炼铁过程富氧及混煤对燃料燃烧性能的影响

Influence of oxygen enrichment and coal blending on fuel combustion performance in ironmaking process

高炉喷吹用燃料的燃烧性能对于高炉冶炼过程来说是非常重要的,使用燃烧性能较好的高炉喷吹燃料更有利于提高煤比、降低焦比,从而降低高炉冶炼成本。为响应节能减排政策,对一些钢铁企业采取了煤粉的限制采购和使用等措施,使得兰炭成为高炉喷吹用燃料的有效替代品。通过工业分析、元素分析和热重分析试验比较了烟煤、无烟煤和兰炭3种高炉喷吹燃料的差异,并研究了不同混合方案以及不同富氧率条件下兰炭燃烧性能的变化。研究结果表明,燃料的综合燃烧特性与其初始燃烧温度、最终燃烧温度和燃烧反应时间均有一定的相关性。3种燃料中,烟煤的综合燃烧特性最好,无烟煤次之,兰炭的综合燃烧特性最弱。为了提高兰炭的燃烧特性,对兰炭和烟煤进行混合燃烧试验,发现随着混合燃料中烟煤含量的增加,混合燃料的综合燃烧特性参数呈现出逐渐增加的趋势,并且在兰炭和烟煤的混合燃烧试验中发现存在协同效应。在研究富氧率对兰炭燃烧性能影响时发现,随着富氧率的增加,兰炭的燃烧性也呈现出逐渐增加的趋势,但是增加的幅度较小。当富氧率由0增加至20%时,兰炭的综合燃烧特性参数从4.53×10^(-14)增加至6.05×10^(-14) min^(-2)·℃^(-3)。综上所述,烟煤的添加以及富氧率的提高均对兰炭的燃烧性能有明显的改善效果。

The combustion performance of the fuel used for blast furnace injection is very important.The use of blast furnace injection fuel with better combustion performance is more conducive to replacing the coke ratio and reducing the cost of blast furnace ironmaking.According to the requirements of the national energy conservation and emission reduction policy,some steel companies have begun to restrict the purchase and use of coal,so semi-coke has become an effective substitute for blast furnace coal injection.The differences between bituminous coal,anthracite,and semi-coke were studied through proximate analysis and thermogravimetric analysis experiments.The changes in the combustion performance of semi-coke under different coal blending schemes and different oxygen enrichment rates were studied.The research results show that the comprehensive combustion characteristics of fuels have a certain correlation with the initial combustion temperature,final combustion temperature and combustion reaction time.Among the three fuels,bituminous coal has the best comprehensive combustion characteristics,followed by anthracite,and semi-coke has the weakest comprehensive combustion characteristics.In order to improve the combustion characteristics of semi-coke,a mixed combustion experiment was carried out on semi-coke and bituminous coal.With the increase of bituminous coal content,the comprehensive combustion characteristic parameters of the blended sample gradually increase.And in the mixed combustion reaction of semi-coke and bituminous coal,a synergistic effect was found.With the increase of oxygen enrichment rate,the combustibility of semi-coke slowly increases.When the oxygen enrichment rate increases from 0 to 20%,the comprehensive combustion characteristic parameters of semi-coke increase from 4.53×10^(-14) to 6.05×10^(-14) min^(-2)·℃^(-3).The above results show that the addition of bituminous coal and the increase of oxygen enrichment rate can significantly improve the combustion performance of semi-coke.