Can You Compost Coal Ashes?

No, ash from burned coal should not be added to the compost heap. Coal ash may contain additives and chemicals that are harmful to plants.

Ash from natural wood is fine to use in moderation. You don’t want to use too much of it because it has high alkaline levels.

Reference: https://composting.ces.ncsu.edu/2017/03/over-100-items-can-be-composted-at-home/

Coal Ash Compost