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The scope of this paper is to introduce a mathematical model based on matrix algebra in order to determine similitude quantities, which can be arranged in specific formats to simulate the field conditions and associated behaviour. The formulation of a typical mathematical model applicable to Geomechanics is demonstrated here. The examples provided are intended to facilitate comprehension and application of the proposed model in practice.

Jan 1, 1989

By Andrés Gómez

El estudio considera la fusión de simulación y gestión de flota como una estrategia de innovación para seguir incrementando el rendimiento de los equipos en el proceso de la mejora continua que se aplica en la minería superficial. Como resultados se tiene el incremento de la producción en las minas que se aplicó en prueba, aunque en un principio no fue fácilmente recibido por lo complicado al inicio de la aplicación. En conclusión, esta innovación de fusión de simulación con los sistemas de gestión de flota en la empresa minera permite mejorar la producción y esto representa un incremento significativo de la producción

Sep 29, 2023

La presente investigación refiere los aspectos de salubridad en las minas de Cercapuquio, a partir del ambiente de actividad del trabajador y su desarrollo fisiológico corporal. El yacimiento minero situado en el distrito de Chongos Alto, provincia de Huancayo, departamento de Junín, tiene una altura máxima de 2400 m.s.n.m, que influye en la formación biológica del hombre andino, puesto que tanto la altitud, temperatura y atmósfera son características morfométricas constituyentes de su fisiología. Sin embargo, según un estudio realizado a los hombres de trabajo provenientes de los departamentos de Junín (89%), Huancayo(7%) y Lima, se estableció que aunque hubieron desviaciones fisiológicas (volumen de sangre,capacidad respiratoria, etc,), las posiblidades de vida en la altitud para el hombre aclimatado son las mismas que para el hombre de mar. Sobre el resultado de estas bases, se evaluaron otras características de la patología del trabajador y los trazos posibles de morbilidad, logrando reducir los altos índices de la enfermedad. Las medidas adoptadas por la minera para proteger al personal empleado fueron: Foto-fluorografía de ingreso para el personal nuevo, instrucciones sobre la alimentación, higiene y prevención de enfermedad, llenado de fichas, control integral de partos respecto de las familias ubicadas en el asentamiento minero, difusión sobre profilaxis de enfermedades, vacunación total, esterelización del agua, etc. Respecto de los índices de morbilidad, se consideraron las patologías desarrolladas en el niño y recién nacido del trabajador, tales como las infecciones respiratorias, digestivas, carenciales, las cuales respondieron de forma óptima al uso de los tratamientos moderno-hidrosalinos, dietéticos y anti-infecciosos.

Jul 20, 1957

By Paul T. Allsman, William H. King

This paper describes the mineral deposits and discusses mining and milling methods and related operating conditions in an important gold , silver , lead , and zinc producing area in Ouray , San Juan , and San Miguel Counties , Colo . , embracing 250 square miles . The area is extremely rigged , ranging in altitude from 8,000 to 14,000 feet . White men first penetrated the area in 1860 , when a group known as "Baker's party " reached the Animas River at the present site of Silverton . Difficulty with the Ute Indians and severe winter conditions forced the group to leave and discouraged prospecting until 1870 when a second party reached the area and succeeded in producing 27 tons of ore yielding $ 150 a ton in gold . In 1874 , a treaty with the Indians opened the way for settlement , and mining was established . The total production of recovered gold , silver , copper , lead , and zinc from 1873 to 1947 in the three counties is valued at $347,057,047 . The greatest amount of the total production of metals has come from quartz veins in a series of volcanic flows and tuffs covering the area and comprising a blanket 4,000 to 6,000 feet thick . The igneous rocks were laid down upon an old , erosion surface and are underlain by Paleozoic and Mesozoic sedimentary rocks and pre - Cambrian metamorphic rocks . The entire series has been intruded in late Tertiary time by volcanic dikes and larger intrusive masses . Because of the great differences in relief generally , mining is con-" ducted through long adits to a depth of nearly 3,000 feet below surface in places . Walls of the veins generally stand well , and shrinkage stoping is the most common method of mining . As virtually all of the ore is sulfide below the zone of oxidation , flotation is the common method of milling . Generally , where gold is important , provision is made for its removal by jigs . Bulk concentration of the sulfides is practiced at smaller mills , but the larger operations make a selective lead and zinc concentrate or a lead , zinc , and copper . concentrate . ·

Mar 1, 1950

By Christopher Mark

This proceedings volume contains papers presented at W U.S. Bureau of Mines (USBM) technology transfer seminars on New Technology for Longwall Ground Control. These seminars were conducted in Washington, PA, on April 12, 1994, and Denver, CO, on May 10, 1994. The papers herein describe several new, highly practical USBM technologies now available for ground control in longwall mines, including lie Coal Mice Roof Rating (CMRR), cable bolts, the MULSIM/NL model, and the Wood Crib Performance Model. Other significant topics addressed include longwall panel layout, coal pillar design, horizontal stress in longwall mines, roof support selection for gate entries, and ground control monitoring.

Jan 1, 1994

By Juan Carlos Injante, Miguel A. Montiel

Fundición Ferrosa SAC, es una empresa metalmecánica Peruana con 50 años de experiencia. Nuestro cliente es una de las principales mineras de Cobre y Molibdeno ubicada en la Sierra Central, en el departamento de Junín. Solicitó en un principio el estudio y la factibilidad de aumentar la vida útil de los revestimientos metálicos (“LINERS”) de un equipo crítico del proceso productivo de la planta concentradora. Optimizar el rendimiento de los revestimientos del cajón alimentador (“FEED CHUTE”) del molino SAG de 40 pies, ofrecía la oportunidad de aumentar la periodicidad del tiempo planificado de parar actividades para efectuar mantenimiento preventivo y para hacer los cambios necesarios de repuestos. Originalmente esta periodicidad era de tres meses.

Sep 1, 2017

By A. George Stern

The literature dealing with the drilling of oil wells has become extensive during the last few years, and oil men can find much information relating to drilling muds in the technical literature of the petroleum industry. Although large tonnages of clay are used in preparing drilling mud (also known as drilling fluid), almost no information has been published to apprise the clay industry of the types of minerals used, with their requirements and limitations. It is from this point of view that the present report has been prepared.

Jan 1, 1941

By Joseph Campbell

El presente trabajo señala la innovación de procesos en la explotación minera de Cerro Verde a partir de 1971. El proceso se inició con la aplicación industrial de la técnica de extracción por solventes para la purificación de soluciones de lixiviación desarrollada por la compañía Ranchers en la mina Bluebird (Arizona) y que fue seguida por operaciones a gran escala en Bagdad (Arizona) y Chingola (Zambia). La mina Bluebird, que practicaba la lixiviación de óxidos en botaderos seguida de los procesos de extracción por solventes (SX) y electrodeposición (EW), fue la primera en demostrar que la innovadora operación “mine for leach” era una alternativa económicamente viable. En ese sentido, el desarrollo de Cerro Verde se dio en dos etapas: el primero, comprendía el minado y la lixiviación de los procesos de SX/EW y la segunda etapa, el tratamiento de los sulfuros secundarios de alta ley y primarios. De forma que se mejoró la cinética de la extracción de cobre, el manejo futuro del Pad 4 tanto para mantener y asegurar su estabilidad como para reducir los problemas de permeabilidad e inventarios de cobre que un pad permanente involucra, así como para manejar apropiadamente las variables metalúrgicas que la lixiviación de los sulfuros requiere.

Sep 13, 2001

By E. H. Burroughs, M. J. Gavin

The references in the following compilation are selected chiefly from the literature of the years 1915-1920 , though a few of the more valuable standard works published before that period have necessarily been included . References to many articles have been omitted purposely , because the material covered by them is duplicated in publications included in the bibliography . It is manifestly impossible for the Bureau of Mines either to recommend or adversely criticize the statements of the various writers , particularly as to cost and profit estimates in articles referring to American shales , but it is hoped that the investigator will use caution in considering such statements , as it is well known that much of the literature on this subject has been published for promotion purposes and is therefore over- enthusiastic . Bearing this fact in mind , the reader should be able to judge for himself the reliability or usefulness of these articles .

Sep 1, 1921

By A. C. Fieldner

Much activity is called for in the present period of hightened national effort, and wise direction of such a program must always be conditioned by positive knowledge gained in years of slow and painstaking study and development. Research and technologic investigations on coal by the Bureau of Mines have been described in a series of annual

Jan 1, 1941

By Caithness SJ, Heape JMT

Following the discovery by CRA of gold at Mt Kare, and the subsequent 1988-90 gold rush, mechanised mining of the alluvial resource is now being carried by a company jointly owned by CRA (51%) and landowners of the area (49%). Mining is currently being carried out using small gravity processing plants fed by hydraulic excavators. Use of hydraulic mining techniques will be limited to over- coming difficulties related to the high clay content of the material and the soft nature of the bedrock. Current resource estimates suggest that the alluvials will have a mining life of three to four years. During this time, exploration of the hydrothermal gold mineralisation at Mt Kare will be carried out by a wholly-owned company of CRA. It is hoped that this will lead to establishment of an economic primary gold resource.

Jan 1, 1991

By Pedro Hugo Tumialán de la Cruz

Dado que el Perú es un país propicio para la exploración de yacimientos mineros, es necesario plantear investigaciones geológicas para encontrar la génesis de estas zonas mineras. En este sentido, se realiza investigaciones de tipo isotopos a efectuarse en el futuro y asi determinar el origen de la variedad de los minerales metálicos en dichos áreas. Para ello, se describe las medidas de cada isotopo a partir de un espectómetro de masa aplicado en laboratorios extranjeros, donde se evalúa los diferentes tipos de isotopos como el azufre, carbono, oxígeno, estroncio, plomo e hidrógeno y se evalúan lo efectos y reacciones de los mismos.

Nov 20, 1978

By J. R. Thoenen

In Progress Rerort 1,4/ a number of facto were demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By W. A. Selvig

EQUIREMENTS of montan wax for industrial use in the United States before World War II were met by imports, nearly all of which came from Germany. An important industry for extraction and refinement of this wax from certain brown coals had developed in Germany. At the beginning of the war, montan-wax imports were shut oft, and American industry was forced to rely largely on substitutes. Since the war, relatively small amounts have been imported from Czechoslovakia. Because of the shortage of montan wax at the close of the war and the fact that industry in the United States had to rely on foreign sources in the past, this investigation was started in 1945 to determine probable yields of wax from domestic lignite. Results of the investigation and the properties of extracted waxes are described in this report. Also included in the report are discussions of the occurrence and geology of lignite deposits of the United States from which samples were obtained for wax extraction and the petrographic composition of lignites, particularly in respect to those components that contribute to wax yields.

Jan 1, 1950

By G. Cusma

El proceso SART (Sulfurización, acidificación, recirculación y espesamiento) iniciado en Yanacocha-Gold Mill (2008), es la primera planta de esta naturaleza en el Perú, donde se busca disminuir los contenidos de plata y cobre en la solución cianurada rica en oro, proveniente de la lixiviación en tanques. En ese sentido, el presente texto describe dicho proceso en el que se trata los minerales con alto contenido de cobre y otros metales, los cuales interfieren en la eficiencia de absorción del oro en el carbón activado.

Oct 21, 2015

Prof. A. Ledebur, Freiberg, Saxony :* Mr. Sauveur has presented and enriched with original observations a valuable summary of the theories advanced hitherto concerning the hardening of steel; but in one particular, it seems to me, his statements call for correction. He says:

Jan 1, 1898

By Ernesto Sirvas Bello

El presente texto señala el control geológico en la explotación de minas de oro. Dicha operación se divide en el control de las operaciones subterráneas y las de tajo abierto. Las primeras se relacionan con la explotación de estructuras vetiformes y las segundas con la mineralización diseminada de oro de “baja ley. Así también, se revisa las reservas porque se considera que en este aspecto ya no interviene el control de calidad, la cartografía, muestreo, dilución pérdida de oro por operación y los procesos de reconciliación de resultados. Finalmente, se muestran ejemplos de problemas que afectan el control de calidad y sus posibles soluciones.

Apr 26, 1999

By W. Wittke

SUMMARY: Geotechnical problems often lead to an increase of construction time and costs for large highway and railway projects. Some reasons, which have led to failures and thus to a delay of construction works as well as to increasing costs, are demonstrated by means of case histories, in which the author was involved as expert or planner. Proposals are made how to identify the reasons and to avoid repetitions. ZUSAMMENFASSUNG: Bei Großprojekten der Verkehrsinfrastruktur stehen häufig geotechnische Aufgabenstellungen im Vordergrund. Wegen geotechnischer Probleme kam und kommt es häufig zu Termin- und Kostenüberschreitungen. Anhand einiger Beispiele, bei denen der Autor als Gutachter und Planer beteiligt war, wird gezeigt, welche Ursachen zu Schadensfällen und damit auch zu Termin- und Kostenüberschreitungen geführt haben. Es werden Hinweise und Anregungen gegeben, wie die Ursachen erkannt und Wiederholungen von Schadensfällen vermieden werden können. RÉSUMÉ: À grands projets de l'infrastructure de la circulation, souvent des tâches géotechniques sont au premier plan. Par suite de problèmes géotechniques, souvent des dates et frais ont été dépassés. Au moyen de quelques exemples, à lesquels l'auteur participait comme expert et planificateur, les causes sont mises en vue qui menaient à des cas de dommage et par cela aussi à des dépassements de dates et frais. Des indications et suggestions sont données pour s'apercevoir des causes et éviter des répétitions de cas de dommages.

Jan 1, 2003

By O. K. Olawale, G. O. Edaogbogun, B. N. Ben‑Festus, F. Ben, F. R. Amodu

The environmental and health implications of artisanal gold mining activities at mining sites across Nigeria have rekindled research interest. This study aimed to assess the scalability of naturally occurring radioactive materials in gold mining sites in Iperindo, Nigeria. Soil samples were collected from three different mining sites and control locations and analyzed for natural radionuclides, mainly 238U, 232Th, and 40K, using gamma spectrometry having a sodium iodide detector. The average activity concentration values of 61.55 ± 3.71, 72.65 ± 4.45, and 1134.99 ± 38.12 Bqkg− 1 obtained from within the mining sites for 238U, 232Th, and 40K, respectively, were above the world permissible values of 33.0 Bqkg− 1 for 238U, 45.0 Bqkg− 1 for 232Th, and 420.0 Bqkg− 1 for 40K. The average activity concentration values of 15.26 ± 3.19, 21.46 ± 4.27, 381.04 ± 23.36 Bqkg− 1 estimated for 238U, 232Th, and 40K, respectively, for the control location were, however, lower than the global permissible values. The study also evaluated other radiological parameters such as radium equivalent, dose rate, annual effective dose rate, internal and external hazard indices, and alpha and gamma indices. The obtained values were 252.83 Bqkg− 1, 119.98 nGyh− 1, 147.15 mSvy− 1, 0.85 Bqkg− 1, 0.68 Bqkg− 1, 0.31 Bqkg− 1, and 1.89 Bqkg− 1 respectively. Except for radium equivalent, external and internal hazard risks, and alpha index, which were significantly lower than the recommended threshold, all other radiological parameters were higher than the recommended global limits. Moderate data reproducibility and a p-value of 0.000574 further reinforced the robustness and reliability of the results obtained in this study.

Feb 22, 2024

By M. H. Kline

The Cranberry magnetite deposits occur in pre-Cambrian granite-gneiss, in a belt extending from 3 miles southeast of Cranberry, N. C., to about 6 miles southwest of Magnetic City, Tenn. The belt forms a curve) elongated to the north, approximately 26 miles in length. The Bureau of Mines investigation has been confined to the eastern part of the belt, comprising the area from Fork Mountain, Avery County, N.C., to the Hcupscup Knob prospects in Carter County, Tenn. The deposits were worked at least us early as 1820. The Cranberry Iron & Coal Co. and its successors operated the Cranberry mine intermittently for about 50 years until 1930, when operations were abandoned.

Jan 1, 1948