The simulation of blast furnace slag was prepared by pure chemical reagents.Test methods like DSC,XRD and SEM were used to study the effect of Al2O3 and MgO content on crystallization of blast furnace slag during fibe...The simulation of blast furnace slag was prepared by pure chemical reagents.Test methods like DSC,XRD and SEM were used to study the effect of Al2O3 and MgO content on crystallization of blast furnace slag during fiber formation.The results show that as Al2O3 and MgO contents in the sample changed,blast furnace slag was crystallized at the average temperature below 1232 K.When the ratio of Mg/Al in the samples is 0.6 calculated by Kissinger equation,crystallization activation energy is at the maximum value and the system is in the most stable condition.The sample crystallization phases are mainly calcium akermanite(2CaO?MgO?2SiO2)and gehlenite(2CaO?Al2O3?SiO2).Secondary crystallization phases are anorthite(CaAl2Si2O8),wollastonite minerals(WOLLA)and pyroxene minerals(cPyrA).Meanwhile,the principal crystallization phases of the samples are different types and have different contents,and the microstructures of the sample sections are different due to the difference between MgO/Al2O3 ratio.展开更多
There is quite abundant resource of ludwigite ore in Liaoning Province of China. Content of MgO in the slag of pyrometallurgical separation of boron from iron is much higher than that in the ordinary slags. Through th...There is quite abundant resource of ludwigite ore in Liaoning Province of China. Content of MgO in the slag of pyrometallurgical separation of boron from iron is much higher than that in the ordinary slags. Through the equilibrium partition ratio of sulfur L S between the metal and the slag in an atmosphere of CO N 2, the acidic coefficients for B 2O 3 and the basic coefficients for MgO were estimated. The basic formulae were given for the blast furnace type slag containing B 2O 3 and high MgO.展开更多
The CaO–SiO_(2)–Al_(2)O_(3)–MgO system is the main component unit in the slag formation process in blast furnace smelting.Its structural changes directly affect the high-temperature metallurgical properties of slag...The CaO–SiO_(2)–Al_(2)O_(3)–MgO system is the main component unit in the slag formation process in blast furnace smelting.Its structural changes directly affect the high-temperature metallurgical properties of slag.Molecular dynamics simulations were thus conducted to analyze the microstructure changes of the quaternary slag system under different basicities and w(MgO)/w(Al_(2)O_(3))ratios.The changes in w(MgO)/w(Al_(2)O_(3))ratio and basicity could affect the stability of each ion-oxygen.Increasing the basicity and w(MgO)/w(Al_(2)O_(3))ratio,the average coordination number of O surrounding Si atom only changed a little and remained approximately 4,indicating that Si exists as a stable structure of the[SiO4]4−tetrahedron in the slag structure,while the average coordination number of O surrounding Al atom changed greatly from 4 to 6,which indicated that the Al existence form could be transformed from[AlO_(4)]^(5−) tetrahedron to[AlO_(5)]^(7−) pentahedron and[AlO_(6)]^(9−) octahedron.Also,the diffusion rate of ions was accelerated with the increase in w(MgO)/w(Al_(2)O_(3))ratio and basicity.Moreover,the self-diffusion coefficients of each ion were obtained,and the magnitudes were observed to be in the following order:Mg^(2+)>Ca^(2+)>Al^(3+)>Si^(4+).The calculation and analysis of the slag viscosity and activation energy of viscous flow under different basicities and w(MgO)/w(Al_(2)O_(3))ratios revealed that the metallurgical properties of slag at high temperature depend on the flow-unit diffusivity and the microstructure stability,simultaneously,the basicity should be controlled between 1.0 and 1.2,and the w(MgO)/w(Al_(2)O_(3))ratio could be controlled between 0.45 and 0.55.展开更多
基金Project(51474090)supported by the National Natural Science Foundation of China
文摘The simulation of blast furnace slag was prepared by pure chemical reagents.Test methods like DSC,XRD and SEM were used to study the effect of Al2O3 and MgO content on crystallization of blast furnace slag during fiber formation.The results show that as Al2O3 and MgO contents in the sample changed,blast furnace slag was crystallized at the average temperature below 1232 K.When the ratio of Mg/Al in the samples is 0.6 calculated by Kissinger equation,crystallization activation energy is at the maximum value and the system is in the most stable condition.The sample crystallization phases are mainly calcium akermanite(2CaO?MgO?2SiO2)and gehlenite(2CaO?Al2O3?SiO2).Secondary crystallization phases are anorthite(CaAl2Si2O8),wollastonite minerals(WOLLA)and pyroxene minerals(cPyrA).Meanwhile,the principal crystallization phases of the samples are different types and have different contents,and the microstructures of the sample sections are different due to the difference between MgO/Al2O3 ratio.
文摘There is quite abundant resource of ludwigite ore in Liaoning Province of China. Content of MgO in the slag of pyrometallurgical separation of boron from iron is much higher than that in the ordinary slags. Through the equilibrium partition ratio of sulfur L S between the metal and the slag in an atmosphere of CO N 2, the acidic coefficients for B 2O 3 and the basic coefficients for MgO were estimated. The basic formulae were given for the blast furnace type slag containing B 2O 3 and high MgO.
基金The authors received financial support from the National Natural Science Foundation of China(No.51874171)University of Science and Technology Liaoning Talent Project Grants(No.601011507-05)Project of"Xingliao Talents Plan"of Liaoning Province(XLYC1902092).
文摘The CaO–SiO_(2)–Al_(2)O_(3)–MgO system is the main component unit in the slag formation process in blast furnace smelting.Its structural changes directly affect the high-temperature metallurgical properties of slag.Molecular dynamics simulations were thus conducted to analyze the microstructure changes of the quaternary slag system under different basicities and w(MgO)/w(Al_(2)O_(3))ratios.The changes in w(MgO)/w(Al_(2)O_(3))ratio and basicity could affect the stability of each ion-oxygen.Increasing the basicity and w(MgO)/w(Al_(2)O_(3))ratio,the average coordination number of O surrounding Si atom only changed a little and remained approximately 4,indicating that Si exists as a stable structure of the[SiO4]4−tetrahedron in the slag structure,while the average coordination number of O surrounding Al atom changed greatly from 4 to 6,which indicated that the Al existence form could be transformed from[AlO_(4)]^(5−) tetrahedron to[AlO_(5)]^(7−) pentahedron and[AlO_(6)]^(9−) octahedron.Also,the diffusion rate of ions was accelerated with the increase in w(MgO)/w(Al_(2)O_(3))ratio and basicity.Moreover,the self-diffusion coefficients of each ion were obtained,and the magnitudes were observed to be in the following order:Mg^(2+)>Ca^(2+)>Al^(3+)>Si^(4+).The calculation and analysis of the slag viscosity and activation energy of viscous flow under different basicities and w(MgO)/w(Al_(2)O_(3))ratios revealed that the metallurgical properties of slag at high temperature depend on the flow-unit diffusivity and the microstructure stability,simultaneously,the basicity should be controlled between 1.0 and 1.2,and the w(MgO)/w(Al_(2)O_(3))ratio could be controlled between 0.45 and 0.55.
