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By N. Sasto, E. Bondi, G. R. Lane

Cyest Corporation has been involved in economic modelling and optimisation with various mining clients within South Africa, and internationally, for the past 5 years. In the mining industry in particular, the relationships between variables that are controllable, and those that are not, and the physical and economic outcomes are complex and often non-linear. These relationships constitute an economic system. In the mining context, although many of the relationships can be accurately quantified on a ?single variable to single variable? basis, such simplistic relationships will not suffice in order to understand the dynamics of an entire mine. One has to specify and quantify the relationships between hundreds, if not thousands, of variables. Furthermore, in reality, these relationships change over time. This is the role of an economic model where all the relevant cause-effect relationships, within pertinent constraints, are accurately represented. Models that are used for optimisation must therefore capture the dynamics of the economic system in question as well as anticipate changes to the relationships between these variables. An accurate economic model is a prerequisite for successful optimisation. Optimisation entails the allocation or configuration of resources, within control of management, which will maximise (or minimise) a desired objective function. An optimal configuration (implying trade-off) of controllable variables therefore exists for a given set of assumptions that will yield a maximised objective function. Due to the multi-variant trade-offs required for optimisation, the concept of the ?Economic Surface? or ?Hill of Value? has been used to represent these optimisation outcomes and to discern the route to an optimal configuration. A good example of this is the volume versus cut-off grade trade-off that yields an optimal value for a particular shaft with its unique geological and economic assumptions. More recently, Cyest has extended these economic models to incorporate risk associated with variance in assumptions and inputs. This is termed DFA (dynamic financial analysis) and incorporates stochastic modelling and some of the latest actuarial techniques around modelling global assumptions (such as pricing and exchange rate). This paper will cover the theory around mine optimisation through some example case studies, and also explain the latest thinking regarding incorporating DFA.

Jan 1, 2007

By Fernando Cabanillas, Wilder Sánchez

En este trabajo técnico se presentan los principales proyectos y actividades relacionadas al manejo de agua que se han realizado dentro de Minera Yanacocha, en la búsqueda de un manejo óptimo de este recurso natural, que mantenga la calidad y cantidad adecuada en los puntos de vertimiento. Se confirma que la adecuada gestión del agua y los sistemas de almacenamiento permiten mantener una descarga constante todo el año e inclusive soportar años muy secos, en beneficio de la población. Asimismo, el trabajo demuestra que la minería en la parte alta de la cuenca es compatible y beneficia el desarrollo de industrias y actividades como la agricultura, ganadería, acuicultura, turismo, entre otras que acontecen dentro del mismo entorno.

Sep 20, 2019

By Hugo Toledo, Karin Batallanos, Antonio Bravo, Rafael Carpio

Este documento técnico ha sido desarrollado a partir de una perspectiva empresarial orientada hacia la optimización de los recursos y activos con el objetivo de aumentar la rentabilidad del negocio. Para lograr este propósito, fue crucial la apertura y sinergia y entre las áreas de Mina, Planta y Mantenimiento, ya que su interacción conjunta desempeña un papel crucial en la consecución de nuestros objetivos.

Sep 29, 2023

By Mary Herrera Maldonado

El presente trabajo señala el uso de microorganismos en el proceso de lixiviación de los minerales a través del aislamiento, catalogación e identificación de esta bacterias oxidantes de azufre, a fin de utilizarlas en reacciones energéticas junto con el sustrato mineral para así comprobar la lixiviabilidad bacteriana por medio de una adecuada extracción de cobre. Para ello, se utilizó material procedente de Cerro Verde, donde se buscó lograr una lixiviación ácida por medio del ácido sulfúrico producido por las bacterias Thiobacillus, obteniendo satisfactoriamente minerales de tipo chalcopirita y calcosita iones solubles, entre otros importantes minerales.

Nov 20, 1978

By CHRISTOPHER D. HEBERT, SCOTT W. HOFFMAN

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2019

By Gamaniel Curasma

El Arco Peruano es un elemento de sostenimiento en forma de un arco de concreto armado con fierro de acero estructural de alta resistencia que se coloca entre las cimbras de acero en los tajeos de producción de la mina Yauricocha con la finalidad de controlar los altos esfuerzos que se producen por el minado masivo del método Sub Level Caving en la mina Yauricocha. Usualmente los altos esfuerzos del minado dañan de sobre manera a las cimbras de acero y en menos de dos meses de su instalación requieren ser reinstaladas para mantener una sección mínima operativa de 3.0 metros requerida para el ingreso de los cargadores de bajo perfil de 6 yd3 de capacidad. Es por esa razón que se implementa este nuevo diseño de sostenimiento en la minería, actualmente aplicado en los tajos de producción del cuerpo Esperanza.

Sep 30, 2022

By Mirian Mamani

Estudio sobre los diferentes tipos de depósitos de zinc ubicables en los Andes Centrales. Tras destacar el extraordinario potencial que ofrece Perú, la autora precisa que debido a que los magmas son fértiles, se formaron yacimientos en columnas corticales favorables para incrementar las concentraciones de zinc en las rocas intrusivas y rocas sedimentarias (calizas y dolomitas); se tienen las mejores estructuras (e.g., fajas corridas y plegadas) que favorecieron el emplazamiento de los fluidos y excitación térmica en el tiempo geológico por radiactividad de los depósitos; y lo más importante, que se encuentran en su mayoría preservados debido a que las tasas de erosión donde afloran son mínimas.

May 31, 2019

By Tomoharu Jogo

Dado que el yacimiento de la mina Huanzalá de la Compañía Minera Santa Luisa es delgado, se utilizó el método de corte y relleno para la extracción de minerales. Posteriormente en 1979, se complementa este método con el Trackless Mining, adquiriendo óptimos resultados en la eficiencia y costo de operación. En este sentido, el objetivo del presente texto es describir la aplicación de este último método -en tanto cambio de sistema de explotación- y se muestre la eficiencia del autosuministro de material de relleno en yacimientos pequeños.

Oct 14, 1980

By Jaime Tumialán

El presente texto describe el planeamiento y ejecución del proyecto Expansión Casapalca realizada a través de la gerencia de operaciones de CENTROMIN PERÚ. En este sentido, el objetivo del texto es incrementar la producción de 2,150 TCS por día utlizando una explotación racional de las reservas probadas del yacimiento. Asimismo, refiere los antecedentes, estudios de factbilidad y las características generales del yacimiento.

Nov 8, 1984

By R K. W Merkle, S Madoom Hussain, T Yellappa

Cr-Ni-Cu¦PGE deposits are known to occur in early Archaean mafic-ultramafic rocks. Early Archaean mafic-ultramafic (MUMF) rocks occur in the western Dharwar craton and range in size from small pods to schist belts. These MUMF pods consist mainly of meta-peridotites, tremolite-actinolite schists, serpentinites, amphibolites and metabasalts. Spinifex, nodular and ocelli textures are also present. The rocks have been subjected to greenschist and amphibolite facies metamorphism. Geochemical studies were undertaken to evaluate the possible occurrence of economically important elements in the mafic-ultramafic enclaves around the major Arsikere-Tavarkere lineament and surrounding gneissic terrain adjoining local shear zones that occur as discontinuous pods between Arsikere and Chennagiri. Talc-serpentine and tremolite- actinolite schists contain chromite which is rimmed by ferrit-chromite. A notable feature of these MUMF rocks is that they exhibit high MgO (22 - 40 per cent), total iron (8.34 - 10.01 per cent), Ni and Cr (~3000, 2800 ppm) contents, with some samples showing komatiitic affinity. The rare earth elements (REE) data show slightly fractionated patterns with enriched LREE (LREE/HREE ~5.0) and negative europium anomalies. The Pt and Pd values reach 6500 and 191 ppb. The MUMF rocks, especially those exhibiting high chromium contents and occurring near shear zones, are potential hosts for economic platinum group element (PGE) deposits.

Jan 1, 2008

By Raúl Gomero-Cuadro

El presente texto describe la importancia de la salud ocupacional -en tanto adecúa la posición del empleo al trabajador. La evaluación comprende tres etapas: recolección de la información, análisis y seguimiento de los hallazgos. Sin embargo, la valoración de la aptitud para el trabajo es mal aplicada para la selección de trabajadores, generando conflictos éticos, económicos y sociales en la realización de los exámenes médicos ocupacionales.

Oct 1, 2016

By César Jaime Fernández

El presente texto señala el objetivo del plan nacional de capacitación minera donde se busca organizar, dirigir y evaluar la capacitación minera mediante un Servicio o Sistema Nacional de Capacitación Minera, así como se se realice una centralización del apoyo nacional o regional de la capacitación y su desplazamiento mediante unidades móviles. Para ello, es necesario un estudio crítico de los métodos de trabajo en uso, de los índices actuales de productividad, el análisis de los puestos de trabajo, la evaluación de los trabajadores en sus niveles de instrucción, su tecnificación y cultura.

Mar 1, 1978

By R. J. Charles

F. C. Bond: This is an outstanding paper on comminution theory and represents a considerable advance in mathematical formulation. It clears the way for a discussion that should ultimately decide whether the work index should be considered as a parameter according to the Third Theory or as a constant. In the empirical differential equation dE = —Cdx/x [1] either Corn must be treated as a variable to satisfy known crushing and grinding conditions. The author has chosen the exponent n as the variable, with C as a constant. According to the Third Theory, in the general case n is a constant equal to 3/2, and C is a variable related to the work index Wi. If x is placed equal to P (the size in microns which 80 pct of the product passes) and F is the size 80 pct of the feed passes, then C equals 5 W1, and dE = 5 -5 Widx/x = 10 Wi 10 Wi w = vP vF which is the basic equation of the Third Theory. It is apparent that this integration involves the error of treating the parameter Wi as a constant, just as the author's treatment involves the error of integrating his variable n as a constant. These errors are probably relatively unimportant, considering the small range of the variables. When more is known about the factors contained in the work index, Eq. 1 can be revised as a partial differential equation. The Third Theory exponent of 1/2, or n = 3/2 in the Charles' differential equation (Eq. l), was not chosen primarily because it is the average between the Kick and Rittinger exponents; this may be merely fortuitous, since it is illogical to define truth as the average between two errors. It was first discovered from the study of a large mass of crushing and grinding data and confirmed by laboratory testing. The general correspondence of the Third Theory equation to actual crushing and grinding results over the entire size reduction range argues strongly that a fundamental phenomenon is involved. The a posteriori theoretical explanation of the constant Third Theory exponent is that the work done in breaking rock is proportional to the length of the crack tips formed. Compressive force applied to the rock results in deformation and strain energy. When this locally exceeds the breaking strength a crack tip forms, the surrounding strain energy flows to the crack tip and extends it to split the rock, with release of the energy as heat. Under rapid impact the crack tip may form before the strain has reached equilibrium, resulting in less energy expenditure and probably a coarser product. In any case, the elastic limit of a brittle material is practically the same as its breaking strength, and the work necessary to form the crack tip is the work required to break. The crack length of a ton of broken rock cannot be measured directly. However, the particle shapes of feed and product are similar, and the crack length is considered equal to the square root of one half of the new surface area formed. It is, therefore, proportional to 1/vD, where D is the equivalent product particle diameter. This is the basis of the Third Theory equation. Many secondary factors can be imposed upon the crack length breakage. These may cause the Third Theory work index to increase or decrease somewhat as the product size becomes finer. The work index is properly a parameter rather than a constant, making it an increasingly valuable practical criterion of the work input required in crushing and grinding.

Jan 1, 1959

By J M. Totterdell

The Permian-Triassic Bowen Basin and the Jurassic-Cretaceous Surat Basin evolved in a backarc tectonic setting behind an active convergent plate margin in eastern Gondwana. Several extensional (Early Permian; Eocene) and contractional (mid-Permian; Early Triassic; Middle-Late Triassic; early Late Cretaceous) intraplate deformational events are recognised in the basins. These can be correlated with similar events in the New England Orogen that was being deformed in the Late Permian-Late Triassic as a foreland thrust belt. The intraplate deformations were probably the consequence of plate interactions, including the accretion of terranes, at the ancient active plate margin, remnants of which now occur in New Zealand.

Jan 1, 1995

By Tom Treleaven

The success of any blast is dependent on the accuracy of the blast design and the field controls used on the shot. This point cannot be over emphasized because when the geometry is not measured and/or field controls are not properly implemented, it can often have devastating effects on the final blast results. Thus drilling accuracy, tiont row burden control, explosive confinement, energy distribution, explosive selection, timing and structural geology become critical parameters in the design of successful blasts. Understanding the actual dynamics of the blast and why certain results were achieved is the fast step in optimizing a blast design. As stated by R. Frank Chiappetta, “Of all the blast monitoring systems available today, high speed videography still remains as the best stand alone instrumentation system for blast diagnostics.” Over the past years I have analyzed hundreds of blasts using either high-speed lowcams (500 frames per second) cameras or standard digital (30 frames per second). These analyses confirm, without a doubt, that shot geometry, in combination with structural geology, is the most important factor in overall blast results. Drilling accuracy is the single most important component in efficient blasting. Having equal mass associated with an equivalent energy is the basis in which blasts are designed. When drilling inaccuracy or borehole deviation occurs, not only is the energy unevenly distributed, but the basis of all design calculations becomes invalid. Over the past several years, quarry and mining operations have employed the use of boretracking measuring devices to measure borehole deviation and hole toe locations. In cases of operations using top hammer drills, it was discovered that the amount of deviation was significant and far greater than they believed they had. Set up error, improper drilling techniques and bit wear were some of the contributing factors. Through video anaysis of boretracked blasts, blast results were directly linked to drilling ..accuracy. The comparisons here took into account blast design, energy factors and hole sequencing.

Jan 1, 2000

By Jimmy Guarnizo

El yacimiento de La Zanja ubicada en el caserío La Zanja, Santa Cruz de Succhabamba, Cajamarca, inició sus actividades de exploración en 1991 y las de producción en el 2010. MLZ construyó el embalse o reservorio llamado Bramadero, que acumula las aguas de escorrentía de la quebrada del mismo nombre durante el periodo de lluvias, las cuales son empleadas para el consumo humano en la unidad minera, y en menor escala durante la época de estiaje para los procesos de operación. En este sentido, el presente texto señala la construcción de la presa Bramadero, la cual genera agua para beneficio de las poblaciones ubicadas aguas abajo de las instalaciones. Asi también cuenta con un programa de monitoreo ambiental para vigilar la calidad y la cantidad de aguas superficiales y subterráneas. Por tal motivo, cuenta con estaciones hidrométricas para evaluar en tiempo real la calidad del agua en los cuerpos receptores del área de influencia de la unidad minera.

Sep 1, 2015

By Louis W. Cope

Many Americans have seen Greenland while flying over it on their way to or from Europe. Few have visited this largest island in the world. Portions of the 20 percent of the territory that are not ice-covered are highly mineralized. Greenland could become very productive if the present interest in exploration increases. The people and Greenland’s history The population of Greenland is 57,000. Twenty percent are Europeans, mainly of Danish decent, while 80percent are native Greenlandic or mixed Greenlandic-European. The native population is the same as the Inuit of the Canadian Arctic. They speak the same language.

Jan 1, 2004

By J. Yianatos

The collection zone residence time distribution (RTD) of mechanical self-aerated flotation cells was characterized for liquid and solid per size class (-45 mm, +45-150 mm and +150 mm). It was found that a single large industrial cell with a volume of 130 to 250 m3, now used in plant operations, can be well represented by an LTST (large and small tank-in-series) model plus dead time. From a scale-up point of view, results showed a similar mixing behavior for industrial cells ranging from 130 to 250 m3. Also, single mechanical cells showed a similar mixing pattern (RTD) when compared to large pneumatic flotation columns. It was confirmed that for practical purposes, the mixing condition in a flotation bank of three or more cells in series can be well described by the classical N tanks-in-series model.

Jan 1, 2008

By E. P. Youngman

The rapidly growing demand for titanium pigments has aroused new interest in actual and potential sources of supply of titanium- bearing ores , which only a comparatively few years ago were almost unmarketable . This paper , which supplements a general circular entitled " Titanium" ( Information Circular 6365 ) , represents a summary of current trade literature and Government reports , together with some hitherto unpublished material that has accumulated in the files of the Bureau of Mines . The purpose of this pamphlet is simply to indicate the commercial possibilities of the deposits , and the discussion is confined almost entirely to the three commercial ores , ilmenite , rutile , and magnetite ( titaniferous iron ore ) .

Oct 1, 1930

By Robert McClure, Frederic Leclercq, Ricardo Chavez

With significant vibration control and fragmentation challenges facing them, the CBS quarry (department of the Nord) successfully integrated a technical partner and mine to mill optimisation to deal with a difficult environment. For the last three years, CBS has been conducting a global production monitoring program similar to the mine to mill concept used in the mining industry. This concept consists of optimising the drilling and blasting while monitoring the effects on the downstream chain (vibration control, loading, hauling, crushing, plant output). Blast optimization is ensured by systematic control of the blast geometry (volumes, patterns, bench and face anomalies, drill deviation) and by the use of constant specific energy blasting. Constant specific energy optimises the work of the explosive in a blasting operation and, when combined with a high accuracy programmable electronic blasting system, reduces the impact of blasting on the environment and enhances blast performance. These techniques ensure consistent blasting results and hence improved site productivity. The improvements achieved have been identified thanks to an effective system designed to monitor the key production parameters.

Jan 1, 2007