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By S. H. Ash

The Pennsylvania anthracite-mining region is the only one in the world of major magnitude. As the deposits of anthracite in the United States are limited virt113.lly to Pennsylvania, the difficulties of this industry have been commonly considered a State rather than a national problem. However, there is also national interest in the conservation and wise utilization of all fuel resources and in the control of interstate waterways. The anthracite industry is confronted with the very se:;-ious :problem of accumu.lation of water in many of the mines. This problem must be solved soon if progressively higr-er mi~ing costs are to be avoided. The water proble~ cannot be solved by the operating compa,nies without State or Federal aid, or both, owing to the magnitude of the work requir~d, diversity of interests of the coal ana surfa.ce ovmerships, hazard to the whole mining community, and interests affec~ed outside the mining region. The cost of abati~ the ever-increasing_surface seepage to mine workings and of handling this seepage once it }3s occurred is beyond the economic resources of most ope~ating ma.'18.gements. The data in this paper giving the high lights of the water problem and indicating what appears to be a step in the right direction are based upon observations made during the past year that the industry desires and believes it is to the npublic interesttr to keep mine workings free of flood end surface waters.

May 1, 1941

By J. K. Whyatt

This report describes a microcomputer-based instrumentation system for structural monitoring of the circular, concrete-lined Silver Shaft in northern Idaho, The 1-ft-thick concrete lining and surrounding rock mass were instrumented with a total of 12 multiple-point borehole extensometers, 16 pressure cells, 22 concrete embedment strain gauges, and 12 thermistors. The instruments were distributed among four test sites and installed immediately above the shaft bottom during sinking at the 2,414, 4,063, 5,191, and 5,955 levels. Limited access to the instruments prompted the development of a microcomputer-based remote data acquisition system that could be operated from the surface. The system scanned the instruments on a programmed schedule, printed out reduced data, and stored the data for plotting and recall. Data acquisition from off-site and uploading of data to mainframe computers were accomplished by the addition of modems to the basic system. The system is suitable for use in monitoring the structural behavior of any deep mine opening, especially in harsh operating environments and where access is limited.

Jan 1, 1986

By William D. Dodge

A typical quality program plan is presented for explosion-proof (XP) electrical enclosures. The plan is suggested for manufactures of XP enclosures which are to be certified by MSHA for mining use. The plan describes the quality system, organization and implementing mechanisms which are to be applied in the manufacture and delivery of certified XP enclosures. Example forms and example procedures are included.

Jan 1, 1984

By Frank E. Cash, Roy G. Stott

This circular describes four modern change houses of the Lake Superior iron - ore district , all conceived and constructed since 1937. The oldest change house described herein was constructed and occupied in 1938 , yet it embodies the modern improvement of air - conditioning . The purpose of this report is to describe and illustrate improvements with regard to health and safety features combined in the construction , arrangement , ventilation , heating ,lighting , and other features , with the aid of photographs , sketches , and diagrams . The modern change house is a fire - resistant structure in which intermingling of men in mine clothes and men in street clothes , hazardous dust , heat and humidity , crowding , poor lighting , slippery and muddy floors , and inadequate facilities for clothes and for bathing have been largely eliminated . The miner coming off shift at a modern mine no longer faces the elements when he gets off the cage . He travels through a tunnel to the change house , where he is cooled gradually by room temperatures as he passes from the mineclothes section and shower room to the street - clothes room . He is assured of dry clothes when he is ready for them . No longer is he sent out of the change house into a muddy yard to drive away as best he can . The modern change house has an improved parking lot and graveled or concreted walkways from it to the change house entrances .

Jan 1, 1949

By L. R. Burdick, J. F. Barkley

"There is a general conceit in the coal trade that the moisture- and ash-free B.t.u. of coal from the same seam, and surely from the same mine,is substantially a constant; that calculation of the moisture- and ash-free B.t.u. value from the proximate analysis and B.t.u. determined in the laboratory will reveal whether a coal came from a given area or seam; and that, having this constant, the B.t.u. value of a coal sample can be calculated fairly closely upon a dry or as-received basis from the moisture and ash values of its proximate analysis.To illustrate with a simple example;"

Jun 1, 1941

By William W. Adams

The stone-quarrying and related industries of the United States made large gains in employment in 1936 over 1935, according to reports furnished by operating companies to the Bureau of Mines, United States Department of the Interior. Not only were more men employed, but also increases were made in the number of man-days of labor performed and in the number of man-hours worked in 1936. The increase in employment, however, was accompanied by an increase in the number of accidental deaths and injuries among the workers and by a slight increase in the accident-frequency rate per million man-hours worked. The fact that the larger number of accidents resulted in only a slight increase in the accident rate is explained by the large gain made in the number of man-hours worked during 1936. The accident rate in 1936, although higher than in 1935, was the lowest and therefore the best that the industry has experienced in any previous year except 1932 since complete and comparable figures first became available in 1916, a period of 21 years. Operators' reports to the Bureau of Mines showed that the industry as a whole employed an average of 80,022 men in 1936 and that the men worked a total of 18,874,254 man-days or 147,064,448 man-hours. Accidents in and about the plants caused 91 deaths and 5,717 nonfatal lost-time injuries among the workers. The number of injuries and deaths represented an accident-frequency rate of 39.5 per million man-hours worked, compared with a rate of 38.2 in 1935.

Jan 1, 1938

By G. F. Livingston, F. K. Shelton, J. C. Stahl, R. E. Churchward

"INTRODUCTION An investigation of the metallurgy of cobalt from domestic ores has been in progress since February 1940 and has resulted in the formation of a hydrometallurgleal process for the production of electrolytic cobalt metal. Previous reports of these investigations have been given by F. K. Shelton; 7/ and Ruth E. Churchwrd, F. K. Shelton, and G. Knickerbocker. 8/ Briefly, the process, as applied to ores containing cobalt oxide, consists of leaching with H2SO3 or, preferably, with H2SO3 and H2SO4, to dissolve the cobalt. The cobalt solution passes through one or more purification stages to remove iron and elements of the copper group, and cobalt carbonate is precipitated under carefully controlled pH conditions. The cobalt carbonate is dissolved in on acid electrolyte containing sulfuric acid, boric acid, and sodium fluoride. The electrolyte then proceeds to electrolytic cells where cobalt is plated as a metal and sulfuric acid is regenerated.The present paper contains the results of several investigations signed to give a more complete chemical and engineering understanding of different unit processes involved in the electrowinning of colbat. Some work has been done to broaden the process to include arseniferrous cobalt ores as well as the oxide ores upon which the investigation was initiated. Most of the data presented herein have been obtained since the release of the previous reports; any changes suggested heroin that conflict with recommendations in earlier reports are based on more complete data and usually are preferable."

Nov 1, 1945

By Peter W. Kauffman

This Bureau of Mines publication is designed primarily to provide mine engineers and production-level mine managers with the following: 1. Information to assist them in making the decision to retreat mine and in selecting the best retreat mining technique for specific mining conditions. 2. Information on mine planning that will enable them to design mine layouts for safe and efficient retreat mining. 3. Information that will enable them to develop a section foreman's handbook. The manual has been organized to gradually increase in level of detail as the reader progresses from beginning to end. Individuals interested in an overview of retreat mining can confine themselves to the first few chapters. Those interested in mine planning, should read the middle chapters as well. Those interested in the development of a foreman's handbook should read the entire manual.

Jan 1, 1981

By S. M. Shelton, W. A. Calhoun, M. M. Fine, T. L. Johnston

"FOREWORDFerrograde manganese ore or its equivalent is essential to the manufacture of every ton of steel produced; although it is well known that there are large deposits of low-grade are in the United States, the production of substantial amounts of ferrograde material from domestic sources presents a problem that becomes more and more critical as the stockpiled ore depleted through inability to procure adequate supplies from foreign sources. Consequently, a program of laboratory,and pilot-plant investigation designed to solve the problem of obtaining a domestic supply of manganese has been undertaken by the Metallurgical Division, Bureau of Mines.This paper is one of a new series that include reports of results obtained in the various investigations conducted under the manganese program. The scope of the program and the organization that was set up to direct and supervise the were discussed in the foreword of the first paper of this series, Report of Investigations 3606 Manganese Investigations. 1. Concentration of Manganese Ores,from the Drum Mountain District, Utah, by S. R. J. D. Vincent, and C. R. Schack. Other reports will be published as the work progresses."

Mar 1, 1942

By G. W. Grove, H. R. Burdelsky, F. E. Griffith

"INTRODUCTION The work of using a system of air locks in unsealing a mine in Ohio following a fire probably was one of the outstanding jobs of its kind in a medium-thick coal bed.The fire in this mine, thought to have been of electrical origin, was discovered at about 1:30 a.m. on December 11, 1941. Forty-four men were working in the affected section at the time; 5 escaped unassisted, and 37, who had barricaded themselves, were rescued. The bodies of two men, who had succumbed after breathing fumes given off by the fire, were brought part way out of the mine before it became necessary to seal the mine.Direct attempts to extinguish the fire with water were abandoned when hazardous amounts of 'carbon monoxide, methane, and other inflammable gases were detected in return air passing through the main haulageway and escape-way of the mine.The mine was completely sealed on the surface at about 8 p.m. on December 12, 1941, with the two bodies remaining in the mine. Sixteen days after the mine had been sealed, the two bodies were recovered. This was accomplished by air-locking through a partitioned-off stairs compartment of a ventilation shaft. This work was done under adverse barometric and atmospheric conditions.A method for collecting representative air samples from the immediate fire area was used successfully by utilizing a vacuum pump on about 10,000 feet of existing water line that had been broken near the fire area.The immediate fire region was sealed, and confined to a relatively small area; the remainder of the mine was recovered, and operations were resumed February 9, 1942, or 59, days from the time of sealing the mine on the surface. This recovery was made by air-locking the main entries inby from the shaft and No. 2 right-face entries.The distance between air locks averaged about 500 feet, and as each new set of seal stoppings and air locks was completed, the old or outby seals were taken out and the area between was ventilated. In ventilating this area, it was often necessary to use line curtains to direct the air into dead-end places."

Oct 1, 1947

By J. R. Thoenen

Occurrences of titanium, zircon, and other heavy minerals are widespread in Florida. Deposits concentrated as "heavy sands" by wave and wind action have been mined an or near Atlantic coastal beaches since 1916. An important inland concentration at Trail Ridge; .believed, to have formed along an ancient share line, was disclosed by preliminary investigations (1947) by the Bureau of Mines. This report describes investigations to determine the extent and grade of "heavy-sand" concentrations in other inland stabilized dune areas in the central and northeastern parts of the peninsular region of the State (fig. 1). Portions of the central highlands south of Trail Ridge and terraces and dunes in the coastal lowlands region, east and northeast of the ridge were investigated. Holes were drilled in 10 areas (see table 1 and fig. 2) along State and County roads and on private property. They were spaced 250 to 2,000 feet. apart to obtain a cross-sectional picture of "heavy-sand" content in the dune areas. These sections were generally placed in east-west directions normal to the general trend Of the peninsula to intercept one or more of the ancient shore lines in the various areas (figs. 3 to 13, incl.). A total of 433 drive piped and 333 jet holes were drilled, and 7,293 bulk and core samples were taken. Intermediate holes were placed at closer intervals when field analysis indicated 1 percent or more of heavy minerals present. All of the holes drilled and the analysis of samples that contain 1 percent or more of heavy minerals are listed in table 2. Profiles (figs. 14 to 20, inclusive) show the more favorable concentrations, which are irregular in outline and erratic in mineral content. The highest concentrations averaged 1.0 to more than 2.0 percent heavy-mineral content, but a few individual hole samples exceeded 3.0 percent in grade.

Jan 1, 1949

By P. Yant, R. R. Sayers, R. D. Lieitch

"PURPOSE OF INVESTIGATIONOf more than 300 bituminous mines examined by Crichton 5 and his assistants in connection with litigation in Indian Creek Valley, Payette County, Pa., only four were found to have alkaline water. That work and many observations from of the authors have shown the general prevalence or acid drainage from bituminous coal mines. In connection with investigations pertinent to coal-mine drainage that are being conducted by the United States Bureau of Mines, it was noted with considerable interest therefore, that a mine in the Thick Freeport bed about 20 miles north of Pittsburgh had no acid water in the workings, As it was thought that this condition might be common to all mines,this condition in this bed most of them were visited, samples of the outflow and from different parts of the mine inside were examined, and such general information as was available was gathered.ACKNOWLEDGMENTSThe authors acknowledge with thanks the courteous assistance of mine officials in connection with collecting the data for this paper, and of the analytical and coal laboratories of the Bureau of Mines for analyses."

Nov 1, 1932

By S. M. Runke

"During the past three years the Bureau of Mines has carried on an extensive research program at the Rolla Laboratory for the beneficiation of low-grade Arkansas baixites by ore dressing methods. As a result of this study a 50-ton pilot mill was designed and constructed at Bauxite, Arkansas, by the Bureau to continue the investigation on a semi-commercial scale. The built both to reduce the experimental work to practice and to obtain operating data that cannot be determined by laboratory or small scaleTen samples of bauxitic material were mined and stockpiled at the plant site to ensure an ample supply of material for milling in the pilot plant. These samples were obtained from various bauxite deposits in Saline and Pulaski Counties, Arkansas. The deposits were selected as typical of a wide range of bauxitic material which would necessitate treatment under different conditions and by various concentration methods. All of the samples contained a higher silica content than permissible in Bayer-grade bauxite and several contained so much iron oxide that the available alumina content of the ore was mate¬rially lowered. From data obtained by milling operations on these ten samples, milling characterietics of most of the ores in the district should be predictable. This paper summarizes the results obtained in the laboratory testing of representative samples of each stock pile, and the results of small scale continuous testing of the composite sample of the ten stock piles in the gravity-flotation pilot plant at the Rolla Laboratory."

Aug 1, 1946

By Paul S. Goodman

This report examines the effectiveness of bonus plans in the coal industry. The analysis uses theoretical, literature review and empirical approaches to determine the impact of bonus plans on safety and productivity in underground coal mines. The basic finding is that the modal bonus plan in underground coal mining does not have a major impact on productivity and safety indicators. The design of the plan, or organizational factors, and the process of introducing the plan all contribute to its relative ineffectiveness. Strategies and options for designing effective plans are presented.

Jan 1, 1987

By C. E. Lapple

To improve mine health and safety conditions, there is need for a portable instrument that mine inspectors can use routinely for rapidly checking concentrations of dust in mine atmospheres. On October 23, 1969, Stanford Research Institute was authorized by the U.S. Bureau of Mines to conduct a study aimed at developing such an instrument under Contract No. H0100186. The results of that study are reported in Technical Report No. 1, "Development of Portable Instrument For Measuring Coal Mine Dust Concentration," August 1970. In that study it was demonstrated on bench-scale that a near-forward optical scattering device gives a linear correlation between mass concentration and optical readout over a range of 2 to 200 mg/m3 with excellent reproducibility. The same correlation was obtained for the Respirable* dust fraction of three different coal dusts within ± 10% and an extreme spread of ± 30%. Based on these results a prototype instrument was designed which was expected to meet all the necessary requirements of a portable instrument for mine use. Because of the excellent results obtained, a further study was authorized by the Bureau of Mines on May 10, 1971 under Contract No. H0111688. The prime objective of this study was to build, calibrate, and deliver to the Bureau of Mines two prototype instruments based on the design previously developed. The emphasis was to be on providing instruments which would meet certain minimum standards of size, weight, response time, sensitivity, ruggedness, reproducibility, permissibility, and cost (ultimate); optimization of the design was to be considered only insofar as it would not significantly delay the development. One instrument was to be delivered after initial calibration of both instruments with Coal Dust PGH. The second instrument was to be used for further calibration with a number of other coal and rock dusts and for assessing other relevant performance characteristics. This report summarizes all the results of this second study.

Jan 1, 1972

By A. C. Fieldner

In 1927 the Carbonization Committee of the American Gas Association proposed cooperation with the Bureau of Mines in the development of suitable methods for determining the carbonizing properties of American coals. It was further proposed to apply these methods in the testing of representative coals and to make the information obtained available to the public through Government publications. A cooperative agreement was signed whereby the Gas Association contributed part of the funds necessary for beginning the project and appointed a committee to consult and advise the Bureau in the work. The Advisory Committee has been reappointed each year, and the Bureau has had the benefit of its advice. The composition and carbonizing properties of 33 coals previously tested have been given in technical papers of the Bureau of Mines and in short reports published for the most part in the Proceedings of the American Gas Association. A complete list of publications on the work previous to 1937 is appended to this report. The present report gives the composition and carbonizing properties of seven additional coals from West Virginia. The data include results of blending tests in which Beckley led low-volatile coal was used with all the high-volatile coals except the Alma coal, with which Pocahontas No. 4 coal was used.

Jan 1, 1938

By K. K. Kelley

The first bulletin (245)3 in this series, which appeared in 1932, summarized the entropy values then available for the elements and inorganic compounds, results being listed for some 150 substances. In the interim advances in the realms of spectroscopy applicable to the determination of thermodynamic properties and in the development of methods of calculation therefrom have added many highly accurate values. Moreover, through the efforts of Prof. W. M. Latimer (286) and his coworkers, satisfactory entropy values are now available for all but a few of the common inorganic ions in aqueous solution. At the same time rapid progress has continued in the study of low-temperature heat capacities in several laboratories, In addition, compilation and correlation of data pertaining to vapor pressures (247), thermodynamic properties of carbonates (258), thermodynamic properties of sulfur and its inorganic compounds (250), and the thermodynamic properties of metal carbides and nitrides (251), which were published as members of this series, have yielded many values. As a result, over 500 usable entropy values for inorganic substances may now be tabulated. This bulletin originally was planned as a second revision of the first member of this series, the first revision (249) having appeared in 1936; however, because of requests for the explanatory section of the first bulletin from those teaching thermodynamics, it was decided to com¬bine the information in the first bulletin and its revision with the data that have appeared since 1935 and to repeat the explanatory material in somewhat more detail. The purpose of this bulletin is therefore to give the available values of the entropies at 298.1° K. of the elements and inorganic compounds, together with enough explanation of the methods employed in calculating entropies to make the results comprehensible.

Jan 1, 1941

By Lloyd R. Michels, Burke Cartwright, S. F. Ravitz

"INTRODUCTION Frequent attempts have be,made in the electrolysis of molten magnesium chloride to regenerate the electrolyte by allowing the chlorice generated at the anwdo to read with magnesium oxide and carbon within the melt according to the following reactions: (1) MgO + C + CL2 = MgCl2 + CO,(2) 2MgO + C + 2C12 = 2MgC12. + CO2.The principal advantages of such a procedure are that (1) the direct source of magnesium is magnesium oxide rather than the more expensive dehydrated magnesium chloride and (2) it is not necessary to handle or dispose of large quantities of chlorine or hydogen chloride.Grätzll 5/ proposed the use of an MgO carbon feed in a more or,less compact form in the anode compartment, of the cell. In a patent issued to Magall Aktiengecellschaft, 6/ a compact mixture of MgO and carbon is used as the anode itself. Kato 7/ and Backer 8/ add the feed in finely divided form to the surface of the anode compartment. The Bureau of Mines 2/ recently made a pilot-plant investigation of the electrolysis of suspension of MgO and carbon from chloride melts, in which it was found that although,current efficiencies of 60 to 70 percent were obtainable, the formation of sludges containing MgO, carbon, and magnesium seriously interfered with the operation of the cell,"

Apr 1, 1945

By A. B. Hooker, L. C. IlsLey

"The last previous Bureau of Mines publication relative to details of permissible electric mine lamps is Bulletin 332, which describes 16 lamps approved prior to May 1930. Some of the lamps have become obsolete through the development of improved models which, with several new types, make it desirable to supplement the Bureau's published data relative to permissible electric mine lamps.In the following descriptions, lamps approved since May 1930 and prior to July 1, 1935, are placed in the three following groups: (1) Electric cap lamps, (2) electric hand lamps, and (3) lamps for miscellaneous applications,ELECTRIC CAP LAMPS APPROVED UNDER SCHEDULE 6B1. Edison model J lamp, approval no. 24. - The features that distinguish this lamp from earlier models of Edison electric cap lamps are:(a) The battery consists of two F-2 cells of square cross section and about 1-1/4 inches higher than M-14 cells in the model H lamp, making the battery narrower and higher than any of the earlier models of Edison cap lamps.(b) The cells are insulated from each other and the Monel-metal casing by enclosure in vulcanized-rubber baglike enclosures. Both cell terminals are insulated from the cell jar.(c) The battery is equipped with rubber-tube Bunsen-valve-type gas vents.(d) The battery casing is secured by a new-type magnetic lock.(e.) The battery and cover terminal clips have been redesigned to give a wiping contact."

Jun 1, 1936

By Eugene W. Bartel

This report describes in detail the circuitry used in the Automated Time Domain Reflectometry System and the testing and modification done to the system to improve the units performance and consistency. The analog ATDR software is described and explained in detail. Also attempts to implement the same Assembly Language program in a higher level language (PLM) are documented along `h two versions of the PLM program - one which uses a data filtering approach to limit noise and another which uses data averaging to reduce noise. The field testing of the analog and digital ATDR units is described along with the hardware modifications that resulted. The analog unit has been abandoned and the digital unit adopted for most field tests. Tests indicate that the digital units are much more consistent and less confusing for the lay-person to operate. The results indicate that the it can locate an abnormality in a test cable to within 5% of the true location (provided the cable phase velocity is known). The units can consistently locate shunt type faults which are less than 300 ohms and series type faults which are greater than 30 ohms.

Jan 1, 1980