Disintegration Characteristics Investigation of Carbonaceous Shale in High-Latitude Cold Regions

Abstract

To investigate the disintegration and microstructure characteristics of carbonaceous shale in high-latitude cold regions, indoor, outdoor, initial particle size, and freeze–thaw disintegration experiments were conducted concerning dry–wet cycles. Two tests were performed: sieving and microscopic scanning electron analysis. The carbonaceous shale disintegration, particle size variation rule, disintegration resistance, and fractal characteristics were studied. The microstructure variations of carbonaceous rock before and after water immersion were compared, and the microscopic mechanism of calving in water was discussed. The results show that: (1) the disintegration of carbonaceous shale is basically achieved after eight dry–wet cycles, and the particle size is concentrated at 2 mm~10 mm; (2) the temperature and freeze–thaw cycle conditions accelerated the disintegration rate and shortened the disintegration stability time of carbonaceous shale; (3) there is a negative correlation between the disintegration resistance index and the disintegrating fractal dimension of carbonaceous shale, and the disintegration resistance of disintegrating carbonaceous shale can be indirectly characterized by the fractional dimension; (4) carbonaceous shale contains two hydrophilic clay particles, kaolinite and montmorillonite, and the difference between the lattice expansion of clay particles, the expansion of adsorbed water film, and mineral dissolution are the main factors leading to the disintegration of carbonaceous rock.

Keywords

• carbonaceous shale
• dry and wet cycles
• disintegration properties
• disintegration resistance index
• freeze–thaw cycle
• fractal theory