Study On Coke Gasification Behavior Based On Matrix Reactivity And Pore Diffusion

By researching the structure of coke and analysing the causes affecting properties of coke,the parameter which has the most important impact on properties of coke has been found.Ten types of industrial cokes are used in the experiments.The cokes are crushed into three different particle sizes.The CRI?coke reactivity index?and CSR?coke strength after reaction?were determined by test.According to thermal gravimetric analysis?TGA?test of fine-grained coke,the gasification reaction characteristic parameter V_F0-10?average reaction rate of conversion 3%¹0%?of fine-grained coke is obtained.Micron pore structure is determined by image analysis method,and nanoscale pore feature is determined by BET specific surface area test.Multiple linear regression is performed among CRI,parameters of pore structure and V_F0-10,an optimized mathematical model is established by SPSS software.This model shows that the proportion of 61¹20 ?m pores have the greatest impact on CRI.According to TGA test of granular coke,V_L3-10 is calculated by gasification reactivity test result.It has higher correlation with CRI,correlation coefficients is 0.9768.However,V_F0-10 has weak correlation with CRI.It is indicated that the large and medium pores structure of fine-grained coke have been destroyed.The granular coke retains these pores structure.Therefore,V_L3-10 has higher correlation with CRI.It verifies the above conclusions.From the view of macro kinetics,the influence of steel slag on thermal properties of coke is studied.Analysis on the effectiveness factor(?_ef)and the Thiele modulus???shows that thermal properties of coke are determined by both the matrix reaction and the pore structure of coke.At last,the CSR prediction method is optimized.Effect of pore diffusion is taken into consideration,and the optimized method can reflect CSR more objectively.The coke structure is largely determined by properties of coking coal.Finding an appropriate coal blending scheme,and coking coal will be utilized more reasonably and effectively.