关键词: 粉煤灰, Al(OH)₃, 多孔陶瓷, 莫来石

Abstract:

In order to improve the comprehensive utilization of fly ash resources,porous mullite materials were prepared by solid sintering using fly ash as the silicon source,alumina hydroxide as the aluminum source,AlF₃ as the crystal whisker accelerator,and V₂O₅ as the sintering aid.The effects of the ratio of fly ash to aluminum hydroxide (28.2:71.8,34.2:65.8,40.2:59.8,46.2:53.8 and 52.2:47.8,respectively) on the properties,the phase composition and the microstructure of the prepared porous mullite materials were studied.The results show that with the ratio of fly ash to aluminum hydroxide increasing,the apparent porosity gradually increases,the compressive strength and bulk density gradually reduce,the diffraction peaks of mullite gradually strengthen,while those of corundum gradually weaken and disappear;when the mass ratio of fly ash to aluminum hydroxide is 52.2:47.8 the sample shows an apparent porosity of 53.1%,the bulk density of 1.12 g·cm^-3,the compressive strength of 22.8 MPa,and the length to diameter ratio of 30.

Key words: fly ash, aluminum hydroxide, porous ceramics, mullite