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By Carlos E. Del Río S

"La I Convención Nacional de Ingenieros de Minas (1954) fue el espacio precedente para presentar estudios sobre la eliminación de impurezas en los concentrados gravimétricos del mineral de Pasto Bueno. Por ello, el objeto de este trabajo se basa en la elaboración de estos estudios anteriores, detallando la refinación de los concentrados, a través de la flotación de los sulfuros metálicos y una separación en tamaños de las colas de la flotación (concentrados de WO) por cicloneo. De tal forma, que se obtenía un 85% de la producción total del tungsteno dentro de los límites permitidos de impurezas. Empero, ciertos minerales como la hubnerita, galena y la pirita, dada la sobremolienda en el proceso de varillas de los sulfuros metálicos y el magnetismo de la primera, no alcanzaban el estado de limpieza adecuado. Por tal motivo, se consideró la separación magnética como el sistema más idóneo para dichas operaciones puesto que el concentrado magnético era más dócil a la refinación por flotación y en el que las pruebas de la misma en escala industrialrespondían de forma óptima en la producción dee la sección de Pasto Bueno, considerándola de manera definitiva. Asimismo, el aumento de la recuperación en la sección gravimétrica abría la posibilidad de ir a concentrados gravimétricos aún más pobres, logrando nuevos aumentos en la recuperación."

Jul 20, 1956

By Gustavo Mammana, Aníbal Amirá

El escenario que enfrenta la minería chilena en materia de productividad plantea el desafío de definir estrategias que contribuyan a optimizar los procesos de dirección, gestión de proyectos y operaciones, agudizados por el envejecimiento de los yacimientos, la disminución de leyes, la fluctuación de los precios de los commodities, y el costo de la mano de obra e insumos. Este trabajo busca difundir las herramientas empleadas y las mejoras obtenidas a partir de la aplicación del Modelo de Excelencia Operacional –ExOpeHS, orientado a aumentar la eficiencia y la productividad en proyectos de ingeniería y construcción, mejorando los procesos de selección y reclutamiento, logística y control de proyectos; así como de la herramienta denominada TF30D, destinada a mejorar en corto plazo los resultados en las faenas mineras Chuquicamata, Centinela y Sierra Gorda (Chile).

Sep 20, 2019

By Christopher C. Jobes

Computer-assisted control of a mining machine can place the operator in a safe, remote location. A guidance system aids remote positioning of a mining machine by determining its position and heading. The mechanical position and heading system (MPHS) is one of several guidance systems being developed at the U.S. Bureau of Mines. The MPHS uses linear position transducers (LPT's) to provide navigation information during face maneuvers. This report presents an overview of the MPHS theory and implementation, including recent design modifications made for more successful underground testing. This report also presents the experimental setup and procedure for the underground test. The test showed that the MPHS provides reliable and accurate results and can, therefore, provide useful guidance information for face navigation.

Jan 1, 1992

By Albert E. Long

THIS GLOSSARY is published lay the Bureau of Mines as a contribution too the mining literature to fill a long-felt need for a compilation of the terms used by the diamond-drilling industry. The first step toward preparation of the glossary was taken in October 1955 when the Diamond Core Drill Manufacturers Association (DCDMA) proposed that the Bureau of Mines undertake the cons compilation and publication of a glossary of the terms used by the diamond-drilling industry. The work was authorized in July 1956, and a preliminary draft of the glossary was completed in may 1958. Copies of the draft were submitted for review to members of the DCDMA and appropriate personnel of the Bureau of Mines. The final draft, incorporating the many helpful suggestions of the reviewers representing both the diamond-drilling industry and the Bureau of Mines, was completed in March 1959.

Jan 1, 1960

By Peeler P. K

The recent renewal of interest in hydrometallurgical routes for copper production has been brought about by the possible future reliance on mixed ores and lower grade deposits, environmental aspects, and energy considerations.A number of hydrometallurgical processes for the recovery of copper have recently been proposed. Flowsheets are developed for two processes which incorporate several treatment methods being experimentally studied in Australia.In the first process a cupric chloride leach is followed by electrowinning whilst the second is based on the formation of cuprous ions, stabuized by acetonitrile and subsequent disproportionation to cupric ions and metallic copper. For the purpose of comparison, flowsheets were also developed for the Arbiter and Cymet processes.Process economics are estimated for the four processes and the results are discussed in relation to competitive pyrometallurgy. None of the four hydrometallurgical processes, with possible exception of the Cymet process, appears to be competitive with established large scale and newly developed pyrometallurgical processes for chalcopyrite.However, because the economics of the individual hydrometallurgical processes depend strongly on specific conditions, a "tailored" process may be competitive with pyrometallurgy in particular circumstances.

Jan 1, 1977

By Mauricio Pero Diez de Medina

El presente texto describe los principales yacimientos de azufre contenidos en el departamento de Potosí, Bolivia. Las zonas auríferas se caracterizan por una serie de volcanes extinguidos que sobresalen del altiplano, donde existen lagunas y fuentes de aguas termales. A nivel regional se distinguen tres zonas: lava superior, zona piroclástica y lava inferior. Asimismo, la explotación, refinación y comercialización del azufre está a cargo de la Corporación del Seguro Social Militar (COSSMIL), del Grupo Barrero, del Grupo Clavija y en menor escala de las Cooperativas Mineras.

Mar 1, 1984

By R. W. Hodder

"Archean lode gold deposits of both vein and chemical sedimentary types typically have major enrichments of certain rare elements, including Au, Ag, As, Sb, B, W, Se, Te and Bi, coupled with low or negative enrichments of the more abundant and mobile base metals, Cu, Pb and Zn. On the other hand, in massive base metal sulphide deposits Au, Ag, Cu, Zn and in some instances Pb are all enriched by a factor of 200 to 2000 t:'Jf'1pared to background and there is no large separation of gold relative to the base metals.The fluids from which gold was precipitated in veins were at temperatures of 320 to 480°C, at lithostatic pressure, had significant C02, and Na """" K; whereas the fluids which generated base metal deposits were at 250-300°C, at hydrostatic pressure, had C02 < < H20 and Na > > K.Many lode gold deposits are characterized by K, C02 and Si additions to their enveloping rocks, whereas base metal deposits typically have a fixation of Fe, Mg, Si and S in footwall rocks. Lode gold deposits may also have a relatively large halo of low-temperature oxidative, sadie spilitization in enclosing volcanic rocks, where seawater has later streamed into cooling stocks or flows that have initially acted to focus gold mineralizing fluids along thermal contraction fractures. The submarine environment is one hydrologically appropriate for the mixing of two initially independent hydrothermal systems, and the blending of their separate characteristics. Hence, lode gold and base metal massive sulphide deposits appear to be products of two distinctly different crustal and hydrological regimes. The former involves a high-temperature, high-pressure discharge of fluids which probably were generated during dehydration accompanying burial and progressive accumulation of volcanic-sedimentary sequences, with an additional influence of marine water in the near-sea-floor environment. The latter represents thermally driven convection of ocean water at lower temperatures and under hydrostatic conditions.Auriferous fluid systems with only minor base metal content could plausibly be generated during dehydration accompanying burial and metamorphism, when the water-to-rock ratio is low and halogen availability is limited by crustal abundance (- 60 ppm Cl). These two factors may constrain the uptake of the abundant base metals into fluids, but the solubility of rare elements is not constrained by limited fluid; and preferential uptake of Au along with other rare elements may be promoted if such elements compete more successfully for the limited halogens than the base metals, and/or have an alternative complexing agent such as CO or C()j-."

Jan 1, 1982

By Alfonso Rizo-Patrón

El presente trabajo describe la importancia de la explotación de los fosfatos de Sechura en la cuenca del Pacífico. Para ello, se evalúa el potencial de recursos naturales aprovechables en una infraestructura concentrada del área de Bavoyar y su implicancia en el aprovechamiento del potencial para el año 2000. Asimismo, es importante la planificación de un programa y una coordinación técnica adecuada de las realidades físicas, geográficas y geológicas de la cuenca señalada, así como la responsabilidad que ello implica.

Nov 20, 1972

By Amado Yataco

"La minería es la actividad económica que genera el mayor porcentaje de impuestos y contribuciones al país. Bajo esta perspectiva, el presente texto determina la influencia de las exportaciones mineras en la evolución del tipo de cambio (soles &US$) y, en una etapa preliminar, inferir cuál es el aporte indirecto de la actividad minera al sostenimiento del Producto Bruto Interno Nacional (PBI)."

Feb 1, 2017

By Christian Huihua, Armando Moyonero, Jorge Escalante, Alberto Valera

A raíz de una mayor demanda de horas hombre para cumplir con el mantenimiento de la flota de camiones de acarreo de Antamina, se puso en marcha la optimización de la gestión del mantenimiento preventivo (PM), cuyas estrategias principales eran la reducción del tiempo de parada de los camiones por PM y la extensión del intervalo de frecuencia de los PM. Así, se logró extender la frecuencia del PM de cada 250 horas a cada 500 horas y se logró reducir el tiempo de parada mensual por PM de 21.0 a 10.5 h por camión, sin afectar la confiabilidad.

Sep 20, 2019

By J. W. Thompson

AN ACT prescribing the mode of maintaining and defending possessory actions on lands belonging to the United States. The People, etc. SEC. 1. Any person now occupying and settled upon, or who may hereafter occupy and settle upon any of the public lands belonging to the United States, unoccupied, except upon lands containing mines of any of the precious metals, may commence and maintain any action for interference with, or injuries done to his possession of said land, against any person or persons so interfering with or injuring such land or such possession. SEC. 2. On the trial of any such cause, the possession or possessory right of the plaintiff shall be considered as extending to the boundaries embraced by the claim of such plaintiff, so as to enable him to have and maintain any action as aforesaid, without being compelled to prove an actual inclosure; provided, that such "claim" shall not exceed in any case one hundred and sixty acres of land. SEC. 3. Every such claim, to entitle the holder to maintain any action as aforesaid, shall be marked out, so that the boundaries thereof may be readily traced, and the extent of such "claim" easily known, and no person shall be entitled to maintain any such action for possession of, or injury to, any claim, unless he occupy the same, or shall have made improvements thereon to the value of $100. SEC. 4. A neglect to occupy or cultivate such "claim," for the period of three months, shall be considered such an abandonment as to preclude the claimant from maintaining any action as hereinbefore mentioned. Sec. 5. Any person or persons claiming the right of possession to land under this act shall have the right to defend said possession and the claim thereto, and all the rights and privileges given them by this act.

Jan 1, 1918

By Luis Briceño Arata

El presente texto señala las posibilidades de evolución cuantitativa de la producción minera del país hasta el año 2000. Para ello, se evaluaron los factores que influyen en la producción, la metolodología de proyección adoptada y así elaborar la producción de elementos estudiados.

Nov 1, 1974

By Elione Moura Carlos

O objetivo principal deste trabalho foi incorporar o resíduo de mármore no desenvolvimento de formulações de massas cerâmicas para obtenção de grês porcelanato. Foram preparadas quatro formulações da massa cerâmica variando-se as proporções de caulim, talco, feldspato, argila de queima clara e do resíduo de mármore nas misturas. Essas matérias-primas foram peneiradas na malha 200 mesh e as porcentagens para cada formulação foi misturada em moinho de bolas por 30 min. Os corpos de prova foram preparados em uma prensa uniaxial com pressão de 25 MPa e sinterizados em forno convencional nas temperaturas de 800°C, 900°C e 1.000°C, com patamar de 60 minutos e taxa de aquecimento de 10°C por minuto, verificando as propriedades das peças. Para obtenção de resultados foram realizados ensaios de absorção de água, retração linear nas peças sinterizadas, massa específica aparente e porosidade aparente, com o propósito de avaliar a variação de retração linear em determinada temperatura de acordo com a porcentagem de absorção de água. Foram realizados também os ensaios de flexão e microscopia eletrônica de varredura - (MEV). As composições estudadas apresentaram resultados satisfatórios dentro dos valores aceitáveis para o devido uso na indústria cerâmica.

Aug 7, 2018

By Pedro Lozada, Juan Prado

El objetivo que hoy se les exige a las técnicas de voladuras controladas es el de minimizar el daño al macizo rocoso remanente protegiendo la integridad de las paredes de la mina y asegurando a la vez la calidad de la fragmentación del material volado facilitando su extracción. Encontrar este equilibrio resulta estar entre los tres principales desafíos que enfrentan las grandes minas a cielo abierto, ya que deben lograr la estabilidad de la mina, dando cumplimiento al diseño de taludes, manteniendo al mismo tiempo buenos resultados en términos de fragmentación y productividad de sus equipos de carguío.

Sep 30, 2022

By Daniel Rodríguez Hoyle

El presente texto revisa la contribución de la minería en el ramo de los insumos. El análisis se divide en cinco partes: la importancia de la minería en el Perú, la naturaleza de la industria minera, desarrollo minero y su influencia en el desarrollo industrial, una mirada hacia el futuro y el período de discusión del tema.

Jul 1, 1980

By Alfred Bodenlos

"El presente texto señala los acontecimientos geológicos en la Cordillera Negra y la deposición de travertino por las fuentes termales todavía activas al oeste de la población de Ticapampa. Los minerales fueron depositados principalmente como rellenos de fisuras, siendo cavernosos y en partes bandeados y sus temperaturas conocidas de formación varían desde baja hasta moderada, lo cual, además de su textura porosa, sugiere que están comprendidos entre las clases epitermal y mesotermal, según sistema propuesto por Lindgren. "

Sep 1, 1957

By H. Kenworthy

Sulfide-ore concentrates containing cobalt, nickel, copper, lead, and iron from the operations of the National Lead Co. at. Fredericktown, Mo., were treated successfully on a laboratory scale to recover more than 90 percent of the cobalt, nickel, and copper. A cobalt -nickel-bearing, lead-copper matte., produced by the St. Joseph Lead Co. at Herculaneum, Mo., was treated to produce a lead-zinc fume, a copper sulfide concentrate, and a cobalt nickel-iron product, netting a recovery of over 75 percent of the cobalt and about 90 percent of the nickel and copper. National Lead Co. bulk concentrates were chlorinated with gaseous chlorine to form anhydrous metal chlorides and sulfur chlorides, sulfur chlorides were recovered by distillation, a high percentage of the ferric chloride was converted to ferric oxide, and the chlorinated residual metals were extracted with water. Metal ions were removed from leach liquors by pH-controlled fractional precipitation as hydroxides. Cobalt solutions "were prepared from cobaltic hydroxide, and procedures were developed to remove contaminating metal ions. Purified cobalt solutions were employed as electrolytes for deposition of high-purity cobalt.

Jan 1, 1953

By Mauro Vivaldino Fernandes

Os desafios para o aprimoramento do desempenho operacional dos altos-fornos constituem um campo aberto para o desenvolvimento e aplicação de métodos de controle que promovam a otimização da operação do reator, aliada ao prolongamento da sua vida útil. O Alto-Forno 3 da Usiminas - Ipatinga, nesta sua 4ª campanha, foi projetado para 15 anos de operação, com uma produção estimada de 41 milhões de toneladas de gusa. Os resultados da campanha atual, em termos de produção e de duração da campanha, superam os dados projetados. Neste contexto, são apresentadas as principais características do Alto-Forno 3 na sua atual campanha, a evolução do seu desempenho em termos de produtividade e tempo de operação, além das principais ações direcionadas para a preservação e estabilidade do sistema de refrigeração e do cadinho, contribuindo para o prolongamento da sua vida útil. Como resultado destes esforços, a vida útil estimada do Alto-Forno 3 é de 22 anos, superando em 7 anos a duração prevista.

Oct 30, 2017

By J. Riss, S. Gentier, A. Marache

The study of the hydromechanical behaviour of fractured rock masses requires a detailed knowledge of the isolated fractures. The aim of the paper is the simulation of the evolution of the void space, located between both walls of a fracture, during a shear test under constant normal stress. Results of the mechanical simulation model are first validated then analyzed in detail. We observe that, during the shear process, there is an opening of the fracture with the creation of preferential channels. These channels are determined at the early phase of the shear process (pre-peak phase), and we observe during the post-peak phase that void areas increase in size rather than the creation of new apertures. Die Untersuchung des hydromechanischen Verhaltens eines zerlegten Felsmassivs erfordert genaue Kenntnisse der einzelnen Spalten. Ziel dieses Artikels ist die Simulation der Evolution des Hohlraumes zwischen den beiden Wänden eines Spaltes während eines Abscherungsexperimentes unter konstantem senkrechtem Druck. Die Ergebnisse der Modellierung werden zunächst mit dem Abscherungsexperiment verglichen und dann im Einzelnen ausführlich analysiert. Während des Abscherungsprozesses tritt eine Öffnung des Spaltes auf, die die Bildung von bevorzugten Fliesswegen fördert. Diese Kanäle werden bereits in einer frühen Phase des Abscherungsprozesses (pre-peak Phase) festgelegt. In der post-peak Phase tritt dann eher eine Vergrößerung dieser Kanäle, als die Bildung neuer Hohlräume auf. L’étude du comportement hydromécanique d’un massif rocheux fracturé ne peut se faire sans une connaissance approfondie des fractures le constituant. L’étude présentée dans cet article concerne la simulation de l’évolution de l’espace des vides présent entre les deux épontes d’une fracture au cours d’un essai de cisaillement à contrainte normale constante. Les résultats du modèle sont tout d’abord validés puis analysés en détail. On constate que, au cours du cisaillement, il apparaît une ouverture de la fracture permettant la création de chenaux préférentiels. Ces derniers sont déterminés très tôt dans le cisaillement (phase pré-pic), et on observe dans la phase post-pic davantage un accroissement de la taille des chenaux plutôt que la formation de nouvelles zones de vides.

Jan 1, 2003

Australian coals tend to be young in geological age and high in ash by world standards; preparation of the coal before marketing is almost universal. On the basis of float and sink data from 39 locations in the Eastern Australian coalfields, the coals are placed in four categories representing increasing difliculty in their washability characteristics. These seem to be related neither to the geological age nor the geographical position of the deposit and Hunter Valley coals, for example, span all categories. The influence of crushing on the washability of Australian coals is briefly considered and from limited data it is concluded to be appreciably smaller than for British or North American coals. A strategy for the float and sink analysis of Australian coals is proposed and the influence of washability characteristics on current trends in the selection of separating processes for coking and steaming products is discussed.

Jan 1, 1979