Hazardous toner waste recycling with galvanic glass waste and spent foundry sand to produce sustainable ceramics

Abstract Several sustainable ceramic composites were prepared from 3 – 7 wt.% of hazardous toner waste, 0 – 42% of spent foundry sand, 0 – 25% of galvanic glass waste, and 30 – 93% kaolin clay. Developed composites were sintered at 1100°, 1150°, 1200°, 1250°, and 1275°C. The ceramics’ flexural resistance values reached up to 12.29 MPa, linear shrinkage varied between 2.99 and 11.20 %, and water absorption – between 19.90 and 10.85%. The investigation of the ceramics structure formation processes using the X-ray diffraction, X-ray fluorescence, SEM, EDS AAS, and lased micro-mass analyze methods showed the synthesis of glassy structures with the inclusion of mullite and cristobalite crystalline structures. The analysis of the chemical composition of the gases emitted during ceramics firing at 1,275°C by the atomic absorption spectroscopy method, as well as the analyses of solubility and leaching of metals from ceramics, showed that the developed composites and technology were in full compliance with Brazilian sanitary standards. The results of the conducted research allow to decrease environment pollution by using hazardous industrial toner waste, galvanic glass waste and spent foundry sand as valuable raw materials to produce sustainable ceramics with high values of mechanical, physical and chemical properties.