. "res, facilities, machinery, tools, equipment, shafts, slopes, tunnels, excavations and other property, real or personal, placed upon, under or above the surface of such land by any person, used in, or to be used in, or resulting from, the work of extracting in such area bituminous coal, lignite or anthracite from its natural deposits in the earth by any means or method, and in the work of preparin" . . . . . . .