摘要
炼焦煤成焦过程中形成的塑性层对炼焦过程的稳定和焦炭质量具有重要影响。塑性层的低透气性和高膨胀压力可能导致推焦电流过大,进而影响焦炉的正常运行。因此,塑性层透气性和膨胀性已成为衡量炼焦煤安全性能的重要指标。为深入探究炼焦煤成焦过程中塑性层透气性及膨胀性的演变,扩展其在炼焦煤评价指标中的应用。以6种不同变质程度的炼焦煤为研究对象,利用核磁共振碳谱(^(13)C-NMR)分析了煤分子结构特性,结合热重分析(TGA)探究煤的热分解行为,检测了煤成焦过程中的吉式流动度、奥亚膨胀度、透气性和膨胀压力,解释了煤在塑性区间的挥发分释放行为,阐明奥亚膨胀度和膨胀压力的相似和差异性。结果表明:透气性能较为全面地反映塑性层变化过程,初始低透气温度(T_(i))随煤变质程度的增加而升高。低透气温区(ΔT_(P))与液气比(LGR)呈二次函数关系,且与煤分子结构单元的大小密切相关。ΔT_(P)较相应的塑性温区(ΔT)更宽,归因于新生半焦的致密结构阻碍了挥发分的释放。膨胀压力能够弥补奥亚膨胀度,是评价气煤和瘦煤膨胀行为的重要参数。初始软化温度(T_(1'))随煤化程度的加深而升高,塑性层最大膨胀压力(SP_(Tmax))随芳香度先升高后降低。SP_(Tmax)、膨胀体积与LGR和ΔP均为正相关关系。
The plastic layer that forms during the coking process of coking coal is crucial for the stability of the coking operation and the quality of the resulting coke.The low permeability and high swelling pressure of the plastic layer can lead to excessive pushing current during coke pushing,affecting the normal operation of the coke oven.Therefore,the permeability and expansion properties of the plastic layer have become important indicators for measuring the safety performance of coking coal.To explore the evolution of permeability and expansion of the plastic layer during the coking process of coking coal and to extend its application in the evaluation indicators of coking coal,six types of coking coal with different degrees of metamorphism were utilized as research subjects.Solid-state nuclear magnetic resonance carbon spectroscopy(^(13)C-NMR)was employed to analyze the molecular structural characteristics of the coal,and thermogravimetric analysis(TGA)was combined to investigate the thermal decomposition behavior of the coal.The study measured the Gieseler fluidity,Audibert-Arnu dilatation,permeability,and expansion pressure during the coal coking process.The study explained the release behavior of volatiles in the plastic interval of the coal,and elucidated similarities and differences between the Audibert-Arnu dilatation and swelling pressure.The results indicate that permeability can comprehensively reflect the changes in the plastic layer.The initial low permeability temperature(Ti)increases with the degree of coal metamorphism.The low permeability temperature zone(ΔT_(P))exhibits a quadratic function relationship with the liquid-gas ratio(LGR)and is closely related to the size of the coal molecular structural units.ΔT_(P) is wider than the plasticity temperature zone(ΔT),attributed to the dense structure of the newly formed semi-coke hindering the release of volatiles.Swelling pressure can compensate for the Audibert-Arnu dilatation degree and is an important parameter for evaluating the expansion behavior of gas coal and lean coal.The initial softening temperature(T_(1'))increases with the deepening of coalification,and the maximum expansion pressure of the plastic layer(SP_(Tmax))first increases and then decreases with the degree of aromaticity.There is a positive correlation between SP_(Tmax),expansion volume,LGR,andΔP.
作者
苗国鹏
杨伯威
邓韶博
崔贝贝
申岩峰
王美君
MIAO Guopeng;YANG Bowei;DENG Shaobo;CUI Beibei;SHEN Yanfeng;WANG Meijun(State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China;Shanxi Coking Group Co.,Ltd.,Linfen 041606,China)
出处
《洁净煤技术》
北大核心
2025年第S2期420-428,共9页
Clean Coal Technology
基金
山西焦化股份有限公司技术开发基金资助项目(GFPMJS(2022)004)
山西省重点研发计划基金资助项目(202102090301002)
关键词
炼焦煤
塑性层
透气性
膨胀压力
coking coal
plastic layer
permeability
swelling pressure
