Coal temperature shall not exceed ___________ to prevent coal dust explosion.

Coal temperature shall not exceed ___________ to prevent coal dust explosion.

• A. 100 degrees Celsius
• B. 150 degrees Celsius
• C. 200 degrees Celsius
• D. 250 degrees Celsius

Answer: (C)

Controlling how hot the coal gets is crucial to preventing coal dust explosions. When coal is heated, the rate of oxidation increases, and a suspended dust cloud can reach its ignition point more easily. Keeping coal temperature at or below 200°C provides a practical safety margin across different coal types and particle sizes, reducing the risk that a dust cloud can ignite from a hot surface or minor ignition source. The exact autoignition temperature of coal dust varies, but many coals will approach ignition risks around this range, so 200°C is chosen as a conservative limit. Lower figures would be overly restrictive for normal operations, while a higher limit would leave too much room for ignition to occur. This temperature limit is part of broader measures to manage dust and heat in mines, along with ventilation and dust suppression.

Controlling how hot the coal gets is crucial to preventing coal dust explosions. When coal is heated, the rate of oxidation increases, and a suspended dust cloud can reach its ignition point more easily. Keeping coal temperature at or below 200°C provides a practical safety margin across different coal types and particle sizes, reducing the risk that a dust cloud can ignite from a hot surface or minor ignition source. The exact autoignition temperature of coal dust varies, but many coals will approach ignition risks around this range, so 200°C is chosen as a conservative limit. Lower figures would be overly restrictive for normal operations, while a higher limit would leave too much room for ignition to occur. This temperature limit is part of broader measures to manage dust and heat in mines, along with ventilation and dust suppression.