A spoil tip (also called a boney pile,[1] culm bank, gob pile, waste tip[2] or bing)[3] is a pile built of accumulated spoil – waste material removed during mining.[4] Spoil tips are not formed of slag, but in some areas, such as England and Wales, they are referred to as slag heaps. In Scotland the word bing is used. In North American English the term is mine dump[5] or mine waste dump.[6]
The term "spoil" is also used to refer to material removed when digging a foundation, tunnel, or other large excavation. Such material may be ordinary soil and rocks (after separation of coal from waste), or may be heavily contaminated with chemical waste, determining how it may be disposed of. Clean spoil may be used for land reclamation.
Spoil is distinct from tailings, which is the processed material that remains after the valuable components have been extracted from ore.