Search Documents

By Kenneth R. Maser

This report describes a research and development program sponsored by the United State s Bureau of Mines. The purpose of the program was to develop reusable explosion-proof bulkheads for a cross-cut emergency shelter, and to study the implementation of such bulk-heads, and the resulting shelters, as part of an emergency escape plan in a normal coal mining environment. The first part of this report reveals a number of significant conclusions regarding the application of emergency shelters. A study of the cause s of, and the conditions prevailing during a mine emergency indicate s that ideal placement of the shelter s would be midway along developing entries, and at the inter section of butt and main entries. The proper spacing of shelters is based on the travel capability of trapped miners, which is in turn dependent on the height of coal. The life of a given emergency shelter, based on an analysis of the above information, will be anywhere from 6 months to 10 years. Consequently, some shelters are regarded as "temporary?, while others "permanent?.

Jan 1, 1975

By Louis Schaffer

The purposes of the research were to assess the applicability of new accident investigation methods to mining accidents, and to adapt those found to be applicable in the development of a new methodology for use in mining. The development included field testing, evaluation and modification of the new methodology. The report is in two volumes. This, volume one, discusses primarily the Phase I work: background research, design of a methodology for field evaluation, and preliminary field tests in Utah mines. Phase I was completed in June, 1980. Also discussed are some activities to prepare for a field evaluation during the period May 1980 -October 1981. Volume 2 discusses the subsequent field tests, modifications of the initial methodology and the results of use of the methodology in two mining companies for a period of approximately eighteen months, and in other companies for selected loss incidents during that period.

Jan 1, 1986

By J. H. Gasper

A cost analysis for two alternative contour mining methods is performed to compare their results. The methods evaluated are: 1) Front-End Loader/Truck Haulback and 2) Scraper Haulback. Before performing these analyses, output requirements and equipment needs are found based on integrating geometric limitations with material properties. The final geometric design establishes limits on clearances, congestion problems and grades (with associated running surface materials). All calculations are kept practical, with assumptions clearly stated. The cost analysis is a unique, easily utilized compilation of several different approaches incorporating cost engineering principles. The strengths of each are welded into a cohesive entity once again aimed at practical application. The results are presented in tabular form.

Jan 1, 1992

Demonstrate the technical feasibility of using nontraditional, low-rank, coal-based fuels and new coal-based technologies for mineral and metallurgical applications. Approach A cooperative research effort was initiated between the Bureau of Mines, U.S. Department of Energy and the minerals industry to extend the application of the fixed-bed gasification process to low-rank Western coals. The research effort enabled cooperators to gain operating experience in the use of hot, raw producer gas for iron ore pellet induration and other high-temperature mineral processes. Researchers were able to gather data regarding the fundamental engineering aspects of the fixed-bed process and gas cleanup for a wide range of solid fuel properties. Applying Fixed-Bed Gasification As a prerequisite to gathering the data needed for the study, the Bureau of Mines designed and installed, at one of its laboratories, a 6.5-ft-diam. single stage, fixed-bed, air-blown atmospheric pressure gasifier. The gasifier was coupled with a hot, raw gas combustion system and iron ore pellet in. duration kiln. The gasifier is rated at 1.5 ton/h capacity of bituminous coal.

Jan 1, 1987

By A. J. Partos

One Liberty Place, at 315 m is the tallest building in Philadelphia, PA USA. It is supported on drilled piers socketed in heterogeneous rock. 3832 kN/m2 end bearing and 383 to 766 kN/m2 shaft resistances were selected. Design load distribution was 40% on the base and 60% by shaft resistance. The maximum compression on the corner core columns is supported by clusters of 3 drilled piers. In order to confirm load distributions along shaft and at the base, Drilled Pier G-10 supporting T13-A type outrigger column was instrumented. This column supports 53,849 kN compressive load which includes 13,440 kN windload. This paper reveals details about the process to select the final design for One Liberty Place together with pertinent Information about site geology, foundation construction, quality control, and methods of steel erection. It also presents detailed Information on the type of Instruments, their calibrations, field fabrication, and installation in the shaft of Pier G-10. Readings of concrete temperatures, computed loads, and load distributions are presented for a period from October 1985 through May 1988. The building was completed in 1987.

Jan 1, 1989

New developments in the pipe conveyor and belt are advanced to address the growth in the capacity, length and complexity of pipe conveyor systems. Improved belt construction can offer better stability during horizontal curves and resistance to twist. Low rolling resistance rubber compound can significantly lower the power consumption and belt tension, producing capital and operation cost savings. Dynamic analysis, when used to analyze the conveyor?s starting and stopping behavior, can improve the design and reliability of long overland pipe conveyor systems. For these three aspects, technical backgrounds and field installations as examples are discussed in this paper.

Jan 1, 2012

By Robert L. Kranz

The U.S. Bureau of Mines (USBM) has been monitoring and studying seismic activity associated with mining in the Coeur d'Alene silver district of northern Idaho. New statistical methods of studying the stope-scale (1-to l00-m) seismicity at one Idaho silver mine are used in this report (part 1) and its companion (part 2). This report deals with methodology and its limitations. The recent concept of fractals and their seismological use is discussed and applied to mining-induced seismicity. Three types of fractal studies are addressed: spatial analyses (including temporal changes of spatial patterns), temporal analyses, and size analyses. Other statistical measures of mine seismicity are also addressed: event mean location, inter-event distance distribution skewness, temporal coefficient of variation, nearest neighbor and next event statistics, and event location planarity patterns. Each of the methodologies discussed (fractal and nonfractal) is presented using sample data from two stopes in the mine. It is shown that stope-scale, mining-associated microseismicity has a fractal nature. The usefulness of demonstrating fractality (scale invariance) for predictive or descriptive purposes depends on recognition of the factors affecting the calculation of fractal dimensions. Several methodological traps are illustrated that can lead to an incorrect conclusion.

Jan 1, 2010

By Robert H. Peters

This U.S. Bureau of Mines report identifies the types of serious accidents that occur most frequently at small underground coal mines and describes the strategies that could help prevent these accidents. A wide variety of methods for improving safety are suggested, including improvements in the design of equipment, work procedures, work schedules, safety programs, and emergency response plans, as well as techniques for diagnosing the potential hazards associated with new technologies and work procedures. Some of the papers in this volume focus on preventing specific types of mining accidents-ones associated with materials handling (primarily back injuries), equipment maintenance, improper machine guarding, and ground failure during retreat mining. Although the recommendations in this volume are heavily influenced by research performed at underground coal mines in the Appalachian coalfields, most of the papers contain advice that is equally pertinent to almost any type of mine.

Jan 1, 1994

By J. R. Emery, D. F. Coates

"FOUR PAPERS ON CEMENTED BACKFILL were given at the Annual General Meeting of The Canadian Institute of Mining and Metallurgy in 1970:Weaver, W. S., and Luka, R., ""Laboratory Studies of Cement-Stabilized Mine Tailings"".Pasieka, A. R., Beattie, H. F., and Espley, G. H., ""Cemented Hydraulic Backill within the Falconbridge Group of Companies"".McLeod, P. C., and Schwartz, A., ""Consolidated Fill at Noranda Mines Limited (Geco Division)"".Clement, W. P., and Sokoloski, R., ""Pumping Cemented Backfill"".These four papers give the impression of a development in mining technology that has been substantially completed. Somewhat over ten years ago, The Inter-national Nickel Company of Canada, Limited and Falconbridge Nickel Mines Limited started experimenting with the addition of Portland cement to mill tailings to produce improved backfill and cheaper floors for scraping. Shortly after, the Canada Cement Company Limited (now Canada Cement Lafarge Ltd.), with full support of the two mining companies, started an extensive research program to provide the technologic-al data necessary to exploit what was obviously going to be a significant development in mining technology."

Jan 1, 1970

By Éder Domingos Oliveira, Carlos Antonio Morais, Ruberlan Gomes Silva

The objective of this study is to assess the impact of different reagents, such as limestone, lime, magnesium oxide, and sodium hydroxide, in experiments carried out in the single purification step and in two consecutive purification steps by raising the pH of a rare earth sulfuric liquor with the aim to remove or reduce the impurity concentrations in the rare earth sulfuric liquor. The choice for the best purification condition was made based on the minimum loss of rare earth elements (REEs), reagent consumption, and residue generation. The exploratory experiments show that it takes place in the two consecutive purification steps, the first one consists in dosing the limestone pulp until it reaches a pH of 3.5 followed by an addition of a lime pulp reaching a pH of 5.0. Under this condition, the results were a total removal of Fe3+, PO4 3− , and Th4+ ions and a reduction of 99%, 87%, and 37% w/w in the Al3+, UO2 2+, and SO4 2− concentrations, respectively, in the purified rare earth liquor. Furthermore, the lowest REE losses (8.3% w/w) and reagent consumption (4.3 kg/m3 ) and also a low residue generation (7.5 kg/m3 ) were observed in this condition. Despite reaching similar results regarding impurity removal, the experiments done with the addition of limestone, lime, magnesium oxide pulps, and sodium hydroxide solution in the single purification step, where the pH was raised to 5.0, presented higher REE losses (64.9%, 42.5%, 44.8%, and 60.9% w/w, respectively) and a higher residue generation (43.2, 25.1, 11.1, and 13.6 kg/m3 , respectively). This occurred due to the co-precipitation of salts containing rare earth elements in their composition. The experiments conducted with limestone, lime, and MgO resulted in a higher consumption of reagents, while the same result was observed when NaOH was used (4.3 kg/m3 ). In the experiments carried out with the addition of magnesium oxide and sodium hydroxide, the respective purified rare earth liquors presented a high concentration of magnesium, sulfate, or sodium, which could impact the quality of the marketable rare earth salts, whereas the salts obtained under the best condition observed in this study seem to be amenable for use as raw material in an attempt to obtain rare earth products with an acceptable chemical quality.

By E. K. Stanek

This report contains the results of several related research efforts, all of which were aimed at enhancement of mine power system safety and reliability. The largest single effort was on optimum spares and maintenance scheduling for various components of a mine power system. Two closely related tasks involved calculation of the minimum arcing faults that could occur on dc trailing cables and the use of trippable load break switches to clear ground faults. Both of these tasks are concerned with reliable fault clearing to prevent shock and fire hazards. Three other closely related tasks were concerned with aspects of mine power system design: (1) alternate network topologies, (2) optimum voltage selection for mine power systems, and (3) selection of system components. The other research task consisted of laboratory tests to ascertain the effects of repetitive, low-level transients on insulation systems.

Jan 1, 1979

The ERMS Process was developed during four years of testwork by Austpac Gold NL to overcome the severe metallurgical problems of the ilmenite atWestport, in the South Island. These deposits have been known for about one hundred years. They were originally mined for gold, and only later attracted attention as a possible source of titanium minerals.   The resource is of world scale and may exceed 20 million tonnes of contained ilmenite. Similar deposits occur at Barrytown further south and together these areas would constitute an important opportunity for export-oriented mineral development, if a viable beneficiation technology were available. Further processing is essential, as the composition of the ilmenite is well below market specifications.

Jan 1, 1993

By David M. Gullikson

As part of its program of petroleum production research the Federal Bureau of Mines has long been engaged in the study and development of systems of analysis of oilfield waters (8, 12, 20, 21, 22, 27, 30).21 However, many of the early chemical procedures developed by the Bureau and widely adopted by the petroleum industry are time consuming, and some are unreliable for determining certain constituents found in California oilfield waters. Because of the need for more rapid and more accurate methods having greater sensitivity with low concentrations of some constituents, a study has been made by the Bureau's Petroleum Research Laboratory at San Francisco, in developing new techniques and modifying previously published techniques for analyzing oilfield waters by flame spectrophotometric, potentiometric, and colorimetric methods. Test solutions were synthesized for testing the suitability and accuracy of the procedures, and the effect of interfering ions. These solutions contained known quantities of characteristic constituents of oilfield waters including sodium, magnesium, potassium, calcium, lithium, strontium, barium, sulfate, chloride, bromide, iodide, carbonate, bicarbonate and borates in a wide range of concentrations. The compositions of these synthetic brines are listed in table 22. Many California oilfield waters contain salts of petroleum-derived organic acids and several synthetic oilfield waters also were prepared to which large quantities of naphthenates or salts of petroleum acids were added.

Jan 1, 1961

By J. P. Dick

THIS paper is a description of the milling practice and metallurgy at the Moneta Porcupine mine, Timmins, Ontario. The results obtained with an all-cyanide circuit and later with flotation followed by cyanidation are described. The ?investigation which prompted the various changes in milling practice have also been dealt with. Moneta ore is possibly the most refractory now being milled in the Porcupine district. This is due to the ultra fine state in which the gold occurs and to its intimate association with pyrite. No doubt there is ore of similar characteristics on the neighbouring properties but it probably forms only a small portion of the tonnage being mined, whereas at Moneta the bulk of the ore requires an extremely fine grind to liberate the gold. The fineness to which an ore can be ground economically has gone far beyond what was thought to be the limit only a few years ago. Formerly, a set of standard screens was all that was required to measure the fineness to which an ore was ground. At present, the Haultain infrasizer is practically indispensable, and the nominal micron has become a familiar unit of measurement to all those dealing with the problems of fine grinding.

Jan 1, 1941

By Lloyd H. Banning

With the ever-increasing demand for energy in all forms, electrical energy generated from geothermal resources could become an important energy source in the next few decades. Geothermal fluids, which contain appreciable quantities of dissolved salts and gases, are generally corrosive to materials of construction. Since data on corrosion of materials in geothermal brines is limited, the literature was surveyed through February 1972 to obtain a compilation of information on corrosion resistance of aluminum and its alloys, copper and copper-base alloys, carbon steel and cast iron, stainless steels, chromium-iron alloys, nickel-and cobalt-base alloys, and titanium in heated brines including sea water.

Jan 1, 1973

By Walter J. Frank

The purpose of the work covered by this contract is to develop a means of designing splice connectors which will significantly improve mine trailing cable splice performance. A brief discussion on splice problems is presented as an introductory means and substantiates the need for the development and test programs outlined in this report. Because of the empirical nature of this effort, time has been devoted to explaining the derivations of the test procedures used. Special attention is given to the splice flexing machine which served as the backbone of the test program. In order to familiarize persons with connector terminology, a section is devoted to a glossary of pertinent terms. Various types of cable joints are also defined. The major effort is a connector design parameter study. Utilizing the optimum parameters developed along with the suggested design procedure outlined in Appendix I should result in significantly improved splice performance and thus meet the objectives of this contract. A field test program was instituted for the purpose of insuring adaptability of connector design and associated installation tooling along with a field performance study. During the course of work, other significant factors affecting splice performance were uncovered. Although not covered by the scope of this contract, a brief discussion is presented for the purpose of stimulating interest in what is considered other fruitful areas for improved splice performance.

Jan 1, 1976

Jan 1, 1968

By W. A. Young

Bull Lake is one of several saline lakes situated a few miles north of Rawlins, Carbon County, Wyo. (figs. and 2).. The Bureau of Mines conducted preliminary investigations of sodium sulfate deposits in many of the lakes and performed detailed work on Bull Lake. This investigation consisted of drilling 11 vertical holes through salt beds using diamond core bits and Iwan-type auger bits. Bull Lake lies in a shallow, closed depression in loosely consolidated sand. The salt beds, ranging in thickness from 2.5 to 26 feet, occur above a thick bed of shale of upper Cretaceous age. The salts appear to have been deposited in the lake from surface and subsurface drainage. The source of salt is undoubtedly the enclosing sedimentary rock's exposed to the west of the basin. Sodium sulfate in the deposits probably is present as mirabilite or Glauber salt (Na2SO4-10H2O). Chief impurities in the deposits arc mud and sand. Other soluble salts present average approximately 1 percent combined. Cores from the 11 holes were analyzed in the Bureau of Mines laboratories at Salt Lake City. Drilling totaled 512 feet. Results of analyses are given in the appendix.

Jan 1, 1951

By Norman G. Foster

The mass spectra of 14 previously unreported alkylthiophenes are pre-sented. Low ionization voltage data of selected compounds from these 14 and 23 previously reported alkylthiophenes are presented and discussed for their value in supporting fragmentation mechanisms analytical correlations. A comparison with and corroboration of earlier correlations is made. Additional correlations concerning detection of side chain branching and the detection of ethyl-alkyl and propyl-alkylthiophenes are made. A discussion of the possible fragmentation routes and mechanism of fragmentation is given. Speculative structures are inferred s out some of the ions and hence this work provides a basis for suggesting fation mechanisms for the alkylthiophenes according to modern theories ass spectrometry. Verification of these mechanisms must await the availability of isotopically labeled molecules which are labeled in specific lotions that permit the definition of the paths of frag-mentation. Some suggestions for further work to generalize on the correlations and studies made to this point are presented.

Jan 1, 1965

La exploración profunda posee una serie de retos, como el incremento de los costos de perforación y la incapacidad de las metodologías convencionales de exploración de obtener datos de calidad. Las nuevas tecnologías tales como ORION 3D, proporcionan un medio para explorar el subsuelo desde la superficie hasta más de 2 km; significativamente mucho más profundo que los 300 m que se pueden alcanzar con los métodos geofísicos tradicionales, los cuales han constituido durante muchos años la columna vertebral de la exploración geofísica. El objetivo fundamental de este trabajo es demostrar la capacidad de ORION 3D de realizar estudios profundos y en un real 3D de depósitos minerales, que representen grandes retos para las empresas.

May 1, 2008