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The Bureau of Mines performed cratering experiments in a homogeneous granite to test scaling laws for charge weights of 0.00476, 0.0220, 0.0900, 0.304, and 1.03 lb. Agreement among the data was best when empirical scaling exponents greater than one-third were assumed. Although the analysis showed that the best empirical scaling exponents were 0.37 for crater volume, 0.38 for crater radius, and 0.39 scaling for crater depth, all three crater dimensions could be scaled with a 0.38 scaling exponent.

Jan 1, 1970

By N. E. Hanna

As part of a program for improving, the safety of permissible explosives, the Federal Bureau of Mines has undertaken an investigation to establish the ability of sodium chloride to reduce the incendivity of permissible explosives to firedamp atmospheres. A motivating influence for this investigation has been the comparatively extensive experience of British and other European investigators, who used sodium chloride as a component of their permitted explosives (1, 5, 6 7).5/ In the United States research and development work of this type has been less extensive, although sodium chloride has been added to permissible explosives as a cooling agent (9) for many years. The results of the first phase of this investigation were presented in a previous paper (8), which established that adding up to 10 percent sodium chloride to permissible explosives reduces the likelihood of ignition of firedamp in the gallery test; however, the results were somewhat inconsistent, and the conclusions were qualified. Accordingly, the investigation was continued with a study of the effect of added sodium chloride as a function of the quantity added and of the particle size of the salt.

Jan 1, 1960

By A. C. Johnson

The Bureau of Mines explored the Three Kids deposit in 1941 as part of a strategic minerals program. Earlier mining and exploration had established the presence of a substantial tonnage of medium-grade wad ore, and drilling and sampling by the Bureau of Mines, in collaboration with the Federal Geological Survey, indicated an additional tonnage such that development and exploitation became more clearly feasible. Private interests, with Government support, undertook to produce metallurgical-grade manganese. The present paper describes the Bureau of Mines exploration and subsequent development. Manganese in the Three Kids area is found in one of the lower members of the Muddy Creek formation in a bed of fine sandstone and silt, which outcrops around the north edge of the River Mountains and generally dips 20° to 40° away from the hills. There is considerable variation in the thickness and grade of the ore. The ore is light weight, having a density of 1.2 to 2.

Jan 1, 1956

By R. T. MacMillan

A number of chemical techniques have been applied to manganese ores from three areas of Aroostook County, Maine. Although large tonnages of these ores have been proved, they are low grade, and their exploitation has awaited a suitable beneficiation scheme. As conventional ore-dressing methods had failed to yield satisfactory results, attention was turned to chemical procedures. Leaching with dilute (7-percent) H2S04 extracted over 90 percent of the manganese from ore of the Dudley farm area, consuming 3.8 pounds of acid per pound of manganese extracted. Ores from the Littleton Ridge and Maple Mountain-Hovey Mountain areas were less amenable to this treatment, yielding approximately 80 and 60 percent of their Mn content, respectively. To increase the percentage extraction of manganese in the latter two ores, a number of factors were varied, including (1) acid concentration in the extracting solution, (2) ratio of acid to Mn in the slurry, and (3) preliminary heat treatment of the ore with a reducing agent. Other acids, including HNO3, HC1, and H2SO3, were tried also; however, no significant improvements in the Mn leached from Maple Mountain-Hovey Mountain ore were made. The manganese extraction of Littleton Ridge ore was raised to 90 percent by providing 9 to 11 pounds of HNO3 per pound of Mn in the ore.

Jan 1, 1954

By N. H. Darton

In mining coal in the anthracite region of Pennsylvania the general custom has been to leave a large percentage of the coal in place as pillars to support the roof. Evidently any practice that involves partial waste of an important mineral resource is bound to be discarded. It is well recognized that one method of obviating probable waste is to fill the workings with cheap or worthless materials, a process extensively employed in the anthracite and some European mines. At present many of the collieries in the anthracite region of Pennsylvania are utilizing refuse from the old culm banks, which formerly were prominent features in the landscape, and are flushing the fine waste underground so that pillars may be reduced in size or removed. As a result the banks are now disappearing and soon will be gone. The fine culm from the breakers and rock from the mines will continue to be available, but the volume of these materials is insufficient to replace any considerable proportion of the coal removed. The next stage of progress suggested is the use of sand. Fortunately there are available large deposits of this material, much of which can be handled by dredges and pumps. This report is issued by the Bureau of Mines in the interest of safer and more efficient mining methods. I ts purpose is to describe the sand deposits in the northern anthracite coal field in Luzerne and Lackawanna Counties, Pa, Much of the information available is presented in the map, Plate I. Field studies, mostly preliminary, were made in the summer of 1911 to determine the distribution, amount, and character of the larger deposits. It was not thought desirable to make a detailed examination of the region because when the coal companies decide to utilize the sand their engineers will make precise surveys and drill test holes. In preparing the map the various coal companies were consulted; they contributed a large number of facts, especially as to the deposits in the buried valley of the Susquehanna between Pittston and Nan- ticoke, where nearly 1,000 test holes have been bored. The results of these borings were placed at the author's disposal, and have been utilized in drawing the boundaries given in the wide valley area and its extensions up Lackawanna River and NewportCreek. Wyoming Valley contains deposits of sand that are 100 feet thick over a wide area, 200 feet thick in places, and over 300 feet thick in the deep old channel south of Plymouth.

Jan 1, 1913

By L. N. Plein, J. W. Paul

"The United States Bureau of Mines, in the interest of the prevention of injuries and fatalities in coal mines, has engaged in a study of the circumstances and conditions under which falls of roof and coal contribute to coal-mine accidents, and this publication is devoted to the result of a study conducted in mince developed in the Pittsburgh or No. 8 coal in eastern Ohio.To emphasize the need of this study a statement of the fatalities which have resulted from falls of roof is presented, followed by a brief description of the field and its geology. The mining methods, regulations, and timbering practices are presented and discuss, as well as supervision and discipline, all of which are important factors in the control of the roof and the prevention of falls of roof material that are liable to result in injury to the underground workmen.During the five-year period, 1924 to 1928, there were 10,820 fatalities in the cool mines of the United States, of which number 5,573 or 51.5 per cent resulted from fells of roof material, such as draw slate or roof coal, and of coal from the fact or sides. These fatalities generally occur singly, consequently they are given little publicity compared with major disasters consulting from explosions which, during the same five-year period, amounted to only 17.8 per cent of the total fatalities.Seven,mines in eastern Ohio, each typical, of mines in its locality, have been carefully studied, and the result of this study is herein presented so the information may be and beneficial to all who may be operating mines having,similar natural or physical conditions.In general, it will be found that measures taken to prevent injuries or fatalities from falls of roof as well as other safety measures, will have the effect of increasing the efficiency and economy in mining operation. The result of the study so far made on the falls of roof problem indicates that such features as mine management, supervision, inspection, discipline, character of roof, timbering methods, and blasting have a direct bearing on any scheme that may be evolved to prevent injury or loss of life by falls of roof."

Mar 1, 1931

By Th. G. Sahama

This paper contains some new thermodynamic data for silicates in the series Mg2SiO4-Fe2SiO4 and MgSiO3-FeSiO3 and Lives the result: of a thermodynamic attack on the problems of stability end paragenoses. Although some data are lacking, satisfactory agreement with mineralogical and petrological observations is indicated.

Jan 1, 1949

Robert C. Horton was sworn in as the new Director of the Bureau of Mines on October 13 in Washington. Horton, 54, was director of the Geology Division of the Bendix Field Engineering Corporation's operations in Grand Junction, Colorado, before being nominated by - it Reagan for this position. A geological engineer, he has been associated with the mining industry in the West for over 35 years. Legislation to expand the Defense Production Act for 1 year until September 30, 1982, was signed by the President on September 30. The Administration had requested, steel a 5-year extension, but the Congress chose to spend another year considering proposed revisions. The Act, among other things, authorizes the allocation of strategic materials for defense purposes and allows incentives including floor prices and Government financing to encourage domestic mineral projects.

Jan 1, 1981

By Floyd R. Hertweck

This Bureau of Mines publication contains analyses and related source data for 349 natural gas samples from 26 States and 2 foreign countries. The 3 samples from foreign countries and 339 of the U.S. samples were collected during calendar year 1983. The remaining seven samples were collected earlier, but releases granting permission to publish were not received until 1983. All samples were obtained and analyzed as part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted since 1917. The analyses published herein were made by the mass spectrometer and chromatograph. The results of these investigations are published annually to make the information available to the petroleum industry and the general public. Twenty-seven publications have presented the results of 13,332 gas analyses made prior to 1983. The first three bulletins (1-3)3 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960; these bulletins have been supplemented annually by information circulars (4-17, 19-24, 26-27) containing 8,104 analyses of sam¬ples collected since 1960.

Jan 1, 1984

By Max J. Spendlove

This Bureau of Mines publication reviews current recycling trends in the United States. Although near-term prospects are poor for recycling most present wastes, urban refuse is an important exception. Such wastes comprise a mine above ground, and much less processing energy is normally required to recycle the constituents of urban ore than to obtain them in equal amounts from natural raw materials.

Jan 1, 1976

By Steven C. Goddard

Since the passage of the Federal Coal Mine Health and Safety Act of 1969, the need for improved duet control methods has become imperative. It has been proposed that one promising dust control technique would be the application of water through the cutter drum. In November of 1972, the Jeffrey Mining Machinery Co., who had been pursuing the development of wet drum miners since 1969, completed the manufacture of a 120M HELIMINER which had sprays in front of the cutting bits on a fixed width drum. On June 27, 1973 Jeffrey and the Bureau of Mines signed the contract numbered B0232060 for the purpose of evaluating "the effectiveness of respirable dust control on a Jeffrey 120M HELIMINER by use of water piped through the head." This evaluation, as described by the contract, was to be accomplished by the collection and analysis of dust samples at various locations of an operating mine production section.

Jan 1, 1974

By S. K. Ash

In arriving at economic losses in coal mining due to accidents, a statistician is confronted with many difficulties on account of the lack of information relative to nonfatal accidents. For comparative purposes the ex¬ perience of those countries, States, or companies that keep complete records can be drawn upon and an extimate can be arrived at whereby one State can be compared with another, or one mine compared with another in the same district. Such a comparison for the United States has been compiled by the United States Bureau of Mines. It will be observed in Table 1 that the cost per ton for accidents in the State of Washington for the year 1927 is higher than for any other State, with the exception of Georgia and North Carolina, with a small combined tonnage of 130,089 tons. (The figures for coal production in Table 1 are taken from Bulletin 319, 1930, of the United States Bureau of Mines.) The reasons why the cost of accidents in Washington might be higher than the average are on account of physical conditions such as steep pitches, faults, igneous intrusions, highly explosive coal-dust, extremely friable coals, presence of gravel and water, very gassy coal beds, rugged topographic conditions, inherently bad roof and floor, thick beds, and heavy cover. The nature of the coal beds requires the use of preparation machinery. The mines are often deep, and topographic conditions are such that long and fast haul¬ age becomes necessary. All of these factors not only tend to cause high cost of production, which is manifested largely in a. lower than average daily pro¬ duction, per man, but..they.also affect to some degree a tendency toward a higher than average cost for accidents.

Nov 1, 1931

By Jay F. Colinet

Longwall mining in lower seam heights may necessitate the use of single-drum shearers to overcome size constraints associated with standard double-drum shearers. To avoid the operational problem of clearance in the tailgate entry with one single-drum shearer, two single-drum machines can be operated on the same face, with each shearer responsible for mining a predefined portion of the face. However, utilization of two shearers on the same face necessitates the positioning of one shearer operator and a jacksetter in the return air of the upwind shearer, thus complicating respirable dust control on the longwall. In an effort to evaluate the unique dust control problems associated with this type of mining, the U.S. Bureau of Mines conducted dust surveys on two multiple-machine longwall operations. Sampling was done to quantify major sources of respirable dust and to identify potential solutions to problem areas. Sampling results indicate that the cutting sequences utilized on multiple-machine faces may have to be designed to minimize dust exposure, as opposed to optimizing productivity or facilitating operational requirements. Also, state-of-the-art dust control techniques typically found on double-drum shearer longwalls must be employed to help minimize the exposure of all face personnel to traditional dust sources.

Jan 1, 2010

By Robert Torbin

The objectives of the Continuous Shaft Lining (CSL) System are to reduce the costs, safety hazards, and time currently required in lining mine shafts with concrete. The CSL will line machine bored shafts downward from the shaft collar on a continuous basis using an inverted, pressurized slipforming technique. The technique for slip-forming downwards has been demonstrated and refined under this program. The approach taken involved laboratory scale testing of key features of the CSL concept. These feature tests included concrete distribution, concrete sealing, concrete slipforming and development of a reliable concrete mix. Based on these results, a full scale above-ground test facility and CSL were designed and fabricated. The objectives of these tests were to demonstrate the viability of the basic concept; to establish operating limits; and to provide input data and information for the design of a second generation shaft lining system. The results of the program have led to a CSL design and operational philosophy which will need to be tested in an underground environment before industry will accept the technology. However, the next generation CSL promises to meet all the original program technical objectives.

Jan 1, 1983

By E. P. Youngman

In the absence of any subsequent enactment of mining legislation, the Turkish mining law in effect in 1914, when Iraq became a British mandate, is still operative. The Constitution, or Organic Law, of Iraq, adopted by the Constituent Assembly on July 10, 1924, in articles 113 and 114, provides that:3 Ottoman en laws date and thao remained and lave pub- lished on or after that date and which have remained in force in Iraq u to the time of the publication of this law shall remain in force in Iraq' so far as circumstances permit, subject to any modi- fication or repeal in conformity with the proclamations, regula- tions, and laws referred to in the following article, and until they are altered or repealed by the legislative power or the High Court issues a decision rendering them null and void in accordance with the provisions of article 86. (Art. 113.) All proclamations, regulations, and laws by the Commander-in- Chief of His Britannic Majesty's Forces in Iraq, the Civil Commis- sioner, and the High Commissioner, and those issued by the Govern- ment of His Majesty King. Faisal, during the period between Novem- ber 5, 1914, and the date of the coming into force of this Consti- tution, shall be considered to be valid as from the date on which they came into force... (Art. 114.) 4 According to a German authority, it is the Turkish law of March 26, 1906, that, with a few modifications, is still in force. This law (similar to the French law of 1810) is discussed in a separate section of this paper.

Jan 1, 1933

By Alan A. Campoli

OD March 20, 1989, a meeting was held at the U.S. Bureau of Mines Pittsburgh Research Center at the request of Senator Pete V. Domenici of New Mexico. The purpose of the meeting was to engender a technical relationship between the National Laboratories and the minerals industry. During the meeting, the Director of the Bureau of Mines, T S Ary, suggested that since the Bureau is the focal point for mining research in the United States, it would be appropriate for the agency to act as the liaison between the National Laboratories and the minerals industry. As the first step in this process, the author was selected to perform a 6-month investigation to better define the proper role of the Bureau in this area. As part of the investigation, the mining and mineral-related technology available at 21 major U.S. Department of Energy (DOE) Research Laboratories was reviewed. It was assumed that the broad range of scientific and technical areas covered DOE research would provide fertile ground for mining-related technologies. It was hoped that the applicability of DOE research to this liaison effort would be indicative of Federal laboratories in general.

Jan 1, 2011

By Michael Hood

High-volume, low-pressure water jets have been employed for erosion of loosely consolidated rocks for centuries. This excavation method finds application in specialized circumstances even today. The use of high-pressure, low-volume water jets for rock cutting is more recent and was made possible by the development of high-pressure water pumps. Despite the benefits often claimed for these systems, high-pressure water jets still have not found widespread application. In this report, the U.S. Bureau of Mines has reviewed the various methods that have been employed using water jets to break rock and has focused on one method, termed "jet-assisted cutting," which was determined to be the closest to commercial development. The current state of knowledge based on laboratory and field experiences using this cutting method is reviewed, and possible future developments for this approach to excavation are assessed.

Jan 1, 1990

By P. R. Tisot

Knowledge acquired from this research contributes to a better understanding of the physical structure of Green River oil shale and provides fundamental data and concepts that may serve to improve oil-shale technology. This study by the Bureau of Mines indicates that oil shale is a highly consolidated organic-inorganic system with no significant micropore structure, pore volume, or internal surface. This system is a form of physical structure that precludes rapid diffusion of either gases or liquids. The mineral matter consists essentially of nonspherical particles that tend to follow a log-normal size distribution. An excess of 99 weight-percent of these particles have equivalent spherical diameters of less than 44 microns--75 weight-percent are from 2 to 20 microns, and 15 weight-percent are less than 2 microns. The surface area (3 to 5 square meters per gram) of these mineral constituents is mainly external surface. The mineral constituents contain some micropore structure--pore radii ranging from 10 to 100 Angstrom--with the pore sizes randomly distributed. Distribution of the organic matter within the inorganic matrix is essentially interparticle and not intraparticle. The organic matter within the micropores of the mineral constituents is less than 4 percent of the total. Estimates made from surface area data suggest that perhaps only a small amount of the organic matter is bonded either physically or chemically to the mineral constituents.

Jan 1, 1963

By F. D. Everett

The Federal Bureau of Mines reviewed the status of tungsten deposits of Utah in 1959. Industrial requirements of tungsten during emergencies have exceeded the domestic supply, and a knowledge of the sources of this strategic element may be helpful in the future. Tungsten occurs as the mineral scheelite in deposits that have been developed or explored on approximately 60 properties in 10 of the Great Basin ranges of Utah, none of which were being worked in 1957-59. Ores from most of the productive areas are similar in that they are contained in tactite deposits on or near the contact of calcareous and acidic intrusive rocks. The tactite ores consist predominantly of the silicate minerals garnet, epidote, and diopside and the carbonate rocks limestone or dolomite. Scheelite, where present, is disseminated irregularly in the tactite. Tungsten ores from Utah mainly have been produced from small deposits worked in World Wars I and II and the Korean campaign. The ores were either hand sorted to a grade ranging from 0.5 to 1.0 percent tungsten trioxide (W03) or were beneficiated in small mills to higher grade concentrates. The largest reserve appears to be in the area of the Notch Peak intrusive in the House Range, Millard County. A large part of the reserve in the House Range is mineralized tactite containing 0.2 to 0.3 percent W03. Research on flotation by the Bureau of Mines has indicated a method of concentrating scheelite in tactite ores that average 0.25 percent W03, with at least 85 percent recovery. The concentrate assays more than 5 percent W03 and can be processed into artificial scheelite ready for industrial use.

Jan 1, 1961

By R. R. French

The industrial minerals industry in the Atlanta, Ga., area was studied in order to better understand problems associated with exploiting mineral resources in and near metropolitan areas. A method for delineating the Atlanta urban area and its component parts was developed so that the factors affecting the location of the minerals industry could be viewed mere objectively in the urban context. Major attention is focused on the area's dominant crushed stone subindustry Demographic and socioeconomic analysis of the Atlanta, Ga., area shows that expansion of the metropolis and its environs will probably eliminate potential mineral resources from the mineral resource base in the area, and that the expanding metropolis will be the primary determinant of future mining sites. Competition for land is accentuated to varying degrees by the incompatibility of wining operations with residential and other environmental requirements. Areas of consideration are suggested to provide maximum development of land and resources for greatest economic benefits it minimum social cost. Further research is recommended to determine market locations in urban areas, optimum operating levels for industrial minerals plants, and alternatives to surface mining.

Jan 1, 1970