underground coal mines

  • Coal mining | World Coal Association

    Surface mining is only economic when the coal seam is near the surface. This method recovers a higher proportion of the coal deposit than underground mining as all coal seams are exploited - 90% or more of the coal can be recovered.

  • The World's Oldest Underground Fire Has Been Burning For ...

    Coal fire in India from January 2011. AP Photo/Kevin Frayer. The American West is also smoldering with underground fires in abandoned coal mines. They melt snow in the winter, set grass fires in ...