부산대학교 도서관

To reveal the influence of pre-oxidation time on coal spontaneous combustion behaviors, temperature-programmed experiments were carried out to analyze the kinetics characteristics of coal primary and secondary spontaneous combustion from the macro viewpoint. By the growth-rate analysis of gaseous compounds, the critical temperature of raw coal (Y0) spontaneous combustion was 70°C. At the critical temperature, isothermal oxidation was performed for 2 h, 4 h, 6 h, and 8 h, and the processed samples were named Y2, Y4, Y6, Y8. It was found that the changing trend of CO concentration increased at first and then decreased with the increase in isothermal pre-oxidation time. Two maximum peak values were found near the 1st and 4th hour in the production of CO2 gas. Spontaneous combustion characteristic parameters and apparent activation energy of oxidized coal showed staged characteristics compared to raw coal. Below 70°C, the order of spontaneous combustion characteristic parameters and the apparent activation energy was Y0< Y2< Y4< Y6< Y8. Above 70°C, the order was Y6< Y8< Y2< Y4< Y0. Isothermal pre-oxidation at the critical temperature could slow down coal secondary low-temperature oxidation and speed up high-temperature oxidation. When isothermal pre-oxidation is at the critical temperature, the pre-oxidation time has double effects on the high-temperature oxidation of oxidized coal. [ABSTRACT FROM AUTHOR]