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By Loren R. Anderson

A probabilistic slope stability computer model was developed at Utah State University and independently evaluated by CH2M Hill Consulting Engineers as a design and analysis tool. Volume I of this report describes the model and Volumes III and IV are users manuals for the computer programs. This volume (Volume II) constitutes the report by the CH2M Hill. It includes a description of a field investigation and stability analysis of an existing tailings dam. Based on the results of the analysis, the tailings dam was evaluated for redesign using probabilistic considerations. Conclusions are made regarding the usefulness of the model as a design tool.

Jan 1, 1982

By Walter B. Lenhart

This paper is one of a series on milling methods and costs being. published by the Bureau of Mines. The milling practices and special problems relating to grinding, tailings disposal, and choice of a treatment process at the Cardinal mill are discussed. The property of the Cardinal Gold Mining Co. is about 18 miles southwest of the town of Bishop, Inyo County, Calif., at an altitude of approximately 8,500 feet. The camp has been designated Bishop Creek by the postal authorities. The property comprises 33 mining claims, including fractions and millsite in sections 19, 20, 29, and 30, T. 8 S., R. 31 E. These claims are located in a general way along the strike of a band of quartzite.

Jan 1, 1938

By Clarke E. Schuetze

This project had as its objective the experimental investigation of water capsule production utilizing the Southwest Research Institute's submerged nozzle encapsulation apparatus (U.S. Patent 3,389,194). Initial efforts on this project involved nozzle configuration and shell formulation optimization. The shell formulation developed on a prior program was modified during the course of the project to obtain the best balance of capsule breakage resistance and water retention. Subsequent effort centered on determining operating conditions which would produce the best quality capsules for each candidate shell formulation as determined by laboratory tests. Some preliminary work was done to increase the production capacity of the encapsulation equipment. The program was extended with major emphasis concerned with scale-up studies of capsule production capacity and the treatment of problems associated with grouting cartridge fabrication. During the course of the program, water-containing capsules were produced which have good long-term water retention, block resistance and adequate strength. Using a single-nozzle design, a production capacity of 15.9kg (35 pounds) per hour was demonstrated to give acceptable capsules based on initial results.

Jan 1, 1978

By W. W. Scott

Measurements of the absolute value of electromagnetic noise and attenuation along a hoist rope were made in an operating hard-rock mine, Lucky Friday Mine, located near Wallace, Idaho. Spectra of electromagnetic noise generated by various pieces of equipment, spectra of specific noise signals at various depths, and noise and attenuation on the 4250 foot (1295 meter) hoist, were measured. Three techniques were used to make the measurements. First, noise was measured over the entire electromagnetic spectrum of interest for brief time periods. Data were recorded using broadband analog magnetic tape for later transformation to spectral plots. Second, noise amplitudes were recorded at several discrete frequencies for a sufficient amount of time to provide data for amplitude probability distributions. A third technique gave attenuation data through the direct measurement of field strength at various depths. The specific measured results are given in a number of spectral plots, amplitude probability distribution plots and amplitude curves as a function of depth.

Jan 1, 1974

By C. E. Wood

A special appropriation made by Congress in July 1940 provided funds for the investigation of methods for recovering manganese from low-grade [ ] domestic deposits. These funds were assigned to the United States Department of the Interior, Bureau of Mines. A committee, identified as the Technologic Committee on Manganese of the National Research Council, National Academy of Sciences, was appointed to recommend the allocation of the funds for investigation of the more promising projects.

Jan 1, 1942

By C. E. Wood

A special appropriation made by Congress in July 1940 provided funds for the investigation of methods for recovering manganese from low-grade [ ] domestic deposits. These funds were assigned to the United States Department of the Interior, Bureau of Mines. A committee, identified as the Technologic Committee on manganese of the National Research Council, National Academy of Sciences, was appointed to recommend the allocation of the funds for investigation of the more promising projects.

Jan 1, 1942

By Joel N. Van Sant

An investigation was conducted to study possible sources of Utah refractory and structural clays that could be used for the manufacture of refractories and light or buff burning heavy-clay products. A field study was made and the clay samples tested to determine their firing characteristics. Results of the Bureau's work indicate many small noncommercial deposits of hypogenic clay occur in igneous rocks. Commercial hypogenic deposits are mostly halloysite clay developed by hydrothermal replacement of limestone. The high firing shrinkage of halloysite precludes its use as a refractory, however, halloysite produced at the Dragon Mine south of Eureka, is used for making oil catalysts. Clays and shales suitable for low heat duty refractory products are found in the Manning Canyon shale, in shales associated with coal bearing rocks, and in the Dakota formation. Some of the clays from the Dakota formation are also suitable for high-duty refractory products.

Jan 1, 1964

By L. Cheng

This report presents the results of a Bureau of Mines laboratory investigation of the effect of water sprays in reducing respirable dust that escaped the face area of a full-scale wooden model of a mine en-try containing a wooden model of a ripper-type continuous mining machine and exhaust brattice. Areas examined were (a) the general effectiveness of a low-pressure water spray system mounted on top of the mining machine boom, a high-pressure spray system mounted under the boom, and the combined top-and bottom-spray systems, and (b) the effect of these three spray systems on the capture of coal dust particles of different sizes. Dust was injected into a sump cavity at the face. Airborne respirable dust concentration was mea-sured behind the brattice with a personal sampler and cyclone, and particle size distribution was mea-sured with a cascade impactor. When used alone, the top-spray system captured about 55 pct of the respirable dust in the face area and the bottom-spray system captured 60 pct; the capture efficiency of each system is decreased when they are used simultaneously. From a mass-concentration viewpoint, each spray system preferentially captures larger dust particles.

Jan 1, 1988

By Mark Davis

As a follow-on to previous investigations, reduced treatment levels for the optimum fire retardant/preservative system were evaluated. An impregnation of 3.5 lbs/ft3 of Fyreprufe followed by 3.5 mils of Albi 107A plus an Albi 144 top coat provides adequate flammability and flame spread protection. However, there is a significant loss in compressive strength at this retention level, particularly parallel to the grain. A pilot-size pressure impregnation cell was installed for use in treating larger quantities of wood. Based on the optimum fire retardant/preservative treatment system - Fyreprufe/ACC impregnation followed by Albi 107A/144 intumescent paint - a model treatment pro¬cess was developed, capable of handling 3 million board feet per year. Associated annualized costs per thousand board feet (K bd. ft.) for treating 12" x 12" timber were calculated to be: Impregnation: $-63.00/K bd. ft. Coating: $112.00/K bd. ft. A literature search was conducted to identify materials and techniques suitable for a localized stench warning system for heated mine timbers. Based on this review, a number of stench warning concepts were developed. Those based on surface coating were given a preliminary laboratory evaluation.

Jan 1, 1982

By Raymond M. Stateham

Infrared and displacement studies were made of an unsupported roof in Kaiser Steel Corp.'s York Canyon coal mine, Raton, N. Mex. Monitoring of the roof continued until the roof over the area was caved. Loose slabs in the roof, about 6 inches thick, were detected by means of associated thermal anomalies, using remote-sensing infrared instruments. Displacement measurements taken during the study indicate that roof movement was cyclic in nature; the cycles appear to have been related to the mine work cycle (work days to idle days).

Jan 1, 1974

By Warren E. Morrison

INCREASED production and utilization of minerals fuels and power accompanied the overall expansion in U.S. economic activity during 1963, which saw continued advances toward higher production, employment, and purchasing power. During 1963, record levels of wages, profits, and consumption were attained, while costs and prices maintained the stability exhibited throughout most of the recovery period. Expanding industrial production, the average index of which went from 118.3 in 1962 to 124.3 in 1963, narrowed the gap of unused manufacturing capacity to an estimated 5 percent. Gross national product (GNP), another major indicator of economic activity, reached a record level of $583.9 million (current dollars) during the year, this being $27.7 billion, or 4.9 percent above 1962. These achievements were somewhat marred by unemployment, which remained at 5.5 percent of the labor force in 1963, and the continued deficit in the U.S. balance of payments. Against this general background, total national consumption of energy resources for the year was equivalent to 49,816 trillion British thermal units (Btu), an increase of 4.2 percent over 1962. This represented a somewhat lower rate of growth than for GNP during the year.

Jan 1, 1964

By Robert F. Stewart

The oxidation of structural materials at high temperatures in gas-cooled systems can be greatly retarded by the addition of small amounts of hydrogen to the inert coolant. In experimental equipment for gasifying coal with heat transferred by helium, the oxidation of graphite and metals (molybdenum, tungsten, and certain stainless steels) by trace impurities in the coolant helium was virtually eliminated by adding 0.1 to 1.0 percent hydrogen. The reaction of hydrogen with praphite does not preclude its use to retard oxidation; at 2,400° F. only 0.2 pound of graphite per square foot per year is lost for each percent of hydrogen in the helium. The addition of hydrogen appeared to prevent the mass transfer of carbon often associated with oxidation of graphite, without causing noticeable embrittlement of stainless steels and molybdenum or other damaging effects. This method has been tested in precision gas-recycle systems and applied successfully for more than a year in a pilot-scale unit operating at 250 pounds per square inch gage and 2,400° F. It is now used routinely and can be applied to many gas-cooled systems operating at high temperatures.

Jan 1, 1962

By D. E. Traut

A fluidized countercurrent ion-exchange system was developed, operated, and evaluated by the U.S. Department of the Interior, Bureau of Mines. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows were continuous except for short periods when resin increments were withdrawn. The exchange of uranyl carbonate between a simulated in situ uranium leach liquor and a strong-base ion-exchange resin together with the subsequent elution with an ammonium chloride solution was studied. The effects of the number of sections, section height, amount of resin withdrawal, solution flow rate, and column diameter were investigated. The kinetic and equilibrium relationships for the absorption and elution steps were also examined. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable in the absorption process, while resin residence time is the determining factor in the elution process. The column was efficient over a range of conditions, but close control was needed for optimum operation.

Jan 1, 1978

By Leslie S. Rubin

A ventilated helical boost pump was developed that can handle varying flow rates and/or solids concentrations while operating at a single rotational speed and without computer assisted feedback controls. The boost pump developed and briefly tested during this program was designed to accomodate flows suitable for a 3-in. diameter pipeline. The boost pump's ventilated design provides the automatic pressure regulation needed to meet the system's requirements for supporting transient pipeline flow.

Jan 1, 1984

By George T. Faust

The petrographer engaged in examining the products resulting from the beneficiation of ores and rock minerals is constantly required to develop new means and methods of assaying microscopically the results of such operations. From time to time investigators have published descriptions of apparatus that have aided in solving problems in processes f physical separation. Thus, in 191.9, Coghill and Bonardi 31 published a paper covering the application of the binocular microscope and camera lucida to the microscopic analysis of pulverized ores. Similar work has been published by Schneiderhohn 4/, Schwartz 5/, and Head and his associates6/, 7/, 8/. The present paper goes further and considers application of the polarizing comparison-microscope to problems directly concerned with mineral dressing where it is desirable to compare analogous products, and in addition it suggests new uses in various related fields. This work was conducted under the cooperative agreements of the Southern Experiment Station of the Federal Bureau of Mines and. the University of Alabama.

Jan 1, 1940

This is the sixth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the Department of the Interior. The first report gave data on motor gasolines sold during the winter of 1935-36.3/ The present report covers 54 brands of gasoline represented by 1,480 samples plus those from the Pacific Coast, which were averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were submitted. In some areas reports were received from 8 to 10 companies on the same brands of gasoline, whereas in other areas only one company reported on a brand. Thus, it can be seen that some of the data are more representative than others. The inclusion of data from several cities within some of the districts has improved the report by reducing the number of brands reported by only one company. Several changes have been made in the districts. A new district, Memphis, Tenn., has been formed to include Arkansas and western Tennessee. The Rocky Mountain areas have been divided into three sections. Salt Lake City and Denver form the Middle Rocky Mountain district; Laramie, Wyo., Idaho, Montana, and Spokane, Wash., are included in the North Rocky Mountain district, and Arizona, New Mexico, and El Paso, Tex., have been combined to represent the South Rocky Mountain district. The Cleveland district has been expanded to include Ohio an,"- Indiana. Eastern Pennsylvania, Maryland, and northern Virginia are included in the Washington (D. C.) district. The Atlanta district includes Georgia, South Carolina; Mississippi, and northern Florida.

Jan 1, 1938

By J. T. McLendon

As part of its research project in developing improved refractory materials for metallurgical applications, the Federal Bureau of Mines obtained hot modulus of rupture data at 1,500°,1,550°, and 1,600° C on samples of 13 refractory periclase materials produced from seawater, lake brines, and natural magnesite. The periclase samples also were characterized to establish chemical and mineralogical composition and microstructure. The results indicated that a high MgO content does not necessarily assure good hot strength and that an optimum and varying CaO-Si02 ratio exists for each individual periclase sample.

Jan 1, 1979

By J. K. Whyatt

The U.S. Bureau of Mines conducted an overcore stress measurement on the 5300 level of the Lucky Friday Mine, Mullan, ID, to investigate the stress regime around an experimental stope in a rock-burst-prone mine. The result indicated a stress field with unexpected magnitude and orientation [s 1 ?135 MPa (19,600 psi) oriented S 80° W). An unusual amount of rock-burst activity was encountered during subsequent excavation. A careful review of the overcore data suggested the overcore strain measurements were valid. Moreover, concentrated rock-burst activity suggested that the measured stress field did exist, but was localized and therefore did not represent the far-field in situ stress field.

Jan 1, 2010

By George A. Savanick

The objective of this research is to develop a method for measuring the tensile strength at the interface between minerals in rock. These measurements reflect the strength of the attractive forces operating at crystalline interfaces in rock. Since these forces act in opposition to the forces set up in various rock fragmentation processes, measuring their strength may help in designing more efficient methods of rock fragmentation. The method developed for measuring the strength of intergranular adhesion in rock involves separating a bicrystal from the rock and determining the tensile strength at its solid-solid interface. This technique has been successfully applied to the study of quartz-feldspar interfaces separated from massive pegmatites, graphic granite, and the Rockville granite, yielding average tensile strengths of 5.86, 8.62, and 10.65 meganewtons per meter squared (MN/m2) (850, 1,250, and 1,524 psi, respectively). The data this technique provides indicate that the members of these bicrystals are strongly adherent. Examirtation of bicrystals broken at the crystalline interfaces indicates that the bonds responsible for this adhesion operate over only a portion of the interfacial area. This work conclusively demonstrates that tensile strength tests can be conducted on small selected areas; for example, grain boundaries in rock. The small-scale zones of strength or weakness determined in this way can be related to the overall strength of the rock.

Jan 1, 1972

By Robert E. Barieau

In the design of plants to separate helium from natural gas , it is necessary to estimate the enthalpies of the various streams at various positions in the process . This Bureau of Mines report surveys the various methods that have been used to determine enthalpies and gives information on the organizations with such capabilities . The minimum information required for developing an enthalpy diagram is presented , and the relative merits of the various methods are discussed . It is concluded that methods that require no mass flow rate or energy measurements are to be preferred .

Jan 1, 1965