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By G. K. Derby

Five different types of drilling systems were developed under the flexible drill program that was initiated by the Federal Bureau of Mines to protect roof bolter operators. The systems were designed for underground coal mines with seams as low as 30 inches, and with roof bolts longer than the height of the seam opening. Four of the developed systems were true flexible drills; the fifth was a remote-controlled, automatic rod changer concept. Only two of the five firms successfully completed testing requirements under the original contracts: BendixCorp.,4 with a true-flex drill; and Ingersoll-Rand Research, Inc., with the rod changer concept. The Bendix drill was rated best, and the Ingersoll-Rand drill was rated second. Because of the closeness of the ratings and the vast differences in the two development concepts, both systems had sufficient potential to justify further development funding for design updating and testing. Also, both systems warranted consideration for inclusion into other ongoing development projects under both safety and energy directed programs.

Jan 1, 1978

By J. V. Batty

Radioisotopes of selenium (se78) and tellurium (Te123) were successfully employed by the Bureau of Mines as tracers in metallurgical research directed to developing improved methods for volatilizing these elements from low-tenor raw materials. Prior research, guided and controlled by conventional analytical methods, was seriously hampered by inconsistent selenium and tellurium analyses, by the slowness of the conventional chemical methods, and by the poor accountability of these volatile elements in test products. Methods were devised and evaluated for admixing the radioactive tracer with typical raw materials and then following the deportment of the selenium and tellurium by radiometric methods with occasional chemical analysis checks. These techniques were found unusually effective in (1) quantifying the completeness and the rate of volatilization of selenium and tellurium while heating the raw materials at different rates to different temperatures and (2) accurately tracing and quantifying the distribution of minute amounts of these volatile elements in the several products made by high-temperature treatment and in the several units comprising the experimental equipment.

Jan 1, 1962

By J. A. Rowland

Manganese-copper alloys containing 60 percent or more electrolytic manganese exhibit an unusual combination of high vibration damping capacity with good strength properties. Properties of the pure alloys were first studied in the laboratories of the Federal Bureau of Mines and have been described in a series of technical papers1/ published from 1941-49. The unusual characteristics of these manganese-copper alloys attracted the attention of research metallurgists and several additional investigations have also been reported in the literature.2/ The engineer, also, was attracted by the combination of high strength and high vibrational damping capacity possessed by these alloys. A wide field of application in structural and machine design was obvious. However, serious difficulties encountered in commercial fabrication of structural or machine components from the alloys retarded attempts at their practical utilization. For this reason the Federal Bureau of Mines, in cooperation with the United States Navy, Bureau of Ships, undertook a program designed to develop practical methods for fabricating a selected group of the high-damping alloys. It is the purpose of this paper to summarize a part of that investigation in a form suitable for use by the metallurgist interested in commercial fabrication of the alloys.

Jan 1, 1955

By Motohisa Kanda

The time and amplitude statistics necessary to adequately describe electromagnetic (EM) noise in mines are illustrated through computer software techniques. They are 1) Allan Variance Analyses (AVA), 2) Interpulse Spacing Distributions (ISD), 3) Pulse Duration Distributions (PDD), 4) Average Crossing Rates (ACR) , and 5) Amplitude Probability Distributions (APD) . These statistics are illustrated using data taken from a rather large store of raw analog data recorded in operational mines. The curves generated for the illustrations characterize the noise environment in the mines from which the corresponding data were taken, and should aid in the design of reliable communication systems for such mines.

By Raymond L. Carpenter

The thermal conductivity, electrical resistivity, and Seebeck coefficient for nine compounds, based on the formula for enargite Cu3AsS3, were measured in a search for efficient materials to be used in thermoelectric generators or refrigerators. Results indicate that one of these compounds, Cu3SbSe4, has thermoelectric properties approaching those of bismuth telluride. An investigation of the effect of adding small quantities of tellurium to Cu3SbSe4 and Cu3SbS4 in order to improve their properties also was made. A figure of merit of 2.1 x 10-4 °C-1 was obtained for Cu3SbSe4 + 0.1 percent tellurium.

Jan 1, 1963

By George H. Schnakenberg

This Bureau of Mines publication describes a passive personal sampling device for N02 in air, developed by the New York University Medical Center under Bureau Grant G0133066. The sampler has been successfully demonstrated in the field and in the laboratory. In corroborative laboratory trials the agreement with reference method is excellent. The overall accuracy is approximately ±5 pct of reading to a precision of about ±l pct. All evidence indicates that these samplers should indicate the time-weighted-average N02 concentration to the above accuracy and precision equally well in the field since effects of wind velocity and relative humidity are negligible and the effects of temperature are about 0.1 pct per °F. The duration of exposure and the approximate temperature are the only data that need to be collected in the field. A two-step analysis procedure in field or service laboratory is then used to obtain the total cumulated exposure to N02 in parts per million-hours (ppm times hours), which can be converted to the time-weighted-average concentration of N02 in ppm by dividing cumulated exposure by the duration of the exposure.

Jan 1, 1976

By Harry Freund, Kenneth H. Hammill, Francis C. Bissonnette

"Gallic acid is a sensitive, stable, colorimetric reagent for the determination of tantalum in the range of 2 to 40 µ g.Ta/ml. The method consists of the fusion of tantalum oxide with potassium pyrosulfate and solution of the cooled melt in saturated ammonium oxalate, followed by development of a yellow complex with an ethanolic solution of gallic acid. The tantalum-gallic acid complex absorbs over a broad region in the blue and near ultraviolet. Adverse effects due to interfering ions and solution conditions, such as oxalate concentration and pH, can be minimized by a suitable choice of wave length.by a suitable choice of wave length.A new and sensitive colorimetric method is provided that has been used successfully at the Northwest Electrodevelopment Laboratory of the Federal Bureau of Mines for determining minor amounts of tantalum.INTRODUCTIONThe development of corrosion-resistant alloys at the Northwest Electrodevelopment Laboratory prompted a review of the analytical chemistry of columbium (niobium) and tantahnn. Not only are these elements difficult to determine in small amounts, but tantalum especially lacks both sensitive and characteristic color reactions. Various phenolic compounds have been suggested as colorimetric reagents for tantalum, Quentin and Wagner (10, p. 24B) 1/ recommend the use of tannin. The use of pyrogallol was suggested originally by Krivoshlykov (6, pp. 59-60), whose method recently has been subject to a number of modifications (3, pp. 249-254; 5, pp. 1340-1344; 1, pp. 1803-18oi; 4, pp. 345-350). The yellow coloration produced by pyrocatechol in an oxalate solution containing tantalum may also be used to estimate tantalum ( 11, pp, ll-1-4-148) . The use of hydrogen peroxide has been recommended also (7, pp. 164-165; 9, pp. 926-931).Aside from a lack of specificity and sensitivity, the major failing of phenolic reagents is their susceptibility to air oxidation. The oxidation products are highly colored and absorb in the same spectral region as the tantalum complex. Holding reductants are not completely satisfactory in minimizing this effect. Increasing the acidity, while retarding the oxidation, has an adverse effect on the tantalum sensitivity."

Sep 1, 1956

By Theodore Kootz

Manufacture of high-grade ferromanganese; as a rule; requires a low-phosphorus-manganese ore with 45 to 55 percent Mn, chiefly obtained in the Soviet Union, the British Dominions, and Brazil. Also, low-manganese ores have already been used for ferromanganese production, especially in North America .and Germany. During World War I, a process was developed in which a high-phosphorus ferromanganese or spiegeleisen was prepared in the blast furnace from law- or high-phosphorus manganiferous ores, then low-phosphorus manganese slag was prepared by refining under an acid slag, and this material was, worked into a low-phosphorus ferromanganese in the blast furnace.9/ Manufacture of useful manganese ores from a phosphorus-bearing spiegel with 12 to. 15 percent Mn, 4.5 percent C,, and 0.5 percent P by slagging in a refining furnace was reported by Joseph, Barrett, and Wood.10/ The spiegel was refined to 0.75 percent Mn, 3.4 percent C, and 0.45 percent P. Thereby, a slag with about 43 to 58 percent Mn and, about 10 percent Si02, was obtained. Hotter melts gave a smaller phosphorus content in the slag than cold melts. In addition, the phosphorus content of the slag varied with the manganese content of the intermediate metal.

Jan 1, 1952

By Ralph H. Espach

The value of careful fractionation in the manufacture of petroleum products is recognized more and more by petroleum refiners. Recent studies have shown that the quality of the products depends largely on the type of fractionating equipment and on the care used in operating the equipment. For example Rue3 has shown that careful fractionation of pressure distillate will greatly reduce the amount of chemical treatment necessary to produce finished gasoline. The advantages of the combination of pipe still and bubble tower in obtaining good fractionation are well recognized in the petroleum industry. However, the equipment designed in the past has in general been much too large for convenient laboratory use. The present paper describes a continuous-distillation apparatus for the laboratory study of fractionation. This apparatus has given very satisfactory results in the study of different crude oils and petroleum products. A discussion of the theory and action of bubble towers has not been given, as this subject has been discussed previously by Cooke and Rue4. It is believed that the distillation curves of the products obtained from this apparatus show clearly its capabilities.

Jan 1, 1928

By George A. Savanick

Coal mine roof shales fracture preferentially at slickensided surfaces because of weak or nonexistent adhesion between two slickensided rock surfaces. The purpose of this Bureau of Mines research was to characterize chemically the thin film of smooth, glossy material that makes up the slickenside. This material was analyzed by electron spectroscopy and ion scattering spectrometry while in place on the rock surface and by standard methods of quantitative chemical analysis on concentrate removed from the rock. These analyses showed that the chemistry and mineralogy of the slickensides are similar to that of the adjacent shale.

Jan 1, 1974

By M. E. Poad, J. K. Whyatt, T. J. Williams

Researchers at the U.S. Bureau of Mimes monitored rock mass response to mining of an experimental underhand longwall stope in Hecla Mining Co.'s Lucky Friday Mine, Mullan, ID. This stope design, the Lucky Friday underhand longwall (LFUL), was proposed as a means of controlling rock bursting while also allowing increased mechanization of mining operations. Instruments were specifically manufactured to monitor three geomechanical factors (backfill performance, ramp stability, and rock mass response) that directly affect the success of stope design. Despite considerable difficulties with instrument installation and survival in the harsh mine environment, especially within the stope fill, sufficient information was collected to suggest that the LFUL method was successful in achieving project goals. This conclusion, in addition to favorable economic and operational evidence, led the mine to adopt the method throughout the mine. Indeed, this study and mining experience suggest that underhand longwall mining could be considered a feasible mining method for rock-burst-prone ground throughout the Coeur d'Alene District. Further Reports of Investigations (RI) in this series present in-depth analyses of the effects of backfill on rock bursting and calibration of a stope numerical model.

Jan 1, 1992

By M. R. Geer

Efforts to evaluate washery performance are nearly as old as the art of coal cleaning, and in former years there was no uniformity in either the methods used or the basic terminology employed. This situation, and the con- fusion it bred, prevailed until about the time of the First International Coal Preparation Conference in 1950, Largely because of the interest of the French coal research organization Cerchar, the subject of evaluating performance was given prime importance at this conference. As a result, there is now a much greater degree of uniformity in terminology and methods of expressing cleaning results. The International Standards Organization currently is working toward international standards of terminology and methods that should improve the situation even more. The various criteria that are used to evaluate the performance of coal- cleaning equipment fall into three categories, depending upon the extent to which they are dependent on the density composition of the raw coal; some are directly dependent, others are only indirectly dependent, and still others are substantially indenpendent.

Jan 1, 1962

By Gerald A. Muson, Fremont F. Clarke

"INTRODUCTION The use of scrap mica as an industrial raw material has grown rapidly during the past two decades. Demands by various industries for ground mica for use in the roofing, paint, rubber, plastics, and wallpaper trades as well as for less extensive uses in insulation, oil-well drilling, welding, pipeline enamel, decorative material, and for other purposes exceed present (1947) supplies.A small proportion of the raw material used comes from the Black Hills of South Dakota, where casual recovery has been practiced in the exploitation of pegnatite deposits for more valuable minerals. The annual production of scrap mica in the Black Hills for the years 1939 to 1946 is shown in figure 19. 4/Although small, this production of scrap mica materially augments the incomes of numerous operators.Volume production of mica would offer attractive opportunities for obtaining steady and more economical supplies of the rare minerals as byproducts. Appreciable supplies of beryl, lithia minerals, sheet mica, tantalite-columbite, and cassiterite could accrue. Furthermore, a stable scrap-mica production would complement the production of quality feldspar, for which the Black Hills pegmatites are noted, and would help balance the economy of pegmatite mineral production.Mechanical methods of separation are requisite to production of enough scrap mica to be generally profitable. Various phases of the characteristics end treatment of mica have been investigated by the Bureau of Mines. A bibliography of these reports is appended.In 1945 the Bureau of Mines conducted pilot-plant tests to recover scrap mica by selective screening of crushed pegmatite. More recently the problem has boon studied in the Pegmatite Research Laboratory to aid in developing technological methods by which scrap mica may be separated from crushed pegmatite."

Feb 1, 1949

The following is a Maintainability Design Checklist for coal mining equipment. The purpose of the checklist is to provide a summary of design review points for the maintainability assessment of new or existing underground equipment. It specifically focuses on the identification of equipment design features, tasks, or procedures that impact equipment downtime, repair costs, labor hours and maintainer skill level requirements. Some checklist points are general in nature. The checklist was designed to be used across all categories of underground equipment. The intent is to draw attention to design features and maintenance procedures that will increase maintainability requirements. You are encouraged to adapt this checklist to site specific or machine specific requirements by: Inserting specific performance criteria for various categories of maintenance tasks. For example; all hydraulic lines on a shuttle car should be replaceable in 15 minutes or 25 minutes, etc. Adding or deleting checklist items for different categories of equipment. You would include environmental control equipment, for example, on face equipment and not on shuttle cars or man trips. Adding additional checklist items based on site or equipment specific maintenance histories or experience, company maintenance standards, or other factors.

Jan 1, 2000

The following is a Maintainability Design Checklist for coal mining equipment. The purpose of the checklist is to provide a summary of design review points for the maintainability assessment of new or existing underground equipment. It specifically focuses on the identification of equipment design features, tasks, or procedures that impact equipment downtime, repair costs, labor hours and maintainer skill level requirements. Some checklist points are general in nature. The checklist was designed to be used across all categories of underground equipment. The intent is to draw attention to design features and maintenance procedures that will increase maintainability requirements. You are encouraged to adapt this checklist to site specific or machine specific requirements by: ? Inserting specific performance criteria for various categories of maintenance tasks. For example; all hydraulic lines on a shuttle car should be replaceable in 15 minutes or 25 minutes, etc. ? Adding or deleting checklist items for different categories of equipment. You would include environmental control equipment, for example, on face equipment and not on shuttle cars or man trips. ? Adding additional checklist items based on site or equipment specific maintenance histories or experience, company maintenance standards, or other factors.

Jan 1, 2000

By Eugene T. Sheridan

This report presents data on individual plants of the fuel-briquet and packaged-fuel industries that were circularized by the Bureau of Mines, United States Department of the Interior, in its annual survey for 1958. Only plants that processed fuels of mineral origin were included; specifically, plants that manufactured briquets from charcoal were excluded. Fuel briquets and packaged fuel are manufactured by mixing fine-sized fuels with binders and compressing into small individual shapes. Both are used mainly for residential heating in the United States, but they differ considerably in appearance and physical characteristics. Briquets usually are produced as small, pillow-shaped forms, 2 to 4 inches in length, weighing from 2 to 4 ounces. Pack-aged fuel consists of 3-to 4-inch cubes, 6 or 8 of which are wrapped in heavy kraft paper to form a package weighing 10 to 15 pounds. Briquets are made with a water-insoluble binder and are designed for rough handling and outdoor storage, whereas packaged fuel generally is made with a water-soluble binder and must be stored indoors to prevent deterioration. Briquet plants are relatively large and usually are at mines or in dock areas where large quantities of fine-sized fuels accumulate. Packaged-fuel plants are smaller and are used chiefly by retail dealers to convert locally available coal and coke fines into a product that can be burned efficiently in residential beating equipment.

Jan 1, 1959

By Fred N. Kissell

A parachute-type stopping intended for changing the course of mine ventilation air during mine emergencies has been designed and tested. Some production uses are also visualized for metal mines. Preliminary tests in the laboratory and underground indicate that the parachute stopping is a workable concept, but further developmental research is required.

Jan 1, 1975

By W. J. Kroll

The production of beryllium metal and its alloys is one of the most difficult tasks in metallurgy. In this report we shall examine the progress made in this work- in the last 15 years; taking into account the outstanding publications, including; those of the patent literature, and the information obtained during our 20 years? experience with this metal. The difficulties experienced' in producing elementary beryllium derive from the physical nature as well as from the chemical behavior of the metal and its compounds. Its oxygen affinity is about the same as that of calcium and a little higher than that of magnesium. Its chlorine affinity is much lower than that of magnesium, about equal that, of manganese, and little higher than that of aluminum. The sulfur and nitrogen affinity is probably almost the same as that of calcium for these elements, and beryllium carbide is probably more stable than aluminum carbide, A14C3. The intermetallic affinity of beryllium may be given in descending order, as follows: Nickel - copper - iron. It forms eutectics with -aluminum and silicon as well as with silver. It does not alloy with magnesium and only partly with calcium. Its oxide melts at 2,570° C., but CaO and BaO form readily fusible eutectics with BeO(65).3/ No igneous solvents are known for BeO, which behaves id this regard like Mgo. The beryllium silicate is a strong compound, the aluminete much less so; however, CaO easily displaces Be in the heated mixtures. The Anhydrous chloride hydrolyzes, and it cannot be made from aqueous liquors. It sublimes at 488° C, and melts at 405° C., The fluoride, which, is very Soluble in water, hydrolyzes also, but a kind of oxyfluoride of the approximate formula 2 BeO?5 BeF2 can be made from solutions by dessication. The fluoride melts at 800° C, and boils above 1,100° C. It forms very stable double fluorides with alkalifluorides, which have very low melting points and are fairly soluble in water. They are more stable than the analogous fluosilicates and the sodium fluoaluminate cryolite.

Jan 1, 1945

By Robert H. Bedford

As a result of the Bureau's general survey of quicksilver deposits in California, the Guadalupe mine area was among those chosen for exploration. Exploration, such as that at the Guadalupe, was aimed primarily at maintaining or increasing production of quicksilver during the critical wartime period. The project as originally planned contemplated sampling the dumps and prospecting some promising surface exposures by bulldozer trenches. Salvage was the objective in the first case and new ore in the second. Later, a program. of diamond drilling was added, designed to add both to ore reserves and to geological information. This report summarizes the history, notes the location and physical features, mentions property and ownership, and presents a brief description of the mine. The geology is outlined, and the work done by the Bureau of Mines is explained and supplemented with accompanying maps. The work involved repairing 1-1/4 miles of roads; bulldozing 13 trenches by removing 2,345 cubic yards of dumps to provide for sampling; digging and sampling 9,284 linear feet of hand trenches, digging and sampling numerous test pits; and drilling 7 diamond-drill holes, totaling 1,000 feet. A total of 419 samples, including 10 percent check samples, were taken. Exploration work in California at the time of this project was under the direction of Spangler Ricker, supervising engineer of the California field office, the late Robert Bedford was in charge of the fieldwork on this project.

Jan 1, 1950

By Hanns J. Billmayer

This report, which covers the period from April 1975 to November 1975, describes the work performed in compliance with the requirements of Contract No. H0357091. The purpose of this contract was the development of protective canopy concepts applicable to rail haulage equipment used in underground coal mines.

Jan 1, 1976