Thermal behaviour of zircon/zirconia-added chemically durable borosilicate porous glass

► DTA proved to be more effective over dilatometer in determining the glass transition temperature and other thermal characteristics, e.g. formation of surface or bulk nucleation. ► Fine powders are prone to cristobalite precipitation when heat treated over a long temperature rage. ► Combination of FTIR and XRD is found to be instrumental in determining the heat treatment temperature and optimising phase separation. ► Selecting appropriate leaching left a skeletal structure consists mostly of silica and zirconia/zircon. This final silica structure has finely distributed nano sized pores.