Flotation behavior and electronic simulations of rare earth minerals in the presence of dolomite supernatant using sodium oleate collector
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摘要
Common rare earth (RE) minerals, such as bastnasite and monazite, may be formed in deposits associated with carbonate gangue, such as calcite and dolomite. Sodium oleate is a widely used collector for the flotation of both RE and gangue minerals, which might, therefore, be an inefficient process due to the lack of selectivity of this collector. Since these minerals are also sparingly soluble in solution, they could release their constituent ions into the solution, which could affect the floatability of other minerals. In this study, the interactions of sodium oleate with bastn(a|¨)site and monazite in the presence of dissolved dolomite species have been investigated. Micro flotation tests were carried out to explore the effects of these dissolved species on the floatability of the RE minerals. Zeta potential measurements and XPS characterization were carried out to understand how the species affect the collector adsorption. To complement these characterizations, density functional theory (DFT) simulations were conducted to investigate the collector-mineral and collector-adsorbed species (on the mineral surface) interactions.The results show that collector-dolomite interaction energy is greater than that of collector-adsorbed species, but lower than collector-monazite interaction energy, explaining the decrease in the minerals’recovery upon exposure to the dissolved mineral species. It is also shown that oleate ions (OI~-) have the strongest interaction with the minerals compared to other oleate species such as acid soap (HOI_2~-) and oleate dimer (Ol_2~(2-)). The behavior (strength and selectivity) of sodium oleate towards RE minerals and dolomite, as compared to other RE mineral collectors (such as aromatic hydroxamate), is attributed mainly to the collector's and the minerals'structure. The long hydrocarbon chain of sodium oleate which imparts hydrophobic characteristic to the minerals, makes it stronger collector than benzohydroxamate.Moreover, sodium oleate (with linear structure), unlike the aromatic hydroxamate, can approach the mineral easier due to lesser steric hindrance effect and higher reactivity of O involved in the interaction,making it less selective. In addition, it can interact easily with dolomite due to the presence of more exposed active sites than RE minerals.
Common rare earth(RE) minerals, such as bastnasite and monazite, may be formed in deposits associated with carbonate gangue, such as calcite and dolomite. Sodium oleate is a widely used collector for the flotation of both RE and gangue minerals, which might, therefore, be an inefficient process due to the lack of selectivity of this collector. Since these minerals are also sparingly soluble in solution, they could release their constituent ions into the solution, which could affect the floatability of other minerals. In this study, the interactions of sodium oleate with bastnasite and monazite in the presence of dissolved dolomite species have been investigated. Microflotation tests were carried out to explore the effects of these dissolved species on the floatability of the RE minerals. Zeta potential measurements and XPS characterization were carried out to understand how the species affect the collector adsorption. To complement these characterizations, density functional theory(DFT) simulations were conducted to investigate the collector-mineral and collector-adsorbed species(on the mineral surface) interactions.The results show that collector-dolomite interaction energy is greater than that of collector-adsorbed species, but lower than collector-monazite interaction energy, explaining the decrease in the minerals' recovery upon exposure to the dissolved mineral species. It is also shown that oleate ions(OI~-) have the strongest interaction with the minerals compared to other oleate species such as acid soap(HOI_2~-) and oleate dimer(OI_2~(2-)). The behavior(strength and selectivity) of sodium oleate towards RE minerals and dolomite, as compared to other RE mineral collectors(such as aromatic hydroxamate), is attributed mainly to the collector's and the minerals' structure. The long hydrocarbon chain of sodium oleate which imparts hydrophobic characteristic to the minerals, makes it stronger collector than benzohydroxamate.Moreover, sodium oleate(with linear structure), unlike the aromatic hydroxamate, can approach the mineral easier due to lesser steric hindrance effect and higher reactivity of 0 involved in the interaction,making it less selective. In addition, it can interact easily with dolomite due to the presence of more exposed active sites than RE minerals.
Common rare earth(RE) minerals, such as bastnasite and monazite, may be formed in deposits associated with carbonate gangue, such as calcite and dolomite. Sodium oleate is a widely used collector for the flotation of both RE and gangue minerals, which might, therefore, be an inefficient process due to the lack of selectivity of this collector. Since these minerals are also sparingly soluble in solution, they could release their constituent ions into the solution, which could affect the floatability of other minerals. In this study, the interactions of sodium oleate with bastnasite and monazite in the presence of dissolved dolomite species have been investigated. Microflotation tests were carried out to explore the effects of these dissolved species on the floatability of the RE minerals. Zeta potential measurements and XPS characterization were carried out to understand how the species affect the collector adsorption. To complement these characterizations, density functional theory(DFT) simulations were conducted to investigate the collector-mineral and collector-adsorbed species(on the mineral surface) interactions.The results show that collector-dolomite interaction energy is greater than that of collector-adsorbed species, but lower than collector-monazite interaction energy, explaining the decrease in the minerals' recovery upon exposure to the dissolved mineral species. It is also shown that oleate ions(OI~-) have the strongest interaction with the minerals compared to other oleate species such as acid soap(HOI_2~-) and oleate dimer(OI_2~(2-)). The behavior(strength and selectivity) of sodium oleate towards RE minerals and dolomite, as compared to other RE mineral collectors(such as aromatic hydroxamate), is attributed mainly to the collector's and the minerals' structure. The long hydrocarbon chain of sodium oleate which imparts hydrophobic characteristic to the minerals, makes it stronger collector than benzohydroxamate.Moreover, sodium oleate(with linear structure), unlike the aromatic hydroxamate, can approach the mineral easier due to lesser steric hindrance effect and higher reactivity of 0 involved in the interaction,making it less selective. In addition, it can interact easily with dolomite due to the presence of more exposed active sites than RE minerals.
引文
1. Bulatovic SM. Handbook of flotation reagents:chemistry, theory and practice.In:Flotation of sulfide ores. vol. 1. Elsevier; 2007.
2. Wills BA, Finch JA. Froth flotation. In:Finch JA, Wills BA, eds. Wills'mineral processing technology. 8th ed. Boston:Butterworth-Heinemann; 2016:265.
3. Jordens A, Cheng YP, Waters KE. A review of the beneficiation of rare earth element bearing minerals. Miner Eng. 2013;41:97.
4. Yang ZR, Bian X, Wu WY. Flotation performance and adsorption mechanism of styrene phosphonic acid as a collector to synthetic(Ce,La)_2O_3. J Rare Earths.2017;35(6):621.
5. Li M, Gao K, Zhang DL, Duan HJ, Ma LL, Huang L. The influence of temperature on rare earth flotation with naphthyl hydroxamic acid.J Rare Earths.2018;36(1):99.
6. Fuerstenau, Jameson GJ, Yoon R-H. Froth flotation:a century of innovation. Littleton, CO:SME; 2007.
7. Zhang X, Du H, Wang XM, Miller JD. Surface chemistry considerations in the flotation of rare-earth and other semisoluble salt minerals. Miner Metall Process. 2013;30(1):24.
8. Zhang WC, Honaker RQ,Groppo JG. Flotation of monazite in the presence of calcite partⅠ:calcium ion effects on the adsorption of hydroxamic acid. Miner Eng. 2017;100:40.
9. Espiritu ERL, da Silva GR, Azizi D, Larachi F, Waters KE. The effect of dissolved mineral species on bastnasite, monazite and dolomite flotation using benzohydroxamate collector. Colloids Surf, A. 2018;539:319.
10. Predali J. Flotation of carbonates with salts of fatty acids:role of pH and the alkyl chain. Trans Inst Min Metall. 1969;78:C140.
11. Fuerstenau MC, Miller JD. The role of the hydrocarbon chain in anionic flotation of calcite.Trans AIME. 1967;238(2):153.
12. Somasundaran P,Ananthapadmanabhan K.Solution chemistry of surfactants and the role of it in adsorption and froth flotation in mineral-water systems. In:Mittal KL, ed. Solution chemistry of surfactants. vol. 2. New York, NY:Plenum;1979:17.
13. Pugh R, Stenius P. Solution chemistry studies and flotation behaviour of apatite,calcite and fluorite minerals with sodium oleate collector. Int J Miner Process.1985:15(3):193.
14. Kulkarni RD, Somasundaran P. Flotation chemistry of hematite/oleate system.Colloids Surf, A. 1980;1(3):387.
15. Gerdel M, Smith R. The role of lignin sulfonate in flotation of bastnasite from barite. In:Bautista RG,Wong MM, eds. Rare earths, extraction, preparation and applications. TMS; 1988.
16. Dixit S, Biswas A. pH-Dependence of the flotation and adsorption properties of some beach sand minerals. Trans Soc Mining Eng AIME. 1969;244(2):173.
17. Pradip Rai B, Rao TK, Krishnamurthy S, Vetrivel R, Mielczarski J, Cases JM.Molecular modeling of interactions of diphosphonic acid based surfactants with calcium minerals. Langmuir. 2002;18(3):932.
18. Pradip Rai B. Molecular modeling and rational design of flotation reagents. Int J Miner Process. 2003;72(1-4):95.
19. Rai B, Pradip. Design of highly selective industrial performance chemicals:a molecular modelling approach. Mol Simulat. 2008;34(10-15):1209.
20. Rai B. Molecular modeling for the design of novel performance chemicals and materials. New York, NY:CRC Press; 2012.
21. Rath SS, Sinha N, Sahoo H, Das B, Mishra BK. Molecular modeling studies of oleate adsorption on iron oxides. Appl Surf Sci. 2014;295:115.
22. Ataman E, Andersson MP, Ceccato M, Bovet N, Stipp SLS. Functional group adsorption on calcite:1. Oxygen containing and nonpolar organic molecules.J Phys Chem C. 2016;120(30):16586.
23. Ataman E, Andersson MP, Ceccato M, Bovet N, Stipp SLS. Functional group adsorption on calcite:Ⅱ. Nitrogen and sulfur containing organic molecules.J Phys Chem C. 2016;120(30):16597.
24. Predali J-J, Cases J-M. Zeta potential of magnesian carbonates in inorganic electrolytes. J Colloid Interface Sci 1973;45(3):449.
25. Chen G, Tao D. Effect of solution chemistry on flotability of magnesite and dolomite. Int J Miner Process. 2004;74(1-4):343.
26. Gans P. Hyperquad simulation and speciation(HySS). Leeds, England:Protonic Software; 2009.
27. Bonnitcha PD, Kim BJ, Hocking RK, Clegg JK, Turner P, Neville SM, et al. Cobalt complexes with tripodal ligands:implications for the design of drug chaperones. Dalton Trans. 2012;41(37):11293.
28. Albright TA, Burdett JK, Myung-Hwan Whangbo. Orbital interactions in chemistry. Hoboken, NJ:John Wiley&Sons; 2013.
29. Van Cappellen P, Charlet L, Stumm W, Wersin P. A surface complexation model of the carbonate mineral-aqueous solution interface. Geochem Cosmochim Acta.1993;57(15):3505.
30. Skvarla J, Kmet S. Non-equilibrium electrokinetic properties of magnesite and dolomite determined by the laser-Doppler electrophoretic light scattering(ELS)technique. A solids concentration effect. Colloids Surf, A. 1996;111(1):153.
2. Wills BA, Finch JA. Froth flotation. In:Finch JA, Wills BA, eds. Wills'mineral processing technology. 8th ed. Boston:Butterworth-Heinemann; 2016:265.
3. Jordens A, Cheng YP, Waters KE. A review of the beneficiation of rare earth element bearing minerals. Miner Eng. 2013;41:97.
4. Yang ZR, Bian X, Wu WY. Flotation performance and adsorption mechanism of styrene phosphonic acid as a collector to synthetic(Ce,La)_2O_3. J Rare Earths.2017;35(6):621.
5. Li M, Gao K, Zhang DL, Duan HJ, Ma LL, Huang L. The influence of temperature on rare earth flotation with naphthyl hydroxamic acid.J Rare Earths.2018;36(1):99.
6. Fuerstenau, Jameson GJ, Yoon R-H. Froth flotation:a century of innovation. Littleton, CO:SME; 2007.
7. Zhang X, Du H, Wang XM, Miller JD. Surface chemistry considerations in the flotation of rare-earth and other semisoluble salt minerals. Miner Metall Process. 2013;30(1):24.
8. Zhang WC, Honaker RQ,Groppo JG. Flotation of monazite in the presence of calcite partⅠ:calcium ion effects on the adsorption of hydroxamic acid. Miner Eng. 2017;100:40.
9. Espiritu ERL, da Silva GR, Azizi D, Larachi F, Waters KE. The effect of dissolved mineral species on bastnasite, monazite and dolomite flotation using benzohydroxamate collector. Colloids Surf, A. 2018;539:319.
10. Predali J. Flotation of carbonates with salts of fatty acids:role of pH and the alkyl chain. Trans Inst Min Metall. 1969;78:C140.
11. Fuerstenau MC, Miller JD. The role of the hydrocarbon chain in anionic flotation of calcite.Trans AIME. 1967;238(2):153.
12. Somasundaran P,Ananthapadmanabhan K.Solution chemistry of surfactants and the role of it in adsorption and froth flotation in mineral-water systems. In:Mittal KL, ed. Solution chemistry of surfactants. vol. 2. New York, NY:Plenum;1979:17.
13. Pugh R, Stenius P. Solution chemistry studies and flotation behaviour of apatite,calcite and fluorite minerals with sodium oleate collector. Int J Miner Process.1985:15(3):193.
14. Kulkarni RD, Somasundaran P. Flotation chemistry of hematite/oleate system.Colloids Surf, A. 1980;1(3):387.
15. Gerdel M, Smith R. The role of lignin sulfonate in flotation of bastnasite from barite. In:Bautista RG,Wong MM, eds. Rare earths, extraction, preparation and applications. TMS; 1988.
16. Dixit S, Biswas A. pH-Dependence of the flotation and adsorption properties of some beach sand minerals. Trans Soc Mining Eng AIME. 1969;244(2):173.
17. Pradip Rai B, Rao TK, Krishnamurthy S, Vetrivel R, Mielczarski J, Cases JM.Molecular modeling of interactions of diphosphonic acid based surfactants with calcium minerals. Langmuir. 2002;18(3):932.
18. Pradip Rai B. Molecular modeling and rational design of flotation reagents. Int J Miner Process. 2003;72(1-4):95.
19. Rai B, Pradip. Design of highly selective industrial performance chemicals:a molecular modelling approach. Mol Simulat. 2008;34(10-15):1209.
20. Rai B. Molecular modeling for the design of novel performance chemicals and materials. New York, NY:CRC Press; 2012.
21. Rath SS, Sinha N, Sahoo H, Das B, Mishra BK. Molecular modeling studies of oleate adsorption on iron oxides. Appl Surf Sci. 2014;295:115.
22. Ataman E, Andersson MP, Ceccato M, Bovet N, Stipp SLS. Functional group adsorption on calcite:1. Oxygen containing and nonpolar organic molecules.J Phys Chem C. 2016;120(30):16586.
23. Ataman E, Andersson MP, Ceccato M, Bovet N, Stipp SLS. Functional group adsorption on calcite:Ⅱ. Nitrogen and sulfur containing organic molecules.J Phys Chem C. 2016;120(30):16597.
24. Predali J-J, Cases J-M. Zeta potential of magnesian carbonates in inorganic electrolytes. J Colloid Interface Sci 1973;45(3):449.
25. Chen G, Tao D. Effect of solution chemistry on flotability of magnesite and dolomite. Int J Miner Process. 2004;74(1-4):343.
26. Gans P. Hyperquad simulation and speciation(HySS). Leeds, England:Protonic Software; 2009.
27. Bonnitcha PD, Kim BJ, Hocking RK, Clegg JK, Turner P, Neville SM, et al. Cobalt complexes with tripodal ligands:implications for the design of drug chaperones. Dalton Trans. 2012;41(37):11293.
28. Albright TA, Burdett JK, Myung-Hwan Whangbo. Orbital interactions in chemistry. Hoboken, NJ:John Wiley&Sons; 2013.
29. Van Cappellen P, Charlet L, Stumm W, Wersin P. A surface complexation model of the carbonate mineral-aqueous solution interface. Geochem Cosmochim Acta.1993;57(15):3505.
30. Skvarla J, Kmet S. Non-equilibrium electrokinetic properties of magnesite and dolomite determined by the laser-Doppler electrophoretic light scattering(ELS)technique. A solids concentration effect. Colloids Surf, A. 1996;111(1):153.