Search Documents

By J. W. Thompson, M. N. RICH

That there is wide interest in the preparation and properties of metallic zirconium and its salts is indicated by the many articles recently published in scientific and technical journals and the many patents issued. The compounds of zirconium have numerous important uses and more uses will doubtless be found. In the course of the special work on rare metals that were of military importance during the war, the authors of this bulletin were detailed to the Golden mining experiment station of the Bureau of Mines to prepare metallic zirconium and to investigate its properties. A number of investigations in recent years have indicated that sintered or coherent zirconium metal is very resistive to acids; that it can be used for electrodes, and it probably will find metallurgical uses. A steel containing zirconium has been proposed for use in armor plate and automobile parts, and nickel-zirconium alloys have been suggested for high-speed cutting tools and for cutlery. Numerous articles in scientific journals have recommended the use of zirconium oxide as a refractory, an abrasive, a pigment in paints, and as an opaquing agent in enamel ware. The salts have been used in the textile industry' as a mordant and also for weighting silk. When the authors began their investigation, they found it necessary to collect all of the available literature on the general subject of zirconium and its compounds. Pure salts could not be obtained on the market, and in order to get these, as a preliminary step to the preparation of the metal, the literature had to be classified and the methods of preparing the salts investigated. Also, there was much difficulty at first in making satisfactory analyses, and this phase of the work received careful attention. As it was necessary to begin with a historical review of the literature, such a review is given as Part I of this report, and a bibliography is included as Part IV. References to the numbered items in this bibliography are made throughout the text, the usual footnote references being omitted. Analyses of the products and conclusions as to their purity are given under the descriptions of methods of preparation. A table showing the properties of the amorphous metal, and another showing the properties of the coherent metal, will be found under appropriate headings in Part II. No attempt has been made in the historical review to discuss fully all the published information about zirconium and its compounds, but only such material has been assembled as has a direct bearing upon the present work. Considerable difficulty was experienced in collecting this material because of the confusion of terms by various authors who perhaps did not thoroughly understand the chemistry of zirconium.

Jan 1, 1921

By Joseph H. Bilbrey

COBALT is a silvery gray metal which closely resembles nickel in appearance and properties although it is somewhat harder and more brittle. It is rather widely disseminated and is estimated to make up about 0.001 percent of the earth's crust as compared to 0.020 percent for nickel. Cobalt, one of the four ferromagnetic elements, is used for many magnetic applications. It is oxidation resistant, a property which when coupled with its moderately high melting point of 1,495° C., makes it useful in high-temperature applications. Although cobalt had been used by man as a coloring agent for glass and other ceramic products for 4,000 years, it was not isolated as a metal until 1742 and not established as an element until some 40 years later. Early in the 20th century, cobalt began to be used in alloys, and soon these applications displaced ceramics as the major consumer of cobalt. The use of cobalt in alloys gave considerable stimulus to production, and the world output of cobalt increased rapidly, rising from 400 tons in 1920 to 1,400 tons in 1930 and 5,500 tons in 1940. With the advent of the jet plane in the mid 1940's and the consequent increased need for cobalt-bearing high-temperature alloys, cobalt production again increased, reaching 7,900 tons in 1950. The increased demand for cobalt during the Korean war coupled with a large demand for stockpiling caused world production to more than double within the next 10 years, reaching a peak of 17,300 tons in 1959.

Jan 1, 1962

By Ren G. Dong, John Z. Wu, Daniel E. Welcome, Kristine Krajnak

Although the exact mechanisms underlying vibration white finger (VWF) are not clear, it has been speculated that VWF is associated with variations of the blood flow patterns due to the physical damage and/or degeneration in neural and vascular tissue caused by vibration loading [1]. Excessive dynamic deformation of the soft tissues in the fingertip under vibration loading is believed to induce multiple occupation-related hand/finger disorders. However, the in vivo distributions of the dynamic stress/strain of the tissues in the fingertip under vibration conditions have not been studied because they cannot be measured experimentally to date. The goal of this study is to analyze, theoretically, the location and frequency-dependent dynamic deformation of the soft tissue in the fingertip during vibration exposures. [ ] Methods The fingertip considered in the model is the distal phalanx, the portion from the distal end of the fingertip to the distal interphalangeal (DIP) joint articulation (Fig. 1). The external shape of the fingertip was determined using a smooth mathematical surface fitting to the observed fingertip shapes. The fingertip surface was then scaled to the dimensions of a typical male index finger: length 25 mm, width 20 mm, and height 18 mm. The fingertip was approximated to be symmetric, such that only a half of the fingertip was considered in the FE modeling. The fingertip was assumed to be composed of outer and inner skin layers, subcutaneous tissue, bone, and nail. The soft tissues (inner skin layer and subcutaneous tissues) were assumed to be nonlinearly elastic and viscoelastic, while the bone, nail, and outer skin layer were considered as linearly elastic. The simulations were conducted using a displacement-controlled protocol in two stages. First, the fingertip was statically pre-compressed. The contact plate was first displaced towards the finger to achieve a predetermined value of tissue deformation (i.e., 0.5, 1.0, 1.5, and 2.0 mm). Second, the steady-state dynamics responses of the fingertip were analyzed using a linear perturbation procedure. The fingertip was subjected to a continuous harmonic excitation (magnitude 0.5 mm) from the contact interface. The dynamic analysis was performed in a frequency domain ranging from 16 to 2000 Hz. The frequency-dependent distributions of the vibration magnitude and dynamic strain magnitudes in the soft tissues are investigated. Results Typical simulation results for the frequency-dependent distributions of the vibration magnitude in the soft tissues are shown in Fig. 2 (figures show the results with a pre-compression of 2.0 mm). The vibration magnitude at the contact surface is 0.5 mm (specified) for all frequencies, while the vibration magnitudes in the soft tissues are location- and frequency-dependent. It is clear that the fingertip has a major resonance around 125 Hz, at which the vibration magnitudes in the soft tissues are over four times greater than that of the contact plate (0.5 mm). It is interesting to observe that, at this resonant frequency (125 Hz), the soft tissues at the tip has the maximal vibration magnitude while the regions near the contact

Jan 6, 2006

By Michael J. Sapko, Gregory M. Green, Kenneth L. Cashdollar

The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted a joint survey to determine the range of coal particle sizes found in dust samples collected from intake airways of US coal mines. The last comprehensive survey of this type was performed in the 1920s. The size of the coal dust is relevant to the amount of rock dust required to inert the coal dust, with more rock dust needed to inert finer sizes of coal dust. Dust samples were collected by MSHA inspectors from several mines in each of MSHA's 10 bituminous Coal Mine Safety and Health Districts. Samples were normally collected in several intakes at each mine. The laboratory analysis procedures included acid leaching of the sample to remove the limestone rock dust, sonic sieving to determine the dust size, and low-temperature ashing of the sieved fractions to correct for any remaining incombustible matter. The results indicate that particle sizes of mine coal dust in intake airways are finer than those measured in the 1920s. This finer size coal dust in intake airways would require more incombustible matter to be effectively inerted than the 65% incombustible specified in current regulations.

By Rudolf E. Greuer

The existing computer programs for the simulation of ventilation systems under normal ventilation conditions are reviewed and a suitable program for including the influence of mine fires is selected. New program parts are written for the consideration of methane productions in coal mines, heat and gas productions of mine fires, temperature and air composition changes in ventilation systems, and the ventilation forces resulting from the latter. Other program parts are provided for the detection of danger zones and reversed air currents and for the inclusion of recirculated air currents in the network analysis. Existing program and new program parts are combined. The resulting new program can be used for a multitude of assignments. It is designed for the practical ventilation engineer and should be applicable to all types of ventilation emergency plans, in particular mine fire plans. The organization of the program and its mathematical basis are described. A FORTRAN IV listing and several flow diagrams are included. Eight executed examples are discussed, input and output for these examples explained. Storage requirements and execution times are estimated.

Jan 1, 2011

By John W. Chandler

The property of the lava Cap Gold: Mining Corporation is in the Nevada City-Grass Valley mining district about 5 miles east of Crass Valley, Calif. At present (July 1940) the plant is mining end milling about 390 tons of gold-silver ore a day; about 310 men are employed. This paper describes the mining methods used and presents mining costs for 1939, when 60,704 tons were mined by cut-and-fill stoping and 55,676 tons by square-setting.

Jan 1, 1941

By Stanton L. Tainter

As a part of a wartime program to aid in the development of known ore bodies and in the discovery of hitherto unknown deposits of strategic minerals, the Bureau of Mines investigated the feasibility of diamond-drilling the Christmas copper deposit, in Gila County, Ariz., to increase the reserves of milling ore. Upon recommendation of the examining engineer, drilling was begun in September 1942, from the bottom (770) level of the mine. One month later, in cooperation with the Bureau, the Federal Geological Survey started geologic mapping of the mine workings. Since extensive and costly development would be required, the War Production Board concluded that ore below the bottom level could not be mined at that time because of the wartime shortages of equipment and man-power. In January 1943, drilling was moved to the 300 and 400 levels to locate reserves readily accessible for continued production of fluxing ore. This drilling, which was under the supervision of L. G. Marshall, was completed in January 1944.

Jan 1, 1948

By R. Lincoln

A surplus of vanadium has resulted from the tremendous output of uranium, of which vanadium is a byproduct. More knowledge of the properties and characteristics of vanadium as a pure metal has been needed so that industry can take advantage of its availability and use it according to the best principles of conservation. Besides the problem of utilization, there is the ever present need of finding new materials which will satisfy specific and demanding requirements of science and engineering; vanadium or one of its alloys may possess the latent potential for filling some of these needs. Thus this? research project was undertaken by the Bureau of Mines to determine and examine some of the physical and mechanical properties of pure vanadium. A corallary investigation was the determination of the effect of the interstitial contaminants, oxygen, nitrogen, and carbon, on unalloyed vanadium. The vanadium used for these determinations was principally the product of experimental production of the Bureau. The evaluation of this material, as small quantities became available, provided most of the data that have been obtained.

Jan 1, 1962

By H. H. Schrenk, W. P. Yant, F. A. Patty

"INTRODUCTION In accordance with the outline of investigation described in a previous report 5 of the Bureau of Mines dealing with the use of acrolein for detecting leakage of methyl chloride from unit--type refrigerating systems, the work has been extended to include an investigation of its use in a multiple system, This report gives the results of analysis of samples of the gas from representative units of a multiple system charged with methyl chloride containing approximately 0.9 per cent acrolein by volume, The results furnish a basis for estimating the Warning that would be given in event of leakage. The properties and warning intensity of acrolein have been described in a previous report. 5 ACKNOWLEDGMENTSThis investigation was made at the combined request-of Several Inc., Manufacturers of refrigerating, appliances, and the Roeasler Hasslacher Chemical Co., manufacturers of methyl chloride. Acknowledgment is given to R. M. Major, ,chief chemist of the former firm for arranging the experimental site and equipment; to Arthur O. Haseeneall, owner of the apartment building where the investigation was conducted, for his courtesy in permitting the investigation; and to R. R. Sayers, chief surgeon, Bureau of Mines, and surgeon., U. S. Public Health Service, for suggestions and advice."

Sep 1, 1930

By A. B. Hooker, L. C. IlsLey

"Observation of the use of trailing cables in ""mines shows that the chief limiting factor in the life of the cables and their safe use is the smashing or crushing of the cables in service, together with the effects of consequent splicing.Trailing cables are crushed when run over by cars, mining machines; and locomotives or when hit by falls of roof. Crushing damages the insulation and may cause failure at once or in later use. Failure may be either by short circuit between the conductors or by grounding to the track. The failure of a live cable causes electric arcs capable of igniting explosive mixtures of methane and air. Every cable failure in a gassy or dusty mine is, therefore, a real or potential hazard.Some mine operators do not allow the splicing of trailing cables for use in gassy mines, bet require that a damaged cable be immediately replaced and if repaired that it be used only in nongassy mines. Other operators allow the making of temporary splices to permit completion of the shift but require that such splices be remade and vulcanized before the cable is used again.Still other operators allow the continued use of temporary splices, which in general means that a cable is used until the splices give trouble in reeling, or overheat, or pull apart. Then the spliced sections are either cut out or the whole cable is replaced.Splices often determine the useful life of a cable. A splice poorly made may pull apart ueder mechanical strain and cause arcing that burn* the surrounding cable or ignites as or coal-dust. If it has lower conductivity a splice is the first part of the cable to heat; it may become so hot under load that it will burn apart and damage other parts of the cable, or, if it be a soldered splice, the solder may melt and allow parting of the cable. A poorly made splice often has insufficient insulation which may alloy short-circuiting between conductors or permit external contacts capable of giving an electric shock to one handling the cable. The splice is sometimes bulky from too much insulation and takes up too much room on the reel, causing uneven reeling; also by catching on the spooling device the oversized splice may receive expressive pulls and wear. Splicing is therefore a very important factor in the use of trailing cables."

Mar 1, 1932

By A. J. Kauffman

This inventory of the industrial mineral resources of the Pacific Northwest indicates that each of the States comprising this great region annually produces nonmetallic materials valued at mans million dollars. Commodities or their products that have a large, localized market predominate. These include Portland cement, sand and gravel, stone, clay, and lime. The region's output of magnesite, vermiculite, pumice, and diatomaceous earth is outstanding. The magnesite deposits of Stevens County, Wash., are the largest and most important in this country. Mast of the domestic vermiculite production is obtained from deposits in Lincoln County, Mont. Oregon and Idaho rank third and fourth, respectively, as domestic pumice producers. Production data for diatomaceous earth show Oregon second and Washington fourth among the producing States.

Jan 1, 1952

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 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. 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.

Jan 1, 1931

By Andrew St. Amant

This report reviews the first three "investigative and concept generation" phases of the referenced contract, and details task performance of Phase IV. This last phase integrated the most promising concepts from Phases I, II, and III into a prototype detailed design which was manufactured, and then tested on a mine locomotive. The concepts developed during the first three phases provided "Improved Pole Tracking," automatic "Rapid Pole Retraction" in the event of dewirement, and servo-operated "Remote Pole Repositioning" on the trolley wire. The Appendix of this report supplies detailed information for the design and construction of the prototype system which is comprised of an RCB (Remotely Controlled Base subassembly), an RCL (Remote Control Lever subassembly) and an SAU (Servo Amplifier Unit) subassembly.

Jan 1, 1980

By H. F. Yancey

A relatively large proportion of the coal produced in the state or Washington, especially in the coking coal areas is of fine size; hence washing by means of coal-washing tables to reduce the ash content is commonly practiced. For this reason the program of research in coal washing conducted jointly by the U. S. Bureau of mines and the College of Mines, University of Washington, has given special attention to the mechanism of the separation of coal from its impurities as affected by the coal-washing table with the object of

Jan 1, 1931

By H. F. Yancey

A relatively large proportion of the coal produced 1n the State of Washington, especially in the coking coal areas is of fine size; hence washing by means or coal-washing tables to reduce the ash content is commonly practiced. For this reason the program of research in coal washing conducted jointly by the U. S. Bureau of Mines and the College of Mines, University of Washington, has given special attention to the mechanism or the separation of coal from its impurities as effected by the coal-washing table with the object of increasing its efficiency. Previous work has evaluated the role of stratification the influence of size, specific gravity and respective shapes of particles in the feed, and the affect of hindered-settling classification of the feed prior to tabling.

Jan 1, 1931

By Steven R. Ruggieri

This report documents the work performed and the results obtained during the field demonstration of the Remote Sealing System at the USBM's Jenny Mine near Inez, KY in the Fall of 1978. Although various portions of the Remote Sealing System had been used on a number of prior occasions, the field demonstration at Jenny Mine marked the first use of the complete upgraded system including the use of the inert gas generating system for seal placement and the first application of the new froth foam system. The objective of the field demonstration at Jenny Mine was to demonstrate the complete system by emplacing and evaluating several complete underground seals under conditions representing those of a mine fire situation. Several critical sealing conditions were identified including: ? High entry airflow ? Standing water (1 to 2 ft) in the entry ? Flowing water (150 gal/min) ? Irregular roof ? Sealing a 4-way intersection. Four seals were successfully placed under the conditions mentioned above. The demonstration served to verify proposed techniques to handle these conditions as well as to dispel any doubts about the system's capabilities. As a result of the successful field demonstration, the Remote Sealing Equipment is now under the jurisdiction of MSHA's Mine Emergency Operation ready for a mine fire emergency.

Jan 1, 1980

By O. C. Blade

The use of Diesel fuel as a source of power is continuing to increase in the United States. The latest available figures indicate that refineries are delivering in excess of 10,000,000 barrels of this type of fuel per month. Factors contributing to this increased consumption are conversions by a number of railroads from steam to Diesel locomotives and the growing use of Diesel engines in buses, trucks, tractors, earth-moving machinery, water craft, and stationary power plants. The increasing importance of Diesel fuel has led to a need for more information on its characteristics, particularly on the grades and qualities currently being marketed. To supply this information the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, under a cooperative agreement, are conducting annual surveys of Diesel fuels produced in refineries in this country. Samples of Diesel fuel were analyzed by the manufacturers in accordance with instructions from the Motor-Fuels Survey Panel of the Automotive Research Committee of the American Petroleum Institute. Results of the analyses were transmitted to the Bureau of Mines where the data were studied am compiled as shown in the tables of this report. The first survey was made in 1950 and was published as a Bureau of Mines report. The present report shows the results of a similar survey made during 1951.

Jan 1, 1951

By R. G. Warncke

In the 1953 National First-Aid and Mine Rescue Contest, 58 teams from 9 States participated, 14 teams from 6 States in mine rescue and 47 teams from 9 States in first aid. Three of the teams were combination teams in that the same team participated in both the mine rescue and first-aid contests. The States represented and the number of teams from each State are shown in table 1. [ ] The contest was conducted in accordance with the general rules prepared by the Rules Committee and approved by the General Committee of the National First-Aid and Mine Rescue Committee.

Jan 1, 1955

By E. G. Noble

The effects of HBr concentration and temperature on the solubility and hydration state of AlBr3,' CoBr2, PbBr2, MnBr2, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the AI, Pb, K, and Na bromides were sparged with HBr gas at 20°, 40°, and 60° C, and saturated solutions of Co and Mn bromides were sparged at 20° C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr2. Aqueous solubilities at 20° C were, in percent, 51.7 for AlBr3, 53.2 for CoBr2, 1.1 for PbBr2, 59.6 for MnBr2' 39.5 for KBr, and 47.4 for NaBr. At 60° C, the solubilities were, in percent, 53.3 for AlBr3, 2.2 for PbBr2' 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20° C were, in percent, 0.5 for AlBr3, 42.0 for CoBr2, 32.2 for PbBr2, 21.0 for MnBr2, 0.6 for KBr, and 0.3 for NaBr. At 60° C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr3, 41.4 for PbBr2, 1.3 for KBr, and 0.4 for NaBr. CoBr2 precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr2 solubility because of the formation of bromide complexes. PbBr2 in-creased in solubility as HBr concentration increased.

Jan 1, 1988