Correlation Study Between Properties Of Blast-furnace Coke Matrix And Comprehensive Thermal Properties

With the development of large-volume blast furnaces,blast furnace smelting coke quality requirements are getting higher and higher.The matrix properties of coke is one of the influencing factors of coke quality.Therefore,a scientific and reasonable understanding of the ability of coke to resist dissolution and deterioration from the perspective of the matrix is particularly important.The paper firstly measured the reactivity（CRI）and the strength after reaction（CSR）of coke through the national standard and used a new comprehensive thermal property method to detect the dissolution loss rate of coke(CRR₂₅)and the strength after equal dissolution rate(CSR₂₅).The text results of two methods are used for comparative analysis.Then,the matrix reactivity,ash component catalysis and microcrystalline structure of coke were studied separately.And the correlation between coke matrix properties and comprehensive thermal properties was established.More,it provides a theoretical basis for fully understanding the mechanism of coke dissolution deterioration.The main conclusions are as follows:（1）In the comparative analysis of the two methods,it is found that CSR of Coke A（67.20%）is greater than Coke B（62.10%）,indicating that Coke A’s ability to resist dissolution deterioration is stronger.But with the increase of temperatures（1100→1300℃）,the CSR₂₅of Coke A fluctuates greatly（66.49→62.04→67.62%）,while the change trend of Coke B is gentle（66.62→63.91→65.10%）.And the CSR₂₅of Coke B is higher than Coke A before 1250℃.It can be seen that CSR₂₅-T,as an auxiliary indicator of CSR,can better identify the change law of coke’s resistance to dissolution loss and deterioration with temperature.（2）In the analysis of the correlation between matrix reactivity and comprehensive thermal properties,it is found that the CSR₂₅of Coke A and Coke B shows a parabolic trend that first decreases and then increases as the carbon dissolution rate（CMRR）increases.The performance is good,R²is 0.96 and 0.87 respectively.At the same time,the activation energies of Coke A and Coke B are 114.4 k J/mol and 112.1 k J/mol respectively by the modified random hole model（MRPM）.It indicates that the matrix reactivity of Coke B is higher than Coke A.And then,it is more prone to occur dissolution loss reaction.（3）In the analysis of the correlation between the catalysis of ash components and comprehensive thermal properties,it is found that the catalytic index（MCI）of Coke A and Coke B has a certain correlation with CSR₂₅.The greater the MCI,the stronger the catalytic effect on the dissolution reaction.The stronger the damage,the smaller the CSR₂₅.This rule is mainly reflected in the temperatures range of 1200～1300℃.For example,the MCI of Coke A is much larger than Coke B at 1250℃,and the CSR₂₅of Coke A is significantly smaller than Coke B.（4）In the analysis of the correlation between the microcrystalline structure and comprehensive thermal properties,it is found that the microcrystalline height（L_c）and the interlayer spacing(d₀₀₂)are the main influencing factors of CSR₂₅.It makes the microcrystalline structure loose with the increase of L_cand d₀₀₂of Coke A and Coke B.And then,it promotes the coke gasification reaction,accelerates the reaction rate and reduces the strength of the coke after the equal dissolution rate.（5）From the perspective of the matrix as a whole,the influence order of CSR₂₅on thetwo cokes is matrix reactivity,ash component catalysis and microcrystalline structure.