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By Patricia R. Devine

This appendix documents the mathematical approach to deriving the components of change presented in this report. The formulation closely follows that contained in Chapter IV of the documentation for the BEA 1977 Input-Output Tables.' The basic elements for the calculations include the "use" matrix (U), the "make" matrix (M), and any of the ten columns of final demand (generically represented by the symbol y). The use matrix contains information about changes in the technological processes of production, while the make matrix describes the nature of secondary product production in each industry. We adhere to BEA conventions in maintaining careful distinctions between commodity output (c) and industry output (x). The industry-by-industry 1-0 tables supplied by NYU for use in this analysis are square matrices, with the number of commodities and the number of industries both equal to 85. The BLS table for 1982 (commodity by industry) was aggregated and adjusted to be consistent with the earlier tables. The three basic steps for estimating components of change proceed as follows for each column of final demand. 1) Calculate the actual change in output of each commodity for each of the four time periods: 1963-72, 1972-77, 1977-82, and 1963-82.

Jan 1, 1988

By James F. Neill, O&apos

Brown iron ore resources in Barbour, Butler, Crenshaw, and Pike Counties were investigated in a drilling program and geological study by the Federal Bureau of Mines in cooperation with the Alabama Geological Survey and the University of Alabama. The aggregate footage drilled was 18,010 linear feet. When developed, reserves of 12,664,000 long tons of crude ore were indicated, containing from 26.9 to 29.0 percent iron and 0.2 to 1.6 percent manganese under a maximum overburden of 40 feet. Total inferred crude ore for the four counties was calculated to be 827,700,000 long tons. Beneficiation of samples by simulated log washing and use of a 118-inch screen yielded from 46.8 to 51.7 percent iron and 0.2 to 2.6 percent manganese. Screen-test studies indicated no appreciable interlocking between the iron and manganese minerals and the waste particles of materials retained on a 200-mesh screen. Clay was prominent in micron-size slimes. Silica was deleterious in the minus 20-mesh size. While an indicated 2,198,000 dry long tons of usable iron ore can be recovered, sink-and-float tests show that it may be possible for 4,654,000 dry long tons to be recovered by other than log washing. However, applicable commercial processes have not been demonstrated.

Jan 1, 1965

By John J. S. Sebastian

A laboratory-scale investigation was made of the basic problems involved in developing a ceramic heat exchanger to operate at high temperatures for using nuclear heat from gas-cooled process-heat reactors. Technical data were obtained on transferring heat by forced-convection from helium to air in a single-tube vitreous-alumina heat exchanger. Coolant air was passed through the annulus parallel with, and either concurrently or counter to, the flow of helium inside the tube. The data obtained pertain to removing heat from the helium. Average inside film coefficients were determined at mean surface temperatures of 200° to 1,570° F., inlet-gas temperatures of 1,450° to 2,665° F., and Reynolds numbers up to 560. The gas-to-surface temperature ratios were varied from 1.05 to 7.6. The tabulated results are shown in the appendix at the end of this report. The film coefficients of heat transfer were correlated by taking into account the physical properties of the helium at the average fluid temperature. With experimental conditions pointing to a laminar flow, the Nusselt number was found to decrease as the ratio of gas-to-wall temperature was increased to a value of 3. However, within the range tested, gas-to-wall temperature ratios above 3 did not affect the Nusselt number, regardless of the value of the Graetz number. Thus, beyond this point any increase in this ratio ceased to influence the heat-transfer relationship.

Jan 1, 1962

By J. H. East

"INTRODUCTION Diesel locomotives have been used successfully in underground mines of Europe for 18 years, and much has been written on the technical details of the design of these machines and the safeguards provided by the manufacturers. The actual conditions under which' the Diesel locomotives are used have not been publicized as well and consequently are not well-known. In 1945 the writer observed numerous Diesel locomotives working underground in coal and metal mines of several European countries and was favorably impressed with the practical approach to the safe use of this- type of equipment.Recent statistics showing the number of Diesel locomotives in use are not available now because of the World War, but the extent to which this type of mine locomotive was used immediately before the war is indicated by table 1, which classifies the number of locomotives used in several countries according to the type of power, such as compressed air, Diesel, and electric.Mining conditions observed by the writer in the European countries are very different from those in most coal-mining districts of the United States. The surface plants are larger and are permanently constructed of brick or concrete; numerous coal beds are worked through one shaft; the crosscut rock tunnels or levels, driven to intersect the coal beds, are lined with brick or concrete blocks where needed instead of timber; the coal beds dip more steeply and are not as thick as in most fields of the United States."

Sep 1, 1946

By Steven J. Page

Since 1982 standard calibration materials recommended for respirable crystalline silica analysis by the Mine Safety and Health Administration (MSHA) P7 Infrared Method and the National Institute for Occupational Safety and Health (NIOSH) X-ray Diffraction (XRD) Analytical Method 7500 have undergone minor changes in size distribution. However, a critical assumption has been made that the crystalline silica in ambient mine atmosphere respirable dust samples has also remained essentially unchanged in particle size distribution. The objective of this work, therefore, is to compare recent particle size distributions of underground coal mine dust and the silica component of these dusts with estimated aerodynamic particle size distributions of calibration standard materials MIN-U-SIL 5, Berkeley 5, and SRM 1878 used by two crystalline silica analysis techniques. This work provides resolution to a previously reported discrepancy involving the proper sample dilution for the particle sizing method used. Dust impactor sampling data for various locations in 13 underground coal mines were collected between 1991 and 1998 and analyzed for the respirable mass median aerodynamic diameters. The data suggest that the MSHA P7 Method will underestimate the silica content of the sample by at most 8.5 % in the median size range of 0.9–3.6 µm and that it is unlikely one would obtain any significant error in the MSHA P7 Method analysis when the method uses Berkeley 5, MIN-U-SIL 5, or SRM 1878 as a calibration standard material. The results suggest that the NIOSH Analytical Method 7500 would be more appropriate for a dust sample that is representative of the total (no cyclone classifier) rather than the respirable airborne dust, particularly since the mass fraction in the size range below 4 µm is usually a small percentage of the total airborne dust mass. However, the NIOSH Analytical Method 7500 is likely to underestimate the silica content of an airborne respirable dust sample by only 5–10 %. The results of this study also suggest that any changes that may have occurred in the median respirable size of airborne coal mine dust are not significant enough to cause any appreciable error in the current methods used for respirable crystalline silica analysis.

Aug 3, 2005

By D. E. Wolfson

As a part of its overall program of coal carbonization, the Bureau of Mines is studying the coking properties of coals that may be used for metallurgical purposes. The objectives of this study were given in detail in a previous report The inherent suitability of coal for metallurgical purposes depends primarily on (1) chemical composition, (2) preparation characteristics, and (3) carbonization behavior. The first two factors, Be well as the amount of available reserves, are considered in selecting coals for carbonization tests. The selection of coal beds in Harlan County, Ky., for coking tests was based, in part, on recent studies of coal reserves by Wallace,3/ who estimated the recoverable reserves in beds 28 inches or more thick, in tons, as follows:

Jan 1, 1956

By C. Lurie

This final report describes the work performed by Gulton Battery Corporation under USBM Contract No. HO-112033, entitled "Research and Development on Lithium-Nickel Fluoride Batteries For Mint Life Support Equipment". The lithium-nickel fluoride couple was chosen For this investigation because of its high theoretical energy density (626 Wh/lb), its ability to operate at ambient temperatures and the fact that it showed promise as a secondary system. The theoretical energy density of the lithium-nickel fluoride couple is ten times greater than that of the widely used lead-acid battery and three times greater than the silver-zinc battery which has the highest theoretical energy density of the commercially available secondary systems. The experimental program first evaluated the cell components individually. The results of these studies then formed the basis for investigations of cell performance using experimental three-plate cells. These cells consisted of one nickel-fluoride and two lithium electrodes. All work was performed in a glove box under an argon atmosphere which was sufficiently pure to maintain the shiny appearance on freshly prepared lithium surfaces. The major portion of the work effort was concerned with the nickel fluoride electrode. Binder, conductive diluent, fabrication technique, as well as the nickel fluoride active material itself, were considered. Criteria for binder materials were established and six classes of materials encompassing thirteen binders were evaluated. The candidate materials were initially screened for appropriate chemical and physical properties and finally evaluated in three.-plate cells, Two epoxy powders emerged as the most promising binders. Two types of conductive diluent were evaluated. The first is a carbon black of low bulk density and high surface area. This material is a good conductive diluent; however, electrodes fabricated with it lacked good mechanical strength. It was hypothesized that a uni¬form, small particle size, low specific surface area would improve the mechanical properties of the electrodes. Therefore, two samples of graphicic materials, milled to uniform powders in the one-to-ten micron range were evaluated. Electrodes prepared with the graphitic materials had superior mechanical properties, However, their electrical performance was significantly poorer and voltage losses of 0.2 to 0.3 volts were observed. Several electrolyte solutions were evaluated. N-Methyl-2-Pyrrolidone was tested but found to be incompatible in the presence of lithium. Lithium perchlorate, lithium hexafluoroarsenate, and lithium bromide were tested as two-component electrolytes in propylene carbonate solvent and their performance compared with that of the single electrolyte solutions, Lithium perchlorate gave the best performance. Lithium hexafluoroarsenate was also evaluated in methyl formate and appears to give equivalent performance. The lithium perchlorate-propylene carbonate system is preferred as it is easier to handle and less expensive.

Jan 1, 1973

By Douglas F. Scott

In 1985, at the request of the U.S. Bureau of Land Management, the U.S. Bureau of Mines studied an 11,980-acre part of the 33,300-acre High Rock Canyon Wilderness Study Area, CA-020-913B, in order to evaluate its identified mineral resources. No mineral resources were identified during this study, and no significant amounts of gold, silver, mercury, gem-grade opal, or placer gold are present. The study area is located in Washoe County, NV, about 53 miles southeast of Cedarville, CA. No mining districts or mineral production are known, and no oil and gas leases are in the area. No current claims are in the area; however, six placer claims were located in 1911 in High Rock Canyon near its confluence with Mahogany Creek.

Jan 1, 1987

By William G. Pariseau

The research reported here concerns ground control in multi-seam mining and relates mainly to the analysis of stress about multi-seam room and pillar mines. The two variables of most concern are distance between seams and alignment of pillars between seams. The first year results of the two year investigation apply to the development phase of mining when the extraction is typically less than 50 percent. The second year effort is concentrated on retreat mining and barrier pillar safety when the extraction is typically greater than 50%. The procedures in both cases are readily applicable to more than two seams. Although two seam mines are the most frequent type of multi-seam operations, because of the potential for three seam operations in the Western United States, a number of three seam development analyses are also presented. The results enable one to make a rapid assessment of stability of rooms and pillars during production and barrier pillar size during extraction of adjacent panels. In the event of low safety factors, more site-specific analyses can be undertaken.

Jan 1, 1983

By Laurance L. Oden, Jack C. White, Alan D. Hartman

The U.S. Bureau of Mines, under a Memorandum of Agreement with the American Society of Mechanical Engineers (ASME), established design criteria for a facility to field residues from municipal waste combustion. This facility, which is available to potential users on a cost-sharing basis, is also applicable to a variety of inorganic waste materials from smelting or melting operations. The design consists of a mechanical feed handling system, electric arc melting furnace, fume-off gas handling system, and thermal oxidizer for final off gas treatment. Screw conveyors and a bucket elevator deliver up to 2,000 Ib/h of minus I-in material to a three-phase electric arc melting furnace. This unique 800-kVe A furnace has a water-cooled shell and roof to minimize interaction of the melt with the refractory lining. The volume of the hearth below the slag taphole is approximately 1.2 st of steel. The furnace is sealed, allowing atmosphere control within the furnace and fume duct by nitrogen or inert gas injection. A jet-pulsed baghouse removes particulate from the off gas and serves as an acid gas scrubber. The clean off gas is heated to 1,800' F for 1 s in a propane-fired thermal oxidizer before being vented to the atmosphere.

Jan 1, 1993

By Thomas Novak, Robert Goldstein

The analysis of a machine-luminaire configuration is a time- consuming process requiring the construction of a machine mockup, installation of a designated lighting arrangement, and an extensive set of illumination measurements. This entire process, however, is well suited to computer analysis. By simulating the machine geometry and the characteristics of the desired luminaires, the incident light levels can be calculated at the required set of points. This Bureau of Mines paper presents a general description of the techniques involved in performing this simulation.

The contract objective was to evaluate sources of airborne quartz and research control methods that would assist underground mine operators in complying with respirable dust standards which have been reduced because of quartz in the dust exceeding five percent. The work involved: Phase I -evaluate sources of quartz dust at the roof bolter work location; Phase II -evaluate the relationship between the quartz content of the coal and adjoining rock strata and quartz exposure at the roof bolter and continuous miner locations Phase III -conduct laboratory tests to determine performance parameters for roof bolter dust collector systems. The underground surveys for Phases I and II determined: (1) the continuous miner typically is the greatest source of quartz exposure for the miner and roof bolter operators when single-split ventilation is utilized, (2) a statistically significant relationship be­tween quartz content in face material and operator exposure was not determined and data suggested mining equipment and procedures may be more critical. The Phase III lab tests indicated the use of dust hog-type bits, filter cartridges, maximized collector airflow, and reduced bit rpm should be utilized to minimize dust liberation at the roof bolter.

Jan 1, 1985

By A. M. Poston

Introduction of radioactive elements into ore samples and/or pregnant liquors and radiometric tracing thereof have greatly improved control of fusion and extraction studies on beryllium ores and products. Extractive metallurgical research on beryllium, normally guided by the usual laborious analytical methods, is both costly and slow. Recognition of this problem by the Bureau of Mines led to the development and application of radioisotope tracer techniques" as a substitute for chemical analysis at the Salt Lake City Metallurgy Research Center, The result was that much faster progress at significantly lower cost was achieved. This report discusses the problems encountered and resolved in using radioactive tracers and radiometric methods, defines the conditions and techniques for their effective use, and delineates the limitations and flexibility inherent in applying such methods in laboratory-scale beryllium research.

Jan 1, 1962

By David A. Summers

Coal is increasingly viewed as one of the major fuel resources of this country for the remainder of this century. The need to extract a greater percentage of the coal in a given seam, together with advantages of improved safety, indicates that longwall mining will become more widely used within this time frame. A novel method of mining coal on a longwall face, utilizing high pressure water jets, is herein described. The mining machine proposed will exploit the stress conditions which exist on a longwall panel in order to achieve the required productivity while at the same time reducing respirable dust and methane ignition hazards. The water jets will excavate only the boundary of the extracted seam section, and thus the energy requirement of the machine will be minimized. The action of the machine is similar to that of an existing coal plow, except in that the wedge teeth of the plow are replaced by oscillating high pressure water jets. The machine can, therefore, cut to the depth and at the speed of existing shearer units at equivalent power levels. The removal of impact stresses from the machine will reduce downtime required for maintenance and replacement of picks and lower the load on the haulage motor of the system. The ability of the machine to increase the depth of cut without an increase in horsepower will further improve productivity when transportation systems to remove the greater production are in operation.

Jan 1, 1974

By P. L. Woolf

Blast furnace coal injection tests conducted by the Bureau of Mines in cooperation with a consortium of 22 steel companies in 1963-1964 are described. These tests were part of a program of extensive investigation of auxiliary fuel injection in the Bureau's experimental blast furnace located at Bruceton, PA. Seventeen coal tests are described on various coals ranging from anthracite to subbituminous. Factors affecting maximum rates of injection were studied. These included coal size, coal type, and oxygen enrichment. The effect of high sulfur content coal and the means to control metal sulfur were investigated. An epilogue briefly describing the commercial experience with coal injection from 1960 to the present has been included.

Jan 1, 1985

By Michael J. Bertoldi

The purpose of this Bureau of Mines report is to describe the methods and establish the basic economics for dragline, shovel-truck, and scraper mining systems. An overall view of the techniques of preliminary design and the cost involved is presented. Considerations of equipment selection, emphasizing short-range evaluation of required equipment, and a long-range evaluation are considered at a constant production rate over the life of a hypothetical mine. Separate cost analyses for each system were based on 1977 equipment prices, prevailing wage rates, and associated mining costs. Specific engineering and cost breakdown for such items as access roads, transmission line installation, rail spurs, etc., are beyond the scope of this report.

Jan 1, 1977

By L. C. IlsLey

"There is an old saying that ""It is too late to lock the stable after the horse is stolen"". Is not this just what is being done by many mine operators today when it comes to buying safe electrical equipment for gaseous and dusty coal mines?The ""open type"" of electrical equipment or even the ""half safe"" type represents the unlocked stable. After the mine disaster, and after men have lost their lives, the lock is put on - that is, safer equipment is installed.For example, an open type of electric coal drill was used in a gaseous mine in West Virginia, This was the probable cause of the death of 27 men. A half safe type of electric coal-cutting machine was used in a gaseous mine in Pennsylvania. This was likely the cause of the death of 36 men. An unapproved, unsafe type of flame safety lamp was used in a gaseous and dusty mine in Utah. This was the all¬eged cause of the death of 171 men. All three disasters happened within the last six months, and seem to have been avoidable if proper equipment had been used.It is understood that more rigid requirements will be enforced in West Virginia. The committee of State mine inspectors made definite recommendation for im¬proving the conditions in the given mine in Pennsylvania. The Industrial Commission of Utah have already issued new orders which will remedy the use of unsafe lamps in that State.These acts and recommendation are all good and will help prevent accidents in those States in the future. Is it not a pity that such recommendations and order were not made a little earlier before the tell of life had been exacted? Is it not a pity that other States will not take these lessons to heart and safeguard their mines before and not after disasters take place?Electric current can cause accidents in five general ways as follows: (1) By shock to persons; (2) by igniting powder; (3) by igniting gas; (4) by igniting coal dust; and (5) by setting fire to inflammable material such as timber and coal. A great many accidents from these causes are preventable if proper care is taken. Most of the accidents caused by sparks and flashes from electrical apparatus would not take place if approved electrical equipment was used. By approved equipment, the writer means equipment that has been tested and formally approved by the Bureau of Mines. So far as known, up to the present time, no disasters have been caused by sparks or flashes from equipment having the Bureau's approval."

Jul 1, 1924

By Lloyd R. Michels, Burke Cartwright, S. F. Ravitz

"INTRODUCTION Frequent attempts have be,made in the electrolysis of molten magnesium chloride to regenerate the electrolyte by allowing the chlorice generated at the anwdo to read with magnesium oxide and carbon within the melt according to the following reactions: (1) MgO + C + CL2 = MgCl2 + CO,(2) 2MgO + C + 2C12 = 2MgC12. + CO2.The principal advantages of such a procedure are that (1) the direct source of magnesium is magnesium oxide rather than the more expensive dehydrated magnesium chloride and (2) it is not necessary to handle or dispose of large quantities of chlorine or hydogen chloride.Grätzll 5/ proposed the use of an MgO carbon feed in a more or,less compact form in the anode compartment, of the cell. In a patent issued to Magall Aktiengecellschaft, 6/ a compact mixture of MgO and carbon is used as the anode itself. Kato 7/ and Backer 8/ add the feed in finely divided form to the surface of the anode compartment. The Bureau of Mines 2/ recently made a pilot-plant investigation of the electrolysis of suspension of MgO and carbon from chloride melts, in which it was found that although,current efficiencies of 60 to 70 percent were obtainable, the formation of sludges containing MgO, carbon, and magnesium seriously interfered with the operation of the cell,"

Apr 1, 1945

By Robert G. Gibson, Joel D. Gibbons

Measurements and analyses were conducted of whole-body vibration aboard seven commercially available passenger and/or recreational vehicles: sedan; sport-utility vehicle (SUV); pickup truck; moving truck; motorcycle; all-terrain vehicle (ATV); and boat. The purpose of the testing was to measure and assess whole-body vibration exposure in a range of typical vehicle environments in order to gain understanding of typical exposure levels characteristic of activities of daily living. Vehicle models tested (and model year) were: Ford Taurus (1995); Jeep Cherokee Sport (2000); Toyota Tundra SR5 (2002); Ford F-350 (1997); Harley-Davidson Electra Glide Classic (2004); Yamaha Kodiak 400 4x4; and Steiger Craft Model 21 Montauk. All vehicles were tested with their standard factory-installed seats and were operated under a range of normal operating conditions and speeds typical of intended vehicle use. Methods The measurement, processing, analysis, and exposure assessment methods follow the guidance of generally accepted, national and international consensus standards relevant to the evaluation of whole-body vibration, including ISO 2631-1 [1] and ANSI S3.18 [2]. Seats were instrumented with low-mass triaxial accelerometers mounted in seat pads. Accelerometers used in the test are specified to have flat frequency response over the frequency range of 0.5 to 80 Hz, and all accelerometers were recently calibrated traceable to the National Institute of Standards and Technology (NIST). Seat pads were installed following guidance in the relevant standards [1, 2], with sensitive axes of the accelerometers following the standard coordinate system with respect to the seated occupant. (The x-axis represents fore-aft motion; the y-axis represents side-to-side motion; and the z-axis represents vertical motion with respect to the occupant.) Vibration data processing and analysis, including filtering, sampling, frequency-weighting, averaging, summation, and determination of basic and additional metrics followed procedures in the relevant standards [1, 2]. Digitized time series data were acquired and stored using a PC-based data acquisition system. Whole-body vibration exposure analyses were conducted via post-processing. During data processing, recorded periods of seat acceleration that were identified and verified as resulting from occupant-induced motion rather than vehicle motion were excluded prior to exposure analysis. The basic evaluation metric for whole-body vibration is the frequency-weighted root-mean-square (r.m.s.) acceleration, aw. The primary additional evaluation metric is the fourth-power

Jan 6, 2006

By P. C. Tully

The vapor pressure-temperature relationships for saturated pure liquid nitrogen are calculated by the Strobridge equation using a digital computer. This information is presented in two tables: first) in pressure increments of 0.1 psi from 1.8 to 492.9 psia) and second) in temperature increments of 0.1° from 63.15° to 126.26° K. These tables should facilitate the calibration of temperature-measuring devices over this temperature range.

Jan 1, 1967