A quick scan of the area on Old Maps shows a scatter of old coal pits on the first edition 25" map and on most of the subsequent ones. As they're shown as old back then, there are very unlikely to be any abandonment plans, just from looking at the scatter it looks like there may be an outcrop of a coal seam somewhere lower down the hill, with small shaft workings (possibly 18th century) further up the hill. That would be best confirmed by looking at a 6" geological map, which you may find Chesterfield library have.
Coal mines of that age wouldn't leave a great deal in the way of surface remains, at best you might have the footings of small miner's sheds and possibly a gin circle (the circular walk for a horse-powered winding or pumping engine). However, below ground you probably have pillar and stall workings, where the miners excavated out the coal in a grid pattern, leaving pillars of coal to support the roof. That could mean that there are still a whole load of sub-surface voids, which any potential developer would need to check for by test drilling, and if there are voids these would normally need to be filled by grouting if there was going to be building on top.
Follow the horses, Johnny my laddie, follow the horses canny lad-oh!