Why coal burn in coal stock?

Answer 1

cause that's what It does, coal naturally burns in one fuel source so that's what makes it up to be burning in a coal stock, once the coal is burned it creates heat energy which is naturally a nonrenewable resource once it is actually burned.

Answer 2

When coal is stored in a coal stockpile, it can start to self-heat due to the presence of oxygen. If the coal temperatures rise high enough, it can reach a point where it ignites and burns. This process is known as spontaneous combustion.