Preparation and characterization of acid-activated bentonite powders

Önal, Müşerref; Sarıkaya, Yüksel

doi:10.1016/j.powtec.2006.10.034

Cited by 116 publications

(44 citation statements)

References 37 publications

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“…The intensive bands near 916 cm -1 , 845 cm -1 , and 521 cm −1 attributed to Al-Mg-OH, Al-Al-OH and Al-OH-O-Si stretching vibration respectively. The raw bentonite spectrum also contains a band between 796 and 693 cm −1 which are attributed to orthodase and quartz respectively [27] [35]. FTIR spectra of Figures 4(b)-(f) show the decreasing intensity as a result of acid activation bentonite which reflects the leaching of octahedral cations, such as Al 3+ and Mg 2+ from the bentonite structure.…”

Section: Ftir Characterizationmentioning

confidence: 95%

“…Dissolution of these cations remains almost constant by continuing the activation process with higher acid concentrations. However, a considerable amount of these elements is still found in the activated bentonite due to the presence of impurities, mainly feldspar that has calcium, sodium and potassium, and it is resistant to acid attack [27] [28]. It is presumed that at low acid concentration the attack on the structure is weak and that the exchangeable cations replaced by H + ions are few [29].…”

Section: Chemical Compositionmentioning

confidence: 99%

“…The spectrum of the untreated bentonite exhibits absorption bands at 3422 and 1638 cm −1 this is assigned to the stretching and bending vibrations of the OH groups for the water molecules adsorbed on the clay surface, and a band at 3621 cm −1 which represents the stretching vibration of the hydroxyl groups coordinated to octahedral Al 3+ cations [27] [31]. The spectra show sharp band vibrations in the region between 1000 and 400 cm −1 it is described in earlier papers [32] [33].…”

Section: Ftir Characterizationmentioning

confidence: 99%

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Effect of Hydrochloric Acid on the Structural of Sodic-Bentonite Clay

Bendou¹,

Amrani²

2014

JMMCE

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The objective of this work is to determine changes of surface properties of a bentonite after acid activation, using hydrochloric acid solutions (HCl) at room temperature. XRD, FX, FTIR, MEB, and BET analyses of the samples have been carried out to examine the structure of bentonite before and after acid activation. It is found that the raw bentonite is composed of dioctahedral montmorillonite with predominant quantity and certain amounts of quartz, albite and illite, etc. It has an cation exchange capacity (CEC) of 74.32 meq/g which allows it to be characterized as typical sodium bentonite. The changes, at low acid concentrations, are the result from from cation exchange (exchangeable cations with H + ions). Differences of surface area at high acid concentrations (0.25 -0.4 M) were caused by structural changes and partial decomposition of the samples. Data of surface area measurements have showed that with increase of concentration of hydrochloric acid, the surface area increased. The maximum value (837.11 m 2 /g) was reached by the sample activated with 0.4 M HCl. By against, activation with higher concentration (0.6 M) caused a decrease in the surface area.

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Section: Ftir Characterizationmentioning

confidence: 95%

Section: Chemical Compositionmentioning

confidence: 99%

Section: Ftir Characterizationmentioning

confidence: 99%

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Effect of Hydrochloric Acid on the Structural of Sodic-Bentonite Clay

Bendou¹,

Amrani²

2014

JMMCE

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“…By contrast, the content of CaO is decreased to 0.82%. d (001) of modified bentonite is 1.203 8 nm [20] and 2θ is 7.338˚ (see Fig.8), indicating that the Ca-Bent has been successfully modified into a typical Na-Bent under the optimum conditions. Using the modified Na-Bent and the sample Ca-Bent as binders, the balling tests are carried out under conditions that the bentonite dosage is 1.5%, the moisture content of green balls is 8.5%, and balling time is 10 min.…”

Section: Physico-chemical Properties Of Modified Bentonitementioning

confidence: 86%

“…Montmorillonite, 2:1 type layered aluminosilicate, is the main mineral constituent of bentonite [11][12]20]. Aluminium ions in the alumina octahedral sheet can be replaced by other ions, so do the silicon ions in silica tetrahedral sheet.…”

Section: Modification Principle and Experimental Methodsmentioning

confidence: 99%

Sodium-modification of Ca-based bentonite via semidry process

Huang

Zhang

Han

et al. 2010

J. Cent. South Univ. Technol.

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In order to improve the quality of Hunyuan inferior Ca-based bentonite (Ca-Bent), semidry process was used to modify Ca-Bent into superior Na-based bentonite (Na-Bent). The factors affecting sodium-modification were investigated. The optimized experimental parameters are obtained as follows: Na 2 CO 3 dosage 4.0%, ageing time 25 d, briquetting pressure 25 MPa and briquetting moisture 20%. Under the optimization conditions, the modified Na-Bent has a colloid value of 73.6 mL/(3g), dilation of 38 mL/g and water absorption in 2 h (2HWA) of 465%, respectively. The balling results indicate that the modified Na-Bent pellets have higher drop strength and compression strength than the Ca-Bent pellets.

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Acid‐treated Bentonite as filler in the development of novel composite PVA hydrogels

Sánchez

Álvarez

Ollier

2019

J of Applied Polymer Sci

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In this study, novel eco‐friendly hydrogel adsorbents were synthesized based on poly(vinyl alcohol) (PVA) and different contents of an acid‐treated bentonite (1–5 wt %). The hydrogels were prepared by freezing–thawing, which is a simple and nontoxic method. The materials were morphologically and thermally characterized by means of swelling assays, X‐ray diffraction, scanning electron microscopy, dynamic scanning calorimetry, and thermogravimetric analysis in order to evaluate the effect of acid‐treated bentonite loading. The composite hydrogels showed very distinct porous structure and thermal features in comparison to neat PVA as a consequence of the addition of the clay. Moreover, the performance of the obtained composite hydrogels was tested toward the adsorption of cationic (methylene blue) and anionic dyes (methyl red and methyl orange) from aqueous media. The presence of acid bentonite seems to be beneficial for improving the removal capacity of PVA‐based hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47663.

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Preparation and characterization of acid-activated bentonite powders

Cited by 116 publications

References 37 publications

Effect of Hydrochloric Acid on the Structural of Sodic-Bentonite Clay

Effect of Hydrochloric Acid on the Structural of Sodic-Bentonite Clay

Sodium-modification of Ca-based bentonite via semidry process

Acid‐treated Bentonite as filler in the development of novel composite PVA hydrogels

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