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By Walter K. Utt

The process of drilling and bolting the roof is currently one of the most dangerous jobs in underground mining, resulting in about 1,000 accidents with injuries each year in the United States. To increase the safety of underground miners, researchers froth the Spokane Research Laboratory of- the National Institute for Occupational Safety and Health are applying neural network technology to rite classification of mine roof strata in terms of relative strength. In this project, the feasibility of using a monitoring system on a roof drill to assess the integrity of a mine roof and warn a roof drill operator when a weak layer is encountered is being studied. Using measurements taken while a layer is being drilled, one can convert the data to suitably scaled features and classify the strength of the layer with a neural network. The feasibility of using a drill monitoring system to estimate the strength of successive layers of rock was demonstrated in the laboratory.

By Eduardo Aquije

El presente texto describe la investigación cualitativa realizada en el área de influencia directa del proyecto minero Cerro Corona, Cajamarca, donde se analizó la relación entre la intención de los pobladores de la comunidad de apoyar el establecimiento de una operación minera y la percepción del beneficio económico-costo ambiental para la comunidad, el interés económico personal, la percepción de equidad en el proceso de establecimiento del proyecto minero, la confianza en grupos ambientalistas, las instituciones públicas y en la industria minera.

Sep 14, 2009

By Brian M. Harney

The technique of remote sensing, used for many years by earth scientists, is being applied to the detection and monitoring of air pollution. Instrumentation being developed is of a very diverse nature and is effective, Fn varying degrees, at ranges from 1,000 meters to the altitude of a space satellite. This paper describes a number of the recent developments in this new field. Instruments based on spectroscopic, laser, and photographic systems are discussed. Sensors are being developed which utilize correlation spectrometry, interferometry, Raman scattering, Mie scattering, laser line absorption, and simple photographic detection.

Jan 1, 1973

By Víctor R. Cabrera

Para un mayor avance en su producción, las minas de cielo abierto u "open it" de Marcona, utilizan unidades de mayor tamaño en el transporte, puesto que reduce el costo unitario del trabajo. En este aspecto, el objetivo del trabajo describe el uso de máquinas comprendidas para su uso, rendimiento de costo, pala, control de tiempo, tiempo de operaciones y el trabajo con traillas dentro de esta modalidad. etc. Como primer punto, las máquinas cargadoras, las palas mecánicas, etc, incrementan su tamaño constantemente y como tal, las operaciones de transporte cambiaron de uso de ferrocarril a de los camiones con 10,15, 20. 30 y 50 tonelajes por viaje. Posteriormente con el advenimiento de motores diesel, diseño, construcción, perforación y transporte de las máquinas cargadoras, se creó una minería de cielo abierto más económica, flexible y eficiente. En este punto, las operaciones estacionarias, sea con palas o las perforadoras de voladura, utilizaron preferiblemente la energía eléctrica que simplifica la operación y facilita el mantenimiento y las reparaciones. Mientras que las operaciones de perforación, voladura, carguío y acarreo se analiza las características de toneladas rotas por perforación, los cálculos de sobreperforación, los materiales explosivos usados, respectivamente. En cuanto la extracción de palas y volquetes, se evalúa la calidad del disparo, número de voloquetes, capacidad horaria. Finalmente en el trabajo con traillas, se evalúa la influencia del costo de las demoras relativas en las palas y los volquetes, pérdidas de la capacidad potencial de la pala cuando hay insuficiencia de volquetes, asi como las variaciones de la capacidad según la distancia de acarreo.

Jul 20, 1956

By J. E. Johnson

IT is the purpose of the present paper, while not excluding chemical considerations, to deal more extensively with some of the physical and mechanical aspects of the blast-furnace process, and to point out its dependence in these respects on well-known laws. The quantity and cost of ore and flux required to make a ton of iron being determined by circumstances over which the furnace-man, under given conditions as to quality and quantity of product, has commonly little control; the principal item of cost, apart from the saving of labor, which he can aspire to reduce, is that of fuel. To determine the limits of possibility in this direction is clearly the first step in d practical inquiry; and this step is represented herewith in Fig. 1, a diagram showing the total useful effect obtained from a pound of fuel under various conditions, and thus permitting direct comparison, under any given conditions, between actual results and the maximum possible results. The following statements will explain the basis upon which this diagram has been constructed. One pound of fuel, containing 90 per cent. of fixed carbon (which represents average conditions), is taken as the unit. The degree of oxidation of the carbon is measured by the ratio of the two oxides of carbon contained in the top-gases. It is necessary to remember that a considerable quantity of carbon is brought in as carbon dioxide by the flux, and to take account of it and of its condition. It is here considered that the carbon dioxide liberated by the limestone does not affect the analysis of the toll-gases, and that the ratio of CO to CO., will remain unchanged by the addition of limestone; enough CO, being reduced by the solution

Sep 1, 1905

By R. W. Bruhn

The objective of the study is to examine the apparent influence of soil and near surface rock strata on the severity of damage experienced by surface structures subjected to mine subsidence. The report discusses: 1) modes of ground movement that might complicate or be confused with mine subsidence; 2) prevailing concepts concerning mine subsidence in the Northern Appalachian Coal Field and Illinois Basin; 3) apparent influences of soil and near surface rock strata on the character of subsidence-related ground movements; 4) classifications and criteria for characterizing damage due to ground movements; and 5) types of subsidence damage experienced by homes above active mines in western Pennsylvania. Presented is a damage classification system incorporating a severity index for characterizing subsidence damage to homes with basements above active mines. A series of case histories illustrate subsidence damage to structures above active and abandoned mines.

Jan 1, 1983

Researchers, medical organizations, statisticians, and others often use data on the nature and rate of occurrence of occupational diseases in directing their efforts and plans. Very often this information is developed from the reports of the States which describe the nature of work¬men's compensation claims and awards and the frequency with which they are made. To be meaningful, the statis¬tical information must be viewed in the context of the State laws involved. There is considerable variation among the laws of the different States. The Bureau of Mines has responsibilities for protecting the health of persons employed in the mineral industries and for the development of useful mineral products. To assist the Bureau in the accomplishment of its objectives, this compilation has been undertaken. For the benefit of the mineral industries, and any others who may have a similar interest, this volume is made available. An earlier compilation of the Bureau of Mines on this subject was published in 1952.4 However, during the intervening years, sufficient changes have been made in State laws to warrant completely recompiling the information. This publication includes the laws of the States, the District of Columbia, Puerto Rico, and the Virgin Is¬lands through 1964. Only those portions of the workmen's compensation laws which apply to or as ' related to occupational diseases are presented, and in each case enacted additions to and deletions from the basic law have been incorporated into the text of the law, thus snak¬ing it unnecessary to search out the various amendments made each year.

Jan 1, 1967

By Paul M. Tyler

The literature on radium is already voluminous, but mcuh of it is too technical to be intelligible to the average reader, and there is no single publication that covers certain economic features of the radium industry. As a result of the renewed interest in the possibilities of domestic carnotite deposits a number of requests have been made to the Bureau of Mines for information, more particularly with reference to the business aspects of the industry. In order to meet this apparent need, the present paper has been prepared from material available in the files of the bureau. The technical data are compiled from various sources and are believed to be reasonably dependable, but the attempt has been not so much to achieve meticulous scientific accuracy as to brim; together facts of industrial significance and popular interest. GENERAL DESCRIPTION Radium is a brilliant white metal that melts sharply at about 700°C. and volatilizes appreciably at that temperature. With an estimated specific gravity of nearly 6.0, it is more than twice as heavy as aluminum and 25 per cent lighter than irons. Although it has been isolated in its metallic state, it is not used in that form, partly because it tarnishes rapidly even in dry air (forming a nitride), partly because of the greater expense of reducing it to metal, and partly because of the difficulty of dealing with such minute quantities of material. It is used always in the form of its compounds, the most important of which from the vie point of utilization are the bromide, chloride, and sulphate.

Jan 1, 1930

By Gordon T. Austin

The combined value of production of natural abrasives, which include tripoli, special silica stone, garnet, staurolite, and emery, increased in 1993. The increase in the value of tripoli production was the result of an increase in total production. Special silica stone experienced an increase in unit value but decrease in the quantity produced. Garnet showed a 19 % decrease in quantity and an 8 % decrease in value. Staurolite increased about 51 % in the quantity produced and 136 % in value compared with those of 1992. Staurolite's significant increase in value of production resulted from a 56 % increase in the unit value. The fused aluminum oxide industry showed an 8 % decrease in the quantity produced and a 13 % decrease in the value of production. The silicon carbide industry saw an 11 % decrease in the quantity produced and an 8 % decrease in the value of production. Combined, the industries decreased 9 % in quantity and 11 % in value compared with those of 1992.

Jan 1, 1993

This volume constitutes the Survival Subsystem portion of the final report for the Coal Mine Rescue and Survival System (CMR&SS) program, which was conducted by the Westinghouse Electric Corporation under contract to the United States Bureau of Mines (Contract Number H0101262 dated June 17, 1970). The program was directed by the Special Systems Department of the Westinghouse Baltimore, Maryland, facility. The basic objectives of the CMR&SS program were to develop and test hardware to determine the efficacy of a variety of coal mine rescue and survival concepts and techniques. These concepts were drawn from two major sources: the Request for Proposal from the Bureau of Mines1 and the final report on the Mine Rescue and Survival Study conducted by the National Academy of Engineering2 (NAE).

Jan 1, 1971

By J. J. Montoro

The influence of blasting on the excavators’ efficiency, defined as mucking rate (amount of rock mucked per unit time) and mean bucket load (amount of rock loaded in each bucket operation), is investigated. Rock characteristics, blasting parameters (drill pattern, explosive energy, and charging), and the excavator’s performance (truck loading time and number of buckets to fill a truck) were monitored in eleven blasts in an open pit iron ore mine. ANFO, ANFO/emulsion blend, and watergel were used in the blasts and the powder factor was varied between 0.98 and 1.45 kg/m3. The mean bucket load is mainly affected by the bucket size, which is independent of the blasting parameters. Besides the relation with the mean bucket load, the mucking rate was found to be positively correlated with the explosive energy, whereas no significant correlation with the rock properties was found. The analysis of the data, together with other published works, suggests a non-monotonic relation of the mucking rate with the powder factor, with a maximum mucking rate at a certain powder factor. This is especially true when the useful work of the explosive per unit rock volume is used rather than the classical mass powder factor and when only the amount of explosive above grade is considered.

Jan 1, 2007

By Claudia Cooper

La autora desarrolla el importante papel que ha cumplido el sector minero peruano en la forja de un sólido entorno macroeconómico, que da sustento al incremento innegable en el estándar de vida de los peruanos y se constituye en base mínima para generar un mayor progreso. El arribo de grandes capitales mineros al Perú, no solo logró generar estabilidad cambiaria y de consumo en el país, sino también mantener cuentas fiscales sanas.

Dec 31, 2020

By G Mark, K L. Blake, G de Jong, J F. Rotherham, N D. Adshead

Magnetite deposits with distinctive ¦ actinolite ¦ apatite-bearing gangue and spatially-extensive sodic-calcic wall rock alteration occur in both Proterozoic metamorphic terrains and Mesozoic-Tertiary magmatic arcs. Examples from both settings constitute significant sources of iron ore (egKiruna, Sweden; El Romeral, Chile) and some host major Cu-Au deposits that have a local association with K-silicate alteration (eg Cloncurry district, NW Queensland; Copiapo district, Chile). A growing body of evidence points to a hydrothermal origin for these systems involving high temperature, low S oxidised fluids. The Cloncurry magnetite-Cu-Au deposits are products of the local structurally channelised influx of a specialised high salinity ore fluid into larger-scale alteration systems developed during pluton emplacement at greater depths than those associated with subvolcanic (porphyry) Cu-Au deposits. The geological characteristics of deposits in magmatic arcs are consistent with a similar mode of origin albeit in rather different tectonic settings.

Jan 1, 1995

By V. H. Gottschalk

Sponge iron is a product resulting from the reduction of an iron oxide below the temperature at which the product melts. Commercial grades usually contain 80 to 95 percent metallic iron, 2 to 5 percent unreduced iron oxide, and an amount of siliceous gangue material depending on the pur.ity of the are used for reduction. The reducing agent may be gaseous or solid, and a large variety of procedures have been proposed for bringing the reducing agent into reaction with the iron oxide. Of the proposed procedures, the one that has the distinction of having been in continuous commercial operation for the longest time, from 1911 to date, was developed at a ceramic plant in Hoeganaes, Sweden, and yields? a product that has an enviable reputation as furnace feed wherever special, high-quality steels are made.

Jan 1, 1948

By F. Mielli

Ranging between 20% and 40% of the typical mining operational costs, energy in mining operations is a growing concern for the industry. However, this concern is a complex, multi-faceted variable that involves government regulations, societal pressures, cost and competitiveness. A mining company successful in energy efficiency is becoming the standard of a successful company. The suggested energy strategy in mining and mineral processing operations has to follow a well structured approach that entails the following: ? Understanding where energy is being used and why, ? Recommending and implement energy conservation measures, ? Driving visibility to targets and results, ? Leveraging the energy spend across the enterprise, ? Developing a robust energy and sustainability strategy.

Jan 1, 2012

By R. Frank Chiappetta

A new blasting technique has been developed by International Technologies, LLC. to eliminate subgrade drilling, lower ground vibrations, improve fragmentation and reduce explosive consumption. The new technique utilizes a uniquely designed borehole plug, with a bottom hole air deck and a predetermined stemming mass on top of the plug. This combination is referred to as the Power Deck?. Single holes and full scale tests were conducted by Blasting Analysis International, Inc. (BAI) to determine how the system works, the mechanisms behind its success and the best design parameters to use for the given rock conditions. Results have shown reduced or eliminated subgrade drilling, ground vibration reductions of up to 33%, reduced explosive consumption by 16 to 25%, and improved fragmentation by up to 25%. This paper summarizes the methodology, field test setups, analyzes procedures and results for one series of single hole and full-scale tests which were performed in a Pennsylvania, USA quarry.

Jan 1, 2004

By Horacio Destaillat

Desde hace aproximadamente 15 años se encontró por experiencia empírica que se puede “neutralizar” el efecto del plomo sobre la maleabilidad en caliente de cobre proveniente de la refinación térmica de chatarras mediante control de la composición química. Este hallazgo ha resultado de aplicación industrial. Si bien el contenido porcentual de plomo se reduce por refinación convencional y con cierta facilidad hasta 0,02 – 0,03 %, este valor es elevado [1] para laminar en caliente. Bajar el nivel de plomo hasta los valores exigibles por normas, requiere procedimientos especiales y costosos. La técnica cuyo mecanismo aquí se investiga, consiste en ajustar el contenido de plomo y estaño dentro de ciertas proporciones, ya que el balance de estos elementos, permite proceder sin problemas de fisuraciones a la colada y laminación en línea del cobre. Con el control de la composición química del sistema se logra que el plomo y el estaño se adhieran [2] sobre las partículas de eutéctico Cu-Cu2O. Esta disposición micro estructural en borde de grano explica la acción favorable del estaño en la maleabilidad. El procedimiento que aquí se describe no es aplicable a cualquier caso pues no funciona en materiales con contenido elevado de oxígeno (“Tough pitch”) ni en cobres desoxidados. Solamente lo hace en formas de baja sección que hayan sufrido enfriamiento rápido.

Aug 7, 2018

By Jorge Bonilla

"La visión de Milpo por desarrollar sus operaciones más eficientemente y de manera amigable con el ambiente, conllevó al desarrollo de un plan de integración operacional para sus unidades de Pasco. El proceso de integración operacional de las unidades mineras El Porvenir y Atacocha, se constituye en otra iniciativa innovadora aplicada por Milpo y que marca un hito importante en la minería peruana al optimizar el desarrollo de ambas minas con una menor huella ambiental."

Sep 1, 2017

By R. K. Guthrie, H. B. Hill

"INTRODUCTION The Rodessa oil field in Marion and Cass Counties, Tex., Miller County, Ark., and Caddo Parish, La., was discovered in August 1930, when a well drilled to a depth of 5,506 feet in Caddo Parish, close to the surface trace of the Rodessa fault, produced gas in commercial quantities. During the next 5 years 21 gas wells were drilled, and a large reserve of natural gas was developed in the high part of the Rodessa structure underlying the Massive Anhydrite member of the Glen Rose formation.In July 1935 oil was discovered on the flank of the structure when a well drilled to 6,048 feet also in Caddo Parish, was completed as an oil well. The discovery of oil in the Rodessa structure initiated art intensive development program of more than usual interest to geologists, engineers, and operators in the petroleum and natural-gas industry. The complex nature of the different reservoirs, the large volume of ""free"" gas under high pressures and temperatures in the upper part of the reservoirs, and the high gas:oil ratios of some of the wells during the early production of oil presented many problems the solution of which taxed the ingenuity of those responsible for the development and exploitation of the Rodessa field.Early waste of gas and resultant dissipation of reservoir energy led to State intervention, which brought about effective regulation of the quantity of gas blown to the air. Oil production from wells producing more than 2.000 cubic feet of gas per barrel of oil was restricted, and oil allowables generally were based equally upon acreage and upon reservoir pressures. Consequently, oil-production statistics of the field are closely associated with gas:oil ratios and reservoir pressures.The primary object of this report is to present factual and statistical data on well performance in the Rodessa field and to show established trends under certain operating methods and practices in high-pressure gaseous reservoirs, which have been carefully developed and outlined by modern technique and exploited under close engineering supervision.The large size of the Rodessa field, it’s fairly well defined gas caps, and a somewhat definite water table in a part- of the oil- and gas-producing region are of special interest and importance in a study of the fluid and energy relationships in reservoirs. Consequently, the results of much of the authors' work in collecting and compiling date are presented in the form of tables, maps and cross sections to show the relative thicknesses of the different oil-and gas-producing members and their permeability and porosity relationships, and, when possible, the variations in stratigraphy are exhibited in cross sections. Results of a detailed analysis of cores from a number of wells also are presented in tabular and graphic form."

Aug 1, 1943

By Jaime Tumialán

El presente texto describe el diseño y ejecución del sistema con winchas de fricción" Koepe" del pique central de Casapalca, dado que será uno de los más modernos del Perú y su aplicación se realizará en minas con características semejantes. Existen dos sistemas básicos de izaje: el de izaje con wincbas de tambora, donde el cable es enrrollado o desenrrollado en la tambora durante el izaje, y el de izaje con wincbas de fricción ("Koepe"), en el cual el cable pasa sobre la polea o tambora de fricción durante el izaje. Cada sistema tiene sus ventajas y desventajas y solo debe usarse en una correcta aplicación. Las principales ventajas de las winchas de fricción sobre las de tambora son: menor consumo de energía para igual capacidad, menores dimensiones de las partes mecánicas, menor costo de capital y operación, mayor seguridad debido a que se usan varios cables y una mayor capacidad a grandes profundidades.

Jan 1, 1983