1 Introduction Lithium resources are widely distributed in the oilfield brine from the Nanyishan district in the Qaidam Basin(Fan et al.,2007).The investigation of the thermodynamics and phase diagram of the brine sys...1 Introduction Lithium resources are widely distributed in the oilfield brine from the Nanyishan district in the Qaidam Basin(Fan et al.,2007).The investigation of the thermodynamics and phase diagram of the brine system is valuable in providing the theoretic foundation and scientific guidance in the comprehensive exploitation of the mixture salts effectively.Comprehensive展开更多
Using isothermal dissolution method,the phase equilibrium relationship in quaternary system LiCl+NaCl+KCl+H2O and the ternary subsystem LiCl+NaCl+H2O at 288.15 K were investigated.Each phase diagram of two systems was...Using isothermal dissolution method,the phase equilibrium relationship in quaternary system LiCl+NaCl+KCl+H2O and the ternary subsystem LiCl+NaCl+H2O at 288.15 K were investigated.Each phase diagram of two systems was drawn.The phase diagram of LiCl+NaCl+H2O system contains two solid phase regions of crystallization LiCl·2H2O and NaCl.In the phase diagram of LiCl+NaCl+KCl+H2O system,there are three crystallization regions:LiCl·2H2O,NaCl and KCl respectively.In this paper,the solubilities of phase equilibria in two systems were calculated by Pitzer's model at 288.15 K.The predicted phase diagrams generally agree with the experimental phase diagrams.展开更多
The gradient solar pond technique is an economic separating process employed in the inorganic chemical industrial production of salt lake chemical engineering processes. In this paper, a novel isothermal evaporation e...The gradient solar pond technique is an economic separating process employed in the inorganic chemical industrial production of salt lake chemical engineering processes. In this paper, a novel isothermal evaporation experimental method was employed to simulate the evaporation phase equilibrium for the reciprocal quaternary system (LiCl+NaCl+Li2SO4+Na2SO 4+H2O) at 348.15 K to serve as a useful guide for lithium salt production via the depth solar ponds.The isothermal evaporation equilibrium solubilities and physicochemical properties,including the densities and pH values, were experimentally investigated. The dry-salt phase diagram,water-phase diagram, and the diagram of the physicochemical properties versus composition were plotted with respect to the experimental data. The dry-salt phase diagram consists of three invariant points,seven univariant solubility curves, and five crystallization regions, specifically halite(NaCl,Ha),thenardite (Na2SO4,Th),double salt (Li2SO4 · Na2SO4 , Db2), lithium sulfate monohydrate (Li2SO4 ·H2O, Ls), and lithium chloride monohydrate(LiCl·H2O, Lc). Based on Pitzer and its extended HMW model, the Pitzer single salt parameters, mixing ion interaction parameters, and thermodynamic stable equilibrium constants for the quaternary system at 348.15 K were obtained. The calculated phase diagram and experimental isothermal phase diagram at 348.15 K exhibited a great difference. Based on these results, the isothermal evaporation phase diagram can truly reflect the salt sedimentary in salt lakes and can be applied as a useful guide for the solar pond process.展开更多
基金Supported by the NNSFCs (21276194 and 21306136)the Key Pillar Program of Tianjin Municipal S&T (11ZCKGX02800)the Specialised Research Fund for the Doctoral Program of Chinese Higher Education (20101208110003)
文摘1 Introduction Lithium resources are widely distributed in the oilfield brine from the Nanyishan district in the Qaidam Basin(Fan et al.,2007).The investigation of the thermodynamics and phase diagram of the brine system is valuable in providing the theoretic foundation and scientific guidance in the comprehensive exploitation of the mixture salts effectively.Comprehensive
基金supported by the National Natural Science Foundation of China(41903051)the Natural Science Foundation of Qinghai Province(2020-ZJ-970Q)+1 种基金“Thousand Talents Program for High-end Innovative Talents”of Qinghai ProvinceCAS“Light of West China”Program。
文摘Using isothermal dissolution method,the phase equilibrium relationship in quaternary system LiCl+NaCl+KCl+H2O and the ternary subsystem LiCl+NaCl+H2O at 288.15 K were investigated.Each phase diagram of two systems was drawn.The phase diagram of LiCl+NaCl+H2O system contains two solid phase regions of crystallization LiCl·2H2O and NaCl.In the phase diagram of LiCl+NaCl+KCl+H2O system,there are three crystallization regions:LiCl·2H2O,NaCl and KCl respectively.In this paper,the solubilities of phase equilibria in two systems were calculated by Pitzer's model at 288.15 K.The predicted phase diagrams generally agree with the experimental phase diagrams.
基金National Natural Science Foundation of China(U1607123,21773170 and U1707602)the Key Projects of Natural Science Foundation of Tianjin(18JCZDJC10040)the Yangtze Scholars and Innovative Research Team of the Chinese University(IRT_17R81)
文摘The gradient solar pond technique is an economic separating process employed in the inorganic chemical industrial production of salt lake chemical engineering processes. In this paper, a novel isothermal evaporation experimental method was employed to simulate the evaporation phase equilibrium for the reciprocal quaternary system (LiCl+NaCl+Li2SO4+Na2SO 4+H2O) at 348.15 K to serve as a useful guide for lithium salt production via the depth solar ponds.The isothermal evaporation equilibrium solubilities and physicochemical properties,including the densities and pH values, were experimentally investigated. The dry-salt phase diagram,water-phase diagram, and the diagram of the physicochemical properties versus composition were plotted with respect to the experimental data. The dry-salt phase diagram consists of three invariant points,seven univariant solubility curves, and five crystallization regions, specifically halite(NaCl,Ha),thenardite (Na2SO4,Th),double salt (Li2SO4 · Na2SO4 , Db2), lithium sulfate monohydrate (Li2SO4 ·H2O, Ls), and lithium chloride monohydrate(LiCl·H2O, Lc). Based on Pitzer and its extended HMW model, the Pitzer single salt parameters, mixing ion interaction parameters, and thermodynamic stable equilibrium constants for the quaternary system at 348.15 K were obtained. The calculated phase diagram and experimental isothermal phase diagram at 348.15 K exhibited a great difference. Based on these results, the isothermal evaporation phase diagram can truly reflect the salt sedimentary in salt lakes and can be applied as a useful guide for the solar pond process.
