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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Impact of calcination temperature and time on quicklime slaking reactivity

Björnwall, Erik January 2021 (has links)
In this master thesis work calcination parameters' impact on the resulting quicklimes slaking reactivity is investigated. This is done by calcination of three different sedimentary limestones in an N2 atmosphere according to a design of experiment matrix. The limestones are from Wolica Poland, Slite Sweden and Jutjärn Sweden. The temperatures and residence times are varied between 1000ºC, 1050ºC, and 1100ºC for 5 min, 27.5 min, and 60 min. There were seven experiments per limestone sample. The calcination experiments were conducted in an electrical muffle furnace.When the limestone samples were calcined, the resulting quicklimes slaking reactivity was tested according to standard SS-EN 459-2:2010 Building lime - Part 2: Test methods. Four different parameters were used to determine the slaking reactivity, these were the maximum temperature, how much the temperature increases under the initial 30 s, the time it takes for the temperature to reach 60ºC, and the time for the slaking to become 80% finished.From the slaking reactivity experiments, the calcination parameters to produce the most reactive quicklime for the limestone from Wolica and Jutjärn are 1000ºC for 60 min, and for the limestone from Slite 1100ºC for 5 min. For all three limestones the least reactive quicklime was received by calcining at 1100ºC for 60 min. The most and least reactive quicklimes were analyzed in SEM, where it could be seen that the least reactive quicklime samples were coarser compared to the most reactive samples. Depending on what slaking reactivity parameter is of interest, the calcination settings should be different and can be an indication for operation parameters for industrial kilns. The statistical analysis on the experimental model showed that the experiment had a poor statistical fit for most of the experiment. This could be due to that the model possibly was too simple to describe the calcination parameters complex impact on the slaking reactivity.
52

Calcination of Marls to Produce Roman Cement

Hughes, David C., Jaglin, D., Kozlowski, R., Mayr, N., Mucha, D., Weber, J. January 2006 (has links)
no / Marls were identified from a range of European sources and assessed for their Cementation Index, as proposed by Eckel. Two were selected for calcination in a laboratory kiln; one from Folwark in Poland (CI 1.75) and one from Lillienfeld in Austria (CI 2.03). Analysis of historical documents, while not revealing precise kiln conditions, does suggest that they were such as not to yield complete decarbonation of the calcite. Consequently, a series of calcinations was undertaken in which the peak temperature control of the kiln was set in the range 730°C to 1100°C, with residence times in the range 150 to 1250 min. The airflow through the kiln was sufficient to maintain a minimum oxygen content of at least 12 %. The resulting clinker was ground to comply with the 19th century Austrian Norme. Pastes were produced at w/c = 0.65 and assessed for setting time and strength development (6 h to 1 year). Both parameters were highly dependent upon calcination conditions with both ¿low¿ and ¿high¿ calcinations producing slower setting and slower strength development than intermediate conditions. Two strength development profiles were identified; one being the expected continuous increase of strength, albeit with a declining rate of increase with time, while the other showed a three-step sequence of high initial strength, a dormant period which could last for many weeks and a final increase in strength to an age of one year. The cements were compared using X-ray diffraction (XRD). Considerable variation in the composition was noted and related to the calcination conditions. Of particular interest is the formation of both ¿'-belite and ß-belite under differing calcination conditions. Clinker particles were also compared using the SEM in back-scattered electron imaging mode and the development of morphology observed.
53

Pre-hydration as a technique for the retardation of Roman cement mortars

Starinieri, V., Hughes, David C., Gosselin, C., Wilk, D., Bayer, K. 10 January 2013 (has links)
No / The setting of Roman cement is so rapid as to make the use of retardation essential in most practical mortars. This work reports an approach to retardation of Roman cement mortars by means of a pre-hydration process in which pre-determined amounts of water (de-activation water) are added to the cement prior to subsequent mortar formation. It is shown that this process yields both monocarboaluminate and a carbonated AF(m) phase, the balance of which is modified by storage time; the belite phases are not affected. Increases in both de-activation water and pre-hydrated mix storage time yield a longer workable life and slightly lower strength of the mortar. An increase in de-activation water also yields an increase in shrinkage whilst an increase in storage time results in a reduction in shrinkage. Other parameters such as mixing protocol and re-mixing affect workable life without compromising the strength. (C) 2013 Elsevier Ltd. All rights reserved.
54

Correlations between the Mineralogy and Recovery Behavior of Rare Earth Elements (REEs) in Coal Waste

Ji, Bin 12 January 2023 (has links)
Many literatures have been published recently regarding the recovery of REEs from coal-related materials, such as coal waste, acid mine drainage, and coal combustion ash. The recovery of REEs from coal waste has been investigated by the author in recent years, and it was found that after calcination at 600 ℃ for 2 h, a significant improvement in REE recovery can be achieved. In order to reveal the mechanisms of the enhanced REE recovery after calcination, coal waste samples from two different seams, i.e., Western Kentucky No. 13 and Fire Clay, were selected to investigate the modes of occurrence of REEs. Scanning electron microscopy- and transmission electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS and TEM-EDS) analyses were conducted to investigate the mineralogy of REEs in two coal waste samples. Totally, 49 and 50 REE-bearing particles were found from the SEM specimens of Western Kentucky No. 13 and Fire Clay coal waste samples, respectively. Based on the elemental composition analyses and TEM-EDS characterization, it was found that apatite, monazite, and crandallite-group minerals were the major light REE (LREE) carriers, while the heavy REEs (HREE) primarily occurred in zircon and xenotime in these two coal waste samples. Further analyzing the REE content and number of REE-bearing particles, it was confirmed that monazite, xenotime, and crandallite-group minerals were the dominant contributors to the total REE (TREE) contents in both materials. In addition to the mineralogy of REEs, the morphology of REE-bearing particles was also investigated. The SEM images suggested that the particle size of most REE-bearing particles was less than 5 μm. Moreover, not only completely liberated particles, but particles encapsulated by the host minerals present in the two coal waste samples. To identify the changes of mineralogy of REEs after recovery, the leaching solid residues of the raw and calcined coal waste samples were also characterized by SEM-EDS analysis. After REE recovery, the same REE mineralogical results were observed from the leaching residues of the raw coal waste samples. However, as for the calcined samples, the crandallite-group minerals disappeared. These results suggested that the crandallite-group minerals were decomposed into easy-to-leach forms after calcination at 600 ℃, thus leading to the improved REE recovery. Moreover, the number of REE-bearing particles (N) found from per area of the calcined leaching residue was confirmed to be larger compared to that of the raw ones. A combination analysis of these results indicated that two mechanisms of the enhanced REE recovery after calcination can be confirmed: (1) decomposing the crandallite-group minerals into more soluble species; and (2) promoting the liberation of the REE-bearing particles encapsulated in the host minerals. The thermal decomposition of crandallite-group minerals was mainly responsible for the enhanced REE recovery from coal waste. However, as a result of the complex isomorphic substitutions and association characteristics, it is difficult to collect a pure endmember of crandallite-group mineral for characterization. Therefore, florencite-(Ce) was synthesized in this study. X-ray diffraction (XRD), SEM-EDS, TEM, thermogravimetric and differential thermal analyses (TGA-DTA), and acid leaching tests were conducted on the synthesized product. The results showed that the variation in Ce leaching recovery corresponded to the phase transformation of florencite. The gradual transformation of florencite from a crystalline mineral into an amorphous phase resulted in the increases in the solubility of Ce. In addition, the thermal transformation of florencite was an independent reaction, which was not interfered by the host materials, such as kaolinite and coal waste. / Doctor of Philosophy / Coal waste has been identified as a promising alternative source of rare earth elements (REEs). This study showed that calcination can significantly improve the REE recovery from coal waste materials. Scanning electron microscopy- and transmission electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS and TEM-EDS) analyses were conducted to investigate the mineralogy of REEs in two coal waste samples. The results indicated that the REEs mainly present as apatite, zircon, monazite, xenotime, and crandallite-group minerals in the coal waste samples. However, after REE recovery, the crandallite-group minerals disappeared from the calcined coal waste samples. Therefore, it can be confirmed that the calcination treatment resulted in the solubility improvement of crandallite-group minerals in coal waste samples. In order to further investigate the crandallite-group minerals, florencite was synthesized and subjected to a series of characterizations. The results suggested that the thermal phase transformation of florencite from crystalline into amorphous state resulted in the solubility improvement.
55

Improvement of the Optical and Mechanical Properties of Silica Nanoparticle Ionic Self-Assembled Multilayer Anti-Reflection Coatings on Glass and Polycarbonate Substrates

Ridley, Jason Ian 17 March 2010 (has links)
This thesis presents the characterization of the optical and mechanical properties of silica nanoparticle films fabricated by ionic self-assembly, also known as layer-by-layer (LbL) deposition. Utilizing electrostatic attraction of oppositely-charged materials permits uniform and rapid growth of the constituents onto planar and curved surfaces. In this work, silica nanoparticles are adsorbed onto glass and polycarbonate substrates, as well as micron-scale glass fibers, with the purpose of improving the optical quality of the respective media. Several methods are presented to improve the adhesion and cohesion of silica nanoparticle films on glass substrates. In the first method, the substrate and nanoparticle surfaces are coated with materials containing sulfonate end groups. Next, a photo-reactive polycation known as diazo-resin (DAR) is used in ISAM deposition with the modified silica nanoparticles. Subsequent exposure to UV converts the ionic bonds between the DAR and sulfonate groups into covalent ones. The second method to improve the mechanical strength is to heat the ISAM silica nanoparticle film at a high enough temperature (500 °C) to remove the polymer and partially fuse the nanoparticles. This technique is known as calcination and is shown to significantly improve the mechanical robustness of the film without compromising the optical properties. The final method involves the deposition of precursor and capping polymer layers around bulk silica nanoparticle films with both bilayer and quadlayer designs. The addition of these polymer layers improves the surface contact between adjacent nanoparticles but reduces the film porosity and consequently the optical transparency. Currently the calcination technique is the only one that significantly improves the film adhesion and cohesion, but suggestions are offered to potentially improve the performance of films made by the other two methods. An alternative way to functionalize polycarbonate substrates for silica nanoparticle ISAM deposition is also presented. The molecular structure of polycarbonate at the surface can be modified by exposing it to deep UV (λ = 185, 254 nm). By doing so, the surface becomes populated with carboxylate species, and thus permits ISAM deposition of poly(allylamine hydrochloride) (PAH) and silica nanoparticles. A variety of spectroscopic methods show that the molecular structure is changed by this procedure, and SEM shows that UV treatment improves the uniformity of ISAM films on polycarbonate. Finally, PAH/silica nanoparticle ISAM films are deposited onto glass fibers. The fibers are used for mechanical reinforcement of polymer composite optical media. The role of the nanoparticle film on the fibers is to reduce light scattering at the interfaces of materials with different thermo-optic coefficients, in other words, transmittance losses associated with changes in temperature. Fiber bundles coated with silica nanoparticles suffer from unacceptable levels of aggregation, and hence do not currently improve the transmittance over the temperature spectrum. Some evidence is presented, however, to suggest that the transparency can be improved if fiber aggregation during ISAM deposition can be avoided. / Ph. D.
56

Synthèse et caractérisation de silices mésoporeuses hydrophobes à porosité contrôlée / Synthesis and characterization of hydrophobic mesoporous silicas with controlled porosity

Benamor, Taissire 16 December 2011 (has links)
L’influence de paramètres de synthèse et de traitements post-synthèse sur le caractère hydrophobe/hydrophile de silices mésoporeuses organisées (SMO) de type SBA-15 a été étudiée. Ainsi nous avons montré que la durée du mûrissement peut être réduite à la durée nécessaire à la précipitation. La température, l’agitation et la durée de synthèse modulent la morphologie des particules et des agrégats. Le mode de chauffage, la présence d’un sel inorganique et le rapport silice/tensioactif ont un effet sur la structure et la texture du matériau. Concernant les traitements post-synthèse, nous avons considéré l’élimination de l’agent structurant et la fonctionnalisation par greffage. Le taux de silanols diminue suite au vieillissement mais surtout après calcination : cette étape efface les différences en termes de teneur en silanols. C’est la raison pour laquelle une nouvelle méthode d’élimination du tensioactif efficace (dès 300 °C) et rapide (dès 15 min) a été mise en œuvre : la calcination à l’aide d’un four à induction conduit à un matériau avec des propriétés structurales, texturales et une teneur en silanols supérieures à celles d’une SMO de type SBA-15 calcinée par la méthode conventionnelle. La calcination par induction a également été appliquée avec succès sur différents types de SMO telles que la SBA-16 et la MCM-41. Ensuite, l’influence des caractéristiques initiales de la SMO sur la fonctionnalisation par un greffage post-synthèse a été étudiée. Une SMO de type SBA-15 plus hydrophobe a été obtenue avec un greffon possédant une seule fonction condensable. La teneur initiale et probablement l’accessibilité des silanols ont un impact significatif sur le taux de greffage. / The influence of synthesis parameters and post-synthesis treatments on the hydrophobic/hydrophilic character of SBA-15 type ordered mesoporous silicas (OMS) was studied. It was found that the duration of ripening can be reduced to the precipitation time. Temperature, stirring and duration of synthesis steps can modulate the morphology of particles and aggregates. Heating process, presence of an inorganic salt and silica/surfactant ratio are also parameters that affect the structure and texture of the material. Concerning post-synthesis treatments, the elimination of the template and the functionalization by grafting were considered. The rate of silanols decreases during aging but mostly after calcination: this step erases the differences in silanol content. This is why a new method for an effective (at 300 ° C) and fast (for 15 min) removal of the surfactant has been implemented: the calcination using an induction furnace leads to a material with structural, textural properties and silanol content greater than those of a SBA-15 material calcined by the conventional method. The calcination induction has also been successfully applied on different types of OMS such as SBA-16 and MCM-41. Then, the influence of the OMS characteristics on functionalization by post-synthesis grafting was studied. The more hydrophobic SBA-15 material was obtained with a grafting agent possessing a single condensable function. It was also observed that the initial content and the accessibility of silanols probably have a significant impact on the grafting rate.
57

SÍNTESE DE PÓS DE α-ALUMINA COM ADIÇÃO DE SEEDS ATRAVÉS DO MÉTODO PECHINI

Salem, Raphael Euclides Prestes 03 August 2012 (has links)
Made available in DSpace on 2017-07-21T20:42:37Z (GMT). No. of bitstreams: 1 Raphael Euclides Prestes Salem.pdf: 3931677 bytes, checksum: c378168a7c789517c20cf8c142c060f0 (MD5) Previous issue date: 2012-08-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Alumina is a ceramic material of great technological importance, due to its mechanical, electrical, thermal and optical properties. At industrial scale, alumina is obtained from bauxite, by the Bayer process. By this process, α phase, the most stable one, is obtained at temperatures above 1200°C, through a reconstructive transformation of its precedent transition phase, followed by nucleation and growth of particles. With the advance of technology, chemical methods for synthesis of powdered materials have been much studied, due to the need to obtain materials with improved properties. Pechini method was a method developed in the decade of 1960 in order to obtain ceramic oxides through simple procedures and using relatively low temperatures, allowing the production of materials with smaller particle size, controllable properties and high purity. This work aims to synthesize α-alumina powders by Pechini method with addition of α-alumina seeds, thus promoting the formation of α-phase in lower temperature than in the traditional methods. Also, the objective is to study the influence of an oxygen flow in the calcination process and in the elimination of organic matter from the precursor resin. After the synthesis and the formation of precursor resins, the obtained samples with and without the addition of seeds were calcined at temperatures between 500°C a nd 1100°C. The precursor resins were characterized by infrared spectroscopy and differential thermal analysis associated with thermogravimetry, and the calcined powders were characterized by differential thermal analysis associated with thermogravimetry, X-ray diffraction, infrared spectroscopy and scanning electron microscopy. The seeding process promoted a significant reduction in the temperature of formation of α-phase, consequently allowing to form particles with smaller crystallite size, although as strong agglomerates irregularly shaped. The incidence of an oxygen flow on the calcination process contributed in a less significant way to eliminate the residual organic matter, present in the calcined samples even at high temperatures. It is observed that seeding the reaction medium is a simple method to favor the phase transformation of alumina through a mechanism of diffusional nucleation, promoting the formation of α-phase at lower temperatures. / A alumina é um material cerâmico de grande importância tecnológica, devido às suas propriedades mecânicas, elétricas, térmicas e ópticas. Em escala industrial, a alumina é obtida a partir da bauxita, através do processo Bayer. A fase α, a mais estável da alumina, é obtida a temperaturas acima de 1200°C pelos processo tradicionais, através de uma transformação reconstrutiva de sua fase de transição precedente, seguida de nucleação e crescimento das partículas. Com o avanço da tecnologia, métodos químicos de síntese de materiais particulados têm sido muito estudados, devido à necessidade de se obterem materiais com propriedades melhoradas. O método Pechini foi um método desenvolvido na década de 1960 para a obtenção de óxidos cerâmicos através de procedimentos simples e com temperaturas relativamente baixas, permitindo a produção de materiais com tamanho de partícula cada vez menor, propriedades controláveis e elevada pureza. Este trabalho tem como objetivo sintetizar pós de α-alumina através do método Pechini com a adição de seeds (ou germens de cristalização) de α-alumina, assim promovendo a formação da fase α em temperatura mais baixa do que os métodos tradicionais. Também se tem como objetivo estudar a influência de um fluxo de oxigênio no processo de calcinação e na eliminação de matéria orgânica da resina precursora. Após o processo de síntese e a formação da resina precursora, as amostras obtidas sem e com adição de seeds foram calcinadas a 500°C, 600°C, 900°C, 1000°C e 1100°C. As resinas precursoras fora m caracterizadas por espectroscopia no infravermelho e análise térmica diferencial associada a termogravimetria, e os pós calcinados foram caracterizados por análise térmica diferencial associada a termogravimetria, difração de raios X, espectroscopia no infravermelho e microscopia eletrônica de varredura. A adição dos seeds na síntese promoveu uma redução significativa na temperatura de formação da fase , consequentemente permitindo a formação de partículas com menor tamanho de cristalito, porém em forma de aglomerados fortes com formato irregular. Além disso, a incidência de um fluxo de oxigênio no processo de calcinação contribuiu de forma pouco significativa para a eliminação de matéria orgânica residual, presente nas amostras calcinadas ao ar em maior quantidade mesmo após tratamento a altas temperaturas. Observa-se que a adição de seeds no meio reacional é um método simples de favorecer a transformação da célula unitária da alumina através de um mecanismo de nucleação difusional, promovendo a formação da fase a temperaturas mais baixas.
58

Optimisation du procédé de fabrication des varistances à base d'oxyde de zinc. Étude du chamottage des oxydes

Perrot, Christophe 15 April 1994 (has links) (PDF)
Le procédé de fabrication de varistances pour parafoudres élabores par ABB engendre pour 5% des pièces, des mauvaises propriétés électriques. Apres observation du procédé, il s'est avéré que le chamottage, opération de calcination du mélange des additifs de l'oxyde de zinc, en était responsable. En effet les produits de cette calcination étaient fortement hétérogènes, puisque formes de plusieurs couches, lesquelles engendraient des propriétés électriques très différentes. Nous avons donc cherche à homogénéiser la chamotte et ce, par rapport au produit donnant les meilleures propriétés. Pour cela nous avons tout d'abord mis en évidence les principales propriétés des composants du mélange, sublimation et oxydation de l'oxyde d'antimoine. Puis nous avons observé tous les changements de phases intervenant lors de la calcination de ce mélange. La stratification de la chamotte étant engendrée par la diffusion réaction de l'oxygène dans le milieu granulaire nous avons modélisé ce phénomène. Ceci nous a permis de dégager tous les paramètres de l'opération ainsi que leur influence sur la qualité des produits. Nous avons donc pu envisager un nouveau protocole opératoire pour œuvrer en ce sens, et qui passe par exemple par un changement de cycle thermique.
59

Mécanismes de rupture des côtes et critères de tolérance thoracique en choc automobile

Diet, Stéphane 19 January 2005 (has links) (PDF)
La mise en évidence d'une divergence entre l'accidentologie et les crashs tests demande de revisiter les critères de tolérance thoracique. En parallèle, l'émergence des mannequins numériques de crash permet d'appréhender des lésions particulières ; ce que ne permet pas le mannequin physique Hybrid III. Parmi ces lésions, il y a la fracture de côte. Dans ce contexte, ce travail s'est centré sur la réalisation et la validation d'un modèle numérique lésionnel personnalisé des côtes en choc automobile. Se référant à la bibliographie, il a été choisi de faire des essais de flexion trois points, en incluant des mesures de déformations par jauges et un suivi cinématique par vidéo. Les conditions d'essais ont été définies à partir de plusieurs modèles : système masse-ressort ; RDM ; calculs en éléments finis ; et des mesures réalisées sur SHPM. En amont des essais, chaque côte a été scannée pour étudier la géométrie et pouvoir générer son maillage personnalisé en éléments finis. Les essais statiques, utilisant les côtes 6, 8 et 10, montrent un effort maxi croissant des côtes 6 vers 10 et un déplacement à l'effort maxi nettement supérieur pour la côte 10. Les essais dynamiques, avec une vitesse par niveau de côte et un impacteur différent par côté (impacteurs cylindrique et type ceinture) donnent une influence très nette de la vitesse ainsi que de la géométrie de l'impacteur. Il existe une vitesse optimum concernant cet essai, en terme d'effort maxi, comprise entre 0,10 et 0,25 m.s-1. Alors que la ruine de la côte a lieu pour un même déplacement, l'impacteur ceinture permet de supporter un effort maximum supérieur de 30% ; ce qui est cohérent avec les observations en accidentologie. L'étude géométrique montre que les caractéristiques de la côte évoluent avec le niveau, mais pas la concentration linéique de minéraux. Enfin, les premiers modèles numériques lésionnels personnalisés, visant dans un premier temps à reproduire les essais, valident la faisabilité de la démarche et ouvrent des perspectives de développement.
60

Estudo térmico e adsortivo de argisolo caulinítico da região amazônica / Estudo térmico e adsortivo de argisolo caulinítico da região amazônica

Silva, Matheus Antônio da [UNESP] 08 July 2016 (has links)
Submitted by MATHEUS ANTONIO DA SILVA null (0118999881999119725i@gmail.com) on 2016-08-12T01:55:42Z No. of bitstreams: 1 Corrigida dissertação2.pdf: 2484322 bytes, checksum: 10738553dadaaf9fdbd738efd3bb2d48 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-12T13:34:14Z (GMT) No. of bitstreams: 1 silva_ma_me_sjrp.pdf: 2484322 bytes, checksum: 10738553dadaaf9fdbd738efd3bb2d48 (MD5) / Made available in DSpace on 2016-08-12T13:34:14Z (GMT). No. of bitstreams: 1 silva_ma_me_sjrp.pdf: 2484322 bytes, checksum: 10738553dadaaf9fdbd738efd3bb2d48 (MD5) Previous issue date: 2016-07-08 / Tratou-se e modificou-se o argisolo caulinítico da região amazônica, a fim de se obter novos materiais para remoção de contaminantes da fase aquosa. As modificações fora realizadas por dois métodos: tratamento térmico em presença de fibra de cana de açúcar e modificação com surfactantes em solução; com posterior utilização dos materiais modificados na adsorção do corante Azul de Metileno (AM), usado como sonda espectrofotométrica. Tratou-se o argisolo com ataque ácido e troca de cátions e posterior calcinação a 400 0C com e sem fibra, e a 800 0C sem fibra. Os sólidos foram caracterizados por difratometria de raios X, espectrofotometria na região do infravermelho e análise térmica. Procedeu-se também a adsorção do AM em argisolo em presença de surfactante catiônico, Brometo de Cetiltrimetilamônio, e aniônico, Dodecil Sulfato de sódio. O argisolo sem calcinação apresentou apenas argila caulinita e quartzo como constituintes com cristalinidade. As amostras calcinadas a 400 0C com fibra e a 800 0C sofreram o processo de desidroxilação, ocasionando a mudança de fase da caulinita presente no argisolo; com a amostra calcinada a 400 0C sem fibra mantendo a estrutura característica da caulinita e do quartzo. Por meio da análise térmica, foi possível notar que a energia liberada pela fibra é suficiente para promover a mudança de fase da caulinita em temperaturas mais baixas em relação à mesma sem fibra, promovendo o processo de desidroxilação do material em condições ambientais mais brandas. Os estudos de variação no tempo de calcinação e de razão fibra:solo indicaram que ambos influenciam na desidroxilação do material e razões fibra:solo maiores que 1:2 e o tempo de três horas são as condições mais indicadas para a formação da metacaulinita. As isotermas de adsorção de AM evidenciam uma mudança na forma da isoterma de adsorção, onde o argisolo calcinado a 400 0C sem fibra e sem calcinação possuem isotermas do tipo L e maior correlação ao modelo de Freundlich, característicos de adsorção favorável e em multicamadas; enquanto os materiais calcinados a 800 0C e a 400 0C com fibra exibem isotermas do tipo C e correlação com o modelo de Langmuir, comuns a materiais de superfície microporosa e em monocamada. Os estudos de adsorção na presença de surfactantes evidenciaram que a interação do surfactante catiônico com o argisolo e do corante aniônico com o AM desfavoreceram a adsorção e resultaram em menor remoção do corante da fase aquosa. / Kaolinitic clay soil of Amazon region was treated and modified,in order to obtain new materials for removal of contaminants from aqueous phase. The modification was performed by two methods: thermal treatment in presence of sugar cane fiber and modification with surfactants; using the new materials in adsorption of Methylene Blue (AM), used as spectrophotometric probe. The clay soil was treated with acid attack, cation change and after calcination at 400 0C with and without sugar cane fiber, and at 800 0C. All material was characterized by X-ray Diffraction, Infrared spectrophotometry and thermal analysis. Adsorption of AM was proceed in presence of cationic (Cetyltrimethylammonium Bromide) and anionic (Sodium Dodecyl Sufate) surfactants. Samples of clay soil without calcination presents only kaolinite and quartz as compounds with cristallinity. Clay soil calcined at 400 0C with fiber and 800 0C were dehydroxyled, causing a phase change form kaolinite to metakaolin; when the kaolinite structure was maintained in clay soil calcined at 400 0C without fiber. In thermal analysis, the energy released by the fiber is sufficient to cause the phase change of kaolinite at lower temperatures relative to the same without fiber, promoting the process of dehydroxylation of the material in softer environmental conditions. The variation in time of calcination studies and ratio fiber:clay evidence that both influence the dehydroxylation and rates fiber:clay larger than 1:2 and the time of three hours are the best conditions for formation of metakaolin. Adsorption isotherms of AM exhibit changes in isotherms format, clay soil calcined at 400 0C without fiber and clay soil without calcination shows L-type isotherms and best correlation with Freundlich model, typical for favourable multiple layered adsorption; when the materials calcined at 400 0C with fiber and 800 0C shows C-type and correlation with Langmuir isotherms, typical monolayered adsorption in materials with microporous surface. The study of adsorption in presence of surfactants indicated that interactions among cationic surfactant with claysoil and anionic surfactant with AM prejudicing the adsorption of AM and results in less dye remotion of aqueous phase.

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