Mining Publication: Coal Mine Inertisation By Remote Application

Timely and rapid intervention to underground combustion events (fires, explosions, and spontaneous combustion) is the key to successfully controlling the mine atmosphere and restoring a coal mine to production. The focus of this paper is the use of a GAG 3A jet engine system to either combat large out-of-control fires or render an entire mine inert when access to problem areas is difficult or impossible. This system is based on a Soviet-designed agricultural jet engine that consumes aviation fuel with oxygen from the intake air and exhausts combustion gases, mainly carbon dioxide and water, along with the nitrogen from the air and small amounts of carbon monoxide and hydrogen. The system is designed to approach stoichiometric combustion (ideally, pure burning that scavenges all the oxygen from the intake air). Therefore, these exhaust gases are almost entirely inert gases, i.e., gases that do not contribute to, and in fact, can suppress the combustion process due to the lack of oxygen. Other methods to inert mine areas have been used in the United States and abroad, but these methods usually use low-flow inertization equipment or methods. Use of these low-flow inertization equipment and methods has been successful in proactively rendering gob areas inert and has the ability to inert the entire mine workings. Due to the low flow rate, however, a substantial period of time is required. Two events where the GAG-3A system was used in the United States are reviewed.