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Continuously monitor air-borne radon daughters that are a hazard to underground miners. Approach A beta detector continuously counts beta activity collected on a filter paper to allow calculation of exposure in working level units. How It Works At each Site a constant flow pump draws mine air through a fiberglass filter located in front of a beta detector (pancake type Geiger Mueller tube), Radioactive particles (products of the radon 222 gas emanating from the mine walls) collect on the filter and decay, releasing alpha and beta particles as well as gamma rays. A portion of the beta particles penetrate the Geiger tube window and create electrical pulses in the tube. These pulses are then amplified and sent by a coaxial type or shielded electrical cable to a central monitor located some distance from a working level detector. At the central monitor incoming Signals are amplified and fed into two channels, (See the block

Jan 1, 1979

By D. A. O'Keefe, M. M. Wong

To obtain beryllium metal of higher purity , flakes produced from electrorefining scrap metal were used as cell feed for a second cycle of electrore fining at 500 ° C in an electrolyte composed of 51.7 mole - percent LiCl , 36.9 molepercent KC1 , and 11.4 mole - percent BeC¹ · Metallic impurities in the flakes totaled more than 108 ppm , the metallic impurities in the metal obtained from the two - cycle electrorefining were , with the exception of 35 ppm of calcium , below the spectrographic determination limits .

Jan 1, 1964

By John A. Davis, John Gross

This paper is one of a series giving the results of metallurgical tests conducted by: the Alaska station of the Federal Bureau of Iſines, on the recovery of gold from the black sands of placer clean-ups. The data given in this report were obtained from tests on a lot of black sand from a property located on St. Patrick Creek, Fairbanks mining district, Territory of Alaska. This property comprises the Sagan Fraction and adjoining bench claims, and is being operated by J. A. Lillie. The sand ad already been treated at the mine by amalgamation. A sample taken by Mr. Lillie and assayed at the station showed that the gold still remain ing amounted to ll cents per pound. As this gold content was sufficiently high to justify further treatment of the same, 770 pounds were shipped to the station for testing. The reader will note that the gold content is given in cents per pouni, rather than per ton. This is in conformity with practice in the district in valuing black sands, as the quantity obtained at any one time is small, much less than one ton. . The sand consisted principally of schist and quartz, with very little ilmenite and garnet; and no magnetite or sulphides. Most of the gold present as contaminated with quartz, as the free particles of gold had been removed by amalgamation at the mine.

Sep 1, 1920

To rapidly and dependably locate shorts and opens in mining equipment power cables. Approach: The approximate locations of faults are found using a sound pulse echo, then the faults are exactly located with one of two probes. How It Works: To approximately locate u fault in shielded or unshielded cable, the cable is disconnected from the mine power center, and connected to the sound pulse generator. The generator is also connected to the ground conductor of the cable. When the generator is energized, electrical pulses are transmitted, and each moves along the conductor until it reaches a fault. When a pulse reaches the fault an echo returns to the instrument, either a positive pulse if the fault is an open, or a negative pulse if the fault is a short. See Figure 1. The further along the cable the first fault is from the instrument, the longer it takes for the echo to return. The instrument automatically measures the time and calculates the distance. The distance in feet is shown on an illuminated digital display.

Jan 1, 1976

By D. J. Bauer

Liquid-liquid extraction techniques were investigated by the Federal Bureau of Mines for the fractionation of rare-earth solutions. Separatory funnel work using tri-n-butyl phosphate (TBP) for extracting ceric nitrate from solutions containing sulfate ion resulted in almost complete extraction. Similar tests using primary amines for splitting trivalent rare-earth pairs and fractions gave promising results. The ceric nitrate extraction procedure was scaled-up by use of pressure-bubbler equipment, a series of spray towers for extraction, washing, and stripping. In this case only 84 percent ceric nitrate extraction efficiency was achieved. This work was done using dilute sulfuric acid for stripping.

Jan 1, 1960

By Wilbur I. Duvall

Surface vibrations of ground, rock, and structures resulting from blasting or other sources are often measured with portable seismographs. These instruments are usually supported by a three-point mount or tripod which is simply placed on a horizontal surface on which vibration levels are to be measured. The rigid-body motion of a tripod-supported seismograph is considered from the point of view that there should be no slippage of the feet with respect to the surface and none of the feet should leave the surface as a result of imparted motion. From these studies the following design criteria are deduced which assure that the seismograph will respond accurately to vibration levels as large as 1/2 g.:3/ First, the coefficient of friction between the feet and the surface on which the instrument rests should be as large as possible, preferably approaching unity; second, the center of gravity of the instrument should be vertically above the centroid of the three-point mount; and third, the vertical distance between the center of gravity of the instrument and the centroid of the three points of contact with the surface should be less than the perpendicular distance between the centroid point and anyone of the three sides of the triangle formed by the three points of contact. Portable seismographs that do not satisfy these conditions should be clamped to the surface if vibration levels above 0.1 g. are to be recorded.

Jan 1, 1961

Reduce the hazards to which mine personnel are exposed by providing safer procedures for removing dragline wire rope terminations. Background The termination points of wire ropes used on draglines consist of a wedge and socket that lock the rope in place through friction. These components must be separated when the wire rope is changed. At present, the cannon method is the most common procedure used to accomplish this. However this method, using a small cannon and primer (detonator) cord to propel a steel projectile that will knock the wedge out of the socket, has the potential of causing injuries to mine personnel and damage to equipment. The Bureau of Mines, has devised safer, and equally efficient methods of removing wire rope terminations. The Bureau began by studying the cannon method, its merits and draw-backs. Safety guidelines were then developed for the cannon method, and two alternative methods-the pendulum ram and hydraulic pusher-were devised and tested. The Cannon Method The steel projectile used to separate the wedge and socket in the cannon method was found to be very effective. However, the method poses the inherent hazards of any explosive de-vice-hazards that could be increased by lax work procedures. There is no strict uniformity in the manufacture of the cannon or in the work procedures used in the mines employing it. Hazards could be reduced, or even eliminated, with adaption of certain manufacturing and work-procedure guidelines, such as 1) making the cannon and projectile de-signs, as well the work procedures used, uniform, 2) ensuring separate loading of the charge and detonator with insertion of the detonator through a separate port, 3) connecting electrical firing circuits only after the charge and projectile are loaded and the cannon is placed in its final firing position, 4) using approved detonating devices, 5) anchoring the cannon before firing and, 6) placing armor netting over the cannon before detonation.

Jan 1, 1986

By E. S. Longfellow, S. H. Katz

Poisonous hydrocyanic acid gas (HCN) is sometimes evolved in dangerous quantities from cyanides used in metallurgical and chemical operations. This gas is much used for fumigating buildings, ships, greenhouses, and such commodities as grain and cotton to destroy rats, mice and insect pests. Wherever cyanide fumes are evolved, thorough ventilation is necessary in order to render the sur- rounding air safe to breathe. Many persons have been killed by entering tanks and fumigated places too soon, and a simple test for this gas would promote safety. In view of the need for an easy method for quantitatively determining HCN in air, the three color reactions used originally for testing HCN in solution tions *** were modified and adapted. The reactions employ (1) picric acid (CH(NO2)3OH) which is yellow but combines with hydrogen cyanide to form a red- purple dye, isopurpuric acid****; (2) phenolphthalin (CH1604), which is a reduc- tian product of the phenolphthalein (CH4) used for acid indicator, this colorless substance is oxidized***** by presence of HCN to pink colored phenolph- thalin; and (3) guaiacum which oxidized from colorless to blue******. Phenolph- thalin and guaiacum require the presence of copper compounds which catalize the color formation by reduction of cupric cyanide. The chemical processes involved *Associate physical organic chemist, Bureau of Mines, Department of the Interior. **Assistant gas chemist, Bureau of Mines, Department of the Interior. 2014 20 *** Kohn-Abrest, E., Notice toxicologique sur les gas: Arnales des Falsifica- tions, vol. 8, 1915, pp. 215-35. (Tested air with picric acid and guaiacum papers). **** Élasiwietz, H., Ueber eine neue Zersetzungsweise der Trinitrophenylsaure: Anal. der Chemie, vol. 110, 1859, pp. 289-303. ***** Weehuizen, F., Phenolphthalin as reagent for HCN: Pharmaceutrisch weekblad, Utrecht, vol. 42, 1905, pp. 271-2. Abstract, Jour. Chem. Soc., vol. 88, part 2, 1905, p. 489. ****** Schonbein, C. F., Ueber den thatigen Zustand der Helfte des in dem Kupfer- oxydenthaltenen Sauerstoffs und ein darauf beruhendes hochst empfindliches Reagens auf die Blausaure und die loslichen Cyanmetalle: Jour. fur. Praktische Chemie, vol. 106, 1869, pp. 263-70.

Jun 1, 1923

By Seth C. Schaefer

The Bureau of Mines investigated thermodynamic properties of Mn304 (manganomanganic oxide) and Mn203 (manganese sesquioxide). The standard Gibbs energies of formation (?Gf°) of Mn304 and Mn203 from their lower oxides were determined with high-temperature galvanic cells using stabilized Zr02 (zirconia) as the electrolyte. Potential measurements were obtained for the cell Pt, MnO, Mn304//Zr0 2//02(g, 0.0112 atm), Pt, with the overall cell reaction 6Mn0(c) + 02(g, 0.0112 atm) = 2Mn304(c), where- 02 refers to indicated partial pressure of oxygen at the reference electrode. Similar measurements were obtained for the cell Pt, Mn304, Mn203//ZrO2//02(g, 0.0115 atm), Pt, with the overall cell reaction 4Mn304(c) + 02(g, 0.0115 atm) = 6Mn203(c). Equilibrium oxygen pressures for the Mn0-Mn304-02 and Mn304-Mn203-02 systems were measured and may be expressed for the respective systems as [23,400 109 P02 T + 11.91 (764.9 - 1,208.6 K) and log p02 = - 11,957 + 9.66 T (968.6 - 1,208.2 K),] where pressure (p02) is in atmospheres and temperature (T) is in kelvins. Standard thermodynamic properties of Mn304 and Mn203 were derived from these measurements and auxiliary thermodynamic data from the literature.

Jan 1, 1982

By Maria I. De Rosa, Charles D. Litton

The National Institute for Occupational Safety and Health (NIOSH/PRL) con­ducted a series of large-scale experiments to evaluate the effectiveness and safety of various concentrations of an inert gas mixture (CO2,8%;N2, 50%; Ar, 42%) for preventing and sup­pressing cab ?res. Comparison of concentrations effectiveness in yielding safe times has led to the choice of an optimum gas mixture concentration, discharged in the cab through a muf?ed nozzle system, for the development of a dual cab ?re inerting system. Of note is that safety training programs, including the synchronization of performed tasks, need to accompany this technology to enhance operator’s ef?ciency and safety during ?re emergencies within the safe times yielded by the cab ?re inerting system. Cab ?res are caused by the ignition of ?ammable vapors and mists (ball of ?re) that penetrate the cab during prolonged hydraulic ?uid and fuel ?res, and electrical malfunctions involving other cab combustible materials. Often, these ?res force the operator to exit the cab under hazardous conditions during a time needed to perform emergency tasks. Hence, it is important to provide the operator, not only with an engine fire suppression system (dry chemical powder), but also with a cab ?re protection system, effective both in preventing the ignition of ?ammable vapors in the cab, and suppressing cab material ?res.

By Charles L. Kimbell

In 1990, the aggregate value of world international export trade in mineral commodities was estimated at more than $64 billion in current (1990) dollars, about 8.4% higher than that in 1989, but still 8.7% below the record high set in 1980. Table 8 provides a data series for the estimated value of world export trade in all mineral commodities from 1979 through 1990, as well as a breakdown of this total into fuel and nonfuel commodities. It is noteworthy that for this 1990 edition, trade data for the year of review were available in time for inclusion, whereas in previous editions, the latest available global trade data were for the year prior to the year of review. Hence, as regards trade, this edition of Minerals in the World Economy updates the 1989 edition by 2 years rather than by only 1. For this reason, it is appropriate to note that the 1989 global total value for inter-national export trade in mineral commodities was almost $596 billion, 11.1 % above the revised 1988 level of more than $536 billion, both figures expressed in current dollars for the appropriate year. Despite the considerable increase in the dollar value of mineral commodity exports, their share of total export merchandise trade declined to 19.1 % in 1990 from 19.7% in 1989. At 19.1%, this share was very near the recent year record low of 19.0% reached in 1988. The year 1990 was the fourth in a row in which the total value of world mineral commodity export trade increased.

Jan 1, 1993

By D. E. Shanks

The Bureau of Mines investigated the effects of HCI concentration and solution temperature on the solubility and crystal form of the chlorides of Co, Mn, and Ni when sparged with HCI gas at temperatures of 20°, 40°, and 60° C. Increasing HCI concentration in solution caused the chlo-rides of Co, Mn, and Ni to crystallize (salt out) because of the common ion effect. The salting-out crystallization was most effective for NiCI2, which had a solubility of 0.7 pct at 20° C and maximum HCI concentration. COCl2 salted out to a minimum solubility of 9.4 pct at 20° C and 22 pct HCI concentration and increased in solubility at greater HCI concentrations because of the formation of chloride complexes. MnCl2 was intermediate in behavior. The effect of temperature on solubility was greatest for CoCl2 and least for NiCI2, 15 and 7 pct change, respectively, over the temperature range of 20° to 60° C. The salted-out chlorides of cobalt and nickel formed the hexahydrates and those of manganese formed the tetrahydrate in saturated metal chlo-ride solutions at 20° C and low concentrations of HCI. Increasing the temperature or the HCI concentration caused a 108s in waters of hydra-tion. At 60° C, the salted-out crystals of NiCl2 formed the tetrahydrate in HCI concentrations up to 18 pct and the dihydrate at higher concentrations, while cobalt and manganese chlorides formed the dihydrates, even in water.

Jan 1, 1985

By L. M. Demers, D. C. Kuhn

The alveolar macrophage (AM) responds to stimuli such as coal mine dust by releasing inflammatory mediators such as cytokines, growth factors. reactive oxygen species. and eicosanoids. Eicosanoids are synthesized by°AM through the action of cyclooxygenase and lipoxygenase enzymes and serve to modulate the proinflammatory function of this cell as part of the lungs' host defense mechanism. Reactive oxygen species can be generated by AM as a by-product in the biosynthetic pathway of the prostaglandins. AM produces primarily prostaglandin E2, thromboxane A2, and leukotriene B4 as part of the cellular response to an inflammatory stimulus. There is evidence to suggest that eicosanoid production by AM is functionally linked to both surface interaction with mine dust particles like silica and by the phagocytosis of the dust particle itself. In this report, we examined the effects of an antioxidant, vitamin E. on dust-induced synthesis of PGE2 and TXB2 in vitro and in vivo by AM obtained by bronchoalveolar lavage from rats. We also looked at the effects of the surface of silica particles on AM eicosanoid biosynthesis under conditions of calcination, a process that removes exposed hydroxyl groups from the surface of silica particles, thus reducing the likelihood of soluble hydroxyl radical formation. Treatment of AM with vitamin E in vivo and in vitro reduced the augmentation in eicosanoid production usually observed when AM are exposed to mine dusts. These results suggest that vitamin E may effectively reduce the inflammatory and fibrotic response produced by inhalation of mineral dust through an antioxidant mechanism. Silica that has been chemically altered by calcination was unable to activate AM eicosanoid production in vitro when compared to untreated, freshly fractured silica. These findings suggest that the mechanism by which dust particles can activate AM eicosanoid release may involve interaction of surface and/or soluble factors with the cell membrane. Taken together, these studies point to the involvement of AM eicosanoid production as part of the proinflammatory response of this cell to occupational inhalation of mineral dust. - Environ Health Perspect 102(Suppl 10):97-100 (1994)

Dec 1, 1995

By C. H. Elder

An experimental degasification program using a vertical borehole and vacuum pump to drain gas from the gob area of a longwall panel was successful at Bethlehem Mines Corporation, Cambria Division, No. 33 coal mine. Sixty-one million cubic feet of methane has been exhausted during a 9-month period. Daily production time in the panel increased as a result of lower methane levels in the returns. Removal of large quantities of methane in this way and the exclusion of it from the ventilating system will provide reduced cost in mine ventilation and provide a safer environment for the mine.

May 1, 1969

By H. B. Brunot, L. C. IlsLey

The chief object of the Electrical Section of the United States Bureau of Mines is the study of causes and means of preventing accidents resulting from the use of electricity in mines . A large part of this work for the last 20 years has been the inspection and testing of mining equipment under the provisions of schedules which give the minimum requirements considered essential for the safety of equipment intended for use at or near the working faces of dusty or gassy mines . During the first few years of this work , particular attention was paid to the explosionproof features of the various accessories such as motors , controllers , and other parts . The knowledge of the essentials necessary for safe designs of enclosures has since been augmented by field experience and by data obtained in testing a large number and variety of designs . With our present knowledge it would seem that a disproportionate stress was placed on making the various enclosures explosionproof , but not enough thought was given to the danger from wiring and connections outside of explosionproof enclosures . The list of equipment that has met minimum requirements for safety and has been approved as permissible by the Bureau of Mines includes storage - battery locomotives , power trucks , drills , loading machines , conveyors , cutting machines , room hoists , pumps , concrete mixers , and rock-dusting machines . The wiring on some of the machines is comparatively simple and sometimes , except for the trailing cable , may be entirely within the explosionproof enclosures . In general , there is outside wiring between enclosures , and on the larger machines the wiring may be extensive and complicated . In considering the safety of wiring for mining machinery , attention must be given the severe service and unfavorable surroundings imposed by mining conditions . Some of the matters that require consideration are : ground . The lack of care of the exterior wiring to be expected in the average mine . The lack of adequate periodic inspection of the wiring . The absence of adequate facilities for satisfactory inspection and repairs under- The severe conditions of moisture , dirt , mechanical injury , and low voltage encountered in mining service .

Apr 1, 1931

By C. W. Owings, J. J. Forbes

"INTRODUCTION The recent coal-dust explosions in Illinois and Indiana have again brought forcibly to the attention of mining men the fact that mines which liberate little or no methane can have widespread explosions, if dry and dusty conditions exist and if adequate measures are not taken to control the dust hazard by rock dust¬ing or use of water.Even though rock dust has been used more or less extensively for more than 20 years as a means of limiting or preventing coal-mine explosions, many mine operators have requested information on rock dusting and means of allaying coal dust at its source. The purpose of this circular is to summarize available information on these two methods.COAL MINES TO BE ROCK-DUSTEDAll nonanthracite coal mines must be rock-dusted, except those mines or locations in a mine that are too wet or too high in incombustible content to propagate an explosion.Coal dust that contains 20 percent or more moisture may prevent ignition or propagation of an explosion. Such dust can be molded in the hands, and under such condition the roadway would be considered muddy. Mine dust that is only damp is not wet enough to prevent propagation of an explosion. Beads of water standing on accumulations of dust are not indications that the dust is wet. Only those mines or locations in a mine in which the coal dust can be molded in the hand need not be rock-dusted."

Jun 1, 1947

By F. A. Rutledge

The Rainy Creek deposits lie at the western base of the Kilbuck Mountains, about So miles southeast of Bethel, in southwestern Alaska. The deposits were brought to the attention of the Bureau of Mines by placer miners on Rainy Creek after cinnabar concentrates were recovered by their gold-mining operations. In August 1947 the Bureau excavated 1,500 feet of dozer trenches totaling 2,547 cubic yards. Further hand trenching in the bottoms of the dozer trenches on the surface totaled 1,440 linear feet, or 40 cubic yards. Nineteen samples were taken for analyses.

Jan 1, 1948

Develop and evaluate a mechanical position and heading system (MPHS) that provides information about underground mining machine position and heading to aid in the remote positioning of mining machines during face maneuvers. Background While great improvements have been made in mineworker safety, progressive technology continues to create a safer, better working environment for miners by keeping them away from the dangerous face area. In maintaining such high standards of safety, the Bureau is investigating remote, computer-assisted operation of mining systems for underground, highwall, and surface mining applications. A key component of computer-assisted operation is a guidance system. Since there are no guidance systems on any commercial continuous mining machines, the Bureau itself developed and tested the mechanical position and heading system (MPHS). The MPHS is based on linear position transducers (LPT's), and operates on principles of triangulation to provide machine position (xy coordinate), and orientation in the xy plane (yaw or heading). These data are needed in order to keep the continuous mining machine in proper alignment before and during the cutting cycle. The MPHS theory development is in three parts: characterize the sensors used and their configuration; select and define the navigation reference frames; and derive a closed-form solution for determining the position and beading from sensor information. Application of the MPHS theory required the development of hardware, software, and system interfaces.

Jan 1, 1992

The Bureau of Mines evaluated short-delay coal mine detonators manu-factured by three domestic companies for electrostatic sensitivity, strength, and no-fire current level. Electrostatic sensitivity was studied in pin-to-pin and pin-to-case modes employing lO-kV potential. Strength of detonation was measured in the Bureau's underwater test fa-cility. No-fire current was measured using a constant-current power supply unit. Test procedures and experimental data are included.

Jan 1, 1985

By L. D. Tracy

The first study of this subject hits been made in Illinois, but as opportunity affords, similar studies will be made in other States. It is hoped that the data obtained will assist the coal-mining industry to standardize the forms of leases, and so avoid some of the abstruse and ambiguous clauses which slay be found in many of them and the consequent liability of costly litigation. In some of the publications of the Illinois Mining; Investigations prepared under a cooperative agreement with the U. S. Bureau of Mines, the Illinois State Geological Survey and the Engineering Experiment Station of the University of Illinois, the coal areas of the 'State have been divided into eight geological districts, each district being treated separately. This report covers District No. VI of that classification, and it is hopped that studies of the other districts will be completed in the near future and similar results published.

Jan 1, 1926