abstract
Nearly half of the total iron ore volume extracted in mining operations is rejected as tailings and disposed of in containment dams that are liable for considerable environmental impact and human hazard in case of breaching. This work aims to expand the usage possibilities of iron ore tailings and help mitigate the negative impact of tailings-dams without sacrificing the opportunities provided by mining. Materials were collected from four tailings-dams, subjected to a dry separation procedure and characterized (particle size and morphology, chemical and mineralogical composition). Besides the recovered iron ore concentrate, two other powder fractions were produced (clay and sand fractions). The sands showed the greatest uniformity (particle size and shape, mineralogy and chemical composition) and may find use as aggregates in a variety of applications. This work shows that the clays can be used on their own in the production of ceramic tiles. They present adequate plasticity and dry strength, and develop mullite and glass upon firing, showing a rather amenable processing behaviour suitable for both artisanal and full-fledged industrial production. The resulting tiles are dimensionally homogeneous and very compact (vitrified products, classified in groups Bla, Blb or Blla), with high mechanical strength. Either industrialised or artisanal, these materials can be used in the production of brown porcelain tiles and ware, showing a very appealing dark brown lustre. (C) 2019 Elsevier Ltd. All rights reserved.
keywords
MINE TAILINGS; WASTES; RICH
subject category
Construction & Building Technology; Engineering; Materials Science
authors
Fontes, WC; de Carvalho, JMF; Andrade, LCR; Segadaes, AM; Peixoto, RAF
our authors
Ana Maria B C Segadães
Retired Professoracknowledgements
Authors acknowledge the financial support provided by CAPES, FAPEMIG, CNPq, UFOP, UFV and Fundacao Gorceix. Equipment and technical support provided by CEFET-MG (Laboratory of Non-Destructive Testing), UFOP Escola de Minas laboratories (Laboratory of Electron Microscopy NANOLAB-Redemat and Laboratory of Construction Materials, Department of Civil Engineering) and UA/CICECO laboratories (Department of Materials and Ceramic Engineering), is gratefully appreciated. Thanks are also due to the Research Group on Solid Wastes RECICLOS-CNPq for infrastructure use and collaboration.