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Navegando por Assunto "Lama vermelha"

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    ItemAcesso aberto (Open Access)
    Absorção de gases da queima de combustíveis fósseis em torre de recheio estruturado utilizando lama vermelha
    (Universidade Federal do Pará, 2013-03-11) SANTOS, Iara Ferreira; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; SOUZA, Célio Augusto Gomes de; http://lattes.cnpq.br/0800747860976046
    The production of alumina from the Bayer process produces 1-3 tons of waste per ton of aluminum. This residue is known red mud, compound of minerals insoluble in concentrated sodium hydroxide, hematite and other iron oxides, quartz and titanium oxides. The red mud has in its composition varied levels of NaOH, depending on the specific industrial plant used. The purpose of this study is to evaluate the process of absorption of gases from a boiler countercurrent with a suspension of red mud, in a spray tower and a packed column. Experiments were performed varying the type of absorption tower, temperature of the liquid phase and solids content in liquid phase to evaluate the reduction in content of gases of combustion in the output of absorption tower and pH variation with time of operation, it was possible to identify the time required for the occurrence of red mud neutralization, and also a reduction in the content of carbon dioxide, thereunto were performed measurements of the concentrations of gasesin the input and output packed column, and also measurements of temperature and pH. The absorption of CO2 existing in the gases of combustion for suspension of red mud occurs by the carbonation process, where the gas reacts with NaOH present in red mud, with water as catalyst. The results obtained after the experiments were satisfactory, and it was concluded that the process performed in absorption towers is efficient for pH reduction of red mud and reducing the content of CO2 freed to atmosphere, providing a double profit for the environment.
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    Absorção do dióxido de carbono por resíduo de bauxita em torres de absorção
    (Universidade Federal do Pará, 2013-03-04) BOTELHO, Fernando Aracati; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
    One of the most discussed environmental problems on the world scene today is global warming and its implications. Although the greenhouse effect is a natural phenomenon, the increase in emissions of gases such as CO2 from the combustion process may favor its aggravation. Following this line, there is interest in conducting research to minimize the release of this gas in the atmosphere. This work aims to study the process of absorption of carbon dioxide by aqueous phase of bauxite residue (soda and dissolved ions in solution) in spray tower and tower saddles random (both pilot scale), as well as check the pH change in this absorption process to both towers. Evaluate pH change and CO2 absorption capacity by considering the following variables: the type of absorption tower, using the supernatant as the absorbent means and the use of the suspension heated by resistances. The results showed that the suspension of bauxite residue absorbed significant amount of CO2, both the spray tower as the tower saddles. The average absorption rate was around 8.42% for the spray tower and 9.34% for the tower saddles. The ability carbonating the suspension of 27%-p was about 33.3 kg CO2 per tonne of waste and there was a substantial reduction of the alkalinity of the residue by reaction with gaseous effluents with a mean decrease of 4.0 and 3.5 pH units for the tower saddles and sprinkler respectively.
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    Adsorção de lixiviado em carvão de caroço de açaí (Euterpe Olerácea)
    (Universidade Federal do Pará, 2019-05-23) LESSA, Luana Cristina Pedreira; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; ALMEIDA, Hélio da Silva; http://lattes.cnpq.br/0071472719215354
    This study investigated the adsorption of leachate on filter paper with adsorbent poder (coal of açaí and red mud) and the adsorption of leachate previously filtered and then adsorbed on adsorption column with granular fixed bed (coal of açaí). The charcoal used is of vegetal origin generated by a thermo-catalytic cracking process of açaí stone (Euterpe Olerácea), impregnated with sodium hydroxide 2 mol.L-1 (NaOH). The açaí cores were collected from commercial establishments located in the Guamá neighborhood in the municipality of Belém-PA. The leachate was collected at the Central of Processing and Treatment of Urban Waste - CPTR in periods considering the seasonality of the region. It was obtained that for the physical-chemical characterization of the crude leachate the seasonality interferes in the concentrations of the leachate. The mean values of the BOD5/COD ratio indicate that the leachate has recalcitrant elements and low biodegradability characteristics. With the use of the red mud in the preliminary adsorption tests it was concluded that it is an environmental liability to be considered for treatment of leachate by adsorption, since it reduced the total solids concentration. In the preliminary adsorption tests carried out in a series batch and in the column adsorption tests also in the series the acaí coal leaching occurred in the effluent to be adsorbed, thus increasing the concentration of total solids in the final effluent. After adsorption tests in the adsorption column, pH, alkalinity and total solids values increased, however, COD and chloride concentrations decreased. The control chart graphs, for the variation of the COD concentration over time, showed that the adsorption processes were kept under the control according to the method. The mass adsorption of 1000 g of filtered leachate presented the best percentage of removal efficiency for COD, with 75%. The adsorption isotherm model that was best fitted to the experimental data after linearization was the Freundlich model, with R2 of 0.9985. However, by this model the adsorption isotherm was considered as unfavorable, that is, at high solute concentrations the coal does not perform favorable adsorption. The results obtained denote the technical viability of leachate treatment by the use of açaí coal impregnated with 2 mol.L-1 NaOH and crude red mud.
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    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.
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    Avaliação da qualidade dos sedimentos de fundo do Rio Murucupi, Barcarena-PA.
    (Universidade Federal do Pará, 2011-07-15) REIS, Rafael Melo dos; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568
    The development of industrial and urban centres in Barcarena often causes substantial changes in the bodies of water of surrounding areas, primarily in water quality, as a result of inputs of potentially toxic trace elements, as shown the studies of Pereira et. al. (2007), Víglio (2008), Porto (2009) e Pereira (2009). In addition, major environmental accidents has been recorded, mainly related to the disruption and overflow of accumulation dams of industrial waste. In this context, in 2003 and 2009, the river basin Murucupi, wich incudes the urban centres of Vila dos Cabanos and Laranjal, was contaminated by rejects from the beneficiation process bauxite, known as “red mud”. The objetive of this study was to assess preliminarily the bed sediment quality of Murucupi river and distribution of major elements (Al2O3, Fe2O3, TiO2 e Na2O) and trace (Zr, V, Cr, Th, Hf, Ga, La, Sc, Pb, Nb, As, Cd, Cu, Hg, Ni e Zn), enriched in red mud, along the river. For this, triplicate cores were collected with 50 cm deep in bed sediments, in seven ponits along the Murucupí river, in the 5,3 km stretch between the access bridge to the Vila dos Cabanos (M-1 point) and the river mouth (M-7 point). Each sediment core collected in the field was subdivided into five depth intervals in the laboratory: 0-10 cm (A interval), 10-20 cm (B interval), 20-30 cm (C interval), 30-40 cm (D interval) e 40-50 cm (E interval). The triplicate samples from each respective depth interval were then thoroughly homogenised, and later, size, mineralogical and chemical analyses were performed in each sample. The results showed that the sediments are primarily composed of quartz, mica group of minerals, priority muscovite, and albite, in addition to clay – kaolinite, smectite and ilite. The superficial concentrations of the major elements P2O5 and S, and of the trace elements V, Cr, Ga, Pb, Hg and Zn, were higher in M-1 point with a strong decrease toward to mouth, indicating contamination by discharges of urban runoff and domestic sewage from the Vila dos Cabanos and Laranjal. In other hand, the superficial concentrations of S, As and Pb, were high in M-7 point, indicating contributions of these elements from the Arrozal stream, possibily arising from the port of Barcarena and surrounding areas, brought to the mouth of the Murucupi river through tidal movements. The concentrations of these trace elements into beb sediments were much smaller than values measured by Braga (2007) in red mud. This fact is associated to methodological differences used na chemical analysis and to thickness of the sample. However, the statistical correlations performed among Al and Cr, V, Ga and Th, and among Mg, K and Hf, La, Sc and Zr, as well as among Mg, K and the "silt + clay" particle size fraction over the depth, demonstrate that exist a "geochemical signature" of the events of contamination by red mud, recorded in A interval of sediment cores collected in the Murucupi river. The results obtained by the distribution of elements with depth showed that, in general, the major elements Al2O3, MgO and K2O are associated with “silt + clay” particle size fraction, and that the variations in the concentrations of the trace elements, mainly reflect environmental conditions more favorable for mobilization or persistence of these elements over the depth. With regard to the sediments quality, the concentrations mensured for each element were compared with sediment quality indices, known as Sediment Quality Guidelines – SQG, developed by Canada and adopted by Brazil through CONAMA resulution nº 344/2004, and with the indices “consensus-based”, developed by Macdonalds et al. (2000), and also, with reference values of background in the region. Some places, the bed sediments of Murucupi river showed concentrations above ISQG and below PEL for the following elements: 1) Cr in M-1 point, A (38,4 mg.Kg-1) and E (43,1 mg.Kg-1) intervals; 2) Ni in M-6 point, E (18,9 mg.Kg-1) interval, and in point B-1, A (18,6 mg.Kg-1), B (18,3 mg.Kg-1), C (18,4 mg.Kg-1) and E (18,3 mg.Kg-1) intervals; 3) As in M-1 point, C (5,9 mg.Kg-1) interval; and 4) Hg in M-1 point, E (0,199 mg.Kg-1) interval, and in M-2 point, E (0,233 mg.Kg-1) interval. These results indicating that, in these sites, adverses effects to benthic organisms may occur due the high concentrations of Cr, Ni, As and Hg in beb sediments, wich entails additional studies of bioavailability in sediments and toxicity in benthic organisms. Highlights that the elements Pb, Cu, Ni, As, Hg and Zn are enriched over the referece value of regional background at all points sampled in Murucupi river, being that the Cr enrichment also presented in relation to the concentration mensured by Nascimento (2007) in bed sediments of Guamá river. and Pb enrichment only at specific points, related to the hydrodynamics of the river. The results obtained for the Ni raised two hypotheses: 1) in the basins of the Murucupi river and of the reference stream, may exist difusal or eventual sources of contamination for the Ni; or 2) the Ni can be naturally enriched in the region, since the statistical correlations among Mg and Ni in the sediment cores of Murucupi river were good or excellent in nearly all depth intervals. In general, the results obtained showed that the contamination in sediments of Murucupi river is much more associated with difusal sources of pollution, probably from urban runoff and discarges of domestic sewage, than with the environmental accidents involving red mud.
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    Avaliação do tratamento de efluentes da indústria de alumina no contexto dos impactos da mineração na Amazônia Oriental
    (Universidade Federal do Pará, 2014-06-26) BARBOSA, Renata Kelly da Costa; BERRÊDO, José Francisco; http://lattes.cnpq.br/1338038101910673; FRANÇA, Silvia Cristina Alves; http://lattes.cnpq.br/9463680545957601
    The state of Pará has one of the world's largest mineral reserves, and bauxite, the rock from which aluminum is extracted is particularly plentiful here. However, the process for obtaining aluminum produces impactful environmental waste (red mud), a highly caustic residue. The general objective of this study was to characterize the effluent (solid and liquid phases) generated by alumina refining, and to evaluate the efficiency of the DAF ( Dissolved Air Flotation) process in order to improve the quality of this, so that it might be possible to reuse the water. The observed results were as follows: the chromium concentration in Pará River is higher than the legal limit. The riverbed sediment has low bioavailability due to its characteristics of silt and fine sand, and is composed mainly of quartz. The collected phytoplankton and oysters near the refinery showed high levels of aluminum and other chemical elements (Ca, Co, Cu, Mg and S), especially when compared with those from the control point. The red mud is composed of fine particles of chemical composition 50% Fe2O3 and Al2O3. DAF tests showed satisfactory results with solids removal efficiency reaching 99% with T-8 and 99.4% in the E-4f, with final turbidity values less than reached 8.5 NTU. The recycle ratio and the concentration of flocculant were shown to be important variables in the experiments, and showed exhibited better results in the removal efficiency of solids. Acute and chronic ecotoxicological tests showed good results in the efficiency of wastewater treatment by using the DAF. It is expected that this study will contribute to scientific knowledge, and may serve as an alternative for the treatment of effluent from the alumina industry. Moreover, the study reached important results that can help improve the quality of waste water and its reuse in the manufacturing process, which can reduce water consumption and environmental risks.
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    Caracterização das propriedades de fluxo da lama vermelha para fins de dimensionamento de silos: aplicação para tremonhas cônicas
    (Universidade Federal do Pará, 2013-10-07) LOBATO, Júlio César Mendes; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662
    One of the factors that affect the flow of bulk solids in silos is the moisture content, which stands out by favoring the formation of cohesive arches. In this sense, the aim of this work focused on determining the flow properties of the product red mud and its classification as to its flowability due to the variation of moisture content. Having the moisture influence on the flow in conical hoppers lined with smooth metal plates and UHMW (Ultra High Weight Polyethylene molecular ). To that end we used the direct shear apparatus "Jenike Shear Cell", along with the two wall surfaces. To determine the factor flow from the hopper and the angle of inclination to the horizontal, we used the graphics methodology proposed by Jenike for mass flow. And in determining the minimum diameter of the hopper, we applied the equations proposed by Jenike and Enstad. It was found that red mud is cohesive and has flow type hard with little variation for levels of moisture studied. The roughness of parades tested had a mild influence on the slope of the hopper. While the results of diameter variation experienced hopper relative moisture levels analyzed for red mud. From the observations made to flow in the silo acrylic model has been found that it rises to the level of moisture becomes more difficult the flow of red mud product.
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    Caracterização mineralogica do agregado obtido a partir da lama vermelha do processo bayer
    (Universidade Federal do Pará, 2014-12-27) REIS, André Wilson da Cruz; NEVES, Roberto de Freitas; http://lattes.cnpq.br/9559386620588673; MARTELLI, Marlice Cruz; http://lattes.cnpq.br/1213009262936026
    The industrial activities increasingly generate a lot of waste and by-products being stored in the environment, with physicochemical characteristics which can most often be reused. The red mud residue from the Bayer process, is being studied for use in the production of synthetic aggregates, which aims to replace natural aggregates used in construction. This work studies the physical, chemical and mineralogical characteristics of the aggregates synthesized from a mixture of red mud, clay, sand and charcoal in 4 compositions, varying amounts of red mud and clay. The raw materials were pretreated and analyzed by X-ray fluorescence, X - ray diffraction, thermal and particle size analysis. The samples were calcined at 1200 °C for 4 hours. Then subjected to analysis by X-ray diffraction, X- ray fluorescence, differential thermal analysis and scanning for characterization and physical tests electron microscopy. For the study of the observation of synthetic mullite aggregate specimens embedded in resin, and adding 5% HF for 3 to 4 minutes were made. The material presented after sintering, apparent specific gravity average below 2 g\cm3 main crystalline phases by XRD quartz and hematite and the presence of mullite from the HF treatment can be observed.
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    Comportamento de blocos cerâmicos estruturais produzidos a partir da mistura de lama vermelha e argila
    (2011-12) MACÊDO, Alcebíades Negrão; COSTA, Diogo Henrique Pereira e; TRINDADE, Sandro Roberto dos Santos
    The use of new techniques for waste reuse has become increasingly important in construction, especially when it deals with the use of waste from other industries and reduction on the consumption of natural materials. The purpose of this study was to evaluate the use of red mud (LV) waste, alumina metallurgical residue, on the production of structural ceramic blocks. The production of the blocks was carried out at a ceramic industry, using a mixture of 60% of red mud and 40% of clay. After the production of blocks, tests were conducted according to technical standards, such as water absorption and simple axial compression. From the analysis of the results, the conclusion was made that that structural blocks, made from the mixture of clay and LV, complied the standard parameters related to the rate of water absorption and compressive strength, and that the strength of theses blocks was significantly higher than those made from 100% clay.
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    Concretes with red mud coarse aggregates
    (2012-06) OLIVEIRA, Dênio Ramam Carvalho de; ROSSI, Carlos Rodrigo Costa
    Red mud (RM) is a mineral waste, residue of the Bayer process used to obtain alumina from bauxite. While the exploration of rolled pebble damages the environment and is much more controlled by the government, the huge RM disposal areas do not stop increasing and polluting soil, rivers and groundwater sources in Amazon. In this work, the material mixtures used to produce coarse aggregates presented up to 80% of RM, 30% of metakaolin and 30% of active silica as recycled waste. Several tests were carried out to determine the aggregates physical properties and to evaluate the mechanical performance of the concretes with the new aggregates, including hydraulic abrasion strength, and the results were compared to the reference ones, i.e. rolled pebble concretes. Additionally, the sintering process neutralizes any toxic substance as occur in some RM products like tiles and bricks, and these results have encouraged an industrial or semi-industrial production of RM aggregates for concretes.
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    Concreto com utilização de agregado graúdo sintético produzido a partir da lama vermelha: estudos de dosagem, propriedades e microestrutura
    (Universidade Federal do Pará, 2013-08-13) ROSÁRIO, Kátia Alrelhia do; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
    Currently sustainability issues have gained prominence on the world stage in various sectors of society. Several researchers (LIMA, 2006; Hildebrand, 1998; SOUZA, J., 2010, ROSSI, 2009, etc..) Have tried to propose an interaction between the construction industry and those who engage in mineral production and processing, such as the beneficiation of bauxite. In this context, finding viability for the recovery of waste generated in large quantities and no use would contribute to the preservation of the environment, insofar as it would reduce consumption of resources from natural sources and increase the supply of inputs in construction market. This work is discussed the feasibility of producing a concrete, it has characteristics which renders itself to use as raw material in the construction industry, by using an synthetic aggregate obtained from the red mud (bauxite waste improvement) . According to the experimental program to be executed, the aggregates and the concrete produced will have their properties analyzed in order to study the production process and measurement respectively. Aggregates are analyzes of: porosity, water absorption, bulk density and Los Angeles abrasion and concrete, workability, density in fresh and hardened, compressive strength, tensile strength by diametrical compression, tensile bending, water absorption and elastic modulus. It is noteworthy that significant importance is given to the transition zone paste / aggregate, by analysis of the microstructure of concrete produced. Analysis is performed by means of tests: Mercury intrusion porosimetry (MIP) and Scanning Electron Microscopy (SEM). The results of the analyzes of the synthetic aggregates and concrete produced satisfactory results, showing that they have potential for use in the construction industry.
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    Desacidificação de frações destiladas de produto líquido orgânico do craqueamento termo-catalítico de óleos vegetais via adsorção em y-alumina e lama vermelha ativada
    (Universidade Federal do Pará, 2015-04-16) COSTA, Karen Marcela Barros da; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
    This paper studied the adsorption of residual free fatty acids (carboxylic acids) present in distilled fractions from the Liquid Organic Product (PLO) obtained by thermal catalytic cracking of vegetable oil. The objective was to deacidification of distilled fractions obtained from the distillation of the PLO. The experiments were performed using different distilled fractions using three different adsorbents, y-Alumina, Red Mud Thermally activated (400 °C) and Red mud chemically activated with solutions of HCl in different concentrations (0.25, 1 and 2M). The adsorbent capacity relative to adsorption of free fatty acids was evaluated by means of kinetic studies, measuring the change in concentration of free fatty acids present before and after adsorption by determining the Acid Number. The results indicated that increasing the initial concentration of acids decreases the adsorption capacity of the adsorbent, showing that the process is less effective at higher concentrations. For experiments with different percentages of adsorbents seen that when using 0.5% adsorbent to obtain greater efficiency in the removal of fatty acids, which decreases with increasing percentage of adsorbent. The most efficient adsorbent was red mud activated with 1M HCl, which was obtained a reduction of 98% of the fatty acids to a sample with an initial acid number of 4 mg KOH/g. Mathematical modeling indicated that the kinetic model that best represents the process was the Pseudo Second- Order. Therefore, the results show that the adsorbents used are mostly effective in the removal of free fatty acids and the initial concentration of acids in the sample has a direct effect on the performance of adsorption thereof.
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    Desempenho estrutural de blocos, primas, mini-paredes e paredes de alvenaria estrutural confeccionadas com blocos cerâmicos produzidos a partir da mistura de lama vermelha com argila
    (Universidade Federal do Pará, 2014-03-27) COSTA, Diogo Henrique Pereira e; MACEDO, Alcebíades Negrão; http://lattes.cnpq.br/8313864897400179
    New techniques for the improvement of residues have become increasingly important in constructions, especially when it comes to the use of residue from other industries and the reduction of natural raw materials. The objective of this study was to evaluate the use of a residue from the production of metallurgical alumina known as red mud (RM), the structural performance of blocks, prisms, mini-walls and walls made of ceramic blocks with reticulated and circular cross sections, produced from the mixture of clay and RM. Experimental tests were performed corresponding to the characterization of the materials used and testing of compressive strength of units, blocks, prisms, mini-walls and walls. All materials and units met the standard requirements for their correct use in experimental tests. The results of compression tests have shown that elements of the blocks made by mixing clay and RM parameters met the standards and showed satisfactory and superior results to the components made of composite ceramic blocks with 100% clay, usually employed in constructions.
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    Desenvolvimento de uma estrutura sanduíche de base polimérica, produzida com resíduos das indústrias de mineração e metalurgia, para aplicação como painel divisório de ambientes internos na construção civil
    (Universidade Federal do Pará, 2016-07-05) MIRANDA, Rossana Martins; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
    The rechearch proposed to use solid wastes from kaolin and bauxite mining and metallurgical regional industries in a composite of sandwich structure to apply as internal divider panel environments. The blade was of unsaturated polyester matrix, double jute fabric and, kaolin waste (20 wt% polyester) and, the core, of polyurethane expansive and red mud (bauxite waste at process to get alumina), from 0 to 50 wt% PU (increasing by 10 to 10 wt%), in a total of 6 different treatments). The tests carried out were: blade density (ASTM C271/271M – 11), sandwich structure bulk density apparent, sandwich structure porosity, tensile test on the blade (ASTM D5083-10), flatwise tensile test on sandwich structure (ASTM C297/C297M - 04), edgewise compressive test on sandwich structure (ASTM C364/C364M–07), flatwise compressive test on sandwich structure (ASTM C297/C297M - 04), 3-point flexural test on sandwich structure (ASTM D7250/D7250M – 06 e ASTM C393/C393M – 11), Charpy impact test on sandwich structure (ASTM D6110 – 10), flammability test on blade and on sandwich structure (UL 94 - 96) and sound transmission loss test on sandwich structure (ISO 140-3:1995 - E). The results indicated that the choise of polymeric matrices was suitable to reduce weight of such structure mainly the use of a PU expansive. Increasing red mud not contributed to significant increase of sandwich structure bulk density apparent. Kaolin waste reinforcement increased resistance to blade on tensile test. Red mud reinforcement reduced sandwich structure resistance on flatwise tensile, flexural and impact tests. Increasing of red mud didn’t influenced sandwich structure edgewise compressive and flatwise compressive tests but, but it´s use at this sandwich structure, decreased their resistance at the first test and increased at the second test. The PU high flammability was delayed for being cloistered by two blades of polyester and kaolin, proving flame retardant property of kaolin waste. And about sound transmission loss test, the increase of red mud increased that until 20% concentration, after this, stabilized at 25 dB (STC) until 50% red mud. The composite, as a whole, presented feature of a sandwich structure, with a low density core, contributing to reduce structure weight and with higher resistant blades, providing it the desired structural feature to be a divider indoor panel.
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    Desenvolvimento de unidade piloto de transferência de massa gás/líquido: redução da reatividade do resíduo da indústria de alumina através da reação com gases de combustão
    (Universidade Federal do Pará, 2013-02) VENANCIO, Luis Carlos Alves; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505
    The bauxite refining using the Bayer process produces 0.7 to 2.0 tons of the residue known as red mud and about 1.0 ton of CO2 for each ton of alumina produced. The bauxite residue, although not particularly toxic, poses risks to the environment due to its large volume and reactivity. According to the latest technology, part of the moisture is removed and it is stacked on sealed areas specially constructed. More than 95% of the bauxite residue that has been produced (2.6 Bt until 2007) was discarded, especially in ponds on land. This thesis shows the design, construction and operation of a pilot scale gas liquid mass transfer unity with the objective of testing the reduction of the reactivity of the bauxite residue through a reaction with flue gas. As an additional gain, there is a reduction of carbon dioxide and sulfur dioxide emissions. This unity, with three reactors, was designed in order to consume minimal power, process the effluent as efficiently as possible and minimize the investment cost. Twenty-five experiments were realized with duration from 80 to 520 minutes each. The gases were analyzed at the entry and exit with electrochemical cells and non-dispersive infrared sensors. The pH was monitored during and after the reaction in order to evaluate the short and long-term results as well as the stability of the reactions. It was demonstrated the viability of reacting the bauxite residue with the flue gas from the refinery without previous processing with the stabilization pH reaching 10.5.
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    Efeito da adição de lama vermelha como carga nas propriedades mecânicas de compósitos de poliéster insaturado reforçado com fibra natural de curauá (Ananas erectifolius)
    (Universidade Federal do Pará, 2013-06-11) OLIVEIRA, Mauro Júnior Aires de; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/6157348947425968
    Nowadays, due to the increasing need for good mechanical performance and due to the environmental issues, researchers have tried to replace synthetic fibers used in composites (such as glass fiber) for natural fibers. A natural fiber that has already been used in the automobile industry is the curaua fiber (Ananas erectifolius) which shows excellent tensile strength. Expecting to enhance some properties of the composites and to minimize the usage of resin, and this way minimize costs, it has been researched the utilization of fillers incorporated to composites matrices. In recent papers, it has been studied the utilization of red mud (waste of the bauxite industry) as filler due to the great availability, low cost and for being potentially dangerous to the environment. The objective of this work was to evaluate effects of red mud addition on the mechanical properties of Curaua fiber (Ananas erectifolius) reinforced composites. The results showed that the using of red mud as filler in volume fractions equal or higher than 20% and Curaua fiber in volume fraction of 5% was improved significantly the reinforcing effect.
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    Estudo da aplicação da lama vermelha como catalisador na reação de craqueamento térmico catalítico de resíduos de caixas de gordura
    (Universidade Federal do Pará, 2015-07-02) EID, Janaina Guedes; BORGES, Luiz Eduardo Pizarro; http://lattes.cnpq.br/8756886156388456; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
    This study aimed to evaluate the use of residual fat taken from retaining grease traps as an alternative raw material in the biofuel production process. The catalytic process of thermal cracking of the residual fat was carried out in bench scale and pilot using the red mud (LV) calcined at 1000 ° C as catalyst at different concentrations (5%, 10% and 15%). Organic liquids (PLO's) obtained in the cracking experiments were distilled in a bench unit, which was the production of hydrocarbon fractions in bands of light green diesel and heavy green diesel. Thus, PLO'se fractions were characterized by carrying out physicochemical and compositional analysis where the results turned out to be compared according to the specifications established by the standard of ANP No. 65 for diesel S10. The produced in the PLO counter and cracking unit using the pilot content of 5% catalyst (LV calcined at 1000 ° C) when compared with experiments using concentrations of 10% and 15% of LV showed the best results for the acid value, kinematic viscosity and density, confirming that this experiment had one of the best yields of the process and significant results regarding the physicochemical and compositional analysis. Distillation processes of the PLO's done in the distillation unit in Bench Scale showed good yields for hydrocarbon fractions in heavy green diesel range. The heavy green diesel fractions obtained after distillation of the PLO produced with 5% catalyst content showed significant yield and the best physicochemical results of all fractions obtained in this study, especially with regard to the acid value. It was confirmed through analysis of the Infrared, nuclear magnetic resonance, and gas chromatography coupled to a mass spectrometer the presence of hydrocarbons in the composition of the organic liquids.
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    Estudo da extração de compostos de ferro da lama vermelha visando a extração e/ou recuperação de compostos de titânio
    (Universidade Federal do Pará, 2012-04) MAGALHÃES, Edilson Marques; MACÊDO, Emanuel Negrão; SOUZA, José Antônio da Silva; http://lattes.cnpq.br/8718370108324505; http://lattes.cnpq.br/6157348947425968
    The main concerns about waste generation are focused on the effects that these materials can have on human health and the environment, since the hazardous waste generated by industries need particular attention and care, because when improperly managed, become a serious threat to the environment. In this context, this work shows the studies for recycling of red mud as raw material to obtain titaniumcompounds. The study covers three hydrometallurgical routes: red mud calcined at 900°C (LV900), red mud without thermal treatment (LV-STT) and red mud sintered in a reducing atmosphere (LV1300). The leaching experiments were performed with temperature values of 60, 80 e 90°C and sulfuric acid concentration of 20 and 30%. Together with the analysis mathematical modeling was carried out leaching process. Such analysis shown that the red mud can be applied as a source of alternative raw material for the concentration and subsequent recovery of titanium compounds. The kinetic modeling of the curves of data extraction as a function of time and the mathematical model developed in this work, shown that, the chemical reaction step describes the leaching tests. The developed model also allowed obtaining kinetic parameters such as activation energy and velocity of chemical reactions of the leaching process.
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    Estudo da obtenção de biocombustíveis a partir da rota tecnológica de craqueamento utilizando carbonato de sódio e lama vermelha como catalisadores
    (Universidade Federal do Pará, 2013-12-26) OLIVEIRA, Romero Moreira de; MOTA, Silvio Alex Pereira da; http://lattes.cnpq.br/2688995977218366; MACHADO, Nelio Teixeira; http://lattes.cnpq.br/5698208558551065
    In this paper the crude distillation process of the liquid organic product obtained in the catalytic cracking of oil palm (Elaeis guineensis, Jacq) was studied in pilot scale , using the sodium carbonate (Na2CO3) and red mud catalysts by varying the percentage of catalyst in 10% m/m and 15% m/m for the raw material used , an operating temperature of 450ºC in order to obtain fractions of biofuels (bio-gasoline, bio-kerosene and bio-oil) similar to fuels derived from being fixed oil. The catalysts were subjected to a dehydration pre-treatment for 2 hours in an oven at 300°C, subsequently the XRD, IR and TG were performed. Regarding raw materials, physical and chemical analysis, aiming to characterize palm oil were performed. The organic liquid products (PLOs) were subjected to unit operations of separation, decanting and simple filtration bench scale should then be performed physical-chemical and compositional analyzes. The temples were distilled in a Vigreux column six (06) stages, and the condensed fractions were collected according to the ranges of the distillation of gasoline (60ºC - 190ºC) , kerosene (190ºC - 235ºC ) and diesel (235°C - 370°C), later to be characterized. There was a better catalyst efficiency for sodium carbonate 15% w/w as reducing the acid value about 1.7 mgKOH/g , and a conversion of 97% by weight of the oil in PLO was noted also, by increasing the amount of catalyst that favors the obtaining of an end product with better quality. The red mud on the other hand, showed yields of up to 64% m/m products with a low acidity of about 62.90 mgKOH/g, comparing this result with literature data. Based on the final results verified the efficiency of catalysts, the catalyst which sodium carbonate gave products with low acidity and good characteristics for use as fuel.
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    Estudo do comportamento térmico e propriedades físico-mecânicas da lama vermelha
    (2010) MERCURY, José Manuel Rivas; GALDINO, Laécio Gomes; VASCONCELOS, Nazaré do Socorro Lemos Silva; PAIVA, Antonio Ernandes Macêdo; CABRAL JÚNIOR, Aluísio Alves; ANGÉLICA, Rômulo Simões
    The present work studied the thermal behavior, the evolution of the crystalline phases with temperature and the ceramic properties of the red mud (bauxite tailing) from an aluminium industry of the Maranhao state. The research was carried out by Simultaneous Thermal Analysis (TG-DTA), Optical Dilatometry up to 1350 ºC, while the evolution of the crystalline phases was performed by X-ray diffraction analysis upon heating between 750 to 1150 ºC. Physical-mechanical properties, like Specific Surface Area, Particle Size Distribution, Plastic Limit (PL), Liquid Limit (LL), Plasticity Index (PI), Flexural Strength, Water Absorption (WA), Linear Shrinkage After Firing (LS) and the Apparent Porosity (AP) were also determined at the same range of temperature. The following major crystalline phases were detected: hematite, sodalite, and anatase at 750 ≤ T ≤ 850 ºC; and hematite, nepheline and sodalite at 950 ≤ T ≤ 1150 ºC. The technological experiments indicated that red mud can be used for the processing of structural ceramic materials, since it is an inert material between 870-950 ºC and presents highest water absorption and lowest shrinkage and flexural strength. At 950 ≤ T ≤ 1350 ºC, red mud presented a high shrinking of almost 5 to 50 % with total fusion at 1350 ºC, due to the presence of feldspathoids phases in its mineral composition.
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