Aproveitamento de resíduos de caulim e granito na formulação de massas cerâmicas para fabricação de grés porcelanato.

Abstract

In recent years, mining companies mainly beneficiation of kaolin and granite have been cited by environmentalists as sources of contamination and/ or pollution of the environment due to the huge amount of waste generated and often dumped directly into ecosystems, without a treatment process to eliminate or reduce the constituents present. This work aims to evaluate the potential of using waste kaolin and granite, for their application as ceramic raw materials in the production of porcelain stoneware. The formulations studied, F1, F2, F3, F4, F5, F6, F7 and F8 were prepared from the raw clay, kaolin residues and residues of granite. The raw materials were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and thermal analysis (TGA/DSC/DTA). Technological properties of the material were analyzed by tests of water absorption (AA%), apparent porosity (% PA), linear retraction (% RT), apparent specific gravity (MEA), loss on ignition (% PF) and flexural strength at three points (TRF) of the samples sintered at temperatures of 1175, 1200, 1225 and 1250° C with a level of 60 minutes and heating rate of 5°C/ min. Microstructural characterization of the samples was performed using scanning electron microscopy (SEM). The F6 and F8 formulations showed better physical and mechanical properties for the production of porcelain stoneware being can replace the use of conventional materials by waste. The adoption of alternative utilization of these residues may not only reduce the environmental impact of mining kaolin and granite, but also enable the aggregation of value to this material, mainly for industrial use in porcelain-stoneware.