Study of the production of synthetic aggregate made with waste from the Bayer process for the construction industry: part I

The large amount of solid waste, coming from the mining and metallurgy industry, constitutes a serious socio-environmental problem, due to the large amount of volume that is generated. These residues are of great interest to other industries, such as ceramics, for example, and this work presents studies carried out for the recycling of red mud (red mud), as a raw material in the production of synthetic aggregate, aimed at civil construction. Red mud, the main industrial waste in the manufacture of alumina, proved to be an extremely important input in the manufacture of different types of aggregate to be used in concrete due to its physical and chemical characteristics. The result was the possibility of manufacturing aggregates with different physicochemical characteristics, which depend solely on the composition of the mixtures between silica, clay and red mud. For the first phase of this work (part I) the physical characterization of the produced aggregate was evaluated by the apparent specific gravity (MEA) and apparent porosity (PA) varying at temperatures of 1200°C, 1250°C and 1300°C. Finally, to an X-ray diffraction (XRD) analysis.(author)