Characterization of flotation tailings from Samarco and other varieties of sand for use in sand molding in the foundry industry.

Abstract

Foundry sand used for molding should have specific properties so that molds with adequate strength, porosity, etc to produce defect free castings. Thus, characterization of two types of flotation tailings from the mineral processing of itabirites and three types of base sand for molding have been carried out. The resulting properties have been compared to evaluate the suitability of use of typical flotation tailing for the molding process. The main properties determined are the grain shape and structure, chemical composition, grain size distribution, fineness modulus, fines content, moisture content and loss on ignition. Furthermore other properties of these sands prepared with binders have been compared like compactability, permeability and green compressive strength for green sand. For cold set and sodium silicate/CO2 processes properties like tensile strength and bending strength have been evaluated. The results show that the flotation tailing SA2 presented a good potential of use in the foundry.