This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investiga...This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investigated through in situ attenuated total reflectance Fourier transform infrared(ATRFTIR)spectroscopy combined with the two-dimensional correlation spectroscopy(2D-COS)and X-ray photoelectron spectroscopy(XPS).It has been found that BHA/DDA mixed collectors successfully separate ilmenite from titanaugite at a molar ratio of 8:1.Zeta potential experiments suggested that,in the presence of mixed collector system,the BHA-DDA complex adsorbed on the ilmenite surface via the chemically adsorbed BHA and the electrostatically adsorbed DDA,however,the complex adsorbed on the surface of titanaugite unstably.According to in situ ATR-FTIR combined with 2D-COS and XPS results,the interface assembly mechanism of BHA/DDA is summarized as:the function group of BHA molecules first binds to the metal sites on minerals to form bidentate ligand,then DDA co-adsorbed with BHA on the surface of minerals through hydrogen bonding.DDA may change the adsorption modes of some BHA on the ilmenite surface from four-membered ring to five-membered ring,while the modes on the titanaugite surface is true opposite.Finally,recommended adsorption configurations of the BHA/DDA complex on the two mineral surfaces are proposed.展开更多
The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation...The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation experiments were carried out in addition to surface chemistry studies including zeta potential, contact angle, and bubble-particle attachment time measurements at various ultrasonic power levels and conditioning time. The results showed that, the maximum micro-flotation recovery of 77.5% was obtained with 30 W ultrasound power and 2 min conditioning time. In addition, more negative zeta potential values were obtained with ultrasound as well as higher contact angle and lower bubble-particle attachment time, which indicated the increased hydrophobicity of galena with ultrasound.展开更多
The strong collecting performance of N-laurel-1,3-diaminopropane（ND13） with respect to quartz encouraged us to study its separation of hematite and quartz mixtures in a laboratory cell flotation test The results sho...The strong collecting performance of N-laurel-1,3-diaminopropane（ND13） with respect to quartz encouraged us to study its separation of hematite and quartz mixtures in a laboratory cell flotation test The results show that the best separation results can be achieved when the pulp pH is 7.27 and 58.3 mg/L collector plus 6.67 mg/L depressant are added to the mixture.Products with 58.45%,62.78%and 63.72% iron grades can be achieved respectively when mass ratio of hematite to quartz is 2：3,1：1,and 3：2.The adsorption mechanism of ND13 on a quartz surface was investigated by zeta-potential and X-ray photoelectron spectroscopy measurements.The results reveal that electrostatic and hydrogen bonding adsorption take place between ND13 and the quartz surface,and that ND13 mainly interacts with the oxygen atoms on the quartz surface.展开更多
The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided （into） three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and su...The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided （into） three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples, several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena （or sphalerite） and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe（OH）3 formed covers on the cathodic mineral surface, affecting its floatability.展开更多
The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evalu...The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evaluate the mechanism,The calculation results revealed that in the presence of a certain amount of phosphates, metal ions adsorbed at the quartz-H_2O interface will be transferred into solution.Thus the competi- tion for metal ions between phosphates and the quartz surface leads to surface deactivation and re- duced floatability.Various distribution diagrams clearly demonstrate the change of surface complexation as a function of added phosphate concentration.The deactivation products were also evaluated.展开更多
The converter slag from a smeltery in Daye contains 2.01% copper.The floatability of copper has a significant influence on the flotation of converter slag.Flotation tests,contact angle tests and FTIR were conducted to...The converter slag from a smeltery in Daye contains 2.01% copper.The floatability of copper has a significant influence on the flotation of converter slag.Flotation tests,contact angle tests and FTIR were conducted to assess the influences of pH and different flotation concentrators on its hydrophobic process,mechanism and flotation.The results show that since chemisorptions are formed on the surface,hydrophobicity of copper is highly enhanced by xanthate,butylamine dithiophosphate and Z-200.The hydrophobic-surface of copper becomes worse with low recovery in strong acid and alkali situation.When pH value is 10,butylamine dithiophosphate and butyl xanthate are used as the mixed-collector,the grade of copper is 40.01%and that of tailings is 0.37%.展开更多
The correlation between surface complexation at the SiO_(2)H_(2)O interface and quartz notation behavior was studied.Computer assisted calculations,using the programs SOLGASWATER,were adapted in order to con-struct di...The correlation between surface complexation at the SiO_(2)H_(2)O interface and quartz notation behavior was studied.Computer assisted calculations,using the programs SOLGASWATER,were adapted in order to con-struct distribution diagrams of surface speciation in the SiO_(2)-metal ion-H^(+) system in aqueous solutions.Equilib-rium constants for both surface and solution reactions were introduced in the composition matrix.Surface complexation,surface charge as well as notation results were compared and a good agreement was obtained.Furthermore,flotation mechanisms of quartz activation by common metal ions like Ca^(2+),Mg^(2+),Fe^(2+) are quantitatively discussed based on the surface reaction equilibrium constants.展开更多
The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient uti...The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient utilization of lepidolite as a lithium source.Therefore,the processes for the flotation of lepidolite have been studied in depth,particularly the development and use of lepidolite flotation collectors and the action mechanism of the collectors on the lepidolite surface.Based on the crystal-structure characteristics of lepidolite minerals,this review focuses on the application of anionic collectors,amine cationic collectors(primary amines,quaternary ammonium salts,ether amines,and Gemini amines),and combined collectors to the flotation behavior of lepidolite as well as the adsorption mechanisms.New directions and technologies for the controllable flotation of lepidolite are proposed,including process improvement,reagent synthesis,and mechanistic research.This analysis demonstrates the need for the further study of the complex environment inside lepidolite and pulp.By using modern analytical detection methods and quantum chemical calculations,research on reagents for the flotation of lepidolite has expanded,providing new concepts and references for the efficient flotation recovery and utilization of lepidolite.展开更多
In recent years,the study of chalcopyrite and pyrite flotation surfaces using computational chemistry methods has made significant progress.However,current computational methods are limited by the small size of their ...In recent years,the study of chalcopyrite and pyrite flotation surfaces using computational chemistry methods has made significant progress.However,current computational methods are limited by the small size of their systems and insufficient consideration of hydration and temperature effects,making it difficult to fully replicate the real flotation environment of chalcopyrite and pyrite.In this study,we employed the self-consistent charge density functional tight-binding(SCC-DFTB)parameterization method to develop a parameter set,CuFeOrg,which includes the interactions between Cu-Fe-C-H-O-N-S-P-Zn elements,to investigate the surface interactions in large-scale flotation systems of chalcopyrite and pyrite.The results of bulk modulus,atomic displacement,band structure,surface relaxation,surface Mulliken charge distribution,and adsorption tests of typical flotation reagents on mineral surfaces demonstrate that CuFeOrg achieves DFT-level accuracy while significantly outperforming DFT in computational efficiency.By constructing large-scale hydration systems of mineral surfaces,as well as large-scale systems incorporating the combined interactions of mineral surfaces,flotation reagents,and hydration,we more realistically reproduce the actual flotation environment.Furthermore,the dynamic analysis results are consistent with mineral surface contact angle experiments.Additionally,CuFeOrg lays the foundation for future studies of more complex and diverse chalcopyrite and pyrite flotation surface systems.展开更多
Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert...Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.展开更多
It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla we...It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla were investigated,its impact on sulfidation flotation was explored,and the mechanisms involved in both fluoride roasting and sulfidation flotation were discussed.With CaF_(2)as the roasting reagent,Na_(2)S·9H_(2)O as the sulfidation reagent,and sodium butyl xanthate(NaBX)as the collector,the results of the flotation experiments showed that fluoride roasting improved the floatability of chrysocolla,and the recovery rate increased from 16.87%to 82.74%.X-ray diffraction analysis revealed that after fluoride roasting,approximately all the Cu on the chrysocolla surface was exposed in the form of CuO,which could provide a basis for subsequent sulfidation flotation.The microscopy and elemental analyses revealed that large quantities of"pagoda-like"grains were observed on the sulfidation surface of the fluoride-roasted chrysocolla,indicating high crystallinity particles of copper sulfide.This suggests that the effect of sulfide formation on the chrysocolla surface was more pronounced.X-ray photoelectron spectroscopy revealed that fluoride roasting increased the relative contents of sulfur and copper on the surface and that both the Cu~+and polysulfide fractions on the surface of the minerals increased.This enhances the effect of sulfidation,which is conducive to flotation recovery.Therefore,fluoride roasting improved the effect of copper species transformation and sulfidation on the surface of chysocolla,promoted the adsorption of collectors,and improved the recovery of chrysocolla from sulfidation flotation.展开更多
A novel mixed collector (BHOA) was prepared by mixing benzohydroxamic acid (BHA) and sodium oleate (NaOL) and applied to the flotation separation of smithsonite from dolomite. Flotation results showed that NaOL alone ...A novel mixed collector (BHOA) was prepared by mixing benzohydroxamic acid (BHA) and sodium oleate (NaOL) and applied to the flotation separation of smithsonite from dolomite. Flotation results showed that NaOL alone had good collecting performance on smithsonite and common gangue mineral dolomite but had poor selectivity. By using a BHA/NaOL mixed system with a molar ratio of 2:1, the recoveries of smithsonite and dolomite reached approximately 90% and 5%, respectively. Surface tension analysis showed that the surface activity of BHOA was a little higher than that of a single NaOL because of synergistic effects. Zeta potential and X-ray photoelectron spectroscopy measurements indicated that surfactants BHA and NaOL co-absorbed on the smithsonite surface and only NaOL was present on the dolomite surface in the presence of BHOA.展开更多
The potential of copper recovery from flotation tailings was experimentally investigated using a laboratory-mixing tank. The experiments were performed with solid weight percentages of 30 wt%, 35 wt%, 40 wt% and 45 wt...The potential of copper recovery from flotation tailings was experimentally investigated using a laboratory-mixing tank. The experiments were performed with solid weight percentages of 30 wt%, 35 wt%, 40 wt% and 45 wt% in water. The measurements revealed that adding sulfuric acid all at once to the tank rapidly increased the efficiency of the leaching process, which was attributed to the rapid change in the acid concentration. The rate of iron dissolution from tailings was less than when the acid was added gradually. The sample with 40 wt% solid is recommended as an appropriate feed for the recovery of copper. The adaptive neural fuzzy system(ANFIS) was also used to predict the copper recovery from flotation tailings. The back-propagation algorithm and least squares method were applied for the training of ANFIS. The validation data was also applied to evaluate the performance of these models. Simulation results revealed that the testing results from these models were in good agreement with the experimental data.展开更多
A N 2 flotation tank combined with coagulation was developed as a pretreatment equipment of biological process to remove oil and other pollutants in coal gasification wastewater( CGW). With optimal PAC dosage of 20 mg...A N 2 flotation tank combined with coagulation was developed as a pretreatment equipment of biological process to remove oil and other pollutants in coal gasification wastewater( CGW). With optimal PAC dosage of 20 mg / L,the sole coagulation process achieves removal efficiencies of 29. 34% and 26. 83% for oil and COD,respectively. For the sole N 2 floatation process,the optimal N 2 flux and HRT are 20 m3/ h and 20 min. Meanwhile,the oil and COD removal efficiencies are 35. 41% and 14. 26%,respectively. For the combined system of coagulation and N 2 floatation,the optimal parameter values are the same as the ones of separate processes. Correspondingly,the removal efficiencies are 46. 28% and 31. 89% for oil and COD, respectively. Besides,BOD 5 / COD of the effluent is improved. In contrast with conventional dissolved air floatation,the inert gas- N 2 prevents the formation of cyclopentenone, pyridine derivatives, and other heterocyclic aromatic hydrocarbons,thus improving the biodegradability of influent for the subsequent biological processes.展开更多
To achieve efficient flotation separation of brucite and calcite,flotation separation experiments were conducted on two minerals using dodecylamine(DDA)as the collector and potassium dihydrogen phosphate(PDP)as the re...To achieve efficient flotation separation of brucite and calcite,flotation separation experiments were conducted on two minerals using dodecylamine(DDA)as the collector and potassium dihydrogen phosphate(PDP)as the regulator.The action mechanism of DDA and PDP was explored through contact angle measurement,zeta potential detection,solution chemistry calculation,FTIR analysis,and XPS detection.The flotation results showed that when DDA dosage was 35 mg/L and PDP dosage was 40 mg/L,the maximum floating difference between brucite and calcite was 79.81%,and the selectivity separation index was 6.46.The detection analysis showed that the main dissolved component HPO_(4)^(2−)of PDP is selectively strongly adsorbed on the Ca site on the surface of calcite,promoting the adsorption of the main dissolved component RNH_(3)^(+)of DDA on calcite surface,while brucite is basically not affected by PDP.Therefore,PDP is an effective regulator for the reverse flotation separation of brucite and calcite in DDA system.展开更多
The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated...The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated pyrite in high alkalinity and high Ca^(2+)system,whereas arsenopyrite was almost unaffected.In mineral mixtures tests,the recovery difference between pyrite and arsenopyrite after adding ammonium oxalate is more than 85%.After ammonium oxalate and ethyl xanthate treatment,the hydrophobicity of pyrite increased significantly,and the contact angle increased from 66.62°to 75.15°and then to 81.21°.After ammonium oxalate treatment,the amount of ethyl xanthate adsorption on the pyrite surface significantly increased and was much greater than that on the arsenopyrite surface.Zeta potential measurements showed that after activation by ammonium oxalate,there was a shift in the zeta potential of pyrite to more negative values by adding xanthate.X-ray photoelectron spectroscopy test showed that after ammonium oxalate treatment,the O 1s content on the surface of pyrite decreased from 44.03%to 26.18%,and the S 2p content increased from 14.01%to 27.26%,which confirmed that the ammonium oxalatetreated pyrite surface was more hydrophobic than the untreated surface.Therefore,ammonium oxalate may be used as a selective activator of pyrite in the lime system,which achieves an efficient flotation separation of S-As sulfide ores under high alkalinity and high Ca2+concentration conditions.展开更多
Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed us...Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.展开更多
Inefficient flotation of bastnaesite remains a challenge in the production of rare earth elements.This study aimed to investigate the dissolution and adsorption behaviour of species that are commonly released into bas...Inefficient flotation of bastnaesite remains a challenge in the production of rare earth elements.This study aimed to investigate the dissolution and adsorption behaviour of species that are commonly released into bastnaesite flotation pulp from Ca/Ba-bearing gangue minerals.The influence and corresponding mechanisms on the bastnaesite mineral surface and collectors,namely sodium oleate(NaOL),were evaluated experimentally based on micro-flotation,zeta potentials,in situ attenuated total reflection Fourier transform infrared spectroscopy(ATRFTIR),and X-Ray photoelectron spectroscopy(XPS)analyses.The flotation recovery of bastnaesite significantly decreased from ~95% to ~25%,~15%,~80%,~25% when exposed to calcite,fluorite,barite,and mixed dissolved species,respectively.The zeta potential of bastnaesite was pH sensitive,indicating that H^(+) and OH^(−)determine the surface potential of bastnaesite.Solution chemistry analyses revealed that the presence of the dissolved species differed at various pH values.In situ ATR-FTIR demonstrated the different effects of the dissolved species from calcite,fluorite,and barite on collector adsorption.The former two dissolved species mainly depressed the chemisorption of the NaOL monomers(RCOO^(-)),whereas calcite also affected the physical adsorption of the oleic acid molecular dimer(RCOOH·RCOO^(-)).Moreover,the barite dissolved species only affected the physical adsorption of the NaOL species.The results of XPS analysis revealed that dissolved species from these three gangues could pre-adsorbed onto bastnaesite and affected the interaction with the collector.Density functional theory calculations were employed to provide further theoretical insights into the interactions between the dissolved species from calcite,fluorite,and barite and NaOL.展开更多
The flotation tests, zeta potential measurements, and Fourier transform infrared spectroscopy （FTIR） analysis on galena, sphalerite, and pyrite were studied in a collecting-depressing-reactivating （CDR） system. In...The flotation tests, zeta potential measurements, and Fourier transform infrared spectroscopy （FTIR） analysis on galena, sphalerite, and pyrite were studied in a collecting-depressing-reactivating （CDR） system. In this system, sulphide minerals were first collected and acti- vated by the collector, and then depressed strongly by Ca（OH）2 in a strong alkaline solution. Finally, they were reactivated by H2SO4. The flotation tests of pure minerals showed that in the Ca（OH）2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector. Hence, the flotability differences between them were reduced. However, in the H2SO4 re- activating process considerable differences in the flotability between galena and sphalerite/pyrite were produced. That is to say, galena was relatively easy to be reactivated by H2SO4, but sphalerite and pyrite were not reactivated at pH 〉 11. The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values. The results of the FTIR spectra analysis indi- cated that the collectors already adsorbed on the mineral surface were removed partially by Ca（OH）〉展开更多
This study aimed to investigate the effect of varying pyrite(Py)content on copper(Cu)in the presence of different regrinding conditions,which were altered using different types of grinding media:iron,ceramic balls,and...This study aimed to investigate the effect of varying pyrite(Py)content on copper(Cu)in the presence of different regrinding conditions,which were altered using different types of grinding media:iron,ceramic balls,and their mixture,followed by flotation in the cleaner stage.The flotation performance of rough Cu concentrate can be improved by changing the regrinding conditions based on the Py content.Scanning electron microscopy,X-ray spectrometry,ethylenediaminetetraacetic acid disodium salt extraction,and X-ray photoelectron spectroscopy studies illustrated that when the Py content was high,the use of iron media in regrinding promoted the generation of hydrophilic Fe OOH on the surface of Py and improved the Cu grade.The ceramic medium with a low Py content prevented excessive Fe OOH from covering the surface of chalcopyrite(Cpy).Electrochemical studies further showed that the galvanic corrosion current of Cpy-Py increased with the addition of Py and became stronger with the participation of iron media.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.51904249 and 51922091)the Sichuan Science and Technology Program(No.SYZ202074)the Open Research Fund of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF2001).
文摘This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investigated through in situ attenuated total reflectance Fourier transform infrared(ATRFTIR)spectroscopy combined with the two-dimensional correlation spectroscopy(2D-COS)and X-ray photoelectron spectroscopy(XPS).It has been found that BHA/DDA mixed collectors successfully separate ilmenite from titanaugite at a molar ratio of 8:1.Zeta potential experiments suggested that,in the presence of mixed collector system,the BHA-DDA complex adsorbed on the ilmenite surface via the chemically adsorbed BHA and the electrostatically adsorbed DDA,however,the complex adsorbed on the surface of titanaugite unstably.According to in situ ATR-FTIR combined with 2D-COS and XPS results,the interface assembly mechanism of BHA/DDA is summarized as:the function group of BHA molecules first binds to the metal sites on minerals to form bidentate ligand,then DDA co-adsorbed with BHA on the surface of minerals through hydrogen bonding.DDA may change the adsorption modes of some BHA on the ilmenite surface from four-membered ring to five-membered ring,while the modes on the titanaugite surface is true opposite.Finally,recommended adsorption configurations of the BHA/DDA complex on the two mineral surfaces are proposed.
基金the Research Fund of Istanbul University under grant FAB-2017-25658.
文摘The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation experiments were carried out in addition to surface chemistry studies including zeta potential, contact angle, and bubble-particle attachment time measurements at various ultrasonic power levels and conditioning time. The results showed that, the maximum micro-flotation recovery of 77.5% was obtained with 30 W ultrasound power and 2 min conditioning time. In addition, more negative zeta potential values were obtained with ultrasound as well as higher contact angle and lower bubble-particle attachment time, which indicated the increased hydrophobicity of galena with ultrasound.
基金Financial support for this research provided by the National Key Technology Development and Research Programs of China(Nos. 2008BAB32B14 and 2008BAB31B03)
文摘The strong collecting performance of N-laurel-1,3-diaminopropane（ND13） with respect to quartz encouraged us to study its separation of hematite and quartz mixtures in a laboratory cell flotation test The results show that the best separation results can be achieved when the pulp pH is 7.27 and 58.3 mg/L collector plus 6.67 mg/L depressant are added to the mixture.Products with 58.45%,62.78%and 63.72% iron grades can be achieved respectively when mass ratio of hematite to quartz is 2：3,1：1,and 3：2.The adsorption mechanism of ND13 on a quartz surface was investigated by zeta-potential and X-ray photoelectron spectroscopy measurements.The results reveal that electrostatic and hydrogen bonding adsorption take place between ND13 and the quartz surface,and that ND13 mainly interacts with the oxygen atoms on the quartz surface.
文摘The galvanic coupling formed in origin potential flotation systems of sulfide minerals can be divided （into） three types: sulfide mineral-sulfide mineral-water system; sulfide mineral-steel ball-water system; and sulfide mineral-sulfide mineral-collector system. In this paper, taking lead, zinc, iron sulfide mineral systems for examples, several models of galvanic coupling were proposed and the effects of galvanic coupling on flotation were discussed. A galvanic contact between galena （or sphalerite） and pyrite contributes to decreasing the content of zinc in lead concentrate, and enhances remarkably the absorption of collector on the galena surface. During grinding, due to galvanic interactions between minerals and steel medium, Fe（OH）3 formed covers on the cathodic mineral surface, affecting its floatability.
文摘The complexation of phosphates in the quartz-metal ion-H_2O-oleate system was studied. Computer assisted calculations with the aid of the advanced program SOLGASWATER and known equilibrium constants were used to evaluate the mechanism,The calculation results revealed that in the presence of a certain amount of phosphates, metal ions adsorbed at the quartz-H_2O interface will be transferred into solution.Thus the competi- tion for metal ions between phosphates and the quartz surface leads to surface deactivation and re- duced floatability.Various distribution diagrams clearly demonstrate the change of surface complexation as a function of added phosphate concentration.The deactivation products were also evaluated.
基金fnancial support from the National Natural Science Foundation of China(No.51104190)is acknowledged
文摘The converter slag from a smeltery in Daye contains 2.01% copper.The floatability of copper has a significant influence on the flotation of converter slag.Flotation tests,contact angle tests and FTIR were conducted to assess the influences of pH and different flotation concentrators on its hydrophobic process,mechanism and flotation.The results show that since chemisorptions are formed on the surface,hydrophobicity of copper is highly enhanced by xanthate,butylamine dithiophosphate and Z-200.The hydrophobic-surface of copper becomes worse with low recovery in strong acid and alkali situation.When pH value is 10,butylamine dithiophosphate and butyl xanthate are used as the mixed-collector,the grade of copper is 40.01%and that of tailings is 0.37%.
文摘The correlation between surface complexation at the SiO_(2)H_(2)O interface and quartz notation behavior was studied.Computer assisted calculations,using the programs SOLGASWATER,were adapted in order to con-struct distribution diagrams of surface speciation in the SiO_(2)-metal ion-H^(+) system in aqueous solutions.Equilib-rium constants for both surface and solution reactions were introduced in the composition matrix.Surface complexation,surface charge as well as notation results were compared and a good agreement was obtained.Furthermore,flotation mechanisms of quartz activation by common metal ions like Ca^(2+),Mg^(2+),Fe^(2+) are quantitatively discussed based on the surface reaction equilibrium constants.
基金financially supported by the Excellent Youth Scholars Program of State Key Laboratory of Complex Nonferrous Metal Resource Clean Utilization,Kunming University of Science and Technology,China(No.YXQN-2024003)the Central Government-Guided Local Science and Technology Development Fund Project,China(No.202407AB110022)。
文摘The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient utilization of lepidolite as a lithium source.Therefore,the processes for the flotation of lepidolite have been studied in depth,particularly the development and use of lepidolite flotation collectors and the action mechanism of the collectors on the lepidolite surface.Based on the crystal-structure characteristics of lepidolite minerals,this review focuses on the application of anionic collectors,amine cationic collectors(primary amines,quaternary ammonium salts,ether amines,and Gemini amines),and combined collectors to the flotation behavior of lepidolite as well as the adsorption mechanisms.New directions and technologies for the controllable flotation of lepidolite are proposed,including process improvement,reagent synthesis,and mechanistic research.This analysis demonstrates the need for the further study of the complex environment inside lepidolite and pulp.By using modern analytical detection methods and quantum chemical calculations,research on reagents for the flotation of lepidolite has expanded,providing new concepts and references for the efficient flotation recovery and utilization of lepidolite.
基金supported by the National Natural Science Foundation of China(No.52374264)the National Key Technologies Research and Development Program of China(No.2024YFC2909600)the Major Science and Technology Projects in Yunnan Province(No.202402AB080010).
文摘In recent years,the study of chalcopyrite and pyrite flotation surfaces using computational chemistry methods has made significant progress.However,current computational methods are limited by the small size of their systems and insufficient consideration of hydration and temperature effects,making it difficult to fully replicate the real flotation environment of chalcopyrite and pyrite.In this study,we employed the self-consistent charge density functional tight-binding(SCC-DFTB)parameterization method to develop a parameter set,CuFeOrg,which includes the interactions between Cu-Fe-C-H-O-N-S-P-Zn elements,to investigate the surface interactions in large-scale flotation systems of chalcopyrite and pyrite.The results of bulk modulus,atomic displacement,band structure,surface relaxation,surface Mulliken charge distribution,and adsorption tests of typical flotation reagents on mineral surfaces demonstrate that CuFeOrg achieves DFT-level accuracy while significantly outperforming DFT in computational efficiency.By constructing large-scale hydration systems of mineral surfaces,as well as large-scale systems incorporating the combined interactions of mineral surfaces,flotation reagents,and hydration,we more realistically reproduce the actual flotation environment.Furthermore,the dynamic analysis results are consistent with mineral surface contact angle experiments.Additionally,CuFeOrg lays the foundation for future studies of more complex and diverse chalcopyrite and pyrite flotation surface systems.
基金support from the Australian Research Council(ARC)Linkage Project(No.LP230100166).
文摘Selective depression of pyrite remains a major bottleneck in copper flotation,particularly when high-pyrite ores are processed and saline water is used.In such environments,conventional approaches using lime and inert grinding media often fail to discriminate ef-fectively between pyrite and valuable copper minerals due to strong copper activation on pyrite surfaces.This study introduced a novel approach using inorganic radicals generated from peroxymonosulfate(PMS)to selectively oxidize and depress pyrite.Flotation tests with synthetic high-pyrite ore blends showed that PMS significantly reduced pyrite recovery while maintaining or improving chalcopyrite flot-ation.Ethylenediaminetetraacetic acid(EDTA)extraction confirmed selective oxidation of pyrite,and electron paramagnetic resonance(EPR)spectroscopy identified hydroxyl(·OH)and sulfate(SO_(4)^(·-))radicals as the dominant reactive species.Iron ions from grinding me-dia and mineral surfaces were identified as key activators of PMS.A major insight was pyrite’s dual role,acting both as a radical scav-enger and an activator,which made it highly reactive and susceptible to radical-induced oxidation.This process converted surface copper-sulfur species into copper hydroxides,effectively suppressing pyrite flotation.While previous studies have applied EPR to detect radicals in simplified activator/precursor systems,this study provides the first direct mechanistic evidence of radical-driven selectivity in flotation by detecting inorganic radicals in a complex flotation slurry,thereby demonstrating their persistence under industrially relevant conditions and establishing a foundation for more effective and targeted flotation strategies.
基金financially supported by the National Natural Science Foundation of China(No.52374259)the Open Fund of the State Key Laboratory of Mineral Processing Science and Technology,China(No.BGRIMM-KJSKL-2023-11)the Major Science and Technology Projects in Yunnan Province,China(No.202302 AF080004)。
文摘It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla were investigated,its impact on sulfidation flotation was explored,and the mechanisms involved in both fluoride roasting and sulfidation flotation were discussed.With CaF_(2)as the roasting reagent,Na_(2)S·9H_(2)O as the sulfidation reagent,and sodium butyl xanthate(NaBX)as the collector,the results of the flotation experiments showed that fluoride roasting improved the floatability of chrysocolla,and the recovery rate increased from 16.87%to 82.74%.X-ray diffraction analysis revealed that after fluoride roasting,approximately all the Cu on the chrysocolla surface was exposed in the form of CuO,which could provide a basis for subsequent sulfidation flotation.The microscopy and elemental analyses revealed that large quantities of"pagoda-like"grains were observed on the sulfidation surface of the fluoride-roasted chrysocolla,indicating high crystallinity particles of copper sulfide.This suggests that the effect of sulfide formation on the chrysocolla surface was more pronounced.X-ray photoelectron spectroscopy revealed that fluoride roasting increased the relative contents of sulfur and copper on the surface and that both the Cu~+and polysulfide fractions on the surface of the minerals increased.This enhances the effect of sulfidation,which is conducive to flotation recovery.Therefore,fluoride roasting improved the effect of copper species transformation and sulfidation on the surface of chysocolla,promoted the adsorption of collectors,and improved the recovery of chrysocolla from sulfidation flotation.
基金Project(51704329) supported by the National Natural Science Foundation of ChinaProject(2018YFC1901901) supported by the National Key Scientific Research Project of China
文摘A novel mixed collector (BHOA) was prepared by mixing benzohydroxamic acid (BHA) and sodium oleate (NaOL) and applied to the flotation separation of smithsonite from dolomite. Flotation results showed that NaOL alone had good collecting performance on smithsonite and common gangue mineral dolomite but had poor selectivity. By using a BHA/NaOL mixed system with a molar ratio of 2:1, the recoveries of smithsonite and dolomite reached approximately 90% and 5%, respectively. Surface tension analysis showed that the surface activity of BHOA was a little higher than that of a single NaOL because of synergistic effects. Zeta potential and X-ray photoelectron spectroscopy measurements indicated that surfactants BHA and NaOL co-absorbed on the smithsonite surface and only NaOL was present on the dolomite surface in the presence of BHOA.
文摘The potential of copper recovery from flotation tailings was experimentally investigated using a laboratory-mixing tank. The experiments were performed with solid weight percentages of 30 wt%, 35 wt%, 40 wt% and 45 wt% in water. The measurements revealed that adding sulfuric acid all at once to the tank rapidly increased the efficiency of the leaching process, which was attributed to the rapid change in the acid concentration. The rate of iron dissolution from tailings was less than when the acid was added gradually. The sample with 40 wt% solid is recommended as an appropriate feed for the recovery of copper. The adaptive neural fuzzy system(ANFIS) was also used to predict the copper recovery from flotation tailings. The back-propagation algorithm and least squares method were applied for the training of ANFIS. The validation data was also applied to evaluate the performance of these models. Simulation results revealed that the testing results from these models were in good agreement with the experimental data.
基金Sponsored by the Sino-Dutch Research Program(Grant No.SDRP-WRZ)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(Grant No.2013DX10)
文摘A N 2 flotation tank combined with coagulation was developed as a pretreatment equipment of biological process to remove oil and other pollutants in coal gasification wastewater( CGW). With optimal PAC dosage of 20 mg / L,the sole coagulation process achieves removal efficiencies of 29. 34% and 26. 83% for oil and COD,respectively. For the sole N 2 floatation process,the optimal N 2 flux and HRT are 20 m3/ h and 20 min. Meanwhile,the oil and COD removal efficiencies are 35. 41% and 14. 26%,respectively. For the combined system of coagulation and N 2 floatation,the optimal parameter values are the same as the ones of separate processes. Correspondingly,the removal efficiencies are 46. 28% and 31. 89% for oil and COD, respectively. Besides,BOD 5 / COD of the effluent is improved. In contrast with conventional dissolved air floatation,the inert gas- N 2 prevents the formation of cyclopentenone, pyridine derivatives, and other heterocyclic aromatic hydrocarbons,thus improving the biodegradability of influent for the subsequent biological processes.
基金the General Program of the National Natural Science Foundation of China(Nos.51974064,52174239)the National Key R&D Program of China(No.2021YFC2902400)the Outstanding Postdoctoral Program of Jiangsu Province,China(No.2022ZB521).
文摘To achieve efficient flotation separation of brucite and calcite,flotation separation experiments were conducted on two minerals using dodecylamine(DDA)as the collector and potassium dihydrogen phosphate(PDP)as the regulator.The action mechanism of DDA and PDP was explored through contact angle measurement,zeta potential detection,solution chemistry calculation,FTIR analysis,and XPS detection.The flotation results showed that when DDA dosage was 35 mg/L and PDP dosage was 40 mg/L,the maximum floating difference between brucite and calcite was 79.81%,and the selectivity separation index was 6.46.The detection analysis showed that the main dissolved component HPO_(4)^(2−)of PDP is selectively strongly adsorbed on the Ca site on the surface of calcite,promoting the adsorption of the main dissolved component RNH_(3)^(+)of DDA on calcite surface,while brucite is basically not affected by PDP.Therefore,PDP is an effective regulator for the reverse flotation separation of brucite and calcite in DDA system.
基金supported by Yunnan Major Scientific and Technological Projects,China(No.202202AG050015)National Natural Science Foundation of China(No.51504109)。
文摘The activation properties of ammonium oxalate on the flotation of pyrite and arsenopyrite in the lime system were studied in this work.Single mineral flotation tests showed that the ammonium oxalate strongly activated pyrite in high alkalinity and high Ca^(2+)system,whereas arsenopyrite was almost unaffected.In mineral mixtures tests,the recovery difference between pyrite and arsenopyrite after adding ammonium oxalate is more than 85%.After ammonium oxalate and ethyl xanthate treatment,the hydrophobicity of pyrite increased significantly,and the contact angle increased from 66.62°to 75.15°and then to 81.21°.After ammonium oxalate treatment,the amount of ethyl xanthate adsorption on the pyrite surface significantly increased and was much greater than that on the arsenopyrite surface.Zeta potential measurements showed that after activation by ammonium oxalate,there was a shift in the zeta potential of pyrite to more negative values by adding xanthate.X-ray photoelectron spectroscopy test showed that after ammonium oxalate treatment,the O 1s content on the surface of pyrite decreased from 44.03%to 26.18%,and the S 2p content increased from 14.01%to 27.26%,which confirmed that the ammonium oxalatetreated pyrite surface was more hydrophobic than the untreated surface.Therefore,ammonium oxalate may be used as a selective activator of pyrite in the lime system,which achieves an efficient flotation separation of S-As sulfide ores under high alkalinity and high Ca2+concentration conditions.
基金the Iran National Elites FoundationIranian Mines&Mining Industries Development&the Renovation and Geological Survey of Iran for financial support
文摘Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.
基金supported by the National Natural Science Foundation of China(Grants No.51922091 and 51874247).
文摘Inefficient flotation of bastnaesite remains a challenge in the production of rare earth elements.This study aimed to investigate the dissolution and adsorption behaviour of species that are commonly released into bastnaesite flotation pulp from Ca/Ba-bearing gangue minerals.The influence and corresponding mechanisms on the bastnaesite mineral surface and collectors,namely sodium oleate(NaOL),were evaluated experimentally based on micro-flotation,zeta potentials,in situ attenuated total reflection Fourier transform infrared spectroscopy(ATRFTIR),and X-Ray photoelectron spectroscopy(XPS)analyses.The flotation recovery of bastnaesite significantly decreased from ~95% to ~25%,~15%,~80%,~25% when exposed to calcite,fluorite,barite,and mixed dissolved species,respectively.The zeta potential of bastnaesite was pH sensitive,indicating that H^(+) and OH^(−)determine the surface potential of bastnaesite.Solution chemistry analyses revealed that the presence of the dissolved species differed at various pH values.In situ ATR-FTIR demonstrated the different effects of the dissolved species from calcite,fluorite,and barite on collector adsorption.The former two dissolved species mainly depressed the chemisorption of the NaOL monomers(RCOO^(-)),whereas calcite also affected the physical adsorption of the oleic acid molecular dimer(RCOOH·RCOO^(-)).Moreover,the barite dissolved species only affected the physical adsorption of the NaOL species.The results of XPS analysis revealed that dissolved species from these three gangues could pre-adsorbed onto bastnaesite and affected the interaction with the collector.Density functional theory calculations were employed to provide further theoretical insights into the interactions between the dissolved species from calcite,fluorite,and barite and NaOL.
基金financially supported by the National Science and Technology Pillar Program during the Eleventh Five-Year Plan Period(No.2008BAE60B00)
文摘The flotation tests, zeta potential measurements, and Fourier transform infrared spectroscopy （FTIR） analysis on galena, sphalerite, and pyrite were studied in a collecting-depressing-reactivating （CDR） system. In this system, sulphide minerals were first collected and acti- vated by the collector, and then depressed strongly by Ca（OH）2 in a strong alkaline solution. Finally, they were reactivated by H2SO4. The flotation tests of pure minerals showed that in the Ca（OH）2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector. Hence, the flotability differences between them were reduced. However, in the H2SO4 re- activating process considerable differences in the flotability between galena and sphalerite/pyrite were produced. That is to say, galena was relatively easy to be reactivated by H2SO4, but sphalerite and pyrite were not reactivated at pH 〉 11. The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values. The results of the FTIR spectra analysis indi- cated that the collectors already adsorbed on the mineral surface were removed partially by Ca（OH）〉
基金financially supported by the National Key Research and Development Plan of China(No.2022YFC2904603)the National Natural Science Foundation of China(No.52174268)。
文摘This study aimed to investigate the effect of varying pyrite(Py)content on copper(Cu)in the presence of different regrinding conditions,which were altered using different types of grinding media:iron,ceramic balls,and their mixture,followed by flotation in the cleaner stage.The flotation performance of rough Cu concentrate can be improved by changing the regrinding conditions based on the Py content.Scanning electron microscopy,X-ray spectrometry,ethylenediaminetetraacetic acid disodium salt extraction,and X-ray photoelectron spectroscopy studies illustrated that when the Py content was high,the use of iron media in regrinding promoted the generation of hydrophilic Fe OOH on the surface of Py and improved the Cu grade.The ceramic medium with a low Py content prevented excessive Fe OOH from covering the surface of chalcopyrite(Cpy).Electrochemical studies further showed that the galvanic corrosion current of Cpy-Py increased with the addition of Py and became stronger with the participation of iron media.
