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By César Alvarado Olivares

El presente trabajo describe la solución planteada al problema de renovar el equipo de celdas de flotación que por el tiempo de uso (19 años) y por su tipo de diseño, ya no ofrecfa el rendimiento que hoy en día se puede conseguir en esta clase de tratamiento. La solución consiste en

Jan 1, 1963

By José Mormontoy

El proyecto inicial de la Compañía minera Antamina contempló la construcción del túnel por donde pasa la faja # 01 de transferencia del mineral. Posteriormente, otros estudios geológicos confirmaron la presencia de un mineral por debajo de la fase 5, considerándolo como parte de la reserva del mineral. En ese sentido, el presente texto señala los aspectos del minado fase 5, el cual presenta una interacción con la chancadora primaria ya que esta se encuentra al pie de talúd vertical de la fase. El riesgo potencial existe cuando se ejecutan voladuras, dañando la chancadora primaria y el túnel. Por ello, antes de iniciar los trabajos durante esa fase, es necesario realizar un análisis multidisciplinario y evaluar las alternativas seguras de minado.

Sep 12, 2011

"El presente trabajo expone las pautas para la realización de un proyecto de fábrica de cemento, como los factores que influyen en su ubicación respecto al centro de distribución y el tipo de combustible que se emplea para la combustión. El impulso a la creación de una fábrica de cemento, se basa en la existencia de depósitos calcáreos, los cuales estratégicamente ubicados, permiten un mayor progreso económico del país y eliminan la limitación del suministro. Para tal fin, es necesario realizar un estudio económico del consumo considerando el período donde el abastecimiento y costo fueron normales. Otro estudio posible estriba en la comparación de la zona prevista de lde la fábrica con otras áreas de características económicas similares, basándose en la población, movimiento económico y otros elementos de comparación. Una vez determinada la zona, se fija el precio de la venta al público a través de tres elementos: precio de venta en fábrica, costo del transporte y la utilidad del distribuidor. Otros estudios a considerar son los basados en los yacimientos, los cuales complementan mejor la información de la instalación. Entre estos, tenemos a los estudios geológicos, levantamiento topográfico, muestreo sistemático, estudio químico de los minerales y pruebas térmicas y físicas de los productos. La ubicación de la fábrica dependerá si se decide instalar en el sitio de la cantera o en el mismo centro de distribución. Como estudio final, se prevee que la materia prima esté constituída por elementos que químicamente y mineralógicamente sean los más idóneos para así recurrir a materiales de complemento cuya dificultad o facilidad para mezclarlos íntimamente, determine el proceso a utilizarse. En consecuencia, la instalación de dicha manufactura, es el resultado del estudio global de las condiciones provistas en un zona, para así constituirse dentro de un mercado económicamente lucrativo. "

Jul 20, 1957

Las formas de aplicación energética en la industria minera peruana han evolucionado tanto como las fuentes convencionales de generación de energía. En este sentido, el objetivo del texto describe el aporte del carbón y del petróleo como fuentes convencionales de energía y su aprovechamiento para la generación de fuerza en la industria minera del Perú. Asimismo se indican las posibilidades y limitaciones del uso de la energía atómica en dicha generación. El aprovechamiento del carbón como elemento energético no ha logrado superar las espectativas económicas dado su bajo costo de precio en el mercado nacional. De forma que se planteó mejorar el rendimiento de los subproductos derivados de las plantas de carbón, a través de un proceso de homogenización previa, disecado y modificación de los dispositivos en las calderas, asegurando una posible explotación a futuro. A esto se añade el uso de energía eléctrica por medio de la instalación de modernas centrales termoeléctricas a carbón. Respecto de la aplicación de la energía atómica como factor recurrente en la industria minera peruana, se revela un insuficiente rendimiento termodinámico y satisfactorio conlos 700° C necesarios para las turbinas, por lo cual se hace necesario elevar la temperatura a través de una fuente calórifica como el carbón. Mientras que si hablamos de una de las fuentes energéticas de mayor consumo en las mineras como en los plantas hidroeléctricas, el petróleo mantiene su posicionamiento dada la provisión del rendimiento eléctrico. En consecuencia, se busca aprovechar a mayor escala el uso del carbón como combustible en las centrales térmicas mineras por medio de un sistema de control de precio y así establecer una competencia con el petróleo y la generación de la energía nuclear, teniendo en cuenta las condiciones de abastecimiento de energía para su utilización en la región del Altiplano de la zona meridional del país.

Jul 20, 1959

By Franklin R. Olaya

El presente texto señala algunos aspectos geotécnicos de los depósitos de relaves como el marco teórico, los ensayos de laboratorio y campos utilizados en cada una de las cuatro etapas utilizadas. Dicha metodología permite estimar valores de pendientes de disposición de relaves que permitan un equilibrio entre la capacidad de almacenamiento, estabilidad y operación del depósito de relaves.

Nov 1, 2015

By Miguel A. Huaman

El presente artículo tiene el objetivo de discutir las consideraciones técnicas para el análisis de rotura de presas de relaves sobre la base de la experiencia en el desarrollo de estas simulaciones en varias presas de relaves en el Perú, las cuales contemplan dos puntos importantes: la generación del hidrograma debido a la liberación del relave, y el tránsito del hidrograma generado a través de un cauce o terreno natural. Para la generación del hidrograma de rotura de la presa se asumen los probables tipos de falla como terremotos, eventos meteorológicos extremos, manejo inapropiado del depósito, vandalismo, entre otros, de acuerdo a las condiciones o características de la zona.

Sep 1, 2017

By J. Solano

El sostenimiento con pernos de roca requiere de estudios que determinen cuáles son los factores que influyen en el proceso de acción recíproca entre la roca y sus elementos. En ese sentido, el objetivo del presente trabajo es mostrar los resultados de las investigaciones realizadas, basadas en el principio de deformación y compresión sobre la roca en el mismo campo de trabajo. Para ello, es necesario considerar que el desconocimiento de las propiedades físico-mecánicos de la masa rocosa y de instrumentos de investigación, limita el estudio a la determinación del anclaje y la pérdida de tensión de los pernos.

Nov 20, 1972

By Jorge Ganoza

Algunos concentrados de plomo contienen contaminantes que afectan la comercialización del concentrado de cobre debido a aspectos ambientales, así como la calidad del producto final. En ese sentido, el presente texto busca la forma de minimizar la presencia del plomo y de bismuto en el concentrado de cobre, a través de la flotaciónpor chalcopirita. De otro lado, dado que el plomo y bismuto son elementos que tienen similar comportamiento durante la flotación, es factible aislar los minerales de plomo y bismuto.

Nov 1, 2012

By N. Nikolaev

La cantidad de métodos experimentales y analíticos no consideran los factores que influyen sobre el proceso de acción recíproca entre los elementos de sostenimiento y el macizo rocoso. En ese sentido, estamos en condiciones de separar dichos factores en grupos, reuniendo en uno los independientes, y en otros los relacionados entre sí. Por ello, el presente texto señala los métodos adecuados para determinar la influencia de un factor determinado o de un grupo de factores sobre el desarrollo del proceso a través de la determinación del tipo de cabeza de anclaje y de la pérdida de tensión final del anclaje con el transcurso del tiempo.

Jan 1, 1973

By Gonzalo Monge Sancho

"El siguiente estudio presenta una serie de observaciones sobre la Organización de Higiene Industrial y su aplicación directa a la medicina del trabajo. La investigación comprende cinco apartados: el primero, es el diagnóstico en la medicina del trabajo, la cual señala la enfermedad, el ambiente y las condiciones vitales como factores claves para de una futura exploración clínica; la segunda, refiere la higiene como la función que mide los medios y los conocimientos para preservar la salud del individuo, en tanto, verifique su trabajo(condiciones ambientales y factores alterables de la misma; el tercero punto contempla los accidentes como la pugna entre un hombre y el objeto, donde el factor médico, las causas (objetivas y subjetivas),el tipo y las condiciones son determinantes para encontrar el problema; el cuarto elemento describe la medicina preventiva como el conjunto de medidas que realizan un diagnóstico precoz de la enfermedad y el tratamiento de la misma, y por último, está el departamento médico donde reduce la posibilidad de enfermedad del trabajador, los gastos de indemnización y aumenta la confianza y seguridad del trabajador, regulando la función del trabajador de acuerdo a sus condiciones fisiológicas para un mejor rendimiento dentro de la mina. "

Jul 20, 1955

By Y. Y. Jiao, J. G. Cai

To investigate the dimensional effect on shock wave propagation in jointed rock masses, a 2-D and a 3-D calculation of a site test are performed respectively by using Discrete Element Method, the simulated results are compared with test data. It shows that, in modelling shock wave propagation and attenuation in jointed rock masses, when the explosive along explosion chamber is long enough and the joints are dense enough or uniformly distributed, the model can be considered as plane-strain problem, 2-D results are good enough to fit with test data. 2-D modelling, with much more details of rock masses taken into account, can be applied to make critical engineering judgements instead of 3-D modelling in some cases.

Jan 1, 2003

By J Balzary, A Mohais

Dynamic market and operating conditions, coupled with an environment in which multiple objectives and trade-offs are common, pose major challenges for planners and schedulers working in any mining entity. Many mining companies recognise the need to shift from a siloed mining-focused push model to an integrated value chain, demand-driven approach, but there are still fundamental barriers in business process and the supporting technology preventing a consideration of end-to-end optimality.This paper presents some elements of experiences working with companies to adopt such advanced approaches. In addition to algorithmic elements, an approach to phased and gradual deployment of progressively more sophisticated optimisation models is described. From a practical software adoption perspective, it is believed that this last concern is also of primary importance. Next generation approaches to the optimisation of complex bulk commodity demand chains, namely iron ore and coal are presented, with case studies in the world’s largest integrated operations in Western Australia and Queensland from the raw material mined through to market. Utilising accurate simulation models supported by metaheuristic optimisation techniques, a range of ways to engineer a dynamic decision support framework that can adapt and change with the inevitable changes in commodity markets is explored. Objectives such as total revenue, margin, cost, NPV, throughput, asset utilisation, contractual penalties and bonuses, and energy consumption can be managed simultaneously across the mine, plant, logistics network, port operation, shipping and sales domains.CITATION:Balzary, J and Mohais, A, 2014. Consideration for multiobjective metaheuristic optimisation of large iron ore and coal supply chains, from resource to market, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 213–222 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By Schmidt LC

The method of supporting excavated roofs in underground coal mines by conventional roof bolting systems is challenged due to its shortcomings of being time-consuming and leading to possible unsafe installation. Though a few alternatives have been considered, the ultimate and most efficient bolting method has often been conceived as one using a self-drilling roof bolt, or a Rapid Face Bolting System (RFBS). The on-going Rapid Face Bolting Project undertaken by the University of Wollongong includes a special tubular bolt design.The tubular bolt designed for the RFBS is a "single-pass" bolt equipped with cutting tips used to drill a bolthole to accommodate the bolt. Different from that of the coring bit employed in geological site investigations, the principal design consideration for the tubular bolt is low cost associated with a small working life for the cutting tip.

Jan 1, 1991

By M Revell, B Sainsbury, D Sainsbury

This paper extends the existing knowledge associated with the design and placement of prefabricated pastefill barricades through a consideration of asymmetric drive geometry and conditions. The load capacity of prefabricated barricades and their failure modes are considered in relation to abutment geology and barricade geometry that includes curvature and span and drive geometry that includes abutment angles, haunch angles and misalignment. Design charts are provided for typical barricade sizes to provide general guidance for design capacities and optimising location placement based on asymmetric drive geometry. A recent barricade failure is considered in relation to the drive geometry and the potential impact it had on the installed capacity.

Nov 29, 2022

By Marc C. Bétoumay

Workplace safety, health, climatic conditions and rising oil prices are aspects that are important to the mining industry. The need for cleaner energy for underground mine vehicles is requiring serious consideration. A number of alternate energy systems offer clean solutions to diesel emissions while maintaining the current liberty of vehicle movement. This watershed article provides a broad comparison of cleaner diesel and alternative energies for underground production vehicles. Most alternate energies and clean diesel have already been tested in underground production vehicles. There are no technology gaps that would prevent the development of commercial alternative energy power plants, but in the case of alternate energies, second and third generation versions will be required to fully test for safety and operation viability. Full regulatory development is also required and could be done in parallel to power plant testing. Vehicle operation and maintenance manpower would be the same for alternate energy application as for clean diesel. Capital cost for alternate energy power plants will remain higher until the medium term. Owing to significant ventilation savings possible with alternate technologies, operating costs would be reduced.

May 1, 2011

By Sathit Tandanand

Geological differences among various coalfields restrain the applicability of subsidence prediction using existing European methods. To modify these methods for domestic conditions, the Bureau of Mines, U.S. Department of the Interior, developed a method of assessment to evaluate the lithological effects on subsidence in the Northern Appalachian basin by examining data collected from 16 longwall panels in the coalfield. The assessment is partially completed, and the results to date show that the ratio of maximum subsidence to the extraction thickness, known as the subsidence factor, can be expressed in terms of the width-to-depth ratio by a simple exponential equation which has a coefficient tentatively considered as the subsidence index. This index varies with the lithology of a particular site and can be expressed in terms of the percent distribution of weak and strong rocks in the overburden.

Jan 1, 1982

By Omkar N. S. Beruar

Extraction of sill pillars has always been problematic because of high risk of seismicity and rockburst. Depending on a number of factors, a sill pillar can undergo different failure modes and cause problems in the mine. Of these, sudden and uncontrolled failure of part(s) of the pillar leading to highenergy seismic events and rockbursts is a main concern because it is not possible to predict the location and time of a rockburst apart from its potential to cause extensive damage to the mine structures. To date, a comprehensive technique for sill pillar design and recovery does not exist. Conventional methods of pillar design, such as the pillar stability graph method, are utilized to design stiff sill pillars. In these design approaches, the post-peak response of the pillar-rock system is not considered. This is in part due to a lack of clear and comprehensive understanding of the post-peak behaviour and failure mechanism of sill pillars. In general, the strength of a rockmass is described using a failure criterion. When stresses reach the strength of the rockmass, the rockmass does not necessarily become unstable and knowledge of the loads alone is not enough to assess the instability conditions accurately. In fact, it is not possible to predict instability of rockmass based on the strength/stress ratio alone because instability depends not only on this ratio but also on the loading condition and loading system characteristics. The loading system can dictate whether the sill pillar will go through a stable or unstable failure process. This paper examines the influence of various parameters such as the pillar width to height ratio, the extraction rate, and placement of backfill on the Loading System Stiffness (LSS) and the Pillar Stiffness (PSS). The ultimate goal is to design yielding sill pillars that would yield in a stable manner and will reduce the risk of pillar rockburst. Plane strain finite element analysis is conducted using the generalized Hoek-Brown failure criterion with elastic-brittle-plastic parameters. Examples are given to demonstrate how to calculate these stiffness values and assess the stability condition of sill pillars. It is found that increasing the rate of extraction increases the likelihood of unstable yielding of the pillar as has been found in other studies. Placement of backfill in a timely fashion in the stopes above and below the sill pillars increases the stiffness of the loading system. This indicates that backfilling of stopes while creating the sill pillar increases the likelihood of stable yielding of the sill pillar.

Aug 1, 2013

By Getu F. Biftu

There is general agreement among scientists that global surface temperatures have been increasing during the past decades. The increase in temperature is postulated to be the result of either an increase in greenhouse gases emission or climate variability (i.e., due to variations in sun or volcanic activity or El Nino and La Nina events) during past decades and may continue to increase. The effects of a predicted rise in the Earth?s surface temperature include an increase in average global evaporation and increase or decrease in precipitation (Bloomfield, 1992; Mann et al., 1991; Vinnikov et al., 1990; Gan 1995; Zhang et al., 2000a). The general circulation models (GCMs) project a global warming due to greenhouse effects of 1.5-4.5°C by the mid 2050s, with the most pronounced changes taking place in northern latitudes (Nicholls et al., 1996). However, similar predictions at a watershed scale or even a regional scale using GCMs are mot possible yet (Arnell et. al., 1996; Georgievskii et. al., 1996; Zhang et al., 2000a). Detection of historic trends, changes and variability in climatic variables is another indirect means of understanding potential future changes or variability at regional and local scales. The main objective of this paper is to review studies related to climatic change or variability and associated hydrologic changes at a regional scale and local scale, particularly those studies applicable to the Oil Sands Region (OSR) of Alberta. This paper identifies gaps in our current understanding of the hydrologic processes that may be affected by climate change; it discusses potential implications to developments in the OSR; and it explores mitigation opportunities including several that have already been implemented.

May 1, 2004

By P. J. Finnis

This paper describes the use of wire rope on open-pit mining equipment, giving specifications and examples of the performance achieved. Installation methods are also discussed, making the paper of considerable practical use to mine operators.

Jan 1, 1973

By Kazunori Matsushita, Masaru Sakakibara, Kenji Harada, Naotoshi Shinkawa, Mitsuo Nozu

The Sand Compaction Pile (SCP) method has been widely used as a typical countermeasure against liquefaction in Japan, and its effectiveness has been confirmed in many case histories of damages caused by the past large-scale earthquakes. A series of studies were conducted to evaluate the effectiveness of the compaction method and other factors, if any, in sustaining a seismic force that is greater than the assumed one and caused no damage. Based on the results of these studies, the Architectural Institute of Japan (AIJ) has indicated in its “Recommendations for Design of Ground Improvement for Building Foundations” published in 2006 that the liquefaction resistance ratio (tl/sz) of the composite ground, which consists of sand piles and surrounding compacted ground, is higher than the RL calculated by using the SPT N-values of the ground in-between the sand piles. In this paper, statistical analysis of safety factor against liquefaction, FL, was performed by using the SPT N-values of ground in Port Island and Rokko Island which were both fully reclaimed islands in Kobe city during the 1995 Hyogo-ken Nambu Earthquake (classified as intense shaking) and, together with the consideration of relative settlement, resulted in tl/sz of the composite ground being 1.5~2.5 times of tl/sz of the soil in-between piles after improvement. Furthermore, the liquefaction resistance curve of SCP-improved sites obtained from the relationship between SPT N-values and cyclic shear stress ratio during the 2011 off the Pacific Coast of Tohoku Earthquake, which was regarded as long-duration earthquake, was plotted to the left side of the curve originally proposed by Japan Road Association. Thus, the liquefaction resistance of the improved ground was found to be higher than that of the natural ground, even for the same SPT N-values, verifying the validity of the AIJ recommendation.

Jan 1, 2017