Study of the effect of bacteria on the disappearance and transformation of CO in the sealed fire zone of coal mine

When the underground coal mine gob area has been sealed due to the coal spontaneous combustion, under the low oxygen and potentially high temperature environment, the CO concentration could drop sharply and disappear quickly. But it could rise rapidly after re-opening. These indicate that the disappearance is the only index for coal burnt out. In order to find a way how let CO disappear, experiments have been conducted using the newly developed experiment setup for three samples, raw, watered and bacteria-free coal sample. The CO and CO₂ concentration have been monitored and analyzed. The results show the bacteria in the coal do consume CO and increase the chance of CO transfer to CO₂. These results reveal how let CO disappear in a sealed zone from a new aspect. And the accuracy was improved when used gas index to determine combustion status for coal spontaneous combustion. (paper)