Synthesis and Surface Characterization of a Silica White Prepared from High Si:Al Fine Powder
| Periodical | Key Engineering Materials (Volumes 512 - 515) |
|---|---|
| Main Theme | High-Performance Ceramics VII |
| Edited by | Wei Pan and Jianghong Gong |
| Pages | 40-44 |
| DOI | 10.4028/www.scientific.net/KEM.512-515.40 |
| Citation | Nan Chun Chen et al., 2012, Key Engineering Materials, 512-515, 40 |
| Online since | June, 2012 |
| Authors | Nan Chun Chen, Cheng Ju Zhao, Wei Wang, Meng Ying Li |
| Keywords | Precipitation Method, Silica Fine Powder, Silica White |
| Price | US$ 28,- |
This paper describes the synthesis and surface characterization of a new silica white prepared from a high Si:Al fine powder by using the sulfuric acid precipitation method. In the beginning, water and alkali are added to the sieved high Si:Al fine powder. The mixed liquid is then heated until it is boiling and left alone at the same temperature for 2.5 hours before it is filtrated. Applying liquid NaCl (20%) to the filtrated solution before it is heated to 80℃. Applying certain amount of surfactant and H2SO4 (20%) while maintaining the temperature at 80℃ for 3 hours before it is washed, precipitated, filtrated, and dried to produce the final product of silica white. Examinations with XRD and IR show that the silica white is amorphous silicon. It has a PH value of 7-7.5 determined by aqueous suspension method, a white index of 96% and above, a volume average particle diameter of 4.6 - 7.1 µm, a specific surface area of 95.5-103.1 m2/g, an oil absorption rate of 4.34-4.87 ml/g, and a LOI (loss on ignition) of 5.12% at 1000℃. The synthesized silica white has a satisfying uniformity of particle sizes, meeting standard of HG/T 3061-1999.
