STABILIZATION OF PHENOLICS IN FOUNDRY WASTE USING CEMENTITIOUS MATERIALS

A series of experiments were conducted to stabilize the phenolics in f oundry sands from Kansas using four different types of binders - Portl and cement, fly ash, kaolinite, and bentonite. Strength and leachabili ty of stabilized mixes of foundry sand were analyzed to assess their f easibility in construction and geotechnical applications. The results suggest that compressive strength was acquired relatively faster in fl y ash than in cement and, in general, it varied inversely with the pro portion of foundry sand in the stabilized mix. Lesser amounts of pheno lic compounds leached from fly ash-stabilized mixes than from cement-s tabilized mixes. The leachate analyses for both total phenolics and 2, 4,6-trichlorophenol indicate that increasing percent replacement of fo undry sands enhances stabilization. These results are supported by sca nning electron micrographs which showed increased porosity in the case of cement-stabilized mixes. The swelling potential and instability of bentonite-stabilized mixes rendered the leachate quality unpredictabl e. The general conclusion that fly ash stabilizes phenolics better tha n Portland cement may lead to development of a cost-effective solution for stabilizing phenolics in foundry sands and may have important imp lications in the construction industry.