喷吹富氢气体高炉冶炼特点及存在问题的探讨

Discussion on smelting characteristics and problems of blast furnace with hydrogen-rich gas injection

高炉炼铁工序能耗高、CO_(2)排放量大,是钢铁行业节能减排的重点。面对日益严重的能源危机和环境问题,实现高炉冶炼过程的碳减排已经成为人们的共识。在上述背景下,高炉喷吹富氢气体冶炼技术得到了冶金工作者的广泛关注,该技术的主旨在于以氢代碳、降低高炉内碳素还原剂的消耗,实现高炉CO_(2)的减排。基于富氢气体在风口前燃烧的热力学分析,系统讨论了喷吹富氢气体高炉的冶炼特点、存在的问题及解决措施,并对今后的研究工作进行了展望。结果认为,与传统高炉冶炼相比,喷吹富氢气体高炉的冶炼特点发生了显著变化,富氢气体可以促进铁矿石的还原,降低初渣中FeO含量,渣量降低且熔点升高,软熔带压差降低,透气性改善;喷吹富氢气体容易使高炉下部温度降低,气流向中心发展,促进块状带焦炭的气化反应,并影响高温区焦炭和渣铁的接触特征。喷吹富氢气体高炉在发挥氢还原优势的同时,容易出现下部热量不足、煤粉燃烧率降低、铁矿石粉化严重等问题。对于喷吹富氢气体高炉的冶炼过程,建议加强煤气富氢量、金属铁渗碳和焦炭性能三者间相互影响的机理研究,并探索合理的操作炉型,开发适用于喷吹富氢气体高炉冶炼的原燃料条件,同时加快富氢气体运输、储存和喷吹设备的研发,以促进喷吹富氢气体高炉冶炼技术的工业实施。

The smelting process of blast furnace has high energy consumption and high CO_(2)emission,which is the key point of energy saving and emission reduction in iron and steel industry.In the face of increasingly serious energy crisis and environmental problems,it has become a common understanding to achieve carbon emission reduction in blast furnace smelting process.Under the above background,the blast furnace injection hydrogen-rich gas smelting technology has been widely concerned by metallurgical workers.The main purpose of this technology is to replace carbon with hydrogen,reduce the consumption of carbon reducing agent and achieve the emission reduction of CO_(2)in the blast furnace.Based on the thermodynamic analysis of the combustion reaction of hydrogen rich gas in front of tuyere,the smelting characteristics,existing problems and solving measures of blast furnace with hydrogenrich gas injection are discussed systematically,and the future research work is prospected.The results show that compared with the traditional blast furnace smelting,the smelting characteristics of the blast furnace with hydrogenrich gas injection have changed significantly:hydrogen rich gas can promote the reduction of iron ore,reduce the FeO content in the initial slag,reduce the slag content,and the melting point,reduce the pressure difference of the soft melt zone,as well as improve the air permeability.Hydrogen-rich gas injection is easy to reduce the temperature of the lower part of the blast furnace,and develop the air flow towards the center.It can promote the gasification reaction of coke in massive zone and affect the contact characteristics of coke and slag iron in high temperature zone.When the blast furnace of hydrogen-rich gas injection plays the advantage of hydrogen reduction,there are still some problems,such as insufficient heat in the lower part,reduced pulverized coal combustion rate and serious pulverized iron ore.For the smelting process of blast furnace with hydrogen-rich gas injection,it is suggested to strengthen on the mechanism research of interaction among hydrogen abundance of gas,metal iron carburizing and coke properties,and to explore the reasonable operating profile of blast furnace type.The raw fuel conditions suitable for blast furnace smelting with hydrogen-rich gas injection should be developed,and the development of hydrogen gas transportation,storage and injection equipment should be accelerated in order to promote the industrial implementation of smelting of blast furnace with hydrogen-rich gas injection.