Mechanism of Thermoplasticity for Coal Blends Containing Low-quality Coals

Thermoplasticity for coal blends containing a large amount of slightly-caking Enshu coal was evaluated by a dynamic viscoelastic technique using a temperature-variable rheometer. It was found that overlapping of temperature range showing high thermoplasticity for blended original coals during heating is the most important factor to enhance the thermoplasticity of their blends; A Gregory-Enshu coal blend (1:1) showed a high synergistic effect for thermoplasticity, because their temperature ranges of thermoplasticity were quite overlapping. The mechanism of thermoplasticity for blend coals is explained by the "Continuous Self-Dissolution Model" proposed before, which has been used for explaining of thermoplasticity for caking coal alone. Addition of solvent-soluble component in a caking coal to coal blend was significantly effective to enhance the overlapping of thermoplastic temperature range for the coal blend, since the solvent-soluble component has originally a wider temperature range of thermoplasticity during heating.