PILOT DEMONSTRATION OF TECHNOLOGY FOR THE PRODUCTION OF HIGH VALUE MATERIALSFROM THE ULTRA-FINE (PM2.5)FRACTION OF COAL COMBUSTION ASH

Abstract

Dry fly ash samples were collected from 6 of the7 largest power plants operated by Louisville Gas and Electric Company (LG&E). Samples were taken from individual ESP hoppers in a continuous flow through stages of particulate collection. A total of 41 samples were taken from 16 operating units. The samples were thoroughly characterized for pertinent physical and chemical composition. The fly ash samples contained 10 to 50% -10{micro}m material, with higher concentrations of finer particles located in the latter stages of particulate collection. Flotation evaluation was conducted on a continuous flow though a single unit at each power station to assess the viability of using froth flotation to reduce the LOI in the fly ash to very low levels (i.e. 0.5% LOI) in order to enable eventual use as fillers. Ash from all of the units tested responded favorably with the exception of the ash from Henderson Station, which is attributed to a significant proportion of un-combusted or partially-combusted petroleum coke in the ash at this station, Bulk samples of dry ash and pond ash were also collected from Mill Creek, Trimble County, E.W. Brown and Coleman power plants and evaluated for carbon removal by froth flotation. Release analyses showed that flotation could effectively reduce carbon to acceptable levels for most of the substrates tested. The exception was the Mill Creek ashes. The cause of this exception will be further investigated