Insights into the polymorphic transformation mechanism of aluminum hydroxide during carbonation of potassium aluminate solution

Jiang, Youfa; Liu, Cheng-Lin; Xue, Jin; Li, Ping; Yu, Jianguo

doi:10.1039/c7ce01656e

Cited by 12 publications

(11 citation statements)

References 39 publications

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“…28 Bayerite is easily formed due to its higher growth rate than that of gibbsite under the alkaline condition at room temperature. 29,30 When the dose of DMF increases to 400 mL, the peak intensity of the (001) plane increases obviously. It indicates that the crystal size of P3-400-1 increases slightly due to the faster growth of crystal at a high DMF content.…”

Section: Methodsmentioning

confidence: 99%

Fast, Large-Scale, and Stable Preparation of η-Al₂O₃ Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Yang

Cai

Zhou

et al. 2020

Ind. Eng. Chem. Res.

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A fast, large-scale, and stable preparation method was successfully developed to obtain η-Al2O3 microspheres with particle sizes of 3–10 μm from cheap and widely sourced NaAlO2 solution using N,N-dimethylformamide (DMF) as a morphological modifier and a precipitant simultaneously at room temperature. The yield of alumina increases from 33.3 to 77.3% by increasing the dose of DMF from 100 to 400 mL. The utilization efficiency of DMF significantly increased by adding fresh NaAlO2 into the reused filtrate after separating the bayerite precipitate (precursor of η-Al2O3). Importantly, the η-Al2O3 microspheres obtained from the filtrate-reuse experiments show the stable phase structures, morphologies, and pore structure properties. Furthermore, the typical η-Al2O3 microspheres supported Pd catalyst presents a higher catalytic activity of 10.6 g/L for the hydrogenation of anthraquinone than that of the commercial γ-Al2O3-supported Pd catalyst (8.5 g/L), suggesting that the as-prepared η-Al2O3 microspheres have good application prospects for catalytic hydrogenation and related fields.

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Section: Methodsmentioning

confidence: 99%

Fast, Large-Scale, and Stable Preparation of η-Al₂O₃ Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Yang

Cai

Zhou

et al. 2020

Ind. Eng. Chem. Res.

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“…after sintering. [24][25][26][27][28] Adding N-butanol and TMAH as the active solutions along with Al/SiO 2 synthesis strongly affects the crystalline states and sizes of the composites. More amorphous state and smaller crystallite size, which are qualitatively indicated by the broader and lower XRD peaks, are obtained by Al/SiO 2 (T) rather than Al/SiO 2 (B) (see Figures 4 and 5).…”

Section: Mechanical Propertiesmentioning

confidence: 99%

“…The occurrence of γ-Al 2 O 3 , especially in Figure 5, indicates that γ-Al 2 O 3 is likely to form due to sintering Al/SiO 2 mixtures. OHions can easily react with Al powders forming aluminium hydroxide (γ-Al(OH) 3 ), which in turns transforms into γ-Al 2 O 3 after sintering [24][25][26][27][28].…”

mentioning

confidence: 99%

Mechanical Strength and Corrosion Rate of Aluminium Composites (Al/SiO2): Nanoparticle Silica (NPS) as Reinforcement

Munasir¹,

Triwikantoro²,

Zainuri³

et al. 2019

JPS

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The fabrication and characteristics of amorphous silica reinforced Al matrix composites are studied in this paper. The major starting materials were commercial Al powder and extracted nanoparticle SiO 2 (NPS) powder from Indonesian silica sands. Two different active solutions, namely N-butanol and tetramethylammonium hydroxide (TMAH), were introduced during synthesis. Characterisations in terms of physical, mechanical, microstructural and corrosion rate examinations were also employed. Introducing the SiO 2 nanoparticles into the Al matrix has decreased the density and increased the porosity of the composites. The addition of N-butanol into Al/SiO 2 (Al/SiO 2 (B)) led to broader and lower X-ray diffraction profiles than the addition of TMAH (Al/SiO 2 (T)). From the microstructural analysis, we found that the SiO 2 particles enter and agglomerate into the opening gap of the Al sheets. Furthermore, yield strength, ultimate compression strength and modulus of elasticity tended to reduce the addition of SiO 2 . The corrosion rate of Al/SiO 2 (T) was lower than that of Al/SiO 2 (B) composites.

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“…Finally, the authors are not aware of the works fully devoted to prove the stability of aluminium hydroxide under CO 2 atmospheres, see reaction (4). However, from the reports of carbonation of calcium aluminate and sulphoaluminate cement binders [15][16][17], it could be deduced that Al(OH) 3 is not carbonated, which is backed by other publications [22]. Table 1.…”

Section: Introductionmentioning

confidence: 96%

X-ray Total Scattering Study of Phases Formed from Cement Phases Carbonation

2021

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Carbonation in cement binders has to be thoroughly understood because it affects phase assemblage, binder microstructure and durability performance of concretes. This is still not the case as the reaction products can be crystalline, nanocrystalline and amorphous. The characterisation of the last two types of components are quite challenging. Here, carbonation reactions have been studied in alite-, belite- and ye’elimite-containing pastes, in controlled conditions (3% CO2 and RH = 65%). Pair distribution function (PDF) jointly with Rietveld and thermal analyses have been applied to prove that ettringite decomposed to yield crystalline aragonite, bassanite and nano-gibbsite without any formation of amorphous calcium carbonate. The particle size of gibbsite under these conditions was found to be larger (~5 nm) than that coming from the direct hydration of ye’elimite with anhydrite (~3 nm). Moreover, the carbonation of mixtures of C-S-H gel and portlandite, from alite and belite hydration, led to the formation of the three crystalline CaCO3 polymorphs (calcite, aragonite and vaterite), amorphous silica gel and amorphous calcium carbonate. In addition to their PDF profiles, the thermal analyses traces are thoroughly analysed and discussed.

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Insights into the polymorphic transformation mechanism of aluminum hydroxide during carbonation of potassium aluminate solution

Abstract: Polymorphic transformation from bayerite to gibbsite is discussed kinetically and structurally. Possibility of crossovers in Al(OH)3 polymorphs stability is investigated for the first time.

Cited by 12 publications

References 39 publications

Fast, Large-Scale, and Stable Preparation of η-Al₂O₃ Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Fast, Large-Scale, and Stable Preparation of η-Al₂O₃ Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Mechanical Strength and Corrosion Rate of Aluminium Composites (Al/SiO2): Nanoparticle Silica (NPS) as Reinforcement

X-ray Total Scattering Study of Phases Formed from Cement Phases Carbonation

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Insights into the polymorphic transformation mechanism of aluminum hydroxide during carbonation of potassium aluminate solution

Abstract: Polymorphic transformation from bayerite to gibbsite is discussed kinetically and structurally. Possibility of crossovers in Al(OH)3 polymorphs stability is investigated for the first time.

Cited by 12 publications

References 39 publications

Fast, Large-Scale, and Stable Preparation of η-Al2O3 Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Fast, Large-Scale, and Stable Preparation of η-Al2O3 Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Mechanical Strength and Corrosion Rate of Aluminium Composites (Al/SiO2): Nanoparticle Silica (NPS) as Reinforcement

X-ray Total Scattering Study of Phases Formed from Cement Phases Carbonation

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Fast, Large-Scale, and Stable Preparation of η-Al₂O₃ Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature

Fast, Large-Scale, and Stable Preparation of η-Al₂O₃ Microspheres by Fully Utilizing N,N-Dimethylformamide at Room Temperature