Quantitative kinetic and structural analysis of geopolymers. Part 1. The activation of metakaolin with sodium hydroxide

Zhang, Zuhua; Wang, Hao; Provis, John L.; Bullen, F; Reid, Andrew; Zhu, Yingcan

doi:10.1016/j.tca.2012.03.021

Cited by 352 publications

(173 citation statements)

References 52 publications

Supporting

Mentioning

152

Contrasting

Unclassified

Order By: Relevance

“…The higher intensity of these bands in the alkali activated pastes, compared with the SFCC precursor, is consistent with more adsorbed water groups (≡Si−OH … H 2 O and ≡Al−OH … H 2 O) in the aluminosilicate gel (28).…”

Section: Fourier Transform Infrared Spectroscopy (Ftir)supporting

confidence: 59%

Synthesis of geopolymer from spent FCC: Effect of SiO2/Al2O<3 and Na2O/SiO2 molar ratios

Trochez¹,

Gutiérrez²,

Rivera³

et al. 2015

Mater. construcc.

View full text Add to dashboard Cite

This paper assesses the feasibility of using a spent fluid catalytic cracking catalyst (SFCC) as precursor for the production of geopolymers. The mechanical and structural characterization of alkaliactivated SFCC binders formulated with different overall (activator + solid precursor) SiO 2 /Al 2 O 3 and Na 2 O/ SiO 2 molar ratios are reported. Formation of an aluminosilicate 'geopolymer' gel is observed under all conditions of activation used, along with formation of zeolites. Increased SiO 2 /Al 2 O 3 induces the formation of geopolymers with reduced mechanical strength, for all the Na 2 O/SiO 2 ratios assessed, which is associated with excess silicate species supplied by the activator. This is least significant at increased alkalinity conditions (higher Na 2 O/SiO 2 ratios), as larger extents of reaction of the spent catalyst are achieved. SiO 2 /Al 2 O 3 and Na 2 O/SiO 2 ratios of 2.4 and 0.25, respectively, promote the highest compressive strength (67 MPa). This study elucidates the great potential of using SFCC as precursor to produce sustainable ceramic-like materials via alkali-activation. RESUMEN: Sintesis de geopolimero basado en un catalizador gastado de craqueo catalitico (FCC): Efecto de las relaciones molares SiO 2 /Al2O 3 y Na 2 O/SiO 2 . Este artículo estudia la factibilidad de usar un catalizador gastado del proceso de craqueo (SFCC) para la producción de geopolímeros. Se evalúan las características mecánicas y estructurales de los geopolímeros producidos con diferentes relaciones molares (activador + precursor solido) de SiO 2 /Al 2 O 3 y Na 2 O/SiO 2 . La formación de un gel geopolimérico de tipo aluminosilicato se observa a las diferentes condiciones evaluadas, así como la formación de zeolitas. Un incremento en la relación SiO 2 /Al 2 O 3 genera geopolímeros de baja resistencia mecánica, a las diferentes relaciones molares Na 2 O/SiO 2 evaluadas, como consecuencia del exceso de especies silicato provenientes del activador. Este efecto es menos significativo al incrementar las condiciones de alcalinidad (mayores relaciones Na 2 O/SiO 2 ), ya que un mayor grado de reacción del catalizador gastado es alcanzado. Las relaciones SiO 2 /Al 2 O 3 y Na 2 O/SiO 2 de 2.4 and 0.25, respectivamente, promueven la mayor Resistencia a la compresión (67 MPa). Este estudio muestra el gran potencial de uso del SFCC como precursor en materiales cerámicos obtenidos por activación alcalina.

show abstract

Section: Fourier Transform Infrared Spectroscopy (Ftir)supporting

confidence: 59%

Synthesis of geopolymer from spent FCC: Effect of SiO2/Al2O<3 and Na2O/SiO2 molar ratios

Trochez¹,

Gutiérrez²,

Rivera³

et al. 2015

Mater. construcc.

View full text Add to dashboard Cite

show abstract

“…The main vibration band is at around 900 cm -1 for slag and about 1020 cm -1 for fly ash, which are associated with the asymmetric stretching vibration of terminal Si-O and bridge Si-O-T bonds, respectively [12,13]. The difference in the main absorption band illustrates the different glassy networks of the raw materials.…”

Section: Reaction Kineticsmentioning

confidence: 98%

Properties of alkali activated slag–fly ash blends with limestone addition

Gao

Brouwers

2015

Cement and Concrete Composites

191

View full text Add to dashboard Cite

“…The broad peak observed from 20 to 30° 2 θ in MK (Figure 1a) has become wider to 40° 2 θ after the reaction with activator M s 1.67 and shifted to higher angle (Figure 4a), as is known to occur during geopolymer formation from MK. This shift demonstrates the formation of new amorphous phases, usually described as geopolymeric gels (21,22). The presence of the halo can be explained by formation of alkali aluminosilicate gel as the primary reaction product in activation of MK as well as presence of LSG in the composition of MK-A1-G1, where the halo is more pronounced.…”

Section: Xrdmentioning

confidence: 92%

“…All AAM specimens with and without glass waste have mode at 446 cm −1 which corresponds to Si-O-Si or Al-OSi bands (22,23). Mode at 540 cm −1 is typical only for MK-A1-G0 and IC-A1-G0 and it is associated with Si-O-Al bands, where Al is present in octahedral coordination.…”

Section: Ftirmentioning

confidence: 95%

Porous alkali activated materials with slow alkali release dynamic. Role of composition

Būmanis

Bajāre

2018

Mater. construcc.

View full text Add to dashboard Cite

Alkali activated materials (AAM) based on calcined metakaolin or illite clay together with waste by-products, such as waste glass or aluminium scrap recycling waste, were tested as value-added materials for pH stabilization in biogas technology where decrease of pH should be avoided. Porous materials with ability to slowly leach alkalis in the water media thus providing continuous control of the pH level were obtained. XRD, FTIR, SEM and titration methods were used to characterize AAM and their leaching properties. It is clear that composition of the material has an important effect on the diffusion of alkali from structure. Namely, higher Si/Al and Na/Al molar ratios may increase pore solution transfer to the leachate. The leaching rate of alkalis from the structure of AAM is high for the first few days, decreasing over time. It was possible to calculate the buffer capacity from the mixture design of AAM. RESUMEN: Materiales activados alcalinamente porosos con liberación lenta de álcalis. Efecto de la composición.En este estudio se han ensayado materiales activados alcalinamente (AAM) basados en metacaolín o arcilla de ilita junto con subproductos tales como residuos de vidrio o aluminio reciclado, como materiales con valor añadido para la estabilización del pH en tecnologías de biogás donde se debe evitar la disminución del pH . Se obtuvieron materiales porosos con capacidad para lixiviar lentamente los álcalis en medios acuosos, proporcionando así un control continuo del nivel de pH. Se utilizaron técnicas de DRX, FTIR, SEM y métodos de tritación para caracterizar los AAMs y sus propiedades de lixiviación. La composición del material tiene un efecto importante en la difusión del álcali de la estructura. Es decir, mayores relaciones molares de Si / Al y Na / Al pueden aumentar la transferencia de la solución del poro al lixiviado. La tasa de lixiviación de los álcalis desde la estructura de los AAMs es alta durante los primeros días, disminuyendo con el tiempo. Se ha calculado la capacidad del efecto tampón a partir del diseño de mezcla de AAM.Palabras clave: Cemento activado alcalinamente; Tratamiento de residuos; Difusión; Microestructura, pH ORCID ID: G. Bumanis

show abstract

Quantitative kinetic and structural analysis of geopolymers. Part 1. The activation of metakaolin with sodium hydroxide

Cited by 352 publications

References 52 publications

Synthesis of geopolymer from spent FCC: Effect of SiO<sub>2</sub>/Al<sub>2</sub>O<3 and Na2O/SiO2 molar ratios

Synthesis of geopolymer from spent FCC: Effect of SiO<sub>2</sub>/Al<sub>2</sub>O<3 and Na2O/SiO2 molar ratios

Properties of alkali activated slag–fly ash blends with limestone addition

Porous alkali activated materials with slow alkali release dynamic. Role of composition

Contact Info

Product

Resources

About