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By T. A. Klinefelter

ONE OF THE many services rendered by the Federal Bureau of Mines is the identification and general examination of ore and mineral samples. Many of these, coming from almost every State in the Union, are clay and shale samples. Other Government agencies, State geologists, universities, and other laboratories are often requested to make similar examinations. This publication describes methods of testing these samples. An earlier paper, published in 1943, described Bureau of Mines methods of testing such clays.3 This paper was to be followed later with another (part II) that would describe much more thorough testing than did the rather general outline of part I. Part I has been out of print for some time and needs revision, and part II was never written; hence, the present publication is designed to include part I and also those additions intended as part II. The tests presented in part I were simple, requiring only the ordinary equipment to be found in any good chemical laboratory. The second publication was to include a greater number of test procedures and information on increasing the accuracy and precision of those previously given.

Jan 1, 1957

By J. E. Tiffany, J. J. McKitterick

"IntroductionThe Bureau of Mines is investigating the fundamental factors in breaking down coal at the face, which govern the production of lump coal in typical mines working, different coal beds. Tiffany and Nelson in 1923-21 conducted tests on methods of blasting and use of different explosives, in a mine working the Pittsburgh bed in Pennsylvania. They determined come of these factors quantitatively, and compared their results with those obtained when the regular mine practice was followed.Results of Previous InvestigationThe tests by Tiffany and Nelson showed that the use of the cartridge of smaller diameter than that used in mine practice, resulted in an increase of 5 per cent in the amount of lump coal passing over a 1-1/4-inch bar screen, with a reduction of 32 per cent by weight in amount of explosive required. On the other hand, they found that on reducing the weight of charge 20 per cent, and using the cartridge of larger diameter, the round would not throw down the coal satisfactorily.Experiments with ""snubbing"" showed a similar improvement in quantity of lump coal, end the coal that was blasted rolled forward into the working place. however, in recent tests at another mine where the coal Lad different physical characteristics, snubbing did not always result in the coal rolling forward, on account of clinging to the ribs, and was not found to be an advantage. Therein the writers of this paper recommend that tests be made before deciding upon the adoption of snubbing in a particular mine."

Aug 1, 1925

By M. Hertzberg

This Bureau of Mines report describes experimental and theoretical studies of diffusion flames in free convection. The cross-coupling between buoyancy-induced flows and the combustion process is explored as it relates to the size, structure, and radiative balance of flames. New data are presented for the size-dependent radiance oscillations of diffusion flames and for the angular distribution of the total radiant intensity from a small methanol pool flame. Both amplitude and frequency of the measured oscillations are compared with theoretical predictions that are based on a new view of the structure of diffusion flames. This new view, which is at variance with the traditional one, assumes uniform reaction in the diffusive mixing zone, and recognizes the significance of the role played by convective buoyancy and its duality in both aiding and impeding flame propagation. Buoyancy quenches propagation at low burning velocities, introducing a real discontinuity in the combustion rate. A "flammable volume" is thus defined as that bound between lean- and rich-limit contours. However, in the flow disturbances generated by combustion waves that consume that volume, buoyancy aids propagation by promoting the convective mixing of a new flammable volume. The measured radiance oscillations are manifestations of these propagation and remixing cycles.

Jan 1, 1978

By R. H. Nafziger

Owing to the growth of alloy steel production and its influence on tramp element levels when recycled, foundries have expressed concern regarding the quality of scrap used to prepare iron castings. Reliable and current information was unavailable on the amount of tramp elements contained in iron castings over time. Accordingly, the U.S. Bureau of Mines, in cooperation with the American Foundrymen's Society (AFS), analyzed cast iron samples from participating foundries throughout the United States on a quarterly basis to ascertain possible trends. Each sample was analyzed for 28 elements to determine if changes had occurred as a function of several input variables. This bulletin describes the research and presents analytical results and evaluations over a 5-3/4-year period from January 1981 to September 1986. Results show that iron casting compositions are changing with respect to a few tramp elements such as arsenic, cobalt, chromium, tin, and zinc over the period. Changes in charge compositions probably are responsible. Significant variations between zones also were observed with aluminum, arsenic, cobalt, chromium, copper, and manganese.

Jan 1, 1990

By D. Harrington

Every few weeks United States newspapers of 25 or 30 years age ran scare-heads telling of some mine disaster, which was a first-page attraction for a day or two and then was forgotton until another disaster occurred a few weeks later. Interspersed with these disasters were the so-called sniping mine accidents, causing the death of one or two mine workers. The summation of all types of mine fatalities usually exceeded 3,000 a year. In the period 1906-10, inclusive, there wore 84 major explosion disasters (or about 17 per year) in united States coal mines; the fatalities resulting from those disasters numbered 2,388 for the 5-year period. These frightful catastrophies helped to cause the total number of fatalities in our coal mines for the 5 years (including the fatalities from major explosions) to reach the enormous total of 13,288, an average of 2,658 per year. In addition, some hundreds of other typos of mining accidents swelled the annual fatality list to upwards of 3,000. This admittedly deplorable condition created so much Nation-wide comment that Congress was impressed with the necessity of having something done by the Federal Government with a view to trying to halt at least sonic of the excessive loss of life in our mines; in consequence, the Bureau of Mines was created and began to function in July 1910.

Jan 1, 1935

By S. H. Ash

THE ANTHRACITE region of Pennsylvania contains over nine-tenths of the total anthracite deposits of North America and produces all but an insignificant proportion of the total output of anthracite in the Nation. The whole economy of the northeastern section of the United States depends, to a large extent, on the mining of Pennsylvania anthracite, which is shipped to New Jersey, New York, and New England and is a principal source of energy and heat for that entire region. The responsibility of the Federal Government for developing an engineering method that will prevent inundation of the Pennsylvania anthracite mines and keep them in operation has long been recognized. To obtain a reliable picture of the anthracite-mine-water problem and to solve that problem, it is necessary to have factual data on the volume and the quality and character of the mine water handled by the pumping plants in the anthracite region, as well as the kinds of pumps utilized and problems concerning their operation.

Jan 1, 1953

The Thermo-MIE personal DataRAM dust monitor (pDR) is a light-scattering instrument approved for use in gassy underground mines by the U.S. Mine Safety and Health Administration (MSHA). However, the use of light-scattering monitors has been inhibited by concerns about inaccurate readings resulting from changes in dust size distribution and composition, as well as concerns about the impact of moisture in the mine air. Because of this concern, the National Institute for Occupational Safety and Health (NIOSH) evaluated the pDR using available data from laboratory tests and mine surveys. The data show that accuracy can vary widely from test to test and mine to mine. In most cases, the results can be improved by using a companion gravimetric measurement to adjust the pDR data.

Jan 1, 2006

By R. V. Ramani

This volume, the first of a six volume final report, provides an executive summary of the research and results carried out under a grant from the U. S. Bureau of Mines on underground coal mine ventilation. Under the project, a mine ventilation simulator was developed. Sensitivity of leakage and friction factors on the total quantity and pressure requirements was studied. The simulator was applied to a new mine under development, and to an operating mine, to demonstrate the usefulness of the simulator in ventilation planning and in evaluating proposed changes to existing ventilation system. The titles of the other volumes are as follows: Volume II: Mine Ventilation Network Theory Volume III: User's Manual for PSU/MVS Volume IV: Sensitivity of Leakage and Friction Factors Volume V: Application of PSU/MVS to Ventilation Planning of a New Mine Volume VI: Application of PSU/MVS to the Analysis of Modifications to Existing Ventilation Systems

Jan 1, 1977

By Forrest T. Moyer

Injury experience at metal mines and mills (excluding officeworkers) in 1964 was 60 fatal and 3,672 nonfatal disabling work injuries during an exposure time of 149 million man-hours worked. These injuries occurred at a frequency rate of 24.57 per million man-hours and had a severity rate of 3,687 days lost or charged per million man-hours. Employment at 2,363 metal mines and 291 mills, excluding officeworkers, was 68,140 men in 1964. The average number of days worked was 274 The principal cause of fatal injuries at all mines and mills was haulage accidents and in underground mines, only, was falls of ground. The principal cause of nonfatal injuries was handling material accidents. The frequency rate at metal mines and mills in 1964 was slightly below that of 1963, whereas the severity rate was higher. Injury experience at 94 primary nonferrous smelters, refineries, and reduction plants (excluding officeworkers) was 8 fatal and 999 nonfatal disabling work injuries during a worktime of 98 million man-hours worked. The combined injury-frequency rate in 1964 was 10.29 and the injury-severity rate was 1,005. The 36,956 employees worked an average of 329 days during 1964. The principal cause of injuries at these plants was handling material accidents.

Jan 1, 1968

Continuously monitor and record respirable dust levels underground by a reliable, sensitive, and fast-response device. Approach A light-scattering photometer, having a LED (Light Emitting Diode) light source and other significant improvements, has been designed and incorporated into a portable continuous monitor. How It Works The monitor continuously draws air into the sampling inlet through a cyclone that removes dust particles larger than respirable size. The dusty air enters the photometer vertically downward through a cylinder which is intersected by the optical system. (This cylinder appears as a circle in the drawing of the photometer.) The center of he column of dusty air intersects a beam of pulsing light from the LED, causing some of the light to be reflected, scattered, and refracted. Only the light that is scattered at an angle of about 700 from the light beam passes through a lens to the photodetector which generates an output voltage Signal proportional to the dust content in the air. This signal is detected, amplified, and converted to a digital readout directly in milligrams of dust per

Jan 1, 1979

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By Amanda S. Azman

It is known that exposure to high sound pressure levels can lead to permanent hearing loss; however, many workers, in mining as well as other occupational sectors, frequently receive hazardous noise exposures. The National Institute for Occupational Safety and Health (NIOSH) recommends using a criterion level of 85 dB(A) for implementation of hearing loss prevention programs1. But, despite engineering and administrative controls, workers continue to exceed their recommended daily noise dose. Hearing protection devices are worn as a final defense against noise overexposure, but many workers have difficulty communicating or detecting warning signals while wearing them. New electronic technology has been integrated into conventional hearing protectors to allow for some degree of sound restoration. Research is currently being carried out within NIOSH, Pittsburgh Research Laboratory (PRL) to evaluate the performance of sound restoration hearing protectors. Due to certain features of the devices, such as their non-linear performance and possible manipulation of electronic settings, there are obstacles to testing them using the existing standard hearing protector test methodology (ANSI S12.42-1995 and ISO 4869-3:1997). These and other issues related to testing these devices are outlined within this paper, and possible solutions are discussed. Measures of attenuation properties have been done on a set of the devices and preliminary findings indicate that new test methods, or at least modifications of existing methods, must be developed to accurately determine device performance. Furthermore, it is necessary to know not only the attenuation properties of such devices, but also the degree to which speech intelligibility or recognition of warning signals is preserved, as compared with conventional hearing protectors. As additional data is collected a more accurate and reliable test methodology will be developed, and a more comprehensive picture regarding device performance will be determined and disseminated.

Jan 1, 2008

By H. P. Hermance

Preliminary examinations of the Parker and Webb deposits were made by E. E. Maillott, Bureau of Mines engineer in July 1942. The chemical and spectrographic analyses included in this report wore made at the Eastern Experiment Station of the Bureau of Mines at College Park, Md., under the general supervision successively of S. M. Shelton and of Paul M. Tyler, formerly regional engineer, Eastern Region. Beneficiation tests were conducted under the supervision of Frank D. Lamb. The mineral exploration was under the general supervision of J. D. Bardill, formerly district engineer. Acknowledgment is gratefully made to the St. Joseph Lead Co., in particular to John S. Brown and P. J. Mechin for their assistance. Special acknowledgment is made to the American Metal Co., Ltd., ,Ind to T. C. Moore for furnishing core-drill and assay data; to the Universal Exploration Co. and P. B. Jennings; and to the Northern New York Mining Corp. and C. H. Sprague for their permission to publish the core-drill dta. Excellent cooperation was given by Dr. W; M. Agar and C, L. Rogers of the Geological Survey.

Jan 1, 1949

Volume 2 presents the results of studies of Phelps Dodge Corporation's tailings embankments numbers 1West and 2 West, at Morenci, Ariz. The work involved compilation and description of pertinent factors relating to the physical features and operational characteristics of the facility, including information on embankment construction practices; investigation and research of the general geologic and seismicity characteristics of the site and vicinity; limited field exploration and materials sampling and testing at the site; installation and limited monitoring of piezometers, surface movement markers, and slope indicator casing; limited laboratory testing of materials to evaluate the basic index and engineering properties of the embankment and tailings materials; selected engineering analyses of the embankment for various types of potential "failure" conditions; and includes appendices.

Jan 1, 1974

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

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

Jan 1, 1947

By John J. Mulligan

The Bureau of Mines investigated coal deposits at Mount Gran (latitude 76°59' S, longitude 161°07' E), Victoria Land, Antarctica, during the austral summer of 1959-60 as part of the continuing U.S. Antarctic Research Program, which is under the auspices of the National Science Foundation. The coals and associated rocks were measured, sampled, and analyzed. Five coalbeds, ranging in thickness from over 10 feet to scattered fragments of coaly material in sandstone, occur in a sandstone-coal series overlying a series of crossbedded red-buff sandstones. Both series are part of the Beacon group of sediments, and both show some evidence of pressure metamorphism. The sandstones are poorly cemented and are composed dominantly of rounded and often frosted quartz grains. The sediments have been broken and uplifted by a series of massive diabase sills. The broken nature of the sediments precluded an estimate of the amount of coal present. The Mount Gran coals are highly attrital banded anthracites and semianthracites that have most commonly a moderately dull luster but do include bright bands. Coal in contact with or near diabase intrusives is partly graphitic but shows no evidence of coking. Apparently the coal was beyond coking rank before emplacement of the adjacent intrusives. Fragments of the plant Glossopteris indica found with the coal suggest Permian age but do not prove it. The coals appear to be derived from plant remains that collected in shallow basins; individual coalbeds would tend to be lenticular bodies that formed in different places as the dominantly sandy sediments were deposited. The wide distribution of coal indicates that coal-forming conditions prevailed over much of the continent; the great thickness of Beacon sediments indicates that similar conditions may have persisted through a long period of geologic time. Generally similar coal deposits may occupy widely separated stratigraphic positions.

Jan 1, 1963

By R. R. Wells

This report summarizes the results of preliminary mineral-dressing studies by the Bureau of Mines on five samples of copper-bearing ore from various Alaska de-posits. The work on each sample was not extensive enough to warrant individual publication. The results, however, indicate the possibilities and limitations of concentration of the respective ores. The information therefore may be helpful in future development of these ore bodies. Four of the five samples tested were submitted to the laboratory by engineers of the Bureau of Mines as part of the examinations and survey investigations of strategic-mineral deposits in Alaska. This program is conducted to assist development of mineral resources in the Territory and particularly to aid economic exploitation of marginal or complex ores. The fifth sample was submitted by engineers of the Defense Minerals Exploration Administration.

Jan 1, 1956

By Charles L. Kimbell

Virtually every available measure of total world mineral industry activity demonstrated that 1982 was little, if any, better for the industry than 1981 had been. Levels of production, trade, and consumption for virtually every major commodity declined; unit prices for most commodities fell, particularly in terms of constant dollars, and as a result of cutbacks in output and lower prices, capital available for investment within the industry was reduced. These conditions, coupled with the existence of considerable idle capacity, tended to retard investment, although there was an upturn in U.S. oil industry investment overseas. Despite the overall depressed situation of the world's mineral industry, there were indications of possible improvements in market economy countries near yearend, as output of some materials increased marginally and as prices for some mineral commodities reversed their downward trends. The downturns in total world mineral industry activity were not universal from the viewpoint of individual countries. Indeed, output of a number of commodities increased in centrally planned economy countries, and these gains were insufficient to offset declines in market economy countries, thereby sharply altering the proportion of total world output accounted for by each of these two groups of countries. There was a similar shift in consumption on a percentage basis.

Jan 1, 1984

By James Westfield

Following is a brief history of Bureau of Mines Division of Coal-Mine Inspection activities that have favorably effected health and safety and reduced Injuries at coal mines: The Federal cline Safety Code for Bituminous Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines on July 24, 1946, after consulting with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors while inspecting bituminous-coal and lignite mines for the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior on October 8, 1953, after further consulting with representatives of management and mine workers, and was incorporated in the 1952 and subsequent bituminous-coal wage agreements. The agreement of May 29, 1946, betweeen the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bituminous-coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. Federal coal-mine inspectors also had temporary authority to close mines considered imminently dangerous, but authority under Executive Order 9728 was removed on June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1962

By K. K. Kelley

The collection and correlation of thermodynamic data concerning substances of metallurgical interest have constituted one of the major activities of the Pacific Experiment Station of the Bureau of Mines, at Berkeley, Calif., for the past several years. Earlier bulletins (32, 33, 34, 36, 36, 37, 38) s in this series are entitled: (1) Contributions to the Data on Theoretical Metallurgy. I. The Entropies of Inorganic Substances; (2) Contributions to the Data on Theoretical Metallurgy. II. High-Temperature Specific-Heat Equations for Inorganic Substances; (3) Contributions to the Data on Theoretical Metallurgy. III. The Free Energies of Vaporization and Vapor Pressures of In¬ organic Substances; (4) Contributions to the Data on Theoretical Metallurgy. IV. Metal Carbonates--Correlations and Applications of Thermodynamic Properties; (5) Contributions to the Data on Theoretical Metallurgy. V. Heats of Fusion of Inorganic Substances; (6) Contributions to the Data on Theoretical Metallurgy. VI. A Revision of the Entropies of Inorganic Substances-1935; and (7) Contributions to the Data on Theoretical Metallurgy. VII. The Thermodynamic Properties of Sulphur and its Inorganic Compounds. The present paper collects and discusses thermodynamic data relating to metal carbides and nitrides, with the view of obtaining usable heat and free energy of formation relationships. Pertinent data on both classes of substances are difficult to obtain experimentally and consequently are extremely rare; it is therefore necessary in many cases, if equations are to be derived, to introduce certain approximations and assumptions. Lack of adequate means of checking results by utilizing data of different types, such as was done frequently in the bulletins dealing with carbonates and sulphates, are readily apparent to anyone who has made even a cursory examination of the available information. Consequently, some of the relationships derived undoubtedly will be found to be inaccurate when more or better data become available. Nevertheless, in view of the importance of some of these substances, it appears worth while to consider the information available at present and to attempt the formulation of as complete a

Jan 1, 1937