i have a bin inside my basement that will hold 6 tons of coal and i usually burn 6 to 7 tons per year burning almost all year. i usually shut it off a few months in the summer (and I put an Illegal light bulb in the burn chamber to help keep out moisture).
I have next to my bin a 50 gallon barrel that was used to ship food grade olives that my feed tube goes into. Nice thing about the food grade barrel is it has a nice lid on it.
Ashes go onto a pile outside and I am the automatic removal system! My neighbors take my ashes and use them at will, they put them on icey driveways or gardens or just use it as fill at times. My ash pile usually disappears by the end of summer...