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By Mark Colwell, Christopher Mark

This paper summarises the results of a research project whose goal was to provide the Australian coal industry with a rib support design methodology and software tool that could be utilised by suitably qualified colliery staff. The project was primarily funded by Australian Coal Association Research Program (ACARP) and further supported by several Australian longwall operations. The outcome of the project is a design methodology and software tool called, Analysis and Design of Rib Support (ADRS). ADRS is an empirical technique, which recognises that several geotechnical and design factors affect ribline performance and in addition that operational and safety issues essentially dictate the level of performance required. Therefore, the design recommendations associated with ADRS are specific to the Australian coal industry; however the procedure(s) for data collection and analysis could be applied to other countries' 'underground coal industries. Case history data were compiled from 34 longwall and two bord and pillar operations resulting in 204 case histories with each case history data set being defined by approximately 130 individual data fields. In addition monitoring (incorporating stress cells and extensometers) was undertaken at 10 collieries to assess and quantify the effectiveness of different rib support patterns and hardware on rib performance. The monitoring sites allowed for an improved understanding of the mechanisms of rib failure and degradation in terms of its interaction with the installed support and at the various stages of the mining cycle. The design methodology deals with both mains development and gateroad development specific to Australian longwall mines. This paper focuses on longwall gateroads subjected to abutment loading and in particular the travel road which becomes the tailgate of the subsequent panel. The statistical analyses associated with these cases suggested that the level of rib support should be based primarily on the development height and the pillar stress level. The ADRS software guides users through the design process, allowing them to develop rib support plans based on sound science and a broad base of in-mine experience To the best of the authors’ knowledge ADRS is the first systematic rib support design technique to be developed for any country’s underground coal industry. The development and use of empirical models in mining have substantially contributed to improving safety and productivity. ADRS further demonstrates that empirical techniques are particularly relevant and beneficial in dealing with the complexities of geotechnical design associated with underground coal mining.

Jan 6, 2008

By John B. Bennett

In this report estimates are presented of the impact of the passage of five recently proposed "acid rain" bills on electric utility costs for coal-burning utilities servicing the domestic aluminum smelting industry, and on the costs of production for affected aluminum smelters. As aluminum smelting is an energy-intensive industry, domestic increases in electricity prices could affect the industry's competitiveness. Energy costs in U.S. aluminum smelting are compared to aluminum smelting energy costs in the rest-of-the-world. Governmental policies affecting these energy costs are discussed.

Jan 1, 1988

By R. A. Cummings

Certain roof shales in coal mines deteriorate upon exposure to the atmosphere, causing difficulties in the mining operations and adding to the cost. This report presents the results of both field investigations, in a West Virginia mine, and laboratory studies on the effects of atmospheric moisture on roof shales. Based on these observations, a conceptual procedure is presented on how shale deterioration might be predicted during exploration, and guidelines are given as to how air tempering or conditioning chambers may be designed to reduce moisture effects. Recommendations for further studies are included. An annotated bibliography of the literature constitutes the second volume.

Jan 1, 1981

By D. G. Lee

Diesel particulate matter (DPM) often contains small amounts of metal as a minor component but this metal may contribute to adverse health effects. Knowledge of the mechanism for particle formation as well as the size preference of the trace metals is critical to understanding the potential for health concerns. To achieve this, the size and the composition of each particle should be optimally measured at the same time. Single particle mass spectrometer (SPMS) would be the best tool for this objective. In this paper, we therefore will introduce new findings about the mechanism and distribution of the trace metals in DPM, derived from a study where an SPMS was used to analyze freshly emitted DPM. KEY WORDS : Single particle mass spectroscopy, Diesel particulate matter, Characterization, Metal contents

Jan 1, 2006

By George A. Morgan

There was little change in the mineral industry of Benin in 1986, as the economy remained in the grip of a regional recession exacerbated by failing oil prices, which nullified much of the income from Benin's oil production. Benin's industrial sector accounted for less than 10% of the gross domestic product (GDP), with the mineral industry providing about one-half of that total. Several major projects initiated over the last several years continued to perform and/or progress below Government expectations. These included the Save sugar refinery, the Dassa-Parakou section of the Dassa-Cotonou highway, the Benin-Togo Nangbeto hydroelectric plant, the Onigbolo cement plant, and the Semé Oilfield. Funding for these projects is the major source of the Beninese external debt, which was estimated to be over $800 million.2

Jan 1, 1988

By Lucia Kuizon

Results of the U.S. Bureau of Mines' survey of mineral resources in the Cuyama RARE II study area indicate there is no potential for metallic minerals and low potential for the development of gypsum resources. There are no producing or developing mines within the study area. The Santa Barbara Canyon Prospect contains 30,000 tons (27,000 t) of subeconmic gyspum resources, the Wagon Road Prospect 276,000 tons (250,000 t), and the Brush Fence Canyon 61,000 tons (55,000 t). Most of the resource in the Brush Fence Canyon Prospect is outside the area. Gypsum was not observed at the Cuyama River deposit. Present gypsum and gypsite requirements are being met by larger deposits closer to major markets. INTRODUCTION Location (USGS) Present and Previous Studies (to be combined with USGS section) The Bureau of Mines reviewed literature and mining claim records for the study area. A field examination of known mineral properties was made in October 1980; it included mapping and sampling of prospects to evaluate the economic potential of mineral resources.

Jan 1, 1981

By H. R. Shell, Robert C. Johnson, Wilbur H. Warwick

Alpha silicon nitride fibers , Si3N4 , were successfully grown in graphite crucibles by a new method utilizing silicates and silicon ( S in equations below) as sources of silicon and using carbon , aluminum , and silicon as reducing agents (R in equations below ) . The basic reaction mechanism is believed to be generally as follows : 1,300 - 1,500 ° C S + R + N₂ SiO + RO + N₂ › 3Si0 + R + 2N₂ _1,300 - 1,500° C 3RO + Si¸N • ( 1 ) ( 2 ) A build - up of coatings on the solid raw- material particles hindered the evolution of silicon or silicon monoxide vapor and thereby slowed down further formation of silicon nitride fibers . Free oxygen in the crucible caused the formation of amorphous silicon dioxide ( SiO2 ) fibers . This problem was solved by passing , entering , and exiting gases through layers of lump graphite inside the reaction vessel . The silicon nitride fibers grew best around 1,400 ° C. Nitrogen flow rates from 4 to 6 liters per minute were adequate . The fiber widths were generally only a few microns whereas their lengths sometimes reached one - quarter inch or more . Chemical and X- ray analyses indicated that bulk fiber samples were usually 80 to 90 percent Si3N4 . The fibers had good oxidation resistance to about 1,260 ° C. Thermal shock resistance was excellent . Electrical resistance was determined .

Jan 1, 1964

By A. R. T. Denues

The Explosives Division of the Bureau of Mines, United States Department of the Interior, is investigating cushioned blasting at the Explosives Testing Station, Bruceton, Pa. The general interests of this investigation are practical and relate particularly to safety. The immediate concern is an application of cushioned blasting in coal mining In cushioned blasting, various means are employed to reduce the intensity of the application of energy in an explosive action in a borehole. The primary object is to increase the efficiency of the use of explosives.

Jan 1, 1940

By A. R. T. Denues

The Explosives Division of the Bureau of Mines, United States Department of the Interior, is investigating cushioned blasting at the Explosives Testing Station, Bruceton, Pa. The general interests of this investigation are practical and relate particularly to safety. The immediate concern is an application of cushioned blasting in coal mining. In cushioned blasting, various means are employed to reduce the intensity of the application of energy in an explosive action in a borehole. The primary object is to increase the efficiency of the use of explosives.

Jan 1, 1940

By Robert A. Elgin

The Leadville mining-district (fig. 1) covers approximately 8 square miles adjacent to Leadville, the county seat of Lake County, Colo. It is famous for its large production of rich ores containing zinc, lead, copper, gold, and silver. Some manganiferous ores also have been produced.

Jan 1, 1949

By A. J. Kraemer

This paper is the second and concluding report of the results of the twenty-fourth semiannual survey made by the Bureau of Mines of motor gasoline marketed in the United States. The first report7 on this 1931 survey gave the results of the examination of the gasoline samples in accordance with the new Federal specification for United States Government Motor Gasoline.8 The present paper reports results of the examination of the gasolines for color, doctor test, gravity, end point, per cent recovered, copper-dish gum, and steam-oven gum. The retail price and the tax at the time each sample was taken are also reported.

Jan 1, 1932

By Stephen C. Tadolini, Gabriel S. Esterhuizen, Anthony T. Iannacchione

A Major Hazard Risk Assessment (MHRA) was developed in Australia after a series of mine disasters in the 1990’s. A MHRA is used to help prevent major hazards, i.e. fire, explosion, wind-blast, outbursts, spontaneous combustion, roof instability and chemical and hazardous substances, from injuring miners. A MHRA is a structured process that identifies the characteristics of major hazards, assesses and ranks the risk they present, and evaluates engineering and administrative controls to mitigate them. These controls typically consists of a broad spectrum of prevention, monitoring, first response, and emergency response techniques and helps to move an operation from a reactive to a proactive approach towards safety. This paper documents a MHRA performed at an underground mine where strata instabilities and fire hazards may threaten the condition of its escapeways. The objective of this MHRA is to 1) identify what hazards could affect the egress through the mine’s escapeways, 2) determine what unwanted events pose the greatest threat for the mine, and 3) recommend a plan to prevent or recover from the potential disruption of egress through the escapeway. The plan provides information on the key existing controls that should be monitored and audited, and makes recommendation of new potential controls to further reduce related risks. By documenting the use of MHRA to this specific ground control issue, this paper provides a framework for others to judge the merits of this approach and to help design and perform these activities.

By Brian M. Harney

The technique of remote sensing, used for many years by earth scientists, is being applied to the detection and monitoring of air pollution. Instrumentation being developed is of a very diverse nature and is effective, Fn varying degrees, at ranges from 1,000 meters to the altitude of a space satellite. This paper describes a number of the recent developments in this new field. Instruments based on spectroscopic, laser, and photographic systems are discussed. Sensors are being developed which utilize correlation spectrometry, interferometry, Raman scattering, Mie scattering, laser line absorption, and simple photographic detection.

Jan 1, 1973

By JOHN BUZARD

In the following pages the writer has endeavored to give an account of the many methods, advantages, and disadvantages of preparing and burning powdered coal. For much of the information jmparted the writer is indebted to various firms in the United States and Canada whose plants he visited, also to the technical press. Manufacturers and operators of coal-fired furnaces can not afford to disregard the possible advantages of pulverizing their coal before burning it. Hence the purpose of this bulletin will be fulfilled if it leads them, after making careful estimates, either to abandon their present method of burning cGal on grates or stokers, and install the pulverizers, conveying system, powdered-coal feeder, and burner best suited for burning powdered coal in their plant, or to reject, as uneconomical, the replacement of their present system of burning coal by a system for pulverizing and burning it. No research work on the combustion of powdered Canadian fuels has been carried out by the Mines Branch, Department of Mines; but if this research work were carried out scientifically by competent engineers, chemists, and physicists, it would show how powderedcoal furnaces and burners should be designed to gi ve an efficiency higher than they give at present.

Jan 1, 1923

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 Noel N. Moebs

Valley Camp No. 3 mine was the scene of an experimental shortwall introduced in 1973 in an attempt to improve the recovery from the Pittsburgh coalbed in the Ohio Valley area where adverse ground conditions have imposed partial extraction methods with only 40 to 55 percent recovery of the valuable resource. The Bureau of Mines, under a cooperative agreement with Valley Camp Coal Co., monitored ground pressures and caving in the shortwall section in an effort to determine whether the roof strata, notably the limestone main roof, will cave to the extent that roof pressures at the face are relieved and whether the powered roof supports can sustain the roof load. The Bureau's efforts included mapping of clay veins, instrumentation of chain pillars and shortwall panels with encapsulated pressure cells, recording hydraulic pressures in the legs of the shortwall chocks, and core drilling underground and from the :surface. The experimental shortwall was a qualified success. Recovery increased 5.4 percent compared with partial extraction. Pressures in chain pillars and the abutment zone were not excessive. Hydraulic pressures in the chock legs did not approach the yielding pressure. Apparently, the limestone strata caved and the roof pressure at the face was relieved.

Jan 1, 1976

By Jacqueline A. McClaskey

The U.S. Bureau of Mines (USBM) Information and Analysis Directorate 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. The USBM's data collection activity was instituted by the 47th Congress in an appropriations act of August 7, 1882 (22 Stat. 329), which placed the collection of mineral statistics on an annual basis. The most recent authority for the USBM survey activity is the National Materials and Minerals Policy, Research and Development Act of 1980 (Public Law 96-479, 96th Congress). This act 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, 1995

By M. B. Balachandra

A three-dimensional finite element analysis was performed of an instrumented section of a double-entry coal mine in order to provide a comparison between field measurements and existing analytic techniques. The BMINES computer code was used to perform the analysis. The sequence of excavation of the entries was considered, as well as the installation of rock bolts and cribbing during the mining cycle. The materials In the region under investigation were idealized into four rock types and coal. The rocks were assumed to be isotropically elastic, perfectly plastic. Coal was represented by an elastically anisotropic (transverse isotropy) and plastically isotropic model. A fracture yield criterion of the Coulomb form was used for all materials. The strength and stiffness of all materials were substantially reduced from available laboratory data to account for in-situ properties. Qualitative trends and stress distributions obtained from the calculation were found to be reasonable. However, computed displacements and closures were greatly exaggerated and an excessive degree of inelastic deformation was indicated in the coal, especially adjacent to the excavated faces. It was established that both these effects were the result of an excessive reduction in the strength and stiffness of the materials. The analysis underscores the need for three-dimensional calculations by identifying a number of important structural response parameters that would be either outside the scope of, or misrepresented by, two-dimensional analyses. The analysis also emphasizes the need for comprehensive and accurate measurement of material properties in order fully to exploit the power of the analytical techniques to generate reliable predictions.

Jan 1, 1976

This Bureau of Mines report is a compilation of information on computer models of mineral commodity markets in the Federal Government, The directory was compiled by the Analytic System Working Group of the Interagency Minerals Information Coordinating Committee to support the formulation of policies related to nonfuel minerals.

Jan 1, 1984

By W. G. Pariseau

A two-dimensional finite element program has been modified and extended to account for some of the rock mechanics complexities associated with single entry development of longwall coal mine panels. Program capability includes arbitrary assignment of element properties without regard to element ordering, anisotropic elastic, plastic and brittle rock properties that may be time dependent (aging), arbitrary mining sequences and provision for the effects of artificial support on the adjacent strata. Failure is according to an extended von Mises criterion that may be linear or quadratic in form; flow rules are obtained from the yield function taken as the plastic potential, but brittle behavior is treated as a discontinuous process of material properties change with deformation. In either case the extent of failure is calculated from the external boundary conditions. Application of the program to essentially two-dimensional problems resulted in lose agreement between calculated displacements and field measurements in the double entry system. Bleeder entries were stable in one locality and not in another. Artificial support had little influence on stability.

Jan 1, 1978