ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation and Refinement of Microamorphous Silica

D. Hršak, J. Malina, and G. Sučik

Faculty of Metallurgy, University of Zagreb, Sisak, Croatia

E-mail: gabriel.sucik@tuke.sk

Received: 10 December 2002  Accepted: 22 January 2004

Abstract: The application of sulfuric acid for the leaching of serpentinite ore has been investigated in order to prepare the high-purity powder of amorphous SiO₂ with great surface area.
Serpentinite with high content of antigorite was milled to particles under 200 µm in size and then thermally treated with the aim to destroy the crystal structure of antigorite. The highest leaching extent was achieved by H₂SO₄ solution with concentration 5 mol dm^-3, while optimum leaching time was 4 h.
Characterization and refinement of the prepared powder were also performed. By the leaching process a good-quality powder of microamorphous silica with 97.36 mass % SiO₂ was prepared, having the surface area 162 m² g^-l and 71.10 % of particles under 9 µm in size. After a relatively simple refinement procedure, the content of SiO₂ was increased to 98.72 % and BET surface area to 180 m² g^-l.

Full paper in Portable Document Format: 583a191.pdf

Chemical Papers 58 (3) 191–194 (2004)