for the price you pay for coal, i'd use them to fill depressions in the yard - they're not good for much else. perhaps you can try selling them back to the mine
a few years ago when i was screening coal for my stoker (I wanted to use up larger sizes that I had before i bought stoker size) I crushed what i had by putting it in rows in my driveway and driving my diesel pickup tires over them. then to screen it I took 1" mesh, rolled it into the size of a 55 gal drum, framed it w/ 2/2's and put a rebar shaft down the middle, and a hand crank on the end, it was sloped @ about 15º. this allowed me to shovel the coal into it, screen it into one wheelbarrow, and have the pieces too large to fit through the screen drop out the other end into another wheelbarrow; worked well. since your getting coal that needs to be screened, you might want to set something like this up, only perhaps w/ an electric motor and a dryer belt to spin it if you want it to be an easy/quick one man operation.