Incorporation of metallurgical wastes as inorganic fillers in resins

Abstract

This work aims at incorporating industrial wastes arising from the metallurgical sector, as fillers into polymeric resins. The waste materials that were investigated are: brass foundry sand, ferrous slag, inert steel aggregate for construction, white slag from steelmaking ladle secondary treatment, electric arc furnace dusts and aluminum anodizing wastewaters treatment sludge. Two different types of resins were used: a thermoset phenolic resin normally used for the manufacture of foundry molds and a thermoplastic aqueous dispersion vinyl-based resin generally used for soils stabilization and retaining dust. The selection of the most suitable resin for each residue depends on the characteristics of the resins and the waste particle size: for powder residues, it was used a vinyl-based resin, whereas for larger particle size residues a phe- nolic resin has been employed. The goal was to maximize the use of residues; therefore 5 to 15% of phenolic resin or vinyl-based aqueous water dispersion in different concentrations from 10 to 400ml/l was used in the composite preparation and compared to composites made of undi- luted resin. Test samples were prepared by compression molding of parts at room temperature and characterized by mechanical testing (compression and flexion), water absorption test and water leachate analyses (pH determination, soluble salts, and determination of the content of leached elements). After analysis of the main characteristics of these composites it was found that industrial waste incorporation in polymeric resins is a viable way to give value to these presently discarded materials.