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By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

APPENDIX C SCALING RELATIONSHIPS 1. Scaling Law for Fly Ash Crater Formation The scaling law derived for predicting crater diameters at different scales is developed below by considering the equation of motion of individual fly ash particles. It is assumed that the air drag on each particle is characterized by Stokes flow, and at the borehole - passage intersection the air velocity and the fly ash particle velocity are the same. The equations of motion for a fly ash particle are the following, (see Figure C-1).

Jan 1, 1973

By Kenneth P. Klouse

The current rulemaking on mine illumination makes it necessary for mine personnel to have an understanding of the behavior of light. They must be able to understand many terms that are new to the industry and must be familiar with the use of various types of photometers. With this knowledge, the enforcement criteria for mines can be understood and compliance can be maintained.

Jan 1, 1976

By Deno Pappas, Gregory Molinda, Eric Bauer, Christopher Mark, Daniel Babich

Groundfalls are much more likely to occur in coal mine intersections than in entries. NIOSH is using the experience of U.S. coal mines to determine the factors which influence intersection instability and provide guidelines for the safe excavation and support of intersections. Detailed field investigations have resulted in a database of U.S. coal mines containing 12 mines and 639 roof falls so far. By using the roof fall rate as the outcome variable, correlations between roof geology (CMRR), intersection span, and roof support have been established. Case studies have indicated that replacing 3- way intersections with 4-way intersections may not reduce the total number of roof falls. Additionally, the size of intersection spans tend to decrease with lower (weaker) CMRR. Protocols have been established for the collections of roof bolt parameters. The performance of individual roof bolts can now be tracked with roof fall rate.

Table XXXIII itemizes the cost associated with the installation of an irrigation system and the application of latex and water in the three experimental areas at Lanse. There were no external labor charges (non- Research Center) except for the installation of the water meter. Cost of pipe and fitting are high because long lines were required at each of the three different locations; these costs were minimized by using plastic instead of metal pipe. Fifteen of the seventeen drums of latex received were used, five drums for each area. [ ] In tank-car lots latex would cost about $0.25/lb so that raw material cost for a 4000 lb/acre application would be in the range of $1,000 per acre. Equipment costs for setting up and irrigation are sensitive to size of area to be irrigated, design of system, and availability and cost of water. A realistic range is estimated to be between $200-500/acre.

Jan 1, 1972

Mine closing methods should be carefully considered. If not properly sealed, an abandoned mine may continue to produce acid water. Since 60 to 90 percent of the total acid discharged from all coal mines is from abandoned mines,(58) some states require that provisions for sealing be contained in the mining permit application. Closing an operation to prevent harmful mine drainage into nearby runs and streams is a subject of much concern to states as a result of continuing problems from long abandoned mines which were improperly closed.

Jan 1, 1970

By J. Nielen van der Merwe

For the last 3 decades, coal pillars in the Republic of South Africa have been designed using the well-known strength formula of Salamon and Munro that was empirically derived after the Coalbrook disaster. The database was recently updated with the addition of failures that occurred after the initial analysis and the omission of failures that occurred in a known anomalous area. An alternative method of analysis was used to refine the constants in the formula. The outcome was a new formula that shows that the larger width-to-height ratio coal pillars are significantly stronger than previously believed, even though the material itself is represented by a reduced constant in the new formula. The formula predicts lower strength for the smaller pillars, explaining the failure of small pillars that were previously believed to have had high safety factors. Application of the new formula will result in improved coal reserve utilization for deeper workings and enhanced stability of shallow workings.

Jan 5, 1999

By Jami M. Girard, Ed Mchugh

Slope stability accidents are one of the leading causes of fatalities at U.S. surface mining operations. The Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is currently conducting research to reduce the fatalities associated with slope failures. The purpose of this paper to discuss some of this research and to present potential new technologies for slope monitoring and design. The paper also briefly discusses various warning signs of slope instability, introduces the most common slope monitoring methods, describes the limitations of various slope monitoring systems, and presents some field results using some of this new technology.

By G. H. Schnakenberg

In response to the underground mining industry's growing concern with the exposure of workers to the diesel particulate matter (DPM) component of diesel exhaust, a method was developed to estimate the average workplace concentration of DPM that could be expected from using the new lower DPMemitting engines now being approved by the US Mine Safety and Health Administration (MSHA) when these new engines are equipped with state-of-the-art exhaust-control, technology for filtering and combusting DPM. The resulting estimate uses the MSHA-reported particulate index for these engines, the prevailing rule-of-thumb ventilation rate of 150 cfm/hp and the available diesel-exhaust filter technology that has been shown to be at least 80% effective in reducing tailpipe DPM. In the estimate calculation, every engine used in an underground mine is assumed to be equipped with this control technology. Under the stated reasonable conditions, an average DPM level of 90 µg/m3 (mass) is predicted as technically feasible.

By Kathleen M. Kowalski-Trakofler

This paper discusses human judgment and decision making under stress. The authors review selected recent literature across various disciplines and suggest a definition of stress within the context of decision making during the management of emergencies. They also discuss fieldwork by the Pittsburgh Research Laboratory, NIOSH, which explores traumatic incident stress, the relationship between previous training and performance under stressful conditions, and human behaviour in underground mine fires. The authors assert that stress is one of the factors that decision makers must contend with in most life-or-death situations. They suggest that a better understanding of individual judgment and decision making activities whilst under stress would yield a better understanding of how people reach the choices they make in emergencies. This enhanced understanding would be of enormous value to emergency managers, researchers and policymakers.

Jan 1, 2003

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

C 2 Complete Hoisting Systems A Above Ground Installations A total of seven companies were identified who supply complete emergency escape hoist units for above ground installations The units have been designed predominately to meet the needs of coal mine operators to satisfy the requirements of the Coal Mine Health and Safety Act of 1969. The seven companies are as follows 1 Dover Conveyor and Equipment Co. 2. Coeur d' Alenes Co. 3. Connellsville Corp. 4. Scott Midland 5. W W Williams Co. 6. Equipment Corporation of America 7. Timberland Ellicott Table VIII contains detailed specifications and price information on each of these units. The units have a number of similarities

Jan 1, 1976

By M. Beus, R. Iverson, A. Dreschler, V. Scott

This paper describes research to improve safety during transport of ore and waste in underground mines. Field tests are underway in mines in Idaho and Montana. Strains measured on structural support members in an ore pass provided information about total forces acting on the structure as material was dumped into it. Results show that measured static loads were considerably less than actual total weight of the material dumped and that dynamic loads were subject to many factors, such as effects of blasting to remove hang-ups. Comparisons of measurements and computer results using a particle flow code indicated that several difficulties remain before achieving realistic determinations and models of the dynamic effects of particle flow in ort: passes and impact loads on the gates. Impact loads were overestimated in computer analyses as compared to loads measured in field tests. An alternative design approach based on softening the chute and control gate assembly is being proposed.

By M. Terry Hoch, George J. Karabin, James M. Kramer

This paper introduces the fracture mechanics approach—a unique way to predict the stability of a coal mine panel. The technique uses analytic equations to calculate the stress, strain, and yield characteristics of coal support systems. It uses fracture mechanics to model almost every type of mine support structure. Another feature is a method that incorporates field-tested knowledge into the analytical analysis. For example, this technique can model the yield characteristics of a coal seam by combining empirical pillar strength equations into the analytic analysis. It may be possible to simulate multiple-seam mining by incorporating subsidence methods into the analysis. The method is simple and quick, which makes it attractive for stress analysis software. It should be more accessible to those in the mining industry who do not have expertise in rock mechanics or numerical modeling. Although the purpose of this research is for modeling coal mines, it should be adaptable to any mine in a tabular deposit.

Jan 1, 1999

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

APPENDIX C - HOISTING SYSTEMS - AVAILABLE EQUIPMENT C 1 - Introduction A survey has been made of available hoisting equipment which has applications for use in metal and non-metal mine emergency escape hoist systems. The information was gathered from a number of sources, including representatives in the USBM and MESA, mine operators, personal visits and telephone interviews with manufacturers, field visits to inspect equipment, advertisements, catalogues and indices of manufacturers. Wherever possible, technical specifications and prices were checked out with the manufacturer, or supplier. The sections on individual sub-systems and components, such as automatic control systems, winches and controls, are not intended to be all encompassing surveys. Rather a reasonable number of representative units in each category are discussed. The sample is large enough to provide a general picture of the kind of equipment available, including the abilities and limitations and a reasonable price range. The survey has been divided into six categories 1. Complete Hoisting Systems A Above ground installations B Below ground installations 2. Hoist Assemblies ^(Man-rated) 3. Hoists (not Man-rated)

Jan 1, 1976

By H. C. Ko

As part of the Bureau of Mines effort to provide thermodynamic data for the advancement of mineral technology, the standard enthalpies of formation for ZnO?2ZnSO4 and COS04-6H20 were determined by HC1 acid solution calorimetry. The values are -550.31 ±0.28 and -641.33 ±0.15 kcal/mot, respectively.

Jan 1, 1982

By C. M. Mason

A series of gelatinous permissible explosives was prepared with increasing sodium nitrate content and subjected to an improved technique for evaluating incendivity in coal dust-air and coal dust-gas-air mixtures. Those explosives containing an appreciable amount of sodium nitrate were found to be very hazardous in coal dust-air and coal dust-gas-air mixtures.

Jan 1, 1969

By Gerald T. Homce, Michael R. Yenchek, H. Kenneth Sacks, James C. Cawley

Abstract—Overhead electric power lines present a serious electrocution hazard to personnel in a variety of industries. Overhead lines, typically uninsulated conductors supported on towers or poles, are the most common means of electric power transmission and distribution, and are exposed to contact by mobile equipment such as cranes and trucks. Equipment contacting energized overhead lines becomes elevated to a high voltage, and simultaneous contact by personnel of the “hot” frame and ground can cause serious electrical shock and burns. Industries where risk of these accidents is greatest include construction, mining, agriculture, and communications/public utilities. An estimated 2300 accidental overhead line contacts occur each year in the U.S. This paper describes a practical low-cost concept to detect actual contact of mobile equipment with a high-voltage line and provide a warning. Accident statistics indicate that more than half of the fatalities could be prevented by such a device. Index Terms—Crane, electrical shock prevention, engineering control, mining, mobile equipment, power line.

By J. C. Edwards

Fire experiments were conducted in the Safety Research Coal Mine (SRCM) at the National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, with coal, diesel-fuel, electrical-cable, conveyor-belt, and metal-cutting fire sources to determine the response of fire sensors to products-of-combustion (POC). Metal oxide semiconductor (MOS) and smoke fire sensors demonstrated an earlier fire detection capability than a CO sensor. This capability was of particular significance for a conveyor-belt fire in which the optical visibility was reduced to 1.52 m with an increase in CO of less than 2 ppm at a distance of 148 m from the fire. Application of a neural-network program to the sensor responses from each type of fire source resulted in correct classifications of coal, diesel-fuel, cable, belt, and metal-cutting combustion with a mean of 96% of the test data correctly classified.

Jan 1, 2000

By L. Prosser, A. Iannacchione, G. Esterhuizen

The potential for roof falls in underground mines remains a clear and present danger for mine workers. An investigation of ground conditions in nearly 50% of the nation’s underground stone mines found that the state of roof stability is primarily determined in a limited and subjective manner. These large opening mines, with roof heights typically of 7 m or more, make physical observation difficult. Although some mines use monitoring techniques to gain additional information on roof stability, this practice is usually short-term and localized to address ground conditions in a particular section or part of the mine. A methodology to assess the risk for a roof fall is proposed in a preliminary fashion based on engineering judgment acquired from extensive underground stone mine experience and examination of related literature. The proposed method utilizes an observational technique to identify the risk of roof falls in three categories. Case study scenarios provide a realistic picture of model implementation. Providing the mine level decision maker with an accurate assessment tool to ascertain the level of risk related to ground conditions is expected to reduce mine worker injuries and fatalities. Moreover, the presences of danger can be overcome with a clear picture of quantified ground conditions.

By J. W. Horne

The quantitative determination of salt in petroleum ins generally divided into two steps - (1) extraction of salt from the oil and (2) accurate measurement of the extracted salt. This paper presents a method used by the Bureau of Mines for quantitatively extracting the water-soluble chloride salts4/ from petroleum and discusses important details attendant on the success of the method. Among these details are homogeneity in the dispersion of salt crystals, emulsified brine and other impurities in the oil sample, complete solution of the salt, and total extraction and titration of all the aqueous phase. Recently, the chlorides of sodium, calcium, and. magnesium produced with and present in various oils have developed growing problems of salt deposition and corrosion in the petroleum industry. Therefore, a technical study of various emulsions and salts that accompany petroleum is being made by the Bureau of Mines in cooperation with the State of Oklahoma. One report (5)5 reviewing the literature pertinent to the study has been published.

Jan 1, 1940

By Charles L. Kimbell

This study is intended to serve three roles. First, it is an extension of the previous works under the same title that have been the overview and summary chapter of the international volume of Minerals Yearbook since the inception of that volume. Following the traditional format of past chapters, the basic statistical presentations herein deal chiefly with 1989, and in some instances with 1988, the latter only because more recent, comprehensive global statistics for 1989 are simply not yet available owing to delayed data collection and processing in some countries and continued governmental suppression of data in others. The second role of this study is to provide an update to the coverage of events impacting on the world's mineral industry that have occurred between the end of 1989 and the preparation of this study. Inclusion of this update is almost essential because of the potential effect of some of these events on global mineral industry activities.

Jan 1, 1992