| 摘要 |
<p>The invention relates to a silica of mesoporous structure, employed in the preparation of ceramics, and to a process for preparing the same. According to the invention, the silica has an X ray-amorphous structure, exhibiting a monomodal or bimodal granulometric distribution, with an average particle size in the range of 25...80 nm and 1300...4500 nm, a density of 1.82...2 g/cm, a specific surface of 250...400 m/g and an average pore size in the range of 2.3...200 Angstrom. The process, as claimed by the invention, consists in solubilizing the micronized serpentinite with a solution of mineral acid, at the temperature of 80...97°C, for 1...2 h, separating the resulting mixture to obtain a silica cake which is washed 3...5 times with water at the temperature of 95...100°C, after which there take place a filtration and a drying operation in an electric furnace, at a temperature of 80...95°C, for 3...6 h, wherefrom there also results a residual solution which is treated with alkaline solutions at the temperature of 30...60°C, to finally result in hydrated compounds with Fe or Mg.</p> |
