Research Article
A Novel Environmental Route to Ambient Pressure Dried Thermal Insulating Silica Aerogel via Recycled Coal Gangue
Table 2
Acid leach experiment of the coal gangue.
| | Sample | Calcination temperature (°C) | Calcination time (h) | HCl concentration (mol/L) | Reaction period (h) | Silicon concentration in the residue (%) |
| | CSi-1 | 750 | 1 | 4 | 2 | 72.84 ± 1.50 | | CSi-2 | 750 | 2 | 5 | 3 | 79.06 ± 1.13 | | CSi-3 | 750 | 4 | 6 | 5 | 79.10 ± 2.55 | | CSi-4 | 850 | 1 | 5 | 5 | 79.03 ± 0.81 | | CSi-5 | 850 | 2 | 6 | 2 | 78.37 ± 3.10 | | CSi-6 | 850 | 4 | 4 | 3 | 75.45 ± 1.72 | | CSi-7 | 950 | 1 | 6 | 3 | 68.88 ± 2.31 | | CSi-8 | 950 | 2 | 4 | 5 | 74.43 ± 1.55 | | CSi-9 | 950 | 4 | 5 | 2 | 68.69 ± 2.10 |
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