Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collect...Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collector was investigated by flotation experiments,contact angle measurements,adsorption measurements,localized electrochemical impedance spectroscopy(LEIS)measurements,and X-ray photoelectron spectroscopy(XPS)analyses.The results showed that K_(2)FeO_(4)strongly depressed arsenopyrite in a pH range of 4−11,and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^(−4)mol/L K_(2)FeO_(4)and 5×10^(−5)mol/L PEX at pH 8 or 10.In the presence of K_(2)FeO_(4) and PEX,the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly.LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface.XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.展开更多
As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel ox...As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel oxidizing agent for materials chemistry,especially for the oxidation of carbon materials.However,the reported reactivity in liquid phase(H2SO4 medium)is confusing,which ranges from aggressive to moderate,and even incompetent.Meanwhile,the solid-state reactivity underlying the“dry”chemistry of ferrate(VI)remains poorly understood.Herein,we scrutinize the reactivity of K2FeO4 using fullerene C60 and various nanocarbons as substrates.The results unravel a modest reactivity in liquid phase that only oxidizes the active defects on carbon surface and a powerful oxidizing ability in solid state that can open the inert C=C bonds in carbon lattice.We also discuss respective benefit and limitation of the wet and dry approaches.Our work provides a rational understanding on the oxidizing ability of ferrate(VI)and can guide its application in functionalization/transformation of carbons and also other kinds of materials.展开更多
The synergetic effect and underlying mechanism of potassium ferrate(PF)with tea saponin(TS,a biosurfactant)in producing short chain fatty acids(SCFAs)from anaerobic fermentation of waste activated sludge(WAS)were expl...The synergetic effect and underlying mechanism of potassium ferrate(PF)with tea saponin(TS,a biosurfactant)in producing short chain fatty acids(SCFAs)from anaerobic fermentation of waste activated sludge(WAS)were explored in this work.Experimental results showed that 0.2 g PF(g TSS)^(-1)(total suspended solid)combined with 0.02 g TS(g TSS)^(-1) could further improve SCFAs’production,and the maximum SCFAs content reached 2008.7 mg COD L^(-1),which is 1.2 and 4.5 times higher than those with PF and TS individually added,respectively,and 5.3 times higher than that of blank WAS on Day 12.In the model substrates experiments,the degradation rates of bovine serum albumin and dextran with combination of PF and TS were 41.3%±0.1% and 48.5%±0.06%,respectively,on Day 3,which are lower than those in blank WAS(with degradation rates of 72.3%±0.5%and 90.3%±0.3%).It was revealed that the oxidative effect of PF and the solubilization of TS caused more organic matters to be dissolved out from WAS,providing a large number of biodegradable substances for subsequent SCFAs production.While WAS pretreated with the combination of PF and TS,the relative abundances of Firmicutes increased from 6.4%(blank)to 38.6%,and that of Proteobacteria decreased from 41.8%(blank)to 21.8%.The combination of PF and TS promoted the hydrolysis process of WAS by enriching Firmicutes,and then increased acetic acid production by inhibiting Proteobacteria that consumed SCFAs.Meanwhile,at the genus level,acidogenesis bacteria(e.g.,Proteiniclasticum and Petrimonas)were enriched whereas SCFAs consuming bacteria(e.g.,Dokdonella)were inhibited.展开更多
This paper investigated the effects of potassium ferrate(PF)on the flotation performances of chalcopyrite and galena.The flotation results showed that PF obviously depressed galena,but had little effects on the floata...This paper investigated the effects of potassium ferrate(PF)on the flotation performances of chalcopyrite and galena.The flotation results showed that PF obviously depressed galena,but had little effects on the floatability of chalcopyrite within pH range of 4.0–12.0.Zeta potential tests showed that the addition of PF induced the formation of more amounts of hydrophilic species on the surface of galena under an alkaline environment.Industrial grade O-isopropyl-N-ethyl thionocarbamate(IPETC)chemically adsorbed on the surface of the PF-treated chalcopyrite and galena after its addition.Contact angle measurements showed that with the addition of PF,the contact angle of the galena surface significantly decreased compared with the chalcopyrite surface.Localized electrochemical impedance spectroscopy(LEIS)tests showed that the addition of PF increased the impedance of the galena surface.X-ray photoelectron spectroscopy(XPS)analyses revealed that the formation of hydrophilic species,namely lead sulfite,lead hydroxide and ferric hydroxide,on the galena surface,decreased its floatability in the presence of PF,while the formation of hydrophobic species,namely copper disulfide and elemental sulfur,on the chalcopyrite surface,maintained its floatability.Finally,a descriptive model for the reaction of PF with chalcopyrite and galena was proposed.展开更多
The possibility of direct analytical applications of ferrate（Ⅵ） solution,which was freshly electrogenerated in low-concentration NaOH electrolyte,was studied by a flow-injection-chemiluminescence（FI-CL） system.It...The possibility of direct analytical applications of ferrate（Ⅵ） solution,which was freshly electrogenerated in low-concentration NaOH electrolyte,was studied by a flow-injection-chemiluminescence（FI-CL） system.It was found that some inorganic ions, organic molecule and biomolecule could enhance the chemiluminescence emission caused by ferrate（Ⅵ）-luminol reaction.V（Ⅴ）, Ca（Ⅱ）,Mg（Ⅱ）,phloroglucinol,and bovine hemoglobin（Hb） chosen as samples were successfully detected by this developed method.The analytical characteristics of the system for the analytes determination including linear ranges,correlation coefficients, limits of detection combined with FI analysis were studied.展开更多
^(99)Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照^(235)U靶生产裂变^(99)Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变^(99)Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点...^(99)Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照^(235)U靶生产裂变^(99)Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变^(99)Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释剂、水相初始pH、萃取时间、温度、离子液体浓度等对萃取Mo(Ⅵ)的影响。结果表明,选用甲苯作为稀释剂时,Cyphos IL 101对Mo(Ⅵ)的萃取效果最好,在pH=3条件下,萃取率高达98.87%;萃取为自发进行的过程,且可在5 min达到平衡;选用1 mol/L Na_(2)CO_(3)作为反萃剂,一次反萃可将负载有机相中96.56%的Mo反萃到水相中。构建的离子液体Cyphos IL 101萃取体系对Mo与主要杂质Sr、Cs、Te等有很好的分离效果,体现了其对Mo(Ⅵ)的高选择性萃取能力。以上结果可为将离子液体Cyphos IL 101引入裂变^(99)Mo的分离工艺流程提供参考。展开更多
基金the National Natural Science Foundation of China(Nos.52074139,51904129)Basic Research Project of Yunnan Province,China(No.202001AU070028)+2 种基金Basic Research Project for High-level Talents of Yunnan Province,China(No.KKS2202152011)Open Foundation of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,China(No.CNMRCUKF1602)the Testing and Analyzing Funds of Kunming University of Science and Technology,China(No.2020T20150055).
文摘Potassium ferrate(K_(2)FeO_(4)) was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of arsenopyrite and chalcopyrite using potassium ethyl xanthate(PEX)as a collector was investigated by flotation experiments,contact angle measurements,adsorption measurements,localized electrochemical impedance spectroscopy(LEIS)measurements,and X-ray photoelectron spectroscopy(XPS)analyses.The results showed that K_(2)FeO_(4)strongly depressed arsenopyrite in a pH range of 4−11,and the flotation separation of chalcopyrite from arsenopyrite could be realized in the presence of 5×10^(−4)mol/L K_(2)FeO_(4)and 5×10^(−5)mol/L PEX at pH 8 or 10.In the presence of K_(2)FeO_(4) and PEX,the contact angle and the xanthate adsorption capacity of arsenopyrite decreased significantly.LEIS measurements showed that the addition of ferrate could significantly increase the impedance of the arsenopyrite surface.XPS analyses further confirmed that ferrate accelerated the oxidation of arsenopyrite surface.
基金financial support from National Key Research and Development Program of China (2017YFA0207500)National Natural Science Foundation of China (51673114,51973111)Shanghai Science and Technology Committee (17ZR1447300)
文摘As a high-valent iron compound with Fe in the highest accessible oxidation state,ferrate(VI)brings unique opportunities for a number of areas where chemical oxidation is essential.Recently,it is emerging as a novel oxidizing agent for materials chemistry,especially for the oxidation of carbon materials.However,the reported reactivity in liquid phase(H2SO4 medium)is confusing,which ranges from aggressive to moderate,and even incompetent.Meanwhile,the solid-state reactivity underlying the“dry”chemistry of ferrate(VI)remains poorly understood.Herein,we scrutinize the reactivity of K2FeO4 using fullerene C60 and various nanocarbons as substrates.The results unravel a modest reactivity in liquid phase that only oxidizes the active defects on carbon surface and a powerful oxidizing ability in solid state that can open the inert C=C bonds in carbon lattice.We also discuss respective benefit and limitation of the wet and dry approaches.Our work provides a rational understanding on the oxidizing ability of ferrate(VI)and can guide its application in functionalization/transformation of carbons and also other kinds of materials.
基金supported by the National Natural Science Foundation of China(No.41276067)the Air Liquide(China)R&D Co.,Ltd.(No.20200216).
文摘The synergetic effect and underlying mechanism of potassium ferrate(PF)with tea saponin(TS,a biosurfactant)in producing short chain fatty acids(SCFAs)from anaerobic fermentation of waste activated sludge(WAS)were explored in this work.Experimental results showed that 0.2 g PF(g TSS)^(-1)(total suspended solid)combined with 0.02 g TS(g TSS)^(-1) could further improve SCFAs’production,and the maximum SCFAs content reached 2008.7 mg COD L^(-1),which is 1.2 and 4.5 times higher than those with PF and TS individually added,respectively,and 5.3 times higher than that of blank WAS on Day 12.In the model substrates experiments,the degradation rates of bovine serum albumin and dextran with combination of PF and TS were 41.3%±0.1% and 48.5%±0.06%,respectively,on Day 3,which are lower than those in blank WAS(with degradation rates of 72.3%±0.5%and 90.3%±0.3%).It was revealed that the oxidative effect of PF and the solubilization of TS caused more organic matters to be dissolved out from WAS,providing a large number of biodegradable substances for subsequent SCFAs production.While WAS pretreated with the combination of PF and TS,the relative abundances of Firmicutes increased from 6.4%(blank)to 38.6%,and that of Proteobacteria decreased from 41.8%(blank)to 21.8%.The combination of PF and TS promoted the hydrolysis process of WAS by enriching Firmicutes,and then increased acetic acid production by inhibiting Proteobacteria that consumed SCFAs.Meanwhile,at the genus level,acidogenesis bacteria(e.g.,Proteiniclasticum and Petrimonas)were enriched whereas SCFAs consuming bacteria(e.g.,Dokdonella)were inhibited.
基金supported by the National Natural Science Foun-dation of China(Nos.51964027 and 52264028)Basic Research Project for High-level Talents of Yunnan Province(No.KKS2202152011)open foundation of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF1602).
文摘This paper investigated the effects of potassium ferrate(PF)on the flotation performances of chalcopyrite and galena.The flotation results showed that PF obviously depressed galena,but had little effects on the floatability of chalcopyrite within pH range of 4.0–12.0.Zeta potential tests showed that the addition of PF induced the formation of more amounts of hydrophilic species on the surface of galena under an alkaline environment.Industrial grade O-isopropyl-N-ethyl thionocarbamate(IPETC)chemically adsorbed on the surface of the PF-treated chalcopyrite and galena after its addition.Contact angle measurements showed that with the addition of PF,the contact angle of the galena surface significantly decreased compared with the chalcopyrite surface.Localized electrochemical impedance spectroscopy(LEIS)tests showed that the addition of PF increased the impedance of the galena surface.X-ray photoelectron spectroscopy(XPS)analyses revealed that the formation of hydrophilic species,namely lead sulfite,lead hydroxide and ferric hydroxide,on the galena surface,decreased its floatability in the presence of PF,while the formation of hydrophobic species,namely copper disulfide and elemental sulfur,on the chalcopyrite surface,maintained its floatability.Finally,a descriptive model for the reaction of PF with chalcopyrite and galena was proposed.
基金supported by the National Natural Science Foundation of China(No.20005005)Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory(Wuhan University)(No. HBRCEBL2007004)the Opening Foundation of State Key Laboratory of Agricultural Microbiology(No. AML-200905)
文摘The possibility of direct analytical applications of ferrate（Ⅵ） solution,which was freshly electrogenerated in low-concentration NaOH electrolyte,was studied by a flow-injection-chemiluminescence（FI-CL） system.It was found that some inorganic ions, organic molecule and biomolecule could enhance the chemiluminescence emission caused by ferrate（Ⅵ）-luminol reaction.V（Ⅴ）, Ca（Ⅱ）,Mg（Ⅱ）,phloroglucinol,and bovine hemoglobin（Hb） chosen as samples were successfully detected by this developed method.The analytical characteristics of the system for the analytes determination including linear ranges,correlation coefficients, limits of detection combined with FI analysis were studied.
文摘^(99)Mo是重要的医用放射性核素,溶剂萃取法是反应堆辐照^(235)U靶生产裂变^(99)Mo的分离方法之一。为探讨离子液体Cyphos IL 101用于裂变^(99)Mo分离的可能性,本研究评价了离子液体Cyphos IL 101在硝酸体系中对Mo(Ⅵ)的萃取行为,重点考察了稀释剂、水相初始pH、萃取时间、温度、离子液体浓度等对萃取Mo(Ⅵ)的影响。结果表明,选用甲苯作为稀释剂时,Cyphos IL 101对Mo(Ⅵ)的萃取效果最好,在pH=3条件下,萃取率高达98.87%;萃取为自发进行的过程,且可在5 min达到平衡;选用1 mol/L Na_(2)CO_(3)作为反萃剂,一次反萃可将负载有机相中96.56%的Mo反萃到水相中。构建的离子液体Cyphos IL 101萃取体系对Mo与主要杂质Sr、Cs、Te等有很好的分离效果,体现了其对Mo(Ⅵ)的高选择性萃取能力。以上结果可为将离子液体Cyphos IL 101引入裂变^(99)Mo的分离工艺流程提供参考。
