2004 Volume 90 Issue 9 Pages 739-742
Thermoplasticity for coal blends of a high-caking Goonyella coal and a slightly-caking Witbank coal was evaluated by a dynamic viscoelastic technique using a temperature-variable rheometer. At several blend ratios, effect of heating rate on the thermoplasticity for blends was investigated. At a heating rate of 3°C/min, for the coal blends containing 50% Witbank coal, the thermoplasticity was almost the same as Witbank coal alone, suggesting that Witbank coal has any negative effect for thermoplasticity of the blends with Goonyella coal. In contrast, in the cases of less than 30% Witbank coal contained, a sufficient thermoplasticity to produce metallurgical cokes was observed. On the other hand, when the heating rate was increased to 10°C/min, even for the blend containing 70% Witbank coal, a high thermoplasticity was obtained. This result indicates that the slight increase in heating rate greatly affected the thermoplasticity of coal blends. In addition, it is suggested the coal blend containing 70% slightly-caking Witbank coal can be used for cokemaking, when the heating rate is increased to 10°C/min during heating.
