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By Sidney Katell

The reaction of coal, oil, or natural gas with air and oxygen and/or steam yields a gas containing varying amounts of impurities. Depending on the raw material and the end use of the product, these impurities include solids, such as dust or slag, and gases, such as hydrogen sulfide, carbon dioxide, and nitrogen. Considerable effort has been expended in developing and operating purification systems, and the literature is replete with equipment data and operating results. The research problems, the design, and the operation of the various systems have been the subjects of patent applications, journal articles, and textbooks.

Jan 1, 1959

By Merwin H. Howes

In constructing the NORAD Combat Operations Center, controlled blasting techniques were employed to achieve smooth walls and to avoid shattering the rock beyond excavation lines. Extraordinary measures were taken to stabilize the rock to permanently preserve the openings. Rock stabilization was accomplished by means of reinforced concrete and gunite linings, rock boltings, installation of chain-link fabric, and epoxy resin and cement grouting. A particular zone of weakness at a vital location was supported by exceptionally thick reinforced concrete lining, rock bolts, and cement grout.

Jan 1, 1966

By Joseph P. DuCarme

The U.S. Bureau of Mines explored new methods and technology for extracting coal from the Appalachian Mountain region of the Eastern United States. These methods were aimed at extracting coal from thin seams and focused on the use of "roof-fall-tolerant" (RFT) mining concepts. These methods could be used on existing, abandoned highwalls or in conjunction with new highwall mining. The research was conducted using small-scale and quasi-full-scale physical models to obtain experimental results. Details are provided on (1) the quasi-full-scale model for cross-ridge mining, (2) the quasi-full-scale model for down-ridge mining, (3) the test results of these models, and (4) recommendations for future research. Significant results include demonstration of the RFT concept, a discussion of expected coal produced from these methods, and recommendations for future research.

Jan 1, 2010

By Nar S. Dalal, Xianglin Shi, Val Vallyathan

"INTRODOCTIONIn an earlier communication 1 from our laboratory it was reported that mechanical crushing of coal and quartz under normal air atmosphere generates of free radicals on the particle surfaces, and that these radicals decay with time, hence pointing to a higher toxicity of fresh dusts in relationship to pneumoconiosis and silicosis. More recently Fubini et al.2 have also reported the detection by electron spin resonance (ESR) of the formation of SiO. and Si-type of radicals from quartz particles crushed under atmospheric conditions. In agreement with earlier ESR studies on single crystals of quartz crushed under high vacuum ( -10-10 torr>3 and subsequent exposure to air,3 and to other gases,4 these radicals were identified2 as being formed by the homolytic cleavage of the Si-0-Si bonds and the reactions of the Si• and SiO- radical with atmosphere. Fubini et al.2 also suggested that these radicals might be involved in the mechanism of the fibrotic action by silica, either by transforming the particle surface into a selective oxidating agent or as an initiator of a sequence of reactions leading to fibrosis. Earlier Gabor and Anca5 bad reported that lipid ·peroxidation caused by free radicals on the silica surface might be involved in the red blood cell membrane damage. Thus far, however, no parallel cytotoxicity, fibrogenicity, and free radica1 studies on a given quartz dust sample have been reported, except for some earlier work from our laboratory.1·6·7 We now present more recent results obtained from parallel cytotoxicity, fibrogenicity, and free radica1 measurements on a freshly made quartz dust. The dust's free radica1 content was measured using ESR spectroscopy while its cytotoxicity potential was estimated via hemolysis. Hemolysis was employed as the toxicity test because it is a widely used method for estimating the potential of a dust for disrupting the cell membrane. 8 The fibrotic potential was followed by measuring the dust-induced lipid peroxidation, using linoleic acid as a model lipid. As discussed below, the results obtained suggest new clues to the mechanism of the quartzrelated cytotoxicity and fibrogenicity. MATERIALS AND METHODSReagentsCrystalline quartz particles with a size range of 0.2-2.5 mm were obtained from the Generic Respirable Dust Technology Center, Pennsylvania State University, University Park, Pennsylvania. These particles were crushed in air to obtain quartz dust samples with particle sizes smaller than 20 microns. We chose to work with a dust with mixed particle sizes, rather than a specific range, as an effort to simulate the mining atmosphere. An agate mortar-pestle arrangement was used for the crushing and grinding because of the close similarity of the structure of agate to that of quartz. Diethylenetriaminepentaacetic acid (DETAPAC) were purchased from Sigma. All other chemica1s were purchased from Fisher or Aldrich.Hemolysls ExperimentsHemolytic activity of silica was measured, following an established procedure,9 as the amount of hemoglobin released from a 2 % suspension of sheep erythrocytes after incubation with 10 mg of silica dust for one hour at 37 °C. The hemoglobin release was estimated via the absorbance at 540 nm using a Gioford spectrophotometer. The procedure was calibrated by substituting the silica dust by a phosphate buffer solution as a negative control (background) and O.S % Triton-X-100 as a positive control (100% hemolysis). The percentage of hemolysis was calculated as follows:"

Jan 1, 1990

By B. J. Moore

This publication contains routine analyses and related source data for 278 natural gas samples from 14 States. All of the samples were collected during calendar year 1973 as part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 Fifteen previous publications have presented the results of 10,201 gas analyses prior to 1973. The first three, Bulletins 486,4 576,6 and 617,6 contain analyses and related source data on 5,218 gas samples collected from 1917 through 1960. The other 12 publications,7 which were issued as information circulars, supplement the three bulletins and contain 4,983 analyses of samples collected since 1960. This publication is the 13th publication supplementing the three bulletins.

Jan 1, 1974

By F. E. Griffith, C. H. SEELING

Cardox blasting is used widely in coal mines in the United States . A model of a Cardox blasting device was approved by the Bureau of Mines subject to certain conditions and limitations , and the approval was extended to other models from time to time . Certain special hazards are entailed in the use of Cardox as with explosives . One of these is flying shells . In some blasts , the Cardox shell is violently ejected from the borehole and flies like a projectile , frequently ricocheting off solid objects and striking points considerably off the line of its initial flight . Flying shells have been known to pierce the webs of structural - steel beams , to pass through both sides of allsteel mine cars , to be driven through stout hardwood timbers , to knock out timber sets , to damage loading equipment , and to break or short - circuit power lines . A considerable number of shot - firers and other workers have been struck by flying shells and killed or injured . Accidents from this cause , although not as frequent as other types of mine accidents , are usually serious , closely approximating accidents caused by blasting with ordinary explosives . The increasing number of such accidents prompted a Bureau of Mines field investigation of possible methods of preventing dangerously violent ejections of Cardox devices . This report contains pertinent data collected during the investigation and describes methods tested and discarded as well as the development and proof of an apparently satisfactory method .

Jun 1, 1943

By Clayton A. Landsidle

There has been little change in timbering methods in anthracite mines for 75 years, and technical information on strata control is almost wholly lacking. In order to assist the industry to establish technical data, the Bureau of Mines and a Northern field operator are cooperating in underground experiments, the first phase of which has been to investigate pneumatic packing. The four principal methods of packing in mining are hydraulic, pneumatic, mechanical, and hand. The hydraulic pa caring system is believed to have originated at Shenanodah, Pa., in 1864,4/ to prevent destruction of a church by surface subsidence after underground coal mining. This method was used again in 1884 to arrest an underground fire at Buck Ridge colliery, near Shamokin, Pa. In 1901 hydraulic packing was introduced to Europe in Upper Silesia, where it gained in popularity owing to the availability of large quantities of sand suitable for flushing .5/ Hydraulic packing has a number of disadvantages. Chief among these are the softening effect of large quantities of water on the mine floor conducive to heaving action; drainage and punning costs; and the inability to fill roof cavities completely in flat beds.

Jan 1, 1953

By Oliver Bowles

"Introduction.During recent months the Bureau of Mines has conducted a detailed study of the slate industry with special reference to increased efficiency in its production, preparation and utilization. The results of these investigations will be incorporated in a forthcoming bulletin. The purpose of this preliminary paper is three-fold. One object is to bring to the attention of slate producers certain modifications in manufacture and classification which would encourage a wider use of slate. A second purpose is to direct the thought of roofers toward the importance of proper laying of slate, and the third object is to acquaint the general public with its enduring qualities.Origin and character.Without entering into any detailed discussion of the origin and history of slate, a subject to be covered in the bulletin mentioned, it may be of interest to the general reader to know that slate is originally formed from mud or soft clay, carried down by streams and laid down in successive layers in deep water. The pressure of superimposed materials gradually compresses the clay into a firm rock known as shale. In many places this shale was, during the succeeding ages, subjected to intense pressure and folding due to mountain-building forces within the earth. This intense pressure, together with high temperature, changed the clay into other minerals such as mica, chlorite, and silica, which are very resistant to weathering, and also developed a very definite cleavage or splitting direction which characterizes the rock as slate. It is this property which renders slate of value for roofing, for, by using a broad chisel and a wooden mallet, a slate worker can readily split it into thin sheets which are later trimmed into rectangles of various sizes."

Jul 1, 1921

By J. Dean Warner

In 1984 and 1985, as part of its critical and strategic minerals studies, the Bureau of Mines investigated lode and placer tin occurrences near Rocky Mountain (Lime Peak), in east-central Alaska. The lode occurrences consist of mineralogically complex, generally fault-controlled veins, and contain an average of approximately 0.05 pct Sn, as cassiterite. Beneficiation testing of two bulk samples of the vein material produced concentrates containing 65 and 59 pct of the total tin values at grades of 0.35 and 13.9 pct, respectively. Although as much as 30 million short tons (MMst) of mineralized rock containing up to 20 MMlb Sn may be present, the grade of these occurrences is too low to be considered economic at this time. Trace amounts of cassiterite were also identified in surface samples of glacial out-wash gravels collected along North Fork Preacher Creek, which partially drains the area of tin lode deposits near Lime Peak. Low tin grades in the samples do not account for the former erosion of a large volume of lode tin mineralization from near Lime Peak; higher tin grades may be present in gravels closer to bedrock.

Jan 1, 1988

By Janet Torma-Krajewski

Job tasks that involve exposure to work-related musculoskeletal disorder (WMSD) risk factors may impact both the risk of injury and production downtime. Common WMSD risks factors associated with mining tasks include forceful exertions, awkward postures, repetitive motion, jolting and jarring, forceful gripping, contact stress, and whole body and segmental vibration. Mining environments that expose workers to temperature/humidity extremes, windy conditions, and slippery and uneven walking surfaces also contribute to injury risk. National Institute for Occupational Safety and Health (NIOSH) researchers worked with powder crew members from the Bridger Coal Company to identify and rank routine work tasks based on perceived exposure to WMSD risk factors. This article presents the process followed to identify tasks that workers believed involved the greatest exposure to risk factors and discusses risk reduction strategies. Specifically, the proposed prill truck design changes addressed cab ingress/egress, loading blast holes, and access to the upper deck of the prill truck.

Jan 1, 2009

By Ronald B. Stotelmeyer

This report summarizes studies of 55 Idaho national forest roadless areas completed by the U.S. Bureau of Mines (USBM) in the period 1966-1992. These roadless areas have been recommended for addition to the National Wilderness Preservation System, proposed as special management areas, or otherwise recommended for study by the U.S. Forest Service or the Idaho congressional delegation. The Bureau of Mines' studies indicate which parts of the roadless areas contain mineral resources. They also show where mining and prospecting are likely to occur in the future, where mineral production has occurred in the past, and where abandoned mine workings (possible hazards) would be encountered. The number of mine and prospect workings found are a measure not only of surface disturbance, but of areas not wilderness in character.

Jan 1, 1994

By R. R. Faddick

A mineral slurry data hank has been compiled, containing slurry pipelining data on sixteen ores, concentrates, and tailings. The data bank it in the form of a computer print-out all they necessary system constants and headloss data for each mineral commodity. The purpose of the data bank was to assist in the development of a universal head loss correlation for mineral slurries, if such a thing exists. Present headloss correlations were tested and found to be inconsistent for the various mineral slurries. Consequently, a different approach was taken, that of compiling a library or Stanton diagrams relating friction factor and Reynolds numbers for a given slurry in a given pipe diameter. The advantages of the diagrams arc demonstrated and discussed. While this correlation shows excellent potential, it is necessary that additional work, both theoretical and experimental, be performed. In addition, two equations are given from which a design velocity may be obtained to minimize deposition or formation of bedload. The equations are based on data taken from the mineral slurry data bank.

Jan 1, 1972

By H. H. Heady

A naphtha obtained by destructive, recycle hydrogenation of crude shale oil, produced by gas-combustion retorting of Colorado oil shale, was found by the Bureau of Mines to contain 49.1 percent paraffins, 20.3 percent cycloparaffins, 7.8 percent olefins, and 22.8 percent aromatics. The naphtha contained only minor amounts of sulfur, nitrogen, and oxygen compounds. Compounds containing less than 5 carbon-atoms per molecule were removed by distillation before analysis. The paraffins where predominantly straight-chain compounds; n-Hexane was present in the largest quantity, and the other straight-chain paraffins decreased in amount as the molecular weight increased. The cycloparaffins, which contained both cyclopentanes and cyclohexanes, were evenly distributed throughout the boiling range. Although the naphtha had been produced by hydrogenation, it contained a small quantity of olefins. Straight-chain olefins with a terminal double bond comprised about two-thirds of these compounds. Among olefins with an internal double bond, those having trans configuration were present in three times the quantity of those in the cis form. In the aromatics all but one of the alkylbenzenes having nine or less carbon-atoms per molecule were identified; toluene was present in the greatest quantity. Only a few of the higher molecular-weight homologs were identified. The composition of the naphtha was computed from analyses of 105 narrow¬boiling distillation fractions. Volume, density, refractive indices, bromine number, and an ultraviolet spectrum were determined on each fraction. From these data the hydrocarbon-group composition of each fraction was estimated. A silica gel adsorption analysis was used to check the values of nearly one-third of the fraction calculated from physical-property data. Mass and infrared spectra were obtained on some fractions for identifying individual compounds or types of compounds, such as terminal olefins.

Jan 1, 1960

By B. J. Moore

This publication contains routine analyses and related source data for 419 natural gas samples from 22 States collected during calendar year 1964 as part of a continuous survey of the United States for occurrences of helium in natural gas. This survey has been conducted by the Bureau of Mines since 1917. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4863/ and 576.4/ Six previous publications have been made to present the results of 6,293 gas analyses made by the Bureau of Mines, Helium Activity, prior to 1964. The first three, Bulletins 486,5/ 576,6/ and 617,7/ contain analyses and related source data on 5,214 gas samples collected from

Jan 1, 1966

By J. M. Davidson

The potassium mineral polyhalite (K2SO4.MgSO4.2CaSO4.2H2O) found in large deposits in western Texas and southeastern New Mexico is associated with varying amounts of halite (sodium, chloride, NaCl) and anhydrite (calcium sulphate, CaSO4). Although the anhydrite, because of its low solubility and slow rate of solution, is relatively inert, the halite is dissolved immediately in any process solution with which the polyhalite comes in contact. Limited quantities of sodium chloride in the liquors used for the hot extraction of polyhalite materially improve the results obtained, but only a very small sodium chloride content may be desired in the entering polyhalite in other procedures, such as Bureau of Mines process. In all of the processes suggested for the recovery-of potassium sulphate from polyhalite the control of the sodium chloride content will be desirable, if not absolutely essential to efficient operation.

Jan 1, 1934

By Robert W. Geehan

"INTRODUCTION The Bureau of Mines, in cooperation with the Federal Geological Survey, explored the Crowell fluorite mine by core drilling in 1945. Claims investigated are in sec. 14, T. 12 S. R. 47 E., M. D. B. & M., in southern rye County, Nev., about 5 miles east of 'Beatty.The twelve holes drilled by the Bureau totaled 3,661 feet. During 1945 the mine operator drove extensive exploration drifts, in part to verify results of the Bureau's work. The drilling program was designed to test for extensions of ore bodies known in the mine.The Crowell mine has shipped Ore to steel plants on the west coast for the past 20 years. During the war this market called for all the fluorite the mine could produce, but previously there were periods when it was difficult to sell ore or concentrates.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Nines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.Special acknowledgment is due to Glenn Allen, district engineer;A. C. Johnson, chief, Reno Division, Mining Branch; S. R Zimmerley, chief, Salt Lake City Division, Metallurgical Branch; W. R. Thurston of the Federal Geological Survey for advice on geological problems; and J. Irving Crowell, Jr., operator of the property, for his cooperation."

Nov 1, 1946

By R. S. Norman

The objective of this program was to select approximately 100 acoustic materials for flammability evaluation. Noise control programs have been initiated on several types of mining equipment and vehicles which can be used in underground coal mines. Often, the materials which are used in these noise reduction programs have not been tested for flammability properties according to the same reference standard. During this program a variety of materials were selected for measurement according to ASTM E-162 procedures. A radiant heat energy source was used to measure flammability properties of 15.2 x 45.7 cm. samples. In the absorptive materials category, 45 percent of the materials tested had a flame spread index of less than 25. For barrier, damping, and isolation materials the corresponding values were 40, 43, and 9 percent.

Jan 1, 1979

By H. B. Hill

The Salt Flat field, formerly called the Toe -Bruner field, is located northeast of the town of Luling in Caldwell County, Tex. This field, which is a fault structure, approximately parallels and is about 5 miles east of the Old Luling field. The proved area is approximately 1,280 acres, on which 332 producing wells (September, 1930) have been drilled. The majority of the wells are producing from the Edwards limestone at an average total depth of 2,700 feet. A few wells are producing from the Austin chalk or from other formations above the Edwards limestone. The Wilcox formation is exposed, and the fault trace in places is scarcely evident. The strike of the structure is approximately 111. 20 to 45° E. The displacement of the fault is probably 200 to 500 feet. The discovery well was completed in the Austin chalk by the Lutex Oil Co. during April, 1928. In October, 1928, the Sun Oil Co. completed the discovery well in the Edwards pay. This well was an important discovery, as it indicated the potential oil possibilities of the Edwards limestone in echelon fault structures. The discovery led to the development of the third fault field in the Edwards limestone and opened up a large area for future prospecting. The total oil production for the Salt Flat field to and including September, 1930, was 19,833,215 barrels. The most reliable figures available of water production were compiled for a number of leases and wells in the south half of the field. These data show that the water percentage for the average well in this part of the field increased steadily from 30 per cent for January, 1929, to 81 per cent for December, 1929. The estimated daily water production of the entire field for December, 1929, was about 82,000 barrels as compared with a daily oil production of 29,725 barrels; or approximately 2.7 barrels of water were produced with each barrel of oil 14 months after the discovery well was completed in the Edwards pay. Estimates of water production in the (Old) Luling field, which is near the Salt Flat field, place the daily water production at about 150,000 barrels (July, 1929) as compared with a daily oil production of 11,000 barrels. These figures indicate that in the Luling field approximately 14 barrels of water must be lifted for each barrel of oil produced. The Luling field was discovered in August, 1922, and a peak annual production of 10,210,000 barrels was reached during 1924. The production during 1928 was 5,057,000 barrels of oil from an average of 567 producing wells for the year. Although water appeared early in the life of the Luling field, the oil production has been well sustained. Another feature of outstanding interest is the comparatively few producing wells that have been abandoned on account of water during the soven years of operation of this field. Comparison of data between the Luling and Salt Flat fields is of importance because of the nearness of the two fields. The Luling field is a narrow strip or "shoestring" approximately 8 miles long, with a maximum width of 3,400 feet. Production is obtained in the Edwards limestone at an average depth of 2,200 feet on the upthrow side of a fault. Similar conditions of accumulation are found in the Salt Flat field at greater depth to Salt Flat field as outlined (April, 1930) is about 7 miles long? with a maximum width of 2,000 feet. At the time the field work was begun (July, 1929) in the Salt Flat field, drilling operations had been almost completed in the south half of the field, while the north half was still under development. Cross sections and a structure contour map interpret the subsurface conditions in the south half of the field, where the water conditions first became serious.

Jan 1, 1931

By G. E. McElroy

When mechanical ventilation is to supersede the natural ventilation of a mine it is desirable to determine what resistance the mine as a whole offers to the flow of air in order to specify properly the limiting duties of a ventilating fan. The relation of pressure to volume of flow for the mine as a whole may be calculated from experimental data, or it may be determined directly by measurements of volume of flow and the natural draft pressures causing flow; but in both methods the determinations are affected by many variables. With the intention of making a practical application of both methods, a small metal mine in process of development at Butte, Mont., was selected by the writers as the object of experiments planned to compare the mine resistances determined by measurements of natural draft and volume of flow with those calculated from experimental data. Four sets of teats were made with natural draft in October, 1925, December, 1925, April, .1926, and September to December, 1926; the last set consisted of a series of weekly observations. DESCRIPTION OF MINE The mine selected for the experiments was a typical vertical shaft metal mine in the development stage. No stoping had been done, and ventilation was confined to shafts, crosscuts, drifts, and raises. Figure 1 is a dia¬grammatic sketch of the main openings. All were timbered with full sets on approximately 5-foot centers. The shaft compartments were 4 by 4.5 feet, and one in each shaft was partly blocked by staggered manway landings. A pump column in the upcast shaft was discharging about 280 gallons a minute of water at 70° F. from the 1,000-foot level. The drifts were slightly sinuous, but the crosscuts were exceptionally straight and uniform in area; both drifts and crosscuts were about 5 by 7 feet in cross section. The raises were composed of vertical sections joined by frequent 450 offsets; each had three 4.5 by 4.5-foot compartments, of which two were plank-lined ore chutes and one was partly

Jan 1, 1928

By Anatol Wojtowicz

This research program was conducted to determine if respirable coal dust emanating from a continuous mining machine can be suppressed more effectively by a high expansion foam than by the water sprays conventionally used. A high expansion foam system was developed and tested on a continuous mining machine under actual operating conditions. The utility of the system was demonstrated. Test results tend to show that foam application is more effective than water sprays in suppressing respirable coal dust. However, because of the extreme variability of the test conditions, scatter in the sampling data, and other factors, not enough data was obtained to form a firm conclusion that foam is more efficient than a water spray in suppressing respirable coal dust. Sufficient statistical data was obtained, however, to indicate that foam is more efficient than water in suppressing total float coal dust.

Jan 1, 1974