Síntese e caracterização de argilas pilarizadas com pilares mistos Al/Co

Two pillaring methods were tested to synthesize pillared clays containing mixed Al/Co pillars. Using the first method, based on the traditional procedure, were obtained materials containing different Co concentrations: 10, 25, 50, 75 and 100 % of Co in the pillaring solution. Just the experiments with low concentrations (10 and 25 % of Co) has formed pillared clays, whereas the sample with 25 % of cobalt showed best results compared with the one obtained just using Al as pillaring agent (basal spacing higher than 18 Å and surface area bigger than 300 m²/g). The 27Al NMR results pointed out the formation of mixed Al/Co pillars due to decreased between the intensities of AlVI/AlIV signals, indicating that the AlIV content decreased while Co content increased, suggesting the isomorphic substitution of Al atoms for Co in the Keggin ion structure (pillaring agent). For the samples containing 75 and 100 % of cobalt, it was verified the formation of others materials, which could be identified as hydrotalcite like compounds. The second pillarization method was named mixed layers, because the objective was to intercalate clay layers with hydrotalcite layers. Thus, after calcination, the hydrotalcite layers would dehydroxylate, resulting just in the metals oxides, intercalated between the clay sheets, thus generating, a pillared clay. For this purpose, were tested 4 synthesis procedures: physical mixture, mixture in water, ionic exchange under reflux and in situ synthesis. Of these, the method which showed the best results was the in situ synthesis, in which basal spacings of 14 Å (after calcination) were obtained, indicating that the samples are intercalated with metal oxides (Mg and Al). This procedure was reproduced with a Co-Al LDH (layered double hydroxide) and similar results were obtained, testifying the method reproducibility

Avaliação de floculante natural à base de Moringa oleifera no tratamento de água produzida na indústria do petróleo: aplicação da técnica combinada floculação/flotação

The principal effluent in the oil industry is the produced water, which is commonly associated to the produced oil. It presents a pronounced volume of production and it can be reflected on the environment and society, if its discharge is unappropriated. Therefore, it is indispensable a valuable careful to establish and maintain its management. The traditional treatment of produced water, usualy includes both tecniques, flocculation and flotation. At flocculation processes, there are traditional floculant agents that aren’t well specified by tecnichal information tables and still expensive. As for the flotation process, it’s the step in which is possible to separate the suspended particles in the effluent. The dissolved air flotation (DAF) is a technique that has been consolidating economically and environmentally, presenting great reliability when compared with other processes. The DAF is presented as a process widely used in various fields of water and wastewater treatment around the globe. In this regard, this study was aimed to evaluate the potential of an alternative natural flocculant agent based on Moringa oleifera to reduce the amount of oil and grease (TOG) in produced water from the oil industry by the method of flocculation/DAF. the natural flocculant agent was evaluated by its efficacy, as well as its efficiency when compared with two commercial flocculant agents normally used by the petroleum industry. The experiments were conducted following an experimental design and the overall efficiencies for all flocculants were treated through statistical calculation based on the use of STATISTICA software version 10.0. Therefore, contour surfaces were obtained from the experimental design and were interpreted in terms of the response variable removal efficiency TOG (total oil and greases). The plan still allowed to obtain mathematical models for calculating the response variable in the studied conditions. Commercial flocculants showed similar behavior, with an average overall efficiency of 90% for oil removal, however it is the economical analysis the decisive factor to choose one of these flocculant agents to the process. The natural alternative flocculant agent based on Moringa oleifera showed lower separation efficiency than those of commercials one (average 70%), on the other hand this flocculant causes less environmental impacts and it´s less expensive

Uso de resíduos de queima de casca de café e argila da região sul da Bahia na obtenção de isolador elétrico cerâmico

The electrical ceramic insulators industry, uses noble raw materials such as siliceous and aluminous clays of white burning, in order to provide plasticity of the mass and contribute to electrical and mechanical properties required of the product, and feldspar with the flux function In literature references the composition of the masses indicates that the clay participates in percentage between 20 and 32, and feldspar 8 to 35, these materials have significant cost. In this research was performed the total replacement of commercial clay, for white burning clay from Santa Luzia region in southern Bahia and partial replacement of feldspar by ash residue of husk conilon coffee burning, from extreme south of Bahia. The objective of replacement these raw materials is to aver its technical feasibility and call attention for the embryo pole of ceramic industry for the existing in the south and extreme south of Bahia, which has significant reserves of noble raw materials such as clay white burning, kaolin, quartz and feldspar, and generates significant volume of gray husk conilon coffee as alternate flux. Clay Santa Luzia is prima noble material whose current commercial application is the production of white roofing. The residue of coffee husk ash is discarded near of production sites and is harmful to the environment. Phase diagrams and statistic design of experiments, were used for optimization and cost savings in research. The results confirmed the expectations of obtaining electrical ceramic insulators, with white burning clay of Santa Luzia and partial replacement up to 35.4% of feldspar, by treaty residue of conilon ash coffee husk burning. The statistic design that showed best results was for formulation with percentages of: clay 26.4 to 30.4%; kaolin 14.85 to 17.1%; feldspar 12.92 to 16.96%; R2 residue 7.08 to 9.2% and Quartz 32.5 to 38.75%, relative to the total mass of the mixture. The best results indicated; 0.2 to 1.4% apparent porosity , water absorption 0.1 to 0.7%, flexural strength 35 to 45MPa , dielectric strength 35-41 kV/cm , the transverse resistivity 8x109 2.5x1010 Ω.cm and for the dielectric constant ε/ε0 7 to 10.4, specification parameters for manufacturing ceramic electrical insulators of low and medium voltage.

Estudo da adição de resíduos de quartzitos para obtenção de grés porcelanato

In States of Paraíba (PB) and Rio Grande do Norte (RN), northeast of Brazil, the most significant deposits of non-metallic industrial minerals are pegmatites, quartzites and granites, which are located in Seridó region. Extraction of clay, quartz, micas and feldspars occurs mainly in the cities of Várzea (PB), OuroBranco (RN) and Parelhas (RN). Mining companies working in the extraction and processing of quartzite generate large volumes of waste containing about 90% SiO2 in their chemical composition coming from quartz that is one of the basic constituents of ceramic mass for the production of ceramic coating. Therefore, this work evaluates the utilization of these wastes on fabrication of high-quality ceramic products, such as porcelain stoneware, in industrial scale. Characterization of raw materials was based on XRF, XRD, GA, TGA and DSC analysis, on samples composed by 57% of feldspar, 37% of argil and 6% of quartzite residues, with 5 different colors (white, gold, pink, green and black). Samples were synthesized in three temperatures, 1150°C, 1200°C and 1250°C, with one hour isotherm and warming-up tax of 10°C/min. After synthesizing, the specimens were submit to physical characterization tests of water absorption, linear shrinkage, apparently porosity, density, flexural strain at three points. The addition of 6% of quartzite residue to ceramic mass provided a final product with technological properties attending technical norms for the production of porcelain stoneware; best results were observed at a temperature of 1200°C. According to the results there was a high iron oxide on black quartzite, being their use in porcelain stoneware discarded by ethic and structural question, because the material fused at 1250°C. All quartzite formulations had low water absorption when synthesized at 1200°C, getting 0.1% to 0.36% without having gone through the atomization process. Besides, flexural strain tests overcame 27 MPa reaching the acceptance limits of the European Directive EN 100, at 1200°C synthesizing. Thus, the use of quartzite residues in ceramic masses poses as great potential for the production of porcelain stoneware.

Tratamento de argila montmorilonítica para a produção de nanocompósitos poliméricos com retardo de propagação de chama

Compared to conventional composites, polymer matrix nanocomposites typically exhibit enhanced properties at a significantly lower filler volume fraction. Studies published in the literature indicate t hat the addition of nanosilicate s can increase the resistance to flame propagation in polymers. In this work, a treatment of montmorillonite (MMT) nano clay and the effect of its ad dition o n flame propagation characteristics of vinyl ester were studied. The resea rch was conducted in two stages. The first stage focused on the purification and activation of the MMT clay collected from a natural deposit to improve compatibility with the polymer matrix . Clay modification with sodium acetate was also studied to improve particle dispersion in the polymer. The second step was focused on the effect of the addition of the treated clay on nanocomposites ’ properties. Nanocomposites with clay con tents of 1, 2, 4 wt. % were processed. T he techniques for the characterization of the clay included X - ray fluorescence (XRF), X - r ay d iffraction (XRD), thermogravimetric a nalysis (TGA), d ifferential scanning c alorimetry (DSC) , s urface area (BET) and Fourier transform infrared spectroscopy (FTIR). For t he characterization of the nanocomposites , the techniques used were thermogravimetric a nalysis (TGA) , differential scanning c alorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) , scanning electron mi croscopy (SEM), transmission electron m icroscopy (TEM), and the determination of tensile strength, modulus of elasticity and resistance to flame propagation. According to the results, the purification and activation treatment with freeze - drying used in thi s work for the montmorillonite clay was efficient to promote compatibility and dispersion in the polymer matrix as evidenced by the characterization of the nanocomposite s . It was also observed that the clay modifica tion using sodium acetate did not produce any significant effect to improve compatibilization of the clay with the polymer. The addition of the treated MMT resulted in a reduction of up to 53% in the polymer flame propagation speed and did not affect the mechanical tensile strength and modulus o f elas ticity of the polymer, indicating compatibility between the clay and polymer. The effectiveness in reducing flame propagation speed peaked for nanocomposites with 2 wt. % clay, indicating that this is the optimum clay concentration for this property. T he clay treatment used in this work enables the production of vinylester matrix nanocomposites with flame - retardancy properties .

Lâminas de água salina e doses de adubação orgânica na produção de palma Miúda adensada no semiárido

Cactus pear is an important forage for livestock in semi-arid region of Brazil, due to its adaptation to climate conditions in this region, high productivity and nutritional value. The yield of this cactus has positively responded to techniques such as planting density, fertilization and cutting managements, however, in Rio Grande do Norte State, only certain areas have favorable climate conditions to the development of this crop. Drip irrigation, with a small amount of water, has proven to be an alternative to the viability of cactus pear cultivation in these areas. The research aimed to evaluate the effects of different levels of saline water and manure organic fertilization on the morphological characteristics and production of fresh and dry matter of the prickly-pear cactus cv. Miúda (Nopalea cochenillifera Salm Dick) in a dense planting system. The experiment was conducted at the Experimental Station of Terras Secas (EMPARN), Pedro Avelino, latitude 5°31'21" South and longitude 36°23'14" West. The soil was classified as Typical Cambisol Haplicum Carbonate and the water used in irrigation, C4S1T3 (5,25 dS.m-1), with planting spacing of 2.0 x 0.25 m (20,000 plants ha-1). A completely randomized design in a split plot was used, where water levels (0, 7.5, 15.0 and 30.0 mm month-1) with 10 days intervals, were the main plots and organic fertilization (0 , 25 and 50 Mg ha-1 yr-1) the subplots, with four replicates. The measured morphological characteristics were number of cladodes, height and volume of the plant; length, width, perimeter, thickness, area and cladodes area index, fresh and dry matter production, dry matter content, water use efficiency (WUE) and damage promoted by cochineal pest (Diaspis echinocacti) and soft rot (Erwinia carotovora). There was no influence (P>0.05) of organic fertilization on most variables, particularly in relation to the production of fresh and dry matter. The water levels had a significant influence (P<0.05) on most variables, promoting higher height and volume of the plants, larger and thicker cladodes, and increase on fresh and dry matter production (13.55 Mg DM ha-1 yr-1). The absence of irrigation caused a significant expansion in plant damage caused by the cochineal pest and when irrigated with different water levels there was an increase in damage and stand loss, caused by soft rot, been more intense at the higher water level.

Estudo de tensoativos na organofilização de argila bentonítica para uso em fluido de perfuração à base de óleo

Due to the great challenges encountered in drilling wells, there is a need to develop fluids with appropriated properties and able to meet all the requirements of drilling operations. The physicochemical and rheological properties must be carefully controlled so that a fluid can exercise all its functions. In perforations sensitive to contact with water and "offshore", it becomes necessary the use of oil based drilling fluids, but the bentonite clay cannot be used without a previous surface modification so that their surfaces become hydrophobic. Lately, the oil companies in Brazil use imported organoclays in the preparation of oil-based drilling fluids. The study aimed to modify a calcium clay to increase the affinity of the same organic phase of oil-based drilling fluids, applying three surfactants (OCS, CTAB and UTM 150) at different concentrations. The results indicated that the surfactants UTM 150 and CTAB showed better results compared to OCS. Considering the type of surfactant and concentration as variables used in the statistical analysis, the results indicated that only the surface tension and concentration of calcium oxide in response to organophilization process showed statistically significant effects. The organophilizated clay has potential for application in oil-based drilling fluids.

Estudo da adição de argila expandida na formulação de concretos leves

Lightweight concrete has been the subject of several studies towards the development of new building materials. Emphasis has been given on the particle size effect and nature of aggregates used as raw materials. The present study includes an analysis of the materials that make this kind of concrete, analyzes of mechanical properties such as compressive and tensile strength, in addition to assessments of the interface concrete aggregate/matrix interface, porosity and absorption profile of chloride ions in lightweight concrete based on expanded clay. The experiments were carried out by molding cylindrical samples 100 mm in diameter and 200 mm in height. The dosage experiments were performed without additives or with the addition of minerals: (T1) 1: 2.01: 1.10: 0.78 (T2) 1: 2.00: 1.32 : 0.62 - (T3) 1 :1.93 :1.54: 0.47 (cement : sand : expanded clay 0500 : expanded clay 1506).The water to cement ratio was set to 0.43. Expanded clay minerals with different average particle sizes were used, i.e., 9.5 mm/0500 and 19 mm/1506. The larger aggregate was coated by a glassy layer, yielding lower water absorption characteristics to the concrete. The results showed that the use of light expanded clay aggregates is a technically interesting solution to the production of lightweight concrete for construction applications

Estudo do efeito da adição da escória de aciaria no processamento e propriedades finais de telhas cerâmicas

This research presents an overview of the addition steelwork dust of ceramic shingles in order to contribute to the utilization use of such residue. The ceramic industry perspective in the Brazilian State of Piauí is quite promising. Unlike other productive sectors, the ceramic industry uses basically natural raw materials. Its final products are, in short, the result of transforming clay compounds. These raw materials are composed primarily of aluminum oxide, silicon, iron, sodium, magnesium, end calcium, among others. It was verified that steelwork dust is composed primarily of these same oxides, so that its incorporation in to structural ceramics is a very reasonable idea. Both clay and steelwork powder were characterized by AG, XRF, XRD, TGA and DTA. In addition, steelwork dust samples containing (0%, 5%, 10%, 15%, 20% and 25%) were extruded and burned at 800°C, 850°C, 900°C and 950°C. Then t echnological tests of linear shrinkage, water uptake, apparent porosity, apparent density and flexural strengthwere carried at. The results showed the possibility of using steelwork powder in ceramic shingles until 15% significant improvement in physical and mechanical properties. This behavior shows the possibility of burning at temperatures lower than 850ºC, thus promoting a product final cost reduction

Síntese, aplicação e avaliação do efeito do teor de fósforo da celulose fosfatada em argamassa de alvenaria com aditivo comercial a base de hidroxi-etil-metil celulose (HEMC)

Generally, cellulose ethers improves mortar properties such as water retention, workability and setting time, along with adherence to the substrate. However, a major disadvantage of the addition of cellulose ethers in mortars is the delay in hydration of the cement. In this paper a cellulose phosphate (Cp) was synthesized water soluble and has been evaluated the effect of their incorporation into mortar based on Portland cement. Cellulose phosphate obtained was characterized by spectrophotometry Fourier transform infrared (FTIR), X-ray diffraction (XRD), elemental analysis and scanning electron microscopy (SEM). Mortar compositions were formulated with varying phosphorus content in cellulose and cellulose phosphate concentrations, when used in partial or total replacement of the commercial additive based hydroxyethyl methyl cellulose (HEMC). The mortars formulated with additives were prepared and characterized by: testing in the fresh state (consistency index, water retention, bulk density and air content incorporated) and in the hardened state (absorption by capillarity, density, flexural and compression strength). In mixtures the proportion of sand:cement of 1:5 (v / v) and factor a / c = 1.31 and water were held constant. Overall, the results showed that the celluloses phosphates employed in mortars added acted significantly when partially substituting the commercial additive. With regard to consistency index, water retention and bulk density in the fresh state and absorption by capillarity and bulk density apparent in the hardened state, showed no appreciable differences as compared to the commercial additive. The incorporated air content in the fresh state reduced markedly, but did not affect other properties. The mortars with cellulose phosphate, partially replacing the commercial additive showed an improvement of the properties of flexural strength and compressive strength

Efeito da adição de feldspato e/ou resíduo de caulin em formulações à base de argila ilítica

The red pottery industry in Piauí state is well developed and stands out at the national context for the technical quality of its products. The floor and wall tile industry, however, is little developed since the state has only one company that produces red clay-based ceramic tiles. This thesis aims at using the predominantly illitic basic mass of the above mentioned industry, with the addition of feldspar and/or kaolin residue in order to obtain products of higher technical quality. Kaolin residue consists basically of kaolinite, muscovite mica and quartz; the feldspar used was potassic. In this experiment, basic mass (MB) was used for experimental control and fifteen formulations codified as follows: F2, F4, F8, F16, F32, FR2, FR4, FR8, FR16, FR32, R2, R4, R8, R16 and R32. All raw materials were dry-milled, classified, formulated and then humidified to 10% water. Thereafter, test samples were produced by unixial pressing process in a rectangular steel matrix (60.0 x 20.0 x 5.0) mm3 at (25 MPa). They were fired at four temperatures: 1080°C, 1120°C, 1160°C, with a heating rate of 10°C/min during up to 10 min in an electric oven, and the last one in an industrial oven with a peak of 1140°C, aim ing to confirm the results found in laboratory and, finally, technological tests were performed: MEA, RL, AA, PA, TRF and PF. The results revealed that the residue under study can be considered a raw material with large potential in the industry of red clay-based ceramic tiles, since the results found both in laboratory and in the industry have shown that the test samples produced from the formulations with up to 4% feldspar and those produced with up to 8% feldspar and residue permitted a reduction in the water absorption rate and an increase in the mechanical resistance while those samples produced with up to 4% residue had an increase in the mechanical resistance when compared to those produced from the basic mass and that the formulation with 2% feldspar and residue presented the best technological properties, lowering the sintering temperature down to 1120°C

Formulação de bloco intertravado cerâmico com adição de resíduos urbanos e industriais

The production of waste from urban and industrial activities is one of the factors of environmental contamination and has aroused attention of the scientific community, in the sense of its reuse. On the other hand, the city of Salvador/Ba, with approximately 262 channels, responsible for storm water runoff, produces every year, by the intervention of cleaning and clearing channels, a significant volume of sediments (dredged mud), and thus an appropriate methodology for their final destination. This study aims to assess the influence of incorporation of these tailings in arrays of clay for production of interlocked block ceramic, also known as ceramic paver. All the raw materials from the metropolitan region of Salvador (RMS) were characterized by x-ray fluorescence, x-ray diffraction, thermal analysis (TG and TDA), particle size analysis and dilatometry. With the use of statistical experimental planning technique, ternary diagram was defined in the study region and the analyzed formulations. The specimens were prepared with dimensions of 60x20x5mm³, by uniaxial pressing of 30 MPa and after sintering at temperatures of 900°, 1000º and 1100ºC the technological properties were evaluated: linear shrinkage, water absorption, apparent porosity, apparent specifies mass, flexural rupture and module. For the uniaxial compression strength used cylindrical probe body with Ø 50 mm. The standard mass (MP) was prepared with 90% by weight of clay and 10% by weight of Channel sediment (SCP), not being verified significant variations in the properties of the final product. With the incorporation of 10% by weight of manganese residue (PFM) and 10% by weight of the Ceramic waste (RCB) in the mass default, in addition to adjusting the plasticity due to less waste clay content, provided increased linear firing shrinkage, due the significant concentration of K2O, forming liquid phase at low temperature, contributing to decreased porosity and mechanical resistance, being 92,5 MPa maximum compressive strength verified. After extract test leachate and soluble, the piece containing 10% of the PFM, was classified as non-hazardous and inert material according to NBR10004/04 ABNT. The results showed the feasibility on using waste, SCP, RCB and PFM clay mass, at temperatures above 900ºC, paver ceramic production, according to the specifications of the technical standards, so that to exceed the 10% of the PFM, it becomes imperative to conduct studies of environmental impacts

Estudo de Matérias-Primas do Rio Grande do Norte para Uso em Revestimento Poroso: Influência do teor de dolomita e temperatura de calcinação nas propriedades físico-mecânicas

The state of Rio Grande do Norte presents a great potentiality for the production of ceramic tiles because of having natural raw material in quantity and quality making its economical exploration possible, beyond the great energetic differential of the state, the natural gás. This works aims to study the influence of the dolomite and granulometry concentration and calcinations temperature in the obtaining of formulations for porous coverings which have to be coherent to the project,s specifications. The experiments have involved the physical-chemical and mineralogical characterizations of raw materials and mechanical tests in the dry and burnt proof bodies preceding a mixture experiment planning with the use of the response surface methodology, in order to get the best raw materials combinations to produce a ceramic mass with specific properties. The twelve ceramic masses studied in this work were prepared by the via dry process, characterized, shaped by uniaxial pressing and sinterized in the temperatures of 940ºC, 1000ºC, 1060ºC, 1120ºC and 1180ºC, using a fast burning cycle. The crystalline phases formed during the sintering in the temperatures in study have revealed the presence of anorthite and diopside beyond quartz with a remaining phase. These phases were the main responsible ones by the physical- mechanical properties of the sinterized proof bodies. The proof bodies after the sintering stage have presented water absorption higher than 10% and a good dimensional stability in all studied temperatures. However, the flexural breaking strength results in the temperatures of 940ºC, 1000ºC and 1060ºC, under the temperature zone of the vitrification of ceramic whiteware do not reach the flexural breaking strength specific for the porous wall tile (15 MPa), but in the temperature of 1120ºC next to the vitrification temperature zone, some whiteware ceramic (formulations) has reached the specified value for the porous wall tile. The results of this work have showed that the studied raw materials have great importance for used in the production of porous wall tiles (BIII)

Tratamento eletroquímico de efluente proveniente de caixas separadoras de água e óleo de postos revendedores de combustíveis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Análise paramétrica do método de injeção alternada de água e CO2(WAG) em reservatórios de petróleo

After the decline of production from natural energy of the reservoir, the methods of enhanced oil recovery, which methods result from the application of special processes such as chemical injection, miscible gases, thermal and others can be applied. The advanced recovery method with alternating - CO2 injection WAG uses the injection of water and gas, normally miscible that will come in contact with the stock oil. In Brazil with the discovery of pre-salt layer that gas gained prominence. The amount of CO2 present in the oil produced in the pre-salt layer, as well as some reservoirs is one of the challenges to be overcome in relation to sustainable production once this gas needs to be processed in some way. Many targets for CO2 are proposed by researchers to describe some alternatives to the use of CO2 gas produced such as enhanced recovery, storage depleted fields, salt caverns storage and marketing of CO2 even in plants. The largest oil discoveries in Brazil have recently been made by Petrobras in the pre -salt layer located between the states of Santa Catarina and Espírito Santo, where he met large volumes of light oil with a density of approximately 28 ° API, low acidity and low sulfur content. This oil that has a large amount of dissolved CO2 and thus a pioneering solution for the fate of this gas comes with an advanced recovery. The objective of this research is to analyze which parameters had the greatest influence on the enhanced recovery process. The simulations were performed using the "GEM" module of the Computer Modelling Group, with the aim of studying the advanced recovery method in question. For this work, semi - synthetic models were used with reservoir and fluid data that can be extrapolated to practical situations in the Brazilian Northeast. The results showed the influence of the alternating injection of water and gas on the recovery factor and flow rate of oil production process, when compared to primary recovery and continuous water injection or continuous gas injection