Caracterização e utilização de rejeito de minério de ferro PELLET FEED em pavimentos de blocos intertravados de concreto

Abstract

Today, Brazil is at the second place in the world ranking of iron ore producers. This production is very significant in the countrys trade balance. However, the activities of mining and iron ore beneficiation also take to significant environmental impacts, especially relating to the generation and disposal of large amounts of tailings. In order to minimize these impacts, mining companies and researchers are developing studies aiming the optimization of the beneficiation process, reducing the amount of waste generated and/or the use of tailings as raw material to other sectors, especially construction works. In this context, this research aims to study the technical feasibility of using the iron ore pellet feed tailings in the production of floor interlocking concrete blocks. The tailings were subjected to physical, chemical, mineralogical and environmental characterization. The tailings consist, mainly, of hematite (Fe2O3), quartz (SiO2) and kaolinite (Al2Si2O5(OH)4) and is environmentally classified as waste class II A, non-inert, according to Brazilian norm. The waste presented physical, chemical and environmental properties adequate for its use as a filler material in the interlocking pavements. In this study were assessed three concrete mixtures: a reference and two containing tailings additions in the proportions of 5 and 10% of the cement mass. The concrete samples were submitted to compressive strength tests, water absorption and abrasion resistance. Comparative analysis between the concrete with 5% of tailings and the reference, the concrete with characteristic resistance higher estimated presented tailings at 6.6%. The concrete with 10% of estimated characteristic resistance higher than presented tailings in 3% in relation to the reference. What indicates the potential use of tailings in the production of interlocked block concrete floors.