Thermodynamic theory of flotation for a complex multiphase solid–liquid system and high-entropy flotation

Abstract

The flotation of complex solid–liquid multiphase systems involve interactions among multiple components, the core problem facing flotation theory. Meanwhile, the combined use of multicomponent flotation reagents to improve mineral flotation has become an important issue in studies on the efficient use of refractory mineral resources. However, studying the flotation of complex solid–liquid systems is extremely difficult, and no systematic theory has been developed to date. In addition, the physical mechanism associated with combining reagents to improve the flotation effect has not been unified, which limits the development of flotation theory and the progress of flotation technology. In this study, we applied theoretical thermodynamics to a solid–liquid flotation system and used changes in the entropy and Gibbs free energy of the reagents adsorbed on the mineral surface to establish thermodynamic equilibrium equations that describe interactions among various material components while also introducing adsorption equilibrium constants for the flotation reagents adsorbed on the mineral surface. The homogenization effect on the mineral surface in pulp solution was determined using the chemical potentials of the material components of the various mineral surfaces required to maintain balance. The flotation effect can be improved through synergy among multicomponent flotation reagents; its physical essence is the thermodynamic law that as the number of components of flotation reagents on the mineral surface increases, the surface adsorption entropy change increases, and the Gibbs free energy change of adsorption decreases. According to the results obtained using flotation thermodynamics theory, we established high-entropy flotation theory and a technical method in which increasing the types of flotation reagents adsorbed on the mineral surface, increasing the adsorption entropy change of the flotation reagents, decreasing the Gibbs free energy change, and improving the adsorption efficiency and stability of the flotation reagents improves refractory mineral flotation.

Keywords

multicomponent flotation reagent / adsorption entropy change / equations of thermodynamic equilibrium / adsorption equilibrium constant / high-entropy flotation

References

[[1]] Mehrabani JV, Mousavi SM, Noaparast M. Evaluation of the replacement of NaCN with Acidithiobacillus ferrooxidans in the flotation of high-pyrite, low-grade lead-zinc ore. Sep. Purif. Technol., 2011, 80(2): 202,

[[2]] Yin WZ, Zhang LR, Xie F. Flotation of Xinhua molybdenite using sodium sulfide as modifier. Trans. Nonferrous Met. Soc. China, 2010, 20(4): 702,

[[3]] Cao QB, Wen SM, Li CX, Bai SJ, Liu D. Investigation on molybdenite separation from a complex sulfide ore. Adv. Mater. Res., 2013, 634–638: 3408,

[[4]] B.Q. Yang, H. Yan, M.Y. Zeng, P.L. Huang, F.F. Jia, and A.P. Teng, A novel copper depressant for selective flotation of chalcopyrite and molybdenite, Miner. Eng., 151(2020), art. No. 106309.

[[5]] R.P. Liao, Q.C. Feng, S.M. Wen, and J. Liu, Flotation separation of molybdenite from chalcopyrite using ferrate (VI) as selective depressant in the absence of a collector, Miner. Eng., 152(2020), art. No. 106369.

[[6]] Y. Chen, X.M. Chen, and Y.J. Peng, The depression of molybdenite flotation by sodium metabisulphite in fresh water and seawater, Miner. Eng., 168 (2021), art. No. 106939.

[[7]] Taheri B, Abdollahy M, Tonkaboni SZS, Javadian S, Yarahmadi M. Dual effects of sodium sulfide on the flotation behavior of chalcopyrite: I. Effect of pulp potential. Int. J. Miner. Metall. Mater., 2014, 21(5): 415,

[[8]] Qiu XM, Yang HY, Chen GB, Tong LL, Jin ZN, Zhang Q. Interface behavior of chalcopyrite during flotation from cyanide tailings. Int. J. Miner. Metall. Mater., 2022, 29(3): 439,

[[9]] J.M. Hao, J. Liu, Y.L. Yu, H.L. Gao, X.Y. Qin, and X. Bai, Depressants for separation of chalcopyrite and molybdenite: Review and prospects, Miner. Eng., 201(2023), art. No. 108209.

[[10]] Yin ZG, Sun W, Hu YH, Zhai JH, Guan QJ. Evaluation of the replacement of NaCN with depressant mixtures in the separation of copper–molybdenum sulphide ore by flotation. Sep. Purif. Technol., 2017, 173: 9,

[[11]] Yin ZG, Sun W, Liu JD, et al.. Investigation into the flotation response of refractory molybdenum ore to depressant mixtures: A case study. Int. J. Min. Sci. Technol., 2016, 26(6): 1089,

[[12]] Chen X, Gu GH, Chen ZX. Seaweed glue as a novel polymer depressant for the selective separation of chalcopyrite and galena. Int. J. Miner. Metall. Mater., 2019, 26(12): 1495,

[[13]] Yu JS, Liu RQ, Wang L, Sun W, Peng H, Hu YH. Selective depression mechanism of ferric chromium lignin sulfonate for chalcopyrite–galena flotation separation. Int. J. Miner. Metall. Mater., 2018, 25(5): 489,

[[14]] Lu L, Liang S, Zhang XR, Zhu YG, Hu Z, Wang CX. Advanced research on galena depressant in copper–lead sulfides flotation separation. Conserv. Util. Miner. Resour., 2020, 40(2): 105

[[15]] Sun RF, Liu D, Du Y, Zhang BY, Guo R, Wen SM. Research status and development of separation of chalcopyrite and galena. Multipurpose Util. Miner. Resour., 2021, 4: 80

[[16]] Chen JH, Feng QM, Lu YP. Research on a new organic depressant ASC for separation chalcopyrite and galena. Multipurpose Util. Miner. Resour., 2000, 5: 39

[[17]] Ai GH, Xie ZF, Yan HS, Zhong JF, Huang X. Experimental study on mineral processing of a copper lead zinc polymetallic mine in inner Mongolia. Nonferrous Met. Miner. Process. Sec., 2015, 3: 15

[[18]] Pu ZJ, Wei DZ, Lv XJ, Kou XY. Advanced research on depressants used for flotation separation of Cu–Pb sulfide minerals. Multipurpose Util. Miner. Resour., 2018, 4: 13

[[19]] Yu L, Liu QJ, Yuan HW, Gao Y, Song JW. Flotation separation of copper–lead mixed concentrate. J. Kunming Univ. Technol. Nat. Sci., 2017, 42(1): 26

[[20]] Zhang Y, Liu RQ, Sun W, Wang L, Dong YH, Wang CT. Electrochemical mechanism and flotation of chalcopyrite and galena in the presence of sodium silicate and sodium sulfite. Trans. Nonferrous Met. Soc. China, 2020, 30(4): 1091,

[[21]] Xu LH, Tian J, Wu HQ, Lu ZY, Sun W, Hu YH. The flotation and adsorption of mixed collectors on oxide and silicate minerals. Adv. Colloid Interface Sci., 2017, 250: 1,

[[22]] Rosen MJ, Gu B. Synergism in binary mixtures of surfactants. 6. Interfacial tension reduction efficiency at the liquid/hydrophobic solid interface. Colloids Surf., 1987, 23(1–2): 119,

[[23]] Zhou Q, Somasundaran P. Synergistic adsorption of mixtures of cationic gemini and nonionic sugar-based surfactant on silica. J. Colloid Interface Sci., 2009, 331(2): 288,

[[24]] Wu DD, Wen SM, Liu J, Shen HY, Bai SJ. The effect of mixed collectors on zinc oxide flotation. Adv. Mater. Res., 2012, 524–527: 1124,

[[25]] Wang Z, Huang SK, Xiao JH. Influence of head-group size of combined collectors on their performance in floating smithsonite. Min. Metall. Eng., 2020, 40(4): 49

[[26]] Wang L, Hu GY, Sun W, Khoso SA, Liu RQ, Zhang XF. Selective flotation of smithsonite from dolomite by using novel mixed collector system. Trans. Nonferrous Met. Soc. China, 2019, 29(5): 1082,

[[27]] Mehdilo A, Irannajad M, Zarei H. Flotation of zinc oxide ore using cationic cationic and cationic–anionic mixed collectors. Physicochem. Probl. Miner. Process., 2013, 49: 145

[[28]] Hosseini SH, Forssberg E. Physicochemical studies of smithsonite flotation using mixed anionic/cationic collector. Miner. Eng., 2007, 20(6): 621,

[[29]] Zhang ZH, Zhang XH, Ye ZP, Dai ZL, Tong JT, Guo JG. The study on new technique for flotation of wolfram from Shizhuyuan polymetallic ores using GY method. Min. Metall. Eng., 1999, 19(4): 22

[[30]] Xiao QS, Li CG, Kang GY. Study on technological flowsheets for flotation process of Shizhuyuan polymetallic ore with CF method. Min. Metall., 1996, 5(3): 26

[[31]] Z. Wei, W. Sun, H.S. Han, X.H. Gui, and Y.W. Xing, Flotation chemistry of scheelite and its practice: A comprehensive review, Miner. Eng., 204(2023), art. No. 108404.

[[32]] Zhang YZ, Gu GH, Wu XB, Zhao KL. Selective depression behavior of guar gum on talc-type scheelite flotation. Int. J. Miner. Metall. Mater., 2017, 24(8): 857,

[[33]] Wang ZM, Feng B, Chen YG. Flotation separation depressants for scheelite and calcium-bearing minerals: A review. Int. J. Miner. Metall. Mater., 2023, 30(9): 1621,

[[34]] Zhao G, Wang S, Zhong H. Study on the activation of scheelite and wolframite by lead nitrate. Minerals, 2015, 5(2): 247,

[[35]] Dong LY, Jiao F, Qin WQ, Zhu HL, Jia WH. Activation effect of lead ions on scheelite flotation: Adsorption mechanism, AFM imaging and adsorption model. Sep. Purif. Technol., 2019, 209: 955,

[[36]] Han HS, Hu YH, Sun W, et al.. Fatty acid flotation versus BHA flotation of tungsten minerals and their performance in flotation practice. Int. J. Miner. Process., 2017, 159: 22,

[[37]] J.J. Wang, Z.Y. Gao, H.S. Han, W. Sun, Y.S. Gao, and S. Ren, Impact of NaOL as an accelerator on the selective separation of scheelite from fluorite using a novel self-assembled Pb–BHA–NaOL collector system, Appl. Surf. Sci., 537(2021), art. No. 147778.

[[38]] Z. Wei, W. Sun, H.S. Han, G.R. Liu, J.H. Fu, and Y.W. Xing, Probing a colloidal lead-group multiple ligand collector and its adsorption on a mineral surface, Miner. Eng., 160(2021), art. No. 106696.

[[39]] Zhao C, Sun CY, Zhu YG, Zhu YM, Yin WZ. Study of the mechanism of the Fe–BHA chelates in scheelite flotation. Minerals, 2022, 12(4): 484,

[[40]] Wang X, Wen SM, Zuo Q, et al.. Interaction of manganese ions with scheelite surfaces and its effect on collector adsorption and flotation. Separations, 2022, 9(11): 365,

[[41]] Cai JZ, Deng JS, Wang L, et al.. Reagent types and action mechanisms in ilmenite flotation: A review. Int. J. Miner. Metall. Mater., 2022, 29(9): 1656,

[[42]] Ma FY, Zhang P, Tao DP. Surface nanobubble characterization and its enhancement mechanisms for fine-particle flotation: A review. Int. J. Miner. Metall. Mater., 2022, 29(4): 727,

[[43]] Feng QC, Wen SM, Zhao WJ, Chen HT. Interaction mechanism of magnesium ions with cassiterite and quartz surfaces and its response to flotation separation. Sep. Purif. Technol., 2018, 206: 239,

[[44]] Q. Wei, L.Q. Feng, L.Y. Dong, F. Jiao, and W.Q. Qin, Selective co-adsorption mechanism of a new mixed collector on the flotation separation of lepidolite from quartz, Colloids Surf. A: Physicochem. Eng. Aspects, 612(2021), art. No. 125973.

[[45]] Fang S, Xu LH, Wu HQ, et al.. Comparative studies of flotation and adsorption of Pb(II)/benzohydroxamic acid collector complexes on ilmenite and titanaugite. Powder Technol., 2019, 345: 35,

[[46]] Li FX, Zhong H, Zhao G, Wang S, Liu GY. Adsorption of α-hydroxyoctyl phosphonic acid to ilmenite/water interface and its application in flotation. Colloids Surf. A, 2016, 490: 67,

[[47]] Liu WJ, Zhang J, Wang WQ, et al.. Flotation behaviors of ilmenite, titanaugite, and forsterite using sodium oleate as the collector. Miner. Eng., 2015, 72: 1,

[[48]] Xu LH, Tian J, Wu HQ, Yi FC, Dong FQ. A review on the synergetic effect of the mixed collectors on mineral surface and its application in flotation. Conserv. Util. Miner. Resour., 2017, 2: 107

[[49]] D.X. Zhang, J.H. Kang, and W.X. Zhu, Selective flotation separation of fluorite and calcite by utilising a novel anionic/nonionic collector, Colloids Surf. A: Physicochem. Eng. Aspects, 642(2022), art. No. 128687.

[[50]] Y.C. Miao, S.M. Wen, Q. Zuo, Z.H. Shen, Q. Zhang, and Q.C. Feng, Co-adsorption of NaOL/SHA composite collectors on cassiterite surfaces and its effect on surface hydrophobicity and floatability, Sep. Purif. Technol., 308(2023), art. No. 122954.