配加铁矿粉对铁焦微观结构及性能的影响

 为了研究在炼焦过程中配加铁矿粉对焦炭性能的影响，在气煤中配加0、5%和10%的铁矿粉炼制铁焦，采用I-型转鼓、差热分析仪、SEM、XRD和光学显微镜对铁焦的强度、反应性、微观结构、微晶结构和光学组织进行研究，并采用Coats-Redfern方法计算气化反应的动力学参数。结果表明，在气煤中配加铁矿粉可以有效提高铁焦的转鼓强度及反应性，随着铁矿粉配比的增加，铁焦的堆垛高度Lc]值逐渐减小，石墨化程度降低，并且铁焦的气孔逐渐减小，且附着于气孔表面的铁原子密度增大，出现成片含铁区域，焦炭结构中各向同性结构和镶嵌结构减少，残炭结构增多。根据动力学分析可知，配加0、5%和10%的铁矿粉制得的铁焦，其活化能分别为228.4、235.5和256.7 kJ/mol，并且发现表观活化能与指前因子具有动力学补偿作用。

Effect of iron ore fines addition on microstructure and properties of iron-coke

In order to clarify the effect of iron ore fines which were added during coking process on the coke properties, three different iron ore blend ratios (0,5%and 10%) were used to make iron-coke. I-type drum、thermogravimetric analy-ser、SEM、XRD and optical microscope were used to investigate the properties of iron-coke,such as strength,reactivi-ty,microstructure,crystallite structure and optical texture. Moreover,the method of Coats-Redfern was used to calcu-late the kinetics parameters of the gasification reaction. The results showed that it could increase the cold strength and re-activity of iron-coke by adding iron ore fines into gas coal. With the increase of iron ore blend ratio,the stacking height Lc value of iron-coke and the gphitization degree decreased. The pore size of iron-coke became smaller as well. The den-sity of Fe atom attaching to the surface of the pore increased,and a piece of iron region was found. The isotropic and mosaic structure in coke was reduced,while the residual carbon structure was increased. According to the kinetics analysis,the activation energy of iron-coke with 0,5% and 10% iron ore fines blend ratio was 228.4,235.5 and 256.7 kJ/mol,respectively. Meanwhile,it was found that the apparent activation energy and pre-exponential factor had a kinetic compensation effect.