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By K. Hennings

Noise from vibrating screens is generated in two ways: 1) Noise due to the material being processed and, 2) noise from the screen itself. Non-metallic decks had been shown previously to reduce material noise. The noise reduction and change in screening performance was quantified for six non-metallic decks using dolomite, granite and coal as the materials. The non-metallic decks were from 2 to 7 dBA quieter and from -1 to +10 percent less efficient as compared to a steel wire cloth deck of the same open area. Damping of the sidewalls and isolation of the drive mechanisms had been shown, in a development configuration, to reduce the noise of the screen itself. Tests of four prototype damping treatments gave reductions up to 4.9 dBA and the mechanism isolators gave an additional 2.1 dBA. The treatments were successfully life tested in two ways: 1) Lab tests to a simulated 25,000 hours were conducted on samples of the treatments in a corrosive salt spray to simulate coal plant wash water and, 2) the full size treatments were run on a full size screen for 5,000 hours.

Jan 1, 1980

By James R. Boyle

The mining methods and practices used at the Young zinc mine, American Zinc Co. of Tennessee, have resulted in a low-cost, high-yield operation. Zinc ore (sphalerite) occurs in limestone-dolomite beds of the Kingsport Formation and is mined by modified room and pillar method. Utilizing trackless mining equipment which incorporates a high degree of flexibility, this operation has had a steady increase in productivity.

Jan 1, 1965

By Jr. Reistle

The tests reported in this paper were made in the East Texas field in the summer and fall of 1932 as a part of the Bureau of Mines study of the operation of flowing wells and reservoir performance; and to determine, if possible, the minimum reservoir pressure necessary to produce the wells in this field by natural flow through different sizes of flow strings. The minimum reservoir pressure that would be required to Maintain natural flow through 2 1/2-inch tubing was determined experimentally for the existing energy conditions in the East Texas field. With the present available data, however, it is impossible to predict accurately or to determine by calculation the necessary energy requirements for maintaining the vertical flow of oil and gas mixtures under all conditions. Although some valuable data were obtained which seem to have application to the solution of problems involving vertical flow, this important research of the petroleum industry is so involved that more study of the complicating factors influencing the flow of oil-gas mixtures through vertical pipes is required.

Jan 1, 1933

By E. D. Gardner

This paper discusses small-scale lade gold mining and milling. It is abstracted from a bulletin being prepared by the United States Bureau of Mines entitled "Equipping, Developing, and Operating Small Gold Mines." Gold is widely distributed in the mountainous regions of the United States; relatively few deposits, however, can be profitably worked on a large scale. Because of the high intrinsic value of gold, ores containing this metal may be very rich; hence it is possible to mine profitably smaller bodies of gold ore than of the more common metals.

Jan 1, 1934

By R. R. Schehl

The Bureau of Mines analyzed the structure of a high-grade metallurgical coke, carbonized at different temperatures in the range 500° to 1,000° C, through X-ray diffraction studies. Growth in the crystallite size with increasing coking temperature was calculated from profile analysis and compared with values obtained from the radial distribution function. The carbonization temperature appeared to have little influence upon the stack height, whereas the layer diameters more than doubled in size between 500° and 1,000° C. These results are comparable to those obtained from other studies of poorer quality cokes.

Jan 1, 1974

By Nicholas Kyriazi

A joint effort by the U.S. Bureau of Mines and the U.S. Mine Safety and Health Administration (MSHA) was undertaken to determine how well self-contained self-rescuers (SCSR's), deployed in accordance with Federal regulations (30 CFR 75.1714), survived the underground environment with regard to both impact damage and aging. This report presents findings regarding laboratory-tested SCSR's from 1982 through 1990. The SCSR's were tested on human subjects and on a breathing and metabolic simulator (BMS). These results indicate that most of the apparatus, if they pass their inspection criteria, perform as expected except for units with manufacturing defects or design deficiencies. However, when the apparatus are carried in and out of the mine daily and stored at the working section, they may suffer abuse. Physical signs of abuse, unless extremely obvious, are frequently not detected by the miners or mine operators. This poses a potential danger to a user in an emergency. Recommendations include improved training in inspection procedures.

Jan 1, 2010

By W. A. Dunkley

During the past year and a half the Western United Corporation of Aurora , Illinois , has been distributing carburetted water ges from its Lockport , Ill . , plant , to an extensive territory , under an initial pressure ranging up to 90 lb.. per sq. in . The most distant distributing point on the system is at Harvard , Ill . , about 35 miles from the plant.. The territory supplied is approximately 85 miles long and 35 miles wide , the total mileage of rains being 1223 , or approximately 24 per cent of all the gas trains in Illinois outside the city of Chicago .

Feb 1, 1923

By Irving Wender

The oxo reaction consists of catalytic conversion of olefins by reacting the olefins with CO and H2 (water gas) to aldehydes that contain one more carbon atom than the starting olefin. The aldehydes are then generally reduced with hydrogen to primary alcohols in a second stage. The two-stage process is called the oxo process. The word "oxo" is derived from the German "oxierung" (ketonization); thus the exact English equivalent of "oxo" is "keto". The oxo process may be applied to nearly all olefins. A wide range of pressures and temperatures may be used in both stages. The pressure range usually employed is 150 to 200 atmosheres. The temperature in the first stage is usually about 140° C. and in the second or hydrogenation stage about 180° C. Although a standard Fischer-Tropsch catalyst may be used for both steps, cheaper catalysts have been utilized to effect hydrogenation of the aldehydes. Most of the information for this, report on the oxo process was gathered from Technical Oil Mission microfilms. T.O.M. Reels 14, 55, and 134 were especially valuable. T.O.M. Report 6 by H. M. Weir was very helpful. Information on the oxo process is scattered throughout documents captured in enemy territory, and the present report does not include all the available data. Some of the information was procured by personal interview. Where, in the body of this report, certain investigators are quoted, the source of the statement is either personal interview or the T.O.M. reports.

Jan 1, 1948

By O. C. Blade

The term "Ichtnyol" is a name applied loosely to certain preparations used in pharmacy. These preparations do not occur as such in nature but are manufactured by various chemical processes. Ichthyol is the name trademarked for a product manyfactured by the Irhthyel-Gescllschaft (Cordes Hermanni & Co.) of Hamburg, Germany, and marketed in thin, country by Merck & Co., Inc., (5, 86, 87)3/. Although used in the literature rather loosely, the correctly applied word refers to the product obtained by sulphonating and then neutralizing with ammonia a distillate from the oil retorted from a certain high-sulphur bituminous shale found near the village of Seefeld in the Austrian Tyrol. Due to the fact that fossils of fish and marine animals occur in the limestone associated with the bituminous shale, these deposits have long been known as, the "lchthyolite schistc of Seefeld" ( 55) . The Greek word "ichthys"" for fish and the Latin word "oleum" for oil are the words from which the term is derived. The crude, tarry shale oil, whose distillate is the raw material for the sulphonation process, has been referred to since the Middle Ages as "Dürsten" or "Tirschen" oil, and the term "ichthyel oil" has been used occasionally in the literature to designate the retorted crude oil (92, 93, 106, 117). The first application of the name "Ichthyol" to a particular product is credited to Schröter (35, 129). Various names for products manufactured by sulphonating bituminous distillates have been coined, and in some of these names the root from the word ichthys has been retained. Some of these names can be found in New and Nonofficial Remedies under the heading, Sulphoichthyolate Preparation, and Substitutes (5).

Jan 1, 1938

By R. G. Nelson

The mechanical properties of low-hafnium, arc-melted, Kroll-process zirconium are presented. The effect of temperature on the ultimate strength, yield strength, proportional limit, elongation, hardness, Young's modulus, electrical resistivity, and impact strength are shown, The effects of cold work and annealing on the tensile properties, bend radius, and formability, as determined by cupping tests, are also given, Tensile properties are compared, in part, to those obtained on earlier graphite-melted zirconium and on crystal-bar zirconium. INTRODUCTION The commercial production of high-purity, low-hafnium bearing zirconium has been achieved, and this metal is becoming available for industrial use. However, there is little published information regarding the physical and mechanical properties of this product; and, since there have been many improvements in the production and arc-melting techniques of zirconium in the past 3 years, it was considered advisable to present the properties of the vastly improved zirconium representative of current production.

Jan 1, 1954

By J. G. Walters

This report presents the results of an investigation in Which the chloroform solubilities of coals and chars are related to rank, temperature of thermal treatment, time at a given temperature, vacuum thermal treatment, plasticity, oxidation, blending, and mass spectral analyses and molecular weights of the extracts. It was found that the quantity of chloroform extract obtained from chars can be altered by creating a vacuum above the charge during preparation of the char, increasing the time at temperatures within the plastic temperature range, and by utilizing different rates of heating to attain a given temperature. Relationships found between the chloroform solubilities of chars produced at temperatures within the plastic temperature range and the relative fluidities in this temperature range indicate that the chloroform-soluble portion of the char is a significant component of the plastic mass. Chloroform-extract yields from chars made from blends of coals cannot be calculated from chloroform-extract yields obtained from chars made from the component coals.

Jan 1, 1967

By A. B. Coates, J. E. Crawshaw

"The use of such methods and apparatus as the Dautriche method and the Mettegang recorder for the determination of the rate of burning of black blasting powder and other strictly burning explosives has been found to give such erratic results that no reliance can be placed on the data thus obtained. Consequently, investigators of those factors which may affect the burning rate, such as size of grain, absolute density, chemical composition, and means of ignition have had to rely mainly on observations made during practical use for determination of the part played by each. Such tests are very difficult of interpretation.The purpose of this paper is to describe a method used by the explosives division of the Bureau of Mines for the investigation of such explosives and to present the results of an investigation using that method.The investigation was concerned with the effect of grain size, initial pressure, and means of ignition on the rate of burning or rate of pressure development of black blasting powder as compared with pellet powder.The Bichel pressure gauge was used for these tests, with the slight modification to the apparatus and method described in U. S. Bureau of Mines Bulletin 15.4 These modifications consisted of reducing the speed of the revolving drum on which the time-pressure record is taken, measuring the speed of the drum by a belt-driven tachometer, and introducing an induction coil in series with the electric squib or electric detonator to mark on the time pressure record the instant at which the squib or detonator was fired."

May 1, 1929

By W. A. Stickney

The Bureau of Mines conducted beneficiation and smelting studies on siliceous offgrade manganese samples to indicate effective methods of manufacturing silicomanganese from materials that cannot be economically beneficiated to meet General Services Administration (GSA) specifications for stockpiling. Laboratory and pilot-plant flotation tests were conducted on 2 samples, 1 from the waste-tailings dump of the Domestic Manganese & Development Co , Butte, Mont., and the other from the Nettie mine in the Butte-Philipsburg area. Smelting tests were made on the combined concentrates from the pilot-plant flotation tests and on part of the tailings sample The flotation scheme found to be adequate in laboratory tests and later in the pilot-plant tests consisted of flotation by a fuel oil-tall oil emulsion in an acid circuit (pH )-1-.8 to 5.0). The oil-emulsion reagent flocculated the manganese minerals and selectively floated them from the siliceous gangue, In the pilot-plant flotation test on Butte-mill tailings 90.1 percent of the manganese was recovered in a concentrate that analyzed 32.6 percent Mn, 4.8 percent Fe and 28.1 percent Si02. In the test on Nettie mine ore 90.8 percent of the manganese was recovered in a concentrate that analyzed 36 6 percent Mn, 5.5 percent Fe, and 26-4 percent Si02.

Jan 1, 1956

By William J. Wuest

The technical analysis of parameters that can influence roof and rib reinforcement is important to the operation of safe and profitable underground mines. One such parameter, studied in this U.S. Bureau of Mines investigation, is the effect of time on untensioned, resin-grouted bolt anchorage characteristics. A group of seventy-three 4-ft-long bolts with three different grout column lengths were I installed in a stable coal mine roof. The bolts were then subjected to standardized pull tests at various intervals throughout a 37-month period. For each test, load-deformation data were reduced to determine axial stiffness and yield point. The magnitudes of these two anchorage characteristics at the time of installation were compared with results from subsequent pull tests to determine if anchorage capacity deteriorated. Bolts with 18-in grout columns were studied over 9 months, and no measurable loss occurred. Bolts with 48-and 24-in grout columns were studied over 37 months and also exhibited no measurable loss.

Jan 1, 2010

By Alvin Schallis

The. problem of supplying enough magnesia for the American war effort has become highly important. Before hostilities began, only about two-thirds of our, require vents came from domestic sources; now they must supply almost all the magnesia we need. A further burden is placed upon our own supply by the fact that more and more magnesia is being required, not alone to pace the war tempo of general industrial activity, but also to replace chrome ore in refractories and to make magnesium metal. The domestic magnesite and brucite industry is equipping itself to satisfy much of this greater demand for magnesia, but the remainder must be obtained elsewhere. The principal sources of magnesia are magnesite, brucite, dolomite or high-magnesium limestone, natural brines, sea water, salt-works bitterns, magnesium silicates, and magnesium salts. Although dolomite is tae subject of this paper, it should be considered in perspective with all these highly competitive sources of magnesia.

Jan 1, 1943

By Walter R. Storms, Allan B. Bowman

This paper , which describes mining methods and practices at the Mineral Hill copper mine , is one of a series being prepared by the Division of Minerals of the Bureau of Mines on mining methods , practices , and costs in various mining districts. of the United States . The Mineral Hill mine is situated on the northeastern piedmont of the Sierrita Mountains at an altitude of 3,650 feet in sec . 35 , T. 16 S. , R. 12 E. , and sec . 2 , T. 17 S. , R. 12 E. , Pima mining district , Pima County , Ariz . ( fig . 1 ) . The claims (figs . 2 and 3) are in a gently rolling area with only scant desert vegetation . The average annual precipitation is about 11 inches . The nearest surface water is the Santa Cruz River , an intermittent stream 8 miles east of the mine . The property is owned by the Banner Mining Co. , a Nevada corporation . This report presents a brief history of the mine , describes the geology of the area and the ore deposits , outlines methods of prospecting and exploration , and gives methods of sampling and the estimation of ore reserves and values . Development and stoping methods are explained , and methods of underground transportation , ventilation , mine drainage , and safety measures are described . The concluding section of the paper is a section on milling . The Mineral Hill mine is an old mine that was reopened in 1951 after having been closed for 30 years .

May 1, 1957

By D. B. Dow

The presence of sulphur compounds in petroleum and its products is, generally speaking, undesirable, and the problems involved in removing such compounds are of great importance to the petroleum refiner and to the manufacturer of gasoline. There are several types of these compounds which are dissimilar in physical and chemical characteristics, as evidenced by different objectionable features which they exhibit, and special treatments have been developed to meet conditions existing in various products. This paper deals with the treatment of natural-gas gasoline for the removal of certain sulphur compounds which, if not removed, impart on objectionable odor and in addition badly discolor the product. The presence of this particular type of sulphur compounds is detected by the "doctor" test.* In some instances natural-gas gasoline is purchased on "doctor" test specifications, and the ordinary purchaser, while not buying on "doctor" specifications, is insistent in his demand for a water white product. Gasoline which fails to meet the "doctor" test, if not received by the buyer within a few weeks after time Of manufacture, may be "off color" enough to warrant a deduction from the market price.

Jan 1, 1923

By J. J. Sammarco

Light emitting diodes (LEDs) are emerging as viable replacements for incandescent-based cap lamps used in mining. The photometric and energy characteristics of these light sources differ in important ways. The present paper describes the performance of LED and incandescent sources in cap lamps in terms of correlated color temperature, color rendering, light output, electric power, ambient temperature and airflow, and light source aging. Importantly, these characteristics can influence a miner?s ability to spot mining hazards thus impacting safety. Secondly, some of these characteristics interact with the operating life of the cap lamp?s battery power, such that differences between LED and incandescent sources can be magnified toward the end of a 10­hour battery discharge cycle. Empirically, we have determined that after 8 hours at an ambient temperature of 25 °C, the average light output of an incandescent cap lamp can decrease to about 69% of its initial value when powered by a lead-acid battery and it can decrease to about 65% of its initial value when powered by a nickel-hydride battery. An LED-based cap lamp using a constant current drive circuit can maintain about 96% of its initial value when powered by a nickel-hydride battery. Real-world tests addressing the effects of ambient temperature and airflow on the light output of an LED and incandescent cap lamp were conducted in the NIOSH Safety Research Coal Mine (SRCM). The LED cap lamp yielded a vertical average illuminance improvement of approximately 9.5% and the INC cap lamp yielded a vertical average illuminance degradation o f approximately 4%. The differences between LED and incandescent cap lamps were further quantified by the calculation of ?mesopic luminance? data that indicated for the same photopic luminance (i.e., as measured using a conventional light meter) the LED cap lamp could be up to 38 % more efficient than the incandescent cap lamp with a lead-acid battery at the end of the 10-hour driving cycle. Lastly, accelerated life tests were used to empirically determine light output depreciation as the incandescent light source age approached its useful life. There was about a 35% decrease in light output. This is quite considerable, especially given that the light output will decrease an additional 30% to 45% over the period of a 10-hour shift. The implications of the differences between LED and incandescent sources are discussed. This information is crucial in determining how visual performance could be affected for real-world conditions where batteries discharge during the work shift and as the light source ages. To date, only idealized conditions have been used for LED and incandescent cap lamp visual performance research.

Jan 1, 2008

By J. W. Stevenson

The Bureau of Mines investigated the influence that atmospheric pressure changes exert in a gassy coal mil on a ventilating air current with a system of bleeder entries. During the season when abnormal barometric fluctuations usually occur, recording instruments monitored the air current ventilating an active coal-producing area. It HL he rate of coal production caused a more significant change in methane concentration than did barometric change. The hazard that accompanies methane release due to expansion of the gob gases during atmospheric lows was minimized by the effective bleeder system.

Jan 1, 1966

By H. Kenworthy

The purpose of the study described in this publication is to develop methods for recovering simple master alloys or single metal components from discarded and scrapped S-816 alloy, The Bureau of Mines started this investigation late in 1955 after the need became apparent for a method of reclaiming high-temperature alloys from an ever-increasing accumulation of rejected and wornout jet engine turbine buckets. Laboratory studies showed the following: (1) Pyrometallurgical separations are not selective enough, (2) several methods can be used for effective chemical dissolution of the major constituents of the alloy, (3) a master alloy or complex salts of cobalt and nickel can be separated, (4) chromium, contaminated by several other metals, may be segregated, and (5) more time and effort need to be expended in separating the minor constituents and improving the purity of the major metals removed. Difficult and incomplete chemical separations were attributed to the complexity of alloy composition, as were the long tedious chemical analyses o' products. For determination of several of the metallic components, standard methods of separation and routine analytical procedures had to be considerably modified to achieve satisfactory results. The overall technical problems involved in separating S-816 components do not appear to be insurmountable; however, refinement of several of the methods used in this investigation is desirable.

Jan 1, 1961