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By L. A. Morely

The overall objective of the subject contract was to investigate the application, economic, and safety considerations of electrical-shock prevention techniques applied to surface and underground mines. Volume I of the four-volume final report starts by summarizing all research performed, and synopses of the three other report volumes are included. The balance of this volume concerns one major task of the contract, the protection of maintenance personnel. After specifying the scope of work for the task, electrical is defined, and needed ground-fault relay characteristics to prevent ventricular fibrillation are established. This is followed by an analysis of alternating-current systems, a comparison of these systems with respect to body currents, and the advantages and disadvantages of the various ground-fault protection techniques. An analysis of direct-current systems for off-track vehicles is then covered. These analyses form the basis for the research recommendations which along with suggestions for future research, conclude the report volume.

Jan 1, 1982

By Richard A. Busch

Inadequate engineering design criteria for coal refuse embankments has allowed hazardous impoundment structures in coal mining areas to be created. A necessary first step to develop adequate design criteria is the determina¬tion of basic, respresentative physical property data on the materials that constitute typical refuse embankments. An extensive field and laboratory program was undertaken by the Federal Bureau of Mines. Much physical property data was generated. Additonal petrographic analysis and large scale triaxial compression testing was performed by others. The data presented here should aid in establishing design parameters for coal refuse embankments

Jan 1, 1974

This is the seventh 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 gasolines sold during the winter of 1935-36.3/ The present report covering 1,875 samples represents the products of 83 companies plus those from the Pacific coast, which were averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were submitted. For the regular grade 985 samples consisting of 73 different brands are averaged. The premium grade consists of 489 samples of 40 different brands. The third grade has 401 samples averaged from 51 different brands. In this report the districts have been reduced to 21 by combining North and South Texas into one district. Fl Paso samples are reported with the South Rocky Mountain district, and Amarillo, Tex., has been included with the Middle Rocker Mountain district. In the present survey samples from Fort Smith, Ark., have been included in the Tulsa area, Indianapolis has been included in the St. Louis district. Cleveland represents the State of Ohio. Samples from Little Rock, Ark., and North Carolina have been included in the Memphis district. The Pittsburgh district includes samples only from this State and Wheeling, W. Va. The actual sampling points in each area are indicated an table 1.

Jan 1, 1939

This study estimates costs of producing bituminous coal and lignite by strip-mining methods in 12 hypothetical mines. Basic costs are developed by geographic area, rank of coal, and output capacity. Seam thickness and depth and type of overburden are considered typical for the area in which the hypothetical mine would be located. The cost analyses are based on the use of new equipment, the prevailing union wage scales, and the payment of all miscellaneous costs including royalties, contributions to the miners' welfare fund, and license and permit fees. All model mines are considered to have a life span of 20 years. Capital costs of bituminous strip mines with a capacity of 1 million tons per year range from $12.7 million in the Appalachian region to $16.0 million in the Interior province. The corresponding selling price, assuming a discounted cash flow return of 12 percent on investment, is $5.40 and $6.95 per ton, respectively. For bituminous coal strip mines producing 3 million tons annually, a capital investment of $24.9 million will render a selling price of, $3.46 per ton in the Interior province, whereas a similar mine in the Appalachian region requires a capital investment of $28.0 million to produce coal selling for $4.01 per ton. Subbituminous strip mines of 5 million tons of output per year range in capital costs from $28.7 million in the Southwest to $13.9 million in Wyoming and Montana. Coal produced in the Southwest would sell for $3.03 per ton, while coal from Wyoming and Montana would sell for $1.83 and $1.64 per ton, respectively. The capital costs for the strip mining of lignite range from $6.4 million for an output capacity of 1 million tons annually to $20.7 million for an annual capacity of 5 million tons. The corresponding selling prices of $3.01 and $2.12 per ton, respectively, Indicate the advantages of a large-capacity strip mine.

Jan 1, 1972

By Ned Baker

Details are given of a fuel-induction system for a hydrogen, fueled engine. The induction system was designed to preclude backfire otherwise common in hydrogen fueled engines. System features and test data are presented and discussed in the context of the requirements peculiar to use in an underground mine environment. The fuel induction-system when tested in conjunction with a modified Caterpillar 3304 engine provided backfire free engine operation and satisfactory engine performance.

Jan 1, 1982

By S. H. Lorain

This paper is one of a series on mining methods and costs being published by the U. S. Bureau of Mines. The operations of the Quartz Hill Mining Co., near Dewey, Mont., afford an interesting example of the cost of mining small bodies of direct shipping ore; they also illustrate the effect of the unavoidable periods of unusually high exploration and development costs in this type of mining upon the cost per ton of producing ore. The importance of skilled geological guidance and the necessity of avoiding unnecessary overhead and capital expense at small mines are shown. Operating conditions at Quartz Hill are typical of those in many other mining districts of southwestern Montana. It is believed that the costs presented here may be of value in the preliminary estimation of costs to be expected by conservative operators under similar conditions elsewhere. The information contained in this paper was obtained during a visit to the Quartz Hill mine in August 1936.

Jan 1, 1937

By Fred W. Johnson

The first section of this circular has been prepared with a view to answering inquiries frequently received by the Bureau regarding laws governing the staking of claims and regulations covering requirements for holding them and obtaining title in fee to placer ground. These laws and regulations were summarized briefly in Information Circular 6796, "Placer Mining in the Western United States." These laws, however, are administered by the General Land Office, Department of the Interior, and it has been considered advisable to combine an authoritative résumé thereof by the Commissioner of that Bureau with information on small-scale placer mining previously published by the Bureau of Mines. The second section of this circular is largely a revised reprint of Information Circular 6611, "Small-Scale Placer Mining Methods", first published in April 1932 for the purpose of answering the many daily inquiries then being received on this subject. This circular has been reprinted repeatedly, and about 30,000 copies have been distributed, most of them in response to applications therefor. At present (June 1937) requests for this publication continue to be received daily.

Jan 1, 1938

By R. L. Bolmer

Driving long development raises probably is one of the most hazardous and expensive operations in underground mining. The safe handling of men and materials becomes more difficult and more time consuming in the higher sections of the raise. The efficient ventilation of these sections often is a major problem. This information circular describes a unique method by which Resurrection Mining Co, safely and efficiently completed a 622-foot vertical raise at its Irene shaft near Leadville, Colo. The method used by the company involved driving a raw, 6-foot-diameter ventilation raise and emergency escapeway, using a work cage that was suspended on a hoisting rope extended down a small-diameter drill hole. Although the method was new and experimental, the raise was completed in record time. Overall costs were less than they would have been with conventional methods. The company's initial experience suggested improvements both in design and operating technique that should prove of value to others who contemplate using the cage method of raising

Jan 1, 1958

By G. W. Josephson

WHILE methods of utilizing blast-furnace slag have been developing, a great deal of literature on the subject has accumulated, but no comprehensive summary of information that would be helpful to engineers, contractors, architects, chemists, and others in under-standing and more successfully using this byproduct of the iron and steel industry has been published in the English language. The National Slag Association recognized the need for such a publication, and the Problems Committee of the Association under-took in 1943 to accumulate the necessary material. Over a period of several years this committee compiled pertinent information in manuscript form, and in 1948 the Bureau of Mines and the National Slag Association made an agreement whereby the Bureau was to prepare the data for publication as a cooperative bulletin of the Bureau of Mines and the National Slag Association.

Jan 1, 1949

By Jules Gordon

Presents the results of mining tests conducted on a forward rotating bucket wheel excavator designed to continuously mine coal at 1080 tons/hour, Goals of the program are to determine the feasibility of the forward rotating bucket wheel principle as an effective means of reducing fragmentation and loading costs associated with surface mining, with additional benefit in reducing, coal preparation costs and stripping overburden. Tests took place at the Navajo Mine in Fruitland, New Mexico, Results show that the excavator performed as expected and can reduce fragmenting and loading costs up to 80°. Presented are: 1) production machine design specifications and projected economies extrapolated from the test data, and 2) recommendations for further work in dust control.

Jan 1, 1977

By P. C. McWilliams

Theoreticians in soil mechanics have been pursuing a probabilistic approach to the factor of safety of an embankment or darn for the past 10 years. The motivation for this work is in contrast to the current practice of deterministically computing a factor of safety and treating it as an absolute with no regard to its inherent statistical variability. Basic to the probabilistic approach is the selection of an appropriate statistical model to represent the histogram or probability density function (PDF) of the factor of safety values, Rather than simply assuming which PDF is appropriate, the Bureau of Mines collected data at two waste disposal embankments for consideration, This report addresses three candidate models, using the techniques of nonlinear curve fitting, and identifies the "best" model. A propagation of error formula for estimating the variability of Fellenius? factor of safety is also discussed.

Jan 1, 1983

By Alice V. Peter

Meerschaum or sepiolite is employed principally in tobacco pipes and cigar and cigarette holders, although a few other uses of minor importance are Down. The unique value of a meerschaum pipe is derived from the owner's pleasure in watching the color deepen with smoking and in having the color "set" at the desired shade. The name "meerschaum" (German for "sea foam") is applied because the material, when pure and dry, will float on water. Owing to its resemblance to the porous, bonelike structure of the cuttlefish, or septa, it is also known as sepiolite. There are a few scattered deposits of meerschaum in. the United States which have yielded a small product ion, but the world's supply of the' material is obtained fined principally from Asia Minor, Meerschaum deposits near Eski-Shehir, Turkey, are said to have been worked 2,000 years ago, but commercial exploitation is a development of the last hundred years DESCRIPTION AND PROPERTIES Meerschaum is a hydrous magnesium silicate (H4Mg2Si3010) having the following theoretical analysis: Si02, 60.8 percent; MgO, 27.1 percent; H20, 12.1 percent. It is a soft. (H.2 - 2.5), fine-grained, earthy, white, gray, or yellow material. It is very light weight when pure (specific gravity, 1 to 2) and is highly absorbent. Because of its porosity the proportion of water present in the mineral is affected by the humidity'of the atmosphere. In a moist atmosphere the water content may be as much as 21.7 percent. Then wet the material is soft and somewhat plastic. When dried again it becomes lard and tough. The toughness is especially apparent in some forms that have a fibrous or leathery texture.

Jan 1, 1934

By Oliver C. Ralston

The minerals that enter welding-rod coatings and fluxes are the main subject of this report. Few mineral producers know just what minerals and what grades and quantities of minerals are required by the welding trade, and it is for their information that this report has been prepared. The various methods of welding are discussed extensively enough to inform this type of audience. Specialists in welding probably will find little on welding that is of value to them, but they may learn something more about the minerals or mineral products that they use. The authors did not find it easy to prepare this publication, and any needed corrections will be welcomed. Regarding welding, research, Jenks4/ 1 points out that while the process of welding in simple in operation, the phenomena attending its use are extremely complicated, and the efficient and safe use of welding requires an understanding thereof. Although the fluxes and the coatings used have solved many problems, many other problems require the joint effort of the whole industry; therefore, it is hoped that this report will be found of practical value.

Jan 1, 1940

By M. J. Ankeny, J. J. Forbes

"One of the main functions of the U. S. Bureau of Mines, as authorized by Congress, is to investigate safety and health conditions, to disseminate information regarding safe and unsafe practices in mining, and to aid in improving safety and health conditions of mining communities and in promoting the welfare of the miner. Among several methods of reaching the miner and interesting him in safety work, perhaps the most effective is through the 11 mine safety stations and 11 railroad cars known as mine rescue, or more correctly, mine safety cars.Frequently, the Bureau of Mines receives requests for information regarding the purpose, equipment, personnel, and construction of its safety cars used in the field service. It is the intention of this circular to present to the mining public in particular, and to the public in general, some definite information regarding these safety cars and their functions.The cars are operated throughout the mining fields of the United States and are headquartered as follows (see fig. 1): Car 1, Reno, Nev.; Car 2, Raton, N. M.; Car 3, Pittsburgh, Pa.; Car 4, Terre Haute, Ind.; Car 5, Pineville, Ky.; Car 6, Pittsburg, Kans.; Car 7, Huntington, W. Va.; Car 8, Duluth, Minn.; Car 9, Butte, Mont.; Car 10, Des Moines, Iowa; Car 11, Anchorage, Alaska.One of the most important purposes of the U. S. Bureau of Mines safety cars is to render service at mine fires and explosions where human life is endangered. State mine inspectors and other interested persons are supplied with itineraries of the car operating in their districts from time to time, so that they may know at all times where the car can be found in case of emergency. When these disasters occur the car may be reached direct or through its field headquarters, and upon receiving word of a mine disaster, or request for assistance, it immediately proceeds to the scene of trouble. Frequently a special locomotive is supplied by the railroads and in many instances the movement of the car is given the right of way over all other railway traffic. Upon reaching the destination, the facilities and personnel of the car are immediately available for rescue and recovery operations.Following most mine disasters a thorough investigation is made by engineers of the Bureau of Mines, and a confidential report is submitted to the operator. The information gained in this manner from a large number of mine fires and explosions, together with the knowledge gained from the experimental work carried on at the Experimental mine of the bureau at Bruceton, Pa., serves as a basis upon which the bureau is able to recommend preventive measures whereby similar occurrences may be averted. The bureau car is often used as headquarters for the investigating engineer when such an examination is being made."

Mar 1, 1931

By O. M. Schaus

The following is a description of the methods employed at the Eureka-Asteroid mine, which is situated on the Gogebic range, at Ramsey, Mich. The mime is operated by the Castile Mining Co. under the direction of Oglebay Norton & Co. This paper has been prepared in accordance with an outline furbished by the United States Bureau of Mines, and in one of a series, on mining methods and costs covering the principal minim operations throughout the United States. ACKNOWLEDGMENTS The author acknowledges the assistance of the mining organization of the Castile Mining Co. in the preparation of this paper.

Jan 1, 1930

By Geo. Adams Roalfe

THIS PAPER is one of a series being pre¬pared for and published by the United States Bureau of Mines describing, methods of mining and crushing and the costs of operation at commercial crushed-stone plants throughout the country. These papers are 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 operators, as well as to the industry as a whole. On the other hand, operating, costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue. Acknowledgments The author wishes to acknowledge the [ ]

Jan 1, 1932

Electrical trailing cable used to power coal mining machinery is frequently damaged in usage because of tensile strain or crushing effect of mining machines running over the cable. One of the repair problems is finding the exact location of a short or open in this cable so it may be spliced or otherwise repaired. The U.S. Bureau of Mines and FMC corporation signed Contract No. H0 122011 in August, 1971, to develop instrumentation for finding faults in coal mine trailing cable. This report describes performance of several existing instruments as trailing cable fault locators and also construction details and performance records of several cable fault location instruments that FMC designed, built and tested as part of this project.

Jan 1, 1973

By E. D. Gardner

About 300 tons of gold ore per week was being produced in February 1934 by Thomas D, Herron and Con Laster from the old lake Superior and Arizona workings; the ground was leased from the Magma Copper Co. The workings adjoined but were not a part of the Magma mine. The lessees had been employees of the Magma Copper Co, at the time the Magma closed down for the summer of 1932. Work on the lease began in July 1932 on an exposure of $2-per-ton ore disclosed in a drift; after a few hand-drilled rounds were blasted the gold content increased to about $30 per ton. Extensive sampling by pannings elsewhere of exposed portions of the vein indicated that other ore shoots existed. The last work previously done in the mine was during the World War, when lessees mined a number of small shoots of copper ore. In some of the stapes the copper miners had left a quartzose streak on the hanging wall that carried $15 per ton of gold. This material did not look as if it cried values and evidently never had been sampled. The first shipment of gold ore was made on September 28, 1932. Up to April 1, 1933, 3,778 tons had been shipped and from September 1, 1933, to January 31, 1934, 3,125 tons.

Jan 1, 1934

Surface mining and reclamation of a southeastern Ohio site with sandstone-shale overburden resulted in (as compared to premining levels): 1) runoff volumes and peak rates that increased by a factor of from 2 to 10 during mining and after reclamation, 2) destruction of the "aquifer" perched on the underclay of the mined coal bed and gradual, but, as yet incomplete redevelopment of this aquifer after reclamation, 3) no immediate effect on another, lower perched "aquifer", 4) up to 100 times greater sediment concentrations in runoff. Results were influenced by increasing annual precipitation amounts through the period of record; 1978, 1979, and 1980 (postreclamation years) experienced precipitation amounts approaching or exceeding long-term normalcy for the area. Part of the reason that the site produced more runoff after reclamation than before mining is that the premine condition was one of an open, porous soil under woodland, while the postreclamation condition was one of a compacted, bulldozed soil. Sediment concentration results were influenced by failure of the postreclamation erosion control system and by a series of detention reservoirs above the stream monitoring station.

Jan 1, 1983

By Ren G. Dong, Richard McCormick, Dan E. Welcome

Vibration exposure at workplaces is generally multi-axial. The health effects of vibration exposure also likely depend on the vibration direction. Therefore, there is a wide interest in the simulation of multi-axial vibration in laboratory experiments. Advances in technology have led to the development of a new 3-D test system for studying hand-transmitted vibration exposure and health effects. The purposes of this paper are to introduce the system and to present the results of its preliminary evaluations. Test System As shown in Figure 1, the system is basically composed of three vibration generators, a multi-axis vibration control system, instrumented handle, handle fixture, and shaker-fixture linkages (stingers). [ ] Figure 2 shows the array of three vibration generators (MB Dynamics, Energizer BLACK-500 lbs) and their associated support bases and foundation developed by MB Dynamics (Cleveland, USA), which create the 3-axis simultaneous motion. These electrodynamic exciters are powered by power amplifiers which provide current proportional to the analog drive signal from a controller. The controller (JAGUAR Multi-Input/Multi-Output closed-loop vibration controller) was provided by Spectral Dynamics, San Jose, California, USA). NIOSH-designed instrumented handle was equipped on the system.

Jan 6, 2006