TECHNOLOGICAL CHARACTERIZATION AND REUSE OF MAGNETITE WASTE IN ASPHALT MIXTURES AND CONCRETE: A REVIEW

Abstract

Magnetite consists of a mineral with excellent magnetic and mechanical properties, being present in iron extraction tailings, which are available worldwide in millions of tons deposited in landfills. In relation to variety of the material characteristics, according to specificities of the extraction deposit and processing and reprocessing operations, for its technological application it´s fundamental to perform waste characterization. The most promising forms of magnetite tailings reuse refer to its application in asphalt mixtures and concrete. In this context, this work approaches the main techniques for the technological characterization of magnetite tailings and their contributions, as well as results of studies for incorporation of mineral byproduct into asphalt and concrete. It has been identified that techniques used analyze the tailings and/or composite asphalt material and concrete considering the physical, chemical, mineralogical and thermodynamic properties. The magnetite tail as a partial and integral substituent of the filler material has been found to improve the corrosion resistance and cracking of the asphalt mixtures. In addition, the use of magnetite powder, extracted from waste, improves stiffness and elastic response, as well as promotes microcracks cure of bituminous mixture. Incorporation of powdered mineral waste in the concrete resulted in improvements in the workability and strength of the material. The information in this review provides an overview of the characterization techniques and recycling prospects of magnetite tailings in civil construction.