Estudo da combinação de resíduo de scheelita, pó de pedra e manipueira com aglomerantes para produção de tijolos ecológicos

Abstract

The high quantity of residues from mineral and vegetal extraction, which cause serious environmental impacts when improperly deposited, can be widely used by the construction industry, one of the largest consumers of the planet's natural resources, promoting a circular economy. Several researches have been carried out with the use of residues in construction materials, with emphasis on the soil-cement brick, also called ecological brick. Carrying out a systematic research, it was verified the use of scheelite residue and stone powder in construction materials, which generate large quantities in the State of Rio Grande do Norte. In place of the hydration water, cassava wastewater, the liquid waste from the process of processing cassava for the production of flour, has been used. Aiming at an ecological brick, for use in society that replaces soil and water for waste, is developed this study of scheelite residue, stone powder and cassava wastewater combination with the addition of binders. The physical, chemical and mineralogical characterization of the materials was carried out. Then the compaction test was carried out to evaluate the best combination of the solid waste mixture, being determined in 50% of each residue. Technological essays were carried out on cylindrical specimens with addition of cement and / or lime hydrated with water, obtaining satisfactory results for cement formulations. These cement formulations were used in the production of bricks, with the addition of cassava wastewater, replacing water, by 11% in relation to the total mass of solid waste. The technological essays of the bricks showed satisfactory results, justified by the high packaging between the residues and properties of the cassava wastewater, being observed cement phases in the analysis of Scanning Electron Microscopy and X-Ray Diffraction. The ecological brick is promising for use as sealing masonry, being able to be competitive in the market due to the low cost and easy availability of the wastes, highlighting the formulation with 9% addition of cement to the waste mixture.