Effect of surface treatment on thermal stability of the hemp …
The thermal behavior of hemp-poly lactic acid composites with both untreated and chemically surface modified hemp fiber was characterized by means of activation energy of thermal degradation.Three chemical surface modification employed were; alkali, silane and acetic anhydride. Model-free isoconversion Flynn–Wall–Ozawa method was …
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Environmental applications of thermally modified and acid …
On the other hand, thermal treatment of sepiolite at 600 °C could remove 61% chloridazon, whereas 1 M H 2 SO 4 treatment could remove only 5% (González-Pradas et al., 2005) despite the higher surface area produced during the acid activation (surface area: 458 m 2 g − 1 for acid activation and 125 m 2 g − 1 for thermal treatment …
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Effect of clay on crude oil combustion by thermal analysis
This research was aimed to investigate the role of clay on the combustion and kinetic behavior of crude oils in limestone matrix. For this purpose, simultaneous TG (thermogravimetry) and DTA (differential thermal analysis) experiments were performed at three different heating rates as 10–15 and 20°C min–1, respectively. A uniform trend of …
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Effect Of Thermal Activation On Clay Surface
Feb 01, 2010 · ... this article is to report on the effects of cationic and ... the activation energies of anionic clay ... clay type, thermal history, and surface ... Fabrication of bio based epoxy–clay nanocomposites Green ...
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Comparative study of the effect of structural
Surface charge distribution obtained as zeta potential indicated that thermally activated clays are loaded with more negative charge in the interval of pH 2–8. The effect of thermal activation on the Cd(II) adsorption capacity of bentonite, sepiolite, and vermiculite its depend of the type of structure and thermal stability of each clay.
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Kaolinite structural modifications induced by mechanical activation
This study presented a complete study on the effect of mechanical activation (MA) on kaolinite's (and typical kaolin impurities) structures, which complements a previous study of the reactivity of mechanically activated kaolin ( Mañosa et al., 2022 ). In this work, a synergistic combination of novel techniques was used to enhance the …
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Kaolinite structural modifications induced by mechanical …
Mechanical activation. Kaolin. Dehydroxylation. Kaolinite. Metakaolin. 1. Introduction. Clays are some of the most used materials in the industry, and among …
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Activation of clay in cement mortar applying mechanical, …
Different techniques such as mechanical activation, chemical activation and thermal activation have been employed to activate clay used as a cement replacement material. The clay was activated mechanically by grinding it to 250, 360 and 420 m2/kg
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Thermal and Mechanical Activation in Acid Leaching …
4.1 Effect of Thermal Activation. The thermal ... The mechanical activation increases the specific surface area, the crystal structure disordering phase, decreases the activation energy, and causes oxidation of sulfates. ... Using intensive milling in the activation of clay minerals leads to the formation of an amorphous material by breaking ...
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Acid Activation of Clay Minerals
Acid activation is a common chemical modification of clays, usually bentonites, with a hot solution of a mineral acid (typically HCl or H2 SO 4), and it is used for both scientific and industrial purposes. The aim is to obtain partly dissolved material of increased specific surface area, porosity and surface acidity.
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THE EFFECT OF THERMAL TREATMENT ON SOME OF THE …
The activation energies related to the dehydration and dehydroxylation of CaB calculated from the thermogravimetric data are 33 and 59 kJ mol −1, respectively. The average deformation enthalpies, in the respective temperature intervals between 200–700°C and 700–900°C, were estimated to be 25 and 205 kJ mol −1 using CEC data …
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Effects of high temperature treatment on physical-thermal …
The results obtained indicate that the thermal conductivity and diffusivity as well as the bulk density of clay decrease rapidly as the temperature increases from room …
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Sulphuric Acid Activation of a Calcium Bentonite
The surface properties of the acid-activated clays are enhanced further (more porous and homogeneous) if the acid activation is followed by thermal activation (Tebeje et al. 2022;Toor et al. 2015 ...
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Characterization of activated bentonite clay mineral and …
Before acid activation (NB), the bands at 3620 and 3386 cm −1 are assigned to the O–H stretching vibration of the silanol (Si–OH) groups from the clay (coordinated to octahedral Al 3+ cations) and HO–H vibration of the adsorbed water molecules on the bentonite surface, respectively (Emmerich et al. 1999), while the band …
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Physico-chemical characterization of thermally treated bentonite
Samples of original and thermally treated bentonite at 650 °C 4 h were characterized with chemical analysis, X-ray diffraction, thermal analysis, mercury porosimetry, differential scanning calorimetry, physisorption measurement and scanning electron microscopy.These consequence of the heating have been found. The chemical …
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Effects of mechanical and thermal activation on
During thermal activation, the interlayer, hydrate and absorbed water were removed from the surface of the kaolinite particle, and the crystalline lattice structures were completely or partially ...
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The Effect of Heating on the Surface Area, Porosity and Surface …
The Effect of Heating on the Surface Area, Porosity and Surface Acidity of a Bentonite - Volume 54 Issue 3 ... High temperature thermal effects of clay and related materials American Mineralogist 36 182 ... (1995) Evolution of porosity and surface acidity in montmorillonite clay on acid activation Industrial and Engineering Chemistry …
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Thermal activation, characterization and performance …
Thermal activation is observed to increase the intensity of quartz peak due to the removal of impurities and removal of water from the bentonite structure. This …
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Removal of chromium (VI) ions from aqueous solutions by
During the same year, Akar et al. (2009) also investigated the removal of Cr(VI) using Turkish montmorillonite clay and also evaluated the effect of activation and modification. The removal of Cr ...
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Effects of the carbonization temperature and
To optimize the production of coal-based activated carbon, the effects of carbonization temperature on the surface functional groups, crystal characteristics, degree of graphitization, thermal stability and mechanical strength of char were studied; additionally, the effects of intermediate cooling on the pore structure, adsorption …
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Environmental applications of thermally modified and acid …
The two most common modification methods of clay minerals are thermal modification and acid activation. The aim of this paper is to critically review the current status of thermally modified and acid activated clay minerals for environmental …
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Chapter 7.1 Acid Activation of Clay Minerals | Request PDF …
The thermal treatment, acid activation, and mechanochemical activation resulted in changes in the surface properties of the clay minerals: specific surface area, porosity, and distribution of ...
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Effects of different clay minerals on thermal conversion of …
Moreover, the activation energy of the reaction in different temperature intervals decreased due to the existence of clay minerals, with chlorite exerting the most pronounced effect on the ...
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Effect of the Acid Activation Levels of Montmorillonite Clay …
For other modifications, the origin of the clay mineral has an interesting effect of the properties of resulting modified clays [46,47]. For example, in case of acid activation processes, two clay ...
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Mechanochemical activation of natural clay …
Abstract. Mechanochemical activation can be defined as a process able to induce structural disorder through intensive grinding. In certain conditions, it may increase the chemical reactivity of the …
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Environmental applications of thermally modified and
Both thermal and acid activation are effective processes to enhance the adsorption of contaminants by clay minerals. Several environmental applications have …
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High Performance Illitic Clay-Based Geopolymer: Influence …
Demonstrate the feasibility of an illitic clay-based geopolymer is the purpose of this study. If the thermal activation of standard precursors such as kaolin is a well-known process, the reactivity of illitic precursors required the combination of thermal and mechanochemical activation.
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Concerning Adsorption of Clays Subjected by Heat and …
When clays are activated thermally (within temperature range 0–400 ℃) and chemically (by cationic salts), their adsorption capacity increases. It is due to the …
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Clay calcination technology: state-of-the-art review by the …
The window for practical thermal activation is larger in kaolinite (600–950 °C) than illite (700–950 °C) or montmorillonite (800–900 °C) [12, 77, 78]. Above these temperatures, a crystalline aluminosilicate spinel, which converts to mullite when temperature is increased further, is formed, and quartz is also known to convert to ...
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Improving the pozzolanic reactivity of clay, marl and
The thermally activated clay and marl exhibited highest pozzolanic reactivity than the mechanochemically treated counterparts owning to the formation of free lime …
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