Material characteristics affecting formcoke

The influence of aggregate and binder phase characteristics on formcoke products has been studied by investigating the compaction kinetics of the system and determining the mechanical strength of the briquettes produced. The char phase was characterized in terms of density, hardness and porosity and the binder phase with respect to rheological properties. Results indicate that binder phase fluidity affects compaction viscosity during the particle flow stage of compaction and that char porosity influences final briquette bulk density by affecting the amount of total compaction required to obtain a given bulk density. In general, increased total compaction was shown to result in higher product bulk density with the attendent higher gross composite strength. The latter relationship was seen to be approximately linear over the range of bulk porosity found in this study. A higher briquette strength was found for systems with aggregates carbonized at lower temperatures. Similarly the binder phase fluidity was also seen to affect briquette strength, higher fluidity resulting in higher strength. It was concluded that this was due to increased binder penetration in the highly porous char carbonized at lower temperatures. With no significant pore structure in the aggregate, as found with high temperature char, briquette strength was seen to become approximately constant for the three binder coals used.