Fly ash is the fraction of combusted coal that becomes suspended in plant flue gases.
The fly ash available for beneficial use is captured primarily by mechanical particulate collection devices, such as an electrostatic precipitator or baghouse.
The remaining fly ash that passes through these particulate collection devices either escapes into
the atmosphere or is captured through sulfur dioxide [SO2] control devices (i.e., scrubbers),
resulting in its incorporation into the FGD solids. The chemical composition of the beneficially used fly ash is variable and dependent on multiple factors, such as the geographic source of the coal burned.
“Environmental releases of constituents of potential concern from coal combustion residuals fly ash concrete and FGD gypsum wallboard during use by the consumer are comparable to or lower than those from analogous non-CCR products, or are at or below relevant regulatory and health-based benchmarks for human and ecological receptors,” the EPA said in its report.
“EPA supports the beneficial use of coal fly ash in concrete and FGD gypsum in wallboard.”
Click here to read the full report.