摘要
近年来,在中国“碳达峰”“碳中和”战略背景下,低碳高炉炼铁已成为中国低碳冶金技术发展的重要方向。在高炉炼铁工序,由于大量使用化石燃料及炉顶煤气利用率低,导致CO_(2)排放量过多。为降低高炉炼铁的碳排放,提出富氢碳循环氧气高炉新工艺。以碳循环氧气高炉为研究对象,通过数值模拟与实验室试验相结合的方式,对高炉内软熔带上部含铁炉料的还原行为和焦炭气化行为进行了研究。通过SEM-EDS对烧结矿和球团矿的还原程度及渣铁分离现象加以分析,同时采用矿相显微镜对焦炭气化后的微观形貌进行表征。通过数值模拟和实验室试验得到的高炉内含铁炉料还原度变化规律基本一致,验证了数值模拟与实验室试验相结合方法的可行性。研究表明,在高炉的同一竖直方向上,随着位置的降低,含铁炉料的还原度和金属化率不断升高,焦炭的气化率不断上升。在高炉中心位置软熔带上方,含铁炉料的还原度为0.91,金属化率为67.58%,焦炭的气化率为20.91%。在高炉边缘位置软熔带上方,含铁炉料的还原度为1,金属化率为96.91%,焦炭的气化率为21.36%。并且,随着炉料下行,还原后含铁炉料的金属铁面积越大,渣铁分离越明显,观察到的焦炭孔隙越大。在碳循环氧气高炉内,由于炉顶煤气循环,高炉煤气中CO利用增多,CO_(2)排放量减少,高炉煤气的二次利用率提高,这为低碳绿色冶金提供了应用理论基础。
In recent years,in the context of China′s"peak carbon dioxide emissions and carbon neutrality"strategy,low-carbon blast furnaces have become an important direction for the development of low-carbon metallurgical technology in China.Due to the large use of fossil fuels and the low utilization rate of top gas in the ironmaking process of blast furnaces,excessive CO_(2)emissions are caused.In order to reduce carbon emissions from blast furnace ironmaking,a new process of hydrogen rich carbon recycle oxygen furnace(HyCROF)has been proposed.In this paper,the reduction behavior and coke gasification behavior of iron bearing burden in the carbon recycle oxygen furnace(CROF)were studied by combining numerical simulation and laboratory experiments.The reduction degree of sinter and pellet and the separation phenomenon of slag and iron were analyzed by SEM-EDS,and the microscopic morphology of coke after gasification was characterized by mineral phase microscopy.The variation pattern of ironcontaining charge reduction in the blast furnace obtained by numerical simulation and laboratory experiments is basically consistent,which verifies the feasibility of the combined method of numerical simulation and laboratory experiments.The research shows that in the same vertical direction of CROF,with the reduction degree and metallization rate of the iron-containing furnace material increasing as the position decreases,the gasification rate of the coke continues to increase.Above the soft melting zone in the center of CROF,the reduction degree of the iron-containing furnace material is 0.91,the metallization rate is 67.58%,and the gasification rate of coke is 20.91%.Above the soft melting zone at the edge of CROF,the reduction degree of the iron-containing furnace material is 1,the metallization rate is 96.91%,and the gasification rate of coke is 21.36%.In addition,with the downward movement of the furnace charge,the larger the metal iron area of the reduced iron-containing furnace charge,the more obvious the slag iron separation,and the larger the observed coke pores.In the carbon cycle oxygen blast furnace,the utilization of CO in blast furnace gas increases,CO_(2)emissions decrease and the secondary utilization of blast furnace gas increases due to the top gas circulation,which provides a theoretical basis for the application of low carbon green metallurgy.
作者
魏汝飞
郑雪婷
李家新
焦璐璐
毛晓明
许海法
WEI Rufei;ZHENG Xueting;LI Jiaxin;JIAO Lulu;MAO Xiaoming;XU Haifa(School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243002,Anhui,China;School of Energy and Environment,Southeast University,Nanjing 210096,Jiangsu,China;China Baowu Low Carbon Metallurgy Innovation Center,Shanghai 200126,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第8期69-81,共13页
Iron and Steel
基金
国家自然科学基金钢铁联合基金资助项目(U1860113)。
关键词
高炉炼铁
碳循环
炉料还原
焦炭气化
低碳炼铁
blast furnace ironmaking
carbon cycle
charge reduction
coke gasification
low carbon ironmaking
