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By G. E. McElroy

This paper3/ is one of a limited series being prepared by the Bureau of Mines to supplement a more extensive series on mining and preparation methods in the various mining districts of the United States. It describes ventilation methods and practices at the anthracite collieries in the Northern field of the anthracite measures of Pennsylvania as obtained by personal inspections in twenty of the larger collieries during 1933 and 1934 and from supplementary information furnished then and later by operating officials. This field is one of the four major divisions - Northern, Eastern Middle, Western Middle, and Southern - into which the anthracite deposits of Pennsylvania are naturally divided, and constitutes, in plan, a slightly bowed lens, about 60 miles long, and that extends from Forest City on the north through Scranton, Pittston, Wilkes-Barre, and Nanticoke to Shickshinny on the south with a. maximum width of 6 miles. It is the oldest and largest producing field of the four, and has produced continuously from 1S09. The total anthracite production for the State reached a peak of about 100,000,000 tons a year in 1917, but in recent years production has averaged about 50,000,000 tons, of which somewhat over half comes from this Northern field. The operations of three of the largest producing organizations in the State are almost wholly included in this field, as well as about half of the operations of two others of the six largest producers, It comprises the first 14 of the 25 numerically designated anthracite State inspection districts.

Jan 1, 1937

By Aleksandar D. Bugarski

Three types of uncatalyzed diesel particulate filter (DPF) systems, three types of high-temperature disposable filter elements (DFEs), and one diesel oxidation catalytic converter (DOC) were evaluated in underground mine conditions for their effects on the concentrations and size distributions of diesel aerosols. Those effects were compared with the effects of a standard muffler. The experimental work was conducted directly in an underground environment using a unique diesel laboratory developed in an underground experimental mine. The DPF systems reduced total mass of aerosols in the mine air approximately 10-fold for light-load and 20-fold or more for high-load test conditions. The DFEs offered similar reductions in aerosol mass concentrations. The efficiency of the new DFEs significantly increased with accumulation of operating time and buildup of diesel particulate matter in the porous structure of the filter elements. A single laundering process did not exhibit substantial effects on performance of the filter element. The effectiveness of DPFs and DFEs in removing aerosols by number was strongly influenced by engine operating mode. The concentrations of nucleation mode aerosols in the mine air were found to be substantially higher for both DPFs and DFEs when the engine was operated at high-load modes than at low-load modes. The effects of the DOC on mass and number concentrations of aerosols in mine air were relatively minor when compared to those of the DPF and DFE systems.

Jan 1, 2009

By Robert C. Steckley

A study of joints in Marathon County, Wis., was made to determine the orientation of regional paleotectonic stresses and to develop a method of using optical diffraction analysis (ODA) in studying joint orientations and spacings. Standard geologic and petrofabric techniques employing the use of a geologic compass and a Schmidt net were used in gathering, describing, and reducing joint orientation data. Analysis of selected outcrops with ODA indicates that ODA can be applied to study both joint orientations and spacings. ODA is shown to be a rapid method that can be used to complement standard petrofabric techniques, especially in the study of joint spacings.

Jan 1, 1972

By Harold J. Bennett

The purpose of this study was to develop methods for the financial evaluation of mineral deposits. This includes the selection of the best alternative mining and processing methods and production rates. This was done by performing a financial evaluation through computer simulation using sensitivity and probabilistic risk analysis. The criterion used to measure the relative advantages of these investment and operating alternatives is the discounted-cash-flow rate of return. Included is a description of the theory and methods used in the probabilistic analysis approach, which is based on the premise that the expression of a range of values in establishing an estimate for a parameter is more realistic than the choice of a single value. Numerous simulations are made using randomly selected values of the input parameters resulting in a frequency distribution of the rates of return and their relative probability of occurrence. The sensitivity analysis method is described and combined with the probabilistic analysis to interrelate mineral reserves, capital investments, operating costs, and production rates. The ability to vary these input parameters on successive runs has permitted the selection of the best alternative mining and processing methods and production rates for a given mineral deposit. For illustrative purposes the evaluation of a mineral deposit was performed using three alternative mining and processing methods at three different quantities of resources and various production rates and prices. The computer program used in this analysis was written in FORTRAN II for maximum compatability and should run without modification on most computers having BK (8,000-word) core memory, a card reader, and printer (120 characters per line).

Jan 1, 1970

By Burton Scott

A device for detecting carbon monoxide at ppm levels is described which is based on the measurement of infrared absorption at 4.65 microns. The unique feature of the nondispersive infrared instrument is contained in the optical design which includes a confocal cavity, increasing the effective optical path length by a large factor, thus greatly reducing the required package size. The cavity has the effect of reducing the total amount of radiation passing to the detector, but at the same time increasing the percent attenuation observed when adding CO, by a factor called gain. The radiation is chopped by a filter wheel which contains narrow band filters at 4.0 and 4.65 microns. The resultant signal produced by the pyroelectric detector is demodulated by the electronics to product an automatic gain control signal, proportional to the total radiation, and a difference signal, proportional to the CO present. Tests of a breadboard model are described which show cavity gains of 10 with noise levels equivalent to 2 to 10 ppm CO.

Jan 1, 1975

By D. S. Burgess

This report summarizes the incidents that preceded the December 9, 1970, propane-air explosion in Port Hudson, Mo., and then attempts to establish the nature of the explosion from the ensuing events. Special emphasis is given to possible ignition sources, the distribution of flammable vapors, and the analysis of blast damage. Both near-and far-field damage indicated that this explosion may be attributed to the detonation of propane in air with an energy release equivalent to that from about 50 tons of detonating TNT.

Jan 1, 1973

By G. N. Schrauzer

Work has been carried out in the development and testing of carbon monoxide (CO) detection devices which use silica-gel impregnated with metal salts. If carbon monoxide is present, the ?detection gel? (the treated silica-gel) changes from a yellow to a blue-green or blue color. The detection gel "regenerates", i.e., returns to its original yellow color, within 4-24 hours after removal from air containing CO. The detection gel exhibits a threshold of CO response which can be adjusted over a wide range of CO concentrations, typically from 50-500 ppm in air. The preparation of detection gel using salts of palladium, molybdenum and copper is described. Also reported are the results of testing the detection gel&apos;s response to carbon monoxide under varying conditions of temperature and humidity and in the presence of some potentially interfering gases. Low levels of hydrogen sulfide (~ 5 ppm)1 nitrogen dioxide (< 7 ppm), and acetylene (> 200 ppm) were found to affect the detection gel. Temperature and humidity were also found to affect the detection gel&apos;s response. Increasing temperature shortens the gel?s response time while increasing the humidity delays the gel?s response and alters the threshold of the gel. A brief discussion of the further research and development necessary to stabilize the detection gel?s desirable characteristics is included. Descriptions of testing equipment and procedures are covered in detail.

Jan 1, 1978

By J. H. East

"INTRODUCTION Diesel locomotives have been used successfully in underground mines of Europe for 18 years, and much has been written on the technical details of the design of these machines and the safeguards provided by the manufacturers. The actual conditions under which' the Diesel locomotives are used have not been publicized as well and consequently are not well-known. In 1945 the writer observed numerous Diesel locomotives working underground in coal and metal mines of several European countries and was favorably impressed with the practical approach to the safe use of this- type of equipment.Recent statistics showing the number of Diesel locomotives in use are not available now because of the World War, but the extent to which this type of mine locomotive was used immediately before the war is indicated by table 1, which classifies the number of locomotives used in several countries according to the type of power, such as compressed air, Diesel, and electric.Mining conditions observed by the writer in the European countries are very different from those in most coal-mining districts of the United States. The surface plants are larger and are permanently constructed of brick or concrete; numerous coal beds are worked through one shaft; the crosscut rock tunnels or levels, driven to intersect the coal beds, are lined with brick or concrete blocks where needed instead of timber; the coal beds dip more steeply and are not as thick as in most fields of the United States."

Sep 1, 1946

By E. D. Gardner

This is one of a series of paper&apos;s being published by the Bureau of Mines on placer mining; it is written as a supplement to Information Circular 6788, "Placer Mining in the Western United States, Part III", by E. D. Gardner and C. H. Johnson which was published in February 1935. Since Information Circular 6788 was written (1933), considerable advance has been made in the technique of mining placer gravels with power shovels and draglines. Although new washing plants continue to be built in accordance with untried designs the trend of new installations is toward proved equipment. A substantial number of plants are now being operated successfully (1937).

Jan 1, 1938

By L. C. IlsLey

Most State enacting bodies have deemed it necessary to specify a maximum speed at which men may be hoisted or lowered in mine shafts. Since most mine cages are not closed in, as are passenger elevators in office buildings, and since, ordinarily, neither the starting tin g nor stopping of the cage is as general as that of these elevators, such regulations are all the more necessary for the comfort and safety of the men. It is also quite generally recognized that it is dangerous to over-crowd cages. Hence, a number of States have limited the number of men that may be on cage at one time.

Jan 1, 1939

By J. L. Potter

An inert-gas fusion technique was applied by the Bureau of Mines to the oxygen analysis of mixed-fluoride electrolytes used in electrowinning uranium and the rare-earth metals. Method development included: (1) Thermodynamic and experimental evaluation of the temperature required to quantitatively remove oxygen from a fluoride melt; (2) installation of a water and an acid trap to entrain the volatilized fluorides; (3) development of a suitable sample-preparation technique for the heterogeneous fluoride baths in which both pulverizing and pelletizing were necessary to achieve reproducible results; (4) comparison of platinum flux and dry crucible techniques, which showed that the use of platinum was not necessary. The accuracy of the method was evaluated by analyzing fluoride baths containing known amounts of oxygen added as the metal oxide. In the 0.05-to 0.5-percent range, the relative error was about ±5 percent.

Jan 1, 1962

By Thomas J. Peters

A mineral survey of the Sill Hill RARE II area (No. 5304), covering 5,200 acres (2,100 ha) of the Cleveland National Forest, San Diego County, California, was conducted by the U.S. Bureau of Mines and the U.S. Geological Survey. This survey was in conformance with the Resource Planning Act (RPA) of 1974, as amended by the National Forest Management Act of 1976, to provide mineral resource information for study area classification. Bureau of Mines personnel made an economic appraisal of mineral deposits by searching pertinent geological and mining publications as well as U.S. Bureau of Land Management, U.S. Forest Service, and U.S. Bureau of Mines files and records. Known mines, prospects, and mineralized localities were examined during 1981, and sampling and mapping were done where warranted. The Geological Survey &apos;did geologic mapping, geochemical sampling, and geophysical surveys to aid this study.

Jan 1, 1983

By M. R. Geer

Efforts to evaluate washery performance are nearly as old as the art of coal cleaning, and in former years there was no uniformity in either the methods used or the basic terminology employed. This situation, and the con- fusion it bred, prevailed until about the time of the First International Coal Preparation Conference in 1950, Largely because of the interest of the French coal research organization Cerchar, the subject of evaluating performance was given prime importance at this conference. As a result, there is now a much greater degree of uniformity in terminology and methods of expressing cleaning results. The International Standards Organization currently is working toward international standards of terminology and methods that should improve the situation even more. The various criteria that are used to evaluate the performance of coal- cleaning equipment fall into three categories, depending upon the extent to which they are dependent on the density composition of the raw coal; some are directly dependent, others are only indirectly dependent, and still others are substantially indenpendent.

Jan 1, 1962

By Albert W. Deurbrouck

The percentage of coal cleaned mechanically has increased greatly in the past 30 years. This technological change in preparation methods, accompanied by mechanical innovations in most phases of coal mining, has enabled the industry to supply quality coals at competitive prices. The Bureau of Mines has contributed to this progress by conducting research on coal-preparation problems, by evaluating the performance of domestic-and foreign-made preparation equipment, and by recording advances as they occur in industrial coal-cleaning practices. The Bureau&apos;s work in this field is recorded in the more than 150 technical and scientific publications listed in this volume. These reports, published by the Bureau over the past half century, document the Nation&apos;s progress in a vitally important phase of fuel technology.

Jan 1, 1961

By John E. Trombly

System objectives and design criteria for an in-mine ULF radio paging system are discussed Coding formats, frequency and bandwidth selection criteria leading to the system design are discussed. The prototype call alert transmitter and pocket page receiver is functionally described. The report includes circuit descriptions, schematics, parts lists, printed circuit fabrication and assembly drawings. The report concludes with an estimate of the manufacturing cost for each assembly.

Jan 1, 2011

By James L. Eirls

Tracor MBA under a contract to U.S. DOI Bureau of Mines designed, developed, fabricated and demonstrated a conveyor belt service machine. It is self-contained, battery powered, rubber tired and capable of handling, storing and transporting conveyor belting, wire rope and associated structures for sectional conveyor belts. While moving the tail section to its next position the machine discharges the belting, wire rope and belt structures. The belting is elevated and separated to provide for the insertion of the structures with minimum expended effort. A hydraulic system provides the power for steering, braking, winding or unwinding under controlled tension the belting and wire rope, operating a load-bed slat conveyor, raising, lowering and locking connection hitches and powering external hydraulic tools. Also, a pneumatic system is available to operate air impact tools. The service machine, with its present components can function in coal seams as thin as 48 inches, double wind conveyor belting 42 inches wide, 400 feet long, load or unload 3/4" wire rope on two separate reels and is controlled by two operators. A complete belt move using this machine requires only four workers. Successful underground demonstrations were conducted in coal mines located in West Virginia and Kentucky.

Jan 1, 1983

By Richard L. Fowler

An automatic steering control system was designed, installed and tested on a coal mine shuttle car. The system utilizes sensors and associated signal processing electronics developed under a previous phase of this contract. The automatic steering system performs the routine guidance functions of turning corners and straight-through tramming. The shuttle car driver retains full authority of speed, braking, load and unload functions and at any time may exercise his option with manual override or steering. Steering information is generated from signals derived from the existing Lateral Guidance sensor subsystem, and all operational features of the previously developed open-loop system are retained. Above ground system tests were conducted in a simulated mine constructed of wood panel ribs. Results were in good agreement with prior hybrid computer simulations undertaken to validate the basic control system over a broad range of conditions and to select system parameter values. The automatic steering system was successfully demonstrated in the above ground simulated mine to USBM technical representatives. Designed to meet USBM permissibility requirements, the system is ready for a Phase II underground testing program. Testing in actual underground mine environment is expected to provide additional data regarding recommended performance improvements and implementation techniques.

Jan 1, 1975

By Michael S. Miller

In 1987 and 1988, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied the 3,100-acre Borah Peak Wilderness Study Area (10-047-004) and a 708-acre parcel adjacent to the north in order to evaluate their identified mineral resources. The study area is located in Custer County, ID, about 18 mi northwest from MacKay. The study area lies along the western foothills of the Lost River Range and is underlain by quartzite, sandstone, shale, argillite, dolostone, and limestone. The Lost River fault, a major active fault, lies along the length of the study area. Large alluvial fans spread out from valleys originating east of the study area.

Jan 1, 1989

By George C. Price

The Bureau of Mines conducted this study in the Roslyn No.5 coalbed in the State of Washington to determine the feasibility of mining hydraulically the portion of the coalbed that was steeply pitching. All of the experimental mining was done while advancing raises and rooms. A Bureau-developed hydraulic mining machine was used successfully in the pitching coalbed. It consisted of a remotely controlled monitor mounted on a self-advancing roof support unit of the type commonly used for roof support in longwall mining systems. The coal cutting rates averaged 0.73 and 0.54 ton per minute in raise and room mining, respectively, while using water volumes up to 230 gpm at a pressure of 4,000 psig. Productivity averaged 4.7 and 5.2 tons per man-shift for raise and room mining, respectively, compared with 7.5 and 8.5 tons per man-shift, respectively, by conventional hand mining methods.

Jan 1, 1965

By Anderson Dana

THIS PAPER describing methods and costs of mining and preparing gravel and sand for market at the Port Jefferson plant of the Seaboard Sand and Gravel Corporation, is one of a series of articles on gravel and sand mining, prepared for and published by the U. S. Bureau of Mines, which is designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs, It is recognized that publication of total costs might in many instances cause embarrassment to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical [ ]

Jan 1, 1932