Volatile release from maceral concentrates of pulverised coals used for pulverised coal injection at temperatures of 1550 °C and their relationship with density

Abstract The impact of macerals and their pyrolysis behaviour on pulverized coal injection (PCI) combustion in blast furnaces is unclear. At present, a coal’s combustibility is considered to be related to its volatile content, as measured by the proximate analysis, alone, even though it is known that some coals’ performances do not follow this trend Elliott et al. (2013) . The impact of coal macerals, particularly vitrinite, on volatile release, was therefore assessed by pyrolysing maceral concentrates in a drop tube furnace with a preheated gas. Maceral concentrates produced from 5 coals with a range of rank were used. The density of the maceral concentrates was found to influence volatile release under elevated heating rates, at 1550 °C. The graphitic nature of the resulting char was also found to depend on the density of the maceral concentrate from which the char was produced.