When
coal is burned, about 10% remains as ash. The heavy ash settles beneath the
burner. A light ash, called coal fly ash (CFA), condenses and forms in the hot
gases above the burner. Previously, CFA exited smokestacks of coal-burning
industries, mainly electricity-producing utilities. But because CFA consists of
concentrations of the toxic substances found in coal, such as heavy metals
including mercury, arsenic, chromium IV and radioactive elements, regulations in
Western nations require CFA to be trapped and sequestered. There is much public
concern that the toxins will enter drinking water supplies through dumping,
seepage, and spills. Coal fly ash is a major industrial waste product worldwide.
CFA forms in micron and submicron size particles, see image at right, courtesy
of Wabeggs:
CC BY-SA 3.0. The particles form injust the size range needed to spray into the atmosphere
for inhibiting rainfall. Because it formed under conditions which are
not-natural, water is capable of extracting portions of its toxic substances.
These then can be analyzed in post-spraying rainwater and compared to laboratory
water-leach experiments on CFA.
When
coal is burned, about 10% remains as ash. The heavy ash settles beneath the
burner. A light ash, called coal fly ash (CFA), condenses and forms in the hot
gases above the burner. Previously, CFA exited smokestacks of coal-burning
industries, mainly electricity-producing utilities. But because CFA consists of
concentrations of the toxic substances found in coal, such as heavy metals
including mercury, arsenic, chromium IV and radioactive elements, regulations in
Western nations require CFA to be trapped and sequestered. There is much public
concern that the toxins will enter drinking water supplies through dumping,
seepage, and spills. Coal fly ash is a major industrial waste product worldwide.
CFA forms in micron and submicron size particles, see image at right, courtesy
of
Wabeggs:
CC BY-SA 3.0. The particles form in
just the size range needed to spray into the atmosphere
for inhibiting rainfall. Because it formed under conditions which are
not-natural, water is capable of extracting portions of its toxic substances.
These then can be analyzed in post-spraying rainwater and compared to laboratory
water-leach experiments on CFA. 