Preparation and Properties of Activated Coal Gangue Geopolymer

Abstract

Abstract: The original coal gangue was analyzed both qualitatively and quantitatively, the calcination temperature of activated coal gangue was optimized, and the effects of sodium-aluminum ratio (n(Na)/n(Al)=0.52, 0.57, 0.62) and the activator modulus (M=0.66, 0.69, 1.32, 1.65) on the compressive strength and microstructure of activated coal gangue geopolymer were investigated. The microstructure of activated coal gangue geopolymer was characterized by XRD, FT-IR and SEM. The results show that activated coal gangue at high temperature is helpful to activate the active components in coal gangue. When the calcination temperature is 600 ℃, the kaolinite facies disappears completely and “the bulge peak” area is relatively large, which can be used to prepare activated coal gangue geopolymer. The increase of n(Na)/n(Al) promots the geopolymer reaction, and the compressive strength is also increased. Meanwhile, the compressive strength is also increased with the increase of the excitation modulus. When n(Na)/n(Al) is 0.62 and the activator modulus is 1.65, the compressive strength of the sample on 7 d reaches to 52 MPa. The product of activated coal gangue geopolymer is sodium silicate hydrate (N-A-S-H) gel, the hydration product is compact and has good performance.

Key words: calcination temperature, coal gangue, geopolymer, material strength, microstructure

CLC Number:

TU52

WANG Fei, LIU Ze, HAN Le, XIE Fuzhu. Preparation and Properties of Activated Coal Gangue Geopolymer[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(3): 914-920.

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