Abstract
This study concerns with the thermoplastic performance of "Hyper-coal", and its applicability for the coke material, which replaces to the high value coking coal. Hyper-coal (HPC) is an ashless coal, which is made by applying the solvent de-ashing technology. Coal is extracted with the coal derived recycling solvent, which consists mainly with 2-ring aromatics, at 360380°C, and the solid material (RC, insoluble coal including ash) is removed by gravity settling. From the coal extraction examination with a number of coals, we found that HPC has a high heat value (>35 MJ/kg) and an excellent thermal plasticity. HPC revealed much more excellent fluidity from lower temperature to higher temperature range than that of the parent coal. Moreover, not only from the coking coal, but also from the low rank coal, which has no thermal plasticity, the produced HPC revealed an excellent thermal plasticity.
In addition, the mixture of HPC and RC also revealed the thermal plasticity, even though the parent coal was brown coal.
The characteristics and strength of the cokes, made by addition of HPCs were investigated. The thermal plasticity was improved when HPC was added to various coals. The value of the I-type coke strength was maximum level when the HPC addition into blended coal was at 0.5 wt%. But excessive addition of the HPC deteriorated I-type coke strength. To get the reason, the coke breeze particle distributions in I-type coke strength tests were examined. We confirmed that amounts of fine breeze (<0.25 mm) correlated with I-type drum index.
