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By Luis Martín Tejada

Para la evaluación de la estabilidad de taludes en minería superficial se utilizan diferentes métodos de modelamiento y planeamiento como el de simulación numérica. En ese sentido, el presente texto describe el método de tensión-deformación, cuyo base se encuentra en el método numérico de elementos finitos, y así localizar la probable superficie de ruptura. También se describe los mecanismos de ruptura en taludes altos, el cálculo del FS y algunas características del programa de elementos finitos PLAXIS.

Sep 9, 2007

By Abigaid Gonzáles

La presente investigación desarrolla contenido relacionado al procedimiento de servidumbre minera regulado por diversas normativas sectoriales que evidencian que, desde la entrada en vigor de la ley de tierras y sus reglamentos complementarios, dicho procedimiento actualmente está en desuso porque el titular de la actividad minera no tiene confianza, ni voluntad de recurrir ante la autoridad minera, pues prefiere ahorrar tiempo y reducir costos.

Sep 29, 2023

By Jesús Frisancho, Rosmery Delgado, Enrique Callo, Juan Calizaya

El complejo volcánico Ciénaga-Mirador está conformado por flujos de lava, flujos piroclásticos, tobas de composición andesítica, dacítica y riolítica; asociados a pórfidos daciticos dioríticos y brechas freáticas e hidrotermales con matriz de óxidos. Estos depósitos conforman un borde de caldera y domos a lo largo de fallas EW; la mineralización se presenta en forma de oro libre acompañado con óxidos de hierro, asociados a cuerpos de sílice masiva, “vuggy” y arenosa. Se realizaron dataciones U-Pb en zircones en la Universidad de Otawa (Canadá). Las edades de las rocas intrusivas fueron entre 13.85 ± 0.16 Ma y 14.05 ± 0.24 Ma. Se procesó data de espectrometría de reflectancia (TerraSpec) y las alteraciones hidrotermales fueron reconocidas como sílice-alunita-pirofilita, paragonito-muscovita, muscovita-dickita y caolinita-montmorillonita-illita, las cuales definieron un depósito epitermal de alta sulfuración con transición a pórfido. Con la caracterización petroquímica de magmas fértiles a partir de rocas volcánicas e intrusivas y la ocurrencia mineral a escala distrital y regional se define a Ciénaga-Mirador como un depósito epitermal de Au-Ag y pórfido Au con bajo potencial de desarrollo.

May 22, 2019

By Oliver Gago Porras

Dadas las modificaciones constantes en los métodos de explotación actual de la minería, se ha previsto reducir costos operativos y optimizar la productividad y seguridad minera. Por tal motivo, la mina Quiruvilca utilizó el método de explotación corte y relleno en la ejecución de sus vetas angostas. Sin embargo, la factibilidad del método tradicional señalado, no delimita el empleo de otros métodos de explotación, ni genera inversión alguna. En este sentido, el presente trabajo describe la aplicación del sistema numérico en la mina Quiruvilca a través de los métodos de explotación de tajeo con almacenamiento provisional y por subniveles en algunas vetas, con la finalidad de incrementar su productividad y tonelaje, así como eliminar el importe de su operación en los tajos correspondientes.

Apr 1, 1991

By José Luis Solis

Para la exploración minera se obtiene muestras del subsuelo a profundidades variables, las cuales son enviadas posteriormente al laboratorio para realizar los análisis respectivos. Sin embargo, esto incluye pérdida de tiempo y genera errores en los resultados como consecuencia de la manipulación de las muestras. En este sentido, el presente texto señala el análisis por activación neutrónica de gammas inmediatos (Prompt Gamma Neutron Analysis Activation, PGNAA) como el método más adecuado para la evaluación de muestras del subsuelo. El método consiste en exponer la muestra a un haz de neutrones y detectar la radiación gamma debido a la captura neutrónica. La radiación gamma emitida es característica del núcleo correspondiente a cada elemento de la muestra, donde la intensidad y la energía de la radiación gamma se mide con un detector espectrométrico, de modo que se puede determinar el elemento y la cantidad de la misma presente en la muestra. Este sistema puede ser aplicado en minas de carbón, cobre, hierro, fosfatos, etc. Una vez que el sistema se calibra, los resultados se pueden obtener después de la toma de datos en una perforación.

Sep 19, 2006

By Fredy Rijalba Palacios

"El presente texto señala el proceso de ingeniería donde se evalúa y modeliza la distribución de los desplazamientos y la interacción de la geomecánica de las cámaras de explotación. La modelización se realiza en la mecánica de los medios contínuos y por medio de métodos numéricos, utilizando la técnica de los elementos finitos. Primero, se estudia el modelo geológico donde se obtuvo el modelo geomecánico del terreno rocoso, luego se formula el modelo numérico, incluyendo las excavaciones. Finalmente se plantea el diseño de la configuración geométrica de la mina que ofrece la más segura estabilidad del terreno intervenido y que permite extraer el mayor volumen posible de reservas minerales, con el método de explotación apropiado."

Oct 1, 2016

By Daniel Novario, Juan Rodríguez, Miguel Herrera

En general los indicadores de rendimiento y eficiencia están en función a los parámetros operativos de entrada y salida del proceso y para el caso del sistema de compresión de aire se dispusieron una serie instrumentos y dispositivos tales como medidores de energía eléctrica, sensores de flujo y presión en la descarga de cada compresor y sensores de condiciones ambientales como humedad relativa, temperatura ambiente y presión atmosférica. Todos estos parámetros son integrados al sistema de control de Minera Poderosa,donde se realizan los procesamientos y cálculos para la medición de rendimiento y eficiencia en línea, además de una estructura de reportes donde también se despliegan alarmas, horas de operación, horas de falla, entre otros.

Sep 29, 2023

By Jhon F. Chávez

"El presente texto describe las técnicas de análisis, diseño y optimización de las mallas de sostenimiento activo, de forma que optimiza las condiciones de seguridad y reducción de costos de sostenimiento en las labores de la minera Iscaycruz, así como los sobrecostos por daños a instalaciones y equipos por accidentes relacionados a falla en el sostenimiento activo."

Jan 1, 2016

By Jhon F. Quijano

En el presente artículo se documentan los trabajos realizados con el objeto de mostrar las técnicas de análisis, diseño y optimización de las mallas de sostenimiento activo, logrando con ello grandes e importantes resultados en las condiciones de seguridad y reducción de costos de sostenimiento en las labores de la Unidad Minera Iscaycruz.

Sep 1, 2017

By Juliano Cesar Cecilio

O trabalho surgiu mediante a necessidade de reduzir o custo na compra de anéis de laminação em 50% do que é praticado atualmente. Os anéis de laminação utilizados atualmente no 1º passe de laminação do laminador de perfis leves são anéis fabricado de aço ferramenta D2 e tem um custo alto para serem fabricados. No processo de laminação de perfis leves utilizamos cassetes onde são alocados esses anéis e para realizar a laminação de cantoneiras faz-se necessário a montagem de 4 anéis bi-partidos no eixo superior e 2 anéis bi-partidos no eixo inferior totalizando 6 anéis por cassete, além de reservas que temos que garantir para a realização de trocas por desgaste por laminação. Para o processo de fabricação de barra chata utilizamos 2 anéis de mesa lisa 1 no eixo superior e outro no eixo inferior, além de reservas para possíveis trocas. Tendo em vista o alto número de anéis que devemos ter para nosso processo resolvemos desenvolver esses anéis a partir de cilindros sucatas de um dos laminadores de nossa unidade, de modo a reaproveita-los e com isso eliminar a compra dos anéis de aço ferramenta D2. Após o desenvolvimento realizamos o teste com os cilindros do laminador DEMAG da unidade de Barra Mansa e os anéis apresentaram performance muito semelhante ao dos que utilizamos atualmente. Com isso todos os cilindros no final de vida útil do laminador de Barra Mansa são nos enviados para passar pelo processo de usinagem serem reutilizados.

Jul 30, 2018

By R. W. Luhning, S. D. Gittins, J .. A. Haston

"The Underground Test Facility (UTF) project operated by the Alberta Oil Sands Technology and Research Authority (AOSTRA) north of Fort McMurray has achieved marked success in field testing mining access and horizontal well in situ recovery of bitumen from the Athabasca oil sands.Mine access has provided for effective placing and operation of horizontal wells in the oil sands from a tunnel system in the underlying limestone. Performance of the in situ recovery process, Steam Assisted Gravity Drainage, has substantially exceeded forecasts made at the start of the project. Over-all results of the program to date show great promise for horizontal well in situ technology as a competitive source of bitumen from Alberta's vast oil sands deposits. The potential economics of a commercial expansion at the site are reviewed in this paper.IntroductionIn situ recovery o f bitumen from the Athabasca oil sands has puzzled the oil industry for many year s, but a breakthrough appears close at hand. The Underground Test Facility (UTF) project initiated by the Alberta Oil Sands Technology and Research Authority (AOSTRA) has had notable success in the piloting of horizontal well processes, which offer prospects for commercial development even under the highly competitive situation facing the Canadian industry . This paper describes the project briefly and presents the potential economics of commercial development on the UTF lease."

Jan 1, 1990

By J. C. O'Rourke

"This paper presents an overview of Alberta Oil Sands Technology Research Authority's in situ oil sands recovery project at its underground test facility near Fort McMurray. It covers the rationale for horizontal wells drilled from tunnels below the oil sands, the tunnel layout, the drilling program, and the recovery process and facilities. INTRODUCTIONThe Alberta Oil Sands Technology and Research Authority (AOSTRA) has constructed an Underground Test Facility (UTF) in the Athabasca oil sands deposit in northern Alberta, approximately 50 km northwest of Fort McMurray (Fig. 1). The facility initially is to serve as an underground laboratory from which to field test new approaches to in situ recovery of the bitumen (oil) in the Athabasca deposit.The UTF employs mine access to get at the effective exploitation of an oil reservoir. It does so, however, under conditions considerably more difficult than those faced by most other applications of the technology. Because of the unconsolidated nature of the McMurray formation, the development of drilling chambers directly in the reservoir would be prohibitively expensive. Further, mobilization of the extremely viscous bitumen requires intensive steam stimulation with the attendant concerns of large, complex well completions and potentially hazardous operations Over-all, the oil sands presents mining, drilling and operations challenges which push the technology to a new state-of-the-art. The UTF as it now exists consists of:• a 20 000 ha lease with all-weather road access;• 925 m of 5 m by 4 m tunnels in the limestone 15 m below the oil sands at roof depth of 178 m below the surface (Fig. 2);• two 3 m diameter steel lined shafts to a depth of 213 m;• administration and sur face mine support facilities from which to operate the UTF (Figs. 3 and 4);• underground piping systems to transport drill fluids, steam, produced fluids and services to and from the future well heads underground (Fig. 5);• surface steam generation and production handling facilities (Figs . 3 and 4).• a drilling rig and auxiliary systems specifically designed to drill long horizontal wells into the oil sands from tunnels in the underlying limestone (Fig. 6);• an experienced staff to engineer and operate the facility (Fig. 7)"

Jan 1, 1989

By F. Channier

The paper provides the most recent information on the construction of the AP60 phase 1 plant of Jonquiere which is due to be commissioned and started up in the first quarter of 2013. HSE management on site by RTA, and cooperation with local equipment manufacturers and contractors of the Saguenay-Lac Saint Jean region are highlighted in this section. The AP60 phase 1 Jonquiere plant aims to demonstrate of the AP60 technology at an industrial scale and allows the further developments of the AP60 cell. The advantages of the AP60 cell technology in terms of productivity, power consumption and environmental footprint are also briefly presented in the paper.

Jan 1, 2011

By Tianming Sun, Gabriella Tranell, Ragnhild E. Aune, Mark William Kennedy

Rare Earth Elements (REEs) are critical for the production of many advanced materials and products. Mining and primary production of REEs are generally associated with significant environmental impacts. By recovery of REEs from secondary sources, through recycling or as a byproduct, the adverse environmental impacts may be partly avoided. In the present study apatite concentrate originating from iron ore beneficiation done by LKAB in Kiruna, Sweden, is explored as a possible source for REEs. The composition and distribution of the REEs within the concentrates are studied using ICP-MS, XRD and SEM-EDS/EPMA, as well as the melting point and heat of fusion using DTA-TGA-MS. The behavior of the material during melting has also been studied through wetting and slag saturation experiments. The overall aim of the study is to evaluate the implications for future smelting experiments aimed at concentration and recovery of the REEs.

Jan 1, 2015

By C. A. F. Pinto

In the present work compared flotation kinetics of apatite with four different collectors was established. Sodium oleate and rice bra~ oil were used to represent conventional collectors. The new collectors included a sulfosuccinate and a sulfosuccinamate. It was observed that the collection ability of each reagent was very dependent upon the mineral size ranges. The results-were analyzed in terms of size-by-size recovery curves. Flotation rates were also very dependent on size ranges of the mineral particles. One of the new collectors displayed higher flotation rates for coarser particles than the other reagents tested. Synergetic effects were also apparent when a conventional collector was mixed to a new collector.

Jan 1, 1991

By Å Sandström

Loussavaara-KiirunavaaraAB?s (LKAB) iron ore mine, Kiirunavaara, is of magnetite type and associated with apatite, a calcium phosphate mineral. Rare earth elements (REE) have been found in connection with the apatite but also in other minerals. An apatite concentrate was produced by flotation, in order to investigate the possibilities to extract REE from the apatite by hydrometallurgical means. The content of rare earth elements calculated as oxides (REO) was 0.44% in the concentrate. Initially, leaching was done with large excess of sulfuric acid, hydrochloric acid, and nitric acid to study the REE solubility with different acids. In sulfuric acid, the leaching recoveries of the different REE varied between 35% and 69%. The reasons for the relative low recoveries, were that the rare earth elements precipitated together with huge amounts of gypsum, that was formed during leaching. However, both hydrochloric- and nitric acid gave almost complete extraction of the REE into solution. Analysis of the small leaching residue obtained, revealed, that mainly the light REE remained in the residue indicating that a small part of the light REE were present in the concentrate, in some acid, insoluble mineral other than apatite. With the aim to separate the REE from the phosphoric acid, the solutions from hydrochloric- and nitric acid leaching were neutralized to a pH of approximately 2 with ammonia. During neutralization, REE were precipitated as phosphates with good recoveries and a concentrate of 10.5% REO suitable for further upgrading was obtained, while the remaining solution can be used for fertilizer production. In further solvent extraction studies, it was shown, that after re-dissolution the REE could be effectively extracted by Cyanex 923, thus allowing for purification from calcium and phosphate ions. The REE were finally stripped from the organic phase and a REE nitrate solution was produced. Keywords: apatite, rare earth elements, REE, leaching, solvent extraction, cyanex 923

Sep 1, 2012

By O. Martinsson

The Kiruna area is an important mining province in northern Sweden, which is dominated by Fe- and Cu-Au deposits. Economically most important for the region, are the apatite iron ores with an annual production of c. 43 M ton of crude Fe-ore and a total production of more than 2000 M ton of ore the last 100 years. The apatite iron ores in the Kiruna area are dominated by either Magnetite or Haematite and contain varying amounts of apatite giving them a content of Fe and P, which varies between 30-70 % and 0.05-5 %, respectively. A typical geochemical feature of the ores is the strong enrichment of REE that is caused by a high content of REE in apatite and the occurrence of Allanite and Monazite containing 22.4 and 69.8 wt% REO, respectively. At Kiirunavaara, the content of REE in apatite varies between 0.07 to 1.57 wt% REO with a dominance for the light rare earths. The variation in REE-content of apatite depending on textural and paragenetic aspects is not known but apatite grains may display a strong LREE-depletion due to hydrothermal alteration. Monazite occurs as rod-shaped or tabular inclusions in apatite and is suggested, to have formed in response to hydrothermal alteration of apatite after the emplacement of the ore. Inclusions are mainly found in the central part of apatite grains occurring in veins and schliren, while they are rare in apatite occurring disseminated in the ore. Monazite also occurs as larger grains outside apatite and together with Allanite is found in texturally and paragenetically different settings within the ore. These occurrences of REE-minerals may largely be a product of LREE mobilized by alteration of apatite after the emplacement of the ore. However, REE-minerals including Allanite and Monazite might also have formed directly from late magmatic fluids. Keywords: apatite, monazite, allanite, ree, kiirunavaara, iron ore of kiruna type, mineral chemistry

Sep 1, 2012

By Bertil I. Pålsson

The most common REE containing mineral that is worked today is bastnäsite. It means that mineral processes are adapted to it and that the metallurgical separation techniques for winning of individual REE are adapted to bastnäsite concentrates. For all other deposit types, suitable mineral processing methods and separation technologies need to be adapted and/or developed. Preliminary mineralogical analyses indicate that slightly less than half of the REE in the tailings dumps at LKAB/Kiruna are associated to apatite. The rest is in the minerals monazite (maybe associated to apatite) and allanite. At least allanite is probably not floatable with reagents commonly used for apatite. Mass and element distributions for the tailings sand reveal that very little apatite is present above 300 µm, and that approx. 30 % is below 20 µm. REE does not follow P2O5 completely and are also present in coarser fractions. Flotation results show that the best condition for both apatite and REE winning is pH 9, high collector addition and low dosage of water glass. Under these conditions, the lab-scale flotation gives an apatite concentrate with at least 30 % P2O5 at 70 % recovery. REE follows apatite in the cleaner steps but only partly. Its recovery is approx. half compared with apatite. The reason for the low REE recovery is likely to be that REE to a large extent is trapped in non-winnable minerals, especially allanite. The REE grades in the concentrate are expected to be in the range 3000 ? 4500 g/ton. Keywords: flotation, REE, apatite, monazite, allanite

Sep 1, 2012

By M M. M LT Tassinari, A B. Braz, L M. SantÆAgostino, C Ulsen

Several mineral resources have been recognised to alkaline igneous rocks. In general, these mineralisations present low P grades, so a complex concentration process is required to achieve commercial grade concentrates. This process is guided not only by the ore characteristics, such as apatite grain size and liberation degree, gangue minerals and slimes content, but also by different apatite varieties, iron oxi-hydroxide surface coating and roughness. The main techniques applied to apatite and phosphate ore characterisation, such as optical microscopy, cathodoluminescence (CL) microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), surface techniques and magnetic separation are discussed, aiming to evaluate distinct apatite varieties and their technological behaviour.

Jan 1, 2008

By T. Banerjee, Y. Dumais, R. Lemire

"Agnico Eagle LaRonde produces over 300,000 ounces of gold annually, along with silver, zinc and copper by-products. The LaRonde plant consists of a conventional SAG and Ball mill circuit, followed by flotation. Load management is imperative for maintaining stability in grind size and ensuring consistency of the flotation feed. In flotation, the mass pull profiles of the cells and reagent dosage rates need to be managed to maximize recovery, while maintaining product quality. This is achieved by controlling the air, level and reagent addition set-points across the circuit. However, disturbances such as feed size distribution, ore hardness and mineralogy make it challenging to maintain efficient control using traditional control techniques. LaRonde therefore worked to develop a progressive control strategy, targeting stability and optimization. This started with a year-long instrumentation upgrade campaign, focusing on optimizing the performance and reliability of plant-wide instrumentation. The process was then optimized, leveraging AwaRE advanced controllers running in closed loop with PARC modules embedded within the PLC. The installation of 8 PFC cameras in flotation changed the flotation operation from a level and air control based strategy, to one that controls mass pull. This new control philosophy has allowed the plant to effectively manage mill load, improving grind size and providing increased throughput with better flotation performance.INTRODUCTION Background Since 2015, Agnico Eagle LaRonde has been conducting an optimization campaign to maximise the performance of plant assets leveraging instrumentation and control. The grinding and copper flotation circuits were identified as the areas having the greatest opportunities and value proposition for advanced control. A disciplined approach was followed to design and implement a progressive control solution to achieve operational excellence."

Jan 1, 2018