A novel hydroxamic acid,N-hydroxy-9,10-epoxy group-octadecanamide(N-OH-9,10-O-ODA),was synthesised by modifying the structure of oleic acid.The carboxyl group of oleic acid was converted into an N-hydroxy amide group,...A novel hydroxamic acid,N-hydroxy-9,10-epoxy group-octadecanamide(N-OH-9,10-O-ODA),was synthesised by modifying the structure of oleic acid.The carboxyl group of oleic acid was converted into an N-hydroxy amide group,and an epoxy group was introduced into its structure.N-OH-9,10-O-ODA was used as a novel collector in the flotation separation of spodumene from one of its associated gangue minerals,specifically albite.N-OH-9,10-O-ODA exhibits remarkable selectivity,with a stronger affinity for collecting spodumene particles compared to albite particles.Zeta potential measurements and X-ray photoelectron spectroscopic analysis reveal that the adsorption quantity of N-OH-9,10-O-ODA on spodumene surface is comparable to that on albite surface.First-principles calculations demonstrate the diverse adsorption configurations of N-OH-9,10-O-ODA on surfaces of spodumene and albite,leading to its distinct collecting abilities for spodumene and albite particles.展开更多
Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable.In the hydrometallurgy of concentrate,collectors adsor...Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable.In the hydrometallurgy of concentrate,collectors adsorbed on concentrate can damage ion-exchange resin and increase the chemical oxygen demand(COD)value of wastewater.In this work,we proposed a new scheme,i.e.,desorbing the collectors from concentrate in ore dressing plant and reusing them in flotation flowsheet.Lead nitrate and benzohydroxamic acid(Pb-BHA)complex is a common collector in scheelite flotation.In this study,different physical(stirring or ultrasonic waves)and chemical(strong acid or alkali environment)methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were explored.Single-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min,the highest desorption rates of Pb and BHA from the scheelite concentrate were 90.48%and 63.75%,respectively.Run-of-mine ore flotation tests revealed that the reuse of desorbed Pb and BHA reduced the collector dosage by 30%for BHA and 25%for Pb.The strong alkali environment broke the chemical bonds between Pb and BHA.The cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite surfaces.This method combining ultrasonic waves and strong alkali environment can effectively desorb the collectors from concentrate and provide“clean”scheelite concentrate for metallurgic plants;the reuse of desorbed collector in flotation flowsheet can reduce reagent cost for ore dressing plants.展开更多
To conduct extensive research on the application of ionic liquids as collectors in mineral flotation,ethanol(EtOH)was used as a solvent to dissolve hydrophobic ionic liquids(ILs)to simplify the reagent regime.Interest...To conduct extensive research on the application of ionic liquids as collectors in mineral flotation,ethanol(EtOH)was used as a solvent to dissolve hydrophobic ionic liquids(ILs)to simplify the reagent regime.Interesting phenomena were observed in which EtOH exerted different effects on the flotation efficiency of two ILs with similar structures.When EtOH was used to dissolve 1-dodecyl-3-methylimidazolium chloride(C12[mim]Cl)and as a collector for pure quartz flotation tests at a concentration of 1×10^(−5)mol·L^(−1),quartz recovery increased from 23.77%to 77.91%compared with ILs dissolved in water.However,quartz recovery of 1-dodecyl-3-methylim-idazolium hexafluorophosphate(C12[mim]PF6)decreased from 60.45%to 24.52%under the same conditions.The conditional experi-ments under 1×10^(−5)mol·L^(−1)ILs for EtOH concentration and under 2vol%EtOH for ILs concentration confirmed this difference.After being affected by EtOH,the mixed ore flotation tests of quartz and hematite showed a decrease in the hematite concentrate grade and re-covery for the C12[mim]Cl collector,whereas the hematite concentrate grade and recovery for the C12[mim]PF6 collector increased.On the basis of these differences and observations of flotation foam,two-phase bubble observation tests were carried out.The EtOH promoted the foam height of two ILs during aeration.It accelerated static froth defoaming after aeration stopped,and the foam of C12[mim]PF6 de-foaming especially quickly.In the discussion of flotation tests and foam observation,an attempt was made to explain the reasons and mechanisms behind the diverse phenomena using the dynamic surface tension effect and solvation effect results from EtOH.The solva-tion effect was verified through Fourier transform infrared(FT-IR),X-ray photoelectron spectroscopy(XPS),and Zeta potential tests.Al-though EtOH affects the adsorption of ILs on the ore surface during flotation negatively,it holds an positive value of inhibiting foam mer-ging during flotation aeration and accelerating the defoaming of static foam.And induce more robust secondary enrichment in the mixed ore flotation of the C12[mim]PF6 collector,facilitating effective mixed ore separation even under inhibitor-free conditions.展开更多
基金financial support from the National Natural Science Foundation of China(Nos.91962223,52104287,U2067201)Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources and Open Foundation of State Key Laboratory of Mineral Processing,China(No.BGRIMM-KJSKL-2022-14)。
文摘A novel hydroxamic acid,N-hydroxy-9,10-epoxy group-octadecanamide(N-OH-9,10-O-ODA),was synthesised by modifying the structure of oleic acid.The carboxyl group of oleic acid was converted into an N-hydroxy amide group,and an epoxy group was introduced into its structure.N-OH-9,10-O-ODA was used as a novel collector in the flotation separation of spodumene from one of its associated gangue minerals,specifically albite.N-OH-9,10-O-ODA exhibits remarkable selectivity,with a stronger affinity for collecting spodumene particles compared to albite particles.Zeta potential measurements and X-ray photoelectron spectroscopic analysis reveal that the adsorption quantity of N-OH-9,10-O-ODA on spodumene surface is comparable to that on albite surface.First-principles calculations demonstrate the diverse adsorption configurations of N-OH-9,10-O-ODA on surfaces of spodumene and albite,leading to its distinct collecting abilities for spodumene and albite particles.
基金financially supported by the National Natural Science Foundation of China(Nos.52304314 and U23A20602)the Leading Talents of S&T Innovation of Hunan Province,China(No.2021RC4002)+2 种基金the Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2024-16)the Open Foundation of Key Laboratory of Green Separation and Enrichment of Strategic Metal Mineral Resources(No.2023-02)the Fundamental Research Funds for the Central Universities of Central South University(No.2024ZZTS0008).
文摘Flotation is the most common method to obtain concentrate through the selective adsorption of collectors on target minerals to make them hydrophobic and floatable.In the hydrometallurgy of concentrate,collectors adsorbed on concentrate can damage ion-exchange resin and increase the chemical oxygen demand(COD)value of wastewater.In this work,we proposed a new scheme,i.e.,desorbing the collectors from concentrate in ore dressing plant and reusing them in flotation flowsheet.Lead nitrate and benzohydroxamic acid(Pb-BHA)complex is a common collector in scheelite flotation.In this study,different physical(stirring or ultrasonic waves)and chemical(strong acid or alkali environment)methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were explored.Single-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min,the highest desorption rates of Pb and BHA from the scheelite concentrate were 90.48%and 63.75%,respectively.Run-of-mine ore flotation tests revealed that the reuse of desorbed Pb and BHA reduced the collector dosage by 30%for BHA and 25%for Pb.The strong alkali environment broke the chemical bonds between Pb and BHA.The cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite surfaces.This method combining ultrasonic waves and strong alkali environment can effectively desorb the collectors from concentrate and provide“clean”scheelite concentrate for metallurgic plants;the reuse of desorbed collector in flotation flowsheet can reduce reagent cost for ore dressing plants.
基金supported by the National Natural Science Foundation of China(No.51874221)the Open Foundation of Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials,Guangxi University(No.2022GXYSOF 11).
文摘To conduct extensive research on the application of ionic liquids as collectors in mineral flotation,ethanol(EtOH)was used as a solvent to dissolve hydrophobic ionic liquids(ILs)to simplify the reagent regime.Interesting phenomena were observed in which EtOH exerted different effects on the flotation efficiency of two ILs with similar structures.When EtOH was used to dissolve 1-dodecyl-3-methylimidazolium chloride(C12[mim]Cl)and as a collector for pure quartz flotation tests at a concentration of 1×10^(−5)mol·L^(−1),quartz recovery increased from 23.77%to 77.91%compared with ILs dissolved in water.However,quartz recovery of 1-dodecyl-3-methylim-idazolium hexafluorophosphate(C12[mim]PF6)decreased from 60.45%to 24.52%under the same conditions.The conditional experi-ments under 1×10^(−5)mol·L^(−1)ILs for EtOH concentration and under 2vol%EtOH for ILs concentration confirmed this difference.After being affected by EtOH,the mixed ore flotation tests of quartz and hematite showed a decrease in the hematite concentrate grade and re-covery for the C12[mim]Cl collector,whereas the hematite concentrate grade and recovery for the C12[mim]PF6 collector increased.On the basis of these differences and observations of flotation foam,two-phase bubble observation tests were carried out.The EtOH promoted the foam height of two ILs during aeration.It accelerated static froth defoaming after aeration stopped,and the foam of C12[mim]PF6 de-foaming especially quickly.In the discussion of flotation tests and foam observation,an attempt was made to explain the reasons and mechanisms behind the diverse phenomena using the dynamic surface tension effect and solvation effect results from EtOH.The solva-tion effect was verified through Fourier transform infrared(FT-IR),X-ray photoelectron spectroscopy(XPS),and Zeta potential tests.Al-though EtOH affects the adsorption of ILs on the ore surface during flotation negatively,it holds an positive value of inhibiting foam mer-ging during flotation aeration and accelerating the defoaming of static foam.And induce more robust secondary enrichment in the mixed ore flotation of the C12[mim]PF6 collector,facilitating effective mixed ore separation even under inhibitor-free conditions.
