Introduced a new gravity and flotation separator with double-tailing dtsctaarge tor nne coat~, u,u ,,,~,.~ cation and cyclone scavenging with flotation in an original way. The beneficiation performance of it was good....Introduced a new gravity and flotation separator with double-tailing dtsctaarge tor nne coat~, u,u ,,,~,.~ cation and cyclone scavenging with flotation in an original way. The beneficiation performance of it was good. The results show that the gravity and flotation separator with double-tailing discharge can produce high-quality clean coal of 10.46% ash from free coal of 35.56% ash. It can discharge the fine and coarse tailings separately.展开更多
Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger in...Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite.展开更多
The flotation separation of cassiterite and dravite was realized using lead complexes of benzohydroxamic acid(Pb-BHA)as a collector and sodium fluosilicate(SF)as a depressant.Zeta potential tests confirmed that SF ena...The flotation separation of cassiterite and dravite was realized using lead complexes of benzohydroxamic acid(Pb-BHA)as a collector and sodium fluosilicate(SF)as a depressant.Zeta potential tests confirmed that SF enabled the selective depression of dravite.The results of Fourier transform infrared(FTIR)spectroscopy analysis demonstrated that hydroxyl-containing groups in the hydrolysis products of SF selectively chemisorbed on the surface of dravite.X-ray photoelectron spectroscopy(XPS)analysis results further demonstrated the strong chemisorption of SF hydrolysis products(F-containing groups and hydroxyl-containing groups)on dravite(Mg sites).Consequently,the adsorption of Pb-BHA on dravite was selectively prevented.Based on the results,a selective depression model of SF on cassiterite and dravite was proposed.展开更多
The efficient recovery of fluorite is paid more and more attention with the increasing application especially in strategic emerging industries.In this study,acrylic acid-2-acrylamido-2-methylpropane sulfonic acid copo...The efficient recovery of fluorite is paid more and more attention with the increasing application especially in strategic emerging industries.In this study,acrylic acid-2-acrylamido-2-methylpropane sulfonic acid copolymer(AAAMPS)was first used as the depressant in fluorite flotation,and its effect on the flotation separation of fluorite and dolomite in sodium oleate(NaOL)system was investigated.The depression mechanism was analyzed by contact angle measurement,zeta potential test,FTIR and XPS analyses.The micro-flotation test results showed that dolomite can be inhibited in fluorite flotation system in the addition of 2 mg/L AA-AMPS and 20 mg/L NaOL at pH 10.The CaF_(2) grade increased from 49.85%in the artificial mixed mineral to 89.60%in the fluorite concentrate.The depression mechanism indicated that AA-AMPS could adsorb strongly on dolomite surface by the chelation with Ca and Mg active sites.Moreover,the further adsorption of NaOL on dolomite surface was prevented by the AA-AMPS adsorption,but that on fluorite surface was little affected,thereby increasing the difference in the hydrophobicity and floatability of the two minerals.展开更多
The effects of combined microwave and hydrogen peroxide(H_(2)O_(2))oxidation on the flotation separation of molybdenite and chalcopyrite,as well as the underlying mechanism were investigated via microflotation,zeta po...The effects of combined microwave and hydrogen peroxide(H_(2)O_(2))oxidation on the flotation separation of molybdenite and chalcopyrite,as well as the underlying mechanism were investigated via microflotation,zeta potential,contact angle,X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and atomic force microscopy(AFM)analyses.The microflotation experiments showed that the effective inhibition of chalcopyrite can be obtained through combined oxidation pretreatments with low microwave power and H_(2)O_(2)consumption.The zeta potential,contact angle and XPS analyses indicated that the surface hydrophobicity of molybdenite changed minimally after different treatments,whereas significant amounts of hydrophilic oxidation species were formed on the surface of chalcopyrite,thus decreasing its surface hydrophobicity and floatability.Moreover,the SEM and AFM analyses indicated that more uniform oxidative products were formed on the chalcopyrite surface,further significantly increasing the surface roughness.展开更多
Lepidolite,feldspar,and quartz are silicate minerals with similar chemical properties,complicating their flotation separation.Current collector systems require strong acidic conditions for effective separation but sti...Lepidolite,feldspar,and quartz are silicate minerals with similar chemical properties,complicating their flotation separation.Current collector systems require strong acidic conditions for effective separation but still face challenges related to low separation efficiency and recovery rates.This study proposed a novel collector,ammonium dodecylsulfate(ALS),to selectively extract lepidolite from feldspar and quartz using highly selective flotation methods.Microflotation experiments showed that ALS significantly outperforms other collectors in collecting lepidolite compared to feldspar and quartz.At pH 7,lepidolite recovery reached 95%,while flotation recoveries for both feldspar and quartz were below 10%.Mixed pure mineral flotation tests revealed that at pH 7 and ALS concentration of 2.5×10^(-4) mol·L^(−1),the Li_(2)O content in the concentrate was 4.21%,with a recovery rate of 95.01%.Separation efficiency and Gaudin selectivity index values were recorded.Solution chemical analyses showed that at pH 7,ALS completely ionizes into NH_(4)^(+)and CH_(3)(CH_(2))_(11)OSO_(3)^(−).Various analytical techniques,including high-speed photography imaging,contact angle measurements,Fourier transform infrared spectroscopy,zeta potential analysis,and X-ray photoelectron spectroscopy,confirmed that the anion CH_(3)(CH_(2))_(11)OSO_(3)^(−)adsorbs chemically onto aluminum sites on lepidolite's surface,while the cation NH_(4)+binds through electrostatic interactions and hydrogen bonding.The combined adsorption of these ions on lepidolite's surface enhanced its hydrophobicity.In contrast,ALS showed minimal adsorption on feldspar and quartz surfaces,which remained hydrophilic,enabling efficient selective flotation separation of lepidolite from both feldspar and quartz.展开更多
n-octylphosphonic acid(OPA)was introduced as a novel collector for ilmenite flotation and its effectiveness was compared with the conventional chelating collector,benzohydroxamic acid(BHA).Micro-flotation tests demons...n-octylphosphonic acid(OPA)was introduced as a novel collector for ilmenite flotation and its effectiveness was compared with the conventional chelating collector,benzohydroxamic acid(BHA).Micro-flotation tests demonstrated that OPA was a highly effective and selective collector for separating ilmenite from titanaugite over acidic conditions(optimal pH around 3),which was also supported by adsorption amount measurements.X-ray photoelectron spectroscopy(XPS)tests indicated that the chemisorption of OPA onto ilmenite surface was much stronger than that of BHA.Solution chemistry diagram analyses indicated that OPA could dissociate well at pH 3.0 and mostly exist in anion form.DFT calculations further confirmed that OPA was much easier to adsorb onto ilmenite surface with shorter bond length and lower adsorption energy in comparison with BHA.Therefore,OPA maintained good collecting ability and selectivity for ilmenite flotation in the strongly acidic pulp,providing valuable insights into new collector design and development.展开更多
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
The floatability of andalusite and quartz was studied using sodium petroleum sulfonate as collector, being successfully applied in the real ore separation. The collecting performance on minerals was interpreted by mea...The floatability of andalusite and quartz was studied using sodium petroleum sulfonate as collector, being successfully applied in the real ore separation. The collecting performance on minerals was interpreted by means of zeta potential measurement and infrared spectroscopic analysis. The single mineral experiments showed that andalusite got good floatability in acidic pH region while quartz exhibited very poor floatability in the whole pH range. At pH 3, the presence of Fe3+ obviously activated quartz, causing the identical flotation behavior of the two minerals, and calcium lignosulphonate exhibited good selective inhibition to quartz. The real ore test results showed that andalusite concentrate with 53.46% Al2O3 and quartz concentrate with 92.74% SiO2 were obtained. The zeta potential and infrared spectroscopic analysis results indicated that chemical adsorption occurred between sodium petroleum sulfonate and andalusite.展开更多
Environmentally friendly flotation reagent,polyaspartic acid(PAPA),was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite.The depression mechanism of PAP...Environmentally friendly flotation reagent,polyaspartic acid(PAPA),was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite.The depression mechanism of PAPA was revealed by contact angle measurements,Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis and inductively coupled plasma(ICP)measurement.The micro-flotation tests with single minerals showed that PAPA selectively depressed Cu-activated sphalerite,while chalcopyrite remained floatable.Moreover,a concentrate containing 31.40%Cu with a recovery of 92.43%was obtained in flotation tests of artificially mixed minerals.Results of contact angle measurements,Zeta potential measurements and FT-IR spectrum revealed that PAPA exerted a much stronger adsorption on Cu-activated sphalerite surface than on chalcopyrite surface,preventing the further adsorption of sodium diethyl dithiocarbamate(DDTC)on its surface.ICP measurements indicated that PAPA had an excellent complexing ability with Cu^(2+)in flotation pulp,weakening the activation of Cu species on sphalerite surface and producing selective depression.展开更多
A copper-molybdenum iso-flotability flotation process has been developed to efficiently improve the recovery ofmolybdenite from Duobaoshan porphyry Cu-Mo ores.The effects of flotation approach,type of collector,feed p...A copper-molybdenum iso-flotability flotation process has been developed to efficiently improve the recovery ofmolybdenite from Duobaoshan porphyry Cu-Mo ores.The effects of flotation approach,type of collector,feed particle sizedistribution,rougher pH value and reagent dosage on the recovery of molybdenite were evaluated systematically.The results suggestthat compared with kerosene and diesel oil,transformer oil has stronger dispersion capability in water media and better flotationselectivity for molybdenite,providing a higher molybdenum recovery under low reagent dosage.Moreover,compared with bulkflotation approach,the iso-flotability flotation approach using transformer oil as a collector can obtain superior Mo recovery(90.77%)and grade(0.80%)in the cleaner concentrate,and increase the Mo recovery and grade by over18%and5%in the final Moconcentrate,respectively.The results of commercial flotation further indicate that the iso-flotability flotation approach is a rationaland effective route to beneficiate the porphyry Cu-Mo ores.展开更多
Polyaspartic acid(PASP)was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of scheelite and calcite using sodium oleate(NaOL)as a collector was investigated by ways...Polyaspartic acid(PASP)was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of scheelite and calcite using sodium oleate(NaOL)as a collector was investigated by ways of flotation experiments,zeta potential measurement,contact angle measurement and infrared spectroscopic analysis(IR).The results show that PASP exhibits stronger inhibition capability and selectivity than acidified water glass,and the flotation separation of scheelite from calcite can be realized in the presence of 6 mg/L PASP and 20 mg/L NaOL at pH>6.In the presence of PASP,the zeta potential of calcite surface almost keeps unchanged after adding NaOL,and the contact angle decreases sharply.Therefore,it is indicated that PASP significantly decreases the adsorption of NaOL on calcite surface.By contrast,it has no distinct effect on the adsorption of NaOL on the scheelite surface,which is further confirmed by IR results.展开更多
Tragacanth gum(TG)was explored as a depressant to realize the flotation separation of molybdenite and talc.The flotation experiments indicated that when using potassium butyl xanthate(PBX)as a collector,molybdenite sh...Tragacanth gum(TG)was explored as a depressant to realize the flotation separation of molybdenite and talc.The flotation experiments indicated that when using potassium butyl xanthate(PBX)as a collector,molybdenite showed excellent floatability while talc was completely depressed by TG,thus realizing the flotation separation of the two minerals.X-ray photoelectron spectroscopy(XPS)analysis results showed that TG was adsorbed on molybdenite surface via chemisorption.The results of contact angle measurement,Fourier transform infrared(FTIR)spectroscopy,and time-of-flight secondary ion mass spectrometry(ToF-SIMS)indicated that the pre-adsorption of TG on molybdenite could not hinder the further chemisorption of PBX on molybdenite.Because PBX has no collecting ability on talc,the flotation separation of molybdenite and talc came true using PBX to collect molybdenite and TG to depress talc.展开更多
The flotation separation of magnesite from calcium-containing minerals has always been a difficult subject in minerals processing.This work studied the inhibition effects of carboxymethyl cellulose(CMC),sodium lignosu...The flotation separation of magnesite from calcium-containing minerals has always been a difficult subject in minerals processing.This work studied the inhibition effects of carboxymethyl cellulose(CMC),sodium lignosulphonate,polyaspartic acid(PASP)and sodium silicate on flotation behaviors of magnesite,dolomite and calcite,providing guidance for the development of reagents in magnesite flotation.The micro-flotation results showed that among these four depressants,sodium silicate presented the strongest selectivity due to the highest recovery difference,and the flotation separation of magnesite from dolomite and calcite could be achieved by using sodium silicate as the depressant.Contact angle measurement indicated that the addition of sodium silicate caused the largest differences in surface wettability of the three minerals,which was in line with micro-flotation tests.Furthermore,zeta potential test,the Fourier transform infrared(FT-IR)spectroscopy and atomic force microscope(AFM)imaging were used to reveal the inhibition mechanism of sodium silicate.The results indicated that the dominated component SiO(OH)3of sodium silicate could adsorb on minerals surfaces,and the adsorption of sodium silicate hardly affected the adsorption of NaOL on magnesite surface,but caused the reduction of NaOL adsorption on dolomite and calcite surfaces,thereby increasing the flotation selectivity.展开更多
Carboxymethyl cellulose(CMC)was introduced as a depressant in reverse flotation separation of quartz from magnesite.The flotation behavior and surface properties of magnesite and quartz exposed to CMC were studied by ...Carboxymethyl cellulose(CMC)was introduced as a depressant in reverse flotation separation of quartz from magnesite.The flotation behavior and surface properties of magnesite and quartz exposed to CMC were studied by zeta potential tests,atomic force microscopy imaging and contact angle measurements.The addition of CMC as the depressant in reverse flotation using dodecylamine(DDA)as the collector exhibited a selectively depressive performance towards magnesite and achieved an improved recovery of magnesite.The study of surface properties demonstrated that CMC and DDA exhibited different adsorption strengths on the surface of magnesite and quartz.It was found that the adsorption of CMC on magnesite surface was stronger than that of DDA,which hindered the subsequent adsorption of DDA on magnesite surface.On the contrary,the quartz surface was strongly adsorbed by DDA instead of CMC,which proved that the addition of CMC did not influence the flotation of quartz.展开更多
The physical and chemical properties of feldspar and quartz are highly similar,thus they cannot be easily separated effectively.In this work,the flotation separation of feldspar from quartz using sodium fluosilicate(N...The physical and chemical properties of feldspar and quartz are highly similar,thus they cannot be easily separated effectively.In this work,the flotation separation of feldspar from quartz using sodium fluosilicate(Na_(2)SiF_(6);SF)as a selective depressant was investigated.Moreover,the influence mechanism of SF on the selective flotation separation of feldspar and quartz was investigated via flotation tests,chemical analysis of flotation solution,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and contact angle analysis.The results of the flotation tests show that feld spar and quartz without SF treatment have good floatability.After SF treatment,feldspar still has good floatability,whereas quartz has significantly reduced floatability.Flotation solution chemical analysis shows that the functional group plays an important role in depressing the quartz is[SiF_(6)]^(2-).FTIR,XPS and contact angle analysis results show that[SiF_(6)]^(2-)is adsorbed only on the surface of quartz.Thus,a thin hydrophilic SiOF layer is generated on the surface,which interferes with the adsorption of the collector on the surface of the quartz.This phenomenon leads to a significant reduction in quartz's floatability.Therefore,SF has a good ability to separate feldspar from quartz by flotation.展开更多
Lime(CaO)and sodium humate(NaHA)were used as the combined depressant for arsenopyrite pre-treated by CuSO_(4) and butyl xanthate.Micro-flotation tests show that the combined depressant CaO and NaHA achieved the select...Lime(CaO)and sodium humate(NaHA)were used as the combined depressant for arsenopyrite pre-treated by CuSO_(4) and butyl xanthate.Micro-flotation tests show that the combined depressant CaO and NaHA achieved the selective depression of arsenopyrite.Closed-circuit lab-scale test results indicate that the synergistic effect of CaO+NaHA achieved a satisfactory flotation separation of sphalerite and arsenopyrite,for which the Zn grade and recovery of Zn concentrate were 51.21%and 92.21%,respectively.Contact angle measurements,adsorption amount measurements and X-ray photoelectron spectroscopy analysis indicate that the dissolved calcium species(mainly as Ca(2+))were adsorbed on the mineral surfaces,thereby promoting NaHA adsorption.Moreover,the surface of the arsenopyrite absorbed more amount of calcium species and NaHA than that of the sphalerite,thereby accounting for the strong hydrophilic surface of arsenopyrite.The adsorption of NaHA on arsenopyrite was mainly chemical adsorption through its carboxyl groups and Ca atoms,whereas that on sphalerite surface was relatively weak.展开更多
Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic ac...Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.展开更多
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
Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulator...Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.展开更多
基金Supported by the Natural Science Foundation of China （50974094） the National High-tech R ＆ D Program of China （863 Program） （2007AA05Z317）
文摘Introduced a new gravity and flotation separator with double-tailing dtsctaarge tor nne coat~, u,u ,,,~,.~ cation and cyclone scavenging with flotation in an original way. The beneficiation performance of it was good. The results show that the gravity and flotation separator with double-tailing discharge can produce high-quality clean coal of 10.46% ash from free coal of 35.56% ash. It can discharge the fine and coarse tailings separately.
基金supported by Fundamental Research Projects of Yunnan Province,China(Nos.202101BE070001-009,202301AU070189).
文摘Mineral fulvic acid(MFA)was used as an eco-friendly pyrite depressant to recover chalcopyrite by flotation with the use of the butyl xanthate as a collector.Flotation experiments showed that MFA produced a stronger inhibition effect on pyrite than on chalcopyrite.The separation of chalcopyrite from pyrite was realized by introducing 150 mg/L MFA at a pulp pH of approximately 8.0.The copper grade,copper recovery,and separation efficiency were 28.03%,84.79%,and 71.66%,respectively.Surface adsorption tests,zeta potential determinations,and localized electrochemical impedance spectroscopy tests showed that more MFA adsorbed on pyrite than on chalcopyrite,which weakened the subsequent interactions between pyrite and the collector.Atomic force microscope imaging further confirmed the adsorption of MFA on pyrite,and X-ray photoelectron spectroscopy results indicated that hydrophilic Fe-based species on the pyrite surfaces increased after exposure of pyrite to MFA,thereby decreasing the floatability of pyrite.
基金supported by the National Natural Science Foundation of China(No.52122406)the National Key Research Center and Development Program of the 14th Five-year Plan of China(Nos.2022YFC2905104,2022YFC2905105).
文摘The flotation separation of cassiterite and dravite was realized using lead complexes of benzohydroxamic acid(Pb-BHA)as a collector and sodium fluosilicate(SF)as a depressant.Zeta potential tests confirmed that SF enabled the selective depression of dravite.The results of Fourier transform infrared(FTIR)spectroscopy analysis demonstrated that hydroxyl-containing groups in the hydrolysis products of SF selectively chemisorbed on the surface of dravite.X-ray photoelectron spectroscopy(XPS)analysis results further demonstrated the strong chemisorption of SF hydrolysis products(F-containing groups and hydroxyl-containing groups)on dravite(Mg sites).Consequently,the adsorption of Pb-BHA on dravite was selectively prevented.Based on the results,a selective depression model of SF on cassiterite and dravite was proposed.
基金Project(52004333)supported by the National Science Foundation of ChinaProject(2021CB1002)supported by Hunan International Joint Research Center for Efficient and Clean Utilization of Critical Metal Mineral Resources,China。
文摘The efficient recovery of fluorite is paid more and more attention with the increasing application especially in strategic emerging industries.In this study,acrylic acid-2-acrylamido-2-methylpropane sulfonic acid copolymer(AAAMPS)was first used as the depressant in fluorite flotation,and its effect on the flotation separation of fluorite and dolomite in sodium oleate(NaOL)system was investigated.The depression mechanism was analyzed by contact angle measurement,zeta potential test,FTIR and XPS analyses.The micro-flotation test results showed that dolomite can be inhibited in fluorite flotation system in the addition of 2 mg/L AA-AMPS and 20 mg/L NaOL at pH 10.The CaF_(2) grade increased from 49.85%in the artificial mixed mineral to 89.60%in the fluorite concentrate.The depression mechanism indicated that AA-AMPS could adsorb strongly on dolomite surface by the chelation with Ca and Mg active sites.Moreover,the further adsorption of NaOL on dolomite surface was prevented by the AA-AMPS adsorption,but that on fluorite surface was little affected,thereby increasing the difference in the hydrophobicity and floatability of the two minerals.
基金support by the National Natural Science Foundation of China(Nos.52104266,52074206,52374278)Key Research and Development Project of Shaanxi Province,China(No.2023GXLH-054).
文摘The effects of combined microwave and hydrogen peroxide(H_(2)O_(2))oxidation on the flotation separation of molybdenite and chalcopyrite,as well as the underlying mechanism were investigated via microflotation,zeta potential,contact angle,X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM)and atomic force microscopy(AFM)analyses.The microflotation experiments showed that the effective inhibition of chalcopyrite can be obtained through combined oxidation pretreatments with low microwave power and H_(2)O_(2)consumption.The zeta potential,contact angle and XPS analyses indicated that the surface hydrophobicity of molybdenite changed minimally after different treatments,whereas significant amounts of hydrophilic oxidation species were formed on the surface of chalcopyrite,thus decreasing its surface hydrophobicity and floatability.Moreover,the SEM and AFM analyses indicated that more uniform oxidative products were formed on the chalcopyrite surface,further significantly increasing the surface roughness.
基金supported by the Project of the National Natural Science Foundation of China(No.52274263)the Key Research and Development Program of Jiangxi Province(No.20214BBG74001)the Major Science and Technology Innovation Project of Yichun(No.2023ZDKJGG03).
文摘Lepidolite,feldspar,and quartz are silicate minerals with similar chemical properties,complicating their flotation separation.Current collector systems require strong acidic conditions for effective separation but still face challenges related to low separation efficiency and recovery rates.This study proposed a novel collector,ammonium dodecylsulfate(ALS),to selectively extract lepidolite from feldspar and quartz using highly selective flotation methods.Microflotation experiments showed that ALS significantly outperforms other collectors in collecting lepidolite compared to feldspar and quartz.At pH 7,lepidolite recovery reached 95%,while flotation recoveries for both feldspar and quartz were below 10%.Mixed pure mineral flotation tests revealed that at pH 7 and ALS concentration of 2.5×10^(-4) mol·L^(−1),the Li_(2)O content in the concentrate was 4.21%,with a recovery rate of 95.01%.Separation efficiency and Gaudin selectivity index values were recorded.Solution chemical analyses showed that at pH 7,ALS completely ionizes into NH_(4)^(+)and CH_(3)(CH_(2))_(11)OSO_(3)^(−).Various analytical techniques,including high-speed photography imaging,contact angle measurements,Fourier transform infrared spectroscopy,zeta potential analysis,and X-ray photoelectron spectroscopy,confirmed that the anion CH_(3)(CH_(2))_(11)OSO_(3)^(−)adsorbs chemically onto aluminum sites on lepidolite's surface,while the cation NH_(4)+binds through electrostatic interactions and hydrogen bonding.The combined adsorption of these ions on lepidolite's surface enhanced its hydrophobicity.In contrast,ALS showed minimal adsorption on feldspar and quartz surfaces,which remained hydrophilic,enabling efficient selective flotation separation of lepidolite from both feldspar and quartz.
基金supported by the National Natural Science Foundation of China(No.52074357)the Vanadium Titanium Union Foundation,ChinaChina Postdoctoral Science Foundation(No.2019M650188)。
文摘n-octylphosphonic acid(OPA)was introduced as a novel collector for ilmenite flotation and its effectiveness was compared with the conventional chelating collector,benzohydroxamic acid(BHA).Micro-flotation tests demonstrated that OPA was a highly effective and selective collector for separating ilmenite from titanaugite over acidic conditions(optimal pH around 3),which was also supported by adsorption amount measurements.X-ray photoelectron spectroscopy(XPS)tests indicated that the chemisorption of OPA onto ilmenite surface was much stronger than that of BHA.Solution chemistry diagram analyses indicated that OPA could dissociate well at pH 3.0 and mostly exist in anion form.DFT calculations further confirmed that OPA was much easier to adsorb onto ilmenite surface with shorter bond length and lower adsorption energy in comparison with BHA.Therefore,OPA maintained good collecting ability and selectivity for ilmenite flotation in the strongly acidic pulp,providing valuable insights into new collector design and development.
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.
文摘The floatability of andalusite and quartz was studied using sodium petroleum sulfonate as collector, being successfully applied in the real ore separation. The collecting performance on minerals was interpreted by means of zeta potential measurement and infrared spectroscopic analysis. The single mineral experiments showed that andalusite got good floatability in acidic pH region while quartz exhibited very poor floatability in the whole pH range. At pH 3, the presence of Fe3+ obviously activated quartz, causing the identical flotation behavior of the two minerals, and calcium lignosulphonate exhibited good selective inhibition to quartz. The real ore test results showed that andalusite concentrate with 53.46% Al2O3 and quartz concentrate with 92.74% SiO2 were obtained. The zeta potential and infrared spectroscopic analysis results indicated that chemical adsorption occurred between sodium petroleum sulfonate and andalusite.
基金financial supports from the National Natural Science Foundation of China(Nos.51974364,51904339)Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral,China(No.2018TP1002)。
文摘Environmentally friendly flotation reagent,polyaspartic acid(PAPA),was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite.The depression mechanism of PAPA was revealed by contact angle measurements,Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis and inductively coupled plasma(ICP)measurement.The micro-flotation tests with single minerals showed that PAPA selectively depressed Cu-activated sphalerite,while chalcopyrite remained floatable.Moreover,a concentrate containing 31.40%Cu with a recovery of 92.43%was obtained in flotation tests of artificially mixed minerals.Results of contact angle measurements,Zeta potential measurements and FT-IR spectrum revealed that PAPA exerted a much stronger adsorption on Cu-activated sphalerite surface than on chalcopyrite surface,preventing the further adsorption of sodium diethyl dithiocarbamate(DDTC)on its surface.ICP measurements indicated that PAPA had an excellent complexing ability with Cu^(2+)in flotation pulp,weakening the activation of Cu species on sphalerite surface and producing selective depression.
基金Project(51374249)supported by the National Natural Science Foundation of ChinaProject(2016zzts103)supported by the Fundamental Research Funds for the Central Universities of China+1 种基金Project(2015BAB12B02)supported by the National Science-Technology Support Plan,ChinaProject(2013B090800016)supported by Guangdong Provincial Science and Technology Plan,China
文摘A copper-molybdenum iso-flotability flotation process has been developed to efficiently improve the recovery ofmolybdenite from Duobaoshan porphyry Cu-Mo ores.The effects of flotation approach,type of collector,feed particle sizedistribution,rougher pH value and reagent dosage on the recovery of molybdenite were evaluated systematically.The results suggestthat compared with kerosene and diesel oil,transformer oil has stronger dispersion capability in water media and better flotationselectivity for molybdenite,providing a higher molybdenum recovery under low reagent dosage.Moreover,compared with bulkflotation approach,the iso-flotability flotation approach using transformer oil as a collector can obtain superior Mo recovery(90.77%)and grade(0.80%)in the cleaner concentrate,and increase the Mo recovery and grade by over18%and5%in the final Moconcentrate,respectively.The results of commercial flotation further indicate that the iso-flotability flotation approach is a rationaland effective route to beneficiate the porphyry Cu-Mo ores.
基金financial support from the Youth Science Foundation of China(No.52004333)。
文摘Polyaspartic acid(PASP)was used as a novel environmental-friendly depressant,and its inhibition effect on flotation performance of scheelite and calcite using sodium oleate(NaOL)as a collector was investigated by ways of flotation experiments,zeta potential measurement,contact angle measurement and infrared spectroscopic analysis(IR).The results show that PASP exhibits stronger inhibition capability and selectivity than acidified water glass,and the flotation separation of scheelite from calcite can be realized in the presence of 6 mg/L PASP and 20 mg/L NaOL at pH>6.In the presence of PASP,the zeta potential of calcite surface almost keeps unchanged after adding NaOL,and the contact angle decreases sharply.Therefore,it is indicated that PASP significantly decreases the adsorption of NaOL on calcite surface.By contrast,it has no distinct effect on the adsorption of NaOL on the scheelite surface,which is further confirmed by IR results.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(No.51664020)the Natural Science Foundation of Jiangxi Province,China(No.20202ACBL214010)+1 种基金Open Foundation of State Key Laboratory of Mineral Processing,China(No.BGRIMM-KJSKL-2020-12)Open Foundation of Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources,China(No.2018TP1002).
文摘Tragacanth gum(TG)was explored as a depressant to realize the flotation separation of molybdenite and talc.The flotation experiments indicated that when using potassium butyl xanthate(PBX)as a collector,molybdenite showed excellent floatability while talc was completely depressed by TG,thus realizing the flotation separation of the two minerals.X-ray photoelectron spectroscopy(XPS)analysis results showed that TG was adsorbed on molybdenite surface via chemisorption.The results of contact angle measurement,Fourier transform infrared(FTIR)spectroscopy,and time-of-flight secondary ion mass spectrometry(ToF-SIMS)indicated that the pre-adsorption of TG on molybdenite could not hinder the further chemisorption of PBX on molybdenite.Because PBX has no collecting ability on talc,the flotation separation of molybdenite and talc came true using PBX to collect molybdenite and TG to depress talc.
基金supported by the Youth Science Foundation of China(No.52004333)the Key Laboratory of Hunan Province for Clean and Efficiency Utilization of Strategic Calcium-containing Mineral Resources(No.2018TP1002).
文摘The flotation separation of magnesite from calcium-containing minerals has always been a difficult subject in minerals processing.This work studied the inhibition effects of carboxymethyl cellulose(CMC),sodium lignosulphonate,polyaspartic acid(PASP)and sodium silicate on flotation behaviors of magnesite,dolomite and calcite,providing guidance for the development of reagents in magnesite flotation.The micro-flotation results showed that among these four depressants,sodium silicate presented the strongest selectivity due to the highest recovery difference,and the flotation separation of magnesite from dolomite and calcite could be achieved by using sodium silicate as the depressant.Contact angle measurement indicated that the addition of sodium silicate caused the largest differences in surface wettability of the three minerals,which was in line with micro-flotation tests.Furthermore,zeta potential test,the Fourier transform infrared(FT-IR)spectroscopy and atomic force microscope(AFM)imaging were used to reveal the inhibition mechanism of sodium silicate.The results indicated that the dominated component SiO(OH)3of sodium silicate could adsorb on minerals surfaces,and the adsorption of sodium silicate hardly affected the adsorption of NaOL on magnesite surface,but caused the reduction of NaOL adsorption on dolomite and calcite surfaces,thereby increasing the flotation selectivity.
基金the financial support from the National Natural Science Foundation of China(No.51774041)。
文摘Carboxymethyl cellulose(CMC)was introduced as a depressant in reverse flotation separation of quartz from magnesite.The flotation behavior and surface properties of magnesite and quartz exposed to CMC were studied by zeta potential tests,atomic force microscopy imaging and contact angle measurements.The addition of CMC as the depressant in reverse flotation using dodecylamine(DDA)as the collector exhibited a selectively depressive performance towards magnesite and achieved an improved recovery of magnesite.The study of surface properties demonstrated that CMC and DDA exhibited different adsorption strengths on the surface of magnesite and quartz.It was found that the adsorption of CMC on magnesite surface was stronger than that of DDA,which hindered the subsequent adsorption of DDA on magnesite surface.On the contrary,the quartz surface was strongly adsorbed by DDA instead of CMC,which proved that the addition of CMC did not influence the flotation of quartz.
基金financially supported by the Project of the National Natural Science Foundation of China(No.52274263)the Key R&D Plan Projects in Jiangxi Province(No.20214BBG74001)。
文摘The physical and chemical properties of feldspar and quartz are highly similar,thus they cannot be easily separated effectively.In this work,the flotation separation of feldspar from quartz using sodium fluosilicate(Na_(2)SiF_(6);SF)as a selective depressant was investigated.Moreover,the influence mechanism of SF on the selective flotation separation of feldspar and quartz was investigated via flotation tests,chemical analysis of flotation solution,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and contact angle analysis.The results of the flotation tests show that feld spar and quartz without SF treatment have good floatability.After SF treatment,feldspar still has good floatability,whereas quartz has significantly reduced floatability.Flotation solution chemical analysis shows that the functional group plays an important role in depressing the quartz is[SiF_(6)]^(2-).FTIR,XPS and contact angle analysis results show that[SiF_(6)]^(2-)is adsorbed only on the surface of quartz.Thus,a thin hydrophilic SiOF layer is generated on the surface,which interferes with the adsorption of the collector on the surface of the quartz.This phenomenon leads to a significant reduction in quartz's floatability.Therefore,SF has a good ability to separate feldspar from quartz by flotation.
基金the National Natural Science Foundation of China(Nos.51974364,51904339,52074355)the 13th Five-Year National Key R&D Program of China(No.2020YFC1909203)。
文摘Lime(CaO)and sodium humate(NaHA)were used as the combined depressant for arsenopyrite pre-treated by CuSO_(4) and butyl xanthate.Micro-flotation tests show that the combined depressant CaO and NaHA achieved the selective depression of arsenopyrite.Closed-circuit lab-scale test results indicate that the synergistic effect of CaO+NaHA achieved a satisfactory flotation separation of sphalerite and arsenopyrite,for which the Zn grade and recovery of Zn concentrate were 51.21%and 92.21%,respectively.Contact angle measurements,adsorption amount measurements and X-ray photoelectron spectroscopy analysis indicate that the dissolved calcium species(mainly as Ca(2+))were adsorbed on the mineral surfaces,thereby promoting NaHA adsorption.Moreover,the surface of the arsenopyrite absorbed more amount of calcium species and NaHA than that of the sphalerite,thereby accounting for the strong hydrophilic surface of arsenopyrite.The adsorption of NaHA on arsenopyrite was mainly chemical adsorption through its carboxyl groups and Ca atoms,whereas that on sphalerite surface was relatively weak.
基金the support of Natural Science Foundation of China (51804238, 51904214)the Open Foundation of State Key Laboratory of Mineral Processing, BGRIMM Technology (No. BGRIMM-KJSKL-2021-22)the Fundamental Research Funds for the Central Universities (2021IVA110, 2021IVA039)。
文摘Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.
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supported by the National Natural Science Foundation of China (Nos.51974064,52174239,and 52374259)the Open Project of the Key Laboratory of Solid Waste Treatment and Resource Utiliza-tion of the Ministry of Education,China (No.23kfgk02).
文摘Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.
