I have only used tsc anthracite coal, I just changed from nut to rice. I like the rice better for even heat. "i run a long forge". As for clinkers maybe a 1/4 lb. To 20 lbs. Of coal. Really not bad at all.
What voltage do you have in your shop and what size breaker do you have running the shop. I ask because of the start up amp draw and overall amp draw could give you a triping breaker nightmare. I built my own 2x72 grinder and went with a Grizzly H5379 Motor 1 HP Single-Phase 1725 RPM TEFC 110V/220V
I wired it up for 110vac and it runns like a champ.