Abstract
Coal fire is a serious hazard in China and also in other coal-producing countries. A lot of studies have been done by many
investigators. This paper analyzes the environmental hazards of coal fire and introduces the current prevention methods. The
study reveals that coal fires in Northwest China still induce severe hazards. They result in serious air pollution, water pollution,
ecological disturbance and geological disasters, which are analyzed in detail. The current coal fire prevention methods mainly
focus on fire position detection and fire extinguishing. The detection methods of geological investigation, remote sensing,
geophysical exploration and chemical detection are analyzed. In addition, the extinguishing methods of peeling and removing,
water or grout injection, foam injection, gel injection, three-phase foam and sand-suspended slurry are also discussed. It can be
concluded that some progresses have been made in coal fire prevention. However, because of the complexity of coal fire, it is still
difficult to detect and extinguish coal fire efficiently.