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By Simon Strauss

Durante la II Guerra mundial y la guerra de Corea, el gobierno estableció precios máximos uniformes aplicables a todos los vendedores de productos de consumo de primera necesidad idénticos. Dichos cambios estaban basados en el criterio industrial de costos y las consideraciones de suministro. Como consecuencia, se crearon problemas en la regulación de precios por la confusión que existe en la industria del zinc puesto que no se hace ninguna distinción entre las regulaciones sobre los precios para productos de primera necesidad y las regulaciones de los precios de otros artículos y servicios. En ese sentido, el presente texto describe el contexto de este regulación y las posibles soluciones para amortiguar dicha situación, de form que los controles de precios deben ser aplicados mediante tarifas a todos los vendedores de productos standard de primera necesidad como fue el caso en la segunda guerra mundial y durante la guerra de Corea.

Nov 1, 1973

By Glenn Buchana

El presente texto señala algunos aspectos técnicos y comerciales del dragado del depósito fluvial. Para ello, es necesario conocer el origen y desarrollo del depósito fluvial. El depósito fluvial es una masa de grava superficial, la cual es producto del desmoronamiento y erosión de rocas sólidas que contienen partículas o pepitas de oro, diamante, estaño, platino u otros minerales valiosos que proceden de las rocas o de las vetas. Entre los tipos de depósitos aluviales tenemos: depósitos aislados pequeños y poco profundos, los depósitos de mediana profundidad, depósitos profundos y los marinos. La explotación se realiza a través de tres sistemas: draga cortadora de succión, la dragalínea de cangilones y la planta de tratamiento flotante.

Nov 1, 1979

Since mid-July, most domestic producers have been marketing 99.5 percent unalloyed aluminum ingot at 53-57 cents per pound. Dealers in the United States have recently quoted ingot at 52.3-52.8 cents. On October 2, London Metal Exchange will trade aluminum, selling contracts on a cash and a 3-month basis. New York dealers were quoting August ingot at 52.3 52.8 cents. The Bonneville Power Administration announced that, effective December 20. 1978, electric power rates charged primary aluminum producers in the Pacific Northwest would be increased The increase (equivalent to about 4 cents per pound of aluminum produced) will raise the average rate to about 8.7 mills per kw-hr compared to 3.2 mills per kw-hr.

Jan 1, 1978

By E. D. Gardner

This paper discusses small-scale lade gold mining and milling. It is abstracted from a bulletin being prepared by the United States Bureau of Mines entitled "Equipping, Developing, and Operating Small Gold Mines." Gold is widely distributed in the mountainous regions of the United States; relatively few deposits, however, can be profitably worked on a large scale. Because of the high intrinsic value of gold, ores containing this metal may be very rich; hence it is possible to mine profitably smaller bodies of gold ore than of the more common metals.

Jan 1, 1934

By N. B. Aughenbaugh

This report summarizes the results of an investigation into the causes of coal mine roof instability caused by the environmental characteristics of the air ventilated through a mine. The field studies, which were mostly in the Illinois Coal Basin, concentrated on collecting data of surface weather conditions, mine air characteristics (relative humidity and temperature), roof material types, roof movements, and characteristics of roof deterioration. The field studies revealed seasonal changes in weather are reflected in the mine air. The intake air undergoes rapid tempering along its course as it interacts with the ambient mine conditions. There are seasonal moisture interchanges between the mine rock and air, and a mine will lose more water than it gains on a yearly basis. The field studies also established that when the roof rock is shaley, seasonal changes in the humidity will cause roof deterioration because of the detrimental action of moisture on the shale. Roof falls were inventoried and classified by geometry. In the laboratory investigations, physical tests proved unreliable for evaluating shales for roof stability. The Franklin slake test lacks the sensitivity needed to differentiate shale durability for roof stability. A relative humidity test that reveals the sensitivity of a shaley rock to moisture change was devised. Environemntal chamber studies showed that neither temperature nor barometric pressure have a direct influence on shale durability. Photoelastic studies showed that the rate and depth of moisture absorption into a shale is controlled by bedding planes, fractures, and holes interrupting the exposed surface.

Jan 1, 1976

By Dave J. Porter

Si bien, los proyectos son el camino para que una organización minera cumpla con su estrategia, la gran mayoría de su historial de cumplimientos son un fracaso puesto que el impacto del proyecto no es tan rico en sus etapas y las organizaciones mineras no pueden cumplir con su visión y estrategía. En ese sentido, el presente texto señala la importancia de una adecuada gestión de proyectos para que la organización minera cumpla con su estrategia. Así, la madurez de la gestión de proyectos es un indicador de éxito continuo y requiere de visión, compromiso en las etapas iniciales, ya que sus ganancias son difíciles de cuantificar.

Apr 1, 2012

The Kaiser Aluminum and Chemical Corp. announced plans to raise June ingot prices by 4 cents to 57 cents per pound. Producers? April value for 99.5 percent unalloyed aluminum ingot was at 53 cents per pound. Domestic merchants last month were quoting the metal at 48-49 cents per pound. Primary aluminum producers began restarting production facilities following the settlement of the coal strike. Noranda Aluminum Inc. recalled workers to prepare potlines for production at its plant at New Madrid, Mo., which had closed February 14, 1978 due to the shortage of coal. Eastalco Aluminum Co. resumed full capacity production at its Frederick, Md. smelter where production had been cut by 30 percent. Anaconda Aluminum Co. resumed full capacity production at its Sebree, Ky. smelter.

Jan 1, 1978

By Fredy Gutiérrez, Nilton Apaza

En el año 2012, a causa de la situación inestable de la operación y por contar con una visión no muy proyectada al crecimiento organizacional, Raura se encontraba inmersa en una situación económica muy crítica y a punto de declarar su cierre. Por ese motivo, se replantea la visión estratégica de la operación y se alinea a la filosofía de la excelencia operacional por etapas. La principal apuesta de Raura es ser considerada una empresa de clase mundial, para lo cual, bajo un nuevo enfoque de gestión, en los últimos 5 años se implementaron diversas decisiones estratégicas que tuvieron impactos positivos. Así, se logró ser una de las operaciones más rentables de la división minera del grupo Breca.

Sep 20, 2019

By Kenneth L. Cook

From March 1944 to July 1945 the Division of Geophysical Exploration of the Federal Bureau of Mines made magnetometer surveys of some of the principal iron ore deposits of the Iron Springs district, Iron County, Utah. The district comprises a belt about 23 miles long and 3 miles wide. Most of the large ore bodies are found as pods of replacement ore within a favorable limestone bed lying at the margins of three separate igneous intrusions in the district The magnetic surveys were confined chiefly to this geologically favorable zone at the margins. The iron ore is a mixture of magnetite and hematite. The magnetite content of the ore ranges from 14 to 58 percent. Magnetic anomalies of 1,250 gammas or more were usually found over the near-surface ore bodies. About 62,000 magnetometer stations were taken over a total traverse distance of about 300 miles. Outcropping ore bodies were surveyed to determine, insofar as was possible from the magnetic data, their probable length, width, depth, extent, strike, dip, and tonnage. Geologically favorable areas where no ore is exposed were explored in an endeavor to find new ore bodies. Favorable locations were determined for exploratory diamond drilling, both in areas of exposed ore bodies and in areas of newly discovered magnetic anomalies. Forty-five separate magnetic anomalies that indicate the possible existence of ore bodies were observed. Of these, 13 anomalies are caused by outcropping ore bodies of proved commercial size. Five are caused by non-outcropping ore bodies of proved commercial size which were discovered, in whole or in part, as a result of the geophysical surveys. Of the remaining anomalies, which lie in virtually un-tested areas where few or no ore bodies are exposed, six probably are caused by large, unexposed replacement ore bodies, nine are possibly caused by large, unexposed replacement ore bodies, and six are probably caused by unexposed magnetite veins of some small commercial importance,

Jan 1, 1949

By Shigeru Tsutsumi

The rapid development of transportation facilities in Japan focused the attention of this country on the possibility of converting the existing coal resources (of which there was an abundance) into liquid fuels, for which there was a constantly increasing demand. Previous work had indicated that this could be accomplished by utilizing one of two processes - the Bergius process, in which high temperatures and high pressures were employed to effect direct liquefaction of the coal, and the Fischer-Tropsch process, in which an indirect liquefaction of coal was accomplished by the production of liquid hydro-carbons from hydrogen-carbon monoxide mixtures. This report describes some investigations into the latter process, which was first developed by Fischer and his colleagues in the Coal Laboratory in Muhlheim, Germany, in 1923. By 1932, these investigators had achieved a 60-percent theoretical yield (152 ml. of liquid hydrocarbons per cubic meter of 2H2:ICO synthesis gas) by using a precipitated Co-Th02 catalyst.3/ At the same time (1932), Dr. Kita of Kyoto Imperial University and Messrs. Fujimura and Tsuneoka obtained 145 ml. of gasoline (C5+) per cubic meter of synthetic gas by using a Co-Cu-Th-U catalyst. 4/ This report is a description of the experimental results subsequently obtained at the Fuel Research Institute, Kawaguchi City, Saitama, up to 1935.

Jan 1, 1951

By Manuel Montañez

Nexa Resources está comprometida con el desarrollo de las comunidades campesinas del entorno de sus operaciones. En ese contexto se inserta el proyecto descrito en este artículo, el cual está orientado a mejorar la calidad de vida de las comunidades del área de influencia de unidad minera Atacocha (Pasco). El proyecto analizado incluye el fortalecimiento de habilidades y valores locales, el desarrollo de capacidades para acceder al mercado y una adecuada transferencia tecnológica y técnica para un manejo sostenible de los recursos pecuarios (vicuñas).

Aug 30, 2020

By Iván Salas

Los bofedales (humedales altoandinos) son considerados ecosistemas frágiles, con características y recursos singulares, con baja resiliencia ante eventos naturales y presión antropogénica los cuales producen una profunda alteración en su estructura, composición y funciones, estas características hacen que la protección de estos ecosistemas sea legislada a nivel nacional e internacional. Hudbay Perú viene ejecutando el Plan de Manejo de Bofedales como parte de su compromiso de compensación ambiental el cual tiene como objetivo mejorar las condiciones del ecosistema del Bofedal de Cochapampa ubicado en territorio de la comunidad campesina de Chilloroya a 4300 m.s.n.m (comunidad de influencia directa de la Unidad Minera Constancia).

Sep 30, 2022

By Andrés Galarza Flores

En la minería metálica subterránea se desarrollan casos frecuentes de accidentes por gaseomiento a través del monóxido de carbono y los vapores nitrosos. En este sentido, el texto describe un programa de seguridad que comprende la higiene industrial, la composición de los gases nitrosos, su origen en la industria minera, los límites permisibles de los vapores nitrosos, el reconocimiento y evaluación de los gases nitrosos en las fuentes conocidas, los vapores nitrosos en el organismo humano, los casos de accidentes con vapores nitrosos y las medidas preventivas.

Nov 20, 1978

By Amy B. Cerato

The application of this study is to use helical anchors as a foundation system for small wind tower (1 ? 10 kW) guyed cables. Helical anchors are currently used to anchor guyed cables of telecommunication and electric towers. However, the increased dynamic vibrations a wind turbine adds to the tower and foundation system under working loads, as well as extreme environmental conditions (e.g., straight line winds, ice load or sudden furling shocks), require additional knowledge about the behavior of helical anchors. These field conditions were simulated in this study by instrumenting a working tower with load cells and 3-axis accelerometers to gather data on wind speed and tower response. These tower responses were then transmitted to the helical anchors through an extensive, large-scale testing program that included monitoring the performance of the helical anchor foundation under dynamic loads, subject to natural variations in both wind regimes, precipitation (water level) and variations in helical anchor geometry. This paper specifically discusses the effects of helical anchor geometry on helical anchor performance under long-term dynamic loads.

Jan 1, 2008

By R. W. Bee

This project, sponsored by the U.S. Bureau of Mines, Division of Environment, addresses two major subjects: refuse removal and subsidence monitoring. The refuse removal task consisted of developing a methodology for selecting the most economical combinations of coal mine breaker refuse and rock banks, disposal sites and material moving systems (trucks, trains, belt conveyers and pipelines). To prepare plans for moving refuse in the Lackawanna Valley of Northeastern Pennsylvania, refuse banks were inventoried, underground disposal sites identified and unit cost data prepared for the various material moving systems. The subsidence monitoring task consisted of defining the phenomenon of coal mine induced surface subsidence, establishing operational requirements, cataloging sensors and techniques to detect and measure subsidence and testing of the most promising techniques (photoelastic patch, tiltmeter, strain gage, microseismic and precise surveying). A preliminary system for a 700 acre area in Scranton utilizing 267 grid sensors, seven microseismic sensors and precise surveying techniques was designed with initial and annual operating costs determined. Two minor tasks supported both main subjects: zoning in the Northern Anthracite Field of Pennsylvania and Technology Transfer of subsidence vulnerability prediction techniques.

Jan 1, 1972

By K Ringwood, J Cummings, C J. Moran

The development of a water accounting framework that enables consistent and contextual reporting of minerals operationsÆ water use, represents a key sustainable development objective that many Australian minerals companies have committed to. A future water accounting framework will require: key terms and definitions for water metrics for use in the Australian minerals industry that are consistent with the wider water sector, a suite of metrics representing key components of an operationÆs water balance, a calculation method for some of the metrics, and a reporting protocol. This paper presents the methodology that was used to derive these four components. Existing accounting frameworks were reviewed and key terms and definitions that were consistent with current regulatory requirements and voluntary approaches were proposed. A calculation methodology was developed to obtain some of the key indicators and variables that cannot be easily measured directly (eg water loss through evaporation). The adopted terms and definitions typically require a combination of empirical and estimated data. To test the proposed definitions and calculation methodology, values for water metrics were derived for eight sites, selected to test a variety of commodity and biophysical situations. The proposed framework and definitions could deal with the specific situations selected as case studies. The associated calculation methodology produced complete accounts at various levels. Some elements of the accounts could be directly checked against available data and simulations. The framework captured well variations in the reuse efficiencies; reuse efficiency could even vary for similar processes. It is concluded that this preliminary accounting framework provides a consistent language and metrics for quantifying and communicating water management, both at the intersection of the site with the surrounding landscape (through detailed reporting of site inputs and outputs) and within operational activities. Using this consistent framework for quantifying and documenting water use within an operation will provide a platform for compiling and comparing minerals industry water use with other sectors. This may support benchmarking activities within regions or companies and help demonstrate leadership amongst water users in water resource stewardship. The approach presented here is applicable to a wide variety of mining and processing activities, and biophysical environments, and following a period of stakeholder engagement and third party review, is being refined as a first step towards developing nationally consistent water use reporting for the Australian minerals industry.

Jan 1, 2009

By M. N. Barbier

Según la obra del Ministerio de Educación Nacional de Francia existen 112 escuelas de ingenieros que este año formarán total alrededor de 6.000 ingenieros. Sin embargo, surgen algunos problemas en la formación de esta profesión como: aquellos ligados al reclutamiento de los alumnos de las escuelas de ingenieros, para obtener el mayor número posible de alumnos jóvenes y bien preparados, y los relacionados a la actividad misma de las escuelas de ingenieros, tales como programas, métodos de enseñanza y relaciones con la industria. En ese sentido, el presente texto revisa dichos problemas y plantea soluciones respecto a ellos como: diversas mejoras en el régimen de los concursos de las grandes escuelas y duracíón de la preparación, así como una reducción del número de materias enseñadas y la adopción de métodos activos de la enseñanza en lugar de aquéllos que se limitaban a exigir la presencia física de los alumnos.

May 1, 1965

By Eder Salazar

El presente texto describe la optimización de la productividad en la empresa minera a través de la mejora contínua en la cadena de valor en SMEBSAA, los siete pasos de la calidad, proceso de mina, planta, soporte y la cuantiificación de dicha mejora en la cadena de valor en SMEBSAA. Asimismo, la implementación de los diversos sistemas de gestión refuerzan los resultados, siendo el Sistema de costeo basado en actividades el gran agrupador de toda la información de los módulos: Logístico, Control Patrimonial, Orden de Servicio, Planillas y Contabilidad.

Sep 12, 2005

By Luis Noval Noval García

El objetivo de la ventilación es desarrollar una atmósfera saludable, segura y apta para la realización del trabajo por parte del personal. En ese sentido, el presente texto señala los gases como problemas comunes presentados dentro del ambiente minero tales como asfixia por anoxia (caso de inhalación) intoxicación, envenenamiento y muerte (letal) e inflamación y explosión (Productos). Para eliminar estos riesgos se debe eliminar las causas a través de una buena ventilación. Asimismo, es necesario conocer las propiedades de los gases, disponer de equipos para detectar su presencia y procurar los medios para eliminarlos.

Sep 1, 1984

By Robert S. Hill

"In November 1942, a preliminary report on the Swartz Mining District by John H. Soule, an engineer of the Bureau of Mines, recommended an exploratory program of diamond drilling. The existence of zinc and lead deposits in this region had been known for many years. In 1943 and 1944, the Federal Geological Survey made a detailed study of the same area. Later work done by the Bureau of Mines in this district followed the suggestions made by these geologists.3/In the latter part of 1944, Felix A. Vogel, Jr., another Bureau engineer, made a study of the Grey Eagle mine in the Kingston Mining District, a few miles northeast of the Swartz district, and his recommendations for diamond drilling were followed in so far as funds permitted. Drilling was started in October 1943 and was completed in June 1945.4/In its program of exploration of Mineral deposits, the .Bureau of Mines 'Ms as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution t national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples of ore and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.With respect to this report, special acknowledgment for assistance is due to C. H. Johnson, chief of the Rolla Division, Mining Branch, and to various members of the Geological Survey."

Sep 1, 1946