A multi-particle characterization index describing the degree of fragmentation was proposed.Thermal fragmentation and pulverization properties of Huadian oil shale under different pyrolysis conditions were systematically investigated using the self-designed drum pyrolysis reactor

and the fragmentation mechanism was analyzed.The results showed that in thermo-mechanical force coupled loading mode

the rate of pulverization was 3.96 times of the sum of the individual loading modes

which indicated the synergistic effect of the coupled loading mode.The thermal force was the main influencing factor

its essence was the evolution of the internal pore structure

and the mechanical force was to enhance the phenomenon of fragmentation.The relative breakage rate and the pulverization rate were consistent with the change trend of pore structure.The smaller the feeding particle size

the smaller the overall degree of fragmentation.The higher the oil content

the greater the degree of fragmentation.The pulverization rate of the lean sample is lowest due to the higher content of calcite which was difficult to decompose into fine particles.Fragmentation and pulverization were two relatively independent concepts;there was no correlation between them.