Made available in DSpace on 2016-12-08T17:19:23Z (GMT). No. of bitstreams: 1 Gabriel Beck de Albuquerque.pdf: 1997107 bytes, checksum: 541a09517c8455984a0d555701225b7e (MD5) Previous issue date: 2014-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The growth of the ceramic materials market has impelled manufacturers and researchers to find solutions for cutting costs in products and increase diversity in materials. Regarding this, the domestic industry has displayed traits to promote Brazilian plants, so they can excel globally. Thus, the influence exerted on different process variables, in the synthesis of ceramic pigments utilizing the crystalline Wollastonite structure was employed for the purpose of uncovering new pigments studied in this present research work, since in the course of establishing the crystalline structure, a greater quantity of chromophore ions can be incorporated in the Wollastonite structure. Two series of pigment formulations based on the same initial compositions were prepared seeking to achieve this objective, considering additions in mass percentage. The influence from this variation was followed up by the trials to define the structure and evaluate the final properties. After determining the mass of the utilized reagents, the blends were homogenized utilizing conventional grinding followed by calcination. The formulations of nickel were synthesized at 1100 and 1200 °C. However in chrome pigments, the calcination temperatures were 1000, 1150, and 1250 °C. In all the heat treatment temperatures, the employed heating rate was 5°C/min and the only threshold at the maximum temperature for 3 hours. The characterizations of the obtained pigments were achieved by way of X-ray diffractometry, scanned electronic microscopy, and the analysis of particle size distribution. The pigments were applied to a type of transparent ceramic enamel, containing zinc in its formulation. Afterwards, colorimetric analyses were performed. The results displayed evidence that it is possible to obtain the desired result, as well as other types of silicates. The raw material used as a chromophore agent could even exert a negative influence preventing the formulation of pigment. / O crescimento do mercado de materiais cerâmicos pressionam os fabricantes e pesquisadores a encontrarem soluções para reduzir o custo do produto e aumentar a diversidade de materiais. Neste sentido, a indústria nacional dispõe de características que ajudaram a indústria cerâmica a se destacar em nível mundial. Com o intuito de buscar novos pigmentos, no presente trabalho, procurou-se estudar a influência de diferentes variáveis de processamento na síntese de pigmentos cerâmicos utilizando a estrutura cristalina da wollastonita, já que no decurso do estabelecimento da estrutura do cristal, uma maior quantidade de íons cromóforos pode ser incorporada a estrutura da wollastonita. Visando atingir este objetivo foram preparadas duas séries de formulações de pigmentos com base na mesma composição inicial, mas com variação nos teores de íons cromóforos empregados, considerando-se adições em percentual em massa. A influência desta variação foi acompanhada com os ensaios de determinação de estrutura e de avaliação de propriedades finais. Após determinação da massa dos reagentes utilizados, as misturas foram homogeneizadas utilizando moagem convencional seguido de sintetização. As formulações de níquel foram sintetizadas a 1100 e 1200 °C. Já para os pigmentos de cromo, as temperaturas de sintetização foram 1000, 1150 e 1250 °C. Em todas as temperaturas do tratamento térmico foi utilizado taxa de aquecimento de 5°C/min e patamar único na temperatura máxima de 3 horas. As caracterizações dos pigmentos obtidos foram realizadas através de difratometria de raios X, microscopia eletrônica de varredura e análise da distribuição do tamanho de partículas. Os pigmentos foram aplicados em esmalte cerâmico, tipo transparente contendo zinco em sua formulação. Posteriormente, foram realizadas análises colorimétricas. Os resultados evidenciaram que é possível obter o resultado desejado, além de outros tipos de silicatos. É possível, também, concluir que o aumento do teor de cromóforo nas formulações não é efetiva na otimização da produção dos pigmentos. Considerando as temperaturas testadas, de forma geral, o aumento da temperatura favorece a formação do silicato desejado e em temperaturas mais baixas e reação entre as matérias primas é incompleta. As imagens feitas por microscopia eletrônica evidenciam, em condições de síntese bem características, a formação de fase líquida. Após sintetizados os pigmentos desenvolveram coloração verde com variação na tonalidade e luminosidade. Nos testes de aplicação, as amostras obtidas apresentaram superfícies irregulares e coloração assimétrica, independentemente do percentual de pigmento adicionado, com variação de tonalidade.

Orientador: Sílvio Rainho Teixeira / Resumo: A falta de sincronismo entre o desenvolvimento industrial e a conscientização ambiental trouxe inúmeros impactos adversos ao meio ambiente. A quantidade de resíduos industriais gerados diariamente aumenta, enquanto a adoção de sistemas de gerenciamento ainda falha em muitos aspectos. Assim, o objetivo principal deste trabalho é desenvolver materiais vitrocerâmicos através da mistura de Areia Descartada de Fundição (ADF) com resíduos sólidos oriundos da indústria de papel e celulose (grits e lama de cal), visando o desenvolvimento de novos produtos que sejam ecologicamente corretos. Os materiais vitrocerâmicos obtidos a partir da cristalização do vidro com os resíduos de ADF, grits e lama de cal foram preparados utilizando o método tradicional, de fusão do composto, para a produção dos vidros; e, posterior cristalização, para obtenção das vitrocerâmicas. De acordo com a composição química dos materiais precursores e das misturas, os vidros foram obtidos à temperatura de 1450 °C. O trabalho foi desenvolvido em duas etapas principais: caracterização dos materiais precursores e preparação e caracterização dos vidros e vitrocerâmicas. Os estudos de caracterizações foram feitos através das técnicas de análises granulométrica, morfológica, mineralógica, química, térmicas e tecnológicas. Foram obtidos 6 materiais vítreos distintos, intitulados de vidros I, II, III, IV, V e VI. Os vidros foram caracterizados por Difração de Raios X (DRX), Fluorescência de Raios X (FRX) e análise de ca... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The lack of synchronism between industrial development and environmental awareness has brought numerous adverse impacts to the environment. The amount of industrial waste generated daily increases, while the adoption of management systems still fails in many ways. Thus, the main objective of this work is to develop glass-ceramic materials by mixing Waste Foundry Sand (WFS) with solid residues from the cellulose and paper industry (grits and lime mud), aiming at the development of new products that are environmentally friendly. The glass were obtained using the traditional melting-quenching method. The produced glasses were controlled by the crystallization process to obtain the glass-ceramics materials. According to the chemical composition of the precursor materials and the chemical composition of the mixtures, the glasses were fused at 1450 °C. The work was developed in two main stages: characterization of the precursor materials and preparation and characterization of glasses and glass-ceramics. The characterization studies were made through the techniques of particle size, morphological, mineralogical, chemical, thermal and technological analysis. Six distinct vitreous materials were obtained, entitled glasses I, II, III, IV, V and VI. The glasses were characterized by the analysis of X-Ray Diffraction (XRD), X-Ray Fluorecence (XRF) and differential scanning calorimetry. After identifying the crystallization peaks of each glass, heat treatment was given (temperatures high... (Complete abstract click electronic access below) / Doutor

This thesis focused on testing the suitability of reactive filter media used for phosphorus (P) removal from wastewater as fertilizers, thus recycling P to agriculture. The work compared the P sorption capacity of several materials in order to assess their suitability as a source of P for plants. The selected materials (Filtra P, Polonite and wollastonite) were saturated with P and used as soil amendments in a pot experiment. The amendments tended to improve the yield of barley and ryegrass compared with no P addition. The amendments also increased soil pH, P availability and cation exchange capacity in the studied soils. The substrates studied here can be of particular interest for acid soils. Of the materials studied, Polonite appears to be the most suitable substrate for the recycling of P from wastewater to agriculture / QC 20101103

The glass-ceramics containing apatite [Ca10(PO4)6(O,F2)] and wollastonite [CaO&amp / #8226 / SiO2] crystals as the predominant crystalline phases, (A-W glass-ceramics) were produced through controlled crystallization of the glasses in the MgO-CaO-SiO2-P2O5-F system. Phases formed in the crystallized counterpart of the glasses were identified by powder X-ray diffraction (XRD) analysis. The crystal morphology of the resultant glass-ceramics was examined using a scanning electron microscope (SEM). The crystallization kinetic parameters consisting of the activation energy for crystallization, (E), the Avrami parameter, (n), and frequency factor of the glass were determined with regard to small amount of TiO2 additions using non-isothermal differential thermal analysis (DTA). The values for E and n for apatite and wollastonite were 460 kJ/mol and 433 kJ/mol, and 3.1&plusmn / 0.1 and 1.5&plusmn / 0.1, respectively. When 4 wt% TiO2 was incorporated into the base glass, the values for E decreased to 408 and 320 kJ/mol for apatite and wollastonite, respectively / but the values for n increased from 3.1&plusmn / 0.1 to 3.3&plusmn / 0.1, and from 1.5&plusmn / 0.1 to 1.9&plusmn / 0.1 for apatite and wollastonite, respectively. TiO2 is an effective nucleating agent in this glass system for promoting the precipitation of both apatite and wollastonite crystals. Structure oriented changes in the indentation microhardness and tribological properties of the A-W glass-ceramics were evidenced. The microhardness at the free surface was 650&plusmn / 12 HV, but decreased with increasing depth distance from the free surface and attained 520&plusmn / 8 HV at a distance 0.5 mm below the free surface. The wear rate at the free surface was 0.7&plusmn / 0.05 &times / 10-4 mm3/Nm, but increased as the distance from the free surface increased and became 2.9&plusmn / 0.15 &times / 10-4 mm3/Nm at a distance 0.5 mm below the free surface. Tribological properties of the A-W glass-ceramics were compared with those of commercially available dental ceramics including IPS Empress 2&reg / , Cergo Pressable Ceramic&reg / , Cerco Ceram&reg / , Super porcelain EX-3&reg / , and bovine enamel. The wear rate, friction coefficient, and wear mechanisms of the A-W glass-ceramics were similar to currently used artificial dental materials.

The cement and concrete industry stand for approximately 8% of the global CO2 emissions. The demand of concrete and cement is expected to increase rapidly with the growing world population and increased urbanization. This makes it of the utmost importance for the industry to try to mitigate its emissions. One way to reduce the industry’s environmental impact is by mineral carbonation curing through which CO2 can be sequestered in the concrete. This investigation studied the CO2 uptake of wollastonite (CaSiO3) which can be used for mineral carbonation. The CO2 uptake of different brands of wollastonite powders for different temperatures, pressures and water to solid ratios were tested through carbonation, and the samples were then analyzed through XRD, SEM and particle size analysis. The results showed large differences in CO2 uptake between the brands of wollastonite powders. They also indicate that lower temperatures lead to higher CO2 uptake but also possibly slow down the reaction rate and that higher CO2 pressures seem to increase CO2 uptake though the effect is small. There was significant variation of the effects of the water to solid ratios on CO2 uptake between the tested brands. The morphology of the powders also seemed to be of little relevance as an amorphous and crystalline powder were the two best performing powders, similarly particle size is not indicated by the result to have a large effect on CO2 uptake, though further studies are required to fully determine the effect of the morphology and particle size. / Cement- och betongindustrin står för cirka 8% av de globala koldioxidutsläppen. Efterfrågan på betong och cement förväntas öka snabbt med den växande världsbefolkningen och ökad urbanisering. Detta tyder på hur viktigt det är för industrin att minska sina utsläpp. Ett sätt att minska industrins miljöpåverkan är genom härdning av betongen via mineral karbonatisering, en process som binder in koldioxid i betong. I detta arbete studerades koldioxidupptagningen av mineralen wollastonit (CaSiO3) som kan användas för mineral karbonatisering. Olika märken av wollastonitpulvers koldioxidupptag vid olika temperaturer, koldioxidtryck och vattenhalter testades genom karbonatisering och proverna analyserades därefter genom XRD-analys, SEM-analys och partikelstorleksanalys. Resultaten visade stora skillnader i koldioxidupptagning mellan varumärkena av wollastonitpulver. De visar även att lägre temperaturer leder till högre upptag av koldioxid, men att reaktionshastigheten potentiellt saktar ner vid låga temperaturer. Högre koldioxidtryck verkar öka koldioxidupptagningen men effekten är liten. Det fanns signifikant variation av effekterna av vattenhalterna på koldioxidupptagning mellan de testade varumärkena. Pulvrens morfologi verkade inte ha en stor effekt då ett av de två bäst presterande pulvren var amorft och det andra kristallint. På samma sett verkade partikelstorleken inte ha en stor påverkan på koldioxidupptaget men ytterligare studier krävs för att fullständigt kunna bestämma effekten av morfologin och partikelstorleken.

Determining mafic mineral composition of asteroid bodies is a topic reviewed by M.J. Gaffey et al. (2002). The iterative procedure discussed can be implemented as an algorithm, and such efforts revealed weaknesses that are examined in this work. We seek to illustrate the limits of this method and graphically determine its predictions. There are boundaries in the formulae given where the equations break down. In ranges where mafic mixtures are predicted, a method is illustrated that allows a decoupling of these mixtures into the constituents.

Com o objetivo de avaliar os efeitos da interação entre o silício (Si) e o fósforo (P) na planta e no solo, foram realizados três experimentos. No primeiro experimento, avaliou-se o efeito de duas fontes de Si (wollastonita e filossilicato) em diferentes doses (0 a 250 mg dm-3) sobre o aproveitamento do P do superfosfato triplo marcado com o radioisótopo 32P. Utilizouse o arroz (Oryza sativa) como planta teste. Neste primeiro experimento, as duas fontes de Si promoveram incremento na quantidade do elemento nas plantas, porém tiveram comportamento diferente quanto à produção de matéria seca da parte aérea e de P acumulado, tendo apenas o filossilicato promovido ganhos para estas variáveis. Constatou-se que o maior acúmulo do P pela planta em relação ao tratamento controle (sem Si) foi devido à maior absorção do nutriente do solo e não do fertilizante, sendo baixo o aproveitamento do superfosfato triplo pelas plantas para as duas fontes de Si. No entanto, a wollastonita liberou maiores quantidades de Si no solo em relação ao filossilicato. No segundo experimento foram avaliadas as formas de aplicação (em sulco ou misturado ao solo) de Si e P no aproveitamento do P do superfosfato triplo pelo arroz. Aplicou-se uma dose de Si (125 mg dm-3) intermediária daquelas utilizadas no primeiro experimento para ambas as fontes de Si, wollastonita e filossilicato, e a mesma dose de P (53 mg dm-3). De acordo com os resultados desse experimento, as duas fontes de Si apresentaram respostas similares, não havendo diferença para nenhuma variável analisada. No terceiro experimento foi realizado um teste de incubação (sem planta), no qual se aplicou as mesmas doses de Si do primeiro experimento (0 a 250 mg dm-3) e a mesma dose de P (53 mg dm-3), a fim de avaliar o comportamento da liberação de Si pelas fontes wollastonita e filossilicato em função do tempo, entre 0 a 90 dias. Foram realizadas coletas mensais de amostras do solo. Verificou-se que ambas as fontes de Si apresentaram a maior liberação deste elemento no solo próximo aos 60 dias após a aplicação. O teor de P no solo, no terceiro experimento (de incubação do solo), apesar de ter sido aplicado em uma única dose, comportou-se de maneira similar ao Si, tendo aumentado com o passar do tempo e obtendo valor máximo próximo de dois meses após a aplicação. Nos três experimentos, verificou-se que apesar do extrator ácido acético indicar maior teor de Si no solo, o extrator cloreto de cálcio obteve dados mais coerentes quando comparado com o Si acumulado na parte aérea das plantas de arroz. Dessa forma, a utilização do Si pode constituir um componente útil para o manejo da adubação, tendo em vista que houve interação positiva com o P, que é um dos nutrientes mais limitantes nos solos brasileiros. / With the aim of evaluating the effects of the interaction between the silicon (Si) and phosphorus (P) in plant and soil, three experiments were carried. In the first experiment, the effect of two sources of Si (wollastonite and phyllosilicate) at different doses (0-250 mg dm- 3) on P recovery from triple superphosphate labeled with the radioisotope 32P was evaluated. We used the rice (Oryza sativa) as a test plant. In this first experiment, the two sources of Si promoted increase in the amount of the element in plants, but have different behavior regarding the production of dry matter of shoots and P uptake, with only the phyllosilicate promoted gains for these variables. It was found that the greater accumulation of P by the plant compared to the control treatment (without Si) was due to higher absorption of nutrients from the soil and fertilizer, and low utilization of the triple superphosphate by plants to the two sources of Si However, wollastonite released higher amounts of Si in the soil in relation to the phyllosilicate. In the second experiment the application forms (in groove or mixed with soil) of Si and P in P recovery from triple superphosphate for rice were evaluated. Applied a dose of Si (125 mg dm-3) intermediate from those used in the first experiment for both sources of Si, wollastonite and phyllosilicate, and the same dose of P (53 mg dm-3). According to the results of this experiment, the two sources of Si showed similar responses, with no differences for any variable analyzed. In the third experiment a test incubation (no plant) in which applied the same doses of Si in the first experiment (0 to 250 mg dm-3) and the same dose of P (53 mg dm-3) was performed to order to evaluate the behavior of the wollastonite for Si sources and phyllosilicate a function of time, between 0-90 days. Monthly collections of soil samples were taken. It was found that both sources of Si had the highest soil release in the next 60 days after application. The content of P in the third experiment (incubation ground), although it has been applied in a single dose, behaved similarly, and increased with the passage of time and getting maximum near two months the application. In three experiments, we found that despite the extractor acetic acid indicate higher Si content in the soil, the extractor calcium chloride obtained more consistent data when compared with the Si accumulated in shoots of rice plants. Thus, the use of Si can be a useful for fertilization management component, considering that there was a positive interaction with P, which is one of the most limiting nutrients in Brazilian soils.

Com o objetivo de avaliar os efeitos da interação entre o silício (Si) e o fósforo (P) na planta e no solo, foram realizados três experimentos. No primeiro experimento, avaliou-se o efeito de duas fontes de Si (wollastonita e filossilicato) em diferentes doses (0 a 250 mg dm-3) sobre o aproveitamento do P do superfosfato triplo marcado com o radioisótopo 32P. Utilizouse o arroz (Oryza sativa) como planta teste. Neste primeiro experimento, as duas fontes de Si promoveram incremento na quantidade do elemento nas plantas, porém tiveram comportamento diferente quanto à produção de matéria seca da parte aérea e de P acumulado, tendo apenas o filossilicato promovido ganhos para estas variáveis. Constatou-se que o maior acúmulo do P pela planta em relação ao tratamento controle (sem Si) foi devido à maior absorção do nutriente do solo e não do fertilizante, sendo baixo o aproveitamento do superfosfato triplo pelas plantas para as duas fontes de Si. No entanto, a wollastonita liberou maiores quantidades de Si no solo em relação ao filossilicato. No segundo experimento foram avaliadas as formas de aplicação (em sulco ou misturado ao solo) de Si e P no aproveitamento do P do superfosfato triplo pelo arroz. Aplicou-se uma dose de Si (125 mg dm-3) intermediária daquelas utilizadas no primeiro experimento para ambas as fontes de Si, wollastonita e filossilicato, e a mesma dose de P (53 mg dm-3). De acordo com os resultados desse experimento, as duas fontes de Si apresentaram respostas similares, não havendo diferença para nenhuma variável analisada. No terceiro experimento foi realizado um teste de incubação (sem planta), no qual se aplicou as mesmas doses de Si do primeiro experimento (0 a 250 mg dm-3) e a mesma dose de P (53 mg dm-3), a fim de avaliar o comportamento da liberação de Si pelas fontes wollastonita e filossilicato em função do tempo, entre 0 a 90 dias. Foram realizadas coletas mensais de amostras do solo. Verificou-se que ambas as fontes de Si apresentaram a maior liberação deste elemento no solo próximo aos 60 dias após a aplicação. O teor de P no solo, no terceiro experimento (de incubação do solo), apesar de ter sido aplicado em uma única dose, comportou-se de maneira similar ao Si, tendo aumentado com o passar do tempo e obtendo valor máximo próximo de dois meses após a aplicação. Nos três experimentos, verificou-se que apesar do extrator ácido acético indicar maior teor de Si no solo, o extrator cloreto de cálcio obteve dados mais coerentes quando comparado com o Si acumulado na parte aérea das plantas de arroz. Dessa forma, a utilização do Si pode constituir um componente útil para o manejo da adubação, tendo em vista que houve interação positiva com o P, que é um dos nutrientes mais limitantes nos solos brasileiros. / With the aim of evaluating the effects of the interaction between the silicon (Si) and phosphorus (P) in plant and soil, three experiments were carried. In the first experiment, the effect of two sources of Si (wollastonite and phyllosilicate) at different doses (0-250 mg dm- 3) on P recovery from triple superphosphate labeled with the radioisotope 32P was evaluated. We used the rice (Oryza sativa) as a test plant. In this first experiment, the two sources of Si promoted increase in the amount of the element in plants, but have different behavior regarding the production of dry matter of shoots and P uptake, with only the phyllosilicate promoted gains for these variables. It was found that the greater accumulation of P by the plant compared to the control treatment (without Si) was due to higher absorption of nutrients from the soil and fertilizer, and low utilization of the triple superphosphate by plants to the two sources of Si However, wollastonite released higher amounts of Si in the soil in relation to the phyllosilicate. In the second experiment the application forms (in groove or mixed with soil) of Si and P in P recovery from triple superphosphate for rice were evaluated. Applied a dose of Si (125 mg dm-3) intermediate from those used in the first experiment for both sources of Si, wollastonite and phyllosilicate, and the same dose of P (53 mg dm-3). According to the results of this experiment, the two sources of Si showed similar responses, with no differences for any variable analyzed. In the third experiment a test incubation (no plant) in which applied the same doses of Si in the first experiment (0 to 250 mg dm-3) and the same dose of P (53 mg dm-3) was performed to order to evaluate the behavior of the wollastonite for Si sources and phyllosilicate a function of time, between 0-90 days. Monthly collections of soil samples were taken. It was found that both sources of Si had the highest soil release in the next 60 days after application. The content of P in the third experiment (incubation ground), although it has been applied in a single dose, behaved similarly, and increased with the passage of time and getting maximum near two months the application. In three experiments, we found that despite the extractor acetic acid indicate higher Si content in the soil, the extractor calcium chloride obtained more consistent data when compared with the Si accumulated in shoots of rice plants. Thus, the use of Si can be a useful for fertilization management component, considering that there was a positive interaction with P, which is one of the most limiting nutrients in Brazilian soils.