Recycling ceramic waste as a raw material in sanitary ware production

Abstract

This study characterized discarded sanitary ware waste (SWW) that could not meet quality requirements. To understand the composition of such SWW, samples were collected, processed, and characterized. This SWW was used to substitute granite in ceramic slips, and the final recycled sanitary ware compositions of 5%, 10%, 25%, 50% and 100% were obtained. Then, the mixtures were evaluated based on density, rheology, linear shrinkage, water absorption, and flexural strength. The results for viscosity and pyroplastic deformation in specimens containing the ceramic waste were better than the reference slip used in a production line. Results for density, water absorption and linear shrinkage showed no significant difference from the control samples. Although the replacement of more than 5% of granite reduced the flexural strength, no tested specimen was below the minimum value required by the industry.

Effects of sintering temperature on microstructure and properties of sanitaryware ceramic produced with waste material

“…It decreased the temperature of the liquid phase formation and the viscosity of the glassy phase [45,47,49]. The effect of fluxing ingredient used as an auxiliary component to help the sintering of ceramic product and the formation of the liquid phase in Sanitser VC is reported in the literature [13,21,50].…”

“…The disappearance of the exothermic peak between 300 and 450 °C, associated with the combustion of organic materials present in the clays, was certainly due to the effect of glass, which was found in the blend. In fact, obvious rheological changes have been observed in the Sanitser VC, which does not require the addition of deflocculants to disperse the clays [13,21,50].…”

“…All data was correlated with better microstructural homogeneity and a lower amount of amorphous phase. Different papers have reported that introducing a flux (partially) provides better technological properties (water absorption and bulk density, overall) at lower firing temperatures, compared to the traditional commercial formulation [50,60,61]. These studies are important because they lead to a decrease in the cost of firing due to the lower firing temperature.…”

Development of Coloured Stoneware Bodies through the Incorporation of Industrial Cr/Ni Electroplating Sludge

“…With this secondary raw material, a reduction of 140 °C in the firing temperature was achieved without compromising the properties of the tiles. The use of discarded sanitaryware waste as a raw material in sanitaryware production was also explored [25]. This residue aimed to substitute feldspar in the ceramic composition and in all tested compositions (substitution, in weight, from 5% to 100% of the feldspar) no significant deviations from the control formulation were observed for density, linear shrinkage and water absorption values.…”