Question 574 Deck General

The correct answer is D) Freshly worked coal is more dangerous than weathered coal. The reason this is the correct answer is that freshly mined or worked coal is more susceptible to spontaneous combustion compared to coal that has been exposed to air and weathered. Freshly mined coal contains a higher percentage of volatile matter and is more reactive, increasing the risk of spontaneous heating. As coal weathers over time, the volatile content decreases, making the coal less prone to spontaneous ignition. The other options are incorrect because: A) The risk of spontaneous combustion does not necessarily decrease after 72 hours of loading; B) Coal does not absorb nitrogen from the air to cause spontaneous heating; and C) Dry coal is actually more liable to spontaneous heating than wet coal, as moisture can inhibit the oxidation process that leads to spontaneous combustion.