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This Bureau of Mines investigation addressed two primary issues of air velocity measurement in mines: the determination and use of correction factors, and the development of guidelines for the selection of a suitable site at which the measurements should be taken. Other facets of the investigation included a comparison of measurement methods and devices, and aircourse cross-sectional area measurement. The study consisted of theoretical, laboratory, and in-mine investigations. The measurement devices included in the experimental phase were vane anemometer, vortex shedding anemometer, a prototype thermoan-emometer, smoke tube, and oil of wintergreen sprayer. The measurement methods included single-point centerline, timed-point traverse, continuous traverse for the anemometers, and various distances and cloud positions for the smoke tube and oil of wintergreen devices. The study resulted in guidelines for measurement site selection that are applicable to most inmine situations. It also showed that the use of correction factors is problematic. There are many potential pit-falls and there are cogent arguments against using certain correction factors. However, generalized correction factors were developed that can be successfully applied in routine ventilation work, provided that their use is properly understood.

Jan 1, 1985

By L. C. George

The Bureau of Mines measured vapor pressures of selected mixtures in the binary system SnCla-ZnC12 by the static pressure method. Equations expressing the vapor pressure) and the heat and free energy of vaporization) as functions of temperature were developed by numerical analysis based on the sigma-plot method. It was found that the vapor pressure of any SnCl2-ZnCl2 mixture) at any temperature within the range of this investigation) could be accurately calculated from the derived values for the heat and free energy of vaporization for the mixture, with a probable error of 0.01 cm Hg or less.

Jan 1, 1967

By J. A. Organiscak

The U.S. Bureau of Mines investigated the relationship of bituminous coal seam parameters and the amount of airborne respirable dust generated at longwalls. Dust and coal samples were obtained from 20 longwalls operating in geographically representative coalfields throughout the United States. Statistical analyses of coal seam parameters and airborne respirable dust measurements indicate a likely causal relationship between seam type and respirable dust. Low-ash, high-volatile coal seams were associated with higher airborne respirable dust levels. A negative linear correlation (significant at the 95-pct confidence level) was observed between the seam's ash content and airborne respirable dust, explaining up to 18 pct (R2 = 0.18) of headgate dust level variation and up to 15 pct of tailgate dust level variation. Volatile matter was found to have a positive linear correlation with tailgate dust level, explaining 16 pct of the variation. Further data examination indicates that these relationships with dust are most likely nonlinear, because of improved R2 values over the linear correlations. However, a notable portion of longwall dust production is influenced by other operational parameters, so additional research under more controlled conditions is needed to determine the seam's causative functions.

Jan 1, 2010

By L. C. IlsLey

The theory and practice followed by the Bureau of Mines in investigating electrical equipment4/ made for service in gassy mines are of particular interest not only to manufacturers but also to those organizations that deal with safety anal inspection at the mines. This publication purposes to discuss the theory upon which tests of equipment in explosive atmospheres are based and to consider inspection and other matters pertaining to investigations made by the Bureau in ascertaining whether a machine merits approval. The material in this report is taken from an earlier bulletin,5/ which is row out of print, and has been revised and brought up to date to make the information again available to manufacturers, inspectors, and others interested in the development of safe equipment.

Jan 1, 1954

By F. M. Jenkins

Longwall mining systems are used to mine approximately 50 pet of the world's total underground coal production. Single entries are the predominant method of longwall development in Europe and Asia, where mining conditions are more severe than those encountered in the United States. During the 1970's and early 1980's, the U.S. Bureau of Mines and the U.S. mining industry invested nearly $20 million in single-entry and related research. This report reviews the accomplishments of single-entry research in the United States and describes two U.S. single-entry field projects: the Sunnyside single-entry project in central Utah and the tunnel-boring project in northern West Virginia. Also discussed are a single-entry study conducted by North American Mining Consultants (NAMCO) and a single-entry design study conducted by Ketron, Inc. This Bureau report compares the resulting technology with European counterparts to further assess the utility and efficiency of U.S. systems.

Jan 1, 1990

By L. C. IlsLey

The theory and practice followed by the Bureau of ones in the investigation of electrical equipment4/ made for service in massy mines are of particular interest not only to manufacturers but also to those organizations that deal with safety and inspection at the mines. This publication proposes to discuss the theory, upon which tests of equipment in explosive atmospheres are based and to consider inspection and other matters pertaining to investigations made bar the Bureau in ascertaining whether a machine merits approval.

Jan 1, 1941

By J. T. Matson

This paper describing the mining practice at the Pecos mine of the American Metal Co. of New Mexico, a subsidiary of the American Metal Co., Ltd., is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in the various mining districts of the United States. The mine is producing about 18,000 tons per month of zinc-lead-copper ore, chiefly by the square-set and cut-and-fill methods. Costs are given for 1927, 1928, and 1929, the whole producing life of the mine to date.

Jan 1, 1930

By Len Blackman

The Absaroka-Beartooth Study Area is a tract of approximately 1.4 million acres of National forest land in southern Montana, part of the Greater Yellowstone Area. This study evaluated the mineral potential of four mineral terranes containing undiscovered resources in the area. The geological data is probabilistic, with estimates of the possible number: of deposits and their grades and tonnages. Possible future development scenarios range from no development to many mines, including some very large. As two thirds of the study area is within the Absaroka-Beartooth Wilderness, the future development scenarios reflect the area's mineral potential, not what we expect to see in the foreseeable future. Based on the analysis performed on these four terranes, the most likely future scenario for the study area would include the potential for two medium sized, (predominately) gold, mines, each employing a few hundred workers. There is a small chance, less than 5%, that a large Porphyry Copper or Superior Iron deposit would be discovered and be economically feasible to develop.

Jan 1, 1994

By T. A. Sullivan

The Bureau of Mines investigated modified sulfur concretes as one part of a program for utilizing sulfur in construction materials. The use of modified sulfur was studied as a means of preventing the stressing action in the concretes caused by the allotropic transformation of sulfur on solidification. Unmodified sulfur concretes have been prepared that have compression, flexural, and tensile strengths equivalent or better than Portland concretes. However, most of these concretes have been vulnerable to deterioration by weathering, temperature fluctuations, and freeze-thaw cycling. The sulfur was modified by reaction with dicyclopentadiene or dipentene before use as an aggregate binder. Sulfur concretes and modified sulfur concretes were pre-pared from acidic and basic type aggregates. Physical properties of the optimum mixtures were determined and compared with each other and with Portland cement concretes. The best results were obtained by reacting sulfur with 5 pct dicyclopentadiene to prepare modified sulfur concretes. Field testing of the concretes are in progress. Present results show that modified sulfur concretes are superior to unmodified sulfur concretes and equal or better than Portland concretes in compressive, flexural, and tensile strengths. Long-term aging characteristics of both modified and unmodified sulfur concretes are being determined.

Jan 1, 1976

By Frank E. Federspiel

In 1992, the Bureau of Mines conducted a mineral resource investigation of the 78,000-acre Garns Mountain study area in southeastern Idaho. The area had been proposed for Wilderness. It is underlain by Paleozoic to Mesozoic-age sedimentary rocks about 11,000 feet thick. Rocks have been faulted, offset, and folded as part of the northerly-trending Idaho-Wyoming Overthrust Belt. Study area mineral occurrences are: phosphate in the Permian Phosphoria Formation; coal in the Cretaceous Frontier end Bear River Formations; and uranium in carbonaceous and phosphate-bearing shales and coal of these formations. Four zones of phosphate are estimated to contain about 528 mitt ion tons of rock with over 10% P205; samples of phosphate-rich rock also contained as much as 3950 ppm chromium, 3280 ppm vanadium, 23 ppm gallium, and 5540 ppm zinc. Fragments of poor-quality coal and carbonaceous shale were found in the area; coal was mined near the northeast border. Uranium content up to 0.016% U3O8 is in carbon-rich shales. Oil and gas were drilled for, with minimal success, in folded sedimentary rocks (frontier and Nugget Sandstone) in the Horseshoe anticline, near the east border. Examined workings included 12 dozer cuts, 4 trenches, 2 prospect pits, and 2 caved adits. No production is known, and no leases or claims are held for the area.

Jan 1, 1992

By William J. Douglas

This document describes the development of a conventional mining equipment data base, and an approach for conducting industrial engineering studies of arbitrary mining systems employing network techniques. Data was acquired through underground time studies. Each member of a four-man field team was assigned to a specific machine during each shift for which observations were conducted. Using digital wrist watches and networks describing the man-machine interactions, all events occurring luring the course of each shift were recorded on cassette tapes. The tapes were transcribed, coded, keypunched, and validated using computerized editing techniques. The resulting data files were processed to provide statistics relating to activity durations and event frequencies. The results were used to evaluate operator, machine, and system performance for each section which was observed. Equipment, reliability, and maintainability analyses were conducted using the industrial engineering data files in conjunction with historical information collected at the mine site.

Jan 1, 1976

By A. C. Johnson, es Hol, E. O. Binyon

"INTRODUCTION AND SUMMARYThe tungsten properties of Lincoln Mines, Inc., and North Tem Flute Mining and Development Co. were first explored by the Bureau of Mines in 1942. Work on the project comprised trenching, sampling, a small amount of road and trail construction, and a small amount of core drilling. From April 13 to December 10, 1944, additional diamond drilling was done by the Bureau of Mines to test the lateral and downward extensions of the various tactite zones along the contact south of the Lincoln mine, including the property of the North Tem Piute Mining & Development Co.Claims leased by the Lincoln Mines, Inc., are in secs. 25 and 36, T. 3 S., R. 56 E.; secs. 30 and 31, T. 3 S., R. 57 E.: and sec. 1, T. 4 S., R 56 E., M. D. B. & M., in the Tem Piute Mining District, near the north end of the Timpahute Range in west central Lincoln County, Nev. D. B. Fegles is president of Lincoln Mines, Inc. and general offices are in the Wesley Temple Building, Minneapolis, Minn.In June 1945, the Atolia Mining Co. leased the property and purchased the mill and mining equipment from Lincoln Mines, Inc. P. R. Bradley is president of the Atolia Mining Co., whose offices are in the Crocker Building, San Francisco, Calif. This company surrendered the lease on the property on September 30, 1948. The property owners are continuing operations and are now engaged in building a 20-ton mill.The claims of the North Tern Flute Mining & Development Cc. are in sec. 1, T. 4 S., R. 56 E., M. D. B. & M. Merle F. Schofield is president of the company and maintains an office at Hike, Nev. These claims were leased by H. P. Laslett, of the Utah Nevada Mining Co., in 1945 and by the Atolia Mining Co. in 1946. The owners are now doing some exploratory work."

Jan 1, 1950

By Leonard F. Heising

At the Groveland-mine iron ore is mined by open-pit methods and concentrated by means of spirals and flotation. A brief history of the mine and its early development is given. The ore deposit is described, with emphasis on those physical characteristics that affect the choice of mining and milling methods. Development and mining, which include breaking ground, loading, transportation, engineering, and operating control; are explained, and the milling method is described Mining and milling costs are given in percent of total cost.

Jan 1, 1963

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 William Catron

This paper is one of a series being prepared by the United States Bureau of Mines on mining methods, practices, and cuts in the various reining districts of the United States. The mining methods described are those used in the mines of the Cananea Consolidated Copper Co., a Mexico corporation whose holding company in the United States is the Greene Cananea Copper Co. The mines are at Cananea, Sonora, Mexico, 25 miles directly south of the international boundary, approximately in 31° nor to latitude and 110 to 130° west longitude. Cananea is connected with the boundary towns of Naco and Nogales, Ariz., by a standard-gage railroad.

Jan 1, 1930

This report is in partial fulfillment of Contract S0241051 awarded to COMINEC on June 27, 1974. 'Me purpose of the work under this contract is to develop a conceptual design for an automated longwall mining system. The conceptual design will serve as the basis for future design and development of an automated longwall mining system capable of sustained production in excess of 2,500 tons per shift with reduced manpower which will ultimately be demonstrated in an area where conventional longwall mining has been successful. 1.2 DEFINITION OF THE PROBLEM 1.2.1 Why An Automated System The most obvious benefit of automation and remote control in a longwall mining system is the reduction of accidents consequent upon a reduced working force in the hazardous face areas. However, another important aspect of the problem is the skilled labor shortage which is being compounded by the need for vastly increased coal production. The United States coal mining industry had a working force of almost 600,000 miners in 1928 but was able to muster only 145,000 miners in 1970. The miners required to staff the additional working sections and the new mines necessary to meet our energy needs are simply not available. Only automation and remote control will permit a reduced work force with increased production by keeping the face equipment operating continuously.

Jan 1, 1975

By Michael D. Balen

During the years 1987 through 1989, the Bureau of Mines Alaska Field Operations Center (Bureau) in cooperation with the Western Field Operations Center and the Alaska Division of Geological and Geophysical Surveys (ADGGS), conducted mining, geological, and geochemical investigations in the 5.7 million-acre Valdez Creek Mining District (VCMD). This investigation was conducted as part of the Bureau's continuing Mineral Land Assessment (MLA) mining district studies program. The Bureau's MLA program is designed to provide reliable and comprehensive mineral resource information that supports mineral resource policy and land use decisions made by Congress and Federal land management agencies. The information also provides the basis for decisions that would expand the domestic supply of important mineral resources, primarily strategic and critical minerals. Much of the MLA work is done jointly with cooperating State or U.S. geological surveys.

Jan 1, 1992

By G. R. Strimbeck

This is a report on experimental work on development of a gasification process operating at near atmospheric pressures and using finely pulverized coal entrained in oxygen and steam. The gasifier was designed by The Babcock and Wilcox Co. in cooperation with engineers of the Bureau of Mines Morgantown station. The test work discussed in this report covers the first 34 tests made in the pilot plant in which a strongly coking Sewickley-bed coal, ground to either 70 or 90 percent through a 200-mesh screen, was used.

Jan 1, 1954

By E. J. Kloos, R. H. Schutz, B. I. Ferber

To protective devices, the Bureau of Mines has established five schedules of minimum performance requirements for the approval of respirators. The current revisions of these schedules include 13D for self-contained breathing apparatus, 14F for gas masks, 19B and the amendments to 19B for supplied- air respirators, 21B for dust, fume, and mist respirators, and 23B for chemical cartridge respirators. Copies of these schedules may be obtained from the Bureau of Mines, Publications Distribution Section, 4800 Forbes Avenue, Pitts- burgh, Pa., 15213. Approval tests on respirators are performed only at the request of the manufacturer of the respirator and at his expense. If the device meets the approval requirements, a certificate of approval is granted on the complete respirator. This certificate states that as long as the respirator is manufactured as originally approved, or in accordance with any changes covered by an exten- sion of the original approval, the manufacturer may advertise and sell his respirator as being approved by the Bureau of Mines. Many industries and regulatory agencies require that respirators approved by the Bureau of Mines be used where respiratory protection is needed. The Bureau of Mines, how- ever, has no regulatory power over the use of the respirators that it approves. It acts as an impartial testing agency to insure the availability of suitable and safe respirators. At frequent intervals, the Bureau of Mines purchases approved respirators and replacement parts on the open market. These are examined for conformity to the approved status, and are checked to insure that the manufacturer's pro- duction facilities are maintaining a satisfactory quality control.

Oct 1, 1965

By Raymond B. Ladoo

"The recent discovery and exploitation of petroleum territory have resulted in the enactment of new petroleum laws in most of the South American Republics. The activities in the discovery of these new fields were engendered by the knowledge of the fact that present producing fields must within well defined periods be exhausted. Oil operators were willing to take the initial steps in exploitation in the absence of legislation that applied strictly to petroleum operations. The enactment of modern legislation in many of these Republics encouraging and protect¬ing exploitations may cause tremendous oil activities in these countries, and the results may be comparable with the magnitude of the undertakings and the prestige of the companies now entering this territory.These, oil fields are admirably located for convenient distribution of petroleum by water to all the Nations using oil as fuel for shipping and industrial concerns. The oil markets of the western coast of South America will derive immense benefits from the Panama Canal. This navigation route brings these markets into direct ocean shipment with the Atlantic coasts of the Western and Eastern Hemispheres.One deterrent to oil production in the Republics of South America is the want of inland. transportation facilities, but the recent laws of these Republics without exception provide for acquiring rights of way for pipe lines and other modes of transportation; and doubtless the great interests and. syndicates already operating in these regions will, as production increases, provide ample pipe line transportation sufficient to convey to the coast the oil produced. It way be assumed, from the legal guarantees afforded, and from operating equipment and machinery that are now being concentrated that refineries will be erected at shipping points for the purpose of making these petroleum products accessible to the world."

May 1, 1921