Thermo-swelling Behavior of Australian Coking Coals from Different Basins: Relating to Rank and Maceral Compositions

Abstract

Eight Australian coking coal samples (RvMax from 0.8 to 1.6) from six different basins were employed to investigate the effect of coal maceral compositions and rank on thermo-swelling behavior. Coal pyrolysis experiments were conducted at a heating rate of 5 °C/min from room temperature (25 °C) to 1000 °C with a top coal particle size of 212 μm. Thermoplasticity of coal was evaluated on the basis of the change of permeability of coal pellets, plastic range, swelling factor (defined by maximum swelling %/vitrinite %), and heat of exothermic reactions during the primary devolatilization. The endothermic and exothermic processes were identified by the estimate of the apparent specific heat using the computer-aided thermal analysis (CATA) technique, while swelling and permeability of gas flowing through coal pellets were simultaneously investigated with extended volumetric measurement downstream and pressure sensor upstream, respectively. Volatile evolution profiles of heating coal samples with temperature we...