Journal articles on the topic 'Kaolinite – Analysis'
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1
Mbey, Jean Aimé, Cyrill Joël Ngally Sabouang, Thomas Beauregard Makon, Sandotin Lassina Coulibaly, and Sakéo Kong. "The thermal dehydroxylation of kaolinite using thermogravimetric analysis and Controlled rate thermal analysis." Journal of the Cameroon Academy of Sciences 16, no. 3 (April 19, 2021): 235–45. http://dx.doi.org/10.4314/jcas.v16i3.4.
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The aim of this work was to identify parameters that could influence the conversion of kaolinite into metakaolinite. To this end, the dehydroxylation of four kaolinites, using controlled rate thermal analysis (CRTA) and thermogravimetric analysis (TGA), was investigated. X-ray diffraction (XRD) and Fourier transform infra-red (FTIR) were used to confirm the kaolinitic nature of the samples. Their crystallinity was evaluated using the Hinckley index from the XRD patterns and transmission electron microscopy (TEM) was used for morphological observation of the clay platelets. The thermal analyses of the samples indicate, for all samples, low defects as revealed by the low amount of adsorbed water on the clay surface. The dehydroxylation temperature from both techniques was influenced by the sample crystallinity and particle size. It was observed from both techniques that increase crystallinity resulted in highdehydroxylation temperature. Also, the influence of the clay platelets size on the dehydroxylation temperature, is proposed. All the results indicate that crystallinity and particle size are parameters that could be used to control the temperature for the conversion of kaolinite to metakaolinite.
Keywords: Kaolinite; Crystallinity, Dehydroxylation; Thermal analysis
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Liu, Dongna, Yun Zhang, Anchao Zhou, Emmanuel Nnachi, Shuting Huo, and Qi Zhang. "The Kaolinite Crystallinity and Influence Factors of Coal-Measure Kaolinite Rock from Datong Coalfield, China." Minerals 12, no. 1 (December 30, 2021): 54. http://dx.doi.org/10.3390/min12010054.
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In order to ascertain the kaolinite crystallinity of Carboniferous Permian coal-measure kaolinite rocks, seven groups of fresh samples were collected from below the ground in the Xiaoyu mine, Datong coalfield. Microscopy, X-ray diffraction (XRD), differential thermal analysis (DTA), infrared (IR) spectroscopy and X-ray fluorescence (XRF) spectrometry methods were applied to the samples. The petrographic analysis results show that the kaolinite rocks are characterized as compact, phaneritic, clastic, sand-bearing, sandy and silty types; the kaolinite content in the Shanxi formation and upper Taiyuan formations was more than 95%, while it was 60–90% in the middle and lower Taiyuan formations. Based on the Hinckley index and the features of XRD, DTA and IR of kaolinites, crystallinity was classified as having three grades: ordered, slightly disordered and disordered. The kaolinites’ SiO2/Al2O3 molar ratio was about 1.9–5.7, with a chemical index of alteration (CIA) of about 95.4–99.5. This research suggests that the kaolinite crystallinity correlates positively to its clay mineral content, purity and particle size, which are also related to the SiO2/Al2O3 molar ratio and CIA. The original sedimentary environment and weathering have a direct influence on kaolinite crystallinity, and the existence of organic matter is conducive to the stable existence of kaolinite. The study results have significance for the extraction and utilization of coal-measure kaolinite and the development of kaolinite crystallography and mineralogy.
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Bauluz, B., M. J. Mayayo, A. Yuste, and J. M. González López. "Genesis of kaolinite from Albian sedimentary deposits of the Iberian Range (NE Spain): analysis by XRD, SEM and TEM." Clay Minerals 43, no. 3 (September 2008): 459–75. http://dx.doi.org/10.1180/claymin.2008.043.3.10.
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AbstractThe kaolinite from Albian sedimentary deposits (Escucha and Utrillas Formations) of the Iberian Range (Spain) have been investigated. This research has shown the presence of different types of kaolinites (detrital and diagenetic) along with micaceous phases in these deposits. Detrital kaolinites show anhedral morphology, low crystallinity and a degree of ordering as well as the presence of interstratified smectite layers. They constitute the matrix of the claystones and siltstones and were probably formed as a consequence of intense weathering processes in the source area during the warm period of the early Cretaceous. Diagenetic kaolinites have been recognized in the sandstones and siltstones, with kaolinite growing between ‘expanded’ mica flakes and vermiform and euhedral kaolinite forming the matrix. They have euhedral morphologies, high crystallinity and a high degree of ordering. They grewin situas a response to incipient diagenesis by K-feldspar dissolution and/or organic acid-rich fluids derived from the maturation of organic matter in shales.
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Drits, Victor A., Boris A. Sakharov, Olga V. Dorzhieva, Bella B. Zviagina, and Holger Lindgreen. "Determination of the phase composition of partially dehydroxylated kaolinites by modelling their X-ray diffraction patterns." Clay Minerals 54, no. 3 (August 1, 2019): 309–22. http://dx.doi.org/10.1180/clm.2019.39.
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AbstractModelling of experimental X-ray diffraction (XRD) patterns is used to determine the phase composition of partially dehydroxylated kaolinite samples. To identify unambiguously the presence of two or three phases in the heated kaolinite samples, the full range of their XRD patterns has to be analysed. Two different kaolinites, from Imerys (UK) and from Georgia (USA; KGa-21), were studied. The heating temperatures were selected to cover the entire range of dehydroxylation for both kaolinites (400–550°C for Imerys and 400–495°C for KGa-21). Two different dehydroxylation pathways were observed. At each stage of partial dehydroxylation, the kaolinite from Imerys consisted of the original, non-dehydroxylated kaolinite and of a fully dehydroxylated phase, metakaolinite. During partial dehydroxylation of kaolinite KGa-21, each product formed at a given heating temperature consisted of three phases: the original kaolinite; a dehydroxylated phase, metakaolinite; and a phase with diffraction features corresponding to a defective kaolinite-like structure. To determine the content of metakaolinite in a partially dehydroxylated specimen, its experimental XRD pattern was reproduced by the optimal summation of the diffraction patterns of the initial kaolinite and metakaolinite. A procedure that reveals the basic diffraction features of the third phase is suggested. The XRD patterns and thus the structures of the metakaolinites formed after dehydroxylation of the Imerys and KGa-21 samples differ substantially. The conventional determination of the initial kaolinite and metakaolinite contents in partially dehydroxylated kaolinite based on the analysis of basal reflections and weight losses may lead to overlooking the formation of the intermediate phases.
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García-Vicente, Andrea, Adrián Lorenzo, Juan Morales, Emilia García-Romero, and Mercedes Suárez. "Field Spectroscopy Applied to the Kaolinite Polytypes Identification." Environmental Sciences Proceedings 6, no. 1 (February 25, 2021): 16. http://dx.doi.org/10.3390/iecms2021-09353.
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A detailed characterization of a group of kaolin samples rich in some minerals of the kaolinite group was done. The mineralogical and structural characterization was conducted by X-ray diffraction (XRD) together with the study of the spectroscopy response in visible-near infrared and short wave (VNIR–SWIR), and the main objective was the determination of kaolinite polytypes. The XRD patterns group the samples according to the kaolinite polytype into five kaolinites, two dickites and six halloysites. Diagnostic peaks for kaolinite, dickite polytypes and halloysite were identified in the spectra and in the second derivative of the SWIR region. The position and intensity of the peaks in the second derivative were statistically treated with the aim of classifying the spectra according to the polytype. In good agreement with the XRD results, the statistical analysis of the spectroscopic data, both by cluster analysis and by principal components analysis, allows an unequivocal classification of the samples according to the polytype from their VNIR–SWIR spectra.
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Mbey, Jean-Aimé, Jean Mermoz Siéwé, Cyrill Joël Ngally Sabouang, Angelina Razafitianamaharavo, Sakeo Kong, and Fabien Thomas. "DMSO Intercalation in Selected Kaolinites: Influence of the Crystallinity." ChemEngineering 4, no. 4 (December 21, 2020): 66. http://dx.doi.org/10.3390/chemengineering4040066.
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The present study deals with the relation between crystalline order in kaolinites and their ability to intercalate DMSO. Raw clays and kaolinite–DMSO complexes are analyzed using FTIR, XRD powder diffraction and differential scanning calorimetry and thermogravimetric analysis (DSC-TGA). The crystallinity is accessed using the Hinckley index (HI) from the raw clays’ XRD patterns and the p2 factor from their FTIR spectra. The intercalation ratio is evaluated from XRD and compared among the samples. The thermal analyses show a decrease in the dehydroxylation temperature in the DMSO–kaolinite complexes, indicating a decrease in the interlayer cohesion that may be useful to improve the delamination of kaolinite. The analysis of the coherent scattering domain size in the raw and the DMSO-intercalated samples indicates that the ordering is not affected during the DMSO intercalation. From these results, it is deduced that DMSO intercalation is favored by an increased crystallinity, as revealed by the intercalation ratio from XRD and the DSMO release during DSC-TGA analysis.
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Mackenzie, R. C., L. Heller-Kallai, A. A. Rahman, and H. M. Moir. "Interaction of Kaolinite with Calcite on Heating: III. Effect of Different Kaolinites." Clay Minerals 23, no. 2 (June 1988): 191–203. http://dx.doi.org/10.1180/claymin.1988.023.2.06.
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AbstractThe degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves for kaolinite-calcite mixtures depends on the kaolinite sample used as well as on the factors previously established. Although no two of the ten kaolinite samples employed, even if from the same general locality, produced identical effects under all experimental conditions, a general relationship between locality of origin and degree of distortion was noted. The crystalline species detected in the products of heating, after standing in air at room temperature, included portlandite, calcite, aragonite, vaterite and the high-temperature phases gehlenite, α′-Ca2SiO4, and 12CaO. 7Al2O3. The actual species present again depended on the kaolinite sample. Although the results cannot be directly related to the volatiles evolved along with water on dehydroxylation of the different kaolinites, a tentative explanation is offered on the basis of the effects of the volatiles on the surfaces of the particles present.
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Gardolinski, J. E. F. C., and G. Lagaly. "Grafted organic derivatives of kaolinite: I. Synthesis, chemical and rheological characterization." Clay Minerals 40, no. 4 (December 2005): 537–46. http://dx.doi.org/10.1180/0009855054040190.
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AbstractSeveral new interlayer-grafted derivatives of kaolinite were synthesized by esterification of inner-surface hydroxyl groups with alkanols, diols and glycol mono-ethers starting with the dimethyl sulphoxide intercalate. The derivatives were characterized by X-ray powder diffractometry, thermal analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The grafted molecules are arranged in monolayers between the kaolinite layers, with typical basal spacings of ~11.3 Å. Rheological studies of aqueous dispersions of the modified kaolinites revealed an exponential increase of the yield value and apparent viscosity with increasing alkyl chain length of the grafted molecules.
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Basyoni, M. H., M. A. El Askary, N. A. Saad, and R. J. Taj. "Mineralogy of the Tertiary Clay Deposits in Makkah and Rabigh Quadrangles, West Central Arabian Shield, Saudi Arabia." Sultan Qaboos University Journal for Science [SQUJS] 7, no. 2 (June 1, 2002): 259. http://dx.doi.org/10.24200/squjs.vol7iss2pp259-277.
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The mineralogy of the Tertiary clay deposits in Makkah and Rabigh quadrangles was thoroughly investigated by X-ray diffraction and differential thermal and thermogravimetric analyses in addition to other techniques. Results show that the investigated samples are predominantly composed of montmorillonite (Ca++ and/or Mg++ rich variety) and kaolinite, associated with subordinate illite and minor chlorite. Mixed layer montmorillonite-illite is recorded only in two samples. The relative abundance of these minerals by X-ray diffraction analysis showed that the studied clay deposits are of three types. The first, which is the most common, is highly montmorillonitic, the second is made up of a mixture of montmorillonite followed by kaolinite and illite and the third is highly kaolinitic with some montmorillonite. Generally, kaolinite shows a southward increase in Makkah quadrangle while chlorite, as a minor component, shows a northward increase in Rabigh quadrangle.
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Lieberknecht, Gabriela, Patrícia Helena Lara dos Santos Matai, and Laurindo de Salles Leal Filho. "Bibliometric analysis on kaolinite flotation." REM - International Engineering Journal 70, no. 4 (December 2017): 477–82. http://dx.doi.org/10.1590/0370-44672016700119.
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Delvaux, B., M. M. Mestdagh, L. Vielvoye, and A. J. Herbillon. "XRD, IR and ESR study of experimental alteration of Al-nontronite into mixed-layer kaolinite/smectite." Clay Minerals 24, no. 4 (December 1989): 617–30. http://dx.doi.org/10.1180/claymin.1989.024.4.05.
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AbstractThe formation of kaolinite from Al hydroxy interlayered Garfield nontronite has been carried out at 225°C in hydrothermal conditions. The kaolinitization process, which proceeds through mixed-layer kaolinite/smectite intermediates, was followed by XRD, IR and ESR spectroscopy, chemical analysis and charge properties. The smectite content of the clay products decreases regularly with the duration of the hydrothermal treatment. The CEC and the structural Fe content of the deferrated products show a similar trend. IR features specific to nontronite disappear and are barely detectable as the smectite content of the mixed-layer clay falls below 30%. In contrast, the ESR spectrum of nontronite is characterized by a broad g2 signal that remains even after prolonged hydrothermal treatment. The calibration of the g2 ESR signal, due to Fe-smectite, shows that the synthetic kaolinites have low Fe contents (∼ 1% Fe2O3) indicating that the kaolinitization process involves destruction of the 2:1 layers and the subsequent neoformation of kaolinite and Fe oxides. As illustrated by the study of deferrated soil clay samples, representing a weathering sequence Fe-smectite → kaolinite + Fe oxides, ESR spectroscopy proved to be a powerful Fe probe for detecting Fe-rich smectite in kaolinite/Fe-smectite mixed-layer clays.
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Ramadji, Christian, Adamah Messan, Seick Omar Sore, Elodie Prud’homme, and Philbert Nshimiyimana. "Microstructural Analysis of the Reactivity Parameters of Calcined Clays." Sustainability 14, no. 4 (February 17, 2022): 2308. http://dx.doi.org/10.3390/su14042308.
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Four (04) different types of clays from Burkina Faso were studied for their potential applications in the production of calcined clays as substitution materials for Portland cement. The study aimed at analyzing the factors affecting their reactivity. The untreated clays were subjected to various tests to highlight the intrinsic properties that can influence their reactivity. After the treatment by calcination, the clays were subjected to various pozzolanicity tests and microstructural analysis in order to evaluate their influence on the microstructure of the cement paste. The results showed that the reactivity of calcined clays is strongly related to the intrinsic properties of the raw clays, such as the content and the structure of kaolinite: disordered kaolinite reacts better than ordered kaolinite. After the calcination, the reactivity depends on the amorphous phase (amorphous content) of the clays, which influences the strength activity index. This study established a correlation between different parameters to easily identify the main properties of calcined clays that can influence their pozzolanic reactivity. All the results showed that the kaolinite content is a determining factor in the reactivity of clays before calcination. However, the study showed that the amorphous content of kaolinite is the determining parameter of the reactivity of calcined clays, as calcination can lead to the recrystallization of kaolinite.
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Conconi, M. S., M. Morosi, J. Maggi, P. E. Zalba, F. Cravero, and N. M. Rendtorff. "Thermal behavior (TG-DTA-TMA), sintering and properties of a kaolinitic clay from Buenos Aires Province, Argentina." Cerâmica 65, no. 374 (June 2019): 227–35. http://dx.doi.org/10.1590/0366-69132019653742621.
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Abstract The technological properties of a local kaolin, considered as a potential industrial material, were correlated with the thermal behavior and sintering processes carried out through a series of thermochemical analyses. The chemical and mineralogical characterization of the material was carried out, together with a simple microstructural characterization. The used material corresponded to the kaolinized basement rocks (saprolite zone) mined at La Verónica quarry, Chillar area, Azul County, Argentina. The complete kaolinite-metakaolinite-spinel-mullite thermal series was characterized. Sintering behavior was studied; a viscous phase sintering mechanism was proposed. Apparent density and porosity of fired ceramics were measured. A light-firing color was confirmed by colorimetry. The viscous phase mechanism was possibly described thanks to the multi-technique thermal behavior analysis complemented by XRD analysis. These results permitted to establish formulation and processing strategies of ceramic materials based on the studied clay. The possible applications include: tile manufacturing, sanitary ware, tableware, kaolinitic proppants, chamotte and refractory materials.
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Wu, Yankun, Shichong Yang, Wencui Chai, and Yijun Cao. "Interaction Forces between Diaspore and Kaolinite in NaOL Solution Probed by EDLVO Theory and AFM Analysis." Minerals 12, no. 9 (September 3, 2022): 1123. http://dx.doi.org/10.3390/min12091123.
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Molecular force plays an important role in the interaction between collector and minerals, which directly reflects the intrinsic reason for the selectivity and collection of the collector to minerals. In this work, the interaction forces between sodium oleate (NaOL) and minerals (kaolinite and diaspore) were directly characterized by atomic force microscopy (AFM) combined with EDLVO theory. The results show that after interacting with NaOL, the zeta potentials of kaolinite and diaspore were more negative, and the hydrophobicity of minerals increased. EDLVO calculation results indicate that electrostatic repulsion dominated the interaction forces between mineral particles, and the van der Waals interaction energy, electrostatic interaction energy, and hydrophobic interaction energy increased after NaOL treatment. AFM measurements show that the NaOL collector increased the attraction force of diaspore-diaspore and kaolinite-kaolinite particles, and the increase in attraction force for diaspore-diaspore particles was larger than in kaolinite particles, which was consistent with the EDLVO results. The adhesion force between the NaOL collector and the diaspore surface was larger than in kaolinite, confirming the fact that NaOL had better collection and selectivity for diaspore than kaolinite. This work improves understanding of the interaction mechanisms between NaOL collector, diaspore, and kaolinite minerals.
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Verkouteren, Jennifer R., Eric S. Windsor, Joseph M. Conny, Robert L. Perkins, and J. Todd Ennis. "Analysis of kaolinite/chrysotile mixtures by ashing and x-ray diffraction." Powder Diffraction 17, no. 3 (September 2002): 196–201. http://dx.doi.org/10.1154/1.1481038.
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A simple ashing procedure for a mixture containing kaolinite and chrysotile is described that converts kaolinite to amorphous metakaolinite while retaining the diffraction intensity of chrysotile. This ashing procedure removes the X-ray diffraction (XRD) pattern overlap between kaolinite and chrysotile that can interfere with the analysis of even high concentrations of chrysotile. Samples are ashed at 460 °C in a muffle furnace for 40 h to completely convert kaolinite to metakaolinite. The complete conversion of 1 g of kaolinite under these conditions was determined for two standard kaolinite samples from Georgia, KGa-1 and KGa-2. Two of the most common types of commercial chrysotile, long-fiber Canadian and short-fiber Californian chrysotile, are demonstrated to retain diffraction intensity after ashing at 460 °C. Both chrysotile samples have the same integrated intensity for the (002) reflection prior to ashing, although the peak breadths for the two samples are quite different. Ashing at 480 and 500 °C reduces the diffraction intensities of both chrysotile samples by 15%, and broadens the peaks by approximately 3%. Using the prescribed ashing procedure and x-ray diffraction with an internal corundum standard, two kaolinite-bearing building materials containing chrysotile near 0.01 mass fraction were analyzed. The ashing procedure has additional advantages in reducing some samples to powders and removing volatile components, thereby eliminating some sample preparation procedures and concentrating any chrysotile present in the sample. The removal of volatile components improves the sensitivity of XRD analysis to concentrations below 0.01 mass fraction chrysotile.
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Lu, Fangqin, Lingyun Liu, Fanfei Min, Jun Chen, and Mingxu Zhang. "Density Functional Theory Analysis of the Adsorption Interactions of Carbon Impurities in Coal-associated Kaolinite." Processes 7, no. 11 (November 1, 2019): 782. http://dx.doi.org/10.3390/pr7110782.
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Kaolinite is a difficult-to-float clay existing in coal slurries which negatively impacts coal flotation. A better understanding of its adsorption behavior would improve coal-slurry processing. Carbon impurities in the kaolinite can affect this behavior. The appearance and elemental surface composition of the carbon impurities precipitated by kaolinite oxidative treatment were microscopically analyzed, and their chemical speciation and relative C and O contents were probed. The mechanisms of adsorption on the main kaolinite cleavage planes ((001) and (001) surfaces) for two carbon-impurity structural models, a phenolic hydroxyl unit (Ph–OH) and carbon hydroxyl unit (C–OH), were considered using density functional theory methods. The carbon impurities consisted mainly of C and O, with C present mostly as C–C, C–H, and C–O species, and O existing mainly in –OH and C–O structures. Both Ph–OH and C–OH units adsorbed stably on the kaolinite (001) and (001) surfaces through hydrogen bonding between the hydroxyl groups and surfaces. A strong electrostatic attraction occurred between the Ph–OH benzene ring and kaolinite surfaces, whereas the carbon ring in C–OH did not interact with either surface. Finally, for both units, adsorption on the kaolinite (001) surface was more stable than on the (001) surface.
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Du, Xiao Man, Qin Fu Liu, and Hong Fei Cheng. "Preparation and Analysis of Kaolinite Intercalated by Potassium Acetate." Advanced Materials Research 150-151 (October 2010): 1220–24. http://dx.doi.org/10.4028/www.scientific.net/amr.150-151.1220.
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The kaolinite-potassium acetate composite was prepared by the immersion method. The intercalation composites were characterized by means of Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Fourier transformation infrared (FT-IR) and High-resolution thermogravimetric analysis (HRTG). The results of XRD show that the intercalation of kaolinite by potassium acetate causes an increase of the basal spacing from 0.718 to 1.42nm. Thermal analysis shows the dehydroxylation of kaolinite decreased from 464 °C to 459.5 °C after intercalation of potassium acetate and three endotherms at 280, 323 and 459.5 °C attributed to the loss of water in the composite, potassium acetate and hydroxyl in the composite.
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Abdallah, Samy. "Remediation of Copper and Zinc from wastewater by modified clay in Asir region southwest of Saudi Arabia." Open Geosciences 11, no. 1 (October 12, 2019): 505–12. http://dx.doi.org/10.1515/geo-2019-0041.
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Abstract To investigate the efficacy of modified clay minerals to remediate heavy metals from industrial wastewater, two natural clay sediments dominated by kaolinite were selected. Since the kaolinite clay has low cation exchange capacity, some modifications were made using unusual treatments thermal transformation and acid activation techniques were used to increase exchangeability properties for producing modified kaolinite. The increased exchangeability was demonstrated through various methods. Results of X-Ray diffraction analysis verified the transformation of Kaolinite as indicated from disappearing all the diffractogram peaks due to kaolinite. In infra-red spectroscopy, the presence of a broad band with little change in the intensity in the region coupled with broad Si-O bending vibration band and Si-O-Al compound vibration bands explain the extent of structural disorder as a response of modification treatment. From a mineral structural viewpoint, destruction through heat treatment exposes directed –OH bonds located between the tetrahedral and octahedral layers (amorphization). It has been observed that after an acidification treatment, the –OH groups become less stable and lead to the newly formed vacant sites during the modification treatments accommodate extra structural water; thereby; broadening the –OH bands in the I.R spectrum. Scanning Electron Microscope study has clearly demonstrated that, transformation in kaolinite structure from from hexagonal original shape to edgeless shape and values of Cation Exchange Capacity C.E.Cwere increased from 8.2 to 18.41 Meq/100g and from 12.66 to 28.53 Meq/100g in both Sinai and Aswan sediment, respectively. Result of the present study has indicated that crystalling structure of kaolinte tranformed to collapsed structure after modification treatment and the new structure can absorb a large amounts of pollutant metallic ions including Zn and cu from wastewater. Observed increase of metal ions removed by modified clays are due to increase of exchange sites produced by the acid leaching on a collapsed kaolinite framework. A comparison of relative removing values between Zn and Cu revealed that the removing kinetics of Cu is more favored under identical molar concentrations than Zn.
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Mohd Nabil, Nur Najwa-Alyani, and Lee Sin Ang. "Selecting Suitable Functionals and Basis Sets on the Study Structural and Adsorption of Urea-Kaolinite System Using Cluster Method." Indonesian Journal of Chemistry 22, no. 2 (February 15, 2022): 361. http://dx.doi.org/10.22146/ijc.68599.
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Kaolinite is an essential mineral with numerous applications across many sectors. One of them is in the agricultural industry, in which it is a crucial component in the method of controlled-release fertilizer. This manuscript reports the use of different functionals and basis sets on the structural and electronic properties of kaolinite's surface, intending to find reliable methods among those tested. Four different functionals, B3LYP, CAM-B3LYP, M06-2X, TPSSTPSS, complemented with various basis sets, were used in this study. The results show that TPSSTPSS complement with 6-311G** provides good agreement with previous research and experimental results among different functionals and basis sets used. The quantitative analysis was done to optimize the kaolinite molecule. Selected extrema points were used to place the urea molecule for the interaction of urea-kaolinite studies. The urea's interaction with kaolinite was reported at a different interaction site in the gas phase and different orientations of the urea molecule. Urea molecule was optimized above the Al–O and Si–O surfaces with their energy difference calculated. Our results showed that both surfaces act as promising adsorbents among the different orientations of the urea on both the Al–O and Si–O surfaces. However, Al–O, and Si–O had another preferable interaction site to the urea molecules.
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Ruby, C., Ph Refait, J. M. R. Génin, T. Delineau, and J. Yvon. "Evidence of structural Fe(II) ions in Font-Bouillant kaolinites: a Mössbauer study." Clay Minerals 34, no. 3 (September 1999): 515–18. http://dx.doi.org/10.1180/000985599546307.
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Ferric oxides or hydroxides are common minor components of kaolinites. If free, these minerals can be removed by Fe reduction and leaching (Mehra & Jackson, 1960), but Fe3+ions can substitute for Al3+ions in the octahedral sites of kaolinite (Weaveret al., 1967; Malden & Meads, 1967). Moreover, Fe2+ions can also substitute trioctahedrally in place of dioctahedral Al, leading to a local composition of Fe-antigorite (Cuttler, 1980).The Font-Bouillant quarry (Charentes, France) is the source of disordered kaolinite known as ‘FU7, U-7-10 or FBT’ (Caseset al., 1982, 1986). The samples used in this study were considered in an earlier genetic analysis of the deposit (Delineau, 1994; Delineauet al., 1994) and were analysed previously by X-ray diffraction (XRD), infrared (IR) spectroscopy, electron paramagnetic resonance (EPR) and UV-visible spectroscopy by Delineauet al. (1994) (Table 1).
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Silalahi, Imelda H., Nelly Wahyuni, and Irwan Irwan. "FOTODEGRADASI FENOL DALAM LEMPUNG TERPILAR TIO2 (PHOTODEGRADATION OF PHENOL ON TIO2-PILLARED-KAOLINITE." Indonesian Journal of Pure and Applied Chemistry 3, no. 2 (April 30, 2021): 26. http://dx.doi.org/10.26418/indonesian.v3i2.46491.
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Photodegradation of phenol on TiO2-pillared-kaolinite was observed. Pillarization of kaolinite was conducted through intercalation of polyoxotitanium sol into clay suspension followed by calcination giving TiO2-kaolinite which showed an increase in specific surface area and total pore volume compared with the kaolinite. The analysis of XRD demonstrated no significant change on d-space of second order of kaolinite structure associated with 2q 26.61°, but diffractions with regard to 2q 25.3° and 48.0° interpreted for TiO2 anatase were seen on the diffractogram of TiO2-kaolinite. The significant decrease of phenol concentration was observed in the presence of both kaolinite and TiO2-kaolinite under UV illumination (hn ³ 365 nm) compare with the photoreaction without the kaolinite materials however the degradation rate of phenol on TiO2-kaolinite was faster than that on the kaolinite-only where 50% of phenol was consumed after 45 minutes of reaction. Kinetic study showed the photoreaction of phenol on TiO2-kaolinite follows the first order reaction with the reaction rate constant of 1.8 x 10-2 min-1.
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Saffa, A. M., and K. H. Michaelian. "Quantitative Analysis of Kaolinite/Silica and Kaolinite/KBr Mixtures by Photoacoustic FT-IR Spectroscopy." Applied Spectroscopy 48, no. 7 (July 1994): 871–74. http://dx.doi.org/10.1366/0003702944030008.
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Photoacoustic FT-IR spectroscopy was used to quantify kaolinite in binary mixtures with KBr and silica, with the use of a linear relationship between the reciprocals of photoacoustic intensity and kaolinite concentration. The method is valid for both dilute and concentrated mixtures; an average error of 12% was obtained for kaolinite concentrations ranging from 15 to 80%. The technique thus compares favorably with more common approaches that require low analyte concentrations. It is concluded that quantitative photoacoustic infrared spectroscopy is feasible provided that the magnitude of the product of thermal diffusion length and absorption coefficient is taken into account.
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Du Plessis, Pieter I., Michael F. Gazley, Stephanie L. Tay, Eliza F. Trunfull, Manuel Knorsch, Thomas Branch, and Louis F. Fourie. "Quantification of Kaolinite and Halloysite Using Machine Learning from FTIR, XRF, and Brightness Data." Minerals 11, no. 12 (November 30, 2021): 1350. http://dx.doi.org/10.3390/min11121350.
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Quantification of halloysite and kaolinite in clay deposits from X-ray diffraction (XRD) commonly requires extensive sample preparation to differentiate the two phyllosilicates. When assessing hundreds of samples for mineral resource estimations, XRD analyses may become unfeasible due to time and expense. Fourier transform infrared (FTIR) analysis is a fast and cost-effective method to discriminate between kaolinite and halloysite; however, few efforts have been made to use this technique for quantified analysis of these minerals. In this study, we trained machine- and deep-learning models on XRD data to predict the abundance of kaolinite and halloysite from FTIR, chemical composition, and brightness data. The case study is from the Cloud Nine kaolinite–halloysite deposit, Noombenberry Project, Western Australia. The residual clay deposit is hosted in the saprolitic and transition zone of the weathering profile above the basement granite on the southwestern portion of the Archean Yilgarn Craton. Compared with XRD quantification, the predicted models have an R2 of 0.97 for kaolinite and 0.96 for halloysite, demonstrating an excellent fit. Based on these results, we demonstrate that our methodology provides a cost-effective alternative to XRD to quantify kaolinite and halloysite abundances.
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Abdel-Rehim, A. M. "Thermal analysis of topaz synthesis from kaolinite." Thermochimica Acta 340-341 (December 1999): 377–86. http://dx.doi.org/10.1016/s0040-6031(99)00283-x.
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Sahnoune, F., N. Saheb, B. Khamel, and Z. Takkouk. "Thermal analysis of dehydroxylation of Algerian kaolinite." Journal of Thermal Analysis and Calorimetry 107, no. 3 (May 11, 2011): 1067–72. http://dx.doi.org/10.1007/s10973-011-1622-6.
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Tang, Wufei, Hongfei Li, Sheng Zhang, Jun Sun, and Xiaoyu Gu. "The intercalation of ammonium sulfamate into kaolinite and its effect on the fire performance of polypropylene." Journal of Thermoplastic Composite Materials 31, no. 10 (November 2, 2017): 1352–70. http://dx.doi.org/10.1177/0892705717738291.
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Kaolinite has often been intercalated before being introduced into polymers to improve its dispersibility; however, the conventional intercalation usually reduces the flame retardancy of the composite. This work reports our recent efforts on improving both the flame retardant efficiency and dispersibility of kaolinite in polypropylene (PP) by intercalating with ammonium sulfamate (AS). The intercalation had been performed through three steps: dimethyl sulfoxide was firstly introduced into kaolinite layers under supersonic wave, then it was replaced by potassium acetate-aqueous (KAc), and finally the intercalated KAc was replaced by AS to obtain AS-intercalated kaolinite. The structure of intercalated kaolinite was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, and thermogravimetric analysis (TGA). The flammability evaluation by limit oxygen index, vertical burning test (UL-94), cone calorimeters test (CONE), and TGA indicated that the fire resistance, thermal stability, and physical properties of PP can be effectively enhanced by the introduction of AS-intercalated kaolinite. The peak heat release rate (pHRR) value of PP composite containing only 1.5 wt% intercalated kaolinite (1169 kW m−2) had been reduced 13.2% compared with that of the sample containing 1.5 wt% raw kaolinite (1346 kW m−2). The morphology analysis from scanning electron microscope images and XRD patterns demonstrated that the compatibility and dispersibility of kaolinite in PP had been significantly improved by intercalation. The flame retardant mechanism of AS-intercalated kaolinite in PP was proposed.
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Tunney, James J., and Christian Detellier. "Interlamellar amino functionalization of kaolinite." Canadian Journal of Chemistry 75, no. 11 (November 1, 1997): 1766–72. http://dx.doi.org/10.1139/v97-610.
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The interlamellar surface of kaolinite has been modified with molecules possessing amino functionalities. Either the dimethyl sulfoxide intercalate of kaolinite (Kao/DMSO) or the N-methylformamide intercalate of kaolinite (Kao/NMF) were used as starting materials. One of the products, an ethanolamine functionalized kaolinite (Kao–EOA) was resistant to thermal decomposition in both air and N2 atmospheres up to temperatures greater than 150 °C. Based on results from thermal analysis, IR analysis, 13CCP/MAS NMR spectroscopy, and elemental analysis, a structural model is proposed in which every third interlayer surface hydroxyl group on the aluminol (Al-OH) surface of kaolinite is either replaced with an interlayer Al-OCH2CH2NH2 group or is strongly H-bonded to an aminoalcohol molecule. A mixture of both types of linkages could coexist. The amino groups that point away from this surface are each keyed into the -(SiO−)6 macro-rings of the adjacent silicate surface, resulting in an amino-functionalized ordered two-dimensional organo-mineral assembly. Keywords: kaolinite, halloysite, organo-mineral nanocomposites, clay functionalization, supramolecular assemblies.
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Firoozi, Ali Akbar, Mohd Raihan Taha, Tanveer Ahmed Khan, Farzad Hejazi, Ali Asghar Firoozi, and Jamal M. A. Alsharef. "A Novel Method for Mixing Nanomaterials with Soil." Nano Hybrids and Composites 25 (April 2019): 46–68. http://dx.doi.org/10.4028/www.scientific.net/nhc.25.46.
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Mixing of nano-sized powders with soils (macro-sized powders) is a noteworthy issue for geotechnical projects. Thus, this study examined the horizontal ball mill mixing of nano-copper oxide with kaolinite. Ball milling parameters (rotation speed, weight ratio of balls to powder and milling time) of the planetary ball milling were optimized for proper mixing of nano-copper oxide and kaolinite powder. Results showed that increase in mixing time decreased the agglomeration of nano-copper powders and kaolinite and increased the homogeneity of nano-copper powder with kaolinite particles. The quality of mixing was assessed through intensity and scale of segregation using concentration data obtained through energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analyses. It was observed through these two tests that, increase in ball milling time after 6 hours resulted in grain size reduction. Field emission scanning electron microscopy analysis showed that nano-coppers were regularly found on the surface of kaolinite particles after 6 hrs. of horizontal milling at 4:1 ratio of balls to powder mixture. Furthermore, 24 hrs. mixing resulted in grinding of kaolinite particles and hence their size was reduced. Particle size analysis confirmed these results, as the highest size span value of 3.417 was observed after 6 hrs. milling with speed of 200 rpm.
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Chen, Xing Gang, Man An, Xiao Ming Sang, Gui Xiang Hou, Shou Wu Yu, and Yi Shen. "Effect of Intercalated Agents on Thermal Deintercalation of Kaolinite." Advanced Materials Research 476-478 (February 2012): 710–13. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.710.
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A series of intercalated kaolinite with formamide, potassium acetate and acrylamide were prepared. The thermal deintercalation processes of these composites were studied using a combination of X-ray diffraction and thermal analysis technique. X-ray diffraction spectra showed acrylamide could be indirectly intercalated into kaolinite layers. The activatory energy of thermal deintercalation of acrylamide from kaolinite-potassium acetate composites was 15.60 kJ/mol, higher than that from kaolinite-formamide composites, 9.51 kJ/mol. The reason was that strong hydrogen bondings between acrylamide and potassium acetate were formed in kaolinite layers.
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Lakel, Abdelghani. "Microstructural Studies of Materials DD1 and KT2 By X-Ray Diffraction." Journal of Building Materials and Structures 6, no. 1 (March 31, 2019): 20–31. http://dx.doi.org/10.34118/jbms.v6i1.65.
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In this work, we have studied two Kaolin .kaolin DD1 which consists of two main phases (kaolinite and Halloysite) and Tamazert kaolin .kaolin KT2 whose main constituents are kaolinite, quartz and mica. Our choice was set on the component that is Kaolinite because of the existence of the latter in both kaolins. A correction of Lorentz-Polarization was carried out prior to the diffraction data, which has been achieved using LWL program dome. The true profile was extracted by this program. The methods used for the micro structural analysis of the present in the two Kaolins are the Warren - Averbach and the Williamson – Hall methods Scherrer's relationship has been applied in cases where the compound is devoid of strains.
The study revealed that the kaolin Kaolinite DD1 is devoid of micro constraints. Which similar analysis has shown that the Kaolinite in KT2 incorporates the strains. This was confirmed by the Williamson - Hall method as well as Fourier analysis. The evaluation of strains in the Kaolinite of KT2 has been dome the method of Warren - Averbach and Williamson – Hall diagram. The average value of this constraint found by the first method us 0.15 and 0.21 by the second method gave. The average size of crystallites of the Kaolinite in DD1 was found between 29 A and 230 A.
by the method of Warren - Averbach and about 118 A by the method of Williamson - Hall. Range the second Kaolinite the Kaolinite KT2, the size obtained was respectively 98 A and 130 A using to by methods. The study of the size distribution showed that the dominant size of Kaolinite in DD1 and KT2 is about 40 A (42%) and 58 A (32%). respectively.
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Campos, Valquiria, Leandro C. Morais, André H. Rosa, Leonardo F. Fraceto, and Pedro M. Büchler. "The Effect of Anionic Sorption on the Metakaolinite." Materials Science Forum 660-661 (October 2010): 1015–18. http://dx.doi.org/10.4028/www.scientific.net/msf.660-661.1015.
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This paper reports an investigation on the effect of thermal activation of kaolinite. It is well known that during calcinations (400–650°C), kaolinite loses the OH lattice water and is transformed into metakaolinite or amorphous material. Arsenic is trace element that is toxic to animals including humans. The adsorption of arsenic on kaolinite was investigated at varying pH and thermal pretreatment. Calcination of sample is carried out at 650 °C for 3 h. The decomposition of kaolinite is recorded using methods of thermal analysis. The resultant product is identified by XRD. Laboratory experiments were conducted examining the effect of arsenic by thermally modified kaolinite. The Langmuir isotherm was used to describe arsenite and arsenate sorption by the calcined kaolinite. The equilibrium parameters used were based on experimental data obtained for the dynamic adsorption process of arsenic. Removal of arsenate using natural kaolinite was satisfactory, whereas arsenic was not removed by adsorption with thermally modified kaolinite. Moreover, the adsorption of arsenic by kaolinite and metakaolinite decreases with increasing pH.
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Apata, A. C., and S. I. Adedokun. "Geochemical Analysis of Ilaro-Papalanto Highway Subgrade." LAUTECH Journal of Civil and Environmental Studies 5, no. 1 (September 27, 2020): 146–53. http://dx.doi.org/10.36108/laujoces/0202/50(0141).
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In this study, the geochemical analysis of the subgrade at different locations of Ilaro-Papalanto highway was conducted using Atomic Absorption Spectrometry (AAS) and X-Ray Diffractometry (XRD). The predominant oxides present in both soil samples are Silicon Oxide (40% - 45%) and Aluminium Oxide (31% - 34%), and the average silica content of Ilaro and Papalanto are 45.71% and 40.71% respectively, which implies that Ilaro soil sample is more chemically inert and structurally stable than Papalanto soil samples. The average sesquioxide content of Papalanto (36.27%) is higher than that of Ilaro (32.87%), while the silica sesquioxide ratio (SSR) of Papalanto (1.12%) is less than that of Ilaro (1.39%), therefore both soil samples are in advanced stage of weathering but Papalanto soil is more lateritic than Ilaro. Geochemical analysis using XRD indicated the presence of three clay minerals (Kaolinite, Illite and traces of Montmorrrilonite) and one major non-clay mineral, Quartz. The average proportion of Kaolinite in the soil samples are 9% (Ilaro) and 28% (Papalanto), but the average values of Quartz are 62% and 69% for Ilaro and Papalanto, respectively. The higher proportion of sesquioxide and Kaolinite from Papalanto samples is an indication of more failures observed in the region.
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Sagita, Christyowati Primi, Limpat Nulandaya, and Yehezkiel Steven Kurniawan. "Efficient and Low-Cost Removal of Methylene Blue using Activated Natural Kaolinite Material." Journal of Multidisciplinary Applied Natural Science 1, no. 2 (April 17, 2021): 69–77. http://dx.doi.org/10.47352/jmans.v1i2.80.
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Clays are low-price and very useful material for water treatment purpose. In this work, we reported the application of activated natural kaolinite material which obtained from Wediombo beach, Yogyakarta for methylene blue adsorption. The natural kaolinite material was activated under an acidic condition to obtain the activated kaolinite material. The activated kaolinite material was characterized using Fourier transform infrared, X-ray diffraction, scanning electron microscope, and surface analysis. From the adsorption experiment, the activated kaolinite material gave moderate adsorption percentages for methylene blue. The adsorption kinetics followed the Ho and McKay kinetic model while the adsorption isotherm followed Langmuir model. The qmax value for methylene blue adsorption using activated natural kaolinite material was at a moderate level (3.40 mg g-1). The plausible adsorption mechanism of methylene blue on the surface of activated kaolinite material happened through hydrogen bondings and/or electrostatic interactions. These findings are important for a wastewater treatment using a low-cost adsorbent material.
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Romero-Guerrero, L. M., R. Moreno-Tovar, A. Arenas-Flores, Y. Marmolejo Santillán, and F. Pérez-Moreno. "Chemical, Mineralogical, and Refractory Characterization of Kaolin in the Regions of Huayacocotla-Alumbres, Mexico." Advances in Materials Science and Engineering 2018 (November 1, 2018): 1–11. http://dx.doi.org/10.1155/2018/8156812.
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In the present work, the chemical, mineralogical, refractory, and microstructural characterizations of kaolinites from the Huayacocotla-Alumbres region, which is between Veracruz and Hidalgo border, by X-ray diffraction (XRD), polarization optical microscopy (POM), scanning electron microscopy (SEM), refractoriness proof (pyrometric cone equivalent), and thermogravimetric analysis (TGA) were carried out. The analysis by POM showed that the kaolinization degree in this region is variable due to the presence of primary minerals, such as plagioclase, feldspar, and quartz. Additionally, hydrothermal alteration of the epithermal type was determined by oxidation of sulfides (pyrite and galena) and chlorite association. With the X-ray diffraction technique, andalusite and kaolinite were identified as the majority phases in Huayacocotla and quartz was identified as the majority phase in Alumbres. The minority phases, such as dickite, kaolinite, and cristobalite, were observed in both zones. The SEM technique was useful in the determination of the morphology of kaolinite and impurities of Na, Mg, K, and Fe of the complex clay illite-andalusite-dickite group. Thermogravimetric analysis was useful to discover the decomposition temperature and reveal the significant difference between 400 and 800°C, which showcases the greatest mass loss due to dehydration and carbonates decomposition. The mullite phase was detected at approximately 1000°C in the kaolin samples. The refractoriness tests were important to determine the stability temperature of kaolin, which is between 1300 and 1600°C. This stability temperature makes it feasible to use the kaolin as a refractory material for both low and high temperatures. The variables that affect the kaolin stability temperature were determined by principal components with the XLSTAT free program.
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Machida, Shingo, Ken-ichi Katsumata, and Atsuo Yasumori. "Regioselective Approach to Characterizing Increased Edge Availability in Layered Crystal Materials following Layer Expansion: Reaction of Kaolinite with Octadecyltrimethylammonium Salts." Materials 15, no. 2 (January 13, 2022): 588. http://dx.doi.org/10.3390/ma15020588.
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In this paper, the regioselective reactions of kaolinite and methoxy-modified kaolinite (MeO-Kaol), methanol-expanded kaolinite, with octadecyltrimethylammonium salts are compared. This study mainly concerns the reactions of kaolinite or MeO-Kaol with octadecyltrimethylammonium chloride (C18TAC) in methanol and the subsequent exhaustive washing of the resultant products with ethanol. X-ray diffraction patterns of the products reveal no intercalation of C18TAC between pristine kaolinite layers. Additionally, intercalation and subsequent deintercalation of C18TAC proceed in the product using MeO-Kaol. In the Fourier-transform infrared spectra, the intensities of CH2 stretching bands of the product prepared using MeO-Kaol drastically increase compared to those using kaolinite. In addition, CH2 stretching bands of the product using kaolinite are hardly observed without enlarging the spectrum. The product using MeO-Kaol also displays mass loss in the range of 200–300 °C in the thermogravimetric curve and a nitrogen content with 0.15 mass% estimated using the CHN analysis. These results therefore demonstrate an increase in the available reactive edges in the layered crystal material following an expansion of the stacked layers.
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Mahdavi, Fariba, Rashid Abdul, and Yusop Khanif. "Intercalation of urea into kaolinite for preparation of controlled release fertilizer." Chemical Industry and Chemical Engineering Quarterly 20, no. 2 (2014): 207–13. http://dx.doi.org/10.2298/ciceq121004001m.
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In this study urea was intercalated between layers of kaolinite by dry grinding technique to be used for preparing controlled release fertilizer. X-ray powder diffraction (XRPD) patterns confirmed the intercalation of urea into kaolinite by the significant expansion of the basal spacing of kaolinite layers from 0.710 nm to 1.090 nm. Fourier transform infrared spectroscopy (FT-IR) also confirmed the hydrogen bonding between urea and kaolinite. Based on CHNS elemental analysis, 20% (wt.) urea was intercalated between kaolinite layers. The urea-intercalated kaolinite was mixed with hydroxypropyl methylcellulose (HPMC) binder and was granulated to prepare the nitrogen-based controlled release fertilizer. To study the nitrogen release behavior of granules, ultraviolet/visible (UV-Vis) spectroscopy was used through the diacetyl monoxime (DAM) colorimetric method. The result of UV-Vis spectroscopy showed that intercalation of urea into kaolinite decreased the nitrogen release from 25.50 to 13.66 % after 24 hours and from 98.15 to 70.01% after 30 days incubation in water. According to the results, the prepared controlled release fertilizer (CRF) behaved according to the standard for CRFs.
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Caglar, Bulent, Beytullah Afsin, Erdal Eren, Ahmet Tabak, Cagri Cirak, and Osman Cubuk. "Key words: Sound Diffraction; Lined Duct; Integral Transform; Wiener-Hopf Technique; Expansion Coefficients; Pole Removal Technique." Zeitschrift für Naturforschung A 65, no. 11 (November 1, 2010): 1009–19. http://dx.doi.org/10.1515/zna-2010-1111.
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The intercalation of dimethyl sulphoxide (DMSO), pyridine (Py), ethanolamine (Ea), and Nmethyl formamide (NMF) molecules into the kaolinite interlayers led to an appreciable decrease of 3697 cm−1 of the hydroxyl band. The appearance of the peaks at 3662, 3541, and 3504 cm−1 proved that the DMSO species are intercalated between the kaolinite layers through forming H-bonds with internal-surface hydroxyl groups. The intensities of the 942 and 796 cm-1 bending peaks arising from inner-surface hydroxyls decreased and new vibrational features appeared due to the intercalation of the guest species. The d001 value of pure kaolinite was found at 7.18 A° , and the d001 values were seen at 11.26, 11.62, 10.77, and 10.67 °A for kaolinite-dimethyl sulphoxide (K-DMSO), kaolinite-pyridine (K-Py), kaolinite-ethanolamine (K-EA), and kaolinite-N-methyl formamide (K-NMF) composites, respectively. The endothermic differential thermal analysis (DTA) peaks at a temperature of 108 - 334 ◦C reflected the changes in the physicochemical properties of the intercalated species. The thermal stability increase followed the order of K-Py<K-NMF<K-Ea<K-DMSO. Based on the thermal analysis data, the intercalation ratios of the composites above were determined as 80.0, 40.0, 81.6, and 82.0%, respectively. The specific surface areas are affected by the intercalation geometry of the composites within the gallery spacing. The surface areas of the K-DMSO, K-Py, and K-EA complexes increased whereas the surface area of K-NMF decreased with respect to that of untreated kaolinite.
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Cheng, Hongfei, Qinfu Liu, Jing Yang, and Ray L. Frost. "Thermogravimetric analysis of selected coal-bearing strata kaolinite." Thermochimica Acta 507-508 (August 2010): 84–90. http://dx.doi.org/10.1016/j.tca.2010.05.004.
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Spence, Adrian, and Brian P. Kelleher. "FT-IR spectroscopic analysis of kaolinite–microbial interactions." Vibrational Spectroscopy 61 (July 2012): 151–55. http://dx.doi.org/10.1016/j.vibspec.2012.02.019.
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Vasconcelos, Igor F., Elizabeth A. Haack, Patricia A. Maurice, and Bruce A. Bunker. "EXAFS analysis of cadmium(II) adsorption to kaolinite." Chemical Geology 249, no. 3-4 (April 2008): 237–49. http://dx.doi.org/10.1016/j.chemgeo.2008.01.001.
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Balek, V., and M. Murat. "The emanation thermal analysis of kaolinite clay minerals." Thermochimica Acta 282-283 (July 1996): 385–97. http://dx.doi.org/10.1016/0040-6031(96)02886-9.
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Zhang, Yinmin, Qinfu Liu, Zeguang Wu, Qiming Zheng, and Hongfei Cheng. "Thermal behavior analysis of kaolinite–dimethylsulfoxide intercalation complex." Journal of Thermal Analysis and Calorimetry 110, no. 3 (December 2, 2011): 1167–72. http://dx.doi.org/10.1007/s10973-011-2038-z.
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Itiowe, K., R. Oghonyon, and B. K. Kurah. "Lithofacies Analysis and Qualitative Minerology of the Sediments of #3 Well in the Greater Ughelli Depobelt, Niger Delta Basin." Journal of Scientific Research 13, no. 2 (May 1, 2021): 601–10. http://dx.doi.org/10.3329/jsr.v13i2.49948.
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The sediment of #3 Well of the Greater Ughelli Depobelt are represented by sand and shale intercalation. In this study, lithofacies analysis and X-ray diffraction technique were used to characterize the sediments from the well. The lithofacies analysis was based on the physical properties of the sediments encountered from the ditch cuttings. Five lithofacies types of mainly sandstone, clayey sandstone, shaly sandstone, sandy shale and shale and 53 lithofacies zones were identified from 15 ft to 11295 ft. The result of the X-ray diffraction analysis identified that the following clay minerals – kaolinite, illite/muscovite, sepiolite, chlorite, calcite, dolomite; with kaolinite in greater percentage. The non-clay minerals include quartz, pyrite, anatase, gypsum, plagioclase, microcline, jarosite, barite and fluorite; with quartz having the highest percentage. Therefore, due to the high percentage of kaolinite in #3 well, the pore filing kaolinite may have more effect on the reservoir quality than illite/muscovite, chlorite and sepiolite. By considering the physical properties, homogenous and heterogeneous nature of the #3 Well, it would be concluded that #3 Well has some prospect for petroleum and gas exploration.
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Chen, Bo, Feng Wang, Jian Shi, Fenjun Chen, and Haixin Shi. "Origin and Sources of Minerals and Their Impact on the Hydrocarbon Reservoir Quality of the PaleogeneLulehe Formation in the Eboliang Area, Northern Qaidam Basin, China." Minerals 9, no. 7 (July 15, 2019): 436. http://dx.doi.org/10.3390/min9070436.
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The Lulehe sandstone in the Eboliang area is a major target for hydrocarbon exploration in the northern Qaidam Basin. Based on an integrated analysis including thin section analysis, scanning electron microscopy, X-ray diffraction, cathodoluminescence investigation, backscattered electron images, carbon and oxygen stable isotope analysis and fluid inclusion analysis, the diagenetic processes mainly include compaction, cementation by carbonate and quartz, formation of authigenic clay minerals (i.e., chlorite, kaolinite, illite-smectite and illite) and dissolution of unstable materials. Compaction is the main factor for the deterioration of reservoir quality; in addition, calcitecement and clay minerals are present, including kaolinite, pore-filling chlorite, illite-smectite and illite, which also account for reservoir quality reduction. Integration of petrographic studies and isotope geochemistry reveals the carbonate cements might have originated from mixed sources of bioclast- and organic-derived CO2 during burial. The quartz cement probably formed by feldspar dissolution, illitization of smectite and kaolinite, as well as pressure solution of quartz grains. Smectite, commonly derived from alteration of volcanic rock fragments, may have been the primary clay mineral precursor of chlorite. In addition, authigenic kaolinite is closely associated with feldspar dissolution, suggesting that alteration of detrital feldspar grains was the most probable source for authigenic kaolinite. With the increase in temperature and consumption of organic acids, the ratio of K+/H+ increases and the stability field of kaolinite is greatly reduced, thereby transforming kaolinite into mixed layer illite/smectite and illite. Within the study area, porosity increases with chlorite content up to approximately 3% volume and then decreases slightly, indicating that chlorite coatings are beneficial at an optimum volume of 3%. A benefit of the dissolution of unstable minerals and feldspar grains is the occurrence of secondary porosity, which may enhance porosity to some extent. However, the solutes cannot be transported over a large scale in the deep burial environment, and simultaneous precipitation of byproducts of feldspar dissolution such as authigenic kaolinite and quartz cement will occur in situ or in adjacent pores, resulting in heterogeneity of the reservoirs.
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Kassa, Adamu Esubalew, Nurelegne Tefera Shibeshi, and Belachew Zegale Tizazu. "Characterization and Optimization of Calcination Process Parameters for Extraction of Aluminum from Ethiopian Kaolinite." International Journal of Chemical Engineering 2022 (March 10, 2022): 1–18. http://dx.doi.org/10.1155/2022/5072635.
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The present study aimed to optimize the calcination process parameters (viz., temperature, time, and particles size) for the extraction of aluminum from Ethiopian kaolinite. The kaolinite calcination was done in the temperature of 600–700°C, time of 120–180 min, and particles size of 106–355 μm. The extraction of aluminum from calcined kaolinite was carried out at fixed acid concentration of 3 M, temperature of 80°C, liquid-to-solid ratio of 12 mL g−1, time of 120 min, and stirring speed of 700 rpm. The chemical composition of kaolinite was determined using XRF. Moreover, kaolinite, metakaolinite, and extracted aluminum were characterized by XRD, TGA, DSC, and FTIR. The XRF result of the kaolinite was mainly silicon oxide (55.76% w/w), aluminum oxide (32.02% w/w), and loss on ignition (11.17% w/w). Calcination of kaolinite produced amorphous metakaolinite due to the dehydroxylation reaction as shown by the FTIR results. Three endothermic peaks and one exothermic peak were detected in the thermal analysis of the kaolinite due to water removal, impurities decomposition, dehydroxylation reaction, and phase change from metakaolinite to spinel, respectively. The extracted aluminum proportionally increased with kaolinite calcination temperature and time. However, the extracted aluminum increased as the particles size reduced. The extracted aluminum was in the form of aluminum chloride hexahydrate and trigonal crystalline structure. The optimum values of the degree of conversion of kaolinite dehydroxylation reaction and extracted aluminum of 0.992 and 71.28% w/w were obtained at the optimum kaolinite calcination temperature of 700°C, time of 180 min, and particles size of 106 μm, respectively.
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Vo, Nhat Dai. "A comparison of shrinkage cracking between clay minerals by crack parameters using image analysis." Science and Technology Development Journal 20, K4 (July 31, 2017): 5–12. http://dx.doi.org/10.32508/stdj.v20ik4.1107.
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Experiments have been conducted in laboratory to present a comparison of shrinkage cracking based on an observation and a quantitative determination of crack parameters. Photographs of surface cracks for three different types of clay mineral belonging to different groups – Bentonite, Kaolinite and Illite – are processed using image analysis. Each of soil types is tested with four sample thicknesses ranging from 5 to 20 mm at an interval of 5 mm. The measurements of crack parameters for clay mineral soils show that area and width of cracks in case of Bentonite are much larger than those while length of cracks appears to be slightly less than that in other cases. Number of cracks in case of Bentonite are smaller than those in cases of Kaolinite and Illite. Additionally, compared with Illite, area, length and width of cracks in case of Kaolinite are slightly larger while the other crack parameters seem to be same.
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Mbey, Jean Aimé, Fabien Thomas, and Sandrine Hoppe. "Kaolinite dispersion in cassava starch-based composite films: a photonic microscopy and X-ray tomography study." Journal of Polymer Engineering 38, no. 7 (August 28, 2018): 641–47. http://dx.doi.org/10.1515/polyeng-2017-0302.
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Abstract In the present study, a combined use of photonic microscopy, scanning electron microscopy and 3D X-ray tomography is carried out in order to analyze the dispersion and the distribution of raw and dimethyl sulfoxide (DMSO)-intercalated kaolinite used as filler in cassava starch-based films. It is shown that the association of these techniques allows a valuable analysis of clay dispersion in polymer-clay composite films. In the case of kaolinite-starch composite films on which this study is focused, it is obvious that previous intercalation of kaolinite with DMSO is an efficient way to improve dispersion and distribution of kaolinite in a starch polymer matrix.
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Liu, Xiaoxu, Xiaowen Liu, and Yuehua Hu. "Investigation of the thermal behaviour and decomposition kinetics of kaolinite." Clay Minerals 50, no. 2 (June 2015): 199–209. http://dx.doi.org/10.1180/claymin.2015.050.2.04.
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AbstractPrevious work on the structural and thermal properties of various types of kaolinite have led to different conclusions, rendering comparison of analytical results difficult. The objectives of the present study were to investigate the thermal behaviour of kaolinite and to carry out a kinetic analysis of the decomposition of kaolinite at high temperatures. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetry-differential scanning calorimetry (TG-DSC) were used to study the mechanism of the thermal decomposition. The modified Coats–Redfern, Friedman, Flynn–Wall–Ozawa and Kissinger decomposition models were used to determine the decomposition mechanism of the kaolinite sample. The dehydroxylation of kaolinite occurred at ∼600°C with the formation of metakaolin, which then transformed into either γ-alumina or aluminium-silicon spinel together with amorphous silica. The results of the XRD and FTIR analyses indicated that the γ-alumina, or aluminium-silicon spinel and amorphous silica phases, transformed into mullite and α-cristobalite, respectively, after decomposition at 900°C. Good linearity was observed with the modified Coats–Redfern, Flynn–Wall–Ozawa and Kissinger models from room temperature to 1400°C and the range of the activation energy determined was 120–180 kJ/mol.
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Storey, J. M. V., and P. M. Hillock. "THE RELATIONSHIP BETWEEN AUTHIGENIC KAOLINITE, RESERVOIR QUALITY AND TRAP HISTORY IN WONNICH-I." APPEA Journal 37, no. 1 (1997): 340. http://dx.doi.org/10.1071/aj96021.
Full textAbstract:
A significant decrease in permeability is seen within the oil and water legs of the Wonnich-1 oil and gas discovery well in TP/8, despite an increase in porosity of 4-5 per cent by volume. The anomalous zone contains abundant authigenic kaolinite. The prompt integration of wireline log and core data allowed the presence of this kaolinite to be postulated at an early stage in the appraisal of the well. It also led to the proposal that the authigenic kaolinite was derived through the dissolution of detrital potassium feldspar and that its distribution was related to a palaeo-hydrocarbon contact. This hypothesis was used to design a tailored special core analysis and petrographic study including fluid inclusion, mercury injection and critical velocity analyses. The results confirmed the model and indicate that the bulk of the additional porosity within the anomalous zone is microporosity. In addition, the results show that where water is the flowing phase, the authigenic kaolinite becomes mobile at an interstitial velocity of approximately 4.4 jim/s. This equates to a water offtake rate of 5,700 BWPD, making kaolinite movement in the immediate vicinity of the well bore likely in any Wonnich oil development scenario. Pore throat sizes in the Wonnich reservoir appear to be sufficiently large that the kaolinite will pass through leading to an increase in permeability rather than a decrease. As a consequence, kaolinite movement is likely to lead to an increase in water production since it will occur preferentially in areas of water breakthrough.
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Akinmosin, A., and C. V. Melifonwu. "Sedimentological and Scanning Electron Miscroscopic Descriptions of Afowo Oil Sand Deposits, South Western Nigeria." GeoScience Engineering 63, no. 4 (December 1, 2017): 20–32. http://dx.doi.org/10.1515/gse-2017-0019.
Full textAbstract:
AbstractSedimentological and scanning electron microscopic analyses of some shallow reservoir tar sand samples in parts of Southwestern Nigeria were carried out with the aim of characterizing the reservoir properties in relation to bitumen saturation and recovery efficiency. The production of impregnated tar from the sands requires the reservoir to be of good quality. A total of thirty samples were collected at different localities within the tar sand belt (ten out of these samples were selected for various reservoir quality analyses based on their textural homogeneity). The result of particle size distribution study showed that bulk of the sands is medium – coarse grained and moderately sorted. The grain morphologies are of low to high sphericity with shapes generally sub-angular to sub-rounded, implying that the sands have undergone a fairly long transportation history with depositional energy having a moderate to high velocity. The quartz content was made up of about 96% of the total mineralogical components; the sediments of the Afowo Formation can be described to be mineralogically and texturally stable. The result of the scanning electron microscopy (SEM) analysis revealed that the oil sands contained minerals which had been precipitated and occurred as pore filling cement; these minerals include sheet kaolinite, block kaolinite, vermiform kaolinite, pyrite crystals and quartz. The SEM images also showed micro-pores ranging from 0.057µm to 0.446µm and fractures. The study showed that the clay minerals contained in the Afowo reservoir rocks were mainly kaolinite. Kaoline unlike some other clays (e.g Montimorillonite) does not swell with water, hence it is not expected to have any negative effects on the reservoir quality, especially during enhanced oil recovery operations.From overall results of the reservoir quality assessment, Oso J4 and Gbegude sands should be expected to make better reservoirs with good oil recovery efficiency due to their low content of fines and better sorting characteristics when compared to sediments of other areas.