Porous wollastonite (CaSiO3) powders were fabricated by a polymer solution technique. Silica sol and calcium nitrate were dissolved in de-ionized water without any precipitation, and polyvinyl alcohol (PVA) was mixed as a polymer carrier. An explosive exothermic reaction during the calcination process resulted in a porous powder structure. The crystalline development and specific surface areas of the calcined powders were dependant on the polymer content and type of silica sol. The porous powders were crystallized to beta-CaSiO3 at a lower temperature of about 900 degrees C than that of other synthesis methods, and the calcined powders were ball-milled to fine particles and densified at 1200 degrees C with an uniform grain size of a phase.

Keywords: Wollastonite, Powder technology, Polyvinyl alcohol, Porous particles, Ball milling, Sintering