The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method,which presents challenges in terms of prolonged production cycle and a...The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method,which presents challenges in terms of prolonged production cycle and ammonia nitrogen pollution.The present study explored the synthesis of crystalline yttrium carbonate in a sodium carbonate system,employing a conventional mother liquor derived from yttrium chloride.The growth of yttrium carbonate was explored through the lens of density functional theory(DFT)calculations,unveiling a novel perspective on its formation mechanism.The synthesized yttrium carbonate demonstrates enhanced crystallinity,with a D50value of 19.75μm achieved under reaction conditions comprising a temperature of 60℃,stirring rate of 200 r/min,feeding rate of 4 mL/min,and aging time of 30 h.The molar ratio for precipitation is set at 1.6:1.The morphology of yttrium carbonate undergoes a transition from needle-like structures to sheet-like formations,ultimately culminating in the formation of spherical aggregates.The variation in surface energy among distinct crystal planes and CO_(3)^(2-)configurations within crystal cells accounts for this phenomenon.The DFT calculations unveil a progression of growth and trans formation in yttrium carbonate,commencing from a one-dimensional configuration and culminating in a multidimensional morphology.展开更多
Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge.This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2...Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge.This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2-methylpropanesulfonic acid(AA/AMPS)as a depressant to separate chalcopyrite and galena.Flotation tests revealed a significant reduction in galena recovery when AA/AMPS was employed,with minimal impact observed on chalcopyrite.In artificial mixed ore flotation,AA/AMPS was found to enhance the efficiency of copper and lead separation,surpassing K_(2)Cr_(2)O_(7).Furthermore,the effectiveness of AA/AMPS in facilitating copper-lead separation has been validated in practical ore flotation.The presence of AA/AMPS inhibited the adsorption of SBX onto galena,as confirmed by zeta potential and contact angle measurements.However,the adsorption on chalcopyrite remained unaffected.Through analyses using Atomic Force Microscope,X-ray photoelectron spectroscopy,and Density Functional Theory,a robust chemical interaction between the reactive groups in AA/AMPS and Pb sites on galena was uncovered,resulting in the formation of a hydrophilic polymer layer.This layer impedes SBX adsorption and reduces galena's floatability.In contrast,no significant chemical adsorption was observed between AA/AMPS and Cu and Fe sites on chalcopyrite,preserving its SBX affinity.Overall,AA/AMPS shows promise in replacing traditional depressants for Cu-Pb sulfide ore separation,enhancing environmental sustainability.展开更多
Ameliorating the problem of low leaching efficiency,long leaching period,and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources.In this study,the surfactant sodium do...Ameliorating the problem of low leaching efficiency,long leaching period,and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources.In this study,the surfactant sodium dodecyl sulfate(SDS) is used to enhance the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect for the first time.The effects of surfactant concentration,leaching agent dosage,solution flow velocity,and solution pH on the leaching rate were explored,and the mechanism of SDS was discussed.Under the optimum conditions,the addition of a small amount of SDS(mass fraction0.04%) can increase the leaching rate by about 5%,shorten the leaching period,and reduce the consumption of the leaching agent.SDS significantly ameliorates the seepage effect of the ore body by reducing the surface tension of the leaching agent and ameliorating the wettability of the mineral surface.This effect is the main factor that improves the leaching efficiency.DFT(density functional theory) calculation results show that SDS can react with rare earth ions,which reduces the adsorption strength on clay mineral surfaces.Hence,rare earth ions are easily exchanged by ammonium ions,and mass transfer is enhanced.展开更多
Pore network structure of ore body is a diffusion channel of leaching agent solution that exerts a significant influence on seepage.The ore body structure,pore distribution,pore and throat size,and pore network charac...Pore network structure of ore body is a diffusion channel of leaching agent solution that exerts a significant influence on seepage.The ore body structure,pore distribution,pore and throat size,and pore network characteristics of topsoil,weathered,and semiweathered layers of ionic rare earth ore in southern Jiangxi Province were explored in this study.The effect of leaching operation on the pore structure was investigated,and main factors affecting the seepage were analyzed.Results showed that the semiweathered layer presents a dense structure and a small number of unconnected pores.Pores of topsoil and weathered layers are mainly long and narrow column openings with some planar fractures.Even pore distribution and large size span were observed.Compared with the weathered layer,the topsoil layer demonstrates larger voids,smaller average pore volume and equivalent radius,and fewer coordination throats;however,the average equivalent radius of the throat in the topsoil layer is larger and largescale channels exist through ore body vertically.Hence,permeability of the topsoil layer is significantly higher than that of the weathered layer.Colloidal clay minerals migrate easily and the occurrence of silting in the small porosity blocks the throat and significantly decreases the permeability of the ore body in the leaching process.The equivalent radius of the throat is the key to the seepage.Reducing the migration of fine particles is an effective measure to protect the throat and shorten the leaching period.展开更多
Under the background of increasingly scarce ore worldwide and increasingly fierce market competition,developing the mining industry could be strongly restricted.Intelligent ore sorting equipment not only improves ore ...Under the background of increasingly scarce ore worldwide and increasingly fierce market competition,developing the mining industry could be strongly restricted.Intelligent ore sorting equipment not only improves ore use and enhances the economic benefits of enterprises but also increases the ore grade and lessens the grinding cost and tailings production.However,long-term research on intelligent ore sorting equipment found that the factors affecting sorting efficiency mainly include ore information identification technology,equipment sorting actuator,and information processing algorithm.The high precision,strong anti-interference capability,and high speed of these factors guarantee the separation efficiency of intelligent ore sorting equipment.Color ore sorter,X-ray ore transmission sorter,dual-energy X-ray transmission ore sorter,X-ray fluorescence ore sorter,and near-infrared ore sorter have been successfully developed in accordance with the different characteristics of minerals while ensuring the accuracy of equipment sorting and improving the equipment sorting efficiency.With the continuous improvement of mine automation level,the application of online element rapid analysis technology with high speed,high precision,and strong anti-interference capability in intelligent ore sorting equipment will become an inevitable trend of equipment development in the future.Laser-induced breakdown spectroscopy,transientγneutron activation analysis,online Fourier transform infrared spectroscopy,and nuclear magnetic resonance techniques will promote the development of ore sorting equipment.In addition,the improvement and joint application of additional high-speed and high-precision operation algorithms(such as peak area,principal component analysis,artificial neural network,partial least squares,and Monte Carlo library least squares methods)are an essential part of the development of intelligent ore sorting equipment in the future.展开更多
Rare-earth modification Bi2WO6 composites(RE/Bi2WO6)were studied by experimental performance and theory computation based on the different 4 f orbits of selected rare earth elements(La,Ce,Gd,and Yb).The prepared RE/Bi...Rare-earth modification Bi2WO6 composites(RE/Bi2WO6)were studied by experimental performance and theory computation based on the different 4 f orbits of selected rare earth elements(La,Ce,Gd,and Yb).The prepared RE/Bi2WO6 was characterized by XRD,SEM/TEM,XPS,UV-vis DRS,and N2 adsorption to learn their physical-chemical properties.Azo dye Rhodamine B(RhB)was photodegraded as a target pollutant to investigate the photocatalytic activity of prepared RE/Bi2WO6 composites.The results of experiment and computation show that four rare earth elements with different electron configurations retain the phase and morphology of Bi2 WO6 and enhance the removal efficiency of RhB under simulated solar irradiation.The optimum doping contents are 0.01%,0.05%,0.05%and 0.01%for La-,Ce-,Gd-,and Yb-doped Bi2WO6,respectively.However,light rare earth La and Ce doped composites indicate some difference in visible light adso rption capacity and mineralization on RhB co mpared with heavy rare earth Gd and Yb doped composites.Both La/Bi2WO6 and Ce/Bi2 WO6 possess larger pore size and higher mineralization ability than Gd/Bi2 WO6 and Yb/Bi2WO6 under the same experimental conditions while Gd/Bi2WO6 and Yb/Bi2WO6 show stronger red shift to the visible light due to the more 4 f electrons.The hole oxidation plays a major role in the photodegradation of RhB by all RE/Bi2WO6.展开更多
Spodumene is a silicate mineral rich in lithium.However,the gangue mineral,albite has similar crystal chemical structure and composition to spodumene.In this work,the density functional theory(DFT)calculation was take...Spodumene is a silicate mineral rich in lithium.However,the gangue mineral,albite has similar crystal chemical structure and composition to spodumene.In this work,the density functional theory(DFT)calculation was taken to research the floatability from the perspective of crystal chemistry.And contact angle test and reagent adsorption test were used to support the simulation results.In addition,the weighted total density of broken bonds is proposed for the first time to judge the generation probability of cleavage surface.The DFT calculation results display that the Na and Al sites on the albite surface are the adsorption sites of water molecules.While the water molecules only bond with Al atom on the surface of spodumene and each Al site can adsorb only one water molecule.Thus,the wetting effect of water molecules on the albite surface is stronger than that of spodumene.This is consistent with the result of contact angle.In sodium oleate system,the oleic acid anion is adsorbed on the spodumene surface in form of a multicomponent ring while the albite is a single ring.Theoretically,oleic acid anion can be strongly adsorbed on the surface of spodumene and albite under vacuum.The adsorption strength of spodumene is higher than that of albite.However,on hydrated surface,the adsorption strength of oleic acid anion on mineral surface is greatly reduced due to the interaction between water molecules and metal site on mineral surface.Thus,spodumene and albite are hard to float without external activated ions in sodium oleate system.展开更多
In this study, we selected yttrium as the representative of REEs to investigate the impacts of exogenous yttrium on soil physicochemical properties and microbiota. The results showed that exogenous yttrium has no sign...In this study, we selected yttrium as the representative of REEs to investigate the impacts of exogenous yttrium on soil physicochemical properties and microbiota. The results showed that exogenous yttrium has no significant effect on soil physical properties but a significantly negative impact on soil chemical properties. The results of high-throughput sequencing demonstrate that exogenous yttrium significantly decreases the number of OTUs, ACE, Chao 1, and Shannon indices while increases the Simpson index（P 〈 0.05）, indicating the low soil microbial diversity. The relative abundances of soil microbes are significantly changed at phylum and genus level. Principal component analysis（PCA） showed the significant difference of microbial community between yttrium treatments（YCl_3-250 and YCl_3-500） and non-yttrium treatment（CK） and the similarity of that between YCl_3-250 and YCI_3-500. Proteobacteria and Bacteroidetes are found to be the most tolerant phyla to exogenous yttrium while Verrucomicrobia the most sensitive phylum. Redundancy analysis（RDA） results suggest that exogenous yttrium affects soil microbiota only through changing the soil chemical properties but not soil physical properties, and C/N ratio is the key environmental factor.展开更多
基金Project supported by the National Natural Science Foundation of China(52174250,92062110)the Youth Jinggang Scholars Program in Jiangxi Province(QNJG2020048)。
文摘The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method,which presents challenges in terms of prolonged production cycle and ammonia nitrogen pollution.The present study explored the synthesis of crystalline yttrium carbonate in a sodium carbonate system,employing a conventional mother liquor derived from yttrium chloride.The growth of yttrium carbonate was explored through the lens of density functional theory(DFT)calculations,unveiling a novel perspective on its formation mechanism.The synthesized yttrium carbonate demonstrates enhanced crystallinity,with a D50value of 19.75μm achieved under reaction conditions comprising a temperature of 60℃,stirring rate of 200 r/min,feeding rate of 4 mL/min,and aging time of 30 h.The molar ratio for precipitation is set at 1.6:1.The morphology of yttrium carbonate undergoes a transition from needle-like structures to sheet-like formations,ultimately culminating in the formation of spherical aggregates.The variation in surface energy among distinct crystal planes and CO_(3)^(2-)configurations within crystal cells accounts for this phenomenon.The DFT calculations unveil a progression of growth and trans formation in yttrium carbonate,commencing from a one-dimensional configuration and culminating in a multidimensional morphology.
基金supported by the Cultivation plan of National Science and Technology Award reserve Project of Jiangxi Science and Technology Department(No.20192AEI91003)the Major science and technology projects of Qinghai Province(No.2018GX-A7)。
文摘Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge.This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2-methylpropanesulfonic acid(AA/AMPS)as a depressant to separate chalcopyrite and galena.Flotation tests revealed a significant reduction in galena recovery when AA/AMPS was employed,with minimal impact observed on chalcopyrite.In artificial mixed ore flotation,AA/AMPS was found to enhance the efficiency of copper and lead separation,surpassing K_(2)Cr_(2)O_(7).Furthermore,the effectiveness of AA/AMPS in facilitating copper-lead separation has been validated in practical ore flotation.The presence of AA/AMPS inhibited the adsorption of SBX onto galena,as confirmed by zeta potential and contact angle measurements.However,the adsorption on chalcopyrite remained unaffected.Through analyses using Atomic Force Microscope,X-ray photoelectron spectroscopy,and Density Functional Theory,a robust chemical interaction between the reactive groups in AA/AMPS and Pb sites on galena was uncovered,resulting in the formation of a hydrophilic polymer layer.This layer impedes SBX adsorption and reduces galena's floatability.In contrast,no significant chemical adsorption was observed between AA/AMPS and Cu and Fe sites on chalcopyrite,preserving its SBX affinity.Overall,AA/AMPS shows promise in replacing traditional depressants for Cu-Pb sulfide ore separation,enhancing environmental sustainability.
基金supported by the National Natural Science Foundation of China (Nos. 51774153 and 92062110)。
文摘Ameliorating the problem of low leaching efficiency,long leaching period,and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources.In this study,the surfactant sodium dodecyl sulfate(SDS) is used to enhance the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect for the first time.The effects of surfactant concentration,leaching agent dosage,solution flow velocity,and solution pH on the leaching rate were explored,and the mechanism of SDS was discussed.Under the optimum conditions,the addition of a small amount of SDS(mass fraction0.04%) can increase the leaching rate by about 5%,shorten the leaching period,and reduce the consumption of the leaching agent.SDS significantly ameliorates the seepage effect of the ore body by reducing the surface tension of the leaching agent and ameliorating the wettability of the mineral surface.This effect is the main factor that improves the leaching efficiency.DFT(density functional theory) calculation results show that SDS can react with rare earth ions,which reduces the adsorption strength on clay mineral surfaces.Hence,rare earth ions are easily exchanged by ammonium ions,and mass transfer is enhanced.
基金supported by the National Natural Science Foundation of China(Nos.51774153,92062110)National Key Research and Development Program of China(No.2021YFC2901702)。
文摘Pore network structure of ore body is a diffusion channel of leaching agent solution that exerts a significant influence on seepage.The ore body structure,pore distribution,pore and throat size,and pore network characteristics of topsoil,weathered,and semiweathered layers of ionic rare earth ore in southern Jiangxi Province were explored in this study.The effect of leaching operation on the pore structure was investigated,and main factors affecting the seepage were analyzed.Results showed that the semiweathered layer presents a dense structure and a small number of unconnected pores.Pores of topsoil and weathered layers are mainly long and narrow column openings with some planar fractures.Even pore distribution and large size span were observed.Compared with the weathered layer,the topsoil layer demonstrates larger voids,smaller average pore volume and equivalent radius,and fewer coordination throats;however,the average equivalent radius of the throat in the topsoil layer is larger and largescale channels exist through ore body vertically.Hence,permeability of the topsoil layer is significantly higher than that of the weathered layer.Colloidal clay minerals migrate easily and the occurrence of silting in the small porosity blocks the throat and significantly decreases the permeability of the ore body in the leaching process.The equivalent radius of the throat is the key to the seepage.Reducing the migration of fine particles is an effective measure to protect the throat and shorten the leaching period.
基金supported by the National Science and Technology Support Program of China(No.2012BAC11B07)the Jiangxi Science and Technology Innovation Base Plan(No.20212BCD42017)。
文摘Under the background of increasingly scarce ore worldwide and increasingly fierce market competition,developing the mining industry could be strongly restricted.Intelligent ore sorting equipment not only improves ore use and enhances the economic benefits of enterprises but also increases the ore grade and lessens the grinding cost and tailings production.However,long-term research on intelligent ore sorting equipment found that the factors affecting sorting efficiency mainly include ore information identification technology,equipment sorting actuator,and information processing algorithm.The high precision,strong anti-interference capability,and high speed of these factors guarantee the separation efficiency of intelligent ore sorting equipment.Color ore sorter,X-ray ore transmission sorter,dual-energy X-ray transmission ore sorter,X-ray fluorescence ore sorter,and near-infrared ore sorter have been successfully developed in accordance with the different characteristics of minerals while ensuring the accuracy of equipment sorting and improving the equipment sorting efficiency.With the continuous improvement of mine automation level,the application of online element rapid analysis technology with high speed,high precision,and strong anti-interference capability in intelligent ore sorting equipment will become an inevitable trend of equipment development in the future.Laser-induced breakdown spectroscopy,transientγneutron activation analysis,online Fourier transform infrared spectroscopy,and nuclear magnetic resonance techniques will promote the development of ore sorting equipment.In addition,the improvement and joint application of additional high-speed and high-precision operation algorithms(such as peak area,principal component analysis,artificial neural network,partial least squares,and Monte Carlo library least squares methods)are an essential part of the development of intelligent ore sorting equipment in the future.
基金Projects supported by the National Natural Science Foundation of China(21408277)China’s Postdoctoral Science Fund(2016T90967)+2 种基金Program of 5511 Talents in Scientific and Technological Innovation of Jiangxi Province(20165BCB18013)Jiangxi Poyang Yingcai 555 ProjectProgram of Qingjiang Excellent Young Talents,JXUST。
文摘Rare-earth modification Bi2WO6 composites(RE/Bi2WO6)were studied by experimental performance and theory computation based on the different 4 f orbits of selected rare earth elements(La,Ce,Gd,and Yb).The prepared RE/Bi2WO6 was characterized by XRD,SEM/TEM,XPS,UV-vis DRS,and N2 adsorption to learn their physical-chemical properties.Azo dye Rhodamine B(RhB)was photodegraded as a target pollutant to investigate the photocatalytic activity of prepared RE/Bi2WO6 composites.The results of experiment and computation show that four rare earth elements with different electron configurations retain the phase and morphology of Bi2 WO6 and enhance the removal efficiency of RhB under simulated solar irradiation.The optimum doping contents are 0.01%,0.05%,0.05%and 0.01%for La-,Ce-,Gd-,and Yb-doped Bi2WO6,respectively.However,light rare earth La and Ce doped composites indicate some difference in visible light adso rption capacity and mineralization on RhB co mpared with heavy rare earth Gd and Yb doped composites.Both La/Bi2WO6 and Ce/Bi2 WO6 possess larger pore size and higher mineralization ability than Gd/Bi2 WO6 and Yb/Bi2WO6 under the same experimental conditions while Gd/Bi2WO6 and Yb/Bi2WO6 show stronger red shift to the visible light due to the more 4 f electrons.The hole oxidation plays a major role in the photodegradation of RhB by all RE/Bi2WO6.
基金supported by the National Natural Science Foundation of China(No.52064017)Key Research and Development Project of Jiangxi Province(No.20181BBG70050)+2 种基金Natural Science Foundation of Jiangxi Province(No.20202BABL204034)Science and Technology Research Project of Education Department of Jiangxi Province(No.GJJ190425)the Youth Jinggang Scholars Program in Jiangxi Province,and Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology.
文摘Spodumene is a silicate mineral rich in lithium.However,the gangue mineral,albite has similar crystal chemical structure and composition to spodumene.In this work,the density functional theory(DFT)calculation was taken to research the floatability from the perspective of crystal chemistry.And contact angle test and reagent adsorption test were used to support the simulation results.In addition,the weighted total density of broken bonds is proposed for the first time to judge the generation probability of cleavage surface.The DFT calculation results display that the Na and Al sites on the albite surface are the adsorption sites of water molecules.While the water molecules only bond with Al atom on the surface of spodumene and each Al site can adsorb only one water molecule.Thus,the wetting effect of water molecules on the albite surface is stronger than that of spodumene.This is consistent with the result of contact angle.In sodium oleate system,the oleic acid anion is adsorbed on the spodumene surface in form of a multicomponent ring while the albite is a single ring.Theoretically,oleic acid anion can be strongly adsorbed on the surface of spodumene and albite under vacuum.The adsorption strength of spodumene is higher than that of albite.However,on hydrated surface,the adsorption strength of oleic acid anion on mineral surface is greatly reduced due to the interaction between water molecules and metal site on mineral surface.Thus,spodumene and albite are hard to float without external activated ions in sodium oleate system.
基金Project supported by the National Science&Technology Pilslar Program of China during the Twelfth Five-year Plan Period(2012BAC11B07)National Science&Technology Benefiting Program of China(2013GS360203)+5 种基金"Gan Po 555 Project"Leading Talents Training Program,Outstanding Doctoral Dissertation Project Fund of JXUST(YB2016005)Innovation Special Fund for Graduate of Jiangxi Province(YC2014-B059)the Sciences&Technologies Landing Plan of Jiangxi Province for Universities(KJLD14042)the Technology Support Plan of Jiangxi Province(20151BBG70005)the National Natural Science Foundation of China(51564023,21407070)High-end Foreign Experts Project(GDW20177200147)
文摘In this study, we selected yttrium as the representative of REEs to investigate the impacts of exogenous yttrium on soil physicochemical properties and microbiota. The results showed that exogenous yttrium has no significant effect on soil physical properties but a significantly negative impact on soil chemical properties. The results of high-throughput sequencing demonstrate that exogenous yttrium significantly decreases the number of OTUs, ACE, Chao 1, and Shannon indices while increases the Simpson index（P 〈 0.05）, indicating the low soil microbial diversity. The relative abundances of soil microbes are significantly changed at phylum and genus level. Principal component analysis（PCA） showed the significant difference of microbial community between yttrium treatments（YCl_3-250 and YCl_3-500） and non-yttrium treatment（CK） and the similarity of that between YCl_3-250 and YCI_3-500. Proteobacteria and Bacteroidetes are found to be the most tolerant phyla to exogenous yttrium while Verrucomicrobia the most sensitive phylum. Redundancy analysis（RDA） results suggest that exogenous yttrium affects soil microbiota only through changing the soil chemical properties but not soil physical properties, and C/N ratio is the key environmental factor.
