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By F. S. Crawford

Safety devices and guards are often looked upon as the last word in safety by the men around the shop or large industrial plant . However , thorough knowledge of the details of their jobs and of the dangers attending them are even more important . It should be unnecessary for all men to go through the experience of the first man to meet an unknown danger , but that appears to be about the only way by which many learn . Practically every danger connected with the job around a mine , blast furnace , steel mill , foundry , coke oven , cement mill , or other operation , was encountered for the first time by someone , and if he was fairly fortunate he either got hurt or just missed being injured and lived to tell his " budaies " how it happened; he spread the knowledge of that particular danger . Sometimes , but not often , a man can foresee a danger . If he could always be on guard and remember everything he had ever learned and also know everything that had happened to the other fellow , and then let that knowledge keep him aware of the dangers in his own immediate " job , " so that he would work the safe way for both himself and the other fellow , he would have what safety engineers call " safety consciousness . " Being safety conscious is a fine attribute , as it really means knowing all about one's job . A man who is really safety conscious is one of the best and most efficient workmen in the whole plant . The boss wants men of that kindmen who want to learn and who try to learn every little detail about their jobwhere there is danger of spoiling the heat or getting burned by hot metal in a steel plant or of loading rock instead of coal or ore in a mine . Such men know how to do whatever job they are on easily and with the least amount of hard work and at the same time get it done as quickly as possible with safety . A man who is safety conscious has to nearly all intents and purposes developed eyes in the back of his head , if he is in a big mill where there if something going on all around him . These eyes are not real eyes , but they are what might be termed a sixth sense which he has developed by his experience in the mill as well as in other dangerous work which he may have done before in other plants . There may be occasions when a man's safety consciousness will leave him for just a short time ; this is likely to happen when he is thinking about a quarrel he had with his wife which has not been cleared up happily , or perhaps when he has bought too many things on installment and with sickness at home

Apr 1, 1931

By Victor E. Kral

"INTRODUCTION The Segerstorm-Heizer property was examined by engineers 3/ of the Bureau of Mines in May and June 1942 and Mach 1943. As a result of these examination, the Nevada State Department of Highways,constructed 9.3 miles of graveled road under the mine access-road program. A magnetometer survey was made by the Geophysical Division 4/ in October 1943, and as a result the Mining Branch set up and conducted a core-drilling,project. Work on the deposit started May 24, 1944, and was suspended on July 31, 1944, but was resumed on December 4, 1944 and continued until completion on March 27, 1945.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as it, primary objective the more effective resource to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploration work, and prepares the final report. The Metallurgical Branch, R. G. Kinickerbocker, chief analyses samples and performs beneficiation tests."

Mar 1, 1947

By Richard W. Lewis

Domestic production of greensand (glauconite) increased 15 percent in quantity and 13 percent in value compared with that of 1964. Since only two firms were in operation, statistics on production and sales for the year are not reported in order to avoid disclosure of individual company confidental data. The average annual production for the 5-year period 1961-65 was 4,306 tons valued at $200,200. The material was marketed for use as a soil conditioner and a water softener. An article of mineralogical interest was published concerning the New Zealand glauconites.2

Jan 1, 1966

By B. W. Gandrud

In 1927 Coghill5 showed that there is considerable liberation of the iron oxide mineral from gangue when the Alabama red iron ores are ground to a size suitable for classification and tabling, but that there is not sufficient to make possible a high extraction and a high grade of concentrate. Coghill states: High extraction and high grade of concentrate cannot be obtained without grinding to a size comparable with flotation or cyanide practice. If grade of concentrate be sacrificed the grinding need not be so severe.

Jan 1, 1934

By Sabri Ergun

Previous studies of magnetic separation of pyrite from coals have been reviewed critically. Magnetic susceptibilities of United States coals of differing rank have been measured. The effects of crushing, magnetic mixing, drying, weathering, and heat treatment on the enhancement of the magnetism of pyrite have been analyzed. The importance of size distribution of pyrite in the coal and the necessity of crushing to liberate the pyrite has been discussed. It has been found that the inherent susceptibilities of the carbonaceous, mineral-free portions of coals (? -0.5 X 10-6 in cgs units) and of relatively pure pyrite isolated from coals (? -0.3 X 10-6) do not permit efficient separation of pyrite from coal; the average susceptibility of the magnetic fraction of coal must be raised to 3 X 10-6. Friction forces encountered in crushing sedimentary pyrite embedded in coal do not increase its susceptibility. Subsequent weathering or heat treatment below 400° C leads to the formation of iron sulfate and hence increases the effective paramagnetism of pyrite. Ferromagnetic compounds of iron are not formed in significant quantities at temperatures below 400° C. The degree of liberation and apparent susceptibility of pyrite are the most important parameters in its separation. It is concluded that effective beneficiation of coals can be achieved by magnetic separation. A sufficient increase in the susceptibility can be achieved by converting less than 0.1 percent of pyrite into ferromagnetic compounds of iron. Such conversions occur only at temperatures >500° C. An investigation of the dielectric properties of coals and pyrite in the frequency range 0.1 to 60 Mhz indicates that the imaginary dielectric constant of the pyrite is about 100 times larger than that of coal. Exploratory experiments indicate that pyrite can be selectively heated to temperatures above 500° C without appreciable rise in the temperature of coal. It appears that dielectric heating of coals in the Ghz frequency range is the most feasible method of enhancing the paramagnetism of pyrite.

Jan 1, 1968

By Terry S. Cory

This report covers antenna design, analysis, and development work suited for use with a wireless radio communication system operating at medium frequency. The work includes the test and evaluation of prototype vehicular antennas developed during the program.

Jan 12, 1978

By Kathleen Madland Kowalski

In recent years the issue of human stress response in emergency workers has begun to receive attention. This paper presents a rationale for considering human stress as a significant factor in the management of emergencies. It discusses the concept of stress, Critical Incident Stress in emergency responders, and introduces the Critical Incident Stress Debriefing (CISD) process. It is suggested that, in a disaster, the CISD process can improve the effectiveness of response teams on site, their turnaround time on site, and post disaster time off the job. This paper, prepared by a US Bureau of Mines research psychologist, offers some ideas to the mining industry in general, mine rescue trainers, and more universally, to those responsible for developing emergency management plans.

By David R. Flinn

This Bureau of Mines report describes methods to electrodeposit erosion-resistant titanium diboride coatings from molten alkali metal borate baths at 900° C. These coatings have been shown to be highly resistant to material loss during impingement with high-velocity alumina and silicon carbide powders, and they show promise as protective coatings to reduce metal loss in erosive chemical environments, such as coal gasification systems. The most erosion-resistant coatings were prepared on nickel, Inconel, and molybdenum from an electrolyte containing LiBO2, NaBO2, Na2Ti03, and TiO2. The best coatings were deposited at current densities of [~]20 ma/cm2, using titanium or titanium diboride anodes. Erosion-resistant coatings were shown to exhibit (1) a high degree of crystallographic orientation along the (100) or (110) planes, (2) a chromium impurity level of less than 3 pct, and (3) a uniform, smooth, consolidated surface appearance when viewed under a microscope or by scanning electron microscopy. Optical spectroscopic studies of the molten electrolyte suggest that the lower valent (+3) titanium ion predominates in the baths.

Jan 1, 1979

By E. D. Gardner

"In recent years efficient safety organizations have been considered essential at all well-managed metal mines. Statistics from numerous mines throughout the country show that the expense of operation of these safety departments is repaid many times by the saving due to fewer accidents. Men trained in first aid, mine rescue and fire-fighting are important parts of the safety organization at most mines. It is more desirable, however, to lay stress ma accident prevention and fire precautions rather than on first aid and fire fighting. Both of these phases of safety work have been well developed in the Globe Miami district. The co-operative mine rescue organization* in this district under Orr Woodburn, is one of the best in the country. Mine rescue teams are kept trained at all the mines and the oxygen breathing apparatus is constantly maintained in good condition. Miners are also trained in first aid, and are offered incentives to make themselves proficient both in mine rescue and first-aid work.The Old Dominion Company is among the leaders in the safety movement in the Globe-Miami district. The safety department at this mine was established January 1, 1914, and has been developed to a high degree of efficiency. W. G. McBride, general manager of the company, takes an active part in the safety work and has given Albert Talon the safety inspector, his active support in developing the organization. The success of the department is dos largely to the ability, tact, and personality of the men directing the work.The following description of the establishment and operation of the safety organization at this mine was prepared from information supplied by Mr. Tallon."

Jun 1, 1921

By R. H. Sprute

Underground accumulations of slimes in the Henderson mine are routed to two large collection pits where they are dewatered and consolidated by application of direct current. Densified material is then removed to ore cars by rubber-tired front-end loaders and transported out of the mine. This Bureau of Mines report describes the electrical dewatering installation and compares its efficiency of operation with that predicted from preliminary laboratory studies performed by the Bureau. Direct current from a 150-kw rectifier (applied for 44 hours at 400 amperes and 65 to 70 volts) converted slimes containing 25.3 percent solids to material ranging from 44 to 65 percent solids. Better results can be expected if the ramp and front sections of the pits are treated separately, using higher current density.

Jan 1, 1980

By H. P. Rue

For the proper control of gasoline treating plants there is need of a quick test for corrosion. In "sweetening" gasoline that is, in treating it to remove evil smelling mercaptans or to convert them to disulphides or sulphides the sodium plumbite ("doctor") method is generally used. This method involves agitation of the gasoline with "doctor solution's (sodium plumbite made by dissolving litharge in a solution of caustic soda) in the presence of free sulphur3. One of the common mistakes in the technique of this process is the addition of too much free sulphur, which will dissolve in the gasoline and cause it to be corrosive. In the operation of a continuous sweetening; or treating plant, a check on the corrosiveness of they product is imperative at all times. The copper-strip test commonly used in specifications take, so long to perform that the plant may fail to function properly for some time before the operator discovers it. The writer has investigated a rapid corrosion test method involving the use of metallic mercury, recently developed by Messrs. G. T. Granger, refinery superintendent, and A. B. Comstock, chief chemist, of the Barnsdall Refineries, Inc., Okmulgee, Okla. They have used this test successfully for several months in controlling the operation of their continuous treaters any have come to the conclusion that it has several advantages over the copper-strip test. Chief among these is the time caved, as the copper-strip test takes at least one-half hour, while the mercury test can be wade in about five minutes. It is very evident that this is an important item in controlling a continuous treater.

Jan 1, 1928

By F. Varley

Researchers from the National Institute for Occupational Safety and Health (NIOSH), in cooperation with mine operators, conducted a study of heat stress exposures among mine rescue workers in underground mines. Mine rescue workers face extreme heat loads as they enter hot and poorly ventilated environments, particularly when they are wearing breathing apparatuses. The burden of wearing a closed-circuit breathing apparatus (CCBA), the inability to drink fluids for extended periods of time, and the potential for ventilation disruptions and fires combine to increase the risk of heat illness during a response to an emergency. In this research, ambient environmental conditions and heat strain indicators were measured using conventional ventilation monitoring tools during mine rescue training exercises. Heat strain was measured with an ingestible temperature-sensing pill that measured core temperature continuously. In addition, a heart-rate monitoring chest strap was used to indicate physical strain resulting from physical activity and heat. Both core temperature and heart rate data were transmitted to a remote recorder worn by a rescuer and time-stamped. Team activities were also observed to determine the contribution of work rate to a person’s total heat load. The effectiveness of several engineering controls, such as cooling the air inhaled by rescuers through an apparatus, wearing cooling vests, and supplying water through the CCBA masks, were investigated. Administrative controls, such as limiting the duration of exposure and controlling the work rate through forced-rest regimens, were also evaluated. Results to date are discussed, and tools for evaluating team condition and estimating the length of time it would be safe for rescuers to work are proposed.

By Richard L. Rains

The Bureau of Mines conducted a mineral investigation of the 29,000-acre Dixie Summit area near Elk City, Idaho, during the summer of 1989. At the Petsite mine a marginally economic, identified resource of 4.9 million tons with an average grade of 0.023 ounces gold per ton was delineated. Possible resources of gold, along with silver, copper, lead, and zinc, occur in at least eight other lode deposits. Placer gold may be recoverable by recreational-sized suction dredges in some stream drainages, Five lode mines in the study area have produced over 5,516 ounces of gold (placer gold production was not recorded), 4,757 troy ounces of sliver, 36,746 pounds of lead, and 3,800 pounds of copper. Current mining claims in or adjacent to the study area total 460 lode and 70 placer claims. There are two patented lode claims within the Dixie Summit study area.

Jan 1, 1991

By M. E. Tyrrell

Magnesia spinel (MgO.Al203) recovered from dusting slags in the system MgO.Al203-2Ca0.SiO2 is in the form of single crystals most of which will pass 35-mash. This investigation was undertaken by the Bureau of Mines to evaluate the concentrates as a refractory raw material. Three specific types of refractory bricks were studied: (1) dense, (2) lightweight bubble, and (3) insulating. Test specimens ware fabricated 1 by dry pressing, fired to 1,675° C., and tested by procedures common to the industry. The concentrates produced a refractor, having satisfactory density and mechanical strength; however, spinal is sensitive to thermal shock and the possibility of producing a spall-resistant brick using aggregate of such small grain-size must be considered remote. Lightweight refractorias fabricated of spinel bubbles were the most promising of the types tested. They were 30 percent lighter in sight than the dense refractory, their mechanical strength was good, and definite superiority in thermal shock resistance was indicated.

Jan 1, 1962

By Franklin D. Cooper

This Bureau of Mines study reviews current and proposed methods of extracting copper from sub-mill-grade ore by leaching. The amount of copper produced by hydrometallurgy has increased dramatically in recent years and will probably be about 200,000 tons per year by 1970.

Jan 1, 1968

By Frank K. McIntosh

The Wood mine area was investigated by the Bureau of Mines in -1941 by a magnetic survey and a gravitational survey. Surface trenches were excavated, and diamond-drill holes were bored at the strongest anomalies developed in common by the two surveys. In the last century', several widely separated bodies of chromite with some magnetite had been exploited in a 'serpentine belt near its contact with schist. At one time this district held a virtual monopoly on the production of chromite. Known ore bodies now are exhausted. Owing to the relatively high specific gravity of chromate compared to normal rocks, a gravitational survey was run to determine which magnetic anomalies were worthy of diamond drilling. Linear feet of trenching totaled 1,710 feet. Ten holes were diamond drilled, which totaled 2,272 feet. The log of the drilling is shown in the text in a tabulation of drill-hole data.

Jan 1, 1948

By L. C. IlsLey

"Nearly every piece of electrical equipment used in mines ""breathes."" In other words, motors, controllers, rheostats, switches, and other similar equipment, even though encased in seemingly tight compartments, breathe in the atmosphere that surrounds them.As the apparatus is used, the temperature of metallic parts is changed generally in positive direction through the heat by friction and the heat due to the electric current. When the apparatus is idle it gradually cools down to the temperature of the surrounding atmosphere.This increase of temperature during operation and return to normal temperature when operation stops alternately raises and lowers the temperature of the atmosphere within the compartments which, in strict accordance with Charles' law -will expand or contract in proportion to any given temperature change.As compartments are not gas-tight, such expansion and contraction will force the atmosphere out of the compartment =on expansion and suck the surround¬ing atmosphere into the compartment during contraction, hence the term ""breathing.""Investigators2 of explosion-proof equipment have recognized that such an interchange would take place and have designed their equipment to safeguard possible explosions within the compartments."

Jun 1, 1927

By E. J. Gleim

For many years mining men have sought for a portable device that would be direct reading and permit more positive detection of methane than was possible with flame safety lamps, which depended so largely on the training, skill, and personal ability of the user. Through the years, after the discovery that methane contributed to many mine explosions, considerable effort and large sums of money have been expended in searching for and developing instruments that would be practical, and, at the same time, reliable and safe to use. Very early in the history of the Bureau of Mines, some of its engineers were unsuccessful, after many trials, in attempts to develop such an instrument. Commercial firms, however, persisted in research until today a number of instruments are on the market that have proved to be practical in coal-mine service. It is hoped, however, that further research will bring about improvements in accuracy and other desirable features. BUREAU OF MINES STANDARD FOR METHANE DETECTORS The Bureau of Mines recognized the need for establishing minimum requirements on which to base official approval of suitable Instruments. This standard was prepared as Schedule 8. It was revised before being issued in printed form. The revision was published as Schedule 8A in 1920 and was revised on two other occasions. The present edition, known as Schedule BC, was issued October 31, 1935.

Jan 1, 1954

By Michael S. Miller

The U.S. Bureau of Mines (USBM) conducted mineral investigations in the 1,227,000-acre Emigrant Trail study area of Nevada during 1992. During the USBM investigation of 25 areas of development interest, 190 mineral localities were identified and 260 rock and 50 alluvial samples were taken. At least 0.5 million troy ounces of gold, 2.3 million troy ounces of silver, 3.3 million pounds of copper, 10.9 million pounds of lead, 2.4 million pounds of zinc, 500 tons of alunite, 40,000 tons of sulfur, 9,000 pounds of mercury, and 21,000 pounds of tin have been mined from the area and vicinity. Adjacent to the study area, gold is being mined at large, open-pit gold mines, the Hog Ranch and Hycroft Resources, Inc., Sulphur mines, and new production is planned at the Rosebud LAC/Equinox. Hog Ranch mine is nearing depletion, but resources of more than 0.5 million troy ounces of gold and about 5 million ounces of silver are estimated for the Rosebud LAC/Equinox project and more than 0.4 million ounces of gold for the Hycroft Resources, Inc., Sulphur mine. Significant investigations are occurring at SP Ridge and other sites near Scossa and at the Dan claims in the Southern Calico Mountains. Precious opal, placer gold, and geothermal energy resources occur in the study area and vicinity.

Jan 1, 1993

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

"Flame safety lamps have been used for about one hundred years in coal mines where a dangerous accumulation of explosive mine gas (methane) might occur and thus render the use of ordinary unprotected flame lamps dangerous. Flame safety lamps are not only used for illumination, but also for detecting the presence of dangerous percentages of methane mixed in the air of the mine.The safety of the lamp depends chiefly upon the cooling qualities ofThe safety of the lamp depends chiefly upon the cooling qualities of the wire gauze used to permit free circulation of the air through the lamp. If one enters a part of the mine where methane is present in the air, the methane enters the lamp and coming in contact with the wick flame is ignited and continues to burn within the gauze without igniting the methane surrounding the lamp. If the air within the mine is traveling at a velocity of several hundred feet per minute the burning gases may be driven through the gauze by the air current. If the gauzes are properly designed and of the proper material, these burning gases will be so cooled as they pass through the gauze that they will not cause an ignition of the gas surrounding the lamp. In order to test the effectiveness of a given safety lamp, tests are made in moving explosive mixtures of gas and air arranged to simulate mine conditions.The Bureau of Mines investigated many features relative to the safety of flame lamps and in 1915 established an official schedule known as Schedule 7 whereby flame lamps having certain prescribed qualifications would be approved as permissible for use in gaseous mines."

May 1, 1920