Spoil tip

A spoil tip (also called a spoil bank, boney pile, gob pile, bing, batch, boney dump or pit heap) is a pile built of accumulated spoil - the overburden or other waste rock removed during coal and ore mining. These waste materials are typically composed of shale, as well as smaller quantities of carboniferous sandstone and various other residues. Spoil tips are not formed of slag, but in some areas they are referred to as slag heaps.