Utilization of steel slag as mold material for green molding castings to minimize silica dust in foundry process

The feasibility of black steel slag as mold material in sand casting, either as full or as partial replacement of silica sand in green bonded mixtures has been investigated. Selective grinding and size classification processes were applied to the slag to reach the proper particle size distribution. A series of comparative characterization tests were carried out on the silica sand and the crushed slag, as well as on a range of mixtures of these two molding materials.  Standard test specimens prepared with varying crushed slag contents showed better mechanical properties, such as compression and shear strength, than those obtained with 100% silica sand specimens. These enhanced results make the steel slag a suitable and interesting candidate for molding processes, that offers measurable benefits in terms of costs, availability and occupational safety and health compliance to foundries.