COAL COMBUSTION ASH HAULBACK

摘要

Coal mining disturbs large tracts of land which must be reclaimed. Unfortunately, iron sulphides which are common in most coals and the adjacent strata weather, forming acid mine drainage (AMD) which degrades surface and ground water. Burning of coal produces combustion by products, most of which are placed in ponds or landfills. Suitable disposal areas are difficult to find and permit, especially in urban areas. This has led to ash haulback - where the waste generated during coal burning is hauled back to a mine for disposal. The potential advantages of coal combustion ash haulback are: 1. Disposal occurs in a disturbed area (mine) rather than disturb additional land near the power plant. 2. The same vehicles used to haul coal from the mine can be used to return the ash to the mine. 3. Ash, if alkaline, may provide neutralization of acidic water or mine overburden commonly found at coal mines. 4. Low permeability ash could reduce ground water flow through the mine backfill, thus reducing leaching of acid forming constituents or metals. Placement of ash in surface mines provides an efficient, cost-effective method of disposal while at the same time contributing to reclamation of the mine. Wise natural resource management suggests a reasonable approach to disposal of coal ash is to return it to its original location - the mine.