Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-06-15T17:35:43Z No. of bitstreams: 1 IGOR PINHEIRO DE BRITO – DISSERTAÇÃO (PPG-CEMat) 2015.pdf: 1768632 bytes, checksum: 11cd82aad3da13be877e15e53ad3eae1 (MD5) / Made available in DSpace on 2018-06-15T17:35:43Z (GMT). No. of bitstreams: 1 IGOR PINHEIRO DE BRITO – DISSERTAÇÃO (PPG-CEMat) 2015.pdf: 1768632 bytes, checksum: 11cd82aad3da13be877e15e53ad3eae1 (MD5) Previous issue date: 2015-08-31 / Capes / Nos últimos anos, novos depósitos de argilas foram descobertos no Estado da Paraíba, a caracterização destes depósitos é de fundamental importância para estabelecer o melhor uso industrial dos mesmos. Neste contexto, o presente trabalho teve como objetivo caracterizar argilas provenientes de jazidas do município de Cubati-PB, visando estabelecer seus usos adequados como matérias-primas cerâmicas. Para tanto, as matérias-primas foram submetidas às seguintes técnicas de caracterizações: física, química, mineralógica e térmica. Posteriormente, foram preparados corpos de prova por prensagem uniaxial a 19 MPa, estes foram secos em estufa a 110°C, e submetidos a queima nas temperaturas de 750°C, 850°C, 950°C e 1150°C. Em seguida determinadas as propriedades físico-mecânicas: retração linear de queima (RLq), absorção de água (AA), densidade aparente (DAp), porosidade aparente (PA) e módulo de ruptura à flexão (MRF). As argilas A, B e C são adequadas para uso em cerâmica branca e a argila D para cerâmica vermelha. E todas as argilas contém composição mineralógica adequada para uso em cerâmica vermelha. / In recent years, new clays deposits have been discovered in the state of Paraiba, the characterization of these deposits is of fundamental importance to establish the best industrial usage. In this context, the aim of this study was characterized clays in the municipality of Cubati-PB, to establish their appropriate uses as ceramic raw materials. Therefore, the raw materials were subjected to the following characterization techniques: physical, chemical, mineralogical and thermal. Later, specimens were prepared by uniaxial pressing at 19 MPa, before dry at 110°C, and submitted to firing at temperatures of 750°C, 850°C, 950°C and 1150°C. It were determined the physical and mechanical properties: linear firing shrinkage (LFS), water absorption (WA), apparent density (DAp), apparent porosity (PA) and flexural modulus of rupture (MRF). The clays A, B and C are suitable for use in white ceramic and D to red ceramic. And all the clays contain adequate mineralogical composition for use in red ceramic.

O presente trabalho teve como objetivo geral determinar a distribuição espacial de depósitos de argilas cauliníticas brancas na região de São Gabriel da Cachoeira, estado do Amazonas, por meio de estudos de campo e análise de imagens orbitais. Foram desenvolvidos estudos em duas escalas distintas. Um de detalhe, com coleta de amostras em uma área de 0,3km2 e com pontos de amostragem eqüidistantes de 50m, e outo regional em área de 65km2 com características geoambietais semelhantes àquelas observadas na zona de estudo detalhado. Buscou-se selecionar variáveis pedológicas (textura e cor do solo, concentração de óxidos e oxidróxidos de ferro), topográficas e fitofisionômicas relacionadas às possíveis ocorrências de depósitos de argilas cauliníticas brancas. Para a área de detalhe determinou-se a textura, a cor e a concentração de óxidos e oxidróxidos de ferro para os primeiros 100cm do solo. Os resultados obtidos foram mapeados e posteriormente associados aos dados de relevo, tipo de solo e vegetação local. A partir do estudo em escala local verificou-se que a textura do solo e a concentração de óxidos e oxidróxidos de ferro variam nos primeiros 100 cm de solo, na transição dos Latossolos para os Espodossolos. Foi possível verificar, a partir da espacialização em superfície contínua dos atributos dos solos analisados e das correlações com a vegetação e com a topografia local, que os depósitos de argilas cauliníticas brancas estão limitados aos locais com condições pedológicas específicas, o que permite a identificação indireta através do estudo dos padrões espectrais da vegetação e da morfologia do terreno. Com base em técnicas de sensoriamento remoto e geoprocessamento, efetuo-se o mapeamento regional da vegetação e da geomorfologia e realizou-se a associação destes atributos com os dados estudados em escala local para a determinação de depósitos de argilas cauliníticas brancas em escala regional. Nesta escala, os resultados mostraram que a ocorrência de tais depósitos limita-se a condições geoambientais, intimamente associadas com o regime hídrico e com a topografia da região, que permitem sua formação e provável desaparecimento com a evolução dos processos de hidromorfia, devido à erosão geoquímica e conseqüente aplainamento das colinas residuais. Concluindo, os depósitos de argilas cauliníticas brancas ocorrem em condições geoambientais específicas associadas aos topos de colinas residuais, na transição entre o sistema pedológico Latossolo/Espodossolo associados à fitofisionomias transicionais entre as formações da Floresta Ombrófila Densa e da Campinarana / This study had the mainly objective to determine the spatial distribution of white kaolinitic clay deposits in São Gabriel da Cachoeira region, Amazonas State, in field studies and by satellite images analysis. The study was carried out in two different spatial scales. At field study (detailed area) was sampled 50 points to describe an area of 0.3 km², with equidistant sampling points of 50 m. The extrapolation was made through a regional scale study in an area of 65km², adopting vegetation and soil features similar to those observed in field study scale. The select pedologic variables (soil texture and color, concentration of iron oxides and oxidroxides), topographic and vegetation features related to the possible white kaolinitic clay deposits occurrence were selected for analyses. Through the field study area, it was determined the texture, color and iron oxides and oxidroxides concentration for the first 100 cm of soil depth. The results were spacialized and thereafter correlated to topographic aspect, soil unit and local vegetation. In the field scale study it was showed that soil texture and oxides and oxidroxides concentrations have an expressive variability in the first 100 cm of soil depth, considering the transition between Oxisols and Spodosols. It was observed, through the soil attributes maps and correlation with vegetation and the local topography features, that the white kaolinitic clay deposits are limited to sites with specific soil conditions, which allows indirect identification by studying the spectral patterns of vegetation and terrain morphology. Based on remote sensing and GIS techniques, it was made the regional vegetation and geomorphology maps, and the association of these attributes with the maps made at field scale study showed the determination of white kaolinitic clay deposits on a regional scale. On this scale, the results showed that the occurrence of such deposits is limited to geo-environmental conditions, closely associated with the water system and the topography of the region, allowing their formation and disappearance due to hydromorphic processes and geochemistry erosion, what causes the flattening of residual hills. The white kaolinitic clay deposits occur in specific geo-environmental conditions associated with residual hill tops between the boundary transition of the Oxisol/Spodosol pedologic system associated with transitional vegetation units between the Dense Rain Forest and Campinarana

O presente trabalho teve como objetivo geral determinar a distribuição espacial de depósitos de argilas cauliníticas brancas na região de São Gabriel da Cachoeira, estado do Amazonas, por meio de estudos de campo e análise de imagens orbitais. Foram desenvolvidos estudos em duas escalas distintas. Um de detalhe, com coleta de amostras em uma área de 0,3km2 e com pontos de amostragem eqüidistantes de 50m, e outo regional em área de 65km2 com características geoambietais semelhantes àquelas observadas na zona de estudo detalhado. Buscou-se selecionar variáveis pedológicas (textura e cor do solo, concentração de óxidos e oxidróxidos de ferro), topográficas e fitofisionômicas relacionadas às possíveis ocorrências de depósitos de argilas cauliníticas brancas. Para a área de detalhe determinou-se a textura, a cor e a concentração de óxidos e oxidróxidos de ferro para os primeiros 100cm do solo. Os resultados obtidos foram mapeados e posteriormente associados aos dados de relevo, tipo de solo e vegetação local. A partir do estudo em escala local verificou-se que a textura do solo e a concentração de óxidos e oxidróxidos de ferro variam nos primeiros 100 cm de solo, na transição dos Latossolos para os Espodossolos. Foi possível verificar, a partir da espacialização em superfície contínua dos atributos dos solos analisados e das correlações com a vegetação e com a topografia local, que os depósitos de argilas cauliníticas brancas estão limitados aos locais com condições pedológicas específicas, o que permite a identificação indireta através do estudo dos padrões espectrais da vegetação e da morfologia do terreno. Com base em técnicas de sensoriamento remoto e geoprocessamento, efetuo-se o mapeamento regional da vegetação e da geomorfologia e realizou-se a associação destes atributos com os dados estudados em escala local para a determinação de depósitos de argilas cauliníticas brancas em escala regional. Nesta escala, os resultados mostraram que a ocorrência de tais depósitos limita-se a condições geoambientais, intimamente associadas com o regime hídrico e com a topografia da região, que permitem sua formação e provável desaparecimento com a evolução dos processos de hidromorfia, devido à erosão geoquímica e conseqüente aplainamento das colinas residuais. Concluindo, os depósitos de argilas cauliníticas brancas ocorrem em condições geoambientais específicas associadas aos topos de colinas residuais, na transição entre o sistema pedológico Latossolo/Espodossolo associados à fitofisionomias transicionais entre as formações da Floresta Ombrófila Densa e da Campinarana / This study had the mainly objective to determine the spatial distribution of white kaolinitic clay deposits in São Gabriel da Cachoeira region, Amazonas State, in field studies and by satellite images analysis. The study was carried out in two different spatial scales. At field study (detailed area) was sampled 50 points to describe an area of 0.3 km², with equidistant sampling points of 50 m. The extrapolation was made through a regional scale study in an area of 65km², adopting vegetation and soil features similar to those observed in field study scale. The select pedologic variables (soil texture and color, concentration of iron oxides and oxidroxides), topographic and vegetation features related to the possible white kaolinitic clay deposits occurrence were selected for analyses. Through the field study area, it was determined the texture, color and iron oxides and oxidroxides concentration for the first 100 cm of soil depth. The results were spacialized and thereafter correlated to topographic aspect, soil unit and local vegetation. In the field scale study it was showed that soil texture and oxides and oxidroxides concentrations have an expressive variability in the first 100 cm of soil depth, considering the transition between Oxisols and Spodosols. It was observed, through the soil attributes maps and correlation with vegetation and the local topography features, that the white kaolinitic clay deposits are limited to sites with specific soil conditions, which allows indirect identification by studying the spectral patterns of vegetation and terrain morphology. Based on remote sensing and GIS techniques, it was made the regional vegetation and geomorphology maps, and the association of these attributes with the maps made at field scale study showed the determination of white kaolinitic clay deposits on a regional scale. On this scale, the results showed that the occurrence of such deposits is limited to geo-environmental conditions, closely associated with the water system and the topography of the region, allowing their formation and disappearance due to hydromorphic processes and geochemistry erosion, what causes the flattening of residual hills. The white kaolinitic clay deposits occur in specific geo-environmental conditions associated with residual hill tops between the boundary transition of the Oxisol/Spodosol pedologic system associated with transitional vegetation units between the Dense Rain Forest and Campinarana

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-04T19:50:45Z No. of bitstreams: 1 IVNA DANIELE SOUZA PEREIRA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2113912 bytes, checksum: e7cd84f19623986d5ca5b0df7875190e (MD5) / Made available in DSpace on 2018-04-04T19:50:45Z (GMT). No. of bitstreams: 1 IVNA DANIELE SOUZA PEREIRA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2113912 bytes, checksum: e7cd84f19623986d5ca5b0df7875190e (MD5) Previous issue date: 2014-08-29 / Capes / No Estado da Paraíba há grandes ocorrências de minerais não metálicos principalmente de argilas bentoniticas, ball clays, caulins, feldspatos, quartzo, calcários e micas. Recentemente foram descobertos novos depósitos de argilas no município de Sossego, propiciando assim, uma expectativa de ampliação de insumos minerais na região. Assim, este trabalho tem por objetivo caracterizar física, mineralógica e tecnologicamente argilas esmectíticas do Município de Sossego, PB, Brasil, para uso em fluidos de perfuração. Para tanto, as argilas foram beneficiadas e caracterizadas através das seguintes técnicas: granulometria a laser (AG), difração de raios-X (DRX), análise química (EDX), capacidade de troca de cátions (CTC), análise termogravimétrica(TG) e térmica diferencial (DTA). Em seguida as argilas foram transformadas em sódicas por meio de tratamento com carbonato de sódio (Na2CO3), hexametafosfato de sódio (NaPO3)6 nos teores: 75, 100, 125 e 150meq/100g de argila seca, além de serem ativadas com a combinações de (Na2CO3) e óxido de magnésio (MgO), em seguida realizou-se o estudo do comportamento reológico das dispersões no intuito de determinar viscosidade aparente (VA), viscosidade plástica (VP), volume de filtrado e pH. Os resultados mostraram que as argilas estudadas eram constituídas de esmectítica, caulinita e quartzo, apresentando teores de MgO e CaO, evidenciando que são bentonitas policatiônicas. Com relação ao uso das argilas como agente viscosificante para fluidos de perfuração, observou-se que as amostras de AM2 ativadas com Na2CO3 atenderam parcialmente as especificações necessária para uso em fluidos de perfuração base água. Já as amostra ativadas com (NaPO3)6 não desenvolveram melhoria nas suas característica reológicas, logo seu uso como fluido de perfuração não é viável. A combinação de Na2CO3 e de MgO produziu um melhoramento nas propriedades dos fluidos produzidos, demonstrando ser aplicável na perfuração de poços. / In Paraíba's large occurrences of non-metallic minerals mainly of bentonite clays, ball clays, kaolin, feldspar, quartz, limestone and mica. Recently discovered new deposits of clays in the city of Sossego, providing an expected expansion of mineral inputs in the region. This work aims to characterize physical, mineralogical and technologically smectite clays Municipality Sossego, PB, Brazil, for use in drilling fluids. For both, the clays were processed and characterized by the following techniques: laser granulometry (AG), X-ray diffraction (XRD), chemical analysis (EDX), cation exchange capacity (CEC), thermogravimetric analysis (TG) and differential thermal analysis (DTA). The clays were then transformed into sodic by treatment with sodium carbonate (Na2CO3), sodium hexametaphosphate (NaPO3) 6 in levels: 75, 100, 125 and 150meq / 100g of dry clay, and being activated with combinations (Na2CO3) and magnesium oxide (MgO), then held up the study of the rheological behavior of the dispersions in order to determine apparent viscosity (VA), plastic viscosity (PV), filtrate volume and pH. The results showed that the clays of smectite were formed, kaolinite and quartz, with MgO and CaO contents, showing that bentonites are polycationic. Regarding the use of clays as viscosity agent for drilling fluids, it was observed that the samples activated with Na2CO3 AM2 partially met the necessary for use in water based drilling fluids specifications. As for the sample activated to (NaPO3)6 did not develop improvement in rheological characteristic, then its use as drilling fluid is not feasible. The combination of Na2CO3 and MgO produced an improvement in the properties of the produced fluids, proving to be applicable in drilling wells Keywords: bentonite, rheology, characterization, drilling fluids.

Marine clay deposits are characterized by very soft to soft consistencies (undrained strength 1-50 kPa), presence of saline pore solution and low-swelling clays. Besides, loss of metastable structure on disturbance, poor undrained strengths of soft clays is contributed by high water contents. Presence of saline pore solution and low-swelling clays (illite, chlorite, kaolinite) play an important role in developing metastable structure of soil sediments deposited in marine environment. The pore solution salinity regulates the “physico-chemical (A - R) stress” that in turn has significant bearing on development of the metastable structure. Metastable structure refers to edge-face, edge-edge associations in card-house arrangement of platy/elongate particles that develop during deposition. Loss of metastable structure of soft marine clays upon disturbance leads to excessive settlements and slope failures. Besides A - R forces, metastable structure of marine clays is contributed by cementation bonds, thixotropic hardening, ion leaching, formation or addition of dispersing agents and chemical weathering. Secondary compression also causes bonding of micro-structural units that increase stiffness and strength of the metastable structure. Review of literature brings out that majority of studies examining the role of physico-chemical factors on the engineering behavior of marine clays have focused on illite rich sediments. However, non-swelling clay, namely, kaolinite is also encountered in marine deposits (example, Pusan clay, Singapore clay, Sarapui soft clays). Kaolinites differ from illites in being 1:1 mineral (unit layer comprises of 1 silica sheet bonded to 1 gibbsite sheet) and having strong hydrogen bonding between unit layers. Consequently, kaolinite particles are thick (0.3 to 3 ìm thickness) with low surface area (10 to 20 m2/g). Also the hydrogen bonding between unit layers do not allow them to separate on hydration. Combination of very low isomorphous substitution (Al for Si 1 in 400), low cation exchange capacity (3 meq/100g), and low surface area, lead to negligible development of diffuse double layer repulsion forces between kaolinite particles. Strong positive edge (developed on broken bonds at particle edges from adsorption of hydrogen ions) negative face attraction between kaolinite particles, encourages flocculation of particles at range of water contents. It was therefore considered of interest to examine the engineering response of kaolinites to changes in pore solution salinity from leaching effects. The focus of the thesis is hence to gain better understanding of physico-chemical (pore solution salinity, A - R forces) and mechanical (secondary compression, loss of overburden) factors towards development of metastable structure of kaolinite clays deposited in synthetic seawater environments in the context of their compressibility and undrained strength characteristics. Laboratory experiments are performed with kaolinites that are slurry consolidated in conventional consolidometers in saline and synthetic seawater solutions. The metastable structure developed by consolidated specimens is relevant to alluvial marine sediments that contain kaolinite (example, Pusan clay, Singapore clay, Sarapui soft clays). The structure of the thesis is as follows: Chapter 1 gives an introduction to the thesis. Chapter 2 provides a detailed review of literature on the role of chemical factors (pore solution composition, A - R forces, osmotic suction) and mechanical processes (secondary compression and overconsolidation) in developing metastable structure of kaolinite specimens subjected to slurry consolidation and the consequent influence of metastable structure on compression, undrained strength and sensitivity characteristics of clay specimens. The Chapter also defines the scope and objectives of the study. Chapter 3 details the experimental program undertaken to bring out the role of chemical factors and mechanical processes in influencing the 1-dimensional compression and undrained strength characteristics of slurry consolidated kaolinites prepared in saline medium. Chapter 4 delineates the role of chloride salt solutions (sodium, magnesium and calcium) and synthetic seawater solution in contributing to the metastable structure developed by slurry consolidated kaolinites at various vertical effective stress (óv’) and the consequent influence of metastable structure on 1-dimensional compression, undrained strength and sensitivity characteristics of the clay. Chapter 5 examines influence of secondary compression on metastable structure developed by kaolinites that were slurry consolidated in 24.53 g/L sodium chloride and synthetic seawater solutions and the consequence of the developed metastable structure on undrained strength and sensitivity. The chapter also examines the consequences of secondary compression experienced by soft overconsolidated kaolinites on their undrained strength and sensitivity characteristics. Chapter 6 examines the relative influence of differential osmotic stress and electrochemical stress on the consolidation behaviour of kaolinite specimens that are slurry consolidated in sodium chloride solutions. The osmotic efficiencies (á) of kaolinite were obtained using the Fritz-Marine Membrane Model. Chapter 7 summarizes the major conclusions of the thesis.