ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Preparation and Refinement of Microamorphous Silica
D. Hršak, J. Malina, and G. Sučik
Faculty of Metallurgy, University of Zagreb, Sisak, Croatia
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)