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By Sean Gallagher, Christopher A. Hamrick, Arnold C. Love

Twelve subjects participated in an investigation of the biomechanical stresses of asymmetric lifting in stooped and kneeling postures. Three factors were manipulated in this study: Posture (stooped or kneeling), height of lift (35 or 70 cm), and weight of lift (15, 20, or 25 kg). Subjects were required to lift or lower a box every 10 seconds for a period of 2 minutes. Electromyography (PIG) of eight trunk muscles was collected during a lift in this period. The PIG data, normalized to maximum extension and flexion exertions in each posture, were input to a biomechanical model and used to predict compression and shear forces at the L, level of the lumbar spine. Results from the EMG-driven biomechanical model indicated that compression was greater when lifting to a higher shelf (p < 0.001), and indicated a significant interaction between posture and the weight of the lifting box (p < 0.01). Peak lateral shear was not significantly affected by any main effects or interactions (p < 0.05). Anterior shear was increased with increasing height of lift (p < 0.001), and also by the posture x weight interaction (p c 0.01). A multivariate analysis of variance (MANOVA) indicated a complex relationship for recruitment of the eight trunk muscles, with the triple interaction being significant (p < 0.001). The results of this investigation will be used to evaluate safe loads for lifting in these restricted postures.

By Foster Fraas

Review of the literature on solid solutions discloses that the relation between composition and magnetic susceptibility is not linear . Recalculation using a transformation of composition values to parameter v values provides for a linear relation with the magnetic susceptibility to the 1/2 power . Application to minerals is illustrated by the olivine and enstentite series .

Jan 1, 1964

By Peter H. Toepfer

This report presents the factual data obtained by the Bureau of Mines during diamond-drilling investigation of the Sunset copper deposit in the Index mining district, Snohomish County, Wash. The Sunset mine, first produced copper ore in 1902, but its main period of activity was from 1923 through 1930, The mine has produced 263,500 tons of ore, from which 1,500 ounces of gold, 156,000 ounces of silver, and 12,912,000 bounds of copper-were recovered. The mine has, been idle since 1946

Jan 1, 1953

"Initiated as a part of the Bureau of Mines program for development of strategic minerals for national defense, various mines in the Poughkeepsie Gulch and Mineral Point mining districts were examined by C. R. Wilfley, W. R. Hamilton, .and N. E. Wvvlwy, Jr., Bureau Of 'Mines engineers, in July and August 1943, July 1944, and September 1945. In a subsequent report a proposal was made to evaluate this isolated area 'of some 15 square miles located in Ouray and San Juan Counties, Colo.Reconnaissance work in the area was begun in June 1946. Mapping and sampling were begun in July and was completed in Pougkeepsie Gulch and extended westward to include the Hendrick Gulch area of the east side of Ironton Park. Project work was recessed for the winter on October 15, 1946 after approximately 6 square miles of the Poughkeepsie Gulch,district been mapped and 801 samples had been taken.In this report the physical features, climate, and ore deposits districts are described, and a brief history of mining and production lead, zinc; and silver is given.The individual mines and prospects in, the area are described in detail.A list of patented claims and ownerships is given in appendix I, and analyses of samples are tabulated in appendix II.The San Juan preliminary project was directed by Paul T. Allsman, chief, Salt Lake City Branch, Mining Division and was supervised by William M. Traver, Jr., supervising engineer, Colorado Field. Office.Chemical analyses were made by the Salt Lake City laboratory under the direction of H.E. Peterson, chemist, and S. R. Zimmerley, chief, Salt Lake City Branch, Metallurgical Division.Harold A. Waddington, president, Great Divide Mining & Milling Corp., and Ernest Miller, owner, Como Consolidated Mines, were particularly cooperative in making available maps and data concerning their properties."

Sep 1, 1949

By C. L. Klingman

In extracting helium from natural gas at Bureau of Mines helium plants, a continuous analysis of the helium content of inlet and outlet gas streams is required to determine extraction efficiency. An analyzer, using established principles of gas chromatography to effect the analysis, has been developed by the Bureau of Mines to meet this need. It will record the helium content of inlet or discharge gases from helium-extraction plants every five minutes, continuously, without the attendance of an operator. A 25-inch column of activated charcoal is used as a partitioning agent; nitrogen is the carrier gas; and a hot-wire, thermal-conductivity cell is the detector. A 1.0 mv, strip chart indicates the unbalance of the detector cell, Sample size is 0.37 cc, and carrier gas flow rate is 75 cc, per minute. Significant improvements in helium extraction have been demonstrated by using the chromatograph in three helium-extraction plants.

Jan 1, 1961

By Walter R. Storms

This paper, which describes the mining methods of the Potash Co. of America in Eddy County, N. Mex., is one of a series being prepared by the Mining Branch, of the Bureau of Mines on mining practices and methods in various mining districts of the United States. 4, T. The mine and plant of Potash Co. of America are situated in sec. 20 S., R.. 30, E.,. N. M. P. M., about 22 miles by paved road northeast of Carlsbad (fig. 1). A spur line of the Atchison, Topeka & Santa Fe Railroad also connects the mine with Carlsbad.

Apr 1, 1948

By J. W. Paul

Withdrawing timber in coal mines is done for the purpose of inducing the roof to cave in the mined-out areas and thereby relieve stresses in the immediate roof material over the working places adjacent to the breakline of the roof, thus preventing the crushing of the ends of pillars and adding to the safety of those engaged in pillar extraction. A secondary purpose is the recovery of timber for further use either as prop-, crossbars, lagging, sprags or cap pieces. At some mines timber is withdrawn as a precaution against fire which may he of spontaneous origin, because wood always aids a fire of any origin. With some of the power-driven types of machines now in use a greater proportion of mine timber may be recovered, and in mines where pillars are left too narrow for their removal some of the timber in rooms might be salvaged for further use.

Jan 1, 1933

By Van H. Manning

"Under the organic act establishing it, the Bureau of Mines is authorized to conduct investigations designed to improve health and safety conditions in the mineral industry and to promote efficient development and utilization of our mineral resources. The field of the Bureau's activity, therefore, begins with the commercial development of mineral deposits and ends with the production and utilization of the final marketable product.In order to serve more efficiently the various sections of the country, the Bureau has established, in addition to its main offices at Washington, D. C., eleven field experiment stations, three field offices and several mine rescue cars and mina rescue stations. These field branches are so distributed as to cover most of the mining districts of this country, including Alaska. The field service in general deals with specific experimental problems, cooperative work with non-governmental institutions, and mina rescue work, while the Washington office is the administrative head and is responsible for the distribution of general information, the chiefs of the technical and administrative divisions of the Bureau being stationed there.The Bureau is prohibited by law from doing work exclusively for the benefit of any private company or individual. Generally speaking, the Bureau does no assaying, ore testing, or similar service work for the benefit of private companies or individuals. In response to requests for work of this sort a list of assay and ore testing laboratories is supplied. In referring inquiries to com-mercial laboratories or consulting engineers, care is taken to mention several names so as to avoid designating any one establishment or engineer."

Apr 1, 1920

By Charles L. Kimbell

World political events that occurred subsequent to yearend 1989 but that bear heavily on the global mineral industry have been of such significance that they cannot be disregarded, and certainly they contribute to any type of "outlook?. However, to write of them simply as "forecasts" in an "outlook" section of this study would be to unjustly pretend to status as prophets. Thus, this section covers events that have occurred not as predictions but rather as history. The section also includes an element with some broad statistical information, but this is included last rather than first for two reasons: the information is subject to considerable re- vision as additional data become available and as preliminary returns are corrected; and the authors view it as less important than the events that govern the statistics. The Near East and the Crisis There.- Of all 1990 political events influencing the world&apos;s mineral industry, the Iraqi invasion of Kuwait and the remarkable events that followed this aggression must head the list. The almost immediate imposition of economic sanctions, involving embargoes on shipment of virtually all goods into and out of Iraq, caused severe dislocations in the production and trade of mineral commodities, not only within the region itself, but with a ripple effect, into other world areas as well.

Jan 1, 1992

By D. Harrington

Although the hysteria. with regard to silicosis end other occupational diseases seems largely to haws passed, and more careful sober consideration is being given this subject, it would be very poor policy for any employer to take the stand that the storm has blown over and that he can safely relax and revert to the status of 5, 10, or more years ago in such matters. The real fact is that occupational-disease compensation is nor in its infancy and can be expected to grow by leaps and bounds. At present, while 46 States of the Union3/ and the District of Columbia have compensation acts, only the following have some fern of occupational-disease legislation: California, Delaware, Connecticut, District of Columbia, Illinois, India a, Kentucky, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Jersey, New York, North Carolina, North Dakota, Ohio, Pennsylvania, Rode Island, Washington, West Virginia, and Wisconsin. Silicosis appears to be compensable under those acts in California, Connecticut, District of Columbia, Illinois, Kentucky, Massachusetts, Missouri, New York, North Carolina, North Dakota, Ohio, Pennsylvania, West Virginia, and Wisconsin; possibly it may be interpreted as compensable in others. Occupational-disease legislation (largely relating to silicosis) has seen under consideration in some form relatively recently in Arkansas, California, Delaware, Idaho, Maryland, Kansas, Massachusetts, Michigan, Minnesota, Montana, Nebraska, New Jersey, Ohio, Pennsylvania, Tennessee, Utah, and. Washington at least. It will be surprising if comparatively broad or inclusive occupational-disease legislation will not be on the statute books of nearly every State in the Union within the next 5 years. With this situation confronting him, the far-sighted industrialist who has the best interests of his organization at heart will immediately begin to "put his house in order," if he has not already done so, by studying possible occupational-disease hazards to his employees; moreover, he will promptly apply all known remedial measures or will attempt to devise such measures if none of those already devised seem to apply to his establishment.

Jan 1, 1939

By H. R. Babitzke, H. Kato, R. E. Siemens

An investigation was made to provide further information for evaluating columbium- hafnium alloys for use as high - temperature structural materials . The columbium- hafnium system was investigated between 700 ° and 2,400 ° C by melting point , thermal analysis , X - ray diffraction , electrical resistivity , and metallographic techniques . The equilibrium diagram is the beta isomorphous type , with columbium tending to stabilize the beta phase . Addition of 60 atomic percent columbium stabilizes the beta phase at 700 ° C. The allotropic transformation temperature of hafnium is 1,750 ° ± 20 ° C. A minimum melting point occurs near 75 atomic percent hafnium .

Jan 1, 1964

By Jeanne A. Zimmer, Brad Smith, Steve Viles, Andrew B. Cecala

A recent report evaluating silica exposure levels in the metal/nonmetal mining industry noted that bag packaging and loading are some of the occupations at the greatest risk. In addition to dust problems, the bag-stacking process is labor intensive, making lost-time injuries common due to back fatigue and strains. During the bag-stacking process, a significant amount of dust can be generated, mainly from product on the outside of the bags and from dust escaping the bag valve upon impact of the bag on the pallet. In an effort to address dust-exposure and back-fatigue issues, Malvern Minerals Co., Hot Springs, Ark., made two major improvements to its ground silica stacking facility. First, the company purchased a semi-automated bag palletizing system (Figure 1). With this system, the bag stacker does not lift the bags, but slides them across a metal table. Small jets of air exit through perforations in the table top (similar to an air hockey game), allowing workers to more easily slide each bag into the proper position. After each layer of bags is completed, the table slides open, and the entire layer of bags is loaded onto an underlying pallet. The table then closes, readying it for another layer of bags. After the entire pallet is loaded, the unit delivers the pallet to a shrink wrap and forklift pick-up area. In addition to this semi-automated palletizing unit, Malvern Minerals purchased an Overhead Air Supply Island System (OASIS) to lower the bag stacker&apos;s dust exposure. The OASIS takes outside air, directs it through MEASURING RESPIRABLE DUST The bag stacker&apos;s respirable dust exposure was monitored using a RAM-1 instantaneous dust monitor to evaluate the impact of the various changes on the palletizing process and dust-control equipment. The bag stacker wore a vest that held the 10-mm Dorr-Oliver cyclone, which classifies the respirable portion of dust. Flexible tygon tubing was used to connect the cyclone to the RAM-1 dust unit, allowing the bag stacker to perform the palletizing process with minimal interference. The RAM-1 measures respirable dust concentrations by light scattering with a sensing chamber. This device closely simulates gravimetric measurements when calibrated for a specific dust. This instrument is ideal for comparative evaluations, as was the case in this study. Since the RAM-1 is not an MSHA-approved instru¬ment for dust compliance sampling, the dust concen¬trations listed in this article should be used as a com¬parative value of respirable dust concentration and not to determine actual dust concentrations from a com¬pliance standpoint.

By Michael A. Trevits

During the time period from 1990-2007, there were 1601 reportable fires that occurred in the U.S. mining industry (an average of 89 fires per year). The leading causes of U.S. mine fires include flame cutting and welding operations, frictional heating and ignitions, electrical shorts, mobile equipment malfunctions, and spontaneous combustion. The National Institute for Occupational Safety and Health (NIOSH) is conducting a program of research addressing metal/nonmetal and coal mine fire prevention, detection, management and suppression. In the metal/nonmetal area, work was focused on technology transfer and training, and research to reduce the number of mobile equipment fires and their hazards. In the coal arena, research is underway to determine the root cause of cutting and welding-related fires and to evaluate the effects of ventilation schemes relative to the spontaneous combustion risk in longwall mines. Relative to fire management, research is ongoing on remote mine seal installation and remote mine fire suppression technologies. Finally, research is continuing to develop comprehensive and usable smoke management techniques and to develop mine fire growth models, propagation, and suppression. This paper presents a summary of some of the mine fire research and provides an overview of the next phase of the NIOSH mine fire research program.

Jan 1, 2010

By Thaddeus B. Evans

This information circular is one of a series describing mining methods and costs, being published by the Bureau of Mines. The Sunbright mine of the Foote Mineral Co. at Sunbright, Va., is the southernmost underground limestone mine in the State. It is a comparatively recent operation, and a description of its rapid development to production stage may have particular interest for the limestone-mining industry. ACKNOWLEDGMENTS Acknowledgment is made to the executives of the Foote Mineral Company including F. B. Shay, vice president in charge of production, W. B. Towner, general production manager; and to the members of the company staff at Sunbright for their assistance in preparing this paper.

Jan 1, 1957

This volume summarizes the contract work performed over a nine-month period by Westinghouse Electric Corporation on a Cost Plus Fixed Fee Contract for the Department of Interior&apos;s Bureau of Mines. The contract has been extended primarily to carry out improvements recommended for equipment produced under the contract for communicating with and locating trapped miners. These improvements will enhance the performance and utility of this equipment for operational use in actual mine emergencies. An additional complete set of the equipment will also he furnished to the Bureau under this extension. The work of the basic contract was to design, produce and test hardware in accordance with the Westinghouse response to a Bureau of Mines Request for Proposal which was based technically on recommendations of a study performed for the Bureau by the National Academy of Engineering (NAE). The NAE study made suggestions for new equipment in three areas of need:

Jan 1, 1971

This chapter analyses the parameters influencing initial design of communication systems, for new mines and upgrading existing systems. Paragraph 5.2 outlines those variables that must be taken into account during the design stages of a new wired phone system. Recommended features, general requirements, and how they can be implemented are treated in this section. Paragraph 5.3 describes ways of improving or extending the range of trolley carrier phone systems and pager phone systems already installed in the mine. 5.2 New Phone System Design The task of designing an adequate communication, control, and monitoring system for an underground mine must be addressed on a system basis. In addition to insuring that effective voice communication is established, any new system should take into account present and future requirements of remote control and monitoring functions. Chapter 4 illustrated the drastic savings in response time that can be realized when remote control and monitoring are integrated into the overall communication system. The importance of including control and monitoring in the overall design plan for any system cannot be overemphasized. Because each mine is unique, and thus usually has its own special operating characteristics and communication requirements, there is no such thing as "the one best system" to meet the requirements of all mines. The optimum communication, control, and monitoring system for a mine must be one that has been tailored to meet the special requirements of that particular mine. Factors that must be considered during system design include- a. Type of mine and mining methods (low- or high-seam coal, deep hardrock mine, stope caving, longwall, room and pillar, etc.). b. Maximum number of working sections. c. Expected mine growth rate and eventual maximum size. d. Haulage methods (tracked trolley, diesel, belt, etc.). e. Underground power distribution system (dc, ac, or both). f. Features desired (two-way radio paging, private line capability for emergency use, etc.). g. Redundant or backup systems for use during outages of the normal system. Although no two mines are alike, the following items have been established as the main characteristics desired for any underground communication system: 1. Multiple Communication Paths to Outside--the objective here is to give all telephones a second method of communicating with the surface. 2. Audible Emergency Signaling--the communication system provides the main means of alerting miners during emergencies. The system should include means to broadcast distinct audible signals for emergency signaling. Initiation of these signals should probably be controlled from. a central outside point, such as a surface control room. 3. Emergency Override--provisions should be included to permit any conversation to be overridden with emergency communication. 4. Selective Area Page--as mines grow larger it is apparent that the entire telephone system paging mode need not be activated each time a call is initiated. When the general area of a

Jan 1, 1984

By W. K. Overbey

Surface fracture trace density, changes in roof rock type, and topographic unloading due to drainage were mapped for the mining areas located in the Blacksville-Osage, W. Va., quadrangles to investigate their influence on mine roof falls. Using these factors, a technique was developed to predict probable roof fall areas ahead of projected mining operations. As a feasibility test of this proposed technique, areas were delineated where one, two, and all three of these factors were operating to formulate a "potential hazard map" for comparison with roof fall observations that were made. The limited evidence suggests that in combination these factors are reliable predictors of where roof falls are likely to occur. This technique promises to be a useful tool in planning mining operations.

Jan 1, 1973

By A. B. Hooker

[Permissible electric cap lamps represent a workable balance between the amount of light needed and the various limiting conditions, such as the weight the miner can carry conveniently, cost of the lamp, including upkeep, and adequacy or practicability of the lamp as regards safety, mechanical strength, and general performance. Other things being equal, the coot desirable lamp is one that gives the greatest amount of useful light. Conversely, with a given amount of light the most desirable lamp is one that its the most efficient respecting weight, cost, and performance.]

Jan 1, 1935

By A. B. Hooker

[Permissible electric cap lamps represent a workable balance between the amount of light needed and the various limiting conditions, such as the weight the miner can carry conveniently, cost of the lamp, including upkeep, and adequacy or practicability of the lamp as regards safety, mechanical strength, and general performance. Other things being equal, the coot desirable lamp is one that gives the greatest amount of useful light. Conversely, with a given amount of light the most desirable lamp is one that its the most efficient respecting weight, cost, and performance.]

Jan 1, 1935

This report describes a U.S. Bureau of Mines investigation into the removal of gate road chain pillars in conjunction with longwall retreat mining. The research objective was to determine, through evaluations of the loads imposed on the gate road pillars and supplemental support elements in the entries, how the pillars, supplemental support, and entries were affected by the longwall abutment pressure. To achieve this goal, vibrating wire stressmeters and hydraulic flat jack pressure cells were installed in the support elements to monitor stress change caused by abutment pressure as a function of longwall face advance. The findings documented in this report are the result of information collected from instrumentation and observation at the mine. Pillar and support loading measurements and stability observations revealed that the roof and the support elements remained stable during panel retreat, while the face progressed at a normal rate of advance. The ability to safely and efficiently mine chain pillars during panel retreat increases resource recovery and can provide several other benefits described in this report.

Jan 1, 2010