The structures and elasticities of phase B silicates with different water and iron（Fe） content are obtained by firstprinciples simulation to understand the effects of water and Fe on their properties under high pres...The structures and elasticities of phase B silicates with different water and iron（Fe） content are obtained by firstprinciples simulation to understand the effects of water and Fe on their properties under high pressure.The lattice constants a and b decrease with increasing water content.On the contrary,c increases with increasing water content.On the other hand,the b and c decrease with increasing Fe content while a increases with increasing Fe content.The decrease of M（metal）–O octahedral volume is greater than the decrease of SiO polyhedral volume over the same pressure range.The density,bulk modulus and shear modulus of phase B increase with increasing Fe content and decrease with increasing water content.The compressional wave velocity（Vp） and shear wave velocity（Vs） of phase B decrease with increasing water and Fe content.The comparisons of density and wave velocity between phase B silicate and the Earth typical structure provide the evidence for understanding the formation of the X-discontinuity zone of the mantle.展开更多
This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for...This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for the resource utilization of smelting slag.An intricate correlation between metallic elements and dominant phases was constructed.Typical silicate phase olivine(OL)was synthesized as a paradigm to examine alkali depolymerization,unveiling the optimal conditions for such depolymerization to be an alkali to olivine molar ratio of 1:5,a reaction temperature of 700℃,and a duration of 3 h.The underlying mechanism of alkali depolymerization within silicate phases was elucidated under these parameters.The reaction mechanism of alkali depolymerization within silicate phases can be encapsulated in three sequential steps:(1)NaOH dissociation and subsequent adsorption of OH^(-)to cationic(Mg or Fe)sites;(2)disruption of cation-oxygen bonds,leading to the formation of hydroxide compounds,which then underwent oxidation;(3)Na^(+)occupied the resultant cation vacancy sites,instigating further depolymerization of the intermediate Na_(2)(Mg,Fe)SiO_(4).The articulated mechanism is anticipated to furnish theoretical underpinnings for the efficacious recuperation of metals from smelting slags.展开更多
Rare earth element(REE) is widely used in various fields of geology.Study of the existing forms of REE in geological objects is a necessity for us to solve geological problems related with REE.This paper tried to make...Rare earth element(REE) is widely used in various fields of geology.Study of the existing forms of REE in geological objects is a necessity for us to solve geological problems related with REE.This paper tried to make it clear the existing forms of REE in gold-bearing pyrite in Jinshan gold deposit by stepwise dissolution test with ICP-MS analysis.Results showed that content of REE in fluid-inclusions of gold-bearing pyrite was very low,which only took about 0.07%–0.70% of the ΣREE,and that of pyrite phase ...展开更多
The grain boundaries of polycrystalline oxygen ion conductors presented a blocking effect on the oxygen ionic transport across them. It was found that the apparent specific grain boundary conductivity was 2-3 orders o...The grain boundaries of polycrystalline oxygen ion conductors presented a blocking effect on the oxygen ionic transport across them. It was found that the apparent specific grain boundary conductivity was 2-3 orders of magnitude lower than the bulk conductivity in the temperature range of 200-500 °C for normal purity Ce0.85Sm0.15O1.925 (SDC) with an average grain size of 320-580 nm. The apparent specific grain boundary conductivity increased with decreasing average grain size. It was found that the space charge potential was nearly independent of grain size, and the reason was analyzed. The increase of the conduction path width was responsible for the increase in the apparent specific grain boundary conductivity.展开更多
基金Project supported by the Science Fund from the Key Laboratory of Earthquake Prediction,Institute of Earthquake Science,China Earthquake Administration(Grant No.2016IES010104)the National Natural Science Foundation of China(Grant Nos.41174071,41273073,41373060,and 41573121)
文摘The structures and elasticities of phase B silicates with different water and iron（Fe） content are obtained by firstprinciples simulation to understand the effects of water and Fe on their properties under high pressure.The lattice constants a and b decrease with increasing water content.On the contrary,c increases with increasing water content.On the other hand,the b and c decrease with increasing Fe content while a increases with increasing Fe content.The decrease of M（metal）–O octahedral volume is greater than the decrease of SiO polyhedral volume over the same pressure range.The density,bulk modulus and shear modulus of phase B increase with increasing Fe content and decrease with increasing water content.The compressional wave velocity（Vp） and shear wave velocity（Vs） of phase B decrease with increasing water and Fe content.The comparisons of density and wave velocity between phase B silicate and the Earth typical structure provide the evidence for understanding the formation of the X-discontinuity zone of the mantle.
基金financially supported by the National Natural Science Foundation of China(Nos.22006040 and 22376070)the National Key Research and Development Program of China(No.2019YFA0210404)the Research Project on Characteristic Innovation of University Teachers(No.2022XJZZ02)。
文摘This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry.Findings delineated the silicate phase as the pivotal and predominant constraining phase for the resource utilization of smelting slag.An intricate correlation between metallic elements and dominant phases was constructed.Typical silicate phase olivine(OL)was synthesized as a paradigm to examine alkali depolymerization,unveiling the optimal conditions for such depolymerization to be an alkali to olivine molar ratio of 1:5,a reaction temperature of 700℃,and a duration of 3 h.The underlying mechanism of alkali depolymerization within silicate phases was elucidated under these parameters.The reaction mechanism of alkali depolymerization within silicate phases can be encapsulated in three sequential steps:(1)NaOH dissociation and subsequent adsorption of OH^(-)to cationic(Mg or Fe)sites;(2)disruption of cation-oxygen bonds,leading to the formation of hydroxide compounds,which then underwent oxidation;(3)Na^(+)occupied the resultant cation vacancy sites,instigating further depolymerization of the intermediate Na_(2)(Mg,Fe)SiO_(4).The articulated mechanism is anticipated to furnish theoretical underpinnings for the efficacious recuperation of metals from smelting slags.
基金supported by the National Natural Science Foundation of China (40373025)
文摘Rare earth element(REE) is widely used in various fields of geology.Study of the existing forms of REE in geological objects is a necessity for us to solve geological problems related with REE.This paper tried to make it clear the existing forms of REE in gold-bearing pyrite in Jinshan gold deposit by stepwise dissolution test with ICP-MS analysis.Results showed that content of REE in fluid-inclusions of gold-bearing pyrite was very low,which only took about 0.07%–0.70% of the ΣREE,and that of pyrite phase ...
基金Project supported by the National Natural Science Foundation of China (50872041)the National Foundation for Fostering Talent in Basic Science of China ( J0730311)
文摘The grain boundaries of polycrystalline oxygen ion conductors presented a blocking effect on the oxygen ionic transport across them. It was found that the apparent specific grain boundary conductivity was 2-3 orders of magnitude lower than the bulk conductivity in the temperature range of 200-500 °C for normal purity Ce0.85Sm0.15O1.925 (SDC) with an average grain size of 320-580 nm. The apparent specific grain boundary conductivity increased with decreasing average grain size. It was found that the space charge potential was nearly independent of grain size, and the reason was analyzed. The increase of the conduction path width was responsible for the increase in the apparent specific grain boundary conductivity.
