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By M. F. Koehler

[THE LITERATURE contains relatively few thermodynamic values for interoxidic compounds, and these often are unreliable. This is especially true of data for ferrites and aluminates for which heat of formation determinations may involve extreme experimental difficulties. This report contains the results of new experimental work for obtaining the heats of formation of five ferrites (Ca2Fe2O5, CaFe2O4, MgFe2O4,, NaFeO2, and LiFeO2) and one aluminate (CaAl4O7), and a review and revision of previous similar work of this laboratory on five aluminates (Ca3A12O6,, 12/7 CaO-Al2O3, CaAl2O4, NaA1O2, and LiAlO2), The results for the 11 compounds are combined with entropy and high-temperature heat content data to derive tables of heats and free energies of formation (both from the oxides and from the elements) for the temperature range 298° 1,800° K, The relative stabilities of the compounds are discussed. The presented data all have application to ceramic reactions, and those for the calcium and sodium aluminates are applicable in considering soda-lime sintering processes for extracting alumina from silicate minerals such as day and labradorite.]

Jan 1, 1961

By William N. Patterson

This report describes the design and testing of an improved quiet hard rock percussion drill. The improved drill incorporates a tappetless design with independent rotation in a hand held drill weighing 50 lbm. Laboratory and field testing in three mines were conducted. The testing showed improved drilling performance with no increase in measured noise levels over the fist design.

Jan 1, 1985

By W. J. Fullerton

This paper is one of a series prepared for the United States Bureau of Mines discussing the methods used in crushing and grinding materials for cement manufacture, and deal particularly with the methods used at the Howes Cave plant of the North American Cement Corporation. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs might in many instances cause embarrassment to individual producers as well as to the industry as a whole. On the other hand, operating costs are essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1932

By James H. Aase

Shales from 10 locations in Michigan were sampled, tested, and evaluated to determine their suitability as raw materials for producing lightweight aggregate by rotary-kiln methods. Sampling procedures and the geology of the shale units tested are discussed. Preliminary testing in a muffle furnace preceded extensive testing in a l6-inch by 14-foot rotary-kiln. Rotary-kiln products from these shales ranged in weight from 35.5 to 61.2 pounds per cubic foot (pcf). Concrete test specimens made pith selected aggregates were evaluated to determine the qualities of the concrete. Compressive strengths of the concrete ranged from 2,830 to 4,240 psi after 28 days of curing. Unit weight of the concrete ranged from 94.8 to 101.5 pcf. Lightweight aggregate suitable for use in structural concrete meeting ASTM standards was produced by the rotary-kiln method using shale samples from two locations.

Jan 1, 1967

Under contract from U. S. Bureau of Mines, Harza Engineering Company in cooperation with Eastern Associated Coal Corporation, conducted a ground control study of two mechanized longwall panels at the Federal Number 2 Mine. The mine is located in Northern West Virginia, and the coal is mined from the Pittsburgh Coal Seam. The prime objective of the study was to collect data which will aid in the proper selection of the longwall supports system and to control the entry caving problem. Instruments installed in the mine were borehole pressure cells, convergence recorders, roof sag recorders, horizontal roof strain indicators, differential floor movement systems, and lateral roof and floor movement systems. Instruments installed on the surface, above the instrumented longwall panels, consisted of slope indicator system, vertical bed settlement probe system and shear displacement detecting system. A comprehensive surface subsidence study was conducted in conjunction with the instrumentation. In addition to the instrumentation and monitoring, special tests were conducted to determine the bearing capacity of the roof and floor rocks, in situ modulus of coal, roof and floor rocks, and response of borehole pressure cells to ground stress. Cores of coal measure rocks were collected for the physical property tests. Face observations were made to detect various roof behavior parameters under the different jack setting pressures. This report essentially describes the instrumentation work, special tests and presents the data collected.

Jan 1, 1976

"The mission of the Respirable Dust Center is to enhance the health, safety and productivity of the miners 'through advancing the fundamental .understanding of all aspects of respirable dust associated with mining and milling and the interaction of dus.t and lungs for reducing the incidence and severity of respirable dust disease. All Dust Center activities are focussed to be responsive to this mission which is shared by several federal agencies closely associated with the Generic Mineral Technology Center for Respirable Dust such as USBM, M,SHA, and NIOSH, and the mining industry. While significant progress has been achieved in making mine atmospheres cleaner and healthier, respirable dust disease remains the nations worst industrial hazard. GOALSThe goals of the Respirable Dust Center have been formulated to recognize the diverse scientific, engineering and medical aspects of respirable dust as well as the need to enhance the interaction, education and technology transfer in the respirable dust area.The Center goals are to:1. Enhance the understanding of the scientific, engineering and biological characteristics of fine and respirable mineral particles, fibers, organic aerosols, and complex particles found in the mining and milling atmospheres.2. Advance the understanding of the physical behavior of airborne respirable dust particles in flowing streams under different. stimuli during mining and milling.3. Advance fundamental understanding of the causative mechanisms for the occupationally related lung impairments and the airway diseases of mine and mill workers.4. Establish the relationship between natural and cultural factors (mine geology, mineralogy, mining and milling methods, equipment and control measures) in the generation, exposures, and pathogenic properties of fine particles.5. Contribute to the development of control mechanisms for reducing ambient respirable dust concentrations, worker exposure, the incidence and severity of dust related lung disorders and disease prevention in mining and milling atmospheres.6. Enhance functional integration among the various research personnel in the Center, as well as, with other groups, such as MSHA, NIOSH and USBM involved in respirable dust research and control.7. Develop technically trained personnel for employment in the mineral industry for respirable dust research and control.8. Enhance the availability of respirable dust-related information utilizing several technology transfer avenues."

Jan 1, 1990

By Russell R. McLellan

Under the Heavy Metals Program, investigations were conducted at the old Badger dill placer mini in Nevada County California to collect data and information regarding drilling and sampling methods and deposit characteristics. The studies contributed to a team effort by five Bureau of Mines research groups to develop new or improved placer mining technology in the Tertiary gold-bearing channel gravel of northern California. This report describes the techniques used and the results obtained in the sampling and drilling stage of deposit delineation studies that were conducted by the Denver Mine Systems Engineering Group. Sampling included the collection and processing of 400 tons of largo and small volume samples from drill holes, underground workings, surface pits, and blast hole rounds. A total of 355 samples averaging 2,296 pounds per sample provided reasonably accurate data for analysis of the gold distribution. These studies indicate that the bulk of the gold is within 40 foot of bedrock in stacked, lenticular zones of cemented gravel that are largely confined to the relatively narrow, meandering course of the deepest portion of the bedrock channel. Drilling studies involved the testing of three types of truck-mounted drills including rotary, bucket and vibratory, none of which proved to be a completely versatile tool for sampling quickly and reliably both consolidated and unconsolidated gravel.

Jan 1, 2012

By E. W. COCHRANE, R. HOPKINS, G

The number of completed petroleum refineries in the United States continued to decline in 1938, but the total capacity to process crude oil increased materially. This information was obtained in connection with the Bureau's annual canvass of refinery capacity as of January 1, 1939. In spite of the addition of a half dozen plants in Illinois and the inclusion in this year's list of several more "pot-stills" in Montana, the total number of plants, and inactive, declined from 551 on January 1, 1938, to 538 on January 1, 1939. was entirely in shut-down plants, as the number of operating plants rose from both active The decline 431 to 435. Yost of the plants dismantled were situated in Wyoming and Texas, parts or several from the latter being transported to Illinois. About 10 more East Texas refineries were dismantled in 1938, leaving about 15 plants in the field, only 8 of which were operating on January 1, 1939. Although the total completed capacity increased from 4,351,151 barrels on January l, 1938, to 4,508,555 barrels on January l, 1939, the operating capacity declined, and the inactive capacity increased about 50 percent, or from 380,955 to 574,770 barrels. These shifts in capacities reflect the comparative slump in the refining industry in 1938 after the prosperous year 1937. Daily average crude runs in 1938 were 3,192,000 barrels, from which it may be figured that the operating ratio for the active units was about 81 percent of crude and for all completed equipment 74 percent. The highest daily throughput in 1938 was about 3,400,000 barrels, at which time the reserve capacity represented in the active equipment was at least 500,000 barrels, in addition to about that much capacity shutdown. In an emergency, much more reliance could be placed on the reserve capacity of the active equipment, as much of the shut-down capacity is obsolete at present specifications and prices. Regarding obsolescence, the refiners reported 418,165 barrels of their idle capacity in good condition on January l, 1939 and 156,605 barrels in poor condition. However, it is probable that the former reflects an optimistic viewpoint. Refinery activity, as represented by new construction and dismantling, declined materially in 1938. The new capacity added in 1938 was 378,350 barrels compared with 394,680 barrels in 1937. Probably 1939 will see a much larger decline, as the new capacity under construction on January 1, 1939, totaled only 142,250 barrels compared with 283,020 barrels the preceding year. The capacity represented by the new plants was negligible throughout

Oct 1, 1939

By C. B. Manula

This report is volume 5 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation, and ventilation. This volume of the final report describes the Subsidence subsystem of the Master Design Simulator. This subsystem uses the finite element method to simulate ground movement caused by an advancing mining face in an underground coal mine. The model is structured around the concept that the ground mass is a layered media of different thicknesses and material properties. Gob areas are considered to be unfilled with broken rock at the beginning of mining. After mining starts, the gob areas are filled with broken material which provides resistance to the lowering of the overlying strata. The model is tied to the Geology and Reserves subsystem, but it can also operate as a free standing routine. A case study is presented illustrating the application of the model. A detailed user's manual, including a program listing, is included in the appendices.

Jan 1, 1974

By P. G. Pigott

The lack of technical information regarding the physical characteristics of kaolins and bauxitic kaolins, rejected during the mining of bauxite near Eufaula, Ala., has retarded their commercial utilization. This investigation was undertaken to determine their behavior when used in refractories. Ores were evaluated as refractory raw materials by compounding dry-press mixtures and specialties following procedures common to the industry. Products now on the market were used for comparison in laboratory evaluation.

Jan 1, 1959

By T. Bertke

This document assesses the environmental aspects of a preliminary design for processing kaolin clay as the domestic resource for recovery of alumina by a hydrochloric acid leach-HCl gas induced crystallization process. The report covers waste sources, control measures, and potential environmental and health effects applicable to the process technology.

Jan 1, 1980

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is in-tended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By Robert W. Decker

This report presents a survey of published novel coal cutting (mining) concepts and a brief discussion of each one. A preliminary evaluation follows which identifies promising concepts, emphasizing reduced dust generation and economic production potentials. The promising concepts are then studied more deeply and evaluated in more detail with recommendations given for further development action. The concepts recommended for further work include: Roan and Pillar Mining: Deep Cutting Continuous Miner Linear Cutting Rotary Head Miner Longwall Mining: Oscillating Continuous Water Jet Miner Deep Cutting Shearer

Jan 1, 1981

By D. P. Lindroth

The thermal diffusivity above 298 K, up to 400 K and at pressures from ambient down to 10-10 torr was measured for the following six igneous rock types: tholeiitic basalt, obsidian, rhyolite, granodiorite, gabbro, and dunite. The thermal diffusivity data were obtained by the laser flash method. Extreme values range from a low of 5.3X10-3 cmF/sec for rhyolite at 383 K and 2X10-7 torr to a high of 13.4x10-3 crrf/sec for dunite at 298 K and 760 torr. Data are also included on a commercial fused silica, which was used as a standard.

Jan 1, 1974

By John C. Edwards

The Bureau of Mines developed a mathematical model to predict the oxygen requirements for a miner evacuating a mine. The model accounts for variations in the miner's escape speed with mine airway height, and for the empirically determined expressions for the weight-specific oxygen uptake rate for upright walking, stooped walking (duck-walking), and crawling. A Fortran computer program that is user oriented was prepared based upon the model's constitutive equations. Specific instructions for utilizing the program, as well as applications to miner evacuation from a mine, are presented.

Jan 1, 1986

By E. E. Maust

The present work is part of an ongoing Bureau of Mines effort to provide a better understanding of the fundamental phenomena involved in sulfide flotation, the role of oxygen in xanthate adsorption being one essential issue. Galena was chosen as the material around which to develop a conceptual model, partly because of its demonstrated oxygen sensitivity and partly because information on its properties and flotation behavior constitutes the largest part of the fundamental information available on sulfides of commercial importance. The model is formulated primarily in terms of surface electronic energy levels produced by oxygen and xanthate and is further developed using existing experimental evidence and its implications. Four major functions of oxygen are elucidated, and the relationship of these to the formation of lead xanthate, dixanthogen, and a surface compound is discussed. Though yet incomplete, the model provides a useful framework within which the results of diverse experiments can be related to one another in their proper perspective, as shown by a brief discussion and resolution of some apparently discordant results reported in the literature.

Jan 1, 1976

By H. F. Coward, G. W. Jones

"IntroductionIn the course of an investigation on the influence of black damp (a mix of nitrogen and carbon dioxide) on the limits of inflammability of fire damp (methane) in air, some new information was obtained concerning the factors that determine whether or not a gas mixture is capable of self-propagation of flame. Volume for volume, carbon dioxide exceeds nitrogen in its extinctive action on flame, an effect which is generally attributed to the higher molecular heat capacity of the former. Argon, a as of lesser heat capacity than either, proved to Lave less extinctive notion. If, as seemed likely, the extinctive action of a chemically inert gas could be attributed entirely to its heat capacity, then helium should behave like argon; equal volumes of these two oases should exhibit equal extinctive action, for their molecular heat capacities are nearly identical at laboratory temperatures and, in all probability, remain constant up to and beyond flame temperatures. The experiments reported here show, however, that helium has proved to be more extinctive of methane flames than argon.Method Used in ExperimentsThe limits of inflammability of methane, in various ""atmospheres"" composed of mixture of air with one or other of the diluent were determined in a vertical glass tube, 6 feet long and 2 inches in diameter. The lower end of the tube was opened by sliding away a ground-glass joint and the flame of a small spirit lamp was immediately passed across the aperture. The tube was sufficiently long to enable observers to judge whether a flame was self-propagation for if a mixture were incapable of continued self-propagation pf flame, the lamp of flame formel above the source of ignition was extinguished within feet of its passage up the tube."

Jun 1, 1926

By M. G. Wallis

This report presents the results of a study to develop a detailed mining method design based on longwall mining with sublevel caving. The method is applicable to low-dipping coal seams 20 or more feet thick such as are found in the western United States. The report covers (1) the development and description of the mining method, (2) evaluation of the engineering feasibility of the design, (3) estimates of productivity and recovery, and (4) an engineering cost analysis and economic feasibility evaluation of the mining method design.

Jan 1, 1977

The following report summarizes the results of engineering feasibility studies whose purpose was to assess the probable efficiency, reliability, safety and cost of a number of possible methods for removal of radon gas from the ambient air in underground mines. Fourteen candidate techniques were evaluated. Seven of these were based on specific individual principles, and seven were based on combinations of these principles. The individual principles were as follows: 1. Activated charcoal 2. Organic fluids 3. Semipermeable membranes 4. Molecular sieves 4. Cryogenics 6. Chemical reaction 7. Centrifuge The combinations were: 8. Cryogenics and activated charcoal 9. Cryogenics and molecular sieves 10. Cryogenics and chemical reactions 11. Membrane filters and organic fluids 12. Membrane filters, cryogenics and activated charcoal 13. Membrane filters and chemical reactions 14. Silica and an Organic Fluid

Jan 1, 1975

By Donald O. Capstick

A mineral survey of the approximately 144,000-acre Borah Peak study area was conducted by the U.S. Bureau of Mines in 1985 at the request of the U.S. Forest Service. The area studied included the Borah Peak RARE II roadless areas (No. 14210, 119,864 acres of land recommended for wilderness designation; and No. X4210, 18,440 acres of land recommended as non-wilderness) and other contiguous Forest Service administered land. The study area is in Challis National Forest in southeast Idaho about 30 miles south-southeast of Challis, ID. Burnt Creek, a conterminous study area to the northeast, on lands administered by the U.S. Bureau of Land Managment, was examined concurrently. Dolomite and limestone inferred reserve bases exceed 1 billion tons each within the Borah Peak study area. The material is widespread and of high quality. Extensive sampling and more detailed mapping are required to better define the resources; however, ample dolomite and limestone occur nearby, outside the study area. Dolomite is the main constituent of several geologic formations within the study area. Sample analyses indicate that the more than 1,000-ft-thick Jefferson Formation dolomite is the most pure and is equivalent to material being mined at a dolomite-to-magnesium processing plant near Addy, WA. Analyses from limestone-bearing formations underlying much of the study area indicate that large quantities of the limestone may be suitable for a variety of uses.

Jan 1, 1987