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By Keith L. Harris

Buoyed primarily by growing consumer spending, the economy rebounded from a weak second quarter. According to preliminary estimates released by the Department of Commerce, real gross national product (GNP) grew $2 1.9 billion during the third quarter, producing a seasonally adjusted annual growth rate of 2.4%, compared with a rate of 0.6% in the second quarter of 1986 and 4.1% for the third quarter of 1985 (table 1). Third-quarter real personal consumption expenditures and Government purchases of goods and services rose $42 billion and $7 billion, respectively, but those gains were partially offset by the continuing decline of gross private domestic investment, off $16 billion, and the growing trade deficit, up $11 billion. Three quarters of the growth in consumer spending occurred in the durable goods sector as consumers responded to discounted financing offered by automobile manufacturers attempting to lower inventories of 1986 vehicles, Increased purchases of other durable goods, such as furniture and home furnishings, also contributed to the strength of the durable goods sector. The success of the automobile inventory reduction program as well as weak factory output led to a $20 billion decline in inventory growth. Investment for housing and producers' durable equipment expanded, however, and mitigated some of the impact of slower inventory depending on gross private domestic investment, Capital spending for nonresidential structures declined for the third consecutive quarter. The declining capital spending and the growing trade deficit continued to be significant and interrelated problems for the economy. Real capital spending for new plants and equipment during 1986 is expected to decline 2.5% after rising 8.7% in 1985 and 15.8% in 1984 (table 2). It is likely that capital expenditures bottomed out in the second quarter and that they will expand in the third and fourth quarters. The first-half decline was partially attributed to uncertainty arising from the pending tax- overhaul bill. Furthermore, there is little impetus for corporations to invest in new capacity since factories are operating at less than 80% of capacity (table 3) largely because of the continuing growth of imports. The growth rate of the trade deficit dropped sharply in the third quarter to less than half that of the previous quarter. Low oil prices, declining auto- mobile and steel imports, and increased exports of agricultural goods contributed to this decline. The continued low growth of the economy caused the Federal Reserve System to reduce the discount rate for the fourth time this year (in late August), drop ping it to 5,596, the lowest level in about 9 years. Inflation, as measured by the fixed- weighted GNP price Index, continues to remain low, but rose from the revised second-quarter level of 1.7% to 2.596, mostly because of rising food costs.

Jan 1, 1986

By D. F. Coates

El presente texto describe los procedimientos que deben seguirse en la selección de pernos para sujeción de techos, proyecto de patrones y control de varios aspectos de la reacción del terreno, de acuerdo al Departamento de Minas del Gobierno de Canadá. El objeto del empernado es proporcionar el soporte del techo para el período de tiempo limitado -que es corriente en la construcción antes de que sean colocados los forros permanentes en las labores de extracción y galerías. Consecuentemente, esto no cubre el uso de los pernos en lugares tales como puntos de arrastre en los pozos de las minas y en las instalaciones permanentes.

Sep 1, 1972

By Alfredo Solano R

El presente trabajo señala la geología y estructura del yacimiento minero de Antamina, ubicado en el departamento de Ancash. Para ello, se describe su historia, su geología compuesta por rocas sedimentarias, ígneas, metamórficas; la mineralización, su exploración geofísica, técnicas de exploración y el cálculo de reservas encontradas.

Nov 20, 1978

By Manuel Peña Vásquez

El presente texto señala el método análitico de cálculo como el más rápido en el desarrollo de las triangulaciones. Anteriormente los cálculos de las triangulaciones se realizaban por ecuaciones trigonométricas denominadas fórmulas logarítmicas, dada su facilidad para resolverlas por cálculo logarítmico. Sin embargo, estas fórmulas no son las más adecuadas cuando se usan máquinas calculadoras. Por ello, el método analítico ha probado ser el más útil por la economía de tiempo y la precisión en los resultados, así como su efectividad contra los errores.

Nov 1, 1962

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 Enrique Garay

Actualmente el geólogo de mina toma información rutinaria, mapea los bancos de la mina, los taladros para voladura y loguea los núcleos de perforación y fragmentos del aire reverso. Para la localización en el campo utiliza un GPS que tiene una estación en tierra que permite triangular en tiempo real. En ese sentido, el presente texto señala la importancia de la función del geólogo y las herramientas de campo que utiliza para la exploración y la definición del modelo geológico en la mina Pierina. Así para la digitalización del mapeo geológico utiliza el programa AutoCad, en el caso de mapeo de taladros para voladura emplea un Colector de Datos que posee una hoja de calculo que permite recoger datos del tipo de alteración, porcentaje de arcillas, dureza y tipo de mineralización. Finalmente, la información que genera el geólogo de mina es útil para diferentes usuarios ya que sirve para mejorar el cálculo de reservas, manejar el control eficiente del minado de mineral y desmonte, así como generar el soporte geológico a los geotecnistas responsables del estudio de estabilidad de taludes del tajo abierto, así como desde el punto de vista ambiental es posible definir zonas con potencial de generar drenaje ácido de rocas.

Aug 25, 2002

By Luis Alberto Gonzales Cueva

El presente trabajo describe la aplicación del sistema de gestión de seguridad en el Consorcio Minero Horizonte, el cual cuenta con un certificado de Seguridad y Salud Ocupacional alineado a los requisitos de la norma OHSAS 18001:2007. Este sistema se enfoca en crear una nueva cultura de trabajo mediante el desarrollo y aplicación de herramientas de gestión para la prevención y control de los riesgos tales como: Análisis de Peligro Riesgo Control (PRC), Reporte de Ocurrencias, Verificación de Estándares Operativos (VEO), Pasaporte, Administración en una Página, etc. También CMH ha desarrollado un software denominado sistema @lerta+, el cual es una herramienta tecnológica de la gestión de Seguridad y Salud Ocupacional que proporciona soporte para planificar, coordinar, controlar, registrar y analizar la información relacionada con los peligros y riesgos de la operación minera.

Sep 14, 2009

By C. H. Schack

Extractive metallurgy techniques currently employed to recover silver from primary ores and secondary scrap were reviewed and evaluated to identify and delineate metallurgical problems whose resolution would increase the supply of silver from domestic materials. The survey revealed that practically all primary silver is recovered by froth flotation concentration of various types of ores, followed by smelting and refining of the separate lead, copper, and zinc concentrates. Silver losses during the complex processing are, with rare exception, inconsequential. Furthermore, any silver production gain from base metal ores, which contribute about two-thirds of the total primary silver, is directly dependent no improvement in the market for the base metals. Statistical data on new and old silver scrap are wholly inadequate to make reliable conclusions about scrap processing problems and the possibility of increasing the recovery of silver from the many forms of secondary silver-bearing materials. The available information indicates (1) that efficient silver reclamation practices are employed by the larger users of silver, and (2) that recovery of additional secondary silver involves solution of problems of collection rather than of processing. Several possibilities exist for limited increases in silver production from primary ores by improvement in metallurgical practices. Specifically, research is needed to (1) solve the problem of recovering silver from the copper ores of the Copper Range district, Michigan; and (2) devise economically feasible methods for recovery of silver from presently marginal or submarginal ores char because of grade, location, and frequently complex nature cannot presently be exploited by conventional techniques.

Jan 1, 1965

By D. T. Randall, H. W. Weeks

The burning of coal without smoke is a problem that concerns the Government directly because of the advantages of smokeless combustion both in public buildings and on naval vessels. In addition, smoke abatement is a factor in conserving the fuel resources of the United States. Hence, as part of its general investigation of the best methods of utilizing the coals of this country, the Bureau of Mines, which is in charge of the fuel-testing work formerly carried on by the United States Geological Survey, has made extended tests to determine the conditions necessary for the smokeless combustion of bituminous coal in boiler furnaces. Bulletin 39,a a preliminary report, treats the smoke problem from a theoretical point of view, detailing the steps that are being taken by . municipalities, manufacturers, and citizens to abate smoke, also showing the possibility of a clean city. The present bulletin not only shows that bituminous coals high in volatile matter can be burned without smoke, but also that large plants carrying loads that fluctuate widely, where boilers over banked fires must be put into service quickly and fires forced to the capacity of their units, can be operated without producing smoke that is objectionable. Proper equipment, efficient labor, and intelligent supervision are the necessary factors.

Jan 1, 1912

Chromium, a critical mineral for which the United States is largely dependent on foreign sources, is the subject of a new report just issued by the Interior Department's Bureau of Mines. The report is the first in a new series called "Mineral Commodity Profiles" (MCP's). Designed to give an updated review of important events affecting critical minerals, it also presents a comprehensive description of industry structure, supply-demand relationships, technology, and outlook for the future.

Jan 1, 1977

By Nancy Redhead

El buen funcionamiento de los equipos de una fábrica depende de la energía eléctrica. Si ocurriesen problemas con esta, se resuelven con tecnologías convencionales como la utilización de bancos de condensadores, filtros activos, UPS, estabilizadores de tensión y protectores de sobretensiones. Sin embargo, el riesgo de utilizarlas es que algunas veces son incompletas o no son compatibles. En ese sentido, el presente texto plantea una nueva tecnología utilizada en otros países que corrige los problemas eléctricos de forma completa y segura. Este un sistema automático completo de ahorro de energía y de la calidad de la onda eléctrica que está dotado de un microprocesador y analiza el voltaje, corriente, factor de potencia y armónicos. Asímismo, permite recuperar la energía perdida para luego filtrarla y devolverla a la red -al tiempo que se agrega una carga adicional sin necesidad de incrementar el tamaño de los transformadores o conductores.

Apr 1, 2013

By Sacha Gueronik

El presente trabajo señala la repercusión del CIPEC sobre el precio del cobre en los demás países y en un futuro inmediato, así como describe las relaciones entre la política minera y la política de desarrollo referidos a los países en vías de desarrollo. Para conocer la importancia de dicha institución, es necesario señalar sus funciones y las características básicas entre los cuatro países miembros: Perú, Chile, Congo y Zambia. Posteriormente, se analiza la política de estos países participantes para definir dos objetivos importantes. El primero, señala el aumento de la producción mineral -en tanto haya posibilidad de crecimiento del mercado de cobre- y así crear condiciones favorables para el crecimiento a largo plazo de consumo. Mientras que el segundo, refiere cómo el CIPEC debe afontar el desequilibrio de los países entre las tasas de crecimiento de las exportaciones y de las importaciones a través de cambios rápidos en sus estructuras económicas para facilitar al mismo tiempo la industrialización y el desarrollo de la producción agrícola .

Nov 20, 1969

By Medardo Echegaray R.

El presente texto señala la utilización del complejo acético para la determinación colorimétrica del fierro en la industria. De acuerdo a los estudios realizados anteriormente, se encontró que el método es simple, rápido, económico y exacto en su proceso y aplicación de muestras ambientales. Las condiciones óptimas de trabajo requeridas son que las lecturas deben efectuarse a 465 mu, la zona de máxima exactitud está comprendida a 2 y 30 mg. de Fe, el color correspondiente al complejo sigue la ley de Beer en el rango indicado, la curva de trabajo es reproducible, el color es estable y el pH puede variar de 3. 5 - 4. 4 sin afectar el resultado. Finalmente, no existe interferencia por el manganeso, fluor o níquel, pues el cromo solo interfiere cuando se encuentra en cantidades mayores a su máxima concentración permisible (O. l mg).

Jul 20, 1961

By Walter Estrada, Fernando Valencia, Jaime Luyo

La gasificación por plasma es un proceso térmico a alta temperatura en el que los desechos se descomponen en elementos fundamentales y compuestos simples en un entorno anaeróbico. El sistema presentado en este artículo actúa como un digestor al transformar las moléculas de carbono y otras sustancias en compuestos menos contaminantes. Se utilizó una mezcla de cianuro disuelto en agua como muestra de ensayo —procedente de aguas de una mina—, que se sometió al componente radiante de plasma, y se estudió la energía generada actuando sobre la purificación y transformación de las muestras.

Sep 30, 2019

By Elmer Ccahuana, Filiberto Mamani

La determinación del tajo óptimo involucra varios aspectos como la metalurgia, costos operativos, precios de metales, etc. para dimensionar la geometría del tajo. No obstante, la metodología tradicional no incluye el blending3 como parámetro de optimización del tajo a pesar de que existen muchas minas a tajo abierto, en especial auríferas, que emplean la mezcla de materiales para el procesamiento de los mismos. Pysight4 es un algoritmo que permite determinar el tajo óptimo por aproximación a través de generación de tajos para los escenarios en base a la combinación de las leyes de corte por materiales.

Sep 29, 2023

By James T. McCartney, Joseph D. Davis

For more than 10 years coke-oven technologists have been investigating the expanding properties of coal on a scale larger than that afforded by laboratory test tubes. Koppers 4/ was among the first to realize that coals can not be differentiated satisfactorily with respect to expansion in coke ovens by the simpler test-tube methods; in his first method 80 grains of fine coal were coked in a cylinder heated from the bottom, so that the zone of fusion (plastic layer) advanced from the bottom to the top. The scale of test was too small; it has been modified by other investigators, but without significant improvement in practical application of the results. Somewhat later Koppers and Jendne 5/ experimented with a small-scale coke even, one wall of which was movable, in which the layer-coking in a coke oven could be simulated closely. This oven was heated from both sides. Their results with this oven showed a peak in the time-pressure curves near the end of the coking, period when the two plastic layers, advancing from opposite walls, meet. They also found that although the smaller oven was heated from one side only and did not show the Pressure peak characteristic of two-sided heating, it still gave results entirely too high. Russell built an oven similar to the movable-wall oven of Koppers and Jenkner and compared results obtained in it on Beckley expanding coal with these obtained on the some coal in the Altieri 7/ small-scale apparatus. Both tests were conducted at the same constant pressure, but heating was from two sides in Russell's oven and from one side in the Altieri tester. Russell found that the two types of test gave comparable results under constant pressure conditions even though the heating procedures were quite different. He showed later, however, that a "borderline" coal 8/ that contracted in the Altieri tester at constant pressure developed a peak pressure of 4 pounds per square inch in the movable-wall oven heated from both sides at constant volume. He concluded from this that testing at constant volume gave results more accurately indicative of dangerous expansion tendencies than those at constant pressure. He also found that heating from both sides in this oven gave higher pressure than heating from one side only.

May 1, 1942

By Joel T. Werner

Tire costs represent one of the highest controllable costs in open-pit mining, accounting for approximately 10% of mining costs. Tire monitoring technology has evolved rapidly in recent years and is emerging as a viable tool for extending tire life and reducing costs. The majority of the major tire manufacturers and several independent companies are in various stages of developing monitoring systems that capture and store vital tire data. Previously this information had only been accessible when the vehicle passed a fixed point in the mine, or when mine personnel manually downloaded the data. Integrating this technology with a mine management system enables remote collection and management of trend and alarm data. Mine personnel can now monitor a tire?s health parameters at any time, anywhere on site, regardless of the vehicle?s location. Anomalous tire conditions can be detected early and corrective actions taken. This information can then be integrated with other major onboard systems, operating conditions, and geographical information. Tire monitoring no longer exists as a stand-alone technology, but has evolved into an important integrated tool for mine operators. This paper will review the current status and benefits of integrating this emerging technology with a real-time mine management system.

May 1, 2002

By C. H. Schack

Extractive metallurgy techniques currently employed to recover silver from primary ores and secondary scrap were reviewed and evaluated to identify and delineate metallurgical problems whose resolution would increase the supply of silver from domestic materials. The survey revealed that practically all primary silver is recovered by froth flotation concentration of various types of ores, followed by smelting and refining of the separate lead, copper, and zinc concentrates. Silver losses during the complex processing are, with rare exception, inconsequential. Furthermore, any silver production gain from base metal ores, which contribute about two-thirds of the total primary silver, is directly dependent in improvement in the market for the base metals. Statistical data on new and old silver scrap are wholly inadequate to make reliable conclusions about scrap processing problems and the possibility of increasing the recovery of silver from the many forms of secondary silver- bearing materials. The available information indicates (1) that efficient silver reclamation practices are employed by the larger users of silver, and (2) that recovery of additional secondary silver involves solution of problems of collection rather than of processing. Several possibilities exist for limited increases in silver production from primary ores by improvement in metallurgical practices. Specifically, research is needed to (1) solve the problem of recovering silver from the copper ores of the Copper Range district, Michigan; and (2) devise economically feasible methods for recovery of silver from presently marginal or submarginal ores that because of grade, location, and frequently complex nature cannot presently be exploited by conventional techniques.

Jan 1, 1965

By Alberto Guizado

A la fecha ciertos consumidores de energía eléctrica, entre los que se encuentran las empresas mineras, pagan mensualmente, además del IGV e Impuesto de Promoción Municipal, otras 3 obligaciones, considerados, por no pocos, como subsidios cruzados y en ciertos casos como impuestos, cuyos egresos son directamente proporcional al consumo de la energía eléctrica (a mayor uso del suministro, corresponde aumento en los pagos).

Sep 29, 2023

1. Domestic Production and Use: In 1975.12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 67% of production capacity. Washington, Oregon, and Montana accounted for 37% of the total production; Gulf Coast States 21%, Northern States 29%, and other Southern States 13%. Output of primary metal in 1975 was valued at $3.0 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1975, building accounted for about 21%; transportation 19%; electrical 14%; packaging 18%; and consumer durables, 9%.

Jan 1, 1976