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By Marilyn Biviano

This analysis was conducted in response to concerns raised by the Chairman of the Energy and Commerce Committee of the House of Representatives regarding the potential impacts on automobile production, GNP and employment resulting from embargoing south African supplies of the platinum-group metals, platinum and rhodium. This analysis should be considered an addendum to the recently released study in which the direct economic costs I of a U.S. embargo on selected South African strategic and critical materials are estimated. The estimated GNP and employment impacts result when a mineral shortage reduces domestic industrial production and are in addition to the direct costs estimated in the earlier study. The direct cost to this nation resulting from a decision to embargo six south African strategic and critical minerals was estimated at $1.85 billion per year during the 1988-1992 time frame of the study. The estimated direct costs include the costs to U.S. consumers resulting from higher strategic mineral prices, lower mineral consumption, and the cost of developing higher cost domestic mineral resources. A large proportion of the costs result from the shortage of the two metals: platinum and rhodium. The average direct annual cost of embargoing is estimated at about $1.4 billion for platinum and $384 million for rhodium.2

Jan 1, 1988

By R. K. Koch

The vapor pressures of liquid columbium and liquid hafnium were deter-mined by the Langmuir free evaporation method as a part of the Bureau of Mines program on the study of transition metals. An electron-beam furnace with a water-cooled copper crucible was used for melting. Temperature was measured with a two-color ratio pyrometer. Least-squares analyses of the vapor pres-sure data gave the following equations: [Logp (atm) = 5 .429 -31,310 T] for liquid columbium in the range 2,740° - 3,140° K, and [Log p (atm) = 5,690 28 T] for liquid zirconium in the range 2,500° -2,810° K. Third-law evaluations of each data set gave mean heats of sublimation (298.15° K) of 175.1±3.2 kcal/mole and 148.3±1.2 kcal/mole for columbium and hafnium, respectively. Second-law standard heats of sublimation determined from sigma plots and from sigma-prime plots agreed fairly well with the third-law values. The sigma-prime plots gave standard entropies of sublimation of 30.96±0.84 eu and 33.S6±0.44 eu for columbium and hafnium, respectively.

Jan 1, 1968

By Thomas W. Thompson

The Zebulon manganese deposit has been known for a number of years. It is situated about 3 miles east of Zebulon, Wake County, N. C., on the Avon, Privett property (fig. 1). The deposit outcrops as a vein, or dike averaging-16 to 20 feet in width. Drilling by the Bureau of Mines has shown that this outcrop results from consolidation of a number of small stringers near the surface. The surface width and the Percentage of manganese oxides (resulting from. weathering) diminish with depth. Below 50 to 80 feet, the vein material is mainly quartz and spessartite garnet. The deposit was first examined by W. T. Benson, a Bureau of Mines engineer, in 1941. The Bureau conducted a diamond-drilling exploratory program an the property from November 7, 1944, to January 25, 1945. A. total of 2,508.5 feet was drilled in 14 holes along the strike of the deposit.

Jan 1, 1950

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars arc characteristically of the 'fire door" type that is frequently encountered on outside exit doors of many public, and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes arc added to the face equipment machinery for which they arty required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in "Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/Automatic Emergency Brakes" by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. I. Judy (our consultant), etc:

Jan 1, 1974

By James H. Cobbs

The purpose of this study is to investigate the application of boring equipment to the production of anthracite coal from steeply pitching beds. Both raise boring and augering equipment were considered. Previous studies (11) have indicated that boring equipment may have definite applications to the development of steeply pitching anthracite beds. This investigation was to carry forward previous work to determine the possible application of the two different types of equipment being considered. Previous conclusions have been substantiated by the results of this study.

Jan 1, 1975

By R. W. Stahl

Coal mining has been revolutionized by the continuous miner. This machine has replaced, or has combined into 1, 3 former operations: Cutting, blasting, and loading. During the 25-year period before this machine was introduced, advances had been made in transportation, but the actual "coal getting" remained virtually the same. As frequently occurs, the multiple-purpose continuous miner introduced a new hazard--more rapid liberation of methane. The coal output formerly obtained from 10 to 20 working places might now be obtained from 1. It is true that circulation of air was generally increased; but the bulk of this machine virtually precludes continuous flow of air across the face, where gas may accumulate. Apprehension about this possible hazard led the Bureau of Mines to test face atmospheres during operation; and Report of Investigations 5288, Methane Buildup During Cutting and Continuous Mining Operations (published in 1956), presents proof that real danger may be present in many otherwise well ventilated mines.

Jan 1, 1958

By W. H. Ode, W. A. Selvig

"INTR0DUCTIONAccording to the Standard Specifications for Classification of Coals by Rank of the American Society for Testing Materials (A.S.T.M. Designation: D388-38).1/ high-volatile bituminous coals, subbituminous coals, and lignites are classified on the basis of calorific values on the ""moist"", mineral-matter-free basis. The moist basis refers to coal containing its natural bed moisture but not including visible water on the surface of the coal. It is assumed that the natural bed moisture of coal in the ground represents the moisture-holding capacity of the coal when in equilibrium with air at approximately 100 percent relative humidity. This moisture is sometimes referred to as inherent moisture as opposed to extraneous moisture, which wets the surface of the coal.To simplify procedures for determining the moisture-holding capacity of coal it is assumed, for all practical purposes that the moisture content of coal when brought to a standard condition of moisture equilibrium in an atmosphere of 97 percent relative humidity and 300 C. represents the bed moisture of the coal. The A.3.T.M. specifications provide that this condition of moisture equilibrium shall be obtained by bringing the coal to a standard condition of moisture equilibrium at 300 C. in a vacuum desiccator containing a saturated solution of potassium sulfate (97 percent relative humidity) according to the procedure proposed by Stanfield and Gilbart. 4/ No mention is made in the specifications for bringing partly air-dried samples to their natural bed moisture condition probably because of the hysteresis effect that has been noted by various investigators. 5/ In this connection it has been found from sorption studies that the adsorption and desorption curves for lignite are not entirely reversible. The hysteresis effect has been explained by some investigators as resulting from shrinkage of the lignite during drying, which causes a collapse of some of the capillaries, so the dried lignite cannot take up as much water as it held originally."

Apr 1, 1953

By G. R. Hopkins

"The average heat requirement per barrel of crude refined in the United States rose from 579,000 B. t. u. in 1940 to 584,000 B. t. u. in 1941. This marked the second successive year in which there was an apparent loss in fuel efficiency at refineries. This ""loss"" took place despite an increase in crude runs, which used to be an invariable indicator of a lower average.Probably the chief factor in the increased heat requirement in 1941 was the gain in the over-all gasoline yield from 43.1 percent in 1940 to 44.2 percent in 1941. Possibly another important factor was the further use of obsolete equipment to increase throughput.The refiners used more of all kinds of fuel excapt coke in 1941 than in 1940. However, the only fuels which increased materially in relative importance were refinery gas, which contributed 51.6 percent of the total heat units in 1941 compared with 50.7 percent in 1940, and natural gas, the share of which rose from 17.1 percent in 1940 to 18.0 percent in 1941. The changes in the percentages for the other fuels were as follows: Oil decreased from 25.7 to 24.1 percent; acid sludge fell from 2.7 to 2.5; coal remained at 3.4 percent; and coke (including steam) fell from 0.5 to 0.4 percent.New records for fuel efficiency were set in all three of the districts east of the Mississippi, namely, East Coast, Appalachian, and Indiana, Illi¬nois, etc. All the ether districts reported higher average fuel requirements in 1941, except the Louisiana Gulf and Arkansas-Louisiana inland.Since the year of the first statistics, the refiners have steadily increased their purchases of electricity. In 1941 total purchases were 1,862,996,000 kilowatt-hours, or 11 percent more than in 1940."

Apr 1, 1943

By T. L. Marchewka

As part of its program to conserve the Nation's natural resources by developing improved performance materials, the Bureau of Mines, U.S. Department of the Interior, in cooperation with the U.S. Department of Energy, has conducted an investigation of materials of construction able to withstand the high temperature and hostile environments encountered in coal gasification units. Refractory pipe liners are required when extremely hot gases or abrasive solids are transported between processing units in the gasification plants. One promising technique for producing refractory pipe (or refractory pipe liners) is centrifugal casting. For this study, the effect of processing variables such as workability, additives, reinforcement and spinning time, and centrifugal force were evaluated using four commercial refractory concretes. In addition, data on characteristics such as strength, density, abrasion, and spalling resistance of 5-inch-diam refractory pipe were developed. Techniques for forming large-diameter (19-inch) refractory pipe also were evaluated. The test results indicated that all four refractory concretes could be made into strong, homogeneous pipe, but that optimum casting parameters had to be determined for each specific composition. The investigation revealed that the major controlling factor in the production of the centrifugally cast pipe was the workability of the refractory concrete.

Jan 1, 1979

By L. H. Banning

Recent dry-top electric smelting tests at the Northwest Electrodevelopment Experiment Station, Albany, Oreg., indicate that a high-titanium slag and a good grade of pig iron can be produced from alluvial Idaho ilmenite. A total of 120 tons of concentrates were smelted during this investigation, to yield an average of 0.5 ton of slag and 0.3 ton of pig iron per ton of ilmenite. Power consumption averaged 1,400 kv.-hr. per ton of ilmenite, at a feed rate of 400 to 500 pounds per hour, when operating at an electrical energy input of 290 to 370 kilowatts. The optimum operating voltage appeared to be 110 volts, phase-to-phase. Graphite electrode consumption averaged 15.6 pounds per ton of ilmenite smelted. Magnesite furnace refractory withstood the corrosive action of the hot metal and slag better than carbon refractory.

Jan 1, 1955

By W. Hermanson

This report, which covers the period from January 16 to October 21, 1974, describes the work performed in compliance with the requirements of contract no. H0242028 and modifications 1 and 2 thereto. The purpose of the contract was to further reline and modify three of the canopies (shuttle car, loader, and roof drill) which were developed under contract no. H0220031, and to conduct further testing and demonstration of the relined designs. Modifications I and 2 involved conducting further in-mine evaluations of the face. drill and cutter canopies, also developed under contract no. H0220031. In addition to the canopy modifications, the contract involved an evaluation of an operator's seat concept for a shuttle car which was developed for the USBM by another contractor.

Jan 1, 1974

By D. S. Harper, C. O. Carman

A German coal planer was put in operation in the Keystone mine of the Eastern Associated Coal Corp. , Keystone , W. Va . , in August 1960 . At present , the planer is mining in the fourth panel . The blocks of coal mined were 340 by 1,900 feet in panel 1 , 340 by 1,660 feet in panel 2 , 590 by 1,900 feet in panel 3 , and panel 4 , currently being mined , is 590 by 1,900 feet . Almost one- half million tons of coal have been mined from these four panels . An 11 - man crew handles the complete planer operation and produces an average of 500 tons of clean coal per shift . Self - advancing hydraulic props are used to support the roof over the entire face . Roof control and action on all of the panels has been highly satisfactory . During periods of extreme pressure , some additional support is required in the tail entry where evidence of weight from the retreating longwall extends about 200 feet outby the face . The time lost from production by moving equipment between panels has been reduced steadily . The move from panel 3 to panel 4 required 5 days , but it is believed that even that time could be reduced .

Jan 1, 1963

By F. S. Crawford

A large number of operators of various industries in the United States do not appear to realize the great returns in dollars and cents which result from intelligently directed safety work . Managers of co 1 mines , metal mines , open-pit mines , quarries , steel mills , cement mills , oil rei meries , iron works , or other industrial operations , should by all means realize the great waste resulting from accidents , in order to appreciate the necessity for a continuous accident -prevention policy . While the prevention of accidents is worth while from the humanitarian standpoint alone , it has an equally important economic side , and before our mining industrial operations will be made as safe as they should be , it is apparent that this dollars and cents viewpoint must be given full recognition in order to bring before many of the men who run the industries the great importance of this phase of industrial management . : There is a tendency upon the part of the opera or who has not given thought to the cost of accidents ( and there are many mining operators of this type) to insure his company against compensation losses and against catastrophes for which he can secure insurance , and think he has done his duty ar an executive . Even though industrial operations were not compelled to pay compensation , and even if the management were not moved by humanitarian motives to try to stop accidents , it would pay many times over to carry on accident prevention work vigorously and continuously. : In some parts of the United States , the state compensation and insurance requirements are such that the operator does not receive a reduction in his insurance rate per men employed upon having made safety installations or upon having achieved a reduction of accidents in his plant . Under such conditions the management frequently does not feel encouraged to emert much effort in bettering the accident rate . However , when the responsible officials of a company realize the much greater harm to an operation which results from doing no accident - prevention work , and the great benefit in reduced costs which usually follows effective safety work , they should be inclined to do almost everything possible to reduce accidents , regardless of considerations as to accident compensations . There are enough indirect costs resulting from accidents to wreck many types of business ; excessive accidents result in disorganization and failure , while immunity from accidents usually means a smoothly running efficient organization .

Sep 1, 1930

By C. B. Daellenbach

A prototype particulate size analyzer system was developed that would rapidly determine size distributions of homogeneous and two-mineral materials in the 74-micrometer (200-mesh) to 7-micrometer size range. The system sizes particles in a series of hydrocyclone elutriation steps and senses the weight of the five sized fractions by nuclear attenuation techniques. Size distribution of materials was determined from experimentally developed mathematical relationships that existed between particulate weight and the measured transmittance of gamma rays from an Americium-241 source. In the developmental phases, size distributions of three minerals (quartz, magnetite, and hematite) and a laboratory prepared two-mineral mixture of quartz and magnetite were accurately determined by the prototype system. In later stages of the investigation, semiconcentrates, an intermediate magnetic product from a taconite plant, were evaluated. Using 25-gram feed samples of this industrial material, the analyzer system was found to predict weight percentages for individual size fractions with an accuracy of ±0.85 percent or better at a 95-percent confidence level.

Jan 1, 1974

By Glen C. Reed

"The Avon mica district of Latah County, Idaho, is situated on a heavily forested spur of the Thatuna Range at an average altitude of 4,000 feet. The nearest rail connection is at Avon, a small farming settlement 7 miles to the south. The main supply point is Moscow, Idaho, which is 35 miles by graveled and graded county roads from Avon.Discovery of mica-bearing pegmatites in 1885 was followed in 1888 by exploitation of several outcrop deposits. Although factual data are unavailable, past production appears to have been well in excess of $100,000. Recent production (September 191 to April 1945) amounted to 65,824.78 pounds of trimmed sheet mica and 33,294.17 pounds of punch mica having a total gross value of $434,298.The several properties of the district are variously owned by estates, individuals, and the State. When active, all wore under lease or sublease to individual operators.The deposits are in an area of pre-Cambrian schists adjacent to a small granitic outlier of the Idaho batholith. The pegmatites are nearly concordant in dip and strike to the foliation of the enclosing schists. The more persistent bodies are usually tabular, lenticular, or pegmatite. Individual dikes range in length from 10 feet or less to 300 feet.The recoverable crude mica content of the pegmatites ranges downward from a maximum of 115 pounds per ton of pegmatite mined. Material discarded in rifting and trimming operations further reduces recovery to a maximum of 5 pounds per ton -of pegmatite mined. The average recoverable sheet content of the 'recently operated .deposit is estimated at 2 pounds per ton of pegmatite -mined. Available data indicate that about 21 percent of the district's recent production of trimmed sheet mica has been ""Group A"" material suitable for exacting condenser requirements. A few of the dikes contain local concentrations of beryl.Reserves of the three known major deposits of the district are estimated at about 600 to 1,000 tons of combined ""indicated"" and ""inferred"" crude block mica. One of these deposits is inferred to contain between 150 and 450 tons of beryl.It is believed that those mica reserves are minable only under a cost-market price ratio similar to that established during 1943 and 1944. A small part of the reserves can be ""high-graded"" under the present price structure. Profitable recovery of the beryl would require a market price four to five times that paid in 1944.Preliminary examination of the Avon mica district was made by the Bureau of Mines in the summer and fall of 1942. A study of the Muscovite mine and a brief reconnaissance of the surrounding district led the Bureau to recommend that the district be explored by angle-dozer trenching."

Jul 1, 1946

By Roy H. Poston

The following paper is one of a series on mining methods and practices being published by the United States Bureau of Mines, and deals with the sinking of the Pim shaft (No. 7) of the St. Louis Smelting and Refining Works of the National Lead Co. in the southeast Missouri lead belt. The shaft was sunk in 1922 and 1923 on a tract several miles south of the company's main plant located at St. Francois, Mo., in St. Francois County. The author is indebted to W. H. Comins, local manager of the company, with whose permission this article has been written, for his helpful criticism; and to E. T. Campbell, geologist, and M. Cross, underground shop foreman; and to W. A. Cole, manager of the E. J. Longyear Development Co., who had general supervision of the work and supplied detailed performance and cost data.

Jan 1, 1932

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 Edward D. Thimons

The Bureau of Mines conducted a state-of-the-art study of techniques currently employed to close large openings in underground mines. A large opening was considered to be any opening over 10 feet high and having a cross section of at least 200 square feet. Five salt mines and one limestone mine were visited to observe various methods of sealing large openings. Because of the variations in conditions from mine to mine, no definite conclusions could be drawn as to which is the best method. In mines where waste material is available, stoppings built by piling waste material are efficient and economical. Where waste material is not available properly constructed brattice cloth stoppings are superior to those built from wood, concrete block, or urethane foams.

Jan 1, 1975

By S. C. Schaefer

Thermodynamic properties of indium oxide (In203) have been studied with a high-temperature galvanic cell employing stabilized zirconia electrolytes. In the temperature range 790° to 1,230° K the free-energy change for the cell reaction 21n(1) + 3Cu20(c) = In203(c) + 6Cu(c) together with the standard free energy of formation of cuprous oxide gives the standard free energy of formation of indium oxide from the elements as ?Gf° = -218.78 + 75.34 X 10-3T ±0.7 kcal/mole. A third-law analysis yields the standard enthalpy of formation: ?Hf°298.15 = -221.5 kcal/mole.

Jan 1, 1971

By Kathleen M. Kowalski

This research explores the emergence of leadership in a crisis situation. The study by the U.S. Bureau of Mines focuses on three underground mine fires and the resulting evacuations. The subjects for this study are 48 coal miners, who evacuated the mines as part of eight escape groups, The subjects described their escape during an open-ended interview. Data were coded according to: (a) evidence of leadership behavior, (b) evidence of lack of leadership behavior, and (c) characteristics of the individual in each group who led the subjects out of the mine. During analyses, attributes of the leaders, who facilitated the escapes, were noted and compared as were instances of lack of leadership. The structure of the group leadership before the crisis was compared with the reality of the leadership during the crisis. Some groups experienced an apparent breakdown of leadership during their escape, while others witnessed the emergence of leadership. Consensus characteristics of the leaders, who emerged during these crises, are discussed and generalizations drawn. Research into leadership during emergency escapes is needed to provide information for training in prevention, escape, and rescue. The authors suggest questions for further investigation and topics for further inquiry into the area of leadership evolvement during crisis.

Jan 1, 1994