Efeito da adição do resíduo de γ-alumina de catalisadores nas propriedades tecnológicas de revestimentos cerâmicos

Abstract

The growing generation of industrial waste has driven the search for sustainable alternatives that enable its reintegration into production chains, especially in the ceramic industry. In this context, the use of waste as a secondary raw material emerges as a strategy aligned with the principles of circular economy, reduction of production costs, and mitigation of environmental liabilities. Therefore, this research aimed to evaluate the influence of incorporating a spent activated alumina residue into a standard monoporosa ceramic mass intended for the production of BIII-type ceramic tiles, seeking not only to validate the technological performance of the material but also to propose an environmentally appropriate disposal route for the residue, with potential to reduce the consumption of natural raw materials during the industrial process. The standard ceramic mass and the activated alumina residue (γ- Al2O3) were previously sieved and dried in an oven for 24 h at 110 °C. Subsequently, they were chemically and mineralogically characterized by X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). The raw materials were then homogenized to formulate compositions containing 0%, 2%, 4%, and 6% by weight of residue. The test specimens were shaped by uniaxial pressing in a 60×20×5 mm mold under a pressure of 40 MPa, resulting in the green bodies. Afterwards, the samples were sintered at two different temperatures, 1000 °C and 1100 °C, with a total firing time of 1 h and 30 min and a 10-minute holding time. The sintered specimens were evaluated through technological tests of linear shrinkage, water absorption, apparent porosity, bulk density, scanning electron microscopy, and flexural strength. The results showed that the incorporation of up to 4% of activated alumina residue did not compromise the technological performance of the formulations, keeping them within the normative limits established by ABNT NBR ISO 13006/2020 for BIII-class ceramic tiles. Only the 6% formulation exhibited more significant changes in the evaluated properties, indicating this percentage as the maximum recommended incorporation limit to maintain the commercial classification of the product. Thus, the controlled addition of the residue proves to be a feasible alternative for the ceramic industry, contributing to the reduction of environmental impact, reduction in the use of natural raw materials in the production of ceramic tiles, while promoting the valorization of industrial waste.

The growing generation of industrial waste has driven the search for sustainable alternatives that enable its reintegration into production chains, especially in the ceramic industry. In this context, the use of waste as a secondary raw material emerges as a strategy aligned with the principles of circular economy, reduction of production costs, and mitigation of environmental liabilities. Therefore, this research aimed to evaluate the influence of incorporating a spent activated alumina residue into a standard monoporosa ceramic mass intended for the production of BIII-type ceramic tiles, seeking not only to validate the technological performance of the material but also to propose an environmentally appropriate disposal route for the residue, with potential to reduce the consumption of natural raw materials during the industrial process. The standard ceramic mass and the activated alumina residue (γ- Al2O3) were previously sieved and dried in an oven for 24 h at 110 °C. Subsequently, they were chemically and mineralogically characterized by X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). The raw materials were then homogenized to formulate compositions containing 0%, 2%, 4%, and 6% by weight of residue. The test specimens were shaped by uniaxial pressing in a 60×20×5 mm mold under a pressure of 40 MPa, resulting in the green bodies. Afterwards, the samples were sintered at two different temperatures, 1000 °C and 1100 °C, with a total firing time of 1 h and 30 min and a 10-minute holding time. The sintered specimens were evaluated through technological tests of linear shrinkage, water absorption, apparent porosity, bulk density, scanning electron microscopy, and flexural strength. The results showed that the incorporation of up to 4% of activated alumina residue did not compromise the technological performance of the formulations, keeping them within the normative limits established by ABNT NBR ISO 13006/2020 for BIII-class ceramic tiles. Only the 6% formulation exhibited more significant changes in the evaluated properties, indicating this percentage as the maximum recommended incorporation limit to maintain the commercial classification of the product. Thus, the controlled addition of the residue proves to be a feasible alternative for the ceramic industry, contributing to the reduction of environmental impact, reduction in the use of natural raw materials in the production of ceramic tiles, while promoting the valorization of industrial waste.