Record Display for the EPA National Library Catalog

RECORD NUMBER: 24 OF 28

OLS Field Name OLS Field Data
Main Title Pilot-scale investigation of closed-loop fly ash sluicing /
Author Litherland, S. T. ; Nassos, P. A. ; Owen, M. L. ; Winton, S. L.
Other Authors
Author Title of a Work
Litherland, S. T.
CORP Author Radian Corp., Austin, TX.;Environmental Protection Agency, Research Triangle Park, NC. Air and Energy Engineering Research Lab.
Publisher U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory,
Year Published 1985
Report Number EPA/600/7-85/021A; RAD-83-211-004-35; EPA-68-02-3163
Stock Number PB85-204378
Subjects Fly ash. ; Water reuse. ; Coal-fired power plants--Waste disposal--United States. ; Coal-fired power plants--United States--Waste disposal
Additional Subjects Feedback control ; Fly ash ; Slices(Concentrators) ; Air pollution control ; Solid waste disposal ; Pilot plants ; Electric power plants ; Feasibility ; Scaling ; Leaching ; Mathematical models ; Gypsum ; Closed loop systems ; Coal fired power plants ; Waste water reuse ; Computer applications
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB85-204378 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 01/01/1988
Collation 170 pages : illustrations ; 28 cm
Abstract
The report gives results of a pilot-scale demonstration of the technical feasibility of closed-loop operation of fly ash sluicing systems. Chemical species leached from the ash increase the dissolved solids concentration of recycled sluice water to a point where equipment scaling may occur. Tests were conducted at two power plants using a 50-gpm pilot unit to demonstrate the feasibility of closed-loop operation, both with and without sluice water treatment. An ash sluice computer process model was developed to predict chemistry and process conditions in full-scale systems. Fly ash sluicing systems handling highly reactive alkaline ashes cannot be operated closed-loop without treating the sluice water to control scale formation. Adding acid to adjust pH was effective in controlling calcium carbonate scale formation in the sluice water return line; however, it increased the potential for gypsum scale formation. Gypsum was ultimately the limiting species which prevented reliable closed-loop operation at the plants tested. Increased ash/water contact time in a reaction tank was not adequate to control the potential for gypsum scale formation at the residence time tested. The ash sluice computer process model proved to be accurate in predicting the chemical composition and potential for scale formation in the pilot unit.
Notes
Caption title. "May 1985." "EPA/600/7-85/021." Microfiche.