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By Charles Will Wright

The purpose of this paper is to present briefly certain preliminary results of the study of mining methods by the United States Bureau of Mines; to show the relative importance of each method in terms of tonnages mined and man-hours consumed; to give to the mining engineers and particularly to the young student of mining a better understanding of the principal mining methods; and to indicate changes now in progress and to present suggestions for improvements in the art of mining. Questions of mine development and details of underground practice such as drilling and blasting, loading, hauling, hoisting, ventilating, pay systems and mine management are omitted, as these have been or will be discussed in other bureau publications.

Jan 1, 1931

By José Luis Calderón Jiménez

"Dadas las limitaciones económicas de los gobiernos locales y poco apoyo del Estado, la mina Poderosa recibe presión de la población para cubrir el déficit de servicios que requiere el distrito de Pataz y mejorar la calidad de vida de sus pobladores influencia. En ese sentido, la mina desarrolló un modelo de organización que busca fortalecer las capacidades de gestión y presencia del Estadoa través del proyecto que implica el fortalecimiento de los CODECOS mediante reconocimiento municipal e inscripción en registros públicos y la capacitación a los líderes y autoridades en talleres, pasantías y encuentros con expertos. Así, se mejora la relación con la comunidad de forma sostenible y armoniosa."

Sep 1, 2016

By Cristhian Guillén, Ned Vásquez

El presente trabajo técnico describe y analiza el proyecto para la implementación de la tecnología de explosivos denominada emulsión bombeable aplicado en el carguío mecanizado de tajos de producción SLS con perforaciones ascendentes y descendentes realizado en mina Cerro Lindo. Este proyecto tiene la finalidad de mejorar los KPIs (Key Performance Indicator) que actualmente maneja la operación. Por ello, el área técnica del sitio ha elaborado un protocolo de implementación, para efectuar la introducción y validación de la propuesta de valor de esta nueva tecnología.

Sep 29, 2023

By Edgar Carlos García Flores

El presente texto señala al Perú como modelo de sistemas de explotación minera para Bolivia -en tanto desarrolle, prepare y explote las minas con calidad y así incrementar la producción de sus operaciones mineras. Asimismo, describe los procedimientos idóneos para seleccionar las tablas geomecánicas, la ingeniería de explosivos, equipos de acarreo y los elementos de sostenimiento adecuados para las excavaciones subterráneas con el objetivo de tener operaciones de calidad, seguras y óptimas.

Feb 1, 2015

El presente trabajo describe el sistema y los métodos para la extracción del oro en la planta de beneficio de Andaray Gold Mines, alcanzando una productividad óptima en el campo metalúrgico. La mina está situada en San Juan de Chorunga, provincia de Condesuyos, departamento de Arequipa, donde sus yacimientos mineralizados son de dos tipos: los yacimientos descompuestos que contienen limonita y oro libre, perteneciente a la mina Mercedes , y los de mineral piritoso aurífero, que comprenden chalcopirita y ojos de galena, perteneciente a la mina San Juan. El proceso de explotación se inicia con el transporte del mineral hasta su descarga en la parrilla de apertura. E mineral que no pase por la parrilla, se deriva a la chancadora durante 10 horas. Posteriormente pasa por la molienda para luego ser clasificado. Allí se adicionan los reactivos para la flotación y su análisis de malla. Producto de la flotación se obtiene el concentrado. El filtrado de los concentrados conlleva su envío a la molienda secundaria durante un período de seis horas. En este estado, la partícula de oro se encuentra limpia y en óptimas condiciones para la amalgamación y cianuración, donde el mercurio y la amalgama son exprimidos en una lona, destilándose, y se procede a la solución del oro, respectivamente. El método seguido es la agitación neumática, que suelta aire comprimido para la elevación del concentrado por el tubo elevador. Prosiguen los efectos de decantación, operación, control del cianuro y del alcali libre, precipitación, clarificación, limpieza y función de los precipitados. En el laboratorio se realiza el control de muestras del circuito de flotación, cianuración y de las barras, utilizando los métodos de soluciones de cianuro, ensayo de concentrados, minerales de mina, cabeza y relaves y ensayos de los precipitados. Finalmente, los cuadros de consumo de reactivos, mostrarán la eficacia del sistema y los resultados económicos de la planta de beneficio, como los costos, eficiencia de plata y mano de obra.

Jul 20, 1957

By Harold J. Bennett

This study was performed by the Bureau of Mines to evaluate the potential supply of primary copper from domestic resources. A tonnage-price relationship was developed indicating the quantity of copper that could be produced economically from known deposits at various copper prices and at various rates of return on the required capital investment. Costs of production are based on estimated capital and operating costs for mining, concentrating, smelting, and refining the copper. Total known recoverable copper resources are 189 million short tons of which 83 million tons could be economically recovered assuming a price of $0.50 per pound of copper, credit for the recovery of byproducts, and a 12-percent rate of return on capital investment. The quantities of recoverable byproducts associated with the 83 million tons of recoverable copper are molybdenum, 1.8 million tons, gold, 43 million troy ounces, and silver, 740 million troy ounces.

Jan 1, 1973

By G. H. Wigton

This paper, describing the concentrator practice of the Chief Consolidated Co., is one of a series being prepared by the United States Bureau of Mines. The concentrator adjoins the town of Eureka, Utah, in the Tintic mining district. The Chief Consolidated, Eureka Lilly, Plutus, and Grand Central mines, all of which are owned or controlled by the Chief Consolidated Mining Co., are the principal sources of milling ore. The ore is transported from mines to mill by railroad. Although all the mines are within 3 miles of the mill, the railroad distance varies from 1 mile to 12 miles.

Jan 1, 1930

By Jorge A. Rivas López

El presente estudio señala la organización de la sección del carbón, sistema de operación y la experiencia adquirida en algunas campañas realizadas. El proceso de prospección sigue una línea de afloramiento usando guías litológicas y estructurales. Sin embargo, no hay un método general de prospección ya que depende de factores versátiles y de la topografía propia de cada región. De otro lado, la necesidad de localizar yacimientos de carbón en terrenos cubiertos por terrenos agrícolas, dio origen a la creación de campañas de prospección como el "Goal Prospecting Section" que fue creada en la División de Carbón de la Corporación. El tipo de organización de la Sección, es de Línea y Plana Mayor. Para ell sistema de operaciones se realiza perfiles en lugares donde los afloramientos de carbón y las rocas son nítidos. Dichos perfiles permitirán localizar los puntos de afloramiento en otros sitios por correlación, obteniendo conclusiones geológicas

Jul 20, 1960

By Elipio Pérez Coronado

El presente trabajo describe la aplicación del método de corte y relleno descendente mecanizado y el método de almacenamiento provisional en la mina Santa Bárbara, ubicada en Cerro de Pasco. Para el primer método, son mayores e intedependientes las operaciones unitarias, limitando la producción y generando mayores costos en el relleno chancado. Mientras que el segundo método, es aplicable en los cuerpos "Vasconia" y "Manuel", siempre que cumpla con tres condiciones principales que hacen posible su efectividad en la mina: la primera, señala que la explotación se realice en los pisos superiores y luego, en los inferiores; la segunda, refiere que la explotación son mayores las se haga en retirada y la tercera indica que el espacio no debe ser rellenado. En este sentido, el método de almacenamiento provisional resulta ser el más idóneo para la explotación de cuerpos irregulares en la mina Santa Bárbara puesto que su capacidad al término del acarreo de mineral es ilimitada.

Nov 8, 1984

By Gregory B. Beacher

Analyses have been performed on geotechnical properties of copper, uranium and phosphate (gypsum) tailings materials, with the intent of identifying typical measures of variability within and among sites, and of characterizing such variability for use in reliability modeling of tailings embankments. In all, data from approximately 41 sites were analysed. Fairly consistent results were obtained for within site variabilities. However no one probabilistic model was found to be applicable to all sites. The distributional forms for most of the data sets are regular, and tend toward Normality when spatial trends are removed. At many of the sites sufficient in situ data were available to allow estimates of vertical autocorrelation distances and measurement noise. Available data indicate that variability in pore pressures may have a more important effect than strength property variation. A major problem in interpreting available strength property data results from the unknown drainage conditions during testing.

Jan 1, 1983

By Arthur B. Cummins

It is appropriate to discuss diatomite at an AIME meeting in San Francisco. California has led the nation, and the world, in the production of diatomite products for more than 40 years. It appears that our State will maintain this position for a long time to come. Diatomite today ranks high in the list of California mineral commodities, with a total value since 1889 well in excess of $100 million. California's production has more than doubled since 1942. In 1959, the value of diatomite production in California is exceeded only by the following industrial mineral materials-borates, stone, sand and gravel and cement20,28. Also, not unimportant is the production of diatomite in each of our other Pacific Coast States, including Nevada. First, let us define diatomite. It is a sedimentary siliceous rock of organic origin, which consists mainly of the fossilized remains of diatoms. Diatoms are microscopic aquatic plants which have the capacity of precipitating silica bio-chemically so as to form a part of their organized structure. In the economic sense, we are not concerned with the numerous types of sedimentary materials which contain minor amounts of diatom residues, or with impure or highly indurated siliceous materials, which may have been formed from diatomite2. Diatomite (synonyms--diatomaceous earth, kieselgurO is a term generally restricted to material of such qualities as to be suitable for commercial uses. Diatomaceous silica is a designation which is best used to distinguish the basic component of diatomite, that is, the substance of the silica shell itself, and which is the major' constituent of beneficiated diatomite or processed diatomaceous products.

Jan 1, 1959

By Frank H. Buchella

Principal factors influencing equipment selection can be grouped into five basic categories. Tonnage Requirements, Ore and Waste Loading, transporting, and ground preparation equipment are largely determined by tonnage requirements. Generally, the greater the tonnage requirements, the larger the equipment size selected. Large size equipment is appropriate for a production of about six million tons (total) per month, medium size for three mil- lion tons, and small size for one million tons or less.

Jan 1, 1973

By V. Rajaram

Rock reinforcement systems are used in open pit and underground mines to stabilize the rock mass in-situ and provide safe working conditions. Significant progress has been made to date in the design and implementation of rock reinforcement systems to accommodate bad rock conditions and larger excavations. However, the rationale for the design of rock reinforcement systems remains essentially the same and can be categorized into three groups, namely 1. to create a beam of competent rock in stratified formations, 2. to resist sliding motion in jointed rock, 3. to passively support the superincumbent loads in highly stressed ground. Case histories of the rock reinforcement sys¬tems that illustrate these design approaches will be presented in this paper.

Jan 1, 1983

By Jessica M. Wempen, Michael K. McCarter

"Differential Interferometric Synthetic Aperture Radar (DlnSAR), a satellite-based remote sensing technique, has potential application for measuring mine subsidence on a regional scale with high spatial and temporal resolutions. However, the characteristics of Synthetic Aperture Radar (SAR) data and the effectiveness of DlnSAR for subsidence monitoring depend on the radar band (wavelength). This study evaluates the effectiveness of DinSAR for monitoring subsidence due to longwall mining in central Utah using L-band (24 cm wavelength) SAR data from the Advanced Land Observing Satellite (ALOS) and X-band (3 cm wavelength) SAR data from the TerraSAR-X mission.In the Wasatch Plateau region of central Utah, which is characterized by steep terrain and variable ground cover conditions, areas affected by longwall mine subsidence are identifiable using both L-band and X-band DlnSAR. Generally, using L-band data, subsidence magnitudes are measurable. Compared to X-band, L-band data are less affected by signal saturation due to large deformation gradients and by temporal decorrelation due to changes in the surface conditions over time. The L-band data tend to be stable over relatively long periods (months). Short wavelength X-band data are strongly affected by signal saturation and temporal decorrelation, but regions of subsidence are typically identifiable over short periods (days). Additionally, though subsidence magnitudes are difficult to precisely measure in the central Utah region using X-band data, they can often be reasonably estimated.INTRODUCTIONDifferential Interferometric Synthetic Aperture Radar (DlnSAR) is a satellite-based remote technique that can be used to measure surface displacement over large regions with high spatial resolution. Under good conditions, displacements can be measured with centimeter to subcentimeter accuracy (Buckley, 2000; Massonnet and Feig!, 1998). DlnSAR also has high temporal resolution, and imaging periods typically range from 10 to 50 days (Rosenqvist, Shimada, and Watanabe, 2004; Roth, 2004). In the last two decades, the application of DlnSAR for mine subsidence monitoring has been demonstrated in coal basins in Europe, Australia, China, and the United States (Camec and Delacourt, 2000; Ge, Chang, and Rizos, 2007; Ge et al., 2008; Ismaya and Donovan, 2012; Ng et al., 2010; Perski, 2000; Perski and Jura, 2003; Popiolek and Krawczyk, 2006; Wegmuller et al., 2005; Wright and Stow, 1999; Zhao et al., 2014; Xinglin et al., 2014). Overall, these studies have demonstrated good data resolution, strong relationships between mine development and subsidence, and reasonable agreement between displacements measured by DinSAR and displacements measured by conventional surveys."

Jan 1, 2016

By Charles D. Haynes

Outside air for ventilating coal mines in Alabama varies considerably in both temperature and moisture content during the year. Alternate condensation and evaporation of the moisture on mine roofs may result in stresses detrimental to the strength of mine roof. It is well known that the clays in shales absorb moisture, and many investigations have noted the weakening of shales by absorption of moisture. Parker (1970) concluded that there is an annual cycle of rock deterioration in mine roof rock caused by the annual temperature-humidity cycle at the surface. He further noted that moisture reduces the strength of dry rock by one-half, that moisture added to dry rock can cause failure in compression, and that drying of wet rock causes tensile stress buildups by shrinkage. His recommendations for alleviating the moisture-temperature problem was to seal the rock in critical areas and to control ventilation so that air temperature will be lower than rock temperature. The latter recommendation will avoid condensation on the rock surfaces. Hartmann and Greenwald (1941) published the results of a very comprehensive experimental project to determine the effect of temperature and humidity changes on the behavior of mine roof. Their general conclusions included statements that roof rocks were very sensitive to moisture changes, but had low coefficients of thermal expansion. The coefficients were twice in the direction normal to the bedding plane as compared to the parallel

Jan 1, 1975

By Carolina Machado de Castro Amaral

A necessidade de treinamento é uma realidade nas indústrias. A qualificação de operadores é importante para garantir segurança e prevenir perdas econômicas. Nesse contexto, o objetivo desse trabalho é desenvolver e avaliar um simulador de treinamento de operador. O estudo de caso é um moinho vertical, comumente utilizado na indústria de cimento. Nessa direção, passou-se pela construção de um supervisório, pela modelagem e simulação dinâmica de um moinho vertical e, por fim, pela elaboração e execução de um treinamento. Para tal, foram construídos três cenários de situações anormais, além da consideração da operação normal. Ainda em relação à metodologia, treinaram-se dois grupos de alunos com métodos distintos de ensino: o primeiro recebeu apenas um treinamento teórico, através de uma apresentação multimídia; e o segundo, após esse treinamento teórico, recebeu um treinamento prático, ou seja, do tipo aprender fazendo, a partir do contato direto com o simulador de processos. De modo geral, percebeu-se que o contato com a prática possibilitou um maior entendimento da operação do moinho vertical, do grau de dependência entre as variáveis de entrada e de saída, e das variáveis utilizadas para a recuperação do processo à operação normal, contribuindo ainda para uma maior fixação do conhecimento teórico. Esse trabalho é resultado de uma parceria UniversidadeEmpresa, cujas atividades foram desenvolvidas por um grupo de alunos de graduação em Engenharia Química.

Aug 17, 2017

By Frank Schrader

INTRODUCTION THE present sketch is submitted by request in the hope that it may serve as a basis for geologic discussion of the mining camps in Mohave County, which is experiencing a marked revival of activities. The region, commonly known as the Mohave district and Kingman district, lies in western Arizona in the southern part of Mohave County, bordering California and Nevada on the west (Fig. 1). Kingman, the principal-town; is situated near the center of the area. on. the Atchison, Topeka & Sante Fe Transcontinental Railway. This region is composed of naked desert ranges of mountains and broad detritus-filled valleys, the southern extension of the characteristic topography of the Great Basin. In altitude it varies from 500 ft. in the southwest to 8,300 ft. on Hualpai Peak southeast of Kingman. The mountains trend north-northwest. They rise about 3,000 ft. above the valleys, are generally rugged and were formed mainly by erosion. They are composed in the main of a, complex of pre-Cambrian granitoid rocks which underlies the area as a whole. Like the valleys, they average about 10 miles in width. Beginning on the east, they are the Grand Wash Cliffs, the Cerbat Range, the Black Mountains or River Range, and the Eldorado Range. The upper or dominantly cliff half of the Grand Wash Cliffs, marking the edge of the Colorado Plateau, is composed of nearly horizontal sedimentary Paleozoic strata of the Grand Canyon section, and the lower half of the underlying pre-Cambrian complex. The Cerbat Mountains situated in the central part of the area, and the Black Mountains situated between Detrital-Sacramento Valley on the east and Mohave Valley, the great trough of the Colorado River, on the west, are locally flanked or overlain by Tertiary volcanics (Fig. 2). The latter consist of five groups of mountains of which the most important is the Black Mesa group on the south. The Eldorado Range, rising from the great trough of the Colorado on the west and containing Searchlight, Eldorado Canyon, and other camps, is topographically and geologically similar to the Black Mountains.

Jan 10, 1916

By Brahm Prakash, R. Schuhmann

Chemical conditions for flotation and nonflotation of quartz with oleic acid as collector and barium, calcium, aluminum, iron, and tin as activators were studied using a simple vacuum-flotation technique in glass-stoppered graduates. The detailed study of barium activation led to an interpretation based on ideal Langmuirian chemisorption.

Jan 1, 1950

By João Lucas Ribeiro e Fernandes, Geraldo Lúcio de Faria, Altair Lúcio de Souza

A ovalização de bobinas é um problema recorrente no processo de fabricação de tiras de aços médio carbono por laminação a quente. Mesmo com o sucesso da etapa de laminação, a ovalização posterior de bobinas pode ocorrer, gerando transtornos à operação e aumento de custos de fabricação. Alguns autores apontam que o fenômeno de ovalização de bobinas pode ocorrer devido a aspectos metalúrgicos, mecânicos e geométricos. Estudos disponíveis na literatura técnica já exploraram as possíveis causas mecânicas e geométricas. Entretanto, existem poucos dados disponíveis que abordem o aspecto metalúrgico, ou seja, o efeito da decomposição tardia da austenita durante, ou mesmo após a etapa de bobinamento. Nesse contexto, este trabalho se propôs a avaliar, por meio da aplicação da técnica de dilatometria, a possível influência das transformações de fases tardias como uma das causas de ovalização em bobinas de um aço do tipo SAE 1050. Ciclos térmicos que simulam, com boa aproximação, algumas possíveis condições de resfriamento acelerado e bobinamento da tira foram aplicados em corpos de prova padronizados em um dilatômetro de têmpera. Diferentes combinações de velocidade de resfriamento e temperaturas de bobinamento foram avaliadas, sendo possível sugerir que uma diminuição na velocidade de resfriamento da tira após a laminação e um pequeno abaixamento na temperatura de bobinamento, em relação aos valores atualmente utilizados na indústria, pode diminuir significativamente a influência da componente metalúrgica na ocorrência da ovalização nesse tipo de aço.

Oct 18, 2019

During 1990-1999, a total of 458 fires occurred in all coal mining categories; 157 of those fires caused 164 injuries and 2 fatalities. The greatest number of fues and fire injuries occurred at surface mines, whch also had the highest risk rate values. A total of 66 fuefighting interventions were required. Of these, there were 25 mine rescue team interventions in underground mines, including 5 mobile equipment firefighting interventions, and 41 fire brigade and fire department interventions at all surface operations, including 19 mobile equipment interventions. In all, 50 fires destroyed or heavily damaged equipment (including 16 pieces of mobile equipment) because of failure of other firefighting methods, late fire detection, undetected fires, or fire size. A total of 1 14 fires were detected late by smoke, and 42 fires were not detected.