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In 2005, 14,666 mining operations reported employment statistics to the Mine Safety and Health Administration (MSHA).1 Almost half (48.5%) were sand and gravel mines, followed by stone mines (30.6%), coal mines (14.1%), nonmetal mines (5.0%), and metal mines (1.8%).

Jan 1, 2008

By J. W. Jensen

Alloys of manganese and copper containing from 65 to 80 percent manganese possess mechanical strength and vibration-damping capacity in an unusually high degree. The success of their use in reducing vibration in structures depends, to some extent, on their fatigue properties. This report describes the results of fatigue tests on alloys of four compositions. Three metallurgical conditions were investigated for each alloy. Or the basis of the data in this report, the general rule that vibration-damping manganese-copper alloys are comparable to mild steel in hardness and strength may be extended to include fatigue strength. Methods for casting and fabricating these alloys were described in a previous report,4 which contained data on the mechanical and damping properties of the solid-solution alloys, and on alloys aged for 2 hours at 450° C. The aging heat treatment of solution-treated alloys results in optimum mechanical and damping properties throughout the range of specified composition. However, in the present work, measurements also were made on alloys aged for 2 hours at 500° C., because it was theorized that the additional precipitation of a-manganese under these conditions might have a pronounced effect on the fatigue strength of the alloy.

Jan 1, 1961

By Nan C. Jensen, Oliver Bowles

"INTRODUCTION Limestone (which consists essentially of calcium carbonate) and dolomite (calcium magnesium carbonate) occur widely in the United States. Their presence is of vast economic importance, because they are used much more extensively than any other form of rock. In 1945, limestone (which, broadly, includes dolomite) was quarried in every State except Delaware, New Hampshire, North Dakota, and Rhode Island, and also in Hawaii and Puerto Rico. Total production (including that used in cement and lime manufacture) exceeded 151,700,000 tons, or 79 percent of the quantity of all kinds of stone sold or used during that year.Important well-known uses of limestone are as concrete aggregate, road material, railroad ballast, for liming the land, for cement manufacture, as riprap for shore protection, harbor work, and spillways at dams, and as building stone.. None of these uses, however, are considered herein. The purpose of this paper is to discuss the industrial and chemical uses that are less widely known and yet are of tremendous importance in a great variety of processing industries. Important examples are dolomite as a refractory furnace lining and limestone as a fluxing agent in blast furnaces, and as a raw material employed in sugar, paper, glass, and alkali manufacture.PRIOR REPORTIn May 1941, the Bureau issued a report 4/ that described these uses in some detail. As new and important developments have taken place during the ensuing years, a revision and representation of the salient features of these uses seem desirable. Asphalt filler and mineral wool uses included in the earlier report are omitted from this paper because they are identified more closely with the highway and building industries, respectively, than with the industrial applications."

May 1, 1947

By Barbee J. Scheibner

This Bureau of Mines report describes the geology and physical properties of core samples at the Sunnyside coal mine No. 1, Sunnyside, Utah, and was written in conjunction with the Single-Entry Program conducted at the mine. The objective of this program was to test the hypothesis that the single-entry system in the Sunnyside mine, supported in the center by open cribs and divided by a fire-resistant partition, is equivalent to or better than a two-entry sys-tem. Drill cores, taken underground at 15 sites in the single-entry study area, facilitated the construction of geologic cross sections of the entries. Physical property data obtained from the drill cores was used in a three-dimensional finite element analysis program to evaluate the stability of the openings, the support requirements, and the de formation characteristics of the roof and floor material. Data on 10 physical property parameters for 5 rock types plus coal are also tabulated and discussed.

Jan 1, 1979

Several federal and state agencies have promulgated regulations that require the installation of operator protective structures on mobile equipment used in mining, construction, agriculture and logging industries. These regulations cover many different types of vehicles, from small farm tractors to large rubber-tired front-end loaders, and require structures that help protect the operator from death or injury from vehicle overturns, from falling tree tops and logs, from falling rocks, and from tree limbs in clearing operations. Two general types of vehicle operator protective structures have evolved over the past twenty years. The first of these is the "Roll-Over Protective Structure" or "ROPS" that is essentially a "roll bar" or "roll cage" that provides a relatively safe area for the vehicle operator if the vehicle should tip over and roll. The second protective structure is the "Falling Object Protective Structure" or "FOPS" that provides overhead protection against falling material. The terms "ROPS" and "FOPS" are often used interchangeably (sometimes inaccurately) with "cabs", "canopies", "roll bars', "protective structures" and other such descriptive names. In this report, 'ROPS" describes the function of the structure; 'FOPS" also describes a particular function. Thus a ROPS/FOPS could describe a cab or a canopy that provides both roll-over protection and falling object protection.

Jan 1, 1976

By R. S. Norman

The objective of this program was to select approximately 100 acoustic materials for flammability evaluation. Noise control programs have been initiated on several types of mining equipment and vehicles which can be used in underground coal mines. Often, the materials which are used in these noise reduction programs have not been tested for flammability properties according to the same reference standard. During this program a variety of materials were selected for measurement according to ASTM E-162 procedures. A radiant heat energy source was used to measure flammability properties of 15.2 x 45.7 cm. samples. In the absorptive materials category, 45 percent of the materials tested had a flame spread index of less than 25. For barrier, damping, and isolation materials the corresponding values were 40, 43, and 9 percent.

Jan 1, 1979

By N. A. Tolch

[In this partner ?propulsive strength? or "strength" is defined as the relative propulsive effect of an explosive as determined by means of the United States Bureau of Mines ballistic pendulum. The data presented are derived from one particular strength testing device and do not necessarily represent the relative execution value of the different explosives in actual blasting. However, it is believed that the data obtained with the ballistic pendulum fire indicative of the relative propulsive or heaving force and are of value until propulsive strength can be expressed in more fundamental units.]

Jan 1, 1929

By Charles A. Steen

Publication of this information circular results from an invitation extended to the Bureau of Mines by the Utex Exploration Co. to visit the company mine, on the Mi Vida claim about 39 miles southeast of Moab, in the Big Indian mining district, San Juan County, Utah. The Bureau is pleased to present this record of the Utex mine -- a property that in the relatively short period of 4 months has become one of the major uranium-ore producers on the Colorado Plateau. The ore deposit was discovered in July 1952 by Charles A. Steen, a geologist-prospector, now chief geologist of the Utex Exploration Co., in tae course of drilling the first diamond-core borehole in the Big Indian district. High-grade ore, 14 feet thick, was penetrated by the borehole. Sinking of a shaft, from which to develop the ore body, was begun in October, and the first shipment of ore left the property December 6, 1952. Ore production, as recorded on ore-settlement sheets received by the company up to July 15, 1953, totaled 16,000 tons averaging, 0.51 percent U305 and 1.25 percent V205. Discovery of the ore body and the large production of ore were achieved without any financial assistance from the Government.

Jan 1, 1953

By Alfred L. Ransome

GOLD output in Alaska in 1950, following a 2-year decline, increased to the highest point since 1942. Tills unexpected gain in production of the Territory's greatest value commodity was largely responsible for the increase in the over-all value of mineral output in the Territory to $17,852,000 from $15,549,000 in 1949. Although coal continued to rank second to gold in value of output, production was slightly less than the record production of 1949. The mining of platinum continued to be an important factor in the mineral industry, with production of crude platinum metals exceeding that of 1949. The output of lead was three times the 1949 production, and silver gained 46 percent over the previous year's total. Copper and zinc production-entirely as byproducts from other ores-showed an increase, but remained minor. Production of tin was relatively small, but substantially above the total for 1949.

Jan 1, 1953

By Clarence Hall, J. J. Rutledge

Many of the fatal accidents in coal mines have resulted from the Explosives used in Use of explosives for breaking down the coal. These accidents have resulted both from the use of explo- sives that were not suitable and from the careless or improper use of suitable explosives. Investigation has shown that one of the commonest causes of dis- astrous explosions in the coal mines in this country has been a blown- out shot of black blasting powder or dynamite. The dangers that attend the use of these explosives were perceived several years ago, and in consequence the attention of powder manufacturers was directed to the production of explosives that would be less liable to ignite inflammable gas or dust. The manufacturers have been so successful in their efforts that it is now possible to obtain explosives which yield much shorter and quicker flames than black blasting powder or dynamite, and hence are much less dangerous to use in fiery or dusty coal mines. of explosives. To find out which of the many grades of short-flame explosives Government tests have the qualities that render an explosive most effective and least dangerous for mining coal, the United States Government established a testing station at Pitts- burgh, Pa., in 1908. This station is now under the charge of the Federal Bureau of Mines. Before the station was opened a state- ment of the requirements that the explosives in question would have to satisfy was drawn up and sent to manufacturers. A number of these sent explosives to be tested, and on May 15, 1909, a list of the explosives that had passed the tests was published. Since that date other brands of explosives have been tested and three more lists have been issued. The latest list, published in Miners' Cir- cular 2, Bureau of Mines, contained the names of no less than 71 explosives that had passed the tests prior to January 1, 1911.

Jan 1, 1912

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

APPENDIX D DEVELOPMENT AND EXPERIMENTAL VERIFICATION OF ACOUSTIC SEAL CHECKER THEORY 1. Introduction In Section 7 of the report the acoustic seal checker concept was described in a general manner and the parameters which affect the signal level at the microphone were discussed briefly. In this appendix the theoretical basis will be presented and the experimental program described which permitted the extension of the theory into practice. The basic goal of the acoustic seal checker is to relate the reduction in sound pressure level to the size of the residual hole in the fly ash barrier. The smallest hole size that may be measured is determined by the signal to noise ratio, where the noise in this case includes the ambient noise in the mine, the internal microphone noise and the sound transmitted from the acoustic source via the flanking paths through corridors adjacent to the one being sealed. The latter source of noise can be discriminated against, at the expense of increased complexity of the acoustic system, by employing a pulsed source and pulse gating of the microphone signal set to accept sound via the barrier path and to reject the delayed flanking path signals. In order that the acoustic system be insensitive to precise source and microphone location and to permit assessment of system performance on an acoustic power flow basis, a broad frequency band of pseudo-random noise is emitted by the loudspeaker source. The preferred frequency range must be determined, the advantage of a directive source must be assessed, and the necessity

Jan 1, 1973

By Alexander May

This report describes a new method of weighing based upon observing the apparent weight of an object ill two separate pure gases. The method is presented in terms of experimental data which prove its soundness, but does not attempt to show the maximum accuracy possible with this technique. The new method incorporates the underlying principle that the apparent weight of an object is a linear function of the density of the atmosphere in which the object is weighed. The coefficients of this linear function are the true mass and volume of the object. From this functional relationship the true mass and volume of the object may be determined.

Jan 1, 1970

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Nicaragua has been prepared from the best available information in Washington , but is released subject to correction and amplification , if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Jul 1, 1930

By Irving Hartmann

[The explosability of coal dusts has been the subject of many investigations studies have been conducted in laboratories, in galleries and in coal faire; of several countries to obtain information on the causes, development, and prevention of mine explosions. Early laboratory experiments on it American colas dealt with pressures developed in test bomb by explosions of dust clouds and with, the effects of gas in the dust atmosphere.5/ Later, the emphasis shafted to evaluation of the relative fleet flammability and the ignition temperatures of coal dusts.6/ Much worthwhile effort was devoted to the development of Laboratory apparatus and test procedures that gave good correlation with large-scale explosion tests in the Experimental cost mine. In recent years a number of special problems were studied, mostly with bituminous Pittsburgh coal dust]

Jan 1, 1954

By D. R. Mathews

Electrorefined vanadium was evaluated with respect to tensile properties and the effects of interstitial contaminants in the temperature range of 77° to 273° K. The yield strength of 18,500 psi and hardness of 63 diamond pyra-mid hardness (DPH) of electrorefined vanadium are approximately equal to that of iodide crystal bar vanadium. The ductile-brittle transition temperature was found to be below 77° K, but with 0.175 weight-percent oxygen or 0.10 weight-percent nitrogen, it increased to between 123° and 190° K. With carbon content up to 0.11 weight-percent, the transition temperature remained below 77° K. The yield strength of the interstitial-containing alloys can be expressed by: au = 7.5 + 480 (pct N) + 290 (pct 0) + 280 (pct C), where au is the upper yield stress in 1,000 psi at 273° K. Profuse deformation twinning occurred in the alloys tested at 77° K. However, twinning could be suppressed by dissolved oxygen or nitrogen in excess of 0.15 and 0.086 weight-percent, respectively. Carbon, even though present in excess of the solubility limit, did not affect twinning.

Jan 1, 1965

By John C. Feeley

This paper is the result of a field study of prospect drilling in the Florida phosphate fields. The objective is to describe the drilling methods employed . . Since the general policies of the operating companies in the land - pebble area do not permit the dissemination of prospecting information and costs thereof , the writer has carefully avoided mentioning names and locations except by reference to existing publications ,

May 1, 1949

By E. J. Lintner

This paper is one of a series being prepared by the Bureau of Mines describing; gypsum mining and crushing methods and costs at various operations throughout the, United States. These papers are designed to dissemminate technical information regarding methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs may in many instances cause embarrassment to the individual operator 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 tabulation shall ensue. The following report deals specifically with the mining and primary crushing methods employed at the plant of the Ebsary Gypsum Co., Inc., Wheatland, Monroe County, N. Y. This company is capable of maintaining a maximum yearly production of 220,000 tons of crushed gypsum, thereby ranking as one of the largest gypsum operators of the State. The methods and practices employed typify the standard methods followed by gypsum producers in western Now York State, The bed of gypsum mined lies only 35 feet beneath the surface and is above average thickness for this vicinity.

Jan 1, 1937

By Martin J. Gavin

[The theory of fractional "eduction" of oil from oil shale has been used by several inventors as the basis for the design of retorts for the production of oil f roan the oil shales of the United States. The term fractional "eduction" gives expression to the rather common belief that when an oil shale is he-test et produces light, low-boiling oils at to temperatures, and increasingly heavier, higher-boiling oils as the temperature of retorting rites. The theory evidently had its is origin in the fact that crude petroleum may be fractionally distilled, yielding light oils at low distillation temperatures, and heavier oils as the distillation temperature increases. Thus, gasoline is produced from petroleum at relatively log: temperatures, kerosene at a higher temperature, and heavier products such as gas-oil and lubricating distillates at still higher temepratures, The writers have examined several oil-shale retorts designed to take advantage of the belief that crude, and en some cases refined, gasoline can be recovered from the shale at low temperatures; kerosene at higher temperatures, and so on. Such retorts are usually designed to operate continuously, and. have several vapor-pipes lending from them at differing intervals and passing to separate condensers. Designers of such retorts expect that the distillate from the low-temperature parts of the retort will be gasoline, and that as the shale basses to zones of increasingly higher temperatures, the vapor lines leading from these zones will remove increasingly heavier products such as kerosene, gas-oil, etc.]

Jan 1, 1924

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Haiti has been prepared from the best available information in Washington, but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Sep 1, 1930

By C. F. Ellis

Interest in the composition of automobile exhaust gases has been greatly accelerated by recent studies that have indicated that these gases contribute to smog formation in urban areas. Several analytical methods have been published for the analysis of the hydrocarbons in the exhaust gases, but similar information has not been published on the analysis of the oxygenated compounds. This report presents procedures for chemical analyses of certain oxygenated compounds, procedures for sampling the exhaust gases for these analyses, and the analytical results of some experimental work in which these procedures were used. A stationary 1956 model, 170 horsepower, V-8, dynamometer-mounted engine, operated to simulate vehicular cruise conditions, was used for the study. Exhaust gases produced from a regular-grade Midcontinent gasoline during 15-40- , and 60-mile-per-hour cruise operations were analyzed by chemical methods for formaldehyde, total aldehydes, total carbonyls, total alcohols, carbon associated with the oxygenated compounds, and the oxides of nitrogen. Experimental results indicate: 1. The range of concentrations of the total of the functional groups of oxygenated compounds, expressed as moles per million moles of water-free exhaust gases, is about 90-100; the concentrations increase with engine speed. 2. Aldehydes comprise about 80-90 mole- percent of the total of the oxygenated groups, and formaldehyde accounts for about 50 mole-percent of the total aldehydes. 3. The order of magnitude of the concentration of the carbonyls is the same as that for the aldehydes, indicating that ketones are not a major group. A colorimetric test indicates that methyl ketones Constitute about 2 mole-percent of the oxygenated compounds.

Jan 1, 1961