Bid to snuff out threat from old mines

Engineers from the Universities of Edinburgh and Strathclyde are studying piles of coal, shale or other minerals left over from industrial mining to assess how best to cope with hidden risks.

Their research was presented at the Geological Society of America Annual Meeting in Minneapolis, Minnesota.

The heaps, also known as bings, can self-ignite many years after they are formed and burn slowly for years afterwards, leaching chemicals, emitting greenhouse gases and raising the risk of landslip.

Temperature probes and thermal imaging were used to study a burning bing in North Lanarkshire, Scotland.

The 30-metre high waste heap began smouldering in 2009, some 80 years after the pit was closed.

"Examining slow-burning fires in piles of shale or coal helps us to understand the dynamics of how these fires move slowly but burn large amounts of fuel, and how fissures of air within the heap can fuel the burning" said Dr. Guillermo Rein, School of Engineering at the University of Edinburgh.

The researchers are studying how the fires develop and spread, and hope that this new understanding will enable the development of low-cost, effective ways to manage the fires.

The team were able to discover how the fire took hold and developed, and pinpointed channels within the heap that deliver air to fuel the smouldering.

This will help protect the local communities by limiting the risk of landslip as well as safeguarding the local ecosystems and environment.

Provided by University of Edinburgh