Colliery spoil refers to the waste material generated during the process of coal mining.
This material, also commonly known as mining waste or mine dump, is an accumulation of various discarded substances from mining operations. Primarily, colliery spoil consists of:
- Sedimentary strata material: Rock and soil originating from the layers of earth directly adjacent to the coal seams.
- Operational waste: Debris and waste produced from the excavation and sinking of mine shafts, as well as other related mining works.
- Dirt: General soil and earth that is removed during the extraction process.
- Coal fragments: Small pieces and remnants of coal that are not deemed suitable for sale or further processing.
Furthermore, if washery waste—the by-product from washing coal to remove impurities—has been deposited, colliery spoil may also contain the residual chemicals used in those coal-washing processes.
This accumulated material often forms large mounds or tips near former or active coal mines, presenting environmental and land management challenges.
