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By Hamid Maleki

A comprehensive study consisting of stress determinations, core logging, laboratory testing, and numerical analyses was conducted to investigate the cause and potential alternatives to the coal bump conditions that developed in the Second North Panel of the Little Dove mine near Buntington, Utah. Roof rock characteristics were such that a cave did not develop above this 420 ft wide panel. After 700 ft of pillar retreat, severe coal bump conditions developed during pillar mining. The coal bump conditions resulted from excessive pillar stress which was caused by load transfer from the extracted, noncaving, portion of the panel. Site specific data and numerical modeling techniques were used to back-analyze the bump prone condition. This back- analysis lead to the identification of critical stress, closure, and energy release levels. These critical levels were then used to evaluate alternative pillar mining sequences in the hope that the potential for coal bumps could be reduced. It was found that while alternative sequences offered some potential improvement over the pillar mining sequence used in the mine, alternative pillar mining sequences would not significantly reduce the potential for bumps. For the roof characteristics at this mine, coal bumps are best avoided by developing narrow panels or significantly wider panels, which incorporate properly sized barrier pillars. Narrow panels, on the order of 300 ft, would not cave, but panel pillar stresses and the potential for umps would be moderated by the reduced r' panel width. Wider panels, of approximately 650 ft, would allow a cave to develop, also reducing panel pillar stresses and coal bump potential.

Jan 1, 1987

By S. Iverson

Fall of ground accidents continue to be a source of injury in underground metal mines. MSHA accident statistics indicate that most rock fall accidents occur at a new face where drilling and blasting methods are used. Removing loose rock by scaling is imperative to removing the potential for rock fall injury. Detection of potentially loose rock could improve the scaling process and result in fewer rock falls. Infrared thermal imaging cameras were investigated as far back as 1966 as a tool for loose rock detection. Early on it was clear that sensitivity (e.g. detectable temperature increment) is a key factor in this application. Both pixel resolution and temperature resolution have greatly improved with modern instruments. This paper describes an evaluation of modern infrared thermal imaging camera technology to detect loose rock conditions at six underground metal mines in the western U.S. It was found that thermal images provide a high resolution visual discrimination between loose rock and intact rock. However, detecting loose rock was difficult in cases where the rock and ventilation air were at the same temperature. Loose rock was detected when rock was both warmer and cooler than the ventilation air temperature. Warm rock with cool ventilation air provided the best conditions for detection.

Feb 23, 2014

By GORDON H. FISHER

During the year 1945, the drilling pace in West Texas increased above that in the year 1944, and represented the highest number of well completions since 2941. The 1680 new wells drilled 8,287,958 ft. of hole for a per well average of 4933 ft. This depth is approximately 30o. ft. deeper than the average for the year 1944. Although the deepest well drilled in West Texas (Phillips Petroleum Company's Ada Price No. 1, in Pecos County) was completed during the year. 1944 to a depth of 15,279 ft. and tested the Ellen-burger horizon, the producing depth record for West Texas was set during the year 1945 with the completion of Amerada Petroleum Corporation's Jones No. I-A, in the Jones Ranch field, Gaines County, which now is producing at 11,422 ft. from the Devonian formation.

Jan 1, 1946

By Fausto Valdeavellano

El presente texto es una sistematización sobre políticas de desarrollo minero y sus interrelaciones con la realidad nacional a través de un marco conceptual metodológico adecuado. Para ello, se considera las dimensiones del desarrollo minero, las alternativas tecnología-producto, los aportes de la minería al desarrollo integral y los instrumentos relevantes para la aplicación de las políticas que interesan. Asimismo se presenta formas de formular, aplicar y evaluar políticas y planes mineros, así como se perfila la búsqueda de un consenso nacional para la adecuación de dichas políticas.

Nov 20, 1978

By Robert F. Mehl, Dana W. Smith

It has been shown that quenched iron of high purity exhibits a Wid-manstiitten figure much resembling martensite in appearance.1 This figure exhibits a maximum of four directions of the surface traces that characterize it, suggesting that a Fc forms from y Fe in plates parallel to the (III), octahedral, planes in the y lattice. Because of this, and also beqause of the general similarity to the structural appearance of martensite and to the Widmanstatten figure obtaining in slowly cooled hypoeutectoid steels it has been suggested2 that the orientation relationships obtaining between the y and a phases in pure iron are identical with those demonstrated in martensite3 and in slowly cooled hypoeutectoid steels,4 and indeed that the crystallographic mechanism of formation of a Fe from y Fe is the basic mechanism determining the orientation relationships found in both martensite and in slowly cooled hypoeutectoid steels. This paper will present experimental evidence in support of this view. Experimental Technique The analysis of the crystallographic mechanism of transformation in pure metals is beset with special difficulties, though some information

Jan 1, 1934

By Richard G. Geyer

One aspect of a program to improve the chances of survival following coal mine disasters is the development of a communications sys tem which will allow surviving miners to make their circumstances known to rescue teams. At present, it appears that an electromagnetic system may be most practical. The development and design of an effective electromagnetic communications link for signalling between mine workings and the surface requires knowledge of pertinent physical properties of the rocks overlying the mine workings and the characteristics of the ambient noise against which a communications signal must be recognized. Knowledge of the overburden electrical transmission properties is useful not only for determining a practical operating transmitter frequency at a given mine, but also for ensuring the best possible electromagnetic coupling for routine or emergency communication purposes. Field studies of the electrical transmission properties of the overburden of coal mines in Colorado, Illinois, and Pennsylvania generally show that a relatively uniform and unimodal electrical conductivity distribution exists provided that the region has not been subject to considerable structural or metamorphic deformation such as that observed in the Gary District of West Virginia. Measurement s of ambient surf ace electromagnetic noise levels at several mines in Colorado, Illinois, and West Virginia were taken and analyzed and are presented in the form of amplitude histogram plots both as a function of frequency and time of day. These amplitude histograms may be used in conjunction with overburden resistivity data in implementing an uplink communications beacon system which will yield a specified signal- to-noise ratio at the surf ace. Numerous C .W. field transmission tests were made in various coal mining environments with use made of either a buried vertical-axis transmitting loop or a short insulated grounded current line. These transmission tests were made from 20 Hz to 20,000 Hz in frequency and at several geographic surface receiving sites. The results of these field measurements show, in general, good agreement with theoretically calculated results. Since the produced surf ace magnetic field from a buried vertical-axis loop source or the produced surface horizontal electric field from a buried horizontal current line show better agreement with theoretical results, they could be used for beacon location system. One criterion would be in detecting the equatorial and polar null lines of the horizontal electric field component which is normal to the direction of emplacement of a buried transmitting line current source. A second criterion would be in the surface mapping of the maximum in the vertical magnetic field directly over a vertical-axis loop transmitter and the associated null is the vertical magnetic field at a horizontal offset distance which is about 1.4 times the depth of burial of the transmitter. Finally, a third criterion would lie in the surface mapping of the null in the horizontal magnetic field directly over the vertical-axis beacon and the associated maximum in the horizontal magnetic field at an offset distance from the transmitter axis of half the depth of burial of the loop transmitter. In mapping the vertical magnetic field over a buried vertical-axis loop transmitter, the size effect of the transmitter loop must be taken Into account when the separation distances between the transmitter and receiving sensor are less than ten times the effective radius of the source loop; increasing the size of the transmitting source relative to the source-receiver separation distance shifts the null in the vertical magnetic field to greater offsets. In mapping either the vertical or horizontal magnetic field over a buried vertical-axis loop transmitter, care should be exercised in ascertaining that measured nulls and maxima are along radials through the axis of the buried source loop. For the main part, coupling experiments show that ambient electromagnetic noise in coal mining districts is less of a problem above 1000 Hertz. But secondary and perhaps undesirable maxima and null phenomena (as well as penetration problems) would occur in many coal mine provinces in the behavior of the surface horizontal magnetic field (over a buried vertical-axis loop transmitter) if transmission frequencies as high as 10 kHertz were used.

Jan 1, 1974

By Kot F. Unrug

In the premining stage of engineering design, the only available data are obtained from core drilling. It is often not sufficient for a realistic design of strata control. During the development, an access to the geological formation is created, enabling in situ testing. Obtained data can be utilized accordingly to improve preliminary design. The available methods for testing are described with emphasis on their application for a longwall system. The optimum design ensuring continuous operation of the high output longwalls is critical because their downtime is very expensive. Optimization of ground control measures also has the potential for substantial savings by elimination of unnecessary support.

Jan 1, 1994

By Turker Hudaverdi, Yasar Agan

This study tries to predict blast-induced flyrock using intelligent modelling techniques. Flyrock is a site-specific phenomenon. Design variables and rock properties highly influence flyrock throw distance. Site investigations were conducted in a sandstone quarry. Fundamental operational parameters, blast dimensions, bench face condition, and rock mass structure were monitored. Stepwise regression technique was applied for variable selection. Burden–hole diameter ratio, in situ block size, and powder factor were determined as the most significant parameters. Considering output of stepwise regression, artificial neural network, ANFIS, and Gaussian process regression techniques were applied to predict flyrock throw. A comprehensive validation was performed using twelve different performance indices. Pre-determination of input parameters supported development of successful soft computing applications. Rock block size was found to be an appropriate input variable for flyrock modelling. In addition to classical performance indices, standardized and symmetric accuracy metrics were quite useful in model validation process. The intelligent models predict flyrock range with an error less than 6 m. The mean percentage errors are lower than 10%. ANFIS seems to be the best model for flyrock prediction. The calculated mean absolute error is 5.36 for ANFIS model.

Nov 12, 2023

By Peter Grandstone, D. A. Jessup, D. B. Taliaferro

"INTRODUCTION Water flooding of oil sands in Texas as a means of secondary recovery of oil has been practiced mainly in the north-central part of the State, which includes the old shallow fields in eight counties, extending south through Wichita and Clay Counties on the Red River into Brown County.The Texas Railroad Commission, is empowered ""to promote conservation and prevent waste in the drilling, completion, operation, and abandonment of oil wells"" and ""to issue regulations necessary for fulfillment of these ends,"" granted The Texas Co. the first permit to inject water into the oil-bearing sand on December 7, 1935. The permit was granted after the Commission had conducted a number of hearings, which were attended by many operators interested in that method of secondary recovery. Through December 31, 1944, the Commission had granted 50 permits for water flooding. Of that number, 45 permits were issued for projects in north Texas, the remaining 14 being distributed throughout west and south Texas. By the end of 1944, there were 33 active and 5 abandoned water-flooding projects in the North Texas area, as is in figure I.Oil production in the North Texas area started in 1904 from the shallow sands (ranging from 100 feet to 800 feet in depth) of the Petrolia (or Henrietta) field in northern Clay County. Development was rapid and unrestricted during the boom period from about 1911 to 1918, and considerable waste of both produced oil and reservoir energy resulted."

Jul 1, 1946

By W. R. Hardwick

This paper describes block -caving methods and practices of the Bagdad Copper Corp. in Yavapai County , Ariz . It is one of a series being prepared by the Federal Bureau of Mines on mining methods , practices , and costs in various mining districts of the United States . The story of the Bagdad caving operation is of particular interest because the ore body was not as thick as at other mines where the method had been successful . At Bagdad the caving method worked very well as a smallscale operation of 300 tons per day but was abandoned when production was increased to 2,000 tons per day . The Bagdad mine is in western Yavapai County , Ariz . , about 22 miles northwest of Hillside , a station on the Phoenix -Ash Fork branch of the Atchison , Topeka & Santa Fe Railway system ( fig . 1 ) . Copper ore now is mined by open -pit methods . The ore is concentrated , and the concentrates are trucked to Hillside and shipped by rail to a custom smelter . Some molybdenum sulfide is produced as a byproduct . This report gives a brief history of the district , describes the ore de- posit , and outlines the methods of prospecting , exploration , and estimation of ore . Development and former underground mining , including stope preparation , stoping , and transportation , are described . Extraction of ore , production rates , miscellaneous operations related to mining , wage and contract systems , and method of concentration are described . The final section discusses mining costs . The underground mine was visited by the author several times between 1937 and 1942 , and some information has been drawn from personal notes . The property again was visited in June 1957 , and maps and plans for this paper were furnished by the company at that time ; they have been edited to conform with Bureau of Mines format . The underground mine could not be visited then because it had been closed in 1948 when open -pit mining was begun .

Jan 1, 1959

By Ernest A. Curth

A 3-month study in 1971 of the Essen Roof Support and Rock Mechanics Research Center's program of roof and support evaluation included 25 mine trips. German miners must adopt mining methods and environmental control measures involving methane drainage and water infusion to improve productivity under severe natural conditions. Pressing problems in ground control must be solved such as cavities in front and above the supports at longwall faces and excessive convergence in gate roads. The Center developed automatic data processing methods to quantify the results of roof and support surveys and to establish criteria. Another approach to ground control is the study of mine models. The Center's laboratory has the facilities to test elements of powered roof support and whole assembled units. Face automation and roof control by powered shields are novel developments that are under close scrutiny in the field as well as in the laboratory. Though the Essen Center's roof and support evaluation techniques are tailored to the needs of the coal mining industry of the Federal Republic of Germany under conditions vastly different from those in the United States, some application may be found here, for instance, monitoring faces and roadways and preventive maintenance of hydraulic systems.

Jan 1, 1974

By João Guilherme Dessi

Neste trabalho estudou-se a microestrutura e a interface de um tubo bimetálico cladeado por centrifugação, constituído externamente em aço API 5L X65Q e internamente pela superliga de Ni-Cr Inconel 625, ambos vazados pela mesma posição relativa no tubo. O vazamento do Inconel 625 causou erosão no aço que diminuiu de intensidade do lado de vazamento (região mais quente) para a o lado oposto (região mais fria), onde a região de interdifusão não se apresentou mesmo uniforme. Nas regiões mais quentes (lado vazado e meio do tubo) ocorreu o cladeamento completo, com uma interface continua entre ambos os materiais constituintes, enquanto que na região mais fria a interface apresentou descontinuidades. O aço apresentou microestrutura ferrítica-perlítica com a região adjacente a interface descarbonetada, com grãos ferriticos nanométricos em uma região estreita de 3 µm. O Inconel 625 apresentou uma microestrutura de dentritas de austenita Ni-cfc com fases de Laves interdentríticas, devido a aumento do teor de Fe, com alta densidade de discordâncias na região adjacente a interface livre de precipitados.

Aug 8, 2018

By Robert H. Peters

This report presents a literature review conducted by the U.S. Bureau of Mines. The review summarizes what has been learned from recent empirical studies of the relationship between mine safety and characteristics of miners, mine management, and mining companies. The review is based on literature published in the United States during the period from 1976 to 1988. In addition to summarizing the empirical findings, this report discusses the implications and limitations of these studies, and gives recommendations for improving mine safety. An annotated bibliography section appears in the appendix.

Jan 1, 2009

By D. Randolph Berry

Foster-Miller Associates has developed a set of guidelines to permit hoist manufacturers, mine owners, and MESA mine inspectors to design, purchase, install or inspect a safe and effective Emergency Escape Hoist, as required by the Coal Mine Health and Safety act of 1969. A series of surveys were carried out to determine: 1. The attitudes and local needs of the MESA District Managers. 2. Current escape hoist installations. 3. Equipment available for future designs. 4. Foreign methods and equipment for mine rescue. From these survey studies, preliminary guideline objectives were developed.

Jan 1, 2012

By N. A. C. Smith, A. C. Fieldner, R. R. Sayers

Gases and vapors given off by petroleum and its products have long been recognized as somewhat injurious, when inhaled in high enough concentrations. The petroleum industry has recognized these effects and has tried to minimize the possibility of employees encountering dangerous concentrations of the vapors. Petroleum gases and vapors have not, however, been considered as actively poisonous, in the sense that hydrocyanic (prussic) acid and phosgene are poisonous; men have been exposed to them repeatedly, and for long periods, without any marked ill effects. Light Mexican crude oil when first introduced into the United States for refining was handled in much the same way as was customary with other apparently similar crudes; but experience soon showed that some toxic substance escaped from the crude during production and transportation and in most of the refinery operations. After a preliminary investigation several of the larger companies decided that the gases from the petroleum were the source of trouble, and therefore took precautions, wherever possible, to protect the men from exposure to these gases. With the increasing use of Mexican crude, this problem has become important. The present report covers the work done on the subject by the Bureau of Mines and the Public Health Service under a cooperative agreement with the American Petroleum Institute.

Jan 1, 1925

By W. Wittke

SUMMARY: Geotechnical problems often lead to an increase of construction time and costs for large highway and railway projects. Some reasons, which have led to failures and thus to a delay of construction works as well as to increasing costs, are demonstrated by means of case histories, in which the author was involved as expert or planner. Proposals are made how to identify the reasons and to avoid repetitions. ZUSAMMENFASSUNG: Bei Großprojekten der Verkehrsinfrastruktur stehen häufig geotechnische Aufgabenstellungen im Vordergrund. Wegen geotechnischer Probleme kam und kommt es häufig zu Termin- und Kostenüberschreitungen. Anhand einiger Beispiele, bei denen der Autor als Gutachter und Planer beteiligt war, wird gezeigt, welche Ursachen zu Schadensfällen und damit auch zu Termin- und Kostenüberschreitungen geführt haben. Es werden Hinweise und Anregungen gegeben, wie die Ursachen erkannt und Wiederholungen von Schadensfällen vermieden werden können. RÉSUMÉ: À grands projets de l'infrastructure de la circulation, souvent des tâches géotechniques sont au premier plan. Par suite de problèmes géotechniques, souvent des dates et frais ont été dépassés. Au moyen de quelques exemples, à lesquels l'auteur participait comme expert et planificateur, les causes sont mises en vue qui menaient à des cas de dommage et par cela aussi à des dépassements de dates et frais. Des indications et suggestions sont données pour s'apercevoir des causes et éviter des répétitions de cas de dommages.

Jan 1, 2003

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is intended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By J. E. Nesset, L. S. Urbanoski, J. R. Goode

"The benefits and advantages of pre-competitive, collaborative industry/university research are not always well appreciated. This paper presents the case study of a current collaborative project between CAMIRO-Metallurgical Processing Division and McGill University that is investigating the understanding and prevention of sphalerite activation in lead and copper-lead flotation circuits. The benefits of the research findings to the sponsors can be maximized by an approach which links the researchers themselves with the sponsors at frequent, interactive project review sessions. Some examples of the findings and their application to industry are also presented along with a general update on CAMIRO-MPD.INTRODUCTIONThe history of Canadian efforts in the area of collaborative pre-competitive research is not long when compared to Australia (AMIRA) and Britain (MIRO). AMIRA (Australian Mineral Industry Research Association) began over 40 years ago and has had a well recognized role in bringing together industrial sponsors and researchers to fund a large variety of very significant development projects in that country, The total AMIRA funding effort for mineral processing work currently exceeds some $Aus 40 million with new projects valued at about $Aus 12 million initiated each year. This high level of commitment by industry has contributed to establishing Australian researchers and their facilities as among the best in the world.Canadian companies have traditionally funded much of their R & D in-house with extensive facilities and large funding commitments. The past 2 decades have seen most of these facilities disappear. The current situation is one in which only the largest integrated metal and mining companies have retained their own R & D groups (e.g. INCO, Falconbridge, Noranda). Industry-funded research at universities was primarily through individual efforts by the mining companies and rarely included collaboration with other mining companies, equipment or chemical suppliers, or engineering firms."

Jan 1, 2001

By W. C. Phalen

During the search for deposits of soluble potash salts in the United States, carried on by the United States Geological Survey, much information was collected on the salt resources and industry of the United States. The more important features of the information thus gathered, compiled, and digested may be classified under five headings, as follows: 1. Geology of the salt deposits of the United States. 2. Theories relating to the origin and formation of salt deposits. 3. Chemical composition of saline materials in the United States, principally rock salt and natural and artificial brines. 4. Statistics of salt production in the United States. 5. Technology of salt production. The first four items are not discussed in this report, but their treatment will comprise a separate report published by the Geological Survey,a which will supplement this report, relating to salt-making processes, and will describe comprehensively the salt resources of the United States. Persons desiring a copy of that report should apply to the Director of the United States Geological Survey, Washington, D. C.

Jan 1, 1917

By Marcelo Marchesi Martinelli, Caio Henrique Vidigal

Gasômetros são equipamentos de grande valia para aumento da eficiência energética e ambiental de empresas siderúrgicas integradas, sendo estes equipamentos responsáveis pelo controle da pressão do gás resultante das transformações dos processos siderúrgicos, controle este realizado através das variações de volume abaixo dos pistões. Quando não há disponibilidade de operação dos gasômetros faz-se necessário o uso de torres de queima para controle das pressões das redes de gases. Em dezembro de dois mil e dezoito fora realizada a troca da selagem do gasômetro de gás de Coqueria da ArcelorMittal Tubarão, que utiliza a tecnologia M.A.N. (Selo a óleo). Utilizando técnicas da metodologia Lean, modificando o mindset e alterando antigos paradigmas foi possível realizar a manutenção, de forma eficaz, em 32 dias, 28 a menos que o último trabalho similar realizado e 13 dias a menos que a meta proposta para a parada, aumentando a recuperação de gás de Coqueria, maximizando ganhos de geração elétrica e minimizando a exposição a riscos ambientais associados a parada. As ideias apresentadas neste artigo são de grande valia para a evolução do pensamento crítico e sistêmico sobre a manutenção, não só em gasômetros, mas em todo o contexto de realização de atividades já consolidadas.

Aug 1, 2019