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By N. A. Eilertsen

This paper presents the results of intermittent study begun in 1956 by the Federal Bureau of Mines of yieldable steel arches and yieldable steel ring sets installed for support of development openings in metal mines. Observations were made of this type of support in several iron mines in the northeast and north-central states. The sets, both arches and rings fabricated in the United States, are made from a hot-rolled, cold bent, structural U-shaped steel section in two weights, 15 pounds and 21 pounds per foot. The lighter section is generally used, It is 4.41 square inches in cross section area, and the calculation is that a 6-foot length of this structural shape installed as a supporting column, will safely carry the same load as a Douglas fir post of the same length but of 22 times the cross-sectional area of the steel.

Jan 1, 1962

By Karl R. Becker

A variety of commercial detonators (fuse type and electric instantaneous and delay types) were subjected to impact and thermal stimuli to determine initiation stimulus levels and the dominant parameters in resistance to initiation. In the impact trials the detonators were impacted along their length to find the most sensitive region; threshold initiation limits obtained for these regions ranged from 3.47 to 20.82 joules (2.6 to 15.4 ft-lb). The friction sensitivity of the explosive component was an important parameter in determining sensitivity; various construction features of nonexplosive components played a role as well. In the thermal sensitivity trials, the detonators were heated from ambient to 100° C at an average rate of about 1.0° C/min, and thereafter at 0.5° C/min until they exploded; the explosion temperatures observed ranged from 121° to 188° C. These temperatures correlated quite well with the reaction temperatures of certain characteristic explosive components used by different manufacturers. The data also indicated an effect of confinement on explosion temperatures of detonators.

Jan 1, 1975

By J. R. Thoenen

This circular is part 6 of the third paper (entitled "Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes; part 2, power scrapers, slackline cableway excavators, and hydraulic monitors; part 3, hydraulic, clamshall, ladder, and diaper dredges; part 4, haulage equipment, particularly industrial cars with locomotive or hoist as the motive power; part 5, conveyor belt, motor truck, pump and pipe line, towboat and barges, and aerial-trams haulage. This circular discusses the application of these various types of equipment to the different types of sand and gravel deposits and contains a reference bibliography. It completes the discussion of excavating problems.

Jan 1, 1936

By Robert L. Lagace

This final report documents the work done by Arthur D. Little, Inc. (ADL) on behalf of the U.S. Bureau of Mines, Pittsburgh Mining and Safety Research Center (PMSRC), on Contract H0122026 (which began in August of 1971). Under this contract ADL provided technical assistance to the Bureau on a task basis on virtually all aspects of the Bureau's programs related to present and planned emergency and operational communications and miner location systems for underground coal mines. The work consisted of independent investigations, analyses, experiments, breadboard and prototype hardware development, workshops and technology transfer seminars on mine communications, and on-going evaluations and guidance related to the Bureau's contracted programs on electromagnetic noise, mine communications systems, and trapped miner location. This final report documents the work in two volumes, Volume I, "Emergency and Operational Mine Commun¬ications," and Volume II, "Seismic Detection and Location of Isolated Miners." The Tables of Contents of both Volumes are included in each Volume.

Jan 1, 1974

By D. J. MacDonald

Wettability measurements and laboratory waterflood tests were compared under a wide variety of conditions. Experiments were conducted with synthetic and natural crude oils, treated and untreated outcrop and oilfield sandstone cores, and synthetic brines with and without caustic, detergent, or phosphate additives. Measurements were made on equilibrated and unequilibrated systems at 77° and 150° F. Wettability was evaluated by the Bureau of Mines method from capillary pressure curves determined with a centrifuge. The waterflood data were fitted by empirical curves; the parameters of the curves characterize primary and subordinate production and also give the ultimate oil recovery. Results showed that wettability measurements at 77° F were useful predictors of recovery efficiency in waterflood tests run at both temperatures. Oil recovery in the early stages of waterflooding increased with increasing water wettability; however, the ultimate recovery was highest at a slightly oil-wet condition. The oil displaced at highest speed in the centrifuge was correlated with ultimate recovery in waterflood tests. Chemical additives to the brine sometimes lowered wettability and also sometimes improved waterflood recovery, but wettability and recovery were not correlated with additives present. The effect of additives on recovery in waterflooding was best seen in water-oil ratio curves.

Jan 1, 1974

By Forrest T. Moyer

To keep the mineral and allied industries informed of trends in the causes of accidents and to point out the need for corrective measures, the Bureau of Mines collects, analyzes, and publishes, periodically health and safety statistics. This report includes data for 1961 on injury experience, with related employment statistics, at coal mines in the United Status. These data are presented in tabular form under the following headings; General Injury Experience Tables 1 to 6: Current data on number of injuries, degree of injury, frequency and severity rates, average severity, and related employment and production data by work location.

Jan 1, 1963

By Warren E. Morrison

INCREASED production and utilization of minerals fuels and power accompanied the overall expansion in U.S. economic activity during 1963, which saw continued advances toward higher production, employment, and purchasing power. During 1963, record levels of wages, profits, and consumption were attained, while costs and prices maintained the stability exhibited throughout most of the recovery period. Expanding industrial production, the average index of which went from 118.3 in 1962 to 124.3 in 1963, narrowed the gap of unused manufacturing capacity to an estimated 5 percent. Gross national product (GNP), another major indicator of economic activity, reached a record level of $583.9 million (current dollars) during the year, this being $27.7 billion, or 4.9 percent above 1962. These achievements were somewhat marred by unemployment, which remained at 5.5 percent of the labor force in 1963, and the continued deficit in the U.S. balance of payments. Against this general background, total national consumption of energy resources for the year was equivalent to 49,816 trillion British thermal units (Btu), an increase of 4.2 percent over 1962. This represented a somewhat lower rate of growth than for GNP during the year.

Jan 1, 1964

By William M. Hinton

This report describes the approach, procedures, and results of a program to develop training materials for roof bolter operators. The objective of the program was to design and produce a training sequence which would prepare roof bolter trainees for job performance. Data was collected and analyzed using the general procedures of Instructional Systems Development (ISD). Input data came from a previous roof bolter training analysis program. This data was expanded and structured through a series of ISD steps: objectives hierarchies, media selection, syllabus, lesson specifications, and train¬ing materials development. The resulting program consisted of an ordered sequence of 15 lessons. The media mix for the 15 lessons included lectures, slide-tape lessons, and hands-on instruction using operational roof bolters. Contents of all lessons were reviewed and approved by the Bureau. The key recommendations were to (1) validate the materials and measure relative effectiveness of media formats; (2) survey mines for training resources and conditions - match materials to user capabilities, rather than selection state of the art technology/media; (3) develop job performance aids (JPAs) rather than simulators; (4) create a style/media/JPA development guide for use in future projects of this kind.

Jan 1, 1982

The condition of the domestic mining industry is obviously affected by the cycles in general business conditions. This study, the results of which are presented in a series of 78 charts, attempts to examine the interrelationships between the general business indicators and the major statistical measures for the base-metals industries during the cycles in the United States economy following World War II. For these industries the cyclical problem is perhaps less acute than the secular-trend problem. However, short-run fluctuations in production and employment do have very important impacts upon the welfare of the regions which derive a significant portion of their income from base-metals mining and processing industries. Any information concerning the normal patterns of development as the industries enter into a cyclical recession will permit better forecasts and perhaps help promote measures to alleviate the distress that occurs. Also, a systematic study of the comparative movements among the statistical measures during a series of cycles can bring to the fore the economic causation involved, and perhaps, after intensive study, can lead to a better method of short-range forecasting for these industries. This study has not fully achieved these aims. However, observations which significantly aid the interpretation of the current monthly statistics on these commodities are made, and some very general conclusions are drawn. The charts are presented so the interested people can examine them and draw additional conclusions. The charts refer specifically to cyclical analysis. The technique of indexing each cycle to its turning point effectively subordinates the longer term trend movements of the data. Thus, certain general conclusions flowing from this study and from the continuing economic research of the Office of Chief Economist will aid the reader by clarifying the frame of reference within which the charts should be examined.

Jan 1, 1961

By W. R. Reed, J. A. Organiscak

Haul trucks have the potential to generate large amounts of respirable dust. This respirable dust has been shown to be a health hazard to personnel, especially if it has a high silica content. Lack of dust sampling data from haul trucks prompted the completion of a study to quantify respirable dust concentrations. These field studies were conducted measuring instantaneous respirable dust at stationary locations from passing haul trucks at a stone quarry and at a coal mine site. Fugitive dust levels from haul trucks were analyzed to characterize dust dispersion. This analysis indicates safe following distances for haul trucks and other heavy equipment to avoid overexposure of respirable dust from the lead haul truck.

By R. H. Grau, S. B. Robertson, F. Garcia, A. C. Smith, T. P. Mucho

Researchers working for the National Institute for Occupational Safety and Health (NIOSH) at the Pittsburgh Research Laboratory are developing ways to protect the health of miners. Part of that effort is devoted to improving the air quality in underground stone mines by developing ventilation techniques that can be used in these types of operations. The air quality in these large opening nonmetal mines can be significantly improved by using diesel particulate matter (DPM) controls along with sufficient ventilation quantities to remove contaminants. Practical methods of ventilating these underground stone mines can be accomplished by using mine layouts that course and separate ventilation air through the use of stoppings. The design, construction, and maintenance of effective stoppings in large openings have been a real challenge to mine operators. Several different types of stoppings have and can be used for this application. The choice of stopping design, material used, and construction techniques should be dependent upon a number of factors such as the intended life and effectiveness desired.

By R. G. Peluso

Methods and results of studies to determine friction and shock losses encountered in auxiliary face ventilation systems utilizing flexible, spiral-reinforced ventilation tubing are presented. The results, tabulated in graphic form, simplify fan selection and enable mine operators to design adequate auxiliary ventilation systems. Problem illustrates the use of graphs.

Jan 1, 1968

By Walter E. Pittman

In its role of providing technical assistance to the mining industry, the Bureau of Mines' Tuscaloosa Research Center has conducted research to develop trapped miner location systems which would aid in locating miners trapped by underground mining disasters. Efforts to produce electromagnetic systems for the location of trapped miners underground and to communicate with them were surveyed, from the 1920's to 1981. Theoretical studies of through-the-earth electromagnetic transmissions are described as well as studies of the electrical characteristics of various rocks, minerals, and soil. Several trapped miner location systems are reviewed including the Westinghouse systems, the DEVELCO system, and an automated three-dimensional location system, and the phase difference of arrival technique. Tangential research, relevant to trapped miner location systems is described. A comprehensive bibliography covering all aspects of trapped miner, through-the-earth electromagnetic location and communications systems is appended.

Jan 1, 1982

By E. J. Gleim

[of- ac tore affecting the e -success of recent conveyor miningsystems forLt. extraction. 1 GL C ,_tfreedom shoot &apos;_)`u 2--ethe.1 is coal while e en othershot firers re:7 t _e&apos; _U-tin , w J, e coal .Z- 311.ing States conveyors because ;-.;lax .ca requires thatblasting be limited to when c .. men os. _o tend neces¬sary officials 1 s . re out c-z ,r 7t ...y e:e l z<: woes no t a -¬#to 1 C" such restriction on blasting conveyor miningbeen extendedWhere ere t ere. re no _ c: t&apos;_ _c tit-----! . kind cutlasting;,1CL?; C&apos;. _ z)carried anI-7LC. AT continuouslyHowever, unless et._&apos;0:, precations are taken under r&apos;t e , accidents, n is or such, as111 electricity r 1C- from.J--_,._.1t ,° =&apos;1?without usingholes, as well as numerous-o _&apos;1&apos;-1 -= e troublehe record of mineexplosions (some of themSo so _C&apos;_ °:&apos;,v 0f rock- dusting]

Jan 1, 1941

The mineral industry of Benin contributed less than 1% of the 1977 gross domestic product (GDP), which was estimated at $500 million.&apos; Other than limestone and salt, no exploitable mineral deposits have yet been discovered in Benin, which has been rated by the United Nations as one of the world&apos;s least developed nations. In 1977, the economy was further weakened by petroleum price increases and severe drought. The country continued to depend on foreign assistance, which averaged $20 million per year, to finance development projects. The country&apos;s first 3-year plan, which was put into operation in October 1977 after many delays, allocated more than $1 billion to projects in infrastructure, agriculture, and light industry. The most important infrastructure project was the expansion and modernization of the port of Cotonou, valued as an entrepôt port for the transit of goods to the neighboring countries of Niger and Nigeria. Plans called for an increase in handling capacity to 1 million tons of cargo annually, the improvement of port and cargo handling operations, and the upgrading of the efficiency of the Port Autonome de Cotonou (PAC) management system. The $46 million project was to be financed by a consortium led by the International Bank for Reconstruction and Development (IBRD) and including Canada, France, Nigeria, and Abu Dhabi. Construction was scheduled to begin in 1978 and be completed in 1980.

Jan 1, 1981

By Virgil A. Marple

The objective of this contract was to investigate time-integrated and real-time methods for determining the diesel exhaust particulate concentration in underground mines, in particular, coal mines. The microorifice uniform deposit impactor (MOUDI) is recommended for obtaining the time-integrated measurement of the size distribution. The mass concentration of diesel exhaust particles can be obtained from the particle size distribution of mine aerosols. On a mass basis, diesel exhaust particles are primarily in the submicrometer size range while coal dust particles are larger. Size distribution measurements made in the laboratory and in three underground coal mines exhibited two distinct modes with the diesel exhaust particles in the smaller particle mode and the coal particles in the larger particle mode. The point of separation between the two modes occurred in the 0.7 to 1.0 pm size range. The separation was found to be independent of mass fraction of the diesel exhaust particles, particle concentration and sampling site. Methods recommended for further consideration as real-time monitors of diesel exhaust aerosols in mines are photometers and filter pressure drop techniques. A preclassifier would be required in both cases to separate the larger dust particles from the sample. The Metrex Mineral/Diesel Photometer should also be investigated further once the electronics problems are eliminated.

Jan 1, 1986

By Jerry E. Olson

In 1986, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied part of the 20,071-acre South Fork Wilderness Study Area (OR-005-033) and part of the 8,791-acre Sand Hollow Wilderness Study Area (OR-005-034) in order to evaluate their identified mineral resources. The study areas are located in Crook County, OR, about 58 air miles east from Bend. The areas studied are underlain by Tertiary- and Quaternary-age volcanic and tuffaceous sedimentary rocks. No mineral resources were identified in or adjacent to the study area. Except for common opal and agate occurrences along the northern boundary of the study areas, no mines, prospects, or mineralized zones occur within the study areas. Bentonite is periodically mined less than 1 mi southwest of the Sand Hollow study area boundary. Neither of the study areas has geothermal leases, but both areas are under lease for oil and gas.

Jan 1, 1987

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&apos;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 J. Torma-Krajewski, C. Hipes

Although many mining companies apply ergonomic principles, it is usually done either informally and/or reactively. An example of an informal approach is replacing worn equipment (such as seats) with models that have ergonomic features. Another example is modifying a task to eliminate safety hazards. Such approaches reduce risk-factor exposures that can lead to musculoskeletal disorders (MSDs). A reactive approach is followed when modifying a task/ equipment after an MSD occurs. However, neither of these approaches involves a systematic method of proactively applying ergonomic principles to actually prevent injuries or illnesses. This paper discusses how Vulcan Materials Company applied ergonomic principles and implemented interventions to reduce risk-factor exposures.

By M. J. Ferrante

The preparation and subsequent reduction of vanadium trichloride was investigated as a process for the production of high-purity vanadium metal. Chlorine was reacted with vanadium oxide in the presence of carbon to vanadium tetrachloride. The contaminant vanadium oxytrichloride was also formed and later converted to tetrachloride by reaction with chlorine in the presence of activated charcoal. Vanadium tetrachloride was stirred continuously during thermal dissociation to vanadium trichloride powder from which volatile contaminants were removed by distillation. The vanadium trichloride powder was reduced to vanadium sponge by controlled feeding of the trichloride into molten magnesium. Excess reductant and byproduct salt were removed from the vanadium sponge by high-vacuum distillation. Batches as large as 6.5 kilograms of sponge metal were prepared at an average reaction efficiency of 98 percent. Vanadium sponge after consolidation by arc-melting contained 820 to 11330 ppm of interstitial impurities and had a hardness between Rockwell B 40 and 70, This metal exhibited excellent workability at room temperature. The purification of impure vanadium metal by electron-beam melting resulted in lowering interstitial impurities from 1,890 to 504 ppm and hardness from Rockwell B 87 to 28.

Jan 1, 1968