Don't know if this is what you are looking for, but for several years I
have operated a coke-fired crucible furnace that pre-heats its air
blast. On the average it can melt about 2 1/2 lb. brass to 1 lb. coke,
so with a coke cost of $95.00/ton this comes to about $0.047 worth of
fuel per pound of brass, or approximately $1.00 worth to melt a 50 lb.
pot. I haven't checked the price of coke recently so the cost may be a
bit higher now.
Mike