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By T. Kessler

The purpose of this investigation was to evaluate the application of a spark-source mass spectrograph equipped with a spinning-electrode system for the study of various high-molecular-weight materials derived from coal. Conclusions from the investigation of anthracene, phenanthrene, chrysene, coronene, truxene, a coal-tar pitch (800 to 850 C softening point), and anthracene-chrysene synthetic mixtures follow: 1. Simplified mass spectra of anthracene, phenanthrene, chrysene, coronene, and truxene, from which the molecular weights were easily determined, were obtained by the spinning-electrode system. 2. Eight structural types having molecular weights from 178 to 252 corresponding to compounds previously observed in an electron impact mass spectrum of a coal-tar pitch sample were affirmed by this technique. 3. Mass spectra obtained from synthetic mixtures of anthracene and chrysene demonstrated that the technique is applicable for semiquantitative analysis.

Jan 1, 1967

By R. E. Heithecker, Van A. Mills

"Crude oils are capable of dissolving quantities of gas under pressure. This fact has been known for some time, but questions have arisen as to the effects of gas in solution upon the characteristics of the oil. Previous investigations4 show that gas in solution in an oil affects the viscosity and surface tension of the oil, but the effects on the volume and A. P. I. gravity of the oil have not been known. The results given in this report show that there is a decided change both in volume and in the A. P. I. gravity of the oil due to the solution of the gas in the oil under pressure. As gas is dissolved, the volume of the oil and the A. P. I. gravity increase. The converse of this phenomenon is also true: if the gas is released from a saturated oil, there is a shrinkage in volume and a decrease in A.P.I. gravity due to the release of gas from solution. However, various oils show marked tendencies to retain a portion of the dissolved gas upon releasing the pressure to that of the atmosphere. This retained gas has an appreciable effect on the volume and A. P. I. gravity of the oil because the oil does not resume its initial volume or gravity while it retains dissolved gas. In a sense the oil has been ""freshened"" and will not return to its original or weathered volume until it loses some of the lighter fractions. Wiggins5 has shown that a fresh oil decreases both in volume and in gravity because of the weathering of the lighter fractions while the oil is standing in storage tanks.This paper includes data attained during the determination of volume and gravity correction factors to be applied in the oil recovery investigations of the Bureau of Mines. Three oils having a wide range in gravity were used in determining the correction factors. These oils were from the Bartlesville-Dewey field, Oklahoma, the Seminole field, Oklahoma, and the Inglewood field, California. The same gas that was used in the oil recovery experiments was used throughout this investigation. Determinations were made of the volume and A.P.I. gravity increases resulting from the gas going into solution at 200, 400, 600, 800, and 1,000 pounds pressure; also the increases in the volume and gravity of the oil due to retained gas were determined after the dissolved gas was liberated from solution by releasing the pressure to that of the atmosphere.Samples of residual and liberated gas were taken throughout the investigation in order to study the selective absorption and selective retention by the oil of the various constituents of the gas. The analyses of these gas samples showed that there was selective absorption and selective retention of the constituents of the gas. The tests on Inglewood crude gave the most pronounced example of selective absorption and selective retention of the gas.All of the tests were conducted at a constant temperature of 709F."

Oct 1, 1928

By S. C. Schaefer

Thermodynamic properties of indium oxide (In203) have been studied with a high-temperature galvanic cell employing stabilized zirconia electrolytes. In the temperature range 790° to 1,230° K the free-energy change for the cell reaction 21n(1) + 3Cu20(c) = In203(c) + 6Cu(c) together with the standard free energy of formation of cuprous oxide gives the standard free energy of formation of indium oxide from the elements as ?Gf° = -218.78 + 75.34 X 10-3T ±0.7 kcal/mole. A third-law analysis yields the standard enthalpy of formation: ?Hf°298.15 = -221.5 kcal/mole.

Jan 1, 1971

By T. L. Joseph

The size and accessibility of the Minnesota manganiferous iron ore deposits make them attractive as a potential source of erromanganese, which is essential in the production of steel. For several years the Bureau of Mines has been conducting experiments to determine the feasibility of producing ferromanganese from these ores by a three-step process which involves (1) the smelting of the ores in the blast furnaoe to produce a high-phosphorus spiegel; (2) the treatment of the spiegel produced from step 1 in an electric or open-hearth furnace to separate the manganese from the phosphorus and the iron; and 3) the smelting of the high-manganese slag from step 2 to produce forromanganese. The details of the first two steps of the process and the results of tests with the experimental furnaces Lave been given in previous reports.5 The m$ or part of the experimental work on the second step has been conducted in a half-ton open-hearth furnace. Some preliminary tests showed, however, that the electric furnace has some distinct advantages over the open hearth for producing, from high-phosphorus spiegel, a slag containing from 45 to 55 per cent manganese and phosphorus and iron in amounts required for ferro-grade ore. The electric furnace tests described in this paper were made to get more information as to the possibilities of the electric furnace in connection with this problem and to study the fluxing effect of alumina on high-manganese slags. Herty, Conley, and Royer have reported' results of laboratory tests which showed that slags containing from 60 to 75 per cent MnO, from 8 to 10 per cent S102, and small amounts of CaO MgO, and FeO, were sufficiently fluid at 1,450° to 1,550° C. to pour readily if 12 to 14 per cent alumina was present. With a normal A1203 content resulting from the A1203 in the

Jan 1, 1931

By J. E. Tiffany, Gaigler. Z. C.

"PREFACEIn presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 16 and 21 outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible.In view of a recent publication recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 16 and condition 2 on page 21. An explosive or a blasting device enumerated in the permissible lists of this Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.PERMISSIBLE EXPLOSIVES TESTED UNDER SCHEDULE 17CAn active list of permissible explosives was published in December 1937 as part of Bureau of Mines Report of Investigations 3361, under the title ""Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1937.n This list included 196 brand names.Changes in the list that have been authorized to June 30, 1938, placed 7 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Twelve permissible explosives were transferred from the active to the inactive list. The present list contains 191 brand names. The brand names of the permissible explosives placed on the active list are as follows:"

Oct 1, 1938

By Daryl R. Tweeton

The Bureau of Mines compared the effects of surface-active chemicals with those of pure water on core-drilling rock and quartz and on fracturing quartz. The objectives were to determine if these chemicals assist drilling and fracturing rock and if zeta potential control was worth pursuing as an aid to full-scale drilling. All tests were performed in the laboratory. No significant increases in drilling rates were observed for 1 to 10,000 ppm Al (as AlC13) in flushing water when drilling microcline or serpentine, nor for 1 to 10,000 ppm Mg (as MgC12) when drilling microcline or marble. Concentrations near those giving a zero zeta potential were used with microcline and marble. A 50-pct rate increase was observed for drilling quartz in 0.7 ppm oleylammonium acetate, which gave a zero zeta potential. No other concentrations were used. No effect on the tensile strength of quartz thread in 0.05 ppm Al (as AlC13), which gave a zero zeta potential, was observed. Heptanol, reported to give a zero zeta potential on quartz, did not reduce the bending strength of small quartz bars below that in water. These generally negative findings raise doubt about the usefulness of zeta potential control in full-scale drilling. The results, combined with previous studies, suggest that controlling physical properties of drilling fluids, such as viscosity, is more useful than altering chemical properties.

Jan 1, 1976

By R. V. Ramani, R. Bhaskar

"IntroductionThe behavior of dust clouds in mine atmospheres has been a subject of longstanding interest due to both health and safety reasons. Pioneering studies in Germany and SMRE focussed on ambient dust concentration, principally aimed at determining optimum velocities for effective dilution. A summary of studies related to this area is provided by Hall,(l) Efforts to understand dust deposition from the explosion hazard point of view led to experiments in return airways (2-4) followed by experiments in longwalls.(5) Concerted efforts, either experimental or theoretical, were not made until recently to relate ambient concentration with dust deposition in mines. In 1974 Hwang et a1 (6) developed a computer model to predict dust concentration which considered deposition-concentration relationships. Also, experimental studies involving concurrent dust deposition and ambient concentration were conducted in the U.S. by Courtney et al (7 ) in operating mines. Efforts to relate theory with experimental results have been made by Owen (8) and Hwang et al (6 ) for dust deposition. There has been limited work, however, to determine the application of the theories and assumptions from aerosol sciences for modeling dust flows in mine atmospheres. (9 ) This is the objective of the work currently underway in the Generic Technology Center on Respirable Dust since· 1983 under a project titled, ""Prediction of Ambient Dust Concentration in Mine Atmospheres."" The scope of the project activities include:1. Development of a mathematical model to predict dust deposition and concentration in mine atmospheres.2. Experimental studies on dust transport and deposition in mine airways.3. Comparison of the model results with the experimental data."

Mar 1, 1989

By J. C. Meeks, C. L. Klingman

An instrument that is sensitive , portable , safe , and low in cost was developed by the Bureau of Mines for detecting helium leaks by comparing the thermal conductivity and flow rate of the atmosphere around the suspected leak against a reference of helium- free air . A vacuum pump pulls the sample gas through a restriction and over thermistor elements , the combined electrical output of which is affected by thermal conductivity and flow rate of the sample gas . Tests showed that the battery - operated Helium Leak Detector was effective and rugged instrument that could be operated safely in explosive atmospheres . The instrument could also detect , but not identify , other gases such as methane , hydrogen , argon , carbon dioxide , and Freon 12 .

Jan 1, 1964

By Albert S. Konselman

This paper describes the mining methods and operating costs for 1938 at the South Burns shaft, situated in the Cripple Creek district, Colorado. The shaft is operated by Golden Conqueror Mines, Inc., through which portions of the properties of the Acacia Cold Mining Co., The Free Coinage Gold Mining Co., and The United Gold Mines Co. are worked under lease. During 1938, 30,773.61 dry tons of ore averaging $9.59 in gold per ton was mined. Of this, 10,138.439 tons averaging $10.65 per ton was produced on company account, and 20,635.171 tons averaging $9.05 per ton was produced by "split-check" lessees.

Jan 1, 1940

By Timothy A. Clancy

In support of research on forming ceramics from mining and processing wastes, the Bureau of Mines tested various commercial refractories to evaluate their resistance to melts of these wastes. Sixteen refractories of various types were exposed in slag erosion tests to two siliceous waste melts with Si02/CaO ratios of 4.0 and 2.2, The extent and nature of slag attack were then determined for each refractory. The nature of slag attack was investigated through scanning electron micrographs and microprobe elemental distributions. The refractories that performed best in resisting attack by the melts were high-alumina types, and of the refractories tested, the most resistant was a 90-pct-Al203, 10-pct-Cr203 refractory.

Jan 1, 1983

By Douglas C. Corner

This is the first of a series of papers dealing with modern tunnel-driving methods, compiled in accordance with an outline prepared by engineers of the United States Bureau of Mines and to be published in a series of information circulars by the bureau. This series will supplement a similar and earlier series of papers dealing with mining methods and costs. ACKNOWLEDGMENTS The author desires to express hiss appreciation, of the assistance of A. C. Dennis, manager for the West Construction Co. Contractors, and Franc: E. Winsor, chief engineer for the Boston Metropolitan District mater Supply Commission who furnished much of the data and detailed description of operation appearing in the following pages. C. F, Jackson, mining engineer, United States Bureau of Mines, collaborated in the preparation and arrangement of the text.

Jan 1, 1931

By R. H. Lien

The Bureau of Mines investigated nitrous oxide (N20) stability when used as a solvent for organic removal from metal powder surfaces. Both supercritical and subcritical conditions were studied. This investigation was prompted by the occurrence of a violent reaction when supercritical N20 was being used to deoil a metal powder grinding waste sample that contained 20 to 25 wt pct cutting oil. Tests were conducted to determine the cause of the reaction and to define stability limits. Test data showed that the waste's oil fraction reacted violently with N20 acting as an oxidizer; the metal powder acted as a promoter to reduce the ignition temperature. Although the data were scattered, this temperature appeared to reach a minimum at a certain pressure (dependent on vessel and sample size). The minimum ignition temperature for a 0.64-g sample in a 72-cm3 vessel was 360° C at 200 psig. As the sample size increased, the ignition temperature decreased. For example, when the sample size was increased to 10 g, a reaction occurred at 240° C and 600 psig. Because of the variability of ignition temperature with pressure and sample size, safe operating conditions were not established. Overall, this research showed that extreme caution should be exercised when using N20 in an organic or organic-metal system.

Jan 1, 2011

By W. H. Eddy

The Bureau of Mines conducted laboratory batch flotation tests and continuous pilot plant flotation tests on a complex calcareous fluorspar ore from Cave-in-Rock, Ill., to determine the technical feasibility of producing commercial-grade concentrates by the sodium fluoride-calcium lignin sulfonate-fatty acid method of concentrating fluorspar previously developed by the Bureau. The continuous flotation tests, treating about 150 pounds of ore per hour, produced fluorspar concentrates assaying 96.4 percent CaF2; 90 percent of the fluorspar was recovered.

Jan 1, 1967

By L. C. IlsLey

"There are two general classes of accidents that prevail in and about mines, namely - (1) those that through the nature of mining work can only be lessened, and (2) those that by proper precaution can be eliminated altogether. Explosive accidents that ordinarily take place while explosives are being transported in and about mines belong to the second class, that is, by proper care all such accidents can in general be avoided.The following table gives a brief summary of several accidents and disasters that have occurred in the United States and indicates the need of universal preventive measures as a basic part of all State regulations.ACCIDENTS AND DISASTERS OCCURRING WHILE TRANSPORTING EXPLOSIVES.***"

Sep 1, 1923

By R. T. DeWoody, W. C. Miller, W. Chester

Studies were made to determine the effect of the shape of a pneumaticrock- drill exhaust muffler on its efficiency, and the origin and reduction of exit noise from the mufflers. Tests of mufflers of three different shapes proved that the shape is not critical and that a muffler could be incorporated into the shell of the drill. Petal diffusers are beneficial in reducing exit noise but add another projection to the machine. Increasing the number of exit openings while maintaining the same area of exit opening has a markedly beneficial effect on the exit noise and appears to be the most satisfactory treatment.

Jan 1, 1964

By E. P. Youngman

The basic mining law of Esthonia is the law that was passed by the Parliament (Riigikogu), or State Assembly, on March 17, 1927 (effective Avril 1, 1927), superseding the Russian Mining Law Book VII of the Code) issued in 1912. References in this digest are only to articles of the Law of Merch 17, 1927. However, the law concerning all industrial enterprises (Riigi Teataja No. 28, 1920, Law No. 106) governs not only mills and refineries but also mining operations themselves (arts. 2 and 3). No access was ad to that law. Esthonia is not well supplied with minerals; its industries are primari- ly agriculture and dairy farming. Natural gas, prites, lead, zinc, iron ore, salt, and mineral waters have been found but never as yet in deposits of commer cial size. The production of oil shale is of some importance; and peat, which covers as much as 5 per cent of the total area of the country, is mined in sub- stantial quantities. Cement rock, gypsum, fire clay, and phosphate rock likewise are produced, though only on a small scale.

May 1, 1930

By Harry Perry, Mary S. Esfandiary

This is a revision of a directory of coal research organizations throughout the world that was first published in 1961 as Bureau of Mines Information Circular 8008. Because of the wide acceptance of the first edition , a revision which would supply up- to - date information on coal research and which would facilitate communication among organizations of similar interest seemed important . This compilation includes the names and activities of organizations of various types -government , university , private , and industry . The areas of investigation that each organization is engaged in are indicated in broad terms : Analysis and constitution , mining and geology , preparation , briquetting , combustion , high- and low-temperature carbonization , gasification , conversion to solid and liquid fuels , and health and safety . Publications issued by and describing the work of each organization are cited ; almost all of the organizations also publish results of their investigations in the technical press . Selected technical and trade publications that publish information on the science and technology of coal and are not published directly by any of the organizations listed are cited in the pages following the list of organizations in each country . Information that would improve coverage and accuracy of the next revision of the publication will be welcomed by the Bureau of Mines .

Jan 1, 1966

By Hylton R. Brown

This publication, an abstract of a progress report covering an investigation of hazards in thermal coal-drying plants has been prepared according to the suggestions and recommendations of a committee6/ appointed by J. J. Forbes, Director of the Bureau of Mines, when the original report was reviewed at a meeting of representatives of the mining industry, operators of coal-drying plants, coal-mine workers, and the Bureau in Washington on May 6, 1955. The investigation on which the report is based was made in accordance with action taken at a previous conference in Washington on May 19, 1954, called by Director Forbes to consider what should be done to prevent explosions and fires in coal-drying plants. Scope of Investigation The investigation was planned to obtain information considered essential for properly appraising fire and explosion hazards in different types of coal driers. A questionnaire sent to Bureau personnel provided preliminary information on coal-drying facilities at more than 270 preparation plants. Information on methods used in operating different types of driers, with their furnaces, fans, cyclones, and other auxiliary equipment, was obtained by personal visits or conferences with the operators at 13 plants. Factual data on operating temperatures, composition of the drying gases, air flow, dust loading of the air or gas currents, use of water sprays, auxiliary air controls, and other factors were obtained by conducting full-scale tests at six different plants and making laboratory investigations with samples of dust and gas collected during the tests.

Jan 1, 1956

By Raymond B. Ladoo

Talc mining ·in the state of New York was first started about 1876, but important production did not start until 1880, when about 4,000 tons were shipped, In 1883 the production was about 6,000 tons valued at $75,000, or an average of $12.50 per ton, From this date the production gradually inc~eased to a peak of 93,236 tons in 1916, valued at $961,510 or about $10,30 per ton, In 1918 the production declined to 71,167 tons valued at $902,100, or about $12,70 per ton. For ma.ey years New York ,-Jas the largest producer in the United states, but in 1917 and 1918 its output was surpassed by Vennont in tonnage thou[;h not in value. In June, 1920, there were three companies producing talc in the Gouverneur district, st. La,1Tence Co'Ul'lty, and one near Natural Bridge.

Oct 1, 1920

By E. C. Tarpley, H. M. Cooper, R. F. Abernethy

"INTRODUCTION The float-and-sink test 5/6/ is generally the first test used in determining the washing characteristics of coal. The simplest form of the test is that of using one solution of such specific gravity that the test sample is separated into ""float"" and ""sink"" fractions. In practice, however, a series of solutions is used, and the sample is separated into a number of fractions of a definite specific-gravity range. Analyses of a series of fractions of this type are often referred to as the ""specific-gravity analysis,"" and are of great value in the selection, construction, and operation of commercial washing equipment.The test is rather simple to use, provided a number of conditions are recognized and as many as possible held constant, such as:1. In laboratory testing, two types of solution are available -Aqueous solutions of calcium and zinc chlorides.Mixtures of organic liquids such as carbon tetrachloride, benzene, gasoline, bromoform, etc.2. Absorption of the solution by the coal,3. Solvent action of the solution toward the coal.4. Constancy of specific gravity during the test is affected by temperature changes, dilution, and evaporation.5. Personal technique of the test, such as the time the coal is in the liquid, rate of adding the sample to the liquid, stirring, time of draining, etc.6. Moisture content of the coal as tested."

Dec 1, 1947