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Pellets prepared with mechanically activated iron ore

Mourao, Marcelo Breda; Takano, Cyro
Fonte: WILEY-BLACKWELL Publicador: WILEY-BLACKWELL
Tipo: Artigo de Revista Científica
ENG
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66.72%
This work analyses pellets prepared with iron ore that has been mechanically activated by high energy ball milling. Pellet feed iron ore was submitted to high-energy ball milling for 60 minutes, and the resulting material was analysed through measurements of particle size and specific surface area, as well as X-ray diffraction. Pellets were prepared from this material. The pellets were heated at temperatures ranging from 1000 to 1250 degrees C in a muffle furnace, and submitted to the maximum temperature during 10 - 12 minutes. The samples were then tested regarding crushing strength, densification and porosity, and were examined in a scanning electronic microscope. The results were compared to those obtained with similar samples made from non-milled pellet feed. It has been shown that through high-energy ball milling of iron ore it is possible to achieve pellets presenting high densification and compressive strength at firing temperatures lower than the usual ones.

Carbothermal Reduction of Iron Ore Applying Microwave Energy

de Castro, Edmilson Renato; Mourao, Marcelo Breda; Jermolovicius, Luiz Alberto; Takano, Cyro; Senise, Jose Thomaz
Fonte: WILEY-BLACKWELL; MALDEN Publicador: WILEY-BLACKWELL; MALDEN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.78%
This paper presents the results of a study on carbothermal reduction of iron ore made under the microwave field in equipment specially developed for this purpose. The equipment allows the control of radiated and reflected microwave power, and therefore measures the microwave energy actually applied to the load in the reduction process. It also allows performing energy balances and determining the reaction rate with high levels of confidence by simultaneously measuring temperature and mass of the material upon reduction with high reproducibility. We used a microwave generator of 2.45?GHz with variable power up to 3000?W. Self-reducing pellets under argon atmosphere, containing iron ore and petroleum coke, with 3.5?g of mass and 15?mm of diameter were declined. We obtained the kinetic curves of reduction of iron ore and of energy consumption to the process in the maximum electric field, in the maximum magnetic field and at different values of power/mass. The data allow analyzing how the microwave energy was actually consumed in the reduction of ore.; Maua Institute University Center of Technology; Maua Institute University Center of Technology; FAPESP; FAPESP [02404-0]; University of Sao Paulo; University of Sao Paulo

A exploração de minério de ferro no Brasil e no Mato Grosso do Sul.; The iron ore mineral exploration in Brazil and Mato Grosso do Sul.

Lamoso, Lisandra Pereira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/05/2001 PT
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66.67%
Esta pesquisa trata da produção do espaço geográfico pela indústria mineral de ferro através do processo de industrialização brasileiro, utilizando a categoria da Formação Social e a Teoria dos Ciclos Juglarianos. A industrialização brasileira ocorreu através da substituição escalonada de importações, transferindo recursos de áreas com capacidade ociosa para áreas deficitárias. A partir da Segunda Guerra Mundial, o desenvolvimento tecnológico ampliou a capacidade de transporte das embarcações, barateando os custos de frete e isso fez com que a produção das minas localizadas em países não-tradicionais na exploração de minério de ferro fossem inseridas no mercado internacional. Os investimentos na expansão da capacidade encontraram limites na fase depressiva da década de oitenta. Na década de noventa, as grandes empresas de mineração participaram de investimentos nos serviços públicos (infra-estrutura de transportes e energia). Na década de noventa também, tem início a expansão do uso do gás natural como matriz energética para a indústria brasileira. Esse fator encaminha para a superação de parte das deficiências na infra-estrutura instalada na região Noroeste do Estado de Mato Grosso do Sul...

Modelagem e simulação da cadeia produtiva do minério de ferro.; Iron ore supply chain: modeling and simulation.

Castro Neto, Laherce Ribeiro de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/08/2006 PT
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66.67%
O sistema produtivo da mineração de ferro é caracterizada por um ciclo de produção longo com processo integrado em série e contínuo, desde a mina até a distribuição. Este último estágio é realizado, em grande parte, por meio do modal aquaviário. Nesse sistema dinâmico e complexo em que as operações portuárias e os processos produtivos são aleatórios, problemas logísticos podem ser identificados, acarretando custos de espera por sobreestadias de navios nos portos, traduzidos em multas, custos de manuseio e manutenção de estoques e custo de vendas perdidas pelo não-atendimento do planejamento de vendas, entre outros. Pela possibilidade da realização de experiências, da observação, da aprendizagem e da avaliação do comportamento do sistema mediante a mudança de estado das variáveis de decisão, tais como, programação da produção e nível de estoque de segurança, bem como a mudança da forma de operação, a construção de um modelo para simulação da operação desse sistema pode ser de grande utilidade na busca das possíveis soluções para maior eficiência do mesmo. O objetivo principal deste trabalho foi construir um modelo de simulação do sistema produtiva do minério de ferro que comercializa produtos acabados no mercado transoceânico e estudar o comportamento desse sistema perante mudança de estado das variáveis representadas pela seqüência de programação da produção...

Certificado de material de referência de minério de ferro utilizando programa interlaboratorial; Certification reference material of iron ore by interlaboratory program

Bispo, João Marcos de Almeida
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/02/2007 PT
Relevância na Pesquisa
66.76%
O Brasil é um dos grandes produtores mundiais de minério de ferro e exporta a maior parte da sua produção. No comércio internacional é importante assegurar a comparabilidade dos resultados analíticos obtidos em diferentes laboratórios. Uma variação de 0,1 % na média do teor de ferro pode aumentar ou diminuir em muito o valor de um grande carregamento de minério. Assim, os sistemas de garantia da qualidade dos laboratórios necessitam de materiais de referência. Este trabalho estudou a preparação de um lote de minério de ferro (pelotizado) como material de referência, certificando os teores de vários constituintes por meio de um programa interlaboratorial. Treze laboratórios participaram do programa e dezoito componentes do minério tiveram seus teores certificados: Fetotal (65,1%), SiO2 (2,76%), Al2O3 (0,46%), TiO2 (0,056%), P (0,026%), S (0,003%), MnO (0,094%), CaO (3,31%), MgO (0,043%), K2O (0,013%), Ba (0,004%), Zn (13 mg/kg), Cu (10 mg/kg), Co (12 mg/kg), Cr (56 mg/kg), Pb (15 mg/kg), Ni (14 mg/kg), V (48 mg/kg).; Brazil is one of the great worldwide iron ore producers and exports most of its production. In the international trade it is important to make sure the comparison of the analytical results among different laboratories. A variation of 0...

Estudo experimental de briquetes autorredutores e auto-aglomerantes de minério de ferro e carvão fóssil.; Experimental study of self-reducing self-agglomerated iron ore and brown coal briquettes.

Tanaka, Marcio Toshio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 27/03/2014 PT
Relevância na Pesquisa
66.83%
Este trabalho consiste no estudo da obtenção de aglomerados autorredutores na forma de briquetes a frio tratados termicamente, utilizando minério de ferro e carvão fóssil como matérias-primas. Esta promissora tecnologia tem como premissa a utilização da termo-plasticidade do carvão fóssil para conferir resistência e promover a auto-aglomeração. A obtenção de briquetes dá-se através de três etapas: condicionamento da mistura, briquetagem a frio e tratamento térmico. Os finos de carvão e minério são misturados e homogeneizados. A mistura, então, passa por processo de briquetagem a frio para compactação, promove o aumento de contato entre as partículas de carvão e minério. Finalmente tratamento térmico é realizado para obter a forma de um corpo sólido e coeso de auto-aglomerado autorredutor. O objetivo deste trabalho é determinar as melhores condições de obtenção de briquetes através do estudo de variáveis ao longo do processo de fabricação, utilizando a resistência mecânica como parâmetro. As variáveis estudadas são: granulometria do carvão, envelhecimento do carvão, percentual de carvão na mistura, adição de aglomerantes, pressão de compactação na briquetagem e temperatura de tratamento térmico. Os resultados obtidos neste estudo indicam que estas variáveis afetam significativamente a resistência mecânica. Utilizando-se o carvão Chipanga...

Cokrigagem de razões logarítmicas aditivas (alr) na estimativa de teores em depósitos de ferro; Cokriging of additive log-ratios (alr) for grade estimation in iron ore deposits

Boezio, Maria Noel Morales; Costa, Joao Felipe Coimbra Leite; Koppe, Jair Carlos
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
Relevância na Pesquisa
66.69%
Os produtos do minério de ferro são definidos pelos teores de ferro e dos conta- minantes e, também, pelas partições granulométricas. Os dados que provêm dos depó- sitos de ferro constituem dados composicionais, sendo um vetor de variáveis com uma soma fechada dada pelos balanços de cada espécie, nas diversas frações granulométri- cas, ou pelas espécies em cada fração granulométrica. As somas fechadas conduzem a correlações espúrias e, uma condição chamada de viés negativo. Essa condição impede as estimativas de satisfazerem os balanços e possibilita que algumas estimativas sejam negativas ou estejam fora do intervalo de valores dos dados originais. As metodologias clássicas da geoestatística não levam em consideração esses fatos e as práticas comuns utilizam alternativas que forçam o fechamento das somas, tais como a utilização do modelo de corregionalizacão intrínseca, a determinação de uma variável por diferença ou a distribuição do erro, sendo que, em estimativas negativas, estas devem ser subs- tituídas por valores válidos. Nesse artigo, apresenta-se a cokrigagem de razões loga- rítmicas aditivas (alr), transformação desenvolvida para dados composicionais, como uma metodologia alternativa para se determinarem teores em minérios de ferro...

Effect of particles size range on iron ore flotation

Lima,Neymayer Pereira; Valadão,George Eduardo Sales; Peres,Antônio Eduardo Clark
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 EN
Relevância na Pesquisa
66.72%
Flotation is one of the main concentration processes being employed for many classes of minerals (sulfides, oxides, silicates, phosphates, for example) at different particle sizes. In the iron ore industry, reverse quartz flotation has been successfully employed for particle sizes below ISOfim after the desliming process. The high demand for iron ore products has made flotation the main process for concentration in this industry, thus a better understanding of its mechanisms and the effect of the particle sizes in the process has become imperative. Flotation tests were carried out with three different size fractions of an itabirite iron ore, obtained using cyclone classification after desliming. The results showed distinct behaviors of the different size ranges. Higher etheramine dosages are required when coarse and fine fractions are floated separately and also this procedure is more sensitive to variations in etheramine dosages and pH values. The differences in particle size distributions and the specific surface area may explain the different flotation behavior of the distinct size fractions. The split flotation circuits for coarse and fine particles indicated an increase of 3% points in the metallurgical recovery with reduction of SiO2 content in final concentrate...

Comparison between bentonite and serpentinite in the production process of iron ore pellets

Carmignano,Ottavio Raul Domenico Riberti; Carvalho,Cornélio de Freitas
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 EN
Relevância na Pesquisa
66.64%
Pelletizing iron ore fines is an agglomeration process that through a thermal treatment converts the ultra-fines fraction thereof into small balls ranging in size from 8mm (0.31 in.) to 18mm (0.71 in.), with adequate characteristics for feeding steel reduction works. The binder more used to make pellets is bentonite, which is an item of significant cost in the process. The present paper aims at evaluating the use of serpentinite instead of bentonite. The results obtained show that the full substitution of bentonite for serpentinite is unfeasible. However a potential does exist for using serpentinite and bentonite together in the iron ore palletizing process in the proportion of 1:1.

Iron ore particles on four seaweed species from Camburi Beach (Espírito Santo state, Brazil)

Nassar,Cristina Aparecida Gomes; Yoneshigue-Valentin,Yocie
Fonte: Universidade de São Paulo, Instituto Oceanográfico Publicador: Universidade de São Paulo, Instituto Oceanográfico
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2006 EN
Relevância na Pesquisa
66.82%
The present study estimated the iron-ore concentration found on four species of seaweed. The species tested grow on a site heavily contaminated by this ore, in the city of Vitória, state of Espírito Santo, Brazil. Under natural conditions, the iron ore reached a temperature 5.0ºC higher than the sand on a sunny day. All the species had iron ore adhered to their fronds. Udotea cyathiformis was the species with the highest iron-ore concentration varing from 0.07 to 0.90 g wet weight, followed by Lobophora variegata (from 0.07 to 0.62 g wet weight), Padina gymnospora (from 0.08 to 0.55 g wet weight) and Ulva fasciata (from 0.05 to 0.25 g wet weight). Even after four changes of water over a 12-hour period, the fronds still had particles adhered to their outside cell wall. All the species showed similar tendencies to release the iron, with the highest percentage of particles (40 to 60%) released in the first change of water.

Application of iron ore mud in powder form in posartland cement presence

Aristimunho,P. B.; Bertocini,S. R.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2012 EN
Relevância na Pesquisa
66.64%
Among the products generated in the processing of iron ore, the mud washing, in most cases, is stored in tailing dams without a commercial use. This study aimed to evaluate, at the technical point of view, the application of mud washing iron ore in Portland cement mortar. Specimens were molded with varied proportions of cement, sand and mud washing in powder and then submitted to physical and mechanic tests. The results showed that the replacement of sand by the mud washing (emphasis to 20% substitution) improved the mechanical performance of mortars. It evidences the technical feasibility of the material under study.

Iron-ore dust and its health impacts

Banerjee, K.; Wang, H.; Pisaniello, D.
Fonte: Australian Institute of Environmental Health Publicador: Australian Institute of Environmental Health
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
66.85%
Different lung diseases including lung cancer are the major occupational diseases among the workers of iron ore dust. However, health hazards that arise due to exposures to the ore dust vary considerably due to its variable composition in different mines. Iron oxide and silica predominantly contribute to its toxicological properties. By intratracheal instillation in experimental animals, iron oxide exhibits low toxicity and much less inflammation and damage compared to crystalline silica. Carcinogenicity of iron oxide is found to be negative. Silica is the probable contributor of the elevated incidence of lung cancer among the iron ore dust-exposed workers. Epidemiological findings in different parts of the world due to this occupational hazard have also been discussed in this article. It has been concluded that iron ore dustexposed workers need to be examined periodically in order to determine early symptoms. Routine environmental monitoring and chemical composition evaluation of iron-ore dust are also recommended.; K.K. Banerjee and H. Wang; Copyright © 2006 Australian Institute of Environmental Health

Processes for phosphorus removal from iron ore - a review

Pereira,Antônio Clareti; Papini,Rísia Magriotis
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2015 EN
Relevância na Pesquisa
66.67%
This paper aims at reviewing literature on the occurrence of phosphorus in iron ores from the mines around the world. The review extends to the phosphorus removal processes of this mineral to meet the specifications of the steel industry. Phosphorus is a contaminant that can be hard to remove, especially when one does not know its mode of occurrence in the ores. Phosphorus can be removed from iron ore by very different routes of treatment. The genesis of the reserve, the mineralogy, the cost and sustainability define the technol ogy to be applied. The articles surveyed cite removal by physical processes (flotation and selective agglomeration), chemical (leaching), thermal and bioleaching processes. Removal results of above 90% and less than 0.05% residual phosphorus are noticed, which is the maximum value required in most of the products generated in the processing of iron ore.

Iron ore review 1990-1998

Sousa,Wilson Trigueiro de; Merschmann,Luiz Henrique de Campos; Silva,José Thomaz Gama da
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2002 EN
Relevância na Pesquisa
66.84%
One of the world's largest iron-ore reserves lies in Brazil. The country is a major iron-ore producer and exporter due to modern mines, an efficient railway and port network and skilled mining personnel. A review of this reality is presented in this paper. This review considers the general aspects of iron ore, such as definitions, geology, world resources and reserves, ore size specifications, mining, ore treatment and transport. Moreover, it summarizes the worldwide iron ore market in the 1990's.

Effects of iron-ore particles on propagule release, growth and photosynthetic performance of Sargassum vulgare C. Agardh (Phaeophyta, Fucales)

NASSAR,CRISTINA A.G.; LAVRADO,HELENA P.; YONESHIGUE-VALENTIN,YOCIE
Fonte: Sociedade Botânica de São Paulo Publicador: Sociedade Botânica de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em // EN
Relevância na Pesquisa
66.89%
The effect of iron-ore particles on the propagule release and growth of Sargassum vulgare C. Agardh was tested under treatments with different concentrations of iron-ore particles: 0.1, 1.0, 10.0 g.L-1 and a solution of 10.0 g.L-1 of filtered iron-ore. Filtered seawater was used as control. Photosynthesis vs. irradiance (P-I) curves were calculated for S. vulgare in the presence of iron-ore and in seawater. There was no significant difference in the number of propagules released by the receptacles or in the percentage of zygote formation among the treatments. The released propagules acted like aggregation centers for the particles, those more heavily coated with iron (10.0 g.L-1) exhibiting the highest sinking velocity (32.6 ± 9.8 mm.s-1). No difference in the percentage of embryo survival was detected during the first week in culture. After four weeks the embryos grew in all treatments. Maximum frond development (5.3 ± 0.8 mm) was observed in treatment of seawater enriched with Provasoli's medium (PES) while initial filoids did not develop in three treatments without PES and with iron-ore (0.1 g.L-1, 1.0 g.L-1 and 10.0 g.L-1). The values for Pmax, alpha and respiration showed no significant differences between the P-I curves. The calculated value for I K was 106.26 µmol.m-2.s-1 to the control curve and 981.49 µmol.m-2.s-1 to the iron-ore curve. The results indicate that the iron-ore particles in high concentration reduce the growth of S. vulgare as they recovered the embryos...

Iron ore particles on four seaweed species from Camburi Beach (Espírito Santo state, Brazil)

Nassar, Cristina Aparecida Gomes; Yoneshigue-Valentin, Yocie
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Peer-reviewed Article Formato: application/pdf
Publicado em 01/09/2006 ENG
Relevância na Pesquisa
66.82%
The present study estimated the iron-ore concentration found on four species of seaweed. The species tested grow on a site heavily contaminated by this ore, in the city of Vitória, state of Espírito Santo, Brazil. Under natural conditions, the iron ore reached a temperature 5.0ºC higher than the sand on a sunny day. All the species had iron ore adhered to their fronds. Udotea cyathiformis was the species with the highest iron-ore concentration varing from 0.07 to 0.90 g wet weight, followed by Lobophora variegata (from 0.07 to 0.62 g wet weight), Padina gymnospora (from 0.08 to 0.55 g wet weight) and Ulva fasciata (from 0.05 to 0.25 g wet weight). Even after four changes of water over a 12-hour period, the fronds still had particles adhered to their outside cell wall. All the species showed similar tendencies to release the iron, with the highest percentage of particles (40 to 60%) released in the first change of water.; Minério de ferro particulado sobre quatro macroalgas da Praia de Camburi (Estado do Espírito Santo-Brasil). O presente trabalho determinou a concentração de minério de ferro presente em quatro macroalgas. As espécies testadas ocorrem em um local extremamente contaminado por este particulado, na cidade de Vitória...

Isolation and identification of iron ore-solubilising fungus

Adeleke,Rasheed; Cloete,Eugene; Khasa,Damase
Fonte: South African Journal of Science Publicador: South African Journal of Science
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 EN
Relevância na Pesquisa
66.86%
Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO), Alternaria (for isolates SFC2 and KFC1) and Epicoccum (for isolate SFC2B). The use of tricalcium phosphate (Ca3(PO4)2) in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K) and phosphorus (P). The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate), than the fungus (a maximum of 21.36% removal, from shale). However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate) than the spent liquid medium (a maximum of 29.25% removal, from conglomerate). The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic...

A finite difference model of the iron ore sinter process

Muller,J.; de Vries,T.L.; Dippenaar,B.A.; Vreugdenburg,J.C.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2015 EN
Relevância na Pesquisa
66.69%
Iron ore fines are agglomerated to produce sinter, which is an important feed material for blast furnaces worldwide. A model of the iron ore sintering process has been developed with the objective of being representative of the sinter pot test, the standard laboratory process in which the behaviour of specific sinter feed mixtures is evaluated. The model aims to predict sinter quality, including chemical quality and physical strength, as well as key sinter process performance parameters such as production rate and fuel consumption rate. The model uses the finite difference method (FDM) to solve heat and mass distributions within the sinter pot over the height and time dimensions. This model can further be used for establishing empirical relationships between modelled parameters and measured sinter properties. Inputs into the model include the feed material physical properties, chemical compositions, and boundary conditions. Submodels describe relationships between applied pressure differential and gas flow rate through the bed of granulated fine ore particles, combustion of carbonaceous material, calcination of fluxes, evaporation and condensation of water, and melting and solidification. The model was applied to typical sinter test conditions to illustrate the results predicted...

Microbial community study of the process: and groundwater of the Sishen Iron-Ore Mine, South Africa

Williams,PJ; Surridge,AKJ; Cloete,TE
Fonte: Water SA Publicador: Water SA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2008 EN
Relevância na Pesquisa
66.72%
Investigating the microbial community of the Sishen Iron-Ore Mine in South Africa has become a topic of interest. Micro-organisms could prove to be useful in bioleaching processes, resulting in the minimisation of the negative impact that certain substances, such as phosphorus (P) and potassium (K), have on the economic functioning of the mine. The objective of this investigation was, therefore, to determine which micro-organisms were indigenously present in the process- and groundwater systems of the mine. Groundwater samples and three different process water samples were collected from the mine, followed by chemical- and microbial community analyses. Microbial inhibition was observed in all the process water samples due to the relatively high levels of copper, chromium and zinc present. Aeromonas hydrophila proved to be the dominant bacterial species in all the process water samples, whereas Pseudomonas aeruginosa and Herbaspirillum spp. were observed in the groundwater of the mine. None of the isolated micro-organisms have been implicated in bioleaching practices, and therefore these organisms will not be included as candidates for the removal of P and K from the iron-ore of the Sishen Iron-Ore Mine.

Development of a method for evaluating raw materials for use in iron ore sinter in terms of lime assimilation

Ferreira,W.; Cromarty,R.; de Villiers,J.
Fonte: Journal of the Southern African Institute of Mining and Metallurgy Publicador: Journal of the Southern African Institute of Mining and Metallurgy
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2014 EN
Relevância na Pesquisa
66.8%
Steel is produced in a basic oxygen furnace from hot metal obtained from a blast furnace. A sintered iron ore with good high-temperature properties (strength and permeability) should be used as feed to the blast furnace. The quality of this sintered ore depends on the reactivity of the iron ore used as feed to the sinter plant during the lime assimilation step in the sintering process. The penetration test is the standard method for evaluating the reactivity of iron ore with lime. It is, however, difficult to determine the exact depth of penetration from the standard test. A new test method is proposed that allows automatic evaluation of iron ores in terms of lime assimilation with increasing temperature. A comparison of the coefficients of variation for the new and standard methods for each ore type demonstrates that the results of the new test are more reproducible and more precise than those of the standard method. The test is also less time-consuming and easier to implement.