Discussion on smelting characteristics and problems of blast furnace with hydrogen-rich gas injection
The smelting process of blast furnace has high energy consumption and high CO2 emission,which is the key point of energy saving and emission reduction in iron and steel industry.In the face of increasingly serious ener-gy 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 smel-ting technology has been widely concerned by metallurgical workers.The main purpose of this technology is to re-place carbon with hydrogen,reduce the consumption of carbon reducing agent and achieve the emission reduction of CO2 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 hydrogen-rich 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 hydrogen-rich 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 tempera-ture of the lower part of the blast furnace,and develop the air flow towards the center.It can promote the gasifica-tion 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 suit-able for blast furnace smelting with hydrogen-rich gas injection should be developed,and the development of hydro-gen gas transportation,storage and injection equipment should be accelerated in order to promote the industrial im-plementation of smelting of blast furnace with hydrogen-rich gas injection.
hydrogen-rich gas injectionsmelting of blast furnaceiron ore reductiontheoretical combustion tem-peraturecoke
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