Multiple linear equation of pore structure and coal–oxygen diffusion on low temperature oxidation process of lignite  

作　　者：Xianliang Meng Mingqiang Gao Ruizhi Chu Guoguang Wu Qiang Fang 

机构地区：[1]School of Chemical Engineering and Technology, China University of Mining & Technology [2]Key Laboratory of Gas and Fire Control for Coal Mines, China University of Mining & Technology

出　　处：《Chinese Journal of Chemical Engineering》2016年第6期818-823,共6页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(51204179,51204182);the Natural Science Foundation of Jiangsu Province,China(BK20141242)

摘　　要：This work aimed at studying the feasibility of calculating the coal-oxygen diffusion properties during the low temperature oxidation process of lignite so as to predict its spontaneous combustion process. Coal samples were oxidized in air ambient under different temperatures. Scanning Electron Microscope was used to indicate the surface morphology changes of oxidization. Then, based on fractal theory and flow characteristics, the ffactal dimension of gas diffusion in the pore ways was calculated under different temperature. Considering pore size distribution, connectivity distribution and Fick diffusion mechanisms, the relationship between the gas diffusivity change with pore area ffactal dimension and porosity was investigated, and multiple linear equation of the coal- oxygen diffusion coefficients and pore parameters was obtained. Comparison between the experimental data and model prediction verifies the validiW of the model. The research provides a theoretical basis for the prediction model of coal-oxygen diffusion law.This work aimed at studying the feasibility of calculating the coal–oxygen diffusion properties during the low temperature oxidation process of lignite so as to predict its spontaneous combustion process. Coal samples were oxidized in air ambient under different temperatures. Scanning Electron Microscope was used to indicate the surface morphology changes of oxidization. Then, based on fractal theory and flow characteristics, the fractal dimension of gas diffusion in the pore ways was calculated under different temperature. Considering pore size distribution, connectivity distribution and Fick diffusion mechanisms, the relationship between the gas diffusivity change with pore area fractal dimension and porosity was investigated, and multiple linear equation of the coal–oxygen diffusion coefficients and pore parameters was obtained. Comparison between the experimental data and model prediction verifies the validity of the model. The research provides a theoretical basis for the prediction model of coal–oxygen diffusion law.

关 键 词：Coal spontaneous combustionOxidationPore structureDiffusion 

分 类 号：TD752.2[矿业工程—矿井通风与安全]