The hydrothermal transformation of solid geopolymers into zeolites

He, Yan; Xue-min, Cui; Mao, Jin; Liu, Leping; Liu, Xing-dong; Chen, Jinyu

doi:10.1016/j.micromeso.2012.05.039

Cited by 67 publications

(22 citation statements)

References 13 publications

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“…Thus, Si in MK3 seemed to be combining with more Al atoms than that in MK1. In the 27 Al NMR spectra, the 0, 25–30, and 50–60 ppm peaks are assigned to six- [Al(VI)], five- [Al(V)], and four-fold coordination [A1(IV)] states, respectively [12,13]. The 27 Al NMR spectra of MK0 showed a broad peak from –50 to 50 ppm, suggesting that MK0 contained Al(VI), Al(V), and A1(IV) states.…”

Section: Resultsmentioning

confidence: 99%

Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

et al. 2013

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Zeolite-geopolymer hybrid materials have been formed when kaolin was used as a starting material. Their characteristics are of interest because they can have a wide pore size distribution with micro- and meso-pores due to the zeolite and geopolymer, respectively. In this study, Zeolite-geopolymer hybrid bulk materials were fabricated using four kinds of kaolinitic clays (a halloysite and three kinds of kaolinite). The kaolinitic clays were first calcined at 700 °C for 3 h to transform into the amorphous aluminosilicate phases. Alkali-activation treatment of the metakaolin yielded bulk materials with different amounts and types of zeolite and different compressive strength. This study investigated the effects of the initial kaolinitic clays on the amount and types of zeolite in the resultant geopolymers as well as the strength of the bulk materials. The kaolinitic clays and their metakaolin were characterized by XRD analysis, chemical composition, crystallite size, 29Si and 27Al MAS NMR analysis, and specific surface area measurements. The correlation between the amount of zeolite formed and the compressive strength of the resultant hybrid bulk materials, previously reported by other researchers was not positively observed. In the studied systems, the effects of Si/Al and crystalline size were observed. When the atomic ratio of Si/Al in the starting kaolinitic clays increased, the compressive strength of the hybrid bulk materials increased. The crystallite size of the zeolite in the hybrid bulk materials increased with decreasing compressive strength of the hybrid bulk materials.

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Section: Resultsmentioning

confidence: 99%

Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

et al. 2013

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“…However, since separation factor does not change, it can be concluded that the zeolite layer is not formed uniformly on the geopolymer support and the distributed formed zeolites within the pores or on the support surface with functionality of adsorption act to separate water from alcohol. The researchers also showed that formation of uniform selective zeolite layers on porous supports via hydrothermal method is very sensitive to the gel formula and hydrothermal conditions [19,29]. Figure 6, formation of the perfectly uniform selective zeolite layer can be observed.…”

Section: Pv Test Resultsmentioning

confidence: 98%

“…Zeolite layers can be prepared via growth of zeolite crystals by means of methods like sol gel [17], microwave [18] and hydrothermal synthesis [19]. Actually, zeolite membranes are some kinds of microporous ceramic materials consisting of aluminosilicates with different ratios of aluminum to silicium.…”

Section: Introductionmentioning

confidence: 99%

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Ceramic membrane synthesis based on alkali activated blast furnace slag for separation of water from ethanol

Azarshab

Mohammadi

Maghsoodloorad

et al. 2016

Ceramics International

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“…Alkali-activated binders generate 80% less carbon dioxide than portland cement [2]. "Alkali-activated binders" are also known as "geopolymers", as they were first named by Davidovits in the 1970s [3]. Geopolymers may be considered as environmentally friendly materials, since the production of geopolymer cement does not contribute to the appearance of greenhouse gases [4].…”

Section: Introductionmentioning

confidence: 99%

Physical and Mechanical Properties of Silica Fume and Calcium Hydroxide Based Geopolymers

2017

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Conventional portland cement has found worldwide usage in the production of cementitious materials in recent years. Nevertheless, environmental problems such as high demand of raw materials, energy consumption and high amount of carbon dioxide emission take place before and during manufacturing process. The attempts have been made to seek alternative binders and develop supplementary materials for construction sector. Therefore, this study reports the results of an experimental program on the comparison of geopolymers with different compositions in terms of evaluating their physical and mechanical behavior. For that purpose, the effect of binder types and amount of binders and alkali activator (sodium hydroxide) was investigated. In addition, acidic pumice and waste aluminium particles were also used as fine aggregate and air entraining agent, respectively, in geopolymer production. The test results revealed that as the content of alkali activator increased, compressive and flexural strength decreased. Addition of waste aluminium particles decreased bulk density and strength owing to the some extent of entrained air.

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The hydrothermal transformation of solid geopolymers into zeolites

Cited by 67 publications

References 13 publications

Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

Ceramic membrane synthesis based on alkali activated blast furnace slag for separation of water from ethanol

Physical and Mechanical Properties of Silica Fume and Calcium Hydroxide Based Geopolymers

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