Search Documents

By F. S. Crawford

It has been said that safety promotion passes through four stages--the band-playing, the machine-guarding, the protective equipment, and finally the educational stage; the last is the most important in the development of the safety program. It has been estimated that only 15 percent of accidents can be pre- vented by machine guarding and protective equipment; the other 85 percent must be stopped by the safety efforts of the individual workers and their supervisory officials, and one of the fundamentals of safety work is the education of workers to develop safety consciousness or safety mindedness. One way of educating men to think about safety is by the use of posters. Safety engineers at the Calumet 2 Hecla mines in Michigan have been conduct- ing a safety contest among the men by the use of posters of an unusual type in addition to those usually employed to illustrate bad practices and to display the number of days without a lost-time accident. The first requisite for the success of the safety poster is a good artist or draftsman; in the poster contest instituted at the Calumet & Hecla mines two sheets were prepared illustrating various conditions in the slope workings, including a large number of unsafe practices. The object of the contest was to get the men to think about safety through criticism of the unsafe conditions displayed on the posters. The following notice accom- panied the posters:

Feb 1, 1935

By E. C. Lane

This report on properties of commercial motor fuels is the twelfth in a series made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the Interior. The first report contained data on motor gasolines sold during the winter of 1935-36.3/ The -present report, covering the summer of 1941, presents analytical data for 1,857 samples, representing the products of approximately 135 companies. -As in previous surveys, these companies include both large and small suppliers. In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted, and these data are published exactly as they were received. Conforming to previous surveys, the data cover three groups of samples -- regular-price, premium-price, and third-grade gasolines -- and each group has been aver aged separately. The number of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, are as follows: Regular price, 1,010 samples, 291 items, and 86 brands; premium price, 577 samples, 263 items, and 78 brands; third-grade gasoline, 270 samples 159 items, and 74 brands. The meanings of these terms as used in the surveys are as follows: Sample: The individual supply of gasoline obtained at the filling station and analyzed in the laboratory.

Jan 1, 1942

By E. J. Murphy

The Bureau of Mines developed a fast, reliable modification of the Griess-Ilosvay procedure suitable for field analysis for NO2 in the fumes from explosives. Known concentrations of NO2-air mixtures were analyzed for the nitrous acid or nitrite formed in the reaction with three Griess-Ilosvay-type reagents by diazotizing and coupling. Comparison was made of the Rider-Mellon, Saltzman, and Patty-Petty procedures; the three procedures are in agreement if sufficient time of contact between NO2 and the reagents is allowed. In experiments to obtain an accurate factor for converting NO2 to nitrite, overnight contact was allowed in order to be sure conversion was complete. The factor was found to be 75 percent with a standard deviation of ±3.2. Low and erratic results were found using either the Saltzman or Patty-Petty reagents as absorbing liquids unless several hours' contact was allowed. If dilute NaOH solution was used as the absorbing liquid instead of a Griess-Ilosvay-type reagent, 92 percent of the overnight conversion factor was found after a 3-minute shaking time and a la-minute standby time. The Saltzman reagent was preferable for fieldwork with the dilute NaOH solution as the absorbent because of its easy application, rapid reaction, and intense color even at low NOB concentrations.

Jan 1, 1967

By G. W. Birge, D. E. Wolfson, J. G. Walters

Seventeen samples were carbonized by the BM -AGA pilot - plant test method and in industrial ovens . Chemical and physical properties of the samples were determined , and the physical properties of the cokes prepared by the two methods were compared . Since the capacity of the plants from which these samples were obtained is about 30 percent of the 1959 total for the United States , the data given in this report are indicative of the chemical and physical properties of blends used to produce industrial cokes and the acceptable chemical and physical properties of the resultant coke .

Jan 1, 1964

By Hal J. Kelly

A picture of the ceramic industrial potential of the Pacific Northwest States is presented by reviewing the present ceramic industries, raw-material resources, and current market demands. A resume is given of the industrial plants manufacturing ceramic ware as well as available information on raw-material resources. No attempt was made to prospect for new deposits but rather to evaluate, insofar as possible, those already known. Since much of the industry is concentrated on the Pacific coast, most of the information available on resources concerns deposits in that area. Large, undeveloped districts in Montana and Idaho, however, offer promise of larger reserves of ceramic raw materials. Average annual production, some operating costs, and annual power consumption are given for each of the plants. Production and some cost figures are listed to show the limited nature of the present industry and to suggest fields open for new development.

Jan 1, 1956

By David E. Siskind

The Bureau of Mines studied environmental blast effects in six occupied residential structures. Airblast, ground, and structure vibrations were measured both inside and outside residences for seven quarry production blasts. Walls and floors responded to the blast noise and vibration by shaking at their own natural frequencies, often with greater peak particle velocities than the ground outside the structures or their foundations. The vibrations of the houses generated noticeable internal noise, correlating with the arrival of the groundborne energy. The later arriving airblast wave was predominantly at low infrasonic frequencies (1.0 to 1.5 Hz) and had similar amplitude and frequency characteristics both inside and out-side the structures. Significant structural motions resulted from the air-blast overpressures for at least two of the seven blasts. The most severe airblast effect occurred at a house 1,800 feet from a 5,047-pound (200-lb/ delay) blast. This stucture was subjected to a peak 0.16-in/sec particle velocity and 130 dB(L) airblast. The wall of the second floor responded to the ground vibration and airblast by shaking at particle velocities of 0.15 and 0.28 in/sec, respectively. Analysis of these data and those from additional field studies will be used to identify appropriate, safe, and reasonable impulsive noise levels, measurement techniques, and factors of design applicable to minimizing the adverse environmental effects of blasting.

Jan 1, 1976

By Edward W. Parsons

To determine in what part and to what extent creep or movement exists in an installed rock-bolt anchor and the effect of the creep or bleedoff on the tension load on a rock bolt, as well as the effect of normal mining activity on the rock-bolt load and anchor, the Bureau of Mines conducted tests in the laboratory and in two mines using four types of expansion-shell anchors, the wedge bolt, and in one mine, explosive-anchored rock bolts. Specially mounted heavy-duty springs, calibrated to obtain load readings from spring movement, were installed on the test bolts to prevent a drastic reduction in tension load caused by slipping or seating of the anchor. A dial gage, reading to 0.0001 inch, measured movement of the anchor shell against the rock and seating of the anchor wedge plug in the shell. While all bolts had electrical resistance strain gages for load reading, only readings from the laboratory tests were used because those from the field tests were erratic. The tests revealed that most load loss resulting from static loading is due to the slippage and seating of the serrations on the anchor shell into the drill-hole wall. Dynamic loading, primarily from sudden shocks from nearby blasting, and possibly from ground movement or mining activity, will cause the anchor wedge plug to seat in the anchor shell.

Jan 1, 1969

By Brian R. Zelenka

The Bureau of Mines (Bureau) reviewed all available information regarding geologic and depositional processes contributing to potential coastal and offshore platinum group metal (PGM) placer deposits around the Goodnews Bay Mining District. The Bureau found that favorable environments for PGM along with gold and chromite enrichment include: (1) buried paleofluvial channels; (2) recent paleofluvial channels with little marine sediment overburden, (3) beach deposits, particularly in the upper swash zone and near back beach environments; (4) paleostrand lines; (5) shoal lag deposits inside the mouths of Goodnews and Chagvan bays; and (6) bases of far offshore tidal ridges which may represent reworked glacial deposits. Limited geologic and compositional (assay) data prevent determination of deposit size and grade of PGM mineralization for each deposit class. Future geologic sampling requirements for demonstration of identifiable offshore and beach PGM-bearing placers are discussed. Beach and offshore sampling programs conducted by the Bureau in 1986 will contribute additional information providing verification of specific deposit classes.

Jan 1, 2011

By Lito C. Mejia

Diesel-powered equipment operating in a gassy underground mine could conceivably ingest a methane-air mixture from the mine atmosphere that could cause the diesel engine to overspeed, or exceed its rated speed. Engine overspeed, particularly if extreme (engine runaway), could result in personal injury, a possible mine explosion, and/or catastrophic engine failure. In this report, the Bureau of Mines reviews the literature on the potential hazards of methane-induced diesel engine overspeed. Also included are the Bureau's findings from consultations with representatives of the diesel engine industry to determine the specific engine behavior that could he expected under the overspeed condition. The report summarizes data on mine accidents involving methane, discusses results of tests on the compression ignition of methane in diesel engines, and examines fuel governors and intake-air-cutoff devices, two kinds of devices used to prevent overspeed. Analysis of the information gathered suggests that the conditions necessary to cause a diesel engine to overspeed uncontrollably are not likely to occur, particularly if the engine is equipped with flame-proofing devices. The available literature and lack of actual overspeed case histories suggest that the safety devices currently in use are sufficient to prevent diesel engine overspeed.

Jan 1, 1984

By H. C. Young

This paper deals with roof bolting in Alabama coal mines and iron-ore mines from the time it was introduced in early May 1948 to May 1, 1953, a 5-year period. The Tennessee Coal & Iron Division of the United States Steel Corp. began systematic roof bolting in early May 1948 in a coal mine and in an iron-ore mine, which had some of the poorest roof conditions in the Alabama mines. After the efficiency of roof bolting had been proved by the Tennessee Co. it was gradually adopted by other companies throughout the State, until in May 1953 approximately 53 percent of Alabama's total coal production and 100 percent of Alabama's total iron-ore production, mined underground, was being produced from roof-bolted areas. Statistics in this report will show the advancement made in roof bolting in the 5 years and also the amount of roof bolting that was being done as of May 1, 1953. Significant progress has been made in the coal and iron-ore mines of Alabama in reducing the roof-fall fatality rates during the past several years by adopting systematic roof bolting. The groundwork was laid through successful experiments early in 1948 by the Tennessee Coal & Iron Division of the United States Steel Corp. in cooperation with the Federal Bureau of Mines. This experimental work was based upon the previous experience of the St. Joseph Lead Co.2/ in its Southeastern Missouri mines.

Jan 1, 1954

By F. E. Joyce

The Bureau of Mines studied copper-nickel minerals (mainly sulfides) of the Duluth Gabbro Complex in north-eastern Minnesota to determine their response to selective high-temperature sulfatization techniques. The gabbro, containing 0.44 percent copper and 0.13 percent nickel, was ground to minus 325 mesh and sulfatized in a heated, rotating, stainless steel bench-scale retort. Tests demonstrated that over 95 percent of the copper and 80 percent of the nickel can be converted to water-soluble sulfates, depending upon the roasting conditions employed. Yield equations were developed using regression analysis for predicting the extraction of copper and nickel between the temperature limits of 520° to 670° C, the roasting time limits of 3 to 7 hours, and S02 limits of 10 to 40 percent in S02-air mixtures.

Jan 1, 1971

By R. O. Dannenberg

A metallic displacement process, utilizing easily available steel wool or steel window screen, was devised and successfully used for the recovery of silver from waste photographic fixing solutions. Laboratory and prolonged commercial-scale testing established that the iron filament type unit will efficiently precipitate silver, as a high-grade sludge, from acidic waste photographic fixing solutions ranging in grade from less than 1 to over 10 grams of silver per liter. Data and design information are presented to facilitate the construction and operation of a practical unit of any desired size. A smelting process for recovering pure silver from precipitated sludge containing 27 to 80 percent silver was devised.

Jan 1, 1968

By T. E. Gray

This report describes preparation characteristics of the significant coalbeds in Marion County, W. Va., as determined by the Bureau of Mines. It is one in a series telling what coals are suitable for producing metallurgical coke, either as mined or after beneficiation. Over 9.4 million tons of coal was produced in Marion County, W. Va., in 1958, of which almost 6 million tons was cleaned mechanically in nine cleaning plants. All of the coal mechanically cleaned came from the Pittsburgh bed. The Bureau of Mines estimated that 1,578 million tons of recoverable coal remained in the county in beds 28 inches or more thick as of January 1, 1955.

Jan 1, 1960

By Jack C. White

As part of an investigation of the production of alumina by the nitric acid leaching of kaolinitic clay, the Bureau of Mines designed, built, and tested a fluidized-bed system for the calcination of aluminum nitrate nonahydrate to alumina, while recovering nitric acid. The calciner consisted of an 8-in-square by 36-in-tall vessel containing 18 in of fluidized solids. Molten aluminum nitrate, sprayed directly into the fluidized solids, formed sandy, granular alumina by growth of successive layers on fluidized particles. Solids were fluidized in a dense bed at temperatures of 250° to 500° C with steam, air, or mixtures thereof. Decomposition of nitrate ranged from 4 to 10 pet during single-pass steam or air fluidization, respectively. Alumina dust losses and low throughput are significant unsolved problem areas.

Jan 1, 1982

By J. H. Holden, C. C. Shale, G. R. Strimbeck, W. S. Bowie

Electrical characteristics are presented for air in a 2 - inch pipe - type electrostatic precipitator operating under dynamic conditions at temperatures of 600 ° to 1,500 ° F and pressures of 0 to 80 psig using a negative discharge electrode . Results of this one - geometry study show that current - voltage relationships are a function of air pressure and temperature and indicate that precipitators can be used at any temperature through about 1,350 ° F over the full range of pressure . Corona starting voltage and sparkover voltage vary directly with pressure and inversely with temperature . At temperatures above 1,350 ° F use of precipitators may be limited to operations at pressures somewhat above atmospheric pressure . Theoretical derivations are presented that relate the effect of gas density on corona starting voltage and the effect of ion mobility on corona current . Deviation from the theory is noted at high current levels . Theoretical discussion is presented to explain the apparent electrical limitations for use of precipitators at high temperature , low gas density , and high corona currents , conditions at which calculated ionic velocities are extremely high . Experimental results are interpreted in terms of the theory presented . 1,500 ° F thermal ionization does not appear to be a critical factor .

Jan 1, 1963

By M. M. Fine

A laboratory mineral-dressing investigation of manganese ore from the Martin mine, Independence County, Ark., succeeded in recovering ferrograde manganese products. Sintered flotation concentrates analyzing 40.7 and 41.4 percent manganese at overall recoveries of 54.6 and 47.7 percent, respectively, were produced from preconcentrated feed, Preconcentration of the ore for flotation included treatment by magnetic separation and by a combination of magnetic separation and heavy-medium processing. The mineral-dressing study of the Martin mine rhodochrosite ore was part of a general program of the Bureau of Mines to develop domestic sources of strategic minerals, including manganese. Several such potential sources of manganese exist in the Batesville, Ark., district, one of which is represented by the Martin mine. Although the Martin mine area has not been delimited with respect to total reserve tonnage, it is considered to be one of the more important occurrences of manganese in the district. It is estimated that several 100,000 tons of manganese carbonate ore are present in this and similar properties.

Jan 1, 1954

By Jerry E. Olson

In 1988, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied additional areas, encompassing 11,303 acres, on the east and west sides of the 20,727-acre Badlands study area (Olson, 1987) in order to evaluate their identified mineral resources. The Badlands study area additions are located in Crook and Deschutes Counties, OR, about 10 and 18 miles east of Bend, OR. No mineral resources were identified. The additional areas studied are underlain by Tertiary-and Quaternary-age basalt flows which are largely covered by a veneer of sand and silt. No mines, prospects, mining claims or mineralized areas occur within or near the Badlands study area additions. Slab lava of marketable grade and quantity was not found in either area. None of the study area is of current interest for geothermal resources, but the eastern study area addition has been leased (1984) for oil and gas.

Jan 1, 1989

By B. K. Shibler

During the investigation of the occurrence of manganese deposits in the Western United States, examining engineers of the Bureau of Mines collected 2-ton samples from five manganese properties near Golconda, Nev. Extensive laboratory tests were made to determine the amenability of these ores to standard ore-dressing methods of concentration. The Tom Major property, one of those sampled, is situated 12-1/2 miles south of Golconda, Humboldt County, Nev. The deposit is described as a bed about 5 feet thick in a thinly bedded shale and dolomite formation. The sample tested was obtained from the manganese bed, but the examining engineer reported: "The mining of an appreciable tonnage at reasonable cost would perhaps cut in half the grade represented by the sample."

Jan 1, 1951

By Robert M. Becker

Part 5, the last of this series, deals with the theoretical confirmation and application of results developed in parts 1 and 2. The bulk-sampling variances of Hassialis and Kassel and Guy are compared with those in part 2, both as to formulation and as applied to ores and coal. The results provide confirmation for much of the development in part 2. Examples are presented for determining the reliability of bulk samples with respect to various measurable characteristics. These characteristics include, for example, assays for elements or compounds and particle surface area. The bulk samples considered consist either of a given weight, a given volume, or a given number of particles. In addition to problems of sample reliability, some of these examples may also be applicable to quality control. Several possible applications of results developed in parts 1 and 2 are outlined. These include tests for random data, degree-of-mixing indices, and particle-fineness indices.

Jan 1, 1966

By E. E. Harton

Bureau of Mines Information Circular 7516, Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants, was published in October 1949 to aid in estimating investment and operating costs of processes for manufacturing synthetic liquid fuels. Development of such processes by the Bureau of Mines was authorized by Public Law 290, 78th Congress. This bibliography included references to and abstracts of publications appearing from. 1930 to September 1948 on all processes in general use in the petroleum refining and chemical industries. Bureau of Mines Information Circular 7705, Supplemental Bibliography on Investment and Operating Costs for Chemical and Petroleum Plants, was prepared to cover the area from September 1948 through June 1952.

Jan 1, 1956