LEACHATE TESTS
ON SELECTED FOUNDRY CUPOLA DUSTS AND SLUDGES
William C. Boyle, Professor
Robert K. Ham, Professor
Department of Civil and Environmental Engineering
University of Wisconsin
Madison, Wisconsin 53706
James Pastene, Environmental Engineer
Union Carbide Corporation
South Charleston, West Virginia 25303
Robert Stanforth, Research Assistant
Water Chemistry Laboratory
University of Wisconsin
Madison, Wisconsin 53706
Emission control dusts from gray and ductile iron foundry furnaces are generated when
metal oxides, coke dust, ash, and combustion gases found in the raw materials are entrained
in the furnace fumes. Particulates in the exhaust from the furnaces are entrapped in air
pollution control devices and separated as a dust or sludge. Initially, EPA determined these
dusts or sludges were hazardous wastes as defined by the Resource Conservation and Recovery Act (RCRA) [1]. In response to the comments received and in acknowledgment of
the economic impact of such a listing to the foundry industry, EPA decided to gather further information on gray iron foundry emission control residuals in order to determine if
the waste should be listed.
This paper presents a summary of the results of an independent study conducted at the
University of Wisconsin (U.W.) sponsored by the American Foundrymen's Society with
cooperative assistance by EPA. Foundry sites in Pennsylvania and Michigan were selected by
the EPA Office of Solid Waste, and samples were collected, split, and shipped by EPA or
their contractor to the University of Wisconsin and the EPA Environmental Monitoring Systems Laboratory, Las Vegas (EMSL/LV).
The detail sampling program and results of this study are found elsewhere [2,3).
PROJECT OBJECTIVES AND SCOPE
The major objective of the project was to determine the concentrations of cadmium,
chromium, and lead which were extracted from samples of cupola dusts or sludges collected
from selected gray iron foundries. Cupola dusts/sludges referred to in this report are defined
as solid wastes from emission control devices on cupola, electric arc, or induction furnaces.
Extraction procedures employed included both the EPA extraction procedure (EP) and a
distUled water extraction. A secondary objective was to determine the total concentration of
cadmium, chromium, and lead within the solid waste by either a digestion procedure or
neutron activation analysis. An additional goal of the study was to conduct parallel extractions and total metal concentration analyses on mixed foundry wastes collected from the
same foundry sites. Finally, extraction procedures and analyses were conducted in triplicate
so as to evaluate the precision of the methods employed.
784