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Cortes de cabelo e brincadeiras temidas por serem potencialmente perigosas têm sido substituídos por ações solidárias e de integração durante a chegada dos novos alunos (calouros) ao ambiente universitário, desde a primeira turma ingressante em cursos de bacharelado tecnológicos da Universidade Federal de Alfenas/MG – Campus Poços de Caldas, no ano de 2009. Essa postura institucional objetiva coibir a cultura violenta e constrangedora da recepção dos calouros de engenharia pelos veteranos. Nesse sentido, o Projeto de Extensão Calouro Cidadão visa incentivar os discentes a participarem de ações de caráter social e educativo que, de forma prazerosa e construtiva, proporcionam momentos de integração e boas-vindas entre os discentes, além de humanizar o trote na universidade, por meio de atividades de cunho social, filantrópico e educativo, visando uma mudança positiva de atitudes entre calouros e veteranos. O projeto tem suas ações concentradas na primeira semana de aula de cada período do ano. Alguns exemplos de ações são palestras informativas sobre o funcionamento da Universidade, mutirão de arrecadação de alimentos e roupas, ida ao Lar São Vicente de Paulo, ida à APAE, ida ao hemocentro, dentre outras. Este projeto está pautado na indissociabilidade do ensino, pesquisa e extensão e, tendo em vista a aceitação e o interesse dos alunos em dar continuidade ao trabalho e de nunca terem ocorrido denúncias de trote violento dentro ou mesmo fora do campus, é possível perceber que o contexto de trote não violento está se enraizando na cultura do campus.

The present work aimed to characterize the firing behavior of glazes formulated using samples of rocks from the region of Poços de Caldas as a substitute for feldspar. Four formulations were performed, using samples before and after a magnetic separation process. The raw materials were analyzed for their chemical-mineralogical characteristics and the formulations were characterized using Binil Surface Application and fusibility button test, in colorimetric and brightness analyzes. The formulations were also characterized for their coloration compared to the standard glaze, holding nepheline. It was verified that the potassium rock sample presented dark colors (post-magnetic separation), making it impossible to use. The foyaite samples showed promising results, before and after the magnetic separation. According to the results of the colorimetric analysis as the fusibility tests were performed, the non-magnetic samples were clearer due to a comparison of the standard sample of nepheline in both fluorescent light and sunlight, indicating that these samples have potential for use in the formulation of glazes and are interesting alternatives to nepheline and feldspars.

Made available in DSpace on 2019-10-06T16:31:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01. Added 1 bitstream(s) on 2019-10-09T18:35:27Z : No. of bitstreams: 1 S0366-69132019000500054.pdf: 678468 bytes, checksum: 69e9d0956f50530b55dc822509d61aed (MD5) Concrete used in civil engineering is a composite obtained from the combination of coarse and fine aggregates, cement and water, and its cost and quality are normally associated to the proportion of its constituents (ceramic formulation), as well as the reduction of water consumption. The aggregates used in concrete may have diverse origins, and the syenite extracted at Pedra Branca Alkaline Massif is one of the materials that can be used for this substitution. In order to do so, a reference formulation of concrete was calculated and optimized using the mathematical models of Andreasen, and syenite was added substituting 25, 50, 75 and 100% of the fine aggregate. In order to maintain the original granulometric distribution, an algorithm was developed to compensate the different particle size distributions. The grain size correction guaranteed the maintenance of the original properties of the concrete, reaching values of mechanical strength above 35 MPa. University of São Paulo FZEA, Av. Duque de Caxias Norte 225 Institute for Theoretical Physics UNESP Federal Institute of Sul de Minas Federal University of Alfenas Institute for Theoretical Physics UNESP

O presente trabalho teve por objetivo principal caracterizar as litofacies e as composicoes minerais presentes nas rochas sedimentares da Formacao Estrada Nova, na regiao Centro-Sul do estado de Sao Paulo. Os resultados mostraram que a descricao de facies aliada a caracterizacao mineralogica mostrou-se uma ferramenta importante na avaliacao preliminar destas rochas para uso como materia-prima cerâmica. Foram identificadas cinco litofacies: no Membro Serra Alta (Folhelho siltico laminado, Siltito laminado e Siltito macico) e no Teresina (Siltito intercalado e Ritmito arenoso). As litofacies do Membro Serra Alta de acordo com as suas caracteristicas indicam deposicao em ambiente plataformal profundo “offshore” em processo de decantacao de baixa energia, as vezes ocorrendo processos de tracao a qual propiciou a formacao de camadas com laminacoes plano paralela composta de areia de granulometria fina. No Membro Teresina, observou-se que as litofacies apresentaram cor vermelha, granulometria grossa e um aumento das camadas de arenito com cimentacao carbonatica em direcao ao topo formando estruturas ritmicas. A presenca de camadas de arenito nas porcoes intermediarias e topo do Membro Teresina representam variacoes da mare, com retrabalhamento por ondas em ambiente “lower shoreface” e a cor vermelha indica a transformacao de um ambiente redutor para oxidante. As analises dos difratogramas de raios X nas litofacies da Formacao Estrada Nova mostraram baixa frequencia do mineral feldspato do tipo albita e do argilomineral ilita e elevada presenca de calcita, especialmente no Membro Teresina. A baixa frequencia dos minerais ilita, albita e elevada do mineral calcita, em especial nas litofacies do Membro Teresina limitam a sua utilizacao como materia-prima unica na producao de revestimentos cerâmicos. No Membro Serra Alta, a granulometria mais fina e a presenca mais frequente da ilita indica seu aproveitamento cerâmico na composicao de massas para a industria cerâmica de revestimento e estrutural. Estudos de caracterizacao tecnologicas posteriores definirao os usos mais adequados destas rochas como materias-primas cerâmica.

Resumo O porcelanato é um tipo de placa cerâmica de revestimento que vem se destacando atualmente por apresentar boas propriedades estéticas, como a superfície decorada, e mecânicas, como a baixa absorção de água e elevada resistência mecânica e ao ataque químico. As matérias-primas utilizadas para a produção de porcelanato são principalmente a argila e o feldspato. O feldspato é uma das matérias-primas responsáveis pela sinterização durante a queima e auxilia no desenvolvimento de baixa porosidade e elevada resistência ao desgaste da peça cerâmica. Porém, o Brasil apresenta reservas de feldspato em regiões distantes dos centros produtores, fato que encarece a produção deste produto. Dessa forma surge como alternativa a utilização de nefelina para substituir o feldspato, total ou parcialmente, pois este mineral apresenta características bastante similares. Para verificar a influência de tal substituição nas propriedades do porcelanato, inicialmente foi necessário realizar o estudo das propriedades reológicas e físicas da suspensão utilizada na produção. Os resultados encontrados mostraram que a viscosidade da suspensão tende a aumentar com a adição de nefelina, assim como a densidade aparente da peça após a queima. Abstract The porcelain is a type of ceramic tile which has been contrasted for its good aesthetical, such as decorated surface, and mechanical properties, such as low water absorption and high mechanical and chemical attack resistance. The raw materials used for porcelain tiles production are mainly clay and feldspar. Feldspar is one of the raw materials responsible for the sintering during firing and it helps on the development of low porosity and high wear resistance of the ceramic piece. However, Brazil presents feldspar sources in regions distant from production centers, leading to higher cost for the porcelain tiles production. Thus, nepheline is thought as an alternative to substitute feldspar, totally or partially, since this mineral presents very similar characteristics. In order to verify the influence of this substitution to the properties of the porcelain tiles, it was necessary initially to study the influence of nepheline addition in both rheological and physical properties of the suspension. The results showed that the viscosity of the suspension increases with the addition of nepheline, as well as the apparent density of the fired piece.

This paper aims to evaluate the effects of calcination temperature and manganese doping on optical properties and phase evolution of Mn-doped TiO2 pigments. The powders were prepared by the polymeric precursor method at Mn contents of 0, 1, 2 and 3 % and calcined at 600, 700 and 800 °C. The results demonstrated that crystalline powders were produced in all conditions evaluated. It was further noted that the samples calcined at 600 °C were composed of rutile and anatase TiO2 polymorphs. However, the anatase phase was completely converted into rutile at temperatures above 700 °C. The particle size increased with increasing temperature. The same behavior was observed for the measured crystallite sizes. The Mn3+ ion charge was determined as the main valence for manganese ions in the TiO2 host. Oxygen vacancies are the probable crystal defects formed for charge balancing in the Mn-doped rutile structure. The results obtained for the powder with 3 % Mn and calcined at 800 °C demonstrated dopant cation segregation to form Mn2O3. It is important to emphasize that the absorbance values of the powders increase in the visible range when adding manganese compared to the absorbance values of pure TiO2. The band gap of the powders was reduced in accordance with the content of doping: from 3.04 eV (0 % Mn) to 2.05–2.20 eV (3 % Mn), with small differences depending on the calcination temperature. The increase in visible light absorbance led to a brown color in Mn-doped materials. Thus, the color intensity varied with the Mn content, ranging from light brown to dark brown powders. In conclusion, the temperature of 700 °C was established in this paper as the best condition to produce Mn-doped TiO2 pigments, based on the absence of anatase polymorph, small contents of residual carbon, and undetectable amounts of Mn2O3 due to segregation.

A Formação Corumbataí na região de Rio Claro - Limeira - Araras é representada por uma sucessão de siltitos, constituídos principalmente por filossilicatos (predominando illita, embora também ocorram montmorillonita, biotita, clorita, caulinita e interestratificados regulares e irregulares, quartzo, plagioclásios e feldspatos potássicos, carbonatos, hematita, goethita e zeólitas, de origem autígena e/ou detrítica. Quimicamente as rochas da Formação Corumbataí são classificadas principalmente como wackes e secundariamente como folhelhos, cuja principal fonte são rochas ígneas félsicas e/ou rochas sedimentares quartzosas. A aplicação de índices de maturidade química nas rochas analisadas sugere que estas são quimicamente imaturas e que a fonte foi submetida a condições de intemperismo moderado. Diagramas discriminantes para ambientes tectônicos sugerem que a fonte dos sedimentos da Formação Corumbataí são rochas quimicamente semelhantes a rochas formadas em margem ativa e/ou arcos de ilha, embora depositados em outro contexto geotectônico (bacia intracratônica).

In concrete manufacture, cement (Portland type is the most used), water and aggregates (classified into coarse and fine) are used. With the use of several raw materials the generation of waste is inevitable, both in construction and in other sectors, such as the industries producing ceramic materials. Among the types of waste from such industries, can be mentioned the ceramic scrap (from the sanitary ware industry). According to the above, the aim of this research was to study the addition of ceramic scrap as a coarse aggregate in different proportions in the concrete formulation. In order to do this, was select wastes from an industry in the south of Minas Gerais (Brazil), and prepare specimens to determine the fresh (slump test, adhesiveness and porosity) and hardened (compression strength) of concrete. Were fabricated five concrete formulations, one reference (RC) and four with ceramic scrap substituted for coarse aggregate in the proportions of 25% (CSCI), 50% (CSC-II), 75% (CSC-III) and 100% (CSC -IV). Fresh concretes, two formulations did not show adhesiveness (CSC-III and CSC-IV) and two a small water runoff (CSC-I and CSC-II), however, without compromising the concrete’s workability. Regarding the compression strength, the average values presented were very good, including the formulation with 100% ceramic scrap (fc = 47.78 MPa). Another important aspect observed in the rupture modes was the small adhesion between the ceramic scrap and the mortar due to the glazing in the contour of the waste. As for the porosity of the concretes, those with 25%, 75% and 100% of ceramic scrap in their composition presented lower values than the reference concrete. Keywords: Ceramic scrap; Concrete; Waste; Mechanical properties.

The process of beneficiation of a peaty ceramic raw material extracted from the Poços de Caldas region, MG, through the composting method to reduce organic matter (OM) was analyzed. The raw materials used in separate piles were divided, keeping one of the samples pure (TP) and adding bovine wastes in the second (TB). The process lasted 6 months and, at the end of each month, the amount of MO was analyzed by the Walkley-Black method. Results of maximum degradation of 56%±6% of OM in the TB and 47%±5% of OM in the TP were obtained. The ceramic characterization of the processed raw material was then carried out. It has been proved that the proposed method is efficient for the decrease of OM in the ceramic raw material. Regarding the composting product, the results were positive, showing that this material can be used in ceramic applications.

Porous ceramics have certain unique properties such as high toughness and resistance to heating at elevated temperatures. These properties make them products of great interest for applications on the field of filters and biomaterials. This paper proposes a new technique, called gelatinization, for processing this class of ceramics in order to obtain materials with more controlled pore size, plus a more homogeneous distribution. In order to check the efficiency of this technique, it was used as a raw material powders of calcined alumina and titania, previously characterized, mixed with unflavored gelatin, water and dispersant for holding the ceramic conformation. Three different formulations (with 40, 50 and 55% of solids content) were investigated using alumina and titania separately. The results indicated that the most suitable composition in terms of moldability was 55% of solids. It was also observed that the use of this technique to obtain bodies of high porosity is feasible; however, more detailed studies of sintering are necessary to obtain parts after firing in a close future. Due to the high porosity obtained the green, a detailed study of the sintering conditions is crucial to obtain parts with physical integrity.

Water-reducing additives for concretes are high efficiency dispersants that promote reduction of viscosity in suspensions, minimizing the amount of water used to hydrate the cement, thus enabling the fabrication of concrete with excellent properties. However, different forms of interaction between cement and additives are observed. In this work the properties of concrete formulated with three dosages of a polycarboxylate-based water-reducing additive and cement type CPII E-32 from two distinct manufacturers were investigated. In the experimental part, we verified the importance to use this technology justified by excellent results obtained for mechanical resistance and plasticity properties of the concretes. Through statistical analysis it was possible to point a discrete superiority in compositions using Holcim cement in function of its physical and chemical characteristics, in which the interaction process showed to be more efficient.

The Starch Consolidation method of molding technique is based on the ability of starch swell and gelatinize in water, so the green bodies are formed from suspensions, generating controlled porosity after firing; however, it is strongly influenced by gelatinization temperature, starch used, content and type of dispersant, pH and viscosity. This work involves the statistical analysis of possible relations between viscosity, content of dispersant and pH. Slurries containing alumina, water and starch were prepared, settling the solids in 40% and varying the starch content of 10, 20, 30, 40 and 50%, compared to the solids at the mixture. PH and viscosity measurements were made of the slurries as a function of added dispersant. Were obtained and analyzed measures of each parameter, using the Pearson correlation, verifying the existence of an almost perfect correlation between most of the parameters studied.

The Santa Gertrudes ́ Ceramic Polo is the Brazilian region with national and international prominence in the manufacturing of ceramic tiles. Some raw materials used by ceramic industry and coatings industries in this region were characterized in terms of chemical-mineralogical and microscopic view, in order to promote the best technological characterization of them. For this, chemical analysis of major elements and trace X-ray diffraction and microscopic analysis by SEM, TEM and Electron microprobe were performed by ICP-MS. The results showed that the raw materials commonly referred to as "clays" are actually constituted by various mineral phases, which directly influence the properties of the same ceramics. Also showed that, by virtue of this constitution, different formulations can be developed, using the best raw materials found in the region of Santa Gertrudes, SP.

Made available in DSpace on 2020-12-10T20:06:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The Corumbatai Formation is a Permian sedimentary unity comprising siltstones, claystones and very fine sandstones, deposited above calcific shales, bituminous shales and dolomitic limestones from the Irati Formation, indicating severe changes in tectonic and climatic conditions in a short span during the evolution of the Parana Basin. Through geochemical analysis of major elements, it is possible to observe that some characteristics of the Corumbatai Formation indicate that the climate on the period of deposition was arid or semiarid, with low contribution of fluvial and pluvial waters, and that, as expected, the chemical signature of the sediments are similar to the adjacent orogenic belts, despite that no tectonically active areas or magmatic arcs were registered in the surroundings of the Parana Basin during Permian. These aspects suggest that the aridization of the Pangea Supercontinent started earlier than considered so far, and that the source areas for this sedimentary unity most probably were distant from the basin, being that the main possible transportation process of the detritic grains should be aeolian. Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Dept Mineral & Petrol, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Dept Appl Geol, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Alfenas Fed Univ, Sci & Technol Inst, Adv Campus Pocos Caldas, BR-37715400 Pocos De Caldas, MG, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Dept Terr Planning & Geoproc, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Dept Mineral & Petrol, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Dept Appl Geol, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Inst Geosci & Exact Sci, Dept Terr Planning & Geoproc, Rio Claro Campus,Av 24-A,1515 Bela Vista, BR-13506900 Rio Claro, SP, Brazil

O uso de operações mais complexas de cominuição e concentração de minerais na indústria mineral têm crescido, em função da queda dos teores e maior complexidade dos minérios disponíveis. Uma alternativa para enfrentar a alta dos custos com a instalação e operação de usinas de beneficiamento mineral é a pré-concentração, usando-se métodos gravimétricos de beneficiamento. Com isso, descarta-se, antes da alimentação da usina de beneficiamento, uma fração com pouca ou nenhuma quantidade do mineral de interesse, reduzindo assim a massa a ser processada nas operações seguintes. Os benefícios gerados pelo uso da pré-concentração por meio de beneficiamento gravimétrico são significativos, garantindo, por exemplo, o aumento da produção de metal contido de uma usina sem necessidade de se recorrer a uma extensão da capacidade de moagem ou flotação e a extensão da vida útil da mina, devido à redução do teor de corte. O objetivo principal deste trabalho é avaliar o potencial de redução dos circuitos de cominuição de minerais sulfetados provenientes de um depósito de zinco, chumbo e cobre, utilizando a metodologia de pré-concentração em meio denso. Foram desenvolvidos ensaios em escala laboratorial, buscando assim o aumento do teor dos metais de interesse que alimentam a moagem e a avaliação do WI de alimentação da usina.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:02:49Z No. of bitstreams: 1 S0366-69132012000300010.pdf: 3435163 bytes, checksum: 56461ebf455fd5d8286c789458f3912c (MD5) Made available in DSpace on 2013-08-22T19:02:49Z (GMT). No. of bitstreams: 1 S0366-69132012000300010.pdf: 3435163 bytes, checksum: 56461ebf455fd5d8286c789458f3912c (MD5) Previous issue date: 2012-09-01 Made available in DSpace on 2013-09-30T20:04:03Z (GMT). No. of bitstreams: 2 S0366-69132012000300010.pdf: 3435163 bytes, checksum: 56461ebf455fd5d8286c789458f3912c (MD5) S0366-69132012000300010.pdf.txt: 29623 bytes, checksum: d170f5e966deca6ff5a78acfd6bc2010 (MD5) Previous issue date: 2012-09-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:16:26Z No. of bitstreams: 2 S0366-69132012000300010.pdf: 3435163 bytes, checksum: 56461ebf455fd5d8286c789458f3912c (MD5) S0366-69132012000300010.pdf.txt: 29623 bytes, checksum: d170f5e966deca6ff5a78acfd6bc2010 (MD5) Made available in DSpace on 2014-05-20T15:16:26Z (GMT). No. of bitstreams: 2 S0366-69132012000300010.pdf: 3435163 bytes, checksum: 56461ebf455fd5d8286c789458f3912c (MD5) S0366-69132012000300010.pdf.txt: 29623 bytes, checksum: d170f5e966deca6ff5a78acfd6bc2010 (MD5) Previous issue date: 2012-09-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Estudou-se um material da base da Formação Corumbataí, proveniente de uma mineração de argila, que apresenta restrições de uso em cerâmica devido à sua dureza e, principalmente, ao alto conteúdo de matéria orgânica. Verificou-se que o material apresenta características naturais ótimas para a fabricação de argila expandida diretamente a partir de fragmentos de rocha, mostrando comportamento piroplástico com expansão significativa se submetido à queima rápida. A caracterização da matéria-prima e do produto foi realizada mediante análise de carbono orgânico, difração de raios X, microscopia ótica e testes de queima. Foram determinadas as condições de queima para obter argila expandida utilizando forno de queima rápida e forno a rolos, ambos de laboratório, obtendo corpos com densidade variável (que podem chegar a valores menores que 0,5 g.cm-3) até o limite de expansão. Esta densidade é obtida devido à formação de poros fechados e uma película externa vítrea, que proporcionam uma resistência mecânica alta aos fragmentos expandidos. This paper refers to the study of the material of the base of the Corumbataí formation (Parana Basin, Brazil) of a clay mine, which presents limits for its use in ceramic tiles in dry grinding process due to its hardness and, especially, the high content of organic matter in relation to the clay overlaid. The characterization of the raw material and the product was accomplished by organic carbon analysis, X-ray diffraction, optical microscopy and test-firing. Firing conditions were determined to get expanded clay, using fast firing static kiln and a continuous roller kiln, both from laboratory equipment, getting samples with variable density up to the limit of expansion, with density that can reach values lower than 0.5 g.cm-3 because of the formation of closed pores and an external vitreous foil which provide a high mechanical resistance to the particles. UNESP IGCE DPM UNIFAL Instituto de Ciência e Tecnologia Núcleo de Engenharia de Minas UNESP IGCE DPM

The manufacture of ceramic products involves the knowledge of the whole process, starting with the raw materials that are traditionally treated as clays. The term clay according to Santos [1] means a material with earthy texture and low grain size, which develops plasticity when mixed with a limited amount of water. The clay (or mudstone from the geological point of view) is a finely divided rock, consisting mainly of clay minerals, plastic materials and minerals that may contain non-plastic, and some materials which are not considered clay minerals, such as calcite, dolomite, gibbsite, quartz, alumina, pyrite, and others. Chemically, clays are composed of hydrated silicates of aluminum and iron, containing also a certain amount of alkaline and earth alkaline elements.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:02:51Z No. of bitstreams: 1 S0370-44672006000400005.pdf: 196587 bytes, checksum: ad2335339aea8110705cdbddcfab080c (MD5) Made available in DSpace on 2013-08-22T19:02:51Z (GMT). No. of bitstreams: 1 S0370-44672006000400005.pdf: 196587 bytes, checksum: ad2335339aea8110705cdbddcfab080c (MD5) Previous issue date: 2006-12-01 Made available in DSpace on 2013-09-30T20:04:07Z (GMT). No. of bitstreams: 2 S0370-44672006000400005.pdf: 196587 bytes, checksum: ad2335339aea8110705cdbddcfab080c (MD5) S0370-44672006000400005.pdf.txt: 19281 bytes, checksum: 0a63a707c54ff10b99f252ed62b4f840 (MD5) Previous issue date: 2006-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:16:27Z No. of bitstreams: 2 S0370-44672006000400005.pdf: 196587 bytes, checksum: ad2335339aea8110705cdbddcfab080c (MD5) S0370-44672006000400005.pdf.txt: 19281 bytes, checksum: 0a63a707c54ff10b99f252ed62b4f840 (MD5) Made available in DSpace on 2014-05-20T15:16:27Z (GMT). No. of bitstreams: 2 S0370-44672006000400005.pdf: 196587 bytes, checksum: ad2335339aea8110705cdbddcfab080c (MD5) S0370-44672006000400005.pdf.txt: 19281 bytes, checksum: 0a63a707c54ff10b99f252ed62b4f840 (MD5) Previous issue date: 2006-12-01 Na região de Rio Claro (SP), localiza-se o Pólo Cerâmico de Santa Gertrudes, responsável por cerca de 50% da produção nacional de revestimentos. Durante o beneficiamento da argila e preparação da massa, cerca de 2 a 3% argila fina é colocada em suspensão no ar, sendo quase toda retida nos filtros de manga. Esse material fino, por problemas de homogeneização ou tecnológico, representa perda de material e se constitui em um potencial agente de contaminação do ar e da água, necessitando ser armazenado. A presente pesquisa buscou viabilizar o aproveitamento do pó retido nos filtros, no próprio processo, através da granulação da massa por aspersão de barbotina preparada com o pó. Investigaram-se a composição ideal da barbotina e a influência dessa metodologia no produto final, comparando a massa granulada por aspersão com a massa-padrão. In the region of the Rio Claro (SP) is located the Santa Gertrude's Ceramic Pole, responsible for around 50% of the national ceramic tile manufactured. During the clay's ore treatment and powder preparation, 2 to 3 percent of the fine clay is lost in the air, in suspension. Almost all the material is restrained in bag filters. Currently, because of blending problems, this fine material represents a loss of material, which could become a potential agent for air and water contamination, and this material needs to be stored. This research examined the possible use for the filter-bag dust while in process, through granulation of the material by aspersion of the barbotine prepared with a powder. We investigated the ideal composition of the suspension and the influence of this method in the end product, comparing the granulated mass by aspersion with the standard mass. Universidade Estadual de São Paulo Universidade Estadual de São Paulo DPM IPT

A importância dos minerais de terras raras, considerados “materiais da terceira onda”, se deve a sua relação com o desenvolvimento tecnológico. A China por muito tempo dominou a produção e vendas no mercado mundial, adotando nos últimos anos severas medidas protecionistas que acabaram por forçar diversos países a optar por outras formas de suprimento para suas demandas. A necessidade de procurar novas fontes de minerais estratégicos levou ao desenvolvimento ou retomada de programas de exploração em diversas áreas. Dentre essas, destaca-se o Planalto de Poços de Caldas – MG, que corresponde a um depósito laterítico desenvolvido sobre um complexo alcalino intrusivo em domínios de embasamento cristalino. Nesse contexto geológico observam-se comportamentos distintos quanto aos processos de laterização e/ou oxidação que ocasionam a lixiviação de certos elementos e enriquecimento residual dos menores móveis, podendo formar um depósito econômico dependendo das condições locais. São apresentados dados oriundos de extensa revisão bibliográfica acerca do potencial geológico deste depósito e propõe-se a aplicação de técnicas de baixo custo para os trabalhos prospectivos no maciço.

Poços de Caldas é um importante centro hidrotermomineral do Brasil, o qual apresenta depósitos de argilas não plásticas para as quais não há registros significativos a respeito da caracterização direcionada destes materiais, o que prejudica estudos de aplicação industrial. Estas argilas não plásticas, não aproveitadas, vêm sendo armazenadas em galpões ou a céu aberto, o que gera um elevado custo para a indústria, além de transformar-se em um passivo ambiental. No presente trabalho realizou-se o estudo químico-mineralógico de seis amostras de argilas de baixa plasticidade, além da caracterização preliminar destas amostras quanto à granulometria, plasticidade e propriedades cerâmicas básicas, visando ampliar os horizontes das investigações destes materiais. Este estudo preliminar mostrou que, de maneira geral, as amostras são compostas por minerais refratários como caulinita e gibbsita, apresentando teores menos significativos de outras fases, como quartzo, vermiculita e illita. Juntamente às análises químicas, estes dados permitiram o agrupamento das matérias-primas em dois grupos em função de sua refratariedade, norteando assim, a caracterização posterior. Dentre as amostras, há material com potencial uso na formulação de massas de porcelanato, além de uma amostra turfosa, cuja aplicação está relacionada à correção de solos. Poços de Caldas is an important "hydro-thermo-mineral" center in Brazil, where non-plastic clays deposits can be found with no significant records about their characterization, impeding the studies of industrial application. These non-plastic clays, not used, have been stored in sheds or open, which creates a high cost to the industry, and become an environmental liability. In the present work, the chemical-mineralogical study of six samples of non-plastic clays was realized, and also the preliminary characterization of these samples about the grain size, plasticity and basic ceramic properties, to expand the horizons of researches about such materials. This preliminary study showed that, overall, the samples are composed of refractory minerals such as kaolinite and gibbsite, with less significant amounts of other phases such as quartz, illite and vermiculite. The chemical analysis permitted the grouping of raw materials into two groups according to their refractory properties, guiding to the subsequent characterization. Among the samples, there is material with potential use in porcelain formulation, and also a peat sample, which implementation is related to soil correction.

Syenitic rocks with a high nepheline content near Lavrinhas (SP), 234 km northeast of the city of Sao Paulo, may be potentially useful for the production of ceramic products. Based on the mineralogy and texture of this raw material, the best methods of processing these syenitic rocks for fluxing properties are indicated here. In addition, chemical analyses and melting tests were carried out in order to evaluate the melting color before and after magnetic separation, as well as the potential use of this material in glazes and engobes, as compared to a Nepheline standard. Preliminary tests showed that after removal of superficial iron oxide, the raw material bearing nepheline has potential for use in the formulation of porcelain masses, replacing other fluxing materials which have higher added value.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T19:02:53Z No. of bitstreams: 1 S0370-44672007000400006.pdf: 329139 bytes, checksum: 33e7ae8941bb5104cfd7e54605e03752 (MD5) Made available in DSpace on 2013-08-22T19:02:53Z (GMT). No. of bitstreams: 1 S0370-44672007000400006.pdf: 329139 bytes, checksum: 33e7ae8941bb5104cfd7e54605e03752 (MD5) Previous issue date: 2007-12-01 Made available in DSpace on 2013-09-30T20:04:09Z (GMT). No. of bitstreams: 2 S0370-44672007000400006.pdf: 329139 bytes, checksum: 33e7ae8941bb5104cfd7e54605e03752 (MD5) S0370-44672007000400006.pdf.txt: 30435 bytes, checksum: 35ba2539ba1812e0287cb83de655eeea (MD5) Previous issue date: 2007-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T15:16:28Z No. of bitstreams: 2 S0370-44672007000400006.pdf: 329139 bytes, checksum: 33e7ae8941bb5104cfd7e54605e03752 (MD5) S0370-44672007000400006.pdf.txt: 30435 bytes, checksum: 35ba2539ba1812e0287cb83de655eeea (MD5) Made available in DSpace on 2014-05-20T15:16:28Z (GMT). No. of bitstreams: 2 S0370-44672007000400006.pdf: 329139 bytes, checksum: 33e7ae8941bb5104cfd7e54605e03752 (MD5) S0370-44672007000400006.pdf.txt: 30435 bytes, checksum: 35ba2539ba1812e0287cb83de655eeea (MD5) Previous issue date: 2007-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Siltitos e argilitos da Formação Corumbataí são fontes de matéria-prima para a indústria cerâmica do Pólo de Santa Gertrudes. Litotipos provenientes de três minas (Tute, Granusso e Cruzeiro), localizadas na região de Rio Claro - SP, foram caracterizados quanto à curva de defloculação, conteúdo crítico de sólidos e tempo de envelhecimento (propriedades reológicas). Os litotipos representam desde a base até o topo da coluna estratigráfica dessa formação. Os resultados reológicos foram correlacionados com a composição mineralógica. Os representantes da base estratigráfica apresentaram boa defloculação, quase não necessitando adicionar defloculante, e, de forma geral, continham illita, feldspato, quartzo, hematita, clorita e interestraficados de clorita - argilomineral expansivo ou de illita - argilomineral expansivo. A maioria dos litotipos do topo defloculou, porém a quantidade ideal de defloculante foi superior aos adicionados às amostras da base. Os litotipos do topo continham carbonatos, além dos minerais supracitados. Uma amostra coletada no topo da mina Tute, com sinais evidentes de intemperismo, não defloculou. Os carbonatos presentes nos estratos superiores da formação e a alteração supérgena prejudicaram a defloculação. A quantidade máxima de sólidos na barbotina foi 66% em peso para os litotipos do topo da formação. Os litotipos testados apresentaram o fenômeno de envelhecimento da suspensão, porém as barbotinas, após 120 horas de seus preparos, ainda apresentavam viscosidades semelhantes àquelas usadas pela indústria de placas cerâmicas para revestimento. Siltstones and mudstones from the Corumbataí Formation are exploted as raw material for the ceramic industries of Santa Gertrudes' Cluster. Lithotypes from three quarries (Granusso, Tute and Cruzeiro), located in the Rio Claro region - SP - Brazil, were characterized rheologically (deflocculation curve, solid critic content and aging time), representing the entire stratigraphic column of this formation. The results obtained were correlated with the mineralogical composition. The lithotypes in the lower part of the formation deflocculated very well, with small doses of deflocculant, and were generally composed of illite, feldspar, quartz, hematite, chlorite, and interstratified (chlorite together with expansive clay minerals or illite together with expansive clay minerals). The majority of the lithotypes found at the top of the formation deflocculated. However, for this to occur, a greater amount of deflocculant was necessary, in comparison to the amount used for the bottom samples. The lithotypes found at the upper part contained the same minerals as the bottom, but in addition, carbonates were found. One of the samples, collected at the top of Tute quarry showed evidences of weathering and did not deflocculate. The carbonates at the top strata and the supergenic alteration damaged the deflocculation. The maximum amount of solids in the suspension was 66% in weight for the lithotypes from the top. The test samples presented characteristics of suspension aging, however after 120 hours their viscosity was similar to that used in the tile industry. UNESP IGCE Pós-graduandos em Geologia Regional UNESP IGCE DPM IPT CCB CITEC UNESP IGCE Pós-graduandos em Geologia Regional UNESP IGCE DPM

CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior In mineral processing, a detailed characterization of multiphase particulate systems is fundamental to guarantee an efficient separation of the valuable minerals. A precise analysis allows the process engineer, for instance, to evaluate the optimum concentration route and to achieve the best metallurgical recovery possible. One of the most important aspects of the ore is mineral liberation, as it defines the maximum possible grade for subsequent mineral concentration processes. Scanning electron microscope-based (SEM-based) automated image analysis systems have been used to obtain information concerning mineral liberation. One of the limitations of SEM-based techniques for mineral liberation assessment is the unavoidable loss of 3D information, leading to significant stereological errors. In this regard, X-ray microtomography emerges as a solution that allows three-dimensional imaging and direct measurement of spatial characteristics of mineral ores, eliminating stereological issues. In this thesis, high-resolution X-ray microtomography was used to evaluate the characteristics of liberation of a metallurgical bauxite ore and of an iron ore tailing. Mineralogical characterization showed that the bauxite ore was composed by 54.5% of gibbsite as the aluminum-bearing mineral, 39.8% of kaolinite as silicate gangue, and 5.7% of hematite, whereas the iron ore tailing was constituted by 88.8% of quartz, 10.4% of hematite, and 0.8% of goethite. The liberation analyses were carried out with respect to compositional liberation (grade) and textural liberation (surface exposure), in both 2D and 3D perspectives to assess the degree of stereological bias. For the bauxite ore, grade distributions in 2D and 3D were correspondent when all possible cross-sections were considered in 2D. However, 2D surface exposure did not converge accurately to the 3D fashion due to the loss of 3D information. In the case of the iron ore tailing, the stereological effect was more pronounced in surface exposure quantification. There was a linear relationship between grade and surface exposure and also between particle size and surface exposure. A comparison of the results of SEM-based and X-ray microtomography for the iron ore tailing evidenced the fact that only a 3D technique would be able to represent the real characteristics of particulate systems. No processamento de minerais, uma caracterização detalhada de partículas é fundamental para garantir uma separação eficiente dos minerais de interesse. Uma análise precisa permite que engenheiro, por exemplo, avalie a melhor rota de concentração e obtenha a melhor recuperação metalúrgica possível. Um dos aspectos mais importantes do minério é a liberação mineral, pois define o teor máximo possível para os processos subsequentes de concentração mineral. Equipamentos automatizados de análise de imagem baseados em Microscopia Eletrônica de Varredura (MEV) têm sido utilizados para obter informações sobre o grau de liberação mineral. Uma das limitações das técnicas baseadas em observações ao microscópio para avaliação da liberação de minerais é a perda inevitável de informações em 3D, levando a erros estereológicos significativos. Nesse sentido, a microtomografia de raios-X surge como uma alternativa que permite a obtenção de imagens tridimensionais e medição direta das características espaciais dos minérios, eliminando os efeitos estereológicos. Nesta tese, microtomografia de raios-X de alta resolução foi utilizada para avaliar as características de liberação de um minério de bauxita metalúrgica e de um rejeito de minério de ferro. A caracterização mineralógica mostrou que o minério de bauxita era composto por 54,5% de gibbsita como mineral contendo alumínio, 39,8% de caulinita como ganga silicatada e 5,7% de hematita, enquanto o rejeito de minério de ferro era constituído por 88,8% de quartzo, 10,4% de hematita e 0,8% de goethita. As análises de liberação foram realizadas em relação à composição (teor) e à textura (superfície exposta), em ambas as perspectivas 2D e 3D, para avaliar o grau do erro estereológico. Para a bauxita, as distribuições de teor em 2D e 3D foram correspondentes quando todas as seções transversais foram consideradas em 2D. No entanto, o grau de exposição da superfície 2D não convergiu para o 3D, devido à perda de informações 3D. No caso do rejeito de minério de ferro, o efeito estereológico foi mais pronunciado na quantificação da exposição superficial. Foi observada uma relação linear entre o teor e o grau de exposição da superfície, bem como entre o tamanho da partícula e a exposição da superfície. Uma comparação dos resultados de métodos automatizados de análise de imagem baseados em MEV e microtomografia de raios-X para o rejeito de minério de ferro evidenciou o fato de que apenas uma técnica 3D seria capaz de representar as características reais de sistemas particulados.