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Mining men and State officials in their efforts to make mining safer are confronted from time to time with various complicated questions. In recent gears these questions have tended to increase with the use of mechanical appliances. Twenty-five years ago electricity had been used but little in mires; today there is practically no other means of transmitting power employed in American mines, except that in metal mines compressed air is used, chiefly for drilling and for operating small portable hoists. In coal mines there has been a great increase in mechanization, which tends to concentrate the work of production in small areas and to increase the local difficulties of ventilation; also, it has intensified locally the hazard from coal dust as well as firedamp in bituminous and subbituminous mines. The answers to the questions that arise are not always obvious, as is shown by the fact that even able, experienced men differ in their opinions of the best, way to overcome a particular mining hazard. The difficulty of .solving the problems is also demonstrated by the varying provisions in mine-safety rules, both in official regulations and in the rules of those mining companies that are endeavoring to do more than follow the letter of the law. Such differences of opinion as to the best way of meeting a difficult situation are often found within the same mining organization, and, similarly, varying opinions are held by different members of the Bureau of Mines staff.

Jan 1, 1937

By Candice Stevens

The Territory of Afars and Issas is to receive its independence from France on June 27, 1977. The Territory's economic income was based on entrepôt trade through the port of Djibouti and trans-shipment of goods on the Chemin de Fer Franco-Ethiopian (CFE) railroad. The Territorial budget was scheduled to in- crease from $32.6 million3 in 1976 to $36 million in 1977, despite severe shortfalls in 1976 stemming from inflation and a persistent balance-of-trade deficit. Subsidies from France continued to sustain the economy, and the French pledged to provide approximately $140 million in aid annually after independence. In 1976, financial agreements were concluded with a number of Arab oil-producing countries, including Saudi Arabia which granted $10 million toward development projects. The new Republic of Djibouti is scheduled to become the 49th member State of the Organization of African Unity (OAU) and the 21st member of the Arab League, and to receive aid from their financial institutions. The port of Djibouti and the CFE railroad constituted the Territory's main economic resources. Traffic at the port greatly

Jan 1, 1980

By A. C. Fieldner

"INTRODUCTION In a previous report3 prepared for the American Gas Association, the influence of washing coal on coke properties and on gas and by-product yields was discussed on the basis of answers to questionnaires sent to coke-oven superintendents and a review of the literature on the subject. This review indicated that the elimination of free impurities by cleaning coal improved coke quality by (a) reducing ash and sulphur, (b) decreasing clinker trouble in burning the coke, (c) diminishing cross fractures in the coke, resulting in greater resistance to breakage on handling, and less small coke and breeze, and (d) greater uniformity in chemical composition and physical properties of coke. Washing also reduced the sulphur in coke and gas and increased the yield of gas and by-products per ton of dry coal charged.This paper is supplementary to the previous report and presents some experimental data obtained with Pittsburgh bed coal from Pennsylvania and Mary Lee bed coal from Alabama.ACKNOWLEDGMENTSGrateful acknowledgment is made to F. J. Pfluke, of the Rochester Gas and Electric Cc., of Rochester, N. Y., for the plant test data on screened lump and washed coal; and to Ray W. Arms, Manager of the Coal Cleaning Department, of Roberts & Schaefer Co., of Chicago, for the data on effect of air cleaning."

May 1, 1931

Argentina follows Venezuela and Mexico as the largest producers of crude petroleum and natural gas in Latin America. Argentina 1S practically self-sufficient in fuels, but relies substantially on imports for its supply of copper, iron ore, ferroalloys, sulfur, and fertilizers. Mining activity is limited and is in an incipient stage of growth, considering the country's potential for mining. Most nonfuel mineral output in 1979 consisted primarily of minerals used for construction, while only 9% are other nonmetallic, and 2% are metallic minerals. Argentina is Latin America's major producer of boron minerals and uranium (yellow cake). Mineral exports consist primarily of borates, uranium concentrates, and of late, some tin. These exports have in the past been shipped mostly to Great Britain. London banks have been involved in arranging financing for St. Joe Minerals Corp. IS planned development of the El Pachon copper deposit (see map), and were being counted upon to also back the development of large copper and manganese projects. The following is a review of Argentine mineral production in 1979: (For 1981, the production of boron minerals is put at 167,000 metric tons and uranium at 300,000 metric tons.)

Jan 1, 1982

By David K. Hylbert

This study was designed to investigate roof falls in room-and-pillar drift coal mines and to determine geologic methods for predicting unstable roof conditions. The study area was located in Harlan County, Kentucky and the Bailey Creek (Harlan coal bed) and Highsplint (Darby coal bed) mines were selected for study. Correlations were made laterally between surface outcrops and within the mines using lithologic and trend analysis criteria. Lithologic criteria compared cyclic changes in roof strata. Results indicated that roof falls are associated with zones of weakness within or between five vertical cycles recognized. Abrupt lateral facies changes occur. In the Highsplint mine the roof was classified in four categories or conditions using 98 rib sections for control. Structure contour and isopach maps were used to project axial trends of the sandstone roof. A roof-fall zone was examined using ten NX cores taken from the roof and included lithologic, petrographic and clay mineral studies. At the Bailey Creek mine roof failure was caused by the heading direction being driven subparallel to paleochannel directions. Computer programs were used in trend analysis studies. Cross-bedding, paleo-channel trough axis and sole mark studies indicated a 350 discrepancy between surface and in-mine trough axes at Highsplint. A direct relationship between joint and "slip" frequency and direction with sandstone roll trends was found. Surface joints compared well with drainage Segments, hilt did not correlate with roof falls in areas of mines under overburden in excess of 600 feet.

Jan 1, 1977

By Oliver Bowles

Whiting or Paris white is a fine-grained preparation of calcium carbonate having a wide variety of uses. Until recent years it was prepared almost exclusively from certain north European chalks. With the curtailment of imports of European chalk during the World War of 1914-18, however, finely ground limestone, of domestic origin was used more extensively to satisfy the American demand.

Jan 1, 1942

By Robert H. Peters

This report presents a literature review conducted by the U.S. Bureau of Mines. The review summarizes what has been learned from the large volume of empirical studies on the effectiveness of eight types of interventions intended to increase organizational effectiveness via in the management of human resources. The interventions concern the following: recruitment, selection, training, objective feedback, goal setting, reward systems, participative management practices and organization development. Although many of these interventions appear to have the potential for improving the safety and efficiency of mining operations, it does not appear that they are being widely used. Examples are given of the successful use of a few of these interventions at mining operations. An analysis of the relationship between coal mine productivity and safety is also presented. This analysis generally supports the view that good safety performance and high productivity are NOT incompatible goals. In fact, safe mines also tend to be more productive and vice versa.

Jan 1, 1992

By Michael J. Sapko, Gregory M. Green, Kenneth L. Cashdollar

The National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted a joint survey to determine the range of coal particle sizes found in dust samples collected from intake airways of US coal mines. The last comprehensive survey of this type was performed in the 1920s. The size of the coal dust is relevant to the amount of rock dust required to inert the coal dust, with more rock dust needed to inert finer sizes of coal dust. Dust samples were collected by MSHA inspectors from several mines in each of MSHA's 10 bituminous Coal Mine Safety and Health Districts. Samples were normally collected in several intakes at each mine. The laboratory analysis procedures included acid leaching of the sample to remove the limestone rock dust, sonic sieving to determine the dust size, and low-temperature ashing of the sieved fractions to correct for any remaining incombustible matter. The results indicate that particle sizes of mine coal dust in intake airways are finer than those measured in the 1920s. This finer size coal dust in intake airways would require more incombustible matter to be effectively inerted than the 65% incombustible specified in current regulations.

By Samuel P. Harteis

Many mining operations rely on retention bulkheads to provide a barrier between impounded water and active mine workings. However, bulkhead failures can cause catastrophic flooding that puts the underground workforce at risk. Underground observations and evaluations of existing bulkheads indicate that a systems approach is required when building an underground water or slurry retention system. In addition to engineering the bulkhead, the designer must ensure the quality control of materials and workmanship of the bulkhead, the reaction of the mine strata when exposed to water under pressure, and methods to monitor the performance of the retention system. Researchers from the National Institute for Occupational Safety and Health (NIOSH), with the assistance of the Mine Safety and Health Administration (MSHA), conducted an extensive review of bulkhead permits submitted to the MSHA Technical Support office in Bruceton, PA. In addition, the researchers visited accessible bulkhead installations at undeground mining operations to gather information related to construction practices, maintenance issues, and monitoring and emergency response procedures. Several key items were identified that must be considered when permitting the installation of an underground fluid retention system.

Jan 1, 2008

By L. K. Weaver

The Bureau of Mines has started an engineering study of oil recovery by miscible-phase displacement. As a preliminary part of the investigation a literature and patent study was made to prevent duplication of work already done, to become acquainted with those actively engaged in research of this type, and to learn where the recovery method has been attempted. This bibliography gives results of this study. The bibliography includes 254 references to U.S. and foreign patents and published literature relating to miscible-phase displacement processes of oil recovery. It is divided into the following sections: (1) U.S. patents, (2) foreign patents, (3) literature references, (4) author index, and (5) publication and source reference. The patents and literature references are listed alphabetically by author by intervals of years. References to February 1963 are included.

Jan 1, 1963

By Don Conrad, Tom Friend, Bill Wiehagen, Lynn Rethi

On-the-job training (OJT) is a very common method of teaching job skills. Much of the training is done by experienced workers. This paper discusses small investments that can help improve the effectiveness of OJT. Effective OJT involves some structure and planning in the transfer of responsibility for task performance from the trainer to the novice. Assisting the OJT trainer could involve helping develop up-to-date job analyses and offering strategies for teaching and evaluating job skills. The scope of this paper addresses (1) organizational considerations supporting structured OJT, (2) general strategies for structuring OJT, (3) a typical approach for conducting OJT, (4) characteristics and duties of OJT trainers, and (5) limitations of OJT as a teaching method. Health, safety, and operational skills can be connected through training. Haul truck operator training is used to illustrate some of the concepts discussed in this paper.

Jan 1, 2002

By Allan F. Smith

The influence of hydraulic fluids on spontaneous heating in bituminous coals is determined by measurement of the temperature increases produced in coal-fluid mixtures heated to a temperature sufficient for the initiation of self-heating. Similar tests on as-received coal samples and water-coal mixtures are compared with the results obtained for the various hydraulic fluids. Three of the four coals were sampled from coalbeds known to have a history of spontaneous heating. The data provide a basis for predicting the possible effects in gob or carbonaceous refuse of coal mines.

Jan 1, 1963

Develop a new technique of in situ rock stress measurement which can be used when and where the conventional methods, such as the overcoring stress relief methods and the hydrofracturing method, cannot be effectively applied. Approach The Bureau of Mines developed basic principles to determine existing biaxial stresses in rock mass by using an instrumentation package consisting of one 3.8-cm-diameter hydraulic cylindrical pressure cell (CPC) and two 5.7-cm-diameter cement-capsulated flat hydraulic borehole pressure cells (BPC) to he installed in a single drill hole.

Jan 1, 1988

By S. M. Shelton, W. A. Calhoun, M. M. Fine, T. L. Johnston

"INTRODUCTION An extensive test program is in progress by the Bureau of Mines to determine ways and means of recovering ferromanganese-grade ore 6/ from the wide-spread domestic manganese and manganiforous iron deposits. Samples for testing were received from the Interstate Manganese Co. in northeastern Tennessee, 11 miles west of Mountain City and 10 miles southwest of Damascus Va. The ore deposit occurs in the residual material of the Shady dolomite 7/ as an unconsolidated mixture of hard and soft manganese oxides and clay.Numerous tunnels and pits have developed a large reserve of ore in an area of about 15 acres. One pit 250 by 50 by 20 feet is being mined by rower shovels. The ore is hauled to a washing plant for log-washing, hand-sorting, and jigging. Coarse concentrates from the washing plant are marketed without further beneficiation.ACKNOWLEDGMENTSThe authors wish to acknowledge the assistance of R. F. Fisher, who made the roasting and magnetic tests."

Mar 1, 1942

By Staff

The goal of the U.S. Bureau of Mines diesel engine research program is to reduce exhaust emissions from diesel-powered equipment used in underground mines. This research has led to significant advances in aerosol measurement and to the development of more effective emission controls. This Information Circular contains reports of some of the presentations made at the Bureau's Information and Technology Transfer Seminar on Diesels in Underground Mines given in Minneapolis, MN, on September 29-30, 1992. The seminar emphasized the measurement and control of diesel particulate matter emissions. Topics covered include a discussion of the health issues associated with the use of diesel equipment underground, an overview of regulations, measurement techniques for diesel exhaust aerosol, levels of diesel exhaust pollutants found in mines, and modern emission controls. An appendix is included that contains a report describing the capabilities of the Bureau's diesel emissions research laboratory, two papers describing the effects of engine maintenance or: emissions, a paper describing the monitoring of carbon dioxide in mine air as an indicator of air quality, a glossary, and a list of abbreviations and acronyms.

Jan 1, 1992

By Patrick J. Coleman, John C. Kerkering

Problem: Mining in the United States remains one of the most hazardous industries, despite significant reductions in fatal injury rates over the last century. Coal mine fatality rates, for example, have dropped almost a thousand fold since their peak in 1908. While incidence rates are very important indicators, lost worktime measures offer an alternative metric for evaluating job safety and health performance. The first objective of this study examined the distributions and summary statistics of all injuries reported to the Mine Safety and Health Administration from 1983 through 2004. Over the period studied (1983 2004), there were 31,515,368 lost workdays associated with mining injuries, for an equivalent of 5,700 person years lost annually. The second objective addressed the problem of comparing safety program performance in mines for situations where denominator data were lacking. By examining the consequences of injuries, comparisons can be made between disparate operations without the need for denominators. Total risk in the form of lost workday sums can help to distinguish between lower and higher risk operations or time periods. Method: Our method was to use a beta distribution to model the losses and to compare underground coal mining to underground metal/nonmetal mining from 2000 to 2004. Results: Our results showed the probability of an injury having 10 or more lost workdays was 0.52 for coal mine cases versus 0.35 for metal/nonmetal mine cases. In addition, a comparison of injuries involving continuous mining machines over 2001 2002 versus 2003 2004 showed that the ratio of average losses in the later period to those in the earlier period was approximately 1.08, suggesting increasing risks for such operations. Discussion: This denominator free safety measure will help the mining industry more effectively identify higher risk operations and more realistically evaluate their safety improvement programs. Impact on Industry: Attention to a variety of metrics concerning the performance of a job safety and health program will enhance industry's ability to manage these programs and reduce risk.

By W. G. Payne, A. C. Richardson, B. L. Gandrud

"INTRODUCTION The Connellsville mine of the Yolande Coal & Coke Co. is in the southwestern part of Jefferson County, Ala., about 30 miles southwest of Birmingham. The mine is on the Blue Creek bed, which is about 6 feet thick and dips at a angle of 18º. The bed is worked by the room-and-pillar method and is mined by both machine and hand methods. The Blue Creek bed at this point yields a high ash, low-volatile coal with excellent coking properties. Because of its exceptionally low volatile content and high coking strength, this coal is excellent for blending with Alabama coals of higher volatile content and weaker coking properties to form blends suitable for production of metallurgical coke.A sample of washed coal taken during this investigation gave the following analysis on an as received"" basis: Moisture, 8.3 per cent; volatile matter-, 20.2 per cent; ash, 8.0 per cent; fixed carbon, 63.5 per cent. The high ash content of this coal limits the quantity which can be utilized when low-ash coke is required. In the Birmingham district it is usually difficult to sell as coking coal a product that contains more than 8.0 per cent ash. To produce a. coal with this ash content at Connellsville presents a somewhat difficult washing problem. This paper gives the results of an investigation that was conducted by the Southern Experiment Station of the U. S. Bureau of Mines in cooperation with the University of Alabama and the Yolane Coal & Coke Co. for the purpose of determining the washing characteristics of the coal and the possibility of reducing its ash content on coal-washing tables.The practice at the Connellsville washery at the time of beginning this investigation was to crush the run-of-mine coal to pass a 1 1/2-inch round-hole screen and to treat the satire output on two primary, 3-compartment jigs. A. middling product was recovered from the primary jigs which was re-treated on a single-compartment rougher jig. This system yields a product of acceptable ash content, but the yield is low and the loss of good coal in the refuse is high."

Feb 1, 1933

By M. E. Poad, J. K. Whyatt, T. J. Williams

Researchers at the U.S. Bureau of Mimes monitored rock mass response to mining of an experimental underhand longwall stope in Hecla Mining Co.'s Lucky Friday Mine, Mullan, ID. This stope design, the Lucky Friday underhand longwall (LFUL), was proposed as a means of controlling rock bursting while also allowing increased mechanization of mining operations. Instruments were specifically manufactured to monitor three geomechanical factors (backfill performance, ramp stability, and rock mass response) that directly affect the success of stope design. Despite considerable difficulties with instrument installation and survival in the harsh mine environment, especially within the stope fill, sufficient information was collected to suggest that the LFUL method was successful in achieving project goals. This conclusion, in addition to favorable economic and operational evidence, led the mine to adopt the method throughout the mine. Indeed, this study and mining experience suggest that underhand longwall mining could be considered a feasible mining method for rock-burst-prone ground throughout the Coeur d'Alene District. Further Reports of Investigations (RI) in this series present in-depth analyses of the effects of backfill on rock bursting and calibration of a stope numerical model.

Jan 1, 1992

By J. A. Cooper

The objectives of this research were to define the chemical composition and physical characteristics of the aerosols associated with attached radon daughters in operating uranium mines, and to investigate the relationship between these aerosol parameters and operating conditions. Major Results and Conclusions The organic, inorganic and radiological characteristics of test chamber and active U-mine aerosols have been measured as a function of particle size. These measurements represent the first detailed analyses of the organic and inorganic components in U-mine aerosols and the first determinations of the details of the individual and total radon daughter distributions in operating U-mines. The following is a list of the major results and conclusions:

Jan 1, 2012

By Elaine T. Cullen

Underground mining, like many high-risk industries, is facing a crisis in the near future. This industry has traditionally relied on a master-apprentice relationship to train new workers, but experienced miners are retiring in large numbers, leaving few "masters" to properly train their replacements. With a recent resurgence in mining, many new miners are entering the workforce each day. The rise in the number of inexperienced workers has implications for worker safety in an industry in which one mistake can blow up the entire workplace. The explosion in the Darby Mine in May 2006 that killed five miners illustrates what can happen in hazardous environments such as underground mines. The Health Communications Team at the National Institute for Occupational Safety and Health Spokane Research Laboratory was asked to address this problem by developing new training and safety awareness materials to promote safe flame cutting and welding practices. This article describes how occupational ethnographic techniques provided insights needed for "new product development." The result of this work was a national initiative to raise awareness and to protect underground coal miners from the dangers of flame cutting and welding in an environment filled with solid fuel and methane (natural gas). Although this project was initially designed for the mining industry, the approach and lessons learned are applicable to any high-risk industry and should be of interest to other social marketing or occupational safety and health professionals.

Jan 1, 2009