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By J. E. Miller

Primary standard gas mixtures were developed for more accurate calibration of analytical instruments at the Bureau of Mines Helium Research Center and for calibration of analytical instruments used in the helium conservation program. A 10-kg-capacity balance is used to weigh a 4-kg metal cylinder filled to high pressure (1,800 psi maximum) with the component gases of the desired mixture. At 1,800 psi, a cylinder contains about 60 g of helium, or 420 g of nitrogen. An accuracy of ±0.05 mole-percent or better is claimed for each component in the mixtures.

Jan 1, 1965

By J. D. Davis

THE CARBONIZING properties of Chilton-bed coal from Lorado No. 5 mine, HE Logan County, W. Va., were determined by Bureau of Mines-American Gas Association tests at 600°, 700°, 800°, 900°, and 1,000° C. and by expansion tests. Chemical analyses, agglutinating and plasticity tests, and low- and high-temperature assays also were included in the investigation. Blends with low-volatile Pocahontas No. 3 coal were carbonized at. 900° C. The Chilton coal bed lies in the Kanawha, or Upper Pottsville formation of the Pennsylvanian system; the estimated original reserves are nearly 3.2 billion tons. The bed was 39/1 to 57 inches thick in the Lorado No. 5 mine, and the coal was 38 to 57 inches thick. The carbonization sample contained 62.6 percent fixed carbon on the dry, mineral-matter-free, basis, and the heating value on the moist, mineral-matter-free basis was 15,190 B. t. u. per pound; it therefore ranks as high-volatile A bituminous. It contained 1.8 percent moisture, 35.2 percent volatile matter, 57.9 percent fixed carbon, 5.1 percent ash, and 0.7 percent sulfur, as carbonized. The sulfur was largely organic, and the ash softened at 2,630° F. The agglutinating value determined on a silicon carbide-coal mixture of 15:1 was 6.8. In the Gieseler test the coal softened at 327° C., fused at 407° C., attained a maximum fluidity of 5,730 dial divisions per minute at 435° C., and solidified at 487° C. Maximum resistance in the Davis plastometer was 45.5 pound-inches.

Jan 1, 1951

By H. L. Riley, B. W. Gandrud

"INTRODUCTION The Bureau of Mines, United States Department of the Interior, with the cooperation of the University of Alabama and coal producers, has made a series of washability studies to obtain technically and commercially important data regarding the productive coal beds of the State. Based on the system followed in these studies, this report consists principally of screen-sizing and float-and-sink data on the Clark and Gholson beds at Boothton, Ala. A previous washability study 4/ has been made on the Clark bed at Marvel, Ala.SAMPLING AT MINESThe coal from the Gholson and the Clark beds was sampled at the tipple which receives the output,the Boothten No. 3 and No. 4 mines. These two mines are on the Gholson and Clark beds, respectively, but the coal. from both mines is mixed on the tipple and washed in the same washery. The samples taken were minus 4-inch raw coal. The plus 4-inch raw coal is hand¬picked and not washed. AS the 4-inch screen had a capacity in excess of the output of the mines, it was stopped at the end of each mine-car trip. By Observing from which mine incline each trip was hoisted, a separate sample from each bed was cut from the discharge stream of an endless belt which conveys the through 4-inch raw coal to the bin ahead of the washer. The output from each bed was sampled uniformly over the period of a working shift. The two washability samples weighed approximately 3,000 pounds each."

Dec 1, 1947

By J. L. Holman

The Bureau of Mines is conducting research to recover strategic and critical metals such as Ni, Co, and Cr from mixed contaminated super-alloy scrap. One approach being studied involves melt refining of superalloy scrap to produce anodes for electrolytic deposition of Ni-Co alloy. This melt refining of superalloy turnings is described based on melt-oxidation and oxidation-carburization experiments, using roasted superalloy grinding sludge to supply the 0 needed to oxidize Cr and other readily oxidized elements to the slag. Controlled melt-carburization subsequent to oxidation improved the metal phase recovery of Ni and Co to well over 90 pct and decreased electrolytic solubility of Cr, Mo, and W by carbide formation. Electrolytic refining experiments were conducted using a controlled-potential mode (preset cathode potential). Data show effects of Fe and Cr impurities, cation concentration, electrolyte pH, S04-Cl electrolyte ratio, temperature, cathode potential, and cation-selective membrane use on current efficiency, current density, and deposit composition. Disposition of Ni, Co, Cr, MO, W, and Fe is compared for melt-oxidized versus oxidized-plus-carburized anodes. Deposits containing >97 pct Ni + Co (major impurity Fe) have been routinely obtained from scrap anodes. Research is continuing to improve deposit quality in sustained deposition and to recover Cr and other metals from refining slags and anode sludges.

Jan 1, 1986

By Martin Hertzberg

This Bureau of Mines report analyzes diverse observations of the rates and mechanisms for the pyrolysis and devolatilization of coal and polymethylmethacrylate (PMMA). New data are presented for PMMA, together with new morphological evidence for the microscopic structure of the pyrolysis and devolatilization wave front in coals. It is concluded that there is no substantive evidence to support the traditional viewpoint that the pyrolysis and devolatilization rate process occurs isothermally, under chemical rate control; or is described realistically by a classical, unimolecular Arrhenius function of temperature. Instead, the reaction process occurs as a highly nonisothermal, heat-flux-driven, pyrolysis and devolatilization wave front, whose speed of propagation is predictable by internal heat transport constraints. Except for the complication of its charlayer residue, whose increasing thickness insulates the pyrolysis wave front from the heat source flux that drives it, both coal and PMMA behave similarly during pyrolysis and devolatilization. For PMMA, decomposition occurs at a temperature of 3500 to 5500 C; for coal it occurs at 4500 to 6000 C. There is no evidence that the reactant temperature ever exceeds those values regardless of the source temperature to which the samples are exposed.

Jan 1, 1988

By H. W. Kilau

The Bureau of Mines evaluated synthetic fluorspar as a substitute for natural fluorspar flux in basic cupola ironmaking. The synthetic fluor-spars tested were prepared from waste fluosilicic acid generated during the processing of fluorapatite ore. The cupola trials showed the synthetic products to be the equivalent of natural fluorspar from an operational standpoint. However, wet scrubber sampling showed that substantial losses of volatilized fluorine occurred from the cupola during operation. The losses during synthetic fluorspar trials considerably exceeded those from natural fluorspar trials. Laboratory viscosity testing, using a high-temperature rotational viscometer, confirmed this finding and indicated that fluorspar volatility in slags is related to slag basicity. Synthetic fluorspar is accordingly recommended more for highly basic cupola operation (>1.3 basicity) than for neutral or acid operation, because of the increased potential for pollution and baghouse filter detezioration"

Jan 1, 1989

By P. G. Kovalchik

Safe electrical operation of shuttle cars depends upon maintaining the trailing cable's conductor temperature below 90° C. However, trailing cables are wound on and off reels, which changes the heat transfer characteristics of the cable-reel system. Derating factors for trailing cables are an attempt to adjust for this changing heat transfer mechanism in a practical way. The U.S. Bureau of Mines conducted research to determine acceptable derating factors for reeled mine trailing cables, using four cable-reel combinations, representative of industry usage. Cables were continuously and intermittently loaded at different duty cycles with direct currents of different magnitudes. Relationships between the average temperature rise and current load were established for each layer of each cable. Two models were constructed; one used empirical data from the continuous and intermittent load tests, and the other was based on thermodynamic theory. Results obtained from the theoretical model were compared with those from the empirical model for the rated temperature rise of the cable. Both models can be used to simulate a variety of test conditions including those that normally cannot be conducted in the laboratory. This information was used to determine acceptable derating factors for each layer of these cable-reel combinations.

Jan 1, 1994

By G. E. McElroy

This paper3/ is one of a limited series being prepared by the Bureau of Mines to supplement a more extensive series on mining and preparation methods in the various mining districts of the United States. It describes ventilation methods and practices at the anthracite collieries in the Northern field of the anthracite measures of Pennsylvania as obtained by personal inspections in twenty of the larger collieries during 1933 and 1934 and from supplementary information furnished then and later by operating officials. This field is one of the four major divisions - Northern, Eastern Middle, Western Middle, and Southern - into which the anthracite deposits of Pennsylvania are naturally divided, and constitutes, in plan, a slightly bowed lens, about 60 miles long, and that extends from Forest City on the north through Scranton, Pittston, Wilkes-Barre, and Nanticoke to Shickshinny on the south with a. maximum width of 6 miles. It is the oldest and largest producing field of the four, and has produced continuously from 1S09. The total anthracite production for the State reached a peak of about 100,000,000 tons a year in 1917, but in recent years production has averaged about 50,000,000 tons, of which somewhat over half comes from this Northern field. The operations of three of the largest producing organizations in the State are almost wholly included in this field, as well as about half of the operations of two others of the six largest producers, It comprises the first 14 of the 25 numerically designated anthracite State inspection districts.

Jan 1, 1937

By Earl R. Maize

This is the first of a series of reports dealing with development of a method of strengthening bituminous-coal-mine roof. Later reports will describe the progress made with injecting high cohesive and adhesive bonding agents into bedding planes and mine tests of roof strata strengthened by the bonds formed. The concept of strengthening roof strata in coal mines by inserting steel rods in the form of bolts has been widely accepted by the coal industry. The benefits of increased production and safety derived from this type of roof support has more than justified the increased cost of roof bolting. However, not all coal-mine roof structure is amenable to this type of support, and failures occur owing to the heterogeneity and variable character of mine-roof strata.3/

Jan 1, 1957

By Gus Pantages, Bernard D. Blaustein, Charles Zahn, Irving Wender

Oils from coal hydrogenation have been examined at the Bureau of Mines to learn whether any centers of the optical activity reported in coal would survive catalytic hydrogenation at 450-525 ° C and about 8,000 psig pressure , and , if so , to obtain information about the nature of the active products . Oils from carbonization tars also were examined . Optical activity was found in the majority of the distillate fractions of the hydrogenation oils and in almost all distillates from the carbonization tars . No activity was observed in the tar - acid and tar - base fractions examined . Methods for isolating optically active concentrates included distillation through a packed column , liquid chromatography on silica gel , and adduction with urea . For the materials so processed , the optical activity segregated mainly in the paraffin - naphthenic and the hydroaromatic fractions . Although the specific compounds responsible for the optical activity were not isolated , experimental and spectrometric findings indicate that alkylsubstituted cycloalkane , cycloalkene , and hydroaromatic structures are most likely responsible for the optical activity of the concentrates . The optically active centers probably derived mainly from the steroids and terpenes in the biological materials that participated in the formation of coal .

Jan 1, 1964

By Curt D. Jr. Edgerton

This study was made to determine trends in fresh water usage by California petroleum refineries, to Forecast fresh water requirements to 1975, and to evaluate water conservation practices. Statistical data used in the study were obtained largely from published sources and from records of selected companies. An adequate sampling of the State's refining capacity was obtained, and the data were extrapolated to the total California refining capacity. A breakdown of the data was then made on the basis of the following refining regions: (1) the Los Angeles Basin and Southern Coastal region, (2) the Southern San Joaquin Valley, and (3) the San Francisco Bay area. An unpublished forecast of crude oil input to refineries by a major oil company operating on the West Coast was used as a basis for predicting fresh-water usage. The 1963 fresh water intake by California petroleum refineries was 84 million gallons per day. This is expected to increase to 128 million gallons per day by 1975. The fresh-water to crude-oil ratio is increasing in all regions except the Southern San Joaquin Valley. At present, the supply of fresh water available to almost all of the State's petroleum refineries, mostly from surface sources and company-owned wells, is adequate, although shortages may develop within the foreseeable future. Present conservation methods are centered around the following four objectives: (1) minimum intake of fresh water of the lowest possible quality commensurate with sound technologic practice; (2) optimum recirculation (3) proper treatment before discharge; and (4) substitution of air cooling for water cooling.

Jan 1, 1965

By R. P. Beyer

[The Bureau of Mines has measured the low-temperature heat capacities and high-temperature enthalpies of crystalline K2Si2O5 as part of a program for advancing mineral resources technology with energy economy. High-temperature enthalpies of glassy and liquid K2Si2O5 and crystalline K2SiO3 were also mea¬sured. An adiabatic calorimeter operating over the range 5 to 308 K was used for the heat capacity measurements for K2Si2O5 from which the standard entropy at 298.15 K, S°298 = 45.55 ±0.05 cal/deg-mole, was calculated. Tabulated values of Cp°, S°, -(G° -HO°)/T, and H°-HO° from 5 to 300 K are given for K2Si2O5. A copper-block drop calorimeter was used in the enthalpy measurements, operating from 298.15 to 1,198 K for K2SiO3 and from 298.15 to 1,453.8 K for K2Si2O5. No transitions were found for K2SiO3. The KI2Si2O5 showed two reversible first order transitions, one at 510 K with a heat of transition of 0.29 kcal/mole and one at 867 K with a heat of transition of 0.38 kcal/mole. The heat of fusion for K2Si2O5 20 5 was calculated to be 8.42 kcal/mole. Relative enthalpies are given in equation form, and high-temperature values are tabulated for Cp°, S°, - (G°-H°298 )/T, and H°-H°298 . Also tabulated are ?H°, ?G°, and log K for formation of K2SiO3 and K2Si2O5 from both the elements and the oxides.]

Jan 1, 1979

By Joseph D. Davis, G. S. Scott, Palmer B. Place

In the course of investigations made by the Bureau of Mines in cooperation with the Trent Process Corporation, into the properties of mixtures of oil and coal, a comparative study was ma.de of the 'behavior of these mixtures and their cons ti tuents on destructive distillation. Mixtures of a petroleum oil and bitminous coal were first distilled under carefully controlled conditions, and then charges of the eame oil and coal were distilled separately under similar conditions. The quantity and quality of the distillation products were determined, and. resul. ts were compared. This comparison furnished a basis tor judging whether grea, ... er values in products can be obtained by distillation of oil and coal in mixtures than· b:, their separate distillation. In making the mixtures, the method used in t~e Trent process for cleaning coal was followed. The paste or plastic emulsion of oil and coal obtained is called "amalgam".••• When finely pulverized wet coal is mixed with approximately one-third its weight of. oil and agitated with a large excass of waj;er, the coal and oil agglomer-. ate to form a paste or amalgam. A large portion of the extraneous ash original.17 in the coal remains suspended in the water, with which it can be decanted from the amalgam. Ir the latter is now thoroughly drained and kneaded after the manner ot working butter, most of the excess water enclosed can be removed. This, .in brief, constitutes the Trent process for cleaning coal, The effectiveness of the process for cleaning coal has been studied••••. by the Bureau, and the results of the study show, in general, a high ash reduction an:l good recovery of combus ti bl e f'rom coals of medi ,mi and hi~ rg,nk. With coals of tht lowest rank, such as li@!Rlites, the process is only moderately auccessf'ul, owing to the difficulty attending the preparation of coherent amalgams, Oil losses to wate~ and refuse are small, and apparently it would be practical to rotate the same oil in the cleaning process if some efficient method were devised for recovering it from the amalgam, so a distillation process naturally suggested itself.

Dec 1, 1921

By D. Harrington

Correct ventilation of underground workings whether in coal or in metal mines consists in establishing such control of air currents that the miners may work in safety, with maximum comfort and efficiency, and without impairment of health; also in controlling the air flow so that the mine workings may at ordinary times be kept reasonably free of harmful gases or dusts, and so that in time of emergency, as when a fire or an explosion occurs, there may with minimum delay be maintained as much or as little air flow as is desired throughout the mine in its entirety or in certain parts of the mine. Control of air flow is the essential point of any mine ventilating system, and is obtained only by the installation of mechanically operated fans, and other ventilating devices such as doors; overcasts, regulators, etc. Every mine, large or small, coal or metal, should from the outset be equipped with a fan. Much has been written about natural ventilation, and many claims have been made that in specific mines or parts of mines there is sufficient natural air flow. As a matter of fact, there are actually very few if any mines, coal or metal, where natural ventilation creates atmospheres anything like adequately safe or healthful for underground workers even at ordinary times or under ordinary. conditions; and at the time of a fire or an explosion mines depending upon natural ventilation are practically helpless, and are decidedly dangerous for the unfortunates forced to be in them either at the time of the disaster or afterwards when trying to handle conditions arising from the emergency.

Jan 1, 1929

By Edward P. Barrett

The production of sponge iron is one of the earliest arts in the metal¬lurgy of iron and steel. The idea of producing iron direct from ore at temperatures lower than the melting point of, the iron has persisted throughout the centuries. The purpose of this paper is to present a general picture of the methods, proposed or tried within the past 100 years, for producing sponge iron by treating hot ore with heated reducing gases. The abundant literature has been abstracted, and quoted freely. Publications concerning more detailed information on the various methods are referred to in the footnotes and in the bibliography.

Jan 1, 1949

By G. A. Appell

"INTRODUCTION During the summer of 1945, the Bureau of Mines conducted an investigation and program of churn drilling near the village of Tennyson in Grant County, Wis. The work was undertaken as part of a general investigation of the zinc-producing area of southwestern Wisconsin at a time when all effort was being made to increase the production of metals important to the war program.The area for special investigation was selected on the basis of favorable structural disclosures, evidence of widespread zinc mineralization, absence of any great amount of exploration to depth beneath the productive shallow workings, and the favorable results of several churn-drill holes in the village of Tennyson.During the Bureau's investigation, 30 churn-drill holes aggregating5,888 feet were completed.ACKNOWLEDGMENTSIn its program of investigation 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 project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual. Investigative work, and prepares the final report.The work described herein was accomplished under the direct supervision of Francis C. Lincoln and the author, mining engineers of the Bureau of Mines. Final data on the investigation were prepared under the direction of Edward F. Fitzhugh, Jr., chief Minneapolis Division, Mining Branch."

Jun 1, 1947

By Phillip Allender, Wolf Karo, Knox Van Dyke, Lixin Wu, Ali Ardekani, Jorge Garcia, Jaime Gutierrez

"We report that two different micropolystyrene round beads linked to either luminol or lucigenin have been developed. The 1-µ.m-diameter beads arc useful reagents that allow one to perform chemiluminescent (light producing) phagoeytic reactions without opsonization. It is known that luminol reacts with peroxidases (e.g., myeloperoxidase) while lucigenin reacts mainly with superoxide anion. Luminol and lucigenin beads produce cellular chemiluminescence (CL) with neutrophils, macrophages, monocytes, and differentiated human promyelocytic leukemic cells (HL60). When myeloperoxidase (MPO) is present luminol beads evoke higher CL from neutrophils, but when little or no MPO is present, lucigenin beads produce higher amounts of light. Lucigenin beads appear to be active inside these cells where unbound lucigenin does not enter freely.INTRODUCTIONA variety of cells, e.g., neutrophils (Ns) and macrophages (Ms), can engulf foreign particles (1). This engulfing or phagocytic activity is used by the body to kill bacteria and to eliminate foreign particles such as respirable dusts, e.g., coal, silica, or cotton. The neutrophil engulfs or phagocytizes bacteria which are coated with plasma antibodies and/or complement proteins (Fig. 1). The coating or opsonization allows the neutrophil to recognize foreign substances. Usually the absence of opsonization prevents the cell's recognition of a foreign particle and the particle is not phagocytized. Macrophages, particularly the alveolar Oung) cells, do not require opsonization for phagocytosis. Ms should not be selective toward individual dusts because they serve a major role in eliminating a variety of these.Particle size can also be a factor. Usually a particle with a diameter of 0.5-5 µ.m is considered in the respirable range. Larger particles are trapped before they reach the alveoli Oung spaces where oxygen exchange with blood occurs), ·and smaller particles do not generally settle, and are not engulfed by macrophages (2). Tabato and Ikada (3) found that maximal phagocytosis of microspheres takes place when their diameter is in the range of 1.0 to 2.0 µ.m. In addition, they found that beads with hydrophobic surfaces were more readily phagocytized than hydrophilic surfaces."

Jan 1, 1990

By J. Robert Wells

The Bureau of Mines has developed a spectrochemical procedure for determining 19 impurity elements in high-purity titanium metal, titanium oxides, and titanium halides in which all samples are converted to titanium dioxide. Determination of these impurities was studied in the general concentration range of 0 to 1,000 p.p.m., but different determination limits were found for the various elements. The procedure is quantitative for 18 elements but semi-quantitative3 for beryllium and has an overall relative standard deviation of 15.8 percent. Two mixtures were used, one composed of graphite and lithium carbonate plus gallium oxide and the other of graphite and lithium carbonate plus germanium dioxide. Each mixture was blended mechanically with an equal weight of titanium dioxide. Lithium carbonate served as buffer-diluent. Gallium was the internal standard for 1 impurity element, germanium for 7, and titanium for the remaining 11.

Jan 1, 1962

By W. W. Agey

Past investigations on waterborne impurities in the flotation process have been concerned primarily with the treatment of specific ores with particular local waters. Although some anions and cations present in water are known to react with flotation reagents, a definitive study has not been made on the effect of such common ions upon the flotation process. This report describes the fundamental research undertaken to define and measure the adverse and/or beneficial effects of different concentrations and combinations of several common anions and cations when oleic acid is used to froth-float limestone from a pulp of quartz and limestone. Research on the effect of waterborne impurities upon the flotation process was composed of two equally important phases. The first phase comprised development of a procedure for floating limestone from quartz that would give the same results in test after test. Some difficulty was encountered, but once such a procedure was developed, the second phase, comprising study and measurement of the effect of various ions c on to natural water upon the flotation of limestone, was quickly completed.

Jan 1, 1963

By N. S. Dalal, V. Castranova, K. Van Dyke, V. Vallyathan, J. H. Kang

"We have reported previously that crushing or grinding crystalline silica results in the generation of silica-based radicals on the particulate surface and that these radicals can generate hydroxyl radicals in aqueous solution. Data in the present study indicate that freshly ground silica is more cytotoxic and is a more potent activator of alveolar macrophages than comparably sized aged silica. That is, compared to aged silica, fresh silica is 4.2-fold more potent in decreasing the membrane integrity of macro· phages; is 50% more potent in activating hydrogen peroxide secretion by macro· phages; and is 4.frfold more potent in stimulating cellular chemiluminescence. Prosil 28, an organosilane material, is an effective coating agent for fresh silica. It decreases the cytotoxicity of fresh silica by as much as 78% and decreases the ability of fresh silica to induce chemiluminescence from alveolar macrophages by 58%. The data suggest that surface radicals associated with freshly cleaved dust may be an important factor in the induction of pulmonary disease. Furthermore, treating dust with coating agents may substantially decrease toxicity. INTRODUCTIONThe U.S. Department of Labor estimates that over 1.25 million American workers may be exposed to crystalline silica and that nearly 60,000 may be at risk of developing some degree of occupational lung disease (Parkes, 1982; Peters, 1986). Occupations of concern include miners, stone quarry workers, sand and gravel workers, sandblasters, foundry workers, and glass workers. Acute silicosis is characterized by inflammation, alveolar lipoproteinosis, and the rapid development of respiratory disability (Banks, 1986). In contrast, chronic silicosis develops 20-40 yr after initial exposure and is characterized by the appearance of concentric hyalinized nodular lesions and the progressive development of dyspnea (Parkes, 1982; Ziskind et al., 1976)."

Mar 1, 1992