The flotabilities of chalcopyrite and galena with sodium humate(HA) and ammonium persulfate(APS) as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single...The flotabilities of chalcopyrite and galena with sodium humate(HA) and ammonium persulfate(APS) as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single mineral flotation test shows that the slurry oxidation environment and the proper oxidation of galena surface are prerequisites for the depression of galena by sodium humate. The closed-circuit flotation test of copper/lead bulk concentrate shows that the grade and recovery of Cu reach 30.47% and 89.16% respectively and those of Pb reach 2.06% and1.58% respectively in copper concentrate, and the grade and recovery of Pb reach 50.34% and 98.42% and those of Cu reach 1.45% and 10.84% respectively in lead concentrate with HA and APS. The selective depression effect of HA and APS is more obvious than that of potassium dichromate. The results of FTIR analysis and adsorption measurements indicate that the adsorption of sodium humate on the fresh surface of galena is negligible, while after oxidation, sodium humate can be chemically adsorbed on the surface of galena. According to the theory of solubility product, the sodium humate can display the oxidation product PbSO_4, after then, adsorb on the surface of lead chemically to produce inhibitory effect. Thus, it can be seen that the combination of HA and APS is an efficient non-toxic reagent to achieve cleaning separation copper/lead bulk concentrate by flotation. The combination of HA and APS is an efficient non-toxic reagent to achieve cleaning for copper/lead bulk concentrate by flotation.展开更多
Six kinds of galena with different impurities were synthesized and the effects of impurities on the floatability of galena were investigated. The thermodynamic and kinetic parameters on the galena surface were measure...Six kinds of galena with different impurities were synthesized and the effects of impurities on the floatability of galena were investigated. The thermodynamic and kinetic parameters on the galena surface were measured using microcalorimetry, and the adsorption configuration and energy of butyl xanthate on the surfaces of galena with different impurities were simulated by density functional theory. Flotation experiments showed that Ag and Bi significantly promoted the recovery of galena, while Zn, Sb, Mn, and Cu reduced the recovery of the flotation. Microthermokinetic results indicated that the absolute value of xanthate adsorption heat was directly proportional to the flotation recovery of galena. Adsorption heat and reaction rate coefficients of xanthate on galena containing Ag or Bi were larger than those on pure galena, but smaller on galena containing Cu or Sb. Additionally, the relationship between the heat of unsaturated adsorption of xanthate and the adsorption energy of impurity atom on galena surface was investigated.展开更多
A novel synthesized reagent, O,O-bis(2,3-dihydroxypropyl) dithiophosphate (DHDTP), was investigated as depressant on the depression of chalcopyrite and galena, when ammonium dibutyl dithiophosphate (DDTP) was us...A novel synthesized reagent, O,O-bis(2,3-dihydroxypropyl) dithiophosphate (DHDTP), was investigated as depressant on the depression of chalcopyrite and galena, when ammonium dibutyl dithiophosphate (DDTP) was used as the collector in flotation tests. Zeta potential and adsorption measurement were performed to study the interaction between depressant and minerals. The flotation tests of two minerals show that DHDTP has slight depression on chalcopyrite in the whole pH range and strong depression on galena in the pH range of 6-10. When DHDTP dosage is increased, the recovery of galena decreases rapidly, while that of the chalcopyrite decreases slightly. The satisfied separation results of artificially mixed samples are that the copper grade and recovery rates of concentrate are 24.08% and 81%, respectively, when the pH is 6 with 278 mg/L DHDTP. Zeta potential and adsorption measurements show that DHDTP has more strongly adsorotion capacity to galena than chalcoovrite.展开更多
The effects of galvanic interaction between galena and pyrite on their flotation and electrochemical characters were studied by electrochemical,adsorption,flotation and FTIR techniques,respectively.Electrochemical tes...The effects of galvanic interaction between galena and pyrite on their flotation and electrochemical characters were studied by electrochemical,adsorption,flotation and FTIR techniques,respectively.Electrochemical tests indicate that galena is electrochemically more active than pyrite and serves as an anode in galvanic combination with pyrite.The galvanic current density from a mixture of galena and pyrite is 4 times as high as the self corrosion current density of galena,which indicates that the corrosion rate of galena is accelerated.Adsorption tests show that the adsorption of butyl xanthate on galena surface is enhanced,and affected by a combination of pyrite-galena mixtures and conditioning time.Compared with individual mineral particles,galvanic interaction reduces the floatability difference between galena and pyrite.The flotation recovery of galena decreases while that of pyrite increases when two minerals are mixed together due to the influence of galvanic interaction on the formation of hydrophilic/hydrophobic product.The FTIR results show that the formation of dixanthogen on pyrite surface is depressed due to the galvanic interaction.展开更多
Sodium 2,3-dihydroxypropyl dithiocarbonate(SGX), which contains —OH and —CSS— in the molecule, was used to explore selective depression of galena from chalcopyrite in the flotation tests with ammonium dibutyl dit...Sodium 2,3-dihydroxypropyl dithiocarbonate(SGX), which contains —OH and —CSS— in the molecule, was used to explore selective depression of galena from chalcopyrite in the flotation tests with ammonium dibutyl dithiophosphate(DDTP), and zeta potential and adsorption measurements were performed to study the interaction between SGX and minerals. The flotation tests of single minerals show that SGX has slight activation on chalcopyrite and strong depression on galena in the whole p H range. With SGX dosage increasing, the recovery of galena decreases rapidly, while that of chalcopyrite increases slightly. At p H=6, the copper grade and recovery of concentrate are 29.52% and 82.15% respectively when mixture of two minerals is tested. Zeta potential and adsorption measurements indicate that SGX has strong adsorption on galena and slight adsorption on chalcopyrite.展开更多
In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were i...In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were investigated. Single mineral flotation test was organized to research the effect of pulp pH value on the flotation behavior of galena and jamesonite. Electrochemistry property of the interaction of these two minerals with DDTC was investigated by cyclic voltammetry and Tafel tests. Flotation test shows that the recovery of jamesonite in high alkaline pulp is strongly depressed by lime (Ca(OH)2). The cyclic voltammetry and Tafel tests results show that the interaction between galena and DDTC is an electrochemical process. High pH value has little influence on the interaction between galena and DDTC, while it has great effect on jamesonite due to self-oxidation and specific adsorption of OH^- and CaOH^+ on jamesonite surface. Non-electroactive hydroxyl compound and low-electroconductive calcium compounds cover the surface of jamesonite, which impedes electron transfer and DDTC adsorption, thus leads to very low floatability of jamesonite.展开更多
The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respective...The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respectively,as a single depressant and their mixture as a combined depressant.Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant(>80%)within the studied dosage range.Galena flotation was severely depressed with descending depressing order as follows:combined depressant﹥sodium silicate﹥sodium sulfite.Electrochemical analysis confirmed the high affinity of depressants on the galena surface,resulting in the formation of hydrophilic species,such as lead sulfite,lead sulfate,and lead orthosilicate.The oxidation of chalcopyrite surface and depressants did not exhibit any signals;conversely,the self-oxidation of chalcopyrite was depressed.The results of cyclic voltammograms well agreed with flotation results,demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.展开更多
The depression mechanism of zinc sulfate(ZnSO4)and sodium dimethyl dithiocarbamate(DMDC)as the combined depressant on sphalerite was investigated by micro-flotation experiments,ion complexing tests,contact angle tests...The depression mechanism of zinc sulfate(ZnSO4)and sodium dimethyl dithiocarbamate(DMDC)as the combined depressant on sphalerite was investigated by micro-flotation experiments,ion complexing tests,contact angle tests and X-ray photoelectron spectroscopy(XPS)analysis.The micro-flotation tests revealed that ZnSO4+DMDC had a better selective depression effect on sphalerite than using single ZnSO4 or DMDC.Ion complexing tests confirmed that DMDC had a strong complexing capacity with lead ions or hydroxy complexes.Contact angle tests illustrated that ZnSO4+DMDC makes the sphalerite surface more hydrophilic than ZnSO4 or DMDC.XPS analysis indicated that the combined depressant could prevent collector adsorbing on the Pb-activated sphalerite surface by a competitive adsorption method,while the combined depressant and collector were co-adsorbed on galena surface.展开更多
Adsorbing tests between CN? and chalcopyrite or galena were conducted firstly, and then flotation tests of the twocyaniding minerals were investigated in butyl xanthate (BX) system. Results showed that the interaction...Adsorbing tests between CN? and chalcopyrite or galena were conducted firstly, and then flotation tests of the twocyaniding minerals were investigated in butyl xanthate (BX) system. Results showed that the interaction between CN? and the twomineral surfaces were both chemical adsorption and can be described by the Langmuir adsorption isotherm model. In the optimumcondition of pH 6.5 and 4.0 mg/L BX, the recovery of cyaniding chalcopyrite and galena reached 82.1% and 63.9%, respectively. BXimproved the hydrophobicity of the surfaces of the two minerals, although CN? reduced the contact angle on the surface of minerals.The inhibitory effect of CN? on chalcopyrite far outweighed galena. Electrostatic adsorption exists in the interaction between BX andthe surface of galena after cyanide treatment in the pH range of 4.2?8.4, while the interactions between BX and the surface ofchalcopyrite after cyanide treatment is chemical adsorption.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
Texture,geochemistry,and in-situ Pb isotope of galena were investigated to probe the origin of anomalous Ag enrichment in the Dayingezhuang Au(-Ag)deposit.Silver enrichment postdates the main Au mineralization and occ...Texture,geochemistry,and in-situ Pb isotope of galena were investigated to probe the origin of anomalous Ag enrichment in the Dayingezhuang Au(-Ag)deposit.Silver enrichment postdates the main Au mineralization and occurs in the south of the Dayingezhuang deposit.It is primarily associated with galena and the exsolution of Ag-rich sulfosalts(e.g.,matildite)in distal vein-ores related to steeply dipping brittle fractures.Silver-rich galena is characterized by the least radiogenic Pb isotope signature(^(206)Pb/^(204)Pb 17.195–17.258 and ^(208)Pb/^(204)Pb 37.706–37.793),possibly indicating a metasomatized lithospheric mantle or modified lower crustal source for Pb and Ag.Both of these mafic and ultramafic source regions have been previously suggested as Au reservoirs for other Jiaodong Au deposits,implying that the metal reservoir has only a weak control on the uneven Ag-enrichment.Since the Ag-enrichment areas are located in the footwalls of both the Dayingezhuang and Zhaoping faults,the enrichment was most likely dominated by local rotational stress during coeval movements of the two faults in a NE–SW compression and NW−SE extension regime.This work highlights the shallow-crust structural deformation responsible for controlling the flow of late ore-forming fluid resulting in local anomalous metal enrichment.展开更多
基金Project(51274255)supported by the National Natural Science Foundation of ChinaProject supported by the Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
文摘The flotabilities of chalcopyrite and galena with sodium humate(HA) and ammonium persulfate(APS) as the depressant were studied by flotation test, adsorption measurement and infrared spectroscopic analysis. Single mineral flotation test shows that the slurry oxidation environment and the proper oxidation of galena surface are prerequisites for the depression of galena by sodium humate. The closed-circuit flotation test of copper/lead bulk concentrate shows that the grade and recovery of Cu reach 30.47% and 89.16% respectively and those of Pb reach 2.06% and1.58% respectively in copper concentrate, and the grade and recovery of Pb reach 50.34% and 98.42% and those of Cu reach 1.45% and 10.84% respectively in lead concentrate with HA and APS. The selective depression effect of HA and APS is more obvious than that of potassium dichromate. The results of FTIR analysis and adsorption measurements indicate that the adsorption of sodium humate on the fresh surface of galena is negligible, while after oxidation, sodium humate can be chemically adsorbed on the surface of galena. According to the theory of solubility product, the sodium humate can display the oxidation product PbSO_4, after then, adsorb on the surface of lead chemically to produce inhibitory effect. Thus, it can be seen that the combination of HA and APS is an efficient non-toxic reagent to achieve cleaning separation copper/lead bulk concentrate by flotation. The combination of HA and APS is an efficient non-toxic reagent to achieve cleaning for copper/lead bulk concentrate by flotation.
基金Projects(51464006,51164001)supported by the National Natural Science Foundation of ChinaProject(GJR201147-12)supported by Guangxi Higher Education Institutes Talent Highland Innovation Team Scheme,ChinaProject(2012MDZD038)supported by the Key Scientific Research Project of Guangxi University for Nationalities,China
文摘Six kinds of galena with different impurities were synthesized and the effects of impurities on the floatability of galena were investigated. The thermodynamic and kinetic parameters on the galena surface were measured using microcalorimetry, and the adsorption configuration and energy of butyl xanthate on the surfaces of galena with different impurities were simulated by density functional theory. Flotation experiments showed that Ag and Bi significantly promoted the recovery of galena, while Zn, Sb, Mn, and Cu reduced the recovery of the flotation. Microthermokinetic results indicated that the absolute value of xanthate adsorption heat was directly proportional to the flotation recovery of galena. Adsorption heat and reaction rate coefficients of xanthate on galena containing Ag or Bi were larger than those on pure galena, but smaller on galena containing Cu or Sb. Additionally, the relationship between the heat of unsaturated adsorption of xanthate and the adsorption energy of impurity atom on galena surface was investigated.
基金Project(2008BAB34B01)supported by the National Key Technology R&D Program of China
文摘A novel synthesized reagent, O,O-bis(2,3-dihydroxypropyl) dithiophosphate (DHDTP), was investigated as depressant on the depression of chalcopyrite and galena, when ammonium dibutyl dithiophosphate (DDTP) was used as the collector in flotation tests. Zeta potential and adsorption measurement were performed to study the interaction between depressant and minerals. The flotation tests of two minerals show that DHDTP has slight depression on chalcopyrite in the whole pH range and strong depression on galena in the pH range of 6-10. When DHDTP dosage is increased, the recovery of galena decreases rapidly, while that of the chalcopyrite decreases slightly. The satisfied separation results of artificially mixed samples are that the copper grade and recovery rates of concentrate are 24.08% and 81%, respectively, when the pH is 6 with 278 mg/L DHDTP. Zeta potential and adsorption measurements show that DHDTP has more strongly adsorotion capacity to galena than chalcoovrite.
基金Project(51274255)supported by the National Natural Science Foundation of ChinaProject supported by the Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China
文摘The effects of galvanic interaction between galena and pyrite on their flotation and electrochemical characters were studied by electrochemical,adsorption,flotation and FTIR techniques,respectively.Electrochemical tests indicate that galena is electrochemically more active than pyrite and serves as an anode in galvanic combination with pyrite.The galvanic current density from a mixture of galena and pyrite is 4 times as high as the self corrosion current density of galena,which indicates that the corrosion rate of galena is accelerated.Adsorption tests show that the adsorption of butyl xanthate on galena surface is enhanced,and affected by a combination of pyrite-galena mixtures and conditioning time.Compared with individual mineral particles,galvanic interaction reduces the floatability difference between galena and pyrite.The flotation recovery of galena decreases while that of pyrite increases when two minerals are mixed together due to the influence of galvanic interaction on the formation of hydrophilic/hydrophobic product.The FTIR results show that the formation of dixanthogen on pyrite surface is depressed due to the galvanic interaction.
基金Project(2012BAB01B03)supported by National Key Technologies R&D Program of China
文摘Sodium 2,3-dihydroxypropyl dithiocarbonate(SGX), which contains —OH and —CSS— in the molecule, was used to explore selective depression of galena from chalcopyrite in the flotation tests with ammonium dibutyl dithiophosphate(DDTP), and zeta potential and adsorption measurements were performed to study the interaction between SGX and minerals. The flotation tests of single minerals show that SGX has slight activation on chalcopyrite and strong depression on galena in the whole p H range. With SGX dosage increasing, the recovery of galena decreases rapidly, while that of chalcopyrite increases slightly. At p H=6, the copper grade and recovery of concentrate are 29.52% and 82.15% respectively when mixture of two minerals is tested. Zeta potential and adsorption measurements indicate that SGX has strong adsorption on galena and slight adsorption on chalcopyrite.
基金Projects(5110417951374247)supported by the National Natural Science Foundation of China
文摘In order to effectively separate galena and jamesonite and improve the recovery during the mixing flotation, the interaction mechanisms between the minerals and the collector of diethyl dithiocarbamate (DDTC) were investigated. Single mineral flotation test was organized to research the effect of pulp pH value on the flotation behavior of galena and jamesonite. Electrochemistry property of the interaction of these two minerals with DDTC was investigated by cyclic voltammetry and Tafel tests. Flotation test shows that the recovery of jamesonite in high alkaline pulp is strongly depressed by lime (Ca(OH)2). The cyclic voltammetry and Tafel tests results show that the interaction between galena and DDTC is an electrochemical process. High pH value has little influence on the interaction between galena and DDTC, while it has great effect on jamesonite due to self-oxidation and specific adsorption of OH^- and CaOH^+ on jamesonite surface. Non-electroactive hydroxyl compound and low-electroconductive calcium compounds cover the surface of jamesonite, which impedes electron transfer and DDTC adsorption, thus leads to very low floatability of jamesonite.
基金Project(51374247)supported by the National Natural Science Foundation of ChinaProject(2015CX005)supported by Innovation Driven Plan of Central South University,China+1 种基金Project(B14034)supported by the National“111”Project,ChinaProject supported by the Open Sharing Fund for Large-scale Instruments and Equipment of Central South University and Collaborative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources,China。
文摘The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respectively,as a single depressant and their mixture as a combined depressant.Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant(>80%)within the studied dosage range.Galena flotation was severely depressed with descending depressing order as follows:combined depressant﹥sodium silicate﹥sodium sulfite.Electrochemical analysis confirmed the high affinity of depressants on the galena surface,resulting in the formation of hydrophilic species,such as lead sulfite,lead sulfate,and lead orthosilicate.The oxidation of chalcopyrite surface and depressants did not exhibit any signals;conversely,the self-oxidation of chalcopyrite was depressed.The results of cyclic voltammograms well agreed with flotation results,demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.
基金Projects(51974364,51904339)supported by the National Natural Science Foundation of ChinaProject(2018TP1002)supported by the Hunan Province for Clean and Efficiency Utilization of Strategic Calcium-containing Mineral,China。
文摘The depression mechanism of zinc sulfate(ZnSO4)and sodium dimethyl dithiocarbamate(DMDC)as the combined depressant on sphalerite was investigated by micro-flotation experiments,ion complexing tests,contact angle tests and X-ray photoelectron spectroscopy(XPS)analysis.The micro-flotation tests revealed that ZnSO4+DMDC had a better selective depression effect on sphalerite than using single ZnSO4 or DMDC.Ion complexing tests confirmed that DMDC had a strong complexing capacity with lead ions or hydroxy complexes.Contact angle tests illustrated that ZnSO4+DMDC makes the sphalerite surface more hydrophilic than ZnSO4 or DMDC.XPS analysis indicated that the combined depressant could prevent collector adsorbing on the Pb-activated sphalerite surface by a competitive adsorption method,while the combined depressant and collector were co-adsorbed on galena surface.
基金Project(2012BAB08B03)supported by the National Key Technologies R&D Program of China
文摘Adsorbing tests between CN? and chalcopyrite or galena were conducted firstly, and then flotation tests of the twocyaniding minerals were investigated in butyl xanthate (BX) system. Results showed that the interaction between CN? and the twomineral surfaces were both chemical adsorption and can be described by the Langmuir adsorption isotherm model. In the optimumcondition of pH 6.5 and 4.0 mg/L BX, the recovery of cyaniding chalcopyrite and galena reached 82.1% and 63.9%, respectively. BXimproved the hydrophobicity of the surfaces of the two minerals, although CN? reduced the contact angle on the surface of minerals.The inhibitory effect of CN? on chalcopyrite far outweighed galena. Electrostatic adsorption exists in the interaction between BX andthe surface of galena after cyanide treatment in the pH range of 4.2?8.4, while the interactions between BX and the surface ofchalcopyrite after cyanide treatment is chemical adsorption.
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 studying at Lakehead University by the CSU Special Scholarship for Study Abroad from Central South Universitysupported by the National Natural Science Foundation of China (Nos. 42030809, 41772349, 41972309, 42072325)the National Key R&D Program of China (No. 2017YFC0601503)
文摘Texture,geochemistry,and in-situ Pb isotope of galena were investigated to probe the origin of anomalous Ag enrichment in the Dayingezhuang Au(-Ag)deposit.Silver enrichment postdates the main Au mineralization and occurs in the south of the Dayingezhuang deposit.It is primarily associated with galena and the exsolution of Ag-rich sulfosalts(e.g.,matildite)in distal vein-ores related to steeply dipping brittle fractures.Silver-rich galena is characterized by the least radiogenic Pb isotope signature(^(206)Pb/^(204)Pb 17.195–17.258 and ^(208)Pb/^(204)Pb 37.706–37.793),possibly indicating a metasomatized lithospheric mantle or modified lower crustal source for Pb and Ag.Both of these mafic and ultramafic source regions have been previously suggested as Au reservoirs for other Jiaodong Au deposits,implying that the metal reservoir has only a weak control on the uneven Ag-enrichment.Since the Ag-enrichment areas are located in the footwalls of both the Dayingezhuang and Zhaoping faults,the enrichment was most likely dominated by local rotational stress during coeval movements of the two faults in a NE–SW compression and NW−SE extension regime.This work highlights the shallow-crust structural deformation responsible for controlling the flow of late ore-forming fluid resulting in local anomalous metal enrichment.