The utilization of highly reactive and high-strength coke can enhance the efficiency of blast furnace by promoting indirect reduction of iron oxides.Iron compounds,as the main constituent in iron-bearing minerals,have...The utilization of highly reactive and high-strength coke can enhance the efficiency of blast furnace by promoting indirect reduction of iron oxides.Iron compounds,as the main constituent in iron-bearing minerals,have aroused wide interest in preparation of highly reactive iron coke.However,the effects of iron compounds on pyrolysis behavior of coal and metallurgical properties of resultant cokes are still unclear.Thus,three iron compounds,i.e.,Fe;O;,Fe;O;and FeC;O;·2H;O,were adopted to investigate their effects on coal pyrolysis behavior and metallurgical properties of the resultant cokes.The results show that iron compounds have slight effects on the thermal behavior of coal blend originated from thermogravimetric and differential thermogravimetric curves.The apparent activation energy varies with different iron compounds ranging from 94.85 to 110.11 kJ/mol in the primary pyrolysis process,while lower apparent activation energy is required for the secondary pyrolysis process.Iron compounds have an adverse influence on the mechanical properties and carbon structure of cokes.Strong correlations exist among coke reactivity,coke strength after reaction,and the content of metallic iron in cokes or the values of crystallite stacking height,which reflect the dependency of thermal property on metallic iron content and carbon structure of cokes.展开更多
Novel acetylene terminated silazane compounds,with three types of substituent,were synthesized by the aminolysis of dichlorosilane with 3-aminophenylacetylene（3-APA）.Thermal property of the compounds is studied by t...Novel acetylene terminated silazane compounds,with three types of substituent,were synthesized by the aminolysis of dichlorosilane with 3-aminophenylacetylene（3-APA）.Thermal property of the compounds is studied by thermogravimetry analysis （TGA）.It shows that the acetylene terminated silazane has high temperature resistance.The char yield at 1000℃is 77.6,81.9 and 68.7 wt%for methyl,vinyl,and phenyl substituted silazane,respectively.The pyrolysis kinetics of the silazane is investigated by non-isothermal thermogravimetric measurement.The pyrolysis undergoes three stages,which is resolved by PEAKFTT.The kinetic parameters are calculated by the Kissinger method.The role of functionalities on the thermal resistance is discussed.The vinyl-silazane exhibits higher thermal stability because of higher cross-linking density.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51474042)
文摘The utilization of highly reactive and high-strength coke can enhance the efficiency of blast furnace by promoting indirect reduction of iron oxides.Iron compounds,as the main constituent in iron-bearing minerals,have aroused wide interest in preparation of highly reactive iron coke.However,the effects of iron compounds on pyrolysis behavior of coal and metallurgical properties of resultant cokes are still unclear.Thus,three iron compounds,i.e.,Fe;O;,Fe;O;and FeC;O;·2H;O,were adopted to investigate their effects on coal pyrolysis behavior and metallurgical properties of the resultant cokes.The results show that iron compounds have slight effects on the thermal behavior of coal blend originated from thermogravimetric and differential thermogravimetric curves.The apparent activation energy varies with different iron compounds ranging from 94.85 to 110.11 kJ/mol in the primary pyrolysis process,while lower apparent activation energy is required for the secondary pyrolysis process.Iron compounds have an adverse influence on the mechanical properties and carbon structure of cokes.Strong correlations exist among coke reactivity,coke strength after reaction,and the content of metallic iron in cokes or the values of crystallite stacking height,which reflect the dependency of thermal property on metallic iron content and carbon structure of cokes.
文摘Novel acetylene terminated silazane compounds,with three types of substituent,were synthesized by the aminolysis of dichlorosilane with 3-aminophenylacetylene（3-APA）.Thermal property of the compounds is studied by thermogravimetry analysis （TGA）.It shows that the acetylene terminated silazane has high temperature resistance.The char yield at 1000℃is 77.6,81.9 and 68.7 wt%for methyl,vinyl,and phenyl substituted silazane,respectively.The pyrolysis kinetics of the silazane is investigated by non-isothermal thermogravimetric measurement.The pyrolysis undergoes three stages,which is resolved by PEAKFTT.The kinetic parameters are calculated by the Kissinger method.The role of functionalities on the thermal resistance is discussed.The vinyl-silazane exhibits higher thermal stability because of higher cross-linking density.
