A coal sample with at least a maximum fluidity value of 300 DDPM may be coking.
The maximum LT during heating was as an index of the maximum fluidity of the molten cheese.
Maximum fluidity of coal determined by the standardized Gieseler plastometry test was found to correlate well with the amount of volatile matter evolved up to 500 °C and with that evolved in the plastic or fluid stage (between 375 and 500 °C and 400 and 500 °C).
The rheological characteristic values like the softening temperature, resolidification temperature and maximum fluidity of Garin Maiganga and Tai coal samples were not detected; therefore, zero values were observed.
The maximum fluidity (DDPM), G value and free swelling index (crucible number) indicate that the Shankodi-Jangwa coal sample is of medium-coking class.
The maximum fluidity value of 300 DPPM observed in the Shankodi-Jangwa coal sample indicates that the coal is of medium coking.
Table 4 Gieseler plastometric results of the Shankodi-Jangwa coal sample Analytical parameters Characteristic values Softening temperature (°C) 388 ± 3.60 Resolidification temperature (°C) 107 ± 7.21 Temperature range (°C) 455 ± 6.20 Maximum fluidity temperature (°C) 455 ± 6.20 Maximum fluidity per minute (DDPM) 300 ± 10.00 DDPM, dial division per minute.
The agglomerating and rheological properties of the coals revealed that only Shankodi-Jangwa coal has some coking properties with a crucible number of 3.0, temperature range of 107°C, maximum fluidity of 300 and dilatometric G value of 0.96, indicating that it is a low-plasticity and medium-coking coal, which may be blended with strongly coking, low-ash, low-sulphur and high-fluidity coal.
The Shankodi-Jangwa coal sample was observed to soften at a temperature of 388°C, attained a maximum fluidity of 300 DDPM at a temperature of 455°C and finally resolidified at a temperature of 495°C.
