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By E. D. Palmes

This report was prepared by New York University Medical Center, Institute of Environmental Medicine, 550 First Avenue, New York, New York under USBM Grant Number G0133066, Personal Samplers for CO, NO and NO2 in Air. The grant was initiated under the Coal Mine Health and Safety Program. It was administered under the technical direction of the Pittsburgh Mining and Safety Research Center with Dr. George H. Schnakenberg acting as the Technical Project Officer. Mr. L. Young was the contract administrator for the Bureau of Mines. This report is a summary of the work recently completed as part of this grant during the period 3/1/73 to 11/30/76. This report was submitted by the authors in March, 1977.

Jan 1, 1977

By Sam G. Demou

Drag bit cutting tests were conducted chiefly to determine bit forces encountered in rock types representing a range of compressive strength and hardness and thus enable the design engineer to estimate a continuous miner's performance in a range of rock types. Testing was carried out on the Bureau of Mines uniquely designed, instrumented rock cutting device (RCD). This device can make 3-ft-long cuts at various depths and speeds to approximate full-scale drag bit cutting by continuous miners. Point attack and cutter bits were tested on four rock types ranging in compressive strength from 7,200 psi (trona) to 29,600 psi (Valders white rock). Cutting tests were made at depths up to 1 in and speeds up to 70 in/sec. Data included normal and cutting forces, groove depth, groove width, and weight of rock broken. The effect of varying the cutting speed was determined, and specific energies were calculated for the various conditions. The bit wear was also observed. For the rocks tested, compressive strength and hardness are good indicators of forces, specific energy, and wear encountered. Results, especially bit wear observations, show the possibility of extending continuous miners, already being used in trona, to Indiana limestone (10,000 psi). Rapid bit deterioration precludes use in Tennessee marble (16,800 psi) and Valders white rock (29,600 psi).

Jan 1, 1983

By Charles H. Etheridge

A new filter cassette is described which can be used with Coal Mine Dust Personal Sampler Units (CFR, Title 30, Part 74). The sealed cassette design reduces the chances of sample loss due to reverse flushing, impact or cassette opening. The filter capsule weight is approximately 400 milligrams and is stable for at least one year in storage. The alpha quartz content of the filter element is less than 5 nanograms per square millimeter of surface. The cassette is designed to be used with a new sampling head. The manufacturing costs of the new cassette will require an increase of approximately 30% in the selling price.

Jan 1, 1978

By W. E. Robinson

Oil-shale kerogen was processed into oil and oil products before the first oil well was completed by Drake in 1859. However, because of economic and other advantages, natural petroleum has been the principal source of liquid fuels and lubricants since 1859 and is a convenient root of many [organic] chemicals in common use today. In recent years the difference has narrowed between the cost of producing liquid fuels from well petroleum and other sources. This narrowing of cost difference has resulted both from the increased cost of finding new sources of petroleum in the United States and the experimental demonstration of lowered costs for synthetic liquid fuels by the Federal Bureau of Mines and by industry. Available petroleum resources of this country are being reduced and eventually may be inadequate to meet the demand. Alternate means of assuring an adequate supply of liquid fuels for this country include the development of processes for utilizing other carbonaceous materials such as oil shale and coal.

Jan 1, 1960

By J. C. Edwards

A series of four coal combustion experiments (I)' was conducted at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory in the Safety Research Coal Mine to evaluate the response of optical and ionization smoke and CO sensors to a small 0.61 m square smoldering coal fire which transitions to flaming combustion in the presence of diesel emissions. With the increased utilization of diesel engines in underground coal mines, it is important to be able to discriminate fire products-of-combustion (POC) from diesel emissions. One proposed method to accomplish this is the deployment and interpretation of multiple sensors.

Jan 1, 2010

This Bureau of Mines publication presents an overview of mine electrical power systems research currently being conducted by the Bureau. The papers, given at a Technology Transfer Seminar, emphasize the increasing importance of research related to the safety considerations of underground coal mine electrical systems. Selected topics are included that summarize results of research in the areas of electrical shock prevention, explosion-proof enclosures and load centers, discriminating circuit breakers, and trailing cables. Other topics discussed at the seminar are published as separate sections of the Bureau of Mines Hand- book "Application Notes--Mine Electrical Power Systems."

Jan 1, 1982

The Bureau of Mines Minerals Information organization collects worldwide data on virtually every commercially important non fuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 829), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral-material production or consumption.

Jan 1, 1984

By N. A. Pace

This is one of a series of papers being published by the Federal Bureau of Mines for the dissemination of information on methods and practices used in the mining and preparation of crushed stone for market requirements. Performance in terms of units of work or tons produced per machine and per operator man-hour are given whenever that information is available. Direct operating costs are useful for comparing different methods, and are, therefore, included if possible. In addition to the factual description of equipment and methods used, it is desirable to discuss the engineering reasons for the choices that have been made. This paper is particularly concerned with the opertions at the Columbia plant of Palmetto Quarries Co. of Columbia, S.C. The plant is about one-half mile east of the Congaree River and adjacent to the southwest corner of the city of Columbia. Rail access is by the Atlantic Coast Line Railroad, and by a spur strack of the Seaboard Airline Railroad.

Jan 1, 1962

By John C. Machisak

DATA ON INJURY experience at quarries and related plants of the United States are presented in this publication under the following general sections: A) General injury experience: Tables 1-4: Contain current data on number of injuries, injury-frequency rates, work location, accident agency, degree of injury, and related employment data. (B) Injury experience at different kinds of quarries: Tables 5-6: Current data on number of injuries, injury-frequency rates, work location, accident agency, degree of injury, and related employment data. (C) Injury experience by States: Tables 7-19: Current data on the number of injuries, injury-frequency rates, accident agency, degree of injury, and related employment data. (D) Selected injury data: Tables 20-30: Current data on various selected factors of operating conditions at different kinds of quarries, including employment size-groups, length of shifts, comparative severity of injuries, and injury data and related employment experience at dimension-stone and crushed and broken stone quarries, and underground quarries. (E) Mining methods and historical injury experience: Tables 31-32; Employment data and injury experience in the quarrying industries of the United States, by mining method and work location, 1953-58; and historical injury experience and employment data in the quarrying industry, 1911-58.

Jan 1, 1962

By J. M. Singer

In this Bureau of Mines study coal and rock dust beds were entrained by airblasts generated by gas explosions at the closed end of a 0.61-m-diameter explosion tunnel, 49.7 m long. The system was designed to simulate entrainment of mine dust deposits by accidental gas explosion at the coal face of nonintersecting mine passageways. Full-scale mine explosion trials confirmed many of the results of the explosion tunnel experiments and indicated several new features of dust entrainment. Dispersal of 20.3-cm-long stepped dust beds located 35 m from the closed end always began during the early portion of the ascending gradient of the first transient airflow (and pressure) wave, and was usually completed before the end of the first quarter-wave period. Bulk quantities of dust were entrained simultaneously by longitudinal regression from the leading edge of the dust bed and by surface lifting of the top layer. Instantaneous threshold air velocities for bulk quantities of coal and rock dust beds in separate, mixed, and layered configurations were in the same range (5 to 30 m/sec) as previously found under steady-state velocity conditions. Selective lifting of coal dust layers from rock dust occurred when the threshold dispersal velocity of coal dust but not of the underlying rock dust was exceeded.

Jan 1, 1976

By William C. Cooley

This study Identifies and evaluates deposits of noncoal minerals in the U.S. which are most amenable to be mined underground hydraulically and transported hydraulically. A method was developed to screen and compare mineral deposits including economic comparisons. The most applicable minerals for hydraulic mining by borehole monitor jets from underground entries are soft uranium sandstones In Wyoming in locations where water is available. This method with hydrotransport could improve the safety, health and economy of underground uranium mining. Soft oil-bearing sandstones in California and Texas could be mined and transported by this method more safely than by other underground mining methods. Other weak sandstones may be hydraulically mined economically. Man, minerals are too hard to be mined by monitor jet but are amenable to hydraulic transport and hoisting. Uranium sandstone in New Mexico is of interest because of potentially improved health and safety in transport and lower transport cost, Increases in mine output for potash, in New Mexico and trona in Wyoming can be achieved most economically by adding hydraulic hoisting when existing skip capacity is at its limit. Research is recommended to obtain site-specific data on the feasibility of mining uranium ores by monitor jets.

Jan 1, 1981

By Louis E. Dalverny

U.S. Bureau of Mines research to develop diagnostic methods to locate and evaluate fires in abandoned mines and waste banks and techniques to extinguish such fires was applied to an abandoned 60-acre underground bituminous coal mine (Renton, Allegheny County, PA) to locate and extinguish three separated fire zones. Mine fire diagnostics interpret changes from baseline values in subsurface pressures, temperatures, and mine gas composition under imposed pressure gradients induced by a borehole exhaust fan. The effective gas sampling area surrounding each borehole is greatly enlarged. Sampling iterations, using a "communicating" boreholes set, provide "fire signature" information for locating both heated and cold areas. Time-dependent monitoring differentiates heating and cooling periods resulting from combustion front movement and/or fire extinguishment activities. A water injection with fume exhaustion extinguishment effort involved injecting water through boreholes to quench the heated zones while exhaust fans actively removed heated gases from the mine. The technique was ineffective as implemented, primarily because of inadequate spreading of water from the injection points. The Bureau's diagnostic method determined the fire locations and the effectiveness of the water injection with fume exhaustion extinguishment technique.

Jan 1, 2010

By Wilbur L. Webb

An electrically powered methane sampling system for application on mining machines was designed, fabricated and laboratory tested. The system will sequentially draw sample air at a controlled rate from up to three machine positions across the mine face and deliver the air to either an approved methane monitor, methanometer or flame safety lamp. The prime considerations in the design were to provide an intrinsically safe, water and dust resistant control box and an explosion-proof power box capable of being operated from the various mining power sources. The power box contains an internal battery that provides operating power prior to mining machine start-up and alter machine shut-down. The internal battery is recharged automatically when mining machine power is available.

Jan 1, 1977

In July 1982 the Committee on Underground Coal Mine Safety completed its study of safety in U.S. underground coal mines; the results of the study were published in the National Research Council report entitled Toward Safer Underground Coal Mines. One of the findings of this study was: THERE IS A STRONG CORRELATION BETWEEN MINE SIZE AND FATAL INJURIES. THE FATALITY RATE IN MINES WITH 50 OR FEWER EMPLOYEES IS NEARLY THREE TIMES THAT OF LARGE MINES (WITH OVER 250 EMPLOYEES), AND ABOUT TWICE THAT OF INTERMEDIATE-SIZED MINES (WITH 51-250 EMPLOYEES). Although the Committee explored possible reasons for the higher fatality rate in the smaller mines, it was not able to explain this phenomenon fully. Therefore the Bureau of mines requested that the Committee undertake a supplementary study of fatalities in small underground coal mines. The Committee met in the fall of 1982, discussed the problem, developed an approach to it, approved a program of statistical analyses, and authorized a panel of four committee members to explore the problem in greater depth. The panel, in turn, reviewed the results of the statistical analyses and met with the president of the National Independent Coal Operators Association and with several owners of small underground coal mines for a detailed discussion of the unique problems of small mines. Panel members examined 66 individual fatality reports prepared by Mine Safety and Health Administration (MSHA) inspectors who investigated fatal accidents that occurred in small underground coal mines in 1979 and 1980. This report is the result of those studies, analyses, and deliberations. The first draft was prepared by the panel, but the report has been reviewed and approved by the entire Committee.

Jan 1, 2011

By Calvin K. Lee

This Bureau of Mines report describes a simple fire-retardant treatment for wood. The treatment involves preheating the wood surface at high heat flux (~0.6 cal/cm2 sec) to form an in situ surface char layer (~3 mm thick) on the wood. Laboratory-scale fire tests show that the precharring technique improves the fire-resistance of virgin wood by decreasing and delaying generation of volatile gases through thermal insulation effect of the surface prechar layer.

Jan 1, 1978

By S. Ralph Austin

Emanation coefficients of 950 samples of domestic uranium ore were successfully and rapidly determined with fair precision by modifications of the closed-can, gamma-only assay method, using commercially available or similar equipment. Coefficients range from <1 to 91 percent. Emanation varies considerably within each mine and area, but distinct differences among major mining areas were found, ranging from 7.5 percent for Moss Back Member, Chinle Formation, Southwest Lisbon Valley, Utah, to 56.6 percent for Ft. Union Formation (?), Powder River Basin, Wyoming. Coefficients also vary with (1) uranium mineralogy; (2) radium mineralogy; (3) lithology of host rocks; (4) grain size of uranium and radium minerals; (5) comminution of ore; (6) estimated porosity and permeability; (7) moisture content; (8) ore grade; (9) supposed mobility of deposits; age of deposits is unknown but limited by (10) age of host rocks which shows only doubtful correlation with emanation. Data obtained may be used to evaluate effects of investigated parameters on radon concentration in mines and thus to select efficient control measures. Drill-core emanation data allow estimates of probable radon problems in undeveloped deposits.

Jan 1, 1978

By Staff

This U.S. Bureau of Mines publication presents the results of investigations into the fire and explosion hazards of oil shale rocks and dust. Three areas have been examined: the explosibility and ignitability of oil shale dust clouds, the fire hazards of oil shale dust layers on hot surfaces, and the ignitability and extinguishment of oil shale rubble piles.

Jan 1, 1989

By L. A. Neumeier

The Bureau of Mines evaluated creep properties of Zn-Cu-Ti alloys that were annealed after finish-rolling either cold) or at 480° F (249° C). Compositions ranged up to 1.25 pct Cu and 0.36 pct Ti. Most data are for sheet annealed after finish-rolling to 92-pct total reduction. Annealing times were varied at temperatures between 320° and 560° F (160° and 293° C). For a number of the alloys, annealing after hot-rolling at 480° F affects creep properties very differently in longitudinal and transverse sheet directions. The detrimental result is that the anisotropy in creep properties between the two directions can be vastly increased. Conversely, specific annealing treatments of certain heavily cold-rolled alloys result in surprisingly low anisotropy in creep properties and the low anisotropy coincides with excellent creep resistance for both directions. Supplemental data are presented on tensile, hardness, and thermal expansion properties, and microstructures.

Jan 1, 1972

By John R. McWilliams

This report is one of a series published by the Bureau of Mines describing methods and practices at various mines throughout the United States. A previous program, conducted from 1928 to 1939, was well received by the mining industry and technical institutions and provided much source material for engineering textbooks and technical handbooks. The stringent wartime demands on the mining industry, the rapidly changing postwar economic situation, and greatly accelerated technologic growth have combined to render many of the previous data obsolete. The objective of the present program is to assemble reliable technical information on mining methods and practices throughout the country and present it for the use of the mining industry, technical schools, textbook authors, and other interested persons. This report deals with the design and development of the Berkeley open- pit mine at Butte, Mont., owned and operated by The Anaconda Company. The Berkeley pit is but one facet of a well-organized and integrated copper-mining operation involving the entire Butte district. Vein-type mining, important for 75 years, is still in progress at depths from 600 feet to nearly 1 mile; on intermediate levels, low-grade ore left untouched by earlier vein-type mines is being extracted by block caving entire ore zones,3/ and secondarily enriched but lower grade near-surface portions of the same ore zones are being mined by open-pit operations (fig. 1). The Berkeley pit itself is named for the Berkeley mine, one of the old mines that extracted copper ore from high-grade veins in the area that now will be mined by open-pit methods.

Jan 1, 1959

By Harold E. Marr

A simple algorithm is presented for processing digitized X-ray spectra obtained with a Si(Li) or Ge(Li) semiconductor detector coupled to a multi- channel analyzer. The simplified least-squares procedure is used to smooth out the statistical fluctuations in the spectrum by repeatedly fitting a quad- ratic equation to a predetermined number of channels and performing a traveling smooth across the spectrum. A logarithmic transform is applied to the raw data to minimize the distortion of the gaussian-shaped peak profiles. The efficacy of the technique is evaluated by observing the distortion of several gaussian-shaped peaks that have been subjected to the smoothing operation. The locations of maximums and minimums in the spectrum are predicted in the process as well as the values of the peak heights. The convolution integers from a least-squares fit of a quadratic equation are calculated as part of a FORTRAN subroutine. The building-block approach to computer programing in a small laboratory is discussed.

Jan 1, 1972