Study on the Mechanism of Low CSR Coke Used in Blast Furnace Iron Smelting
Author of the article:LI Jie;CHENG Huan;LIANG Yinghua;HUANG Shiping
Author's Workplace：Technical Centre,HBIS Group Shisteel Company,Shijiazhuang050031,China;School of Chemical Engineering,NorthChina University of Science and Technology,Tangshan063210,China;Steel Institute,HBIS Group,Shijiazhuang050023,China
Key Words：coke temperature conditions thermal strength solution loss reaction mode
Abstract：
The mechanism of low CSR coke used in blast furnace ironmaking was discussed by studying its thermal properties under multi-temperature conditions and microstructure.The self-developed thermal performance test method for coke under multi-temperature conditions was adopted to investigate the changes of thermal performance of coke under different temperature conditions,and the microstructure and stomatal structure were analyzed to explain the changes of macroscopic thermal performance with temperature.The results show that low CH coke though the low temperature zone of CSR(1 050℃and 1 100℃)thermal intensity CSR25 value is low,but in 1 150℃and XY coke to realize cross,high temperature(>1 150℃)thermal intensity CSR25 value is higher.The anisotropy of CH coke is low,and the number of small and medium diameter pores is high.Low CH coke at high temperature of CSR has high thermal strength value,this is the main cause of coke can be used for blast furnace ironmaking,it is indicated that the national standard method of CRI,CSR only testing one temperature of 1 100℃is not enough.The low degree of anisotropy in CH coke structure leads to the rapid chemical reaction rate between the stomatal wall matrix and CO2.The number of pores with small and medium diameter in the structure leads to large internal diffusion resistance.The competitive relationship between the two results in the dissolution loss reaction mode of CH coke quickly reaching the surface degradation,which protects the core of the coke and makes the CH coke have higher thermal strength in the high temperature area.This is the deeper mechanism that the low CSR CH coke can be used in blast furnace ironmaking.
