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By Albert E. Keller

This paper describing the timekeeping and pay-roll methods of the Britannia raining and Smelting Co. (Ltd.) is one of a series being prepared for and published by the United States Bureau of nines regarding office procedures in connection with mining operations. The general office of the Britannia Mining and Smelting Co. (Ltd.) is located at Britannia Beach, B. C., a town of about 600 inhabitants at tidewater on the east side of Howe Sound and about 30 miles from Vancouver, B. C. The Beach, as it is locally termed, is a company town consisting largely of about 250 employees of the company and their families. Here is the milling and concentrating plant of over 6,000 tons daily capacity- the main service units comprising the electrical, mechanical, blacksmith and woodworking shops and the local electric-furnace foundry; the central-heating steam plant; the air and electric generating units; the ball-manufacturing plant; the warehouses; and the general store, which serves this community and also acts as distributor for the general stores located elsewhere on the property.

Jan 1, 1932

A list of permissible mine equipment approved by the Bureau of Mines before January 1, 1937, was published in Bureau of Mines Information Circular 6942.3/ Information Circular 7007,4/ published as a supplement thereto, listed equipment approved. Burin', the calendar year 1937. The present list includes most of the material liven in these two publications, as well as approvals that have been issued up to January l, 1940. Some equipment formerly listed has been omitted because it has become obsolete or is no longer actively marketed. The list now includes electrically-operated air compressors, coal drills, loading machines and conveyors, mining machine, mine ones, rock-dusting machines, room hoists, storage-battery gathering and haulage locomotives and storage-battery power trucks, mine telephones, junction boxes, electric cap lamps, flame safety lamps, electric hand and trip lamps, electric flood lens, flashlights, methane detectors, and single and multiple-shot blasting units. The appendix at the end of this circular lists trailing, cables that have passed tests prescribed by Schedule 2D. When equipment passes the inspections and tests prescribed by the United Status Department of the interior, Bureau of Mines, in published "schedules" or standards, it is formally approved as "permissible" for use in gassy mines, and the manufacturer is then permitted to mark it with an approval plate that identifies it as having been approved by the Bureau. The inspections and tests are designed to insure that each equipment satisfies the minimum requirements for safety in use. The Bureau's purpose in investigating equipment of this type and listing that

Jan 1, 1940

By J. S. Berber

Bastnasite is a natural fluocarbonate of the cerium group and affords an abundant and high-grade source of the lighter rare-earth elements. As part of a broad research program in rare-earth element technology, the Federal Bureau of Mines directed extensive experimental work to separating and purifying the rare-earth elements in bastnasite. By the use of a combination of techniques--classical chemical, ion exchange, and solvent extraction--the processing of a bastnasite concentrate to obtain the individual rare-earth elements, or groups of elements, was accomplished. A bastnasite concentrate, containing about 60 percent rare-earth oxides, was sulfated with concentrated sulfuric acid to eliminate the carbon dioxide, fluorine, and silica. Calcination at 1,200° F. made the gangue matter insoluble, thus permitting the separation of the soluble rare-earth sulfates. Essentially 100 percent of the rare-earth elements were recovered by this procedure. Since the rare-earth sulfate solution contained only trace amounts of nonrare-earth elements, subsequent separation procedures were simplified.

Jan 1, 1960

By Ronald B. Stotelmeyer

This report summarizes studies of 55 Idaho national forest roadless areas completed by the U.S. Bureau of Mines (USBM) in the period 1966-1992. These roadless areas have been recommended for addition to the National Wilderness Preservation System, proposed as special management areas, or otherwise recommended for study by the U.S. Forest Service or the Idaho congressional delegation. The Bureau of Mines' studies indicate which parts of the roadless areas contain mineral resources. They also show where mining and prospecting are likely to occur in the future, where mineral production has occurred in the past, and where abandoned mine workings (possible hazards) would be encountered. The number of mine and prospect workings found are a measure not only of surface disturbance, but of areas not wilderness in character.

Jan 1, 1994

By John C. Edwards

Standard smoldering and flaming combustion tests using smaIl coal samples have been developed by the U.S. Bureau of Mines as a method to evaluate the response of a smoke detector. The tests are con-ducted using a standard smoke box designed and constructed according to Underwriters Laboratories. The tests provide a standard, easily reproducible smoke characteristic for smoldering and flaming coal combustion, based upon a comparison of the smoke optical density and the response of a standard ionization chamber to the smoke. With these standard tests, the range of threshold limits for the response of a smoke detector and the detector's reliability can be evaluated for nearly identical smoke visibility and smoke physical characteristics. The detector's threshold response limits and reliability need to be well defined prior to the instrument's use as part of a mine fire warning system for improved mine safety.

Jan 1, 2010

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By E. S. Shedd

The Bureau of Mines investigated electrowinning and tapping lanthanum metal from lanthanum oxide in a fluoride bath. The electrolyte was composed of LaF3, BaF2, and LiF. Metal containing 0.2 percent impurities was produced at a rate of over 2 pounds per hour. Principal impurities were carbon, aluminum, and silicon. Low-carbon metal was produced by continually discharging the carbon oxide gases and maintaining 0.1-atmosphere pressure. Anode reactions and cell design were found to be important factors in cell operation. Both frozen electrolyte skulls and tungsten metal crucibles proved satisfactory for collecting the metal and did not react with the molten lanthanum.

Jan 1, 1966

By Frederick Bloetscher

An improved parachute-type stopping for changing the course of mine ventilation air during mine emergencies has been developed by Goodyear Aerospace Corporation for The Bureau of Mines. The stopping can be quickly deployed by one man from a single attachment point and provides excellent stopping performance with the flow in the design direction. Adding pin and foam attachments between its skirt and the passage-way surfaces improves its performance with flow in the design direction and maintains the stopping with zero or reverse air flows. Stopping performance results for a range of airway sizes including 7.5 X 10 ft simulated airway with pressure differentials of up to 3.0 inches of water are presented. Predicted performance values for this stopping design for larger passageways are also presented.

Jan 1, 1977

By H. Polat, Q. Hu, S. Chander

"The collection efficiency of dust particles was determined in a laboratory dust chamber equipped with a water spray. Measurements were made in the presence of selected nonionic, cationic and anionic surfactants. For the nonionic and the anionic reagents, efficiency was maximum in a narrow range of concentration. The surfactant concentration corresponding to high collection efficiency was usually much below the commonly used concentration of l "", however. In comparison, much higher collection efficiency was observed for a cationic surfactant at extremely low concentrations. For delineating the mechanism of capture of dust particles, surface tension and contact angle results were used to obtain a correlation between the work of adhesion and the efficiency of collection. Such a correlation was reasonable for the nonionic surfactants but not for charged surfactants. In the latter case, electrostatic interactions between charged droplets and particles were more important, especially for the cationic reagent. INTRODUCTIONSeveral methods are used to control dust in mines. These include: ventilation, foam, scrubbers and sprays. This article is concerned with improving the effectiveness of water sprays, which are widely used to remove dust particles during continuous mining, by adding small quantities of surfactants. Water sprays produce small droplets which act as collectors of dust particles suspended in air. Sprays directed at the actual source of dust have the additional property of wetting the coal before the ·particles become airborne (Hamilton, 1974). Wetting agents, also called surfactants, arc known to play an important role in many applications where dust is a problem. However, conflicting reports exist in the literature with regard to the effectiveness of surfactants in water sprays (for a review, see Chander et al., 1988). In spite of the conflicting reports, the use of surfactants for dust control has increased over the years. In a recent study by the Bureau of Mines, a 27'6 reduction in respirable dust levels was observed in a mine test when surfactants were added to sprays (Foley, 1991)."

Mar 1, 1992

By H. D. Baylor

This is the first of a series of papers describing mining methods and costs at cement plant quarries throughout the United States and deals directly with those methods employed and costs obtained at the quarry of the Louisville Cement Co. located at Speed, Ind. ACKNOWLEDGMENTS The author wishes to acknowledge the assistance of Mr. J. M. Buohheit, superintendent of quarries, and Mr. H. E. Schoonover, quarry engineer, in furnishing data and in compiling this report.

Jan 1, 1930

By A. J. Kraemer, O. C. Blade

This report on the properties of commercial motor fuels sold in the United States is a continuation of a series of reports made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee of the Cooperative Research Council (C.R.C. ) and the Bureau of Mines of the United States Department of the Interior . The first report contained data on motor gasolines sold during the winter of 1935-364 . Further reports on motor gasolines sold during the succeeding summers and winters to the summer of 1941 have been issued . No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942 . The present report presents analytical data for 1,120 samples , representing the products of approximately 88 companies . As in previous surveys , these companies include both large and small suppliers . In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were received . Conforming to previous surveys , the data cover three groups of samplesregular - price , premium - price , and third - grade gasolines and each group has been averaged separately. The number of samples , items and brands comprising each group, exclusive of those of the Pacific coast, are as follows : Regular price , 641 samples , 250 items , and 64 brands ; premium price , 439 samples , 222 items , and 68 brands ; third - grade gasoline , 50 samples , 50 items and 19 brands .

Jun 1, 1943

By C. M. Frost

The hydrodesulfurization characteristics of a Venezuelan topped crude oil and a Venezuelan reduced crude oil were determined at temperatures from 740° to 850° F, pressures from 800 to 1,600 psig, and space velocities from 1.0 to 2.0 Vo/Vc/hr. Kinetic calculations showed that under these conditions the desulfurization reaction was first order with respect to sulfur and had an average activation energy of 32.5 kcal/mo1. Catalyst life tests made at 750° F, with pressures of 800, 1,200, and 1,600 psig and space velocities of 1.0 and 1.25 Vo/Ve/hr, showed that the decrease in the relative activity of the catalyst was a logarithmic function of time or volume of oil processed and the amount of vanadium deposited on the catalyst. Comparative tests made with residual fuels prepared from a Wilmington, Calif., crude oil and a Wyoming asphaltic crude oil showed that catalyst life may be extended by processing fuel oil with a low metal content, but it may be shortened by the presence of large amounts of asphalt in the feed.

Jan 1, 1971

By Foster Fraas

A separator for minerals of low magnetic susceptibility and fine particle size in a water suspension is described. A ring-shaped matrix of ferromagnetic fragments rotating so as to pass successively through magnetic-field and field-free regions provides for the separation. Application is illustrated in the separation of hematite and ilmenite from quartz.

Jan 1, 1966

By Arnold P. Pipilen

In a study of the principal factors affecting the transport of coal-water mixtures through a centrifugal pump and a pipeline, the interrelation between solids concentration, velocity, and pressure drop was established for a bituminous lump coal (minus 2 inch) in concentrations up to 48 weight-percent. An optimum concentration was found to exist for maximum capacity of a given pipe-line, and for minimum energy requirements per ton of coal. Coal size degradation by particle fracture took place in the pump; abrasion and attrition to form fines took place in both pump and line. A novel system of studying flow of solid-liquid mixtures in pipelines by the determination of relative sound intensities was developed.

Jan 1, 1966

By D. Harrington

Misuse of explosives and heedless disregard of well-known safety rules covering the use of commercial explosives cause many avoidable accidents resulting in the death or maiming of men who can ill be spared by already undermanned industry at present, and who cannot be spared by their families at any tire. Blasting accidents, when not fatal, are usually serious; the past and present needless loss of life and maiming of men from this cause are appalling and types of waste that can and should be virtually eliminated. Dead, crippled, and maimed men are distinct losses to society as well as to industry, and compensation payments for such accidents represent only a portion of the financial loss, because the value of their lost potential production can only be surmised. By their very nature, explosives are dangerous to handle, otherwise they would not perform the services for which they are used; all men on a blasting crew are subjected to the results of the carelessness of any one member, and in many instances the misuse of explosives by one person has killed scores of fellow workers. Inexperienced men should be assigned to blasting operations only under the close supervision of men well-experienced in the work and familiar with its inherent hazards. Men should be selected for blasting crews that are known to be careful, willing to follow instructions, cool-headed, and unlikely to become excited in an emergency; they should be instructed in the safe handling of explosives in accordance with the safety rules established by the explosives -manufacturing companies or the safety codes of the various industrial organizations. Unfortunately, American industry has never adopted a uniform code for the safe handling of explosives; however, many mining companies have made rules that will eliminate most unsafe practices if established safe procedure is followed carefully. The Bureau of Mines has issued numerous pamphlets giving information on the causes of accidents due to explosives in the mining industry and indicating the ways in which a good proportion of those accidents can be avoided.

Jan 1, 1943

By J. F. Papp

The microstructures of a CF2Br2-inhibited methane flame and its uninhibited analog have been determined using molecular beam-mass spectrometry. The slightly lean flames were stabilized on a cooled porous plug burner at reduced pressure. Composition profiles of stable, intermediate, and radical species and temperature profiles were obtained. Comparisons of the uninhibited and inhibited flame profiles revealed the following inhibition effects; a shift of the primary reaction zone to higher temperatures, a higher maximum flame temperature, an increase in the CH3 concentration, and a reduction in the H2CO, H, 0, and OH concentrations. Kinetic analyses of the data yielded rate coefficients at flame temperatures for the reactions H + CH4 ? CH3 + H2, H + O2 ? OH + O, CO + OH ? CO2 + H, and CH3 + O ? H2CO + H. CF2Br2 is judged to decay by thermal decomposition and abstraction reactions.

Jan 1, 1981

By Hugo E. Camargo

In an effort to reduce Noise Induced Hearing Loss (NIHL) in the mining industry, the National Institute for Occupational Safety and Health (NIOSH) is conducting research to develop noise controls for mining equipment whose operators exceed the Permissible Exposure Level (PEL). The process involves three steps: 1) Noise source identification (NSI), 2) development of noise controls, and 3) evaluation of the developed noise controls. For the first and third steps, microphone phased array measurements are typically conducted and data are processed using the conventional beamforming (CB) algorithm. However, due to the size and complexity of the machines, this task is not straight forward. Furthermore, because of the low frequency range of interest, i.e., 200 Hz to 1000 Hz, results obtained using CB may show poor resolution issues which result in inaccuracy in the noise source location. To overcome this resolution issue, two alternative approaches are explored in this paper, namely the CLEAN-SC algorithm and a variarion of an adaptive beamforming algorithm known as Robust Capon Beamformer (RCB). These algorithms were used along with the CB algorithm to process data collected from a horizontal Vibrating Screen (VS) machine used in coal preparation plants. Results with the array in the overhead position showed that despite the use of a large array, i.e., 3.5-meter diameter, the acoustic maps obtained using CB showed "hot spots" that covered various components, i.e., the screen deck, the side walls, the I-beam, the eccentric mechanisms, and the electric motor. Thus, it was not possible to identify which component was the dominant contributor to the sound radiated by the machine. The acoustic maps obtained using the RCB algorithm showed smaller "hot" spots that in general covered only one or two components. Nevertheless, the most dramatic reduction in "hot" spot size was obtained using the CLEAN-SC algorithm. This algorithm yielded acoustic maps with small and well localized "hot" spots that pinpointed dominant noise sources. However, because the CLEAN-SC algorithm yields small and localized "hot" spots, extra care needs to be used when aligning the acoustic maps with the actual pictures of the machine. In conclusion, use of the RCB and the CLEAN-SC algorithms in the low frequency range of interest helped pinpoint dominant noise sources which otherwise would be very hard to identify.

Jan 1, 2009

The Mine Safety and Health Administration (MSHA) defines an independent contractor as any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine. Contractors that perform specific types of work are required to report the number of employees who work at coal mines and noncoal mines.

Jan 1, 2008

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage arc also described. IntroductionThe association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate ·formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation.In its most general form, the process of agglomeration involves taking discrete, independent particles, bringing them into contact with one another, promoting (or allowing) interparticle adhesion to occur and then causing structure rearrangement, usually under the action of external forces. The relative importance of these steps varies with the nature of the particulate system being agglomerated and with the kinds of agglomerates being produced. Coagulation or flocculation of particles dispersed in fluids is generally dominated by the contact and adhesion steps. In the granulation of powders, on the other hand, particles are already in contact so that structure rearrangement is the principal step."

Mar 1, 1992

By Carl Rampacek, W. A. McKinney

The feasibility of leaching calcareous and siliceous oxidized copper ores by downward percolation with dilute acid was investigated in the laboratory and in a small continuous plant operated by the Federal Bureau of Mines . The crushed ore was leached in deep columns with solutions containing 1 or 5 percent sulfuric acid to dissolve the oxidized copper . Bench - scale laboratory tests on two calcareous ores from the same deposit indicated that a maximum copper extraction , about 72 percent , could be expected from heap leaching a feed as coarse as 1 inch . Laboratory tests on a siliceous ore showed that almost 70 percent of the copper could be extracted by leaching a 1 / 4 - inch feed . The bench - scale tests were supplemented by larger continuous runs wherein the copper was recovered from the leach liquors by precipitation on detinned scrap iron . Leaching the calcareous ore for approximately 10 days recovered 62 percent of the total copper . The sulfuric acid consumption was 9.6 pounds per pound of copper recovered . Treatment of the siliceous ore recovered 62.5 percent of the total copper in a 2.5 - day leach and the acid consumption was 3.7 pounds per pound of copper recovered . Cement copper products that assayed over 71 percent copper were obtained from the leach solutions by precipitation on scrap iron . The bench - scale and continuous tests demonstrated that downward percolation leaching of the calcareous ores was technically feasible but not economically practicable because of high acid consumption by the gangue . Leaching of the siliceous ore was rapid and the acid and water requirements were nominal . The downward percolation leach procedure is simple and requires a minimum of plant equipment .

Jul 1, 1960