岩浆侵入煤系地层在我国广泛存在，侵入后煤体结构和组分发生改变，形成高阶变质煤，但其自燃特性尚不明确。探究岩浆侵入作用对煤低温氧化特性的影响，对开采岩浆侵入煤层自燃灾害的防控具有重要意义。以新安煤矿二采区−350工作面为工程背景，现场采集距侵入体不同距离的煤样，通过测试各煤样的工业成分并分析表面形貌的差异，得出岩浆侵入主要通过接触热演化作用使得原煤变质，表面孔隙和裂隙数量增多，并随着距侵入体距离的增加将变质煤依次划分为强侵蚀煤、弱侵蚀煤和同镜质组高阶煤。基于固定碳、灰分、镜质组反射率以及古地温等指标，采用曲线反推法计算了不同侵入变质煤的分布范围，预测出岩浆侵入影响范围约为侵入体宽度的172.34%～234.68%。采用C80微量热仪对不同变质煤和原煤进行了低温氧化过程热效应的对比研究。结果表明：不同供风量条件下，相比于原煤，强侵蚀煤、弱侵蚀煤和同镜质体高阶煤在低温氧化阶段的初始放热和热平衡温度点分别提前0.2～3.4 ℃和1.9～18.2 ℃，总放热量提高1.72%～135.75%，表观活化能降低1.62%～69.02%，越靠近岩浆侵入体的变质煤，氧化放热能力越强，自然发火期越短；在供氧充足条件下，岩浆侵入仅对距侵入体1.01～2.68 m的强侵蚀煤氧化反应放热能力提升较为显著，其开采量仅约占岩浆侵入影响范围的6.23%～12.15%。因此，在回采进入岩浆侵入区时，应加强对强侵蚀煤自燃的防治，并及时修正该区域煤自燃预报指标的临界值，从而保障煤层安全开采。

Magma intrusion into coal seams is widely existed in China, and the structure and components of the coal body are changed after intrusion to form a high-order metamorphic coal, but its spontaneous combustion characteristics are not clear. It is a great significance to explore the effect of magma intrusion on the low-temperature oxidization characteristics of coal, and to prevent and control spontaneous combustion disasters in mining magma-eroded coal seams. Taking the −350 working face in the second mining area of the Xin'an Coal Mine as the engineering background, the coal samples were collected at different distances from the magma intrusion on the spot. By testing the industrial composition and analyzing the differences in the surface morphology of the samples, it was concluded that magma intrusion metamorphosed the raw coal and increased the number of pores and fissures on the surface, mainly through contact thermal evolution. The metamorphic coals were categorized into strongly eroded coals, weakly eroded coals, and high rank coals of the homogeneous group. Based on fixed carbon, ash, specular group reflectance, and paleo temperature, the distribution range of different intrusive metamorphic coals was calculated by curve backpropagation, and the influence range of magmatic intrusion was predicted to be about 172.34%−234.68% of the width of the intrusive body. A comparative study of the oxidative thermal effect of magma intrusion on metamorphic coal and raw coal was carried out by using C80 microcalorimeter. And the results showed that under different air supply conditions, compared with the original coal, the initial exothermic and thermal equilibrium temperature points in the low-temperature oxidation stage were advanced by 0.2−3.4 ℃ and 1.9−18.2 ℃ for strongly eroded, weakly eroded, and homogeneous high-order coals, the total exothermic capacity was increased by 1.72%−135.75%, and the apparent activation energy was reduced by 1.62%−69.02%, and the closer the metamorphic coal was to the magma intrusion, the more oxidizing and exothermic it was, and the shorter the natural ignition period was. Under the condition of sufficient oxygen supply, magma intrusion enhanced the exothermic capacity of oxidation reaction of the strongly eroded coal within the range of 1.01−2.68 m from the magma intrusion, and its mining volume only accounted for about 6.23%−12.15% of the influence range of the magma intrusion. Therefore, when mining back into the magma intrusion area, the prevention and control of spontaneous combustion of strongly eroded coal should be strengthened, and the critical value of the coal spontaneous combustion forecast index in this area should be corrected in time, so as to guarantee the safe mining of coal seams.