alkali activation of bentonite in Mexico

Reaction of bentonite in low-alkali cement leachates: An overview …

The hyperalkaline (pH~13) leachates from the cement are expected to cause alteration of the bentonite. Low alkali cements produce lower pH (around 10-11) leachates and it is expected that this ...

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(PDF) Influence of Alkaline Activation over …

The performance of the alkaline processes on the properties of cation exchange capacity (CEC) and swelling was studied in three different types of bentonite from Brazil, Argentina and Mozambique.

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The role of aluminium in alkali-activated bentonites

activation. The use bentonite as a possible source of alumino-silicates for alkaline cement manufacture is a new line of action, scantly documented in the literature. In one study conducted by Mingyu et al. [21] to determine the effect of adding bentonite during the alkali activation of ﬂy ash, the clay was found to act as a mere ﬁller,

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Cosmetic and pharmaceutical qualifications of Egyptian bentonite …

Alkali activation of bentonite was carried out through dispersion of 300 g of puriﬁed bentonite in 100 ml of 0.1 M NaCl solution under stirring for 12 h at room temperature for three runs. The clay fractions were then separated from the slurry using a centrifuge for 15 min at 4000 RPM and washed several times with distilled water to be free ...

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The role of aluminium in alkali-activated bentonites

In the pursuit of new sources of aluminosilicates for alkaline cement manufacture, the present paper reports on the compositional and mineralogical assessment of the reactive potential of several types of bentonites. A number of factors affect strength development in these materials, in particular their potentially reactive silica and …

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Alkali fusion of bentonite to synthesize one-part …

Semantic Scholar extracted view of "Alkali fusion of bentonite to synthesize one-part geopolymeric cements cured at elevated temperature by comparison with two-part ones" by M. Peng et al. ... High strength cements can be synthesised by alkali activation of materials rich in Al2O3 and SiO2. In this study, amorphous aluminosilicate polymers ...

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Evaluation of Pozzolanic and Alkali-Activated Reactivity of …

Alkali-activated cement (AAC) is a sustainable building material with low carbon emissions, but it has a growing demand for raw materials. In this study, the potential of low-purity modified calcium bentonite (CB) as a raw material for AAC was evaluated. The thermodynamic changes and pozzolanic properties of calcined CB were determined …

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Bentonite Clays from Southeastern Spain as Sustainable …

The effects of global climate change are becoming more evident and accelerating at an unprecedented pace. For this reason, human activities urgently need a paradigm shift to stop this entropic process before the consequences become irreversible. In this sense, the use of highly eco-efficient materials aimed at conveniently neutralizing …

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Influence of acid activation on the NH3-adsorption …

In this study, the adsorption of NH 3 gas on a bentonite from Ünye (Turkey) in its natural state and after acid treatments, was investigated experimentally at 298 K and up to 100 kPa. Bentonite was treated with HCl solutions of various concentrations (0.5–2.5 M) at …

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One-Part Alkali-Activated Materials Derived from Natural …

It was found that, compared with a metakaolin-limestone-based binary precursor, alkali activation of calcined marl–limestone results in the formation of a higher amount of binder gel with a greater extent of Ca incorporation into the structure of Na aluminosilicate gel and the formation of Ca aluminosilicate and Ca silicate hydrogels.

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Rheological behavior of activated bentonite suspensions and …

In addition, studies on alkali activation of clay minerals showed a significant decrease in CEC value when soda additive was above 2.5 wt.%; it was determined that …

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(PDF) Simultaneous thermal analysis of different bentonite …

K EYWORDS: activation, alkali, bentonite, carbonate, simultaneous thermal analysis, soda, anhydrous sodium. carbonate. Uses of bentonites with high smectit e contents (>60 wt.%) include an imal ...

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Analysis of bentonite specific surface area by kinetic …

Activation of bentonite by alkali and acid solutions is almost. important step in industrial scale. This process is carried out in a. continuous stirred tank reactor at low temperature 50–120 ...

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Using alkali-activated dredge sludge ash-bentonite for low …

Although vertical cutoff walls can effectively contain groundwater pollution, vertical barriers constructed using conventional cement–bentonite-soil (CBS) mixtures exhibit poor permeability and produce considerable CO 2 during cement production. The dredged sludge ash (DSA) has potential to be used as an eco-friendly source for vertical …

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ON THE CHARACTERISTICS OF ALKALI-AND ACID-ACTIVATED BENTONITE …

Acid and alkali activation was performed in ratios (10, 30 and 50%) in order to see the effect of acid and alkali treatment on the properties of Goshica Bentonite.

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Thermal degradation kinetics and structural …

kinetic-parameters such as the activation energies whereas Coats-Redfern (CR) method was used to find the most probable reaction mechanisms involved on the bentonite pyrolysis. XRD

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(PDF) Influence of Alkaline Activation over Swelling and …

The performance of the alkaline processes on the properties of cation exchange capacity (CEC) and swelling was studied in three different types of bentonite from Brazil, Argentina and Mozambique.

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The role of aluminium in alkali-activated bentonites

In the pursuit of new sources of aluminosilicates for alkaline cement manufacture, the present paper reports on the compositional and mineralogical …

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Alkali-hydrothermal activation of tailings with red mud as a

The quartz phase in the bentonite was decomposed after alkali fusion activation at 700–1000 °C for 3 h . High-temperature calcination is required during the alkali fusion process, which higher the manufacturing costs of geopolymer samples. ... Provis JL (2016) Phase evolution of C-(N)-A-S-H/N-A-S-H gel blends investigated via …

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Bentonite reactivity in alkaline solutions: interim results of …

However, bentonite is unstable under alkaline conditions and this has driven interest in low-alkali cements (leachate pH of 10–11). To build a robust safety case, it is important to …

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Bentonite reactivity in alkaline solutions: interim results of …

However, bentonite is unstable under alkaline conditions and this has driven interest in low-alkali cements (leachate pH of 10–11). To build a robust safety case, it is important to have supporting natural analogue data to confirm understanding of the likely long-term performance of bentonite.

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Activation Iraqi bentonite for using as drilling mud

The effective viscosity of bentonite was measured after direct and indirect activation processes (Alkali activation, Heating activation and combined alkali and acid activation).

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On the Characteristics of Alkali- and Acid- Activated Bentonite …

In this paper, it is proposed to modify the Bentonite clay of Kosovo (Goshica region) by acid and alkali activation to be used for oil recycling. Acid and alkali activation was performed in ratios (10, 30 and 50%) in order to see the effect of acid and alkali treatment on the properties of Goshica Bentonite.

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Alkaline buffer characteristics and mechanism of Gaomiaozi bentonite …

Based on the alkaline buffer mechanisms, the thickness of the bentonite buffer barrier without ABC was calculated to be 71.83 cm when the operation time was 10,000 a, which could be used for reference when designing the thickness of the bentonite buffer barrier. ... This was because alkali-activation caused inorganic minerals to …

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Alkali-activated fly ash-based geopolymers with zeolite or bentonite …

Bentonite can be incorporated into the geopolymer structure as filler 40, but it can also react in alkali activation to some extent 41 . Approximately 50-75% of Ag 0 in AgNPs was oxidized to Ag(I ...

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Optimization of bleaching power by sulphuric acid activation of bentonite

Conclusions To bleach an alkali-refined oil, different bleaching earths were produced by sulfuric acid activation of a bentonite under different conditions including varying mass fraction of H2SO4, heating temperature and contact time. The …

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Effect of the Acidic and Alkaline Activation of Bentonite

Abstract A study is performed of the effect the means of activation of bentonite-like clays (acidic, alkaline, combined) have on the adsorption characteristics …

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Influence of clay minerals and associated minerals in alkali activation

Alkali activation is promising for low environmental impact soil stabilisation. Given soils' complexity, there is a lack of fundamental understanding of how the different components in soil influence their alkali activation behaviour. ... Bentonite is a favourable candidate as a sealing material in the deep geological repository to safe ...

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Optimization of bleaching power by sulfuric acid activation of bentonite

Acid activation was carried out by heating muds prepared from Ca-rich bentonite (CaB), sulfuric acid (H 2 SO 4) and distilled water, yielding various bleaching earths (BEs).The roles of each of the process variables, namely mass fraction of H 2 SO 4 (x) in the dried CaB and pure H 2 SO 4 mixture, heating temperature (T) and contact time (t), in the …

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Analysis of bentonite specific surface area by …

Activation of bentonite by alkali and acid solutions is almost important step in industrial scale. This process is carried out in a continuous stirred tank reactor at low temperature 50–120 °C in the presence of activation …

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