Search Documents

By C. E. Wicks, F. E. Block, F. D. Stevenson

The vapor pressures of tungsten (VI ) chloride ( WC1 ) and hafnium ( IV ) iodide ( HFI ) were measured by a metal diaphragm technique . Vapor pressure values were obtained to permit calculation of the thermodynamic properties of the vaporization processes of the compounds . The vapor pressure data of WC16 are represented by the following equations for the liquid , B - solid , and a- solid over the temperature intervals indicated : - log P = 8.194 3,253 /T Liquid , 281.5 ° to 325 ° C : B - solid 230.0 ° to 281.5 ° C : log P a - solid 185.0 ° to 230.0 ° C : log Pam *** = 8.794 - 3,588 / T = 9.615 - 3,996 /T where T is the absolute temperature in degrees Kelvin . The heats of vaporization and sublimation are 14.9 , 16.4 , and 18.3 kcal / g mole , respectively . The entropy of vaporization at the normal boiling point , 330 ° C , was 24.3 eu . The fusion temperature , 281.5 ° C , and transition temperatures , 230.0 ° and 185 ° C , were found by thermal analysis .

Jan 1, 1964

By Karl E. Starch

This Bureau of Mines report is a background study of severance taxes on mineral production. The rates, bases, and other features of State severance tax legislation as of March 1978 are presented, as are the amounts of State severance tax collections for fiscal year 1977, Some statistical comparisons between severance tax collections, total State tax collections, and total value of mineral production in the States involved are presented to portray the relative importance of severance taxes both in State tax revenue systems and in mineral industry revenues. A general discussion of the purposes and principles of taxation, the unique nature of a mining enterprise, the various types of taxes imposed on mineral production, and the character and rationale of the severance tax and its impacts on mining firms sets the severance tax in perspective. A bibliography of materials on the severance tax is included.

Jan 1, 1979

By Leo A. Schrider

A prediction for oil recovery from a pilot waterflood in the Kane oil- field, located in Elk, Forest, and McKean Counties, Pa., was made and compared to actual field performance. Water-injection and production histories, well logs, other field data, and results from laboratory tests of core material were used in this analysis. Performance of the pilot waterflood, initiated in January 1963, was predicted using a modified Craig, Geffen, and Morse calculation technique. Maximum recovery from this low permeable, preferentially oil-wet formation was predicted to be about 22,500 barrels of oil after 300,000 barrels of water had been injected into the pilot waterflood area. After additional field data were collected it became necessary to reevaluate the pilot waterflood area. The gas saturation prior to the waterflood was estimated to have been 20 percent, based on an assumption regarding the required volume of water injected to initiate oil production. In view of the actual field performance, a gas saturation of 13 percent is indicated. When this gas saturation and the method originally proposed by Craig and others are used) the predicted results are more representative. In December 1965, field performance was further analyzed using a hyperbolic-decline curve as presented by Arps. Based upon this evaluation method, the pilot water flood in the Kane sand should produce 37,000 to 42,000 barrels of oil with the injection of 300,000 barrels of water into the pattern. By continuing this secondary-recovery project to a reasonable economic limit, ultimate oil recovery may be as much as 50,000 to 55,000 barrels, or 129 to 142 barrels per acre-foot from 36.5 acres.

Jan 1, 1967

By Jeffrey A. Shibe

A prototype Fire Safety Evaluation System has been developed and is ready to be evaluated by a Peer Consulting Panel and for performing field tests. The system can be used to determine combinations of widely accepted fire safety equipment and under-ground coal mine features that provide a level of safety equivalent to those required by the Code of Federal Regulations-Title 30 for underground coal mines. In this evaluation, equivalent safety performance is gauged in terms of overall level of safety provided rather than by a component by component comparison.

Jan 1, 1987

By E. G. King

Many of the existing thermodynamic values for the titanium halides are estimates, including all the entropies and high-temperature heat contents of their crystalline and liquid phases. This report contains the results of low-temperature heat capacity measurents (which lead to entropy values at 298.15° K,) and high-temperature heat-content measurements of four halides - trichloride, tribromide, tetrabromide, and tetraiodide. The new data are combined with selected heat-of-formation values at 298.15° K. to obtain improved values of the heats and free energies of formation of these halides at high temperatures, thus supplementing the previous data of Kelley and Mah.5/ ACKNOWLEDGEMENTS This investigation was conducted under a cooperative arrangement between the Federal Bureau of Mines and the Department of the Navy, Office of Naval Research. The work was done by Bureau of Mines personnel using Bureau of Mines calorimetric equipment. The Office-of Naval Research supplied the supporting funds and arranged for procuring the samples of the titanium halides. The samples were prepared and analyzed by the Inorganic Chemistry Section, Division of Chemistry, National Bureau of Standards.

Jan 1, 1961

By P. L. Swanson

Stability analyses of fractured and faulted rock masses require delineation of the position, extent, and orientation of geologic discontinuities. The size of the smallest active discontinuity that may potentially be resolved using the spatial distribution of microseismic event locations is Limited by the accuracy and precision of the location methods. At a hard-rock mine in the Coeur D'Alene mining district of northern Idaho, two data sets consisting of calibration blast signals from a known source site and origin time and microseismic event signals were recorded using a stope-wide accelerometer array. These seismic signals are used to quantify various sources of error in event location. Five factors influencing source location errors are examined in this U.S. Bureau of Mines study: (1) biases of the numerical source location techniques, (2) receiver array geometries, (3) uncertainties in receiver positions, (4) errors in picking arrival times, and (5) uncertainties in seismic velocity structure, including the effect of mine openings. In addition, synthetic data (accelerometer positions, travel-time picks and wave velocity) are used to determine the effect of known systematic and random errors on source location calculations. It is shown that the commonly accepted association of minimum travel-time residuals with the best location solution does not necessarily hold true when there is a systematic error in seismic velocity. Recommendations are made for increasing the accuracy and precision of locations of microseismic events detected under similar field conditions.

Jan 1, 2010

By D. E. Shanks

The Bureau of Mines surveyed a variety of inorganic ion-exchange materials to determine their suitability for removing valuable accessory elements and troublesome contaminants from metallurgical process and waste streams. Most of the materials, which included molecular sieves, heteropolyacid salts, and hydrous metal oxides, did not give adequate separations, did not have the necessary stability in strong acids or bases, or were not in a physical form suitable for ion-exchange use. Many of the suitable inorganic materials, especially the hydrous oxides, were capable of cation exchange with high capacity only in basic conditions, which caused hydrolysis of most of the cations tested. Multivalent anions, such as arsenate and phosphate, were easily removed from acidic solutions by hydrous oxides. Hydrous zirconia was the best material for this purpose. Multivalent anions were not easily des orbed because of compound formation; therefore, conventional ion-exchange techniques could not be employed. As an alternative approach, hydrous ferric hydroxide was used as a filter material to remove arsenate and phosphate from acid solutions. One gram of arsenic was removed from solution for each 20 g of ferric hydroxide. Ferric hydroxide is preferable to hydrous zirconia for use as a filter material because of low cost.

Jan 1, 1983

By K. K. Kelley

Sodium-aluminum and potassium-aluminum silicates are among the more important rock-forming minerals of the earth's crust. They also appear as constituents of some metallurgical slags and of some refractory materials. Consequently, knowledge of their thermodynamic properties is interesting and valuable from several viewpoints. This paper reports experimental determinations of the low-temperature heat capacities and entropies at 298.16° K. of albite, jadeite, and nephelite it the sodium-aluminum silicate series and of adularia, ferriferous orthoclase, leucite and kaliophilite in the potassium-aluminum silicate series. Also high-temperature heat-content and entropy increments about 298.16° K. are reported for albite, jadeite, nephelite, and carnegieite in the sodium-aluminum silicate series. Except for a few high-temperature heat-content values for albite, all these data are available for the first time.

Jan 1, 1953

By Arno C. Fieldner

The determination and publication of data o the chemical and physical properties of American coals have been primary functions of the Bureau of Mines since its creation in 1910. In recent years this program has been expanded to meet increasing needs for information on the suitability of coals for the production of coke, gas, and byproducts, and within the last year an experimental coal-hydrogenation plant has been completed. With this addition, the Bureau is able to cover every phase of coal utilization, including combustion, carbonization, liquefaction, and complete gasification. The need for this information is increasing not only to meet the requirements of consumers but also to give the data required to establish the classification and minimum selling price of coal by the National Bituminous Coal Commission.

Jan 1, 1938

By Frederick L. Hoffman

These extracts are sufficient for the purpose of emphasizing the practical difficulties of averaging iron-mining conditions so as to make general vital statistics concerning iron miners useful Tor scientific. purposes. It is self-evident that conclusions based upon iron miners, so called, working largely above ground and employed chiefly in open-cut blasting ~perations or the management of steam shovels, etc., can not be made to apply to miners working continuously underground with an exposure of dust and other conditions quite similar to underground mining methods in the extraction of gold, silver, copper, lead, and other ores. The so-called "milling" process as practiced on the Mesabi Range may here be referred to, the same being explained in the report of the Immigration Commission to consist "in the sinking of a shaft on the edge of the ore body from which a tunnel is run in under the ore and connected with a vertical, funnel-shaped hole from under the surface, through which the ore is 'milled' down into the tramcars placed under the opening under the tunnel. After being loaded at the bottom of the funnelshaped hole, the cars are run out to the bottom 0.£ the shaft. where the ore is dumped into skids or elevators and raised to the ~urface and unloaded into the tipple, where it is loaded into thecal'S ready for shipment." It is properly pointed out that the so-called " milling" process employs some of the features of both the open-pit and underground methods of mining. For these and many other reasons it is self-evident that general statistics concerning iron mining are quite likely to be inconclusive and possibly seriously misleading. Aside from the foregoing the problem is seriously complicated by the extensive employment of foreign labor in the iron-mining ind ustries of the Lake Superior districts and of Negro labor in iron mining in Alabama. Within recent years, according to the report of the Immigration Commission, a considerable displacement has occurred in t~e quality of labor employed in iron mining, the displacement bemg referred to as "progressive," in that one race or group of races has entered the region and taken up the work offered in the lower occupations, the race or races already holdinz such positions having. moved up in the scale of occupation leaving the field to the newcomers. This statement is quite suggestive in that it indicates a comparatively short average trade life or trade exposure, quite at variance with the relatively long average ascer- MINES, QUARRIES, ORE REDUCTION, AND SMELTING. 377 tained for the iron mines of New <Tersey. It is said in the report of the Immigration Commission that- The Scandinavians and the other northern European races have given way to the Finns and Slovenians, and in the open-pit mines the Finns and Slovenians have given way to the south Italian, Montenegrins, Croatins, and other southern European races. In the underground mines the common labor and mining is chiefly done bv Finns and Slovenians because the races from the southern countries can not stand the heavy physical work required in this kind of mining. Here, too, is found the same upward movement, for formerly the English (Cornishmen) and Scandinavians' were in the lower occupations in the underground properties, At present the south Italians, Serbians, Montenegrins, and Croatians are performing the most menial work and are the races who are now at the foot of the scale of occupations. It is a matter of conjecture on the ranges as to who will push these races up or whether they will remain the commou laborers of the region. Inquiry was made into the prevalence of diseases OIl the ranges, but more with reference to outside sanitary conditions than to occupational exposure. The most common diseases on the ranges, however, were ascertained to be pulmonary tuberculosis and typhoid fever, and to a lesser extent smallpox and venereal diseases. With -cgard to pulmonary tuberculosis it is said that the disease is most Eevalent among the Finns and the Swedes, and is chiefly imported, I'here is no reference to a possible connection between disease occur- ~ence and occupational conditions, above or below ground, but there .s no evidence that this aspect of the iron-mining industry was made .he subject of a special investigation.

Jan 1, 1918

By Robert L. Kranz

The U.S. Bureau of Mines (USBM) has been monitoring and studying seismic activity associated with mining in the Coeur d&apos;Alene silver district of northern Idaho. New statistical methods of studying the stope-scale (1-to l00-m) seismicity at one Idaho silver mine are used in this report (part 1) and its companion (part 2). This report deals with methodology and its limitations. The recent concept of fractals and their seismological use is discussed and applied to mining-induced seismicity. Three types of fractal studies are addressed: spatial analyses (including temporal changes of spatial patterns), temporal analyses, and size analyses. Other statistical measures of mine seismicity are also addressed: event mean location, inter-event distance distribution skewness, temporal coefficient of variation, nearest neighbor and next event statistics, and event location planarity patterns. Each of the methodologies discussed (fractal and nonfractal) is presented using sample data from two stopes in the mine. It is shown that stope-scale, mining-associated microseismicity has a fractal nature. The usefulness of demonstrating fractality (scale invariance) for predictive or descriptive purposes depends on recognition of the factors affecting the calculation of fractal dimensions. Several methodological traps are illustrated that can lead to an incorrect conclusion.

Jan 1, 2010

By R. S. Rosso

A program to investigate the effects of hardened washers on the uniformity of roof bolt tension and the resulting ground control in an underground mine was carried out. The complete roof bolt installation and roof bolt loads, mine convergence, and bed separation were monitored for a period of five months. The results show no evidence to support or refute the theory that mechanical roof bolts offer better support when they are installed with a high uniformity of tension. Also shown is the fact that if the bolts are installed with a maximum deviation from the mean torque of ±15% the addition of hardened washers significantly improved the uniformity of the installed tensions in the roof bolts.

Jan 1, 1977

By J. R. Thoenen, B. H. Clemmons, A. H. Reed

"INTRODUCTION AND SUMMARYOverall red-ore reserves in the Birmingham, Ala., area were estimated in 1910 by E. F. Burchard 4/. Since then mining has progressed into areas classed by Burchard as ""unavailable for exploitation"" under conditions existing at that time. This is understandable when it is considered that red iron ore was valued at $1.19 a gross ton at the mine in Birmingham in 19102/ and by 1948 had risen 300 percent; 6/ that skips had replaced cars in slope haulage; that mechanical loading and rubber-tired haulage had replaced hand loading and mule or locomotive haulage; and that other more efficient mining methods had been introduced. Intensive study during the intervening 40 years has been given to ways and means for upgrading the low-grade ores in the area and combining or blending them with raw red and brown ores for improved blast-furnace feed.It is reasonable to expect that future progress in mining efficiency and increased knowledge of the beneficiation characteristics of marginal ores will permit extraction of red-iron minerals now considered uneconomic.The Bureau of Mines has undertaken to restudy iron-ore reserves of the Birmingham area to determine what tonnage and grades of mineral are present; what is necessary to make them amenable to mining; what further advancement is possible in beneficia¬tion methods; and where increased production may be obtained in the area if and when required. This study has been underway for the past 2 years, but research into the beneficiation of marginal ores has been in progress at the Southern Experiment Station for the past 30 years. Many results of that research have been adopted in commercial practice in the area. Other results have not been published but are pre¬sented here in condensed form as an important factor in assessing marginal deposits with respect to their importance as ore reserves.An interim discussion of the salient features of past history and progress, as well as the data developed during the years of research in beneficiation at this station and the present field investigation, will make for a better understanding of the present position as well as be useful in evaluating future potentialities. Discussion in this paper is confined to the main Birmingham Basin area, which contains the largest concentration of hematite ores in the district."

Jul 1, 1953

This information circular describes research the Bureau of fines has conducted to improve technology for recovering precious metals from low-grade resources. Many of the reported findings are recent, and some of the work described is ongoing. Topics discussed include cyanidation of carbonaceous gold ores to enhance gold recovery, a new method for precipitating mercury during cyanide leaching of gold ores, a staged heap leaching process to generate suitable solutions for direct electrowinning of gold, the use of anion-exchange resins to recover gold from cyanide solutions, and precious metals recovery from electronic scrap.

Jan 1, 1986

By P. B. Lorenz

Wettability measurements and laboratory waterflood tests were compared under a wide variety of conditions. Experiments were conducted with synthetic and natural crude oils, treated and untreated outcrop and oilfield sandstone cores, and synthetic brines with and without caustic, detergent, or phosphate additives. Measurements were made on equilibrated and unequilibrated systems at 77° and 150° F. Wettability was evaluated by the Bureau of Mines method from capillary pressure curves determined with a centrifuge. The waterflood data were fitted by empirical curves; the parameters of the curves characterize primary and subordinate production and also give the ultimate oil recovery. Results showed that wettability measurements at 77° F were useful predictors of recovery efficiency in waterflood tests run at both temperatures. Oil recovery in the early stages of waterflooding increased with increasing water wettability; however, the ultimate recovery was highest at a slightly oil-wet condition. The oil displaced at highest speed in the centrifuge was correlated with ultimate recovery in waterflood tests. Chemical additives to the brine sometimes lowered wettability and also sometimes improved waterflood recovery, but wettability and recovery were not correlated with additives present. The effect of additives on recovery in waterflooding was best seen in water-oil ratio curves.

Jan 1, 1974

By W. L. Heidenreich

This report describes the methods and results of field investigations conducted by the Bureau of Mines between December 1956 and December 1957 on seven deposits of nickel-cobalt-iron-bearing laterite and weathered serpentine near the west coast of Puerto Rico east and south of Mayaguez. These deposits were named, for purposes of identification, Guanajibo, Punta Guanajibo, Las Mesas, north and south deposits of the Rosario Southeast group, and the west and east deposits of the Maricao Southwest group. In addition, the lower 17 miles of the Guanajibo River Valley was tested at widely spaced intervals for possible concentrations of magnetite and chromite in the alluvial sands. The objective of the investigations was to appraise, by drilling and sampling, the two largest deposits--the Guanajibo and Las Mesas. Testing of the smaller deposits was much more restricted. Field investigations consisted of mapping, drilling with power auger, sampling drill-hole sections, and pre-paring samples for chemical analyses, mineralogical studies, and metallurgical tests. The work was financed jointly under a cooperative agreement by the Bureau of Mines and the Economic Development Administration, an agency of the Puerto Rican Commonwealth.

Jan 1, 1959

By E. Chin

Although Japan is a major producer of crude steel, it is poor in industrial raw materials. This Bureau of fines report describes Japan&apos;s raw material needs for chromium, cobalt, manganese, nickel, and tungsten to produce ferroalloys and alloy steels. Japanese imports of these ores or metals by quantity and source are given for 1972-81, inclusive, to indicate (1) the changes in the consumption and supply pattern, and (2) the degree of Japan&apos;s dependence on foreign sources. This report also describes measures implemented by Japan to reduce the risk- of supply interruption, and discusses the possible implications of supply shortages.

Jan 1, 1983

By J. R. Thoenen

This paper outlines briefly results of seismic measurements recorded in the vicinity of quarry blasting under practical operating conditions. The data cover field work done from January to the middle of August 1930, during which time records were made of 61 blasts in 19 quarries. Of the tests made, one was in biotite-gneiss, two in dolomite, two in a flintlike volcanic complex, three in gabbrodiorite, five in trap rock, and six in limestone. One quarry was in Alabama, two were in South Carolina, two in New York, four in Kentucky, five in Connecticut, and five in Massachusetts. Explosive charges ranged from 0.30 pound to 41,900 pounds, and the method of shooting varied from mud caps through hammer and wagon drill holes to churn drill holes and coyote tunnel shots.

Jan 1, 1937

By Leonard Obert

Between 1927 and 1957, sodium borate minerals were mined by underground methods in the Kramer District, Kern County, Calif. In 1957, surface mining methods were initiated, and during the next two or more decades it is probable that most of the production from the district will be obtained from open pits. However, part of this borate deposit is sufficiently deep that surface mining may not be economical and, hence, at some future date underground methods may again be employed. This report was prepared to document the underground mining methods employed in the district before 1957. The general geology of the district and the detailed geology of each of four mine sites are presented, together with a mineral and mechanical description of the ore and enveloping rock. The report also describes the stoping, extraction, pillar support, methods of artificial support, and other factors that affect the structural characteristics of these mines.

Jan 1, 1962

By Richard V. Ageton, Harry E. Tufft, E. A. Holbrook

When an underground excavation is made, the rock surrounding the sides and top of the opening is deprived of its natural support and tends to fall. Whenever caving takes place, the time and extent of the caving depend on the character and condition of the rock. In strong homogenous rock, such as solid granite, even a large chamber may stand indefinitely, whereas a soft material, such as clay or a loose material like unconsolidated sand, falls immediately if not supported. Weaknesses in the rocks induced by structural features, such as joints, :fissures, bedding and cleavage planes, and fractures produced by blasting, will cause the falling of insecure blocks or slabs unless means are provided to support these in place. In an unsupported mine opening, as a tunnel, the first slight settling or adjusting movement of the rocks (the "initial creep" or "set") is caused by the great weight of overlying material pressing down the rock masses above and around the roof and sides of the opening until they key together in roughly the form of an arch. The rock, after it has adjusted itself to this shape, becomes. selfsupporting. Timbering is necessa.ry in all mining only to support, therefore, those comparatively small blocks or pieces of rock which tend to loosen from the top and sides of the opening during or after the formation 'of the natural rock arch, and which lie between this natural rock arch and the opening. This statement, of course, has its limitations. For example; a layer of strong rock, like limestone, may act as a beam; then only the material under the limestone will need support. Timbering is not, as is commonly supposed by the layman, used to supp!ort the huge mass of rock between the back (roof) of an underground opening and the surface. It would be impossible to place enough timbers in a:ny underground opening to support such a mass. This fact is not'·perceived by all miners.

Jan 1, 1923