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The Bureau of Mines has long been active in promoting the purchase of coal for Government use under specifications that define the requirements in terms of heating value of the coal, expressed in British thermal units, and the composition as shown by proximate analyses. To these, when required, are added the ash-softening temperature, the free-swelling index, and the Hardgrove grindability index. Under most of these specification contracts, the bidders guarantee the quality of the coal, and that guaranteed by the successful bidder becomes the standard of his contract. The deliveries are sampled in accordance with instructions1 issued by the Bureau of Mines, and the samples are analyzed in the Bureau laboratory to determine whether the coal is of the quality guaranteed by the contractor; if it is not, a price adjustment is made. The Government, with the exception of the Tennessee Valley Authority, purchased approximately 5.5 million tons of coal in fiscal year 1971. In connection with these purchases, the Bureau analyzed 4,366 samples. These are published (table 1) for the use of Government officials and the public. Such analyses of delivered coal and tipple samples (samples collected at mine tipples as coal is being loaded into railroad cars or trucks) provide valuable data for use in evaluating future bids. In addition, the continuous sampling of coal as delivered is a check on the practical results obtained in burning the coal.

Jan 1, 1972

By Verônica Scarpini Candido

O uso cada vez mais frequente do poli metacrilato de metila (PMMA), muitas vezes em substituição ao vidro temperado, se deve a sua alta rigidez, praticidade, leveza e transparência. No entanto, as normas de fabricação atuais na indústria de polímeros recomendam testes específicos nesses materiais. O presente estudo tem o objetivo de testar mecanicamente as propriedades do material Polimetacrilato de Metila (PMMA) em condições que simulem um ambiente muito mais agressivo do que o usual. Para tanto foram realizados testes de espectroscopia na região do infravermelho (FTIR), análise termogravimétrica (TGA), testes de tração e impacto Izod, e análise por Microscopia Eletrônica de Varredura (MEV). Os resultados revelaram que o Polimetacrilato de metila (PMMA) manteve suas propriedades mecânicas em tração até a temperatura de 105°C. No que se refere à resistência ao impacto, a temperatura influenciou negativamente no desempenho desse polímero.

Oct 30, 2017

By Earle Schumacher

THE solidus line above the solid solution field in the lead-antimony system was originally determined by Dean and his associates1 from heating curves. They did not regard this line as having been accurately fixed and in their more recent publications2 the curves drawn do not follow closely the original data. The precise location of the solidus line is of importance in the extrusion of lead-antimony cable sheath, as the temperature of the metal in this process must be less than the lowest temperature at which any part of the alloy in the lead-press charge becomes liquid. It is very desirable, however, to operate at as high a temperature as possible, as the rate of extrusion for a given pressure is approximately doubled for an increase of 10° C. in temperature. The precise location of this line is also important, in the investigation of ternary systems of lead, antimony and a third metal. For these reasons, and because of the differences reported in the literature, data were secured on the lead-antimony solidus line by the classical quenching-test procedure.

Jan 1, 1927

By William W. Adams

Not since complete records of accidents first became available has the safety record of the quarrying and related industries of the United States been as favorable as it was in 1940. The combined accident-frequency rate was lower and therefore better than in any year since 1916, the first year for which complete and comparable figures are available. Although operating companies began to furnish accident reports to the Bureau of Mines in 1911, the reports for that year and the next few years were obviously incomplete as to number of accidents reported, especially slight injuries involving only 1 or 2 days of disability of the injured employees. By 1916 the reports from operating companies appeared to be reliable as to completeness of coverage of slight injuries. Although the number of men employed in 1940 was by no means a record, it represented a gain over each of the 2 preceding years. Likewise, the number of man-hours worked during 1940 was larger than in 1938 and 1939.

Jan 1, 1942

By A Horne, Z Graszkiewicz, D Dettrick, R Evan, B Neal

"Most of VictoriaÆs rivers and aquifers are already fully allocated or reaching full allocation. In regions without a well-established water market, access to water entitlements to facilitate new development is limited. In areas with established water markets, mine developers face an undue cost burden in circumstances where they are only planning to consume a fraction of the water entitlements that they purchase. The challenge for water managers is to ensure protection of water resources and other water users without creating an unnecessary disincentive for those types of developments that return most of the water that they take from water sources. The opportunity for development of a mine is explicitly linked to a particular location and must be developed where a resource is located or it cannot be exploited at all. Regulatory arrangements that facilitate development may have a positive impact on economic development, particularly where water availability is a potentially limiting factor. Net volume licensing has the potential to allow increased economic outcomes through improved licensing of access to water. Net volume licensing differs from traditional water licensing in that it authorises access to water on the basis of ænet useÆ rather than æthe gross volume takenÆ. This paper asks under what conditions net volume licensing is likely to be feasible and effective. In particular, the paper examines the information and accuracy requirements to allow net volume licensing decisions to be made. This work is based around five case studies in Victoria that were used to examine the potential for net volume licensing for mines and quarries. Assessing a potential net volume licensing arrangement requires the regulating authority to have an understanding of the inputs and outputs of water to a site. In contrast, assessment of take and use licences consider only a single input. It was concluded that the conditions that lend themselves to net volume licensing include: well understood water inputs and outputs, including appropriate accuracy of information where the location of site water inputs and outputs are the same where the timing of extraction and discharge can be managed to minimise impact on the water resource.A key remaining challenge is establishing an accounting framework that allows net volume licensing under current water resource limits. CITATION:Graszkiewicz, Z, Horne, A, Neal, B, Evan, R and Dettrick, D, 2013. The practicalities of implementing net volume licensing of water use in mines and quarries - a discussion based on Victorian case studies, in Proceedings Water in Mining 2013, pp 241-250 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By Thomas A. Gwynn

When Lewis and Clark first pushed their boats up the Missouri River, Meriwether Lewis reported the presence of coal in the western states by saying in 1802 that it "burnt tolerably well and afforded but little flame or smoke but produced a hot and lasting fire". Lewis would have been amazed and bewildered at the history of coal development in this region and the more recent political-socio-economic-environmental confrontations of today. Certainly without this coal the railroads would not have readily pushed into our western states, and the progress of this region would have suffered. The coal industry has passed from a period when "coal was king" to a period of depression in the industry, but its importance is being revived. A contributing and simultaneous environmental concern has emerged in the nation and in many states during the past ten years, partly caused by newly imposed standards for sulfur content of fuels. Much of the midwest and eastern coal cannot be used because of high sulfur content, shifting attention to the low sulfur coal deposits of the western states. In the western states, lands disturbed by strip mining or even underlain by strippable coal are small compared to the total acreage, and usually mining operations are on lands not under cultivation. There are some farm lands being disturbed by surface mining, but this is often over-emphasized. In states like New Mexico and Arizona the percentage is less. The value of the minerals underlying the surface certainly must be considered along with the value of the surface, and sometimes proper reclamation following mining can result in higher ultimate usage of the land.

Jan 1, 1974

By M. A. Elliott, H. H. Schrenk, L. B. Berger, John C. Holtz

"INTRODUCTION Diesel-powered locomotives designed specifically for underground operation were used in the construction of some of the tunnels that comprise the Delaware Aqueduct in New York State. Before this there had been limited use of Diesel-powered equipment such as trucks, bulldozers, and shovels in tunnel construction in various parts of the country, but this equipment was used without modification for underground use and, in some instances, appar¬ently without due consideration of the hazards that might be created by the introduction of fuel-burning equipment into confined underground spaces.As certain definite advantages were apparent if Diesel haulage could be used in tunnel construction in some sections of the Aqueduct, the contractors who were to construct the tunnels in these sections were desirous of using, this type of haulage equipment if it could be used with safety. This matter was given careful consideration by the various agencies concerned with the establishment of safe practices on the Aqueduct project before tunnel driving was started. Of chief concern were the quantities of toxic or objectionable materials that would be discharged into the tunnel air by the exhaust of the locomotives and the volume of ventilating air that would be required to dilute these exhaust gas products to concentrations permissible in the atmosphere of working places."

Jan 1, 1947

By Irven A. Jacobson

This literature survey consists of references dealing with gaseous state thermal decomposition reactions of organic nitrogen and sulfur compounds. The reference source for the survey was the Chemical Abstracts from 1930 to 1956, inclusive. Original articles were not studied. The starting date was set at 1930 because previous to this time much of the work is questionable. This report is in three parts: Part I lists nitrogen compounds; Part II, sulfur compounds; and Part III, compounds containing both nitrogen and sulfur. The organization of the classes of compounds is alphabetical: Part I - amides, amines, amino acids, ammonia, azides, azines, azo compounds, heterocyclic nltrogen compounds, hydrazine, nitrates, nitriles, nitrites, nitro compounds and miscellaneous nitrogen compounds; Part II - disulfides, sulfides (including double and triple sulfides), thiols, thiophenes and xanthates; Part III - thioacid amides, thiazoles, thiocyanates and thiuram disulfides. A class formula is included with each class name. The R's used in these class formulas may refer to hydrogen or to the same or different radicals when more than one R appears.

Jan 1, 1960

By Bodo Peinemann

For more than 35 years Lurgi has been providing its fluid bed roasters on a world­wide basis. The current total annual capaci­ty of the 250 Lurgi roasters approaches 26 million mt of sulphide minerals, including gold-bearing flotation pyrite concentrates. While the stationary fluid bed has been uti­lized for roasting exclusively, Lurgi has now commercially introduced its Circulating Fluid Bed (CFB) technology for gold roasting in a successful effort to maximize gold re­covery.

Jan 1, 1990

By A. E. Seaton

In this paper it will be my endeavor to trace the development of the marine engine and its appurtenances, and the general progress that has taken place in marine engineering generally during the past fifteen years, rather with the object of attributing much of it to the successful efforts of the makers of iron and steel, thereby rendering my thanks to them for the valuable service they have contributed to my profession, than to recount what has been achieved by the skill, ability and perseverance of my colleagues in shipbuilding and engineering. The engineer has been at all times dependent on the ironmaster, and on more than one occasion his progress has been barred by the inability of the latter to overcome some obstacle to success in his manufacture. But on the other hand, it is equally true that the ironmaster has often been ahead of the engineer, and has been prepared, long beforehand, to supply that which would make a success for the marine engineer if he would avail himself of it.

Jan 1, 1891

By A. V. Wilke

The metallurgical balance is a tool usually applied in the mining industry. The final result is used for different objectives. All the existing software for the calculation of the metallurgical balance fits the numbers in such way that a logical correspondence between the input and output materials exist. Nevertheless, the accuracy of the metallurgical balance strongly depends on the quality of the input data. Division El Teniente of Codelco Chile has been optimizing the metallurgical balance system the last 14 years. As well, it has participated in the development of corporate norms to optimize the operations of sampling and weighting systems. As a consequence, the precision and the accuracy of the metallurgical balance have been improved in a significant way. Also the understanding of process variability was enhanced. The improvements have allowed Codelco to discover and minimize hidden losses and to better support top management decisions. The present paper describes the main aspect of the continuous improvement process.

Jan 1, 2009

REFERENCES AND FOOTNOTES 1. U.S. Department of the Interior, Office of Surface Mining. Surface Coal Mining Reclamation: 10 Years of Progress: 1977-1987. Washington, D.C. August 3, 1987.48 pp. (For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington D.C. 20402.) 2. The Rural Abandoned Mine Program (RAMP), authorized by Section 406 of SMCRA, provides for the control and prevention o f erosion and sediment damages from unreclaimed abandoned mine lands. 3. The Small Operator Assistance Program (SOAP), authorized by Section 401(b)(1) and 507(c) of SMCRA authorizes up to 10 percent of the fees collected for the Abandoned Mine Reclamation Fund to be used for technical assistance to help qualified small mine operators obtain techincal data needed for permit applications. Operators who produce fewer than 300,000 tons of coal per year are eligible for assistance. 4. OSM regulations 30 CFR 816.42 and 817.42 require water from areas distrubed by mining activities be in compliance with all applicable state and federal water-quality laws and effluent limitations for coal mining established by the U.S. Environmental Protection Agency. 5. Sourse: Abandoned Mine Lands Fee Collection System, Data from OSM-1 form. 6. Sourse: Abandoned Mine Lands Fee Collection System, Data from OSM-1 form. 7. Source: OSM Field Office Annual Reports. 8. Johnson, W. and G.C. Miller, Abandoned Coal-Mine Lands: nature, extent, and cost of reclamation. U. S. Bureau of Mines, 1979,29 pp. PHOTOGRAPHIC CREDITS Front cover, pp. i, 1, 2 bottom, 7 right, 10 bottom left, l 1 top, l l bottom right, 12 top, 13 bottom, 14 bottom right, 15,16 bottom, 17 top, 17 bottom right, 18 bottom, 19, 20 bottom, 21 top, 22, 23, 24 bottom, 25 bottom, 26 bottom left, 26 bottom right, 27, 28, 29 top, 30 bottom, 32 bottom right, 33 top, 34 top, 35 top left, 35 bottom left, 35 bottom right, 36 top, 37, top right, 37 bottom, 38 bottom, 39, 41, 42 top, 43 bottom, 44 bottom left, 44 bottom right, 45, 46, 47, and 53: Chuck Meyers, OSM. Page 2 top and center: Tony Fuhs. Page 3: John Sharkowicz, OSM. Page 6 left: North American Coal Corp. Pages 6 right, 7 left, l l bottom left, 13 top left, 13 top right, 17 bottom left, 21 bottom, 25 top left, 25 top right, 29 bottom, 30 center, 32 top, 32 bottom left, and 38 top: Bob Welch, OSM. Page 10 top left: Donald Stump, OSM. Pages 10 right, 14 top right, 14 center right, 18 top, and 44 top: Ron Hill, EPA. Page 12 bottom: Texas Utilities Co. Pages 16 top, 20 top, 24 top: Tennessee Valley Authority. Page 26 top right and 26 center left: Richard Dick, U.S. Bureau of Mines. Pages 30 top, 33 bottom left, 33 bottom right, 35 top right, 36 bottom, 37 top left, 40 top, 40 bottom, 42 bottom, 43 top left, and 43 top right: Jim Boyer, OSM. Page 31 top left, and 31 top right: Bruce Wage, Western Energy Co. Page 31 bottom: Rex Wilson, OSM. Page 34 bottom: West Virginia Division of Abandoned Mine Lands. Page 35 center: William Weist, Jr., OSM.

Jan 1, 1992

By Ralf Plinninger, Pafos Busch, Richard Gradnik

This paper presents the details of the Bad Bergzabern tunnel project. This tunnel is the main part of the B427 federal road bypass, intended to improve the regional traffic infrastructure and to reduce the traffic load in the historic city centre of the health resort Bad Bergzabern. Located in the south-western part of Germany, the project area is situated at the eastern margin of the so-called Palatinate Forest, a low mountain region of mainly triassic sediments with a complex and variable geological history. The German federal government, represented by the office of mobility of Rhineland- Palatinate, awarded the contract to BeMo Tunnelling, a specialized Tunnelling company with a long history of innovation and success in NATM tunnelling. The contract includes the construction of two separate tubes with a length of approximately 1,44 km (0.9 mi)—the road (main) tunnel with a cross section of 101 m2 (1,090 sq ft) and a parallel rescue tunnel with a cross section of ca. 23 m2 (250 sq ft.) Both are connected by six cross passages. Tunnels and cross passages are excavated according to the principles of the New Austrian Tunnelling Method (NATM). Due to BeMo Tunnelling’s technical expertise and capabilities, the project team was able to engineer a speed-up concept that saves money and time for the construction team and client. This paper presents the innovative approach BeMo Tunnelling made to optimize the execution of the tunnelling works and the challenges the project team is facing with regard to a complicated geological situation, countermeasures against an increasing effect of climate change and volatile prices for construction materials.

Jun 13, 2023

By Young C. Kim

Introduction and Objective of This Paper Computerized open pit mine models* are more and more used today for feasi¬bility studies as well as for long range mine planning. In fact, using these models is becoming an enforced practice due to various reasons. One main reason is its capacity to evaluate several designs in a fraction of time required by manual effort. Another reason is the necessity to evaluate several. pit designs due to ever decreasing grade of the orebody and increasing financial risk due to smaller profitability margin. In spite of today's accepted use of computer models, very little guidelines are available which the average practitioner can follow either to choose or to build the type of model best suited for his need. Consequently, the objectives of this paper are: 1. To review the current state of the art in the computerized open pit mine models. 2. To provide some suggestions for model selection. 3. To share our experiences in developing a model for a highly irregular copper ore deposit (see Appendix).

Jan 1, 1977

By Warren Hastings

This paper describes the methods and costs, in units of labor end materials, of sinking a 7 compartment vertical shaft 1,261 feet through a fractured, water-saturated formation. The shaft, designed for hoisting 2,500 tons a day, is at Friedensville, Lehigh County, Pa., approximately 6 miles south of Allentown and Bethlehem. It was sunk by the E. J. Longyear Co. under contract to the New Jersey Zinc Co. Preparation for shaft sinking W8A begun July 1, 1947, and sinking was completed August 18, 1952. A total of 604,858 man hours was required to sink the shaft.

Jan 1, 1954

By E. P. Carman

This report is the 19th in a series summarizing Bureau of Mines research and technologic work on coal and related investigations. The first 17 reports covered fiscal years; however, the 18th report3/ covered the 18 months from July 1, 1952, to December 31, 1953, to permit the publication of this and subsequent reports on a calendar-year basis. Most of the material in this report relates to publications by Bureau authors issued during the reporting period. Some work is referred to on which the results have not yet been published or may not be published for security or other reasons. In a few instances publications are mentioned that were issued before the reporting period but were not included in previous reports. Further details on the published work described herein may be found in the publications cited in the footnotes. Research and technologic work on coal by the Bureau is directed toward developing and encouraging increased conservation of coal resources through safer and more efficient mining, preparation, and utilization. Significant advances were made during the year in these fields, particularly in coal-mine safety and in preparation and utilization of the various ranks of coals.

Jan 1, 1956

By Robert S. Young

During the last quarter-century, exploration for metallic deposits in Maine has been sporadic with peaks generally coinciding with periods of high metal prices. Known cases of regional or semi-regional evaluations are few; most efforts have been local and usually intensive. On the basis of broad geologic groups, the State has been divided into five fundamental environments: ( 1) coastal metamorphic belt; (2) southern volcanic belt; (3) Silurian slate belt; ( 4) northern volcanic belt; and ( 5) Devonian slate belt. Although not restricted to these areas, exploration in recent years has been concentrated in the northern and southern volcanic belts. Notable examples of recent exploration activity, directed to sulfide minerals, include: ( 1) the Knox County nickel-copper-bearing ultramafic rocks; (2) the Harborside (Cape Rosier) copper-zinc deposit; (3) the Second Pond (Black Hawk) zinc-copper-lead-silver deposit; ( 4) the Big Hill-Barrett lead-zincsilver- copper-gold zones; (5) the Parmachenee copper-zinc belt; ( 6) the Moxie Lake nickeliferous peridotite; and (7) the Attean quartzmonzonite molybdenum-copper occurrences. The Second Pond and Harborside prospects appear to be close to production. Systematic investigations for non-metallic deposits appear to have been aimed principally toward limestone, asbestos, diatomaceous earth, and spodumene-bearing pegmatites. Advances in prospecting methods, high metal prices, a favorable business outlook, increasing cooperation from large landholders, and some discoveries support the probability of increased exploration activity in Maine during the coming decade.

Jan 1, 1968

By Frederick Bloetscher

Means of improving the U.S. Bureau of Mines Brattice Window Method have been investigated by Goodyear Aerospace Corporation (GAC). An extensive series of laboratory tests at GAC and a series of tests in three operating coal mines of the Bethlehem Mines Corporation were conducted. The GAC laboratory tests defined the window coefficients and the accuracy of the method using different measuring techniques for a range of window sizes and shapes with window areas from 0.0873 to 4.0 square feet for flow velocities through the windows of from 100 to 1000 FPM. The results indicated that for the range of window sizes and window flow velocities investigated a single window coefficient value can be used with little error for each window size and for each flow direction, for the investigated range of window flow velocities. The mine tests developed techniques for quickly erecting the Temporary Test Stopping (TTS) in a cross-out, making the measurements, taking down the TTS and moving it and the test equipment to the next cross-cut. The time period for the total cycle ranged from 15-45 minutes depending on the properties of the cross-cut's surfaces. The total weight of the TTS and test equipment carried by the two miners conducting the tests was approximately 40 pounds. Correlation was obtained between the sum of the leakage values past 10 consecutive individual stoppings using the brattice window method and the value for the difference in the airway flow values before and after the 10 consecutive stoppings when the value for the sum of the leakages for the 10 was significant when com¬pared to the airway flow values. The mine tests reiterated the importance of using the largest TTS window(s) consistant with making accurate anemometer measurements for the best results with the brattice window method.

Jan 1, 1978

[Mr. Scott Aberle Western Energy Co POB 99 Colstrip, MT 59323-0099 Mr. Brian L. Acton Oxbow Carbon & Minerals Inc 1601 Forum Pl-#P2 West Palm Beach, FL 33401 Mr. Laine W. Adair Genwal Resources Inc POB 1420 Huntington, UT 84518-1420 Mr. Thomas D. Aderman The North American Coal Corp 14758 Preston Rd #1100 Dallas, TX 75240-7891]

Jan 1, 1998

By Richard N. Spencer

"El surgimiento de los laboratorios combinados del Banco Minero del Perú en la industria minera facilitó las investigaciones y tratamientos en la composición de los minerales. Por tal motivo, el objeto del presente texto es remarcar la función del laboratorio químico del Banco Minero del Perú, en tanto le suministre información analítica y compleja sobre el campo mineral inorgánico, asi como garantice los resultados analíticos uniformes con la más alta calidad. Asimismo la disposición de dicha entidad química, abarca las compras del Banco Minero, plantas de beneficio del Banco Minero y el control químico requerido por las nuevas unidades de los laboratorios Metalúrgico y Petrográfico que son parte integrante de este Laboratorio Central. En este punto,el laboratorio petrográfico, como fuente permanente de información básica ayuda al geólogo o metalurgista y planifica mejor la función del laboratorio central, mientras que el metalúrgico, desarrolla pruebas de molienda de minerales, flotación mecánica y no mecánica, y pruebas de concentración por gravedad. Posteriormente están las secciones de recepción, trituración y muestreo del laboratorio, las cuales se componen del departamento de trituración, departamento de muestreo y departamento de archivo, respectivamente. Finalmente, este equipo de laboratorio, cuenta con un laboratorio de Microscopia, de preparación de muestras para el examen microscópico yde ensayos especiales, que en conjunto permiten un mejor tratamiento y descripción sobre los minerales a investigar."

Jul 20, 1956