Effect of SiO2/Na2O mole ratio on the properties of foam geopolymers fabricated from circulating fluidized bed fly ash
来源期刊：International Journal of Minerals Metallurgy and Materials2014年第6期
论文作者：Ze Liu Ning-ning Shao Tian-yong Huang Jun-feng Qin Dong-min Wang Yu Yang
文章页码：620 - 626
摘 要：Geopolymers are three-dimensional aluminosilicates formed in a short time at low temperature by geopolymerization. In this paper, alkali-activated foam geopolymers were fabricated from circulating fluidized bed fly ash（CFA）, and the effect of SiO2/Na2O mole ratio（0.91–1.68） on their properties was studied. Geopolymerization products were characterized by mechanical testing, scanning electron microscopy（SEM）, energy-dispersive X-ray spectroscopy（EDX）, and X-ray diffraction（XRD）. The results show that SiO2/Na2O mole ratio plays an important role in the mechanical and morphological characteristics of geopolymers. Foam samples prepared in 28 d with a SiO2/Na2O mole ratio of 1.42 exhibit the greatest compressive strength of 2.52 MPa. Morphological analysis reveals that these foam geopolymers appear the relatively optimized pore structure and distribution, which are beneficial to the structure stability. Moreover, a combination of the Si/Al atomic ratio ranging between 1.47 and 1.94 with the Na/Al atomic ratio of about 1 produces the samples with high strength.
Ze Liu，Ning-ning Shao，Tian-yong Huang，Jun-feng Qin，Dong-min Wang，Yu Yang
School of Chemical and Environmental Engineering, China University of Mining and Technology
摘 要：Geopolymers are three-dimensional aluminosilicates formed in a short time at low temperature by geopolymerization. In this paper, alkali-activated foam geopolymers were fabricated from circulating fluidized bed fly ash（CFA）, and the effect of SiO2/Na2O mole ratio（0.91–1.68） on their properties was studied. Geopolymerization products were characterized by mechanical testing, scanning electron microscopy（SEM）, energy-dispersive X-ray spectroscopy（EDX）, and X-ray diffraction（XRD）. The results show that SiO2/Na2O mole ratio plays an important role in the mechanical and morphological characteristics of geopolymers. Foam samples prepared in 28 d with a SiO2/Na2O mole ratio of 1.42 exhibit the greatest compressive strength of 2.52 MPa. Morphological analysis reveals that these foam geopolymers appear the relatively optimized pore structure and distribution, which are beneficial to the structure stability. Moreover, a combination of the Si/Al atomic ratio ranging between 1.47 and 1.94 with the Na/Al atomic ratio of about 1 produces the samples with high strength.
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