1. School of Safety Science and Engineering,Xi’an University of Science and Technology,Xi’ an　 710054,China; 2. Shaanxi Key Laboratory of Prevention and Control of Coal Fire,Xi’an University of Science and Technology,Xi’ an　 710054,China; 3. Sichuan Coal Industry Group Limited Liability Company, 154,Changshun Street,Chengdu　 610000,China

离子液体作为新型阻化剂可溶解破坏煤中活性基团，抑制煤氧化反应进程，从根本上达到阻化煤自燃的目的。但不同变质程度煤样微观结构不同，而且离子液体成本较高，因此，难以在煤自燃领域现场实施应用。基于此，考察了离子液体对不同变质程度煤自燃热行为特征的影响，且从经济性和实用性方面考虑，选用低浓度(质量分数为5%)1-丁基-3-甲基咪唑四氟硼酸盐([BMIM][BF4])对褐煤、长焰煤、气煤以及1/3焦煤进行热重-差热联用(TG-DSC)实验和热物性参数测试实验，得出离子液体处理不同变质程度煤的特征温度、热效应及热物性参数变化规律。结果表明:离子液体延后了煤失重过程中的特征温度，提高了煤自燃过程中的初始放热温度和最大热释放速率温度，对最大放热速率以及放热量都有着明显的抑制效应，且抑制作用随着煤变质程度的升高而减弱，说明离子液体对于低阶煤效果较好;与原煤样相比，离子液体处理煤样的热扩散系数和导热系数较低，比热容则较高，说明离子液体降低了煤体之间热量传递的速度，增加了煤体温度上升所需的热量，弱化了煤体因温差传递热量的能力，对煤样的传热性能起到了抑制作用，并且煤的变质程度越低，抑制效果越明显。结果可为离子液体抑制煤自燃领域的推广及现场应用提供借鉴。

Ionic liquid (IL) is a new type inhibitor,which can inhibit the active functional groups in the molecular structure in coal,and inhibit coal oxidation process. However,different metamorphic coal samples have different micro- structures. Moreover,IL has high cost,which is difficult to implement in the field of coal spontaneous combus-tion (CSC). To investigate the effects of IL on the thermal properties of CSC with different metamorphic levels,consid-ering economics and practicality, low concentration ( 5 mass% ) 1-butyl-3-methylazole tetrafluoroborate ([ BMIM][BF4 ]) is used to treat coal samples. Using simultaneous thermal analysis (STA) and laser flash apparatus (LFA), the oxidation and exothermic behaviors of four types of coal were analyzed. The characteristic temperature,thermal effects and thermophysical parameters of coal with different metamorphic levels of IL treatment were obtained. The re- sults show that the [BMIM][BF4 ] delayed the characteristic temperature of coal mass loss,increased the initial / maxi- mum heat release temperature,and reduced the maximum heat release rate / thermal release during CSC. Moreover,the inhibition effect decreases as the levels of coal metamorphism increases. Compared with the raw coal sample,the ther- mal diffusion coefficient and thermal conductivity of the treated coal sample are lower,and the specific heat capacity is higher. Namely,the [BMIM][BF4 ] reduces the rate of heat transfer between coal bodies and weakens the ability to transfer heat due to temperature difference,increases the heat required to raise the temperature of the coal bodies. In addition,the lower the levels of coal metamorphism,the more significant the inhibiting impact on CSC. The study re- sults provide a theoretical basis for the promotion and application of IL inhibit at CSC field.

DENG Jun,LÜ Huifei, LI Dajiang, et al. Thermal behavior effects of 1-butyl-3-methylimidazole tetrafluoroborate on coals spontaneous combustion with different metamorphic levels[J]. Journal of China Coal Society,2019,44(1):254-262.