Hydrotalcite and hydrocalumite as resources from waste materials of concrete aggregate and Al-dross by microwave-hydrothermal process

Abd-El-Raoof, F.; Tawfik, A.; Komarneni, Sridhar; Ahmed, S.E.

doi:10.1016/j.conbuildmat.2019.02.105

Cited by 19 publications

(3 citation statements)

References 36 publications

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“…As shown by the results, BD had hydroxyl, carboxyl, and other oxygen-containing functional groups, which could provide more active sites for CR adsorption . The absorption peaks at 3642 and 3585 cm –1 in the spectrum of LDH4 were attributed to the stretching vibration of Ca 2+ - and Al 3+ -bonded OH on the laminate . Also, the peaks at 1357–1476 and 873 cm –1 were caused by the stretching vibration of CO 3 2– .…”

Section: Resultsmentioning

confidence: 80%

“…The soybean dreg could be used as a cheap adsorption material since it contains rich oxygen-containing functional groups and has a loose and porous structure. − However, the specific surface area of the soybean dreg is small; therefore, its adsorption performance needs to be further improved. According to the previous literature, the main methods to improve the adsorption properties of biomass adsorbents included modification, carbonization, and preparation of composites. − Recently, combined with the advantages of biomass organic adsorption materials and traditional inorganic adsorption materials, the organic/inorganic composite adsorbents had attracted much attention. − For example, Abu-Danso et al found that the maximum adsorption capacities of clay/cellulose composites for Pb (II) and Cd (II) reach 389.78 and 115.96 mg·g –1 , respectively . Mirjavadi et al reported that the magnetic zeolite/cellulose nanofibers showed high adsorption capacity for the removal rate of Zn 2+ .…”

Section: Introductionmentioning

confidence: 99%

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Preparation and Adsorption Properties of Soybean Dreg/Hydrocalumite Composites

et al. 2021

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The application of biomass-based composites in the field of adsorption has attracted extensive attention. Herein, soybean dreg/hydrocalumite composites were prepared by in situ self-assembly from soybean dregs and applied to the adsorption of Congo Red (CR). The composites were characterized by scanning electron microscopy, X-ray diffraction, Fourier infrared spectroscopy, and N2 physical adsorption–desorption. The results showed that the adsorption property of soybean dregs/hydrocalumite for CR was better than that of soybean dregs or hydrocalumite. Effects of preparation and adsorption conditions on the adsorption of CR by soybean dregs/hydrocalumite were also investigated. The removal rate of soybean dregs/hydrocalumite (30%BD-LDH) prepared under the optimized conditions reached 97.4% with a 486.8 mg·g–1 adsorption capacity. Also, the adsorption capacity of 30%BD-LDH was about 2.4 times and 3.0 times that of hydrocalumite and soybean dregs, respectively. In addition, the adsorption process of CR by 30%BD-LDH was more in line with the pseudo-second-order kinetic and Langmuir isothermal models.

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Section: Resultsmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Preparation and Adsorption Properties of Soybean Dreg/Hydrocalumite Composites

et al. 2021

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“…Ref. [29] synthesised HC using CaO, Al 2 O 3 and K 2 CO 3 within an hour at 100 • C with microwave irradiation assistance. There also exist several thermodynamic studies [21][22][23][24] and studies concerning pressure-induced reactions [16] in the system CaO-Al 2 O 3 -H 2 O.…”

Section: Introductionmentioning

confidence: 99%

Green Synthesis of Hydrocalumite (CaAl-OH-LDH) from Ca(OH)2 and Al(OH)3 and the Parameters That Influence Its Formation and Speciation

Gevers

Labuschagne

2020

Crystals

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Hydrocalumite is a layered double hydroxide (LDH) that is finding increased application in numerous scientific fields. Typically, this material is produced through environmentally polluting methods such as co-precipitation, sol-gel synthesis and urea-hydrolysis. Here, the hydrothermal green (environmentally friendly) synthesis of hydrocalumite (CaAl-OH) from Ca(OH)2 and Al(OH)3 in water and the parameters that influence its formation are discussed. The parameters investigated include the reaction temperature, reaction time, molar calcium-to-aluminium ratio, the morphology/crystallinity of reactants used, mixing and the water-to-solids ratio. Hydrocalumite formation was favoured in all experiments, making up between approximately 50% and 85% of the final crystalline phases obtained. Factors that were found to encourage higher hydrocalumite purity include a low water-to-solids ratio, an increase in the reaction time, sufficient mixing, the use of amorphous Al(OH)3 with a high surface area, reaction at an adequate temperature and, most surprisingly, the use of a calcium-to-aluminium ratio that stoichiometrically favours katoite formation. X-ray diffraction (XRD) and Rietveld refinement were used to determine the composition and crystal structures of the materials formed. Scanning electron microscopy (SEM) was used to determine morphological differences and Fourier-transform infrared analysis with attenuated total reflectance (FTIR-ATR) was used to identify possible carbonate contamination, inter alia. While the synthesis was conducted in an inert environment, some carbonate contamination could not be avoided. A thorough discussion on the topic of carbonate contamination in the hydrothermal synthesis of hydrocalumite was given, and the route to improved conversion as well as the possible reaction pathway were discussed.

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Dissolution characteristics of black aluminum dross in Na3AlF6-AlF3-Al2O3 molten salt system

Zuo

Liu

et al. 2023

Rare Met.

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Hydrotalcite and hydrocalumite as resources from waste materials of concrete aggregate and Al-dross by microwave-hydrothermal process

Cited by 19 publications

References 36 publications

Preparation and Adsorption Properties of Soybean Dreg/Hydrocalumite Composites

Preparation and Adsorption Properties of Soybean Dreg/Hydrocalumite Composites

Green Synthesis of Hydrocalumite (CaAl-OH-LDH) from Ca(OH)2 and Al(OH)3 and the Parameters That Influence Its Formation and Speciation

Dissolution characteristics of black aluminum dross in Na3AlF6-AlF3-Al2O3 molten salt system

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