Notes on the Potential for the Concentration of Rare Earth Elements and Yttrium in Coal Combustion Fly Ash Hower, James ; Groppo, John ; Henke, Kevin ; Hood, Madison ; Eble, Cortland ; Honaker, Rick ; Zhang, Wencai ; Qian, Dali Abstract Publication: Minerals Pub Date: June 2015 DOI: 10.3390/min5020356 Bibcode: 2015Mine....5..356H