Search Documents

By B. V. Johnson

The Federal Bureau of Mines has conducted research in support of the National Aeronautical and Space Administration's (NASA) Apollo program to acquire fundamental scientific and engineering knowledge of lunar-mineral resources for NASA's Office of Advanced Research and Technology. Equipment and techniques were developed to conduct soil shear tests in a simulated lunar environment. Shear tests performed with this equipment in ultrahigh vacuum and controlled laboratory atmosphere showed that simulated lunar soil increased in strength in the simulated lunar environment.

Jan 1, 1973

By Kyle W. Charlton

The Bureau of Mines utilizes special testing methods for the analysis of underground mine atmospheres for use during or after mine disasters and fires. These methods depend upon drawing sample gas to the surface through multiple tube bundles with the subsequent analysis of grab samples or the automatic analysis by often remotely located instruments on a continuous, 24-hour basis. During cold weather, low ambient temperature causes condensation and freezing of condensable vapors in the sample which can result in delayed response times or complete blockage of the sample line. This report covers research and resulting development conducted by the Bureau of Mines to produce a reliable method to selectively remove condensable vapors and particulate in the sample gas stream under worst-case field conditions. The effort resulted in two prototype systems which have greater field utility than originally anticipated. The innovative project resulted in two patent applications submitted through the Bureau of Mines.

Jan 1, 1981

By John H. Soule

Appreciable quantities of sine and lead orus have been produced from the West. Pinos Altos district of Grant County, N. sex. This area was visited many times by engineers of the Bureau of ines. D. H. Johnson and 4. R. Storms visited the district in haren 1943 in connection with an acrenu road to toe wines. M. H. Storma again visited the area in July 1943 in connection with a hetals Feserve Corporation loan on the Routen-Thomas

Apr 1, 1948

By L. H. Wullstein

Nitrogenase activity (C2H2 reduction) was found to be associated with the following grasses in the field: Agropyron dasystachyum, Agropyron smithii, Aristida purpurea, Oryzopsis hymenoides and Stipa comata. Uptake of fixed nitrogen was also demonstrated for these grasses. Two unidentified nitrogen fixing bacteria were isolated, one from Stipa comata and one from Aristida purpurea. Cynodon dactylon and Agropyron cristatum were successfully inoculated with the unknown isolate obtained from Stipa comata. The inoculated plants exhibited nitrogenase activity (C2 H2 reduction) whereas uninoculated controls gave negative results.

Jan 1, 1982

By Merwin H. Howes

In constructing the NORAD Combat Operations Center, controlled blasting techniques were employed to achieve smooth walls and to avoid shattering the rock beyond excavation lines. Extraordinary measures were taken to stabilize the rock to permanently preserve the openings. Rock stabilization was accomplished by means of reinforced concrete and gunite linings, rock boltings, installation of chain-link fabric, and epoxy resin and cement grouting. A particular zone of weakness at B vital location was supported by exceptionally thick reinforced concrete lining, rock bolts, and cement grout.

Jan 1, 1966

By Joseph L. Buckley

A total of 55 conveyor belt fire tests were conducted in the Bureau of Mines Fire Test Gallery, located at the Factory Mutual (FM) Fire Test Center West Glocester, R.I. The objectives of these tests were to: 1) determine the fire resistance and burning characteristics of various conveyor belt materials under simulated mine conditions; 2) provide essential data for designing a reliable bench-scale conveyor belt fire resistance test; and, 3) determine fire test conditions that will discriminate between low, moderate and high fire resistant materials. Belts, representative of those which mold he found in underground coal mines were examined under n umber of experimental conditions which included; ignition intensity; air flow rate; ratio of belt bright (h2) to overall gallery height (h1); exposure time; and, belt width. It was found that fire propagation could be achieved for some "fire resistant" belts (complying with the present Schedule 2G standard for approval) when exposed to an Ignition source of =6000 Btu/min for a 15-min period at a belt height ratio of 01.66. There appears to be a dependency of flame propagation on air flow rates and belt width, although the tests performed do not provide a quantitative trend. Recommendations are made for additional work to resolve some anomalous date and to fill voids in the rest program.

Jan 1, 1978

By William O. Vanderburg

The fluorescence of many minerals, when excited by different wave lengths, of ultraviolet radiation, has long been recognized as a spectacular laboratory phenomenon. Since the original display in the British Museum, the phenomenon has been used frequently for educational purposes and public demonstrations. Its practical application for the rapid detection of certain minerals in ores and mill products at the zinc mine at Franklin, N. J., has been described.3 Due to technical improvements in ultraviolet-radiation apparatus, fluorescence has found a new field of application in the tungsten-minim; industry. Although fluorescence of scheelite (calcium tungstate) has been known for a number of years, the practical application of the phenomenon is the outgrowth of a program of cooperative research conducted by Ott F. Heizer, manager of the Nevada-Massachusetts Co., Inc. , Mill City, Nev., and Dr. Paul F. Kerr of Columbia University. Special portable lights for fluorescing scheelite have been developed and utilized in underground geological work. Thanks are due Ott F. Heizer for permission to publish data included in this paper.

Jan 1, 1935

By E. C. Lane

[This Is the ninth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the interior. The first report gave data on motor gasoline sold during the winter of 1935-36.3/ The Present report presents analytical data for 2,033 samples, representing the products of approximately 80 companies, which, as in previous surveys, include both large and small suppliers. In addition, the Pacific coast is represented by data that were average by the Pacific Coast Technical Group before 'being submitted and are published exactly as they were received. As in previous surveys, the data are divided into the three groups of samples of regular-price, premium-price, and third-grade gasolines, and each group has been averaged separately. The cumber of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, arc as follows: Regular price, 1,066 samples, 208 items, and 49 brands; premium price, 575 tamales, 154 items, and 38 brands; third-grade gasoline, 7;4 samples, 150 items, and 53 brands. The meanings of these terms as used in the surveys tar as follows: Sample: The individual supply of gasoline obtained at the filling station and analysed in the laboratory.]

Jan 1, 1940

By Terry J. Close

U.S. Bureau of Mines personnel studied the 33,900-acre Silver Peak Range North Wilderness Study Area (NV-060-338), in order to evaluate its identified mineral resources. The area studied lies between the towns of Silver Peak and Dyer, about 40 miles southwest of Tonopah, in Esmeralda County, Nevada. There are no producing mines in the area studied. However, development of Sunshine Mining Company?s Sixteen-to-One silver-gold mine, located in the Silver Peak mining district near the eastern edge of the study area in the early 19801s, has stimulated recent interest. The Sunshine Mining Company claimed two sites within the study area in 1985. Also, Intermountain Resources, Incorporated, located a group of claims at a prospect along the west side of the study area in the Dyer mining district, and in 1986, began drilling. Other claimants are holding two other claim groups by assessment. At the five currently (1987) held sites, precious metals occurrences are being investigated. There are no patented mining claims or mineral leases in the study area.

Jan 1, 1987

Combine the MSHA and OSHA versions of the HazCom Helper into one easy-to-use software tool.

Jan 6, 2007

By Frederick H. Raab

The electromagnetic retransmission system is a new, automated method of locating trapped mine workers. This technique overcomes many 1 imitations inherent in electromagnetic direction finding by reducing the effects of the conducting ground to an acceptable maximum, by finding position accurately in the presence of antenna tilt, and by eliminating the need for the receiver to be located directly above the subsurface transmitter. Three transportable three-axis magnetic-dipole transmitters on the surface create a system of electronic grids in which the phases of the downlink Signals convey position information. The subsurface retransmitter modulates the uplink carrier of the existing beacon transmitter with the received downlink signal; the coal-pillar loop antenna is used for both receiving and transmitting. The uplink receiver uses a three-axis antenna and extensive digital signal processing. A small computer integrates data, estimates position, and controls system operation through VHF-FM communications. Both coal-mine and deep-mine operation are possible by selecting appropriate transmitting power and signal frequencies. This report shows such systems to be both feasible and practical.

Jan 1, 1980

By R. O. Pynnonen

This publication presents a study by the Federal Bureau of Mines of 494 accidents in open-pit iron-ore mines, beneficiation plants, and shops of the Lake Superior district from March 1949 to June 1956. These accidents caused 499 lost-time injuries, including 12 fatalities. A similar Bureau publication, Information Circular 7744, Analysis of 346 Accidents, Underground Iron-Ore Mines, Lake Superior District, was published in April 1956. Accident reports were analyzed by the Bureau to show the causes of in-juries and the unsafe practices or conditions that caused the accidents. Also shown are the time charges, times of occurrence, ages of the injured by job classification, and experience of the injured in mines and on the job being performed when hurt. Detailed information is presented on approximately 27 percent of the total number of disabling accidents that occurred in open-pit iron-ore mines, beneficiation plants, and shops in the district during the period covered. The text also contains tabulations of the accident experience and graphs with straight-line injury-frequency, injury-severity, and fatality trends for the period 1946-57.

Jan 1, 1959

By Louis H. Berkelhamer

"INTRODUCTION In the present war, with increasing demands on foundrymen for speedy production of sound castings, the role of sand in foundries has paramount importance.Foundry sands include both molding sands and core sands. Molding sands are those used in making molds, whereas core sands include those used for ""cores"" that fill the parts of the mold intended to be openings or hollow spaces in the casting. Core sands are, as a general rule, relatively coarse-grained as compared to molding sands. Coarse-grained sands, however, are required in making molds for large castings.Owing to the intimate relationship between properties of the sand and casting defects, it is necessary (for most efficient foundry work) to keep a close check on the molding sands used and to properly select and prepare a sand for a specific job. A mold is essentially an unfired refractory composed to meet specific requirements as to strength, permeability, and resiliency. Good green strength is important in preparing and handling the mold. Low dry and hot strengths contribute to cutting and washing, whereas high strengths cause difficult shake-out, with subsequent loss of sand. When molten metal is poured into the mold: a dried skin is attained, and gases from moisture and combustibles are driven off. Excessive moisture necessary for the proper working of a sand, as well as poor venting due to low permeability, are factors responsible for producing such defects as blows and pinholing. The skin of the mold, upon contact with molten metal, first expands and later contracts; these conditions are favorable for producing scab defects. Contact with the molten metal sometimes causes the skin of the mold to sinter or fuse and may produce a sand burn on the casting. Then again, the mold may develop excessive hot strength rapidly, thereby causing a cracked casting. Experienced foundrymen can other such relationships, too numerous to be included here."

Sep 1, 1944

By Gregory Molinda

Historically, coal miners have known that roof shales can deteriorate in contact with humid mine air, causing massive roof falls and injuries from falling rock. It is critical to recognize rocks prone to weathering and to adequately support these rocks in order to ensure the long-term stability of the openings. In a recent study, NIOSH has used a wet/dry cycling test to determine the moisture sensitivity of over 800 specimens of roof rock from 25 U.S. coal mines. Fireclays and some gray shales are the most moisture-sensitive. Rocks with disturbed bedding, in contrast to flat-bedded rocks, are also more sensitive to water. Black shales are relatively un-reactive to moisture and serve to protect more reactive gray shales above. Mines that have roof rocks with moisture-sensitivity indexes above 40% can experience slaking roof conditions, and many require high coverage surface controls. Three case studies are presented in which the moisture-sensitivity index is correlated to roof conditions underground, and can be used to indicate long term deterioration. Engineering measures are described to control moisture-sensitive roof. In one case, roof screen not only reduces injuries from rock fall but also is shown to reduce roof falls. Keywords: coal mining, roof control, slaking, roof support, rock falls

Jan 1, 2008

By D. K. Caddel

Several problems exist with the present design of coveralls used by miners in low coal (seam height 48 inches or less). The back portion of the coveralls often tears when roof bolts or rough areas in the roof are hit. Movement in the shoulder area is restricted. Female low coal miners find it difficult to purchase coveralls that fit properly, and must remove both their hard hat and safety belt in order to urinate and defecate. The objective of this research was to design coveralls which would alleviate these problems. The following features were incorporated into the coveralls; padding in the upper back area to avoid tearing, an action pleat in the shoulders to increase mobility, an inseam zipper to more easily allow miners to perform their bodily functions, and reflective tape to increase visibi¬lity of the miner. A heavyweight denim fabric was used to increase warmth and durability of the coveralls. The coveralls were assessed K long four parameters (comfort, safety, worker productivity, and fabric suitability) using both an in-field assessment by low coal miners and simulation studies. The experimental coveralls proved superior to conventional coveralls along all four parameters. Work clothing sizes for female miners were developed.

Jan 1, 1982

By Lon A. Williams

This report, authorized under Contract Number H0220065, Amendment Number Six, documents the results of an investigation of lighting system modifications and designs for working place illumination in high and low coal entries of underground coal mines. The portable and machine mounted system designs, both modified and prototype, represent a continuation of work performed under Contract Number H0111403, Amendment Number One. See the Final Technical Report dated May 26, 1972 for detailed information concerning this prior Contract. All modified and prototype systems met the performance requirements of Bureau of Mines Specification 2G, as proved by test. In addition, the systems met the requirement for illumination, as specified in the Contract and in the proposed standards which were generated in response to Public Law 91-173.

Jan 1, 1976

By Sheridan J. Rodgers

Toxic fumes generated during shot firing under actual mining conditions were measured. Eight shots with Gelodyn-2X and seven shots with Tovex-100 4VT were monitored. Average CO values for Gelodyn-2X and Tovex-100 4VT were 0.20 ft3/lb and 0.09 ft3/lb, respectively. Average N0x values for Gelodyn-2X and Tovex-100 4VT were 0.049 ft3/lb and 0.026 ft3/lb, respectively. The results obtained with these in-mine tests will be used by the U.S. Bureau of Mines in the development of a large chamber method of measuring fumes from shotfiring of explosives.

Jan 1, 1977

By Chas. F. Jackson

This paper is published as a progress report for the first half of 1929 on the study of wining methods and costs in the Eastern and Central States. Data obtained from 25 mines using open-stope methods are correlated and summarized. Some of these mines have been described in considerable detail in reports already published as Information Circulars. In addition to the published reports on individual mines, considerable data have been obtained from other mines which were visited and studied during the course of the investigation. Many of these mines will later be described in detail in separate papers, and when the field has been covered in this manner it is planned to issue a bulletin on open-stops methods of mining which will amplify the subject matter of the present paper. Definition of ?Open-Stops?. - The term "open-stopes" as employed by the Bureau of Mines is applied to all naturally supported stopes; that is, stopes in which the excavated ore is not replaced by support of an artificial nature other than preps or stulls and in which the ore or (and) capping are not caved during the active life of the stopes.

Jan 1, 1931

By A. E. Gooch

The Bureau of Mines conducted research in an attempt to provide a more sound basis for recommending improved artificial support during deepening of the main shaft of the Lucky Friday mine in the Coeur d'Alene mining district of northern Idaho. Field measurements of closure across the short axis of the 13-by 26-foot shaft were as high as 16 inches. Elastic/plastic finite-element (F/E) analyses were made, reducing the values of large-scale in situ rock mass properties until field closure measurements generally corresponded to displacements in the F/E analyses. Resulting plots of rock mass displacements, stresses, and areas of plastic failure display the results of creating openings (shaft, in this case) in deep mines in difficult ground conditions requiring artificial support.

Jan 1, 1976

By P. A. Croce

A total of 17 mine gallery fire tests (23 including sub-tests) were completed during this report period (10/1/76 - 11/30/77), directed at identifying a hazardous timber-set fuel-loading in a mine passageway that is otherwise free of combustibles. Results of these initial tests show that the capability of a particular fuel loading for propagating a fire is dependent upon the imposed ventilation air velocity and the ignition intensity, although this dependency needs to be better defined. It is also apparent that care must be taken when relating gallery test fire behavior to actual mine fire behavior, because of the restrictive length of the gallery. Present data indicate that some modification to the instrumentation scheme may be advantageous before proceeding with future tests.

Jan 1, 1978