Thermal Properties Of Coke Used In Blast Furnace Of Baotou Steel And Coke Thermal Properties In Ore-coke Coupling Reaction

The thermal property of coke used in blast furnace is one of the important factors to ensure the smooth running of blast furnace and improve the production index of blast furnace.With the development of blast furnace ironmaking technology,there is a deviation when the traditional thermal properties index of coke,that is,coke reactivity(CRI)and post reaction strength(CSR),are used to guide blast furnace production,therefore,the researchers put forward two new evaluation indexes,namely,the post-reaction strength(CSR₂₅)and the reaction rate(CRR₂₅) with isothermal equal loss rate of 25%.At the same time,for the same kind of coke,when different iron ore is used,the performance of coke will inevitably change.This paper takes the coke of blast furnace used in Baotou Steel as the main research object,carries on the CSR₂₅and the CRR₂₅determination to the three main coke,obtains the new appraisal index and the traditional appraisal index difference;according to the thermal properties of three kinds of coke,two kinds of coke were selected for the experimental determination of ore-coke coupling reaction,in which four groups of ore blending categories were selected to obtain the influence of different iron ore on coke properties.To provide theoretical guidance for the rational selection of coke for blast furnace.The main results of this paper are as follows:(1)With the increase of reaction temperature,the change of Coke1-4 and Coke7-8CSR₂₅showed the trend of decreasing first and then increasing,but the change trend of Coke9-10 CSR₂₅was not obvious;and the lowest value of three kinds of coke appeared at 1200?.(2)When the most serious deterioration reaction of the three kinds of coke occurs,the influence of the most serious deterioration reaction on the strength of the three kinds coke after dissolution is different,the influence of Coke1-4 and Coke7-8 on the most serious deterioration reaction is obvious,when it is below or above the temperature corresponding to the most serious deterioration reaction,there are obvious increase in strength after dissolution;the influence of Coke9-10 on the most serious deterioration reaction is not obvious,when it is below or above the temperature corresponding to the most serious deterioration reaction,the strength after dissolution,there are no obvious change in strength after dissolution.(3)For the low-reactive coke,the maximum pressure(?p_max)and droplet characteristic value(S)of the furnace charge increase obviously with the increase of alkali metal content in iron ore;for the high-reactive coke,the maximum pressure(?p_max)and droplet characteristic value(S)of the furnace charge decrease obviously with the increase of alkali metal content in iron ore.(4)The experimental method of national standard coke thermal properties can not explain the change trend of upper layer coke dissolution rate(CSL_U)with coke reactivity(CRI)in the ore-coke coupling reaction,while the experimental method of coke comprehensive thermal properties can explain the change trend of upper layer coke dissolution rate(CSL_U)with coke average reaction rate(CRR₂₅)in the ore-coke coupling reaction,With the increase of coke average reaction rate(CRR₂₅),the dissolution loss rate of the upper layer coke of ore-coke coupling reaction(CSL_U) also increases.