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By Andrew St. Amant

This report reviews the first three "investigative and concept generation" phases of the referenced contract, and details task performance of Phase IV. This last phase integrated the most promising concepts from Phases I, II, and III into a prototype detailed design which was manufactured, and then tested on a mine locomotive. The concepts developed during the first three phases provided "Improved Pole Tracking," automatic "Rapid Pole Retraction" in the event of dewirement, and servo-operated "Remote Pole Repositioning" on the trolley wire. The Appendix of this report supplies detailed information for the design and construction of the prototype system which is comprised of an RCB (Remotely Controlled Base subassembly), an RCL (Remote Control Lever subassembly) and an SAU (Servo Amplifier Unit) subassembly.

Jan 1, 1980

By Lloyd A. Morley

This annual report details progress under USBM Grant G0155003 during the project period of January 1, 1977 through December 31, 1977. The report contains four principal chapters covering accomplishments in the mine electrical safety research areas of continuous monitoring, battery and battery-charging safety, and computer modeling. Highlights of the work are summarized in the last report chapter.

Jan 1, 1978

By Clayton R. Morlock

Airblasts have been monitored at four coal strip mines and at a limestone quarry. Thirty-seven production blasts have been monitored with three seismographs, resulting in one hundred and eleven complete air pressure records. Instrumentation selection use is described. Data analysis includes an assessment of the predictability of peak overpressures by means of the cube root scaled distance law. It is found that predictability for the cases studied here is not good. An extensive discussion of possible explanations is included. A detailed analysis of the frequency content of the observed airblasts, of considerable importance in evaluating potential annoyance problems, has been made for all records. A computer program has been written to simulate airblasts induced by multiple-hole blasts. A series of small experimental blasts have been detonated and monitored in order to allow an assessment of the program. It is clear that airblasts, especially when induced by very small charges and monitored at very close distances, are highly sensitive to detonation times. Retrofitting of airblast records occasionally was possible, but considerably improved field work is required to validate or refute the computer model.

Jan 1, 1983

By Robert E. Barieau

In the design of plants to separate helium from natural gas , it is necessary to estimate the enthalpies of the various streams at various positions in the process . This Bureau of Mines report surveys the various methods that have been used to determine enthalpies and gives information on the organizations with such capabilities . The minimum information required for developing an enthalpy diagram is presented , and the relative merits of the various methods are discussed . It is concluded that methods that require no mass flow rate or energy measurements are to be preferred .

Jan 1, 1965

By John C. Nigro

This Bureau of Mines report summarizes the performance characteristics of a 30-day around-the-clock gasification-pelletizing test conducted in October and November of 1980 with North Dakota Indianhead lignite. Gasification was conducted in a commercial-size, 6.5-it-diam, Single-stage, fixed-bed, atmospheric pressure producer with a rated capacity of about 30 million Btu/hr. Iron oxide pellets made from a commercial hematite concentrate were fired with the low-Btu gas in a 2.8-ft-diam by 35-ft-long pilot plant rotary kiln at a rate of 900 lb of pellets per hour. Gasifier operations at fuel feed rates up to 3 tons of lignite per hour and hematite pellet induration with raw 160-Btu/std ft3 lignite gas are described.

Jan 1, 1982

By Robert H. Peters

This report presents a literature review conducted by the U.S. Bureau of Mines. The review summarizes what has been learned from the large volume of empirical studies on the effectiveness of eight types of interventions intended to increase organizational effectiveness via in the management of human resources. The interventions concern the following: recruitment, selection, training, objective feedback, goal setting, reward systems, participative management practices and organization development. Although many of these interventions appear to have the potential for improving the safety and efficiency of mining operations, it does not appear that they are being widely used. Examples are given of the successful use of a few of these interventions at mining operations. An analysis of the relationship between coal mine productivity and safety is also presented. This analysis generally supports the view that good safety performance and high productivity are NOT incompatible goals. In fact, safe mines also tend to be more productive and vice versa.

Jan 1, 1992

By George B. Clark

The purpose of this investigation was to determine the feasibility of designing and testing the elements of a small charge blasting system which will eliminate, or reduce to acceptable levels, most of the undesirable features of current underground drill and blast systems, i.e., 1) air blast, 2) ground vibrations, 3) flying fragments, 4) overbreak and fracture of surrounding rock, and 5) the cyclic nature of drill and blast operations. The experimentation was conducted in tunnels in granite and the results indicate that the basic technical concepts of the project were achieved. The next step is to design, construct, and test a prototype machine.

Jan 1, 1976

By E. P. Youngman

Tantalum is a rare element ; estimates indicate that there is less tantalum than gold in the earth's crust . After remaining a laboratory curiosity for many years , it was used to a limited extent and for relatively few years (1903- 1911) for incandescent electric-light -bulb filaments . Another wave of interest in tantalum appeared when its electrolytic-valve action was taken advantage of in charging storage batteries , especially for radio work . Tantalum chargers were eventually displaced by other types of chargers , but for a time they were manufac tured in sufficiently large numbers to create a demand for the metal and to bring about its production on a commercial scale in the United States . As tantalum became available in larger quantities and at substantially lower prices , and as high prices for platinum encouraged the employment of tantalum as a substitute , the metal was put to many new uses . Ferrotantalum was made and sold before the World War , and patents have been taken out for a number of special alloys for industrial purposes , but probably the largest use for the metal to-day is in vacuum tubes .

Aug 1, 1930

By R. J. Pokora

This Bureau of Mines report is an applications manual that can be used by the nonmetallic mining industry for guidance in installing noise control materials into crushing and screening plants. These noise control modifications were installed and successfully tested at three operating quarries. This report identifies the major noise sources that can be encountered in crushing and screening plants, and discusses the applicable noise control materials and techniques that a plant operator can utilize on a retrofit basis to reduce equipment noise.

Jan 1, 1984

By Shail J. Butani

In 1986, the Bureau of Mines conducted a probability sample survey, Mining Industry Population Survey, to measure such employee characteristics as occupation; principal equipment operated; work location at the mine; present job, present company, and total mining experience; job-related training during the last 2 yr; age; sex; race; and education. The population estimates are necessary to properly analyze the Mine Safety and Health Administration (MSHA) injury (includes illness and fatality data) statistics; that is, to compare and contrast injury rates for various subpopulations in order to identify those groups that are exhibiting higher than average injury rates. This report uses the survey's results to characterize the U.S. coal mining workforce from March through September 1986. A companion report, Information Circular (IC) 9193, "Characterization of the 1935 Metal and Nonmetal Mining Workforce:' provides similar information for the U.S metal and nonmetal mining industry.

Jan 1, 1988

By R. S. Dean

The possibility of cheap electric power for a number of mining areas in this country has suggested to many the idea of electric smelting of nonferrous ores in small units at or near the mines. The electric smelting of nonferrous ores was tested fairly thoroughly 20 years ago by United States Bureau of Mines and by others, and the fact that it did not achieve continuing workable success in any instance is sufficient proof that it offered no advantages at that time.

Jan 1, 1937

By R. D. Leitch

"The pollution of streams has received much attention during the last few years, and although there are many other and more serious forms of pollution, the problem of acid mine drainage is important in certain sections of the country, particularly in Pennsylvania. At the request of the United States Public Health Service the Bureau of Mines undertook to determine some of the factors contributing to formation of acid mine waters, the yearly variations in quantity and quality of drainage, effect of mining methods, and various other questions arising in connection with the problem; some attention was also given to its economic phases.In acknowledgment, the writer wishes to thank Dr. R. R. Sayers, Chief surgeon; A. C. Fieldner, chief chemist; and W. P. Yant, supervising chemist, health laboratory section of the Pittsburgh Experiment Station, all of the Bureau of Mines, under whose direction the work was conducted.Because no data of a like nature had previously been determined, and with the thought that such data would throw additional light on the general subject, a stream having a number of mines draining into it was selected for observation in both high-sulphur and low-sulphur bituminous-coal districts, as designated in commercial rating. These mines and streams were visited in both wet and dry seasons to note the quantity and variations in acidity of mine drainage and the subsequent effect on streams. Maps of these streams with the sampling points are shown in Figures 1 and 2. In a report of this nature a great deal of tabular data is best emitted, but reference to the maps will serve to indicate the factors that determined sampling points, such as tributary streams and gobs."

Sep 1, 1928

By Catharine T. Fogg

The Bureau of Mines investigated the availability of flake and high-crystalline natural graphite from 4 domestic and 25 foreign mines and deposits in 11 market economy countries (MEC's). Demonstrated resources were estimated to be 95 million metric tons (Mmt) containing 5.61 Mmt of recoverable flake and high-crystalline graphite products. Fifty-five percent (3.17 Mmt) of the total recovered product is estimated to comprise plus 100-mesh (150-µm) flake pro-ducts and "lump" and "chip" high-crystalline products, designated as "graphite A" in this study; 45 pct (2.44 Mmt) of the total is minus 100-mesh (150-µm) flake products and "dust" high-crystalline products, designated as "graphite B." Total production costs, including all costs needed over the life of each operation, were determined at a 0-and 15-pct discounted-cash-flow rate of return (DCFROR) for both graphite A and graphite B products. For a 15-pct DCFROR, 1.74 Mmt (54.9 pct) of the graphite A products is available at $600/mt or less and 2.13 Mmt (67.2 pct) is available for $800/mt or less. For the same DCFROR, 1.08 Mmt (44.3 pct) of the graphite B is available at $200/mt or less, and 1.71 Mmt (70 pct) is available at $325/mt or less. No domestic resources were determined to be economic at present prices. A sensitivity analysis of the relative economics of the Alabama graphite deposits under various operational parameters is presented in an appendix. All evaluations are in January 1984 dollars.

Jan 1, 1987

By Frank E. Cash, Max S. Peterson

"INTRODUCTION Falls of ground cause the greatest number of accidents at underground metal mines. Statistics compiled by the Federal Bureau of Mines show that during a 13 - year period ended in 1943, falls of ground caused 35 percent of the fatalities and 16.8 percent of the nonfatal injuries at underground metal mines in the United States. 4/ Expressed on a basis of a million man-hours worked, the frequency rate was 0.355 for fatalities and 11.76 for nonfatal injuries. Although some progress has boon made in preventing rock-fall accidents over a 30- or 40-year period, the problem is still a major one requiring the diligent efforts of management and employees.In the Lake Superior district: where organized safety programs have been in effect for more than 30 years, the record is more favorable. Statistics compiled by the Lake Superior Mining Section of the National Safety Council reveal that over a 6-year period ended in 1945 the frequency rate of fatalities per million man-hours was 0.277, and the rate for nonfatal injuries was 2.38 from falls of ground.Although the above-given statistics do not cover equal or concurrent periods, the improvement in accident experience in the Lake Superior district over the national average, is obvious. This improvement is due to more effective methods of ground support or more rigid enforcement of the use of known methods.It is hoped that the following information about ground-support practices in the Lake Superior district will assist operators of other mines in their efforts to reduce accidents from falls of ground."

May 1, 1948

By Forrest T. Moyer

Need for lightweight building materials was created in the latter part of the nineteenth century by a radical change in building design in which dead load or structural weight was transferred from thick, heavy, load- bearing walls of former construction practice to a load-carrying framework of beams and columns with thin walls. This new design was brought about by the introduction of structural steel followed by reinforced concrete and structural concrete as materials for the erection of the load-supporting frame. The new materials and method of construction made possible the erection of skyscrapers and the building of bridges with long spans, and made feasible additions of one or more floors to existing buildings. As size and design of the load-bearing framework are controlled chiefly by dead load, the natural result was a. search for and use of light- weight materials in partitions, floors, and exterior walls. However, these thin walls created problems of heat and sound. insulation, so that building materials which possessed good heat- and sound-insulating properties in addition to light weight were objects of extensive research. One group of materials developed to fill this need comprised lightweight concretes, of which some were obtained by the use of lightweight aggregates. Although the advantages of lightweight.materials were evident from the first skyscrapers, there was a transition.stage.between the old bearing- wall and modern skeleton-frame types of building, with the heavy and massive construction of the former superimposed upon the latter. Hence, it was not until the period between 1910 and 1930 that the new lightweight concretes were recognized and used more extensively in the erection of large, nonresidential buildings. From this type of construction, light- weight-aggregate concretes entered-fields of residential and small non- residential building; in which they were found desirable for production of prefabricated, large-size; masonry units. Although the weight of each unit was reduced sufficiently to enable one man to handle it easily, properties of the new concretes other than light weight were the principal factors in the ready acceptance of these new materials in residential building. Manufacture of precast units includes complete lines of masonry and back-up blocks, bricks; floor beams, columns and partition, roof, and floor tiles and slabs. Recent improvements in casting machinery, development of the vibration-pressure machine, and a more thorough study and knowledge of the requirements and properties of the concrete mix have all contributed materially to the rapid expansion in use of lightweight aggregates in this industry.

Jan 1, 1942

By James E. Hill

Tremendous improvements in mining technology have been witnessed during the past 100 years. For example, before 1860 all blastholes were drilled manually and blasting was done with low-energy black-powder. During the 1860's both the pneumatic rock drill and high-energy dynamite were introduced, ushering in an era of mining mechanization that has steadily progressed since that time. Today, with the rapid implementation of the latest advances in communication science, mining technology is moving into a new era that goes beyond mechanization as such. Transistors, transducers, scanners, telemetry, and the like, all terms largely derived from the new communication sciences, add up to what is popularly know as automation-the communication of machine with machine. Automation is now playing an important role in selected parts of the mining process, such as hoisting, hydraulic roof supports, and underground surface locomotive haulage and belt conveyor systems. But this year marked the first attempt to auto-mate the total mining process with the commencement of production at the British National Coal Boards Bevercotes mine. If this full-scale experiment proves successful, it could lead towards other fully automated mines in both Britain and other parts of the world. This decade, there-fore, could be considered the one that provided the foundation for the mines of the future.

Jan 1, 1966

By Bill Linville

Producing oil, gas, and coal in sufficient amounts to satisfy U.S. demands for fuels, electrical power, and chemicals promises to be one of the country's major challenges during the 1970's. Adding significantly to this challenge is the urgent task of satisfying soaring fuel and power demands without destroying the natural environment or jeopardizing long-range requirements for resources. The Bureau of Mines, U.S. Department of the Interior, is engaged in a comprehensive program of research to help industry meet this challenge. This report reviews the aims of the research program and accomplishments in 1970; the first 11 sections cover coal programs, nine sect ions are then devoted to petroleum, and the concluding five sections deal with oil shale research. Figure 1 shows the nationwide distribution of Bureau of Mines energy research installations; Full addresses are given in appendix A. Many of the publications resulting from the Bureau?s energy research efforts are discussed throughout the report; others are listed in appendix B.

Jan 1, 1971

By W. S. Sanner

This report describes the commercial application of the launder screen in anthracite-industry fine-coal cleaning operations. No new device, the launder screen has been used since the early part of the present century to size, screen, classify, and deslime the fine-anthracite sizes (Buckwheat Nos. 1 through 5) recovered by "river-coal" men dredging along streams draining the anthracite fields. The launder screen is stationary, has no moving parts, requires ample water for operation, and can be constructed economically on the job. Essentially, it consists of a wooden trough with baffles placed through its width to form a well system. The wells are covered by fine-mesh woven-wire screening. Each well is tapped with a number of orifices, and the hydraulic suction head developed in this manner removes high-gravity fines and slimes through the screening as underflow to waste. Material retained on the screen surface discharges as overflow product.

Jan 1, 1954

By MINE SAFETY BOARD

RECOMMENDATIONS OF THE UNITED STATES BUREAU OF MINES ON CERTAIN QUESTIONS OF SAFETY AS OF FEBRUARY 3 , 1933

Jul 1, 1933

By Paul M. Tyler

According to Lindgren , the economic importance of pegmatites stems from the fact that they represent the principal natural storehouse of two classes of mineral products : (1 ) common minerals in exceptional size and purity and ( 2 ) several of the rarest minerals , which are not commercially available from other types of deposits . Most pegmatites can be described simply as coarse- to very coarsegrained granites . Pegmatite includes coarse -textured igneous rocks of any composition , such as syenitic , alkali syenitic , dioritic , or gabbroitic ; but basic pegmatites are far less common than those that are associated with acid rocks and correspond approximately to the mineral composition of ordinary granite . Moreover , only a very few basic pegmatites can be considered as economic sources of useful minerals . Whereas , in ordinary granitic rocks the individual minerals usually measure 1/8 to 1/4 inch across , in pegmatites they are characteristically over 1 inch and often more than 12 inches in diameter . Although some of the constituents of the pegmatite may be only a fraction of an inch in length , single crystals more than 10 feet long are by no means unusual , and some crystals are enormous . A whole quarry was operated in the Urals within a single crystal of feldspar . Huge quartz crystals are quite common although usually imperfect . Muscovite plates 10 feet in diameter have been mined in India , and the Purdy mica mine in Canada contained a mica crystal measuring 6.5 by 9.5 feet and weighing nearly 7 tons , which supplied more than $20,000 worth of trimmed mica sheet . A loglike crystal of spodumene in the Etta mine in the Black Hills of South Dakota was 42 feet long . Giant crystals of beryl weighing several tons apiece have been mined from several properties . Because so many rare minerals are found in substantial concentration only in pegmatites , it is a common fallacy to suppose that pegmatites are always enriched in rare elements . Traces of most of these elements , of course , are found in almost all igneous rocks , and they reappear in the sediments derived from igneous rocks . It does not follow , however , that all or even most pegmatites contain higher percentages of rare elements than other granitic rocks . Geological evidence points to the probability that notable concentrations of rarer minerals or elements in pegmatites are more or less fortuituous , such additions often being ascribed to events subsequent to the original emplacement of the main body of the pegmatite . Most pegmatites consist principally of potash , feldspar , and quartz . Even mica , although commonly present , is not an essential constituent . Probably

Feb 1, 1950