Coal as a fossil fuel can catch fire by both natural and man-made causes. Some causes of coal fires can be found in:

• spontaneous combustion
• forest fires close to coal seams
• traveling fire from one seam to the other
• natural hazards (e.g. thunderstorms)
• old mining techniques (e.g. insufficient ventilation of the mine shafts, old generators and lighting systems that spray sparks)
• external heat sources (e.g. illegal distillation of alcohol in Indian coal mines)
• human induced (careless acts of mine workers)

Spontaneous combustion:
Spontaneous combustion is one of the most frequent reasons for coal fires. The term 'spontaneous combustion' means that coal can start to burn without any recognizable outer influence. It is caused by coals ability to react with oxygen contained in the air. As a result of the oxidation process the temperature of the coal starts to rise. If the temperature reaches a certain temperature noxious gases are produced such as carbon dioxide. Finally, if the temperature still continues to rise the coal reaches the flash point and starts to burn.

Spontaneous combustion depends, amongst others:

• on coal type,
• temperature,
• availability of oxygen,
• exposure to surface,
• thickness of coal seam,
• as well as methods of mining.

TOP