vitrification

Vitrification is a process where a substance is converted into a glass, or a glassy, amorphous solid. In the context of industrial ceramics, vitrification is a crucial step during firing. As ceramic materials are heated, crystalline compounds melt, forming a glassy liquid phase. This partial vitrification helps to bond particles together, reduce porosity, and consolidate the ceramic object, making it stronger and less permeable to fluids.1

In nuclear applications, vitrification is a favored method for the disposal of radioactive waste. High-level waste is incorporated into a solid form, typically borosilicate glass, to immobilize radioactive species and minimize leaching into the environment. The Vycor process is an industrial example where a sodium borate melt separates into two phases. One phase is dissolved, leaving a porous silica skeleton that can be used for various applications or sintered into a dense silica product. Devitrification, the opposite of vitrification, is the unwanted crystallization of glass during the cooling process.234