Virginia Tech and Kentucky both have had projects for grazing on mined land. I do know Virginia Tech is still doing their's. I will see if I can find a link to their info. It does work but takes a lot more acres.
the big coal mine about 30mi from me reclaims all of their mined out land.they plant grass back on it digg the pools.fert an bale hay off the reclaimed land.an sell the hay.they also fence the land off.