Research Interests:
Research Interests: Engineering and Recycling
A collection of 125 papers on mine planning and selection of equipment, covering such topics as: design and planning of surface and undergroung mines; planning and equipment selection for difficult mining conditions; equipment selection... more
A collection of 125 papers on mine planning and selection of equipment, covering such topics as: design and planning of surface and undergroung mines; planning and equipment selection for difficult mining conditions; equipment selection procedures; and mine and equipment information systems.
Research Interests:
Research Interests:
Research Interests:
Entre os depositos de estanho em producao no mundo destacam-se os do norte do Brasil e os do Sudeste da Asia, a partir da Indonesia ate a Birmânia. Os ela Australia, da China, da URSS, e da Bolivia, na parte oriental dos Andes, sao tambem... more
Entre os depositos de estanho em producao no mundo destacam-se os do norte do Brasil e os do Sudeste da Asia, a partir da Indonesia ate a Birmânia. Os ela Australia, da China, da URSS, e da Bolivia, na parte oriental dos Andes, sao tambem importantes. Cinco paises, Bolivia, Brasil, Indonesia, Malasia e Tailândia responderam em 1987 por 78,28% da producao,mundial. A maios parte do estanho produzido nos paises subdesenvolvidos ou em desenvolvimento e consumido pelos paises industrializados de economia de mercado . Entre paises, os EUA e o Japao sao os maiores consumidores de estanho. Apenas o consumo destes dois paises supera o da CEE. O estanho tem o seu maior uso na fabricacao de folhas ?de- flandres, utilizados, principalmente, em embalagens para alimentos e bebidas. Nos ultimos anos, o consumo de folhas ?de- Flandres diminui, assim como a quantidade de estanho usada na producao de tais chapas. A solda e outro importante uso final do estanho. Diferente da industria de folhas ?de-Fl...
Research Interests:
Research Interests:
... CORADI, Lucas B. Usos de Rochas na Arquitetura. 2009. 181f. ... CHIODI FILHO, Cid. Critérios Gerais de Classificação e Especificação de Rochas para Revestimento. Revista Pedras do Brasil, Vitória, ES, Ed. ... 2005. FRASCÁ, MHBO Rocha... more
... CORADI, Lucas B. Usos de Rochas na Arquitetura. 2009. 181f. ... CHIODI FILHO, Cid. Critérios Gerais de Classificação e Especificação de Rochas para Revestimento. Revista Pedras do Brasil, Vitória, ES, Ed. ... 2005. FRASCÁ, MHBO Rocha como Material de Construção. ...
Este estudo abrangeu o setor da mineracao do ferro e a sua transformacao. Foram abordados os itens tecnicos e economicos da siderurgia, mostrando alguns aspectos da historia, da tecnologia e suas implicacoes economicas, tais como, a... more
Este estudo abrangeu o setor da mineracao do ferro e a sua transformacao. Foram abordados os itens tecnicos e economicos da siderurgia, mostrando alguns aspectos da historia, da tecnologia e suas implicacoes economicas, tais como, a producao, o consumo e o comercio. Na area da mineracao do ferro, tambem foram destaca dos os aspectos tecnicos e economicos que definem este minerio como um bem economico, abrangendo a geologia, as reservas minerais, a estrutura da industria, a producao, o consumo e o comercio. As analises efetuadas sobre os aspectos tecnicos e economicos tiveram dois objetivos: primeiro, calcular a instabilidade do mercado brasileiro de minerio de ferro, e, em seguida, verificar a possibilidade de sucesso de uma associacao entre os paises produtores exportadores de minerio de ferro. o calculo da instabilidade, atraves de um indice desenvolvido por Louise S. powers, 1980, mostrou que, na producao de minerio de ferro, a instabilidade brasileira foi maior do que a mundial....
Research Interests:
Abstract This paper reports and discusses the results of an experimental investigation on hydraulic transportation of iron ore concentrate and its effect on slurry wear, pure erosion and pure corrosion of a carbon steel pipe. For this, a... more
Abstract This paper reports and discusses the results of an experimental investigation on hydraulic transportation of iron ore concentrate and its effect on slurry wear, pure erosion and pure corrosion of a carbon steel pipe. For this, a specially designed test-loop was built to simulate long distance iron ore transportation, allowing also to determine pure erosion effects by means of a specially designed cathodic protection system. Pure corrosion damage was evaluated by linear polarization measurements in filtered ore concentrate, i.e., in the absence of particles. The results revealed that pure erosion and pure corrosion effects were much lower than the measured wear, evaluated as pipe thickness loss, indicating an important synergism between erosion and corrosion. Wear damage results in microcraters aligned in the flow direction, which merge with each other likely due to enhanced electrochemical activity fed by the erosion process. Evaluation of the effect of the pumping time on the ore concentrate characteristics revealed that particles sizes decreased while the sphericity factor increased leading to lower wear rates. Finally, a mechanism explaining the pipeline wear associating erosion, corrosion and the material microstructure as well as a methodology to forecast the pipelines thickness loss as a function of the ore concentrate travelling distance were also proposed.
Research Interests:
Abstract Microflotation experiments and zeta potential measurements of fluorapatite, wavellite, and turquoise with the use of alkyl amines and amylopectin were conducted. The highest floatability values were achieved in the presence of... more
Abstract Microflotation experiments and zeta potential measurements of fluorapatite, wavellite, and turquoise with the use of alkyl amines and amylopectin were conducted. The highest floatability values were achieved in the presence of dodecylamine, exceeding the floatabilities with octylamine between 30% and 90%. Above their respective isoelectric points, the phosphates reached approximately 100% of floatability with dodecylamine. The strong dependence of surfactant adsorption on hydrocarbon chain length was also evidenced by zeta potential results. In the presence of 1 × 10−3 M dodecylamine solution, the surface charge of the phosphates changes from negative to positive until approximately pH 12, while the octylamine was not able to reverse the surface charges. The fluorapatite and wavellite floatabilities were not significantly affected by the amylopectin; however, in the presence of this depressant, the turquoise floatability, with octylamine as collector, decreases abruptly from 93% to 30%. The greater differences observed between turquoise and the other phosphates can be ascribed to their extremely complex structures, chemical composition and its dissolution in aqueous media.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Expert Systems, Environmental Economics, Fuzzy Logic, Fuzzy set theory, Fuzzy Expert System, and 13 moreMining, Neural Network, Investments, Knowledge building, Copper, Mining Industry, Process Design, Profitability, expert System, Ore Genesis, Environmental Impact, Return on Investment, and Gold mining
Gold mining projects are a rare opportunity in the minerals industry. They require relatively small capital and give high profitability and fast return on investment compared with other mineral projects. To expand or maintain gold... more
Gold mining projects are a rare opportunity in the minerals industry. They require relatively small capital and give high profitability and fast return on investment compared with other mineral projects. To expand or maintain gold production, continuous development of new deposits and fast implementation of new mining sites are needed. Process design is one of the major issues. As simple
Research Interests:
ABSTRACT Nickel-lateritic ore is the most common source of nickel in Brazil. The Niquelaˆndia deposit, located in State of Goias, is one of the most famous deposits due to the large amounts of nickel associated with both oxidized and... more
ABSTRACT Nickel-lateritic ore is the most common source of nickel in Brazil. The Niquelaˆndia deposit, located in State of Goias, is one of the most famous deposits due to the large amounts of nickel associated with both oxidized and mainly silicated ores. The terms oxidized and silicated ores are used to specify two different ores formed exclusively by oxides and silicate (clay) minerals, respectively. The aim of the present study was to characterize thoroughly the silicated ore to identify the Ni-bearing clay minerals and their crystal chemistry in support of developing a better mineral-processing method or optimizing the current one to improve Ni recoveries. X-ray diffraction, chemical analyses, scanning electron microscopy, and Fourier transform infrared (FTIR) spectroscopy demonstrated that nickel is associated with Ni-rich stevensite and to a lesser extent with Fe-rich montmorillonite. The crystal chemistry performed by FTIR spectroscopy revealed that Ni is present in the octahedral positions, substituting for Mg or Fe, which results in significant chemical and layer-charge heterogeneity in the samples. This heterogeneity seems to be responsible for reduction in Ni recoveries during the hydrometallurgical process. Key Words—Clay Minerals, Crystal Chemistry, Fe-montmorillonite, Nickel, Smectite, Stevensite.
Research Interests: Geology and Soil sciences
Research Interests:
Gold mining projects are a rare opportunity in the mineral industry. They require relatively small capital and give high profitability and fast return on investment compared with other mineral projects. To expand or maintain gold... more
Gold mining projects are a rare opportunity in the mineral industry. They require relatively small capital and give high profitability and fast return on investment compared with other mineral projects. To expand or maintain gold production, continuous development of new deposits and fast implementation of new mining sites are needed. Process design is one of the major issues. As simple
Research Interests: Expert Systems, Environmental Economics, Fuzzy Logic, Fuzzy set theory, Fuzzy Expert System, and 13 moreMining, Neural Network, Investments, Knowledge building, Copper, Mining Industry, Process Design, Profitability, expert System, Ore Genesis, Environmental Impact, Return on Investment, and Gold mining
Gold mining projects are a rare opportunity in the minerals industry. They require relatively small capital and give high profitability and fast return on investment compared with other mineral projects. To expand or maintain gold... more
Gold mining projects are a rare opportunity in the minerals industry. They require relatively small capital and give high profitability and fast return on investment compared with other mineral projects. To expand or maintain gold production, continuous development of new deposits and fast implementation of new mining sites are needed. Process design is one of the major issues. As simple
Research Interests:
Research Interests:
Companhia Brasileira de Alumínio (CBA) has bauxite processing plants at Poços de Caldas and Itamarati de Minas, and a new processing plant at Miraí that has been operating since June, 2008; all of them are in the State of Minas Gerais.... more
Companhia Brasileira de Alumínio (CBA) has bauxite processing plants at Poços de Caldas and Itamarati de Minas, and a new processing plant at Miraí that has been operating since June, 2008; all of them are in the State of Minas Gerais. The plants haveunits for the crushing, scrubbing and screening operations. The screened oversize is the concentrate or washed bauxite. At Itamarati de Minas, the fines are de-slimed and concentrated by gravity separation of the iron-titanium minerals in Reichert spirals followed by HIWMS. The tailings still contain bauxite, which can be separated by reverse froth flotation (flotation of the quartz and depression of the bauxite), using starch as a depressant and amine as a promoter; the pH must be around 10.0. The iron and titanium bearing minerals are depressed with the bauxite and an additional magnetic separation operation is necessary on the depressed bauxite. This paper describes the work performed on Itamarati de Minas samples on a bench scale at...
Every year, the number of discarded electro-electronic products is increasing. For this reason recycling is needed, to avoid wasting non-renewable natural resources. The objective of this work is to study the recycling of materials from... more
Every year, the number of discarded electro-electronic products is increasing. For this reason recycling is needed, to avoid wasting non-renewable natural resources. The objective of this work is to study the recycling of materials from parallel wire cable through unit operations of mineral processing. Parallel wire cables are basically composed of polymer and copper. The following unit operations were tested:
Research Interests:
Research Interests:
Abstract The process of flotation is commonly used for the recovery of molybdenite from mine tailings, but it produces low-content concentrates, thereby resulting in a product with low economic value. The low economic value is due to the... more
Abstract The process of flotation is commonly used for the recovery of molybdenite from mine tailings, but it produces low-content concentrates, thereby resulting in a product with low economic value. The low economic value is due to the presence of talc, which is a naturally hydrophobic mineral that is also floated with the molybdenite during the flotation process. Separability studies were conducted in a Partridge–Smith cell using dextrin as a molybdenite depressant in solution at different concentrations and pH values to produce a technical-grade concentrate (i.e., 90% MoS2). These basic studies were accompanied by measurements of the zeta potential and contact angle, which was determined by the capillary rise method. The results of these floatability studies were used in bench tests of flotation, which were performed in a Denver D-12 cell. A molybdenite concentrate of 93.4% MoS2 was obtained when dextrin was used at a concentration of 100 g/t.
Research Interests:
This article presents a kinetic evaluation of froth flotation of ultrafine coal contained in the tailings from a Colombian coal preparation plant. The plant utilizes a dense-medium cyclones and spirals circuit. The tailings contained... more
This article presents a kinetic evaluation of froth flotation of ultrafine coal contained in the tailings from a Colombian coal preparation plant. The plant utilizes a dense-medium cyclones and spirals circuit. The tailings contained material that was 63% finer than 14 µm. Flotation tests were performed with and without coal “promoters” (diesel oil or kerosene) to evaluate the kinetics of flotation of coal. It was found that flotation rates were higher when no promoter was added. Different kinetic models were evaluated for the flotation of the coal from the tailings, and it was found that the best fitted model was the classical first-order model.
Research Interests:
Companhia Brasileira de Alumínio (CBA) has bauxite processing plants at Poços de Caldas and Itamarati de Minas, and a new processing plant at Miraí that has been operating since June, 2008; all of them are in the State of Minas Gerais.... more
Companhia Brasileira de Alumínio (CBA) has bauxite processing plants at Poços de Caldas and Itamarati de Minas, and a new processing plant at Miraí that has been operating since June, 2008; all of them are in the State of Minas Gerais. The plants haveunits for the ...