The lime-Cu^(2+)-xanthate process is commonly used for the flotation separation of sphalerite from pyrite.In this process,lime is added to the pulp to inhibit the floatability of pyrite.However,the excessive use of li...The lime-Cu^(2+)-xanthate process is commonly used for the flotation separation of sphalerite from pyrite.In this process,lime is added to the pulp to inhibit the floatability of pyrite.However,the excessive use of lime can result in pipeline blockage and inadequate recovery of associated precious metals.Therefore,it is necessary to develop new flotation process that minimizes or eliminates the use of lime.In this paper,a novel Fe^(3+)-Cu^(2+)-butyl xanthate process was developed as an alternative to lime for separating of sphalerite from pyrite.The flotation results indicated that with the artificially-mixed minerals,the flotation recovery of pyrite was lower than 16%and that of sphalerite was higher than 47%at pH 5.0−10.0.The zeta potential measurements revealed that ferric ion preferred to adsorb on pyrite,and copper ion displaced with zinc ion from the lattice at the interface of sphalerite.The wettability analyses indicated that the hydrophobicity of sphalerite surface increased apparently after being treated with Fe^(3+)-Cu^(2+)-BX,while the hydrophobicity of pyrite surface remained nearly unchanged.With XPS analysis,Cu-S bond and hydrophilic ferric hydroxide were detected separately on the surface of sphalerite and pyrite after conditioning with Fe^(3+)-Cu^(2+)-BX,which facilitated the flotation separation of sphalerite from pyrite with butyl xanthate collector.展开更多
This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal me...This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal method,demonstrating a significant improvement in photocatalytic NO removal under visible light irradiation.For high-flux simulated flue gas,the composite with 10%SnS_(2)(denoted as SNCN-10)showed exceptional NO removal efficiency,reaching up to 66.8%,along with excellent reusability over five consecutive cycles.Detailed band structure and density of states(DOS)calculations confirmed the formation of a characteristic heterojunction.Spin-trapping ESR spectroscopy identified·O_(2)^(-)−as the key reactive species driving NO oxidation.Additionally,in situ DRIFT spectroscopy revealed that SNCN-10 facilitated the conversion of NO to nitrate through intermediate species,including bridging nitrite and cis-nitrite(N_(2)O_(2)^(2-)).Kinetic studies further indicated that NO oxidation followed the Langmuir-Hinshelwood(L-H)mechanism.Based on density functional theory(DFT)calculations of free energy changes,a comprehensive reaction pathway for NO oxidation was proposed.These findings provide valuable insights for the development of efficient photocatalytic strategies for NO removal.展开更多
The sluggish kinetics of the sulfur redox reaction(SRR)and the shuttling effect of lithium polysulfides(LiPSs)both restrict the practical application of lithium-sulfur(Li-S)batteries.Heterostructures,with their pronou...The sluggish kinetics of the sulfur redox reaction(SRR)and the shuttling effect of lithium polysulfides(LiPSs)both restrict the practical application of lithium-sulfur(Li-S)batteries.Heterostructures,with their pronounced electroactivity and structural stability,showcase their potential as electrodes/functional separators for lithium-sulfur batteries.Herein,we proposed a bifunctional catalyst exhibiting strong adsorption and rapid catalytic conversion of LiPSs through in situ UV photocatalytic synthesis of Ti_(3)C_(2)@TiO_(2)heterostructure.The TiO_(2)nanoparticles act as the anchoring center for LiPSs,while the electrically conductive Ti_(3)C_(2)ensures the rapid diffusion of these LiPSs from TiO_(2)to the catalytically active Ti_(3)C_(2)layer across heterogeneous interfaces.The Li-S batteries with Ti_(3)C_(2)@TiO_(2)-40 min-PP separator delivered a high initial capacity of 1283 mA∙h/g,which decreased slightly to 691 mA∙h/g after 200 cycles at 1C.This work advances the understanding of the synergistic effect of polysulfide adsorbents and conductive agents in inhibiting shuttle effects,and offers a method for designing polysulfide barriers in lithium-sulfur batteries.展开更多
基金Project(52204363)supported by the National Natural Science Foundation of ChinaProject(2024JJ8042)supported by the Hunan Natural Science Foundation,ChinaProject(22C0220)supported by the Education Department of Hunan Province,China。
文摘The lime-Cu^(2+)-xanthate process is commonly used for the flotation separation of sphalerite from pyrite.In this process,lime is added to the pulp to inhibit the floatability of pyrite.However,the excessive use of lime can result in pipeline blockage and inadequate recovery of associated precious metals.Therefore,it is necessary to develop new flotation process that minimizes or eliminates the use of lime.In this paper,a novel Fe^(3+)-Cu^(2+)-butyl xanthate process was developed as an alternative to lime for separating of sphalerite from pyrite.The flotation results indicated that with the artificially-mixed minerals,the flotation recovery of pyrite was lower than 16%and that of sphalerite was higher than 47%at pH 5.0−10.0.The zeta potential measurements revealed that ferric ion preferred to adsorb on pyrite,and copper ion displaced with zinc ion from the lattice at the interface of sphalerite.The wettability analyses indicated that the hydrophobicity of sphalerite surface increased apparently after being treated with Fe^(3+)-Cu^(2+)-BX,while the hydrophobicity of pyrite surface remained nearly unchanged.With XPS analysis,Cu-S bond and hydrophilic ferric hydroxide were detected separately on the surface of sphalerite and pyrite after conditioning with Fe^(3+)-Cu^(2+)-BX,which facilitated the flotation separation of sphalerite from pyrite with butyl xanthate collector.
基金The project was supported by Natural Science Foundation of Shandong Province(ZR2021MB104)National Natural Science Foundation of China(22078174).
文摘This study aims to enhance the photocatalytic performance of 2D/2D heterojunctions for NO removal from marine vessel effluents.SnS_(2)/g-C_(3)N_(4) composites were successfully constructed via a facile solvothermal method,demonstrating a significant improvement in photocatalytic NO removal under visible light irradiation.For high-flux simulated flue gas,the composite with 10%SnS_(2)(denoted as SNCN-10)showed exceptional NO removal efficiency,reaching up to 66.8%,along with excellent reusability over five consecutive cycles.Detailed band structure and density of states(DOS)calculations confirmed the formation of a characteristic heterojunction.Spin-trapping ESR spectroscopy identified·O_(2)^(-)−as the key reactive species driving NO oxidation.Additionally,in situ DRIFT spectroscopy revealed that SNCN-10 facilitated the conversion of NO to nitrate through intermediate species,including bridging nitrite and cis-nitrite(N_(2)O_(2)^(2-)).Kinetic studies further indicated that NO oxidation followed the Langmuir-Hinshelwood(L-H)mechanism.Based on density functional theory(DFT)calculations of free energy changes,a comprehensive reaction pathway for NO oxidation was proposed.These findings provide valuable insights for the development of efficient photocatalytic strategies for NO removal.
基金Project(2023JJ10062)supported by the Hunan Province Funds for Distinguished Young Scientists,ChinaProject(2023RC3051)supported by the Science and Technology Innovation Program of Hunan Province of ChinaProject(kh2401026)supported by the Science and Technology Program of Changsha of China。
文摘The sluggish kinetics of the sulfur redox reaction(SRR)and the shuttling effect of lithium polysulfides(LiPSs)both restrict the practical application of lithium-sulfur(Li-S)batteries.Heterostructures,with their pronounced electroactivity and structural stability,showcase their potential as electrodes/functional separators for lithium-sulfur batteries.Herein,we proposed a bifunctional catalyst exhibiting strong adsorption and rapid catalytic conversion of LiPSs through in situ UV photocatalytic synthesis of Ti_(3)C_(2)@TiO_(2)heterostructure.The TiO_(2)nanoparticles act as the anchoring center for LiPSs,while the electrically conductive Ti_(3)C_(2)ensures the rapid diffusion of these LiPSs from TiO_(2)to the catalytically active Ti_(3)C_(2)layer across heterogeneous interfaces.The Li-S batteries with Ti_(3)C_(2)@TiO_(2)-40 min-PP separator delivered a high initial capacity of 1283 mA∙h/g,which decreased slightly to 691 mA∙h/g after 200 cycles at 1C.This work advances the understanding of the synergistic effect of polysulfide adsorbents and conductive agents in inhibiting shuttle effects,and offers a method for designing polysulfide barriers in lithium-sulfur batteries.
