Navegando por Assunto "Cerâmica"

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Acesso aberto (Open Access)
Application of bauxite waste from amazon region in the heavy clay industry
(2013-12) HILDEBRANDO, Edemarino Araujo; SOUZA, José Antônio da Silva; ANGÉLICA, Rômulo Simões; NEVES, Roberto de Freitas
In this work, a method was developed for the application of red mud, an alkaline leaching waste, from a bauxite processing plant located in northern Brazil (Amazon region) as starting material for heavy clay products. Samples were prepared by pressing blends of red mud and clay, which were then fired at temperatures from 900 ºC to 1190 ºC. Characterization was carried out by chemical analysis, differential thermal analysis (DTA) and X-ray diffraction (XRD), and the following ceramic properties were evaluated: water absorption, linear shrinkage and flexural strength. In order to evaluate the Na+ stability in the dense ceramic, leaching tests were also carried out on the specimens after sintering process. Results indicated that samples with 50 and 70 wt% of red mud are proper for being used in the production of ceramic bodies, due to its excellent properties, mainly high mechanical resistance and low water absorption, showing thus, an option to minimizing the environmental impacts caused by the aluminum industry.
Acesso aberto (Open Access)
Aprendizagem territorial, cooperação e inovação em espaços rurais: o caso da aglomeração ceramista de Eldorado dos Carajás (Pará/Brasil)
(Servicios Académicos Intercontinentales S.L., 2018-03) LEITE, Alegria dos Santos; FERNANDES, Danilo Araújo; SOARES, Daniel Araújo Sombra; KATO, Érika de Souza
The paper points out the ability of the ceramic industries in Eldorado dos Carajás, Southeast Pará, regarding to a local productive arrangement formation, in order to boost its outcomes for the improvement of local economic development indices. Therefore, this work by reasoning the evolutionary school background, which sees the cooperation as facilitators of learning, generation and dissemination of technological innovations as crucial for socio-economic development. In this sense, it was made a field research with surveys and the data were processed with statistical techniques of descriptive and multivariate analysis, whose purpose was to detect and identify underlying factors able to influence the possibilities of the companies reach a higher or lesser degree of inter-organizational integration and group companies in sets with homogeneous behavior patterns. The analysis showed extremely low indicators in the dimensions of learning and innovation, and null indicators in cooperation dimension. As well, these companies exhibited reduced levels of performance. These results are disappointing when considering the possibility of structuring a dynamic productive arrangement, the innovative character and which may give rise to a local innovation system.
Acesso aberto (Open Access)
Aproveitamento do rejeito de caulim na produção de alumina para cerâmica e sílica de baixa granulometria
(Universidade Federal do Pará, 2000-11-29) FLORES, Silvia Maria Pereira; NEVES, Roberto de Freitas; http://lattes.cnpq.br/9559386620588673
The Amazon region detains 10% of the world reserves of kaolim. Since the seventy's, two great amazonic beds of kaolim are explored, producing kaolim for paper cover. In the beneficiation process, it's generated an elevated volume of polluted industrial residue which is deposited in extensivas and onerous lagoons of sedimentation. Because of the residue is very voluminous, these lagoons become an environmental problem of great proportions, due the extensivas deforested areas used for their constructions ( Barata, 1998). In this work, are suggested altematives of economic utilization of this residue, which is constituted, mainly, by a suspension of the claymineral kaolinite, for the production of pozolane, aluminium sulphate, the synthesis of the ammonium alum and alumina for ceramics utilization. The methodology constitutes in the drying and the calcination of the residue, followed by the extraction of the AI retained by the acid lixiviation H2SO4 ) followed by the ammonium alum crystallisation, for the reaction with the concentrated NH4OH, by means of pH control, and later calcination at 1200°C, getting a-Al2O3, with no sodium and Iow granulometry. From the aluminas obtained, are made bodies of proof smashed and sintered at 1600°C, to the determination of the ceramics properties, which are compared to one of the commercial alumina. After the acid lixiviation for the AI extraction, results as an insoluble material, an amorphous silica, for which it is suggested, as an additional contribution, an economic application, using it as artificial pozolane in building portland cement, making mechanics tests for the evaluation of its performance. The material that were used and synthesized were characterized throught the use of the X ray diffraction, eletronic scanning microscopy, the infra-red spectroscopy, thermogravimetry, differential thermic analisys, particle size analysis, specific area BET, porosity, chemical analisys throught umid means and throught X ray fluorescence.
Acesso aberto (Open Access)
“Aqui... a gente não vende cerâmica, a gente vende é cultura”: um estudo da tradição ceramista e as mudanças na produção em Icoaraci – Belém – PA
(Universidade Federal do Pará, 2006-10) XAVIER, Leandro Pinto; CAMPELO, Marilu Marcia; http://lattes.cnpq.br/8338592541775616
Acesso aberto (Open Access)
Avaliação da durabilidade de concretos produzidos com agregados graúdos reciclados provenientes de cerâmicas vermelhas com diferentes taxas de pré-saturação
(Universidade Federal do Pará, 2013-09-05) REIS, Felipe José Losada; SOUZA, Paulo Sérgio Lima; http://lattes.cnpq.br/4933212993218783
The amount of waste generated by the construction industry has been calling attention lately due to the size with which acts as the environmental impact of using non-renewable natural sources materials and increasing the amounts of waste produced by the urban environment. In Brazil, this estimate is around 90,000 tons generated per day. The proposed use of aggregate from CW ( construction waste ) as part of structural concrete becomes even more interesting from the moment we are seeking a reduction in costs for the production of concrete , carrying environmentalist mentality when sparing use of natural resources which some are already starting to run out. Banks of sand and pebble sources begin to fade due to the wide use of these aggregates in the concrete produced in Belém and inland cities in the state of Pará. The need for new sources of aggregates makes us seek in construction waste likely sources of aggregates responding in a similar fashion to natural. Considering this proposal, this dissertation evaluated the durability of concrete produced with the addition of ceramic CW through trials of water absorption by capillarity, carbonation, chloride ion penetration and electrical resistivity. To that end, we replaced the natural coarse aggregate by ceramic coarse aggregate by 50%, where this percentage of recycled aggregate was subjected to the rates of pre - saturation of 60 %, 80 % and 100 %. According to the results it can be seen that the presence of RCCA (recycled ceramic coarse aggregate), regardless of the degree of pre- saturation was significant in all the results, the fact that the concrete while leaving more susceptible to loss of durability, it showed a pattern of behavior in relation to the reference mixtures. The closest matches conventional concrete mixtures were made by containing pre- saturated with water at a rate of 80 % ceramic aggregates.
Acesso aberto (Open Access)
Caminhos dos saberes: a cerâmica de Icooraci-PA, elementos históricos e influências
(Universidade Federal do Pará, 2017-06) BRITO, Geovana Nascimento Brito; SALIS, Dione Vieira
Film production that presents itself is the result of a research carried out on ceramic parts in the region of Icoaraci-PA. When we visited the area of sale of Mr. Rosemiro Pereira, we came across a set of knowledge acquired by him, during his 69 years of profession, what gave us go a long way through their narratives, the historical and aesthetic influences of the ceramics produced in Icoaraci: marajoara, tapajônicas, maracá and rupestre. The images were recorded in October 2016 in Icoaraci-PA.
Acesso aberto (Open Access)
O caulim duro da região do rio Capim, Pará: mineralogia, geoquímica e avaliação das propriedades cerâmicas
(Universidade Federal do Pará, 2003-02-28) CARNEIRO, Bruno Santana; NEVES, Roberto de Freitas; http://lattes.cnpq.br/9559386620588673
Acesso aberto (Open Access)
Ceramic raw materials from the State of Maranhão, Brazil. Part 1: chemical and mineralogical characterization and technological properties of clays from São Luis, Rosário, Pinheiro and Mirinzal
(2012-12) MERCURY, José Manuel Rivas; CORREIA, Gricirene Sousa; VASCONCELOS, Nazaré do Socorro Lemos Silva; CABRAL JÚNIOR, Aluísio Alves; ANGÉLICA, Rômulo Simões
This work involved the characterization of clays collected in the municipalities of São Luis, Rosário, Pinheiro and Mirinzal (state of Maranhão, Brazil), based on specific mass, specific surface area, cation exchange capacity (CEC), particle size distribution, X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG-DTA) and Atterberg limits. Technological tests for ceramic applications were also carried out on compacts pressed under 20 MPa and heat-treated at 850, 950, 1050, 1150 and 1250ºC. Our results indicated that two of the clays composed of kaolinite, quartz, and anatase with high plasticity limits, have excellent properties and can be used in the whiteware industry. The other ones are red-firing clays and have a mineralogical composition of quartz, kaolin, feldspar, montmorillonite, hematite and goethite. The latter showed low and moderate values of plasticity, which makes them suitable for the production of heavy clay products.
Acesso aberto (Open Access)
Contrastes químicos, mineralógicos e de fertilidade entre solos tipo terra preta arqueológica: sítio da Mata, no limite Oriental da Amazônia, e sítio Porto de Santarém, no Baixo Amazonas
(Universidade Federal do Pará, 2012-06-18) SILVA, Uibirá Sena; KERN, Dirse Clara; http://lattes.cnpq.br/8351785832221386; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302; https://orcid.org/0000-0002-0134-0432
Dark Earth sites are usually found in Amazonian Region. They stand out for their great content of ceramic fragments, urns, and lithic artifacts. Their soils present higher fertility if compared with the neighboring soils. Amazonian Dark Earths origins are related to pre-historic human activity of people who lived in ancient settlements in Amazonian Region for long periods of time. Recent researches reveal that the ceramic fragments from those sites present fertility as high as the soils, and even higher; and for that reason, when the ceramics fragments are exposed to weathering conditions, they could constitute in a potential source of nutrients for the soils that surround them. This study investigated the properties of soils and ceramic fragments from two ABE sites in distinct regions within the Amazon: Sítio da Mata, in São Luís City, Estate of Maranhão, region of forest-savanna transition; and Sítio Porto de Santarém, at the Tapajós River’s outfall, a former rain forest area that is currently intensively urbanized. This research aimed to characterize and compare the material from both sites, and correlate them to de different geomorphologic contexts in which they’re inserted. In the Sítio da Mata was sampled material from the ABE soil profile and from adjacent soil profile, and in Sítio Porto de Santarém, was sampled material only in the ABE soil profile. The samples comprised both soil and ceramic fragments matrices. The material was subjected to particle size analysis (soil samples only), X-Ray Diffraction (XRD) analysis, total chemical analysis by ICP-MS/OES, and fertility parameters analysis. Phosphorus fractionation was also performed in aim to determine the phosphorus species (P-Ca, P-Fe-Al, and organic P) present in soils and ceramic fragments samples. This study investigated the properties of soils and ceramic fragments from two ABE sites in distinct regions within the Amazon: Sítio da Mata, in São Luís City, Estate of Maranhão, region of forest-savanna transition; and Sítio Porto de Santarém, at the Tapajós River’s outfall, a former rain forest area that is currently intensively urbanized. This research aimed to characterize and compare the material from both sites, and correlate them to de different geomorphologic contexts in which they’re inserted. In the Sítio da Mata was sampled material from the ABE soil profile and from adjacent soil profile, and in Sítio Porto de Santarém, was sampled material only in the ABE soil profile. The samples comprised both soil and ceramic fragments matrices. The material was submitted to particle size analysis (soil samples only), X-Ray Diffraction (XRD) analysis, total chemical analysis by ICP-MS/OES, and fertility parameters analysis. Phosphorus fractionation was also performed in aim to determine the phosphorus species (P-Ca, P-Fe-Al, and organic P) present in soils and ceramic fragments samples. ABE from both sites showed high contents of the sand fraction, and soil texture varied from silty-loam to loam sand in Sítio da Mata and sandyloam in the entire ABE profile in Sítio Porto de Santarém. Mineralogical composition in both soils showed no significant differences: they consist most of quartz and kaolinite as primary mineral phases, and anatase and muscovite as accessory mineral phases. Chemical analysis reveal that the soils are composed most for SiO2 and Al2O3, confirming the mineralogical results, and Fe2O3 and TiO2 in minor quantities. P2O5, CaO, K2O and MgO are present in amounts below 0,5%, however, they show higher values in the soils from Sítio Porto de Santarém if compared to Sítio da Mata. Among the trace elements analyzed, only V, Cu, Zn, Sr and Ba stand out, and also show higher values in Sítio Porto de Santarém’s soils. Amounts and distribution patterns for Rare Earth Elements (REE), when normalized by condrits, are similar in both sites, showing enrichment of Light REE, strong positive anomaly for Ce, and negative anomaly for Eu. Differences only in the available P, Ca2+ and Mg2+ contents, although in relatively low values, suggest different anthropic influence over the pre-ABE soils. ABE soils from Sítio Porto de Santarém show higher fertility given for the higher contents of available P, ranging from 72,9 to 305,7 mg Kg-1, and Ca2+, ranging from 3,52 to 5,16 mg Kg-1, compared to 5,4 to 12,7 mg Kg-1 of P content and 0,96 to 2,31 mg Kg-1 of Ca2+ content in Sítio da Mata’s soils. Cation Exchange Capacity (CEC), sum of bases, base saturation and soil organic matter (SOM) were also higher in ABE from Sítio Porto de Santarém. Ceramic fragments from both sites are composed by quartz and metakaolinite, and also illite and anatase. Albite and microcline were detected only in ceramic fragments from Sítio Porto de Santarém. Therefore, they are composed mainly by SiO2 and Al2O3, and in smaller amounts, by Fe2O3 and TiO2. At Santarém, however, ceramic fragments contain also high amounts of P2O5, ranging from 3,49% to 5,37%, and the values for CaO, K2O, Na2O, Cu, Zn, Sr and Ba exceed those from Sítio da Mata. The contents and distribution pattern for REE are similar in ceramic fragments from both sites, with enrichment of LREE, positive anomaly for Ce and negative anomalies for Eu and Ho. Therefore, the ceramic fragments from both sites are mineralogicaly distinct, although they’re immersed in a similar soil matrix. The presence of phosphorus is compatible with others ceramic fragments found in different ABE sites. The fertility of ceramic fragments from Sítio Porto de Santarém showed better rates, with slightly higher pH if compared to ceramic fragments from Sítio da Mata, higher amounts of available Ca2+, K+ and mainly available P, besides higher CEC, sum of bases and base saturation, corroborating the higher fertility of the soils from Sítio Porto de Santarém. Phosphorus fractionation shows that in soil matrix from the studied sites, phosphorus is mainly related to organic compounds, while in ceramic fragments matrix, it is mainly related to nonapatite inorganic compounds. Apatite phosphorus is present in small amounts in both soil and ceramic fragments matrices. Therefore, it is likely that phosphorus present in organic material discarded by ancient people, as various kind of bones, among others, when submitted to tropical pedogenesis, were gradually dissolved, releasing phosphorus, which was partially fixed as Fe-Al phosphates, common mineral phases in tropical soils, as well as organic matter, abundant in ABE, respectively representing the nonapatite inorganic phosphorus and the organic phosphorus fractions.
Acesso aberto (Open Access)
A etnomatemática e a etnofísica da cerâmica produzida na Vila “Cuéra” em Bragança (PA)
(Universidade Federal do Pará, 2018-10-10) ROSARIO, Samuel Antonio Silva do; SARAIVA, Luis Junior Costa; http://lattes.cnpq.br/8517177215677066; https://orcid.org/0000-0002-3938-7658
Acesso aberto (Open Access)
A física da argila: um estudo visual sobre a produção de cerâmica na comunidade Vila Que Era
(Universidade Federal do Pará, 2020-09) ROSARIO, Samuel Antonio Silva do; SILVA, Carlos Aldemir Farias da
Acesso aberto (Open Access)
Os fragmentos de cerâmica arqueológica como fonte potencial de fertilidade dos solos TPA
(Universidade Federal do Pará, 2014-09-26) RODRIGUES, Suyanne Flavia Santos; KERN, Dirse Clara; http://lattes.cnpq.br/8351785832221386; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302
Soils of the Amazon Dark Earth (ADE) type are known for their high fertility, which contrasts with the typically poor soils found throughout most of the Amazon. The fertility of these soils appears to persist even after their intensive use for agriculture. The ADE are usually rich in sherds, important evidence linking them to the occupation of the region by prehistoric populations. Many studies have focused on the stylistic characteristics of the vessels represented by these sherds, although less attention has been paid to the chemical and mineralogical features of this material, which are important for the identification of the raw material use to produce the artifacts, provenience, technology, and in particular the origin of their relatively high P content. These high levels of P are derived from aluminum phosphates, which are generally amorphous to variscite-strengite, and have been linked to the use of the pots for the preparation of food. While the possible role of the sherds in the maintenance of the fertility of ADE has been widely discussed, no experimental data have been presented to confirm this connection. This study presents systematic evidence that the sherds contribute to the fertility of the soils. For this, sherds were obtained from three archeological sites with distinct characteristics located in different parts of the Amazon: Monte Dourado 1 (Almeirim, Pará), Jabuti (Bragança, Pará), and Da Mata (São José de Ribamar, Maranhão). Initially, 325 sherds were first described mesoscopically and then their chemical and mineralogical composition was determined by XRD, optical microscopy, TGA/DTA, FT-IR, SEM-EDS, ICP-MS and ICP-OES. Different parameters of fertility were then measured, followed by gaseous adsorption tests, and finally, P desorption assays. These data were used to identify the raw materials used in the fabrication of the vessels, details of the productive process, modifications occurring during the use of the utensils and after being discarded, with the aim of evaluating the potential contribution of these sherds to the fertility of the ADE soils. The hypothesis of contamination by nutrients from foods during the use of the vessels for the preparation of meals was confirmed by a laboratory experiment simulating cooking conditions using ceramic pots similar to the archeological artifacts, and measuring the incorporation of Ca and P during the cooking process. The results indicate that the ancient ceramicist peoples used raw materials available in the area surrounding their habitation sites. The composition of the sherds, all of which are made from a matrix of metakaolinite and quartz, and occasionally muscovite, indicating raw materials rich in kaolinite and quartz, which are fundamental to the production of ceramic artifacts. The presence of metakaolinite indicates that the pots were fired at approximately 550°C. However, the addition of different types of antiplastic contributed to chemical and mineralogical variation among sites in the overall composition of the sherds. At Da Mata, only cariapé was used, while at Monte Dourado 1, the cariapé was mixed with crushed rocks with a complex mineralogical content, and at Jabuti, shells were used in addition to cariapé. Amorphous phosphates are common to all the sites, albeit at distinct levels, with crystalline aluminum phosphates of the crandallite-goyazite type being found only at Jabuti, and Fe-Mg-Ca phosphates, segelerite, being exclusive to Monte Dourado 1. The amorphous phosphates and crandallite-goyazite were considered to be indicators of the use of the original pots (from which the sherds were derived) for the preparation of food, whereas the segelerite was interpreted as a neoformation following exposure of the fragments to the hydromorphic conditions that persist to the present day. The lowest phosphorus concentrations-1.04% of P2O5 on average- were recorded at Da Mata, and were similar to the majority of sherds studied up until now, whereas the highest concentrations (a mean of 7.75%) were recorded at Jabuti, the highest values yet reported. At Monte Dourado 1, the mean concentration was 2.23%. It seems likely that the high levels of P, Ca, and Sr are related to a diet rich in shellfish, as reflected in the diversity of shells fragments found in the sherds. The high levels of calcium recorded at Monte Dourado 1 reflect the presence of labradorite in the temper. The potential fertility of the sherds is clearly greater than that of the ADE soil when analyzed without the ceramics. It thus seems reasonable to assume that the sherds are the source of the macro- and micronutrients found in the soil. This was confirmed through desorption assays, which showed that P was desorbed at a slow rate, a characteristic which may be especially important for the persistence of fertility. This process is best described by the Freundlich model, which indicates the occurrence of interactions among the adsorbed ions. The experiment that simulated cooking conditions indicated that the Ca and P may be adsorbed into both the sides and lids of the ceramic pots, albeit with higher concentrations being accumulated in the sides. While calcium was adsorbed, no phase of this element was identified, either amorphous or crystalline, probably because the duration of the experiment was too short. By contrast, the chemical adsorption of the P did occur, and after 600 h of cooking, variscite, an aluminum phosphate, formed in the sides of the pots. Aluminum phosphates may thus form in the ceramic vessels during the cooking of food. These results indicate that the presence of aluminum phosphates in the matrix of the ceramic vessels represents a reliable indicator of their use as cooking vessels, and that the sherds of these utensils in the soil constitute a potentially important source of fertility.
Acesso aberto (Open Access)
Mineralogia, química e avaliação da fertilidade potencial de fragmentos cerâmicos de sítio de terra preta: Caxiuanã, Juruti, Barcarena e Quebrada Tacana.
(Universidade Federal do Pará, 2010-06-24) SILVA, Glayce Jholy Souza da; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302
Small areas with Amazonian Dark Earth (ADE) soils stretch across the Amazon region. Among its most striking features stand out the high nutrient content and contain human occupation remains. Ceramic fragments are the most frequently recovered in these soils. The high content of phosphorus in the ADE has long been reported and recent studies show that the fragments also contain them. In order to relate the fertility of the ADE to the abundant presence of ceramic fragments, this work aimed to investigate the chemical and mineralogical composition as well as evaluating the fertile character of the fragments and their ability to release nutrients to the soil. For this goal it was selected 44 ceramic fragments collected at four sites: Barcarena, Caxiuanã, Juruti and Tacana at Leticia in Colombia. The mineralogical analysis was performed by x-ray diffraction (XRD), and the determination of antiplásticos and textural aspects of optical microscopy and scanning electron microscopy. The composition was determined by ICP-MS via alkaline fusion. The extraction of the nutrients phosphorus, potassium, calcium, copper, zinc, manganese, magnesium, iron and sodium was performed with Mehlich 1. In the desorption tests were used only suspensions containing citric acid (pH 4.5-5.5) in allusion to the presence of humic acids in TPA soils. The fragments contain quartz and metakaolin as common stages and distinguish each other by the presence of talc, calcite and hematite fragments in Raimundo site; chlorite in Quebrada Tacana and Barcarena; cristobalite in Raimundo and Quebrada Tacana. The high content of SiO2 and Al2O3 agree with the dominant mineralogy, quartz and kaolinite; K2O composes the feldspars and micas, especially in Juruti; CaO are in low concentrations, except for Raimundo because of the presence of shells in both fragments and in the soil; whereas P2O5 reached values of 0.9, 2.9 and 4.7% in the fragments of the Raimundo, Quebrada Tacana and Juruti sites, respectively, without finding crystalline mineral phase; in Barcarena is virtually absent. The microcrystalline nature of the metakaolinite plasmic observed under an optical microscope, constitutes the matrix. The amorphous nature is indicated by the high background observed in most diffraction patterns and the classification as metakaolinite as permitted by the high content of SiO2 and Al2O3; together they represent more than 50% of bulk composition. The tempers ranged from according to the origin of the fragments. Cariape is common in the fragments of Raimundo, Quebrada Tacana and Barcarena; cauixi in Juruti’s fragments; coal in Quebrada Tacana, while shells are restricted to fragments of Raimundo. The results for fertility showed that the fragments of Quebrada Tacana and Juruti stand out in the contents of available P reaching 1045 e 2250 mg/dm³, respectively, while very low concentrations of this nutrient were found in Barcarena fragments. With reference to exchangeable K all fragments showed high contents, the largest variations were found for Zn, Mg, Mn, while exchangeable Ca stood out in fragments of the Raimundo site. Tests for desorption prove that the fragments release nutrients, especially phosphorus, found in high contents in samples from the Quebrada Tacana and Juruti, and even nutrients like calcium and magnesium, present in low concentrations also undergo desorption. These results indicate that ceramic vessels were made from basic clayey raw material, common, represented by kaolinite and quartz, in other words clays. The mineralogical variations are reflections of local geology and the different tempers added to the ceramic. The kaolinite present in some fragments is a new-formed product from the changes experienced by the fragment rich in SiO2 and Al2O3. The metakaolinite is a product of burned of raw material (rich in kaolinite). Different tempers added could be related to preference or availability of each people in the region, whose importance for the manufacture of ceramic materials was known. The nutrient contents of the fragments are favorable to agriculture, especially phosphorus (except in Barcarena) and potassium. Moreover, they are able to release them in the presence of an organic acid, which is common product of decomposition of organic matter and is exuded by the roots of some plant species, indicating that the fragment can assume the same behavior in the soil.
Acesso aberto (Open Access)
Oleiros da “Fazendinha”: entre o capital e o saber ecológico na produção da cerâmica caeteuara
(Universidade Federal do Pará, 2016-12) SILVA, Aline Costa da; ARAÚJO, Lorram Tyson dos Santos
Antônio Maria Macêdo is part of the third generation of a family of Portuguese descent who works in the production of caeteuara ceramics, in a community known as Fazendinha, in the municipality of Bragança-Pará. The video records, in the person of Mr. 102 Nova Revista Amazônica – ANO IV – Volume 3 – DEZEMBRO 2016 – ISSN: 2318-1346 Paixão, that behind the pieces manufactured by hand and recognized in the region, there are ecological knowledge simbricados, fruits of the interaction of the family that works in the production of the crafts and its relationship of appreciation and affection with the environment . In the process of making the pottery, the use of the seed bathed in the oil of andiroba, the white clay without odor carefully removed from the várzea, the guard of the roots of the Siribeira on the banks of the Caeté and the aesthetics of the road built crooked to the river, because More beautiful, exemplify the symbiosis between man and nature, whose relationship seeks, in the face of the need for survival, to reconcile the conquest of capital with the environmental preservation carried out by man
Acesso aberto (Open Access)
Transformações térmicas e propriedades cerâmicas de resíduos de caulins das regiões do rio Capim e do rio Jari – Brasil
(Universidade Federal do Pará, 2006-03-23) MARTELI, Marlice Cruz; ANGÉLICA, Rômulo Simões; http://lattes.cnpq.br/7501959623721607; NEVES, Roberto de Freitas; http://lattes.cnpq.br/9559386620588673
Mullite, Al6Si2O13, is a relatively rare mineral in nature, formed under exceptional conditions of high temperature and pressure, which can be used to synthesize this mineral. Mullite presents excellent mechanical resistance at high and normal temperatures; low thermal expansion coefficient; good chemical and thermal stability. Such characteristics explain the importance of mullite in traditional and advanced ceramics. This research proposes the development of a process to synthesize mullite using the wastes from kaolin processing industries located in the rio Jari (Monte Dourado-PA) and rio Capim (Ipixuna-PA) districts. Preliminary studies are made on the synthesized materials for application as base materials for grog and silicon-aluminum refractory bricks. The steps are: (a) mineralogical and chemical characterization, verifying the differences between the materials; (b) processing through calcinations of the wastes at increasing levels of temperature with 100 oC increments, ranging from 600 to 1500 oC, during 3 hours at each level, so mineralogical changes can be observed and; (c) the study of temperature and impurities effects through X-ray powder diffraction, scanning electron microscopy, green bodies cleavage, thin layer and polished section; and of ceramics properties, through green bodies retraction (shrinking). The results of this work indicate that detrites from kaolin industries at rio Jari and rio Capim are constituted mainly by kaolinite. The PR samples showed a higher level of structural order than the CR samples. The increase in calcination temperature favored agglomeration in both samples. A higher content of Fe in the CR samples influenced mullite formation, activation energy, and linear shrinking in sintering. Also, through to the results of the refractarity essays, both industrial waste samples showed that they can be used as starting materials for refractories and grog.
Acesso aberto (Open Access)
Utilização da opção de diferimento na avaliação de implantação de projeto de mecanismo de desenvolvimento limpo em uma empresa de cerâmica vermelha
(Universidade Federal do Pará, 2009-09-25) NEGRÃO, Léony Luis Lopes; ICHIHARA, Jorge de Araújo; http://lattes.cnpq.br/5726366418302065
The evolution of the theory of option pricing considers a set of tools to manage and exploit the value arising from the uncertainty and volatility that expand the parameters of the value-adding to the concepts of managerial flexibility. Within this context, this study was to evaluate the implementation of economically Clean Development Mechanism in a red ceramic company located in Production Arrangement of Bindure, northeastern Para The evaluation aims to demonstrate the value of managerial flexibility of Deferral adjustments made according to the methodology proposed by Copeland & Antikarov (2001), which adds to the traditional evaluation of the discounted cash flow Real Option – OR – that the research found, and it is based by means of literature review to formulate the method. This follows a determination of the essential steps for the analysis of the variables that comprise the model, and has allowed the ordering of the results for the values of the OR considered including value present and managerial flexibility, with the method the company object of research. Finally, as a result of this study concluded that the Theory of Real Options through Option Deferral or Postponement contribute information to assist in management decisions to invest in projects when compared to traditional methods of evaluation are considered as uncertainties inherent in the project as the real environment.