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 impr...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 de-scribe 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 compon-ents 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.展开更多
High-entropy REBa_(2)Cu_(3)O_(7-δ)(RE=Y_(0.7)+Dy_(0.2)+Gd_(0.2)+Sm_(0.2)+Eu_(0.2))(HE-REBCO) superconducting films doped with multiple rare earth elements were successfully fabricated with thickness up to 800 nm by a...High-entropy REBa_(2)Cu_(3)O_(7-δ)(RE=Y_(0.7)+Dy_(0.2)+Gd_(0.2)+Sm_(0.2)+Eu_(0.2))(HE-REBCO) superconducting films doped with multiple rare earth elements were successfully fabricated with thickness up to 800 nm by a trifluoroacetate-metal organic deposition(TFA-MOD).The enhanced entropy change ΔS of the HEREBCO system promotes the c-axis growth of REBCO thin film in the competition with a/b-axis growth.The microstructure and element distribution were investigated by the transmission electron microscopy(TEM) and energy dispersive spectroscopy(EDS).The results show that HE-REBCO films have a great amount of stacking defects,lattice distortions and various rare earth oxides.Furthermore,the microstrain of HE-REBCO films increases significantly compared to the undoped YBCO and(Y,Dy)BCO films.Finally,the superco nducting critical temperature(T_c^(onset)) of HE-REBCO films is about 93 K,and the in-field properties are significantly improved,especially at the temperature of about 77 K.The maximum pinning force density(F_(p,max)) of the HE-REBCO samples at 77 K is 1.7 times higher than that of the undoped YBCO films.展开更多
基金supported by the Yunnan Science and Technology Leading Talent Project(No.202305AB350005)National Science Foundation for Young Scientists of China(No.51404118).
文摘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 de-scribe 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 compon-ents 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.
基金Project supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB25000000)National Natural Science Foundation of China (52172271)。
文摘High-entropy REBa_(2)Cu_(3)O_(7-δ)(RE=Y_(0.7)+Dy_(0.2)+Gd_(0.2)+Sm_(0.2)+Eu_(0.2))(HE-REBCO) superconducting films doped with multiple rare earth elements were successfully fabricated with thickness up to 800 nm by a trifluoroacetate-metal organic deposition(TFA-MOD).The enhanced entropy change ΔS of the HEREBCO system promotes the c-axis growth of REBCO thin film in the competition with a/b-axis growth.The microstructure and element distribution were investigated by the transmission electron microscopy(TEM) and energy dispersive spectroscopy(EDS).The results show that HE-REBCO films have a great amount of stacking defects,lattice distortions and various rare earth oxides.Furthermore,the microstrain of HE-REBCO films increases significantly compared to the undoped YBCO and(Y,Dy)BCO films.Finally,the superco nducting critical temperature(T_c^(onset)) of HE-REBCO films is about 93 K,and the in-field properties are significantly improved,especially at the temperature of about 77 K.The maximum pinning force density(F_(p,max)) of the HE-REBCO samples at 77 K is 1.7 times higher than that of the undoped YBCO films.
