Wollastonite glass-ceramics was prepared by using the milling and sintering process with a mixture of two different powders. As a solution to environmental and waste recycling problems, powder mixtures consisting of dry sludge bottom ash and waste glass powder were used to make Wollastonite glass-ceramics. The chemical durability, crystallinity, morphological properties and chemical compositions of the specimens before and after acid immersion were observed by field emission-scanning electron microscopy (FE-SEM) and an energy dispersive X-ray spectrometer (EDS). Various mechanical properties, such as density, compressive strength, bending strength and Vickers hardness were also investigated. Various heat treatment temperatures [850, 950 and 1050 oC] were used to obtain glass-ceramics before and after the acid immersion of the optimum chemical durability and to find adequate mechanical properties for practical usage. As the heat-treatment temperature was increased from 850 oC to 1050 oC, the mechanical properties improved, especially the glass-ceramics in a dense acicular type of crystals of the Wollastonite phase at 1050 oC, in particular, and all specimens before and after acid immersion, in general.

Keywords: Wollastonite glass-ceramics, Chemical durability, Milling, Mechanical properties