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By W. R. Reed

Dust dispersion modeling is a subject that has had a large amount of research activity. Much of the research has focused on large-scale global or regional dispersion models. Other models have been created for industry-specific purposes. Furthermore, some of the past research has focused on dust dispersion modeling in the mining industry. This report presents the various dust dispersion models that have been developed specifically for the mining industry. The report first gives a brief background of the regulatory environment that helped to promote development of such models. It then presents an overview of the mathematical concepts used in this dispersion modeling. Finally, each of the various models developed for the mining industry are described, along with their associated mathematical algorithms and any field validation conducted on the different models.

Jan 9, 2005

Despite the strange names given to its parts, the eye is not a very complicated organ. If you think of the eye simply as a detector of light, you will be able to understand the mechanics of central vision, peripheral vision and adaptation described below. These three processes of seeing are basic, not only to mining, but also to everyday activities. A number of simple experiments are described In this chapter to demonstrate different types of seeing processes. Try the experiments. They really make the point. Light rays reflecting from objects enter the eye through a lens and fall on the back surface called the retina. The retina 1s lined with millions of tiny light sensors called "rods" and "cones." These sensors, in turn, are connected to the brain by the optic nerve.

Jan 1, 1976

By Summer S. Smith

The year 1916 broke all previous records of mineral production in the Territory. As a consequence, there has been a noteworthy increase in the number of mines in active operation or under development, though the greater part of the increased output is the result of greater activity at mines already producing rather than of opening new mines. Owing to available funds not being sufficient to meet the cost of travel in the interior of the Territory during the winter months, the Federal mine inspector was unable during the spring to visit the placer mines of the interior as has been his custom in the past. However, by working in close cooperation with the Territorial in- spector, who left Juneau in June to take the first boat down the Yukon to Fairbanks after the spring break-up, it was possible to visit hurriedly all the larger mining centers of the Territory. The Territorial inspector covered the districts from Fairbanks to Nome and the Federal inspector covered those of southeastern and south- western Alaska. A number of applicants have begun mining coal on ground held under free-use 10-acre permits, and have furnished coal for local use. The larger leasing units in the Bering River and Matanuska coal fields have been advertised and applications for leases have been submitted. These applications came too late in the fall for active development to begin before the end of the year. The Government railroad has been built from Anchorage to the center of the Matanuska coal field, and private interests have under- taken the building of a standard-gage road from a point known as Goose City on Controller Bay to Canyon Creek, in the Bering River field. Capital has become interested in the oil fields on Controller Bay, and plans have been made for more active exploration and production. The work of the Federal mine inspector is still handicapped by the lack of funds for additional field assistants and of the office ac- commodations necessary for carrying on the work with the efficiency that its importance warrants.

Jan 1, 1917

By S. B. Flagg, J. F. Barkley

In the past few years an awakened activity in power-plant econ- omies has resulted in a marked improvement in the equipment for generating and utilizing steam. Although the improvement in design and construction of steam-driven prime movers has been greater than that of the steam-generating equipment, the economies obtained with the more efficient engines and turbines have stimulated interest and activity in eliminating unnecessary boiler and furnace losses. Much attention has been given to the boiler room in efforts to obtain proper combustion of the coal, because of the importance of the coal item in costs of power production. As evidence of this increasing interest may be cited the record of the development within the past few years of new apparatus for the analysis of flue gases. Many new forms of apparatus have appeared, including those for the determination of carbon dioxide, oxygen, and carbon monoxide, and others for indicating and for recording the content of carbon dioxide only, as carbon dioxide content is usually a good indicator for the control of furnace operation. Because of the large number of steam-power plants operated by the Federal Government and the number of CO, recorders used therein the Bureau of Mines undertook to collect information regard- ing the practical application of such recorders. Articles published from time to time concerning CO, recorders have been mostly descrip- tive, giving little reliable information as to the results that could be expected from the various types of instruments in ordinary prac- tice, and most of the tests made have been of a laboratory nature. Tests of several different types of recorders were made under service and laboratory conditions in order to obtain needed information. The purpose of the Bureau of Mines in publishing the results is to show the factors which may affect the accuracy of a CO, recorder and the manner in which a recorder should be tested. Readers should note that the remarks on different recorders apply to the instruments tested and not to later instruments of the same makers. In the course of the tests the following details were determined: 1. The lag in recording changes of composition of a flowing gas. 2. The accuracy of each type of recorder.

Jan 1, 1916

A primary objective of the Surface Mining Control and Reclamation Act is to establish uniform national regulatory standards to protect the environment during mining and for reclaiming land after it is disturbed by current and future surface coal mining. In recognition of the wide range of climatic and geologic conditions in coal-producing areas, Congress provided that individual states may establish their own programs for regulating surface and underground coal mining and reclamation on private land. The standards for state programs must be at least as effective as the federal standards. Initial and Permanent Regulatory Programs Congress recognized the importance of establishing regulations to implement the Act as quickly as possible, while recognizing that the preparation of such complex regulations would be a lengthy process. Consequently, a two-phase schedule was established. An abbreviated initial program was put in place immediately, followed by a more extensive and detailed permanent regulatory program. The initial program regulations were published in December 1977, and mine permits issued by states after February 1978 were required to conform with those regulations. Regulatory provisions contained in the initial program included 12 basic performance standards, continuation of existing state permitting, bonding, and enforcement processes (although if those features did not already exist, they did not have to be added), a federal inspection frequency of once every six months, joint state and federal inspection and enforcement in states that had existing programs, and the prohibition of mining in the specific areas listed in the Act. Permanent program regulations were published in March 1979, following extensive review and comment from the public, including the coal industry and organized environmental groups. The regula¬tory provisions in the permanent program expanded those in the interim program by including the implementation of all performance standards contained in SMCRA, a new permitting process, a requirement for performance bonds, an increased inspection frequency (one per month), a new enforcement process, and a process for designating lands unsuitable for surface mining. The regulations for the permanent program have been revised several times since 1979; more revisions can be made as new mining and reclamation tech¬niques are developed. Such changes were anticipated by Congress; in fact, a provision in SMCRA for experimental practices encourages advances in mining and reclamation techniques.

Jan 1, 1992

By Staff

The papers contained herein summarize results of various recent Bureau of Mines investigations in the area of mine power distribution systems. They are based on information from Bureau personnel, contractors and grantees, and Mining Enforcement and Safety Administration. Conclusions drawn from a series of parameter measurements on mine power systems, taken over a 3-year span, are presented. Personnel and equipment hazards due to faults on isolated, solidly grounded, and resistance grounded three-phase systems are discussed. Two papers cover dc applications of circuit breakers, including a novel protection scheme for trolley lines. The methods of suppressing induced arcing currents and voltages in a-c machines are evaluated. An evaluation program for ground monitors is described. Acceptance test procedures and the importance of various paparameters for trailing cable splice are covered. A number of techniques for locating faults in trailing cables are described.

Jan 1, 1975

By E. R. McMillan, M. R. Geer, Joseph Daniels, H. F. Yancey

Investigations of coking properties of Washington coals made before 1939 and studies of coking precesses indicated that PiaTceC:Countyx:oals, particularly those from the Vlilkeson-Carbonado--Fairfax area, yield excellent coke structures. ThE: ash content of the cokes W2S relatively high, sulfur ordinarily.was low, and the phosphorus, although variable, was not excessively high for some purposes. For years the coals had been coked in beehive and standard byproducts ovens and had entered Pacific coast markets for every purpose to which coke is adapted. Certain areas of the Roslyn bed of Kittitas County also were known to possess coals with coking properties. This coal had been employed largely for bench-gas manufacture and occasionally, blended with other coals, in byproduct ovens. Coals from other western Washington areas also had baen utilized for coking in the past but were not of immediate significance.

Aug 1, 1943

By Christopher Mark

Australia and the United States both have large, modern underground coal mining industries. Many companies have invested in both countries, and there is growing awareness that technological developments in one country can rapidly affect the other. Yet the ability of technology to pass between the countries depends on comparability of ground conditions. Many Australian observers believe that their ground conditions are significantly poorer than typical U.S. conditions, but some U.S. professionals are not convinced. The author recently visited 10 Australian longwall mines and two room-and-pillar mines. Each mine visit included determination of the Coal Mine Roof Rating, roof support installed, pillar design, and an in-depth discussion of ground control experience. The Australian conditions observed are compared with an extensive data base from U.S. mines. The paper also offers observations on geotechnical data collection, monitoring, and the roles of the mine inspectorate and research community.

This chapter defines light as a type of energy, and tells how different features of light are measured. It 1s important to understand the units of light measurement because they are used throughout the rest of the book. But more Important, this will help you to understand the "regs" and how to get the best out of the lighting you have available! By the time you complete this chapter, you should know what candle-power, foot-candle, and foot-lambert refer to, and you will also be able to tell why the helmet that the new miner wears appears orange to human eyes. Light that you "see" is really radiant energy that hits the retina of the eye. Radiant energy moves out from a light source much like a series of bullets from a number of machine guns being fired at the same time in all directions.

Jan 1, 1976

By Dara Stock, Fred Turin, Kim Cornelius, Lisa Steiner

Growing concern from labor unions, regulatory agencies, and industry about the safety of a prevalent underground coal mining method which utilizes remote control has prompted human factors field evaluation of mining activities. Remote control operations were implemented with little consideration given to human-system interactions. Ideally, collecting and analyzing information prior to implementing new technology would have helped to address potential problems. One such problem that operators and other mine personnel are faced with is the question of where they should safely position themselves to avoid injury while remotely operating machinery. To determine work methods employed by machine operators before and after implementation of the new method, work sampling techniques have been used to provide data about positioning of face crew members at different points in the mining cycle. This data provides information for optimal positioning, leading to safer operating procedures and identifying training shortfalls.

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

Accidents occur when least expected, from sources that we rarely anticipate and with outcomes that can vary greatly. Anyone who has ever been involved in an automobile accident knows, the transition from driving comfortably and safely down a highway to being involved in a potentially life-threatening situation can occur in a heartbeat. Accidents on the job are no different. The mining industry has a relatively small number of electrical injuries, compared to industries such as construction or agriculture, due to the small total employment in mining. Mining does, however, have one of the highest occupational electrocution rates of any U.S. industry, at 2.8 for every 100,000 workers per year. This is approximately four times the average for all industries. Data from the Mine Safety and Health Administration (MSHA) shows that 75 electrical fatalities occurred in the mining industry between 1990 and 1999. Of these, at least 17% involved high-reaching mobile equipment that contacted overhead power lines.

"Reports are sometimes heard of one ill effects of pneumatic tools on the hands of workmen. In consequence of such reports, Dr. Francis M. Barnes, Jr., M..D. of St. Louis, Missouri, was retained by the operators to make an investigation of conditions in the Bedford, Indiana, region, and the result of this investigation was published the Journal of the Missouri State Medical Association, Volume 16, February 1919. A brief review of this report may be of interest to all users of pneumatic tools, or operators of plants where such tools are employed.The investigation was made during December 1917, and involved an examination of general working conditions, and a careful physical examination of stoneworkers who had long used pneumatic tools. As the Bedford district is the most important structural limestone producing center in the country, the results of this investigation may be regarded as fairly conclusive as to the general effect of pneumatic tools on limestone workers."

Jan 1, 1920

Lower the respirable dust exposure of longwall shearer operators by isolating and con-fining the dust cloud near the face. Approach Install conveyor belt screens at various locations on the body of the shearer to contain and hold the dust cloud toward the face side of the machine. This approach provides a cleaner air split in the walkway, over the shearer operators. How It Works On most longwall shearer sections, the dust exposure of the shearer operators is primarily attributable to the machine it-self. The dust cloud originates at the face, and the exposure of the operators depends largely on how quickly this dust spreads into the walkway. Conveyor belt screens placed on the gob side of the body of the machine can reduce the amount of dust which spreads out into the walk-way. In addition, belting may be installed over any open spaces between the shearer under-frame and the panline to prevent conveyor dust from boiling out into the operator's walkway.

Jan 1, 1981

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

By R. C. Buehl, J. P. Riott, M. B. Royer

Sponge iron is the metallic product resulting from the reduction (removal of combined oxygen) of iron ore or other iron oxides at a temperature below the fusion point of iron. It has been used for many years in the production of certain grades of high-quality steel, such as tool and cutlery steels. The sponge iron available commercially in limited quantities for such use was produced from high-grade ores that were almost free from the contaminating elements that are generally considered detrimental to the production of certain grades of carbon tool steel. Interest in sponge iron as a scrap substitute was revived when World War II began, when the serious shortage of scrap metals for use in the production of armament caused great concern as to whether steel production could be maintained at the rate necessary for vigorous prosecution of the war effort. Also, because of the severe shortage, steel manufacturers…

Jun 1, 1947

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 Kenneth L. Cashdollar

This paper reports US Bureau of Mines (USBM) research on the explosibility of coal dusts. The purpose of this work is to improve safety in mining and other industries that process or use coal. Most of the tests were conducted in the USBM 20 litre laboratory explosibility chamber. The laboratory data show relatively good agreement with those from full-scale experimental mine tests. The parameters measured included minimum explosible concentrations, maximum explosion pressures, maximum rates of pressure rise, minimum oxygen concentrations, and amounts of limestone rock dust required to inert the coals. The effects of coal volatility and particle size were evaluated, and particle size was determined to be at least as important as volatility in determining the explosion hazard. For all coals tested, the finest sizes were the most hazardous. The coal dust explosibility data are compared to those of other hydrocarbons, such as polyethylene dust and methane gas, in an attempt to understand better the basics of coal combustion.

By H. H. Clark

The term "explosion-proof," as applied by the Bureau of Mines to an electric motor, refers to a motor inclosed by a casing so constructed that an explosion of a mixture of mine gas (methane) and air within the casing will not ignite a mixture of the same gas surrounding the motor. There are two classes of motors so constructed: First, a totally inclosed class built strong enough to withstand high internal pressures and so designed that the efficiency of all inclosing covers can be satisfactorily maintained; second, a class provided with relief openings or valves designed to relieve the pressure of an explosion within the motor casing and to cool any products of combustion dis- charged through the valves. A satisfactory motor of the first class is much more expensive to build than an equally safe motor of the second class. For this rea- son, attempts to make motors explosion-proof have been confined chiefly to motors of the second class.

Jan 1, 1912

By Richard F. Link, George W. Gladfelter, George S. Koch

Contour maps, useful in mineral industries, for example, in analysis of trends in mineralization, may be constructed through statistical methods of regression analysis programed for an electronic computer, For many applica­tions, the resulting maps are more useful and objective than conventional contour maps that are necessarily subjective because they are drawn by hand methods. In principle, an equation is found that fits a quadratic surface to observed elevations of points referred to a datum plane, The quadratic sur­face, represented by a contour map may take the form of a ridge, valley, dome, or basin, Once an equation has been derived, its coefficients may be used to construct a contour map--showing lines of equal value that are derived from the original observed data points by the averaging process of fitting the quadratic surface. Methods employed are illustrated by an example analysis, based on data from a large vein of the Fresnillo mine, Zacatecas, Mexico. Computer programs to implement the methods are described in an appendix,

Jan 1, 1964

By Jeffrey Kohler, John J. Samrnarco, Thomas Novak, Lloyd Morley

Equipment control functions that were once hardwired are being implemented with software and very large scale integrated (VLSI) devices. Often this transition has resulted in increased flexibility, improved quality, and decreased costs. At the same time, it has created new concerns and challenges concerning worker safety. The visible and well-defined ladder diagram for relay-logic has been replaced by program in which the exact outcome for varied inputs can be more obscure. In the coal mining industry,-efforts to automate longwall mining systems hove resulted in semiautonomous machines operating within the same space as workers This paper describes an effort initiated by the National Institute for Occupational Safety and Health (NIOSH to identify the safety rules related to the use of processor-controlled equipment in mining. Specific findings in the areas of human factors, hardware, and some safety are presented in this paper, and a brief description of a plan to address identified weaknesses is given.