Estudo de caracterização e aplicabilidade comercial de vidro produzido a partir da cinza da casca de arroz como substituto à sílica de minério

Abstract

Glass is widely used in various human activities, and the techniques for its production have evolved over the years, as have its applications, which range from civil construction to packaging. Glass is produced from quartz sand, the extraction of which causes significant environmental impacts. Alternatives using silica-rich materials, such as rice husk ash (RHA), have been employed with the aim of replacing sand, reducing ecological impacts and making use of an abundant waste product. In this study, borosilicate glass samples were produced using RHA and quartz as silica sources, with the following 7 % S O2 % N 2O 7% O % 2O3 For comparative purposes, commercial flat glass was also used. The samples were fabricated at 1500°C and subjected to normative tests to evaluate their properties. The analyses were carried out in accordance with Brazilian standards applicable to glasses used in packaging, pharmaceuticals, civil construction, and road signage. To characterize the samples, analyses of X-ray fluorescence (XRF) and X-ray diffraction (XRD) were performed, along with scanning electron microscopy (SEM), following Brazilian technical standards. The properties evaluated included density, microhardness, thermal shock resistance, water absorption, and acid resistance. Optical tests were also conducted using UV-VIS spectroscopy and thermal conductivity analysis. The results showed that glasses produced with different silica sources exhibit properties comparable to those of commercial glasses, presenting an amorphous structure and transparency in the visible spectrum. The density of the produced samples met the normative parameters, as did their thermal shock resistance, acid resistance, and water absorption. Furthermore, all three types of glass exhibited equivalent thermal behavior, and the analysis of olive oil acidity demonstrated that RHA-based glass preserves food quality similarly to commercial glass.Therefore, the use of RHA in glass production is commercially viable, offering an ecological alternative to the use of sand and contributing to the sustainability of the glass industry. Keywords: Sustainability, circular economy, agricultural disposal.