Mechanical properties of ceramic bodies based on calcite waste

Physico-mechanical properties (flexural strength, Young modulus, bulk density, change of dimensions, porosity) as well as the mineralogical composition were studied on samples with difference content of calcite after firing at 900, 1000, 1100 and 1200 °C. It was found that anorthite and mullite are the main crystalline phases of the fired samples containing the calcite. The anorthite/mullite ratio depends on the firing temperature and the initial amount of calcite waste. The higher the temperature of the firing and the higher the amount of calcite waste, the more anorthite is created in the samples. Presence of calcite decreases sample contraction during sintering. Porosity decreases with the increase of the firing temperature, but the sample with the content of calcite 20 wt% shows approximately constant porosity. Flexural strength and Young modulus of the reference sample and the sample with 10 wt% of calcite waste increase in their value. These mechanical parameters increases very slightly for the sample with 20 wt% of calcite waste.