Effects Of Different Reactive Carbons On Iron Ore Reduction And Top Gas Conditioning Of Blast Furnace

For a long time,various industries have sought processes with low resource consumption,high energy conversion efficiency and low overall emissions.However,due to long-term improvement and optimization,all industries have reached a high level in process level,so it is difficult to achieve a major breakthrough.If we break through the gap between industries caused by the different functions of various industrial departments for a long time,we may achieve a greater breakthrough through the coupling cogeneration between multiple industries and different processes.Therefore,this paper is based on the new process of pure oxygen blast furnace and coal gasification coupling co production,which may greatly reduce the energy consumption and carbon emission of ironmaking and coal gasification process at the same time.The key to realize gas conditioning and reduce coke ratio is to study the gasification difference of different reactive carbon and its impact on iron ore reduction.In this paper,two kinds of highly reactive carbons,charcoal and semi-coke,are used to compare with coke.The gasification reaction process of CO₂,steam and different reactive carbons is studied by gas phase composition analysis.The causes of gasification difference are analyzed by SEM.The dynamic analysis is carried out by using homogeneous model,and the kinetic parameters such as activation energy are obtained.The effects of different reactive carbons on the initial reduction temperature and reduction degree of iron ore were studied through reduction experiments.Through gas phase composition analysis,the quenching and tempering effects of different reactive carbons on CO and H₂were studied,and the temperature requirements for making high reactive carbon play a better quenching and tempering effect were explored.The composition of top gas of pure oxygen blast furnace is calculated by material balance and heat balance,the quenching and tempering experiment was carried out by simulating the actual situation of pure oxygen blast furnace.According to the experimental results,the composition of top gas of pure oxygen blast furnace quenched and tempered with charcoal was estimated.The results show that:（1）the order of the reactivity of the three carbons from strong to weak is charcoal>semi-coke>coke.The starting reaction temperatures with CO₂are 650℃,730℃and 877.5℃and 613.5℃,672℃and 841.5℃respectively.The temperature at which the same kind of carbon and steam start to react and reach the peak value is lower than CO₂,and the reactivity between steam and carbon is higher than CO₂.The difference of the reactivity of the three kinds of carbon has a great relationship with its microstructure.The structure of charcoal is the most loose and coke is the most compact.（2）The activation energies of charcoal,semi-coke and coke reacting with CO₂were 109.51 k J/mol,119.31 k J/mol and176.84k J/mol respectively,and those of steam were 167.59 k J/mol,211.67 k J/mol and238.65 k J/mol respectively.（3）The addition of high reactive carbon can promote the reduction of iron ore,which is better than coke.In blast furnace smelting,a small amount of high reactive carbon can be used to replace coke,so as to reduce the coke ratio,promote the conversion of CO₂and steam to CO and H₂and improve the quality of gas.（4）High reactive carbon has a certain quenching and tempering effect on CO and H₂.After using charcoal to simulate the actual situation of pure oxygen blast furnace,the content of CO increased from 57.59%to 61.12%,and the content of CO₂decreased from 39.45% to 35.97%.