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By John Gross

Studies in grinding efficiencies carried out at the Midvale plant of the U. S. Smelting, Refining & Mining Co. and at the Tooele plant of the International Smelting Co. Were made possible by the cooperation of these two companies with the U. S. Bureau of Mines. Mr. Alan Probert of the U. S. Smelting, Refining & Mining Co. and Mr. E. C. Peterson of the International Smelting Co., devoted their entire time to the work during the respective tests, and their services are hereby gratefully acknowledged. It is a pleasure to acknowledge also the assistance and kindness of the staffs of both companies in making it possible, at considerable trouble and expense, to sample the entire mill circuits and in furnishing the necessary supplies and special apparatus required in the work.

Jan 1, 1929

By Raja V. Rarnani, Robert L. Frantz

"The more than 75 research projects funded throughout the first 10 years of the Dust Center's operation have resulted in numerous cumulative findings fulfilling the goals of the Center. These project descriptions present the methodologies and project-to-project relationships leading to their various accomplishments and demonstrate the mesh between project objectives and Center goals.To develop equipment for collecting respirable dust samples.To develop experimental methods for particle-by-particle characterization of morphology, size, and chemistry.To develop experimental methods for overall respirable dust sample characterization of size distribution, chemistry, and crystallography.The project directly addresses the Center's goals to enhance the understanding of the scientific and engineering characteristics of fine and respirable mineral particles found in mining and milling atmospheres and to establish the relationship between natural and cultural factors (mine geology, mineralogy, mining and milling methods, equipment, and control measures) in the generation of fine particles. The project also aims to contribute to the development of control mechanisms for reducing ambient respirable dust concentrations and worker exposures.The work on this project is related to similar work on Coal Mine Dust Characterization (Project No. 2701/MN1) and Characterization of Dust Particles (Project No. 4203/PS3).Airborne dust sampling was performed at the following locations: 1) a sand and gravel quarry in Southern New Hampshire, 2) a welding facility, 3) a ceramic powder facility, 4) a metal powder facility, and 5) the air in Cambridge, Massachusetts. A portable sampling box incorporating two Sierra personal cascade impactors was designed and produced. At a 2-LPM flow rate, the effective cut-off diameters of the Sierra impactors were 10.0, 6.0, 3.5, 2.0, 0.9, and 0.5 mm, respectively, for each stage, and the air passed through a PVC filter after the last stage. In addition, the sampling box contained a total respirable dust filter. The substrates were weighed carefully before and after collection, and the weight increases were recorded. All films, foils, and filters were put in the balance chamber for more than 8 hours to stabilize the temperature and humidity before weighing. A Cash 21 microbalance (±0.001 mg) was used to weigh the Mylar films, SS films, and filters."

Jan 1, 1995

By E. J. Matson

The Bureau of Mines has been investigating deposits of critical and essential minerals in the United States since 1939. The Rush Creek lead-zinc deposit, Mono County, Calif. (fig. 1), was examined by W. T. Benson in July 1944 and again in September 1945 by D. W. Butner, engineers of the Bureau of Mines. From the results of these preliminary examinations, a core-drilling program (fig. 2) was started in August 1946 and continued until November 1946, when work was stopped on account of inclement weather. Field work was again started in May 1947 and completed in June 1947. The drilling program was laid out to develop the horizontal .and vertical extensions of showings exposed in surface pits.

Jan 1, 1949

By Thomas C. Mowatt

Preliminary Bureau of Mines studies of mafic igneous rocks collected from the Rabbit Creek area, northwestern Alaska, indicated concentrations of platinum (412 to 1,406 ppb) and palladium (343 to 892 ppb) in five of eight samples analyzed. The samples represent boulders and cobbles of mafic/ultramafic rocks from this locality. They are not from outcrop. Petrologically, (on the hand specimen scale) the samples are crudely to well-layered and are troctolitic ± gabbroie in character, with primary igneous mafic minerals strongly altered. Small patches of interstitial sulfide minerals, including chalcopyrite, bornite, pyrrhotite, pyrite, and covellite are associated with these altered zones and elsewhere through the specimens. Copper values ranged from 0.1 to 0.3 pct in samples analyzed semiquantitatively; nickel, cobalt, and chromium contents are low. Chemical, mine alogic, and petrographic relationships suggest that the rocks of similar character outcropping in northwestern Alaska could also be considered as prospective for- concentrations or platinum, palladium, and copper.

Jan 1, 2011

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

"Flame safety lamps have been used for about one hundred years in coal mines where a dangerous accumulation of explosive mine gas (methane) might occur and thus render the use of ordinary unprotected flame lamps dangerous. Flame safety lamps are not only used for illumination, but also for detecting the presence of dangerous percentages of methane mixed in the air of the mine.The safety of the lamp depends chiefly upon the cooling qualities ofThe safety of the lamp depends chiefly upon the cooling qualities of the wire gauze used to permit free circulation of the air through the lamp. If one enters a part of the mine where methane is present in the air, the methane enters the lamp and coming in contact with the wick flame is ignited and continues to burn within the gauze without igniting the methane surrounding the lamp. If the air within the mine is traveling at a velocity of several hundred feet per minute the burning gases may be driven through the gauze by the air current. If the gauzes are properly designed and of the proper material, these burning gases will be so cooled as they pass through the gauze that they will not cause an ignition of the gas surrounding the lamp. In order to test the effectiveness of a given safety lamp, tests are made in moving explosive mixtures of gas and air arranged to simulate mine conditions.The Bureau of Mines investigated many features relative to the safety of flame lamps and in 1915 established an official schedule known as Schedule 7 whereby flame lamps having certain prescribed qualifications would be approved as permissible for use in gaseous mines."

May 1, 1920

By W. G. Messner

Pipelines for transporting crude oil and refined products in the United States totaled 189,982 miles on January 1, 1959. This mileage was less than a 1-percent increase from the 1956 total of 188,540 miles. During the three-year period (January 1956 - January 199), 14,886 miles of new pipe and 10,649 miles of secondhand pipe was laid. Pipe taken up in the same period was 24,093 miles. The facts regarding pipeline mileage were obtained by the Bureau of Mines from pipeline companies and information provided by the Interstate Commerce Commission. Crude-oil gathering lines, as of January 1959, were 40 percent of the United States pipeline mileage and totaled 75,182 miles, an increase of 1,656 miles during the three-year period. Crude-oil trunklines totaled 70,317 miles or 37 percent of the United States pipeline mileage, a decline of 8,277 miles from the 1956 total. Some of this loss is attributed to the converting of crude lines to refined products. Refined product lines in January 1959, totaled 44,483 or 23 percent of the United States mileage, an increase of 8,063 miles during the three-year period.

Jan 1, 1959

By Gerald T. Homce

A system capable of monitoring mine electrical power systems and detecting impending component .failure could significantly improve power system safety and reduce unscheduled equipment downtime. Such monitoring would require a method of evaluating electrical parameters, calculated from terminal values, for indications of component deterioration. The U.S. Bureau of Mines has targeted electrical failure of squirrel cage induction motors and examined the use of mathematical models to aid in this evaluation. The initial stage of this work is complete, and has produced polynomial networks called adaptive learning networks (ALN's) that can detect and quantify winding insulation leakage simulated on laboratory motors. In this modeling process, empirical data from laboratory motors were used to select the electrical parameters most significant for assessing? motor conditions, and mathematical expressions relating these parameters to simulated deterioration were formed. ALN's developed thus far can process readily measured motor terminal information and quantify power and current levels of laboratory-simulated leakage to within 1% and 3% of full load values, respectively, for motors in the 10-to 150-hp size range. The next stage of this research is validation of these ALN's for actual motor failures; this stage is currently underway, using accelerated life testing of laboratory motors.

Jan 1, 2010

By K. R. Van Doren

The polynomial method for estimating virial coefficients from experimental data suffers from three serious defects: (1) There is no known relationship between the polynomial coefficients and the virial coefficients, (2) the values of the estimates depend upon the degree of the polynomial and the particular set of values used for the independent variable, as well as the random errors in the dependent variable, and (3) the variances calculated for the estimates do not represent the mean square errors of estimation. Attempts to overcome these defects have thus far been unsuccessful; these attempts have also failed to account for the fact that none of the virial coefficients are uniquely determined by the values of the dependent variable for a finite set of values of the independent variable. The conclusion is that virial coefficients cannot be reliably estimated from experimental data unless additional information about the virial expansion itself, such as its rate of convergence, is available.

Jan 1, 1969

By Heinz W. Sternberg

A method for the electrochemical reduction of the benzene ring was developed and applied to the electrochemical reduction of coal. Successive electrochemical reductions of a vitrain from low-volatile bituminous coal in ethylenediamine saturated with lithium chloride resulted in the addition of 53 hydrogens per 100 carbon atoms. Ultimate analyses and pyridine solubility of the vitrain recovered after each reduction showed that hydrogen added at the beginning has a much greater effect on solubility than hydrogen added at a later stage. Surprisingly, the removal of sulfur from the vitrain takes place only after the more reactive aromatic rings are reduced. Nuclear magnetic resonance analysis and average molecular weight determination of the extracts of the reduced vitrain samples, representing about 18 percent of the vitrain, showed that these fractions had 95 percent of their hydrogen content on saturated carbon atoms and an average molecular weight of 800 to 900. A study of the effect of operating variables on current efficiency showed that current efficiency is highest with aluminum as cathode material and with lithium chloride as electrolyte. A substantial increase in current efficiency of difficulty reducible olefinic double bonds was achieved by adding a proton donor. This result is significant in connection with the electrochemical reduction of coal which proceeds from readily reducible aromatic double bonds to difficultly reducible isolated double bonds. It is proposed that reduction is achieved by electrolytically generated and subsequently solvated electrons and hence does not require prior adsorption of the substrate at the electrode surface. This offers a distinct advantage for electrolytic reduction of sparingly or insoluble substrates such as coal.

Jan 1, 1967

By Michael G. Zabetakis, Glenn H. Damon, Joseph A. Herickes

The flammability and explosibility of unsymmetrical dimethylhydrazine ( UDMH ) were investigated by the Federal Bureau of Mines to evaluate hazards associated with commercial application of this material as a missile fuel . This program included the following determinations : 1. Temperature limits of flammability in air at one atmosphere pressure ; 2. limits of flammability at selected elevated temperatures and pressures ; 3. 4 . 5. spontaneous ignition temperature in air at one atmosphere and at 200 pressure per square inch gage ( p.s.i.g. ) initial pressure ; spontaneous decomposition temperatures in nitrogen at one atmosphere and at 200 p.s.i.g .; shock sensitivity over a temperature range from about ( ca. ) 25 ° to 50 ° C .; 6. shock sensitivity of reference propellants ( hydrazine , nitromethane , methyl acetylene , etc. ) ; 7 . shock sensitivity of UDMH plus small amounts of selected metal catalysts . Part of the corresponding data was obtained for a mixture of unsymmetrical - dimethylhydrazine and diethylenetriamine ( U - DETA) .

Jul 1, 1960

By E. C. Lane

This paper is the first putt of a report giving the results of the Bureau of Mines' twenty-third semiannual survey of motor gasoline marketed in the United States. A companion report, Part II, is in preparation and will give a more detailed discussion of the whole survey. Results of the determination of copper-strip corrosion, color, sulphur content, copper-dish evaporation residue, and gum content as given by the Bureau of Mines steam-oven method will be presented in the second paper, which will also include the prevailing retail price and the tax at the time the sample was taken. This paper deals specifically with data relative to gravity, Reid vapor pressure,' and distillation (method 100.13).6 The samples tested were divided into "competitive-price gasolines" and "premium-price motor fuels," a method of presentation that was begun with the twenty-second semiannual survey. A total of 312 samples were collected from service station pumps in 20 cities throughout the United States. Of this number of samples, 207 were "com-petitive-price gasolines" and 106 were "premium-price motor fuels." All of the samples were collected in March, 1931, and analyzed at the Petroleum Experiment Station of the United States Bureau of Mines at Bartlesville, Okla. "Competitive-price gasoline" includes those fuels that are sold at the generally recognized local base price and all fuels that are sold below that price. All fuels that are sold at an advance over the generally recognized base price are placed in the class of "premium-price motor fuels." These fuels include Ethyl gasolines, benzol blends, "high-test" fuels, and those fuels that owe their "anti-knock" rating to the process of manufacture rather than to the addition of other material such as Ethyl fluid or benzol. The term "high-test" is generally applied to motor fuels that are more volatile than the regular competitive-price gasolines. "High-test" fuels may also have a high anti-knock rating.

Jan 1, 1931

By William J. Campbell

One of the principal objectives of the Bureau of Mines program for developing super refractory materials is to obtain fundamental data on the physical properties of refractory oxides. This particular investigation obtained accurate thermal expansion coefficients for alpha alumina and evaluated, critically, those coefficients with other published values. High-temperature X-ray diffractometer measurements, by the Bureau, showed that alpha alumina expands anisotropically with expansion parallel to the c axis approximately 10 percent greater than parallel to the a axis. Thermal expansion characteristics of four different alumina samples were determined up to 1,200° C.; the results are presented in both tabular and graphical form. The combined random and systematic errors in the measurements are considered less than 3 percent above 500° C, and approximately 2 percent at 1,000° C. No differences in expansion were observed between the samples or between the heating or cooling cycles.

Jan 1, 1961

By J. W. Thompson

"The recent discovery and exploitation of petroleum territory have resulted in the enactment of new petroleum laws in most of the South American Republics. The activities in the discovery of these new fields were engendered by the knowledge of the fact that present producing fields must within well defined periods be exhausted. Oil operators were willing to take the initial steps in exploitation in the absence of legislation that applied strictly to petroleum operations. The enactment of modern legislation in many of these Republics encouraging and protect¬ing exploitations may cause tremendous oil activities in these countries, and the results may be comparable with the magnitude of the undertakings and the prestige of the companies now entering this territory.These, oil fields are admirably located for convenient distribution of petroleum by water to all the Nations using oil as fuel for shipping and industrial concerns. The oil markets of the western coast of South America will derive immense benefits from the Panama Canal. This navigation route brings these markets into direct ocean shipment with the Atlantic coasts of the Western and Eastern Hemispheres.One deterrent to oil production in the Republics of South America is the want of inland. transportation facilities, but the recent laws of these Republics without exception provide for acquiring rights of way for pipe lines and other modes of transportation; and doubtless the great interests and. syndicates already operating in these regions will, as production increases, provide ample pipe line transportation sufficient to convey to the coast the oil produced. It way be assumed, from the legal guarantees afforded, and from operating equipment and machinery that are now being concentrated that refineries will be erected at shipping points for the purpose of making these petroleum products accessible to the world."

May 1, 1921

By T. W. Quayle

This paper describing mining practices at the United Verde copper mine, Jerome, Ariz., is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts f the United States. At present mining operations are being conducted both underground and by electric shovels in an open pit. The open-pit work has been described by E. M. J. Alenius in a previous publication of the Bureau of Minos;3 the present paper will be confined to a description of the underground mine. The underground methods comprise horizontal cut-and-fill, shrinkage with delayed filling, horizontal square-set, inclined square-set, and top slice. The normal daily production of the underground mine is 3,000 tons of copper ore per day, requiring the employment of 900 men underground.

Jan 1, 1931

By Oliver Bowles

"A Product from Mica Mines.Mica commonly occurs in pegmatites which consist of large crystals of feldspar and quartz, mica constituting but a small proportion of the total rockMuch of the feldspar thus thro n out during the process of mining is pure and of high quality, end the Bureau of Mines has suggested that much of it could be utilized for ceramic purposes. Encouragement is given to such utilization by the fact that several mines now worked for mica were formerly operated for the production of feldspar. ""'here mines are not readily accessible to railroads feldspar utilization might not be feasible, for it is a much lower priced product than mica and cannot therefore bear as heavy transportation expense. '""here mines ire located close to railroads, however, such utilization would tend to reduce the cost of mica mining, and at the same time assist in the solution of the waste disposal problem.The Bureau has recently been informed that some of the feldspar from mica mines near Spruce Pine, N.C., is now being sold and shipped away. An extension of this by-product industry is to be recommended.A Mica Deposit in New York City.The Bureau recently received a mica specimen obtained from a. building excavation at 157th St. and Riverside Drive, New York City. The specimen was about 2 by 4 inches in size, and fairly clear though containing numerous hair cracks. It was obtained only 7 or 8 feet below street level. At greater depth and with more careful methods of excavation material of much better quality might be obtained. The material submitted could be used for mica washers but not for sheet mica. It is stated by an official of a prominent mica company that many such fragments are obtainable in this locality and the possibility of the occurrence of a good mica vein is thereby suggested."

Jun 1, 1920

By M. J. Ferrante

Enthalpy and entropy increments above 298.15° K were determined for cop-per sulfate between 298° and 1,000° K and for copper oxysulfate between 2980 and 1,146° K by the method of copper-block drop calorimetry. Enthalpies, entropies, and heat capacities are tabulated for both compounds. In addition, free-energy functions are tabulated for the sulfate. Equations representing the enthalpies are given for each compound.

Jan 1, 1972

By E. V. Cilento, K. A. DiGregorio, R. C. Lantz

"DIGREGORIO, K. A., E. V. CILENTO, AND R. C. LANTZ. A kinetic model of superoxide production from single pulmonary alueolar macrophages. Am. J. Physiol. 256 (Cell Physiol. 25): C405-C412, 1989.-A kinetic model was developed to describe the production of superoxide (02) by single pulmonary alveolar macrophages (PAM). Model predictions were compared with experimental results obtained from single rat PAM. The 02 was quantified by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate (NBTH,) from video-recorded images of individual cells. The kinetic model considered three reactions: 1 ) the production of extracellular 02 from the reduction of oxygen by NADPH oxidase using intracellular NADPH as the substrate, 2) the subsequent dismutation of 02 to form H,O,, and 3) the reaction of 02 and NBT to form diformazan. NBT specificity for 02 was analyzed by comparing results in the presence and absence of superoxide dismutase (SOD) that catalyzes the dismutation of 02 to H,O,. Measured PAM heterogeneity was accounted for by varying the concentration of intracellular NADPH, its rate of depletion, and the concentration of intracellular NADPH oxidase in the kinetic model. Model predictions compared favorably with experimental results except when SOD was present. This discrepancy may be due to diffusional limitations because NBT is a relatively small molecule (818 mo! wt) compared with SOD (34,000 mol wt). In addition, the cell surface is both ruffled and negatively charged, which may introduce steric hindrances and/ or electrostatic effects, since SOD is also negatively charged, whereas NBT is positively charged.PULMONARY ALVEOLAR MACROPHAGES (PAM) protect the lungs by phagocytizing foreign debris and bacteria. This process is accompanied by the production of superoxide anion (02) at the surface of the plasma membrane (3, 31). Superoxide readily dismutates to form H20 2 and subsequently, other oxygen metabolites which have been shown to be both antibacterial and cytotoxic (21, 25, 35).Superoxide is produced from the reduction of extracellular O, at the surface of the cell membrane by NADPH oxidase by the following reaction (3, 4)"

Jan 1, 1989

By L. L. Brown

As part of the Federal effort to help maintain an adequate supply of fertilizer materials, the Bureau of Mines conducted research to characterize complex low-grade Michigan phosphate materials and to devise methods for recovering fertilizer-grade phosphate concentrates. The rock is from middle Precambrian sedimentary formations in the Marquette Range located in the central part of the Upper Peninsula of Michigan. Occurrence of phosphate-bearing sediments in Precambrian rocks is rare. This deposit, containing 12 to 15 pct P205, is believed to be the richest Precambrian phosphate deposit in the United States. Petrographic examination showed that the conglomeritic rock contains crystalline apatite both in "black pebbles" and in quartz matrix. Attrition scrubbing and sizing tests showed that there is no tendency for phosphate to concentrate in any of the sized fractions. In beneficiation tests, which included grinding to minus 325 mesh followed by phosphate mineral flotation using a fatty acid-fuel oil collector, a phosphate concentrate was obtained that had a grade of 30 pct P205 and a P205 recovery of 72 pct. This concentrate should be suitable for fertilizer manufacture.

Jan 1, 1981

By Theodore Kessler

The purpose of this Bureau of Mines investigation was to determine what new organic compounds or high concentrations of a particular organic species can be formed by exposure of coal derivatives to ultrasonic energy. Tetralin, l-methylnaphthalene, and pyridine were used as model compounds. Gaseous and solid reaction products resulting from the ultrasonic irradiation of these coal derivatives were determined using mass spectrometry. Products from the irradiation of tetralin were studied as a function of time, atmosphere, and sample size. The sonolysis (chemical reactions produced by ultrasonic energy) of tetralin and l-methylnaphthalene produced C2H2, HCN, CH4, H2, CO, and CO2, depending upon the experimental conditions. The ultrasonic irradiation of tetralin also produced diacetylene under certain experimental conditions. The cleavage of organic chemical bonds by ultrasonic cavitation in the absence of water was also observed in this study.

Jan 1, 1967

By Kevin Malone

Chrysotile asbestos occurs in many counties in California, and a small production had been reported at times, but development of deposits had been disappointing. A reconnaissance survey by the Bureau of Mines indicated that several deposits in the serpentine belt in Shasta, Trinity, and Siskiyou Counties might contain enough asbestos of filler grade to supply the growing demand on the west coast. Accordingly from 1956 to 1958 parts of the Mount Eddy and Shasta View deposits were investigated by trenching and diamond drilling to determine their potential. The work comprised construction of roads, bulldozer trenching, excavation of areas for diamond drilling, sampling, and upping. The trenches were excavated to expose the surface extent of some of the asbestos-bearing areas, To determine the downward continuation of asbestos-bearing sections and to secure samples for test purposes, six diamond drill holes, totaling 1,738 linear feet, were drilled in two selected areas. The trenching and core-drilling indicated that the asbestos-bearing material occurs as ribs and lenses of varying thicknesses in a broad belt of serpentine, about 600 feet wide and several miles long,

Jan 1, 1962