| Autor: |
Medyankina, Irina S., Pasechnik, Liliya A., Volkovich, Vladimir A, Kashin, Ilya V, Smirnov, Andrey A, Narkhov, Evgeniy D |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 2020, Vol. 2316 Issue 1, p1-6, 6p |
| Abstrakt: |
Amorphous silica can be prepared from industrial waste, such as wet magnetic separation tailings of titanium magnetite ore beneficiation and red mud from the Bayer processing of bauxite into alumina, with silicon content of 10 to 50% in them. We considered fluoridation of polycomponent technogenic materials by solid-phase synthesis with the change of process temperature and a hydrochemical synthesis by NH4HF2 solution. The variation of the sintering process temperature range allows obtaining the ammonium fluorometallates or simple fluorides. It was found that nanosized silica obtained from waste has a high purity (≥99%), specific surface area (240-300 m2/g), pore volume (0.25-0.28 cm3/g). The experiments demonstrated that to produce amorphous silicon dioxide from waste, a solution should be with an ammonium hexafluorosilicate concentration 80-100 g/l and the process of ammonia hydrolysis should be carried out at 40-80 °C. An efficient method for extraction of SiO2 with a small particle size and high hydrophobic properties from waste is proposed, which currently does not have an appropriate application and is stored on disposal area. Such amorphous silica can be used in the production of catalysts, ceramics, heat- and fire-resistant rubber, and silicon fluoride complexes. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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