What effect does the presence of small amounts of methane have on the explosibility of coal dust?

• A. It increases the explosibility
• B. It decreases the explosibility
• C. No effect
• D. It neutralizes the dust

Answer: (A)

When coal dust is dispersed in air, its explosion potential depends on the fuel present and how the flame can propagate. Adding small amounts of methane introduces another flammable fuel into the mix. As methane burns, it releases heat and energy that help ignite the coal dust more readily and drive the flame front faster through the dust cloud. This extra energy enhances both the rate of combustion and the overall pressure rise of the blast, making the explosion more energetic than a dust cloud alone. So even limited methane increases the explosibility by fueling the flame and speeding its spread.