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By Friedel. Michael J.

The U.S. Bureau of Mines investigated acoustic emission (AE) and the Kaiser effect in six types of rock: St. Cloud gray granodiorite, Barre granite, Dresser basalt, Salem limestone, Berea sandstone, and a volcanic tuff. AE signatures were used for interpreting the rock deformation stage and for indicating mechanisms of failure in uniaxial compression. The research demonstrated the advantages of using the volumetric stress-strain curve, as opposed to the more conventional uniaxial curve, for correlating AE response signatures with deformation stages and fracture processes in the rock. Standardized experimental procedures were used for the AE monitoring. The Kaiser effect was shown to be capable of determining prestress levels to within a few percentage points in uniaxial compression tests. Also, prestress memory was shown to be retained in the rock for periods of up to at least. 5 months, the maximum period of testing. The Kaiser effect AE technology holds promise for providing a comparatively inexpensive and less complex method for examihing stress history in rock. However, since the conftning stress has a pronounced influence on the Kaiser effect, it must be considered in developing technology for determining peak fteld stresses based on the Kaiser effect.

Jan 1, 1990

By Peter L. Swanson

This investigation, which began 90 minutes after the February 3, 1995, seismic event, has benefitted from the assistance of a large number of individuals. These individuals provided information, data, analysis, brainstorming opportunities, field equipment, assistance with communication, conducted rock mechanics tests, and provided insight into mining in the southwestern Wyoming trona district. They include Rich Hodgson, Ron Hughes, Larry Refsdal. Mike Weller, John Kolesar, Joe Vendetti, and Rick Casey (Solvay Minerals), Dave Delling (Solvay consultant - former Solvay President), Karl Zipf (formerly with USBM, now with MSHA), Bob Friend, Bob Ferriter, Dave Ropchan, Jerry Davidson (MSHA Tech Support), Don Stauffenberg, Ben Hohler (Wyoming State Mine Inspector's office), Bruce Presgrave (USGS/NEIC), Chris Wood, Dan O'Connell (Bureau of Reclamation), Sue Nava, Jim Pechmann (University of Utah), John Norgord and members of FMC's mine rescue team (FMC Corp.), Bill Walter (Lawrence Livermore National Laboratory), Ron Gerlick, Kevin Wood, and Mike Harmel (USBM rock mechanics lab), Jim Case (Wyoming State Geological Survey), and Solvay consultants. In addition, many individuals helped us gather information on other recent large mining-related seismic events in Germany, Russia, and Australia. and other parts of the United States. These individuals include Wolfgang Minkley (IfG Institut fur Gebirgsmechanik, Leipzig), Arnfinn Prugger (Potash Corp. of Saskatchewan), Hartmut Spetzler (University of Colorado/ University of Bayreuth), Sergei Stanchits (Ioffe Poly-technical Institute, St. Petersburg), Rocky Thompson (Cyprus-Amax) and numerous seismologists throughout the Internet.

Jan 1, 2011

By A. B. Coates

During the last three years the use of ethylene glycol dinitrate4 (E.G.D.) as at low-freeze (L.F.) agent in place of nitropolyglycerin has become common in the manufacture of explosives of the dynamite type. The usual proportion of D. G. D. in the explosive "oil" is 25 per cent; the remainder, 75 per cant, is regular nitroglycerin. These proportions were probably selected as a continuation of the practice of 25 per cent nitropolyglycerin and 75 per cent regular nitroglycerin.

Jan 1, 1929

By Edmund S. Leaver, Charles E. Van Barneveld

In response to numerous requests from metallurgists and operators for information regarding the status of the sulphur dioxide leaching process , developed at the Southwest experiment station of the U. S. Bureau of Mines , Tucson , Ariz . , the following statement has been prepared . A more complete report is now in course of publication and will appear as Technical Paper 312. This process was devised to provide a cheap and efficient method for treating the so- called "porphyry " copper ores of the Southwest which generally contain both " sulphide " and "nonsulphide " copper minerals , mixed in such proportions that they can only be satisfactorily treated by a method which will concurrently recover both the sulphide copper and the nonsulphide copper . The latter term has been adopted to include all the minerals commonly referred to in operating phraseology in the mills of the Southwest as " oxidized" , " oxide " , or " soluble " copper . confident that the sulphide dioxide leaching process , as developed by us with the cooperation of the Miami Copper Co. and the Arizona Copper Co. , is suitable and commercially available for a wide range of ores .

May 1, 1922

By James W. Townsend

The Vicksburg mining property lies in the southeastern foothills of the Star mining district, Beaver County, Utah (fig. 1). Within a few miles of the Vicksburg mine, lying in a semicircle from south to northwest, are such past producers of lead-silver ores as the Moscow, Hoosier Boy, Red Warrior, Wild. Bill, Harrington-Hickory, and many others. Farther to the north, in the San Francisco district, are the famous Horn Silver and Cactus mines. The formation at the Vicksburg property consists of interbedded limestone, shale, and dolomitic limestone. These beds have been metamorphosed by the intrusion of irregular masses of porphyritic igneous rocks grading from quartz-monzonite to granodiorite. Ore deposition is in north-trending fissures of sheeted zones, contact metamorphic in type. These depositions were subsequently altered to gossan. A preliminary investigation of the Vicksburg property involving surveying, mapping, and sampling was made by W. A. Young and F. H. Gunnell, engineers of the Bureau of Mines, in the fall of 1946. As a result of the investigation, a project was set up to investigate the possibility of ore occurrence at greater depth on the fissures under the mineralized zone by diamond drilling.

Jan 1, 1950

By Manuel Gomez

The heat contents of thermally dried lignite, subbituminous B coal, and their corresponding low-temperature chars were determined at various temperatures below the highest temperature to which these materials had been exposed before testing. Similar studies were made on high-temperature char and coke, spent shale, and ash prepared from both coal and spent shale. Heat content of the carbonaceous materials tested correlated well with temperature. Heat con-tent results for spent shale compared well with the published results. Statistical analysis of experimental data together with published information showed moisture, volatile matter, carbon content, and temperature to be the principal variables influencing the specific heat of coal. The specific heat of devolatilized carbonaceous substances, char and coke, approached that of graphite as the carbonization temperature was increased. The elemental specific heats of coal constituents, estimated from the ultimate analysis and the specific heat of coal, compared favorably with published elemental specific heats.

Jan 1, 1965

By Sam McNary

The U.S. Bureau of Mines used the East Fork Pine Creek watershed to conduct a pilot study for an inactive and abandoned mine lands inventory, during which techniques and methodologies would be developed for subsequent inventories. A total of 177 waste dump samples, 191 mill tailings samples, and 36 stream sediment samples were collected. Water samples were collected from 18 sample sites during five sampling events. Waste dump, tailings, and stream sediment samples were analyzed for antimony, arsenic, cadmium, copper, iron, lead, mercury, and zinc. Results indicate a multidisciplinary approach is necessary: disciplines should include geology, geostatistis, geochemistry, geophysics, biology, hydrology, and remote sensing; small prospects do not generally contribute to watershed contamination, major mine and mill sites may contribute metal enriched sediment of metal enriched water; speciation studies and bioavailability studies are important.

Jan 1, 1995

By E. F. Foerster

The Bureau of Mines used a diphenyl ether calorimeter to determine the heat contents of natural and synthetic blast-furnace slags. For solid slags, enthalpy (HT-H298) at 1,448° to 1,680° K ranged from 282.1 to 348.5 cal/g (±3 percent); liquid slag values were 400.1 to 514 cal/g (±3 percent) in the temperature range between 1,626° and 1,890° K. Experimental results for liquid slags were 14.3 to 16.2 percent higher than the enthalpies calculated from thermodynamic tables; values for solid slags ranged from 5.3 percent lower to 3.9 percent higher than calculated values. Experimental results for liquid synthetic slags ranged from 14.9 to 24.3 percent higher than the calculated enthalpies; values for solid synthetic slags were from 1.0 to 3.4 percent higher.

Jan 1, 1967

By A. J. Forney

Recent experiments used catalysts of plate assemblies in synthesizing high-Btu gas and gasoline indirectly from coal. A gas with a heating value of 925 to 943 Bt-: per cubic foot has been prod u la the hot-gas-recycle pilot plant from synthesis gas (3H2+100) with lathe turnings used as catalyst in the first reactor, and assemblies of parallel sprayed plats of nickel in the second. Solid plates made of Raney nickel, and steel and aluminum plates sprayed with Raney nickel or nickel oxide were tested. Those catalysts had very low resistance to gas flow; 90 percent lower than nickel granules used in previous experiments. In a single stage of synthesis thee nickel plates were only partially successful. Although the heating values of the product gas ranged from 856 to 941 Btu per cubic foot, the carbon monoxide content of he gas was above 0.1 percent. Both steel and wrought turnings were tested in single-stage synthesis, but the conversion of hydrogen and carbon monoxide was too low to attain the desired heating value of 900 Btu per cubic foot in the product gas. Assemblies of plates thermally sprayed with fusel iron were tried in an experiment to make gasoline. A gasoline yield of 52 percent (of the hydro¬carbons produced) was obtained using a 1H2-10O feed These sprayed assemblies were in service for 1,500 hours, the longest that this type of catalyst has been used. When a second reactor containing Raney nickel catalyst was added in series with the first reactor, complete utilization of the feed gas was obtained because in addition to the liquid product, a high-Btu gas with a heating value of 800 Btu per cubic foot was made.

Jan 1, 1965

By L. D. Wyant

That natural gas-gasoline can be used to advantage as a refrigerant is suggested by the fact that the "make" tanks and other parts of the equipment of gasoline plants frequently become coated with frost. The experiments reported in this paper confirm this assumption and indicate that volatile gasoline can be use used to advantage in many refrigerating plants. The Bureau of Mines is making a study of wax distillates in order to find out why satisfactory lubricating oils and waxes can be made easily from certain crude oils and only with difficulty from others. In the commercial distillation of crude petroleum it is customary to separate the distillates into the following groups: (A) Gasolines and naphthas, (B) Kerosenes, (C) Gas oil, and (D) Wax distillate (consisting mostly of light lubricating oil together with small amounts of paraffin Wax).

Jan 1, 1923

By John H. Soule

Appreciable quantities of sine and lead orus have been produced from the West. Pinos Altos district of Grant County, N. sex. This area was visited many times by engineers of the Bureau of ines. D. H. Johnson and 4. R. Storms visited the district in haren 1943 in connection with an acrenu road to toe wines. M. H. Storma again visited the area in July 1943 in connection with a hetals Feserve Corporation loan on the Routen-Thomas

Apr 1, 1948

By Hewitt Wilson

A review is given of the nomenclature, sources, imports, statistics, common methods of preparation, and testing of mineral pigments. A description of the Deer Park-Spokane colored-clay district and the laboratory methods of preparation of these colored clays, others, and siennas follows. The mineral pigments were prepared by washing or grinding the original material as received and by calcination of the yellow ocher and brown sienna with and without manganese dioxide to produce red, brown, and black colors. These prepared powders were tested for fineness, oil absorption, and color as compared with well-known brands of commercial pigments. Similar tests were made with several basalt red clays occurring in the neighborhood of Salem, Oreg., and Kalama, Eatonville, and Clay City, Wash. The color particularly was studied, since this property is the most important commercial characteristic of the minerals. PURPOSE OF INVESTIGATION Since the development of the clay industry in the Pacific Northwest, some curiosity and interest have been aroused by the red and yellow clay or ocherouslike material that has often been found associated with the commercial clay deposits. These include the red and yellow "paint pots" near Deer Park and Spokane in eastern Washington, a red clay at Clay City, another close to Eatonville in western Washington, and red basalt earths near Salem, Oreg., and along the Columbia River near Kalama, Wash. Several companies have been organized to produce pigment colors from two of these deposits but have either discontinued or never started operations.

Jan 1, 1929

By Stephan Stecura

Crystallographic modifications and kinetics of solid-state phase trans-formations were determined for five rare-earth" sesquioxides--La2O3, Nd2O3, Sm2O3, Eu2O3, and Gd2O3. Oxides used for crystal modification studies were prepared by thermal decomposition of the following high-purity salts of the five rare-earth elements--carbonates, chlorides, fluorides, nitrates, oxalates, and sulfates. X-ray diffraction patterns of the cubic and hexagonal oxides were indexed by a graphical method and patterns of the monoclinic oxides by Ito's method. The kinetics of crystallographic transformation were determined by high-temperature X-ray diffractometry. The kinetic data were interpreted using a shrinking sphere model. All of the transformations followed first order kinetics. Activation energies were calculated by application of the Arrhenius equation. These solid-state phase inversions were concluded to occur by a reconstructive transformation mechanism.

Jan 1, 1965

By Tom Retka

This three volume final report summarizes the activities and conclusions of this contract. The objective of the contract was to develop noise control modifications on a retrofit basis, for auger miner coal-cutting systems. Manuals were prepared to assist mine shop personnel in retrofitting the auger miner with these noise controls. Final Report Volume I - Details all vibration and acoustical tests conducted in develop¬ment of the noise controls. Final Report Volume II - Noise Control Modification Manual for the Jeffrey 100-L Auger Miner describes the various noise control modifications to the auger miner, along with fabrication procedures, cost and vendor information. Final Report Volume III - Noise Control Modification Manual for the Jeffrey 94-L Bridge Conveyor describes the various noise control modifications to the bridge conveyor, along with fabrication procedures, cost and vendor information.

Jan 1, 1978

By W. W. Odell

"It is common knowledge that extensive lignite deposits occur in the States of Montana, North and South Dakota and Texas. The total area of these deposits and the total amount of lignite in them is so great that the true economic value of lignite is seldom realized. These deposits underlie areas of thousands of square miles. The area of the lignite lands in North Dakota alone is estimated to be approximately 32,000 square miles. Nearly one-third of the total solid-fuel resources of the United States is lignite and approximately 90 per cent of this lies in the Northwest.To the people of the Northwest the more extended utilization of lignite is of fundamental importance, hence any methods for commercially producing salable products from lignite that promise further development of these great fields deserve careful study.The development of our lignite resources has been slow, partly because the districts wherein lignite is found is not thickly settled or highly developed in manufacturing industries, but also because of the physical and chemical characteristics of the lignite. Lignite is classed as a low-grade fuel and may be con¬sidered as imperfectly developed coal -which has a more or less woody structure; it may be of the brown-coal type or darker, denser and more homogeneous, approaching subbituminous coal in character. As mined it contains more than 30 per cent of moisture exclusive of the -rater of decomposition formed .then it is carbonized or burned. The heating value as determined by the calorimeter is approximately half that of good quality bituminous coal. Upon exposure to the air lignite loses part of its moisture, whereupon the lumps chock and split until after considerable exposure, a large percentage of slack is formed. It cannot be stored in large piles so successfully as come other fuels, and it some instances it is more apt to ignite spontaneously in storage or in transit then the higher grade fuels."

Feb 1, 1924

By H. J. Coleman

Knowledge of the types of naturally occurring sulfur compounds in petroleum is of both theoretical and practical interest to petroleum chemists and geologists. This knowledge has been extended by the identification of 77 sulfur compounds, including 36 thiols, 23 chain sulfides, and 18 cyclic sulfides in a 111° to 150° C boiling range distillate of Wasson, Texas, crude oil. The characterization procedure used in separating and identifying these compounds included isothermal distillation, vacuum fractionation, liquid-solid chromatography (alumina adsorption), chemical treatment, gas-liquid chromatography, microdesulfurization, and infrared analysis. The procedural steps described represent a systematic method of sulfur compound analysis considered applicable for determining the nature and concentration of the sulfur constituents present in any straight-run petroleum distillate of the above-boiling range.

Jan 1, 1966

By Verne E. Hooker

The Bureau of Mines conducted a preliminary investigation to determine the state of stress in crystalline rock outcrops near Atlanta, Ga. The secondary principal stresses in a horizontal plane near the surface are compressive and are 500 to 3,000 psi. The maximum compressive stress is northeast-southwest in the Stone Mountain-Lithonia district but changes to northwest-southeast near Douglasville. The elastic constants were determined from data obtained by static and dynamic laboratory methods and in situ velocity measurements. Results show Young's modulus to be dependent upon both stress level and anisotropy in the rock. Average secant moduli obtained from triaxial tests were used to compute the applied stress from borehole deformation measurements.

Jan 1, 1966

By Marvin L. Whisman

This report describes the preparation of tritium-labeled organic compounds to be used by the Federal Bureau of Mines in studying the role of certain gasoline constituents in gum-forming mechanisms. The gasoline constituents that have been investigated boil within a range of approximately 90 to 230° C. and can be classified as paraffins. naphthenes, olefins, diolefins, monocyclic aromatics, polycyclic aromatics, and organic sulfur, nitrogen,: and oxygen compounds. The technique of Wilzbach has been applied to more than 50 samples. Purification techniques have been developed that accomplish rapid and effective purification as well as removal of labile tritium in a one-step operation. Data are presented to show the rate of exchange between tritium and hydrogen that can be expected for a variety of compounds common to a full-boiling-range gasoline. These values should be useful to other investigators using tracer programs involving tritium labeled compounds.

Jan 1, 1961

By G. E. Bobeck

The first year's work of a proposed three-year study of the effects of the exposure of coal mine roof rocks to the mine atmosphere has been completed. The project has been terminated. The goal of the project was to determine if possible the mechanism or mechanisms by which coal mine roof rocks interact with the mine atmosphere and weaken, and coupled with mechanical stresses, ultimately fail. The scope of the study was limited to the effects of environmental factors on the deterioration of the rocks. While mechanical stresses may play an important role in the interaction of environmental factors, stress effects were excluded from the study. In order to study the effects of environment on coal mine roof rocks, samples were obtained from several coal mines in the western states. The rocks forming the roofs of most of the mines visited were shales of varying composition. These shales were subjected to numerous tests to determine how the rocks changed with time after exposure. In addition, the identity of the minerals present in the shales was determined by x-ray diffraction analysis and by thermal analysis as well as by optical microscopy

Jan 1, 1973

By IRENE AITKENS

The emerald is the most costly of all gems , due to the scarcity of flawless stones . This fact gave rise to the ancient axiom , " As rare as an emerald without a flaw . The finer gems not only command the highest prices at all times , but when flawless are considered the most highly prized of all gem stones . George F. Kunz divides emeralds into two distinct classes : " Exceptional specimens , " which bring as much as $ 6,000 a carat ; and " fine- quality specimens , " which bring about $ 1,000 a carat .

Jul 1, 1931