Thermal and mechanical study from granite and marble industry reject

Abstract

Granite and marble residue from dimension stone companies is solid, not degradable and its composition is principally of silicates (quartz, plagioclase, orthoclase, and mica). These companies produce more than 150,000t per year of residue, which is put in a decant lagoon or a large landfill area, thus resulting in environment pollution. The objective of this work is to investigate the possibility of using residue to obtain ceramic material. For that purpose, thermal analysis has shown to be a great tool to predict the process conditions such as sintering, temperature, heating rate and reaction to manufacture of ceramic elements. The thermal behavior was observed on a TA Instruments SDT 2960 at a heating rate of 4, 6, 8, 10 and 12°C/min in air atmosphere and over the temperature range 25–1400°C. Thermogravimetry (TG) curves showed two decomposition stages, the ideal heating rate was found to be 10°C/min, as it presents less weight loss. Differential thermal analysis (DTA) exhibited endothermic and exothermic events which suggested the sintering temperature at about 1125°C. Post-sintering samples were collected and the point load test conducted to evaluate the material strength.