A new magnesium borate 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O has been synthesized by the method of phase transformation of double salt under hydrothermal condition and characterized by XRD,IR,Raman spectra and TG. Th...A new magnesium borate 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O has been synthesized by the method of phase transformation of double salt under hydrothermal condition and characterized by XRD,IR,Raman spectra and TG. The enthalpy of solution of 2MgO· B_ 2 O_ 3 ·1.5H_ 2 O in 2.9842 mol·L -1 HCl was determined. From a combination of this result with measured enthalpies of solution of H_ 3 BO_ 3 in 2.9842 mol·L -1 HCl(aq.) and of MgO in (HCl+H_ 3 BO_ 3 ) solution,together with the standard molar enthalpies of formation of MgO(s),H_ 3 BO_ 3 (s),and H_ 2 O(l),the standard molar enthalpy of formation of -(3019.76±1.79) kJ· mol -1 of 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O was obtained.展开更多
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
基金ProjectsupportedbytheNaturalScienceFoundationofShaanxiProvinceofChina (No .2 0 0 2B13 )
文摘A new magnesium borate 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O has been synthesized by the method of phase transformation of double salt under hydrothermal condition and characterized by XRD,IR,Raman spectra and TG. The enthalpy of solution of 2MgO· B_ 2 O_ 3 ·1.5H_ 2 O in 2.9842 mol·L -1 HCl was determined. From a combination of this result with measured enthalpies of solution of H_ 3 BO_ 3 in 2.9842 mol·L -1 HCl(aq.) and of MgO in (HCl+H_ 3 BO_ 3 ) solution,together with the standard molar enthalpies of formation of MgO(s),H_ 3 BO_ 3 (s),and H_ 2 O(l),the standard molar enthalpy of formation of -(3019.76±1.79) kJ· mol -1 of 2MgO·B_ 2 O_ 3 ·1.5H_ 2 O was obtained.
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.
