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By Chase E. Sutton

The porosity of a sand is usually the measure of its capacity for holding fluid, although porosity is sometimes selective; that is, a small percentage of the actual pore space (voids), particularly in fine-grained sandstones, may be isolated by the cementing material which prevents the entrance of fluids under normal conditions. Obviously, however, porosity determinations are essential to an engineering study of underground conditions of an oil field, and a simple and reliable method of obtaining a reasonably accurate figure for average porosity is desirable. This report describes a method suggested by Ruasell,3 which was used by the writer in the preparation of a report on the Texhoma-Gose pool, Archer County, Tex.4 The conditions in this pool were particularly favorable for obtaining an average porosity figure, in that some 30 to 35 core samples of the pay sand were available for analysis.

Jan 1, 1928

By S. W. Zoldok

[The Bull Valley iron-ore district lie,; in the northern part of Washington County, Utah, approximately 30 airline miles southwest of the highly productive Iron Springs area (fig. 1). Iron-ore occurrences in the district have been known for many years, but they have not been mined, largely because of the inaccessibility of the area. The Bureau of Mines established a development project in the Bull Valley district in September 1941. Two separate areas, the Pilot and the Cove Mountain, were investigated. The work was planned to increase iron-ore reserves for steel production in the Western United States. During the project period three diamond-drill holes aggregating 1, 000 feet were completed (fig. 2). The program also included 6 408 linear feet of surface trenching and 171 feet of underground work (figs. 2 to 8, inclusive). Analyses were made of 460 samples from the diamond-drill holes and surface and underground excavations. The results of the analyses are given in tables 1, 2, 4, and 5, and the logs of the diamond-drill holes are shown in table 3. Field. work was completed in September 1942.]

Jan 1, 1953

By R. M. GRANTHAM, J. H. SOULE

C. R. Keyes, F. C. Schrader , F. A. Jones ( the first director of the New Mexico School of Mines , whose name was given the deposits ) , and N. H. Darton all described the Jones iron deposits within a decade after their discovery in 1902 . The earliest locations now on record were made in 1927. Interest in iron ores was revived during the second World War . Paul E. Pesonen , of the Bureau of Mines , reported on the deposits in December 1941 and proposed an extensive exploratory program . In March 1942 , the deposit was reported upon by C. H. Johnson , also of the Bureau of Mines , and a definite program of exploration was outlined .

Feb 1, 1947

By P. G. Clites

A laboratory furnace was developed by the Federal Bureau of Mines for use in studying the interrelationships among variables associated with skull melting and casting high-temperature metals. Although additional work is necessary to determine the extent to which the information obtained by using this furnace can be extrapolated to larger furnaces of the same type, many casting characteristics of metals and alloys can be determined on equipment of this size. This furnace is a laboratory-size, consumable-electrode, skull-casting furnace equipped with a water-cooled copper ladle. The ladle, which is a tilt-pour or over-the-lip type, has a volume of approximately 30 cubic inches and provides up to 20 cubic inches of molten metal for castings. Castings of various reactive and refractory metals, including zirconium, titanium, hafnium, columbium, molybdenum, tantalum, and tungsten, have been produced. In addition, castings of iron, chromium, and copper have been made. The simplicity and versatility of the apparatus would make it useful to metallurgical laboratories preparing cast specimens.

Jan 1, 1961

By H. G. Iverson

The effects of adding boron and boron plus carbon to electrorefined vanadium were evaluated with respect to mechanical properties at low temperatures and response to heat treatment. Grain size was significantly decreased with the addition of 0.05 percent boron, the decreases ranging from 30 percent at 800° C to 75 percent at 1,100° C. Increasing the boron content resulted in only a small increase in strength at room temperature, but at 77° K, boron contents of 0.005 to 0.076 percent increased the yield strength of vanadium over 50 percent, from 70,000 psi to 110,000 psi. When boron and carbon were present together, the individual grain-refining effects obtained with either element were retained. Approximately a twofold increase in strength was obtained by age-hardening the alloys containing both boron and carbon. Alloys with only boron additions did not age-harden.

Jan 1, 1968

By A. R. Kirchner

This paper describing the practice at the concentrator of the Minas de Matahambre, S. A., is one of a series being; prepared by the Bureau f Mines on milling methods and costs. The Minas de Matahambre, S. A., concentrator treats the production of the Matahambre mine and has a capacity of 1,300 tons of copper ore per day by selective flotation. During the year 1930 the heads averaged 4.55 per cent copper, the concentrates 29.20 per cent copper and the recovery was 95.96 per cent.

Jan 1, 1931

By Foster Fraas

A comparison has been made between cubes and spheres in the matrix of the high-intensity wet magnetic separator. For two inclined plane surfaces, such as may occur with cubes, the maximum force value, H [dH-dx] is at the point of nearest approach and is much higher than the force resulting from adjacent spheres. Although the maximum force value for cubes is higher, it decreases more rapidly at increasing distances. The maximum force for spheres is at an appreciable distance from the point of nearest approach. At field intensities for magnetic saturation of the iron spheres, the force extends to further distances with greater uniformity approximating that of the constant force or isodynamic field. The force is also independent of the sphere diameter, which permits the scaling of the sphere diameter to provide changes in particle migration distances without changes in force gradient.

Jan 1, 1972

By Robert L. Anderson

A shaft or slope bottom is that portion of a mine that is contiguous to the bottom of the main hoisting shaft or slope. It includes the terminal tracks for loaded-and empty-car storage, locomotive run-arounds, locomotive shops, charging stalls, supply rooms, pump rooms, waiting rooms, and offices for dispatcher, weighmen, and foremen. This paper will deal principally with the arrangement of tracks and the handling of cars on the bottom, but includes other data that may be affected, directly or indirectly, by the bottom lay-out. All of the mines discussed are being operated in comparatively level coal seams.

Jan 1, 1937

By W. M. Deaton

The Keyes Helium Plant of the Federal Bureau of Mines was constructed under an expedited schedule, to supply the urgent and growing demand for helium in atomic energy, missiles, aerology, space exploration, shielded-arc welding, and low-temperature research. Construction began in December 1958 and ended in August 1959. The plant, near Keyes, Okla., processes 2 percent helium-bearing natural gas from the Keyes gasfield. In 1960 the plant produced and shipped 263 million cubic feet of helium (equivalent to an annual rate of 290 million cubic feet). Production cost was $9.11 a thousand cubic feet of helium. A low-temperature process involving two steps is used; the first separates a crude-helium product from the natural gas at about -250° F. and 225 pounds per square inch gage (p.s.i.g.); and the second purifies the crude helium to a high-purity product (Grade-A helium, 99.995 percent helium) at about -320° F. and 2,750 p.s.i.g.

Jan 1, 1961

By Chas. F. Jackson

This paper is published as a progress report for the first half of 1929 on the study of wining methods and costs in the Eastern and Central States. Data obtained from 25 mines using open-stope methods are correlated and summarized. Some of these mines have been described in considerable detail in reports already published as Information Circulars. In addition to the published reports on individual mines, considerable data have been obtained from other mines which were visited and studied during the course of the investigation. Many of these mines will later be described in detail in separate papers, and when the field has been covered in this manner it is planned to issue a bulletin on open-stops methods of mining which will amplify the subject matter of the present paper. Definition of ?Open-Stops?. - The term "open-stopes" as employed by the Bureau of Mines is applied to all naturally supported stopes; that is, stopes in which the excavated ore is not replaced by support of an artificial nature other than preps or stulls and in which the ore or (and) capping are not caved during the active life of the stopes.

Jan 1, 1931

By R. D. Govier

The U.S. Bureau of Mines has developed a thin-film X-ray fluorescence technique to rapidly determine Cu, Ni, Co, Fe, and Cr in super alloy leach liquors. Total analysis time per sample was less than 15 min, as opposed to several hours for traditional wet chemical methods. Precision and accuracy were checked by replicate analyses of solutions similar in composition to leach liquors, whose analyte concentrations were well known. Coefficients of variation for all elements were found to be less than 2 pet. With the exception of the results for Fe, all relative errors of estimation were also found to be less than 2 pet. Bulk liquids are not introduced into the spectrometer; thus, the potential for damage to the instrument by leakage of corrosive liquids is eliminated.

Jan 1, 1989

By Daniel W. H. Su, Gregory J. Hasenfus

This paper demonstrates that finite-element modeling can be used to predict in situ coal pillar strength, especially under non ideal conditions where interface friction and roof and floor deformation are the primary controlling factors. Despite their differences in approach, empirical, analytical, and numerical pillar design methods have apparently converged on fundamentally similar concepts of coal pillar mechanics. The finite-element model results, however, are not intended to suggest a new pillar design criterion. Rather, they illustrate the site-specific and complex nature of coal pillar design and the value of using modeling procedures to account for such complex site-specific conditions. Because of the site-specific nature of coal pillar design, no single pillar design formula or model can apply in all instances. Understanding and accounting for the site-specific parameters are very important for successful coal pillar design. More work remains before the century-old problems related to pillar design are finally solved. Future research should focus on the cross-linkage of empirical, analytical, and numerical pillar design methods.

Jan 5, 1999

By Jack C. White

This U.S. Bureau of Mines report assesses the resource potential of trace metals present in commercial Ti mineral concentrates. Metals of greatest interest: are those defined as "strategic and critical" by the U.S. Congress in 1981. Metals of interest in Ti mineral concentrates are Cb, Cr, Ta, Th, U, V, and Zr. Commercially available Ti mineral concentrates were studied. Characterization and analysis of major and minor constituents were performed by X-ray diffraction, neutron activation, inductively coupled plasma emission, atomic absorption, and classical wet chemical techniques. Of the metals investigated, the Cb, Ta, and V content of some concentrates may be a significant potential resource, depending on their amenability to recovery.

Jan 1, 2010

By J. Howard Bird

The purpose of this publication is to describe the power-distribution system of the mine and refinery of the Duval Sulphur & Potash Company at Carlsbad, N. Mex. This distribution system has been excellently predesigned to meet requirements and fit special conditions encountered at the property. In presenting the material, the authors point out various features that would be desirable for incorporation in other systems under similar conditions. Central location of switchgear in pressurized vaults and ventilation of such equipment with filtered air prevent salt accumulations and contribute to trouble-free operation. The simplification of power-distribution circuits and overload protection, as a result of centralization of switchgear, the use of individual control circuits enclosed in conduit (which aids troubleshooting), and central location of control panels, are factors which contribute to efficient, safe operation. Those features are applicable to many operations where fire or explosion hazards are encountered, or where dusty conditions may exist, as well as in operations where numerous individual drives are involved.

Jan 1, 1959

By Joseph B. Cummings

The Twin Buttes camp embraces eight mines in the Pima mining district. The first mining claims in the camp are said to have been located in 1876, but little mining was done until 1905. Intermittent operation of five of the mi.nes to 1928 yielded 388,231 tons of ore averaging 6.19 percent copper and 8 small tonnage of high-grade oxidized zinc ore. While the Bureau was investigating the area, one mine was active, and it started to produce in 1944. The mines of the Twin Buttes camp are at or near contacts of intrusive granite with Paleozoic limestones and quartzite. The ore shoots lie in metamorphosed sediments adjacent to a zone of garnet rock that separates the ore from the footwall granite. Small fissures that originate at the contact and cut the sedimentaries appear to have been controlling factors in ore deposition. No important ore bodies are exposed at the surface, and those developed wore discovered by sinking on the fissure veins to the contact zone. Most of the area overlying the favorable ore zone is covered by alluvium ranging in thickness from 5 to more than 20 feet.

Jan 1, 1950

By Albert E. Long

Preliminary experiments conducted in 1949 with a few diamond bits in which the diamonds in the bit crowns were set in hard-vector directions indicated that a substantial saving could be effected when a high percentage of the diamonds were oriented in this-manner. It was realized, however, that many additional tests would have to be performed before a positive trend could be established and the possibility of coincidence eliminated. Therefore, a long-range series of experiments was planned to investigate various phases of the problems related to the orienting of diamonds in diamond bits. This report (the third in a series) 2/3 presents the information obtained from tests conducted to investigate more fully the effects of orienting high-grade drill bort in diamond bit crowns. In these tests, the drill bort were oriented in both hard-vector and soft-vector directions in the crowns of AX-size bits. Test drilling was done in a dike of saussuritized dacite porphyry similar to a fine-grained granite in hardness e drillability.

Jan 1, 1954

By William J. Campbell

These investigations were undertaken as part of a program to determine the optimum X-ray spectral lines to use for analyzing the wide variety of samples received by the X-ray Laboratory. Theoretical calculations and experimental data derived from these investigations show that longer wavelength spectral lines, > 2A, are very useful for many analytical problems. Because of the low fluorescence yield of the elements of atomic numbers 13-22 and the small depth of penetration of their X-ray spectral lines, these elements were originally considered to be insensitive; however, these studies show that the wide dispersion of their spectral lines, coupled with their weak beta lines, permits the use of wide collimation, thus increasing the line intensity. More importantly, the background due to scattered primary radiation is very low in the long-wavelength region.

Jan 1, 1959

By D. H. Desy

The Bureau of Mines studied the properties of copper that had been oxide dispersion-strengthened with 2 vol pct of either yttria or alumina. Compounds of copper and aluminum or yttrium, coprecipitated from aqueous solution, were converted to oxides; the copper was reduced, compacted, sintered, and extruded. For the resulting copper-dispersoid composites, room temperature tensile properties after annealing in hydrogen, elevated temperature tensile and stress-rupture properties, and electrical conductivity were determined. Compared with oxygen-free copper, copper-2 vol pct alumina or yttria had improved strength after annealing between 400° and 1,000° C, and improved elevated temperature strength, with little loss in electrical conductivity.

Jan 1, 1969

By N. Greninger

The Bureau of Mines examined the possibility of a seasonal variation of respirable dust concentration in U.S. coal mines. The first step was to review company and MSHA-inspector dust samples that had been collected during the past several years in 14 selected mines for compliance purposes. Results indicated severe scatter in data; most standard deviations of the dust concentrations measured in winter and summer months were comparable in magnitude with the mean values of dust concentrations for the seasons. Therefore, a detailed statistical analysis was conducted. At the 90% confidence level, the company samples of three mines had winter means 0.15 to 0.54 mg/m3 higher than the summer means; six mines had negligible seasonal variations; and five mines had winter means that ranged from higher to lower than the summer means. Inspector data, however, were too sparse for analysis. In view of both the low frequency of occurrence of a seasonal effect and its wide scatter in several of the mines, the study was ended with the conclusion that seasonal varia-tion in respirable dust levels, in general, is an insignificant factor.

Jan 1, 1986

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. By agreement with the American Petroleum Institute, identification of the items is confidential. It presents analytical data for 3,924 samples, representing the products of 116 companies. The samples were collected during June, July, and August, 1954. As in previous surveys, the gasolines covered by this survey include those from both large and small suppliers, The data were obtain& by laboratories of various refiners, motor manufacturers, and chemical companies and submitted to the Bureau of Mines for compilation, A list of the National Motor-Gasoline Survey reports published during the past 10 years is given on page 5.

Jan 1, 1955