A New Approach to Control a Serious Mine Fire with Using Liquid Nitrogen as Extinguishing Media.

Subsurface fires are a common threat for coal mining, since spontaneous coal combustion can easily result in gas combustion and explosion. In this paper, aiming to solve problems of the low efficiency, the line clogging, and some other related field issues in liquid nitrogen perfusion, a fire extinguishing application by using immediate liquid nitrogen infusion was presented. The presented technique is efficient in absorbing heat, and consequently, displacing oxygen and combustible gases. Field tests justified the efficiency of the technique. Only 12 days were taken to unseal the coal mine, which provides a quick and efficient management of the fire zone. Furthermore, by using the presented technique, there was no waste left behind which may impede the subsequent production. The presented technique is of great benefit from the social, economic, and environmental aspects, which indicates its broad application in fire prevention for large-scale coal mines. [ABSTRACT FROM AUTHOR]