Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell: Mo [Mo+MoOu[ZrO2(MgO)[Fe+(CaO-SiO2-Al2O3-MgO-FeO)+Ag[Fe. The influences of slag com...Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell: Mo [Mo+MoOu[ZrO2(MgO)[Fe+(CaO-SiO2-Al2O3-MgO-FeO)+Ag[Fe. The influences of slag compositions and basicity on FeO activities were analyzed. The results reveal that, for slags of fixed (%CaO)/(%SiO2) ratio, MgO and Al2O3 content, there was an increase of FeO activities with increase of FeO content. For slags with constant {(%CaO)+ (%MgO)}/(%SiO2) ratio, fixed FeO and A1203 content, FeO activities decreased when MgO content increased from 5% to 10%, and increased with the increase of MgO content when it was over 10%. The FeO activities increased when (%CaO)/(%SiO2) ratio changed from 1.03 to 1.30 in the slags of constant MgO, FeO and Al2O3 content.展开更多
The sulphide capacity of CaO-SiO2-Al2O3-MgO-FetO slags was studied at 1773 K using gas-slag equilibrium techniques. Utilizing a Pt crucible, the slag was equilibrated with a mixture of gases, namely, CO, CO2, SO2 and ...The sulphide capacity of CaO-SiO2-Al2O3-MgO-FetO slags was studied at 1773 K using gas-slag equilibrium techniques. Utilizing a Pt crucible, the slag was equilibrated with a mixture of gases, namely, CO, CO2, SO2 and N2 to provide the partial pressure of oxygen and sulphur. It was shown that at fixed FetO and Al2O3 contents and a fixed { (%CaO)+(%MgO)}/(%SIO2) ratio, the sulphide capacity decreases with increasing MgO content. At a constant (%CaO)/(%SiO2) ratio and constant MgO and Al2O3 contents, increasing the FetO content of the slags also results in an increase of the sulphide capacity. The rising basicity of (%CaO)/(%SiO2) from 1.0 to 1.4 at fixed MgO, FetO and Al2O3 contents significantly increases the sulphide capacity.展开更多
微纳米α-Al2O3是一种重要的功能材料,因其优异的硬度、耐磨性、耐腐蚀性和高热稳定性,在表面涂层领域得到了广泛应用。随着微纳米技术的发展,微纳米级α-Al2O3作为添加剂在各涂层体系中的应用得到了深入研究,显示出其能够显著改善涂层...微纳米α-Al2O3是一种重要的功能材料,因其优异的硬度、耐磨性、耐腐蚀性和高热稳定性,在表面涂层领域得到了广泛应用。随着微纳米技术的发展,微纳米级α-Al2O3作为添加剂在各涂层体系中的应用得到了深入研究,显示出其能够显著改善涂层性能的潜力。微纳米α-Al2O3颗粒具有较大的比表面积和表面活性,能够增强涂层的机械性能,如硬度和耐磨性,同时提高涂层的耐腐蚀性和耐高温性能。微纳米α-Al2O3也是一种极优良的改性材料,其与有机硅烷、树脂等材料复合改性,既能大幅提升转化膜的应用效果,对其稳定性和耐候性也有较大的促进作用。在金属表面涂层、陶瓷涂层以及复合材料涂层中,微纳米α-Al2O3添加剂被广泛用于提高涂层的使用寿命和稳定性。此外,它在电子器件、航天航空和汽车工业等高技术领域也展现了广阔的应用前景。未来,随着表面技术的发展,微纳米α-Al2O3无铬钝化领域的市场应用将大幅增长,与其他功能性材料的协同作用和复合材料开发也将成为研究的重点。Micro-nano α-Al2O3 is an important functional material, because of its excellent hardness, wear resistance, corrosion resistance and high thermal stability, has been widely used in the field of surface coating. With the development of micro-nano technology, the application of micro-nano α-Al2O3 as an additive in various coating systems has been deeply studied, showing its potential to significantly improve coating properties. Micro-nano α-Al2O3 particles have a large specific surface area and surface activity, which can enhance the mechanical properties of the coating, such as hardness and wear resistance, while improving the corrosion resistance and high temperature resistance of the coating. Micro-nano α-Al2O3 is also an excellent modified material, and its composite modification with organosilane, resin and other materials can greatly improve the application effect of conversion film, and also has a greater role in promoting its stability and weather resistance. In metal surface coatings, ceramic coatings and composite coatings, micro-nano α-Al2O3 additives are widely used to improve the service life and stability of coatings. In addition, it also shows broad application prospects in high-tech fields such as electronic devices, aerospace and automotive industries. In the future, with the development of surface technology, the market application of micro-nano α-Al2O3 chromium-free passivation will grow significantly, and the synergy with other functional materials and the development of composite materials will also become the focus of research.展开更多
CaO-SiO2-Al2O3-MgO-Fex O slag occurs in the production process of Corex ironmaking technology. Most of its metallurgical properties, especially the phosphorus property, are different from the slag produced from blast ...CaO-SiO2-Al2O3-MgO-Fex O slag occurs in the production process of Corex ironmaking technology. Most of its metallurgical properties, especially the phosphorus property, are different from the slag produced from blast furnace or converter. In order to explore the dephosphorization ability of CaO-SiO2-Al2O3-MgO-Fex O slag, its phosphorus capacity was measured at 1673 K by gas-slag-metal equilibrium technique. An iron crucible was used as the reaction vessel, Ag alloy with 0.2 % P was used as the metal phase which equilibrated with CaO-SiO2-Al2O3-MgO-Fex O slag, and a constant flow of CO-CO2-N2 gas was used to provide oxygen partial pressure in the experi- ment. The effects of MgO, Fex O and basicity on slag phosphorus capacity were investigated by single factor test. The results show that the phosphorus capacity rises firstly and then decreases with increasing MgO content under the condition of basicity 1.3, Fe2 O content of 20% and A12 03 content of 12%. The phosphorus value reaches maximum as the MgO content is 8%. When the basicity of slag is 1.1, MgO content is 10%, and Al2O3 is 12%, the phos- phorus capacity increases with the increase of Fe, O content. The phosphorus capacity rises linearly when the basicity is increased from 1.1 to 1. 5.展开更多
The effects of MgO/Al2 O3 ratio on the viscous behaviors of MgO-Al2 O3-TiO2-CaO-SiO2 systems were investigated by the rotating cylinder method.Raman spectroscopy was used to analyze the structural characteristics of s...The effects of MgO/Al2 O3 ratio on the viscous behaviors of MgO-Al2 O3-TiO2-CaO-SiO2 systems were investigated by the rotating cylinder method.Raman spectroscopy was used to analyze the structural characteristics of slag and Factsage 7.0 was adopted to demonstrate the liquidus temperature of slag.The results show that the viscosity and activation energy for viscous flow decrease when the MgO/Al2O3 ratio increases from 0.82 to 1.36.The break point temperature and liquidus temperature of slag initially decrease and subsequently increase.The complex viscous structures are gradually depolymerized to simple structural units.In conclusion,with the increase of MgO/Al2O3 ratio,the degree of polymerization of slag decreases,which improves the fluidity of slag.The variations of liquidus temperature of slag lead to the same changes of break point temperature.展开更多
The reduction rate of Fe^tO in CaOSiO_2Al_2O_3Fe_tO slags with graphite powder has been determined in an alumina crucible at 1 673-1 823 K. The effects of temperature, slag basicity and Fe_tO content on th...The reduction rate of Fe^tO in CaOSiO_2Al_2O_3Fe_tO slags with graphite powder has been determined in an alumina crucible at 1 673-1 823 K. The effects of temperature, slag basicity and Fe_tO content on the reduction rate have also been discussed. Test results show that the reduction rate increases with the increase of temperature or Fe_tO concentration in slags, and the reduction rate has a parabolic relation with slag simple basicity or optical basicity. The maximum reduction rate is observed around CaO/SiO_2=1.5 of molten slags. The reaction order is 1.26 or 1.31, and the reduction activation energy is 126.8 or 129.7 kJ/mol respectively in regard to Fe_tO content or Fe_tO activity calculated by using regular solution model. The reduction rate of Fe_tO in CaOSiO_2Al_2O_3Fe_tO slags with graphite powder is in the range of 0.15×10^-4-0.86×10^-4 molO/cm^2·s.展开更多
目的:检测γ-Fe2O3纳米粒表面油酸的残留量,考察油酸残留量对纳米粒磁共振T1造影效果的影响。方法:采用热分解法制备γ-Fe2O3纳米粒,使用mPEG-P取代γ-Fe2O3纳米粒表面的油酸,得到水溶性的γ-Fe2O3-PEG纳米粒,采用高效液相色谱法测定纳...目的:检测γ-Fe2O3纳米粒表面油酸的残留量,考察油酸残留量对纳米粒磁共振T1造影效果的影响。方法:采用热分解法制备γ-Fe2O3纳米粒,使用mPEG-P取代γ-Fe2O3纳米粒表面的油酸,得到水溶性的γ-Fe2O3-PEG纳米粒,采用高效液相色谱法测定纳米粒表面残留的油酸,并在7T磁共振成像仪下考察油酸残留量与纳米粒T1造影效果的关联。最后,对体外造影效果最优的样品进行了体内磁共振成像测试。结果:建立了油酸的高效液相色谱检测方法,油酸在10~400 μg/mL浓度范围内具有良好的线性关系(r2 = 1),平均回收率为99.86%。通过改变γ-Fe2O3与mPEG-P的投料比,得到γ-Fe2O3-PEG纳米粒表面油酸残留个数分别为100、83、56、33的样品。体外磁共振成像结果表明,油酸残留量较少的纳米粒拥有更好的T1加权成像性能。小鼠体内血管造影显示,本研究制备的γ-Fe2O3-PEG纳米粒与临床使用的钆类造影剂相比,拥有更好的血管成像效果。结论:本研究成果为热分解法制备的氧化铁纳米粒表面油酸的定量分析提供了一种有效的检测方法,以促进该类纳米粒在生物医学领域的应用。Objective: Detection of residual oleic acid on the surface of γ-Fe2O3 nanoparticles and investigation of its impact on magnetic resonance T1 imaging. Method: We prepared γ-Fe2O3 nanoparticles via thermal decomposition, with mPEG-P replacing the oleic acid on the surface of the nanoparticles to yield water-soluble γ-Fe2O3-PEG nanoparticles. The residual oleic acid on the surface of the nanoparticles was quantified using High-Performance Liquid Chromatography, and the relationship between the amount of residual oleic acid and the T1 contrast effect of the nanoparticles was investigated using a 7T magnetic resonance imaging system. Finally, the vivo magnetic resonance imaging of the sample exhibiting the optimal in vitro contrast effect was conducted. Results: We developed a High-Performance Liquid Chromatography method for the detection of oleic acid, demonstrating a strong linear correlation in the concentration range of 10~400 μg/mL (r² = 1) with an average recovery rate of 99.86%. By varying the ratio of γ-Fe2O3 to mPEG-P, samples with oleic acid on the surface of γ-Fe2O3-PEG nanoparticles were obtained, with respective counts of 100, 83, 56, and 33. In vitro magnetic resonance imaging demonstrated that nanoparticles with lower residual oleic acid exhibited enhanced T1-weighted imaging performance. In vivo vascular imaging in mice demonstrated that the γ-Fe2O3-PEG nanoparticles prepared in this study provided better imaging results compared to commercially available gadolinium-based contrast agents. Conclusions: This study presents an effective detection method for the quantitative analysis of oleic acid on the surface of iron oxide nanoparticles synthesized via a thermolytic approach, thereby facilitating the application of such nanoparticles in the biomedical field.展开更多
Fluorite is widely employed as fluxing agent in metallurgy flux , which inevitably leads to serious fluorine pollution.B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3steelmaking fluxes to substitute for CaF2.The e...Fluorite is widely employed as fluxing agent in metallurgy flux , which inevitably leads to serious fluorine pollution.B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3steelmaking fluxes to substitute for CaF2.The effects of B2O3 and CaF2 on the melting properties of this system were investigated.The melting temperatures of fluxes including softening temperature (Ts), hemispherical temperature (Th), and flow temperature (Tf) were measured using the hemisphere method.The results indicate that the fluxing effect of B2O3is more significant than that of CaF2 .When the addition amount of B2O3 (mass percent) exceeds 6% , the melting temperatures of fluxes including Ts , Th and Tf are decreased lower than 1 300℃.The basicity of fluxes has a significant effect on the melting temperature , and the melting temperatures of the fluxes increase with the increase of fluxes basicity.However , when B2O3 is used as fluxing agent , the melting temperature changes little with the basicity increasing from 2.5 to 5.0. These characteristics are suitable for steelmaking process.Moreover , Fe2O3 has an important fluxing effect on this CaO-based steelmaking fluxes.This indicates that the fluxes system is suitable for steelmaking process.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.50574036)
摘要Activities of FeO in CaO-SiO2-Al2O3-MgO-FeO slags were determined at 1673 K by electrochemical of the solid electrolyte cell: Mo [Mo+MoOu[ZrO2(MgO)[Fe+(CaO-SiO2-Al2O3-MgO-FeO)+Ag[Fe. The influences of slag compositions and basicity on FeO activities were analyzed. The results reveal that, for slags of fixed (%CaO)/(%SiO2) ratio, MgO and Al2O3 content, there was an increase of FeO activities with increase of FeO content. For slags with constant {(%CaO)+ (%MgO)}/(%SiO2) ratio, fixed FeO and A1203 content, FeO activities decreased when MgO content increased from 5% to 10%, and increased with the increase of MgO content when it was over 10%. The FeO activities increased when (%CaO)/(%SiO2) ratio changed from 1.03 to 1.30 in the slags of constant MgO, FeO and Al2O3 content.
基金This project was financially supported by the National Natural Science Foundation of China (No.50574036) and Natural Science Foun-dation of HeBei Province, China (No.502267).
摘要The sulphide capacity of CaO-SiO2-Al2O3-MgO-FetO slags was studied at 1773 K using gas-slag equilibrium techniques. Utilizing a Pt crucible, the slag was equilibrated with a mixture of gases, namely, CO, CO2, SO2 and N2 to provide the partial pressure of oxygen and sulphur. It was shown that at fixed FetO and Al2O3 contents and a fixed { (%CaO)+(%MgO)}/(%SIO2) ratio, the sulphide capacity decreases with increasing MgO content. At a constant (%CaO)/(%SiO2) ratio and constant MgO and Al2O3 contents, increasing the FetO content of the slags also results in an increase of the sulphide capacity. The rising basicity of (%CaO)/(%SiO2) from 1.0 to 1.4 at fixed MgO, FetO and Al2O3 contents significantly increases the sulphide capacity.
摘要微纳米α-Al2O3是一种重要的功能材料,因其优异的硬度、耐磨性、耐腐蚀性和高热稳定性,在表面涂层领域得到了广泛应用。随着微纳米技术的发展,微纳米级α-Al2O3作为添加剂在各涂层体系中的应用得到了深入研究,显示出其能够显著改善涂层性能的潜力。微纳米α-Al2O3颗粒具有较大的比表面积和表面活性,能够增强涂层的机械性能,如硬度和耐磨性,同时提高涂层的耐腐蚀性和耐高温性能。微纳米α-Al2O3也是一种极优良的改性材料,其与有机硅烷、树脂等材料复合改性,既能大幅提升转化膜的应用效果,对其稳定性和耐候性也有较大的促进作用。在金属表面涂层、陶瓷涂层以及复合材料涂层中,微纳米α-Al2O3添加剂被广泛用于提高涂层的使用寿命和稳定性。此外,它在电子器件、航天航空和汽车工业等高技术领域也展现了广阔的应用前景。未来,随着表面技术的发展,微纳米α-Al2O3无铬钝化领域的市场应用将大幅增长,与其他功能性材料的协同作用和复合材料开发也将成为研究的重点。Micro-nano α-Al2O3 is an important functional material, because of its excellent hardness, wear resistance, corrosion resistance and high thermal stability, has been widely used in the field of surface coating. With the development of micro-nano technology, the application of micro-nano α-Al2O3 as an additive in various coating systems has been deeply studied, showing its potential to significantly improve coating properties. Micro-nano α-Al2O3 particles have a large specific surface area and surface activity, which can enhance the mechanical properties of the coating, such as hardness and wear resistance, while improving the corrosion resistance and high temperature resistance of the coating. Micro-nano α-Al2O3 is also an excellent modified material, and its composite modification with organosilane, resin and other materials can greatly improve the application effect of conversion film, and also has a greater role in promoting its stability and weather resistance. In metal surface coatings, ceramic coatings and composite coatings, micro-nano α-Al2O3 additives are widely used to improve the service life and stability of coatings. In addition, it also shows broad application prospects in high-tech fields such as electronic devices, aerospace and automotive industries. In the future, with the development of surface technology, the market application of micro-nano α-Al2O3 chromium-free passivation will grow significantly, and the synergy with other functional materials and the development of composite materials will also become the focus of research.
基金Item Sponsored by the State Key Program of National Natural Science Foundation of China(U1360205)National Natural Science Foundation of China(51174074)
摘要CaO-SiO2-Al2O3-MgO-Fex O slag occurs in the production process of Corex ironmaking technology. Most of its metallurgical properties, especially the phosphorus property, are different from the slag produced from blast furnace or converter. In order to explore the dephosphorization ability of CaO-SiO2-Al2O3-MgO-Fex O slag, its phosphorus capacity was measured at 1673 K by gas-slag-metal equilibrium technique. An iron crucible was used as the reaction vessel, Ag alloy with 0.2 % P was used as the metal phase which equilibrated with CaO-SiO2-Al2O3-MgO-Fex O slag, and a constant flow of CO-CO2-N2 gas was used to provide oxygen partial pressure in the experi- ment. The effects of MgO, Fex O and basicity on slag phosphorus capacity were investigated by single factor test. The results show that the phosphorus capacity rises firstly and then decreases with increasing MgO content under the condition of basicity 1.3, Fe2 O content of 20% and A12 03 content of 12%. The phosphorus value reaches maximum as the MgO content is 8%. When the basicity of slag is 1.1, MgO content is 10%, and Al2O3 is 12%, the phos- phorus capacity increases with the increase of Fe, O content. The phosphorus capacity rises linearly when the basicity is increased from 1.1 to 1. 5.
基金Projects(51574067,51904063)supported by the National Natural Science Foundation of ChinaProjects(N172503016,N172502005,N172506011)supported by Fundamental Research Funds for the Central Universities,ChinaProject(2018M640259)supported by China Postdoctoral Science Foundation
摘要The effects of MgO/Al2 O3 ratio on the viscous behaviors of MgO-Al2 O3-TiO2-CaO-SiO2 systems were investigated by the rotating cylinder method.Raman spectroscopy was used to analyze the structural characteristics of slag and Factsage 7.0 was adopted to demonstrate the liquidus temperature of slag.The results show that the viscosity and activation energy for viscous flow decrease when the MgO/Al2O3 ratio increases from 0.82 to 1.36.The break point temperature and liquidus temperature of slag initially decrease and subsequently increase.The complex viscous structures are gradually depolymerized to simple structural units.In conclusion,with the increase of MgO/Al2O3 ratio,the degree of polymerization of slag decreases,which improves the fluidity of slag.The variations of liquidus temperature of slag lead to the same changes of break point temperature.
摘要The reduction rate of Fe^tO in CaOSiO_2Al_2O_3Fe_tO slags with graphite powder has been determined in an alumina crucible at 1 673-1 823 K. The effects of temperature, slag basicity and Fe_tO content on the reduction rate have also been discussed. Test results show that the reduction rate increases with the increase of temperature or Fe_tO concentration in slags, and the reduction rate has a parabolic relation with slag simple basicity or optical basicity. The maximum reduction rate is observed around CaO/SiO_2=1.5 of molten slags. The reaction order is 1.26 or 1.31, and the reduction activation energy is 126.8 or 129.7 kJ/mol respectively in regard to Fe_tO content or Fe_tO activity calculated by using regular solution model. The reduction rate of Fe_tO in CaOSiO_2Al_2O_3Fe_tO slags with graphite powder is in the range of 0.15×10^-4-0.86×10^-4 molO/cm^2·s.
摘要目的:检测γ-Fe2O3纳米粒表面油酸的残留量,考察油酸残留量对纳米粒磁共振T1造影效果的影响。方法:采用热分解法制备γ-Fe2O3纳米粒,使用mPEG-P取代γ-Fe2O3纳米粒表面的油酸,得到水溶性的γ-Fe2O3-PEG纳米粒,采用高效液相色谱法测定纳米粒表面残留的油酸,并在7T磁共振成像仪下考察油酸残留量与纳米粒T1造影效果的关联。最后,对体外造影效果最优的样品进行了体内磁共振成像测试。结果:建立了油酸的高效液相色谱检测方法,油酸在10~400 μg/mL浓度范围内具有良好的线性关系(r2 = 1),平均回收率为99.86%。通过改变γ-Fe2O3与mPEG-P的投料比,得到γ-Fe2O3-PEG纳米粒表面油酸残留个数分别为100、83、56、33的样品。体外磁共振成像结果表明,油酸残留量较少的纳米粒拥有更好的T1加权成像性能。小鼠体内血管造影显示,本研究制备的γ-Fe2O3-PEG纳米粒与临床使用的钆类造影剂相比,拥有更好的血管成像效果。结论:本研究成果为热分解法制备的氧化铁纳米粒表面油酸的定量分析提供了一种有效的检测方法,以促进该类纳米粒在生物医学领域的应用。Objective: Detection of residual oleic acid on the surface of γ-Fe2O3 nanoparticles and investigation of its impact on magnetic resonance T1 imaging. Method: We prepared γ-Fe2O3 nanoparticles via thermal decomposition, with mPEG-P replacing the oleic acid on the surface of the nanoparticles to yield water-soluble γ-Fe2O3-PEG nanoparticles. The residual oleic acid on the surface of the nanoparticles was quantified using High-Performance Liquid Chromatography, and the relationship between the amount of residual oleic acid and the T1 contrast effect of the nanoparticles was investigated using a 7T magnetic resonance imaging system. Finally, the vivo magnetic resonance imaging of the sample exhibiting the optimal in vitro contrast effect was conducted. Results: We developed a High-Performance Liquid Chromatography method for the detection of oleic acid, demonstrating a strong linear correlation in the concentration range of 10~400 μg/mL (r² = 1) with an average recovery rate of 99.86%. By varying the ratio of γ-Fe2O3 to mPEG-P, samples with oleic acid on the surface of γ-Fe2O3-PEG nanoparticles were obtained, with respective counts of 100, 83, 56, and 33. In vitro magnetic resonance imaging demonstrated that nanoparticles with lower residual oleic acid exhibited enhanced T1-weighted imaging performance. In vivo vascular imaging in mice demonstrated that the γ-Fe2O3-PEG nanoparticles prepared in this study provided better imaging results compared to commercially available gadolinium-based contrast agents. Conclusions: This study presents an effective detection method for the quantitative analysis of oleic acid on the surface of iron oxide nanoparticles synthesized via a thermolytic approach, thereby facilitating the application of such nanoparticles in the biomedical field.
基金Item Sponsored by National Natural Science Foundation of China ( 51174099 )Natural Science Foundation of Jiangsu Province of China ( BK2010355 )National Science Foundation for Post-Doctoral Scientists of China ( 20100471382 )
摘要Fluorite is widely employed as fluxing agent in metallurgy flux , which inevitably leads to serious fluorine pollution.B2O3 is employed as fluxing agent of CaO-SiO2-Fe2O3steelmaking fluxes to substitute for CaF2.The effects of B2O3 and CaF2 on the melting properties of this system were investigated.The melting temperatures of fluxes including softening temperature (Ts), hemispherical temperature (Th), and flow temperature (Tf) were measured using the hemisphere method.The results indicate that the fluxing effect of B2O3is more significant than that of CaF2 .When the addition amount of B2O3 (mass percent) exceeds 6% , the melting temperatures of fluxes including Ts , Th and Tf are decreased lower than 1 300℃.The basicity of fluxes has a significant effect on the melting temperature , and the melting temperatures of the fluxes increase with the increase of fluxes basicity.However , when B2O3 is used as fluxing agent , the melting temperature changes little with the basicity increasing from 2.5 to 5.0. These characteristics are suitable for steelmaking process.Moreover , Fe2O3 has an important fluxing effect on this CaO-based steelmaking fluxes.This indicates that the fluxes system is suitable for steelmaking process.