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By J. W. Adams

Measurements of surface magnetic field noise were made at various locations over the Geneva Coal Mine near Price, Utah, on June 12, 1973. The locations selected were on the surface over emergency locator beacons underground at depths between 3S0 meters (1150 ft.) and 488 meters (1600 ft.). The surface terrain where these measurements were made was mountainous, and access was difficult. There were no power lines within several miles, and the weather was clear; therefore, the magnetic noise levels were about as low as will normally occur. Results of measurements of distant sferics indicate rather sharp cutoff frequencies below which broadband, impulsive noise is attenuated. The mechanism of propagation for this noise above the daytime cutoff frequency of 3500 Hz and the nighttime cutoff frequency of 1700 Hz is deduced to be a waveguide formed by the D or F layers of ionosphere as an upper plane and the earth as a lower plane.

Jan 1, 1974

By D. R. Flinn

The Bureau of Mines has studied the electrochemical parameters important to the preparation of coatings of the platinum-group metals. Using molten mixtures of sodium and potassium cyanides in an inert atmosphere, techniques have been developed that permit the preparation of baths for platinum, rhodium, and iridium electrodeposition. Cyclic voltammetric and slow sweep rate linear polarization techniques have been utilized to determine optimum potential and current values for preparation of plating baths and for the electrodeposition of coatings. Techniques are described for the deposition of platinum and rhodium coatings at near 100 percent anode and cathode current efficiencies, and for iridium at approximately 80-percent efficiency. Palladium deposition from these molten cyanide baths remains un-satisfactory. The chemistry of the palladium-containing cyanide bath is discussed. Examples of scanning electron microscope photomicrographs of typical platinum coatings are presented. Techniques are described for the preparation of platinum coatings on large objects.

Jan 1, 1982

By Richard D. Miller

The helium resources base of the United States was estimated by the Bureau of Mines to be 961 Bcf as of January 1, 1983. These resources are divided into four categories in decreasing degree of assurance of their existence: (1) helium in storage and in proved natural gas re- serves, 271 Bcf, (2) helium in probable natural gas resources, estimated at 202 Bcf, (3) helium in possible natural gas resources, estimated to be 351 Bcf, and (4) helium in speculative natural gas resources, which makes up the remaining 137 Bcf. These helium resources are further divided into depleting, nondepleting, and stored classifications. The depleting resources are those associated with natural gas fields that are, or will be, produced for the natural gas they contain. All of the helium in potential (probable, possible, and speculative) natural gas resources is included in this classification. These depleting resources are estimated to contain 789 Bcf of the total helium resource base. Helium resources contained in nondepleting natural gas resources, those in shut-in, abandoned, or otherwise nonproducing natural gas fields, are estimated to total 134 Bcf. There is 38 Bcf of helium in storage in the Federal Government- owned Cliffside Gas Field near Amarillo, TX.

Jan 1, 1985

By L. H. Kalenowski

The metal lithium, its alloys, and its salts are becoming Increasingly important as industrial materials. Lithium metal, because of its great affinity for elements, such as nitrogen, hydrogen, oxygen, sulfur, phosphorus, carbon, and silicon, has become important for a wide variety of uses, ranging from purifying helium gas by removing the nitrogen to scavenging molten metals of undesirable impurities. The excellent fluxing properties of lithium salts have found increasing use in such applications as fluxes for welding aluminum and in lower melting ceramic glazes and coatings. Lithium chloride is one of the most hygroscopic salts known and is widely used as a dehumidifying agent. .About 17 lithium minerals are known. Four of these have commercial importance: Amblygonite, lepidolite, zinnwaldite, and spodumene. Spodumene is the most important source of lithium and lithium salts at present, but sizable deposits of amblygonite occur in the pegmatite area of the Black Hills of South Dakota. The size and nature of these deposits preclude the, possibility of, any assurance of an adequate supply of amblygonite for an operation processing only this mineral. Frequently spodumene and amblygonite occur associated in pegmatite minerals. Preliminary investigations indicate that a simultaneous recovery of spodumene and amblygonite can be made by froth flotation. A single process for treating spodumene and amblygonite or mixtures of thorn, would make possible more use of amblygonite as a source of lithium and obviate the separation of spodumene and amblygonite when they occur together.

Jan 1, 1952

By M. Kanda, W. D. Bensema, J. W. Adams

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating hardrock mine, Grace Mine, located near Morgantown, Pennsylvania. Diesel-powered haulage equipment is used in this mine, and the electromagnetic noise environment it creates was measured to see how it differs from the environment created by electric-powered haulage equipment. One technique measures noise over the entire electromagnetic spectrum of interest for brief time periods. Data are recorded using broadband analog magnetic tape and are later transformed to give spectral plots. The other technique records noise amplitudes at several discrete frequencies for a sufficient amount of time to provide amplitude probability distributions. The specific measured results are given in a number of spectral plots and in amplitude probability distribution plots.

Jan 6, 1974

"There seems to be some confusion between the terms carbon black and lamp black, although in American lampblack is generally understood to be a soot formed by the smudge process. In this process oil, coal tar, resin or some solid, or carbonaceous substance is burned in an insufficient quantity of air, while on the other hand carbon black is a product resulting from the incomplete combustion of gas and is deposited by actual contact of flame upon a metallic surface.The various carbons, such as gas retort coke, oil retort coke, graphite, carbon black, lampblack, vine black, wood-pulp,black, willow charcoal, and blacks made from refuse material such as leather have different characteristics as to flocculence strength of color, and physical structure. These blacks are made by one of the following methods:(1) Formation by direct contact of a flame upon a depositing surface.(2) Production by combustion of an oil, tar, etc., in an inadequate supply of air; the soot is allowed to slowly settle out on the floors and the walls of the collecting chambers.(3) Carbonization of solids and subsequent reduction to a state of small subdivision.(4) Production by heating carbonaceous vapors or gases to a decomposition temperature by external heating with or without air in the forming chamber. This is usually referred to as cracking or thermal decomposition."

Mar 1, 1920

By W. W. Weller

Low-temperature heat capacities of scandium sesquioxide (Sc203) and a mixture of cerium sesquioxide (Ce203) and cerium dioxide (CeO2) were measured over the temperature range from 50° to 298° K. The entropy of scandium sesquioxide at 298.15° K was evaluated directly as S°298.15 = 18.4 ± 0.1 cal/deg mole. That of cerium sesquioxide was extracted by combining the heat-capacity data for the mixture with those for pure cerium dioxide; the result was S298.15 36.0 ± 1.0 cal/deg mole.

Jan 1, 1963

By Frank E. Cash

"INTRODUCTION The producing iron-ore ranges in the Lake Superior district are the Marquette and Menominee in Michigan, the Gogebic in Michigan and Wisconsin, and the Cuyuna, Mesabi, and Vermilion in Minnesota. These ranges produce about 85 percent of the iron ore mined in the United States. The accident experience in connection with this production is better than that of the regions producing the remaining 15 percent. Production and shipments vary slightly from year to year owing to stockpiling underground ore during the winter, or nonshipping, season but closely approximate each other over a period of years. This information circular supplements, combines, and continues the data contained in Information Circulars 7321 3/ and 7410 4/, including statistics for 1946 and 1947.Whereas the title ""Accident Experience"" is used for uniformity and logical indexing throughout this report, ""injury"" will be used as a general term to apply to disabilities of all degrees.During the 8-year period 1940 to 1947, inclusive, 619,054,023 long tons of iron ore was shipped from the Lake Superior district. 5/ Michigan and Wisconsin shipped 117,828,939 tons, or 19.03 percent of the total, and employed approximately 9,260 men. Minnesota shipped 501,225,084 tons, or 80.97 percent of the total, and employed an approximate annual average of 12,260 men. The tons produced and shipped per man employed in Minnesota is much greater than in Michigan and Wisconsin, owing to the large open-cut production in Minnesota."

Jun 1, 1949

By H. W. Kilau

The U.S. Bureau of Mines examined the wettability of bituminous and subbituminous coals before and after exposure to ambient air atmosphere, as part of an ongoing project investigating the coal-wetting abilities of surfactant solutions intended for the suppression of dust during coal mining operations. Exposure periods were generally 7 days or less, and the changes in wetting response were measured with a capillary penetration apparatus. Wetting solutions tested included a nonionic surfactant, two anionic surfactants, and pure distilled water. After exposure, higher ranked bituminous coals treated with nonionic surfactant solution and pure water showed increased wettability, but lower ranked subbituminous coals showed decreased wettability. With the anionic surfactants, the coals demonstrated opposite responses. The wettability changes appeared to be related to the coal moisture content. These changes may be amplified by specific, but incompletely understood, interactions between surfactant polar groups, absorbed water, and the coal surface.

Jan 1, 1989

By Raymond B. Ladoo

Talc mining ·in the state of New York was first started about 1876, but important production did not start until 1880, when about 4,000 tons were shipped, In 1883 the production was about 6,000 tons valued at $75,000, or an average of $12.50 per ton, From this date the production gradually inc~eased to a peak of 93,236 tons in 1916, valued at $961,510 or about $10,30 per ton, In 1918 the production declined to 71,167 tons valued at $902,100, or about $12,70 per ton. For ma.ey years New York ,-Jas the largest producer in the United states, but in 1917 and 1918 its output was surpassed by Vennont in tonnage thou[;h not in value. In June, 1920, there were three companies producing talc in the Gouverneur district, st. La,1Tence Co'Ul'lty, and one near Natural Bridge.

Oct 1, 1920

By A. U. Miller

Since coal -mining records have been kept , reports of all mining States show that each year the lives of many workers have been sacrificed in the production of coal , and Illinois has contributed its share , Illinois reports for the 50 years 1882 to 1932 , inclusive , show that 6,673 men were killed -- 6,121 underground , 340 in the shaft , and 212 on the surface . Of the fatalities underground , 3,116 were caused by falls of roof or sides , 1,111 by haulage , 630 by explosives , 577 by gas explosions , 139 by electricity, and 548 by other causes ; 166 of the shaft fatalities were caused by falling down the shaft , 143 by the cage , and 31 by other causes ; 108 of the surface fatalities were caused by railroad cars , 46 by machinery , and 58 by other causes . Most of those engaged in mining are still of the opinion that it is an extremely hazardous occupation and that it is practically impossible to operate without accidents ; however , students of safety in mining now believe that with the proper attention to accident prevention mining may be conducted with little , if any , greater accident rate than that of other supposedly hazardous industries . There is no mystery connected with accidents in mining ; reports show that the majority are due to two main causes , falls of roof and sides and haulage . Mining companies in Illinois , as well as in other States , have proved in the past few years that the hazards of mining , like those of other industries , can be controlled to a large extent and the mines operated with few if any accidents , provided a great enough effort is made by employer and worker . Although the past accident rate of Illinois may compare favorably with that of other mining States it is higher than it should be ; the fact that 6,673 men (an average of 133.46 per year) were killed in and around the mines of the State between 1882- and 1932 indicates that accident prevention should receive more consideration in the future than in the past .

Nov 1, 1934

By Mark R. Pettitt

After a long series of laboratory and in-mine tests, a cost- effective, mineworthy, reduced-noise auger miner cutting head was de signed, fabricated, and field-tested by Wyle Laboratories under contract to the Bureau of Mines. Compared with standard auger cutting heads, the new heads reduced noise by 10 dBA at the jacksetter's position and by 6 dBA at the operator's position. This report contains detailed fabrication instructions, including engineering drawings, that show how a standard auger cutting head can be modified to produce a reduced-noise auger.

Jan 1, 1984

By F. W. Brown, F. C. Gibson

"INTRODUCTION There is urgent need for a satisfactory permissible multiple-shot blasting unit capable of firing 10 detonators in series and safe for use in underground mining where a. gas-ignition hazard may exist.. As there is at present no entirely satisfactory permissible unit of either the battery or generator type, tile described capacitor-battery type has been developed. Consideration of the Bureau of Nines approval schedule pertaining to the generator and magne to-type units and of the electrical characteristics of the unit described in this report indicate that this unit should meet Bureau of Mines permissible requirements.This report gives a detailed description of the design and operation and results of tests to determine safety of operation in gassy atmospheres.DESIGN AND OPERATION OF UNITOperation of the vibrator-type multiple-shot blasting unit is based upon utilization of the discharge energy from a capacitor charged to a given. voltage and having capacitance adequate to store enough energy to initiate 10 detonators in series. The primary source of energy is a 4-volt cap lamp battery such as is carried for illumination on the person of underground workers in nearly all mines. As this battery is already available and is recharged daily it is considered to be a reliable and convenient source of energy for a blasting unit. Figure 1 is a schematic diagram of the circuit for an improved unit, and figures 2 and 3 are views of the experimental unit. The battery potential is applied through a radio-type synchronous vibrator (8) to an 8-volt center-tapped primary of a small transformer (9) having a high-voltage center-tapped secondary. The vibrator introduces an alternating low-voltage potential into the primary and mechanically produces full-wave, rectified, pulsating, direct current from the secondary. A buffing condenser (11) across the secondary gives the proper wave form for long vibrator life: a resistor (12) its in series with this condenser across the total secondary to protect the transformer in case of• failure .of this capacitor. A voltage divider (10) with an adjustable slider permits accurate adjustment of the potential applied to the high-capacity firing condenser (5)."

Oct 1, 1947

This U.S. Bureau of Mines (USBM) report conveys the results of an economic analysis of minerals in the West Mojave Management Area (WMMA), including the Desert Tortoise Priority Habitat (DTPH), a proposed special land management area. Undiscovered mineral resources were estimated for the entire WMMA, which totals 8.7 million acres. Known mineral resources were studied for the DTPH, which is an area of 1.2 million acres contained within the WMMA. Federal lands within the WMMA are managed by the Bureau of Land Management (BLM). The WMMA includes Federal, State, and private lands in the western portion of San Bernardino County and the eastern portion of Kern County. The center of the study area is 20 miles northwest of Barstow, California (Figures 1 and 2).

Jan 1, 1993

By R. E. Thill

The ultrasonic pulse measurement system described measures velocities of longitudinal (compressional) and shear waves in rock to give values that can be used with density values to determine the dynamic elastic constants of rock. A special feature of this pulse measurement system is its unique acoustical bench that minimizes errors in pulse transit times that are commonly associated with coupling, sample alinement, and sample orientation. Some special features of the acoustical bench are its highly versatile transducer cartridges, a pneumatic ram coupling device, an orientation mechanism, and a vacuum chuck sample holder. The lathe-bed-like construction of the acoustical bench assures automatic alinement of samples and versatility in accommodating samples of various shapes and sizes.

Jan 1, 1968

By Gregory M. Molinda

The U.S. underground coal miner faces a continuing hazard from the fall of roof. At the root of many injuries and fatalities are weak or defective roof strata. Throughout mining history, millions of miles of entry have provided exposure of every conceivable geologic roof hazard. This report describes the geologic origin, association, and potential danger from the most common hazards. Discussions of weak rock include drawrock, rider coals, head coal, stackrock, and stream valley effects. Discontinuities, or roof defects, are described including, clay veins, slickensides, joints, and paleochannels. A number of examples from U.S. coalfields are used to document geologic structure and associated hazards. Roof fall analysis is a methodology used by NIOSH for hazard recognition and prevention; its application and benefit to the industry are discussed.

Jan 10, 2003

Treat contaminated coal mine drainage to meet EPA and State water quality requirements. Approach A model (fig. 1) is presented for selecting, designing, and sizing one or several passive mine drainage treatment systems that can be used in remediation of abandoned mine lands (AML). The three principal types of passive mine drainage technologies for the treatment of coal mine drainage are an aerobic system, a compost wetland, and an anoxic limestone drain. The multistep approach presented here provides a simplified method to characterize the type and magnitude of the water quality problem and then to select either a single treatment system or a combination of treatment systems to address the specific site situation. How It Works Step 1. Discharge Characterization. Characterization of the discharge consists of measuring the discharge flow rate and collecting water samples at the point of discharge for chemical analysis. Both the flow rate and chemistry of a discharge can vary seasonally and in response to storm events. It is important to account for this variability by determining flow rates and water chemistry under various conditions.

Jan 1, 1992

By A. M. Stubbs

The Bureau of Mines has devised a procedure to selectively extract and recover chromic oxide (Cr203) from waste high-temperature shift catalysts that contain approximately 6 pct Cr and 62 pct Fe, both in oxide form. The Bureau's procedure consists of roasting the waste catalyst with sodium hydroxide (NaOH) or sodium carbonate (Na2C03) followed by water leaching. The chromium from the leach liquor was recovered utilizing an oxidation-reduction reaction with pH adjustment to form a hydrous chromic oxide (Crp3oXHp) precipitate. The roast-leach procedure produced chromium extractions greater than 89.7 pct, with product recovery in excess of 99 pct from the leach liquor. The costs of the NaOH and Na2C03 roast processes, including sizing and equipment-related recommendations, were determined by the Bureau's Office of Process Evaluation. The economic evaluation indicates that producing a Crp3 product, at the present time, is not competitive with the present-day cost of imported chromites. The estimated average operating cost for both processes was $5.44/1b of recovered Cr203 concentrate. However, this procedure offers a potential alternative to the disposal of this waste through landfiIl.

Jan 1, 1988

By William J. Campbell

The Federal Bureau of Mines provided five test materials--amosite, short-and long-fiber chrysotile, crocidolite, and nonfibrous tremolite--to the National Institute of Environmental Health Sciences (NIEHS) for studies on the biological effects of orally ingested asbestos-related materials. An inter-agency agreement between the Bureau and NIEHS made possible this program to characterize these test materials. The Bureau in turn received support through contracts with the Ontario Research Foundation for the milling of amosite and crocidolite, and with the University of Maryland for microscopic measurements. The five test materials, which were supplied in quantities of 960 to 1,200 pounds each, were characterized by chemical-instrumental analysis for elemental composition, surface area, density, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, mineralogy, and particle size analyses. Particle size distributions were emphasized because of the current theories relating adverse biological effects to length-width characteristics of durable elongated particles.

Jan 1, 1980

By Forrest T. Moyer

Need for lightweight building materials was created in the latter part of the nineteenth century by a radical change in building design in which dead load or structural weight was transferred from thick, heavy, load- bearing walls of former construction practice to a load-carrying framework of beams and columns with thin walls. This new design was brought about by the introduction of structural steel followed by reinforced concrete and structural concrete as materials for the erection of the load-supporting frame. The new materials and method of construction made possible the erection of skyscrapers and the building of bridges with long spans, and made feasible additions of one or more floors to existing buildings. As size and design of the load-bearing framework are controlled chiefly by dead load, the natural result was a. search for and use of light- weight materials in partitions, floors, and exterior walls. However, these thin walls created problems of heat and sound. insulation, so that building materials which possessed good heat- and sound-insulating properties in addition to light weight were objects of extensive research. One group of materials developed to fill this need comprised lightweight concretes, of which some were obtained by the use of lightweight aggregates. Although the advantages of lightweight.materials were evident from the first skyscrapers, there was a transition.stage.between the old bearing- wall and modern skeleton-frame types of building, with the heavy and massive construction of the former superimposed upon the latter. Hence, it was not until the period between 1910 and 1930 that the new lightweight concretes were recognized and used more extensively in the erection of large, nonresidential buildings. From this type of construction, light- weight-aggregate concretes entered-fields of residential and small non- residential building; in which they were found desirable for production of prefabricated, large-size; masonry units. Although the weight of each unit was reduced sufficiently to enable one man to handle it easily, properties of the new concretes other than light weight were the principal factors in the ready acceptance of these new materials in residential building. Manufacture of precast units includes complete lines of masonry and back-up blocks, bricks; floor beams, columns and partition, roof, and floor tiles and slabs. Recent improvements in casting machinery, development of the vibration-pressure machine, and a more thorough study and knowledge of the requirements and properties of the concrete mix have all contributed materially to the rapid expansion in use of lightweight aggregates in this industry.

Jan 1, 1942