Estudo geoelétrico em ocorrência de manganês supergênico no município de Itapira (SP) por meio do método da eletrorresistividade

The geophysical methods are used as tools that, together with other data, assist in target detail and sizing of ore bodies. This paper presents the results of the application of DC resistivity geophysical method on a manganese mineral occurrence located in Itapira, in the northern portion of São Paulo state, hosted predominantly in schists and quartzits of Itapira Group. The integration of geophysical data resulted in the elaboration of electrical resistivity models, where it was possible observe that the mineralized body, composed predominantly of manganese oxides and hydroxides, has a pattern of high resistivity (above 5000 Ω.m) both surface and subsurface. The contrast with the host rock is characterized mainly by different minerals assemblages and by the presence of local groundwater. The results accomplished in this paper reveal that the application of DC resistivity method is valid in primary evaluations of supergene deposits

Caracterização mineralógica, petrológica e química da sulfetação nos reef's da mina Canavieiras, Jacobina, Bahia

In the Serra de Jacobina, localized in the North Central portion of the state of Bahia, occours the Jacobina Group. It’s a sedimentary basin and the gold deposit is stocked on the basal portion, which consist on quartzites intercalated with oligomítico metaconglomerates of Serra do Córrego Formation. There are controversies about the origin of the gold mineralization, but the currently most accepted hypothesis corresponds to a paleoplacer deposit with subsequent ore remobilization and concentration by hydrothermal process. The sulphidation is one of the main results of hydrothermal process, which was more detail characterized, besides identifying if there was more than one sulfides phase generation and its relationship with gold mineralization. The analyzes were performed from the main reef's (metaconglomerates mineralized levels) of Mine Canavieiras: Maneira, Holandez, Liberino, Piritoso, MU and LU. Chemical analyzes semi-quantitative were developed with EDS in MEV and also petrographics analyses. The main sulfide is pyrite, followed by chalcopyrite. Six groups of pyrite were classified according with chemical composition, however they show similarities in their habit and occurrence. Were identified four types of chlorite, labeled A, B, C, D. Gold occurs in free form, associate to pyrites, to Fe-Ti-Muscovite, to chlorite type B and to microfractures with iron hydroxide. Gold presents three different compositions: pure, with Ag or associated with U-Zr. The results of chemical analysis showed that the hydrothermal process have as their main source, ultramafic rocks present in the Jacobina Basin

Mapeamento geológico e petrologia dos complexos máfico-ultramáficos de Mangabal Sul e Mangabal Norte, região de Sanclerlândia, Goiás

The Mangabal Sul and Mangabal Norte mafic-ultramafic complexes are interpreted as intrusive stratiform bodies in the Goiás Magmatic Arc during the Brazilian cycle, being economically important for harboring significant amounts of nickel and copper sulfides. The main lithotypes of the complexes are gabbronorites, olivine gabbronorites, pyroxenites and peridotites, with variated degrees of deformation, recrystallization and metamorphism superimposed, with metamorphic peak of amphibolite to granulite facies evidenced mainly by the occurrence of coronitic olivine in metamafic rocks and the occurrence of syn-kinematic retrometamorphism associated with the development of the main foliation Sn. The Sn foliation planes show NE-SW preferential direction, consistent with the foliation direction of VIII the enclosing gneisses and schists, also concordant with the general elongation of mafic and ultramafic bodies displayed on map. The sulfide phase presents textures that indicate remobilization, associated with the occurrence of significant amounts of rutile within the ore which reinforces this idea. Along with the sulfides, the occurrence of expressive quantities of titanium oxides such as ilmenite and rutile, make the area more economically attractive. It can be suggested that the Mangabal Norte and Mangabal Sul complexes are contemporary, have the same genetic affinity and suffered the same deformational and metamorphic processes, evidenced by their structural and petrological similarities

Produção de carvão vegetal a partir da madeira de Eucalyptus saligna clone SI70 com tres anos e meio de idade

Charcoal is obtained from carbonization, much used in the steel industry for ore reduction, using as raw material the Eucalyptus. The present study aims to verify whether the main Eucalyptus saligna genetically modified produce quality charcoal with only 3.5 years old. The study was done with material collected from three trees, divided into five discs removed at 0, 25 , 50 , 75 and 100 % of the commercial height of the tree. The procedures adopted were based on standards published by ABNT. The results were satisfactory for the parameters: basic wood density with an average of 0.39 ± 0.0082 g / cm ³; volatile materials from coal with an average of 19.35 ± 3.27 %, fixed carbon content of the coal with an average of 75.62 ± 3.40 % and gross calorific value of coal with an average of 4694.43 cal / g, and unsatisfactory results for ash content averaging 5.03 ± 0.23 when compared to the values found in the literature. It was concluded that the studied wood is able to produce charcoal, but the factors of production should be better observed, such as heating time which exerted direct influence on the determination of ash content

Análise estrutural e microtectônica da inflexão do jordino e depósitos de ouro associados no greenstone belt de Pilar de Goiás

The study area is included in the geological context of the Goias Median Massif, a region where there are associations of Archean granite-gneiss complex (Block Moquém) and a Paleoproterozoic metavolcano-sedimentary sequence ( Pilar greenstone belt ). At the south of area, the greenstone sequence is partially overlain by Neopreoterozoic metasediments of the Araxá Group. The lithostratigraphic units of the Pilar greenstone belt define a shift from about N30W direction (north of the deposit) to N60 and 70W in the region south of the Jordino deposit, where are truncated by the Araxá Group rocks. Mineralogical associations described in this paper allow to indicate that the regional metamorphism that affected the rocks of the greenstone belt and Araxá Group, in the mapped area, reached the upper greenschist facies (garnet zone). Data obtained during mapping and by microtectonics analysis allow to indicate the existence of at least four deformational events that acted on the rocks of the Guarinos greenstone belt and Araxá Group, represented by the phases called Dn-1, Dn, Dn + 1 and Dn+2. It was observed that the pattern of sulphide porfitoblasts in mineralized levels is similar to garnet, biotite and muscovite porfiroblasts (tardi to post Dn) that marks the metamorphic peak of the area

Características de atributos do solo em ambientes da região Sul do estado do Amazonas

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Análise de causas de trincas em carro de translação de empilhadeira/recuperadora

The present work aims to study the possible causes of cracks founded and recovered in translation cars of ore Forklift / ore Reclaimer. To identify the possible causes of cracks observed on the equipment it was used a static approach analysis, using a finite element method as an analysis tool, using a specific structural analysis program. After making the model, a strain gage measurement was necessary because there may be significant amounts of masses of non-structural components that were not modeled and were not available in the drawings, as well as fouling ore. With the calibrated model it was processed analyses with the load cases of dead load, product, wind and excavation. After the processing, it was observed that none of these load cases resulted in values that caused the crack, so another three hypotheses were tested: depression and misalignment, jacking and translation of only three cars. Of these three hypotheses it was observed that the jacking coud be the cause of the cracks, because the distribution of stress. Due to the miss of parameters, like the height utilized in this process, it was not possible to affirm the real stress level

Territórios, multiterritorialidades e memórias dos povos Guarani e Kaiowá: diferenças geográficas e as lutas pela Des-colonização na Reserva Indígena e nos acampamentos-tekoha - Dourados/MS

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fenton-like processes and adsorption using iron oxide-pillared clay with magnetic properties for organic compound mitigation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Field-scale spatial correlation between contents of iron oxides and CO2 emission in an Oxisol cultivated with sugarcane

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mapping of clay, iron oxide and adsorbed phosphate in Oxisols using diffuse reflectance spectroscopy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Adsorção de cádmio em Latossolos sob vegetação de mata nativa e cultivados

Heavy metals are found naturally in soils at low concentrations, but their content may be increased by human activity, making them one of the barriers in management of tropical soils. These chemical elements can be found in the composition of organic and inorganic fertilizers, insecticides, fungicides, mine tailings, and urban waste, and may cause serious damage to the environment and human health. Thus, adsorption studies are essential in assessing the behavior of heavy metals in the soil. The objective of this study was to evaluate the influence of soil chemical, particle size, and mineralogical properties on adsorption of cadmium (Cd), evaluated by Langmuir and Freundlich models, in Latossolos (Oxisols) with or without human activity. Soil samples were collected from the surface layer, 0.00-0.20 m, and chemical, particle size, and mineralogical analyzes were performed. In the adsorption study, concentrations of 0, 5, 25, 50, 100, 200, 300, and 400 mu g L-1 of Cd were used in the form of Cd(NO3)(2). The empirical mathematical models of Langmuir and Freundlich were used for construction of adsorption isotherms. Data were analyzed by means of multivariate statistical techniques, Cluster Analysis and Principal Component Analysis. The data from the adsorption experiment showed a good fit to the Langmuir and Freundlich models. Soils with a lower goethite/hematite ratio and greater cation exchange capacity and pH, showed higher maximum adsorption capacity of Cd.

Utilização de lama vermelha para oxidação eletrolítica assistida por plasma de liga de alumínio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Empobrecimento e podzolização de solos lateríticos da bacia do Rio Negro e gênese dos podzóis na alta Bacia da Amazônia

Pós-graduação em Geografia - IGCE

Caracterização mineralógica e química das fontes de poeira e sua influência na atmosfera da região do polo cerâmico de Santa Gertrudes (SP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)