Diopside glass-ceramics were fabricated by sintering the powder mixtures of waste glass and kaolin

Glass-ceramics with diopside (CaMgSi2O6) as the main crystalline phase were prepared via low-temperature powder sintering method using waste glass and kaolin as starting materials. The effects of kaolin content and sintering temperature on phase composition, micro-structure and properties of as-prepared glass-ceramics were investigated by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Research results showed that the addition of kaolin could promote the devitrification of waste glass during sintering. The formation of diopside crystalline phase mainly originated from the decrease of sodium ion contents in glass phase, which was caused by the crystallization of sodium aluminum silicate. Diopside-based glass-ce-ramics could be achieved under proper combination ratio of waste glass and kaolin, and raising sintering tem-perature was beneficial to formation of diopside. Glass-ceramics prepared by adding 25 wt% kaolin and sintered at 825 C for 2 h showed a maximum bending strength of 114.9 MPa and a bulk density of 2.484 g/cm3.

Automated summary

Glass-ceramics with diopside as the main crystalline phase were prepared using waste glass and kaolin via low-temperature powder sintering method. The addition of kaolin and raising sintering temperature promoted the formation of diopside, leading to enhanced bending strength and density in the glass-ceramics.