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By E. V. Potter

"INTRODUCTION The oscillator and amplifier system described in this paper was developed specifically for driving sound generators of the type developed by H. W. St. Clair and described by him in an article 3/ published several years ago in the Review of Scientific Instruments.Nevertheless, with little or no alteration it can be used to drive any vibrating system in which the vibrating member must be driven at its resonant frequency; the only restrictions are that the driving mechanism be electrical in nature and that the vibrating member be accessible so that some type of pick-up can be coupled to it. Operation of the automatic frequency-control element in the oscillator, however, depends entirely on the operating characteristics of the vibrating member; therefore, in order to completely explain the operation of the circuit, it will be necessary to describe the construction and operation of the vibrator used with it. Only the essential features and characteristics of the vibrator will be described in this article, and the reader is referred to St. Clair's 4/ report for further details."

May 1, 1943

By William T. Boyd

Foreign mining publications describing successful hydraulic mining installations, and successful domestic hydraulic mining in a gilsonite bed, have prompted the Federal Bureau of Mines to conduct a literature survey of foreign publications to determine if the hydraulic mining method can be applied to domestic coal mining. Most foreign publications do not give detailed data about the water pressures, water capacities, and production and manpower requirements for successful hydraulic mining, However, they do provide enough general data on mining conditions, manpower, and equipment used to show that conditions in many bituminous coal deposits in the United States may be favorable for economical coal extraction, using high-pressure water jets. Therefore, the Bureau proposes to conduct a field investigation to determine the most appropriate natural conditions, water pressures, and equipment for successful hydraulic mining of coal beds in the United States with variable dip, thickness, and hardness. In the past, technical personnel reviewing foreign mining reports assumed that a steeply pitching coal bed was necessary for successful hydraulic mining. Although the structure of the coal bed may be a factor in gaining assistance from overburden pressures or help in an integrated hydraulic mining and transportation system, the coal is broken mainly by the action of high-pressure, water-penetrating cracks, fissures, or cleats; therefore, the slope of the coal bed is not necessarily a determining factor in hydraulic mining.

Jan 1, 1959

By Charles B. Kenaban

The possibility of using ultrasonic energy as a tool to improve the electrolytic deposition of copper and zinc from several electrolytes was investigated by the Federal Bureau of Mines. Sound with frequencies of 20, 26, 38, and 400 kilocycles per second and acoustical intensities of 0.25 to 1.5 watts per square centimeter was employed. Measurements of cell voltage, anode and cathode current efficiencies, and electrode potentials were made at various current densities. Effects of ultrasonics on the quality of the deposit and on anode corrosion also was noted. In the electrolytic recovery of copper from an acid copper sulfate solution at 50° C., adherent, well-consolidated deposits are normally obtained up to a current density of 30 amperes per square foot. As the current density is increased above this value, the deposits normally become progressively more spongy and less adherent. Ultrasonic irradiation resulted in adherent and well-consolidated deposits at current densities up to 300 amperes per square foot. Radiation also produced smaller grain size and preferred orientation of the copper crystals. In addition, radiation caused as much as 3-volt decreases in cell voltages at the higher current densities. These decreases were caused chiefly by depolarization of the anode, although small depolarization effects were also noted at the cathode. Radiation apparently did not greatly affect cathode-current efficiencies, but prevented excessive anode corrosion at the higher current densities and resulted in more uniform corrosion. Ultrasonic radiation at a frequency of 400 kilocycles per second was not as effective as radiation at the lower frequencies. Circulation of the electrolyte at rates up to 5 percent of the cell capacity per minute did not produce results comparable to those effected by ultrasonic radiation. Rapid rotation of the cathode up to 1,800 revolutions per minute gave results approaching those obtained with ultrasonics.

Jan 1, 1961

By W. P. Yang, L. B. Berger, G. W. Jones

"Any burning carbonaceous material, unless supplied with enough oxygen for complete combustion, will liberate carbon monoxide. Since tobacco in its many different forms consists largely of carbonaceous material, and duo to the conditions under which it is smoked (burned), carbon monoxide should be liberated. That this is true has been shown by Armstrong.***** who found that undiluted smoke from cigars contained in some tests more than 3.00 per cent carbon monoxide, the amount present depending upon the size and closeness of packing of the tobacco during manufacture and on the rate of burning.****** Cigarets gave much less CO, varying from 0.06 to 1.40 per cent. The rate of consumption and carbon content of the tobacco are not g.ven, so that a correlation of the values reported to conditions in closed spaces where people might be assembled are difficult, if not impossible.The Bureau of Mines is interested in the general question of carbon-monoxide hazards from tobacco smoke, mainly with regard to mine ventilation. In non-gaseous mines, especially metal mines, the question arises, whether, if groups of miners are permitted to smoke while working at unventilated faces or entries, would the accumulation of tobacco smoke in these places create an' additional hazards the to carbon-monoxide poisoning. The results should, in addition be of general interest in connection with ventilation of building and inclosed places where people may be assembled and smoking is permitted. The investigation described in this report was made with the above idea in view."

Oct 1, 1923

By Lloyd A. Morley

The primary goal of this research report is to discuss safety considerations involved in the use of lead-acid batteries for traction purposes in underground coal mines. In order to arrive at the objective, the topic of battery safety has been divided into two specific areas. The first deals with the fact that batteries emit hydrogen gas during and after the charge cycle. Hydrogen gas can be the source of dangerous explosions or mine fires. The second major topic deals with the electrical nature of the battery and battery-charging systems, which also provides a source of mine fires as well as electrocution hazards. In addition to the discussion on battery safety, a literature review has been undertaken to acquaint the reader with some basic concepts inherent to the battery usage process. The result of this research is a set of design specifications and procedural recommendations directed at improving the safety factors inherent in any underground battery usage scheme.

Jan 1, 1977

By C. F. Jackson

This paper has been prepared as a progress report in connection with the series of articles on mining methods and costs which are being published by the U. S. Bureau of Mines in the form of information circulars. When enough circulars have boon completed it is planned to publish a more complete and comprehensive paper in bulletin form dealing with the subject of underground transportation. Progress reports, followed b., bulletins, will be prepared from time to time dealing with other subjects included in the general study of mining methods at individual nines, such as mine development, drilling, and blasting; stoping methods (each principal stoping method to be summarized in a separate paper); Ventilation; wage, contract and bonus systems, etc.

Jan 1, 1931

Kroemer(1-3) and Kroemer et al.(4) define the isoinertial technique of strength assessment as one in which mass properties of an object are held constant, as in lifting a given weight over a predetermined distance. Several strength assessment procedures possess this characteristic. Most commonly associated with the term is a specific test developed to provide a relatively quick assessment of a subject's maximal lifting capacity using a modified weight-lifting device.(1,5) The classic psychophysical methodology of assessing maximum acceptable weights of lift is also considered an isoinertial technique under this definition.(6) While the definition provided by Kroemer(1) and Kroemer et al.(4) has been most widely accepted in the literature, some have applied the term "isoinertial" to techniques that differ somewhat from the preceding definition, such as in a description of the Isotechnologies B-200 strength testing device.(7) Rather than lifting a constant mass the B-200 applies a constant force against which the subject performs an exertion. The isoinertial tests described here apply to situations in which the mass to be moved by a musculoskeletal effort is set to a constant. Is Isoinertial Testing Psychophysical or Is Psychophysical Testing Isoinertial? As various types of strength tests have evolved over the past few decades, some unfortunate developments in terminology have arisen to describe and classify different strength assessment procedures. This is particularly evident in sorting out various tests that have been labeled "isoinertial." One example was cited earlier. Another problem that has evolved is that the term "isoinertial strength" has two connotations. The first is the conceptual definition: isoinertial strength tests include any strength test in which a constant mass is handled. In practice, however, the term is often used to denote a specific strength test in which subjects' maximal lifting capacity is determined using a machine and a constant mass is lifted.(1,5) Partially as a result of this dual connotation, the literature contains references to both "isoinertial strength test" as a psychophysical variant(8) and the psychophysical method as an "isoinertial strength test" (4,9) To lay the framework for the next two chapters, the authors will briefly discuss some operational definitions of tests of isoinertial and psychophysical strength. In stating that the isoinertial strength test is a variant of the psychophysical method, Ayoub and Mital(8) refer to the specific strength test developed by Kroemer(1) and McDaniel et al.(5) Clearly, this isoinertial protocol has many similarities to the psychophysical method: both are dynamic; weight is adjusted in both; and both measure the load a subject is willing to endure under specified circumstances. However, while both deal with lifting and adjusting loads, there are significant differences between the psychophysical (isoinertial) technique and the Kroemer-McDaniel (isoinertial) protocol in their procedures and the use of the data collected in these tests. For our purposes, we designate the

Jan 1, 1998

By C. B. DUTTON, W. F. RITTMAN, E. W. Dean, M. S. HOWARD

NOMENCLATURE USED IN THIS REPORT. In this report the ending ene has been used throughout, except in the bibliography and in quotations from the writings of previous investigators, for all aromatic hydrocarbons, as, for instance, benzene, toluene, xylene. The ending ol, though largely used in technical description, is not correctly applicable to these hydrocarbons, and should be used to designate the impure mixtures of commerce, as distinguished from pure chemical compounds. PRESENT STATUS OF PETROLEUM-REFINING INDUSTRY. Although petroleum is widely distributed, being found in many parts of the world, and although information as to its occurrence and general characteristics seems to have existed from vcry early times, our knowledge of the chemical nature of this substance has been acquired largely within the past 40 years. Within this period a voluminous literature has accumulated, which records work as painstaking as has ever been undertaken in the whole field of chemistry, such as that of C. M. Warren, F. H. Storer, S. P. Sadtler, S. F. Peckham, and C. F. Mabery. Despite this fact, the commercial method of treating crude petroleum for the purpose of procuring marketable products is, in the main, essentially empirical. Much knowledge has been acquired as to methods of separating from crude petroleum such products as are desirable commercially, but little has been done to attain the maximum recovery of such products.

Jan 1, 1916

By J. E. Tress

The Bureau of Mines prepared submicron tungsten powder by reducing tungsten hexachloride with hydrogen. The particle diameters of the resulting tungsten powders ranged from 0.015 to 0.046 micron. Within the limits of the variables investigated, no clear-cut correlation was found between process conditions and final size of the powder. Oxygen was the major contaminant in the product; being present both as an adsorbed gas and as suboxides of tungsten. Studies showed that the powder yielded compacts of approximately 45 per-cent of theoretical density when compacted mechanically. Low-temperature sintering produced more rapid densification in these compacts than in compacts prepared from conventional powders. Adding up to 20 percent ultrafine powder to conventional tungsten powder caused an increase in density upon compaction with maximum densification occurring at approximately 12 percent ultrafine powder.

Jan 1, 1966

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining I research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and, the results are described in this report.

Jan 1, 1983

By Richard H. Spencer, Thomas E. Doerfler, Robert L. Lagace, James M. Dobbie, William S. Hawes

This report assesses the expected detectability, on the surface above mines, of electromagnetic signals produced in the frequency band of 630 to 3030 Hz by a rescue transmitter activated by miners trapped underground. This assessment is based on a statistical analysis of experimental signal and noise data taken at a representative sample of coal mine sites well distributed over the United States underground coal fields. Regression analyses are performed to characterize the signal transmission behavior of overburdens as a function of depth and frequency. The predicted signal behavior is then combined with experimentally based distributions of the background noise, and aural detection characteristics of signals in noise, to generate curves of the expected probability of detection for trapped miner signals versus overburden depth and operating frequency. The implications of these results, and associated recommendations, are presented regarding the detectability of trapped miners, sensitivity analyses and confirmatory tests, and operational utilization considerations for the trapped miners and the search and rescue team on the surface.

Jan 7, 1980

By P. M. Sullivan

A physical beneficiation flowsheet was designed by the Bureau of Mines for reclaiming and recycling metal and mineral values contained in municipal incinerator residues, and a continuous processing plant was installed. Residue samples collected from incinerators located in various parts of the country were processed at a rate of 1/2 ton per hour. Continuous screening, shredding, grinding, magnetic separation, and gravity concentration techniques were applied to produce metallic iron concentrates, clean nonferrous metal composites, clean fine glass fractions, and tine carbonaceous ash tailings. Research to develop systems for refining and upgrading the reclaimed metals and glass into marketable products is also underway. From the engineering data developed in the continuous processing plant, evaluations of the capital and operating costs for plants with capacities of 250, 400, 670, and 1,000 tons of dry incinerator residues per day were made. Research on a parallel system to separate and recover the metals, minerals, glass, paper, and plastics from raw, unburned refuse it currently underway, as are studies on the use of air classification to separate the refuse into organic and inorganic fractions.

Jan 1, 1971

PURPOSE: Evaluate practical technological advances in hearing protective devices for use in different mining environments RESEARCH SUMMARY: Previous NIOSH research shows that miners develop hearing loss much more quickly than nonoccupationally noise-exposed individuals and that miners experience a greater severity of hearing loss than would be expected for nonoccupational noise-exposed persons of the same age and sex. As described in the National Occupation-al Research Agenda, problems created by occupational hearing loss include(1) reduced quality of life due to social isolation and unrelenting tinnitus,(2) impaired communication with family members, the public, and coworkers, (3) diminished ability to monitor the work environment (i.e., warning signals, equipment sounds, etc.), (4) lost productivity and increased accidents resulting from impaired communication and isolation, and (5) expenses for workers? compensation and hearing aids.

Jan 1, 2001

By John H. Thompson

Recent studies ** at the Pittsburgh Experiment Station of the Bureau of Mines have revealed some interesting facts as to the probable behavior of steamed coke in the blast furnace . The literature on the chemistry of the blast furnace was tho roughly reviewed , and with this information in mind , the probable behavior of the coke sulphur in the blast furnace was deduced . Enough small - scale tests were conducted to furnish a check on most of the important deductions , and the conclusions derived therefrom accord with what is already known in regard to the forms of sulphur in coke , and fit in well with the general opinion concerning blast-furnace reactions .

Aug 1, 1923

By A. C. Johnson

The T. L. shaft of the Eureka Corp., Ltd., near Adams Hill, Eureka, Nev., was sunk in 1954 and 1955 to permit exploration and development of the lead-zinc-silver ore that had been indicated by drilling. This paper describes the sinking of the 4-compartment, vertical shaft to a depth of 1,127 feet and includes pertinent details of equipment, methods, and costs. A shaft crew of 10 men, supplemented by 13 hoistmen, topmen, carpenter, and shop crewmen, sank and timbered the 1,127 feet of shaft in 630 workdays. Total labor per foot of shaft was 107.95 man-hours. Supplies per foot of shaft included 20 pounds of explosives, 1.61 pounds of drill steel, and 200 board-feet of timber. Power consumption, including that required for pumping, averaged 3,726 kw.-hr. per foot.

Jan 1, 1958

By R. W. Huber

The successful development of a titanium prototype of the 81-mm. mortar base plate for the Army Ordnance Corps is outlined in this report. Information is presented dealing with forming, forging, and machining, welding and assembly techniques, and design changes relative to this prototype. INTRODUCTION The work of the Federal Bureau of Mines in making ductile titanium available2/ has resulted in the establishment of a new industry. Owing to its strategic importance and the combination of low density and high strength, titanium has received considerable attention as a structural metal. Titanium's favorable strength-to-weight ratio is of particular importance to the Army Ordnance for equipment that is transported by airplane or by foot soldiers.

Jan 1, 1956

By Roy E. Williams

1. The major sources of heavy metal ions in wastewaters of the Coeur d'Alene Mining District are effluents from metallurgical processing plants. Effluents from mine operations provide a secondary source for heavy metal ions. Based on data analyzed by the Federal Water Quality Administration, mercury and arsenic are escaping from some mill waste ponds, but they are in the suspended phase. 2. Metallurgical process effluents are combined with mine waste effluents in tailings ponds, consequently, the quality of the tailings pond decant water is highly degraded. The major effect of combining metallurgical process effluents with mill wastes is a drastic change of pH in the tailings pond. This chance may be an increase or a decrease depending on the metallurgical process. The effluent from an electrolytic antimony plant drastically increases the pH in the tailings pond permitting the removal in solution of antimony via the pond decant system. The addition of low pH effluents to the tailings ponds results in a net decrease in pH which makes lead, zinc, cadmium, and copper more soluble, thereby permitting their removal from the pond via the decant system.

Jan 1, 2011

By W. H. Pomroy

This report describes research by the U.S. Bureau of Mines to design and in-mine test a rapid response pneumatic fire detection system for multilevel metal mines. The relative merits of pneumatic detection are discussed in the context of typical multilevel mine layouts and environments. The Bureau's prototype system is described, with emphasis on design features that counter commonly experienced and/or perceived operating problems with pneumatic detection systems. Finally, the results of a 3-year in-mine performance evaluation of the prototype system are discussed.

Jan 1, 1990

By Jr. Holmes

"The Riley tungsten property of the Northern Nevada Mining Co. was examined by the Bureau of Mines in August 1943, and from February 22 to August 22, 1945, the property was explored by the Bureau.Riley mine, which comprises 60 acres, is in sec. 9, T. 38 N., R. 42 E., Mount Diablo base and meridian, in the Potosi Mining District, on the east slope of the Osgood Range in eastern Humboldt County, Nevada. J. S. Riley is president of Northern Nevada Mining Co., the general offices of which are at 29 East First Street, Reno, Nev.Winnemucca, Nev., 42 miles southwest of the mine and on the main line of the Southern Pacific and Western Pacific Railroads and U. S. Highway 40, is the nearest supply center. The post office for the Potosi district is 15 miles south at Red House, Nev., a station on the Southern Pacific and Western Pacific Railroads. A good dirt road, which leaves U. S Highway 40 about 15 miles east of Winnemucca, extends northeast to the property.Tungsten occurs as scheelite in a characteristic Nevada contact-metamorphic tactite deposit between limestone and granodiorite Fifteen diamond-drill holes were completed for a total length of 2,630 feet.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources, to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.Special acknowledgment is made to A. C. Johnson, chief, :Reno Division, Mining Branch; E. O. Binyon, mining engineer, Reno Division; S. F. Clabaugh and S. Warren Hobbs of the Federal Geological Survey, who made available the un¬published Geological Survey report ""Tungsten Deposits of Osgood Range, Humboldt County, Nevada;"" and S. P. Zimmerley, chief, Salt Lake City Division, Metallurgical Branch, Salt Lake City, Utah.The Riley tungsten property comprises 60 acres of patented land owned by the Northern Nevada Mining Co. of Reno,,a partnership comprising J. E. Riley, H. H. Luce, Phyllis Riley, Beatrice Knight, Gene Crosby, and M. R. Wilson.The property is part of a federal land grant to the Southern Pacific Railroad, from which it was acquired by Tom Dernan many years ago. Two short adits and several shallow pits were excavated in a search for silver ore, but no record of precious metal production exists."

Sep 1, 1946

By E. C. Lane

For a number of years the Bureau of Mines has been studying crude petroleum from the producing fields of the United States, During the past year 10 crude-oil samples have been collected and analyzed from the producing fields of Pennsylvania and New York. This report gives the results of these analyses and for the purpose of comparison also analyses of samples of crude oils taken previously from some of these fields. This survey includes samples from normal producing properties as well as from properties using stimulative production methods such as water flooding and rapressuring. The outstanding feature of the survey is that the crude oils from tike various fields throughout this general area are similar in character and uniform in quality although they were produced from different sands and by various methods. Samples from fields in Venango County, Pa., however, appear to have a lower gasoline content than the others. This report includes two analyses reprinted from Bureau of Mines Bulletin 291.4/

Jan 1, 1938