Leaching of elements from bottom ash, economizer fly ash, and fly ash from two coal-fired power plants

The Role of Mineral Matter in Concentrating Uranium and Thorium in Coal and Combustion Residues from Power Plants in Poland

“…The average thorium content in the fly ash from the LCB and USCB is lower, and the uranium content is higher than in fly ash, which is generated in combusted coal in Poland (according to reference [43]: content of Th = 25.9 ppm, U = 8.6 ppm; according to reference [47]: content of Th = 23.0 ppm, U= 10.6 ppm; shown in Tables 2 and 3). Compared to the combustion residues generated in other power plants (Tables 2 and 3), the Th and U contents in the studied fly ash are similar to fly ash from power plants in the USA (for Th) [48,49] and power plants in Brazil and China (for U) [39,46]. The Th content in the studied slag is similar to the Th content in the slag from other cited power plants, and the uranium content in the slag from the USCB feed coal is the same as in the slag from the Figueira power plant in Australia and Brazil [49,50], whereas from the LCB it is similar to the U content in the slag from power plants in China.…”

Coal ash and children's sleep : a community-based study.

“…Sixty percent of the bottom ash and fly ash produced in the United States is stored in piles, landfills, or holding ponds [15]. These open forms of storage allow the fine fly ash particles to be re-suspended into the ambient air, creating significant fugitive dust emissions.…”

“…During this process, trace elements initially found in the coal are not released, but instead concentrated into small coal ash particles [14]. The concentration of trace elements including nickel, vanadium, arsenic, beryllium, cadmium, copper, zinc, lead, mercury, selenium, radon and molybdenum varies based on the amount originally contained in the coal [1,15].…”

“…Fly ash, the most predominate form of coal ash (80%), is composed of combustible material that is carried by a flue gas stream until it cools and condenses. Once it has condensed, it forms glassy spherules, known as censophers [15]. Studies have found that the exact size of fly ash particles varies, but the average range of respirable particles is between 1.98 and 5.64 dose of coal ash for four hours over a three-day period, the rats accrued 32 µg of coal ash per rat, of which 25% was found in the head, 20% was in the tracheobronchial region and 50% was found in the pulmonary tissue.…”

Pediatric anxiety and/or depression problems : associations with PM10, fly ash, and metal exposure.

“…Fly ash is the largest component of coal ash and is characterized by fine incombustible, inorganic material (3,15). During the combustion process, residuals are carried in the flue gas pathway where some of the material will cool and condense into small, glassy spherules (15,16). Most of these small, spherical fly ash particles measure ≤ 10 µm in diameter and account for 40-70% of coal ash products.…”