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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 J. E. Conley

[Available statistics show that the demands of the American chemical industry for sodium sulphate have been increasing slightly in recent years. The supply from domestic sources, particularly in the form of byproduct salt cake from the acid manufacturers, has been tending to decease due to the growing manufacture of synthetic acid. Both hydrochloric and nitric acids are being synthesized from their elements. The natural result has been that a smaller amount of salt cake is available. Simultaneously, the expansion of the Kraft-paper industry, especially in Lie South, has brought about greater demand for sodium sulphate in that section. This demand is being met by domestic byproduct salt cake, by imported German sodium sulphate made from potash waste liquors, and by favorably situated domestic deposits of Glauber salts and tile anhydrous salt, thenardite. No shortage of natural sodium sulphate exists in the United States, but usually such deposits occur in semiarid regions far re¬moved from transportation facilities and from markets. Moreover, the major portion of the natural deposits is Glauber salt or mirabilite (Na2SO4?10H20), which must be dried or dehydrated in order to most consumer requirements. The waters of hydration represents, roughly, 55 percent of tae total weight of the crude salts and therefore has a very important influence on transportation costs. In marry instances the cost of getting even the dehydrated product to market is the deciding economic factor. Therefore, the recovery or production of anhydrous sodium sulphate from plant-waste liquors or from natural brines of suitable composition might be economically feasible.]

Jan 1, 1936

By Phillip R. Moyle

In 1985 the U.S. Bureau of Mines evaluated the mineral resources of tie Bruneau River and Jarbidge River study areas, Owyhee County, ID, for the U.S. Bureau of Land Management. The study areas, separated by a narrow corridor, include 90,000 acres of the 107,020-acre Bruneau River Wilderness Study Area (ID-111-17) and 47,000 acres of the 75,340-acre Jarbidge River Wilderness Study Area (ID-17-11). They lie 26 miles and 55 miles, respectively, due south of Mountain Home, ID. Approximately 38 placer claims for gold and 182 lode and placer claims for jasper, agate, and limestone were located within and adjacent to the study areas from 1893 to 1981. Currently, there are eight mining claims for jasper at Indian Hot Springs along the corridor between the study areas.

Jan 1, 1987

Workers at the Consolidated Aluminum Corp. primary aluminum smelter at Lake Charles, LA walked out at midnight March 31 when their contract expired. Management personnel operated the smelter and prebaked carbon anode facilities until an agreement for a new 3-year contract was reached April 18. The Aluminum Company of America (Alcoa) began operations at its can recycling facility at Taylor, MS. The facility can process 3 million pounds per month of aluminum and steel cans. Alcoa announced plans to increase the capacity of its aluminum paste and flake production plant at Logan's Ferry, PA by 50 percent. Completion was scheduled for mid-1980.

Jan 1, 1979

By L. E. Schultze

The Bureau of Mines devised a technique to recover a Zn-Pb concen-trate from a geothermal brine. More than 99 pct of the Zn and Ph was precipitated by treating the brine with H2S and controlling the pH with lime. Recycle of the sulfide precipitates increased crystal size and resulted in easily filterable products. A typical sulfide precipitate contained 53 pct ZnS, 8 pet PbS, 24 pct MnS, and 15 pct FeS. Addition of sulfide as FeS or CaS was not effective in precipitating Zn and Pb, but Zn in the brine was selectively removed with a strongly basic ion-exchange resin. A proposed flowsheet for metals recovery is discussed.

Jan 1, 1985

By Thomas L. McVay

The Bureau of Mines made laboratory batch and small-scale continuous flotation tests of a sample of pegmatite rock from a deposit of the Lithium Corporation of America, Inc., near Kings Mountain, N.C., to determine the feasibility of producing commercial-grade spodumene concentrates. Various reagents and flotation procedures were tested to determine the optimum conditions for floating the spodumene and retarding the gangue minerals. The best results were obtained when sodium fluoride and lignin sulfonate were used as the pulp conditioner and oleic acid was used as the spodumene collector. The continuous flotation tests indicated that commercial-grade. spodumene concentrates analyzing 6.4 pct. Li2O could be produced with recovery of 77 pct. of the lithia in the ore.

Jan 1, 1962

By T. T. Read, F. C. Houghten

"The bad effects upon the health and output of miners that result when the ventilating current in a mine lacks sufficient cooling power have been described by Harrington and Sayers in a previous report (1)*** The normal temperature of the human body is about 98.5°F. and whenever work is done by the muscles, indeed even when sitting still, the normal bodily processes generate heat which must be given off, otherwise the body will become overheated and a number of bad effects will be produced. If it were possible to so enclose a man that he could continue to breathe and no heat could escape from his body he would die within a short time. In a series of experiments made at the Pittsburgh Station of the Bureau of McConnell and Houghton (2) found that a dry-bulb and a wet-bulb temperature of 112.5°F could he borne for only 35 minutes, even when the subject was at rest. A wet-bulb temperature of 100.4°F (dry-bulb 157°F) could only be tolerated for 45°F minute. Under such conditions the bodily temperature rises as much as 45°F above normal and the pulse is accelerated. Very uncomfortable sensations are felt when the pulse rate exceeds 135. The human body, like any other internal combustion engine, must be cooled in order to function properly.Under ordinary circumstances the air surroundings people is enough coder than themselves to permit this heat generated within the boiy to be river off with¬out difficulty. At higher temperatures, or when the rate of work, with its corresponding generation of heat is high, the body can not throw off heat fast enough, so it begins to sweat and the evaporation of the sweat cools the body. But the results of the experiments cited above indicate that in still air, even with the body at rent, it can not adjust its temperature when the air is above 90° wet- bulb. J. S. Haldane (4) says ""at a wet-bulb temperature of 60°F the actual amount of work done by the miner begins to fall off; as the wet bulb temperature rinse farther the work Bona gradually diminishes to the vanishing point. Then the temperatures indicated by the wet-bulb exceeds 85°F hard work in a mine seems hardly or the commercial working of a mine the wet-bulb thermometer should not in generaI, be allowed to rise above 80°F, unless perhaps where there it a good current."

Dec 1, 1923

By A. D. Mah

Thermodynamic data on compounds of arsenic and sulfur were critically evaluated by the Bureau of Mines. Changes of standard enthalpy and Gibbs energy, and logarithms of the equilibrium constants were tabulated as a function of temperature for reactions involving these compounds.

Jan 1, 1982

By R. E. Head, Virgil Miller

"INTRODUCTIONRecent investigations at the Intermountain Experiment Station of the Bureau of Mines at Salt Lake City indicate that metallurgists have given little attention to the occurrence of jarosite minerals in the oxidized ores of lead and silver. These investigations have also emphasized the importance of knowing when these minerals occur in the oxidized ores, especially those containing lead, silver, and gold, as their presence is a material factor in selecting a suitable kind of treatment. Since the question of the occurrence of jarosites in oxidized ores has come to the attention of the Bureau of Mines, investigation has indicated that plumbojarosite and argentojarosite are quite common. These two minerals appear to be widely distributed and probably escaped recognition by persons who had attempted to treat certain oxidized lead ores in which the jarosite minerals represented a material portion of the metal content.Consideration of the physical characteristics of the jarosites also indicates that in many cases failure to treat some of the oxidized lead ores with success has been directly due to the fact that the greater portion of their lead and silver content was present as plumbojarosite and argentojarosite. The data and the description of these minerals given in the body of this paper indi¬cate that attempts to recover lead and silver from ores in which appreciable amounts of the metals occur as plumbojarosite and argentojaeosite would be unsuccessful if confined to gravity methods of concentration. There are un-doubtedly considerable tonnages of oxidized lead ores in the various mining regions of this and other countries, and it is quite probable that in some of these ores the metal content of lead and silver may be largely anglesite (lead sulphate) and cerussite (lead carbonate) but that they will also contain cerargyrite (silver chloride), argentojarosite, and plumbojarosite. The treatment of such ores therefore presents an important problem, since a product is discarded from ores from which the recoveries of lead and silver have been below 70 per cent which is probably too low-grade to warrant aftertreatment by any process now in use."

Apr 1, 1928

By R. S. James, E. J. Gleim

Not long after electrically driven equipment was introduced into coal mines it became apparent that the spark-producing parts, such as controllers and motors, required safeguards to prevent the ignition of mine gas that might come into their vicinity. Many of the early designs attempted to provide protective enclosures having ventila¬tion and relief for pressures if ignition should occur within. The principal feature of the Davy safety lamp, namely, the wire gauze, was employed widely for this purpose. Other devices were developed to reduce the temperature of products of combustion escaping through the protected openings to a value below that which would cause ignition of surrounding explosive atmospheres. Although many such devices performed their intended function satisfactorily under laboratory conditions they were not so satisfac¬tory when subjected to the rigorous conditions encountered under¬ground. Corrosion, mishandling, and accumulations of grease and dirt reduced or destroyed their protective qualities after a period of service in the mines. In the United States this has led to abandon¬ment of special devices in favor of what is called " total enclosure " which means that no regular provision is made for ventilation and release of pressure but rather that the housings or enclosures are built strong enough to withstand the explosion pressures without rupture. As a further protection the joints usually are made of broad, closely fitting surfaces. It is impractical to make such joints absolutely gastight in ordinary machine practice when provision must be made for partial or complete disassembly to facilitate ad¬justments and repairs. Therefore, when an explosion occurs within such enclosures flames may escape through the joints. If the latter are broad enough and not separated too widely, however, the flames will be cooled by contact with the metal surfaces (flanges) of the joints, by rapid expansion, or by both cooling and expansion, with the result that an explosive atmosphere surrounding the enclosure will not be ignited. This is termed " flange protection." In testing parts of cutting machines and other equipment for coal mines, with the ultimate object of approving the equipment for use

Jan 1, 1935

By P. M. Sullivan

A physical beneficiation flowsheet was designed by the Bureau of Mines for reclaiming and recycling metal and mineral values contained in municipal incinerator residues, and a continuous processing plant was installed. Residue samples collected from incinerators located in various parts of the country were processed at a rate of 1/2 ton per hour. Continuous screening, shredding, grinding, magnetic separation, and gravity concentration techniques were applied to produce metallic iron concentrates, clean nonferrous metal composites, clean fine glass fractions, and tine carbonaceous ash tailings. Research to develop systems for refining and upgrading the reclaimed metals and glass into marketable products is also underway. From the engineering data developed in the continuous processing plant, evaluations of the capital and operating costs for plants with capacities of 250, 400, 670, and 1,000 tons of dry incinerator residues per day were made. Research on a parallel system to separate and recover the metals, minerals, glass, paper, and plastics from raw, unburned refuse it currently underway, as are studies on the use of air classification to separate the refuse into organic and inorganic fractions.

Jan 1, 1971

By David J. Ellis

The mineral industry of Benin continued to be confined to the production of cement, crude oil, salt, and sand and gravel. Only crude oil and cement were exported, with the value of crude oil exports and cement exports constituting about 20% and 2% of export revenue, respectively. The value of crude oil exports was less than the cost of imports of refined petroleum products. Production of crude oil was unchanged from 1986, averaging 5,500 barrels per day (bbl/d). The Government managed the facilities at the Semé Oilfield while actively seeking a new manager to replace Pan Ocean Oil Co. of Switzerland, whose contract was canceled in 1986. Recoverable reserves of crude oil were estimated to be between 18 and 30 million barrels.

Jan 1, 1989

By Alfred E. Schwaneke

A new high-temperature soft soldering system has been developed by the Bureau of Mines for use on copper, copper alloys, and low-carbon steel; the method is applicable to automobile radiators and home appliances. The system uses a unique sacrificial metal coating method to promote spontaneous wetting and spreading of zinc and zinc alloy solder: on metallic substrates. The 10-5 to 10-6 cm thick, electroplated or sputtered, sacrificial nickel coating is absorbed by the molten filler alloy during soldering and produces a direct solder-substrate metallic bond. Preliminary measurements on butt joints with copper members give tensile strengths up to 22,000 psi at room temperature using 95 Zn-5 Al alloy as solder. Spontaneous wetting, spreading, and capillary penetration are extremely rapid and produce joints as easily as 50-50 tin-lead solders. Recrystallization or annealing of the wrought copper joint members is negligible at the soldering temperatures of 450° to 490° C and lower. A list of fluxes and solder alloys is included in the report.

Jan 1, 1970

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

C THRM 1 C CALCULATION OF MINE HEAD LOSSES FROM ALTIMETER SURVEY DATA TURN 2 C PENNSYLVANIA STATE UNIVERSITY - MINERAL ENGINEERING DEPARTMENT THRM 3 C THRM 4 C THRM 5 C THIS PROGRAM CALCULATES PRESSURE LOSSES USING THERMODYNAMIC RELATION- THRM 6 C SHIPS BASED ON POLYTROPIC FLOW BETWEEN STATIONS. FOR REFERENCE SEE THRM 7 C "A NEW TREATMENT OF MINE BAROMETER SURVEYS" BY M. J. MCPHERSON IN THRM 8 C 'THE MINING ENGINEER' NO. 109, VOL. 129, P 23. THRM 9 C THRM 10 C THRM 11 C THRM 12 C IDENTIFICATION OF ARRAYS THRM 13 C NOTE THE PROGRAM HAS BEEN DIMENTIONED FOR FOURTY (40) DATA POINTS THRM 14 C BASEC(6;2) BASE INSTRUMENT TEMPERATURE CORRECTIONS THRM 15 C TRAVC(6,2) TRAVERSE INSTRUMENT TEMPERATURE CORRECTIONS THRM 16 C BASER(I) BASE INSTRUMENT READING THRM 17 C TRAVR(I) TRAVERSE INSTRUMENT READING THRM 18 C TDRY(I) DRY BULB TEMPERATURE AT TRAVERSE STATION THRM 19 C TWET(I) WET BULB TEMPERATURE AT TRAVERSE STATION THRM 20 C ELEV(I) ELEVATION AT TRAVERSE STATION THRM 21 C VEL(I) AIR VELOCITY AT TRAVERSE STATION THRM 22 C TBDRY(I) DRY BULD TEMPERATURE AT BASE STATION THRM 23 C BASC(I) BASE READING CORRECTED FOR INSTRUMENT TEMPERATURE THRM 24 C TRAV(I) TRAVERSE READING CORRECTED FOR INSTRUMENT TEMPERATURE THRM 25 C BBASE(I) TEMPERATURE CORRECTED BASE READING IN BAROMETRIC THRM 26 C PRESSURE THRM 27 C BTRAV(I) TEMPERATURE CORRECTED TRAVERSE READING IN BAROMETRIC THRM 28 C PRESSURE THRM 29 C BTRAVS(I) BAROMETRIC TRAVERSE READING CORRECTED FOR ATMOSPHERIC THRM 30 C CHANGES THRM 31 C RELHUM(I) RELATIVE HUMIDITY THRM 32 C ASW(I) AIR SPECIFIC WEIGHT TURN 33 C R(I) GAS CONSTANT FOR MOIST AIR THRM 34 C STPRES(I) STATIC PRESSURE CHANCE BETWEEN STATIONS (I) AND (1-1) THRM 35 C TOPRES(I) TOTAL PRESSURE CHANCE BETWEEN STATIONS (I) AND (I-1) TURN 36

Jan 1, 1977

By Robert W. Geehan

A preliminary examination of the Dayton iron deposit was made in 1941 and 1942 by Paul E. Pesonen and O. H. Metzger, engineers of the Bureau of Nines. Trenching and sampling were recommended, to be followed by core drilling if favorable results were obtained. The Bureau of Mines conducted a project at the property from June to December 1942. The deposit is in sec. 6, T. 17 N., R. 23 E.; sec. 31, T. 18 N., R. 23 E.; sec. 36, T. 18 N., R. 22 E.; and sec. 1, T. 17 N., R. 22 E., M. D. B. & M., about 15 miles west of Lahontan Reservoir in Lyon and Storey Counties, Nev. It lies at an altitude of about 4,500 feet north of the Carson Plains, in the foothill section of mountains that rise to about 7,000 feet to the north of the property. The deposit may be reached by driving 12.5 miles northeast of Dayton over U. S. Highway 50, thence northerly 2.7 miles over a dirt road to the property. The climate is hot and dry in summer, with occasional thunderstorms some of cloudburst variety, and frequent high winds. Winters are usually moderate, with light snowfall and some subfreezing temperature.

Jan 1, 1949

By Ronald S. Conti

Historically, underground mine rescue teams have received training only in the course of actual emergencies, or in simulated mine environments, usually on the surface, with placards to identify objects and hazards. Also, while U.S. Federal Regulations require all underground miners to walk escapeways and conduct fire drills every 90 days, this does not fully prepare them for the conditions that may be encountered in real escape situations, such as smoke filled entries. This paper describes technology and realistic training simulations that have been identified for the general workforce and mine emergency responders. Of all the technology evaluated by underground personnel, laser lights and lifelines were most beneficial in leading personnel to safety and out of the mine in smoke-filled passageways. These technological advancements can improve the state of readiness for rescue personnel and increase the chances of survival for personnel escaping from underground emergencies.

By F. R. Lee

THE Bureau of Mines was established in July 1910 to conduct research and to establish standards for mining equipment and practices which would conserve human life, natural resources, and property in the mineral industries. Several lists of equipment approved by the Bureau as permissible for use in gassy coal mines have been issued since then. The lists covering all approved equipment except breathing apparatus and explosives have born consolidated into two publications: Bulletin 343. Permissible Equipment Approved to January 1, 1953, and Information Circular 8220, Permissible Mina Equipment Approved By The Bureau of Mines During 1953-62. The, purpose of this publication is to supplement Bulletin 343 and Information Circular 8220 with a listing of permissible equipment approved during 1963 and 1964. The schedule, (standards) under which equipment listed herein have been approved are, as follows (cities and dates of approval and revision are, given in footnotes) : Schedule 2F,3 schedule 6D,4 schedule 7C,5 schedule 8C,6 schedule 9B,7 schedule 10C,8 schedule 12D,9 schedule 22,10 schedule 24,11 schedule 25B,12 schedule 25B,13 schedule 29A,14 schedule 30,15 and schedule 31.16

Jan 1, 1966

By F. N. Bender

Percolation leaching of wad-type manganese ores was investigated, using a novel system of alternate upward passage of sulfur dioxide gas through moistened ore and downward percolation of wash solutions to extract solubilized manganese. Bench and large-scale tests designed to simulate vat and heap leaching were made on four wad ores from Arizona and Nevada and on a pailomelane ore from Arizona. Three of the wad ores required prebaking at 500° to 600° C. to produce a permeable agglomerate that would not slake during percolation washing. The hard-type ore and one of the wad ores that contained a large amount of granular gangue did not require prior roasting. The deportment of the different ores toward leaching and percolation was studied with particular reference to the influence of the sulfur dioxide - oxygen ratio and the effect of gas dilution on the rate of manganese dissolution, dithionate formation, and acid production. Crushed charges of the ores, as coarse as 1 inch and as fine as 1/4 inch, were treated for periods of 5 to 11 days. Percolation of the gas and leach solutions through the charges was achieved without difficulty. The manganese extractions varied between 78 and 97 percent and depended upon the size and type of ore leached. The average quantity of sulfur dioxide required in the larger scale tests was about 2.6 pounds per pound of manganese recovered. The dithionate formation varied from 0.35 to 0.9 pound per pound of manganese extracted depending upon the strength of leaching gas.

Jan 1, 1957

By L. C. IlsLey

A list of permissible mine equipment, tested and approved p or to July 1, 1934, was published in Bureau of Mines Information Circular 6813/. The present list4/ includes virtually all the electric air compressors, coal drills, mining machines, loading machines, conveyors, mine pumps, room hoists, mine telephones, rock-dusting machines, switches, electric cap lamps, flame safety lanes, electric hand and trip lamps, electric flood lamps, methane detectors, blasting units, storage-battery locomotives, tandem locomotives, mower trucks, and concrete mixers tested and approved by the Bureau to January 1, 1937. The system under which these devices were tested permits the manufacturer, after his equipment has passed certain tests prescribed by the United States Bureau of Mines, to mark his equipment with a seal showing that it has been approved by the Bureau. These tests are designed to insure that equipments have the minimum requirements for safety in use. The only object of the bureau in making such tests and publishing lists of permissible equipment is to help decrease the hazards of mining.

Jan 1, 1937

By Edward A. Barrett, Roberta A. Calhoun

Introduction This Instructor’s Copy contains most of the information needed to use the Wearing Hearing Protection Properly 3-D training reel. It offers practical suggestions on how to use the reel as a training aid, performance objectives for deciding if the training is appropriate for your needs, and discussion notes that provide additional information to the user. The 3-D reel was designed as a self-teaching aid that drillers and others who work at a drill site can use wherever the opportunity for such training presents itself. The latter could be a company preshift requirement or a tailgate session where workers would have an opportunity to view and discuss the reel. It could also be an individual looking at the reel in a pickup truck prior to beginning work at a drill site. The 3-D training reel is versatile in that it can be used for a small group of persons or for a single worker. For any of these situations, information is transferred to the individual by viewing each of the seven colorful, in-depth 3-D scenes and relating the words that appear in each scene to what is depicted in the visual. Acknowledgment The authors thank Linda J. McWilliams, Statistician, NIOSH Pittsburgh Research Laboratory, for her assistance in analyzing the experimental data in this document.

Jan 11, 2004