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By Esteban Bravo

El presente señala la utilidad del último software y equipos desarrollados como herramientas que permiten analizar, monitorear y reparar los problemas que se presenten en el funcionamiento de motores diesel, además de disminuir los costos para su mantenimiento.

Aug 25, 2002

By Gilbert L. Forst

The objective of this program is to identify and evaluate superior, lightweight substitutes for selected coal mine roof support concepts such as crossbars, posts, and crib blocks. Engineering analysis and concept design identified, through tradeoff studies, that some materials are promising, from a technical standpoint, as support substitutes: E-glass reinforced polyester resin, high strength low alloy steel, aluminum, and very high early strength (VHE) cement. An economic analysis indicates that none of the lightweight substitutes are economically competitive with wood on an initial cost basis; however, in terms of life cycle costs based on current dollars, the high strength low alloy steel appears competitive for crossbars, and the VHE cement and E-glass/resin appear competitive for posts.

Jan 1, 1978

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. A senior advisory staff, consisting of the Chief Staff Officer, Chief Scientist, and Chief Mining Engineer, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaisons with other government agencies, mineral industries, and professional societies. Bureau program activities are classified into two major functions: (1) Developing new and improved technology that will make the production and processing of minerals more efficient, safer and more healthful for mineral workers and the public, and more compatible with a quality environment.

Jan 1, 1979

By Hebert Arias, Christian Mendoza, Mervin Tapia

El Complejo Pasco —ubicado en la Cordillera Oriental de los Andes de la sierra central del Perú, en el distrito de San Francisco de Asís, provincia y departamento de Pasco— está constituido por las unidades subterráneas de Atacocha y Porvenir, la operación a tajo abierto Glory Hole y tres proyectos brownfield ubicados en la periferia de la concesión. Tanto Atacocha como Porvenir son depósitos tipo skarn, con mineralización distal de Zn y Pb(+/-Au) y proximal de Zn+/-Cu, asociados a cuerpos hipoabisales de composición cuarzoandesítica y andesítica. Estudios y exploraciones recientes muestran otros tipos de sistemas mineralizados, como brechas tectónicas con reactivación hidrotermal tardía, un sistema epitermal de sulfuración intermedia en vetas, cuerpos irregulares, entre otros, y un sistema tipo pórfido. La Falla Milpo-Atacocha, de rumbo N-S, juega un rol importante, ya que los intrusivos (Stock Milpo y Santa Bárbara) que generan la mineralización del tipo skarn están controlados por esta falla. Existe otro tipo de mineralización, asociado al sistema NW-SE (Falla 13): un sistema epitermal de sulfuración intermedia. Este trabajo pretende mostrar los últimos avances en las interpretaciones metalogenéticas, producto de un intenso programa de exploración (aproximadamente 80,000 m. DDH / 2018) y de un programa de recategorización de recursos (a través de 60,000 m. DDH), que permitirá hacer posible una operación sostenible de 12 años.

May 22, 2019

By Juan Sánchez

En la actualidad, los problemas que la sílice genera en la operación de planta de extracción por solventes (SX) de cobre están bien abordados. Comúnmente, la sílice (SiO2) en forma de sólidos suspendidos es la que tiene mayor ocurrencia y por lo tanto sus repercusiones mejor tomadas, sin embargo, la ocurrencia de sílice en forma de coloide es un problema que, aun agendado, en muchos casos genera tal variabilidad operacional, acarreando problemas de control de la operación llegando incluso a la detención completa de la operación debido a la emulsión de las fase orgánica y acuosa y los correspondientes costos asociados.

Sep 29, 2023

By Theodore Marvin

FOLLOWING the receipt of questionnaires from many parts of the world, the Aviation Committee is completing a review of the use of aviation in mining and petroleum operations. The summary of this study should be available at the 1937 Annual Meeting in New York City, at which time several papers will be presented on specific application of aerial geologizing. From the reports received, there is little question that this air branch of mining is here to stay. Of course, the transportation of personnel arid material continues to merit attention but it is in the division of aerial geologizing that flying is finding its widest, most technical application.

Jan 1, 1937

By J L. Mauk

The Sovereign, Jubilee, Scotia and Jasper Creek prospects occur in an area of ~3.0 km by 2.5 km (~7.5 km2) in the Hauraki goldfield. The prospects are hosted by andesitic to dacitic flows, autoclastic breccias and localised pyroclastic and air fall deposits. Jubilee and Sovereign prospects lie along the northern and southern parts of the Waitekauri Fault, respectively, whereas Scotia is located ~1 km to the E, and Jasper Creek a further ~1.2 km to the ENE. Wall rocks are typically intensely altered, although the degree of alteration becomes more variable east of Scotia and at Jasper Creek. Alteration minerals include quartz, adularia, albite, chlorite, pyrite, illite, interstratified illite-smectite, smectite and calcite. Several of these minerals have distributions that show distinct zonation with adularia most abundant at Sovereign and Jasper Creek, but restricted to shallow levels at Scotia. Illite occurs throughout Sovereign and Jubilee plus the western margin of Scotia where it grades into interstratified illite-smectite; smectite predominates at Jasper Creek. Veins are uncommon and typically narrow, but show distinct zonations. Quartz veins are more abundant at Sovereign and Jubilee, whereas calcite veins are more abundant at Scotia and Jasper Creek. Laumontite veins occur at Scotia, and rare clinoptilolite, mordenite and stilbite veinlets with calcite occur at Jasper Creek. Fluid inclusion in quartz and calcite homogenised between 141¦ to 272¦C and trapped a dilute solution with an apparent salinity of less than 2.6 weight percent NaCl equivalent. Homogenisation temperatures are hottest at Sovereign (average 241¦C) and Jubilee (average 239¦C), cooler at Scotia (average 204¦C) and coolest at Jasper Creek (average 162¦C). Calculated paleowater table elevations suggest the water table was 680 m to 750 m above sea level at Sovereign and Jubilee, 450 m at Scotia and 225 m at Jasper Creek. The current data suggest three scenarios that can explain why Sovereign and Jubilee are deep and hot, whereas Jasper Creek is cool, shallow and marginal; 1.   some or all of the prospects may represent separate overlapping hydrothermal system, 2.   a high-relief hydrothermal system on the side of volcano with an inclined water table and outflow towards Jasper Creek, and 3.   a low-relief hydrothermal system that has been either tilted or block faulted with greatest uplift and erosion to the west.

Jan 1, 2005

By J. C. Barcellos

El presente estudio describe el método de empleo para la determinación del espaciamiento óptimo de muestreo en la Mina Casapalca. La técnica comprende cuatro pasos: recolección y preparación de datos, procesamiento electrónico de datos, análisis de los resultados y la verificación de las conclusiones. Dentro de las conclusiones, se considera que los métodos estadísticos son los más útiles en la solución de los problemas de la industria minera , puesto que cualquier dato numérico pueden ser convertido a un número más simple a través de la computadora.

Nov 20, 1972

By M. Batzle

The upper Arkansas basin has some of the greatest potential for geothermal development in Colorado. Over several summers, students conducted an investigation using seismic, gravity, and magnetics in order to help identify the large structures and basin fill associated with the Rio Grande Rift. Adjacent to Mount Princeton Hot Springs, near surface geophysics was conducted to help understand the faulting and fractures that act as a conduit for hydrothermal flow. The methods used included high frequency 3D seismic, magnetics, gravity, D.C. resistivity, and self potential. Throughout the Mount Princeton area, passive seismic, vertical seismic profiling, and well logging were also used to better understand the geology and activity of the region. The results indicate for the area northwest of the hot springs, a 40 to 50 m thick unconsolidated layer overlying the fractured granitic basement. The DC profile shows a deep geothermal anomaly of low resistivity which correlates with a positive SP anomaly in the same region. In the Chalk Creek valley, a shear zone extends from the north east to the south west, just south of the Chalk Cliffs. There appears to be an upward migration of the water through this shear zone which then flows along the porous sediments towards the south in this area. The deep seismic data collected in the center of the basin suggests that the depth to the basement is approximately 2000m. Also identified on the deep seismic are two major faults on the west end and two minors at the east end of the cross-section. An alteration zone is identified between the faults and a possible Precambrian northeast trending shear zone. The potential for developing an Enhanced Geothermal System (EGS) near the center of the valley is high. Our geophysical results indicate a deep basin fill near the center of the basin providing high temperatures. The range front (Sawatch) fault is observed to penetrate under the center of the basin and is an attractive target for natural fractures.

Jan 1, 2011

By Rogerio Martelli

Os mancais de rolamento dos rolos secadores da linha de estanhamento eletrolítico da CSN são expostos a severa contaminação por água e ácido sulfúrico. O tempo médio entre falhas (MTBF) de cada rolamento da linha é de apenas 30 dias. A CSN aceitou realização de teste com um par de rolamentos autocompensadores de rolos vedados que foram montados em um rolo, com a supervisão da SKF. Os rolamentos do teste operaram por mais de 150 dias, apresentando sobrevida superior a 400% até o momento, sendo que ainda continuam em operação. Há cerca de 60 rolamentos operando simultaneamente na linha, sendo que a solução poderá ser replicada para os demais pontos, aumentando a vida em serviço dos rolamentos e reduzindo custos de manutenção.

Oct 30, 2017

By Gustavo De la Torre

El presente texto describe una serie de herramientas que optimizan los procesos unitarios en la concentradora de Cerro Lindo de compañía minera Milpo S.A.A., cuya base fundamental es el ciclo de mejora continua y productividad en general. Como primer recurso está la Geometalurgia -en tanto identifica los niveles de producción (que dependen de la dureza y moliendabilidad), la recuperación (función de la liberación de las especies mineralógicas) y la calidad del concentrado. Mientras que el segundo recurso estriba en la construcción de un diseño secundario, con el objetivo de liberar eficientemente todos los elementos de valor económico como son el cobre, plomo y zinc, Asimismo, la identificación óptima del tamaño de los valores metálicos flotables y su pronta extracción permiten optimizar la performance metalúrgica, la cual repercute en lograr mejores calidades de los productos por efectos de menor presencia de contaminantes sobremolidos y pérdidas de valore metálicos como lamas.

Oct 21, 2015

By Faruk Oksuz, Cary Hirner, William A. Rochford

Grouting is a frequently utilized remedy in the planning and implementation of ground improvement and tunnel rehabilitation practice. The state-of-art grouting application used for Chicago’s McCook Reservoir project offers a unique alternative to the tunneling industry for pre-excavation grouting as well as tunnel rehabilitation, rescue and post-excavation ground improvements. The McCook Reservoir project included a computerized grouting control and data collection system for a precise and highly effective groundwater cutoff in fractured dolomites. By using balanced and stabilized grout mixes, the effective permeability of the rock mass was reduced over two orders of magnitude to less than 0.1 Lugeon by installing a double line grout curtain. The stable grout mix designs allowed high pressure and effective grouting at depths up to 125 m (410 ft).

Jan 1, 2005

By Jorge Spangenberg, Lisard Torró, Patrick Quispe, al et, Johan Ramírez

Presentamos nuevos datos de isótopos estables de carbono y oxígeno que ayudan a delimitar el origen y la evolución de los fluidos del estadio C en el depósito de Zn-Pb-Ag-In-Sn-Cu de tipo cordillerano de Ayawilca. Los datos isotópicos de rodocrosita hidrotermal indican que los fluidos mineralizantes presentaron valores promedio de 13C y 18O de -13 ‰ (VPDB) y 19 ‰ (VSMOW), respectivamente.

May 10, 2023

By Richard E. Thill

The Bureau of Mines' Oil Shale Data Bank (OSDB) was created in 1976 to serve as a centralized source for the storage, retrieval, and dissemination of technical literature, patents, and information on research projects in oil shale. Thousands of bibliographic references, patents, and research projects relating to the mining of oil shale have been identified, abstracted, and indexed according to selected keyword topics. The resulting data bank listings are contained in three sections, each with a separate keyword breakdown for use in rapidly identifying references pertaining to a specific subject. All references cited in the OSDB were published prior to an established cut-off date of May 1, 1981, when a redirection of Bureau of Mines programs resulted in the loss of project funds and the subsequent phasing-out of data bank operations. ACKNOWLEDGMENTS The oil shale data bank listings are the result of a team effort of the project staff. The contributions of Jimaleen Jansma for keypunching, information acquisition, and data entry, and John Brandenburg and Sandra rake for keywording and information acquisition are gratefully acknowledged. Appreciation is expressed to the staff members of the Smithsonian Science Information Exchange, Washington D.C. for their cooperation in supplying data on recent research projects in oil shale for inclusion in the OSDR listings. Appreciation is extended also to the staff of the Gallegos Research Group for assisting with computer services to obtain the final printouts and transfer of files onto magnetic tape.

Jan 1, 1982

By Fabiano Mendes

Processos industriais de carbonização são tecnologias maduras e operam há mais de 7 décadas. Contudo, o sistema integrado de produção de ferro primário e aços a base de biomassa como fonte de energia e termorredutor, mesmo sendo a alternativa ambiental de menor impacto existente, chega a seus limites tecnológicos, ambiental e econômico, ameaçando a sua sustentabilidade. O grupo Vallourec buscou o processo Lambiotte como base tecnológica para desenvolver seu ambicioso projeto de carbonização contínua, em substituição ao processo artesanal de fornos retangulares de batelada, utilizados atualmente. O esforço experimental de mais de meia década, com a adaptação e profunda reengenharia do processo Lambiotte, que é o que melhor representa esta classe de reatores, para que ele atendesse as condições brasileiras e o uso das espécies de madeira da família dos Eucaliptos culminou no desenvolvimento do processo de carbonização continua Carboval, que demonstrou sua plena capacidade, para atender aspectos econômicos, sustentáveis e de qualidade siderúrgica do carvão vegetal produzido.

Aug 17, 2017

By Maike Von Heymann, Sergio González, Gaelle Dupuis, Ignacio Ishizawa, Claudia Toledo

Anglo American es una compañía minera global líder que cuenta con productos componentes esenciales en casi todos los aspectos de la vida moderna. Nuestro portafolio de operaciones competitivas de primera clase, con una amplia gama de futuras opciones de desarrollo, proporciona muchos de los metales y minerales esenciales para un mundo más limpio, ecológico y sostenible, y que cumpla con las demandas diarias de los consumidores. Como parte de la implementación de nuestro plan de minería sostenible impulsamos la implementación de las plataformas de desarrollo colaborativo, que en el caso de Moquegua se denomina Moquegua Crece.

Sep 29, 2023

By J. Solano

El sostenimiento con pernos de roca requiere de estudios que determinen cuáles son los factores que influyen en el proceso de acción recíproca entre la roca y sus elementos. En ese sentido, el objetivo del presente trabajo es mostrar los resultados de las investigaciones realizadas, basadas en el principio de deformación y compresión sobre la roca en el mismo campo de trabajo. Para ello, es necesario considerar que el desconocimiento de las propiedades físico-mecánicos de la masa rocosa y de instrumentos de investigación, limita el estudio a la determinación del anclaje y la pérdida de tensión de los pernos.

Nov 20, 1972

By R. Luchese de Moraes, J. A. Matthews, C. Feliciano Bruzual

The role of biomass char in blast furnaces has been re-examined by scientists worldwide, as a feasible option to reduce the carbon intensity of ironmaking. This contribution makes a technical and economic analysis of the ferro gusa industry in Brazil, with the last 172 charcoal-Blast Furnaces operating in the world. A key strategic question is presented: what is the current status and future prospects of biomass use in Blast Furnaces? Findings provide significant implications to metallurgists: while ferro gusa from charcoal is regarded as carbon neutral iron with low impurities, there are limiting factors that hinder the further proliferation of charcoal-BFs: biomass generation requires vast extensions of arable land and aggregates have low production capacity. Additionally, most of the charcoal is presently generated in beehive kilns with low yields. These elements combined make charcoal-hot metal expensive in price. With respect to the future prospects of biomass, the injection of small biochar particles through the PCI rigs in BFs (here coined Bio-PCI) and iron ore sintering may offer a practical alternative to significantly reduce the CO2 emissions in the ironmaking process.

Jan 1, 2015

By Paul W. Cleary

Keywords: Reactive pellets, CFD, Lagrangian SPH, Pyrometallurgy In several pyrometallurgical processes, reactive pellets are added to a melt. Heat is transferred to the pellets and reaction products such as gases, metal and slag are formed. For many pyrometallurgical processes traditional grid based CFD methods, such as using the Finite Element Method (FEM) and Finite Volume (or Control Volume methods), produce suitable predictions. However, the inclusion of solids in the bath represents significant challenges for these methods. Smoothed Particle Hydrodynamics (SPH), a Lagrangian simulation method, is able to simulate both the fluid component of the bath and any immersed solid materials, tracking the motion of these solids, and their interaction with the fluid, including gas generation. In this paper, we will summarize the key aspects of the SPH method and will show a series of structured examples illustrating the behavior of the different physics sub-systems that are used in the model of the overall system.

Jan 1, 2005

By Arturo Del Olmo, José Romero, Einari Ojala

La innovación que suponen ciertas tecnologías en el manejo de los relaves puede verse como mejora en muchos casos. Sin embargo, para que sea efectiva la inversión y se justifiquen los costes de operación, la innovación no solo se debe aplicar al proceso en sí mismo, sino a la manera en que este se interrelaciona con otros aspectos intrínsecos a la operación de deposición en la huella existente y al manejo de los residuos, es decir, la estrategia de vertido y transición entre tecnologías, así como la gestión del agua en ellos contenidos, una gestión orientada a su reutilización en el proceso.

Sep 29, 2023