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By V. Mejía C.

A raíz de un informe de un estudio petrográfico de las relaciones de Casapalca presentado por el Sr Kobe, surge la idea de mejorar la molienda, reemplazando los clasificadores por ciclones. En esta perspectiva se buscó liberar los sulfuros enchapados de las partículas de minerales y asi obtener una mejor recuperación. En Casapalca, el aumento de molienda y la instalación de un nuevo molino, permitió que se desarrolle dos nuevos proyectos: la molienda inicial de la carga alimentada y una remolienda de las partículas gruesas en el circuito de flotación de bulk con retorno del material remolido a la cabeza de bulk, concluyéndose que esta última remolienda, generaría un aumento en el consumo de reactivos, elevando el costo de tratamiento. Por tal motivo, se lo descartó y se utilizó la molienda inicial fina.

Jul 20, 1961

By José Adachi

La ventilación de minas es un proceso relacionado a la dinámica de la mina que genera el acondicionamiento del aire circulante a través de las labores subterráneas. Como tal, los requerimientos de la mina se adecúan de acuerdo a la estructura física de la misma. En consecuencia, no existe un sistema de ventilación estático puesto que los sistemas requieren de constantes monitoreos y ajustes para alcanzar una ventilación óptima. Así, el presente trabajo señala los aspectos importantes del diseño de ventilación principal de la mina Condestable realizado entre el período de 1992 y 1993 por encargo de la compañía minera. La metodología empleada comprende mediciones de campo y el cálculo de requerimientos del caudal. Asi también está la construcción del modelo de red de ventilación y el diseño del nuevo ciricuito con ventilación forzada.

Nov 24, 1993

By Gerardo Soto M.

El presente texto señala el potencial mineralógica del proyecto minero Cotonga, situada en la provincia de Huari, departamento de Ancash. La investigación comprende la historia del yacimiento, fisiografía, las exploraciones geológicas y geofísicas, el desarrollo en el stock Cotonga, la geología del yacimiento de Contonga, geología estructural, económica, paragénesis y zoneamiento, el sistema de explotación y el funcionamiento de la planta concentradora.

Nov 8, 1984

By Mario Paredes Malca

El presente trabajo describe el sistema experto por circuito de molienda desarrollado en la Concentradora Toquepala, donde se aplica la tecnología del control experto-basada en conjuntos difusos y modelos matemáticos. Las ventajas que presenta la aplicación de los sistemas expertos comprenden el aumento de la capacidad de tratamiento, la disminución del costo de operación y del porcentaje del producto que no cumple las especificaciones. Asímismo, el sistema experto se integra al sistema de control para asistir al operador en la detección de los casos, donde las operaciones se puedan descontrolar, aunque ésta no sea realmente su principal función. Si se le configura y sintoniza correctamente, el sistema experto detecta, diagnostica en forma continua los problemas de operación y aplica modelos matemáticos y estadísticos de optimización, interactúando con un sistema de control DCS o PLC.

Sep 12, 2005

Pipe Flow Stability of Concentrated Coal-Water Suspensions in the Presence of an Electric Field

Sep 13, 2010

By J. Zegarra W

El presente texto describe las etapas del proceso de metalurgia del tungsteno. Este proceso comprende el conocimiento de la mineralogía y la ganga asociada. La segunda etapa describe el deslamado y preconcentración de los relaves de la planta. Como tercer punto está la flotación y la concentración. Posteriormente se da la lixiviación alcalina a presión de concentrados de tungstenos y por último, está la precipitación de ácido tungstico.

Nov 20, 1978

By Nestor Chavez, Javier Aymachoque, Carlos Ortega, Pedro Vasquez

Mientras que en la minería a tajo abierto es usual realizar planificación estratégica, en las operaciones subterráneas, debido a la complejidad de cada yacimiento, no existe un sistema normalizado para evaluar y optimizar la forma del área de la mina y su producción para obtener el valor real más alto. El objetivo del presente trabajo técnico es mostrar un sistema robusto capaz de optimizar y programar los depósitos subterráneos. Para ello, se evalúan múltiples escenarios de planes mineros en 3D en un plan minero de mina subterránea, analizando en poco tiempo diferentes variables, mostrando la robustez del planeamiento y analizando la incertidumbre asociada a las variables más relevantes. Se presenta un flujo de trabajo completo y práctico que ha mejorado los valores y reducido los riesgos de un proyecto subterráneo.

Sep 20, 2019

[CONTENTS COUNTY NO. OF MINES MINE INDEX PAGE]

Jan 1, 1980

By Hernán Parra, Samir Campomanes, Lily Ponce, María Suárez

En este trabajo se analizan algunas posibilidades de tratamiento de la atacamita con el objeto de posibilitar la extracción del cobre que contiene, así como la del oro que muchas veces acompaña a estos minerales. Se ha probado el esquema lixiviación ácida de cobre seguido de cianuración, así como la flotación y segregación. Los resultados indican que existe una gran posibilidad de tratarlos con éxito mediante métodos de segregación.

Sep 20, 2019

By D. Parks, A. Miller, M. McNinch, R. Jacksha

Each year, hundreds of mine workers are involved in machinery-related accidents. Many of these accidents involve inadequate or improper use of lockout/tagout (LOTO) procedures. To mitigate the occurrence of these accidents, new safety methods are needed to monitor access to hazardous areas around operating machinery, improve documentation/monitoring of maintenance that requires shutdown of the machinery, and prevent unexpected startup or movement during machine maintenance activities. The National Institute for Occupational Safety and Health (NIOSH) is currently researching the application of Internet of Things (IoT) technologies to provide intelligent machine monitoring as part of a comprehensive LOTO program. This paper introduces NIOSH’s two phase implementation of an IoT-based intelligent machine monitoring system. Phase one is the installation of a proof-of-concept system at a concrete batch plant, while phase two involves scaling up the system to include additional sensors, more detailed safety/performance metrics, proximity detection, and predictive failure analysis.

By Gustavo Fierro

Se plantea un enfoque de dimensionamiento de coberturas para cierre de minas, considerando los criterios de estabilidad física, química y biológica a largo plazo. El desafío de una visión integral de solución a este problema se enfoca en proveer soluciones cuantificables que aseguren el comportamiento a largo plazo de la cobertura, de modo tal que se pase de una solución cualitativa a una cuantitativa. Para ello, se emplea el estado del arte en múltiples disciplinas, que si bien en las dos últimas décadas han dejado información valiosa, hasta ahora no estaba orientada a la visión integral del problema.

Sep 20, 2019

By Gustavo Luyo Velit

El presente trabajo describe el programa de exploraciones aplicados en el bloque central Pampahuay del yacimiento carbonífero de Oyón, Lima. El objeto inicial del proyecto fue seleccionar sectores que contengan carbón coquificable y pueda ser explotado de forma planificada, recomendándose la realización de estudios geológicos y mineros de la perforación en los sectores Pampahuay, Gazma, Maray y Parquin. Posteriormente se realizaron otros estudios que permitieron evaluar el yacimiento a partir de tres bloques: Norte (Sector Saquicocha), Central (Sector Pampahuay) y Sur (Sector Cochaquillo - Amazonas), encontrándose que el bloque central reúne mejores condiciones sobre la ubicación del carbón coquificable en volumen industrial. En ese sentido, se sugirió la creación de un programa de exploraciones técnicas en Pampahuay donde se considere la ejecución de labores mineras subterráneas, sondajes diamantinos y la ejecución de pruebas de lavado y coquificación.

Nov 20, 1978

By Eric Schraml

Wardrop Engineering and the Placer Dome?s Campbell Mine Design Team utilized leading edge directional raise boring techniques and an innovative, remote controlled application of steel fibre reinforced shotcrete ground support to achieve improved mine ventilation and a superior, safety focused secondary emergency egress. While more standardized methods may have provided a sufficient solution to either the requirement for a ventilation raise or for a traditional escape ladder way, innovative methodology ensured both objectives were met with a single, enhanced solution. Placer Dome committed to provide a solution that minimized energy consumption, optimized air delivery and facilitated an escape way focused on minimizing the negative physiological aspects associated with mine evacuation. The project was successful in providing a new airway, returning 47 m3/s (100,000 cfm) from the 39 Level to 30 Level, minimizing risk to the raise equipping crew and providing a fully equipped escape hoist. The resulting secure escape environment provided an efficient means of evacuating personnel working at depth without necessitating a potentially dangerous exhausting climb to surface. The project has substantiated, that optimized safety focused design can be achieved without jeopardizing project economics.

May 1, 2002

By B. W. Roberts, V. A. Phillips

A copper alloy containing- 25.5 at, pct Zn and 19.0 at. pct Ni, which was previously found to show an anoma1old.s hardening effect on quenching- from 600 "C and aging- at 400oc, has now been examined by neutron diffraction. No evidence of long-range order was found. The aged sample showed diffuse scattering- consistent with clustering. The anomalous hardening effect is now attributed to lattice strains caused by clustering rather than (long-range) order hardening. SOLID-solution Cu-Ni-Zn alloys (the commercial 'nickel silvers") have been reported to show anomalies in: change of resistivity on cold working,1-6 temperature coefficient of resistance,2-12 resistivity at low temperatures,13,14 parameter (vs temperature),2"4 calorimetric data,2,4 specific heat,15,16 dilation,2-4 and elastic modulus.17 The structure responsible for the anomalies is produced by annealing typically near 400°C and is rather loosely referred to as the ('K-Zustands" (K state), a term coined by Thomas1' who apparently meant simply that the arrangement of atoms on the sites deviated from that expected statistically. Thomas proposed that the K state occurred in a variety of (solid-solution) alloys such as Cu-Ni-Zn, Ni-Cr, Ni-A1, Ni-Cu, Fe-A1, and Fe-Si and is recognized because its formation is strongly temperature-dependent and results in an increase in electrical resistance which can then be decreased by cold working. Later workers on ('nickel silver" have interpreted the K state variously as short-range order, long-range order. or a combination. The present work was prompted by the discovery by Phillips and Jones19 of a substantial hardening effect when an 18 pct "nickel silver" alloy which is fairly close to the Cu2NiZn composition, was reheated in the range 150" to 450 C after previously quenching from 600°C or, alternatively. was slow-cooled from 600°C or above. The phenomenon was attributed to (long-range) order hardening. Due to the similarity in the atomic scattering factors of copper. nickel, and zinc atoms, the ''nickel silvers" are unfavorable for X-ray diffraction studies aimed at detecting ordering. Nevertheless Bialas et a1.,20 using a powder sample containing 47.96 wt pct Cu, 24.03 wt pct Ni, and 27.98 wt pct Zn, slow-cooled from 400" to 200°C taking 500 hr, observed weak super lattice lines. Further unpublished work" using an anomalous dispersion X-ray technique indicates that zinc atoms are regularly ordered at the corner points of the lattice cell, while the nickel and copper atoms are statistically distributed on the remaining sites. Köster 17 also observed X-ray superlattice lines, for example, in an alloy containing 43.5 wt pct Cu, 28.6 wt pct Ni, and 27.9 wt pct Zn superimposed on the basic fcc cell with a = 3.62 kX. He proposed a Cu3Au-type superlattice with the Ll2 structure in which the A sites were statistically occupied by copper and nickel atoms and the B sites by zinc. He adds that substitution must be possible so that zinc atoms partly occupy A sites. Below about 35 pct Cu, Koster had some evidence for a CuAu-type superlattice with the Llo tetragonal fcc structure with a = 3.82 kX, c/a = 0.88 which could be preserved by quenching. This is suggested17722 to correspond to CuNiZn. While the present work was in progress Hirabaya-shi et a1.23 made an independent comprehensive neutron-diffraction study of a single crystal containing 50.05 at. pct Cu, 26.57 at. pct Ni, 0.25 at. pct Mn, 0.13 at. pct Fe, balance zinc. The presence of manganese and iron is surprising since the crystal was supposedly grown from high-purity metals. The homogenized crystal showed evidence of long-range ordering after an anneal of 5 months at about 300°C. Three possible crystal models were proposed. A curious feature of their results23 is that they could not find any neutron-diffraction evidence of ordering in a powdered polycrystalline near-stoichiometric Cu2NiZn alloy. There appears to be some essential difference between a near-stoichiometric Cu2NiZn alloy and one somewhat further off stoichiometry as used by the present authors. Thus Sato14 was able to reproduce the low-temperature resistivity anomaly reported by one of the authors13 on the present alloy if he used a similar composition, but found the normal behavior of the residual resistivity in a near-stoichiometric alloy. satol2 found that the resistivity of a cold-drawn slightly off-stoichiometric alloy increased to a maximum on isothermally annealing at 300°C and then decreased ("over-aged"). Since he could not explain this on the basis of ordering phenomenon, he proposed that zinc atoms were segregating to stacking faults (Suzuki effect) and found etching bands on the surface by replication which were attributed to the widening of faults. Sato suggested14 that the hardening effect observed by Phillips and Jones19 is partly due to the Suzuki effect. EXPERIMENTAL The starting material was 1/4-in.-diam hard-drawn rod of a commercial 18 pct "nickel silver" alloy identical with that used in a previous study by Phillips

Jan 1, 1967

By Fookes R. A, Bunch K, Gravitis V. L, Watt J. S

The combustible volatile matter in coal mine roadway dusts (CVM) has been determined using x-ray backscatter techniques. The correlation between x-ray and chemical techniques is reasonably good for the 92 samples from collieries on the Bulli seam, and the maximum error expected at the maximum level of 11· 5 weight per cent CVM permitted in the N.S.W. Coal Mines Regulation Act, 1912, as amended, is about ± 2·5 weight per cent. This x-ray technique can be used only when the combustible volatile content of the coal matter (cvm) varies within a limited range, and a separate calibration is required for each coal seam.Portable equipment based on a radioisotope x-ray source ahd digital ratemeter makes possible simple and rapid analysis, and with adaptation to use in coal mines should lead to much more comprehensive testing- ofroadways and hence improved overall prevention of coal dust explosions.

Jan 1, 1977

By Marcos Antonio da Cunha

A carga de laminação é um dos principais fatores que provocam o desgaste dos cilindros. Identificar quanto e como é o desgaste ocorrido durante o processo é um problema que a indústria de produtos laminados enfrenta há muitos anos, sendo motivo de muitos estudos nessa área. Esse desgaste, além de gerar custo para o fabricante, gera uma deformação no perfil no passe do laminador, fazendo com que a qualidade do produto final seja afetada. Deseja-se, com este trabalho, detectar e identificar o desgaste ocorrido nos cilindros de um laminador a quente de produtos não-planos na sequência de passe de seção redonda-oval-redonda, durante a produção, ou seja, online. Utilizando-se métodos de cálculo semi-experimentais e ferramentas baseadas em redes neurais, desenvolveu-se um sistema híbrido capaz de prever o desgaste dos canais dos cilindros. Foram realizadas inúmeras leituras dos valores de algumas das principais variáveis durante o processo de fabricação desses produtos laminados de uma grande empresa do ramo. Os resultados medidos foram analisados e foi gerada uma base de dados para a criação do modelo de previsão do desgaste nos canais, baseado em redes neurais artificiais e modelos semi-empíricos de cálculo do perfil de desgaste. O modelo foi testado na planta e os resultados foram bastante precisos.

Aug 16, 2017

By R. Zunich, E. Rybinski, M. Grondin, B. Flintoff

It is uncommon these days to read a business magazine or newspaper without finding a reference to Knowledge Management (KM), and its critical importance to corporate success. One definition of KM is: “getting the right knowledge to the right people at the right time and helping them to put information into action in such ways that strive to improve organizational performance.” In the minerals processing industry we could assert that we have been practicing this for years through effective operator training. In most cases we would probably be wrong. Training has certainly filled the need of addressing safety and basic operational issues, but we must collectively focus on education (learning), and the difference, as measured in outcomes, is not at all subtle. This paper briefly examines the history of training and education in the mining industry, and looks in more detail at the impact of one company’s approach to empower its workforce, while keeping the ultimate goal clearly in mind: “The great end of knowledge is not knowledge, but action.” (T.H. Huxley)

Jan 1, 2001

By K Gordon, A Black

Two remediation strategies have been considered to reduce the levels of acidity and dissolved metals in acid mine drainage discharging from Sullivan Mine, West Coast, New Zealand. The oxidising strategy involves adding alkalinity and dissolved oxygen (DO) resulting in the precipitation of metallic oxides and decreased acidity. The reducing strategy involves removing DO, resulting in the precipitation of metallic sulfides, followed by addition of alkalinity to decrease acidity. Field remediation trials indicate a reducing system may be more effective for this site than an oxidising system. A residence time of only two hours in the limestone layer of a successive alkalinity producing system (SAPS) is sufficient to reduce acidity by 100 per cent, iron by 71 per cent, aluminium by 59 per cent, nickel by 38 per cent and manganese by 26 per cent. The proposed remediation plan will likely include a series of SAPS, followed by an anoxic limestone drain, and settling ponds to capture any remaining precipitates.

Jan 1, 2003

By Juan José Herrera

El presente trabajo señala la importancia de crear un sistema de gestión entre los conceptos de salud, seguridad y medio ambiente en la mina Iscaycruz(Lima) para asi mejorar los niveles de control relativo a estos aspectos, y analizar los sistemas disponibles optados por el sistema integrado sudamericano denominado NOSA. Producto de este sistema de calidad, Iscaycruz logró obtener cuatro estrella NOSA en la primera auditoría y se constituyó como la primera mina peruana subterránea en lograr la certificación internacional de "muy bueno" en Salud, Seguridad y Medio Ambiente. De forma, que la minera está encaminada a ser una operación minera modelo, con una clara concepción de empresa minera segura, limpia y rentable, ética y valores empresariales que consideran la priorización de la salud, seguridad y medio ambiente.

Oct 6, 1999

By W. W. Agey

Under terms of cooperative agreements, the Federal Bureau of Mines Inter-mountain Experiment Station assisted the General Services Administration (GSA) in operating the manganese-ore purchasing depots at Deming. N. Mex., and Wenden, Ariz. A resident metallurgist stationed at the depots directed sampling of the ore lots for assaying, took samples for amenability testing, calculated acceptances for payments to shippers, and served as technical adviser to the depot manager. The Intermountain Experiment Station at Salt Lake City, Utah, tested the amenability of the ores to determine how much of the manganese could be recovered in concentrates assaying a minimum of 40 percent manganese (Mn) and containing a maximum of 16 percent iron (Fe), 15 percent silica (Si02) plus alumina (AI203), 0.3 percent phosphorus (P), and I percent copper (Cu) plus lead (Pb) plus zinc (Zn). All chemical analyses of the ores and test products were done at Salt Lake City. In all, 567 ore lots submitted to the Deming depot were tested by flotation to determine their amenability to concentration into specification-grade material; 421 lots were amenable, and 146 were unamenable, primarily because of high copper content or excessive silica or iron in the flotation concentrate. Chemical analyses totaling 42,700 were made on the ores submitted to the Deming depot and on the products of the amenability-test program.

Jan 1, 1959