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By William R. Vogel

The Bureau of Mines Minerals Information organization collects worldwide data on virtually every commercially important nonfuel mineral commodity. These data form the base for tracking and assessing the health of the minerals sector of the U.S. economy. This data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), to place the collection of mineral statistics on an annual basis. The most recent authority for the Bureau of Mines Minerals Information activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress), which strengthens protection for proprietary data provided to the U.S. Department of the Interior by persons or firms engaged in any phase of mineral or mineral- material production or consumption.

Jan 1, 1988

By Susan M. Moore

Many challenges are faced by workers in lower-seam (42 inches or less) mines. The lower-seam heights confine mine workers to their knees as they perform their daily tasks such as installing roof bolts, delivering supplies, repairing belt, or cutting coal. Miners working in these lower seams often consider kneepads to be their only line of defense against knee injuries. However, healthy knees do not start and stop with kneepads. Other interventions such as changing postures, proper hygiene, and work station design may also be used to reduce mine workers? risks for developing knee injuries. Incorporating these and many other interventions into a mine worker?s ?way of life? is an important step to ensuring a long, healthy career and retirement. Keeping knees healthy is also a key aspect to reducing costs in low-seam mines as the industry battles rising health care costs, and training/recruitment of replacement workers is time-consuming and costly. Educating the workforce about the possible interventions to reduce knee injury risk is a primary objective for the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). Therefore, NIOSH researchers, along with industry and academia, developed a training package to educate the mining community about some possible interventions beyond kneepads that may be used to help decrease knee injury rates. Increased awareness and simple changes are the first steps to reducing knee injuries.

May 1, 2008

By Peter Swanson, John Rettkowski

As part of a research program to reduce injuries and fatalities in the U.S. mining workforce, NIOSH is investigating the potential use of noncontact vibration measurements to identify hazardous ground fall conditions. In the present study, the effectiveness of remote vibration sources in exciting resonant responses in damaged structures is examined. Initial experiments were performed on a damaged concrete slab in a controlled environment. Vibration response was measured with a laser Doppler vibrometer using both single-point and two-dimensional array recordings. Excitation sources included direct mechanical impacts to remote portions of the slab and a remotely located industrial demolition hammer. Surficial damage was effectively delineated with both sources through visualization of vibration response in spectral bands selected to discriminate wave propagation from large-scale slab resonance effects.

By Keith A. Heasley, Frank E. Chase, Christopher Mark

Deep cover retreat mining (overburden in excess of 750 ft) is an important emerging issue which will intensify in the future as the more easily mined shallow seam reserves are depleted. Analysis of Mine Safety and Health Administration (MSHA) statistics indicates that deep cover pillar recovery accounts for a disproportionate share of the underground coal mine roof/rib fall fatalities and injuries. Past research has shown that previously recommended Analysis of Retreat Mining Pillar Stability (ARMPS) stability factors (SF’s) may be excessive for deep cover pillar design. The objectives of this study were to evaluate the various methods and strategies by which panels, production pillars and barrier pillars are developed and extracted under deep cover, and to develop appropriate design guidelines. In the course of the research, 29 mines in 7 states were investigated to collect panel design case histories. At each mine site, underground geotechnical data were collected on the pillar line in order to document roof rock, coalbed and floor conditions. The analyses indicated that squeezes were the most likely failure mode where the depth was less than 1,250 ft, but bumps predominated in the deeper cover cases. Immediate roof rock quality, the ARMPS SF’s, and barrier pillar stability factors were all found to be important parameters in determining the outcomes of the case histories. Design guidelines, including suggestions for barrier pillars to isolate active panels from nearby gobs in bump prone ground, are also proposed.

By J. R. Thoenen

In Progress Rerort 1,4/ a number of facto were demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

By Richard Mainiero

In any construction project involving explosives, care must be taken to protect workers from carbon monoxide (CO) generated by blasting operations. CO is an odorless, colorless gas that can cause illness and death by asphyxiation. In general, the first symptoms include headache, fatigue and lightheadedness. At higher exposures to CO, skin flushing, rapid heart rate, and lowered blood pressure occur. At ever, higher exposure levels, decreased attention span is followed by nausea, vomiting, unpaired coordination, fainting, coma, convulsions and, finally, death. The detonation of explosives in blasting operations generates a range of toxic fumes, but CO is the most insidious because it is colorless, odor less, and is long lasting, since it is not readily removed try reaction with ground water, soil or rock. Additionally CO is generated in relatively large quantities compared to other toxic: fumes. CO may continue to seep out of blasted material long after the odor commonly associated with detonated explosives has dissipated. It is never safe to assume as confined space in the vicinity of a blast is clear of toxic fumes. CO may be present even if the area looks Clear and many hours have passed since the last blast.

Jan 1, 2000

By Henry C. Meeves

The Bureau of Mines investigated the silver production potential of the Leadville (California) mining district, Lake County, Colo., in 1966-67. The mining history of the district, the ground conditions encountered in mining, and the mine-support methods used are reviewed. The drainage problem is discussed in detail. An initial objective was to establish the existence of potential silver resources minable by low-cost open-pit methods, particularly in the silver-bearing manganese halos surrounding the major deposits. The report concludes that under present conditions, development of the deposits in the area is not economically feasible; however, a pioneer rotary noncore drilling program demonstrated that this type of exploration is technically feasible. Potential reserves of silver and associated metals are estimated. Possible mining methods for recovery of the reserves are discussed. Future production possibilities from the various subareas of the district are analysed, considering optimum operating size. Consolidation of small individual holdings for unit operation is recommended. Type of operation, amount of rehabilitation, size and type of concentrating plants required, drainage and other mining problems, and metal price trends are discussed as they bear on economic feasibility of development.

Jan 1, 1970

By N. L. Wimmler

The chromite deposits along the Stillwater complex in Stillwater and Sweetgrass Counties, Mont., have at various times been studied and reported on by the Federal Geological Survey, the Montana Bureau of Mines and Geology, other Government agencies, and private interests, Several of the deposits were explored to a mall extent by the owners during the World War of 1914-17, but no production resulted. The importance of these deposits and the urgent necessity of developing large domestic sources of chromite were realized shortly before the beginning of the recent World War. These deposits were therefore investigated and developed by Government agencies and., as a result, now afford the largest known reserves of chromium in the United States. In 1939, under the authority of the Strategic Minerals Act, the Bureau of Mines and the Geological Survey made preliminary investigations of these deposits. As a result, the Bureau of Mines conducted an extensive program of trenching, diamond core drilling, and sampling. This work was begun in August 1939 and continued to April 1943. The Bureau of Mines also performed numerous metallurgical tests on the beneficiation of the chromite ores and concentrates and for the production of chromium metal there from. Research continues as a means toward utilizing these ores.

Jan 1, 1948

By Katherine Harding

Basic concepts of matrix algebra and manipulations of matrices are presented in such a way that little competence in mathematics is required. Examples are always included to illustrate concepts and techniques. The paper is divided into six sections. The first four sections are devoted to some of the more basic concepts of matrix algebra, whereas the last two sections are concerned with specific applications.

Jan 1, 1967

By McHenry Mosier

This progress report on a national survey of the use of detachable bits in metal mines covers 10 mines. It presents comparative costs for drilling with conventional and detachable bits, describes the reconditioning of drill steel, and gives various data on rock drilling at these particular mines. Reports to follow will include similar data on drilling at other metal mines in the United States. ACKNOWLEDGMENTS This report is based on costs and data developed and furnished by the operators of the mines visited. The author is greatly indebted to the officials and staff members at these mines for their cooperation and assistance.

Jan 1, 1936

By A. J. Kraemer

Few important improvements other than the development of cracking processes were made in technical petroleum refining from 1914 to 1919. Refiners were concerned mainly with enlarging their plants and erecting new plants to meet the growing demand for petroleum products. Shell stills operated as a unit or arranged in series for progressive or continuous distillation were the prevailing distillation equipment. Some improvement was made in condensers, but in most refineries of the period coils of pipe immersed in tanks of water were used to condense vapors and cool liquid products of the stills. Heat exchangers to conserve heat and reduce costs were more highly developed at California topping plants than at other plants. In this connection Wadsworth3/states: It is regretted that information concerning the operation of topping plants with eastern and Middle West oils is not available. The writer carefully canvassed the Middle West, but did not find a plant where operation had progressed beyond the early experimental stages and reliable figures could be furnished.

Jan 1, 1941

Underground coal mining continues to evolve in the U.S., and more reserves are being mined under deeper cover, with worse roof, or with interactions from previous workings. At the same time, the mining community is responding to higher safety standards and intense competitive pressures. The need for effective ground control design has never been greater. Ground control safety issues that have been addressed by recent the National Institute for Occupational Safety and Health (NIOSH) research include: Improving roof support performance; Maintaining safe tailgate escapeways from longwalls; Optimizing pillar design for retreat mining; Controlling multiple seam interactions; Predicting roof conditions during extended cuts, and; Preventing massive pillar collapses. As funding from both government and the private sector has diminished, the emphasis in research has focused on providing the mining community with practical techniques for improved ground control design. Many projects have successfully employed empirical methods that emphasize the statistical analysis of case histories from underground mines. Other projects have employed numerical models and large-scale laboratory testing of roof support elements. Using these data, NIOSH has developed an entire toolbox of computer programs that have been effectively transferred to the mining community.

By Robert S. Warfield

The Federal Bureau of mines and U.S. Geological Survey conducted exploratory investigations and geologic mapping in the Wishbone Hill district of the Matanuska coalfield almost continuously from 1942 through 1958. These investigations delineated reserves of high-volatile bituminous coal necessary to supply the rapidly expanding military and civilian requirements in the Anchorage area. This report describes the program conducted by the Bureau of Mines from 1949 through 1958, and briefly summarizes previous investigations, the results of which have already been published. The coal-bearing structure on both the north and south limbs of the prominent Wishbone Hill syncline was explored by 8,719 feet of churn drilling and 25,460 feet of diamond-core drilling. A total of 33 holes were drilled ranging in depth from 60 to 2,114 feet. To supplement the drilling operations, bulldozer and dragline trenching were undertaken at key locations; about 25,000 cubic yards of dragline trench were excavated in the vicinity of the old Premier mine.

Jan 1, 1962

By George T. Motock

In Germany the extraction of lithium and its salts has been handled mainly by units of the two major concerns - Metallgesellschaft A, G. and Deutsche Gold und Silber Scheide Anstalt, both with headquarters in Frankfurt. Zinnwaldite, which belongs to the mica group, is the major source of the lithium-containing raw material in Germany. Lepidolite and amblygonite also are used when available, but they are imported, as there are no major deposits of these two minerals in Germany.

Jan 1, 1946

By Özgen C. Karacan

It is generally accepted that typical coalbed gases (methane and carbon dioxide) are sorbed (both adsorbed and absorbed) in the coal matrix causing it to swell and resulting in local stress and strain variations in a coalbed confined under overburden pressure. The swelling, interactions of gases within the coal matrix and the resultant changes in the permeability, sorption, gas flow mechanics in the reservoir, and stress state of the coal can impact a number of reservoir-related factors. These include effective production of coalbed methane, degasification of future mining areas by drilling horizontal and vertical degasification wells, injection of CO2 as an enhanced coalbed methane recovery technique, and concurrent CO2 sequestration. Such information can also provide an understanding of the mechanisms behind gas outbursts in underground coal mines. The spatiotemporal volumetric strains in a consolidated Pittsburgh seam coal sample were evaluated while both confining pressure and carbon dioxide (C02) pore pressure were increased to keep a constant positive effective stress on the sample. The changes intemal to the sample were evaluated by maps of density and atomic number determined by dual-energy X-ray computed tomography (X-ray CT). Early-time images, as soon as CO2 was introduced, were also used to calculate the macro porosity in the coal sample. Scanning electron microscopy (SEM) and photographic images of the polished section of the coal sample at X-ray CT image location were used to identify the microlitho types and microstructures. The CO2 sorption-associated swelling and volumetric strains in consolidated coal under constant effective stress are heterogeneous processes depending on the litho types present. In the time scale of the experiment, vitrite showed the highest degree of swelling due to dissolution of CO2, while the clay (kaolinite) and inertite region was compressed in response. The volumetric strains associated with swelling and compression were between ± 15% depending on the location. Although the effective stress on the sample was constant, it varied within the sample as a result of the intemal stresses created by gas sorption-related structural changes. SEM images and porosity calculations revealed that the kaolinite and inertite bearing layer was highly porous, which enabled the fastest CO2 uptake and the highest degree of compression. Keywords: Coal; Carbon dioxide; Sorption; Swelling; Sequestration; X-ray computed tomography; Volumetric strain; Gas outbursts

By J. H. East, D. Harrington

"INTRODUCTION The tremendous expansion of industry during the war and the unprecedented demands for metals and minerals are reflected in the production and use of explosives during that period. The increased use of explosives brought added safety problems to industry because of the necessity of using men as blasters who were not entirely familiar with and some who were totally unfamiliar with the characteristics of some or all of the various explosives. A discussion of the characteristics of the ordinary types of explosives used in: industry should assist in giving a better understanding of the hazards attending their use. Explosives are compounded so they may be used with reasonable safety provided the user understands and follows the procedure recognized as standard safety practice. Short cuts and the failure to understand and use recognized safe practices, as well as the selection of explosives unstited for the work at hand, are all part of the safety problem,The extent to which explosives are used in the United States is shown by a study of the statistics compiled by the Bureau of Mines 4/ regarding them. Some of these statistics are shown below and serve as an indicator of the tremendous number of men engaged in the transportation, storage, and use of explosives. Theme men are exposed to the inherent hazards attending this occupation and they should be familiar with the recognized safe practices relative to explosives."

Sep 1, 1946

Objective The main purpose of this video is to teach mine rescue personnel certain aspects of rescue work that are not traditionally taught. These include the strain caused by working continually under adverse conditions; the "survivor guilt" that occurs from being spared the fate of one's deceased cohorts; and the posttraumatic stress that may be experienced during the sometimes lengthy task of recovering the victims' bodies. Background On November 20, 1968, an explosion rocked the Farmington No. 9 Mine in northern West Virginia (figure 1). The explosion killed 78 of 99 miners who were working in the mine, including all but one member of the mine's rescue team. Some 30 years after the event, researchers from the NIOSH Pittsburgh Research Laboratory (PRL) conducted a video interview with Danny Kuhn (figure 2), the only Farmington No. 9 mine rescue team member who was not working that day and who did not die in the explosion. According to the Mine Safety and Health Administration (MSHA), there are about 80 underground coal mine rescue teams in the United States, and according to the National Mining Association, there are more than 850 underground coal mines. This represents a significant decrease in both over the past decade. The low number of rescue teams is a concern because serious incidents, though fewer, still happen, and if a disaster occurs, there will be fewer rescue teams to respond. This would result in an increased need to use available human resources very efficiently. Much training to prepare these rescue teams still takes the form of what educators call "teaching to the test." In other words, teams practice in order to win mine rescue contests. This test-oriented approach has traditionally been augmented by interactions with others who have responded to real situations or by participating in actual incidents. Given few incidents and fewer rescue teams from whom to derive enrichment, the preparation of coal mine rescue personnel becomes a problem. Recently, more emphasis has been placed on active learning, such as working out problems in smoke. These sessions more nearly simulate the actual conditions that today's team members might rarely encounter. To properly prepare and retain the current coal mine rescue personnel who are left in the workforce, it is necessary not only to offer such hands-on experience, but also to replace the learning narratives that once were passed from team to team. The present video is intended to contribute in that capacity. Approach NIOSH researchers first learned of Mr. Kuhn in the fall of1998. Mr. Kuhn was contacted and agreed to an interview. An oral history interview was conducted with Mr. Kuhn in early November1998. After reviewing the videotape of the interview, researchers determined the content to be so rich as to warrant a second interview in a more formal setting. The second interview was done in early December 1998. During this interview, Mr. Kuhn spent about 2 hours describing the Farmington disaster, including the workplace climate leading up to the explosion, the events that took place in the 10 days after the explosion, and the nearly 10-year effort to safely and successfully recover most of the victims' bodies. The videotape of the second oral history interview with Danny Kuhn was reviewed and edited by NIOSH researchers for content. Careful attention was used to ensure that valuable information was presented, but within a reasonable timeframe. A detailed map of the Farmington No. 9 Mine was edited into the final video and used to highlight critical features as they were being described by Mr. Kuhn. Results and Accomplishments A 60-minute videotape and instructor's guide for use in safety training or other settings was completed. The target audience consists of all those who work in underground coal mines. This training video will help safety instructors better prepare mine rescue team members for the situations that they will encounter when engaging in extended rescue and recovery work. As a result of this expectations training, team members will be more likely to serve their

Mar 1, 2002

By Thomas P. Mucho, David C. Oyler, Jim Pablic, Dennis R. Dolinar

A room and pillar coal operation in central Pennsylvania was experiencing roof cutters and long running roof falls caused by high horizontal stresses. The roof conditions created hazards for the miners, and caused several production panels to be abandoned prematurely. The mine requested assistance from the National Institute for Occupational Safety and Health (NIOSH) in applying the "advance and relieve" mining to reduce the affects of the horizontal stress during panel development. The "advance and relieve" plan that was developed called for removing a pillar on one side of the panel as it was being advanced, thus creating a cave. The caving then relieved a portion of the horizontal stress across the panel. Because the horizontal stress direction is key to the success of this method, stress mapping as well as mining experience was used to establish the direction of the horizontal stress. Subsequent field measurements provided an estimate of the stress magnitude. Three panels were mined using this technique, and good roof conditions were achieved in all these panels. Instrumentation was used to monitor the stress changes in the roof created by the cave. Stress relief of over 1,000 psi was measured 120 ft from the cave and to depths of 20 ft into the roof. The lateral extent of the stress relief zone across the panels appears to be about 400 to 500 ft. This case history has provided much insight into the practical application of the "advance and relieve" method discussed in this paper.

By L. J. Froisland

The U.S. Bureau of Mines conducted laboratory studies on sulfuric acid (H2S04) digestion of alunite [KA13(S04)2(OH)6] as a means for treating domestic deposits of this mineral. Digesting alunite ore in boiling H2S04 at concentrations of 88-wt-pct acid or higher breaks down the alunite and permits a convenient separation of potassium and aluminum. The digestion reaction is a complex sulfation reaction occurring in two stages. In this reaction, the potassium component extracts into the H2S04 for eventual recovery as potassium sulfate k2s04 in a separate unit operation. Aluminum is left as acid-insoluble aluminum sulfate [A12(S04)a], which can be extracted by a 95° C water leach. Additional purification of AI2(S04)a produced in this study is needed to meet cell-grade alumina (Al202) purity specifications. Extraction and separation of potassium and aluminum from the alunite ore were consistently above 90 pct.

Jan 1, 1989

By Peter Swanson, Collin Stewart, Wendell Koontz

A seismic monitoring network has recently been installed in the North Fork Valley coal mining region of western Colorado as part of a NIOSH mine safety technology transfer project with two longwall coal mine operators. Data recorded with this network will be used to characterize mining related and natural seismic activity in the vicinity of the mines and examine potential hazards due to ground shaking near critical structures such as impoundment dams, reservoirs, and steep slopes. Ten triaxial strong-motion accelerometers have been installed on the surface to form the core of a network that covers approximately 250 square kilometers (100 sq. miles) of rugged canyon-mesa terrain. Spread-spectrum radio networks are used to telemeter continuous streams of seismic waveform data to a central location where they are converted to IP data streams and ported to the Internet for processing, archiving, and analysis.