LIU Bo, LIU Moxiang, CHEN Xiaoping. Preparation of SiO2-Al2O3 composite aerogel with high specific surface area by sol-gel method from coal gangue[J]. CIESC Journal, 2017, (5): 2096-2104. DOI: 10.11949/j.issn.0438-1157.20161577.
LIU Bo, LIU Moxiang, CHEN Xiaoping. Preparation of SiO2-Al2O3 composite aerogel with high specific surface area by sol-gel method from coal gangue[J]. CIESC Journal, 2017, (5): 2096-2104. DOI: 10.11949/j.issn.0438-1157.20161577.DOI:
SiO2-Al2O3 aerogel has been synthesized by sol-gel method followed by vacuum drying from Yanzhou coal gangue. Coal gangue was treated in the sequence of low temperature calcination
acid leaching
alkali-activation and sol-gel method. The physical and chemical characteristics of coal gangue
SiO2-Al2O3 aerogel and the intermediate products during the synthesizing process were investigated by means of X-ray diffraction
scanning electron microscope
Fourier transform infrared spectroscopy and nitrogen adsorption
and the gelation mechanism of SiO2-Al2O3 was studied. The results showed that both quartz and kaolinite
which were the main constituents of coal gangue
were transformed into amorphous state after alkali-activation. The SiO2-Al2O3 aerogel was an aggregation of amorphous nanoparticles formed by Si-O-Si
Si-O-Al network skeleton. The SiO2-Al2O3 aerogel had a bulk density of 0.37 g·cm-3
a BET specific surface area of 483 m2·g-1 and a mesoporous structure with a specific pore volume of 1.87 cm3·g-1 and an average pore diameter of 10.29 nm with most probable pore size of 9.32 nm.