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DEMONSTRATION BULLETIN: COGNIS TERRAMET LEAD EXTRACTION PROCESS - TWIN CITIES ARMY AMMUNITION PLANT - COGNIS, INC.
Citation:
Banerjee, P. DEMONSTRATION BULLETIN: COGNIS TERRAMET LEAD EXTRACTION PROCESS - TWIN CITIES ARMY AMMUNITION PLANT - COGNIS, INC. EPA/540/MR-95/535, 1997.
Impact/Purpose:
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Description:
The TERRAMET® soil remediation system leaches and recovers lead (including metallic lead, and lead salts and oxides), and other metals from contaminated soil, sludge, or sediment. The system uses a proprietary aqueous leachant that is optimized through treatability tests for the soil and the target contaminant. Pretreatment may involve dry screening to remove oversize material; the oversize fraction is usually clean after the surfaces are scrubbed through attrition. The sand fraction is pretreated to remove dense metallic or magnetic materials before subjecting the sand fraction to counter-current leaching. The fines fraction is subjected to counter-current leaching to dissolve the absorbed lead and other heavy metal species. Dissolved metal ions are recovered from the aqueous leachate by reduction, liquid ion exchange, resin ion exchange, or precipitation. The TERRAMET® system was evaluated at the Twin Cities Army Ammunition Plant (TCAAP) in August of 1994. The process treated 12 to 15 tons per hour of soil contaminated by lead and copper at levels up to 3,000 ppm. Average removal efficiencies for lead were about 75 percent.