Efecto del enfriamiento de escorias en la recuperación de cobre por flotación.
Loading...
Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Se estudió la factibilidad técnica y económica de implementar el enfriamiento de escorias de cobre provenientes de etapas de conversión, sustituyéndolo por enfriamiento en tazas, tanto en su variante natural como combinada. Para ello, se caracterizó la escoria mediante análisis químico y mineralógico, pruebas de dureza y ensayos de flotación. En estos ensayos, se acondicionó la celda durante cinco minutos y se operó durante doce minutos a 6 L/min de aire y 30 % de sólidos, aplicando dosis de planta, media y baja relación de colectores para evaluar la recuperación de metal valioso, así como la ley y la recuperación en peso.
Posteriormente, se desarrolló un modelo en MATLAB basado en la geometría de la taza y en las propiedades de la escoria (𝜌, 𝑐𝑝, 𝑘). En la primera fase, se simuló el enfriamiento natural por aire y radiación en las aristas, y en la segunda, el enfriamiento forzado con agua en la superficie. Mediante análisis FEA y una animación GIF, se determinó que el tiempo óptimo de enfriamiento fue de 58 horas (seis horas a temperatura ambiente y 52 horas con agua), con caudales de 3,79 L/min para un llenado del 40 % y de 4,31 L/min para un llenado del 66,9 %, procesando 2 880 t de escoria por día y requiriendo 78 tazas por ciclo. El modelo también validó un coeficiente de transferencia de calor natural K = 15 W/m²·K y demostró que la taza de mayor volumen (700 ft³ en Caletones frente a 495 ft³ en Altonorte) removía más calor en los niveles de llenado simulados.
Finalmente, la evaluación económica arrojó un VAN de 27 169 833 USD, una TIR del 22 % y un período de recuperación de cuatro años, considerando la inversión en 110 tazas, un costo de mantención anual del 10 % y proyecciones del precio del cobre en USD para ajustar la rentabilidad del proyecto. Este análisis integral permite visualizar con mayor claridad la viabilidad y el impacto potencial de la implementación del nuevo sistema de enfriamiento en la operación.
The technical and economic feasibility of implementing the cooling of copper slags from conversion stages was studied, replacing the current method with cooling in pots, both in its natural and combined variants. For this purpose, the slag was characterized through chemical and mineralogical analysis, hardness tests, and flotation assays. In these tests, the cell was conditioned for five minutes and operated for twelve minutes at 6 L/min of air and 30% solids, applying plant, medium, and low collector ratios to evaluate the recovery of valuable metal, as well as grade and weight recovery. Subsequently, a MATLAB model was developed based on the geometry of the pot and the properties of the slag (𝜌, 𝑐𝑝, 𝑘). In the first phase, natural cooling by air and radiation at the edges was simulated, and in the second phase, forced cooling with water on the surface. Through FEA analysis and a GIF animation, it was determined that the optimal cooling time was 58 hours (six hours at ambient temperature and 52 hours with water), with flow rates of 3.79 L/min for 40% filling and 4.31 L/min for 66.9% filling, processing 2,880 t of slag per day and requiring 78 pots per cycle. The model also validated a natural heat transfer coefficient K = 15 W/m²·K and demonstrated that the larger pot (700 ft³ in Caletones versus 495 ft³ in Altonorte) removed more heat at the simulated filling levels. Finally, the economic evaluation yielded an NPV of USD 27,169,833, an IRR of 22%, and a payback period of four years, considering the investment in 110 pots, an annual maintenance cost of 10%, and copper price projections in USD to adjust the project's profitability. This comprehensive analysis provides a clearer view of the feasibility and potential impact of implementing the new cooling system in the operation.
The technical and economic feasibility of implementing the cooling of copper slags from conversion stages was studied, replacing the current method with cooling in pots, both in its natural and combined variants. For this purpose, the slag was characterized through chemical and mineralogical analysis, hardness tests, and flotation assays. In these tests, the cell was conditioned for five minutes and operated for twelve minutes at 6 L/min of air and 30% solids, applying plant, medium, and low collector ratios to evaluate the recovery of valuable metal, as well as grade and weight recovery. Subsequently, a MATLAB model was developed based on the geometry of the pot and the properties of the slag (𝜌, 𝑐𝑝, 𝑘). In the first phase, natural cooling by air and radiation at the edges was simulated, and in the second phase, forced cooling with water on the surface. Through FEA analysis and a GIF animation, it was determined that the optimal cooling time was 58 hours (six hours at ambient temperature and 52 hours with water), with flow rates of 3.79 L/min for 40% filling and 4.31 L/min for 66.9% filling, processing 2,880 t of slag per day and requiring 78 pots per cycle. The model also validated a natural heat transfer coefficient K = 15 W/m²·K and demonstrated that the larger pot (700 ft³ in Caletones versus 495 ft³ in Altonorte) removed more heat at the simulated filling levels. Finally, the economic evaluation yielded an NPV of USD 27,169,833, an IRR of 22%, and a payback period of four years, considering the investment in 110 pots, an annual maintenance cost of 10%, and copper price projections in USD to adjust the project's profitability. This comprehensive analysis provides a clearer view of the feasibility and potential impact of implementing the new cooling system in the operation.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Metalúrgico/a.
Keywords
Minería, Escorias de cobre, Flotación (Minerales)