With the development of carbon dioxide sequestration, the influence of carbon dioxide on coal properties has been paid more and more attention by experts and scholars. Scanning electron microscopy was employed to observe the three-point bending characteristics of bituminous coals treated with or without carbon dioxide gas. The experimental results showed that the carbon dioxide gas treatment had obvious effects on the micro-crack propagation of the coal samples. With the carbon dioxide gas treatment, the bending strength, bending modulus and fracture toughness of the coal samples decreased, and the brittleness of the coal materials tended to be alleviated. The influence of the carbon dioxide gas treatment on the brittleness of the coal samples could be estimated by means of the bending energy index α, which is the ratio of the post-peak and pre-peak bending energy. The experimental results also indicated that the fracture lengths and fractal dimensions increased for coals that underwent the carbon dioxide gas treatment.

随着二氧化碳封存技术的发展，二氧化碳对煤质的影响越来越受到专家学者的关注。用扫描电子显微镜观察用或不用二氧化碳气体处理的烟煤的三点弯曲特性。实验结果表明，二氧化碳气体处理对煤样品的微裂纹扩展具有明显的影响。通过二氧化碳气体处理，煤样品的弯曲强度，弯曲模量和断裂韧性降低，并且煤材料的脆性趋于减轻。二氧化碳气体处理对煤样品脆性的影响可以通过弯曲能指数α来估算。，这是峰后和峰前弯曲能量之比。实验结果还表明，经过二氧化碳气体处理的煤的断裂长度和分形维数增加。