Which areas must be treated with rock dust?

Rock dusting in underground mines serves a critical safety function, primarily to reduce the potential for coal dust explosions. The correct response identifies that all intake airways, trackways, beltlines, and return airways must be treated with rock dust.

Intake airways are the passages that supply fresh air to the mine, while return airways carry used air back to the surface. Both are essential for maintaining ventilation and air quality within the mine. Trackways and beltlines are areas where transportation equipment operates, which can stir up dust. By ensuring these areas are treated with rock dust, the risk of combustible coal dust accumulating is minimized, as rock dust helps to mitigate the effects of any potential ignition sources.

The thorough application in all these areas is necessary because they contribute to the overall dust control strategy. By neglecting any of these components—as some of the other choices suggest—there is an increased risk of dust accumulation, thereby raising the potential hazards associated with coal dust explosions. Comprehensive rock dust application is a standard safety measure in underground mining operations.