported by Department of Chemical,Petroleum and Gas Engineering,Iran University of Science&Technology(IUST)
文摘Microfluidic solvent extraction （micro SX） of gadolinium was conducted using a mono- and diester mixture （MDEHPA） as the cationic extractant. A microfluidic Y-Y channel was fabricated using CO2- laser technique in a glass microchip used as the extraction system. Compared with batch extraction, extraction kinetic is found fast, and extraction equilibrium is attained within 15 s. Stoichiometry of the extracted complex is found to be Gd（NOs）3-3MDEHPA using log-log plot method. Additionally, the operating parameters and overall volumetric mass transfer coefficient （kLα） were investigated to determine the mass transfer performance. Optimal condition of microextraction for gadolinium using response surface methodology was determined （feed solutions 31 mg/L adjusted to pH value 2.5, extractant concentration 2.9 vol% and extraction time 13.5 s）. In optimal condition, gadolinium extraction yield is obtained 95.5%. Findings of this study approve simplicity, portability, effectiveness, swiftness, and environmental friendliness microfluidic solvent extraction process and reveal that micro SX is useful in the field of extraction strategic metals present at low concentrations, which are otherwise not technically amenable or economically feasible to extract using current traditional methods.
文摘Bayan Obo, a rare earth element (REE)-Fe-Nb ore deposit, located in central InnerMongolia, near the contact between the North China Platform and Inner MongoliaHercynian Geosyncline, is a unique deposit with a combination of multi-sources, multi-stagesand multi-geneses. The orebodies occur comformably with the host rocks in stratoid,lenticular, lense and brush shapes within the dolomite of the Middle Proterozoic Bayan
