Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,an...Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,and precursor,respectively.Several technologies were employed to investigate the structures and optical properties of FA@Ag NCs,including transmission electron microscopy(TEM),X-ray photoelectron spectrometer(XPS),Fourier transform infrared spectrometer(FTIR),X-ray diffractometer(XRD),fluorescence spectrometer,and ultraviolet visible absorption spectrometer.FA@Ag NCs were suggested to be highly dispersed and spherical with a size of around 2.8 nm.Moreover,the maximum excitation and emission wavelengths of FA@Ag NCs were 370 and 447 nm,respectively.Under the optimal detection conditions,FA@Ag NCs could be used to effectively detect malachite green with the linear detection range of 0.5-200μmol·L^(-1).The detection limit was 0.084μmol·L^(-1).The fluorescence-quenching mechanism was ascribed to the static quenching.The detection system based on FA@AgNCs was successfully used for the detection of malachite green in actual samples with good accuracy and reproducibility.展开更多
Malachite,being highly hydrophilic and difficult to be floated conventionally,is usually beneficiated by sulfidation flotation in industry.However,the complex crystal structure of malachite leads to the formation of v...Malachite,being highly hydrophilic and difficult to be floated conventionally,is usually beneficiated by sulfidation flotation in industry.However,the complex crystal structure of malachite leads to the formation of various fracture surfaces with distinct properties during crushing and grinding,resulting in surface anisotropy.In this study,we explored the surface anisotropy of malachite and further investigated its sulfidation mechanism from the coordination chemistry perspective,considering the influence of the Jahn-Teller effect on malachite sulfidation.Computational results reveal that the penta-coordinated Cu ions on the malachite(201)and(010)surfaces exhibit stronger activity compared to those on the malachite(201)surface.Additionally,the tetra-coordinated structure formed by HS^(−)adsorption on the malachite(010)and(201)surfaces is more stable,with more negative adsorption energy,compared to the hexa coordinated structure formed by HS−adsorption on the(201)surface.The sulfidized malachite surface has an additional pair ofπelectron and smaller HOMO(highest occupied molecular orbital)-LUMO(lowest unoccupied molecular orbital)gap with xanthate molecules,causing strongerπbackbonding with xanthate.This study provides new insights into the surface sulfidation mechanism of malachite and offers a theoretical reference for the design of targeted flotation reagents.展开更多
The intricate grinding process exposes various cleavage surfaces of mineral particles.This paper systematically investigates the structural characteristics of exposed malachite crystal surfaces and the adsorption beha...The intricate grinding process exposes various cleavage surfaces of mineral particles.This paper systematically investigates the structural characteristics of exposed malachite crystal surfaces and the adsorption behavior and mechanism of hydroxamic acid and water molecules using first-principle density functional theory.The study reveals anisotropic surface energies among crystal surfaces,ranked as(201)>(100)>(110)>(001)>(010)>(201).The adsorption of hydroxamic acid and water molecules on malachite surfaces also exhibited anisotropy.The difference in adsorption strength between hydroxamic acid and water molecules on the six exposed surfaces followed the order of(110)>(100)>(010)>(001)>(201)>(201),and the resistance of water molecules to the adsorption of hydroxamic acid on the six exposed surfaces was(110)>(201)>(010)>(201)>(001)>(100).It indicates that the reagent exhibits a strong competitive advantage in adsorption on the(100)surface,and the hindrance of water molecules to reagent adsorption is relatively small,which is favorable for flotation.This study provides theoretical references and innovative insights for the precise design of flotation reagents,as well as for the meticulous optimization of mineral surface interfaces,with the objective of enhancing flotation separation.展开更多
Fluorogen-activating proteins(FAPs)selectively bind to specific fluorophores,inducing fluorescence activation through the inhibition of torsion of fluorophores.This binding-activation mechanism provides a highly speci...Fluorogen-activating proteins(FAPs)selectively bind to specific fluorophores,inducing fluorescence activation through the inhibition of torsion of fluorophores.This binding-activation mechanism provides a highly specific and efficient fluorescence system that minimizes background signals,significantly enhancing the signal-to-noise ratio(SNR)and making it a powerful tool in live-cell imaging.The principle of binding-activation fluorescence is fundamental to point accumulation for imaging in nanoscale topography(PAINT)super-resolution imaging.However,the high binding affinity between traditional FAPfluorophore pairs limits their application in PAINT,thus hindering the rapid and dynamic imaging necessary for high-resolution cellular studies.In this work,we designed malachite green(MG)derivatives with bulky N-substituents to modulate the binding affinity of the MG-d L5^(**)fluorophore-FAP pair.This modification introduces steric hindrance in MG-dL5^(**)system,resulting in reduced binding affinity and practicability for fast,high-resolution PAINT imaging.Among the synthesized derivatives,MG-Pen showed optimal properties,enabling rapid and high-resolution PAINT imaging of dL5^(**)in living cells.This study highlights the potential of MG derivatives optimization in overcoming the limitations of fluorophore-FAP pairs for super-resolution imaging and provides a new approach for enhancing the performance of PAINT in living cell applications.展开更多
A novel collector 1-(2-hydroxyphenyl)hex-2-en-1-one oxime(HPHO)was synthesized from 2-hydroxy acetophenone and butyraldehyde.Its flotation performance and adsorption mechanism to malachite were investigated by flotati...A novel collector 1-(2-hydroxyphenyl)hex-2-en-1-one oxime(HPHO)was synthesized from 2-hydroxy acetophenone and butyraldehyde.Its flotation performance and adsorption mechanism to malachite were investigated by flotation test,zeta potential,Fourier transform infrared(FTIR)and X-ray photoelectron spectroscopy(XPS)analysis techniques.Compared with benzohydroxamic acid(BA),1-(2-hydroxyphenyl)ethan-1-one oxime(HPEO)and sodium isobutyl xanthate(SIBX),HPHO exhibited excellent collecting power to malachite without additional reagents,such as Na2S regulator and methyl isobutyl carbinol(MIBC)frother.Results of zeta potential indicated that HPHO was coated on malachite surfaces through a chemisorption process.FTIR and XPS data gave clear evidence for the formation of Cu−oxime complex on malachite surfaces after HPHO adsorption through the linkage between C=C,—OH,N—OH group and Cu species.展开更多
Sulfamic acid （SA）, which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle siz...Sulfamic acid （SA）, which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle size, reagent concentration, and stirring speed on this leach- ing were studied. The dissolution kinetics of malachite was illustrated with a three-dimensional diffusion model. A novel leaching effect of SA on malachite was eventually demonstrated. The leaching rate increased with decreasing particle size and increasing concentration, reac- tion temperature and stirring speed. The activation energy for SA leaching malachite was 33.23 kJ/mol. Furthermore, the effectiveness of SA as a new reagent for extracting copper from copper oxide ore was confirmed by experiment. This approach may provide a solution suitable for subsequent electrowinning. In addition, results reported herein may provide basic data that enable the leaching of other carbonate miner- als of copper, zinc, cobalt and so on in an SA system.展开更多
Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and...Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy(XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.展开更多
The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and mic...The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.展开更多
Leaching of an oxidized copper ore containing malachite, as a new approach, was investigated by an organic reagent, citric acid. Sulfuric acid is the most common reagent in the leaching of oxide copper ores, but it ha...Leaching of an oxidized copper ore containing malachite, as a new approach, was investigated by an organic reagent, citric acid. Sulfuric acid is the most common reagent in the leaching of oxide copper ores, but it has several side effects such as severe adverse impact on the environment. In this investigation, the effects of particle size, acid concentration, leaching time, solid/liquid ratio, temperature, and stirring speed were optimized. According to the experimental results, malachite leaching by citric acid was technically feasible. Optimum leaching conditions were found as follows： the range of particle size, 105-150 μm; acid concentration, 0.2 M; leaching time, 30 min; solid/liquid ratio, 1：20 g/mL; temperature, 40℃; and stirring speed, 200 r/min. Under the optimum conditions, 91.61% of copper was extracted.展开更多
Methanol,a versatile chemical,fuel additive and potential H_(2) carrier,has attracted great attention.Despite of the wide industrialization,improvement of Cu-based methanol-synthesis catalysts is highly anticipated.Ac...Methanol,a versatile chemical,fuel additive and potential H_(2) carrier,has attracted great attention.Despite of the wide industrialization,improvement of Cu-based methanol-synthesis catalysts is highly anticipated.Accordingly,a series of Cu/ZnO/Al_(2)O_(3) with designed precursor structures were prepared,and its structure-function relationship was investigated to make progress on this area.Results showed the catalyst derived from highly zinc-substituted malachite demonstrated the best catalytic performance in this work.It was found that the well-behaved catalyst possessed relatively high Cu specific surface area and exposed Cu concentration,and the well Cu/ZnO synergy.CuZn alloy was found by In-situ XRD tests,and its effect on the catalyst's thermostability was discussed.Fractional precipitation,which facilitated the Cu^(2+) substitution by Zn^(2+) in malachite lattice,could be an efficient preparation method of the Cu/ZnO/Al_(2)O_(3) catalyst.展开更多
Three-dimensional ordered macro/mesoporous carbon(3DOM/m-C)with high specific surface area was synthesized by colloid crystal template method with chemical activation by KOH and used as the adsorbent for removing mala...Three-dimensional ordered macro/mesoporous carbon(3DOM/m-C)with high specific surface area was synthesized by colloid crystal template method with chemical activation by KOH and used as the adsorbent for removing malachite green(MG)in aqueous solution.The microstructures of the adsorbents were characterized by FESEM,TEM and BET,and the effects of initial dye concentration,contact time,solution pH,and temperature on adsorption performance were investigated.The results show that the 3DOM/m-C exhibits extremely high adsorption capacity of 3541.1 mg/g within 2 h,which could be attributed to the novel ordered hierarchical structure with mesopores on three-dimensional ordered macroporous carbon walls.And the adsorption behavior conforms to the pseudo-second-order kinetic and Langmuir adsorption isotherm.3DOM/m-C can be recycled after being desorbed by absolute ethanol,and still maintains a high capacity of 2762.06 mg/g after 5 cycles.展开更多
In general,malachite is recovered via sulfidization–xanthate flotation,although many unsatisfactory flotation indexes are frequently obtained as a result of the presence of associated calcite.This phenomenon occurs b...In general,malachite is recovered via sulfidization–xanthate flotation,although many unsatisfactory flotation indexes are frequently obtained as a result of the presence of associated calcite.This phenomenon occurs because the dissolved components of malachite and calcite affect the flotation behavior of both minerals.In this study,the effect of the dissolved components derived from malachite and calcite on the flotation behavior and surface characteristics of both minerals was investigated.Flotation tests indicated that malachite recovery decreased when the calcite supernatant was introduced,while the presence of the malachite supernatant increased the recovery of calcite.Dissolution and adsorption tests,along with zeta potential measurements,X-ray photoelectron spectroscopy,Fourier transform infrared spectrometry,and timeof-flight secondary ion mass spectrometry demonstrated that the Ca species in the calcite supernatant were adsorbed on the malachite surface,which hindered the interaction of Na2S with malachite,thereby resulting in the insufficient adsorption of sodium isoamyl xanthate(NaIX)on the surface of malachite.By contrast,the Cu species in the malachite supernatant were adsorbed on the calcite surface,and they provided active sites for the subsequent adsorption of Na_(2)S and NaIX.展开更多
Mechanical activation(MA) of malachite was carried out by dry planetary grinding(DPG) and wet Isa grinding(WIG) methods. When the rotational speed was increased to 400 r/min in DPG, the specific surface area of malach...Mechanical activation(MA) of malachite was carried out by dry planetary grinding(DPG) and wet Isa grinding(WIG) methods. When the rotational speed was increased to 400 r/min in DPG, the specific surface area of malachite reached the maximum and the particle size reached the minimum of 0.7–100 μm. Agglomeration occurred between mineral particles when the rotational speed was increased to 580 r/min in DPG.However, no agglomeration was observed among particles with sizes 0.4–3 μm in WIG. X-ray diffraction analysis showed that, at a 580 r/min rotational speed in DPG, the amorphization degree of malachite was 53.12%, whereas that in WIG was 71.40%, indicating that MA led to amorphization and distortion of crystal structures. In addition, in the Fourier transform infrared(FT-IR) spectra of activated malachite, the bands associated with –OH, CO_3^(2-)and metal lattice vibrations of Cu–O and Cu–OH were weakened, and a new H–O–H bending mode and peaks of gaseous CO_2 appeared, indicating that MA decreased the band energy, enhanced dihydroxylation, and increased the chemical reactivity of the malachite.Furthermore, the leaching behavior of copper ore was greatly improved by MA.展开更多
A green and convenient pathway of preparing iron nanoparticles(FeNPs)with pomegranate leaf(PG)extract for highly effective removal of malachite green(MG)was proposed under ambient conditions.The materials were charact...A green and convenient pathway of preparing iron nanoparticles(FeNPs)with pomegranate leaf(PG)extract for highly effective removal of malachite green(MG)was proposed under ambient conditions.The materials were characterized by scanning electron microscope(SEM),X-ray energy-dispersive spectrometer(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)techniques.The results show that their surfaces are capped and stabilized by PG extract with amorphous nature and without any detection of zero-valent iron.The size and surface valence state of FeNPs are the key factors that affect the MG removal efficiency.As the reagent volume ratio of PG extract to FeCl_(3) increases greater than 1,the cross-linked FeNPs become more obvious,having a homogeneous distribution with the size range from 30 to 40 nm,and show an increasing ratio ofFe(Ⅱ)/Fe(Ⅲ),which is in proportion to the degradation efficiency of MG,reaching higher than 95%in only 2 min by using 50 mg Fe/L FeNPs and 200 mg/L MG.展开更多
Rapid and simple detections of two kinds of prohibited fish drugs, crystal violet （CV） and malachite green （MG）, were accomplished by surface-enhanced Raman scattering （SERS）. Based on the optimized Au/cicada wi...Rapid and simple detections of two kinds of prohibited fish drugs, crystal violet （CV） and malachite green （MG）, were accomplished by surface-enhanced Raman scattering （SERS）. Based on the optimized Au/cicada wing, the detectable concentration of CV/MG can reach 10-7 M, and the linear logarithmic quantitative relationship curves between log/and logC allows for the determination of the unknown concentration of CV/MG solution. The detection of these two analytes in real environment was also achieved, demonstrating the application potential of SERS in the fast screening of the prohibited fish drugs, which is of great benefit for food safety and environmental monitoring.展开更多
In this work,the unique starlike La-doped ZnO-SiO_(2) photocatalysts were constructed by an evaporation and calcination method and characterized in detail.UV-vis reflectance and DFT calculation confirm that the doping...In this work,the unique starlike La-doped ZnO-SiO_(2) photocatalysts were constructed by an evaporation and calcination method and characterized in detail.UV-vis reflectance and DFT calculation confirm that the doping with La allows to obtain a decrease of band gap of ZnO/SiO_(2),which enhances visible light absorbance and oxidizing ability.The photoluminescence intensity reduces greatly,indicating more effective separation of the photo generated carriers of La-doped ZnO-SiO_(2).Photocatalytic activities of Ladoped ZnO-SiO_(2) with different doping ratios under simulated visible light irradiation were evaluated with malachite green(MG) as a model pollutant.Under optimized conditions including solution pH of 8,15 mg/L of MG solution and 15 mg of catalyst dosage,0.2% La-ZnO-SiO_(2) exhibits the best catalytic activity in photodegradations of MG in water.The removal and mineralization efficiency of MG can reach 96.1%and 70.9% in 140 min,respectively.The as-prepared catalysts present superior stability and recyclability after four times reuse.Moreover,selective quenching experiments indicate that hydroxyl radical(·OH),hole(h^(+)) and superoxide radical(·O_(2)^(-)) are the main reactive species responsible for MG degradation.Possible mechanism for photocatalytic elimination of MG over La-doped ZnO/SiO_(2) photocatalyst is finally proposed.展开更多
One of the Iranian copper deposits that is located east of Iran and also known as a primeval one in that area is Mesgaran Field. Old mining works have been clearly seen in the area. Iran is located on global copper be...One of the Iranian copper deposits that is located east of Iran and also known as a primeval one in that area is Mesgaran Field. Old mining works have been clearly seen in the area. Iran is located on global copper belt and as a result it has numerous potential areas as copper deposits. The purpose of this study is identifying possible potentialities of copper mining in less developed regions of Iran with basic modern technologies. In this study, laboratory investigations of this field were done on samples via leaching and the cementation method. According to the study purposes, acid concentration, temperature, time and pulp density were selected as the main factors that were tested in leaching studies. Moreover, pH, temperature, time and the amount of iron powder were factors which were tested for copper cementation. Optimum conditions of leaching studies with 99.11% recovery rate were obtained after 120 grams per liter of H2SO4, 80 degrees Celsius, 2 hours and 100 grams per liter of solid to liquid. On the other hand, optimum conditions of cementation by iron powder were resulted at more than 95% with a pH of 3, 45 degrees Celsius, 1 hour and 1.5 times more than the stoichiometric equation of required iron powder amount to precipitate copper.展开更多
文摘Herein,a one-pot chemical reduction method was reported to prepare folic acid(FA)-stabilized silver nanoclusters(FA@Ag NCs),in which FA,hydrazine hydrate,and silver nitrate were used as capping agent,reducing agent,and precursor,respectively.Several technologies were employed to investigate the structures and optical properties of FA@Ag NCs,including transmission electron microscopy(TEM),X-ray photoelectron spectrometer(XPS),Fourier transform infrared spectrometer(FTIR),X-ray diffractometer(XRD),fluorescence spectrometer,and ultraviolet visible absorption spectrometer.FA@Ag NCs were suggested to be highly dispersed and spherical with a size of around 2.8 nm.Moreover,the maximum excitation and emission wavelengths of FA@Ag NCs were 370 and 447 nm,respectively.Under the optimal detection conditions,FA@Ag NCs could be used to effectively detect malachite green with the linear detection range of 0.5-200μmol·L^(-1).The detection limit was 0.084μmol·L^(-1).The fluorescence-quenching mechanism was ascribed to the static quenching.The detection system based on FA@AgNCs was successfully used for the detection of malachite green in actual samples with good accuracy and reproducibility.
基金Projects(52074356,U22A20170)supported by the National Natural Science Foundation of ChinaProject(2022YFC2904503)supported by the National Key R&D Program of China+4 种基金Project(2023SK2061)supported by the Special Fund for the Construction of Hunan Innovative Province,ChinaProject(2023CXQD002)supported by the Innovation-driven Project of Central South University,ChinaProject(2022RC1183)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(kq2009005)supported by the Changsha Science and Technology Project(Changsha Outstanding Innovative Youth Training Program),ChinaProject supported by the High-performance Computing Centers of Central South University,China。
文摘Malachite,being highly hydrophilic and difficult to be floated conventionally,is usually beneficiated by sulfidation flotation in industry.However,the complex crystal structure of malachite leads to the formation of various fracture surfaces with distinct properties during crushing and grinding,resulting in surface anisotropy.In this study,we explored the surface anisotropy of malachite and further investigated its sulfidation mechanism from the coordination chemistry perspective,considering the influence of the Jahn-Teller effect on malachite sulfidation.Computational results reveal that the penta-coordinated Cu ions on the malachite(201)and(010)surfaces exhibit stronger activity compared to those on the malachite(201)surface.Additionally,the tetra-coordinated structure formed by HS^(−)adsorption on the malachite(010)and(201)surfaces is more stable,with more negative adsorption energy,compared to the hexa coordinated structure formed by HS−adsorption on the(201)surface.The sulfidized malachite surface has an additional pair ofπelectron and smaller HOMO(highest occupied molecular orbital)-LUMO(lowest unoccupied molecular orbital)gap with xanthate molecules,causing strongerπbackbonding with xanthate.This study provides new insights into the surface sulfidation mechanism of malachite and offers a theoretical reference for the design of targeted flotation reagents.
基金Project(52074356)supported by the National Natural Science Foundation of ChinaProject(BGRIMM-KJSKL-2023-06)supported by the Open Foundation of State Key Laboratory of Mineral Processing,China+4 种基金Project(2022RC1183)supported by the Science and Technology Innovation Program of Hunan Province,ChinaProject(kq2009095)supported by the Changsha Science and Technology Project(Outstanding Innovative Youth Training Program),ChinaProject(2023CXQD002)supported by the Innovation Driven Program of Central South University,ChinaProject(B14034)supported by the National“111”Project,ChinaProject(2024ZZTS0655)supported by the Independent Exploration and Innovation Project for Graduate Students of Central South University,China。
文摘The intricate grinding process exposes various cleavage surfaces of mineral particles.This paper systematically investigates the structural characteristics of exposed malachite crystal surfaces and the adsorption behavior and mechanism of hydroxamic acid and water molecules using first-principle density functional theory.The study reveals anisotropic surface energies among crystal surfaces,ranked as(201)>(100)>(110)>(001)>(010)>(201).The adsorption of hydroxamic acid and water molecules on malachite surfaces also exhibited anisotropy.The difference in adsorption strength between hydroxamic acid and water molecules on the six exposed surfaces followed the order of(110)>(100)>(010)>(001)>(201)>(201),and the resistance of water molecules to the adsorption of hydroxamic acid on the six exposed surfaces was(110)>(201)>(010)>(201)>(001)>(100).It indicates that the reagent exhibits a strong competitive advantage in adsorption on the(100)surface,and the hindrance of water molecules to reagent adsorption is relatively small,which is favorable for flotation.This study provides theoretical references and innovative insights for the precise design of flotation reagents,as well as for the meticulous optimization of mineral surface interfaces,with the objective of enhancing flotation separation.
基金supported by the National Natural Science Foundation of China(Nos.22225806,22078314,22278394,22378385)Dalian Institute of Chemical Physics(Nos.DICPI202142,DICPI202436)。
文摘Fluorogen-activating proteins(FAPs)selectively bind to specific fluorophores,inducing fluorescence activation through the inhibition of torsion of fluorophores.This binding-activation mechanism provides a highly specific and efficient fluorescence system that minimizes background signals,significantly enhancing the signal-to-noise ratio(SNR)and making it a powerful tool in live-cell imaging.The principle of binding-activation fluorescence is fundamental to point accumulation for imaging in nanoscale topography(PAINT)super-resolution imaging.However,the high binding affinity between traditional FAPfluorophore pairs limits their application in PAINT,thus hindering the rapid and dynamic imaging necessary for high-resolution cellular studies.In this work,we designed malachite green(MG)derivatives with bulky N-substituents to modulate the binding affinity of the MG-d L5^(**)fluorophore-FAP pair.This modification introduces steric hindrance in MG-dL5^(**)system,resulting in reduced binding affinity and practicability for fast,high-resolution PAINT imaging.Among the synthesized derivatives,MG-Pen showed optimal properties,enabling rapid and high-resolution PAINT imaging of dL5^(**)in living cells.This study highlights the potential of MG derivatives optimization in overcoming the limitations of fluorophore-FAP pairs for super-resolution imaging and provides a new approach for enhancing the performance of PAINT in living cell applications.
基金Projects(2018GDASCX-0934,2020GDASYL-20200302009)supported by Guangdong Academy of Sciences,China。
文摘A novel collector 1-(2-hydroxyphenyl)hex-2-en-1-one oxime(HPHO)was synthesized from 2-hydroxy acetophenone and butyraldehyde.Its flotation performance and adsorption mechanism to malachite were investigated by flotation test,zeta potential,Fourier transform infrared(FTIR)and X-ray photoelectron spectroscopy(XPS)analysis techniques.Compared with benzohydroxamic acid(BA),1-(2-hydroxyphenyl)ethan-1-one oxime(HPEO)and sodium isobutyl xanthate(SIBX),HPHO exhibited excellent collecting power to malachite without additional reagents,such as Na2S regulator and methyl isobutyl carbinol(MIBC)frother.Results of zeta potential indicated that HPHO was coated on malachite surfaces through a chemisorption process.FTIR and XPS data gave clear evidence for the formation of Cu−oxime complex on malachite surfaces after HPHO adsorption through the linkage between C=C,—OH,N—OH group and Cu species.
基金financially supported by the National Natural Science Foundation of China (Nos. 51168020, 51404119, and 51464029)the Natural Science Foundation of Yunnan Province, China (No. 2014Y0845)the Excellent Doctoral Dissertation and Talent Cultivation Foundation of Kunming University of Science and Technology (Nos. 41118011 and 201421066)
文摘Sulfamic acid （SA）, which possesses a zwitterionic structure, was applied as a leaching reagent for the first time for extracting copper from copper oxide ore. The effects of reaction time, temperature, particle size, reagent concentration, and stirring speed on this leach- ing were studied. The dissolution kinetics of malachite was illustrated with a three-dimensional diffusion model. A novel leaching effect of SA on malachite was eventually demonstrated. The leaching rate increased with decreasing particle size and increasing concentration, reac- tion temperature and stirring speed. The activation energy for SA leaching malachite was 33.23 kJ/mol. Furthermore, the effectiveness of SA as a new reagent for extracting copper from copper oxide ore was confirmed by experiment. This approach may provide a solution suitable for subsequent electrowinning. In addition, results reported herein may provide basic data that enable the leaching of other carbonate miner- als of copper, zinc, cobalt and so on in an SA system.
基金supported by Yunnan Fundamental Research Projects (No. 202101BE070001-009)Open Foundation of State Key Laboratory of Mineral Processing (No. BGRIMM-KJSKL-202124)Ten Thousand Talent Plans for Young Top-notch Talents of Yunnan Province (No. YNWR-QNBJ-2018-051)。
文摘Malachite is one of the main minerals used for the industrial enrichment and recovery of copper oxide resources, and copper ions are unavoidable metal ions in the flotation pulp. The microflotation, contact angle, and adsorption experiments indicated that pretreatment with an appropriate concentration of copper ions could improve the malachite recovery, and the addition of excess copper ions reduced the hydrophobicity of the malachite surface. The results of zeta potential tests indicated that sodium sulfide and butyl xanthate were also adsorbed on the surface of malachite pretreated with copper ions. X-ray photoelectron spectroscopy(XPS) results indicated that —Cu—O and —Cu—OH bonds were formed on the surface of the samples. After pretreatment with an appropriate concentration of copper ions, the number of —OH groups on the mineral surface decreased, whereas the number of Cu—S groups on the mineral surface increased, which was conducive to the sulfidization of malachite. After adding a high concentration of copper ions, the —OH groups on the mineral surface increased, whereas the number of Cu—S groups decreased, which had an adverse effect on the sulfidization flotation of malachite. Time-of-flight secondary ion mass spectrometry showed that pretreatment with copper ions resulted in a thicker sulfidization layer on the mineral surface.
基金Project(51474253)supported by the National Natural Science Foundation of China。
文摘The surface hydrophobization and flotation of a xanthate−hydroxamate collector toward copper oxide mineral were compared with the combined collectors of xanthate and hydroxamate through water contact angle(WCA)and micro-flotation experiments.The results showed that S-[(2-hydroxyamino)-2-oxoethyl]-O-octyl-dithiocarbonate ester(HAOODE)exhibited stronger hydrophobization and better flotation performance to malachite(Cu2(OH)2CO3)than octyl-hydroxamic acid(OHA)and its combination with S-allyl-O-ethyl xanthate ester(AEXE).To understand the hydrophobic intensification mechanism of HAOODE to malachite,zeta potential,atomic force microscopy(AFM)and XPS measurements were carried out.The results recommended that malachite chemisorbed HAOODE to form Cu—HAOODE complexes in which the hydroxamate—(O,O)—Cu and—O—C(—S—Cu)—S—configurations co-existed.The co-adsorption of HAOODE’s hetero-difunctional groups was more stable than the single-functionalgroup adsorption of OHA and AEXE,which produced the“loop”structure and intensified the self-assembly alignment of HAOODE on malachite surfaces.In addition,the“h”shape steric orientation of the double hydrophobic groups in HAOODE facilitated stronger hydrophobization toward malachite than the“line”or“V”hydrophobic carbon chains of OHA or AEXE.Thus,HAOODE achieved the preferable flotation recovery of malachite particles in comparison with OHA and AEXE.
文摘Leaching of an oxidized copper ore containing malachite, as a new approach, was investigated by an organic reagent, citric acid. Sulfuric acid is the most common reagent in the leaching of oxide copper ores, but it has several side effects such as severe adverse impact on the environment. In this investigation, the effects of particle size, acid concentration, leaching time, solid/liquid ratio, temperature, and stirring speed were optimized. According to the experimental results, malachite leaching by citric acid was technically feasible. Optimum leaching conditions were found as follows： the range of particle size, 105-150 μm; acid concentration, 0.2 M; leaching time, 30 min; solid/liquid ratio, 1：20 g/mL; temperature, 40℃; and stirring speed, 200 r/min. Under the optimum conditions, 91.61% of copper was extracted.
基金supported by the National Key R&D Program of China(2018YFB0604701)the CHN ENERGY Group Corp.Ltd.(CF9300200004)。
文摘Methanol,a versatile chemical,fuel additive and potential H_(2) carrier,has attracted great attention.Despite of the wide industrialization,improvement of Cu-based methanol-synthesis catalysts is highly anticipated.Accordingly,a series of Cu/ZnO/Al_(2)O_(3) with designed precursor structures were prepared,and its structure-function relationship was investigated to make progress on this area.Results showed the catalyst derived from highly zinc-substituted malachite demonstrated the best catalytic performance in this work.It was found that the well-behaved catalyst possessed relatively high Cu specific surface area and exposed Cu concentration,and the well Cu/ZnO synergy.CuZn alloy was found by In-situ XRD tests,and its effect on the catalyst's thermostability was discussed.Fractional precipitation,which facilitated the Cu^(2+) substitution by Zn^(2+) in malachite lattice,could be an efficient preparation method of the Cu/ZnO/Al_(2)O_(3) catalyst.
基金Projects(U1802254,51871201)supported by the National Natural Science Foundation of ChinaProject(LY18E040003)supported by the Zhejiang Provincial Natural Science Foundation,China
文摘Three-dimensional ordered macro/mesoporous carbon(3DOM/m-C)with high specific surface area was synthesized by colloid crystal template method with chemical activation by KOH and used as the adsorbent for removing malachite green(MG)in aqueous solution.The microstructures of the adsorbents were characterized by FESEM,TEM and BET,and the effects of initial dye concentration,contact time,solution pH,and temperature on adsorption performance were investigated.The results show that the 3DOM/m-C exhibits extremely high adsorption capacity of 3541.1 mg/g within 2 h,which could be attributed to the novel ordered hierarchical structure with mesopores on three-dimensional ordered macroporous carbon walls.And the adsorption behavior conforms to the pseudo-second-order kinetic and Langmuir adsorption isotherm.3DOM/m-C can be recycled after being desorbed by absolute ethanol,and still maintains a high capacity of 2762.06 mg/g after 5 cycles.
基金financially supported by Yunnan Fundamental Research Projects (No.202101BE070001-009)National Natural Science Foundation of China (No.51464029)。
文摘In general,malachite is recovered via sulfidization–xanthate flotation,although many unsatisfactory flotation indexes are frequently obtained as a result of the presence of associated calcite.This phenomenon occurs because the dissolved components of malachite and calcite affect the flotation behavior of both minerals.In this study,the effect of the dissolved components derived from malachite and calcite on the flotation behavior and surface characteristics of both minerals was investigated.Flotation tests indicated that malachite recovery decreased when the calcite supernatant was introduced,while the presence of the malachite supernatant increased the recovery of calcite.Dissolution and adsorption tests,along with zeta potential measurements,X-ray photoelectron spectroscopy,Fourier transform infrared spectrometry,and timeof-flight secondary ion mass spectrometry demonstrated that the Ca species in the calcite supernatant were adsorbed on the malachite surface,which hindered the interaction of Na2S with malachite,thereby resulting in the insufficient adsorption of sodium isoamyl xanthate(NaIX)on the surface of malachite.By contrast,the Cu species in the malachite supernatant were adsorbed on the calcite surface,and they provided active sites for the subsequent adsorption of Na_(2)S and NaIX.
基金financially supported by the Special Funds for the National Natural Science Foundation of China(No.U1608254)the National Key R&D Program of China(No.2018YFC1902002)
文摘Mechanical activation(MA) of malachite was carried out by dry planetary grinding(DPG) and wet Isa grinding(WIG) methods. When the rotational speed was increased to 400 r/min in DPG, the specific surface area of malachite reached the maximum and the particle size reached the minimum of 0.7–100 μm. Agglomeration occurred between mineral particles when the rotational speed was increased to 580 r/min in DPG.However, no agglomeration was observed among particles with sizes 0.4–3 μm in WIG. X-ray diffraction analysis showed that, at a 580 r/min rotational speed in DPG, the amorphization degree of malachite was 53.12%, whereas that in WIG was 71.40%, indicating that MA led to amorphization and distortion of crystal structures. In addition, in the Fourier transform infrared(FT-IR) spectra of activated malachite, the bands associated with –OH, CO_3^(2-)and metal lattice vibrations of Cu–O and Cu–OH were weakened, and a new H–O–H bending mode and peaks of gaseous CO_2 appeared, indicating that MA decreased the band energy, enhanced dihydroxylation, and increased the chemical reactivity of the malachite.Furthermore, the leaching behavior of copper ore was greatly improved by MA.
基金the National Natural Science Foundation of China(No.21407050)the Excellent Young and Middle-aged Science and Technology Innovation Team Plan of Hubei Colleges(No.T201824)。
文摘A green and convenient pathway of preparing iron nanoparticles(FeNPs)with pomegranate leaf(PG)extract for highly effective removal of malachite green(MG)was proposed under ambient conditions.The materials were characterized by scanning electron microscope(SEM),X-ray energy-dispersive spectrometer(EDS),Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)techniques.The results show that their surfaces are capped and stabilized by PG extract with amorphous nature and without any detection of zero-valent iron.The size and surface valence state of FeNPs are the key factors that affect the MG removal efficiency.As the reagent volume ratio of PG extract to FeCl_(3) increases greater than 1,the cross-linked FeNPs become more obvious,having a homogeneous distribution with the size range from 30 to 40 nm,and show an increasing ratio ofFe(Ⅱ)/Fe(Ⅲ),which is in proportion to the degradation efficiency of MG,reaching higher than 95%in only 2 min by using 50 mg Fe/L FeNPs and 200 mg/L MG.
基金Project supported by the National Basic Research Program of China(Grant No.2014CB745100)the National Natural Science Foundation of China(Grant Nos.21390202 and 21676015)the Beijing Higher Education Young Elite Teacher Project
文摘Rapid and simple detections of two kinds of prohibited fish drugs, crystal violet （CV） and malachite green （MG）, were accomplished by surface-enhanced Raman scattering （SERS）. Based on the optimized Au/cicada wing, the detectable concentration of CV/MG can reach 10-7 M, and the linear logarithmic quantitative relationship curves between log/and logC allows for the determination of the unknown concentration of CV/MG solution. The detection of these two analytes in real environment was also achieved, demonstrating the application potential of SERS in the fast screening of the prohibited fish drugs, which is of great benefit for food safety and environmental monitoring.
文摘In this work,the unique starlike La-doped ZnO-SiO_(2) photocatalysts were constructed by an evaporation and calcination method and characterized in detail.UV-vis reflectance and DFT calculation confirm that the doping with La allows to obtain a decrease of band gap of ZnO/SiO_(2),which enhances visible light absorbance and oxidizing ability.The photoluminescence intensity reduces greatly,indicating more effective separation of the photo generated carriers of La-doped ZnO-SiO_(2).Photocatalytic activities of Ladoped ZnO-SiO_(2) with different doping ratios under simulated visible light irradiation were evaluated with malachite green(MG) as a model pollutant.Under optimized conditions including solution pH of 8,15 mg/L of MG solution and 15 mg of catalyst dosage,0.2% La-ZnO-SiO_(2) exhibits the best catalytic activity in photodegradations of MG in water.The removal and mineralization efficiency of MG can reach 96.1%and 70.9% in 140 min,respectively.The as-prepared catalysts present superior stability and recyclability after four times reuse.Moreover,selective quenching experiments indicate that hydroxyl radical(·OH),hole(h^(+)) and superoxide radical(·O_(2)^(-)) are the main reactive species responsible for MG degradation.Possible mechanism for photocatalytic elimination of MG over La-doped ZnO/SiO_(2) photocatalyst is finally proposed.
文摘One of the Iranian copper deposits that is located east of Iran and also known as a primeval one in that area is Mesgaran Field. Old mining works have been clearly seen in the area. Iran is located on global copper belt and as a result it has numerous potential areas as copper deposits. The purpose of this study is identifying possible potentialities of copper mining in less developed regions of Iran with basic modern technologies. In this study, laboratory investigations of this field were done on samples via leaching and the cementation method. According to the study purposes, acid concentration, temperature, time and pulp density were selected as the main factors that were tested in leaching studies. Moreover, pH, temperature, time and the amount of iron powder were factors which were tested for copper cementation. Optimum conditions of leaching studies with 99.11% recovery rate were obtained after 120 grams per liter of H2SO4, 80 degrees Celsius, 2 hours and 100 grams per liter of solid to liquid. On the other hand, optimum conditions of cementation by iron powder were resulted at more than 95% with a pH of 3, 45 degrees Celsius, 1 hour and 1.5 times more than the stoichiometric equation of required iron powder amount to precipitate copper.
