Recovery of Iron Oxides from Polluted Coal Mine Drainage

This SBIR Phase I project will characterize iron oxide precipitates collected from wetlands constructed to treat polluted coal mine drainage in order to determine whether these wastes have commercial value as pigments or ion-exchange media. Chemical and physical characteristics of iron oxide samples collected from four wetlands constructed to treat polluted coal mine drainage will be compared to commercially available natural and synthetic iron oxides. Pigment attributes and ion-exchange capabilities will be assessed using standard industry methodologies. Chemical compositions will be determined by an acid digestion procedure followed by ICP and LC analytical procedures. After the characterization tests are completed, samples from constructed wetlands will be "processes" by heat treatment, screening, and floatation methods to determine how pigment and ion-exchange characteristics might be improved. The results of these measurements and experiments will allow an assessment of the value of "raw" and minimally "processed" iron oxide precipitates from constructed wetlands. If the characterization studies and valuation estimates are promising, a Phase II proposal will be submitted to continue the development of iron oxide processing procedures as well as develop wetland construction techniques that would result in the precipitation of higher quality iron oxide materials.