Assessment of coal spontaneous combustion index gas under different oxygen concentration environment: an experimental study.

Oxygen plays a crucial role in coal spontaneous combustion (CSC), and the magnitude of oxygen concentration determines the oxidation reaction intensity of CSC. This work is aiming to investigate the contribution of oxygen concentration to CSC and to predict the spontaneous combustion stage of coal at different oxygen concentrations. Firstly, experiments on the spontaneous combustion of coal samples at six oxygen concentrations (6%, 9%, 12%, 15%, 18%, and 21%) were carried out combined with a temperature-programmed system.

Investigating the effect of coal particle size on spontaneous combustion and oxidation characteristics of coal.

As a key parameter, the particle size of residual coal contributes greatly to its oxidation characteristics, so it is a significant and far-reaching topic to explore the role of different particle sizes in coal spontaneous combustion disaster. In this work, temperature-programmed system (TPS) was applied to analyze the oxygen consumption rate and CO and CH production rules of six groups of coal samples with different particle sizes in the process of oxidation heating. The critical temperature (CT) and xerochasy temperature (XT) of different coal samples were obtained, and the coal oxidation process was divided into three stages (S1, slow oxidation stage; S2, fast oxidation stage; and S3, combustion stage).