Search Documents

By Clarence O. Babcock

ROCK BEHAVIOR has proved of national interest in a variety of fields. The behavior of rock consequent to a nuclear blast was used to detect such blasts, as criteria for the design of underground military defense installations that would resist nuclear blasts, and for judging the feasibility for peaceful uses of nuclear explosives. An obvious peaceful application of nuclear explosives would be for large-scale rock excavation, and plans were presented during the year to improve the present Panama Canal or create a new canal by this method. These plans were based largely on earlier crater tests that demonstrated rock behavior when subjected to a buried nuclear blast. A knowledge of rock behavior under impact was used to evaluate the materials of the moon by means of the geometric configurations visible in the close-up pictures of the moon surface taken by the U.S. rocket Ranger 7. The composition of the moon must be considered in devising methods for taking samples of the surface layers or in designing underground shelters as bases for future explorations of the moon.

Jan 1, 1965

By C. J. Chindgren, L. C. Bauerle, J. B. Rosenbaum

Modifications of the conventional method of preparing ductile vanadium metal by calcium reduction of V2 05 in a bomb were explored for clues to a more economical procedure . The modifications examined included ( 1 ) omitting the gas purge of the bomb ordinarily used for eliminating atmospheric nitrogen , (2 ) using low- grade vanadium feed materials , ( 3 ) using alternative reductants , such as aluminum , magnesium , and silicon , and reductant mixtures , and ( 4 ) bomb refining of aluminothermic metal produced in open- vessel reductions . The most promising modification appeared to be bomb refining , using calcium to purify vanadium metal -- of low aluminum but high oxygen content-- prepared by open- vessel aluminothermic reduction of vanadium pentoxide .

Jul 1, 1960

By J. S. Hansen

In support of its objective to conserve mineral resources by minimizing premature failure of materials, the Bureau of Mines conducted a cooperative study with the U.S. Department of Energy on the erosion and abrasion resistance of hard materials for valves in coal conversion systems. This report describes a newly developed erosion-testing apparatus and presents data on the erosion resistance of over 200 materials. Erosion resistance of most metals was comparatively low. In contrast, ceramics and cermets such as B4C, WC, SiC, Si3N4, and TiB2, when fabricated to minimize porosity, displayed greater than five times the erosion resistance of metals. Coatings such as boron diffused into Mo and WC, chemical-vapor-deposited TiCN, and electrodeposited TiB2 were highly erosion resistant if applied in thicknesses ranging from 60 to 75 µm. Erosion resistance of cemented carbides was inversely related to metal binder content.

Jan 1, 1979

By C. F. Wingquist

As part of an ongoing study to determine how the wear of mining tools affects dust generation, the Bureau of Mines has measured bit tempera-ture rise during cutting of abrasive rock. Radial bit wear-flat tem-peratures generated by linear cutting in Berea Sandstone were measured as a function of cutting depth and speed. Depths of cut (DOC) were 1/8, 1/4, and 1/2 in, and cutting speeds were 10, 40, and 80 in/s, respectively. Temperature sensing was accomplished by emplacement of a miniature thermocouple into the center of the wear flat. Temperatures observed ranged from 2000 to 5000 C. Correlation between depth and temperature was weak. Temperature increased linearly with speed at 1/2-in DOC, but data taken at 1/8-and 1/4-in DOC produced inconclusive results. The results indicated that at least for deeper cuts (1/2 in), bit temperature, and therefore wear, can be reduced by lowering the cutting speed.

Jan 1, 1987

By H. B. Humphrey, F. E. Cash

The following information on accidents in Alabama during 1930 was compiled from data obtained from the companies represented in a course on accident prevention given by the United States Bureau of Mines in Birmingham. These mines produced nearly three-quarters of the tonnage of that State for the year, and included most of the larger operations in the district. The figures are probably representative of the mines which are doing recognized safety work, and are better than the average for all the mines in Alabama. Table 1 lists the days lost in accordance with the weights given to fatalities and permanent disabilities, part and total, which is the scale used in the National Safety Com¬ petition for Mines, conducted by this bureau. By way of explanation, temporary disabilities are weighted according to actual number of calendar days of disability, including Sundays and holidays — that is, all days are counted except the day of accident and day of employee's ability to return to duty. Hernia is classed as a temporary disability to be charged with the actual number of calendar days during which the employee was unable to work. Table 2 gives the number of accidents and the days lost from each cause at 45 coal mines and 7 iron ore mines, also the average frequency and severity rates.

Aug 1, 1931

By L. L. Oden

The U.S. Bureau of Mines and the Department of Energy (DOE), through its contractor EG&G Idaho Inc., are collaborating on a multiyear research project to evaluate the applicability of three-phase, electric arc furnace melting technology to vitrify materials simulating low-level radioactive and mixed wastes buried or stored at the Idaho National Engineering Laboratory and other DOE sites. The melter is a sealed, 1-t (1.1-st), three-phase, 800-kV?A electric arc melting furnace with 10.2-cm-(4-in?) diameter graphite electrodes, water-cooled roof and sidewalls, and four water-cooled feed tubes. A water-cooled copper fixture provides for continuous tapping of slag. An instrumented air pollution control system (APCS) with access ports for analysis and a feeder based on screw conveyors and a bucket elevator are dedicated to the facility. Test data are provided by an arc furnace analyzer and by sensors indicating feed rate; slag temperature; and temperature, pressure, and velocity in the APCS. These data are received by a data logger, digitized, and transmitted to a personal computer for storage and display. This unique waste treatment facility is available for public and private use on a cost-sharing basis.

Jan 1, 2010

By M. J. Beus

The Bureau of Mines, under a cooperative agreement with Hecla Mining Co., is conducting a rock mechanics study of the 6,200-ft-deep circu-lar, concrete-lined Silver Shaft in northern Idaho. The objective of the project was to instrument and evaluate lining behavior and rock de-formation when a deep shaft is constructed in a high in situ stress field and anisotropic rock mass. Rock mass displacements were moni-tored with multiple-position borehole extensometers. Liner stress and strain were measured with concrete pressure cells and embedment strain gauges. Field data from the 5,955-ft test level show that rock displacement is controlled by rock mass anisotropy. Liner stress and strain levels reflect the high in situ stress field as well as nearby station and raise construction. Maximum stresses measured in the lining, as a result of shaft excavation, are about one-third of its compressive strength. Subsequent loading pocket excavation resulted in signifi-cantly increased stress and strain levels in the liner. Continued monitoring and preliminary analysis of the data indicate that concrete-lined, circular shafts are stable for the high, unequal horizontal stress fields and rock anisotropy encountered in deep-level mining. Adjacent development work can be expected to significantly alter the initial stress and displacement conditions.

Jan 1, 1984

Federal lands often contain extensive mineral resources and decisions affecting access to those lands are made with knowledge of the possible minerals-related consequences. Information is provided to the Bureau of Land Management (BLM) in this report for use in preparing environmental impact statements on the Western Mojave Management Area (WMMA) and the Desert Tortoise Priority Habitat (DTPH). To augment U.S. Bureau of Mines (USBM) efforts such as the Mineral Assessment of the Planned Foil Irwin Expansion, Modified Silurian Valley Alternative, San Bernardino County, California which is in progress, and the Economic Analysis of the Minerals Potential of the East Mojave National Scenic Area; California, the USBM studied mineral deposits and estimated the potential impacts of mining in a segment of the California desert; the 8.7-million-acre WMMA, an area which includes the 1.2-million-acre Desert Tortoise Priority Habitat (DTPH). In addition, this information is intended to assist administrators, legislators, and the concerned public in understanding the economic importance of mineral resources in the California desert, especially that portion designated as the WMMA. See figure 1.

Jan 1, 1993

By Donald R. Irving

ALTHOUGH the quantity of material handled at metal and nonmetal mines in the United States in 1962 was 2.7 billion tons, the same as in 1961, a larger proportion was waste. At metal mines, crude ore production declined 1 million tons and waste output rose more than 18 million tons; at nonmetal mines crude ore production declined 6 million tons and waste output rose 36 million tons. Copper and iron ore producers increased their share of crude ore and material handled from about three-fourths to four-fifths of the national metals total, and sand and gravel and stone producers in-creased their share of the nonmetals total, also from three-fourths to four-fifths. Six States-Arizona, California, Florida, Michigan, Minnesota, and Utah-each handled more than 100 million tons of ore and waste, and together they accounted for 43 percent of the U.S. total. When the large-volume construction materials (sand and gravel and stone) were excluded from the totals, four States-Arizona, Florida, Minnesota, and Utah-supplied over half of the material handled.

Jan 1, 1963

By Philip W. Holland

The U.S. Bureau of Mines has developed an improved method for determining dissolved helium in water in the concentration range of 4.0 x 10-8 to 270 X 10-8 cm3 He (STP)/cm3 H2O. The method is a modification of a previously reported method that was developed for analrzing surface and subsurface waters in geochemical survey work. Water samples are collected in SOD-cm stainless steel cylinders, and the dissolved gases in a sample are extracted into an evacuated cylinder of equal volume. After addition of 30 psig of nitrogen containing less than 2 ppb helium to the extracted gases, the resulting mixture is analyzed for helium using a helium-tuned mass spectrometer. The helium content of the water sample is determined from an empirical calibration that is established by analyzing standard solutions of helium in water. The accuracy of the method is ±7 pct for helium-in-water concentrations above 10 x 10-8 cm3 He (STP)/cm3 H2O.

Jan 1, 1989

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

2, Survey of Representative Group of Metal and Non-mental Mines Before proceeding to develop and analyze Emergency Escape System Guidelines, it was necessary to obtain a broad range of information, including both fact and opinion. Although there were many areas to consider, the surveys had three primary goals 1. To determine the current state of underground escapeway planning and execution in American, metal and non-metal mines. 2. To determine, for a wide range of mining conditions, what difficulties can be encountered in complying with present and proposed escapeway regulatory standards. 3. To determine what improvements could be made and what equipment and technology was available to aid in implementing these improvements. To accomplish these goals, three major surveys were undertaken¬ 1. Survey of MESA and State Mining officials, discussed in Section 2. 1. 2. Survey of representative U S metal and non-metal mines, discussed in Section 2. 2. 3. Survey of manufacturers supplying equipment, primarily hoisting, suitable for use in escape systems, the product information which was obtained is discussed in Section 7.

Jan 1, 1976

By L. C. IlsLey

Investigations for safety of electrically operated mine equipment, safety lamps, and gas detectors are made at the Pittsburgh Experiment Station in accordance with published regulations termed "schedules." These schedules are revised from time to time, not only to keep in step with the progress of the industry, but also to permit much freedom of design as possible without lowering standards of safety. The following schedule covering electrical equipment, safety lamps, and gas detectors are now active: Schedule 2D. Explosion-Proof Mine Equipment. Requirements for Approval of of Storage-Battery Locomotives and Power Tucks, Junction Boxes, and Electric Motor-Driven Equipment.

Jan 1, 1939

The Bureau of Mines has developed test procedures and criteria for evaluating explosive reactivity of explosive-contaminated solid waste substances generated by U.S. Army ammunition plants. These substances are produced as explosive-contaminated sludge from wastewater treatment plants, residues from the burning of munitions and explosives on open ground, and residues from deactivation furnaces. The characterization of explosive reactivity is a prerequisite for disposal of such waste materials, which may be contaminated with primary explosives, propellants, or pyrotechnic materials. The Bureau has proposed two tests for this purpose. These tests were developed to evaluate the explosive reactivity as defined in Title 40, Code of Federal Regulations (CFR), part 261.23(a)(6) and (7). These are the Bureau's gap and internal ignition tests, which determine the sensitivity to shock and thermal stimuli, respectively. This report also includes gap and internal ignition reference data for typical blasting agents, high explosives, propellants, and marginally reactive substances. These reference data were used to establish test criteria. The Bureau has evaluated over 400 samples of contaminated soil, sludge, and burning residues using these two test methods.

Jan 1, 1988

By J. C. Meeks, C. L. Klingman

An instrument that is sensitive , portable , safe , and low in cost was developed by the Bureau of Mines for detecting helium leaks by comparing the thermal conductivity and flow rate of the atmosphere around the suspected leak against a reference of helium- free air . A vacuum pump pulls the sample gas through a restriction and over thermistor elements , the combined electrical output of which is affected by thermal conductivity and flow rate of the sample gas . Tests showed that the battery - operated Helium Leak Detector was effective and rugged instrument that could be operated safely in explosive atmospheres . The instrument could also detect , but not identify , other gases such as methane , hydrogen , argon , carbon dioxide , and Freon 12 .

Jan 1, 1964

By Donald P. Blasko

The first well that produced commercial quantities of oil in the Cook Inlet Basin of Alaska was completed in 1957. Since that time oil production in the basin has increased rapidly and by the end of 1969 had reached an annual rate of 74 million barrels. Five major oilfields had been developed, and two additional discoveries awaited development. Estimated amounts of recoverable oil by primary and secondary recovery methods total 2.7 billion barrels, or 36 percent of the estimated oil originally in place. Repressurization by injecting gas or water in formations containing undersaturated oil has significantly increased the volume of recoverable oil. All production has been from formations of the Tertiary age; that much of it is from depths of 10,000 feet or more is unusual for Tertiary formations. The oils are low in sulfur and contain low to moderate amounts of asphalt.

Jan 1, 1972

By John R. Shattuck

The Shasta and California Iron-ore deposits are 14 miles northeast of Redding, Shasta County, Calif.; and since 1907 have produced more than 300,000 short tons of exceptionally pure iron ore. Although some ore was mined and smelted from 1907 through the First. World War, most of it has been produced from 1942 through 1945 for use in making heavy ship ballast and concrete anchorages for mines. Irregular masses of magnetite, ranging from lumps of a few tons to pods containing about 25,000 tons, occur associated with skarn near the contact between the McCloud limestone and a younger granitic intrusive. Some of the deposits are low-grade, whereas others are nearly pure magnetite. Selective mining and hand sorting are necessary to produce a high-grade product. Investigation of these deposits by the Bureau of Mines included 2,910 feet of diamond drilling, some surface sampling of the principal mineralized zone and beneficiation tests. Resulting factual data are given in the body of this report.

Jan 1, 1948

By K. K. Kelley, W. W. Weller

This report contains experimentally determined heat capacity data for four crystalline sulfides -- AsS , GeS , NiS , and Ni3 S₂ -- over the temperature range from 50 ° to 298.15 ° K. The heat capacity data were used to evaluate the entropies of the sulfides at 298.15 ° K. Entropies of formation from the metals and rhombic sulfur and from the metals and diatomic sulfur gas are also included .

Jan 1, 1964

By Richard L. D?Arcy

This paper describing the mining practice and methods at the United Verde Extension mine, Jerome, Ariz., is one of a series of papers in preparation by the Bureau of Mines presenting the mining methods used in various mining districts of the United States. The United Verde Extension mine is a massive, high-grade deposit of copper sulphide containing some gold and silver and is mined almost exclusively by the conventional square-set method with some local modifications. About 450 men are employed underground and 1200 tons of direct smelting ore is produced per day. Figure 1 is a surface map of the Jerome district.

Jan 1, 1930

By Mark Flower

A 20L ignition test chamber has been used to test suspensions of 7 UK and world traded coals in air and O2/CO2 mixtures typical of oxy-combustion conditions. The coals varied in rank from sub-bituminous to bituminous and were tested in varying concentrations from the ignition limit to 400g/m3. Following each successful test the combustion residue was collected, weighed and analysed within a thermogravimetric analyser, allowing Q factors to be estimated. The ignition limit varied slightly in air, but was mostly around the 200g/m3 level. With the exception of Coal C, which was much harder to ignite, it correlated roughly with coal rank. The ignition limit changed significantly with O2 concentration when in mixed O2/CO2 gases. Only a few high volatile coals ignited in 21% O2/CO2 v/v, and then only with a 2500 J, rather than a 1000J, igniter. An increase in O2/CO2 levels to 30 or 35% gave ignition patterns similar to those carried out in air with a further increase to 40% having little additional effect. In addition the minimum ignition concentration decreased with increase in O2. Heterogeneous combustion or gasification of the coal by CO2 appears to be confirmed by comparing weight loss results for air and O2/CO2 mixtures respectively for an equivalent peak pressure rise.

Jan 1, 2009

By JOEL H. SWARTZ

During a series of resistivity measurements carried out in 1929 and 1930 a number of questions arose concerning the effect of topography on the character of the curves and the depths attained , the ratio of true depth to certain radii interpreted as representing depth , etc. To answer these questions it was decided to undertake a series of experimental investigations on artificial strata . It is the purpose of the present paper to present the results of the studies thus undertaken .

Feb 1, 1931