Development of novel dense glass-ceramics from combination of silicate waste

In the present study, Plasma Vitrified air pollution control Waste (PVW) and recycled pharmaceutical Borosilicate Glass (BSG) are used to form novel glass-ceramic composites. The sinterability of PVW and 11vol%BSG mixtures at different annealing temperature, holding time and particle size are investigated. A simple powder technology processing approach has been followed to ease the number of processing parameters such as heating and cooling rate. The highest density of 2.74g/cm3 of new glass-ceramics was achieved for <38µm particle size powder compacts sintered at 850°C for 30min. Particle sizes of <100µm and <250µm processed under similar conditions showed maximum densities of 2.69 and 2.72g/cm3 at 875°C and 900°C, respectively. The XRD measurements have shown the crystallisation of anorthite and wollastonite phases for the above mentioned processing temperatures, while the complete crystallisation for all samples was observed at 950°C and 30min sintering time. A drastic change in color is observed for different particle sized glass-ceramic composites indicating microstructural differences. This preliminary investigation confirms that the powder route of optimised mixtures of PVW and BSG is suitable to produce glass-ceramics with low porosity for structural applications.