Studies on spontaneous heating liability of some Indian coals and its protective measures

Spontaneous heating leading to fire in coal mines is a major problem worldwide and has been a great concern both for the industry and researchers in this field. Majority of fires existing today in Indian coalfields are mainly due to spontaneous combustion of coal. The auto oxidation of coal ultimately leads to spontaneous combustion which is the major root cause for the disastrous of coal mine. It is a slow process and the heat evolved is carried away by air. This process of self heating of coal or other carbonaceous material resulting eventually in its ignition is termed as “spontaneous heating” or “auto oxidation”. Coal can interact with oxygen in the air at ambient temperature liberating heat. If the heat is allowed to accumulate the interaction rate increases and may ultimately lead to fires known as spontaneous fires. The exact mechanism of the reaction of oxygen with coal is not completely understood as the chemical nature of coal is not yet fully established. So, determination of spontaneous heating liability of coal becomes an important criterion to predict the occurrence of spontaneous heating. Besides Protective measures to be employed may vary on numerous factors.