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By James L. Ash

This report contains the results of a technical and economic evaluation of conceptual systems for the underground mining, rubblization, and in situ retorting of deep oil shale deposits. Study efforts were first directed towards evaluation of the applicable geology, associated minerals, rock mechanics, in situ retorting, access mining, ventilation, rubblization, safety, and environmental impact factors. Conceptual systems were synthesized and then evaluated against these factors from both a technical and limited economic viewpoint. The results of these evaluations were then analyzed and, based upon this analysis, the following two systems were selected for further study: System II: Room and Pillar-Vertical Drill and Blast System IV: Tunnel Boring-Horizontal Ring Drill and Blast Due to the large number of variables to be considered, a computer program was developed and utilized to provide data for the cost trade-off studies and economic analysis. Results of the early computer runs indicated the value of the tool available? in the computer program and led to an extension in the contract to determine the sensitivity of the systems to several of the more apparent significant variables. These results in turn led to a refinement in the design assumptions and a better understanding of the technical and economic options available to an owner-operator of a Vertical Modified In Situ Shale Oil Extraction System. This report is submitted in fulfillment of the requirements of Contract Number 50241073 by Fenix & Scisson, Inc. to the Denver Mining Research Center, United States Department of the Interior, Bureau of Mines. Work was completed as of November, 1976.

Jan 1, 1976

As a result of early experiments in underground mine illumination, the Bureau of Hines recognized the need for additional experience with the underground lighting of coal mines having low seam thicknesses. There was already experience with tile illumination of coal mines having higher coal seams, and this contract with Ocean Energy Inc. (OEI) was undertaken to contribute to the "low coal" experience. For the purpose of this contract, a "low coal? mine is defined as one having less than 45 inches of overall headroom in the working places. As a practical limit, 26 inches was the minimum coal seam thickness to be encountered in this program. In one instance, the maximum coal seam thickness was eight to ten feet, however, this particular work was at the direction of the Technical Project Officer (TPO) by virtue of the unique type of lighting arrangement that was to be evaluated which would be useful for low coal. At the outset of the contract, three major tasks were established. The first two tasks involved the installation of permissible fluorescent lighting equipment at two low coal mines. The intention was to illuminate mining sections in each case consisting of one or more machines. The third task was to illuminate a variety or mining equipment including a longwall. For the purpose of this report, the fol-owing identifies the particular installations associated with each task.

Jan 1, 1976

More gold is being produced now than ever before in recorded history. All over the world huge quantities of ore are being mined and processed, thanks to historically high prices for gold and the use of processing techniques demonstrated as cost efficient in the last 20 years. Over the past 10-15 years prices for many other metals have been depressed, and gold has accounted for a significant proportion of worldwide exploration and development expenditures(l)1. The revenues generated from gold mining are providing greater return on investment, more jobs, and more tax revenues to national governments than ever before. Emerging nations are using the gold industry as a springboard for development; developed nations are continuing to fuel their economies with gold industry revenues; and China and countries of the former Soviet Union are using the gold industry to generate foreign exchange, modernize their mining industries, and take the first tentative steps toward private sector participation in their economies.

Jan 1, 1994

By James L. Hendrix

The applicability of a rotating drum with an attached trommel as a flocculation dewatering device of Florida phosphatic claywastes was studied. Several experiments were conducted in order to determine the important fabrication and operating parameters. Results from the experiments indicated flint the dosage of polyethylene oxide required to form a satisfactory product cake could be reduced by using the rotary drum, which introduces less shear stress into the fluid than a constant stirred tank mixer. It was found that the length of the mixer was the most important parameter. Increased length increased the retention time the flocs stayed in the mixer without dewatering. Such increased time decreased the stability of the flocs. Through analysis of residence time distribution data it was found that the longer mixers approached plug flow characteristics. Other important parameters were trommel length and rotational speed. Mixers from 10 cm diameter to 35.6 cm diameter were tested with good results.

Jan 1, 1982

By Wils L. Cooley

The report covers tests and criteria for the establishment of safe grounding systems for coal mines. The work deals primarily with under-ground coal mines, but much is applicable to surface mines as well. Included is an extensive guide to grounding and bonding procedures for mine surface substations. Xit-Rods are evaluated and shown to deviate from manufacturer's claims. An analysis shows that very long cables are difficult to monitor using audio frequency ground-check techniques. A method is developed to detect failing cable splices without removing the cable from service. Simulation and measurement are compared for a technique to detect bad rail bonds, and an assessment is made of grounding techniques for dc face equipment.

Jan 1, 1979

By V. H. Gottschalk, John Grodd, R. S. Dean

"Elemantary ConsiderationsAlthough magnetiem was first discovered in and derives its name from an oxide of iron found in magnesia and called lodestone its pracical uses date from the discoveries of Faraday concerning its relation to the electric current. We may therefore start our discussion of magnetic properties with Faraday's law for relation between induced electromotive force and the change in a magnetic where e is the electromotive force induced in an electric circuit by a unit rate of change of magnetic flux N, H is the intensity of the magnetic field, S is the area enclosed by the circuit, and i an angle between H and the normal to dS. In the simplest case we could use this law to measure the strength of a magnetic field by passing it at a measured rate through a coil of copper wire and determining the,electromotive force. As a matter of practical convenience, it will be simpler to nee the total quantity of electricity produced by a change of magnetic field. For this purpose we may let i denote the strength of the electric current induced by the change of magnetic field in time in a circuit of area a and resistance R. Then the total electric quantity. Q is given. by"

Mar 1, 1934

By Richard L. Ash

Introduction The blasting capabilities of commercial explosives are often rated according to their loading densities and detonation velocities. Both the density and velocity are relatively easily measured, the values of which can be used for determining the approximate detonation pressure developed by an explosive during any given set of blasting conditions (1-5). Knowledge of the actual rate of detonation attained at all points along a charger's length also is considered to give a good indication of how well the explosive is functioning. Many factors affect the density and velocity and have been thoroughly discussed by various authors (4, 6-12). For recording velocities several methods are available, but the resistance-wire, or probe, continuously recording technique has the distinct advantage of providing a record of the complete progress of an explosive reaction from the time it first initiates. Figure 1 is a copy of a typical record obtained by the procedure with certain significant information indicated. The theory and applications of the method are extensively covered in the literature so need not be reviewed for this report (13-18). Only the specific equipment and procedure employed for this investigation are presented.

Jan 1, 1973

By Thomas J. Peters

Tungsten, silver, lead, zinc, and placer gold occur in the Cucamonga B RARE II area (no. B5174). A strata-bound, scheelite-bearing zone at the Blue Diamond prospect (fig. 1, no. 1) contains an estimated 16,000 tons (15,000 t) of identified, subeconomic resources averaging 0.16 percent tungsten trioxide (W03). There is a high potential for discovering additional tungsten resources at this property. The California-Hercules prospect (fig. 1, no. 5) ha; a mineral occurrence which contains an estimated 1,000 tons (900 t) of tactite averaging 1.3 oz silver per ton (45 g/t), 0.75 percent lead, and 0.72 percent zinc. Another occurrence, at the Blew Jordam Prospect (fig. 1, no. 4) has an estimated 100 tons (90 t) of tactite averaging 10 oz silver per ton (340 ,/t), 3.75 percent zinc, and 2.3 percent lead. There is a moderate potential for discovering silver, lead, and zinc resources at these prospects, which are in metamorphic pendants. There are a few lode gold prospects in the area (fig. 1, nos. 3, 11, 14) are on geologic structures which parallel the San Andreas Fault, northeast of the area. These deposits are not well exposed and have been historically unproductive. Placer gold in area B occurs locally in the beds of intermittent tributaries to Lytle Creek (fig. 1, nos. 10, 12, 13) in concentrations as high as $1.17 per cu yd ($1.53/cu m, at a gold price of $450 per troy oz). The deposits have no significant volume, but could be utilized for recreational panning and suction dredging. In the Cucamonga C RARE II area (No. C5174) placer gold occurrences locally contain as much as $1.23 per cu yd ($1.61/cu m). However, gravel containing the gold appears to be limited to stream beds, and does not occur in sufficient quantity to constitute resources. Recreational panning and dredging also may occur in this area.

Jan 1, 1983

In attempting the predict coal cleat orientation in the subsurface for effective methane degasification of the coal beds in the Warrior coal field of Alabama, approximately 150 rock joint orientations and 45 coal cleat orientations were measured in each of 37 7 ½ minute quadrangles in Tuscaloosa, Walker, Jefferson, Fayette, Winston, Blount, and Bibb Counties. Data from these surface locations, and coal cleat data from eight underground mines was corrected for magnetic declination and titled beds rotated to the horizontal where necessary and plotted on rose diagrams for comparative analysis. Data collected on each joint and cleat consisted of attitude, quality, type, spacing, persistence, lithology, bedding thickness, surface texture, and filling. File data and published and unpublished reports from the State Survey and the State Mine Inspector's Office were re-viewed. Twenty-seven mining companies, most of which supplied information pertinant to the project were also contacted. The information obtained consisted of crop line information structure, and underground mine outlines, all of which were put on 7 ½ -minute topographic quadrangles. LANDSAT-1 imagery and Skylab photography were compared to dominant joint and cleat trends in the study area. Detailed results can be found in an open-file report entitled "Fracture Analyses in a Selected Area of the Warrior Coal Field, Alabama." A master's thesis entitled "The Relationship Between Surface Joints and Subsurface Structure in a Selected Area of the Warrior Coal Field" is being prepared to illustrate the relation-ship of the fracture system to the structure in the Warrior coal field. A proposal has been submitted for research on a project entitled "Rock Fracture Systems and Their Affects on the Extraction of Fossil Fuels in the Warrior Basin, Alabama"

Jan 1, 1976

By John G. Palmer

Continued development of an especially impregnated silica gel capable of reversible chemical detection of carbon monoxide (CO) was reported. The affects of changes in mine-related ambient conditions on the detection catalyst's response were explored. Temperature, humidity, and several interfering gases were found to affect the detection catalyst. The interferents include hydrogen sulfide, nitrogen dioxide, acetylene (and methylacetylene), and ammonia. High humidity decreased the detection catalyst's sensitivity to carbon monoxide for some formulations. Increasing temperature generally decreased the reaction time of the detection catalyst with carbon monoxide. Badges and carriers for the visual presentation of the detection catalyst were constructed. Several variations of these devices included provisions for absorbants and filtering agents which help protect the detection catalyst from gaseous interferents. A variety of catalyst support agents were tested in an effort to find the most suitable. Included were alumina, magnesium oxide, magnesium silicate, and several forms of silica gel. In addi tion to free-flowing forms of these sorbents, thin layer chromatography plates coated with cellulose, alumina, and silica gel and newly developed PTFE entrained silica gels were examined. A limited physical, chemical, and mechanistic characterization of the detection catalyst and the materials used to prepare it has been carried out. Metal component ratio studies, spectral, analytical, pH, and rate measurements were done.

Jan 1, 1982

By Sidney Katell

This report, covering the period January 1968 through December 1968, is a continuation of a series that began with the publication of Information Circular 7516 in October 1949. It is the tenth in a series of reports prepared in cooperation with the American Association of Cost Engineers. The abstracted articles are concerned with all phases of cost of engineering in the field of chemical and petroleum plants and related subjects. They are from the following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Lines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress s 6. Chemical Week. 7. Coal Age. 8. Coal Mining and Processing. 9. Cost Engineering. 10. European Chemical News. 3 11. Hydrocarbon Processing. 12. Industrial and Engineering Chemistry 13. Oil and Gas Journal. 14. Petroleum Engineer. 15. World Oil.

Jan 1, 1969

By R. H. Thompson

Preliminary safe distances for blasting wiring from typical electromagnetic sources are presented. The distances are for underground coal mines and electromagnetic sources in the frequency range below 10 MHz. The distances are based on measurements performed at 3 locations in each of 3 coal mines. The measurement apparatus, measurement procedure, measurement results and the rationale used in the calculation of the safe distances are all described. The safe distances presented are dependent on the measurement results and their interpretation. More measurements are clearly necessary to establish the validity of the suggested distances.

Jan 1, 1985

By Donald R. Johnson

Apparatus providing simultaneous differential thermal analysis, thermo-gravimetry, and evolved gas analysis, has been developed by the Bureau of Mines specifically for thermal study of oil shale and other solid, natural fuels. The apparatus is described in detail, and simultaneous analyses on a single sample of an oil shale mineral, nahcolite, and a thermal analysis demonstration compound, calcium oxalate monohydrate, are presented to demonstrate the instrument's capabilities.

Jan 1, 1970

By Mohan K. Wali

Soil and vegetation development were studied on abandoned mine sites near Velva in Ward County, North Dakota. The sites studied were 1, 7, 17, 30 and 45 years old since abandonment; unmined sites were also studied to provide measures of comparison. Species diversity was the highest at unmined sites (114) and lowest at the I year old site (26); sites 7, 17,30 and 45 years old had 37, 52, 43 and 68 species, respectively. Stand ordination revealed that site ages were the most important in influencing species diversity and composition. Stand-environ-mental complex ordinations encompassing 53 variables showed topographic variables to be the most important followed by site ages. Rates of nutrient accumulations were as follows: organic carbon 13.1 g m-2 yr-1; nitrogen 2.5 g m-2 yr-1; phosphorus 0.01 g m-2 yr-1; potassium 0.49 g m-2 yr-1. Carbon-nitrogen ratios showed the widest range for 1 year old sites (5-40) but 70 percent of the 45 year old sites showed values below 15 which were com-parable to the unmined mixed grass prairie sites. Species distributional diagrams are provided to show their habitat preferences which may be helpful in formulating species prescriptions for revegetation.

Jan 1, 1982

By Tyler Blake

This report describes a study designed to evaluate a pro-posed modification in the cap lamp battery cord intented to reduce the incidence of snagging and catching of the cord. A three phase evaluation was performed comparing a prototype with the standard, currently available cord. First, a ?pull test? equipment was run. The second evaluation was a body conformity study. The third evaluation involved subjects performing common tasks in a low seam coal mine simulator. The results of these evaluations clearly demonstrated significant safety advantages of incorporating coiled cord into the design of the cap cord. The coil cord presented less of a snagging hazard, allowed the wearer more time to respond to a snag, and transmitted lower levels of force to the helmet when snagged. The research team recommended that cap lamp cords be commercially developed which incorporate coiled cord at the battery and helmet.

Jan 1, 1980

By John C. LaScola

The Bureau of Mines investigated coal storage silos to determine how gassy coal must be for methane accumulations in a silo to become hazardous and where such accumulations are likely to occur. Methane concentrations were measured in the open space above the stored coal pile, in the pile, and in the reclaiming area. No methane layering was found in closed-top silos. Reclaiming areas were as gassy as the top part of the silos. Coal samples were collected from the conveyors entering the silos in order to assess the gassiness of the coal. No simple correlation was found between the gassiness of the coal stored and the measured methane concentrations. However, at mines where the average 24-hour gas emission from the conveyor belt samples was 14 ft3/ton or more, fans or open tops were used. It appears that a large fraction of the methane released during storage remains in the void space between the coal particles.

Jan 1, 1980

By Lloyd L. Farnham

This paper is one of a series describing the mineral resources of the Nation, including location, history, production, ownership, geologic setting, and mining methods for most of the known manganese deposits in New Mexico, With few exceptions these descriptions are the result of field examinations by the writer. Of 32 counties, the 12 which occupy the western half of the State contain all the known manganese deposits, These counties are Catron, Dona Ana, Grant, Hidalgo, Luna, Rio Arriba, Sandoval, Santa Fe, Sierra, Socorro, San Juan, and Taos. (See fig. 1.)

Jan 1, 1961

By C. L. Brown

"INTRODUCTION The heavy loss of life from mine fires in some coal mines recently has focused attention on the importance of maintaining reliable communication systems between the active working sections of mines and the surface. A study of conditions following disasters in mines indicates that in several instances lives could have been saved if telephone communication had been available. Communication systems were not installed in some of these mines where disasters occurred, and in other mines they were installed in such a manner as to be rendered useless following a mine explosion or fire. Lives have been lost because of the inability of the rescue crews or persons di-recting the rescue to communicate with trapped men. Cases are known where many lives might have been saved had it been possible to give instructions for escaping or for location of barricades.More than 500 major disasters in which 5 or more lives have been lost have occurred in mines in the United States. The total number of lives lost in these disasters has exceeded 13,000. Some of the victims died instantly; but for many it was hours and in some instances days before death occurred. Evidence found in recovery operations following some of the disasters indi¬cates that many died needlessly because of the lack of suitable means of communication between the underground working areas and the surface.A localized gas and dust explosion in a coal mine in 1930 resulted in the death of 82 men; 2 were killed outright by the force of the explosion, 6 by a combination of burns and afterdamp, and 74 by afterdamp. About 140 men escaped or were rescued following the explosion, Of these, 119 escaped with little or no assistance, 2 were rescued promptly following the explosion, and 19 were rescued from behind a barricade. Seven bodies were re-covered from behind an ineffective barricade in another place; subsequent investigation proved that these men might have been guided to a safe location had an effective communication system been available."

Oct 1, 1946

By L. D. Schmidt

Now that the war is over, there is a great revival in popular demand to decrease pollution of the atmosphere in our cities. Great cities, such as Pittsburgh, are starting to enforce laws against violators of smoke ordinances. The substitution of low-temperature coke for bituminous coal in household heating is a most promising field for helping to eliminate the smoke nuisance. This Information Circular is written to assist in the very worth-while effort to reduce atmospheric pollution. Herein are de- scribed recent German developments in the production of low-temperature coke. Operating and cost data are given on German commercial-scale low- temperature carbonization plants.

Feb 1, 1947

By R. A. Franks, G. F. Friel, J. C. Edwards, L. Yuan

Two mine-fire experiments were conducted in the National Institute for Occupational Safety and Health's (NIOSH) Safety Research Coal Mine (SRCM) at the Pittsburgh Research Laboratory (PRL) which demonstrated that smoke from diesel-fuel fires of 500 kW and 660 kW heat-release rates in a return airway can develop, without causing a complete air flow reversal, into a roof layer that can migrate upwind forming a counter flow to the primary airflow in a crosscut. Subsequently, smoke can penetrate into an intake airway and create a hazardous atmosphere in the intake airway upwind from the fire. Visibility conditions less than 13 m were created by the smoke in the intake airway downwind from the crosscut. Modeling of the event with a three-dimensional, time-dependent, computational fluid dynamics (CFD) program correctly represented the smoke movement.