Beneficial Re-use of CCR for Site Closures using Mining Reclamation Technologies

摘要

Coal combustion residuals(CCR)have been used to backfill underground and surface coal mines since the 1970s,offering not only a cradle-to-grave materials management approach,but also mitigating some of the adverse environmental effects of coal mining.Therefore,issuance of the CCR Rule makes the design premises behind the use of CCR in mine reclamation,as well as the construction methodologies employed,more relevant than before.Properly managed CCR materials,used in well-engineered applications,offer a degree of permanence for ash pond closures and abandoned mine reclamation projects.Where such materials are readily available,they can be used as engineered materials that can be used effectively to control the flow of water,stabilize slopes,improve access roads,and mitigate environmental impacts from acid mine drainage and methane,among others.Due to the applicability of CCR as a building material,clients and contractors alike should entertain the recovery of CCR materials from ash impoundments for use in onsite construction of stormwater channels,dam improvements,caps,revetment walls,and other closure infrastructure.Decades of use of CCR construction materials in mine closures have provided important leachability data and offer some lessons learned that can now be applied to a wide range of closure tasks.Similarly,abandoned mine sites across the country may be able to accept encapsulated CCR as backfill for mutual benefit of clients and state-run abandoned mine programs alike.This paper explores the various considerations behind use of these materials and specifically brainstorms valueadded construction methodologies that draw from the prior long term use of CCR backfill materials in mines.