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By G. L. Neumann

In October 1949 the College Park Branch of the Mining Division instituted a survey of the New England pegmatites. Many of the New England pegmatite deposits were superficially examined, and the Bumpus quarry in Albany, Oxford County, Maine (see fig. 1), was selected for a diamond-drill exploratory-development project to supply information for developing more economical mining methods and no increasing production of beryl and other scarce minerals associated with pegmatitic intrusives. The Bumpus quarry has been mined intermittently by three operators since it was opened in 1927. At the time of drilling, the vein or dike (see figs. 2 and 3) had been mined to a depth of 60 feet for a strike length of 280 feet. The dike averages 40 feet in thickness and dips 50 degrees southeast. The Bureau of Mines drilled seven diamond-drill holes between September 27 and November 27, 1950. These holes showed that the dike persists for at least 350 feet to the east and probably 200 foot to the west of the present excavation. The drilling also indicated that the dip, as exposed at the surface, continued unchanged at 500 to a depth of at least 50 foot below the pit. The dike was not delineated, although it fingered out as pegmatite interbanded with Granite, diorite, and gneiss in diamond-drill hole B-4, approximately 250 feet west of the pit. Further drilling will be necessary to find the extent of this pegmatite dike and to determine the safest and most economic mining system.

Jan 1, 1952

By T. Bieniawski

"INTRODUCTION The Congress theme ""Improvement of Mine Productivity and Overall Economics by Modern Technology"" is probably beat: addressed by the subtheme allocated to this Plenary Session. It is appropriate that .Theme 1 emphasizes the simple point that effective use of geotechnical information is the key to improving mine productivity. In essence, this means that: (1) geological and geomechanics, (rock mechanics) data must be collected in sufficient quantity and of high quality; (ii) data interpretation must be performed specifically for purposes of engineering design; (iii) innovative design approaches should be used to bring about Improvements in productivity and safety.While, each of these three aspects .may: seem obvious to any mining engineer it is a fact that the above sequence is seldom followed and as a result, mining engineering not infrequently lags, behind other branches of engineering when it comes to design creativity, efficiency and safety.. . After all, mining is still-one of the most hazardous occupations and we are gathered here to discuss, at the highest world professional forum, how to use more effectively the modern technology. This however, does not mean that mining engineers are less capable than other engineers or that their achievements are any lesser; far from it! Mining engineers are the cream of the engineering society on whose efforts depends the welfare of mankind. Moreover, they have produced minerals and coal evergrowing quantities against evergrowing difficulties. Yet, we must and can become even better because we are not making full use of the modern technology and rock mechanics knowledge already at our disposal, and. we are not being innovative enough to the full extent of .our capabilities."

Jan 1, 1989

By Roger J. Morrell

The Bureau of Mines conducted drag cutting experiments in hard, abrasive rock in an effort to extend the capabilities of an experimental kerf-core mining machine. The basic kerf-core mining machine cannot be used in hard, abrasive rocks because of the high wear experienced by the kerf cutters. These experiments were conducted in an effort to develop a method of preweakening the rock ahead of the kerf cutters in order to reduce the high cutting loads and hence the higher wear rates experienced by the cutters. The two "preweakening" techniques studied were indenting with mechanical wedges and single and double slotting with diamond saws. The best cutter force reduction achieved with mechanical indenting as 70 pct, whereas double slotting achieved force reductions of up to 99 pct. Conceptual designs of preweakening systems that could be retrofitted onto the basic kerfing cutterhead were developed for both the indenting and the slotting techniques. A high-energy impactor with wedge bit was used for the indenting method, and high-pressure water jets were used for the slotting method. A preliminary technical and economic analysis was performed for both of these full-scale systems to illustrate the methodology and to point out the important technical and economic factors that must be considered.

Jan 1, 1987

By N. E. Hanna

To be authorized for use in coal mines, explosives and blasting devices must pass certain safety tests prescribed in schedule 1F,3/ on the basis of extensive practical and theoretical research by the Explosives Testing Station of the Federal Bureau of Mines. An explosive or blasting device that passes these tests is placed on the active permissible list. As this list is constantly revised, it has been the practice of the Bureau of Mines periodically to publish the names of explosives and blasting devices that have been added to the active list, as well as those that have been transferred to the inactive list; changes in brand names also are reported. This circular covers all permissibles including additions, transfers, and changes made between December 31, 1945,4/ and December 31, 1951.

Jan 1, 1952

By J. W. Horne

The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the non-condensable gases evolved when crude shale oil is distilled under pressure. Hydrogen sulphide is one of the components found in the complex mixture of Gases produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills. The study required a complete extraction of all the hydrogen sulphide from the gas stream after it left the water-cooled distillate condensers and before the gas stream entered the charcoal absorber for removing the light naphtha. In devising the method it was necessary to take into account a constant variation of velocity, pressure, and percentage of sulphide in the total gas stream coming from the still. Ordinarily, the quantitative determination of hydrogen sulphide in gas is made by analyzing small samples taken at regular intervals. This estimation can be accomplished by use of the Bunts gas burette as modified by Tutriler, or by a similar method. In the industries where the flow of gas is constant and of uniform composition, this practice is sufficiently accurate for plant control. For experimental work where many variables have to be taken into consideration, as in the case at band; these methods are not applicable.

Jan 1, 1931

By Paul M. Tyler

Graphite is chemically identical with diamond, both being crystallized allotropic forms of carbon. Graphite obviously differs greatly from diamond in physical properties and is easily recognized by its blackness, its softness (1 to 2 on Mohs' scale), and its slick feel when rubbed between the fingers. Strictly speaking, all graphite is crystalline, but grades in which the individual grains cannot be distinguished with the naked eye are commercially classed as amorphous. Natural mixtures of the two varieties occur in all proportions, and the classification of a given sample as "amorphous" or "crystalline" graphite is based largely upon trade practice. Until recently different varieties of vegetable or animal charcoal, lamp black, soot, gas carbon, and coal ware considered strictly amorphous, but modern examination by X-ray methods indicates that even these materials possess the same internal crystalline structure as graphite, differences in physical properties being perhaps explained by porosity or presence of combined hydrogen or other impurities.

Jan 1, 1941

By Forrest T. Moyer

In conjunction -with the statistical survey of the lime industr-.r in 1939, by the Bureau of Hines, producing companies reported the lime-fuel ratios attained in their plants according to type of kiln and kind of fuel. Each ratio, expressed as the number of pounds of lime burned by a unit quantity of fuel, was weighted according to the tonnage of quicklime pro- . duced at the reporting plant and grouped with similar data from other plants, so that an average ratio for each type of fuel and,kiln could be calculated. By this method the variables trat affect ratios of individual plants are more or less equalized, and the computed average lime-fuel ratios provide a fair measure of kiln and fuel efficiencies during 1939.

May 1, 1941

By Robert E. Barieau

The following zero pressure thermodynamic properties of nitrogen gas are tabulated: [C°p, H° -o, S°], These properties are tabulated in units of joules, gram mole, degrees Kelvin and in calories, gram-mole, degrees Kelvin for every degree Kelvin from 50° to 550°. The same functions are also tabulated in units of British thermal units pound-mole, degrees Rankine for every degree Rankine from 100° to 1,000°.

Jan 1, 1967

By R. V. Ramani, C. B. Manula, A. Owili-Eger

PART 1 THE INPUT AND OUTPUT DATA AND THE MINE SCHEMATIC SHOWING THE FLOWS FROM COMPUTER SOLUTIONS FOR APPLICATION I

Jan 1, 1975

By Lewis V. Wade

This Bureau of Mines work was performed to theoretically determine the effects of specimen radius and specimen boundary conditions on the stress state in the rock near the anchor for rock specimens used to investigate expansion anchor behavior. Finite element analyses were performed on mathematical models of varying radius and boundary conditions. A review of the results of these analyses revealed a definite convergence of all stress measures considered as the specimen radius increased. There was, however, a significant variation in all stress measures as the specimen diameter increased from 8 to 12 inches.

Jan 1, 1973

By Guy E. Dent, Robert S. Sandford, W. T. Millar, Hugo E. Kuehn

"INTRODUCTION AND SUMMARYDuring the latter part of 1943 a magnetometric survey was conducted by the Geophysical Division of the Bureau of Mines at the mine, Putnam County, N. Y., in an endeavor to locate a segment of the body that reports state was cut off by a fault. The Mahepac mine was abandoned about 1895 after producing nearly 1,000,000 tons of high-grade magetite iron ore. The results of the investigation indicate the termination of the ore body by ""pinching"" or a displacement of such magnitude as to place any extension at a considerable distance the original ore body. This report describes the work done on the project and presents the data obtained. ACKNOWLEDGMENTSThe Bureau of Mines has been investigating deposits of critical and essential minerals in the United States and Alaska since 1939. The Mahopac mine was visited by W.T. Millar, an engineer of the Bureau of Mines, on June 5, 1943, accompanied by Dr. William Agar of the Federal Survey, and again on July 29, 1943, accompanied by Dr. A. F. Buddington and H.F. Hawkes, both of the Geological Survey.The mineral investigation was under the general supervision of Paul M. Tyler, formerly regional engineer, Eastern Region; J. D. Bardill, formerly district engineer; and Dr. F.W. Lee, formerly chief. Division, Geophysical Exploration. The work was done under the immediate supervision of W. T. Millar, project engineer. The Geophysical Survey was made by Hugo Kuehn and Guy E. Dent."

Sep 1, 1948

By S. E. Khalafalla

The Bureau of Mines investigated variations in the activation energy for the carbon monoxide reduction of magnetite and ferrous oxide with respect to the state of aggregation of the oxide material. Reduction phenomena can only be satisfactorily explained by including an adsorption step in the reduction process. Summation of the values of the exothermic heat of chemisorption and the variable apparent activation energy for reduction yields a nearly constant value of about 50 kcal for either ferrous oxide or magnetite regardless of whether they are aggregated in pelletized form or coarsely crystalline particles.

Jan 1, 1965

By John W. Buch

Safety and cost in mining coal beds under the extreme pressures found at depth, full extraction to conserve resources, and even surface subsidence to minimize damage of improved areas have directed much well-deserved attention, in the United Kingdom; to roof-control methods. Because the effects of pressure will be felt intensely as our Pennsylvania anthracite mines grow deeper, the senior author took advantage of an opportunity afforded by a mission to Europe3/ to observe, to a limited extent, the effects of pressures found in deep mines and the manner in which they are con trolled. Organized research relating to strata control has been carried on in Great Britain for nearly 25 years. These activities have been ably outlined by Dr. D. W. Phillips.4/ Physical properties of coal-measure rocks, movements of roof and floor, and types of face and roadway supports have been investigated. Same of the forces induced by the extraction of coal have been measured. The results of this research have been publicized and openly discussed, and much progress has been made in establishing a better factual understanding of roof-control problems and their solution.

Jan 1, 1951

"The following articles were produced through funding under Generic Mineral Technology Center for Respirable Dust research. Full articles appear in the proceedings, 3rd Symposium in the Mineral Industries, published in 1991 by the Society for Mining, Metallurgy and Exploration, Inc.Personal Diesel Exhaust Aerosol SamplerV.A. Marple, K.L. Rubow, and Y. TaoParticle Technology, Mechanical Engineering Department, University of Minnesota, Minneapolis, Minnesota(Section ill. Diesel I: Diesel Particulate Measurement, pp. 73-81)Abstract. Techniques are being developed for measuring the mass concentration of respirable diesel exhaust particles found in underground coal mines. Studies have been conducted over the past five years to investigate size selective 18Dlpling techniques to measure the respirable mass concentrations of diesel exhaust and mine dust aerosol particles in underground coal mines. Results from these studies have been used to develop design and performance criteria for a personal diesel exhaust aerosol sampler.Three personal diesel exhaust aerosol samplers have subsequently been designed and evaluated in both laboratory and field settings. These samplers use size selective classifiers for the determination of respirable mass concentrations of mineral dust and diesel exhaust particles. Their designs are based on the premise that diesel exhaust particles are predominantly less than 0.8 µm while mineral dust is greater than 0.8 µm.One design, selected for field evaluation, consists of a 10 mm nylon respirable dust cyclone followed by a 0.8 µm cutpoint impactor and afterfilter. The cyclone removes the nonrespirable particles while the inertial impactor state, collects the mineral dust on an impaction plate and allows the diesel particles to penetrate to an afterfilter. The two sample fractions of the respirable particles ( <0.8 µ.m and >0.8 µm) are gravimetrically analyzed to determine the concentrations of the diesel and mineral dust portions in the respirable coal mine aerosol."

Mar 1, 1992

The National Personal Protective Technology Laboratory (NPPTL) of the National Institute for Occupational Safety and Health (NIOSH) has undertaken a collaborative study with the Mine Safety and Health Administration (MSHA) to determine how well self-contained self-rescuers (SCSRs), deployed in accordance with Federal regulations (30 CFR 75.1714), withstand the underground coal mining environment with regard to both physical damage and aging. Apparatus tested included the CSE SR-100, the Draeger OXY-K Plus, the MSA Life-Saver 60, and the Ocenco EBA 6.5 and M-20. This report presents findings regarding laboratory-tested SCSRs in the tenth phase of testing, from July 2004 to March 2006. The SCSRs were tested on a breathing and metabolic simulator and on a human subject walking on a treadmill. The tests performed in this study are not the tests used for certification (Title 42 of the Code of Federal Regulations, Part 84). The tests performed in this study continue until the apparatus are empty to enable comparison of new versus deployed apparatus. The method for obtaining deployed SCSRs for this evaluation was not a random selection from the deployed population of SCSRs. We sought older apparatus with visible environmental impact rather than newer apparatus, and we attempted to sample a wide range of deployment modes. Although the results of these tests are useful for observing performance of the tested SCSRs, they are not representative of all deployed SCSRs. This report is the last of 10 report phases begun in 1982. Previous reports describe phases 1 through 9 [Kyriazi et al. 1986; Kyriazi and Shubilla 1992, 1994, 1996, 2000, 2002, 2004, 2006] A new evaluation protocol, with revised sampling strategies, test methods, and reporting procedures, is currently being designed to enhance the applicability of the results. The results of these studies suggest that the large majority of SCSRs that pass their inspection criteria can be relied upon to provide a safe level of life support for mine escape purposes. However, the storage and handling in the mining environment seems to have caused performance degradation in some of the apparatus. In this phase, phase 10, we found some CSE SR-100s (93 tested) that exhibited high CO2 levels, stuck-together breathing hoses, starter-O2 failure, breathing hose punctures and tears, high breathing pressures, and loose particulates in the breathing hose. The loose particulates caused coughing in human-subject tests. One MSA Life-Saver 60 (20 tested) in this phase had a stuck-open relief valve. One Ocenco EBA 6.5 (50 tested) had an unattached O2 supply hose. An unexplained phenomenon occurred with two Ocenco M-20s (20 tested): low O2 flow rates preventing their successful use. Almost all of the failures noted involved units that failed their inspection criteria.

Jan 6, 2008

By J. W. Horne

The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the noncondensable cases evolved when crude shale oil is distilled under pressure. Hydrogen sulphide is one of the components found in the complex mixture of uses produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills.

Jan 1, 1931

This chapter analyses the parameters influencing initial design of communication systems, for new mines and upgrading existing systems. Paragraph 5.2 outlines those variables that must be taken into account during the design stages of a new wired phone system. Recommended features, general requirements, and how they can be implemented are treated in this section. Paragraph 5.3 describes ways of improving or extending the range of trolley carrier phone systems and pager phone systems already installed in the mine. 5.2 New Phone System Design The task of designing an adequate communication, control, and monitoring system for an underground mine must be addressed on a system basis. In addition to insuring that effective voice communication is established, any new system should take into account present and future requirements of remote control and monitoring functions. Chapter 4 illustrated the drastic savings in response time that can be realized when remote control and monitoring are integrated into the overall communication system. The importance of including control and monitoring in the overall design plan for any system cannot be overemphasized. Because each mine is unique, and thus usually has its own special operating characteristics and communication requirements, there is no such thing as "the one best system" to meet the requirements of all mines. The optimum communication, control, and monitoring system for a mine must be one that has been tailored to meet the special requirements of that particular mine. Factors that must be considered during system design include- a. Type of mine and mining methods (low- or high-seam coal, deep hardrock mine, stope caving, longwall, room and pillar, etc.). b. Maximum number of working sections. c. Expected mine growth rate and eventual maximum size. d. Haulage methods (tracked trolley, diesel, belt, etc.). e. Underground power distribution system (dc, ac, or both). f. Features desired (two-way radio paging, private line capability for emergency use, etc.). g. Redundant or backup systems for use during outages of the normal system. Although no two mines are alike, the following items have been established as the main characteristics desired for any underground communication system: 1. Multiple Communication Paths to Outside--the objective here is to give all telephones a second method of communicating with the surface. 2. Audible Emergency Signaling--the communication system provides the main means of alerting miners during emergencies. The system should include means to broadcast distinct audible signals for emergency signaling. Initiation of these signals should probably be controlled from. a central outside point, such as a surface control room. 3. Emergency Override--provisions should be included to permit any conversation to be overridden with emergency communication. 4. Selective Area Page--as mines grow larger it is apparent that the entire telephone system paging mode need not be activated each time a call is initiated. When the general area of a

Jan 1, 1984

By L. D. Stewart

The main reasons for developing an induction system for signaling from the cage are, first, to increase safety, and second, to effect economies in the operation of cage and ship hoists, especially when work is being done in the shaft. To-day nearly all mines which employ safe methods have installed safety gates on cages, at the different levels, and at the collar of the shaft. Under the old system in some instances signals could only be Given from the station outside the cage, and in other cases, after the signal was given the only method whereby those riding on the cage could control its movements consisted of pulling the bell-rope hanging in the shaft, an uncertain and somewhat hazardous procedure at best. With the system herein described, however, it is possible, without opening the gates, to signal to the engineer from any place in the shaft whether or not the cage is moving, and finder the same conditions it is possible to converse with the engineer by using the telephone. In short, the cage tender has at all times an opportunity either to signal or talk to the engineer without leaving the cage.

Jan 1, 1931

By Robert W. Freedman, Robert L. Craft, William G. Humphrey

As part of a continuing effort to reduce the weight and bulk of equipment that mining personnel must carry underground, the Bureau of Mines and the Mining Enforcement and Safety Administration (MESA) investigated accurate and convenient gas samplers for use by mine inspectors in sampling mine atmospheres. The samplers are septum-stoppered glass vials commonly used for routine blood sampling. These lightweight, compact samplers yield results comparable with those obtained with conventional bottle samplers of 250-ml nominal capacity.

Jan 1, 1975

By D. Harrington

"The recent discovery and exploitation of petroleum territory have resulted in the enactment of new petroleum laws in most of the South American Republics. The activities in the discovery of these new fields were engendered by the knowledge of the fact that present producing fields must within well defined periods be exhausted. Oil operators were willing to take the initial steps in exploitation in the absence of legislation that applied strictly to petroleum operations. The enactment of modern legislation in many of these Republics encouraging and protecting exploitations may cause tremendous oil activities in these countries, and the results may be comparable with the magnitude of the undertakings and the prestige of the companies now entering this territory.These, oil fields are admirably located for convenient distribution of petroleum by water to all the Nations using oil as fuel for shipping and industrial concerns. The oil markets of the western coast of South America will derive immense benefits from the Panama Canal. This navigation route brings these markets into direct ocean shipment with the Atlantic coasts of the Western and Eastern Hemispheres.One deterrent to oil production in the Republics of South America is the want of inland. transportation facilities, but the recent laws of these Republics without exception provide for acquiring rights of way for pipe lines and other modes of transportation; and doubtless the great interests and. syndicates already operating in these regions will, as production increases, provide ample pipe line transportation sufficient to convey to the coast the oil produced. It way be assumed, from the legal guarantees afforded, and from operating equipment and machinery that are now being concentrated that refineries will be erected at shipping points for the purpose of making these petroleum products accessible to the world."

Jun 1, 1921