Structure and Filtration Performance of Fly Ash-Based Porous Geopolymer

Abstract

Abstract: At present, the working temperature of industrial dust removal filter bag is not higher than 280 ℃. The high temperature flue gas needs to be cooled before filtration. In order to prepare a new type of filter material with high efficiency and good temperature resistance, porous geopolymer was preparedby polymerization reaction with fly ash as the main raw material and H₂O₂ as foaming agent. The morphology, pore structure, flexural strength and filtration performance were characterized. The results show that the optimum addition of H₂O₂ is 0.98%(mass fraction). The average pore diameters of the lower surface and the interior of the porous geopolymer are 17.3 and 171.5 μm respectively, the porosity is 56.2%, the flexural strength at room temperature is 2.2 MPa, the filtration resistance is 6.2×10^-3 MPa, and the filtration efficiency of PM10 and PM2.5 are 98.2% and 93.3%, respectively. After heat treatment at 800 ℃, the flexural strength increases to 3.4 MPa, and the filtration efficiency of PM10 and PM2.5 remains above 90%. The filtration resistance increases by 1×10^-3 MPa. Therefore, the fly ash-based porous geopolymer has a good application prospect as a high-temperature flue gas filtration material.

Key words: fly ash, porous geopolymer, high temperature treatment, filtering performance, pore structure, flexural strength

CLC Number:

TB321

CHEN Xiping, WANG Zhaotian, LUO Hongjie, CHENG Yan, WU Linli, JIANG Hao. Structure and Filtration Performance of Fly Ash-Based Porous Geopolymer[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(6): 2081-2091.

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