The effect of cooling rate on the crystallization of perovskite in high Ti-bearing blast furnace（BF） slag was studied using confocal scanning laser microscopy（CSLM）. Results showed that perovskite was the primary ...The effect of cooling rate on the crystallization of perovskite in high Ti-bearing blast furnace（BF） slag was studied using confocal scanning laser microscopy（CSLM）. Results showed that perovskite was the primary phase formed during the cooling of slag. On the slag surface, the growth of perovskite proceeded via the successive production of quasi-particles along straight lines, which further extended in certain directions. The morphology and structure of perovskite was found to vary as a function of cooling rate. At cooling rates of 10 and 30 K/min, the dendritic arms of perovskite crossed obliquely, while they were orthogonal at a cooling rate of 20 K/min and hexagonal at cooling rates of 40 and 50 K/min. These three crystal morphologies thus obtained at different cooling rates respectively corresponded to the orthorhombic, cubic and hexagonal crystal structures of perovskite. The observed change in the structure of perovskite could probably be attributed to the deficiency of O^2-, when Ti2O3 was involved in the formation of perovskite.展开更多
A simple model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides was developed using optical basicity only. In this model, the temperature dependence of the rate constant can b...A simple model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides was developed using optical basicity only. In this model, the temperature dependence of the rate constant can be described by the Arrhenius law, and the activation energy can be expressed with a linear function of the slag＇s optical basicity. The model was applied to some molten slag systems, such as FeO, FeO-CaO, FeO-SiO2, FeO-Na2O, FeO-CaO-SiO2, FeO-SiO2-P2O5, FeO-SiOE-Na2O, and FeO-CaO-SiOE-P2O5. A comparison between the predicted results and measured data showed that the model worked well.展开更多
Under inert atmospheres and 1473 K,the evaporation rate of SnS from SnO-FeO- SiO_2 and SnO-FeO-CaO-SiO_2 slags mixed with FeS was investigated by measuring the weight Ioss and composition of samples.The experimental r...Under inert atmospheres and 1473 K,the evaporation rate of SnS from SnO-FeO- SiO_2 and SnO-FeO-CaO-SiO_2 slags mixed with FeS was investigated by measuring the weight Ioss and composition of samples.The experimental results show that dur- ing sulfide fuming process the evaporation of SnOfrom slags is negligible in comparison with that of SnS.Addition of CaOto slags can enhance the evaporation rate of SnS.The differential rate equation of evaporation may be expressed as: -d(%Sn)/dt=k(%Sn)(%S) where,the apparent rate constant k was found to be 4.20×10^(-3) for SnO-FeO-CaO- SiO_2 system and 2.88×10^(-3) for SnO-FeO-SiO_2 system,respectively.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51090383)the Fundamental Research Funds for the Central Universities of China(No.CDJZR12130049)
文摘The effect of cooling rate on the crystallization of perovskite in high Ti-bearing blast furnace（BF） slag was studied using confocal scanning laser microscopy（CSLM）. Results showed that perovskite was the primary phase formed during the cooling of slag. On the slag surface, the growth of perovskite proceeded via the successive production of quasi-particles along straight lines, which further extended in certain directions. The morphology and structure of perovskite was found to vary as a function of cooling rate. At cooling rates of 10 and 30 K/min, the dendritic arms of perovskite crossed obliquely, while they were orthogonal at a cooling rate of 20 K/min and hexagonal at cooling rates of 40 and 50 K/min. These three crystal morphologies thus obtained at different cooling rates respectively corresponded to the orthorhombic, cubic and hexagonal crystal structures of perovskite. The observed change in the structure of perovskite could probably be attributed to the deficiency of O^2-, when Ti2O3 was involved in the formation of perovskite.
基金supported by the National Natural Science Foundation of China (Nos. 50834007, 50874128, and 50674012)
文摘A simple model for estimating the rate constant between CO2-CO gas and molten slag containing iron oxides was developed using optical basicity only. In this model, the temperature dependence of the rate constant can be described by the Arrhenius law, and the activation energy can be expressed with a linear function of the slag＇s optical basicity. The model was applied to some molten slag systems, such as FeO, FeO-CaO, FeO-SiO2, FeO-Na2O, FeO-CaO-SiO2, FeO-SiO2-P2O5, FeO-SiOE-Na2O, and FeO-CaO-SiOE-P2O5. A comparison between the predicted results and measured data showed that the model worked well.
文摘Under inert atmospheres and 1473 K,the evaporation rate of SnS from SnO-FeO- SiO_2 and SnO-FeO-CaO-SiO_2 slags mixed with FeS was investigated by measuring the weight Ioss and composition of samples.The experimental results show that dur- ing sulfide fuming process the evaporation of SnOfrom slags is negligible in comparison with that of SnS.Addition of CaOto slags can enhance the evaporation rate of SnS.The differential rate equation of evaporation may be expressed as: -d(%Sn)/dt=k(%Sn)(%S) where,the apparent rate constant k was found to be 4.20×10^(-3) for SnO-FeO-CaO- SiO_2 system and 2.88×10^(-3) for SnO-FeO-SiO_2 system,respectively.
