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By F. W. Hoertel

The Bureau of Mines investigated the use of depleted uranium as a sacrificial anode for the cathodic protection of submerged and underground structures of iron , steel , and copper . Uranium-metal couples were tested in simulated marine environments of varying oxygen contents at pH values between 5.5 and 8.5 and under simulated boiler service condition in Rolla , Mo. , city water . Similar couples were tested in samples of Missouri soils to simulate underground service . Uranium remained anodic to iron , steel , and copper in the simulated marine environments and under simulated boiler service if the electrolyte was oxygen- free city water . Uranium appeared to offer limited protection to iron , low- carbon steel , stainless steel , copper , and zinc in the simulated underground tests . Uranium anodes offer a space advantage because 1 cubic inch of uranium gives approximately the same protection as 2 cubic inches of magnesium or 1-1 /2 cubic inches of zinc .

Jan 1, 1963

By V. H. Gottschalk

Among the procedures developed by the Germans for providing the tonnage of iron powder needed to make rotating bands for artillery shells is the use of a ceramic tunnel kiln, not only for finishing the reduction of centrifugal powders but also for making so-called "brickyard sponge iron," which, after crushing and grinding, seems to yield a product suitable for powder-metallur- gical purposes. The final report issued jointly by the German Powder-Metallurgical Society (DPG) and the Chemical-Metallurgical Branch of the Research Depart- ment of the Metallgesellschaft, Inc. (ZFC of MG) gives the available details of this procedure, which may be regarded as a further development of the process in commercial use since 1911 at a ceramic plant in Hoeganaes, Sweden. The Bureau of Mines' wartime development of the Hoeganaes process also cul- minated in the adaptation of ceramic tunnel kilns for carrying out the solid- carbon reduction of iron ores, and comparison with the German technique should further advance the art. This information circular is issued as a supplement to Bureau of Mines reports of investigations Nos. 3819,2 3822, 3841,2 and 4271, on brick- yard sponge iron and is based on four German reports entitled "Making Iron. Powder in the Tunnel Kiln," translated from FIAT microfilm reel H-46, frames 9190-9209, 9280-9299, 9339-9357, and 9377-9384 (PB L 70042), which represent the four original research reports, Nos. 2005, 2008, 2010, and 2012, respec- tively, of the Metallgesellschaft, Inc.

Aug 1, 1948

By Milton H. Fies

To present some idea as to how the Bureau of Mines may most effectively serve mining, it is necessary that we make some resume of its pact accomplishments in order to determine what, if any, changes will be of greatest service to the industry and to the nation. There are a great many times in life when one begins to wonder whether or not Emerson, in his famous epigram about "mousetraps" and "beaten paths" and "final recognition of intrinsic worth", took into account the item of time. The intrinsic value of any movement, of any work, of any accomplishment will ultimately be recognized, of that there is no doubt, but may a man in history has gone to his end in martyrdom because the world was slow in the acknowledgement of the true excellence of his worth, and this is likewise true of institutions.

Jan 1, 1934

By Arnold B. Hubbard

This report presents a hydrogenolysis study undertaken to obtain information on the constitution of the kerogen or organic material in Colorado oil shale and to determine some of the properties of the hydrogenolysis products. The high yield of hydrogenolysis products was separated, so far as possible, into type compounds; a number were identified. The results thus obtained were used as a basis for proposing the possible existence of certain structures in kerogen. To the authors' knowledge, few or no hydrogenolysis studies have been made of Colorado oil-shale kerogen by others. However, this method has been used in studying the constitution of coal. In general, the coal studies involved treating pulverized coal at different temperatures and hydrogen pressures with different catalysts. In some instances different solvents were used during the treatments.

Jan 1, 1959

By D. Harrington

Springing or chambering of deep drill holes is common practice in some quarries. It involves definite hazards from premature explosion during placing of the springing charges or the final charge due chiefly to heating of the bottom of the holes by the successive exploding of the springing charges or, in some instances, from burning of paper or other material following detonation of the explosives The danger is either unknown or disregarded in many instances by those who place the charges in the holes. Disregard of this hazard probably is, at least in part, responsible for the far too high fatality and injury rate due to charging explosives and premature slots in quarry work. Awareness of the danger' should result in elimination or at least of material decrease in injuries from this cause.

Jan 1, 1941

By C. A. Herbert

During the fiscal year ended September 30, 1932, there were 27 fatalities in the coal mines of Indiana. Four of this number occurred in small mines employing less than 10 men, over which the State Inspection Department has no jurisdiction. In addition to these coal mine fatalities, an explosives accident in a clay mine resulted fatally to one man. Tables 1 and 2, which follow, list the fatalities as to cause and occupation. Table 1. - Fatal accidents by cause, fiscal year ended September 30, 1932 [ ]

Jan 1, 1933

By Henry M. Harris, John E. Kelley, Thomas D. Roberts

A penetrometer apparatus for measuring viscosity of glass at temperatures up to 1,450 ° C was developed for use in establishing the viscosity coefficients required for high- temperature forming of ceramic materials . The major advantage of the method is that it can be used with samples of almost any shape or size without the necessity of forming or measuring shapes to close dimensional tolerances . Also , it has proved accurate in the range of 106 to 109 poises , a gap between the normal limits of other methods . The device , which operates on a single penetrometer principle , was used to determine the absolute viscosity coefficient of substances in centimeter - gram- second units of poises instead of relative penetration - rate units as with other penetrometers . Penetration of the viscous sample was sensed with a linear , variable differential transformer . The output of this transformer was recorded versus time , and the penetration rate was used in calculating the viscosity coefficient . The general equation relating penetration rate and viscosity coefficient was found to be 11 = F ( ln L/a 0.72 ) 2 π UL · where is the viscosity coefficient in poises , F is the penetrator load in dynes , L is the penetration depth in centimeters, a is the penetrator radius in centimeters and U is the penetration rate in centimeters per second . The penetrometer was tested using a standard viscosity sample of sodalime - silica glass obtained from the National Bureau of Standards ( NBS ) . Values obtained at several temperatures all agreed within 10 percent with comparable data calculated from the Fulcher equation derived by NBS for this glass . Equivalent accuracy was obtained with other glasses used to evaluate the apparatus .

Jan 1, 1964

By L. H. McGuire, L. B. Berger

"During the period October 31 to November 4, 1944, tests were conducted by the Bureau of Mines in the Cascade Tunnel of the Great Northern Railway Cc. to determine the effects upon the tunnel atmosphere of the use of a Diesel freight locomotive through the tunnel. These tests were conducted at the request of the company to ascertain whether undesirable conditions might be caused by the discharge of Diesel engine exhaust gas in the tunnel, which was constructed for an electric haulage system and is not provided with equipment for mechanical ventilation. The use of Diesel locomotives on the division that includes the Cascade Tunnel was under consideration as a means of augmenting haulage facilities for the abnormal freight tonnage that must be handled during wartime.As the Bureau of Mines has received requests for information on the extent of contamination of the air of railroad tunnels by Diesel locomotives, this report was prepared to make available for general information the data obtained during the tests in the Cascade Tunnel. As the test locomotive is of a type used on other railroads, and as the bore and grade of the tunnel and the tonnages moved are comparable to such factors on other roads, the data should be sufficiently representative to be of general interest. The exceptional length of the Cascade Tunnel made it an excellent location for obtaining information on the composition of the tunnel air and on the movement of air induced in the tunnel by the passage of trains.The writers are indebted to C. O. Jenks, vice president of the Great Northern Railway Co., who arranged for the tests, and to the following personnel of the railroad who cooperated in the conduct of the tests: I. E. Clary, superintendent, Spokane Division, J. L. Robson, superintendent of motive power, oil and gas equipment, J. F. N. Gaynor, superintendent of electric operations, William Lowney, master mechanic, Spokane Division, and D. F. Marston and Verne Nelson, assistant superintendents of electric operations.The Cascade Tunnel is on the Spokane Division of the Great Northern Railway and pierces the Cascade Mountains some 49 miles west of Wenatchee, Wash. The west end of this division is electrified from Appleyard Station, 2 miles east of Wenatchee, to Skykomish, Wash., a distance of 73 miles. Until the described tests, only electric haulage had been employed through the tunnel since it was first opened to traffic in January 1929.The Cascade is the longest railroad tunnel in the United States - 7.79 miles. The tunnel is single-track, perfectly straight, concrete-lined, and is on an essentially uniform grade of 1.56 percent, ascending from west to east. The cross-sectional area of the tunnel is 314 square feet, the dimensions being shown in figure 1. Elevation of the east portal is 2,880 feet and of the west portal, 2,240 feet."

Jun 1, 1946

By Bruce I. Thomas

The Fairbanks mining district forms an arc 40 miles long and 8 miles wide on the north side of the Tanana Valley in central Alaska. This is a region of broad valleys and rounded hills that range in elevation from 600 to 2,600 feet Lode-gold production started in 1910 and has continued sporadically to the present, but the largest single mine produced only 40 tons per 24-hour day. Total recorded lode-gold production of the district is 241,000 fine troy ounces of gold from ore that averaged 1.32 fine ounces per ton. The ore was mined chiefly from narrow veins and veinlets alined along anticlinal folds at Ester Dome and the Pedro Dome-Cleary area. The only proven reserves are reported to be at the Ryan Lode at Ester Dome and at the Keystone Mines, Inc., holdings in the Pedro Dome-Cleary area. An inferred lode-gold resource for the district of approximately 4,000,000 ounces is considered to indicate only the order of magnitude of the lode-gold potential because of the absence of detailed data needed to evaluate the numerous deposits.

Jan 1, 1973

By M. R. Yenchek

The Bureau of Mines conducted research to determine the relationship between cur-rent load and temperature rises in coal mine trailing cables. Six low-voltage, unshielded, portable power cables were continuously and intermittently loaded with direct current of various magnitudes. Temperature rises within and on the cables were measured with thermocouples, and the data were recorded with a computer. Thermal time constants were calculated, which fixed the periods of the duty-cycle tests. Relationships between average temperature at the conductor-insulation interface and current load were established. The steady-state and intermittent currents that produce a 90° C average conductor-insulation temperature were then determined. Comparisons with Insulated Cable Engineers Association (ICE A) steady-state ratings revealed that 10 to 25 pct more current than recommended ICEA ampacities is required to reach rated insulation temperature. Examination of the maximum intermittent temperatures attained showed that autoignition of coal dust and burn injuries to personnel handling the cable would not be concerns if the temperature at the conductor-insulation interface averaged 90° C.

Jan 1, 1988

By J. W. Paul

Mine foremen are employed in coal mines for two reasons: First, so that the underground work. may proceed in an orderly manner and that each employee gives attention to his duties; and second, by reason of the State law which re- quires the employment of such officials to see that the laws relating to safety are carried out. It may be seen that, with these two duties, the foreman has wide scope of authority and much responsibility. As foreman of operations he has to meet certain economic questions that contribute to the cost of producing the coal, and as the agent of the State he must also supervise and coordinate the work in such manner as to insure that the employees work under safe conditions. As the roof of coal mines is the source of the greatest hazard naturally the care of the roof must take much thought and planning on the part of the fore- man; and this circular is therefore presented to call attention to some things he may do to prevent injury to the workmen by falls of the roof material or coal. Mine foremen, in the principal coal-producing States, are certified by a State board which prescribes certain qualifications, experience, and character, attested by examination and personal endorsement. Certified foremen, therefore, are men who have had experience underground and know roof conditions and timber- ing methods. The suggestions herein are based upon observations made at many mines and collectively embrace practices that have been found to be in effect and pro- moted by experienced mine foremen:

Sep 1, 1930

By Charles J. Stehlik

This report deals with the changing behavior of mine roof bolt and roof rock as a result of repetitious production blasting . Observations were made in the upper shale production headings at the White Pine Copper Co. room and pillar mine , White Pine , Mich . Roof bolt compression pads and a stratascope were used in the investigations , which were carried out in three separate test sites in which nearly identical procedure produced comparative , repetitive , and anomalous observations . Results indicate roof bolt tension change and roof quality deterioration anomalies were coincident with blasting . The hypothesized cause of the anomalies is a seismic shock generated by the blasts .

Jan 1, 1964

By J. A. Eisele

The Bureau of Mines conducted bench-scale cyclic tests to determine the composition of recycled leach liquor in the Bureau?s proposed clay/HCl leach/ HCl sparge process for producing Al203 from clay. The data developed from these tests make it possible to synthesize leach liquors for predetermined steady-state operating conditions when conducting large-scale crystallization tests. The results of two sparge tests were compared. One was a 20-cycle test with a 36-pct-HCl concentration in the mother liquor; the other was a 10-cycle test with a 26-pct-HCl concentration in the mother liquor. The effect of impurity concentrations in the leach liquor on the purity of aluminum chloride (AlCl30?6H20) crystals was determined, but there was poor correlation between this data and results that have been obtained from miniplant-scale work.

Jan 1, 1980

By Frederick K. Allgaier

This report presents the final data from a 5-yr Bureau of Mines study designed to determine the surface subsidence characteristics resulting from longwall coal mining in a geologic environment common to the Western United States, It includes a description of the geologic setting of the study site, the mine plan, measurement techniques, and results of the monitoring program. Measured subsidence values were obtained over four adjacent longwall panels- Major subsidence characteristics such as longitudinal and transverse profiles, angles of draw, time-related subsidence development, and critical width are discussed. The maxima subsidence value of 5.8 ft was 68 pct of the mining thickness. The average angle of draw was 30°, Subsidence at the center of the first panel continued for 46 months following undermining. The lengths of the longwall panels precluded a definitive determination of the critical width and maximum possible subsidence.

Jan 1, 1988

By V. R. Miller

The Bureau of Mines investigated methods for testing the tensile and sheer strength of cast specimens of bulk solder and of soldered joints in order to increase the strength and extend the useful temperature range of soft solders. A spread-area test for determining the wettability of solder on copper surfaces was developed. Mannitol was used as a flux in spread tests to control spreading and to avoid plating, etching, and other side effects of regular fluxes. Data on commercial and high-purity solders obtained by these methods show more consistency than those reported by others from similar tests.

Jan 1, 1967

By E. C. Lane

"In a previous paper the Bureau of Mines. 3/ presented in condensed tabular form all analyses of Texas crude oils made by the Bureau up to March 193K. This previous report states;The first Al well in Texas was drilled near Oil Springs, Nacogdoches County, in 1863-67. However, the first oil field of major importance in the State was discovered at Corsicana,Navarro County, in 1895. Since that time the petroleum industry try in the State has spread and grown until today petroleum from Texas is an important commodity in world petroleum markets.Since March 1939 samples of Texas crude oils from many new fields, and some older fields not covered in the previous report, nave been analyzed. Those analyses arc reported in the present paper. The annual production by years from 1896 to 1940, inclusive, taken from the figures in the Bureau of Mines Minerals Yearbook, are given in table 1. Production for 1896-1940, inclusive, totals 6,579,715,000 barrels.Various authors reported upon developments and production in the Texas fields in the Transactions of the American Institute of Mining and Metallurgical Engineers, Petroleum Division, for 1941. 4/"

Apr 1, 1943

By Albert E. Long

To date the commercial diamond bit setters have been principally interested in the speed with which they could produce a sharp, fast-cutting bit. Thus, a premium has been placed on setters who combine a high degree of manual dexterity with the ability quickly to select the Sharp points and edges of the diamonds and set them in the mold without lost motion. The premium on speed does not allow the setters the time, nor are they trained, to consider also the crystallographic structures of the diamonds which are the clues indicating the harder and more suitable working surfaces. Since early fall of 1949, the Bureau of Mines has been conducting a long-range series of experiments in which drill bort have been oriented in diamond bits in an effort to determine the effects and economic practicability of utilizing the hardest surfaces of the diamond crystal structure. The preliminary experiments completed to date indicate that a substantial saving in diamonds may be affected by using the harder areas of the diamonds as working surfaces in the crown of diamond bits. The experimental work is being conducted by the Bureau of Mines in the laboratories and full-scale mine of the Mining Research Branch, Minerals Technology Division, Region VIII, of the U. S. Bureau of Mines at the Mount Weather Station, Bluemont, Va.

Jan 1, 1951

By Charles H. Foreman

This paper describing the mining practice of the Hecla and Star mines, both located at Burke, Idaho, is one of a series being prepared by the Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. It is partly a revision of articles by the author appearing in volume 72 of the Transactions of the American Institute of Mining Engineers, published in 1925, and in the June 1928, issue of the American Mining Congress Journal. About 26,000 tons per month of lead ore is produced at the Hecla mine. Costs at the mine are given for the year 1928. Stoping operations in the Star mine have covered such a short period, during which time the abnormal expenses of starting were incurred, that they are not given in this paper.

Jan 1, 1930

By K. E. Stanfield

One of the initial projects under the oil-shale research and development phase of the Synthetic Liquid Fuels Act, Public- Law 290, 78th Congress, approved April 5, 1944, was a survey of oil shales of the United States for the selection of a site for an oil-shale demonstration plant. The oil shales were assayed by the conventional Bureau of Mines retort method proposed by Karrick and described by Guthrie in a more recent publication. From previous experience and that had in making these assays, it became evident that the assay method should be modified or replaced by a more satisfactory one. There are several outstanding objections to the Bureau of Mines oil-shale assay method: (1) the oil yields are frequently smaller than those obtained by other types of assay equipment and by commercial retorts; (2) the assayed oil yield represents only a portion of the organic matter in the shale, which under more favorable conditions, may, Jae converted, more completely into oil; (3) the retorting procedure is controlled mainly by trial-and-error methods; and (4) the assay requires approximately 6 hours for completion.

Jan 1, 1949

By Jr. Blake

This work was done to determine the technical feasibility of using the Pedersen process to produce cell-grade alumina and an iron byproduct from the high-silica and titania bauxites of the Pacific Northwest. Smelting of these bauxites with lime and coke at about 1,750° C in an electric arc furnace produced calcium aluminate slags in which at least 80 percent of the alumina was leachable by sodium carbonate solution. After a lime-desilication of the sodium aluminate leach liquors, neutralization of these solutions with carbon dioxide resulted in precipitation of an alumina hydrate of sufficient purity for calcination to cell-grade alumina. Recoveries of byproduct iron averaged over 90 percent; however, the iron contained about 1 percent phosphorous and would require additional refining. Additional small scale tests on these slags showed the following: (1) Titania had little effect on leachability if sufficient additional lime was added to form calcium titanate (CaO.TiO 2); (2) a slag containing about 14 percent silica required a slower cooling rate than one containing 7 percent silica for formation of high percentages of soluble aluminates; and (3) high-silica slags leached better at room temperature for long periods than at 65° C for shorter periods, but low-silica slags leached well by either method.

Jan 1, 1967