Al_2O_3对CaO-Fe_2O_3熔体结晶矿物组成及显微结构的影响
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摘要
通过在CaO-Fe_2O_3熔体中添加Al_2O_3,研究了不同Al_2O_3含量对CaO-Fe_2O_3熔体结晶矿物组成及显微结构的影响。研究结果表明,随着Al_2O_3含量的增加,CaO-Fe_2O_3-Al_2O_3熔体结晶产物中铁酸一钙含量减少。当Al_2O_3含量达到3%时,铁酸二钙与富铁铁酸钙从熔体中结晶,二者含量随Al_2O_3含量的增加而增加。随着Al_2O_3含量的增加富铁铁酸钙的显微结构向细条状转变。同时,熔体黏度随着Al_2O_3含量增加而增加,当Al_2O_3含量超过5%时,熔体内铁酸钙结晶受到显著抑制。
As one of major burdens of blast furnace,the metallurgical performance of high basicity iron ore sinter is highly related to the ironmaking process in blast furnace..In this study,the effect of Al_2O_3 on the composition and microstructures of crystal products of CaO-Fe_2O_3 melt was investigated by changing the Al_2O_3content in CaO-Fe_2O_3 melt.It was found out that the CaFe_2O_4 decreased with increasing Al_2O_3 content.When Al_2O_3 content reached 3%,Ca_2Fe_2O_5 and Fe-rich calcium ferrite crystallized from melt and their content increased with increasing Al_2O_3 content.The microstructure of Fe-rich calcium ferrite became thinner with increasing Al_2O_3 content.The viscosity of CaO-Fe_2O_3 melt was also increased with increasing Al_2O_3content.When the Al_2O_3 content exceeded 5%,the crystallization of calcium ferrite was depressed significantly.
As one of major burdens of blast furnace,the metallurgical performance of high basicity iron ore sinter is highly related to the ironmaking process in blast furnace..In this study,the effect of Al_2O_3 on the composition and microstructures of crystal products of CaO-Fe_2O_3 melt was investigated by changing the Al_2O_3content in CaO-Fe_2O_3 melt.It was found out that the CaFe_2O_4 decreased with increasing Al_2O_3 content.When Al_2O_3 content reached 3%,Ca_2Fe_2O_5 and Fe-rich calcium ferrite crystallized from melt and their content increased with increasing Al_2O_3 content.The microstructure of Fe-rich calcium ferrite became thinner with increasing Al_2O_3 content.The viscosity of CaO-Fe_2O_3 melt was also increased with increasing Al_2O_3content.When the Al_2O_3 content exceeded 5%,the crystallization of calcium ferrite was depressed significantly.
引文
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[2] Bristow N J,Waters A G.Role of SFCA in promoting high-temperature reduction properties of iron ore sinters[J].Transactions of the Institution of Mining and Metallurgy Section C,1991(100):C1-C10.
[3] Shigaki I,Sawada M,Gennai N.Increase in low-temperature reduction of iron ore sinter due to hematite-alumina solid solution and columnar calcium ferite[J].Transactions of the Iron and Steel Institute of Japan,1986(26):503-511.
[4] Loo C E,Wan K T,Howes V R.Mechanical properties of natural and synthetic mineral phases in sinters having varying reduction degradation indexes[J].Ironmaking and Steelmaking,1988(15):279-285.
[5] Lu L,Holmes R J,Manuel J R.Effects of alumina on sintering performance of hematite iron ores[J].ISIJ International,2007(47):349-358.
[6] Shen F,Jiang X,Wu G S,et al.Proper MgO addition in blast furnace operation[J].ISIJ International,2006(46):65-69.
[7] Cores A,Babich A,Moisés M,et al.The influence of different iron ores mixtures composition on the quality of sinter[J].ISIJ International,2010,50(8):1089-1098.
[8] Guo H,Guo X M.Effect of aluminum dissolved in hematite on formation of calcium ferrites at 1473 K[J].Metallurgical and Materials Transactions B,2018,49B(4):1974-1984.
[9] Kalenga M K,Garbers-Craig A M.Investigation into how the magnesia,silica and alumina contents of iron oresinter influence its mineralogy andproperties[J].The Journal of the Southern African Institute of Mining and Metallurgy,2010,110:447-455.
[10] Hessien M M,Kashiwaya Y,Ishii K et al.Sintering and heating reduction processes of alumina containing iron ore samples[J].Ironmaking and Steelmaking,2008,35(3):191-204.
[11] Sukenaga S,Gonda Y,Yoshimura S,et al.Viscosity measurement of calcium ferrite based slags during structural relaxation process[J].ISIJ International,2010(50):195-199.
[12] Saito N,Nakashima K,Mori K.Viscosity of blast furnace type slags[J].Metallurgical and Materials Transaction B,2003(34B):509-516.
[13] Yoshimura S,Kurosawa K,Gonda Y,et al.Penetration behavior of calcium ferrite melts into hematite substrate[J].ISIJ International,2009,49(5):687-692.