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By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

BIBLIOGRAPHY 1. Dougherty, John J. , "Control of Mine Fires", Publication of the Mining Extension Service, School of Mines, Appalachian Center, West Virginia University (1969). 2. Coal Age, "Fire, Explosions and Recovery, Federal No. 1 Mine", November, 1963. 3. Nagy, et al., "Sealing a Coal Mine Passage through a -Nor-ii-hole: A Progress Report", U.S. B. M. Publication No. 6453, (1964). 4. Murphy, et al., "Use of Fly Ash for Remote Filling of Underground Cavities and Passageways", U.S. B. M. Publication No. 7214, (1968). 5. Pennsylvania Drilling Company, Pittsburgh, Pennsylvania. Personal Review of Equipment. 6. Industrial Hazards and Communication, Division of U. S. B. M. Personal Communication with John Murphy and Merle Bowser. 7. Instrument Technology, Inc., Borescopes and CCTV Systems for Inspections of Nuclear Reactors; Personal Communication. 8. "Public Works", July, 1972. 9. The Industrial Hazards and Communications Division of the U.S. B. M. , Personal Communication regarding Cohu Model No. 2006. 10. "Bibliography on Underwater Photography and Photogrammetry", Eastman Kodak Pamphlet No. P-124. 11. Optical Properties and Visual Effects of Smoke-Stack Plumes, U.S. Department of HEW, 1967. 12. Middleton, W. E. K. , "Vision Thru the Atmosphere", Univ. of Toronto Press, 1952. 13. Kodak "High Speed Infra Red" film and Singer Corporation Model TI Silicon Vidicon TV Camera. 14. Night Vision Laboratory, Fort Belvoir, Maryland; Barnes Engineering Company, Stamford, Connecticut, Model, T-101; AGA Inc. , Secaucus, New Jersey, Model, "Thermovision" 680.

Jan 1, 1973

By H. E. Blake

An evaluation was made to determine the economics of utilizing waste fluosilicic acid for production of (1) calcium fluoride, and (2) anhydrous hydro-gen fluoride. Two versions of each process were considered and compared. The evaluation showed that both products could be produced and marketed competitively. Lowest estimated product sales prices required to yield a 25-percent return on investment before taxes (discounted cash flow basis) was $339.34 per ton of hydrogen fluoride and $48.64 per ton of calcium fluoride.

Jan 1, 1971

By J. G. Walters

The method for predicting coke strength developed at Steinkohlenberg-bauverein, Germany, in which experimental parameters are readily determined by small-scale laboratory tests, was found to be applicable to cokes produced from industrially used blends of American coals. Predicted 1-inch ASTM tumbler indices for four industrial blends were found to be in excellent agreement with the experimentally determined values. The laboratory determined prediction parameters include the proximate analysis of the coal the size consist of the coal, and Ruhr dilatometer test data.

Jan 1, 1971

By E. G. King

The work described in this Bureau of Mines report was undertaken to fill a need of industry for high-temperature heat-content data for uranium tetrafluoride. Without such data, heat balance evaluations of processes involving this substance are seriously hampered. Measurements of the heat content of uranium tetrafluoride were conducted at temperatures from 298° to 1,350° K. The melting point and heat of fusion were determined. The results are presented in suitable tabular form, and representative heat-content equations are included.

Jan 1, 1961

By R. P. Beyer

Low-temperature heat capacities and standard enthalpy of formation of copper difluoride (CuF2) were determined by the Bureau of Mines. The low-temperature heat capacities were determined from 11 to 302 K by adiabatic calorimetry. The enthalpy of formation was determined by HC1 solution calorimetry. The standard values of entropy (S°) and enthalpy of formation (?Hf°) at 298.15 K are l8.65±0.03 cal/deg mole and -129.02±0.29 kcal/mole, respectively.

Jan 1, 1978

1. Data from the Mine Safety and Health Administration (MSHA) indicate that a total of 44,015 employees worked in underground mining locations in 2003, corresponding to 44,778 full-time equivalent (FTE) workers. • Ninety percent of underground employees (n = 39,735) were mine operator employees. • Contractors comprised 10% of all underground mining employees (n = 4,280) and comprised only 5.8% of all underground FTEs. • The majority of underground employees worked for coal operators (73.0%; n = 32,130).

Feb 1, 2005

By John C. Machisak

THE INJURY data and related employment experience of the coking industry in the United States for 1955 arc presented in this publication under the following general sections: (A) General Injury experience: Tables 1 to 9: Contain current and comparable data on operating statistics, number and classification of injuries, injury-frequency rates, and accident agencies involved in causing injuries. Data are tabulated for the industry as a whole, for each typo of oven: and for the States in which coke is produced.

Jan 1, 1958

By A. T. Iannacchione

Synopsis Underground stone mining Is an emerging sector of the U.S. mining industry. As this expansion takes mines under deeper cover, and as more efficient mining methods are utilized, effective stone pillar design methods will become even more Important. Current design practices are examined and a discussion of safe mine layouts is presented as a first approach towards weighing the demands for increased production against increased risk. Risks to underground stone-mine workers include rib Instabilities, pillar failures and roof falls. Seventy-two stone-mine pillar designs were examined. Pillars with width to height ratios of less than 1.5 appear more likely to fail when subjected to excessive stress levels. When width to height ratios fall below 1.0 defects in the pillars, such as through-running discon¬tinuities, can have a significant influence on stability. Discontinuity persistence, dip, material properties and orientation are also important determining factors in pillar strength. During the past three years the number of active underground stone mines in the U.S.A. has ranged between 90 and 100. This number is expected to increase as the crushed stone industry responds to growing demands for its products.1 As more of the industry moves to benefit from the advantages of underground mining production from underground stone mines is expected to increase above its current level of approximately 66 000 000 r/year. Parker2 identified four advantages of underground mining operations: (1) surface developments, zoning laws and environmental concerns are often less of an issue; (2) stripping and restoration requirements are eliminated; (3) additional reserves are often available beneath the quarry floor, under pit slopes or under an adjoining property; and (4) space is created for secondary use. Underground mines enjoy the added benefits of work in a constant underground climate, rather than in the variable surface climate, minimization of community concerns by placement of the crushing, sizing and stowing operations underground and reduction of surface vibration concerns through smaller blasts. The drawbacks of underground mining include added health and safety hazards for the stone miners, whose health can suffer from increased exposure to falls of ground, airborne contaminants and fog in large underground openings. Injuries from falls of ground in stone mines have occasionally exceeded the incidence rates for other mineral resources mined underground. 3 Existing underground stone operations, by comparison with stone operations a decade ago, mine more stone at a faster rate and with larger equipment. Because of high demand mines face increased pressure to yield more stone per production blast. A majority of the miners use the V-cut blasting pattern, which limits the depth or pull for each shot to about 4 m. Therefore, to produce more stone, either the mines must work more faces or existing faces must be enlarged. The enlargement of underground openings poses problems in the maintenance o€ strata stability, First, the widths of the mine entries partially control the amount of sag or deflection that any given roof beam can withstand before failure. This deflection can take pi ace quickly after an opening is excavated or much later as weathering processes form additional, thinner beams. Because increased deflection increases the potential for roof beam failure, there is a limit to how wide a room can safely be made. These limits depend on local geological and stress conditions and, to some extent, the cost effectiveness of roof-bolting. Given these room width limitations, underground stone mines have placed more attention on expansion of production through benching where mining thicknesses permit. The heights of rooms partially control the strength characteristics of adjacent pillars: as the room height increases for a given pillar width the pillar width-to-height ratio (w/h) decreases. In general, stone pillars are very strong, but when the width-to height ratio diminishes the potential for pillar rib instabilities and pillar failures increases (see Fig. 1). [ ] In the underground environment the desire to utilize wider rooms, higher benches and multi-level mining results in the potential for unstable ground conditions. Although the number of failed pillars is currently very low, the potential for additional failures will grow if more slender pillars are developed, especially under deeper cover, with wider mining sections and in multi-level operations. It should also be noted that the passage of time acts to decrease the strength of many existing pillars. An examination of current design practices

Three types of communication systems have become popular in solving communication requirements underground: Loud-speaking pager phones, carrier current phones, and magneto ringing phones. Basically, all three are simply single-channel party line systems. Although these systems are quite reliable, the single channel creates a variety of problems. For example- 1. Since no call is confidential, messages are sometimes purposely made vague, especially if accidents or safety topics are being discussed. 2. A potential user must literally "wait in line" until the channel becomes clear for his use; thus, when foremen have to wait to call in reports or supply requests, this single chan-nel creates a serious productivity bottleneck. 3. In many large mines, there are independent branch lines that must be tied together by a dispatcher, adding further delays to the system. To solve these problems, some mines have installed other phone systems-mostly commercial dial phones in industrial enclosures that offer extra channel capacity and private line features. Others have installed a system that combines both dial- and page-phone features in a single unit. Although these do represent improvements, they do not truly solve the overall problems that face modern mines. Besides extra channels, a communication system should have the following features to enhance productivity and safety: 1. A means of paging a roving miner to alert him that he is wanted on the phone. 2. Wireless-to-wired system interconnects by which a miner can talk on the wired phone system by using a remote portable radio. 3. Remote monitors that alert personnel when there is a toxic or explosive gas buildup. 4. Control interfaces that allow remote control of fans, pumps, or other devices. 5. Transmitters and receivers that can serve as emergency links. 6. Loopback that allows an alternate path of communications if the main path is cut. This chapter focuses on equipment and methods to meet the special communication needs of individuals in various places of the underground mine. The communication requirements can be broken down into four categories: 1. The mine entrance (shaft communication). 2. Permanent and semipermanent locations (shop areas, lunchroom, crusher stations, etc.). 3. Mining areas (the room-and-pillar sections, longwall faces, block caving areas, etc.). 4. Haulageways (tracked trolley haulage, diesel, belt haulage). Methods of implementing systems to meet the communication needs of these areas are described in sections 3.2 through 3.5. Section 3.6 discusses methods of satisfying special communication requirements that exist. Major topics in this category include communications with roving personnel, the isolated miner, and motorman-to-snapper communications. Emergency communication systems are described in section 3.7.Detecting and

Jan 1, 1984

By T. M. Kohler, G. L. Finfinger, D. M. Hyman, A. T. Iannacchione

The Bureau of Mines measured methane emission rates from an advancing salt face ranging from 15 to 56 ft3/ton (0.5 to 1.8 m3/t). Small room size, use of a continuous miner, and a well-defined ventilation system made possible air velocity and methane concentration measurements, These measurements, representing data from 18 production days, were con- ducted in an area of abnormally low grade salt, Methane emissions occurred primarily during the advance of the salt face by continuous miner.

Jan 1, 1982

By J. M. Stuve

Calorimetric determinations of the low-temperature heat capacities, standard enthalpy of formation, and high-temperature enthalpies were made of (Na20)4 ?Fe20,(c). The resulting values of entropy (S°), enthalpy of formation (?Hf°), and free energy of formation (?Gf°) at 298.15° K are 104.676 cal/deg mole, -656.2 ±.kcal/mole, and -603.4 A kcal/mole, respectively. Tabulations of Cp°, S°, - (G°-H°298)/T, H°-H°298, ?Hf°, ?Gf°, and log Kf are given to 1,200° K.

Jan 1, 1971

By D. A. O'Keefe, M. M. Wong

To obtain beryllium metal of higher purity , flakes produced from electrorefining scrap metal were used as cell feed for a second cycle of electrore fining at 500 ° C in an electrolyte composed of 51.7 mole - percent LiCl , 36.9 molepercent KC1 , and 11.4 mole - percent BeC¹ · Metallic impurities in the flakes totaled more than 108 ppm , the metallic impurities in the metal obtained from the two - cycle electrorefining were , with the exception of 35 ppm of calcium , below the spectrographic determination limits .

Jan 1, 1964

By Joseph A. DeCarlo

This publication presents a tabulation of oven-and beehive-coke plants in the United States as well as pertinent statistical data on the number, capacity, kind, and condition of the ovens. Coke is an essential raw material in pig-iron production and the coal-chemical materials produced during the coking process are used to manufacture fertilizers, paints, plastics, synthetic rubber, explosives, detergents, nylon, pharmaceuticals; dyes, and many other products necessary to the high standard of living in this country. In table 1 the oven-coke plants in the United States on December 31, 1959, are listed. This shows the name and address of the company, location of the plant, classification or type of ownership, number and type of ovens, annual coke capacity, and the coal-chemical materials produced. The "furnace" plants I are those owned by iron and steel companies and most of them are integrated with blast furnaces to facilitate transportation of raw materials for steel making. Furnace plants represented 87 percent of the total coking capacity and their average annual capacity was 1. 3 million tons. The "merchant" plants are those associated with chemical companies, gas utilities, as well as those that produce metallurgical, industrial, and residential-heating grades of coke and coal-chemical materials for sale on the open market. These coke plants are smaller than furnace plants and in 1959 their average coke capacity was only 520 thousand tons annually. On December 3l, 1959, there were 54 furnace and 20 merchant oven-coke plants in existence in the United States.

Jan 1, 1960

By Mark I. Copeland

The formation of A1203 dispersoids 0,14 and less in size in dilute iron-aluminum alloys by internal oxidation in wet hydrogen and dispersion strengthening of iron by application of the technique to iron powder were found to be feasible by the Bureau of Mines. In flowing H2-1.5 H20 gas, A1203 dispersoids 0.1w and less in size formed (at 650° to 750° C) in Fe-l and 2 Al sheet material but not in Fe-3 or 4 Al alloys. With higher temperatures and/or higher H2O/H2 volume-ratio gases, A1203 and FeA1204 dispersoids >0.14 in size formed in all the sheet materials- Minus 100-mesh Fe 2 Al powders were internally oxidized under conditions that promoted formation of fine A1203 particles in sheet material, and then the oxidized powders were hydrogen reduced, sintered, extruded, and evaluated. During internal oxidation, fine A1203 dispersoids formed within the powder grains, and coarse FeA1204 particles formed on the powder surfaces and grain boundaries. The FeA1204 content was essentially eliminated during sintering by reacting with the unoxidized aluminum that remained in the center of the larger internally oxidized powders. The tensile strength at 800° C depended upon the aluminum-oxygen weight ratio of these elements in the extrusions and reached a maximum of 17,000 psi. The stress-rupture strengths at 800° C of the better alloys were comparable with those of type 310 stainless steel.

Jan 1, 1972

By Robert E. Johnson

THE MILDEST recession of the postwar period ended in the first months of 1961, and the economy climbed steadily during the remainder of the year. The Federal Reserve Board (FRB) Index of Industrial Production climbed from a low point of 102 (1957=100) in February to 115 in December, a rise of 12.5 percent. But economic activity for the year as a whole was only 1.5 percent higher than the 1960 level, as measured by real gross national product (GNP). Although activity increased throughout 1961, much of it was merely regaining ground lost in the decline during the second half of 1960 and the first months of 1961. The FRB index did not re ain the July 1960 high of 110 until June of 1961. Mineral fuels did not fully share in the economic recovery. The (FRB) crude oil and natural gas index rose only 5 percent between February and December. Although the index of monthly coal production increased 11.5 percent during the year, the February level was so low that total production for the year was the lowest since 1954. Total production of energy measured in Btu's was up slightly (1 percent) during the ear. Coal production was down; production of crude oil and natural gas was up. Calculated consumption paralleled production-total up slightly, coal lower, and crude oil and natural gas higher. The most interesting product developments were in coke and residual fuel oil. Sales of coke showed a sharper drop than steel

Jan 1, 1962

By S. L. Windes

"INTRODUCTION For a number of years the bureau of Mines has been engaged in the detection, recording and interpretation of earth- and air-transmitted disturbances, man-made and natural, related to mining operations. For the measure¬ment of such disturbances, special equipment was developed (1, 2, 3, 4, 8) 3/ and results of the measurements have been reported (5, 6; 7,9).In general, the ranges of amplitude end frequency of vibration encountered and recorded in the earth-transmitted disturbances were 0.00005 to 0.1 inch and 5 to 5,000 cycles per second; in the air-transmitted disturbances, pressures ranging from 0.001 to 100 pounds per square inch and 0 to 20,000 cycles per second were recorded.One characteristic of the earlier tests was that either the arrival time of the disturbance to be recorded was predictable or the recording speed was slow enough so that the record covered extended periods of time (for example, 4 hours). As the investigations continued, it became apparent that a recording device was required that would respond to transient vibrations arriving at indeterminate times and at the same time provide a permanent record of displacement or acceleration versus time on a scale that would permit the analysis of waves having frequency components up to 10,000 cycles per second. A film or paper speed of 720 inches per second was found to be adequate, as this provides approximately 3/4 inch of record for each 0.001 second."

Dec 1, 1947

Crosson and Peters treat the errors that result in miner location due to errors in the overburden earth model used for computing location. A parallel effort by J. Powell of PMSRC is discussed here, where the location method used is that of the Westinghouse location program - "Miner". This location program was tested by Powell by using arrival times generated from the overburden earth model of Table l* rounded to the nearest millisecond. Location computations were then made using 3 geophones at a time. The average location is tabulated for all geophone triplets except when 3 geophones are in line. Geophone arrays were as shown in Tables 2 and 3. The manner in which the test was done is illustrated in Figure 1. I. SUMMARY OF RESULTS The arrival time differences, based on the Table 1 earth model, together with geophone locations based on the array geometries of Tables 2 and 3, were entered into the computer, together with a stated depth of 700 feet and an estimated overburden seismic velocity of 10,000 feet per second. These parameter values were processed by the location program - "Miner". Figure 2 illustrates the interpretation of the plots and data. The tabular data and plots of Table 4 and Figures 3, 4, and 5 illustrate the location error results obtained. These plots indicate that for sources within the array, the errors are considerably less than the measured errors obtained during field tests of the present location system. The possible reasons for this discrepancy are noted in Part Eight (Earth Models).

Jan 1, 1974

By R. V. Ramani, C. B. Manula, A. Owili-Eger

ANALYTICAL PRESSURE - VOLUME COMPUTATIONS FOR THE MINE PROTOTYPE A new coal mine is projected, with entrance by slope 1,500 feet long. Nine main entries will be standard for development, five as intake and four as return. One return shaft is planned near the slope bottom, and an intake shaft and portal are planned 5,000 feet north of the slope bottom. The slope will have an area of 150 square feet and a perimeter of 55 feet. A belt and supply track will be within the slope. The return shaft will be circular with a diameter of 18 feet and will be 500 feet deep with an escapeway. Two hundred feet of the shaft and 500 feet of the slope will be concrete lined. Select the fan to operate five units per shift and drive the 5,000 feet to a proposed new portal, using the slope for an intake. Two main splits are planned with the maximum of three units on any split. The amount of air desired at each unit is 25,000 c.f.m; a shop at the slope bottom will require 10,000 c.f.m. In the solution of this or any similar problem, the first step is to determine the resistance factors. CALCULATION OF R FACTORS Slope area = 150 sq. ft.; Perimeter = 55 feet; Length = 1,500 feet. The friction factor K must be established. Five hundred feet of the slope is smooth lined, moderately obstructed by belt; K = 35. The remaining 1000 feet is in sedimentary rock and moderately obstructed; K = 85.

Jan 1, 1975

By Robert L. Chufo

The U.S. Department of Energy Pittsburgh Research Center,1 has developed and field tested a spatial, spectral sensor for measuring the thickness of mineral deposits. Knowledge of the dielectric constant of the material is not necessary because the electrical properties of the media are determined automatically along with the thickness or distance measurement. The technology was developed to measure the thickness of coal remaining in the roof and floor of a mine or the thickness of a coal pillar remaining between two mining entries for the purpose of guiding a mining machine. However, field tests have shown the new technique is equally valuable for measuring the thickness of each layer in a multilayer manmade structure such as highway paving or building foundations and the thickness of geological deposits other than coal, such as, salt, granite and sandstone. The noncontacting electromagnetic technique uses spatial modulation created by moving a simple dipole sensor antenna in a direction along each axes to be measured while the complex reflection coefficient is measured at multiple frequencies over a two-to-one bandwidth. The antenna motion imparts spatial modulation to the data and enables frequency domain signal processing to solve the problem of media, target and antenna dispersion. The technique overcomes the problem of multipath reflections from nearby metal structures and avoids the use of radio frequency absorbing material. In its present form the system measures material thickness of zero to over 3 m to within ±2.5 cm accuracy. The system parameters are variable to suit the application but for most applications default values of 40 cm antenna motion with measurements made at 401 frequencies from 0.6 to 1.4 GHz at each of 32 antenna positions with a power level of 0 dBm or less are more than adequate to provide a satisfactory signal-to noise ratio. In the range of 0 to 10 m the system operates in the continuous wave mode and by simply turning off the transmitter for ranges beyond 10 m the problems of time domain processing are entirely avoided. The technique can be implemented with a vector network analyzer, a servo controlled L-band antenna positioner, an IEEE488 bus controller and a process computer. An electronics package designed and constructed to operate in the harsh mining environment and providing 1, 2 or 3 dimensional image presentation is being evaluated as a replacement for the network analyzer. Key words: Ground penetration radar, Spatial, Spectral

By R. C. Hickman

"INTRODUCTION The most productive area of the eastern Virginia pyrite belt lies to the north of the village of Mineral., in Louisa County. The largest producers of pyrite ore in the area were the Armenius, Boyd Smith, and the Sulphur mines.The Boyd Smith mine started production about 1890 and operated more or less continuously until 1922, when competition from the Gulf States and Spain closed the pyrite mines in Virginia. There are no reliable records of production or value of minerals produced.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the most effective utilization of our mineral resources to the end that they take 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, Oliver C. Palston, chief, analyzes samples and performs beneficiation tests.The project was under the immediate supervision of Mitchell H. Kline, chief, Raleigh Division, Mining Branch, Bureau of Mines.LOCATIONThe Boyd Smith property is reached from Mineral, Va., by traveling north on State Route 522 about 2-1/2 miles. An unsurfaced road, winding in a northwesterly direction, loads to the Boyd Smith headframe, which is about half a mile from State Route 522 (fig. 1). The tract comprises 181 acres."

Aug 1, 1947