44 research outputs found

    Parametric study of the interface behavior between two immiscible liquids flowing through a porous medium

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    When two immiscible liquids that coexist inside a porous medium are drained through an opening, a complex flow takes place in which the interface between the liquids moves, tilts and bends. The interface profiles depend on the physical properties of the liquids and on the velocity at which they are extracted. If the drainage flow rate, the liquids volume fraction in the drainage flow and the physical properties of the liquids are known, the interface angle in the immediate vicinity of the outlet (theta) can be determined. In this work, we define four nondimensional parameters that rule the fluid dynamical problem and, by means of a numerical parametric analysis, an equation to predict theta is developed. The equation is verified through several numerical assessments in which the parameters are modified simultaneously and arbitrarily. In addition, the qualitative influence of each nondimensional parameter on the interface shape is reported.Comment: 7 pages, 12 figure

    Gold Sterile Ore Acid Generation Evaluation, San Juan Argentina

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    One of the problems that mining represents in relation to the natural watercourses is the possible formation of what we call acid mine drainage, which consists in the emission or formation of water effluents of great acidity, usually rich in sulfate and with variable contents in heavy metals. The drainage mentioned is developed from the metal sulfide and sulfate leaching. Researches about the creation of acid drainage suggest that the formation of these depends directly on various factors: primary mineralogy (neutralizer sulfides and minerals), water presence (whether), oxygen diffusion, grain size, microbiological interaction (bacterium), among others. To study these variables and to relate them with geological factors, static (Acid-Base Accounting) and dynamic (Humidity Cell) tests have been developed, among others. The mentioned tests are applied to a case of a gold deposit situated in the Province of San Juan, which is currently very argued because of its mining activity due to its leaching process. In the sterile mineral obtained from the process, kinetics tests were carried out in humidity cells to simulate the natural oxidation of the primary mineral samples. In the obtained leaching, pH values closer to neutrality and a limited solution metal presence were detected, indicating the neutralization ability due to the carbonates ores presence.Fil: Bazan Brizuela, Vanesa Lucia. Universidad Nacional de San Juan. Facultad de Ingenier铆a. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; ArgentinaFil: Sarquis, Pedro Edgardo. Universidad Nacional de San Juan. Facultad de Ingenier铆a. Instituto de Investigaciones Mineras; ArgentinaFil: Brandaleze, Elena. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s; Argentin

    Treatments and Recycling of Metallurgical Slags

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    Steelmaking plants continuously strive to reduce the environmental load in the steelmaking process, resulting in the recycling of energy, water, and other byproducts. In this chapter, techniques for the treatment and recycling of metallurgical slags are described. Metallurgical slags are considered secondary raw materials and are used or added during the process to improve steelmaking practice. Steelmaking slag added into ladle slags makes it possible to minimize slag line wear. BOF-converter slags are also applied in buildup, foaming, or slag splashing practices carried out to prolong the lifespan of refractory lining. Also, EAF slags are commonly used to avoid refractory wear and decrease energy consumption. It is known that cement concrete is one of the most common building materials. Blast furnace crystallized slags are used in cement production, in different percentages. In this sense, understanding the properties of slags is a prerequisite to apply them in different functions. This chapter deals with the measurement and modeling of thermochemical properties of slags, thermophysical properties, and interproperty correlations. Different experimental tests applied in slag characterization are also detailed

    Argentinean copper concentrates: structural aspects and thermal behaviour

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    In Argentina, there are many sources of copper concentrates. Some of them are currently in operation, while others are in the exploration stage. All copper concentrates produced are exported to other countries for copper refinement and to create various finished products. It is desirable that in the near future, these copper concentrates be processed in an Argentinean industrial plant. The aim of this paper was to present the results of a characterisation study carried out on five different copper concentrate samples. The thermal decomposition of the copper concentrates was determined by differential thermal analysis and thermogravimetry (DTA TG). The information was correlated with the chemical composition and the mineralogical phases of the samples identified by X-ray diffraction. A melting test at temperatures of up to 1300藲C was performed to complete the study of the concentrate鈥檚 behaviour during heating. After the test, all of the samples were observed by light and electronic scanning microscopy to identify the different phases generated under high-temperature conditions.Fil: Bazan Brizuela, Vanesa Lucia. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; Argentina. Universidad Nacional de San Juan; ArgentinaFil: Brandaleze, Elena. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s. Centro para el Desarrollo Tecnol贸gico de Materiales; ArgentinaFil: Santini, Leandro Matias. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; Argentina. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s. Centro para el Desarrollo Tecnol贸gico de Materiales; ArgentinaFil: Sarquis, Pedro Edgardo. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; Argentin

    Kinetics roasting low grade concentrates molybdenite

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    El molibdeno es un metal atractivo para la fabricaci贸n de aceros y fundiciones debido a que promueve un marcado endurecimiento, aumentando la resistencia mec谩nica cuando la aleaci贸n se somete a enfriamientos controlados en un rango de temperaturas cr铆ticas. Esto ha provocado un aumento considerable en la demanda de los productos de molibdeno, el cual proviene de concentrados de molibdenita (MoS2) como subproductos de yacimientos tipo p贸rfido cupr铆fero. En este trabajo se presentan resultados de un estudio de concentrados de molibdenita de baja ley, con composiciones levemente distintas, que registran diferencias en los resultados operacionales de tostaci贸n. Estas diferencias, se deben en gran parte a los mecanismos de reacci贸n identificados y a las impurezas presentes en el concentrado como el Fe. Se realizan ensayos para la determinaci贸n de las condiciones 贸ptimas de recuperaci贸n de Mo y se determina las constantes de velocidad para cada muestraFil: Bazan Brizuela, Vanesa Lucia. Universidad Nacional de San Juan. Facultad de Ingenier铆a. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; ArgentinaFil: Brandaleze, Elena. Universidad Tecnologica Nacional; ArgentinaFil: Colque, Enzo. Universidad Nacional de San Juan. Facultad de Ingenier铆a. Instituto de Investigaciones Mineras; Argentin

    A refractory wear predictive model developed for BOF converters

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    In order to contribute to the experience of the BOF operators, related with the wear of the refractory lining, a Wear Predictive Model (WPM) was developed. It is based on the database of many measurements made using a laser scanner. Not only this WPM model could be consider as a tool that supports decision such as doing a gunning repair or not, but also as guide to analyze changes in the initial refractory lining that led to a performance increase or cost reduction, for instance. The wear rate of MgO-C refractory lining depends on the material itself and the different erosive and corrosive agents present during the process. This WPM was developed in a BOF that do not operates with sublance, therefore the areas have been defined as the most critical ones are: barrel (B), tapping area (T), slag lines (horizontal (SLh), vertical (SLv) and the crossing of both (SLc)) and trunnions (T). The results obtained after several scans along many lining campaigns have been tabulated for a subsequent analysis. As output of this statistic WPM, curves with minimum and maximum thickness have been drawn. These curves show two main areas: secure work (WS) operation area and risky work (WR) operation area. It is possible to define the impact of different operating parameters as well. Keywords: Converter, refractory, wear, predictive model.Fil: Brandaleze, Elena. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s. Centro para el Desarrollo Tecnol贸gico de Materiales; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; ArgentinaFil: Torresi Dom铆nguez, Ulises. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s. Centro para el Desarrollo Tecnol贸gico de Materiales; Argentina. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; ArgentinaFil: Santini, Leandro Matias. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas; Argentina. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s. Centro para el Desarrollo Tecnol贸gico de Materiales; Argentin

    Uso de procesos pirometal煤rgicas para la obtenci贸n de renio

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    El renio es un metal que presenta distintos m茅todos de obtenci贸n.El m谩s utilizado es el que se lleva a cabopor la tostaci贸n de la molibdenita. En 茅l se aplican m茅todos pirometal煤rgicos tradicionales como es tostaci贸noxidante, pero tambi茅n existen m茅todos pirometal煤rgicos innovadores como la tostaci贸n con reducci贸ncarbot茅rmica.En este trabajo se estudia el comportamiento que presenta el renio frente al uso de diferentestostaciones, ellas son tostaci贸n oxidante y tostaci贸n con reducci贸n carbot茅rmica. El objetivo es compararambos tratamientos discutiendo los valores de recuperaci贸n de renio.La tostaci贸n oxidante es un m茅todo que genera importantes emanaciones de SO2 al medio ambiente,cuando se aplica a sulfuros met谩licos. En cambio, la reducci贸n carbot茅rmica es un proceso que utiliza el CaOcomo agente captador de azufre y elC como reductor, junto al sulfuro met谩lico, eliminando de esta manera lacontaminaci贸n de la atm贸sfera que hab铆a sido producida por el SO2. Con tal fin, se estudi贸 la relaci贸n molarde CaO 贸ptima con respecto al Re y C, requerida para acelerar la velocidad de reducci贸n y controlar laemisi贸n de S a la atmosfera. De esta manera se determinan la dependencia del sulfuro met谩lico con losfactores operacionales de temperatura de tostaci贸n, concentraciones molares y tiempos de tostaci贸n.Por otro lado, en la tostaci贸n oxidante se trabaj贸 con las variables operativas de temperatura y tiemposde tostaci贸n para determinadas condiciones atmosf茅ricas.En base a los resultados obtenidos de ambas tostaciones se determinaron las condiciones 贸ptimas delas operaciones para la mayor recuperaci贸n de Re.Palabras clave: renio, tostaci贸n, reducci贸n carbot茅rmica

    Simulaci贸n del canal del alto horno n掳 2 por medio de modelos f铆sicos

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    In the operation of the blast furnace through the aim is to diminish metal losses with the slag, that can be as high as 2.5% and to reduce or eliminate the slag carry over, that leads to an increase in the cost of downstream treatment. Another important issue is to minimize the need for repairing the walls and floor, in order to increase their life. A physical model of the Siderar blast furnace N潞 2 through was constructed on 1:5th scale. To determine the flowrate, Froude and Reynolds similarity criteria were taken. The model allows simulation of different casting conditions, giving information about turbulent zones as well as slag separation or entrainement. A trial was made simulating a casting rate of 10 metric tons per minute for a mix of 60% metal and 40% slag. Oil was selected to simulate the slag. The fluid flow was observed in each zone: taphole and first part of the runner, zone of jet impact, zone of separation of slag and hot metal, and the zones of slag runner, skimmer and exit to the hot metal runner. Key words: runner, blast furnace, simulation, water model.En la operaci贸n de los canales de alto horno se busca disminuir las p茅rdidas met谩licas en la escoria, que pueden llegar al 2,5% y tambi茅n reducir o eliminar el arrastre de escoria con el arrabio l铆quido, lo que puede implicar un aumento de costo en los tratamientos aguas abajo. Tambi茅n es importante minimizar las reparaciones de paredes y piso, apuntando a una mayor vida 煤til. Se construy贸 un modelo del canal del alto horno N潞 2 de Siderar en escala 1:5. Para determinar el caudal, se tuvieron en cuenta los n煤meros de Froude y Reynolds. El modelo permite simular diferentes condiciones de colado, dando informaci贸n sobre zonas turbulentas y sobre la separaci贸n y arrastre de escoria. Se hizo un ensayo con condiciones de colado que simulan 10 t de una mezcla de 60% de metal y 40% de escoria. Se us贸 aceite para representar la escoria. Se observ贸 el flujo en cada zona: piquera y comienzo del canal, zona de impacto del chorro, zona de separaci贸n de escoria y metal, y las zonas de los canales de escoria, skimmer, y la salida al canal de arrabio. Palavras-chave: canal, alto horno, simulaci贸n, modelo de 谩gua

    Penetration and dissolution of refractory of magnetite - chrome by fayalite slag

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    Los refractarios magnesia-cromo se han utilizado con 茅xito en diferentes procesos metal煤rgicos a altas temperaturas, tales como hierro y acero, la industria del cemento y procesos pirometal煤rgicos no ferrosos. En particular en la fundici贸n,聽 en los procesos de聽 conversi贸n de refino de cobre. Esos materiales tienen buenas caracter铆sticas en relaci贸n con el uso y los requisitos de resistencia al choque t茅rmico. Sin embargo, representan un problema importante en la contaminaci贸n del medio ambiente. El objetivo de este estudio fue investigar las interacciones entre la escoria generada en el convertidor Peirce-Smith e cobre y los ladrillos refractarios de magnesia-cromo ladrillos. Los fen贸menos de infiltraci贸n y ataques qu铆micos en el material refractario causado por la escoria formada durante el proceso de conversi贸n de cobre se han estudiado mediante el desarrollo de las diferentes pruebas de laboratorio a temperaturas de hasta 1300 掳 C.Magnesium-chrome refractory have been used with success at high temperatures in different metallurgist processes, such as iron and steel, cement industry and non ferrous pyrometallurgist processes. In particular in the smelting, in the processes of reforming of raffinate of copper. Those materials have good characteristics in relation with the use and the requirements of heat shock resistance. However, they represent an important problem for the environment. The aim of this research was to investigate the interactions between the slag generated in the converter Peirce-Smith in copper and Magnesium-chrome refractory bricks. The infiltration events and chemical attacks in the refractory material caused by the slag formed during the copper conversion process have been studied by means of the development of the different laboratory tests at temperatures of until 1300 掳 C.Fil: Bazan Brizuela, Vanesa Lucia. Consejo Nacional de Investigaciones Cient铆ficas y T茅cnicas. Centro Cient铆fico Tecnol贸gico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingenier铆a. Instituto de Investigaciones Mineras; ArgentinaFil: Brandaleze, Elena. Universidad Tecnol贸gica Nacional. Facultad Regional San Nicol谩s; ArgentinaFil: Parra, Roberto. Universidad de Concepci贸n; ChileFil: Go帽i, Christian. Universidad de Concepci贸n; Chil
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