I thought this was interesting and definitely something to be investigated further. I guess the bottom line for me is how acidic any ash is and just how safe are these ideas are? You will wind up with that whole "give and take" argument about the results overtaking the risks.
http://www.cnn.com/2009/TECH/03/20/recycled.coal.uses/index.html
http://www.cnn.com/2009/TECH/03/20/recycled.coal.uses/index.html
