If the results look promising, the team may receive funding in the year 2000 to build a full-scale demonstration at an Illinois mine site. This slurry contains a substantial amount of fine coal, which ranges from sand-sized grains down to microscopic particles. That's becoming increasingly rare as technological advances have made it economically feasible to capture and process a larger proportion of fine coal. Still, millions of tons of fine coal ends up in waste ponds each year, and much more has been sitting for years in mucky or silted-up impoundments.
Coal contains many pollutants.
As the pyrite oxidizes, the slurry turns acidic and begins eating away at sediment. The result can be leaching of hazardous pollutants into groundwater systems and neighboring terrain. From the air, older impoundment sites that haven't been reclaimed often look like dead zones, says Honaker. Current sites, which must meet Environmental Protection Agency requirements, are less frequently a problem. The research aims to remove material from mine ponds and waste impoundments, separate out and clean the fine coal for utility use, and treat the remaining waste, which will then be used to reclaim the pond sites.