High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase co...High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase compositions were measured by electron probe microanalysis(EPMA).A series of pseudo-ternary and pseudo-binary phase diagrams are constructed to demonstrate their applications in copper smelting process and evaluation of the thermodynamic database.Spinel and tridymite are identified to be the major primary phases in the composition range related to the copper smelting slags.It is found that the operating window of the smelting slag is primarily determined by w_(Fe)/w_(SiO_(2))ratio in the slag.Both MgO and Al_(2)O_(3)in the slag reduce the operating window which requires extra fluxing agent to keep the slag to be fully liquid.Complex spinel solid solutions cause inaccurate predictions of the current thermodynamic database.展开更多
The equilibrium phase relations of the CaO–SiO_(2)–TiO_(2)–5wt%Fe_(3)O_(4)system were experimentally investigated at 1400℃ in air High-temperature equilibration-quenching techniques were employed in an electric Mo...The equilibrium phase relations of the CaO–SiO_(2)–TiO_(2)–5wt%Fe_(3)O_(4)system were experimentally investigated at 1400℃ in air High-temperature equilibration-quenching techniques were employed in an electric MoSi2resistance heated furnace,with phase composition analysis conducted using an electron probe microanalyzer and X-ray diffraction.A single liquid region,liquid–solid phase equilibria regions (including liquid–tridymite,liquid–rutile,liquid–perovskite,and liquid–wollastonite),and three-phase equilibria regions of liquid–tridymite–rutile and liquid–rutile–perovskite were found.The 1400℃ isothermal sections of the CaO-SiO_(2)-TiO_(2)-5wt%Fe_(3)O_(4)system in air were projected.The present experimental results exhibited good agreement with the calculation results obtained from FactSage.展开更多
In order to obtain the crystalline forms of the salts of the potassium,ammonium,calcium coexisting chloride system,the phase equilibria relationship of quaternary system K^(+),NH_(4)^(+),Ca^(2+)//Cl^(-)-H_(2)O at 298....In order to obtain the crystalline forms of the salts of the potassium,ammonium,calcium coexisting chloride system,the phase equilibria relationship of quaternary system K^(+),NH_(4)^(+),Ca^(2+)//Cl^(-)-H_(2)O at 298.2,323.2,and 348.2 K was studied by isothermal dissolution equilibrium method.The solubility and density of equilibrium liquid phases of the system were experimentally determined;X-ray powder diffractometer was used to determine the compositions of the equilibrium solid phase at the quaternary invariant point.It is found that the quaternary system is a complex system at these three temperatures.The phase diagram at 298.2 K consists of three invariant points,seven univariate curves and five crystalline phase regions,forming the solid solutions(NH_(4)Cl)_(x)(KCl)_(1-x) and(KCl)_(x)(NH_(4)Cl)_(1-x);while at 323.2 and 348.2 K the phase diagram consists of five invariant points,eleven univariate curves and seven crystalline phase regions,the double salts(KClCaCl_(2))and(2NH_(4)Cl·CaCl_(2)·3H_(2)O),solid solutions(KCl)_(x)(NH_(4)Cl)_(1-x) and(NH_(4)Cl)_(x)(KCl)_(1-x) were formed.Among them,the crystalline phase region of solid solution(KCl)_(x)(NH_(4)Cl)_(1-x) is the largest at three temperatures,indicating that it is the easiest to crystallize in this system.Comparing the phase diagrams of the quaternary system at 298.2,323.2,and 348.2 K,it can be seen that the crystalline form of CaCl_(2) changes with the increase of temperature:CaCl_(2)·6H_(2)O at 298.2 K,CaCl_(2)·2H_(2)O at 323.2 and 348.2 K.From 323.2 to 348.2 K,the crystalline phase regions of(KCl·CaCl_(2))and(2NH_(4)Cl·CaCl_(2)·3H_(2)O)increased gradually.展开更多
In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction,a large amount of phase equilibrium data were collected in the context of the actual process of butadiene p...In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction,a large amount of phase equilibrium data were collected in the context of the actual process of butadiene production by acetonitrile.The accuracy of five prediction methods,UNIFAC(UNIQUAC Functional-group Activity Coefficients),UNIFAC-LL,UNIFAC-LBY,UNIFAC-DMD and COSMO-RS,applied to the butadiene extraction process was verified using partial phase equilibrium data.The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system.COSMO-RS-predicted multiple systems showed good accuracy,and a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method.The predicted phase equilibrium data were checked for consistency.The NRTL-RK(non-Random Two Liquid-Redlich-Kwong Equation of State)and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data.Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process.The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2%compared to that using the commercial simulation software,Aspen Plus and its database.The average deviation was much smaller than that of the simulations using the Aspen Plus database(>10%),indicating that the obtained phase equilibrium data are highly accurate and reliable.The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided.This improves the accuracy and reliability of the design,optimization and control of the process,and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.展开更多
文摘High-temperature experiments were carried out for the slag systems of“FeO”−SiO_(2)−CaO−Al_(2)O_(3)and“FeO”−SiO_(2)−CaO−MgO at 1200℃and p(O_(2))of 10^(−7)kPa.The equilibrated samples were quenched,and the phase compositions were measured by electron probe microanalysis(EPMA).A series of pseudo-ternary and pseudo-binary phase diagrams are constructed to demonstrate their applications in copper smelting process and evaluation of the thermodynamic database.Spinel and tridymite are identified to be the major primary phases in the composition range related to the copper smelting slags.It is found that the operating window of the smelting slag is primarily determined by w_(Fe)/w_(SiO_(2))ratio in the slag.Both MgO and Al_(2)O_(3)in the slag reduce the operating window which requires extra fluxing agent to keep the slag to be fully liquid.Complex spinel solid solutions cause inaccurate predictions of the current thermodynamic database.
基金financially supported from the National Natural Science Foundation of China (No. 52204310)the National Key Research and Development Program of China (No. 2021YFC2901000)+4 种基金the China Postdoctoral Science Foundation (Nos. 2020TQ0059 and 2020M570967)the Natural Science Foundation of Liaoning Province, China (No. 2021-MS-083)the Fundamental Research Funds for the Central Universities, China (No. N2125010)the Open Project Program of Key Laboratory of Metallurgical Emission Reduction & Resources Recycling (Anhui University of Technology), Ministry of Education, China (No. JKF22-02)the Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education, China。
文摘The equilibrium phase relations of the CaO–SiO_(2)–TiO_(2)–5wt%Fe_(3)O_(4)system were experimentally investigated at 1400℃ in air High-temperature equilibration-quenching techniques were employed in an electric MoSi2resistance heated furnace,with phase composition analysis conducted using an electron probe microanalyzer and X-ray diffraction.A single liquid region,liquid–solid phase equilibria regions (including liquid–tridymite,liquid–rutile,liquid–perovskite,and liquid–wollastonite),and three-phase equilibria regions of liquid–tridymite–rutile and liquid–rutile–perovskite were found.The 1400℃ isothermal sections of the CaO-SiO_(2)-TiO_(2)-5wt%Fe_(3)O_(4)system in air were projected.The present experimental results exhibited good agreement with the calculation results obtained from FactSage.
基金Supported by the National Key Research and Development Program of China(2023YFC2906503)Sichuan Province Science and Technology Support Program(2023ZYD0036).
文摘In order to obtain the crystalline forms of the salts of the potassium,ammonium,calcium coexisting chloride system,the phase equilibria relationship of quaternary system K^(+),NH_(4)^(+),Ca^(2+)//Cl^(-)-H_(2)O at 298.2,323.2,and 348.2 K was studied by isothermal dissolution equilibrium method.The solubility and density of equilibrium liquid phases of the system were experimentally determined;X-ray powder diffractometer was used to determine the compositions of the equilibrium solid phase at the quaternary invariant point.It is found that the quaternary system is a complex system at these three temperatures.The phase diagram at 298.2 K consists of three invariant points,seven univariate curves and five crystalline phase regions,forming the solid solutions(NH_(4)Cl)_(x)(KCl)_(1-x) and(KCl)_(x)(NH_(4)Cl)_(1-x);while at 323.2 and 348.2 K the phase diagram consists of five invariant points,eleven univariate curves and seven crystalline phase regions,the double salts(KClCaCl_(2))and(2NH_(4)Cl·CaCl_(2)·3H_(2)O),solid solutions(KCl)_(x)(NH_(4)Cl)_(1-x) and(NH_(4)Cl)_(x)(KCl)_(1-x) were formed.Among them,the crystalline phase region of solid solution(KCl)_(x)(NH_(4)Cl)_(1-x) is the largest at three temperatures,indicating that it is the easiest to crystallize in this system.Comparing the phase diagrams of the quaternary system at 298.2,323.2,and 348.2 K,it can be seen that the crystalline form of CaCl_(2) changes with the increase of temperature:CaCl_(2)·6H_(2)O at 298.2 K,CaCl_(2)·2H_(2)O at 323.2 and 348.2 K.From 323.2 to 348.2 K,the crystalline phase regions of(KCl·CaCl_(2))and(2NH_(4)Cl·CaCl_(2)·3H_(2)O)increased gradually.
基金supported by the National Natural Science Foundation of China(22178190)。
文摘In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction,a large amount of phase equilibrium data were collected in the context of the actual process of butadiene production by acetonitrile.The accuracy of five prediction methods,UNIFAC(UNIQUAC Functional-group Activity Coefficients),UNIFAC-LL,UNIFAC-LBY,UNIFAC-DMD and COSMO-RS,applied to the butadiene extraction process was verified using partial phase equilibrium data.The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system.COSMO-RS-predicted multiple systems showed good accuracy,and a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method.The predicted phase equilibrium data were checked for consistency.The NRTL-RK(non-Random Two Liquid-Redlich-Kwong Equation of State)and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data.Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process.The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2%compared to that using the commercial simulation software,Aspen Plus and its database.The average deviation was much smaller than that of the simulations using the Aspen Plus database(>10%),indicating that the obtained phase equilibrium data are highly accurate and reliable.The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided.This improves the accuracy and reliability of the design,optimization and control of the process,and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.
