Preparation and Utilization of Fine Expanded Perlite

Abstract

Hollow glass microspheres named expanded perlite have been prepared from perlite, but the size is usually above 20 µm. In the conventional preparation method, it is difficult to produce fine expanded perlite with particle size under 20 µm because the water contained in finely milled perlite particle, which is the origin of foaming, is evolved during heating process. A new fluidized sand-bedfurnace has developed and fine expanded perlite particles with particle size less than 15 µm and bulk density under 0.5 g/cm3 are prepared successfully. Using the fine expanded perlite, lightweight composites with alumina and lightweight pottery are successfully prepared by colloidal processing and subsequent heating.