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This sheet explains your audiogram (hearing test) and gives some basic information about protecting your hearing. Keep it so you can refer to it later. What is an audiogram? • An audiogram is often called a “hearing test,” but there’s no pass or fail • It is a written record of your hearing levels • A series of audiograms can track changes in hearing over time • Your hearing threshold levels (the quietest sounds you can hear) are measured in decibels (dB) at different frequencies from low (500 Hz) to high (8000 Hz) Why should I get audiograms? • To measure your hearing ability • To identify hearing problems • To monitor success at maintaining your hearing • To see if noise exposure is affecting your hearing Do I have normal hearing? Compare your hearing threshold levels to this scale: -10 – 25dB Normal hearing 26 – 40 dB Mild loss 41 – 55 dB Moderate loss 56 – 70 dB Moderate/severe loss 71 – 90 dB Severe loss 91 – 100dB Profound loss [ ]

Jan 1, 2008

By K. K. Kelley

Thermodynamics data for silicates have applications in the fields of extractive metallurgy, ceramics, and geochemistry. To facilitate these applications, up-to-date tables of heats and free energies of formation are needed. It is the purpose of this report to supply such tables for anhydrous silicates. During the last 15 years the heats of formation of a substantial number of anhydrous silicates have been reliably determined at or near room temperature. This resulted from the development (first by the Bureau of Mines and later by the Geophysical Laboratory of the Carnegie Institution of Washington, by the Institute of Geology of the University of Helsinki, Finland, and by the Department of Geology of the University of Chicago) of accurate solution calorimeters, employing hydrofluoric acid as the reaction medium. Specific references to work of these laboratories will be made in the next section of this report. Also, entropy data at 298.150 K. and high-temperature heat-content values are available for many of these silicates, mainly owing to work of the Bureau of Mines. Most of these entropy and heat-content data have been compiled in Bureau of Mines Bulletins (13, 15).3

Jan 1, 1962

By W. W. Adams

Rock dust, as a preventive or limiting factor in explosions of gas and coal dust in bituminous-coal mines, was used in larger quantities in 1939 than in any other year except 1937 since annual figures first became available in 1930, Reports from mining companies to the Bureau of Mines revealed that 144,430,000 pounds of rock dust was applied to underground mine workings in mines that produced 126,635,677 short tons of coal during the year. This quantity of rock dust applied averaged 1.14 pounds for each ton of coal produced. Rock dusted mines were the source of 39.7 percent of the total production of bituminous coal from underground mines; 33.2 percent of the total number of underground workers were employed at rock-dusted mines, and 35.9 percent of the total number of man-hours worked underground at all bituminous-coal mines in the United States during 19719 can be accredited to mines so treated.

Jan 1, 1940

By Louis Schaffer

A literature review concerning dredging hazards and dredge safety practices and an examination of MSHA accident and injury statistics on dredge mining in the United States provided the background for an analysis which was completed by visiting 31 dredge operations, dredge manufacturers, and dredging experts. The principal hazards are discussed and countermeasures are suggested in several areas. Drowning is the single largest fatal injury category. Special emphasis is given to the design, care and use requirements of personal flotation devices.

Jan 1, 1984

By William H. Pomroy

The Bureau of Mines, through a 4-year program of combined in-house and contract research, has developed the necessary hardware and software technology to provide rugged, reliable automatic fire protection for surface mining mobile equipment. One element of this program was a continuing effort to help foster rapid mining industry acceptance of the technology by keeping end user costs reasonable. This report is an analysis of the economic impact of surface mining mobile equipment fires and the cost benefit of utilizing automatic fire protection systems to abate these losses.

Jan 1, 1982

By John W. Taber

The Bohemia mining district is a small but intensely mineralized area in western Oregon . For its size , it has made a substantial although somewhat sporadic production of gold throughout a long period of years . The veins also contain lead, zinc , and copper, but in the past these metals have not been recovered in important amounts . In reviewing the progress of mining activity in the district , an effort has been made to gather under one cover all available information on former operations , including methods of mining , production, and geology pertinent to the ore deposits , problems encountered, and other factual data that may affect future mining in the district . A special effort has been made to assemble as many maps of former workings as possible in order that these may be preserved and readily available to assist in future exploration. The data presented herein are based on brief reconnaissance examinations made during several weeks spent in the field in September 1946. These are supplemented by information obtained from various individuals actively or formerly connected with operations in the district . Only the principal properties and several of the more outstanding prospects were actually examined. Many of the older workings were inaccessible.

Aug 1, 1949

By F. A. Penning

This report describes the development of skip and guide desings for vertical shafts in deep vein mines. Skip and guide systems for bottom dump skips are identified as being used in current practice. Mine visits were made to obtain current information on the needs and problems of operating mines. Methods of structural and mechanical analysis of skip bodies and bails are outlined. A dynamic computer model was written to find the dynamic interaction between skips and guides for guides with geometric misalinements. A materials evaluation section identifies currentavailable and applicable materials that can be used effectively for new skip construction. Guide materials are also presented. Analysis includes the economies resulting from streamlined buntons and from low skip payload ratios. Selection of materials is based on strength, abra¬sion and corrosion resistance. Design requirements related to the shaft environment are presented. Consideration for the selection of guides and buntons is also given. Conceptual design includes the concept of cylindrical skips, center-seeking guide rollers, and asymmetric bail design to decrease dynamic interaction. An outline for field tests is presented. Future research areas are: testing, guide geometry measure¬ment, advanced suspension, dynamics, and structural configurations.

Jan 1, 1977

By E. J. Gleim

The importance of "good voltage,? especially for direct-current systems in coal mines, is not always fully appreciated. From the practical 4 aspect there are three viewpoints from which low voltage may be considered, namely: (a) its effect upon operation of electrical equipment, (b) its effect upon cost of maintenance and power, and (c) its effect upon safety in the mine. The design of electrical motor-driven equipment usually is based upon a given or assumed constant value for the voltage of the system; consequently, when there is an appreciable drop below this value, unsatisfactory operation is likely to follow. In the case of shaker conveyors, for example, one manufacturer has pointed out that these conveyors must be operated at a certain definite speed if maximum output is to be secured. As shunt motors are used in the conveyor drives, either a rise or fall in voltage will produce corresponding changes in speed and thus seriously affect the efficiency of the conveyor. The introduction of automatic control for mine equipment has been greatly retarded because the relays, contactors, and other special devices required have failed to function properly when attempt was made to operate them on systems subject to variable and low-voltage conditions.

Jan 1, 1937

As shown in Table 9, consumption has risen steadily for the period November through April, reaching its highest level since June of 1974. Imports remained at a relatively high level in spite of decreased imports from Zaire and Belgium-Luxembourg. Award prices for cobalt sold by the General Services Administration on June 17, 1976 ranged from $5.058 to $5.41211 per pound of contained cobalt. The high bid was about $1 per pound above the current market price set by the major sales agent in the U.S. for cobalt on April 15, 1976. COPPER: Eight domestic producers on July 1 hiked refined copper prices by 4¢ to 74¢ per pound for cathode and to 74.625¢ for electrolytic wirebar. New York Commodity Exchange (COMEX) June pricing of prompt contracted copper averaged 70.6¢, with daily quotes registering between 67¢ and 72.5¢ per pound. In June, London Metal Exchange (LME) cash wirebar prices averaged 70.3¢, trading between a low of 65.5¢ and a high of 73.6¢. End of the month copper stocks totaled 108,758 short tons for the COMEX and 539,350 metric tons for the LME.

Jan 1, 1976

By Paul C. McWilliams

The U.S. Bureau of Mines has, primarily through its contract program, used large-scale centrifuges to determine design criteria for tailing embankments. The centrifuge runs were made at two installations, the University of Cambridge, Cambridge, England and Sandia National Laboratories, Albuquerque, NM. The major problems considered were as follows: slope stability of embankments, modeling erosion and seepage, use of the phreatic surface level to ascertain the validity of centrifuge modeling, and the effects of compaction and weathering on a tailings embankment. This report summarizes the results of the four test series conducted at University of Cambridge and Sandia National Laboratories. A review of prior centrifuge applications to mining problems is included. Consideration is given to future centrifuge application to mining problems in both soil and rock mechanics.

Jan 1, 1989

By H. R. Babitzke

The purpose of this investigation was to develop an alloy of columbium for use at high temperatures and for nuclear applications. The properties of possible alloys were determined, and the more promising ones were selected for further improvement. Criteria for selection were machinability, hardness, workability, tensile strength, and oxidation resistance. Thirteen 100-gram ingots, ranging from 100 percent columbium to 100 percent vanadium, were prepared and subjected to various tests. Also included for comparison were zirconium and the zirconium alloy, zircaloy-2. Test results showed that a columbium alloy, containing 10 atomic percent vanadium merits further development. Besides being workable at room temperature, the columbium-10 atomic percent vanadium alloy has oxidation resistance superior to the other alloys of the series and is also superior to zirconium or zircaloy-2. The latter two materials have comparable neutron-absorption cross sections. The strength and hardness values of the alloys tested were found to increase with increasing vanadium content, reaching a maximum at 50 atomic percent vanadium and decreasing with further increase in vanadium. This behavior is typical of binary alloys wherein each element will retain any proportion of the other in solid solution. INTRODUCTION There is an increasing need for alloys for service at high temperatures. Since current world reserves of columbium metal approximate 1,500,000 tons (1),4 this metal is now readily available. Columbium can ties; be considered a practical base material for high-temperature alloys required in nuclear reactors and in aircraft and space vehicles. General requirements chosen are: (1) Workability, (2) satisfactory mechanical properties at temperatures approaching 1,000° C., and (3) resistance to oxidation at such temperatures.

Jan 1, 1962

By Kenneth H. Johnston

Records show that waterflooding was tried in Osage County as early as 1934, but it was not economically important until a large unitized flood in the North Burbank field was begun in 1950. Development was rapid and by the end of 1960, there were 70 active water flood projects and 16 active pressure-maintenance projects in the County. The locations and status of the water-flood and pressure-maintenance projects in Osage County on December 31, 1960 are shown in figure 1, and information pertaining to these projects as of July 1, 1960 is given in table 1. For the past several years, Bureau of Mines petroleum engineers have arranged tours of selected waterflooding projects for the spring meeting of the Kansas-Oklahoma Water flood Association. These tours are conducted to demonstrate unique operating methods and new field equipment and to provide additional opportunities for exchanging information. Each of these tours has been supplemented by a published report describing in detail the projects visited. This report has been prepared for distribution during the 1961 spring tour of three waterflooding projects and a pressure-maintenance project in Osage County, Okla. (fig. 2).

Jan 1, 1961

By Rupert O. Yantz

This report, authorized under contract Number H0111403 Amendment Number One, entitled, "Exploration of Illumination Concepts for Underground Coal Mines", contains the results of an investigation of methods, procedures, and technology for providing working place lighting in underground coal mines and construction of a prototype, man portable, mine illumination system and a prototype, machine mounted, mine illumination system for use in high and low coal entries of underground coal mines.

Jan 1, 1972

By Felipe Calizaya

This study describes the principles involved in the design of a booster fan installation, the basic requirements, and the provisions needed to guarantee a safe operation of the unit. It also describes how a booster fan should be selected and what measures should be taken so that events such as uncontrolled recirculation of air in a mine can be avoided. A computer program called MFSELECT is presented to assist the ventilation engineer in the design process a For a given mine ventilation network, the program determines the duties of fans and regulators that will fulfill the airflow requirements of a mine and minimize the total power consumption. The application of the program is illustrated by the detailed solution of a sample problem. A Case Study based on the Jim Walter Resources' No. 7 Mine is utilized to describe the basic requirements for the design and operation of booster fans, and illustrate their potential benefits in mine ventilation. Finally, the study discusses a process control system designed to evaluate the safety conditions in the mine and report on the status of both surface fans and underground booster fans.

Jan 1, 1990

By Roger L. Baer

Marine disposal of mill tailings has been practiced worldwide for over a century. However, only recently have the environmental effects of marine disposal been systematically studied. Some early attempts at marine disposal of tailings resulted in adverse impacts to marine life. However, recent advances in tailings disposal methods have included the introduction of engineered submarine tailings discharge systems, advanced environmental assessment and monitoring methods, and oceanographic modeling systems. Successful submarine tailings disposal (STD) has occurred at several mines. The U.S. Bureau of Mines (BOM) has undertaken studies of the disposal of mining and milling wastes in the marine environment. The BOM Alaska Field Operations Center, Juneau, initiated a review of the technology, regulations, and economic aspects of STD. The review illuminated the need for organization of literature on the subject, therefore the Bureau compiled this extensive bibliography on marine disposal of mill tailings. The bibliography presented here contains 1483 references and is also available through diskette in the Word Perfects format. A review of the references indicates that literature on submarine disposal inadequately covers the subject. The majority of the references listed only peripherally relate to the subject. Published literature on the engineering and environmental aspects of STD is severely limited.

Jan 1, 2011

By L. G. Marshall

This report describes dredging and processing of sand and gravel from a glacial-fluvial deposit in the Raccoon River valley near West Des Moines, Iowa. Preliminary cleaning and separation of the sand and gravel at the dredge site with subsequent transportation to separate plants and the production and disposal of the various grades of aggregate material are also described. The geology of the deposit is summarized. A tabulated summary of costs in units of labor, power, and supplies is included.

Jan 1, 1963

To improve communications between mine workings and surface locations during emergency situations and for administrative purposes. The Approach: Development of a device for interconnecting phone systems which permits two-way communication between a public telephone and a mine pagerphone by authorized personnel. How It Works: The system, developed by personnel at the Bureau's Pittsburgh (Pa.) Mining and Safety Research Center, makes connections between the public phone line and mine pagerphone line. As shown in Fig. 1., incoming calls are sensed by the ring detector (4) and the system "answers" the call electronically. To reach the pagerphone system, the caller inserts an audible tone of fixed frequency through the microphone of his telephone. This tone is produced by a miniature, pocket-carried tone generator and is detected by a tone recognition circuit (5). When this hap-pens, relay, switching, and logic circuitry (6) closes the connections between the two phone systems. Simultaneously, a page activator (9) places a DC paging voltage on the mine phone line.

Jan 1, 1974

By Gerald T. Homce, James C. Cawley

This paper updates an earlier report by the authors that studied electrical injuries from 1992 to 1998. The previous information is expanded and supplemented with fatal and nonfatal injury rates and trends through 2002. Injury numbers and rates were used to compare and trend electrical injury experience for various groups and categories. This information allowed identification of at-risk groups that could most benefit from effective electrical safety interventions. The data presented in this paper are derived from the U.S. Labor Department’s Bureau of Labor Statistics’ Census of Fatal Occupational Injuries (CFOI), Survey of Occupational Illnesses and Injuries (SOII) and Current Population Survey (CPS). Between 1992 and 2002, 3,378 workers died from on-the-job electrical injuries. Electricity remained the sixth leading cause of injury-related occupational death. From 1999 through 2002, 4.7% of all occupational deaths were caused by electricity, down from 5.2% in the 1992 to 1998 time period. The cause of death was listed as electrocution in 99.1% of fatal cases. Contact with overhead power lines was involved in 42% of all on-the-job electrical deaths. The construction industry accounted for 47% of all electrical deaths between 1992 and 2002, but showed overall improvement from 1995 through 2002 by reducing its electrical fatality rate from 2.2 to 1.5 per 100,000 workers. An additional 46,598 workers were nonfatally injured by electricity. Contact with electric current of machine, tool, appliance, or light fixture and contact with wiring, transformers, or other electrical components accounted for 36% and 34% of nonfatal electrical injuries, respectively. Contact with underground, buried power lines was involved with 1% of fatal injuries and 2% of nonfatal injuries. NIOSH research aimed at evaluating commercially available overhead power line proximity warning alarms is described. This research is expected to be the initial step for eventual development of a performance standard for such systems.

By A. L. Foote

This is the final report of work accomplished during 1973-75 under U. S. Bureau of Mines Contract No. H0242015, "System for Handling Underground Mine Supplies and Materials." The purpose of the contract was to develop a mechanical device which could safely perform handling tasks that are normally done manually in underground bituminous coal mines. The report discusses studies leading to construct-ion of a battery-operated, three-wheel vehicle with a six-degree-of-freedom manipulator. Supportive design studies included collection and analysis of production, manual functions, and injury data on the underground bituminous coal mining industry. Transfer tasks in section storage and working places were the prime candidates for mechanical handling. Functional specifications were developed for two handling devices (one to handle existing unit loads and one to handle repackaged unit loads) and for a vehicle to mount the handling device. Design concepts for nine different handling devices were developed and a cost/benefit evaluation made for each. Detail design, capital and operating costs, and method improvement savings data were developed for two battery-operated vehicles and for two different manipulators. The three-wheel vehicle with anthropomorphic manipulator was chosen for development.

Jan 1, 1978

By T. R. Achenbach

1. This, the final report to the U. S. Bureau of Mines on the program with the subject title, presents the data obtained from June 29, 1973, to April 20, 1974. 2. Operating in the Illinois #6 coal seam, the effectiveness of foam opposed to water was compared in reducing respirable coal dust. A combination of 39 foam generators and 14 water sprays were used during the foam tests. Sixty one water sprays were operated during the water tests. Data from 24 shifts using foam and 21 shifts using water are presented. 3. Additional work on foam generator design should be undertaken to provide coverage to a wider area with foam. 4. The general attitude of those working on the foam program and with the miner at the face was positive. It is urged that the work be continued. 5. The minor respiratory irritations evidently caused by an aerosol effect of the surfactant should be investigated. 6. The statistical analysis of the tests will be made and reported by the U. S. Bureau of Mines.

Jan 1, 1974