摘要
随着钢铁企业“双碳”目标的提出,明确焦炭在炼铁过程中的作用行为至关重要。同时高炉富氢冶炼技术的推广给高炉内原燃料的反应行为带来了较大的变化,因此,研究在无氢和有氢气氛下不同反应性焦炭在高炉炉料还原-软熔过程中的作用行为对高炉冶炼具有重要意义。模拟高炉实际炉料结构,研究了不同反应性焦炭对矿石还原度和焦炭的气化率及孔隙结构变化的影响,探索焦炭反应性对炉料软熔性能及软熔带透气性的影响,解析不同反应性焦炭与渣铁界面作用行为的变化机理。研究结果表明,焦炭的反应性提高使各温度下矿石还原度和焦炭气化率均提高,各温度下焦炭的表层孔隙率增加,在无氢气氛下孔隙率的增加幅度低于有氢气氛,焦炭内部孔隙结构整体变化幅度较小。焦炭反应性提高后,炉料的软化温度区间减小且向低温区移动,在无氢气氛下熔化温度区间降低,在有氢气氛下熔化温度区间略有增加,焦炭表层碳基体劣化严重且强度降低,料层最大压差增加,透气性劣化,无氢时的影响程度强于有氢时的影响程度。增加焦炭反应性后,在无氢气氛下渣铁分离较好,且炉渣可以与焦炭灰分有效融合,使熔化带向低温区移动;在有氢气氛下,焦炭表层灰分含量较高,且不能及时与炉渣融合更新焦炭表面的活性点位,使熔渣中的浮氏体还原和金属铁渗碳的阻力增加,不利于软熔带透气性能的改善。
With the proposal of the goals of"carbon neutralization and carbon peaking"in iron and steel enterprises,it is very important to clarify the role of coke in the ironmaking process.At the same time,the promotion of hydrogen-rich smelting technology in blast furnace(BF)has brought great changes to the reaction behaviors of raw materials and fuels.Therefore,it is of great significance to study the effect of coke reactivity on the reduction-softening-melting process of BF burden in hydrogen free and hydrogen containing atmospheres,respectively.Simulate the actual burden structure of the BF,study the influence of coke reactivity on the ore reduction degree,coke gasification rate and pore structure,explore the influence of coke reactivity on the softening-melting property of burden and the permeability of the cohesive zone,and analyze the change mechanism of the interaction behavior between different reactive coke and slag iron interface.The results show that,the increase of coke reactivity increases the ore reduction degree and coke gasification rate at various temperatures.The surface porosity of coke increases at various temperatures.The porosity increases less in the hydrogen free atmosphere than in the hydrogen containing atmosphere,and the overall change range of coke internal pore structure is small.After the coke reactivity improves,the softening temperature range decreases and moves to the low temperature zone,the melting temperature range decreases in the hydrogen free atmosphere,and the melting temperature range slightly increases in the hydrogen containing atmosphere.The carbon matrix on the coke surface is seriously deteriorated and the surface strength decreases,the maximum differential pressure increases,and the permeability deteriorates.The influence degree in the hydrogen free atmosphere is stronger than that in the hydrogen containing atmosphere.After increasing coke reactivity,slag iron separation is better in hydrogen free atmosphere,and slag can be effectively fused with coke ash,so that the meltin
作者
兰臣臣
邵建男
张淑会
刘然
毕忠新
郄亚娜
LAN Chenchen;SHAO Jiannan;ZHANG Shuhui;LIU Ran;BI Zhongxin;QIE Yana(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,Hebei,China;Chengde Iron and Steel Company,HBIS,Chengde 067000,Hebei,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第6期18-25,共8页
Iron and Steel
基金
国家自然科学基金资助项目(52204344)
河北省自然科学基金资助项目(E2021209046,22374003D)
唐山科技计划资助项目(21130209C)。
关键词
焦炭
反应性
矿石还原
软熔性能
氢气
coke
reactivity
ore reduction
softening-melting property
hydrogen
