CO_2对焦炭高温气化影响及微观结构分析
|
摘要
为提升高炉冶炼中焦炭的冶金性能并降低CO_2对焦炭的熔损、降低焦比,通过在实验室模拟CO_2对焦炭在高炉中的气化影响,对焦炭在不同熔损条件下的变化及比表面积进行研究计算。结果表明,CO_2体积分数较低时,焦炭的比表面积则是一直增大,在CO_2体积分数较高时,比表面积是先增大减小;傅里叶红外分析结果表明,随着CO_2体积分数增加,焦炭中大分子芳环类物质减少,生成大量气体从焦炭中挥发,伴随其他盐类物质生成。因此,在CO_2体积分数不变的条件下,反应时间增长,表现为焦炭比表面积的增大、微观结构的改变以及部分基团振动峰发生位移,从而导致焦炭发生粉化现象和强度降低。
In order to improve the metallurgical properties of coke in blast furnace smelting and reduce the melting loss of the material by CO_2 to reduce the coke ratio,the effect of CO_2 on coke gasification in blast furnace was simulated in laboratory.The changes and specific surface areas of coke under different melting loss conditions were studied and calculated.The results shows that the specific surface area of coke is always increasing when the CO_2 concentration is lower.When the CO_2 volume fraction is high,the specific surface area first increases and then decreases.Fourier transform infrared analysis shows that with the increase of CO_2 volume concentration,the macrocyclic aromatics in coke decrease,and a large amount of gas is generated and volatilized from coke,accompanied by the formation of other salts.Therefore,under the condition of constant CO_2 volume concentration,with the increase of reaction time,the specific surface area of coke increases,the microstructure changes and the vibration peak of some groups shifts.As a result,the coke is pulverized and the strength is lowered.
In order to improve the metallurgical properties of coke in blast furnace smelting and reduce the melting loss of the material by CO_2 to reduce the coke ratio,the effect of CO_2 on coke gasification in blast furnace was simulated in laboratory.The changes and specific surface areas of coke under different melting loss conditions were studied and calculated.The results shows that the specific surface area of coke is always increasing when the CO_2 concentration is lower.When the CO_2 volume fraction is high,the specific surface area first increases and then decreases.Fourier transform infrared analysis shows that with the increase of CO_2 volume concentration,the macrocyclic aromatics in coke decrease,and a large amount of gas is generated and volatilized from coke,accompanied by the formation of other salts.Therefore,under the condition of constant CO_2 volume concentration,with the increase of reaction time,the specific surface area of coke increases,the microstructure changes and the vibration peak of some groups shifts.As a result,the coke is pulverized and the strength is lowered.
引文
[1] Gudenau H W,Senk D,Fukada K.Coke behaviour in the lower part of BF with high injection rate[C]//International BF Lower Zone Symposium.Illawara:Australasian Institute of Mining and Metallurgy,2002:1.
[2] Hilding T,Gupta S,Sahajwalla V.Degradation behaviour of a high CSR coke in an experimental blast furnace:Effect of carbon structure and alkali reactions[J].ISIJ International,2005,47(7):1041.
[3] Haapakangas J,Uusitalo J,Mattila O.A method for evaluating coke hot strength[J].Steel Research International,2013,84(1):65.
[4] Xing X,Rogers H,Zhang G H.Coke degradation under simulated blast furnace conditions[J].ISIJ International,2016,56(5):786.
[5]崔平,王为为,王忠乐.二氧化碳气氛下的焦炭高温耐压强度研究[J].燃料与化工,2014,45(4):1.(Cui P,Wang W,Wang Z L.Study on High temperature and pressure resistance strength of coke in carbon dioxide atmosphere[J].Fuel and Chemical Industry,2014,45(4):1.)
[6]方觉,王兴艳,郭丽,等.焦炭高温抗压强度研究[J].钢铁,2006,41(5):20.(Fang J,Wang X Y,Guo L,et al.Study on high temperature compressive strength of coke[J].Iron and Steel,2006,41(5):20.)
[7]郭文涛,王静松,佘雪峰,等.焦炭与CO2和水蒸气气化孔隙结构和高温抗压强研究[J].燃料化学学报,2015,43(6):654.(Guo W T,Wang J S,She X F,et al.Study on pore structure and high temperature pressure resistance of coke and CO2and steam gasification[J].Journal of Fuel Chemistry,2015,43(6):654.)
[8] An J Y,Seo J B,Choi J H,et al.Evaluation of characteristics of coke degradation after reaction in different conditions[J].ISIJ International,2016,56:226.
[9]郑经堂,黄振兴.多孔炭材料[M].北京:化学工业出版社,2015.(Zheng J T,Huang Z X.Porous Carbon Material[M].Beijing:Chemical Industry Press,2015.)
[10] Jun C,Xin W,Tingting S.Pore fractal structures and combustion dynamics of cokes derived from the pyrolysis of typical Chinese power coals[J].Fuel Processing Technology,2016,149:49.
[11] Donskoi E,Poliakov A,Mahoney M R,et al.Novel optical image analysis coke characterisation and its application to study of the relationships between coke structure,coke strength and parent coal composition[J].Fuel,2017,208:281.
[12]郭文涛,王静松,佘雪峰,等.焦炭与CO2和水蒸气气化后孔隙结构和高温抗压强度研究[J].燃料化学学报,2015,43(6):654.(Guo W T,Wang J S,She X F,et al.Study on pore structure and high temperature compressive strength of coke and CO2after steam gasification[J].Acta Fuel Chemistry,2015,43(6):654.)
[2] Hilding T,Gupta S,Sahajwalla V.Degradation behaviour of a high CSR coke in an experimental blast furnace:Effect of carbon structure and alkali reactions[J].ISIJ International,2005,47(7):1041.
[3] Haapakangas J,Uusitalo J,Mattila O.A method for evaluating coke hot strength[J].Steel Research International,2013,84(1):65.
[4] Xing X,Rogers H,Zhang G H.Coke degradation under simulated blast furnace conditions[J].ISIJ International,2016,56(5):786.
[5]崔平,王为为,王忠乐.二氧化碳气氛下的焦炭高温耐压强度研究[J].燃料与化工,2014,45(4):1.(Cui P,Wang W,Wang Z L.Study on High temperature and pressure resistance strength of coke in carbon dioxide atmosphere[J].Fuel and Chemical Industry,2014,45(4):1.)
[6]方觉,王兴艳,郭丽,等.焦炭高温抗压强度研究[J].钢铁,2006,41(5):20.(Fang J,Wang X Y,Guo L,et al.Study on high temperature compressive strength of coke[J].Iron and Steel,2006,41(5):20.)
[7]郭文涛,王静松,佘雪峰,等.焦炭与CO2和水蒸气气化孔隙结构和高温抗压强研究[J].燃料化学学报,2015,43(6):654.(Guo W T,Wang J S,She X F,et al.Study on pore structure and high temperature pressure resistance of coke and CO2and steam gasification[J].Journal of Fuel Chemistry,2015,43(6):654.)
[8] An J Y,Seo J B,Choi J H,et al.Evaluation of characteristics of coke degradation after reaction in different conditions[J].ISIJ International,2016,56:226.
[9]郑经堂,黄振兴.多孔炭材料[M].北京:化学工业出版社,2015.(Zheng J T,Huang Z X.Porous Carbon Material[M].Beijing:Chemical Industry Press,2015.)
[10] Jun C,Xin W,Tingting S.Pore fractal structures and combustion dynamics of cokes derived from the pyrolysis of typical Chinese power coals[J].Fuel Processing Technology,2016,149:49.
[11] Donskoi E,Poliakov A,Mahoney M R,et al.Novel optical image analysis coke characterisation and its application to study of the relationships between coke structure,coke strength and parent coal composition[J].Fuel,2017,208:281.
[12]郭文涛,王静松,佘雪峰,等.焦炭与CO2和水蒸气气化后孔隙结构和高温抗压强度研究[J].燃料化学学报,2015,43(6):654.(Guo W T,Wang J S,She X F,et al.Study on pore structure and high temperature compressive strength of coke and CO2after steam gasification[J].Acta Fuel Chemistry,2015,43(6):654.)