中文摘要：

在等温条件下进行了贺西煤焦的CO2气化实验，考察了灰分对煤焦气化特性的影响，分析了煤焦的碳微晶结构．结果表明，相同制焦条件下，原煤焦（Rc）、精煤焦（CC）、尾煤焦（TC）及脱灰煤焦（DC）的石墨化度顺序为DC〉CC〉RC〉TC，对应的气化活性为TC〉RC〉CC，说明灰分抑制煤焦石墨化，并在一定程度上提高了煤焦的气化反应活性；在反应初始阶段，高灰煤焦（灰分含量〉／48．47％）的气化活性较高，气化活性指数Rs（TC）=1．304Rs（RC）=2．421Rs（CC），反应后期随灰层阻力增加，气化活性逐渐降低；受扩散控制的三维扩散模型能较好地反映高灰煤焦的气化过程，而低灰煤焦的气化过程则可通过受化学反应控制的收缩核模型描述．

英文摘要：

CO2 gasification experiments of Hexi coal char were carried out, and carbon crystalline structure of the coal char was analyzed. The results indicate that the graphitization degree of char samples is in the order of demineralized coal char （DC） 〉 clean coal char （CC） 〉 raw coal char （RC） 〉 tailing coal char （TC） under the same coke making conditions, and the gasification activity of char samples in the order of TC 〉 RC 〉 CC correspondingly, showing that the existence of ash inhibits the char graphitization and enhances the gasification reactivity of coal char to some extent. High-ash coal char （ash≥48.47%） exhibits higher gasification reactivity in the initial stage, and the gasification reactivity index （Rs） of coal char is Rs（TC）=1.304Rs（RC）=2.421Rs（CC）. In the later stage, the gasification reactivity of high-ash coal char decreases gradually with the increase of ash layer resistance. CO2 gasification reaction of high-ash coal char can be well described by 3-D diffusion model. However, the best kinetic model expressing the reactivity of low-ash coal char is shrinking core model with chemical reaction controlling.