We tried to produce metallurgical coke from several non-coking and slightly coking coals by use of a hotbriquetting apparatus. Without loading pressure the coals were not caked when they were heated up to 500°C. However, the non-coking coals were caked when they were heated up to 500°C under the pressure larger than 10×105Pa. The compressive strength of the cokes produced by carbonizing the caked coals up to 800°C was very strong, but the CO2 reactivity of the cokes was very high, in comparison with a commercial coke. It is essential to load pressure on the coal between 300 and 450°C when the coal is pyrolyzed to a large extent. Thus, we could produce coke from non-coking coals, but not from coking-coals by this method. This is because the volatile matter could not be removed from coking-coals in a short time under the pressure.
