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By James P. Bennett

The Bureau of Mines investigated the effect of refractory oxide additions, introduced in soluble form, on the high-temperature properties of 90- and 98-pct-MgO brick. Brick samples were soaked in solutions containing Al, Ca, Cr, Co, Fe, Mg, Mn, Mo, Ni, Si, Sr, Sn, Ti, or Zr ions. Additions to 98-pct-MgO brick did not generally result in statistically significant property improvements. Statistically significant improvements were noted in hot modulus of rupture (MOR), slag resistance, and spalling resistance of the 90-pct-MgO brick for additions of Al, Mg, or Sn. High-temperature performance of treated 90-pct-MgO refractories was equal to or approached that of 98-pct-MgO brick. The marked improvements due to tin were obtained with additions of only 1.14 wt pct Sn02.

Jan 1, 1985

By A. B. Hooker, R. A. Kearns

Material used for flame safety lamp gauzes should possess the following qualities: (1) mechanical strength, (2) resistance to corrosion under service con- ditions, (3) a relatively high thermal conductivity, (4) a melting point above the ignition temperature of mine gas. Heretofore, three metals have been used for flame lamp gauzes, namely: steel, brass and copper. While each of these has the requisite qualities to some extent, none of them is an ideal gauze material. Copper gauzes lack mechanical strength, especiall, after they have been heated; brass and copper both have comparatively low melting points so that before the gas ignition is reached the gauze metal is attacked and oxidized under the action of the heat. Steel corrodes readily in damp atmos- pheres and if the lamp stands unused under these conditions for some time, the gauzes become unfit for service. Tests of these three materials have shown that steel offers the highest degree of safety. Manel metal, the natural alloy of nickel and copper, is practically noncor- rodible. Its relting point is approximately the same as that of steel. From time to time it has been suggested that this alloy might be a better gauze material than steel, since gauzes made of Monel metal should have all of the good qualities that steel gauzes possess and, in addition, would not corrode appreciably in ordinary mine atmospheres. One advocate of this use for Monel metal, the International Nickel Co., through their development engineer, Mr. Robert J. McKay, cooperated with the Interior Department, Bureau of ines, to the extent of supplying twelve sets of 30 mesh, Monel-metal gauzes for tests. Those gauzes were made up by the same lamp manufactur- er ho rade the steel gauzes used in the previous investigation. Being made by the same processes as the steel gauzes, these Manel-metal gauzes were needlessly given the same anti-rust coating that is always applied to steel gauzes to prevent any corrosion before the gauzes are used. In previous tests the Bureau of Mines had collected data as to the behavior of steel gauzes. In determining the value of Monel metal as a gauze material, it was planned to obtain similar data with Monel-metal gauzes, and thus make a direct comparison with the steel gauzes. In addition, steel and Monel-metal gauzes

Apr 1, 1923

By C. W. Owings

"Ventilation is one of the most important features of coal mining, and if a mine is exceptionally gassy it is often difficult to ventilate it in such a way as to make it safe. The general system of splitting the main air current so that two, three, or more sets of room entries are ventilated by the same current of air does not provide a safe method if non-permissible electrical equipment, such as cable-reel, crab-reel, or trolley locomotives are used on gathering haulage, or if open-type hoist or pump motors are used. The problem has been greatly simplified at the Crucible mine of the Crucible Fuel Co. at Crucible, Pennsylvania.The system is not only applicable to the room-and-pillar method of mining, but it may be adopted for any panel system of mining. There also appears to be a definite application in mechanized mining, where the rapid extraction often results in inadequate attention to ventilation and where the gassiness of the section generally increases because, as compared to hand loading, the methane has less time to drain off. The system to be described should commend itself to coal-mining men.ACKNOWLEDGMENTSThis investigation was made possible through the courtesy of H. J. Nelms, general superintendent. E. M. Marshall, safety inspector, E. G. Sauers, assistant superintendent, and Thomas Mark, mine foreman, assisted in the collection of information."

Sep 1, 1931

By J. E. Tiffany, N. A. Tolch

The Pittsburgh Experiment Station has made a survey of the properties and characteristics of the brands of fuse manufactured in the United States ; 25 samples were procured from 4 manufacturers representing the different brands offered on the market when the investigation was begun . It is believed that the field was completely covered except for special fuse made to order for a particular job .

Jun 1, 1934

By J. L. Stauffer, L. J. Gaydos, L. M. Demers, D. C. Kuhn

"Eicosanoids and cytokines produced by alveolar macrophages (AM) are key mediators of pulmonary inflammation and fibrosis. In order to determine if eicosanoid production and cytokine production are altered in AM obtained from coal miners, we compared production of prostaglandin E2 (PCE2), thromboxane A2 (TXA2), leukotriene B4 (LTB4), interleukin-1 beta (IL-1B ), and tumor necrosis factor alpha (TNfa.) by cultured AM from normal human subjects and coal miners. The recovery of AM from miners' lungs by bronchoalveolar lavage was significantly greater than that from control subjects. Mean eicosanoid and cytokine production by AM from active miners was also increased compared to AM from control subjects, but this increase was not statistically significant. AM from control subjects produced significantly more TXA2 and TNFa. when exposed to lipopolysaccharide than did AM from miners. The cyclooxygenase inhibitor suprofen reduced PGE1 and TXA1 production and TNF0t. release but had no effect on LTB4 production or IL-1B release by miners' AM. The lipoxygenase inhibitor nordihydroguaiaretic acid attenuated TNFa release, as well as that of LTB4, but had no effect on IL-1B release. Inhibition of thromboxane synthase by UK 38,485 also reduced TNFa release by active miners ' AM but had no effect on PGE1, LTB, production, or IL-1 f3 release. The results of these studies suggest that occupational inhalation of coal dust may increase total lung eicosanoid and cytokine levels and reduce the reactivity of AM to bacterial endotoxin. Furthermore, coal dust-induced changes in both eicosanoid and cytokine release may be subject to pharmacological modulation.The alveolar macrophage (AM) is a primary defensive cell in the lung and is one of the first cell types to encounter inhaled mineral dust. The response of the AM to invading foreign material is designed to enhance the defensive capacity of the lung. However, in the case of occupational inhalation of mineral dust particles, this response may be inappropriate, resulting not in the defense of the lung but in chronic inflammation and fibrosis (Rom et al., 1987; Takemura et al., 1989). The reaction of the AM to chronic mineral dust exposure may involve the exaggerated release of paracrine mediators of lung function, including eicosanoids (oxygenated derivatives of arachidonic acid) and peptides, including cytokines and growth factors (Sibille & Reynolds, 1990). Eicosanoids are involved in bronchial and vascular smooth muscle reactivity, vascular permeability, fibroblast growth, and the recruitment of additional immune cells to the alveolar space (Barnard et al., 1992; Elias et al., 1985; Scott et al., 1982). AM-derived cytokines such as interleukin-1 beta (IL-1 B) and tumor necrosis factor alpha (TN Fa) have a variety of biological activities including the regulation of fibroblast growth and proliferation (Becker et al., 1989; Libby et al., 1989; Schmidt et al., 1984). Interestingly, in vitro studies with macrophages suggest that the production of cytokines may be linked to eicosanoid production, in particular that prostaglandin E2 (PGE2) may down-regulate IL-1 f3 and TN Foe production by the AM (Bonta et al., 1989; Kunkel et al., 1986; Monick et al., 1987)."

Dec 1, 1996

Develop and demonstrate a lightweight material that has low thermal conductivity and that would be suitable for placement using shotcrete methods. This material could be applied in deep, hot mines where mine drifts must be insulated. Its use would decrease mine refrigeration needs and reduce energy costs.

Jan 1, 1994

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

Several ignitions or mine pa, which might have led to explosions, and at least ona mine fire attributed to heated leg wires of electric detonators, have occm.rred. at rn1::.es in which outside shot firing is practiced. Photographs taken at one mine ind.la.ted. that the wires became red hot during firing. These results having been --i·-led. to the .Lttention of the electrical section of the Bureau of the Mines, ignitions the tests and to reportd aid in herein preventing were made future to trouble determine of if this possible kind, the cause of The investigation, which 1• considered preliminary, included tests to determine the conditions tha.t cause gas ignitions from heated. leg wires of electric and. of detonators, copper leg possible wires, remedies The tor samples such of heating, wire used. and in the the relative test were behavior the of reg\llar ironDa. Pont iron and copper leg wires (No, 22 A,W,G.) C\1t from Du. Pont electric detonators.

Aug 1, 1922

By A. L. Engel

A representative sample of gold-silver ore from the Keystone Mine, Manhattan, Nye County, Nev., was submitted for these tests. The ore was an altered diorite rock with very small amounts of sulfide minerals of copper, lead, zinc, antimony, and arsenic disseminated in fine grains throughout. As indicated by test results, much of the silver content of the ore apparently was associated with these sulfide minerals. The gold probably occurred with iron oxides in the ore. Assays showed 0.16 ounce of gold and 2.8 ounces of silver per ton of ore. This investigation was made to study application of activated carbon in the cyanidation treatment of the ore. The treatment proposed for u.se at the mill is as follows: The ore is crushed to minus-10-mesh size and separated into plus -and minus-65-mesh portions. The minus-10, plus 65-mesh sands are cyanided by leaching and the minus -65-mesh slimes by agitating. After 48 hours of agitation the slime pulp is thickened to about 1:1 water:solid ratio, and part of the pregnant solution is recovered. The pulp is then diluted to a 2:1 ratio, and the remaining dissolved values are extracted with the activated carbon. The barren pulp then can be discarded. This procedure eliminates the necessity for further washing the slime pulp and also recovers most of the excess sodium cyanide required for extracting the optimum amount of silver from this portion of the ore.

Jan 1, 1951

By Edward D. Thimons

A remote-actuated stench gas fire-warning system has been designed and tested by the Bureau of Mines. This system makes use of the hard-wire network for the mine's phone pager system, thus greatly reducing the system cost. By locating stench gas canisters with remote-actuation release capabilities near working sections, the fire-warning time can be greatly reduced. In a test of the system in a Missouri lead mine, the time required to warn miners of a fire at two working faces was reduced from about 20min with the conventional system to less than 4 min with the remote-actuated system.

Jan 1, 1984

By D. J. Parker

Ability to signal the hoisting engineer in shaft mines is of utmost importance from the standpoint of safety and economy. The problem of signalling from the cages and especially from the moving cages has received too little attention from mine operators; however, this problem has been given considerable thought and attention by at least one large metal-mining company in Utah which has devised successful, economical, and safe systems of signalling from the cage whether it is moving or at rest. A Report of Investigations on "Methods used in Utah for signalling mine hoists from moving cages," by C. A. Allen, then a metal-mining engineer in the Bureau of Mines, was issued in June, 1920. As this report contains interesting history of systems of signalling from moving mine hoists, and describes several systems then in use, it is here quoted in full.

Jan 1, 1929

By James W. Jensen, Aarne Visnapuu

Experimental modifications have been made by the Bureau of Mines on standard pneumatic rock drills to reduce the noise of the air exhaust, drill steel resonance noise, and noise radiated by the drill body. A close-fitting case and muffler around the drill body, consisting of a metallic honeycomb skeleton filled with viscoelastic absorber on the inside and a durable outer shell, provide both exhaust and drill body noise muff ling and absorption. Drill steel resonance noise is reduced by a constrained-layer treatment consisting of a tubular metal cover bonded to the ouside of the sod by a viscoelastic filler. Damping alloy components have been developed to reduce metallic resonance noise. Combined, these modifications have reduced the drilling noise level in granite from 115 dbA to 97 dbA. Data are presented on the individual and combined effects of these modifications on drilling noise and performance.

Jan 1, 1975

By A. U. Miller

Protection against fire is a greater problem at a coal mine, than at an ordinary industrial plant. Generally mines are located in isolated districts and do not have the protection of city fire departments; consequently fire fighting aquipment must be installed by the mining company. Fire protection around a mine is just as essential as it is in the city.. and undoubtedly is more important if the fire should be underground where many lives would be endangered and all means of escape cut off. A surface fire can generally be attacked from any angle, but an underground fire can be attacked only as conditions will permit.. U. S. Bureau of Mines engineers have investigated many serious mine fires that undoubtedly could have been extinguished in incipiency if a fire extinguisher or fire hose and water had been readily available. In past years very little attention was given..to fire fighting equipment and organization around mines, but in recent years three gen a derde hange of opinion among many of those engaged in mining, and nearly all up-to-date mining companies now have some kind of fire protection about their mine Probably the first company in Illinois to install regular fire fighting equipment and effect a fire fighting organization at its mines, was the Madison Coal Corporation, which operates several mines in Illinois. The main office of this company is in Chicago and the general field office is at Glen Carbon, Ill.

Jul 1, 1930

To provide coal operators with an easy-to-use stress control design procedure to minimize coal mine bumps during room-and-pillar retreat mining conducted with available continuous mining machine technology. Approach The goal of this U.S. Bureau of Mines (USBM) re¬search was to facilitate safe and efficient room-and-pillar retreat mining of bump-prone coalbeds by limiting coalbed stress adjacent to expanding gob areas through variation of section layouts. The first step was design of total-extraction pillars and their associated pillar-extraction plans. The second step was development of a coalbed strength model. The third step was development of stress limit design criteria. The fourth and final step was development of a methodology to estimate the magnitude and distribution of development and abutment loads apllied to the pillar line. The linear geometry of unlimited-width sections allowed for the accomplishment of step four with the tributary-area and linear shear-angle concepts. Increasing overburden depths required limited-width sections separated by barrier pillars to control stress within total-extraction panels. The accomplishment of step four with limited-width section designs required prediction of abutment load distributions for rectangular gobs and apportionment of these loads over mixed pillar sizes. A parametric study of the complicated interaction of various combinations of overburden depths, total-extraction panel widths, and abutment pillar widths was conducted with the USBM-developed boundary-element program MULSIM/NL.

Jan 1, 1995

By E. D. Regad, W. E. Wallace, P. S. Mike, C. A. Hill, V. Vallyathan, M. J. Keane

"Respirable-sized quartz, a well-established fibrogenic mineral dust, is compared with kaolin in erythrocyte hemolysis assays aher treatment with saline dispersion of dipalmitoyl phosphatidylcholine, a primary phospholipid component of pulmonary surfactant. Both dusts are rendered inactive after treatment, but the membranolytic activity is partly to fully restored aher treatment with phospholipase Ai. an enzyme normally associated with cellular plasma membranes and lysosomes. Phospholipid-coated dusts were incubated for periods of 2-72 h at a series of applied enzyme concentrations, and the adsorbed lipid species and hemolytic activity were quantitated at each time for both dusts. Surfactant was lost more readily from quartz than from kaolin, with consequent more rapid restoration of mineral surface hemolytic activity for quartz. Interactions of surfactant and mineral surface functional groups responsible for the mineral-specific rate differences, and implications for determining the mineral surface bioavailability of silica and silicate dusts, are discussed. INTRODUCTIONMineral particles depositing in the lung acinus will contact an aqueous coating containing surfactant molecules spread on the air-liquid interface and dispersed within this hypophase; the primary components of that surfactant are diacyl lecithin phospholipids (King and Clements, 1972; King, 1982). Adsorption of this surfactant can suppress the cytotoxicity of mineral dusts (Marks, 1957). Suppression of hemolytic activity, a measure of membranolytic potential and an indicator of bioavailability of the mineral surface, of respirable-sized quartz and kaolin clay dusts with the adsorption of dipalmitoyl glycerophosphorylcholine or dipalmitoyl lecithin (DPL) has been measured (Wallace et al., 1985). Such contact and adsorption of pulmonary surfactant in vivo may provide a first defense system of the lung against respired dusts."

Mar 1, 1992

By Charles Vaught, Warren G. Lacefield, Ronald D. Wasielewski, Philip K. Berger, Henry P. Cole, John V. Haley, Shannon L. Price

A comprehensive review of published research was carried out to identify methods for teaching and assessing critical but nonroutine skills needed for coping with emergency situations. Computerized searches of the relevant data bases were carried out, along with identification of relevant articles and materials by personal contact with experts in many fields. The citations listed in this bibliography resulted from this systematic literature search and review. The computer searches and an analysis of this literature are described in technical report 1. Specific methods for assessing critical skills proficiency in aviation, medicine, organization management, the military, and other industrial/ technical workplaces were described. The potential application of these methods for teaching and assessing (1) critical first aid and (2) self-rescue and escape skills to underground coal miners in annual refresher training was explored. Research and development activities that may improve mine health and safety training were suggested. Most of the entries in this bibliography were assembled in 1984 through 1985. Study of these materials contributed to the completion of the project research that followed. This later work is reported in the project technical report 2 and the final report. This bibliography is most useful when combined with examination of technical reports 1 and 2 and the final project report.

Jan 7, 1988

By B. W. Naugle

A small-scale laboratory coke oven similar to those described by Swiniarski, Cryan, and Altieri and Fuchs, Sandhoff, Taylor, and Gauger was built by the Bureau of Mines in 1943. Tests made since that time have indicated that such a small oven is of questionable value in predicting the coking pressures to be expected in commercial coke ovens. This summary of the work done has been prepared at the suggestion of the Advisory Committee to the Bureau of Mines-American Gas Association Survey of Carbonizing Prop¬erties of American Coals.

Jan 1, 1948

By Charles H. Atkinson

The Rio Blanco massive hydraulic fracturing demonstration has been undertaken by the Bureau of Mines, Atomic Energy Commission, and a group of 15 industry participants. CER Geonuclear Corp. has been retained as program manager to evaluate the stimulation effects of very long fractures, suitably propped open in thick sections containing multiple intervals of low-permeability gas-bearing sands. The zone of interest for this demonstration includes Fort Union and Mesaverde sands from about 5,800 to 8,.200 feet deep in Rio Blanco County, Colo., about 1 mile from the site of the May 1973 triple nuclear detonation aimed at stimulating production from the same reservoirs. Drilling the test well and evaluating the reservoir prior to fracturing was funded by Government participants; fracturing and production testing will be funded by industry. The test well has row been completed at a total depth of 8,170 feet, and data obtained from logs, cores, production and drill-stem tests indicate reservoir conditions to be less favorable for gas production than anticipated. Structural position is lower than expected, resulting in higher water saturation than was determined for the same sands at the nuclear fracturing location. The lower sands of the Fort Union sequence appear to have higher shale content than has been encountered in other wells in the area. Despite the likelihood that gas productivity will be undesirably low following stimulation, the industry participants decided to proceed with the stimulation program with the thought that the resulting data would be useful. The success of the stimulation test probably will have to be judged by production increase rather than by production volume.

Jan 1, 1975

By Robert Lee Stahl

Comprehensive field tests were made by the Bureau of Mines at the Schwartzwalder mine near Golden, Colo., to determine whether surface geophysical techniques could be used to detect and delineate faults in uranium deposits. The tests included seismic refraction, magnetometer, electrical resistivity, airborne infrared thermal scanning, and airborne photography. Of the several geophysical techniques tested in the field, horizontal resistivity profiling with electrode spacings in the range of 10 to 15 feet was most diagnostic of faults. The method is quick, inexpensive, and accurate and can be easily used by mining company personnel to detect and delineate faults.

Jan 1, 1974

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of El Salvador has been prepared from the best available information in Washington , but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State . Under the terms of the Code of Commerce ( arts . 12ff . ) , foreigners living in El Salvador can engage in business on the same terms as nationals . This involves ( = $434.00 ) - except for those with a working capital , of less than a thousand pesos inscription in the merchants ' register , which can be refused only in case of manifest disability of a permanent nature .

Sep 1, 1930

By R. Agarwal

The in-situ stress field was determined, using the overcoring technique, at two underground sites at the Pea Ridge Mine, Sullivan, Missouri. At one of the sites in magnetite, the three dimensional stress field showed the largest principal stress to be compressive (-4564 psi), nearly horizontal and closely parallel to the strike of the orebody. The smallest principal stress was also compressive (-2047 psi) and nearly vertical. Considerable difficulty was experienced in drilling porphyry rock at the second test site in the host rock. Only one hole was drilled at this site. The secondary principal stresses obtained in the porphyry are -9464 and -4945 psi, respectively. The-test site in magnetite is located at a depth of 2505 feet whereas the site in porphyry rock is at 2475 feet. The vertical stresses: due to overburden loading at these sites are -3590 and -2782 psi, respectively. Field determined values of the vertical stress are -2207 and -5098 psi, respectively. The variance; between the two sets of values is most likely attributable to the orebody formation and the differences in the modulii of the host rock and the orebody.

Jan 1, 1977