Determinación de la intensidad de estallido de aire en minería de block caving.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Debido al agotamiento de los yacimientos de minerales cercanos a superficie, hay una mayor tendencia a la minería subterránea para poder seguir extrayendo estos yacimientos. Existen diversos métodos de extracción subterráneos, tanto auto soportados, como de rellenos o hundimientos, donde estos últimos suelen ser más atractivos en yacimientos masivos debido a las ventajas en términos de costos operacionales y productividad. Sin embargo, están sujetos a diversos problemas geomecánicos y operacionales como los estallidos de aire. Por este motivo, esta investigación se centra en desarrollar una metodología con el objetivo de prevenir o identificar el volumen de airgap y la intensidad de estallidos de aires en la minería de caving. Para esto, primero se realiza una revisión de casos de estudios, identificando que los parámetros más importantes y decisivos en la generación de estallidos de aires son la velocidad de extracción y la formación de arcos en la parte superior de la cavidad. Para estudiar este fenómeno se recurre al acople de los softwares Flac3D y FlowSim BC para la obtención del volumen del airgap. El primer software entrega la geometría de la cavidad que se formaría y el segundo los datos correspondientes al volumen de Airgap generado para un plan de producción predeterminado. Luego, de la literatura se utiliza una fórmula para calcular la velocidad máxima promedio de aire que se esperaría percibir en los puntos de extracción. En el primer caso simulado se aprecia como el volumen de airgap que se genera aumenta producto de que la velocidad de extracción es mayor a la velocidad de propagación del mientras que la simulación del segundo caso se genera la no propagación del caving en el tercer mes de extracción aumentando en gran medida el Airgap dentro de la cavidad debido a que no se detiene la extracción de material. Principalmente se concluye que la metodología propuesta resulta útil para la obtención de volúmenes de airgaps y velocidades de estallidos de aires, donde velocidades de extracción mayores a velocidades de propagación genera un aumento en el volumen de airgap dentro de la cavidad mientras que la no detección de problemas en la propagación del caving aumenta drásticamente este volumen obteniendo alturas de Airgap que van en aumento incrementando la intensidad del estallido de aire que se apreciaría en los puntos de extracción.
The world´s mining has had to resort to underground mining due to the depletion of nearsurface mineral deposits, in order to continue extracting these deposits with great economic values. There are various underground mining methods, self-supported, filling or subsidence. The latter are usually more attractive due to the advantages they offer in massive orebodies. However they are also the ones with the greateast geomechanical and operationals problems. This research focuses on determining a methodology with the aim of preventing or identifying the volume of airgap and the intensity of air bursts in cave mining. For this, a review of study cases is first carried out. The most important and key parameters in the generation of air bursts are the extraction/draw rate and the formation of hang-ups in the cave-back. To study the air bursts and airgap volume generated inside a cave mining, the use of a coupling of Flac3D and FlowSim BC software is necessary. The first software gives the cave geometry that would be formed month by month and the second software gives the airgap volume of that geometry for a specific production plan. Using a equation from the literature it is possible to obtain the average maximum air burst velocity that would be perceived at the draw point. In this research, 2 synthetic cases are elaborated with a production plan of 7 months. Both simulated cases showed an increase bulking as the airgap volume decrease with the increase of this factor. In the first case, due to having a draw speed higher than the propagation speed, the airgap volume increased slowly the first months and quickly in the later months. In the second case, due to a hang-up, the airgap volume increased quickly month by month. Finaly, having a slow draw speed dreceases the airgap volume inside the cave. We can conclude that this proposed methodology is useful for obtaining the airgap volume and air burst velocity, where high extraction/draw rate increase the airgap volume inside the cave if those rate are over the propagation rate of the cave-back, and a non-detection of a hang-up inside the cave drastically increase the airgap volume inside the cave increasing the air burst intensity that would be perceived at the draw points.
The world´s mining has had to resort to underground mining due to the depletion of nearsurface mineral deposits, in order to continue extracting these deposits with great economic values. There are various underground mining methods, self-supported, filling or subsidence. The latter are usually more attractive due to the advantages they offer in massive orebodies. However they are also the ones with the greateast geomechanical and operationals problems. This research focuses on determining a methodology with the aim of preventing or identifying the volume of airgap and the intensity of air bursts in cave mining. For this, a review of study cases is first carried out. The most important and key parameters in the generation of air bursts are the extraction/draw rate and the formation of hang-ups in the cave-back. To study the air bursts and airgap volume generated inside a cave mining, the use of a coupling of Flac3D and FlowSim BC software is necessary. The first software gives the cave geometry that would be formed month by month and the second software gives the airgap volume of that geometry for a specific production plan. Using a equation from the literature it is possible to obtain the average maximum air burst velocity that would be perceived at the draw point. In this research, 2 synthetic cases are elaborated with a production plan of 7 months. Both simulated cases showed an increase bulking as the airgap volume decrease with the increase of this factor. In the first case, due to having a draw speed higher than the propagation speed, the airgap volume increased slowly the first months and quickly in the later months. In the second case, due to a hang-up, the airgap volume increased quickly month by month. Finaly, having a slow draw speed dreceases the airgap volume inside the cave. We can conclude that this proposed methodology is useful for obtaining the airgap volume and air burst velocity, where high extraction/draw rate increase the airgap volume inside the cave if those rate are over the propagation rate of the cave-back, and a non-detection of a hang-up inside the cave drastically increase the airgap volume inside the cave increasing the air burst intensity that would be perceived at the draw points.
Description
Tesis presentada para optar al título de Ingeniero/a Civil de Minas.
Keywords
Minería subterránea, Extracción metalúrgica