According to the graphitization process of coke in the blast furnace,the constant tempera-ture time was set to 0.5h and 1.5h through different heating temperature, the microcrystalline struc-ture,pulverization rate and graphitization degree of the coke samples were analyzed.Experiment result shows,with the increase of secondary heating temperature,La,Lcshowed an increasing trend,and the Laand Lcvalues at high incubation time were significantly higher than those of low temperature and the constant temperature time has a positive effect on the rise of Laand Lc.In general,d002decreases with the increase of secondary heating temperature,and the change of d value at low constant temperature is more obvious.The chalking rate of the coke increases with the increase of the secondary heating tem -perature,and the coke structure is aggravated by the extension of the heating time.The pulverization phenomenon is more obvious and the pulverization rate is also increasing.Since the graphitization process of coke is an exothermic process,the coke calorific value after secondary heating will also de-crease,and the longer the constant temperature will decrease the more calorific value.%针对焦炭在高炉内的石墨化过程,通过不同的加热温度,将恒温时间分别设定为0.5h和1.5h,对试验后焦炭样品进行微晶结构、粉化率及石墨化度等参数测定.实验结果显示,随着二次加热温度的上升,焦炭的La、Lc值均呈上升趋势,且恒温时间对La、Lc值的升高有促进作用;d002随二次加热温度的上升而降低;二次加热温度升高后焦炭的粉化率也随之增大,恒温时间的延长使焦炭结构劣化加剧,粉化现象更加明显,粉化率增大.由于焦炭的石墨化过程是一个放热过程,因此二次加热后的焦炭热值也会下降,且恒温时间越长热值下降越明显.
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