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By Wilbert J. Huff

For the past 9 years , the technical studies conducted by the Explosives Division of this Bureau have been summarized in a series of reports issued annually . The following account presents investigations undertaken from July 1 , 1943 , to June 30 , 1944. The work is detailed under a number of main headings corresponding to the organizational structure of the Division , the various activities being under the immediate direction of unit chiefs , who report directly to the author . Specific credit , however , is due to the individual unit leader and his assistants .

Jan 1, 1945

By E. C. Lane

This report presents the results of the Bureau of Mines' twenty-first semiannual survey of motor gasoline marketed in the United States. The 12 cities in which samples were collected have teen chosen as representative of the more important marketing territories, as it is obviously impractical to obtain a sample of every gasoline sold in the entire country. The survey reveals that the motor gasoline which is being marketed in the United States this winter is decidedly more volatile than that sold a year ago. Samples from all cities show a decided improvement in volatility except those from Laramie, Wyo., which show a small decrease in volatility.

Jan 1, 1930

By D. F. Hambley

This manual contains a step-by-step procedure for the design of ore passes for open pit mines. The manual is comprehensive and deals with all aspects including location, design, construction and operating considerations. In the construction section, all applicable raising and shaft sinking methods are considered and cost estimates and advance rates provided for each. The design process is divided into several sections - rock flow requirements, support design, dump point design and draw point design. Use of this manual provides open pit planning engineers with a means of designing and assessing the feasibility of ore passes for their operations.

Jan 1, 1983

By Howard C. Pettibone

Mine safety personnel reported occurrences of excessive "glove-fingering" and other problems with resin-grouted roof bolt installa tions. To study these problems, the Bureau of Mines designed a test plan to (1) obtain baseline information on several resin cartridges and (2) investigate the variables involved in the installation of a resin bolt. Three brands of resin representative of the industry in January 1983 were selected for cartridge evaluation. The installation variables selected for study were the method of installation, the hole depth, and the hole annulus. These variables were studied by installing a series of bolts in concrete blocks using different values for each variable. Results of the research show overspinning the resin may cause problems, but they can be avoided by using the spin times recommended by manufac-turers. Excessive glove-fingering is not a problem if the manufacturer-recommended installation procedures are followed.

Jan 1, 1987

By John H. Johnson

This report covers the third and final year of work conducted under U. S. Bureau of Mines Grant G0166027, "Monitoring of Mine Air Pollutants". The report discusses work performed in three areas. These are the White Pine Mine (WPM) Experimental Unit, diesel mine-vehicle tailpipe emissions monitoring, and mine ambient air concentration data analysis. The WPM experimental unit was used to study diesel exhaust stratification in an 80 foot long dead-end heading while loading ore with a Wagner ST-5D scoop train LHD. The MTU Mine Air Monitoring Laboratory (MAML) was used to gather temperature and CO2 concentration data at 10 locations. Three different ventilation conditions were compared. The data substantiate the presence of strong buoyant forces of the hot exhaust gases which result in temperature stratification in dead-end headings. The diesel mine-vehicle tailpipe emissions monitoring study involved laboratory measurements of diesel undiluted exhaust pollutant concentrations by the portable tailpipe emissions measurement apparatus (EMA) assembled for in-mine use. The results were compared with simultaneous measurements by standard laboratory exhaust monitoring instruments. These results indicate that accurate field source quality control measurements can be obtained for CO2, CO and NO but NO2 results were low for all engine conditions. The mine ambient air concentration data analysis study included analysis of diesel pollutant concentration data in the Orchard Valley Mine air and comparison of the results with data collected earlier in the White Pine and Brushy Creek mines. The analysis included preparation of lognormal frequency distributions and calculations of C02-based concentration ratios and correlations. In the three mines compared, pollutant concentrations are distributed quite similarly, and the concentrations appear to be controlled to present standards.

Jan 1, 1979

By A. Livingston

This paper on mining practice at the Fresnillo silver mines is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts of North America. Two classes of ore are produced at Fresnillo. A low-grade oxidized silver ore; end a complex-base sulphide are containing gold, silver, lead, zinc, and copper. This paper is confined to a discussion of operations relating to the production of oxidized silver ores. To date, more than 10 Million tons of this ore rave been mined. The present (June, 1931) daily production is 2,000 tons of ore, and approximately 600 men are employed in the mining operations.

Jan 1, 1932

By D. Bienstock, R. C. Kurtzrock, E. R. Bauer, J. H. Field

To remove hydrocarbons and carbon monoxide in automotive exhaust by oxidation , a catalyst of 4.2 percent Uз Og , 1.7 percent Cr₂ 0 , and 1.7 percent CuO supported on 1 /8 - inch y- alumina spheres was tested in a reactor in place of the muffler of a 1 / 2 - ton truck . Tests were made with both nonleaded and leaded gasolines . With the engine at operating temperature , tests were made with the engine idling and with the vehicle cruising at 30 mph . Auxiliary air was added to maintain an oxygen concentration of 3 to 4 percent in the gas leaving the catalytic reactor . The vehicle was operated for 83 hours (about 60 percent of the time with the engine idling ) and 525 miles with nonleaded gasoline . Conversions of 98 percent of the hydrocarbons and 100 percent of the carbon monoxide were achieved with the engine idling and with 7,000 ppm carbon atoms and 4- percent carbon monoxide in the feed to the reactor . Hydrocarbon conversions of 75 percent were obtained at cruising speeds of 30 mph with a feed of 1,700 ppm carbon atoms ; the carbon monoxide concentration was less than 0.3 percent in the feed and was unchanged in passage through the reactor . Identical activity was obtained initially in switching to a gasoline containing 1.9 ml tetraethyl lead (TEL) per gallon . However, there was a gradual loss in activity thereafter . Conversions in tests with the engine idling about 50 percent of the time , had decreased by 23 percent for the hydrocarbons and by 25 percent for the carbon monoxide from their initial values after 122 hours and 1,300 miles of operation with leaded gasoline . The levels of radioactive materials in the exhaust of the reactor and the radiation in the vehicle were negligible .

Jan 1, 1963

By Jack E. Fraley

Because of their noncombustibility, silicate and magnesium oxycements are desirable for sealing shale in underground coal mines. In this Bureau of Mines investigation, cement samples were cured and tested (nonstandard tests) for submersion to note resistance to dissolution (breaking into parts), which is an important property for a coating. Nonappreciable dissolution during 1 week of submersion was set for passing the test. Over half of the coatings passed the test.

Jan 1, 1977

By Wallace W. Roepke

Research to evaluate the lubricity effects achieved by spraying water on the cutting bit of a mining machine or spraying water on the coal during cutting has shown that neither practice affects cutting forces, as had been believed. However, when water was supplied to the cutting zone axially through the bit at 3,000 to 5,000 psi pressure, tangent'ial cutting forces were reduced an average of 30 pct at a I-in depth of cut while normal bit forces were reduced an average of 65 pct. Lower normal forces mean reduced bit wear, faster advance with greater depth of cut, and fewer coal fines.

Jan 1, 1985

By J. B. Gayle

During the past several decades, there has been a steady increase in the number and size of experimental ovens used for carbonization research. Although many were originally intended principally for studies of coal expansion, current practice usually includes determinations of the properties of the experimental cokes. With respect to size and shatter characteristics, the cokes from the larger experimental ovens closely approximate those from duplicate charges carbonized in commercial ovens; however, they are consistently lighter and frequently less resistant to degradation by abrasive forces. To minimize these differences, some operators dry the experimental charges before carbonization. The resulting higher dry coal charge densities do, in fact, yield cokes with gravities closely approximating those produced commercially from the same coal or blend but without drying. The drying of the experimental charges may be criticized on the grounds that it represents a departure from commercial practice and may result in oxidation of the samples; for these reasons, the practice has not been universally adopted.

Jan 1, 1961

By H. P. Greenwald

[For sarno years past the Safety in Minbr. Resaarch J30ard of Great Bri tr-dn ha:1 been making ar.. intensive Gearch for, traterials that \.'ould be 1!\ore ef-ficient than rock dust and th t 'could l1eplace it Jholly or in El:}rt as a muans of prevEll'ltine the propa 'tion' of 'c63.1~dust exnlosions in. mines21 In the course of this \o.'ork several rock c.ur--ts md numerous inorganic compounds I,/ere tested. The result w place incombus.ti ble substFlnces in two main groups~ (1) r.:ho se who sa effect' in suppre aeina Jlihe cor.lbustion of coal dUDt i 0 pro-]

Jan 1, 1940

By R. B. Ladoo

"Present Situation:At the beginning of 1920 a general feeling of optimism was noted in many talc-producing districts. The industry seems to have recovered from the temporary depression of the first half of 1919 and many mills are running at capacity production with their entire output for 1920 contracted for. The imports of talc for 1919 were only slightly larger than in 1918 by weight and probably no more by value. Thus foreign competition has not begun to be seriously felt. Several new companies in this country have been organized, some to operate new deposits and others to continue the work done by others.An interesting phase of the present situation is the possibility of increased use of talc in paint. There is a shortage of barium sulfate used as a paint filler. Since, for some uses, talc is considered second only to BaSo4 as a filler for paint, it is possible that part of the shortage could be relieved by an increased use of talc.A series of physical tests upon all pigment materials used in the manufacture of paints is being conducted for the Paint Manufacturers Association of the United States. It is important that all types of talc be represented in these tests. Producers of finely ground talc, 200 mesh and finer, are urged to submit samples of at least two pounds each of these grades that are available to paint makers with trade name and quality data, to the Institute of Industrial Research, 19th & B Streets, N. W., Washington, D. C., where the tests are being conducted."

Jan 1, 1920

The Bureau of Mines performed cratering experiments in a homogeneous granite to test scaling laws for charge weights of 0.00476, 0.0220, 0.0900, 0.304, and 1.03 lb. Agreement among the data was best when empirical scaling exponents greater than one-third were assumed. Although the analysis showed that the best empirical scaling exponents were 0.37 for crater volume, 0.38 for crater radius, and 0.39 scaling for crater depth, all three crater dimensions could be scaled with a 0.38 scaling exponent.

Jan 1, 1970

By J. K. Whyatt

Assuring ground control safety in many mining and tunneling projects depends, at least in part, on an understanding of in situ stress conditions that will be encountered. Yet it is rarely practical to conduct more than a very limited number of stress measurements. Stresses along the route of a proposed excavation are typically interpolated from available measurements, often assuming a linear variation of stress with depth (or elevation). However, projects where multiple stress measurements are conducted often report more complex variations of in situ stress, usually in apparent relationship to geologic structures. These structures often include lithologies of contrasting elastic properties. A method is proposed for estimating stresses in these cases by first back-calculating regional loads from available stress measurements and then modeling the distribution of stress throughout the rock mass. The method has been successfully applied to a set of in situ stress measurements from the Coeur d’Alene Mining District of northern Idaho, USA. Results provided new insights into district stress conditions and the distribution of rockburst hazards along mine drifts and between various mines. This success should transfer readily to suitable deep tunneling projects.

By R. L. Lincoln

The effects of adding from 1 to 50 atomic percent (a/o) to vanadium were investigated by the Bureau of Mines. Properties studied included as-cast and annealed hardness, microstructure, fabricability at room temperature and elevated temperature, tensile strength, electrical resistivity, and oxidation resistance at 625° and 800° 2. Additions of small amounts of hafnium resulted in lessened as-cast hardness, decreased electrical resistivity, impaired roll- ability, increased oxidation resistance, and greater tensile strength. Larger amount of hafnium caused greater as-cast hardness, increased electrical resistivity, further impaired rollability, continued increase in oxidation resistance, and lessened tensile strength. INTRODUCTION The purpose of this study was to determine the effect of hafnium additions on the properties of vanadium and to learn if this binary alloy had any special or unusual properties. This investigation is a part of a larger research project in which new and expanded uses of vanadium are being sought. Domes tic vanadium is found frequently in combination with uranium, and because of the demand for uranium as a nuclear fuel, there now exists a surplus of vanadium-bearing minerals and vanadium pentoxide as a byproduct of uranium production. Primary principles of conservation demand that greater use be made of this readily available surplus; finding suitable metals to alloy with vanadium to enhance its properties is one way to increase its utilization. This report is the result of an investigation of the effects on the properties of vanadium when hafnium is added in amounts from 1 to 50 a/o.

Jan 1, 1962

By Foster Fraas

Under a very high vacuum of 10-8 torr the transfer of terrestrial mineral beneficiation methods to the vacuum ambient of extraterrestrial locations such as the lunar surface was investigated. In the size range for the electro-static and magnetic separation of ores (minus 35 plus 150 mesh) there is no adhesion of particles produced by crushing and grinding due to the limited contact area, and for repeated contacts area size has a frequency of occurrence in accordance to the normal law. The photoelectric effect which is successful in separating a few minerals in an air ambient has a wider application in a vacuum, while the lack of air viscosity and sound transmission provides for high feed velocities and the adaptation of particle vibration to dispersion and grinding. Contact electrification is reversible upon return to atmosphere.

Jan 1, 1970

By N. E. Hanna

As part of a program for improving, the safety of permissible explosives, the Federal Bureau of Mines has undertaken an investigation to establish the ability of sodium chloride to reduce the incendivity of permissible explosives to firedamp atmospheres. A motivating influence for this investigation has been the comparatively extensive experience of British and other European investigators, who used sodium chloride as a component of their permitted explosives (1, 5, 6 7).5/ In the United States research and development work of this type has been less extensive, although sodium chloride has been added to permissible explosives as a cooling agent (9) for many years. The results of the first phase of this investigation were presented in a previous paper (8), which established that adding up to 10 percent sodium chloride to permissible explosives reduces the likelihood of ignition of firedamp in the gallery test; however, the results were somewhat inconsistent, and the conclusions were qualified. Accordingly, the investigation was continued with a study of the effect of added sodium chloride as a function of the quantity added and of the particle size of the salt.

Jan 1, 1960

By E. C. Lane

This paper is the second report of the results of the United States Bureau of Mines twenty-third semiannual survey of motor fuel marketed in the United States. The first paper, reporting data relating to gravity, vapor pressure, and distillation range of the samples, was published as Report of Investigations 31293. A third and concluding paper giving the results of other tests will be published as soon as these tests have been completed. The present paper deals with the data of the twenty-third semiannual survey presented in accordance with the revised specifications for United States Government motor gasoline. The sample numbers used are identical with those used in Report of Investigations 3129, with additional data included for copper strip corrosion (method 530.22).4 and sulphur content by the lamp method.5 Three hundred and twelve samples were collected and analyzed in this survey. Two hundred and seven samples were competitive-price gasolines and one hundred and five samples were premium-price motor fuels.6

Jan 1, 1931

By H. O. McDonald

The Bureau of Mines reviewed the chemical vapor deposition (CVD) literature of the group IVB, VB, and VIR elements. This review was utilized in the Bureau's research to provide erosion-, abrasion-, and corrosion-resistant coatings for valve components used in coal gasification units. This report attempts to bring together the many CVD references that have been published since 1966. Each of the group IVB, VB, and VLB metal coatings were reviewed, and some of their preparation methods, uses, and properties are given. A total of 160 references were found for the nine elements. Isotope separation, stronger steels, solar absorbers, alloys, superconductors, optical fibers, and coatings to increase the life of materials are some of the new uses for CVD.

Jan 1, 1979

By R. C. Hickman

"INTRODUCTION Marl, consisting of a bed of coarse shell conglomerate from 1 to 5 feet thick, occurs on the Chesapeake Corporation tract and Philbates properties in New Kent County, Va.Nine holes were drilled on these properties in February 1946. ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts prelimi¬nary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, Oliver C. Ralston, chief, analyzes samples and performs beneficiation tests.The project was under the immediate supervision of Mitchell H. Kline, chief, Raleigh Division, Mining Branch.LOCATIONThe Chesapeake Corp. deposit is reached from West Point, Va., by driving west on State Route 33 to the junction of State Route 634, approximately 5 miles. Proceed southeast along State Route 634 about three-quarters of a mile, at which point an old longing road turns north along a ridge and leads to the marl outcrops about one-half mile distant. The Philbates property lies three-quarters of a mile farther west along State Route 33 from the junction with State Route 634. The property lies north of State Route 33 and east of State Route 623 (fig. 1). The marl deposits are on the north end of the farm. The Chesapeake Corp. tract comprises 174 acres and the Philbato property 58 acres."

Aug 1, 1947