Estudo da viabilidade da incorporação de resíduo de quartzito na massa de cerâmica vermelha.

Abstract

In recent years has been increasing concern about the environmental impacts caused by waste, mainly from the ornamental stone processing. These residues may have appreciable content of silicon oxide (SiO2), aluminum oxide (Al2O3), calcium oxide (CaO), and alkali oxides (Na2O and K2O). Furthermore, it may contain significant amounts of iron oxide (Fe2O3). From the mineralogical standpoint, depending on the type of ornamental rock, may be constituted of quartz, feldspar, mica and calcite. These characteristics make the waste attractive natural stone as an alternative raw material for the production of traditional ceramic materials, also emphasizing the aspects related to environmental issues, preservation of nonrenewable mineral resources and the environment. Within this context, this work aimed to study the feasibility of incorporating quartzite residue in a mass employed in the manufacture of red ceramic products. The raw materials were subjected to chemical analysis, particle size, thermal, mineralogical and determination of plasticity. It was also made the classification of waste. Masses were formulated with 5, 10, 15 and 20% by weight of quartzite residue subsequently shaped by means of pressing process, and fired at 800, 900 and 1000 ° C. After burning of the specimens were determined the physical and mechanical properties: water absorption, linear shrinkage, apparent porosity, bulk density and bending strength. Also it evaluated the color and formed mineralogical phases, and fracture surface analysis using scanning electron microscopy. The residue and the masses were analyzed for toxicity characteristics. The results showed that, for the studied mass, can be added up to 20% of quartzite residue.