Characterization of National Clays after Acid Treatment and Thermal

2014 ◽  
Vol 805 ◽  
pp. 662-666 ◽  
Author(s):  
Wellington Siqueira Lima ◽  
André Luiz Fiquene de Brito ◽  
Meiry Glaúcia Freire Rodrigues ◽  
Mariaugusta Ferreira Mota ◽  
Marcílio Máximo Silva
Keyword(s):  
Acid Treatment ◽  
Thermal Activation ◽  
Nitrogen Adsorption ◽  
Acid Activation ◽  
X Ray Diffraction ◽  
Natural Form ◽  
X Ray ◽  
The Common ◽  
Sorption Characteristics

The clay types, kaolinite and smectite, are the most used industrially, mainly due to its sorption characteristics. There have been several attempts to improve the quality and characteristics of the clays, modifying them with different techniques. Two of the common techniques are thermal activation and acid activation. For acid activation, hydrochloric acid was used with a reaction time of 1 hour while the thermal activation the samples calcined at 300oC for 24 hours. This work aims to characterize the gray clay (supplied by Süd-Chemie LTDA) and Brasgel (provided by Bentonit), both in its natural form, as well as in the acid and thermal activation form (300°C). Natural and treated clays were characterized by X-ray Spectroscopy Energy Dispersive (EDX), X-ray diffraction (XRD) and nitrogen adsorption (BET). The results showed a reduction of impurities in the samples and did not comprise changes in the structure of the constituent minerals.

scholarly journals Physical and catalytic characterization of smectites from Boa-Vista, Paraíba, Brazil

Cerâmica ◽  
2003 ◽  
Vol 49 (311) ◽  
pp. 146-150 ◽  
Author(s):  
M. G. F. Rodrigues
Keyword(s):  
Acid Treatment ◽  
Nitrogen Adsorption ◽  
Model Reaction ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Natural Form ◽  
X Ray ◽  
Smectite Clays ◽  
Catalytic Characterization

The original crystalline structure of clay minerals can be altered in a controlled way, through acid or thermal treatments, resulting then in suitable products to be used as catalysts. This paper aims to characterize the red smectite clays of Boa-Vista, Paraíba (Brazil) in their natural form, and after chemical, thermal and acid treatments by X-ray fluorescence, differential thermal analysis, dynamic X-ray diffraction, classic X-ray diffraction analysis, scanning electron microscopy, nitrogen adsorption and model reaction. The results show that acid treatment partially altered the structure of the montimorillonite. An important increase in the surface area of the solid obtained was observed. The obtained reaction for the treated material showed that the clay was more acid than the natural one, yielding a better catalytic activity.

scholarly journals Microwave-Assisted Acid Activation of Clays Composed of 2:1 Clay Minerals: A Comparative Study

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 376 ◽  
Author(s):  
Juan Cecilia ◽  
Laura Pardo ◽  
Manuel Pozo ◽  
Eva Bellido ◽  
Francisco Franco
Keyword(s):  
Acid Treatment ◽  
Nitrogen Adsorption ◽  
High Specific Surface Area ◽  
Acid Activation ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
X Ray ◽  
Layer Sequence ◽  
Microwave Assisted ◽  
Scanning Electron

The effect of the microwave-assisted acid treatment (MAT) on the structure and texture of dioctahedral (montmorillonite) and trioctahedral (saponite) smectites, kerolitic clays and sepiolites were studied by scanning electron microscopy, nitrogen adsorption, X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy. This study shows that in the smectite group of minerals the effectiveness of MAT is notably influenced by the chemical composition of the octahedral sheet, whereas in kerolitic clays it is influenced by the proportion of the expandable phase in the mixed layer sequence. On the other hand, the reactivity of sepiolites depends on the width of the natural fibres. With these treatments, extremely high specific surface area (SSA) increments are achieved in just 16 min. The SSA increments reach values up to 231 m2/g (%ΔSBET = 80) in sepiolites, 198 m2/g (%ΔSBET = 155) in Mg-smectites, and 161 m2/g (%ΔSBET = 61) in kerolitic clays.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

Preparation of Magnetically Modified Zeolites and the Application of Metal Ions Adsorption

2011 ◽  
Vol 299-300 ◽  
pp. 764-769
Author(s):  
Ming Liang Yuan ◽  
Liang Yu ◽  
Jia Hua Tao ◽  
Cong Song
Keyword(s):  
Metal Ions ◽  
Industrial Effluents ◽  
Nitrogen Adsorption ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
Detailed Characterization ◽  
X Ray ◽  
Magnetic Process ◽  
Coprecipitation Process

Natural zeolites combined with the magnetic iron oxides are prepared by a chemical coprecipitation process. A detailed characterization of our magnetically modified zeolite (MMZ) is given, including powder X-ray diffraction (XRD), nitrogen adsorption and vibrating sample magnetometer (VSM). The results reveal that in comparison with Na-zeolite, the structure of MMZ has no obvious change but its surface area increases from 25.13 m2g-1to 100.90 m2g-1. The adsorption properties of MMZ to Pb2+and Cu2+were studied. The results show that the maximum loading capacities for Pb2+and Cu2+in the initial concentration range are 123.74 and 14.633 mg g-1, respectively. The MMZ can be used as an adsorbent for removal of heavy metal ions from industrial effluents or municipal waters, and the saturated adsorbent is separated from the medium by a simple magnetic process.

SEM, XRF, XRD, Nitrogen Adsorption, Fosters Swelling and Capacity Adsorption Characterization of Cloisite 30 B

2012 ◽  
Vol 727-728 ◽  
pp. 1591-1595 ◽  
Author(s):  
Aline Cadigena Lima Patrício ◽  
Marcílio Máximo da Silva ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Quaternary Ammonium ◽  
Cation Exchange Capacity ◽  
Nitrogen Adsorption ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Oil And Grease ◽  
X Ray ◽  
Quaternary Ammonium Cations ◽  
Cloisite 30B

Cationic surfactants, such as quaternary ammonium cations, have been used, in order to ameliorate the oil sorption capacity of inorganics materials, such as clays. Clays modified with quaternary ammonium cations (organoclays) have better performance in sorption, remove oil and grease from water at seven times the rate of activated carbon, as well as they can be used like perforation fluids of oil wells to the oil base, lubricants, among others industries. This work aims characterize the Cloisite 30B using various techniques: X-Ray Diffraction (XRD), Specific Surface Area (BET) and Cation Exchange Capacity. Different organic solvents, namely gasoline, diesel and kerosene were used in order to investigate the clays compatibility after orgophilization.

Preparation and Characterization of Catalysts Fe/SBA-15 for Fischer Tropsch Synthesis

2014 ◽  
Vol 805 ◽  
pp. 678-683
Author(s):  
Ângela da Costa Nogueira ◽  
Jocielys Jovelino Rodrigues ◽  
Liliane Andrade Lima ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Nitrogen Adsorption ◽  
Tropsch Synthesis ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
X Ray ◽  
Acidic Conditions ◽  
Diffraction Peaks ◽  
Adsorption Desorption

In this study catalysts Fe/SBA-15 were prepared for Fischer-Tropsch Synthesis. SBA-15 samples were synthesized under acidic conditions using triblock copolymer Pluronic as a template and tetraethyl orthosilicate as a silica source.The molar composition was: 1.0 TEOS: 0017 P123: 8.14 HCl: 168 H2O. Fe/SBA-15 catalysts with different iron loading (15 wt. % and 20 wt. %) were prepared by wetness impregnation of relative SBA-15 with the desired amount of aqueous iron nitrate. The obtained catalyst were characterized by X ray diffraction (XDR), nitrogen adsorption-desorption and energy dispersive X-ray spectrometry (EDX). After impregnation of Fe the XRD profiles were almost unchanged and exhibited the high diffraction peaks of SBA-15 at low angles. The analysis of nitrogen adsorption-desorption was observed that the values of specific surface area decreased as the concentration of metal impregnated increased. And by the EDX analysis verified that the iron contents obtained are close to nominal levels of iron.

scholarly journals Characterization of bentonite clay from 'Greda' deposit

2011 ◽  
Vol 5 (2) ◽  
pp. 97-101 ◽  
Author(s):  
Nadezda Stankovic ◽  
Mihovil Logar ◽  
Jelena Lukovic ◽  
Jelena Pantic ◽  
Miljana Miljevic ◽  
...  
Keyword(s):  
Ceramic Industry ◽  
Bentonite Clay ◽  
Nitrogen Adsorption ◽  
Raw Material ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
High Silica ◽  
Representative Samples

Based on mineralogical and technological investigations of the deposit 'Greda' important characteristics of bentonite clay were determined. Representative samples of the deposit were characterized with X-ray diffraction, low-temperature nitrogen adsorption, chemical analysis, differential thermal analysis and scanning electron microscopy. It was determined that the main mineral is montmorillonite and in subordinate quantities kaolinite, quartz and pyrite. The chemical composition generally shows high silica and alumina contents in all samples and small quantities of Fe3+, Ca2+ and Mg2+ cations. Based on technological and mineralogical research, bentonite from this deposit is a high-quality raw material for use in the ceramic industry.

Thermal and structural characterization of the ZrO2−x(OH)2xto ZrO2 transition

2001 ◽  
Vol 16 (8) ◽  
pp. 2209-2212 ◽  
Author(s):  
E Torres-GarciÁa ◽  
A. Peláiz-Barranco ◽  
C. Vázquez-Ramos ◽  
G. A. Fuentes
Keyword(s):  
High Resolution ◽  
Metastable Phase ◽  
Nitrogen Adsorption ◽  
The Other ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
X Ray ◽  
Exothermic Process

The exothermic process that occurs around 700 K during calcination of ZrO2−x(OH)2x, associated with the crystallization of the low-temperature tetragonal metastable phase of ZrO2, was analyzed using x-ray diffraction, high-resolution thermogravimetric analysis (TGA), nitrogen adsorption, and modulated differential scanning calorimetry (MDSC). High-resolution TGA allowed us to determine the water loss, resulting from condensation of OH− groups. The amount was 0.137 wt% in our case, equivalent to 1.7 × 10−2 mol of H2O/mol of ZrO2. That corresponds to about one −OH group per nm2 being lost in that process. By using MDSC we determined that the change in enthalpy (∆Hglobal = −15.49 kJ/mol of ZrO2) was the result of two parallel contributions. One of them was reversible and endothermic (∆Hrev = 0.11 kJ/mol of ZrO2), whereas the other was irreversible and exothermic (∆Hirrev = −15.60 kJ/mol of ZrO2). The variability and magnitude of the exotherm, as well as the fact that the accompanying weight loss is so small, are consistent with a mechanism involving the formation of tetragonal nuclei, rather than global crystallization, and hence depend on the number of nuclei so formed.

Synthesis and Characterization of the Catalysts 5 wt.% and 10 wt.% Co/SBA-15

2010 ◽  
Vol 660-661 ◽  
pp. 561-566
Author(s):  
L.A. Lima ◽  
B.V. Sousa ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Ethylene Oxide ◽  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene Oxide ◽  
Desorption Isotherms ◽  
Poly Ethylene ◽  
Adsorption Desorption

Catalysts supported on SBA-15 were obtained by wet impregnation using aqueous solution of cobalt nitrate, where different contents of cobalt (5 wt% and 10 wt%) were prepared. The molecular sieve SBA-15 was synthesized using tetra ethyl ortho silicate (TEOS) as silicate source, and triblock copolymer, poly-(ethylene oxide)-poly (propylene oxide)-poly-(ethylene oxide) PEO-PPO-PEO as the organic structure directing agent. These materials were characterized by X-ray diffraction (XRD), X-ray energy dispersion spectrophotometer (EDX) and Nitrogen adsorption–desorption isotherms (BET). The results from the XRD showed that the molecular sieve mesoporous (SBA-15) was identified by X-ray diffraction, especially from the (210) and (300) peaks, which represent a typical spectrum for the SBA-15. Characterization of catalysts by Nitrogen adsorption–desorption isotherms (BET) made it possible to verify the the samples had been of type IV with hysteresis of corresponding the H2 type the porous materials.

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