Scientific Development Research

To investigate the influence of different oxygen concentrations on the spontaneous combustion characteristics of coal, a programmed temperature experiment was conducted with a heating rate of 5 K/min, a temperature range of 30~400℃ and a gas flow rate of 50 ml/min. By adjusting the flow rates of N₂ and O₂, nine oxygen concentration conditions were achieved: 0%, 3%, 5%, 7%, 10%, 12%, 15%, 18%, and 21%. A systematic experimental study was carried out using a coal sample prone to spontaneous combustion from the Zhundong region of Xinjiang. By monitoring the changes in the concentrations of characteristic gaseous products such as CO and CO₂ during the heating process, the influence mechanism of different oxygen concentrations on the coal oxidation and spontaneous combustion process was analyzed. The experimental results indicate that when the temperature reached 100°C, the CO₂ concentration generated by the coal sample increased significantly with rising oxygen concentration. Meanwhile, the CO concentration initially exhibited exponential growth, peaking at 31,590 ppm and 31,570 ppm under oxygen concentrations of 12% and 15%, respectively. The research results provide a theoretical basis for the formulation of mine fire prevention and extinguishing technologies and the optimization of inert gas fire prevention measures.

Coal; Coal spontaneous combustion; Oxygen concentration; Programmed temperature ramping experiment