Sample records for iron silicates
from WorldWideScience.org

Sample records 1 - 5 shown.



1

Caracterização da parcela magnética de minério fosfático de carbonatito/ Characterization of the magnetic phase from carbonatitic phosphate ore

Borges, Alysson A.; Luz, José Aurélio Medeiros da; Ferreira, Eliomar Evaristo
2008-03-01

Resumo em português O rejeito magnético do Complexo Mineração de Tapira, Tapira - MG, onde se processa rocha fosfática, foi estudado. Suas principais características físicas, químicas e mineralógicas foram determinadas, assim como suas respostas a processos de concentração. A primeira etapa do trabalho envolveu análise granulométrica, análise química, difratometria de raios X, espectroscopia Mössbauer, microscopia ótica e microscopia eletrônica de varredura. Na segunda etapa (mais) , ensaios de separação magnética, flotação e lixiviação ácida foram realizados. O material sob estudo revelou-se composto essencialmente por magnetita, hematita (martita) e ilmenita. A separação magnética resultou em recuperação metalúrgica de ferro acima de 96 %. Sabão sódico de ácido graxo vegetal (Hidrocol) deu melhores resultados no processo de flotação, comparado ao desempenho de amina, quando empregados como coletores de silicatos e apatita, visando à depuração dos minerais portadores de ferro. A atrição preliminar ao condicionamento não influenciou sensivelmente a flotação. Os ensaios de lixiviação visaram a eliminação de fósforo, contaminante crítico nos minérios de ferro. O ácido acético extraiu 0,41 % do fósforo presente, enquanto o ácido clorídrico extraiu em torno de 73 % do fósforo. Estudos ulteriores de otimização de tais ensaios são recomendados, buscando o uso do material sob estudo em siderurgia. Resumo em inglês The characterization of the magnetic fraction of a tail from phosphate rock processing was done. Samples were from Tapira, in Minas Gerais, Brazil. The main physical, chemical and mineralogical properties, as well as this material response to separation processes were determined. The first part of this work encompasses the mineralogical characterization (determination of particle size distribution, X-ray diffraction, Mössbauer spectroscopy, optical microscopy and scannin (mais) g electron microscopy). In the second part, concentration tests by magnetic separation, flotation and acid leaching were carried out. The iron-bearing material is composed predominantly of magnetite, hematite and ilmenite. Wet low intensity magnetic separation has reached iron recovery above 96 %. As far as flotation is concerned, fatty acid soap from vegetal oil (Hidrocol) as a collector for silicates and apatite was better than amine. Attrition or scrubbing prior to conditioning seems not to affect flotation performance in this case. Acetic acid has extracted only 0.41 % of the phosphorus, and hydrochloric acid has depleted 73.05 % of the phosphorus in the samples under leaching.

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2

As escórias de Felgar/Moncorvo

Costa, Horácio Maia e
2009-06-01

Resumo em português No trabalho faz-se o estudo de escórias antigas, existentes no interior da Aldeia de Felgar do Concelho de Torre de Moncorvo, reunidas num monte de modo a constituírem a base da Capela de Santa Bárbara, construída para perpetuar a memória dos mineiros empenhados na exploração do Jazigo de Ferro de Moncorvo (Cabeço da Mua) e dos fundidores que terão trabalhado na Ferraria de Felgar, de onde serão oriundas as escórias. As escórias de Felgar não se encontram dat (mais) adas, pelo que não foi possível relacionar a tecnologia aqui utilizada com a que terá sido adoptada noutras ferrarias da mesma Região, conhecidas pelos depósitos de escórias a que deram origem e que também não estão datadas. A datação permitiria ainda relacionar estas Ferrarias com as que se conhecem em Espanha, distribuídas pelo Norte e Leste, e que estão já bem documentadas historicamente. Este estudo pretende caracterizar metalurgicamente as escórias de Felgar a partir do conhecimento da sua composição química e da estrutura metalográfica. A partir destes estudos admitiu-se que a tecnologia do processo de redução do minério hematítico-magnetítico silicioso do Jazigo de Ferro de Moncorvo (recolhido dos eluviões), com um teor em ferro da ordem dos 50%, terá sido a Forja Catalã. Infelizmente não foram ainda descobertas as ruínas das instalações fixas das Ferrarias o que, a acontecer, traria uma mais valia considerável para o conhecimento das estruturas industriais que teriam sido edificadas. Foi feito o estudo termodinâmico das escórias e do processo de redução deduzido. No caso das escórias foi possível observar a estrutura correspondente à dissociação dos silicatos de ferro (fayalite) após fusão a cerca de 1300ºC e a redução da wustite resultante pelo carbono, através de estudas efectuadas em microssonda. A estrutura de ferro e de sílica em camadas é de grande interesse uma vez que se trata de uma redução na interface da wustite com a sílica com difusão do C e do CO em sentidos contrários através de camadas porosas e deposição de sílica porosa Resumo em inglês This work is the study of old slags, existing within the Village of Felgar the Municipality of Torre de Moncorvo, gathered on a heap in order to form the basis of the Chapel of Santa Barbara, built to perpetuate the memory of miners engaged in exploration the deposits of iron from Moncorvo (Mua) and founders that have worked in Ferraria (Smithy) of Felgar, which will be from the slag. The slag of Felgar is not dated, so it was not possible to relate the technology used he (mais) re with that other ones have been adopted in the same region, known for deposits of slag. Also, this slag isn’t dated. For that, link with the Smithies that are known in Spain, distributed by North and East, and are already well documented historically isn’t possible. This study aims to characterize metallurgicaly the slag of Felgar from the knowledge of chemical composition and metallographic structure. From these studies acknowledged that the technology of the process of reduction of hematite-magnetite siliceous ore from Moncorvo (collected from eluvial deposits) with an iron content in the order of 50%, has been the Catalan Forge. Unfortunately not yet discovered the ruins of the fixed Ferraria of what, to happen, would be a considerable added value to the knowledge of the industrial structures that would have been built. The thermodynamic study was made on the slag and the process of iron reducing, deducted. In the case of slag it was possible to observe the structure corresponding to the dissociation of iron silicates (fayalite) after melting around 1300ºC and the resulting reduction of wustite by carbon, through studies in microprobe. The structure of iron and silica in layers is of great interest since it is the demonstration that the iron reduction happened in the interface wustite-silica with diffused C, as reagent, and the diffusion of CO, reaction product, displacing in opposite directions through porous layers and deposition of porous silica. Thermodynamic study was made on the reduction process of iron ore. The study admits to infer the reduction was possible, in solid state, at the ~700ºC. For that, iron metal produced was take up solid from the Catalan Forge.

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3

Avaliação do efeito da granulometria no processo de flotação/ Study of the effect of particle size on flotation process

Lima, Neymayer Pereira; Valadão, Geoge Eduardo
2008-12-01

Resumo em português A flotação é um dos principais processos de concentração, sendo empregado para diversas classes de minerais (sulfetos, óxidos, silicatos, fosfatos, etc.), como também para uma variedade de tamanhos de partículas. Estudos anteriores mostraram que a flotação pode ser empregada com sucesso para faixas granulométricas entre 10 e 300µm. A seletividade do processo de flotação torna-se muito baixa fora desses limites granulométricos, porque as condições hidrodin (mais) âmicas do sistema são incapazes de manter o nível de flotabilidade ideal das partículas. Diferentes tamanhos de partículas são encontrados nos atuais sistemas de flotação, que podem reduzir a seletividade do processo, devido às diferenças de comportamento. Esse trabalho avaliou a flotação em bancada das frações -150+45µm e -45µm em comparação com a fração global -150µm de um minério de ferro itabirítico, sob diferentes condições de pH, dosagens de reagentes e rotação de condicionamento. Os resultados obtidos mostram que essas frações apresentam diferentes comportamentos no processo de flotação, indicando que é possível aumentar a recuperação em massa e a seletividade, quando essas frações são flotadas separadamente. Resumo em inglês Flotation is one of the main concentration processes and has been employed for many kinds of minerals (sulphides, oxides, silicates, phosphates, etc), and also for different particle sizes. Early studies showed that flotation can be successfully performed for particle sizes from 10 to 300µm. Flotation selectivity becomes very low outside these size limits, because the hydrodynamic conditions can´t maintain the ideal flotability levelfor the particles. Different particle (mais) sizes are found in the present-day flotation machines, which can reduce the process selectivity due to their different behaviors. This work aimed to evaluate the laboratory flotation studies of three particle sizes (-150µm, -150+45µm and -45µm) of an itabirite iron ore under different conditions of pH, reagent dosage, and conditioning rotation. The obtained results show that these size fractions have different behaviors in the flotation process, indicating that it is possible to increase the mass recovery and the selectivity when these fractions are separately flotted.

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4

A utilização de alumino-silicatos como agentes protetores contra a aflatoxicose na alimentação de frangos de corte/ The use of aluminosilicates in broiler feeding as protector agents against aflatoxicoses

Morais, S.A.; Silva, R.D.M.; Domingues, M.A.C.; Fonseca, H.
1993-09-01

Resumo em português O experimento foi conduzido para testar a eficiência de dois alumino-silicatos, no controle da aflatoxicose em frangos de corte (machos). Foram efetuadas análises de sangue para verificação da influência da aflatoxina no perfil sanguíneo das aves. Os resultados mostraram efeito negativo (P(mais) neos de proteína total se apresentaram reduzidos (P Resumo em inglês This experiment was conducted to evaluate the efficiency of two alumino-silicates against deleterious effects of a toxin on growth performance and blood parameters of male broilers. The products did not counteract the negative effects on growth performance. Total protein and gtotamic-oxalacetic transaminase in blood from birds fed contaminated and non contaminated rations, were negatively affected (P(mais) bin time, gamma glutamyl transferase, bilirubin and total iron binding capacity did not show significant differences when compared to the control.

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5

A "fração argila" dos solos do Estado de São Paulo e seu estudo roentgenográfico

Paiva Neto, J. E. de
1942-01-01

Resumo em inglês In the beginning of this work a brief idea was given on what is understood as "clay", on the scientific methods applied to the study of the matter "clay" as well as on its conception with regard to the edaphic studies. A description is given of the methods of total and natural mechanical analyses which were employed in the agro-geological Department. The work is illustrated by a graphic showing the fractions of the mechanical analysis of the chief great soil types of the (mais) State of São Paulo. The fraction clay is then studied by chemical way in the following sequence : 1.° total chemical analysis, 2.° partial chemical analysis, 3.° chemical analysis of the Helmholz layer and 4.° study of the fixation of the ion Ca+ + in the already mentioned Helmholz layer. The first analysis separates and attacks the hydrated aluminium silicates, the hydrated oxyds of iron and aluminium, manganese, etc. In this analysis the relationship between silica and sesquioxyds was determined. The second type of attack or chemical analysis does not affect the hydrated silicates of aluminium, all others go in dissolution. In this analysis were determined chiefly the sesquioxyds in their free form in the clay complex. For the study of the Helmholz layer, i.e. the determination of changeable ions, solutes of NH4Cl N/l, HNO3 N/5, KCl N/l, etc. were used, percolation of these liquids being made through a layer of air dried soil. The relationship between soil and liquid was always 1:10. In this analysis, principally the cations K+, Ca++, Mg++, Al+ + +, H+ etc. were determined. With such determinations the calculations of the following values were obtained: S = sum of the changeable bases in ME; T = total value in ME of the sorptive power of the complex in each 100 g dried soil at 110° C. and V = percentage of saturation of the complexes with bases. Finally, the qualitative radiographic analysis of the fraction clay was carried out by means of the Debye-Scherrer-Hull method. For these studies the Siemens-Berlin apparatus was used, the transformer of which runs with all0-220 volts 60-cycle alternating current. The bulb has a copper anti-cathode and is fed by a current of 13 m.A. of intensity and the difference of potential is of 30,000, 35,000 and 47,000 volts. The flash of X-rays goes through the nickel filter in order to free it of the b irradiations which are deleterious. In this way, inciding vertically on the preparation, radiations CuK a with l = 1,539 A are obtained. The sensible film used was a Lawe-Film-Agfa, with an exposure going from 11/2 to 2 hours with 35,000 V. The chassis has a diameter of 57 mm. More than 500 radiographs of soil samples were taken, of those proceding from all districts of the State, 79 of which are presented in the present work. With this material the different constituents of the clay minerals contained in our soils were known. Thus, in the soils over the Archean geological formation, kaolinite is represented most frequently and abundantly ; the hydrargillite also appears commonly. The soils over the Glacial formation contain the same representatives and oscillations as those just mentioned. In the Corum-batai formation, quartz is the most important constituent. The Botucatu formation (lava) is that which gave origin to our legitimate red soils ; the mineralogical clay constituents of these soils are : 1.° large amount of hydrated oxyds of iron up to 35% of Fe2O3 for each 100 g of soil at 110° C. ; 2.° hydrargillite and 3.° kaolinite. The amount of the latter in the clay complex ranges between 9 and 25%. The sandy soils existing in the geological formations of lower and upper Baurú bear in their clays the following mineralogical constituents : 1.° kaolinite, 2.° montmorrillonitic type (on the upper Baurú only), 3.° hydrargillite (more common on the lower Baurú) and 4.° quartz, generally, in small percentages. These researches made it evident that the constituents of the clay fraction of our soils commonly have a small sorptive power related to the cations; it follows hence that they do not show a great power of retention of manure with the exception of the montmorrillonitic type.

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