Fabrication of ceramic monoliths from diatomaceous earth: effects of calcination temperature on silica phase transformation
The raw diatomaceous earth from the vicinity of Bitola (North Macedonia) showed low bulk density (0.61-0.69 g/cm3), high-water absorption (75-81%) and porosity (66- 72%). The chemical composition was determined with ICP-MS, revealing the following results for the diatomaceous earth: SiO2 (6...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
International Institute for the Science of Sintering, Beograd
2022-01-01
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| Series: | Science of Sintering |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/0350-820X/2022/0350-820X2204495R.pdf |
| Summary: | The raw diatomaceous earth from the vicinity of Bitola (North Macedonia)
showed low bulk density (0.61-0.69 g/cm3), high-water absorption (75-81%)
and porosity (66- 72%). The chemical composition was determined with ICP-MS,
revealing the following results for the diatomaceous earth: SiO2 (63.69
wt%), Al2O3 (11.79 wt%), Fe2O3 (5.95 wt%), MnO (0.15 wt%), TiO2 (0.65 wt%),
CaO (1.51 wt%), MgO (2.24 wt%), P2O5 (0.13 wt%), K2O (1.64 wt%), Na2O (0.93
wt%), LOI (11.21 wt%). XRPD data of the examined sample of clayey diatomite
mainly depicted crystalline behavior with a small presence of amorphous
phase. The crystalline mineral phases mainly comprise: silica (quartz),
feldspars (plagioclase), mica (muscovite), chlorites and dolomite. SEM and
TEM results show cased presence of micro- and nanostructures with pores
ranging from 250 to 600 nm. The clayey diatomite was sintered at three
temperatures (900, 1000 and 1100ºC) for a period of 1 h. XRPD of the
sintered samples at 1100ºC showed certain thermal stability and formation of
new phases (mullite and tridymite) that makes the analyzed diatomaceous
earth suitable for production of various types of ceramic, construction and
thermal insulating materials. |
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| ISSN: | 0350-820X 1820-7413 |