不同配比弱黏结性煤参与配煤炼焦的研究

Research on Different Proportion of Weakly Cohesive Coal Participating in Coal Blending and Coking

选取低煤阶的长焰煤和高煤阶的瘦煤两种弱黏结性煤为研究对象,将其分别配入焦化厂常用的焦煤和肥煤中,对配入不同比例(长焰煤质量分数为3%,4%,5%;瘦煤质量分数为3%,5%,7%)煤样的工艺性质进行分析,并研究所配煤样炼制坩埚焦的热性质、显微强度与光学组织。结果表明:长焰煤挥发分较高,配入质量分数在4%以内时,配合煤样黏结指数G、奥阿膨胀度b、总膨胀度(a+b)及胶质层最大厚度Y等指标劣化程度小,黏结性能小幅下降;配入质量分数增至5%时坩埚焦热性质严重劣化,粒焦反应性PRI值最高、粒焦反应后强度PSR及显微强度MSI值最低。瘦煤挥发分较低,配入质量分数在7%以内时,配合煤样工艺性质、所配煤样坩埚焦热性质在一定范围内波动;长焰煤对所配煤样坩埚焦光学组织指数(OTI)劣化主要表现在焦炭丝质、破片与各向同性的增加,瘦煤对所配煤样坩埚焦OTI劣化主要表现在焦炭细粒镶嵌组织的增加。

Two kinds of weakly cohesive coals,low rank long flame coal and high rank lean coal were selected as the research objects,and they were mixed into coking coal and fat coal commonly used in coking plant.The process properties of coal samples mixed with different proportions(long flame coal mass fraction of 3%,4%,5%;lean coal mass fraction of 3%,5%,7%)were analyzed,and the thermal properties,micro strength and optical structure of crucible coke refined from coal blending samples were studied.The results show that the volatile content of long flame coal is high,when the mass fraction of long flame coal is less than 4%,the deterioration degree of coal adhesion index G,Audibert-Arnu dilatation b,total expansion(a+b)and the maximum thickness Y of colloidal layer are small,and the adhesion performance decreases slightly.When the mass fraction of long flame coal increases to 5%,the thermal properties of crucible coke deteriorate seriously,the PRI value of particle coke reactivity reaches the highest,and the PSR and MSI values of particle coke after reaction are the lowest.The volatile content of lean coal is low,when the mass fraction of lean coal is less than 7%,the process properties of coal samples and the thermal properties of crucible coke fluctuate in a certain range.The deterioration of OTI by long flame coal is mainly reflected in the increase of coke filaments,fragments and isotropy,and the deterioration of OTI by lean coal is mainly reflected in the increase of fine-grained mosaic structure of coke.