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Previsão de desempenho do circuito de moagem de Carajás. / Performance prediction for the Carajás grinding circuit.Bianca Foggiatto 01 April 2009 (has links)
O circuito de moagem de Carajás foi originalmente projetado para moagem de sinter feed, obtendose como produto final pellet feed. O processo consiste em etapas de moagem e deslamagem para que se atinjam as especificações de granulometria e área específica. No processo, como um todo, há geração significativa de finos, que são então descartados, acarretando em perdas de material que poderia ser incorporado como produto. O melhor entendimento das características dos vários tipos de minérios, bem como a previsão do desempenho do circuito de moagem em função de tais características permite estabelecer cenários para promover aumentos na recuperação em massa e na produtividade do circuito. O presente trabalho tem por base a caracterização tecnológica dos principais tipos de minério de Carajás e o desenvolvimento de um método para previsão de desempenho do circuito de moagem, em função de tais características. Para o desenvolvimento do método foram realizados ensaios de moagem em bancada e amostragens no circuito industrial. Os resultados dos ensaios de moagem em bancada serviram para definição das condições operacionais em que o ensaio em bancada melhor representou o circuito industrial, denominado ensaio padrão. Os dados obtidos nas amostragens e na caracterização tecnológica serviram de base para a calibração dos modelos matemáticos dos equipamentos de processo. O modelo calibrado constituiu num excelente recurso para previsão de desempenho. O desempenho do circuito de moagem foi avaliado no que se refere à granulometria e área específica dos produtos obtidos. Ainda foram conduzidas simulações pelo ensaio padrão e pelo modelo calibrado integrado do circuito de moagem, que apontam potenciais dos minérios cujo comportamento na moagem era até então desconhecido. Os dois produtos aqui desenvolvidos são, portanto, de aplicação imediata como recursos para previsão de desempenho e melhoria operacional. / Originally designed for sinter feed grinding, the Carajas grinding circuit includes two ball mills in parallel lines in a closed configuration with cyclones. The ground product is further deslimed in hydrocyclone for achieving the final specifications regarding size distribution and surface area. In this process, there is a significant amount of high grade material, not recovered due to overgrind. Ore characterization was here selected for predicting the grinding circuit performance, which in turn was the basis for optimization. The aim of this work is the characterization of the main Carajas ore types as well as the development of a method that includes these characteristics for predicting the grinding circuit performance. Laboratory grinding tests and samplings in the industrial circuit were carried out to predict the grinding circuit performance. The grinding test results were used to set operational conditions in which the laboratory better represented the industrial circuit. Results from industrial sampling and characterization were the basis for fitting the mathematical models. The fitted model was an excellent resource for the prediction of the grinding circuit performance as well as for the grinding test. To assess the grinding performance, products size distribution and surface area were evaluated. Moreover, simulations of the grinding circuit indicated the potential of some ore types. The derived methods were validated as tools for predicting the grinding circuit performance and for operational optimization.
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Macromineral requirements in male and female Saanen goats /Santos Neto, José Mauricio dos. January 2016 (has links)
Orientador: Kléber Tomás de Resende / Banca: Marcos Jácome de Araújo / Banca: Izabelle Auxiliadora Molina de Almeida / Resumo: Objetivou-se determinar as exigências de Ca, P, Mg, K e Na em machos inteiros, machos castrados e fêmeas da raça Saanen. Foram realizados dois experimentos: um para determinar as exigências líquidas para mantença (Exp. 1) e outro para determinar as exigências líquidas para crescimento (Exp. 2). Setenta e cinco caprinos (26 machos inteiros, 25 machos castrados e 24 fêmeas) foram utilizados para determinar as exigências líquidas para mantença. Desses, 21 caprinos (8 machos inteiros, 7 machos castrados e 6 fêmeas) foram abatidos com peso médio de 16,6 ± 0,40 kg e foram utilizados como grupo referência para estimar a composição corporal inicial. Os 54 caprinos restantes (18 machos inteiros, 18 machos castrados e 18 fêmeas) foram alocados em seis blocos ao acaso, no quais foram incluídos três caprinos do mesmo sexo distribuídos em um dos três níveis de alimentação: ad libitum e ingestão de 75% ou 50% em relação aos animais alimentados ad libitum. Quando os animais alimentados ad libitum atingiram 30 kg de PC foram abatidos juntamente com os outros caprinos do mesmo grupo. Os dados das categorias sexuais e dos níveis de alimentação foram analisados em parcelas subdivididas. A parcela principal foi composta pelas três categorias sexuais e as subparcelas pelos três níveis de alimentação. Os requerimentos líquidos para mantença não diferiram entre as categorias sexuais (P > 0.05), resultando em valores de: 35,4 mg de Ca; 24,7 mg de P; 2,5 mg de Mg; 5,0 mg de K e 3,3 mg de Na/kg PC·d. ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Our study estimated Ca, P, Mg, K, and Na requirements of intact male, castrated male, and female Saanen goats. Two experiments were performed: one to determine the net macromineral requirements for maintenance (Exp. 1), and another to determine net macromineral requirements for growth (Exp. 2). In Exp. 1, 75 goats (26 intact males, 25 castrated males, and 24 females) with initial BW (iBW) of 15.76 ± 0.10 kg were used. These animals were divided in two groups: baseline animals and pair-fed animals. Twenty-one goats (8 intact males, 7 castrated males, and 6 females) were slaughtered at the beginning of the experiment (16.6 ± 0.40 kg BW) to be used as the baseline group. The 54 remaining goats (18 intact males, 18 castrated males, and 18 females) were pair-fed in 6 blocks of 3 goats per sex. The goats within each block were then randomly allocated to one of 3 different levels of intake: ad libitum, restricted-fed to 75% of the ad libitum intake, and restricted-fed to 50% of ad libitum intake. When the animal fed ad libitum reached 31.2 ± 0.58 kg BW, it and the other goats from the same block were slaughtered. The effects of sex and level of intake were evaluated in a split-plot design, where sex was the main plot observation and level of intake was the sub-plot. Daily net macromineral requirements for maintenance did not differ among the sexes (P > 0.05), and the average values obtained were 35.4 mg Ca, 24.7 mg P, 2.5 mg Mg, 5.0 mg K, and 3.30 mg Na per kg BW. The net requiremen... (Complete abstract click electronic access below) / Mestre
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Curva de acúmulo de nutrientes em dois cultivares de alface crespa /Cruz, Renan da. January 2019 (has links)
Orientador: Roberto Lyra Villas Bôas / Coorientador: Aniello Cutolo Filho / Banca: Camila Paula Rossetto Pescatori Jacon / Banca: Natália de Brito Lima Lanna / Resumo: Com o desenvolvimento de novos materiais genéticos para atender o mercado, empresas privadas, públicas e outras organizações lançam no mercado anualmente genéticas novas de cultivares de alface, com novas resistências a doenças, novas adaptações climáticas, ciclos de crescimento diferentes e exigências nutricionais diferentes. Sendo assim, é necessário o desenvolvimento de pesquisas sobre nutrição mineral desses novos materiais genéticos, fornecendo ferramentas para o produtor poder fazer um programa de adubação mais eficiente. O objetivo do projeto foi determinar a curva de acúmulo de nutrientes de dois materiais genéticos de alface crespa, uma de ciclo precoce (Valentina) e uma de ciclo tardio (Isadora), em condições de campo. O projeto foi desenvolvido em parceria com a empresa Sakata Seed Sudamerica Ltda que forneceu o material genético. O delineamento experimental utilizado foi de blocos ao acaso com 7 tratamentos e 4 repetições. Os tratamentos consistiram de 7 épocas de avaliação, considerando os dias de coletas como tratamentos (0; 7; 14; 21; 28; 35; 42). As plantas amostradas periodicamente a cada 7 dias foram analisadas quanto aos parâmetros biométricos e ao teor de macro e micronutrientes durante 42 dias. Com base nesses teores e na massa seca, foi calculada a quantidade de nutrientes acumulado pelas plantas de alface, e foram geradas as curvas de acúmulo de nutrientes de cada cultivar. A cultivar Valentina apresentou maior demanda de nutrientes em relação a cultiva... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the development of new genetic materials to serve the market, private, public and other organizations are lauching new genetic lettuce cultivars annually, with new disease resistance, new climate adaptations, different growth cycles and different nutritional requirements. Therefore, it is necessary to develop research on mineral nutrition of these new genetic materials, providing tools for the farmer to make a more efficient fertilizer program. The objective of the project was to determine the nutrient accumulation curve of two curly lettuce genetic materials, one early cycle (Valentina) and one late cycle (Isadora) in field conditions. The project was developed in partnership with the Sakata Seed Sudamerica Ltda Company, which provide the genetic material. The experimental design was randomized blocks with 7 treatments and 4 replications. The treatments consisted of 7 evaluation times, considering the collection days as treatments (0; 7; 14; 21; 28; 35; 42). Plants sampled periodically every 7 days, were analyzed for biometric parameters and macro and micronutrient content for 42 days. Based on these contents and dry mass, the amount of nutrients accumulated by lettuce plants was calculated, and the nutrient accumulation curves of each cultivar werw generated. The cultivar Valentina presented higher nutrient demand than Isadora cultivar, potassium was the most accumulated nutrient in lettuce plants. The decreasing order of nutrient accumulation was K>N>Ca>P>Mg>S>Fe>Zn>B>Mn>Cu. / Mestre
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Efeito de microminerais orgânicos no crescimento e qualidade do filé de tilápia (Oreochromis niloticus)Miguel, Juliana Samila de Castro January 2020 (has links)
Orientador: Leonardo Susumu Takahashi / Resumo: Os microminerais possuem papéis importantes no metabolismo animal, participam de funções fisiológicas, crescimento, desenvolvimento e saúde em peixes. O objetivo deste estudo foi avaliar a suplementação da dieta com microminerais orgânicos no desempenho produtivo e qualidade do filé de juvenis de tilápia (Oreochromis niloticus). Foram formuladas 3 dietas práticas isoprotéicas e isoenergéticas com três níveis de inclusão (0,0; 1,0 e 1,5%) de um blend de microminerais orgânicos composto por: ferro, zinco, manganês, cobre, selênio e cromo. Foram realizados dois experimentos distintos, um com alimentação durante período pré-abate (7 dias) e outro, durante período longo de alimentação (30 dias). Em cada um dos experimentos, foram utilizados 120 juvenis em fase de terminação com peso médio de 360,6 g, distribuídos aleatoriamente em 12 caixas de 1000 L em um sistema de circulação fechado. Foram avaliados parâmetros da qualidade do filé no período pré-abate (7 dias): potencial hidrogeniônico (pH), rendimento de filé, cor, perdas de peso cozimento (cooking loss), perdas de peso por descongelamento (drip loss) e capacidade de retenção de água (CRA). As análises no após período de 30 dias de alimentação, foram as mesmas do período pré-abate com adição de: parâmetros de desempenho produtivo (ganho de peso, conversão alimentar e taxa de crescimento específico), textura do filé, oxidação lipídica (TBARS), concentração de bases voláteis totais (BVT), concentração de nitrogênio não protéico ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Microminerals play important roles in animal metabolism participate in physiological functions, growth, development and health in fish. The aim of this study was to evaluate the dietary supplementation with organic microminerals in the productive performance and quality of the tilapia (Oreochromis niloticus) juvenile fillet. A 120 juveniles were used in the finishing phase with an average weight of 360.6 g, randomly distributed in 12 boxes of 1000 L in a closed circulation system. 3 practical isoproteic and isoenergetic diets were formulated with three levels of inclusion (0.0, 1.0 and 1.5%) of a blend of organic minerals composed of: iron, zinc, manganese, copper, selenium and chromium.Two different experiments were carried out, one with feeding during the pre-slaughter period (7 days) and the other, during a long feeding period (30 days). In each of the experiments, 120 juveniles were used in the finishing phase with an average weight of 360.6 g, randomly distributed in 12 boxes of 1000 L in a closed circulation system. Parameters of fillet quality in the pre-slaughter period (7 days) were evaluated: hydrogen potential (pH), fillet yield, color, cooking loss, weight loss by defrosting (drip loss) and retention capacity of water (CRA). The analyzes in the period after 30 days of feeding were the same as in the pre-slaughter period with the addition of: production performance parameters (weight gain, feed conversion and specific growth rate), fillet texture, lipid oxidation (... (Complete abstract click electronic access below) / Mestre
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Desenvolvimento inicial do Eucalipto e fertilidade do solo após aplicação de lodo de esgoto e composto de lodo /Silva, Camila Rocha Pergentino da. January 2019 (has links)
Orientador: Iraê Amaral Guerrini / Banca: Roberto Lyra Vilas Bôas / Banca: Cássio Hamilton Abreu Junior / Resumo: O uso de lodo de esgoto como fertilizante orgânico, além de ser uma alternativa para a destinação final desse resíduo, pode melhorar as propriedades do solo, já que é um material rico em nutrientes e matéria orgânica, podendo favorecer o desenvolvimento das plantas. O objetivo deste trabalho foi verificar o efeito da aplicação de doses de lodo de esgoto e composto de lodo no desenvolvimento inicial de um híbrido Eucalyptus. grandis x E. urophylla. O experimento foi conduzido em estufa plástica, sem controle ambiental, e foi composto por 48 vasos contendo 50L de Latossolo textura média. Trata-se de um experimento fatorial, com dois fatores: fertilizante orgânico (lodo de esgoto e composto de lodo - ambos sem adição de calcário) e dose (10, 20, 30, 40 e 50 Mg ha-¹ + K), além de dois tratamentos adicionais (controle e adubação inorgânica indicada para a espécie). Cada tratamento foi composto por quatro repetições. A altura, diâmetro do colo e índice de cor verde foram medidos mensalmente, durante seis meses e a área foliar, massa de matéria seca, nutrição das plantas e fertilidade do solo foram avaliadas ao final do experimento (seis meses após plantio). Os dados foram submetidos à análise de variância, complementado com testes de comparações múltiplas e com ajustes de modelos de regressão polinomial para avaliar o efeito das doses, ao nível de 5% de significância. Tanto o lodo de esgoto, como o composto, nas doses de 40 e 50 Mg ha-1, forneceram quantidades de nutrientes, às pla... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of sewage sludge as an organic fertilizer, besides being an alternative for the final disposal of such waste, it may improve the soil properties, since it is a material rich in nutrients and organic matter, which may favor the development of plants. The objective of this work was to verify the effect of doses of sewage sludge and sludge compost in the initial development of a hybrid of Eucalyptus grandis x Eucalyptus urophylla. The experiment was conducted in plastic greenhouse, without environment control, and was composed of 48 vessels containing 50L of dystrophic medium texture. It is a factorial experiment with two factors: organic fertilizer (sewage sludge and sludge compost - both without limestone) and dose (10, 20, 30, 40 and 50 Mg ha-¹ + K), plus two additional treatments (absolute control and mineral fertilization indicated to the species). Each treatment was composed by four repetitions. The height, stem diameter and index of green color were measured monthly, during six months and leaf area, dry matter mass, plant nutrition and soil fertilizer were evaluated at the end of the experiment. The data were subjected to analysis of variance, complemented with tests of multiple comparisons and adjustments of polynomial regression models to evaluate the effect of doses, at 5% level of significance. Both sewage sludge and sludge compost, in the doses of 40 e 50 Mg ha-1, provided quantities of nutrients to plants and soil, higher than absolute control and greater than or equal to inorganic fertilization but never lower than it, what explain the improvements in the soil fertilizer and in the plants development like higher height, diameter, leaf area and production of dry matter mass when they received these quantities of both of organic fertilizers. So, the sludge and the sludge compost, when used in doses of 40 and 50 Mg ha-1 provided enough quantities of nutrients for plants of Eucalyptus to have... / Mestre
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Stratégie d'échantillonnage des mesures LIBS in situ de la teneur en or dans des échantillons miniers : optimisation par analyse statistiqueNguegang Kamwa, Blandine 31 May 2021 (has links)
Au Québec, 19 mines d'or produisent plus de 1.8 milliard dollars canadiens d'or annuellement. Dans ces mines, des centaines d'échantillons de roches sont collectées quotidiennement, et envoyées au laboratoire afin de déterminer leurs concentrations en or. Étant donné que les résultats du laboratoire ne sont disponibles qu'après 24 à 48 heures, il s'en suit un impact direct négatif sur les activités minières. Les avancées technologiques des dernières années laissent croire que la spectroscopie sur plasma induite par laser (LIBS) pourrait constituer une technologie prometteuse pour mesurer en temps réel et in-situ, la teneur en or de la roche. Considérant la taille de chaque tir produit par le laser sur un échantillon de roche, à savoir 500 µm, de très nombreux tirs seront requis afin d'obtenir un résultat représentatif de l'échantillon analysé. À titre d'exemple, pour un échantillon de carotte de 50 cm de long, et une surface analysée comprise entre 70 et 80%, 10000 tirs lasers ont été effectués afin de s'assurer d'obtenir un résultat représentatif de l'échantillon, avec un temps d'acquisition d'une demi-journée en laboratoire, soit une durée trop longue pour une application pratique dans les mines. Pour cette raison, l'objectif de ce projet est de développer une stratégie afin de minimiser le nombre de tirs LIBS requis sur un échantillon à analyser, tout en demeurant représentatif de ce dernier, et ainsi obtenir une mesure fiable et précise de la teneur en or. Pour ce faire, une analyse statistique descriptive combinée à plusieurs motifs élaborés à partir des 10000 points de mesure est appliquée sur les données LIBS. En se fixant un compromis entre le nombre de tirs à réaliser sur un échantillon (roche) et le temps d'analyse, le motif défini « Boucle » minimise le mieux le nombre de tirs avec un temps d'analyse acceptable par une opération minière. À partir de ce dernier, un protocole d'échantillonnage a été élaboré, où pour être représentatif des échantillons de carottes, 1500 tirs sont nécessaires tandis que pour les échantillons de roches, seuls 100 tirs suffisent. Cependant, il serait important de pouvoir tester ce protocole d'échantillonnage sur plusieurs échantillons miniers afin de pouvoir valider ce dernier. / In Quebec, 19 gold mines produce more than C (dollar) 1.8 billion of gold annually. In these mines, hundreds of rock samples are collected daily and sent to the laboratory to determine their gold concentrations. Since laboratory results are only available after 24 to 48 hours, there is a direct negative impact on mining activities. Technological advances in recent years suggest that Laser Induced Breakdown Spectroscopy (LIBS) may be a promising technology for real-time and in-situ measurement of the gold content of rock samples. Considering the size of each shot produced by the laser on a rock sample, namely 500 µm, many shots will be required in order to obtain a representative result of the sample analyzed. For example, for a 50 cm long core sample, and a surface analyzed between 70 and 80%, 10,000 laser shots were fired to ensure to obtain a result representative of the sample, with an acquisition time of half a day in the laboratory, which is a too long period of time for a practical application in mines. For this reason, the objective of this project is to minimize the number of LIBS shots required on a sample to be analyzed, while remaining representative of the latter, and thus obtain a reliable and accurate measurement of the gold content. For this, a descriptive statistical analysis combined with several elaborate patterns is applied to the 10,000 LIBS data obtained. By setting a compromise between the number of shots to be made on a sample and the analysis time, the Loop pattern minimizes the number of shots with an acceptable analysis time. From the latter, a sampling protocol has been developed, where to be representative of core samples, 1500 shots are needed whereas for rock samples, only 100 shots are needed. However, it would be important to be
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Study of the behavior of iron ore particles in spiral concentratorsSadeghi, Maryam 24 April 2018 (has links)
Les spirales sont des appareils de séparation gravimétrique principalement utilisés dans l’industrie du traitement du minerai de fer. La classification des particules dans la pulpe s’effectue lors de la descente dans les spires en fonction de leur taille et leur densité, des conditions d’opération et de la géométrie de la spirale. L’effet des conditions d’opération (pourcentage solide, débit d’alimentation et débit d’eau de lavage) est évalué sur la performance des spirales en utilisant une spirale WW6E installée à COREM pour traiter un minerai de fer de ArcelorMittal, Québec. Les résultats montrent l’effet dominant du débit de l’eau de lavage et son impact majeur sur les particules grossières. Un circuit fermé de trois spirales parallèles avec 3, 5 et 7 tours est utilisé afin d’évaluer l’influence du nombre de tours. Les résultats préliminaires indiquent que la spirale trois tours fonctionne bien pour le nettoyage tandis que la 7 tour est robuste pour l’ébauchage et l’épuisage. / Spiral concentrators are gravity separation devices widely used in the iron ore industry. Suspended particles in the slurry, descending a spiral trough, are classified according to their size and specific gravity. Operating conditions and spiral geometry influence the classification. The effect of operating conditions, e.g. wash water flow rate, slurry solids concentration and feed rate, is studied on spirals performance. The tests are conducted using a pilot spiral (WW6E) at COREM and an iron ore from ArcelorMittal, Quebec. Results clearly demonstrate the dominant effect of the wash water addition with its major impact on coarse particles. A closed circuit of 3 parallel spirals with 3, 5 and 7 turns at COREM is used to assess spirals performance as a function of the number of turns. Initial results from twelve tests indicate that the 3-turn-spiral is well suited for cleaning, while the 7-turn-spiral is robust for roughing and scavenging duty.
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Modélisation d'un classificateur hydraulique pour l'enrichissement d'un concentré d'oxyde de ferRoy, Jonathan 27 January 2024 (has links)
La séparation gravimétrique est probablement le plus ancien procédé utilisé pour la séparation des minéraux. Le type de séparateur gravimétrique analysé dans le cadre de cette étude est un classificateur hydraulique à lit dense. Ces appareils séparent les minéraux en fonction de leur dimension et de leur densité à l'aide d'un courant d'eau ascendant. L'objectif principal de la présente étude est de développer un modèle phénoménologique qui prend en compte les variables opératoires du classificateur et les dimensions de l'appareil. Le modèle mathématique développé a comme objectif d'aider les opérateurs à améliorer les procédés utilisant des classificateurs hydrauliques, en permettant la simulation de différentes stratégies de régulation et la conception des équipements pour des applications particulières. De plus, l'outil de simulation permet de prédire les états de variables non mesurées et/ou non mesurables comme la densité locale, la composition de la surverse, l'emplacement des interfaces, permettant ainsi d'être utilisé comme capteur virtuel. Toutefois, les montages industriels sont complexes à simuler, parce qu'ils opèrent à des régimes d'écoulement très turbulent tandis que certains des modèles mathématiques existants ne peuvent pas supporter de grandes variations de la concentration solide en fonction de la hauteur, en plus de généralement nécessiter des coefficients qui doivent être déterminés par des essais conduits en laboratoire, dans des conditions contrôlées. Or, pour que l'algorithme de simulation soit utilisable, peu importe les contraintes, il aura fallu introduire de nouveaux concepts pour la modélisation et la résolution du bilan de masse. Il est question, entre autres, de l'ajout de la vitesse de la pulpe, plutôt que celle du fluide, de l'estimation de la concentration solide maximale dans le lit fluidisé, de la prise en compte des caractéristiques de l'alimentation, et de l'estimation de la diffusion turbulente. L'algorithme développé dans nos travaux a été mis à l'épreuve en simulant et comparant les opérations d'appareils installés à l'usine de bouletage d'ArcelorMittal Canada et d'un montage de laboratoire installé à l'Université Laval. Ces équipements sont employés pour séparer les oxydes de fer de contaminants, composés majoritairement de quartz et de silicates de faible densité. / Gravimetric separation is probably the oldest process used by the mining industries for the separation of minerals. The type of gravity separator analyzed in this study is a dense bed hydraulic classifier. These devices separate minerals according to their size and density using a water stream. The main objective of the study is to develop a phenomenological model that considers the operating variables of the classifier and the physical construction of the apparatus. The model developed will be able to help operators improve existing processes by simulating different control strategies and design equipments. In addition, the algorithm can predict variables that are not measured such as the characteristics of the material inside the reactor such as local density, solids concentration, positions of the interfaces. However, the industrial reactors are complex to simulate because they operate at very turbulent flow regimes and some of the existing models cannot handle large solid variation within the reactor. The proposed models in the literature have coefficients that require parameters that need to be determined from tests conducted in the well-controlled environment of a laboratory. In order to develop the simulation algorithm, it was necessary to develop a new way of solving the mass balance and new concepts were introduced in the formulation of the model such as 1) using pulp velocity rather than the fluid velocity, 2) estimating the maximum solid concentration in the fluidized bed, 3) considering the feed characteristics, 4) estimating the turbulent diffusion as a function of the pulp velocity. The developed algorithm was tested by simulating and comparing the operation of hydraulic classifiers used at the ArcelorMittal Canada pellet plant and a laboratory set-up at Laval University. This equipment is used to separate iron oxides from contaminants composed mainly of silicon dioxides.
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Impact de la dilution opérationnelle sur le rendement métallurgique de l'orBoudreau, Mathieu 07 August 2019 (has links)
Ce mémoire rend compte d’une étude avec un minerai aurifère pour quantifier l’effet de la dilution excédentaire sur l’extraction de l’or. Depuis une quinzaine d’années, une tendance d’augmentation de la profondeur des mines souterraines est observée au Canada et dans le monde. Lorsque ces exploitations souterraines atteignent des profondeurs supérieures à 1000 m, elles deviennent sujettes à de fortes pressions et tensions causées par la roche. Cependant, l’effet résultant sur l’extraction du minerai est difficilement quantifiable occasionnant une dilution opérationnelle excédentaire à celle planifiée. Le projet de maîtrise analyse l’impact de cette dilution excédentaire sur le traitement du minerai d’une mine d’or située dans la région de l’Abitibi (nord-ouest du Québec). Pour ce faire, deux types de dilution sont considérés : la roche stérile et le remblai. Les résultats du test de Bond et de données de cyanuration issues de la littérature illustrent dans quelle mesure le taux d’alimentation peut être augmenté pour mitiger l’effet de cette dilution excédentaire et la perte de production en or. La discussion étudie également les points positifs et négatifs du montage conçu pour l’automatisation de la cyanuration du projet.
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Aspectos econômicos e sociais da mineração em Goiás, com ênfase na extração de areia / Economic and social aspects from Goiás mining, with emphasis on sand extractionTibiriçá, Luciana Gonçalves 17 July 2017 (has links)
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Previous issue date: 2017-07-17 / The State of Goiás (Brazil) has in the mining activity a relevant source of gathering funds and
which is part of its history of occupation and formation of urban networks. The mining activity
is administrated by technical criteria defined by the Brazilian Department of Mining Production
(as known as DNPM), being environmental licensing a part that integrates them. With the
pointed requirements on the environmental legislation, the formal mining exploration has
adapted itself in front of the need of conserve/preserve the environment considering the
geological and geographical conditions. Present in several industries, the use of mineral
resources allows the development of varied goods, moving finance market and creating jobs.
From the principles that mining is an activity of wide economic impact, involves environmental
problems and that the mining activity of the State of Goiás needs deep researches of
characterization, we developed this thesis. The assessment of the several mineral was made
by the employment of a methodology in municipal scale, from those with major revenue
arising from the mineral compensation due to the extraction of metallic minerals or non
metallic more profitable currently for Goiás, beyond the sand considering the period between
2010 and 2014. The results show that in the social aspect, the difference between the main
mining municipalities of Goiás is not relevant, even with the contribution from the mineral
compensation. For the municipalities producers of sand, the economic impact is minimum and
there are difficulties in following the recuperation of degraded areas, because the resource is
not enough to enable the manager the actions of local development. / O Estado de Goiás tem na mineração uma fonte de arrecadação relevante e que faz parte de sua história de ocupação e formação das redes urbanas. A atividade mineral é administrada por critérios técnicos definidos pelo Departamento Nacional da Produção Mineral (DNPM), sendo que o licenciamento ambiental é parte integrante dos mesmos. Com as exigências apontadas nas legislações ambientais, a exploração mineral formal tem se adaptado frente à necessidade de conservar/preservar o ambiente considerando as condições geológicas e geográficas. Presente em diversas indústrias, o uso dos recursos minerais permite o desenvolvimento de produtos variados, movimentando o mercado financeiro e gerando
emprego. A partir dos princípios de que a mineração é uma atividade de amplo impacto
econômico, envolve problemas ambientais e que a mineração goiana necessita de pesquisas
de caracterização mais aprofundadas, desenvolveu-se esta tese. Para avaliação dos diversos
minérios empregou-se uma metodologia em escala municipal, a partir daqueles com maior
receita oriunda da compensação mineral decorrente da extração de minérios metálicos ou não
metálicos mais rentáveis atualmente para Goiás, além da areia considerando o período entre
2010 e 2014. Os resultados obtidos demonstram que no aspecto social, a diferença entre os
principais municípios mineradores de Goiás não é relevante, apesar do aporte advindo da
compensação mineral. Para os municípios produtores de areia, o impacto econômico é mínimo
e há dificuldades em acompanhar a recuperação das áreas degradadas, pois o recurso não é
suficiente para possibilitar ao gestor as ações de desenvolvimento local.
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