High temperature thermochemical and thermophysical transformation of porcellanite

Abstract

AbstractCurrently there is interest in Trinidad porcellanite as a potential raw material for ceramic applications. Thus, XRD and SEM techniques have been used in the present work to study high temperature thermochemical and thermophysical transformations in powder compacts of the rock type. Mineralogically, XRD showed that in the as mined state the porcellanite studied was comprised mainly of leucite (potassium aluminium silicon oxide), potassium silicate, and silica. On firing in the temperature range 1150-1350°C, the leucite dissociated into mullite and potassium silicate. Further, on firing at or above 1225°C, the compacts fused as a result of fusing of the alkali (potassium) silicate. SEM techniques showed that the resultant microstructure of the fused compacts was comprised predominantly of silica particles embedded in a dense matrix composed of mullite and potassium silicate.