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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

This report was prepared by Jacob Tolsma and Arnold N. Johnson of the Uniroya 1 Research Center, Wayne, New Jersey. The valuable assistance and suggestions of the project officers, Mr. Ronald D. Hill, Dr. David R. Maneval and Mr. John J. Buscavage is gratefully acknowledged. The authors are grateful to the following Uniroyal personnel: Mr. Daniel Shichman, manager of Engineering Research, and Dr. Emmanuel G. Kontos, manager of the Polymer Physics Research for their direction, encouragement and suggestions regarding the experimental work, and Mr. Mark Olson for the design of the hollow auger soil sampler. We also wish to gratefully acknowledge the efforts and contributions of ideas proposed by our consultants, Dr. Frank T. Caruccio, assistant professor of geology at State University College, New Paltz, New York, and Dr. Pa Ho Hsu, associate professor of soil chemistry, Rutgers University , New Brunswick, New Jersey.

Jan 1, 1972

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.

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 J. G. Linn, H. H. Schrenk, W. P. Yant, R. R. Sayers, John Chornyak, F. A. Patty, S. J. Pearce

"This report is the first of a series dealing with the results of a comprehensive investigation of methanol poisoning, conducted jointly by the Federal Bureau of Mines, Carbide & Carbon Chemicals Corporation, du Pont Ammonia Corporation, and the Commercial solvents Corporation.The study dealt mainly with physiological effects produced by inhalation of methanol vapor, and concentration studied ranged from approximately 500 to 15,000 p.p.m., and periods of exposure from 4 hours daily to continuous. The range of concentrations and periods of exposure were such as to produce acute effects, with and without fatalities, by a singel exposure and chronic poisoning, with and without fatalities, as well as little or no response after repeated daily exposures. In addition to the inhalation experiments, skin absorption was studied, and field surveys were made to ascertain the hazards associated with the manufacture and, use of methanol."

Feb 1, 1942

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.

By J. A. Holmes

As part of its investigation of methods of increasing the efficiency of fuel resources, the Bureau of Mines is continuing the study of the general problems involved in the economic use of fuels in gas pro- ducers that were carried on by the technologic branch of the United States Geological Survey. In the course of this study many inci- dental problems of prime importance have demanded consideration. Among them is the determination, under practically constant con- ditions, of the duration of gas-producer tests necessary to reduce the possible error to a minimum. A discussion of this proper length of test period forms the first part of this bulletin. An attempt to dispel some of the uncertainties that arise in an investigation or to account for some of the minor phenomena often necessitates a systematic and careful study of certain chemical, ther- modynamic, or physical laws, or a combination of these, which in turn may result in information or conclusions of great value. Fur- thermore, seemingly unimportant observations often prove to bear directly upon the design, construction, or manipulation of the machine under test. In attempts to improve the gas producer considerable attention has been given by manufacturers to such questions as fixing or isolating the combustible components of the tar, utilizing the waste heat of the producer for the generation of the steam required by the plant, apply- ing the suction principle to bituminous coal and other tarry fuels, and many allied subjects. Little study, apparently, has been given to the physical-chemical conditions most suitable to the formation of hydro- gen and of carbon monoxide, with a view to regulating the percentages of these gases in generators using fuels other than anthracite coal or charcoal. An attempt was made to introduce such investigations when the operations of the government coal-testing plant began at the Louisi- ana Purchase Exposition in St. Louis in 1904, but owing to adverse conditions these problems were abandoned until the plant was trans- ferred to Norfolk in 1907. The delay in beginning this line of inves- tigations, together with the short testing season at Norfolk, limit the second part of this report to preliminary physical-chemical studies, which, however, were sufficiently significant to warrant careful ex- amination pending more complete researches, which are being carried on at the station located in Pittsburg.

Jan 1, 1911

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 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 G. Molinda, D. Dolinar

Each year, about 2,000 falls of supported roof occur in the more than 800 underground U.S. coal mines. Therefore to help improve the design of primary support systems, the National Institute for Occupational Safety and Health (NIOSH) conducted a nationwide study of roof falls in over 2,500 km of roadways at 37 coal mines. Information on the roof falls as well as other geotechnical, mining, geologic and roof bolting factors were collected and quantified Then a multi variate statistical analysis was conducted on the data with the roof fall rate being the outcome variable The results were used to derive preliminary design guidelines for predicting the roof bolt length, capacity, and pattern required to effectively reduce the roof fall rate. The equations are fairly limited by a relatively high statistical variance in the data. Also reported is a recent survey of U.S roof bolt manufacturers that shows a significant change in bolt types used over the last ten years.

By R. V. Ramani, A. S. C. Owili-eger

The Methane Generator program is a part of the Internal Environ¬mental Sub-system of the Master Design Simulator (MDS). All the sub¬systems of the MDS are controlled and activated by the main program as required. The data requirements for the Methane Generator are supplied by the Geology and Reserves sub-system through common storage. Figure 6 shows the information flow between the Methane Generator and other systems of the MDS. It should be noted that the Methane Generator can also function independently as was described under model application. AREAS OF MISSING INFORMATION In any numerical analysis, the accuracy of the solution depends entirely upon the data available. In gas flow problems, parameters that constitute basic model input data are rock porosity, medium permeability, reservoir pressure and initial reservoir pressure dis¬tribution. Unfortunately, however, most of these characteristics are not available for a lot of coal seams. The need for actual field data cannot, therefore, be adequately emphasized here.

Jan 1, 1974

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 C. J. Johnson, C. J. Bise

"The occurrence of Coal Worker's Pneumoconiosis (CWP) ·has been potentially linked with several characteristics of coal such as rank, volatility, percent content of ash and non-coal components, quartz content, and the presence of several trace elements. According to the National Research Council, numerous epidemiological Studies: indicate that the incidence of CWP varies significantly with the composition and/or the concentration of the coal mine dust.Although advances in dust suppression techniques have markedly reduced respirable dust levels in underground coal mines, the National Research Council has concluded that chemical characteristics of respirable dust from different coal seams should be studied. With this objective in mind, research has been conducted in underground coal mines located in the eastern and mid-western United States, and in the laboratory to characterize the elemental composition of mining-generated airborne dust and laboratory-generated dust derived from samples taken from these mines. The goal of the research is to determine if a relationship exists between mining-generated and laboratory-generated dust from the ·same mine. Results of this research will be presented. ,"

Jan 1, 1988

By Jürgen F. Brune, R. Karl Zipf, Kenneth L. Cashdollar

This paper outlines the legal standards and methods for protecting underground coal mines in the United States from explosions of methane gas and coal dust. It will discuss inspection and monitoring of mine atmospheres, dilution of methane through ventilation, methane drainage prior to, during and post-mining, as well as explosion prevention through rock dusting and sealing of mined-out areas. Recent research findings of the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory on the magnitude of pressures obtained during methane explosions from modeling and full-scale explosion tests at the NIOSH Lake Lynn Experimental Mine will be presented. This work is currently being applied to modeling the structural response of explosion-proof mine seals to pressures from gas explosions. Also, new research will be presented on the inertization of float coal dust in mines through the addition of inert stone dust and on the application of the Coal Dust Explosibility Meter (CDEM), a handheld device developed by NIOSH to directly measure the explosibility of a coal dust - limestone dust mixture based on optical reflectivity.

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 Powell. Alfred R.

"An investigation has been made of the applicability to a variety of coals, other than those from Illinois, of the Powell and Parr method of analysis for the forms of sulphur in coal.A complete study was made of the sulphur in the following coals:- Upper Freeport, Pa.; Pittsburgh seam, Pa.; Pocahontas No. 3, W, Va..; Letcher Co., Ky.; Morgan Co., Tenn.; and Cherokee Co., Kan.The method of analysis gave excellent results when applied to these coals. In the determination of pyrite, the iron-sulphur ratio checked in every case with the theoretical. After the extraction of the pyrite and sulphates, the remaining sulphur was proved to be organic in nature.This work indicated that sulphur exists in coal in three typical forms: - pyrite or marcasite, sulphates, and organic sulphur. A study of the changes which these forms undergo during coking has been made on a variety of coals, and the following five classes of reactions established.First. Complete decomposition of the pyrite and marcasite to ferrous sulphide, pyrrhotite, and hydrogen sulphide. This reaction begins at 300°C., is complete at 600 °C., and generally reaches its maximum between 400 and 500°C."

Mar 1, 1920

Objective To reduce equipment operator exposure to respirable dust in enclosed cabs by examining the effectiveness of retrofitting air pressurization and filtration systems on existing cabs. Background Many types of heavy equipment are used in mining, construction, and agriculture. Most have enclosed cabs to protect the equipment operator from excessive dust and noise exposure. When the equipment is new, controls are normally implemented into the cab to keep these exposures at acceptable levels. However, as this equipment becomes older, many components of the enclosure deteriorate, such as gaskets and seals. This causes the effectiveness of the enclosed cab to be greatly reduced. Once this occurs, the equipment operator's dust exposure can increase to hazardous levels. In surface mining operations, elevated exposures to crystalline silica have caused an excessive incidence of silicosis. Approach A cooperative research study with a mining operation and a cab filtration company was conducted to evaluate the effectiveness of retrofitting an older surface drill with two controls to lower the drill operator's respirable dust exposure. These two controls were: (1) A good air filtering and pressurization system to ensure that clean air was delivered into the enclosed cab. Ideally, the incoming air filter should be 99% efficient in removing particles with an aero- dynamic diameter of 0.3 pm or greater from the airflow. (2) Sufficiently sealing the cab to develop a positive static pres- sure and ensure that dust was not leaking into the cab. This was done by plugging all holes and cracks and maintaining good gaskets and seals. To prevent wind from forcing contaminated air through holes in the cab, the cab's static pressure must be greater than the wind's velocity pressure. During the course of this research, it was found that a floor heater fan used in the drill during the winter months greatly increased the operator’s Respirable dust exposure. Problem Identification Four days of background dust levels were measured as a baseline for this research. These baseline measurements were taken in May 2000 when air temperatures ranged from 60° to 70° F. When this was completed, the two controls were implemented. The first control was to install an improved air filtering and pressurization system on the enclosed cab. This was composed of a two-stage prefilter, a blower, then the respirator-medium secondary filter. Since the secondary filter was on the positive side of the fan, all air delivered into the enclosed cab had to pass through this secondary filter. After the filtering system was installed, the cab was pressurized to a static pressure of0.01 inches of water (w.g.), which is still very minimal. The second control was to seal the cab. New door gaskets were installed, and all cracks and holes in the shell of the enclosure were plugged. This increased the cab pressurization to approximately 0.1 inches w.g.

Mar 1, 2001