Laboratory-scale experiments were conducted to investigate the oxygen content of Si-deoxidized H13 die steel by ferrous oxide-containing slags at 1873 K.The calculation of thermodynamics and kinetics was performed to ...Laboratory-scale experiments were conducted to investigate the oxygen content of Si-deoxidized H13 die steel by ferrous oxide-containing slags at 1873 K.The calculation of thermodynamics and kinetics was performed to evaluate the oxygen level of molten steel through[Si]-[O]equilibrium and[Fe]-[O]equilibrium.The results show that as the FeO content in slag increases,the oxygen content with[Si]-[O]equilibrium(w([O])Si)has almost no change.When both the oxygen content with[Fe]-[O]equilibrium(w([O])Fe)and w([O])Si are less than the initial oxygen content in steel(w(TO)i),the oxygen content in steel(w([O]))depends on the higher value between w([O])Si and w([O])Fe.In the case of w([O])Fe>w(TO)i,the value of w([O])is the difference between the sum of w(TO)i and w([O])Si and the value of w([O])Fe.The reaction rates of[Si]-[O]and[Fe]-[O]are equal,which are controlled by the mass transfer of oxygen in molten steel.The evaluation method is suitable to the whole smelting process of Si-deoxidized H13 die steel.展开更多
CaO-containing carbon pellets(CCCP)were successfully prepared from well-mixed coking coal(CC)and calcium oxide(CaO)and roasted at different pyrolysis temperatures.The effects of temperature,pore distribution,and carbo...CaO-containing carbon pellets(CCCP)were successfully prepared from well-mixed coking coal(CC)and calcium oxide(CaO)and roasted at different pyrolysis temperatures.The effects of temperature,pore distribution,and carbon structure on the compressive strength of CCCP was investigated in a pyrolysis furnace(350-750℃).The results showed that as the roasting temperature increased,the compressive strength also increased and furthermore,structural defects and imperfections in the carbon crystallites were gradually eliminated to form more organized char structures,thus forming high-ordered CC.Notably,the CCCP preheated at 750℃exhibited the highest compressive strength.A positive relationship between the compressive strength and pore-size homogeneity was established.A linear relationship between the com-pressive strength of the CCCP and the average stack height of CC was observed.Additionally,a four-stage caking mechanism was developed.展开更多
Thermocatalytic CO_(2) hydrogenation with"green"H_(2) is one of the most promising carbon-negative technologies,wherein oxygen vacancy engineering serves as a novel strategy to boost the catalytic performanc...Thermocatalytic CO_(2) hydrogenation with"green"H_(2) is one of the most promising carbon-negative technologies,wherein oxygen vacancy engineering serves as a novel strategy to boost the catalytic performance of oxide-containing catalysts.To provide theoretical guidance and promote technical progress in this important field,the status and prospect of oxygen vacancy-boosted thermocatalytic CO_(2) hydrogenation have been thoroughly reviewed herein.Specifically,fundamentals including origin,construction,characterization,and function of oxygen vacancies will be systematically summarized and oxygen vacancy-boosted hydrogenation reactions including methanation,reverse water-gas shift(RWGS),methanol synthesis,and other hydrogenation processes will be comprehensively introduced.In addition,challenges and opportunities from the perspective of engineering strategies,promoting effects,and mediating mechanisms of oxygen vacancies will be succinctly proposed.Overall,this review is expected to gain more insights into the role of oxygen vacancies and shed new light on the design of efficient oxide-containing catalysts.展开更多
基金support from the National Natural Science Foundation for Young Scientists of China(51704021)Fundamental Research Funds for the Central Universities(FRF-TP-20-004A3,FRF-TP-19-030A2,and FRF-TP-16-079A1).
文摘Laboratory-scale experiments were conducted to investigate the oxygen content of Si-deoxidized H13 die steel by ferrous oxide-containing slags at 1873 K.The calculation of thermodynamics and kinetics was performed to evaluate the oxygen level of molten steel through[Si]-[O]equilibrium and[Fe]-[O]equilibrium.The results show that as the FeO content in slag increases,the oxygen content with[Si]-[O]equilibrium(w([O])Si)has almost no change.When both the oxygen content with[Fe]-[O]equilibrium(w([O])Fe)and w([O])Si are less than the initial oxygen content in steel(w(TO)i),the oxygen content in steel(w([O]))depends on the higher value between w([O])Si and w([O])Fe.In the case of w([O])Fe>w(TO)i,the value of w([O])is the difference between the sum of w(TO)i and w([O])Si and the value of w([O])Fe.The reaction rates of[Si]-[O]and[Fe]-[O]are equal,which are controlled by the mass transfer of oxygen in molten steel.The evaluation method is suitable to the whole smelting process of Si-deoxidized H13 die steel.
基金This work was financially supported by the National Key R&D Program of China(No.2018YFB0605900).
文摘CaO-containing carbon pellets(CCCP)were successfully prepared from well-mixed coking coal(CC)and calcium oxide(CaO)and roasted at different pyrolysis temperatures.The effects of temperature,pore distribution,and carbon structure on the compressive strength of CCCP was investigated in a pyrolysis furnace(350-750℃).The results showed that as the roasting temperature increased,the compressive strength also increased and furthermore,structural defects and imperfections in the carbon crystallites were gradually eliminated to form more organized char structures,thus forming high-ordered CC.Notably,the CCCP preheated at 750℃exhibited the highest compressive strength.A positive relationship between the compressive strength and pore-size homogeneity was established.A linear relationship between the com-pressive strength of the CCCP and the average stack height of CC was observed.Additionally,a four-stage caking mechanism was developed.
基金financial supports from the National Natural Science Foundation of China(22378017,21776007)the National Key Research and Development Program of China(2022YFC2105604)are acknowledged。
文摘Thermocatalytic CO_(2) hydrogenation with"green"H_(2) is one of the most promising carbon-negative technologies,wherein oxygen vacancy engineering serves as a novel strategy to boost the catalytic performance of oxide-containing catalysts.To provide theoretical guidance and promote technical progress in this important field,the status and prospect of oxygen vacancy-boosted thermocatalytic CO_(2) hydrogenation have been thoroughly reviewed herein.Specifically,fundamentals including origin,construction,characterization,and function of oxygen vacancies will be systematically summarized and oxygen vacancy-boosted hydrogenation reactions including methanation,reverse water-gas shift(RWGS),methanol synthesis,and other hydrogenation processes will be comprehensively introduced.In addition,challenges and opportunities from the perspective of engineering strategies,promoting effects,and mediating mechanisms of oxygen vacancies will be succinctly proposed.Overall,this review is expected to gain more insights into the role of oxygen vacancies and shed new light on the design of efficient oxide-containing catalysts.
