Tar-rich coal was directly combusted during power generation, resulting in a huge waste of precious oil resources and a large amount of carbon emissions. The idea of intelligent unmanned mining machine (IUMM) for in-situ fluidised mining and conversion of tar-rich coal was proposed to solve the problems of traditional mining and utilisation methods, realise efficient utilisation of tar-rich coal, and achieve net-zero CO₂ emission. A key technology of IUMM is the pyrolysis and fragmentation of tar-rich coal by high-power microwave irradiation. In this study, we carried out experiments on the strength and microstructural changes of tar-rich coal under different microwave irradiation conditions using the high-power microwave irradiation testing system to explore the effects of microwave irradiation on tar-rich coal and provide a reference for the design of IUMM. The X-ray computed tomography was employed to observe and characterize the initiation, growth, connection, and spatial distribution of internal fractures of tar-rich coal under different microwave irradiation conditions. The quantitative relationship between the strength characteristics of tar-rich coal and microwave irradiation conditions was established. The results show that under a fixed microwave power or irradiation time, the overflow rate of coal gas and tar is linearly positively correlated with microwave energy E, and both the uniaxial compressive strength and brittleness of tar-rich coal have piecewise linear negative correlation with E. With the increase of E, the internal fractures grow and connect more, which are synchronised with the decrease of the uniaxial compressive strength and elastic modulus of the tar-rich coal. With equal E input, high-power microwave has a more significant effect on strength weakening, fracturing, and fragmentation of tar-rich coal. Our findings can be used for the subsequent implementation of in-situ pyrolysis and fragmentation technology of IUMM for realising the in-situ conversion, high-efficiency utilisation, and low carbon emissions of tar-rich coal.

富焦煤在发电过程中直接燃烧，造成宝贵石油资源的巨大浪费和大量碳排放。为解决传统开采利用方式存在的问题，实现富焦煤高效利用，实现净零化二氧化碳₂排放。IUMM的一项关键技术是高功率微波辐照富焦油煤的热解和破碎。本研究利用高功率微波辐照测试系统对不同微波辐照条件下富焦油煤的强度和微观结构变化进行了实验，探讨微波辐照对富焦油煤的影响，为研究提供参考。 IUMM的设计。X 射线采用计算机断层扫描技术观察和表征了不同微波辐照条件下富焦油煤内部裂缝的萌生、生长、连接和空间分布。建立了富焦油煤的强度特性与微波辐照条件之间的定量关系。结果表明，在一定的微波功率或辐照时间下，煤气和焦油的溢流率与微波能量E呈线性正相关，富焦油煤的单轴抗压强度和脆性均与E呈分段线性负相关。 . 随着E的增加, 内部裂缝扩展和连接更多，这与富焦油煤的单轴抗压强度和弹性模量的降低是同步的。在E输入相等的情况下，高功率微波对富焦油煤的强度弱化、压裂、碎裂作用更显着。该研究成果可用于后续实施IUMM原位裂解破碎技术，实现富焦煤原位转化、高效利用和低碳排放。