Search Documents

By H. B. Humphrey

[EXPLOSION of gas and dust in coal mines, have caused death t lid injure to mines, and destruction of workings in all countries where coal is mined underground. In the United Stales the first reported explosion wits in Min; explosions have continued to the present. The danger to film ill it mine When an explosion occurs in not always measured by the violence created or by their nevi lies, to the area through which flame and Violence extend. As many, perhaps more, risen have died from gases and lade of oxygen (known as "after-damp") than have been killed by the blast and hart. Me explosions often are caused by it combination of factors, including concentration of methane in air, formation of clouds of dust, and the presence of a flame or spark. These explosion factors have varied with changes ill milting method and practises over the years, but the basis causes have always been the salve. Understanding of the causes and to acceptance of ways to guard against explosions and their effects have been slow to spread from investigates to officials and Own to bosses and miners. To a considerable extent there hats lawn a belief that explosions were a joining risk but might hr, put oil hut could not be presented. Such belief is based on the human failure to maintain and observe necessary precautions. These failures, caused by inertia to change, carelessness, or reliance on continuance, of past explosion-free years, are being reduced in number and effect by education of miners and supervisors and acceptance of higher prevention standards.]

Jan 1, 1959

By Oliver Bowles

Manufacture of lime is one of the oldest industries. Plants are distributed widely and furnish an essential raw material for numerous commodities. Use of lime in hundreds of manufacturing and chemical processes, by the building trades, and in agriculture has created a demand for large production and has necessitated exhaustive research on methods of manufacture and uses. The bibliography of publications on lime is extensive; but, for the most part, each publication has dealt with individual operations. The purpose of this paper is to present a general picture of the industry as a whole. The abundant literature has been abstracted and quoted freely, and the National Lime Association has furnished valuable data for certain sections. Publications containing more-detailed information on the various branches of the industry are referred to in the footnotes and bibliography.

Jan 1, 1952

By Charles Vaught

The purpose of this study was to determine mine workers' state of fie-fighting preparedness and the technology being used to detect and respond to underground coal mine fires. To investigate this problem, 214 underground coal miners were interviewed by U.S. Bureau of Mines researchers. Frequency distributions of workers' responses are presented in this report, along with segments of narrative accounts, to profile miners' fire-fighting capabilities. The data indicated that much variability exists from mine to mine and that there are several important changes operators may undertake in order to make miners better prepared to deal with fire underground: select appropriate sensors, establish and test a warning and communication protocol, construct a system capable of delivering hundreds of gallons of water per minute for sustained periods, institute formal fire preparedness audits, develop case studies of events that occur at an operation to use as teaching and assessment tools, and provide structured practice that can be incorporated into fire drills.

Jan 1, 2010

By D. B. Paterson

In view of decreasing head grades, the relatively high gold price, and recent developments in metal evaluation, an exercise was initiated to determine the extent of gold concentration, the mode of occurrence, and the areas of concentration within the run-of-mine milling circuits of Randfontein Estates Gold Mining Company (Witwatersrand) Limited. The total gold content of three of the thirteen run-of-mine mils in the Group was measured as a typical lock-up of approximately 200 kg per mil. The majority of this gold was concentrated either behind the grid-type body liners or within the pockets of the body liners. This paper is an account of the experimental procedure and the results obtained, and highlights possible means of limiting gold lock-up in future.

Jan 1, 1988

By Kefton H. Teague

This paper deals with the practical application of the Dutch State Mines cyclone separator for fine-coal cleaning. The more important operating variables are discussed, and results of a number of continuous-scale tests on various fine coals with a 6-in. cyclone separator are given. Descriptions of the Cyanamid Pilot Plant and the 50 tph Cyclone Separator Plant at the Emma Washery in Holland are included.

Jan 1, 1950

By Alex Lázaro

El presente texto describe la utilzación de las herramientas de modelaje en la formación de los alumnos de la Escuela de Ingenieria de Minas. Entre los primeros cursos de formación de la especialidad de Minas está: Autocad, Topografía, etc. y entre algunas de las aplicaciones que el alumno desarrolla tenemos: la importación de puntos y líneas hacia los programas de modelamiento; la generación y análisis de taladros, a partir de los datos obtenidos en la exploración, la visualización e interpretación de la realidad, criterios de interpretación del cuerpo Geológico y el desarrollo del modelo de bloques y su análisis. Asimismo, los alumnos desarrollaron proyectos sobre modelamiento y planeamiento de operaciones mineras tales como: proyecto de modelamiento geológico y diseño de cono óptimo y el proyecto de modelamiento geológico y diseño de labores subterráneas.

Aug 25, 2002

By G. M. Bond

Reduction of the emissions of greenhouse gases, such as CO,, is currently the subject of extensive research. A novel strategy is put forward here, based on a biomimetic approach providing accelerated deposition into carbonate form for long-term sequestration. It offers the advantages of a process that: does not require concentration of CO, from flue gases; could potentially be used in an on-site scrubber to provide a plant-by-plant solution to reducing CO, emissions; is an environmentally benign procss with an environmentally benign product; and is based on readily available, low-cost reagents (except perhaps the catalyst).

Jan 1, 1999

By Henri F. Letient

At the 25th Annual B.C. Mine Reclamation Symposium in September 2001, Huckleberry Mines Limited received the Jake MacDonald Reclamation Award for its exemplary mine waste management plan, conceived to prevent the onset of acid mine drainage and facilitate reclamation of the site. The mine is an excellent example of a total mine waste management plan, with all materials scheduled in detail for the life of the mine. The filling plan for the waste management facility takes into consideration the requirement for permanently flooding the potentially acid generating rock. From an acid generation point of view, the tailings fall in the zone of potentially acid generating material. To avoid long-term ARD concerns, it is planned to float pyrite out of the tailings towards the end of the mine life, thereby generating a non-acid generating tailings stream which will be used to cap the deposited mine waste. The pyrite-rich tailings will be discharged into the deeper portion of the impoundment. On closure, a permanent water cover will be maintained over the mine waste. Only beaches of non-acid generating tailings will remain exposed. Mining will be phased to also allow one of the pits to provide storage for potentially acid generating rock and to be flooded at the end of mine life.

May 1, 2002

By R. J. Leary

The natural gas-air burner described in this report was designed and constructed to meet the thermal requirements of a convective process for heating steel scrap. This process involved downward combustion of natural gas with air, blending the combustion products with diluent air, and then passing this tempered stream of gases downward through a porous bed of steel scrap contained in the furnace chamber. The scrap would be heated to a temperature limited by the adiabatic flame temperature of the gas stream in a period that depended on the rate at which heat was supplied per unit of bed cross section. The temperature of the gas stream would be limited to that beyond which an objectionable degree of oxidation would occur; for carbon steel this limit had been found to vary from 1,900° to 2,100° F. with the superficial velocity of the gas stream. The productivity of the process was dependent on the rate of heat input per unit of furnace cross section; for the 3-foot-diameter experimental furnace an input of 680,000 B.t.u. per hour was desired. The burner described was designed to meet these conditions of temperature and heat input. It provided for three streams of entering gases: (1) A primary air-fuel mixture too rich to be combustible, that is, above the upper flammable limit; (2) secondary air for combustion of the primary mixture; and (3) tertiary air, principally for cooling the combustion products to the temperatures desired for process operation. Downward combustion of the primary and secondary streams occurred in a flame stabilized on an annular port, while tertiary air flowed in an annular path surrounding the port and also through an axial channel whose wall formed the inner ring of the annular port. This burner performed beyond the designed heat-input rates while producing stable flames, which were adjusted readily to the temperatures desired. Gas-stream temperatures were easily controlled to within 15° F. of the desired value by simple manual adjustment of the flow valves.

Jan 1, 1959

By M. K. Mohanty

One of the main objectives of this study was to evaluate a fine-coal cleaning circuit using an enhanced gravity separator specifically for a high sulfur coal application. The evaluation not only included testing of individual unit operations used for fine-coal classification, cleaning and dewatering, but also included testing of the complete circuit simultaneously. At a scale of nearly 2 t/h, two alternative circuits were evaluated to clean a minus 0.6-mm coal stream utilizing a 150-mm-diameter classifying cyclone, a linear screen having a projected surface area of 0.5 m2, an enhanced gravity separator having a bowl diameter of 250 mm and a screen-bowl centrifuge having a bowl diameter of 500 mm. The cleaning and dewatering components of both circuits were the same; however, one circuit used a classifying cyclone whereas the other used a linear screen as the classification device. An industrial size coal spiral was used to clean the 2- x 0.6-mm coal size fraction for each circuit to estimate the performance of a complete fine-coal circuit cleaning a minus 2-mm particle size coal stream. The ?linear screen + enhanced gravity separator + screen-bowl circuit? provided superior sulfur and ash-cleaning performance to the alternative circuit that used a classifying cyclone in place of the linear screen. Based on these test data, it was estimated that the use of the recommended circuit to treat 50 t/h of minus 2-mm size coal having feed ash and sulfur contents of 33.9% and 3.28%, respectively, may produce nearly 28.3 t/h of clean coal with product ash and sulfur contents of 9.15% and 1.61%, respectively.

Jan 1, 2008

By Z. A. Md-Nor

Risk management is an established loss-control methodology that has been applied successfully in many industries. Recently, interest in this structured approach has grown in the mining industry. The main objective of this research was to develop a risk-assessment process, which is a part of risk management, that can be used by the U.S. mining industry to more thoroughly characterize risks associated with haul truck-related fatalities. The assessment is based on historical data obtained from the U.S. Mine Safety and Health Administration (MSHA) investigation reports, which includes 113 fatal incidents that occurred from 1995 through 2006. The risk-assessment process used in this research involves the following basic steps: identification of the risks, risk analysis and risk evaluation. The preliminary hazard assessment (PHA) method is used in identifying and quantifying risks. Risk levels are then developed using a pre-established risk matrix that ranks them according to probability and severity. The resulting assigned risk value can then be used to prioritize control strategies. This paper is a part of a detailed study on risk assessment for equipment-related fatalities in mining sponsored by the Western U.S. Mining Safety and Health Training and Translation Center.

Jan 1, 2008

By Hans Jahncke G

El petróleo se forma por rocas porosas, que al producirse se llaman los "reservorios de petróleo". Por lo cual este debe poseer intersticios entre las partículas sólidas, que acumulen ciertos fluidos. Empero este no es el único fluido encontrado, sino que pueden contener aguas, gas, en tanto solución del petróleo libre. En este sentido, el objetivo del texto es señalar el funcionamiento del laboratorio de reservorio, en tanto determine estas propiedades, las cuales son básicas en todos los cálculos de reservorios, determinación de reservas, desarrollo de la producción y las posibilidades futuras de recuperación secundaria. Las funciones del Laboratorio de Reservorios de la International Petroleum Company se dividen en dos partes: El primero refiere el trabajo de campo, que incluye obtención de registros de presión, temperatura y determinación de niveles de fluido en los pozos y el segundo, los trabajos de laboratorio propiamente dichos como la determinación de las propiedades físicas de las rocas del reservorio y de los fluidos que contiene. Estos a su vez comprenden la saturación y permeabilidad. En cuanto a los trabajos de muestras de petróleo del subsuelo, encontramos factores como la presión de saturación, relacion de gas-petróleo, volumen de formación y viscocidad. Asimismo los análisis de trabajos de muestras de gas se realizan mediante el desplazamiento de fluídos por inyección de agua.

Jul 20, 1956

Preheating Feature of Leyner Oil Furnace for Heating Drill Steel The No. 3 Leyner oil-burning furnace, used for heating drill steel, is now made with a preheating chamber. By this addition it is claimed that the heating capacity and, effeciency of the furnace are increased about 50 per cent. This preheater is a section which fits between the body and cover of the furnace of the old design. It may be attached to an old furnace by simply changing a few bolts. Referring to the illustration, it will be seen that the lower chamber is used for the final heating and the upper one for preheating. The type of burner now furnished with this furnace is suitable for either high- or low-pressure air. It hats merely to be throttled for high pressures and when this is done, it, is as efficient as burners designed especially for high pressures and eliminates the noise common to such burners. This furnace burns petroleum or any of its oils, such a, gasoline, kerosene, distillate, etc. Oil heating has many advantages. The steel cannot be injured by absorbing injurious elements such as sulphur, phosphorus or other impurities which :ire present in nearly all coals, nor from unequal heating since the flame imparts a uniform temperature; further, o lie steel is in full view of the operator at all times.

Jan 3, 1916

By R. L. Brown

This report, summarizing the Bureau of Mines research and technologic work on coal and coal products for the period July 1, 1950, to July 1, 1951, is based largely on publications issued during the year. The sixteenth in an annual series, it gives footnote references to publications giving further details of the research and technologic work described, except in a few cases where research data presented herein has not been published previously. During the year, the national fuels situation was generally one of plentiful supply.3/ Mineral-fuel resources appeared adequate for several hundred years at reasonably increasing rates of supply. Coal-production capacity was in excess of demand; petroleum supplies were adequate; and natural gas use was limited only by pipeline capacity. However, it was pointed out that a world war would drastically change this situation of relative plenty, particularly with regard to supplies of petroleum and its products. Conversion to the use of coal on a large scale would be required, and improved methods of mining and of processing and using coal in solid or fluidized form or converted to liquid fuels could materially contribute to our national safety.

Jan 1, 1952

By A. V. Pavlov, A. V. Dubachev, K. L. Kossyrev

The purpose of the given research was to investigate the possibility of high-carbon ferrochromium refining to remove harmful impurities as a result of metal treatment by slag mixtures on the basis of the CaO-MgO-SiO2system. The final conclusions were drawn from experimental results. It was shown that the treatment of high-carbon ferrochromium by SiO2-MgO-CaO slag mixtures with additions of chromium sinter or iron-ore concentrate removes carbon, sulphur and phosphorus from the metal. A mechanism of phosphorus removal from a melt to a gas phase is proposed.

Jan 1, 2004

Effect of Anionic Surfactant on Silica Particle Attachment at the Oil-Water Interface Controlling particle attachment is crucial where powdered solids come into contact with oil and water. Particles are trapped in a deep energy well at the oil-water interface, stabilising emulsions. Here it is shown that adding anionic surfactant causes dramatic changes to the bulk and interfacial structure of silica particle-stabilised oil-in-water emulsions. Exposing particle-stabilised drops to surfactant concentrations above the critical micelle concentration enhances the rate and extent of creaming and flocculation. Mixing particle-stabilised emulsions with surfactant solutions causes drop fragmentation. As the surfactant concentration increases, the average drop size decreases and particles are displaced from the interface during the mixing process.

Sep 13, 2010

By Luis Palomino

El siguiente estudio indica la importancia de la función que ejerce el Departamento de entrenamiento en la Cerro de Pasco Corporation. Para ello, la compañía reconoce el entrenamiento como herramienta básica en el aumento de la producción y reducción de costo, al tiempo que el Departamento asegura el perfeccionamiento de su personal de toda índole. En esta primera etapa de planeamiento, se proponen las siguientes actividades: orientación de nuevos servidores, entrenamiento de supervisores, curso de pre-capataces, curso de instructores, cursos técnicos, cursos vacacionales para universitarios, cursos por correspondencia y clases de castellano. Concluyendo que dicho programa, aumenta el rendimiento de los trabajadores, les crea conciencia y a su vez desarrolla actitudes proactivas, así como se destaca el adiestramiento de los supervisores sobre la técnica de enseñar a sus obreros, y por último, busca que cada compañía elabore su propio programa de acuerdo a sus necesidades de su entrenamiento y según las características de su personal.

Jul 20, 1955

By R. Steele

In addition to compliance with government emissions and reporting requirements, mining and mineral processing companies are increasing energy efficiency to reduce costs and become more competitive in the global marketplace. One of the major obstacles to identifying opportunities for increased energy efficiency is the lack of readily available data on energy use, and more importantly the energy use linked to production data, that identify energy reduction opportunities. As well as energy reduction, mining and mineral processing companies often struggle with the prediction of energy use, and are often penalized for under or over forecasting. Once again, it is the lack of timely information that makes this prediction difficult. This paper looks at expanding the use of a Manufacturing Execution Systems by integrating with Energy Solutions. This will provide automatic, timely information, at a granularity that makes it easier to identify energy reduction opportunities, reduce energy costs, and better predict energy use in a mining and mineral processing operation.

Jan 1, 2011

By M. H. Weinecke, B. P. Faulkner

This paper will discuss the process for making lightweight aggregate, the waste materials that make good lightweight aggregate, the chemistry of making lightweight aggregate and finally a discussion of the commercial prospects for making lightweight aggregate from wastes. Svedala Industries has been making lightweight aggregate (LWA) from waste materials for the last ten years. Many clay-like materials, such as coal-fired boiler ash and washings from a granite quarry, can be used alone or with additional waste materials to produce a commercially saleable LWA.

Jan 1, 2001

By S. Holtermann

Through the process of Riverbank Filtration (RBF), the Louisville Water Company plans to obtain a higher quality source of water for their B.E. Payne Water Treatment Plant (WTP) by means of four collector wells located in the alluvial aquifer along the bank of the Ohio River. The collector wells are connected to a 2,850 L/s (65 mgd) pumping station by a 2,362 m (7,750 ft) long, 3 m (10 ft) finished diameter tunnel located in limestone and shale bedrock, which is approximately 45 m (150 ft) below the surface. High tunnel boring machine (TBM) production rates were achieved in this moderately weak bedrock; most of the tunnel only required support in the crown. An unanticipated water-bearing fault and unanticipated ground behavior proved challenging and required quick thinking to minimize impacts to construction. Tunneling conditions are discussed in detail, together with the methods used for overcoming the groundwater and ground behavior challenges. The tunnel is expected to be completed in April 2009.