Impact of large sized inertinite particles on thermo-swelling and volatile release of coking coals

摘要

A reflux classifier system was employed to concentrate large sized inertinite-rich particles (1.6-2.0 mm) from two different ranked coking coals A and B. The impact of these concentrates on swelling, permeability and volatile evolution rates of another two coking coals C and D was investigated using the Computer Aided Thermal Analysis (CATA) and Dynamic Elemental Thermal Analysis (DETA) techniques. The results indicated that the concentrated inertinite-rich particles contained inertinite up to 75% for both coals A and B. When 25% inertinite particles were blended with 75% coal C or D by mass, the low rank inertinite concentrates A caused higher extents of effect on swelling and permeability than the high rank inertinite concentrates B, leading to higher softening temperatures with smaller plastic ranges. During swelling, inertinite concentrates B can compress volatile evolution rates of both coals C and D, however, inertinite concentrates A promoted volatile evolution rate of coal C. Concentrates from both coals A and B can compress the utilization of volatiles for driving swelling, the blend containing concentrate A used nearly half of volatiles that coals C and D themselves used for driving swelling. This study suggested that the additive internite concentrates not only provided a pathway for gas diffusion, but also interacted with the blended coals, which affected thermoplasticity of the whole blends.