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By Ryan C. Linthicum

A system of steel sheeting and multiple levels of high capacity double corrosion protected soil anchors were used to restrain a major slope failure that occurred at the base of the Watchung Mountains mid-way through construction of a 650,000 SF retail center along Route 22 in Watchung, New Jersey. The implementation of a design-build earth retaining structure was necessary to stabilize and repair the disturbed mountainside in a timely fashion to permit completion of the retail center on a fast track schedule. The tied back steel sheetpile wall was approximately 2,000 feet long and varied in height from 12 to 25 feet. The hillside extended approximately 350 feet above and 600 feet beyond the wall with the main failure scarp extending 50 feet above and 90 feet beyond. The wall was constructed in a top-down manner and required the installation of 475 anchors to resist loads of up to 70 kips/ft produced by the creeping hillside and groundwater flows from both a series of springs and steady state seepage through an inclined zone of fine sand. Incorporation of a unique tie point connection eliminated the need for a waler, facilitating and simplifying modifications to anchor locations based on anchor load test results and conditions encountered during construction. Post grouting also proved to be an essential element in the successful construction. This paper presents the design and the construction methods used to restrain the significant earth lateral loads produced by a slope failure using steel sheeting tied back with high capacity soil anchors with anchor loads distributed to the sheeting through a unique tie point connection on a fast track schedule. Installation techniques, testing programs, and construction quality control are also discussed.

Jan 1, 2003

By A. Timur

Fluid flow properties of porous media have long been of interest in such varied disciplines as geology, geophysics, soil mechanics, and chemical, civil, and mechanical engineering. This interest has resulted in numerous models of porous media that have been proposed, tested, and found to be useful under, at best, only special circumstances. A critical review of most of these models is given by Scheidegger. 1 The application of each new tool to the study of porous media has helped to test some of the existing theories and to form new ideas based on the new parameters being measured. In the application of nuclear magnetic resonance (NMR) techniques to the study of the properties of fluids in porous media, the theoretical studies of Korringa et al.2 resulted in a model for the relaxation of spin polarization of protons in a hydrogenous fluid in a pore of a solid. Seevers3,4 verified this model, established a method for measuring the surface-to-volume-ratio distribution in a porous medium, and proposed a technique for determining specific permeability in sandstones. In the present investigation, the uses of NMR methods are extended and a simple model of porous media is developed from an analysis of pulsed NMR measurements. In this model, the pore spaces of a porous medium are divided into three groups on the basis of their surface-to-volume ratios. To evaluate predictions of the NMR model, laboratory measurements of spin-lattice relaxation time, porosity, permeability, and residual (irreducible) water saturation were conducted on more than 150 sandstone samples obtained from four oil fields in North America. Applications are discussed for estimating the volume of movable fluid, ?p, and the specific permeability, k, of sandstone samples. The former parameter, which can be considered as producible porosity, is expressed by ?p = [1 -- (Swr/100)]? , .... (1) where + is porosity in percent of bulk volume and Swr is the residual (irreducible) water saturation in percent of pore volume at a capillary pressure of 50 Psi. Fast, nondestructive laboratory methods are described for determining porosity, movable fluid, and permeability of sandstone samples from measurements with a pulsed NMR (spin-echo) apparatus. Procedures are given for adapting these methods to samples of irregular shape and small size. Theory General In the Korringa, Seevers, and Torrey2 (KST) model the observed decrease in the spin-lattice relaxation time, T1, of protons of a hydrogenous liquid contained in the pore spaces of a porous solid is attributed to an increase in the correlation time for the random motion of the water molecules and to the presence of paramagnetic centers at the liquid-solid interface. This KST model predicts the observed relaxation time of a hydrogenous liquid in a pore of a solid through

Jan 1, 1970

By Robert McClure, Frederic Leclercq, Ricardo Chavez

With significant vibration control and fragmentation challenges facing them, the CBS quarry (department of the Nord) successfully integrated a technical partner and mine to mill optimisation to deal with a difficult environment. For the last three years, CBS has been conducting a global production monitoring program similar to the mine to mill concept used in the mining industry. This concept consists of optimising the drilling and blasting while monitoring the effects on the downstream chain (vibration control, loading, hauling, crushing, plant output). Blast optimization is ensured by systematic control of the blast geometry (volumes, patterns, bench and face anomalies, drill deviation) and by the use of constant specific energy blasting. Constant specific energy optimises the work of the explosive in a blasting operation and, when combined with a high accuracy programmable electronic blasting system, reduces the impact of blasting on the environment and enhances blast performance. These techniques ensure consistent blasting results and hence improved site productivity. The improvements achieved have been identified thanks to an effective system designed to monitor the key production parameters.

Jan 1, 2007

By Hugo Aduvire

La calidad de los efluentes de mina se relaciona con las características fisicoquímicas de los materiales que entran en contacto con los flujos de agua. Por tanto, para la predicción de movilización de metales y los productos de reacción que se forman en los efluentes, se considera la composición geoquímica de los minerales existentes en los macizos rocosos excavados y de los materiales depositados en botaderos y presas de residuos, así como del agua intersticial presente en estas estructuras. En ese sentido, el presente texto describe la aplicación de tecnologías emergentes en la remediación de aguas ácidas de mina, tanto en las instalaciones se encuentran en operación o abandono, mediante el empleo de procesos físicos, químicos y biológicos que modifican las condiciones de Eh y pH de los drenajes de mina, de forma que se favorezca la formación de especies insolubles y la retención de la carga metálica disuelta en las aguas.

Sep 14, 2009

By Violeta Vigo Vargas

Ante el problema de comprensión lectora y matemática en la educación primaria en la región de Cajamarca, se planteó un proyecto que reduzca el porcentaje de problematización de comprensión y diserción escolar. En ese sentido, el presente texto describe el proyecto que ALAC presenta a través del PRIE. Los objetivos principales son: contribuir a mejorar la calidad y la equidad en la provisión de los servicios de educación y salud en Cajamarca, movilizar talentos y recursos empresariales y públicos, así como contribuir a eliminar las brechas en educación rural de nuestros niños.

Jan 1, 2013

By J C. Volkwein, A D. A Hansen, E Sarver, C Barrett

Ensuring that diesel particulate matter (DPM) levels in underground metal and non-metal mines are maintained below statutory limits is an essential requirement of mine ventilation systems. However, despite the cost of providing ventilation, air ventilation rates are usually based upon models, assumptions, or measurements integrated over long durations rather than actual need. Real-time measurement of DPM, interpreted in terms of mine activity schedules, can offer better ventilation management to keep DPM within regulated levels while controlling costs. This work presents data from three demonstration sites with in-mine applications of an environmental particulate sensor that measured black carbon (BC) as a surrogate for DPM.Aethalometers are a class of environmental monitors that measure the light absorbance of aerosol particles at several optical wavelengths. A model AE33 Aethalometer was operated in three separate mines for periods of two weeks, three months, and seven-plus months, and the data was reported in real time as a concentration of BC. Concentration of aromatic organic compounds, which can indicate other forms of combustion, was also reported. The data was used to:- measure the relative efficiency of a new scale-model DPM air scrubber- determine if ventilation could be reduced in a shotcrete loading facility without compromising air quality- evaluate diurnal and weekly DPM levels in a large-entry stone mine. Instrument data were displayed locally and stored for later downloading in all cases. In one mine, the instrument was connected to a local controller, and in another it was connected to the mine’s underground network so that DPM data was presented in real time to a display in the mine ventilation engineering office on the surface.The results showed that the air scrubber removes from 82 per cent to 95 per cent of the DPM; that DPM produced during shotcrete loading is only a minor part of overall DPM levels; and that wide variations in DPM levels exist in the limestone operation. The DPM monitor operated continuously for extended periods in these underground environments. The only maintenance required was the routine replacement of filter tape, typically on a two-week schedule. A sample diluter, which is currently being tested, could extend the intervals between filter changes. The real-time data output of the Aethalometer is appropriate for direct integration into ventilation-on-demand control systems.CITATION:Volkwein, J C, Barrett, C, Sarver, E and Hansen, A D A, 2017. Application of an environmental ‘black carbon’ particulate sensor for continuous measurement of DPM in three underground mines, in Proceedings Australian Mine Vent Conference 2017, pp 143–150 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Raúl Veramendi

El presente texto describe la aplicación del sistema electrónico en las operaciones de voladura de la mina Cuajone. En ese sentido, los detonadores electrónicos son usados para incrementar la fragmentación en la voladura de rocas aplicando los tiempos de retardo óptimos entre taladros para conseguir la interacción de ondas (Ondas P y S) que incrementa y maximiza los esfuerzos de tracción.

Sep 19, 2006

By Sheldon Wimpfen

La exploración es una actividad que utiliza la prospección geológica, prospección geofísica, sondajes, pozos de exploración o de sondeo, galerías de avance subterráneas, de superficie y socavone. Las etapas de la exploración se desarrollan en cuatro etapas : l evaluación regional, reconocimiento de áreas favorables, evaluación de superficie detallada de las áreas de objetivo. Asimismo, se describe la nueva técnicas de exploración y sus incentivos.

Mar 1, 1980

By André Nogueira

A etapa de flotação convencional do Concentrador 2 ocorre em um circuito com 13 tanques de flotação que recebem o produto dos ciclones limpadores (-0,15mm +0,030mm). O concentrado desta etapa contribui com aproximadamente 80% do volume de produção do concentrador. A necessidade da implantação do sistema de controle avançado de processos (SCAP) advém da alta heterogeneidade na alimentação do concentrador, uma vez que a Samarco não conta com pilha de homogeneização. O objetivo principal do projeto foi maximizar a recuperação metálica da flotação convencional e reduzir a variabilidade do teor de sílica no concentrado final. Aliado ao sistema de análise de imagem de espuma e ao analisador de sílica online, a ferramenta demostrou que, além de atingir os objetivos esperados, trouxe estabilização ao processo e padronização da operação.

Aug 16, 2017

By Tatiane Suelen Santos Silveira, Dagoberto Santos Brandão, Dalila Chaves Sicupira, Graziele Gianini Braga Maria, Marcos Vinícius Fonseca Ferreira, Daniela Barçante Perasoli

O aço inoxidável duplex combina as propriedades mecânicas da ferrita e a resistência à corrosão da austenita, sendo muito utilizado em aplicações industriais que requerem um bom desempenho. Quando submetido a deformações intensas, a austenita transforma-se parcialmente em martensita, aumentando a resistência do aço. Quando o aço é recozido, essa transformação é revertida e a martensita se transforma em austenita, ocasionando um refino de grão do material. Fases secundárias formadas durante o recozimento podem prejudicar suas propriedades mecânicas e corrosivas. Nesse sentido, o objetivo desse trabalho foi avaliar o efeito da temperatura de recozimento na resistência à corrosão do aço inoxidável duplex UNS S32304 laminado a frio. O aço foi submetido à laminação a frio, com deformação de 60%, e posteriormente recozido nas temperaturas de 600°C, 700°C, 800°C e 900°C por um tempo de 0,5 h. A resistência à corrosão foi estudada através da técnica de polarização potenciodinâmica. A laminação a frio promoveu a formação de martensita induzida por deformação (SIM) e a reversão parcial começou a ser observada após recozimento a 600ºC. A ocorrência de SIM promoveu significativa diminuição do potencial de pite e o aumento da temperatura de recozimento aumentou a resistência à corrosão localizada.

Mar 1, 2019

By C. O. Browner

Dados los altos costos que implican la explotación de una mina a tajo abierto, se ha previsto excavar los taludes de las minas lo más erguidos posible. En este sentido, el objetivo del texto describe los métodos actuales para evaluar la estabilidad de los taludes en roca. Para ello, se revisa la influencia de las estructuras rocosas, el agua subterránea y la voladura sobre la estabilidad de los taludes de los tajos. Asimismo, se consideran las condiciones de roca intemperizadas, las lluvias y los temblores presentados en algunas áreas del Perú. Producto de esta revisión, se analizará los problemas típicos de estabilidad para diversos proyectos mineros.

Nov 20, 1972

By Jos. R. Guiteras

This paper is one of r series published by the Bureau of Mines dealing with the mineral resources of western South Dakota. The mining of pegmatite minerals is described mainly from the standpoint of the feldspar industry, as most of the other .pegmatite minerals produced are recovered as byproducts from the mining of feldspar. Feldspar is shipped from the Black Hills by three companies, all operating in the southern Hills. Because the pegmatites of the northern Hills, represented by tae Tinton area, have been described in other papers3/ of this series, the present paper is confined to the pegmatite dikes of the southern Black Hills. Emphasis is placed upon the current activity in pegmatite mining; little attention is given to the history of many famous mines in the district, and information concerning them may be obtained by consulting resorts cited in the bibliography. The field work was carried on from July 28 to October 15, 1938. ACKNOWLEDGMENTS The geology of the Black Hills has been studied almost continuously during the last half century. A wealth of literature has attempted to explain the geology and mineralogy of the pegmatite dikes of this region. The writer acknowledges his indebtedness to all earlier investigators, as well as to the following men, whose assistance in the field was of particular value: F. C. Lincoln, professor of mining, South Dakota School of Mines; Mont Heumphreus, State mine inspector, South Dakota; Harold. H. Eyrich, superintendent, and Batemen Eilbeck, mine foreman, b. E. Schundler Feldspar Co.; J. W. Mitchell, field man, Consolidated Feldspar Corporation; John Wells, mine operator and local mineral buyer, Ouster, S. Dak.; Frank Hughes, general superintendent, and Harry Wasson, nine foreman, Hugo mine; D. W. Peterson, mine superintendent, Etta mine.; Lon Walker, Mine superintendent, Peerless

Jan 1, 1940

By Paul Moore

"El presente texto describe el panorama de los últimos años en la tecnología de la exploración minera y tecnológica. En 2012, las limitaciones de costo, la incertidumbre respecto de la acción de gobierno en otros países como Mongolia, y Argentina y las dificultades para establecer los precios commodities delimitaron un panorama negativo. Sin embargo, en el 2013 la situación cambió puesto que se recuperó el precio de los metales y minerales. De otro lado, existe una tendencia en reemplazar losrecursos que se están agotando en las minas y las exploraciones que se realizan ahora son de mayor profundidad (1,200 a 2,000 m)."

May 1, 2013

By Ronald Utley

El presente texto señala el desarrollo en el diseño y fabricación del equipo de trituración y molienda. Para ello, se revisa el tipo de requisito para engranaje, la producción mejorada y reducción de paralización del trabajo, los molinos de zapata corrediza, chancadoras giratorias móviles en fosa, las características de diseño para bancadoras móviles de tipo primaria y giratoria en pozo y el sistema diseñado para el uso de machacadoras giratorias móviles en fosa.

Mar 1, 1980

By Gregory Molinda

NIOSH has recently completed a study of the interaction between polyurethane (PUR) and coal mine roof in order to determine the mechanism of reinforcement, in both highly fractured rock and unfractured rock. Four case studies of PUR rein­forcement are presented. At a West Virginia site, a borehole camera revealed the location of roof voids and guided the PUR injection. By injecting polyure­thane into a zone from 0.6 to 1.8 m (2?6 ft.) high in the roof, a roof beam was created and ongoing intersection falls were halted. In another highly fractured roof in a western Pennsylvania mine, a total of 5.8 cm (2.3 in.) of rubbleized rock was found in a zone up to 3 m (10 ft.) into the roof. Untargeted PUR injection filled approximately 1/2 of the fractures. These two case studies showed that it is not necessary to fill up 100% of the void space to create stability. In the other two field sites, polyurethane was injected into weak, but unfractured roof. Post-injec­tion video monitoring showed that weak bedding planes were hydraulically wedged open and polyure­thane injected along bedding. The reinforcement value of this injection method is limited because of the wafer-thin layer of PUR introduced along bedding, and the lack of a PUR ??webbing?? which would serve as a structural framework to provide strength. It was determined that video inspection prior to PUR injection can aid in identifying the fracture zones to target, and minimize ??blind?? pumping and loss of PUR.

Jan 1, 2008

By Maria Solórzano, Karina Ramirez

Este proyecto busca incrementar la fuerza laboral femenina en la unidad minera El Porvenir, para lo que se analizan tanto factores externos como internos. Para el análisis externo se realizó una evaluación en colegios, con el fin de conocer si hay interés en carreras relacionadas al rubro de la minería por parte de las estudiantes de cuarto y quinto de secundaria de los colegios aledaños. Asimismo, se evaluaron institutos y universidades para identificar la cantidad de mujeres que estudian carreras relacionadas con el rubro. En cuanto al análisis interno, se identificó la perspectiva tanto de las colaboradoras propias como de empresas terceras, así como se analizó el grado de aceptación por parte de los líderes y colaboradores.

Sep 20, 2019

By A. Yazadni-Chamzini

Risk ranking of projects is one of the importance parts of the complicated risk management procedure. Recognizing the riskiest criteria enable the managers to plan for risk reduction. The first stage for meeting this aim is defining the risky parameters and then working to establish order between them. There are variety methods for risk ranking. The ELECTRE method is one of the best among the multi criteria decision making methods. In this paper with implementing the fuzzy ELECTRE, The risky criteria in the Tehran Subway project are being ranked. The result of this research presents damage and accident of machineries as well as the lack of labor and equipment safety is located in the first order. Collapse factors and local prices are in second rank. Also wrong design, pollution, urban facilities damageable are in third to fifth respectively. Delay and ? are located in the last positions.

Jan 1, 2012

By Rose Vera, Alejandro Luna

El programa “Fortaleciendo capacidades para la empleabilidad local” es una iniciativa que busca incrementar las oportunidades de empleo formal y digno para los moqueguanos. Con un enfoque innovador e integral, y siguiendo los principios del Plan de Minería Sostenible, permite gestionar la oferta de trabajo de Moquegua para conectarla con la demanda laboral de la región y del país, mejorando previamente sus capacidades y competencias. A través de capacitaciones en los sectores y ocupaciones con mayor demanda en el mercado, se incrementan las oportunidades de trabajo para la población local, más allá de la minería.

Sep 29, 2023

"Air Products approached LAC Minerals in 1987 to initiate trials with pure oxygen in the leach circuit at several LAC facilities in Canada. This paper gives an overview of oxygen use and covers specific operating data from the Doyon and Terrains Aurifères mills near Val D'Or in northwestern Quebec. LAC also uses oxygen at the Macassa mill in Kirkland Lake, Ontario.In addition to the LAC facilities, oxygen is currently in use for test purposes at the Holt McDermott mine in Kirkland Lake, Ontario and the Camflo mine near Val D'Or.There are two requirements for oxygen in the cyanide leach mill. Firstly, oxygen is required in the familiar gold dissolution reaction as follows:(1) 4 AU (s) + 8 NaCN (aq) + 02 (aq)+ 2H 20(aq) - 4NaAu(CN) 2(aq)+ 4Na OH(aq)Of the reagents on the left side of the equation, the availability of gold is fixed by the ore in question. Obviously, water is available in excess, 1eaving cyanide and oxygen as the limiting constituents in the process. Most mills operate with an excess of cyanide, which is fairly closely monitored. Dissolved oxygen levels, however, are not normally watched very closely and find their own level based on the temperature, the availability of compressed air and the ability of the ore to consume oxygen.Typical D.O. levels are in the 3-8 ppm range, however levels less than 1 ppm are not uncommon for refractory ores.With pure oxygen, dissolved oxygen levels as high as 30 ppm can be achieved. (Figure #1). This greatly accelerates the kinetics of the leach reaction and may also shift the reaction further towards completion thus increasing gold dissolution slightly."

Jan 1, 1990

By M Armstrong, S J. Coward, A Galli

Mine management is often expected to make rapid evaluation decisions at different stages of projects based on limited and uncertain data. The challenge is exacerbated by having to distil technical complexity into a financial model that is usually designed to produce only one or two key indicators, eg net present value (NPV), internal rate of return (IRR). Mining is a complex environment with many sources of uncertainty ranging from sampling to economics. In order to optimise investment decision-making, an appropriately structured evaluation framework must be utilised. An evaluation framework should be designed to encapsulate and integrate the complexity across the evaluation cycle, ie sampling, resource estimation, mine planning and treatment, and financial and economic modelling. This complexity is diverse and ranges from sampling support, scale effects to understanding the impact of variability, uncertainty and flexibility on operational efficiency and economic viability. These complexities, combined with time and capital constraints, usually do not allow all facets of evaluation to be integrated into the model. The model must strike a balance between simplified estimation techniques and sufficient incorporation of aspects of the project that will make a material difference to the investment decision. This paper demonstrates the impact of the scale of measurement on the valuation of a mineral project. Comparisons are made between global estimation averages using a top-down approach and local estimates using a bottom-up approach. Three sampling campaigns were conducted on a virtual orebody to compare the relative NPV accuracies. Stochastic forward models were run on foreign exchange rates and are compared with the results from a fixed foreign exchange rate model.

Jan 1, 2006