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By William O. Vanderburg

This report 3/gives the results of a reconnaissance of the mining districts in Lander County, Nev., made from March 29 to April 20 and from May 9 to May 21, 1938, during which virtually all of the mining districts n the county were visited. No attempt has been made to include in this report all the mines and prospects in the various mining districts, and it should be stated that whether or not a property is mentioned herein has no. bearing on its merits. The report rovers the situation of the various districts, types of ore deposits, ownership and description of mines and prospects, information on past and current activity, and other information of economic interest likely to be useful to those interested in the development of our mineral resources. The names of the various districts mentioned are those generally used when they were organized for purposes of record and regulation. When originally organized, the districts embraced large areas with no well-defined boundaries, so that the names have little geographical significance.

Jan 1, 1939

By John Organiscak

A majority of continuous mining machines employ a water spray system and a machine mounted flooded-bed scrubber to suppress and capture dust during coal mining. These machine mounted dust control systems must be designed to function within the localized face ventilation system at the mining section to control both dust and methane. Spray systems can impede or improve the scrubber effectiveness in controlling dust or methane at the mining face. Laboratory experiments were conducted to examine the effect of spray type, spray pressure, machine body blocking sprays, and scrubber airflow on dust and gas levels while using a 12.2 m (40 ft) exhaust ventilation curtain setback from the face. These experiments were conducted with the mining machine positioned at the end of a simulated 6.1 m (20 ft) sump and slab cut. Results indicate that the hollow cone nozzles with blocking sprays best complemented the flooded-bed scrubber performance in an exhaust ventilation system. This external spray system notably reduced dust and gas levels on the off-curtain side of the mining machine for both the sump and slab cut as compared to the flat spray nozzles. Higher scrubber airflows reduced dust and gas levels on the curtain side and in the return of the continuous mining machine. The remote operator position, located on the off curtain side and parallel to the inlet end of the exhaust curtain, sustained the most stable and lowest dust levels around the mining machine.

Jan 1, 2010

By P. -É. Boileau, S. Mandapuram, Shiping Ma, S. Rakheja

The absorbed power (PAbs) has been suggested as a better measure of human responses to whole-body vibration, since it relates to the cumulative energy dissipated by the body exposed over a given duration. Moreover, unlike the other measures, the PAbs can adequately account for the intensity of exposure. Although, the vast majority of off-road vehicles impose considerably severe vibration along the horizontal axes, the vast majority of studies on biodynamic response characterization consider only vertical vibration. Only a few studies have reported PAbs responses of the seated human body exposed to horizontal vibration and the major contributing factors [1]. This study aims to characterize the PAbs responses of seated human subjects to horizontal (uncoupled x- and y-axis) vibration as functions of the vibration intensity, subject mass, seat height and the, type of back support. Methods Experiments were conducted using a rigid seat with an adjustable backrest inclination and seat height. The seat was installed on a horizontal vibration simulator and the forces at the seat base and the backrest were measured by three-axis force plates. Two single-axis accelerometers were installed on the seat back and the platform, oriented along the axis of motion. The experiments were performed using three different seat heights (350, 390 and 410 mm), back support conditions (NB- no back support and sitting erect; Wb0- Upper body supported against a vertical back support; and WbA- back supported against an inclined backrest, while sitting relaxed) and three different magnitudes of broad band excitations in the 0.5-10 Hz frequency range (0.25, 0.5 and 1 m/s2 rms acceleration under x-axis and y-axis, applied independently). A total of 8 healthy adult male volunteers with total body mass ranging from 59.4 kg to 92 kg and aged between 21-51 years took part in the experiments. The subjects were seated with their hands in lap, and feet supported on the moving platform for each posture. Each measurement was repeated 2 times, while the data were analysed using a bandwidth of 50 Hz and frequency resolution of 0.0625 Hz. [ ] The data were analyzed to derive the absorbed power characteristics of the body at both seat pan and backrest interfaces, while the coherence among the measured forces and accelerations wer

Jan 6, 2006

By C. A. Geffen-Fowler

This report, sponsored by the Bureau of Mines, presents the results of an examination of the safety of the Blind Shaft Borer (BSB) shaft sinking system and an alternative modified BSB design concept in comparison to conventional shaft sinking technology. Detailed study of the two systems was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the BSB systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the two BSB systems was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that both BSS systems are safer than conventional shaft sinking. The potential risk of conventional shaft sinking operations could be reduced by over 30%, on the average, with the use of the original BSB system, and by an average of about 10% with the modified BSB. Design change recommendations to further improve the safety of these systems include a better fire suppression system, improved man haulage systems and more compact hydraulics. An operational safety manual was also developed for the modified BSB system.

Jan 1, 1981

By Max F. Lee, Warren A. Peck

The applicability of the Q-system [Barton et al. 1974] to Australian underground metal mines is discussed with reference to two common design issues: ground support for horizontal mine development, and assessing the stability of bored raises. Installed ground support in mine development is com-pared to empirical estimates using the Q-system and associated support capacity calculations. Data are graphically presented from 59 specially selected sites at 15 contributing mines. The actual performance of large-diameter raise-bored shafts is also compared to empirical stability assessments using a modified version of Q (Qr, after McCracken and Stacey [1989]). Lower-bound Qr values are plotted against raise diameter for 47 selected sites at 23 mines in Australia and Papua New Guinea. The influence on Q and Qr of some geotechnical aspects of the Australian landscape, the dynamic nature of mines (compared to civil construction), and occupational health and safety regulations are discussed. Stability and support assessments that are based just on Q or Qr are not always conclusive. It is often necessary to consider other rock mass parameters, the regulatory environment, and risk issues. These results are interim; further data collection and analysis are required with regard to comparing actual performance versus empirical assessments.

Jan 5, 2007

By Daniel S. Witkowsky

The Pollution Prevention Act of 1990 provides few specifics to assist the non-fuel mining and mineral processing industries of the United States in achieving pollution prevention (P2) compliance. The U.S. Bureau of Mines (USBM) recognizes the absence of specific information to reduce pollution impacts from mining and mineral processing of hardrock and industrial minerals. Therefore, the USBM has prepared this publication to help reduce or eliminate environmental pollution and to assure the viability of these segments of the domestic mining industry. This report includes worksheets designed to help operators of mining and milling facilities to establish a P2 program. The report can also be used by citizen and environmental groups, State and local governments, and academia to gain an understanding of P2 as it relates to mining and mineral processing.

Jan 1, 1995

By Charles B. Carpenter

The New Hope field was selected for study by; Bureau of lanes engineers because many problems met by, the operators during development and operation were unique to petroleum-engineering experience. Solving these problems is believed to have doubled the ultimate recovery of oil from the field. Since the discovery well was 'completed, in April 1943, an oil-productive area of 4,950 acres- has been delineated by the drilling of 64 wells, four of which were dry holes. Four oil-bearing reservoirs - the Bacon oolitic limestone, and the Hill, Pittsburg) and Elledge sandstones, all, in the Trinity group of the Lower Cretaceous series-- have been penetrated at depths ranging from 7,300 to 8,100 feet. Three of these reservoirs were found to be closed-type or solution gas-drive reservoirs, and one - the Hill - was an open-type or water-drive reservoir. During the course of the study, the Tide Water Associated, Oil Co. and -Seaboard al Co. of Delaware made available to the writers all well records, electric logs; and coring, production,, and pressure data. The ,writers performed Certain field and laboratory- tests on cores of ,the reservoir racks and' samples -of the reservoir Oils. Analyses of cores from the four reservoirs showed average .porosities ranging from 10 to 18 percent, average permeabilities of 17 to 297 millidarcys, and -average 'connate water contents ranging from 25.4 to 30.6 percent. Subsurface and recombined samples of reservoir oils indicated that the oils in the Bacon Hill, and Pittsburg reservoirs contained ,206 to 422 cubic feet of gas in solution per barrel initially, and that the, reservoir oils were undersaturated with gas. No samples' of oil from the Elledge reservoir were analyzed, and because of meager data this reservoir was not studied in detail. 4 The presence of free 'gas' or a' gas cap, however, indicated that the oil in the Elledge reservoir was saturated with gas. The rapid decline in pressures in- the' four reservoirs during the 'first year of operation alarmed the operators and provoked them to investigate the reservoir conditions to determine the cause.

Jan 1, 1949

By E. P. Youngman

Zirconium, formerly distinctly a rare element, is rapidly becom- ing of rather extensive commercial importance. Economic features of the zirconium industry, together with general information regarding the metal and its compounds, are discussed in a separate paper, to which this paper is a supplement. In addition to giving a brief discussion of the four or five de- posits that so far have proved to be commercial sources of the element, this circular summarizes available data (including some hitherto unpub lished material from the files of the Bureau of Mines) upon other occur- rences, including many of scientific interest only, of the two commercial. minerals, zircon and baddeleyite, and also data upon some of the minor minerals, such as eudyalite and cyrtolite, which have attracted addition- al interest in recent years because they are frequently richer in hafnium than the more common zirconium minerals.

Jun 1, 1931

By K. L. Bainbridge

This report describes the results of a study to determine which types of, and to what extent, mining wastes can contaminate groundwater through leaching of acid-forming or potentially toxic constituents. The primary focus of this study was on coal mining wastes, especially overburden spoils and preparation plant refuse. In addition, the potential for contamination by leachates from clean coal stockpiles was also examined. The study approach included investigation of (a) the amounts and geographic locations of mining wastes in the United States; (b) the chemical character of mining wastes, especially with regard to potentially acid-firming or toxic constituents; and (c) the extent to which acid and/or toxic components are leached from mining wastes by rainwater. To evaluate the leachability of coal wastes, a laboratory waste leaching method was developed during this study to specifically simulate the leaching process over a long-term. Waste samples collected during this study were also leached by the EPA extraction procedure and ASTM waste leaching method. Results of the three leach test methods were compared to evaluate their relative capabilities to predict the leachability of mining wastes.

Jan 1, 1980

MFIRE is a computer simulation program that performs normal ventilation network planning calculations, and dynamic transient state simulation of ventilation networks under a variety of conditions. The program is useful for the analysis of ventilation networks under thermal and mechanical influence. MFIRE simulates a mine's ventilation system and its response to altered ventilation parameters, external influences such as temperatures, and internal influences such as fires. Extensive output enables detailed quantitative analysis of the effects of the proposed alteration to the ventilation system Network simulation using digital computers has become widespread throughout the mining industry in recent years. However, as the sophistication of the simulator increases (MFIRE, for example), the complexity of input data requirements and interpretations of results requires more skill and knowledge from the users. Perhaps the most difficult part of using MFIRE is to construct the data set describing the mine's physical layout and its ventilation properties. The initial attempts to get the data set running often reveal unknown or ignored aspects of the mine's ventilation. MFIRE was written in Fortran 77 and compiled with Microway1 Fortran for the Intel 80386 based computers with a 80387 math co-processor. The source code is portable and available for users who wish to modify the source code to operate on other computers. This user manual describes the development of MFIRE, the input format and requirements, the output, common errors, fire parameters, and examples MFIRE application. Valuable reference material is included in the appendices. Knowledgeable users may skip directly to the PROGRAM INSTALLATION AND OPERATION section to begin using MFIRE immediately.

Jan 1, 1995

By J. W. Paul, J. N. Geyer

"GENERAL STATEMENTThe purpose of this report, which is the first of a series of three covering mines in the Fairmont district of West Virginia, is to give the result of a' study conducted in seal mines to ascertain the nature of the safeguards employed to prevent injury to the workmen from falls of roof and coal. In presenting the subject matter, consideration must necessarily be given to factors, features, and conditions such as method of mining, timber regulations and practices, supervision and natural conditions; and, for comparative purposes, a certain amount of statistical matter bearing upon the relation of fatalities and injuries to their causes, tonnage produced, men employed, days worked, and time lost.Those features and practices found to promote safe protection are summarized and suggestions made for such additional safeguards and practices as appear to give greater protection against injury from falls of roof or coal.ACKNOWLEDGMENTSThis study of falls of roof and coal in mines in Harrison County has been conducted by the U. S. Bureau of Mines in cooperation with R. M. Lambie, chief of the Mining Department of the State of West Virginia who assigned L. W. Brown, a district mine inspector, to assist in the field work and in the preparation of individual reports on each mine visited in this study. The writers acknowledge the helpful suggestions and cooperation given by these officials, the latter of whom assisted in the field work and prop red most of these sketches for the individual reports which wore submitted to the operator by the chief of the department. Thin report is a summary of the contents of the individual reports heretofore furnished the individual operator."

Aug 1, 1931

By Jr. Denton

This U.S. Bureau of Mines report presents the documentation for HEAPREC, a methodology for calculating reclamation performance bonds for cyanide heap leach operations. HEAPREC is a template developed for use with Lotus 1-2-33 release 2.01 or newer software. The report is presented in step-by-step "user's manual" format. Appendices contain detailed background and reference material on performance bonding, cyanide detoxification regulation, cyanide detoxification methods, general mine reclamation procedures, and an example bond calculation.

Jan 1, 1992

By Jeffery L. Kohler

This final report on Bureau of Mines Contract J0338028 presents the results of a research effort to predict incipient failure in electric-power-system components. The development of continuous monitoring techniques to detect an incipient failure would represent a significant improvement in system maintainability, availability and safety, This report describes the analytical and experimental aspects of the project. Mathematical models have been developed to study the behavior of cables and motors which are undergoing a deterioration process. These models allow a detailed study of the effect of deterioration on the component's terminal characteristics and performance. The efficacy of using negative-sequence monitoring is a reliable indication of deterioration has been established. Techniques for assessing the sensitivity of the prediction algorithm to component deterioration have been presented. An approach for modelling electrically-excited vibrations, and including these in the algorithm, has been presented.

Jan 1, 1987

By Gordon R. Sima

The contract is concerned with feasibility studies, design and fabrication of a group of prototype hand-held test instruments and machine-mounted test instruments for measurement of electrical shock hazards of mining machines. An instrument for use in open pit mining machine ground wire verification was proposed, developed, built, and tested. This report presents the design and operational theory of the open pit instrument as well as information on the program to improve the original prototype hand-held machine-mounted test instruments.

Jan 1, 1977

By Bill York-Feirn

The Colorado Mine Safety & Training Program (MSTP), in late 2005, completed and began distributing two new training tools; one geared to underground coal mine foremen and the other to surface aggregate employees. Through strong partnerships with MSHA, Colorado Coal Mine Board of Examiners, Colorado Mining Association and the Colorado Rock Products Association, the MSTP continues to create innovative and interactive training tools for not only Colorado, but for the national mining community. "Although we shoot and produce these materials in Colorado, it's important to us to make sure they are useful nationally," said Bill York-Feirn, MS TP Manager. The interactive DVD program "Underground Mine Foreman Certification Study Guide (Coal)," was completed in October 2005. It won the 2005 Grand Prize at the MSHA National Training Materials Competition in Beaver, West Virginia. [ ] This program is fully based upon the requirements of Title 30 Code of Federal Regulations (30 CFR) Parts 48, 50, 70 and 75 for underground coal mine foremen. It contains eight modules plus immediate access to relevant laws in the appendix. Topics covered include: Federal Law, Practical Math Skills, Mine Gases, Ventilation Maps, and scenarios addressing a variety of practical mining concerns. The DVD is designed for self-¬paced study and practice.

Jan 1, 2006

By Thomas O. Glover

Cameroon continued to enjoy sustained economic growth that began with its independence in 1960. Growth in the gross domestic product (GDP) averaged 2.8% per year during the 1960's and the first half of the 1970's. Starting in 1976 and for the succeeding 10 years, the GDP accelerated rapidly owing to the coming on-stream of Cameroon's small but domestically significant offshore oil industry. In 1985, the GDP grew by 7.8%, but in 1986, it was only up 5.5%. The country's sustained economic growth in dollar terms of gross national product (GNP) per capita reached $1,075 in 1986. The ranking in GNP per capita by the International Monetary Fund put Cameroon in the middle-income category for developing countries. The sustained economic growth rate up to 1986 was due to the injection of income from oil into the economy, but crude oil price reductions in 1986 brought a slowdown. In 1986, crude oil production grew to 200,000 barrels per day, an increase of 8.2% from that of 1985. Most of the oil came from the Société Nationale Elf Aquitaine (SNEA) wells in the multifield Rio del Rey complex. Additional output came from the Moudi Field operated by Compagnie Française des Pétroles S.A. Proven oil reserves in Cameroon were 540 million barrels. At 1986 production rates, and in the absence of further discoveries, Cameroon will have exhausted its recoverable oil reserves by the year 1995. Owing to worldwide crude price reductions, the country's oil income fell 60% between 1985 and 1986, from $1.82 billion2 to $0.72 billion. Cameroon's refinery operator commenced operating the Sonara refinery in 1981 at Point Limboh. Sonara's capacity of 43,000 barrels per day was small by most standards. In 1986, natural gas reserves, estimated at 100 billion cubic meters, were not produced commercially because there were no domestic users. Proposals for a multibillion-dollar liquefied natural gas plant at Kribi had been submitted; however, work on the plant had not commenced.

Jan 1, 1988

By Raja V. Ramani

Productive and beneficial use of reclaimed surface-mined land is a concern of industry, government, and the general public. An investigation was conducted of current mined-land planning practices to aid in the development of a procedure for evaluating postmining land use potentials. This investigation considered both the industry and public planning approach to mined-land planning. It included a detailed review of the impact of regulation, factors that determine land use, and current site planning methods employed by the mining industry. The methods of this investigation included three in-depth case studies of surface mines in the eastern, central, and western United States. A site planning pro-cess has been developed and applied to the surface mine case studies to evaluate the economic, environmental and social impacts of postmining land use alternatives. In add it ion, guidelines are proposed to enhance the cooperation between local land use planners and surface mine planners, as well as to improve comprehensive planning with regard to mineral resources at the local and regional level.

Jan 1, 1983

By Stephen C. Tadolini, Steve Bessinger, James Pile, Christopher Mark

The San Juan Coal Mine, located near Farmington, New Mexico, supplies the San Juan Generating Station with more than 6 million tons of coal annually. To replace dwindling surface mine production, San Juan installed a longwall in 2002. The roof rock in much of the underground reserve consists of interbedded coals, carbonaceous shales, and mudstones. Roof support consists of fully-grouted roof bolts, both tensioned and non-tensioned, supplemented by modified cable trusses. Short-encapsulation pull tests conducted by San Juan’s geotechnical engineering department showed that some of the immediate roof layers provided variable bolt anchorage. To ensure that the roof bolts were obtaining the necessary anchorage, additional tests were conducted in a variety of locations. The results have been used to determine the optimum support design for different areas of the mine. Another series of tests evaluated the performance of several bolt and hole diameter combinations. The experience at San Juan Mine shows that short-encapsulation pull tests can provide the information necessary to improve ground control in variable roof conditions. It also illustrates how a pro-active geotechnical engineering program can be an essential component of a state of the art underground coal mine.

By Linneas W. Laage

MFIRE is a computer simulation program that performs normal ventilation network planning calculations, and dynamic transient state simulation of ventilation networks under a variety of conditions. The program is useful for the analysis of ventilation networks under thermal and mechanical influence. MFIRE simulates a mine's ventilation system and its response to altered ventilation parameters, external influences such as temperatures, and internal influences such as fires. Extensive output enables detailed quantitative analysis of the effects of the proposed alteration to the ventilation system Network simulation using digital computers has become widespread throughout the mining industry in recent years. However, as the sophistication of the simulator increases (MFIRE, for example), the complexity of input data requirements and interpretations of results requires more skill and knowledge from the users. Perhaps the most difficult part of using MFIRE is to construct the data set describing the mine's physical layout and its ventilation properties. The initial attempts to get the data set running often reveal unknown or ignored aspects of the mine's ventilation.

Jan 1, 1995

By James L. Elder, J. P. Capp, James J. Dowd

The Bureau of Mines and the Alabama Power Co., jointly, conducted the first experiment undertaken in the United States in underground gasification of coal in place, at Gorgas, Ala. Milton H. Fies, manager of coal operations, Alabama Power Co., proposed the cooperative investigation to Arno C. Fieldner, chief, Fuels and Explosives Branch, Bureau of Mines; and assisted in supervising the experiment. The objectives of the experiment were to determine whether coal in place could be burned successfully and whether the burning could be controlled; the effect of the fire on the coal bed and the overlying strata; and the yield and quality of gas that could be obtained.

Aug 1, 1947