What advantage does rock dust have compared to water in extinguishing mine fires?

Using rock dust to extinguish mine fires offers the significant advantage that it can be carried by the air, allowing it to cover and smother fires effectively in hard-to-reach areas. This airborne capability means that rock dust can be dispersed throughout the mine environment, enveloping the fire and cutting off its oxygen supply, which is crucial since many mine fires can spread rapidly and be difficult to access directly.

This method is especially beneficial in mines where conditions may be hazardous or where water cannot be effectively applied due to the risk of creating additional hazards, such as flooding or instability of mine structures. In contrast to water, which can only be applied to flames or high heat areas, rock dust can quickly settle and create a barrier against combustion, helping to prevent fire rekindling.

While it's true that cost and effectiveness may vary based on specific scenarios, the ability of rock dust to be suspended in the air provides a key tactical advantage in both reaching and controlling mine fires.