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By Isaac Minaya, Jhonny Torre, Mario Carpio, Jesús Fuentes

El litio se considera un elemento estratégico debido a sus diversos usos en industrias tales como la electrónica o la automotriz. Por ello, se debe entender cuáles son los ambientes geológicos (pegmatitas, ambientes volcánicos, ambientes metamórficos y cuencas endorreicas en relación a salares y salmueras) asociados donde alberguen los minerales de litio (silicatos, sales y/o salmueras). Para llegar a ello, se deben conocer las características macroscópicas geológicas de campo y fundamentar su interpretación por medio del apoyo de la instrumentación en los tipos de análisis químicos, mineralógicos, las características microscópicas petrográficas y la caracterización puntual de algunas muestras por la microscopía electrónica de barrido (SEM). Por tanto, en esta publicación se presentan datos preliminares de ocurrencias con valores anómalos de litio en afloramientos de rocas volcánicas, intrusivas (graníticas), aplíticas y metamórficas dentro de las unidades morfo estructurales del Altiplano y la Cordillera Oriental, ubicadas en las regiones de Cusco y Puno. En la zona de Corani (Puno) afloran rocas volcánicas tipo tobas de lapilli con altos contenidos de litio entre 2815 a 3070 ppm, cuya presencia se relaciona a los minerales de micas de litio, denominado lepidolita, como constituyentes inmersas en agregados granoblásticos de cloritas y silicatos, perteneciente al miembro Sapanuta de la formación Quenamari. Por su parte, en la zona de Ocongate (Cusco) las ocurrencias con anomalías de litio (1096 ppm) se encuentran asociados en clinocloros y/o amorfos asociados como constituyente dentro de cuerpos de areniscas, con presencia de vetas de cuarzo, sulfatos de cobre, óxidos de hierro, trazas de pirita y calcopirita, pertenecientes a la formación Ananea.

Sep 20, 2019

By A. F. Marques

The Azores islands are located on a triple junction where the American, African (AFR), and Euroasian (EUR) plates meet. The Mid-Atlantic Ridge (MAR), oriented N-S, represents two branches of the T; an E-W branch defines the EUR/AFR boundary called the Terceira Rift. The nature and structure of this plate boundary, as well as the dynamics of the interaction of tectonics and volcanism remain unconstrained. The Azores plateau is seated on a mantle domain of anomalously low seismic S-wave velocities, and gravity and geoid anomalies, where the apparent thick crust is thought to relate to larger degrees of melting initiated at greater depths [1]. The cause of these anomalies is controversial but many authors consider the presence of an anomalously hot/wet enriched mantle probably supplied by a plume [2]. The geochemistry of the subaerial and most submarine lavas from the plateau reinforces the plume model beneath the Azores [3-4]. The origin, size and present location of the plume is under debate but an area near Terceira is the favoured plume centre [5]. [ ] SEAFLOOR HYDROTHERMAL SYSTEMS IN THE AZORES AREA (36ºN ? 40ºN) More than 150 active and fossil hydrothermal systems are known in the oceanic seafloor [6]. Many more are yet to be found on vast oceanic areas that haven?t been explored [7]. Ever increasing knowledge shows that modern seafloor hydrothermal systems can be hosted in felsic to ultramafic rocks, vary in size and shape and exhibit diverse amounts of sediment cover

Jan 1, 2011

By Oscar V. Mauró Obando

El presente texto describe la energía que contienen los explosivos para sensibilizar a los trabajadores que realizan las tareas de perforación y voladura. Las causas que originan los accidentes relacionados a explosivos son actos y condiciones subestándares, relacionados con el almacenamiento, transporte, manipuleo y uso de los explosivos y accesorios. En ese sentido, se busca la prevención de accidente por voladura, identificación de peligros y cómo eliminar correctamente los tiros cortados en la voladura subterránea, desde un análisis de os ingenieros de seguridad y explosivistas.

Apr 1, 2015

By Sergio Quiñones Manga

En los circuitos de molienda de la Concentradora Toquepala fue implementado el Sistema Experto con el objetivo de optimizar la capacidad de molienda. En este sentido, el presente texto describe la operación de este sistema en dicha concentradora, así como sus beneficios en la minería. El Sistema Experto se basa en una plataforma proporcionada por un software, al cual ha sido integrada en forma de modelos matemáticos y lógicas de control, la experiencia operativa de profesionales y técnicos de la Concentradora Toquepala. De forma que las acciones del Sistema Experto están orientadas a maximizar el tonelaje procesado, manteniendo en la pulpa producida para la flotación, así como las condiciones de calidad adecuadas para optimizar las recuperaciones de los elementos valiosos.

Sep 14, 2009

By A Liu, T Ren

Gas explosion in underground coal workings can pose a serious threat to the safety of mine workers and the entire mine operations. Gas explosion is a very complex thermal-chain reaction in a confined underground environment. Based on combustion and explosion theory, three dimensional (3D) computational models were developed to simulate mine gas explosion flame and overpressure wave propagation in a single entry gateroad in underground coalmines. Six different explosion scenarios were modelled and compared with large scale experimental results and AutoReaGas simulations. Model validations show that the use of shear-stress transport (SST) k-? model together with eddy-dissipation model (EDM) produces good agreement with both experimental and AutoReagas simulation results. Modelling results demonstrated that the changes of temperature versus time can be divided into four stages, ie the initial condition stage, and periods of warm-up, active burning, and burnt-out. Assuming a limited volume of methane is involved in the explosion, the maximum temperature decreases as the distance increases from the explosion point, with the highest temperature reaching about 2460 K. Modelling results show that the evolution of the explosion flame shape experiences four typical stages, ie spherical flame, finger-shape flame, flame with the skirt touching the side walls (ribs) and tulip flame, which are similar to the pattern of a duct explosion. The pressure in the gateroad remains the same as the initial value before the arrival of the explosion wave and then increases rapidly to the maximum value. Modelling results from this study will be used for the design of explosion arresting devices and mine seals in underground coalmines.CITATION:Liu, A and Ren, T, 2017. Computational simulation of gas explosion and its propagation in single entry gateroad, in Proceedings Australian Mine Vent Conference 2017, pp 181–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Horst Peter Wölfel

The goal of biodynamic models is to simulate the vibration behaviour of the human body. In combination with experimental studies biodynamical models can be a powerful tool for the analysis of the effects of vibration exposure on health [1] and comfort. This paper gives an overview of the state of the art of biodynamic whole-body vibration models of humans, addressing both numerical models and hardware dummies. Method Two approaches are distinguished, the phenomenological and the anatomical, as illustrated in Figure 1. [ ] Phenomenological models aim to reproduce the vibration behaviour of humans with respect to particular physical quantities, chiefly the driving-point impedance at the interface to the seat, and partly with respect to other transfer functions. Discrete systems of masses, springs, and dampers with several degrees of freedom whose topology and parameters are determined by structure- and parameter identification methods are used in the sense that the functions derived from measurements are reproduced as well as possible. This paper provides an evaluation of this methodology and defines its range of application as well as its limits.

Jan 6, 2006

By P. R. Geoffoy, T. Koulomzine

"The discovery of the Mogador deposit concealed by 100 feet of overburden was the result of combined application of geological reasoning, ground geophysical surveys, studies of glacial float and extensive diamond drilling. The ground was acquired because it lay on the projected intersection of the Manville and Laflamme River faults. Systematic ground prospecting led to discovery of mineralized floats. A first unsuccessful exploration campaign lasted several years and consisted of 137 drill holes.In 1951 the boulder nests were reexamined and an associat'on of the mineralized float with boulders of a granodiorite, unknown in outcrops of the district, was established. Consequently, ground magnetic surveys were extended and re-interpreted, and a large anomaly interpreted as corresponding to a batholith was outlined. The existence of the batholith was immediately confirmed by drilling and the Mogador deposit discovered in third hole of new drilling programme in a zone of fractured volcanics paralleling southern contact of batholith.The Mogador deposit is a complex replacement of silicified volcanics by pyrite, pyrrhotite, sphalerite, chalcopyrite and galena carrying values in silver and gold. A total of 1,230,000 tons has been indicated, most of it now classified as fully developed proven ore."

Jan 1, 1960

Wildcat strikes in the Appalachian coal fields, primarily in West Virginia, have resulted in an estimated 4.5 million ton loss in coal production during July and through the first week in August. Since then, the strike intensified further, and on August 9, nearly all of West Virginia's 60,000 miners were off the job with another 10,000 miners on strike in eastern Kentucky. The Bureau of Mines estimates that West Virginia's coal output is currently (8/9) eight million tons below last year when the state produced 108 million tons. West Virginia, the Nation's second largest coal producer of coal behind Kentucky, has not failed to mine over 100 million tons a year since 1938. At the end of the second week in August, nearly all coal miners in West Virginia remained out. The strike is a protest against a cutback in union health and retirement benefits. An announcement June 23 about the United Mine Worker's health and retirement fund precipitated the strike, Fund directors said that because of inflation and production losses caused by earlier wildcat strikes and the severe winter, miners would have to pay the first $250 of hospital costs and 40 percent of doctor bills, up to $500 a year. Previously, the funds paid all hospital and doctor bills. According to the West Virginia Coal Association each day of the strike in West Virginia results in a loss of coal production of 500,000 tons, a loss of $3.8 million in miners wages and $1 million in contributions to the UMWA's health and retirement fund.

Jan 1, 1977

By L C. Taylor, H U. Lesiste

This paper describes a method for estimating the density distribution in the soil cap as a function of distance from its top at the time of impact with the target. It provides an estimate of the density distribution in the soil on the center line of the soil cap at the time of target impact for a single depth of burial of the charge and two heights of target and shows that, for the heights of target and the depth of burial considered, the thickness of the soil cap first increases from the in situ value and then decreases. The distribution of soil density along the centerline of the soil cap changes significantly with distance from its original position. These results can be used for validating hydro-code computations and the soil models used in the computations.

Jan 1, 2011

Several primary ingot producers have introduced price changes for July. Howmet Aluminum Corp., Revere Copper and Brass, Inc. and the Anaconda Co, will increase late-July prices of 99.5 percent unalloyed aluminum ingot by 3 cents to 56 cents per pound, Prior to this, Kaiser Aluminum and Chemical Corp. had advanced June ingot values by 4 cents to 57 cents and Consolidated Aluminum Corp., 4.5 cents to 57.5 cents. Domestic merchants held June quotes at a range nearing 50-50.8 cents per pound. ANTIMONY Although NL Industries, since April of this year, stopped publishing prices for RMM and Lone Star antimony grade, values of domestically-refined antimony in alloy are being made available to industry, The current price of this material is $1.75 per pound of antimony contained in alloy, New York dealer-marketed metal was available in June at $1 -13-$1 .20 per pound. Important industrial uses of antimony are for flame retardants, storage batteries, chemicals, pigments, rubber, plastics, glass, ceramics and machinery.

Jan 1, 1978

By J. Damay

El agotamiento de los recursos de alta ley, incertidumbre en la exploración y costos altos de inversión son factores que limitan las decisiones de los futuros inversionistas. En este sentido, el texto plantea técnicas de investigación operacional que el ingeniero de minas pueda evaluar y limitar el riesgo de inversión de la compañí. Asimismo, se muestran las técnicas aplicadas en el grupo "Society Le Nikel Peñaroya". Para ello, se utiliza la geoestadística, valor mínimo y de ley límite, estrategia de la explotación minera, método de clasificaciones comparativas y programas de simulación.

Jan 1, 1982

By Alejandro Freyre B.

"El presente texto señala el proceso de explotación de la veta Shiusha situada en el distrito de las minas de Huarón. La veta es de origen hidrotermal, cuyo rumbo aproximado es E-W, y su buzamiento varía de 75º N en el Estea 85º N al Oeste, uniformizándose en los niveles inferiores en 85º :N. El eje mayor probable del depósito ( plano Nº. 1 '), tiene una inclinación de 25 º E. El depósito se extiende sobre una longitud de 1100 m, entrelas coordenadas 4600 - 57 00 E., pero la calidad y cantidad del mineral son variables en las tres dimensiones. Asimismo, se describe la prospección, preparación para corte y relleno, arranque, intermedias de los tres compartimientos y la aplicación de gradines descendentes vacíos."

Aug 20, 1963

Applications of helium in aerostatics, cryogenics, space, and undersea work are described in papers from the Helium Applications Symposium. Specific subjects include investigations of X-ray sources by means of balloon-borne instruments, meteorological soundings by balloons, powered lighter-than-air flight, tethered balloons, refrigeration techniques, large superconductive magnets, electronic devices, superconducting transmission lines, high-precision thermal conductivity analysis, He3-He4 dilution refrigerators, uses of helium in the atomic energy program, helium-cooled nuclear reactors, power- plant applications for high-temperature gas-cooled reactors, helium welding of stainless steel tubing and pipe, development of helium-shielded arc welding, helium as a diluent in spacecraft atmospheres, helium utilization in the Saturn-Apollo program, and helium utilization in diving environments. Papers from the Helium Centennial Symposium at the national meeting of the American Chemical Society cover the history of the discovery of helium, the history of its development by the Bureau of Mines from a laboratory curiosity to an important item of commerce, the source of helium in natural gases, the world of liquid helium, and liquid helium-3.

Jan 1, 1969

By Robert Thurner

The underground car park "Admonterhof in the historical centre of Graz is an example for the technical and economical success of a complicated structural design using a concept on the basis of the observational method. The intention to built a 20 m deep excavation beneath a protected monument was accompanied by some essential issues: the preservation of the existing state avoiding extensive displacements by means of a girder grid of reinforced concrete, its support on large bored piles and small steel-tube piles with possible active compensation of differential settlements, the excavation support in none built-up areas with secant bored piles, the underpinning of existing buildings with different structures by means of jet grouting. Furthermore the hydraulic gradient and the permeability of a rock formation in a part of the excavation had to be explored with the purpose to control the inflow of groundwater with a level difference of more than 10 m.

Jan 1, 2006

By César Jaime Fernández

El presente texto señala la función de la empresa privada en el desarrollo minero del Perú a través de dar a conocer los conceptos fundamentales que esto implica y asi determinar el crecimiento minero que convenga al país. Asimismo se revisa la evolución del hombre en la actividad económica, la empresa y los sistemas económicos, la empresa privada, la evolución en el Perú, la reforma de la empresa privada en el Perú y la responsabilidad social de las empresas en torno a la realidad peruana y el desarrollo de la confianza de parte de la comunidad en la inversión privada futura.

Nov 20, 1978

By Jack E. Brockway

As tunnel boring machine technology has expanded, so has its range of application. Tunneling machines (TBM's) are tackling tasks today that fifteen years ago were considered "inappropriate". A case in point is incline/decline TBM boring. An incline or decline bore presents peculiar design considerations that differentiate it from a horizontal bore. This paper reviews those design considerations as they apply to TBM's, backup, muck handling and other tunneling subsystems. In addition, several abbreviated case studies are presented. By the review of real life tunneling techniques as well as design considerations, the "appropriateness" of TBM incline/ decline boring today becomes apparent. INCLINE Introduction In contemplating the impact of incline versus horizontal tunnel boring system design, the obvious consideration is gravity. Up-hill boring can be quite different than horizontal boring. Muck, water and machine weight all tend to slide down the incline. In addition, hydraulic and lubrication systems if unaltered, will find their fluids pooled in the lower corners contentedly ignoring such higher elevation items as gears and bearings. In order to address this inherent gravity problem, a review of

Jan 1, 1983

By J. H. Zietsman, S. Maharajh, J. Muller

In the chlorination process for TiO2 pigment production, blends of titania feedstocks such as ilmenite, synthetic rutile (SR), natural rutile, upgraded slag, and chloride-grade slag are reacted with coke and chlorine at a temperature of around 1000°C to form TiCl4 (the main product) and other waste metal chlorides. The TiCl4 is the main feed material for the TiO2 pigment-making process. Feeding different titania materials to the chlorinator affects the amount of coke and chlorine required for the process, the amount of waste generated, waste disposal costs, the amount of TiCl4 produced, and bed build-up rates. These factors influence the value of the feedstock. Generally, a higher TiO2 feedstock is more valued since less waste is generated and less reagents are consumed. To quantify the impact of different feedstocks on the chlorinator, a techno-economic model was developed to describe the chlorination process and estimate process variables at steady state. This paper describes the development of the model and studies in which the model has been used to quantify effects of using different feedstocks.

Jan 1, 2015

By Kate Satish

M/s Konkan Railways Corporation are constructing 760 kms long rail road in the Western Coastal Region of India. The rail road encounters 75 tunnels through the Western Ghats of India with a total length of 78.35 kms, the longest tunnel being 6.5 kms long. The tunnels are of horse shoes shape having a cross section of about 37 Sq.meters

Jan 1, 1996

By Víctor Tenorio

Las restricciones sanitarias impuestas por la pandemia del COVID-19 constituyen un referente forzoso para replantear las actividades de explotación, con el fin de no afectar los objetivos de producción. El obligado distanciamiento social exige contar con equipos teleoperados, vehículos autónomos, una nueva infraestructura de transmisión de datos que permita interactuar a los equipos con eficiencia y seguridad, salas de control para la supervisión centralizada y la incorporación de dispositivos compatibles con la internet industrial de las cosas. Todo ello representa, de acuerdo con el autor de este texto, una oportunidad para reactivar las operaciones y nivelar la tasa de producción, instalando un proceso de cambio que va desde la gerencia hasta los operadores.

Jul 30, 2020

By Albert E. Long

THIS GLOSSARY is published lay the Bureau of Mines as a contribution too the mining literature to fill a long-felt need for a compilation of the terms used by the diamond-drilling industry. The first step toward preparation of the glossary was taken in October 1955 when the Diamond Core Drill Manufacturers Association (DCDMA) proposed that the Bureau of Mines undertake the cons compilation and publication of a glossary of the terms used by the diamond-drilling industry. The work was authorized in July 1956, and a preliminary draft of the glossary was completed in may 1958. Copies of the draft were submitted for review to members of the DCDMA and appropriate personnel of the Bureau of Mines. The final draft, incorporating the many helpful suggestions of the reviewers representing both the diamond-drilling industry and the Bureau of Mines, was completed in March 1959.

Jan 1, 1960