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

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

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 Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sarquis, Pedro Edgardo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Brandaleze, Elena. Universidad Tecnológica Nacional. Facultad Regional San Nicolás; Argentin

Treatments and Recycling of Metallurgical Slags

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

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˚C was performed to complete the study of the concentrate’s 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 Científicas y Técnicas; Argentina. Universidad Nacional de San Juan; ArgentinaFil: Brandaleze, Elena. Universidad Tecnológica Nacional. Facultad Regional San Nicolás. Centro para el Desarrollo Tecnológico de Materiales; ArgentinaFil: Santini, Leandro Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional San Nicolás. Centro para el Desarrollo Tecnológico de Materiales; ArgentinaFil: Sarquis, Pedro Edgardo. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Kinetics roasting low grade concentrates molybdenite

El molibdeno es un metal atractivo para la fabricación de aceros y fundiciones debido a que promueve un marcado endurecimiento, aumentando la resistencia mecánica cuando la aleación se somete a enfriamientos controlados en un rango de temperaturas críticas. 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 pórfido cuprífero. 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 tostación. Estas diferencias, se deben en gran parte a los mecanismos de reacción identificados y a las impurezas presentes en el concentrado como el Fe. Se realizan ensayos para la determinación de las condiciones óptimas de recuperación de Mo y se determina las constantes de velocidad para cada muestraFil: Bazan Brizuela, Vanesa Lucia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brandaleze, Elena. Universidad Tecnologica Nacional; ArgentinaFil: Colque, Enzo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; Argentin

A refractory wear predictive model developed for BOF converters

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 Tecnológica Nacional. Facultad Regional San Nicolás. Centro para el Desarrollo Tecnológico de Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torresi Domínguez, Ulises. Universidad Tecnológica Nacional. Facultad Regional San Nicolás. Centro para el Desarrollo Tecnológico de Materiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santini, Leandro Matias. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional San Nicolás. Centro para el Desarrollo Tecnológico de Materiales; Argentin

Uso de procesos pirometalúrgicas para la obtención de renio

El renio es un metal que presenta distintos métodos de obtención.El más utilizado es el que se lleva a cabopor la tostación de la molibdenita. En él se aplican métodos pirometalúrgicos tradicionales como es tostaciónoxidante, pero también existen métodos pirometalúrgicos innovadores como la tostación con reduccióncarbotérmica.En este trabajo se estudia el comportamiento que presenta el renio frente al uso de diferentestostaciones, ellas son tostación oxidante y tostación con reducción carbotérmica. El objetivo es compararambos tratamientos discutiendo los valores de recuperación de renio.La tostación oxidante es un método que genera importantes emanaciones de SO2 al medio ambiente,cuando se aplica a sulfuros metálicos. En cambio, la reducción carbotérmica es un proceso que utiliza el CaOcomo agente captador de azufre y elC como reductor, junto al sulfuro metálico, eliminando de esta manera lacontaminación de la atmósfera que había sido producida por el SO2. Con tal fin, se estudió la relación molarde CaO óptima con respecto al Re y C, requerida para acelerar la velocidad de reducción y controlar laemisión de S a la atmosfera. De esta manera se determinan la dependencia del sulfuro metálico con losfactores operacionales de temperatura de tostación, concentraciones molares y tiempos de tostación.Por otro lado, en la tostación oxidante se trabajó con las variables operativas de temperatura y tiemposde tostación para determinadas condiciones atmosféricas.En base a los resultados obtenidos de ambas tostaciones se determinaron las condiciones óptimas delas operaciones para la mayor recuperación de Re.Palabras clave: renio, tostación, reducción carbotérmica

Simulación del canal del alto horno n° 2 por medio de modelos físicos

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 Nº 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 operación de los canales de alto horno se busca disminuir las pérdidas metálicas en la escoria, que pueden llegar al 2,5% y también reducir o eliminar el arrastre de escoria con el arrabio líquido, lo que puede implicar un aumento de costo en los tratamientos aguas abajo. También es importante minimizar las reparaciones de paredes y piso, apuntando a una mayor vida útil. Se construyó un modelo del canal del alto horno Nº 2 de Siderar en escala 1:5. Para determinar el caudal, se tuvieron en cuenta los números de Froude y Reynolds. El modelo permite simular diferentes condiciones de colado, dando información sobre zonas turbulentas y sobre la separación 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 usó aceite para representar la escoria. Se observó el flujo en cada zona: piquera y comienzo del canal, zona de impacto del chorro, zona de separación 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, simulación, modelo de água

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

Los refractarios magnesia-cromo se han utilizado con éxito en diferentes procesos metalúrgicos a altas temperaturas, tales como hierro y acero, la industria del cemento y procesos pirometalúrgicos no ferrosos. En particular en la fundición,  en los procesos de  conversión de refino de cobre. Esos materiales tienen buenas características en relación con el uso y los requisitos de resistencia al choque térmico. Sin embargo, representan un problema importante en la contaminación 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 fenómenos de infiltración y ataques químicos en el material refractario causado por la escoria formada durante el proceso de conversión de cobre se han estudiado mediante el desarrollo de las diferentes pruebas de laboratorio a temperaturas de hasta 1300 ° 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 ° C.Fil: Bazan Brizuela, Vanesa Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Investigaciones Mineras; ArgentinaFil: Brandaleze, Elena. Universidad Tecnológica Nacional. Facultad Regional San Nicolás; ArgentinaFil: Parra, Roberto. Universidad de Concepción; ChileFil: Goñi, Christian. Universidad de Concepción; Chil