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By E. B. Kester

Of the many angles from which coal can be studied it is evident that some have a direct and others have only an indirect bearing on its physical or chemical nature . The more drastic the treatment employed in an investigation , the more inferential become the conclusions permissible from the experimental evidence obtained . Thus , ultimate and proximate analyses tell something concerning age , behavior on carbonization , and possible industrial usefulness , but nothing regarding structure or composition in the larger sense . Strong oxidation reveals the fact that benzenoid , pyrrol , and furane rings are prevalent in the chemical substances present , and milder oxidation indicates that the mass of coal , as in the case of the peats and lignites , is humic in character . But beyond such points of information , very little additional can be gained by the use of these more or less vigorous measures . To gain wider knowledge of the actual constituents of coal substance as found investigators have worked out systems of separation by means of solvents , of which a large number have been employed at various times both singly and in combination . The list of solvents includes petroleum ether , benzene , toluene , xylene , ethyl ether , alcohol , acetone , carbon bisulphide , pyridine , quinoline , aniline , phenol , tetralin , glycol ethyl ether glycol ethylether acetate , glycol methyl ether , glycol diethyl ether , pine oil , mesityl oxide furfural , benzaldehyde , ethylene oxide , rosin , caustic potash in solvents , amyl alcohol plus pyridine , chloroform , carbon tetrachloride , acetylene tetrachloride , naphthalene , and others . Once a coal has been extracted it has become common practice to subdivide the extract by means of partial solution in other and weaker solvents . Thus , we find the oily and solid bitumens of Fischer ( 1 ) , 3 Bone ( 2 ) and others ; the alpha , beta and gamma constituents of Wheeler ( 3 ) ; the classification of Novak and Hubacek ( 4 ) embracing oils , resins A , resins B , bitumens An , bitumens Bn , and bitumens Cn ; Crussard's ( 5 ) malthenes , asphaltenes , and carbenes , borrowed from asphalt terminology; and the 40 or more subdivisions of the phenol extract of coal worked out by Frazer and Hoffman ( 6 ) . Perhaps the primary object of interest in these many researches has been to find the coking principle of coal , and to study it and to learn why certain coals form hard , wellfused cokes , and others merely fall to pieces during carbonization . The origin of the various constituents of the gas and tar , the temperature at which each forms , and something of the mechanism of their synthesis have also been sought , as well as new bases for adjudging rank .

May 1, 1931

By N. S. Dalal, X. Shi

"Electron spin resonance (ESR) spectroscopy has been employed to· examine the role of tetraperoxochromate( V) ions (Cro:-) and other Cr(V) species in the generation of hydroxyl (OH) radicals in the reaction of Cr(VI) with H2O 2 in biological media. In contrast to earlier suggestions, the present ESR studies using crystalline K3CrO8 as a source of Cro:- show that decomposition of Cro:- in water or in H2O 2 does not generate significant amounts of OH radicals. Addition of NADH to a solution containing Cro:- yields a Cr(V)-NADH complex, which readily reacts with H2O 2 to generate OH radicals. Similar results obtained from several other biological reductants, including vitamin B2 , indicate that a vacant coordination site on a Cr(V) complex facilitates its reaction with H2O 2 to generate ""OH radicals. We thus suggest that in biological media, reaction [3] instead of [1] or [2] is the major pathway for the OH radical generation: While the carcinogenic potential of Cr(Vl)-based compounds has been well established via epidemiologic and animal studies (1), the underlying biochemical mechanism is still not well understood (2). In a recent development, however, Kawanishi et al. (3) have reported that hydroxyl (OH)2 radicals might be the key species in the mechanism of Cr(VI) toxicity. As to the mechanism of the ""OH radical formation they suggest that Cr(VI) reacts with cellular hydrogen peroxide (H2O 2) to form the tetraperoxochromate(V) (Crog-) ions, which decompose to produce hydroxyl radicals. It was also suggested (3) that the ""OH radicals thus produced cause genotoxicity via DNA base modification and deoxyribose phosphate backbone alterations. More recently Aiyar et al. (4) reported the detection of OH radicals in the reaction of Cr(VI) with H2O 2 in biological media, including the reaction of ""OH radicals with deoxyguanosine to generate 8-hydroxydeoxyguanosine adducts, confirming that ""OH radicals could indeed play a significant role in the mechanism of Cr(VI) toxicity. However, the mechanism for the ""OH generation was not clarified, although the role of Crog- ions as possible precursors was mentioned, somewhat along the lines suggested by Kawanishi et al. (3). The possibility of the participation of Crog- in the ""OH generation has also been indicated by Sugiyama et al. (5), since they mention that vitamin B2 enhances the formation of""OH radicals in the reaction of Cr(VI) with H2O 2 because of the generation of Crog- in the reaction."

Jan 1, 1990

By John C. Gagliardi

The U.S. Bureau of Mines, in cooperation with Carter Mining Co., conducted vibration tests of four off-road vehicle seats. The purpose of the tests was to determine which seat provided the best vibration attenuation under laboratory conditions. Laboratory tests were constructed to simulate the mining vibration environment within the limitations of the test equipment. The acceleration test levels and corresponding response of the seats were low compared to ISO 2631's fatigue-decreased-proficiency time limits. Two of the seats employed mechanical suspensions and two seats employed air suspensions. The seats were tested using a 22,241-N (5,000-lbf) electrodynamic shaker. Mechanical suspension seats were tested with various preload-to-mass ratios (PMR's) and cushion densities. Air suspension seats were tested with various air pressure levels and seat cushion densities. Air suspension seats provided good vibration attenuation if pressurized greater than 552 kPa (80 psi). Mechanical suspension seats' attenuation performance decreased if the PMR exceeded 9.8. Seat cushions of lower density provided less vibration damping.

Jan 1, 2010

By B. H. Caudle, A. D. PUCKETT

This paper summarizes precent knowledge of the ignition qualities of pure hydrocarbons likely to be present in modern Diesel engine fuels, as shown by an extensive search of the technical literature. The report also discusses the possible significance of cetane number and hydrocarbon struc- ture. Cetane or cetene numbers, and other physical properties, are tabu- lated for about 100 hydrocarbons, and a bibliography is appended. In recent years the Diesel engine has enjoyed increasing popularity due to its dependability, inherent characteristics of fuel economy, and the fact that it operates on a fuel that hitherto has been available in comparatively large quantities at a low price. These qualities have en- abled the compression-ignition engine to compete very favorably with other types of prime movers in many fields and have led to predictions of fur- ther rapid expansion in the application of Diesel power. In a survey of the field of all petroleum fuels for combustion engines, Holaday et al (9) have predicted that by 1948 railroads will be using 10 times as much Diesel fuel as was used in 1939 and that over-all consumption will have doubled that of 1939. Other estimates of the yearly demand for Diesel fuels five years hence vary from 2,6 to 5 times the amount used in 1944. Into this picture has come the question of whether the greatly in- creased production to meet this estimated demand is compatible with the maintenance and possible improvement in quality of fuels necessary to satisfy future engines. Unfortunately perhaps for the Diesel engine, factors other than those of simple arithmetical multiplication must be considered. For example, the consumption of oil in central heating plants doubled from 1935 to 1943, and a further increase of 57 percent of the 1943 demand is expected by 1950. Jet propulsion has been developed to the stage where it is entirely practical for military aircraft. Catalytic cracking plants, many of which were constructed to meet the war- time accelerated demand for high-octane gasoline, are taking their place in the refining industry. All these developments, as well as the Diesel engine, require material of approximately the same boiling range. Virgin gas oils make excellent burner fuels, perform most satisfactorily in the gas-turbine units for aircraft according to present information, and are at a premium as catalytic cracking stock.

Jul 1, 1948

By Alexander May

This report describes a new method of weighing based upon observing the apparent weight of an object ill two separate pure gases. The method is presented in terms of experimental data which prove its soundness, but does not attempt to show the maximum accuracy possible with this technique. The new method incorporates the underlying principle that the apparent weight of an object is a linear function of the density of the atmosphere in which the object is weighed. The coefficients of this linear function are the true mass and volume of the object. From this functional relationship the true mass and volume of the object may be determined.

Jan 1, 1970

By Robert M. Becker

Particle mixtures were sampled in the laboratory, using ordinary sampling procedures, to determine whether or not the compound-multinomial probability distribution and other developments of part 2 agreed with experimental results. The objective was accomplished by the Bureau of Mines by comparing the moments and moment relationships of the appropriate probability models with their corresponding experimental values over a fairly wide range. The overall agreement between the corresponding theoretical and experimental values is both good and complete. The results demonstrate that sampling to a constant amount, such as weight, of items per sample is not the same, in general, as sampling to some constant number of items per sample. The results seem to confirm all the developments of part 2 and the application of the compound-multinomial function to bulk sampling.

Jan 1, 1965

By R. D. Brown

This Bureau of Mines report describes a new methodology for identifying and sorting scrap metals using two modern portable instruments: a thermoelectric sorter and a hand-held emission spectroscope. The method, tested on a 27-sample stainless steel and superalloy array, makes it possible to group and/or identify a typical mixture of high-value metal scrap in two or three steps, whereas as many as seven or eight steps are needed to perform the same separations using chemical spot tests. A portable fluorescent X-ray analyzer identified 19 of the 27 alloys in the sample array by name or type; these alloys are included in the microprocessor memory. The remaining alloys were identified by using the analyzer in its elemental analysis mode and comparing the results wit.h alloy specification chemistry.

Jan 1, 1984

By E. L. Garton

The Bureau of Mines for a number of years has been conducting an investigation of crude petroleum from producing fields in the United States and the Western Hemisphere and has published a series of reports on these fields. Analyses of crude-oil samples from many oil fields of Oklahoma are given in Bulletin 2913. Analyses of 21 representative crude oils from various producing zones of the Oklahoma City field are given in this report. A close study of the analyses reveals very few differences in the general characteristics and chemical properties of these oils.

Jan 1, 1932

By Michael Gibbons

A method of monitoring roof stability in underground mines by detecting the changes in resistivity of roof material was tested. The device built by the USBM was tested over a 16 month period at the White Pine Copper Mine in White Pine, Michigan. Three falls of ground were monitored by means of as many as 11 sensors. Data indicate a correlation between changes in resistivity and impending structural failure. Problems were encountered with the high roof electrode impedance in the winter and spring due to the drying out of the roof material. Difficulties also developed in obtaining a permanent bond between the roof rock, the conductive epoxy and the electrode plate. Some data were lost due to timer and fuse problems within the unit. These were eventually rectified.

Jan 1, 1979

By H. P. Greenwald

About mid-December 1936, the safety director of a large coal corporation visited the authors at the Bureau's Experimental coal mine to discuss a rock-dust barrier he had invented primarily for use in trackless entries of coal mines. The rock dust in this device was carried in its original paper containers and means were provided for ripping these open so that the dust might be scattered in the path of an explosion. The inventor termed the device a "bag barrier", and this term has been adopted in the present paper for convenience. At that time the device was in an early stage of development, and the inventor felt that the barrier should be tested to determine whether it had enough promise of being successful to justify further development. The matter was taken under consideration and finally three tests were made during the week of February 15, 1937. It was concluded that while the device did stop an explosion in two of the three tests, it was much loss effective than ordinary rock dusting, and that too few data were obtained to permit direct comparison with tests of other barriers. Apparently, the conditions under which the device could, be successful 'Were somewhat limited, out the limits could not be defined without additional tests.

Jan 1, 1938

By George H. Holmes

This paper , which describes mining methods and milling and manufacturing operations at the gypsum property of the Blue Diamond Corp. , is one of a series on mining methods and practices being prepared by the Mining Division of the Bureau of Mines . The property comprises about 4,000 acres and is in secs . 30 , 31 , 32 , and 33 , T. 21 S. , R. 59 E. , and secs . 5 , 6, 7 , 8 , and 9 , T. 22 S. , R. 59 E. , M. D. B. and M. , Clark County , Nev . , approximately 23 miles by paved highway southwest of Las Vegas , Nev . ( fig . 1 ) . This circular summarizes the history of company operations , describes physical features , labor and living conditions , and the geology . The method of exploration is outlined , and the section on mining methods contains descriptions of open - pit and underground systems , including loading and transportation methods . The crushing plant and tramway are described , as well as plaster-mill and board -plant practices . The boiler plant and organization are described , and wage scales are contained in the concluding section of the circular .

Mar 1, 1950

By IRVINGC. ALLEN, W. A. Jacobs

Realizing the great importance and wide application of petroleum and its products for fuel,lighting and lubrication, and the absence of authentic and comprehensive information in the literature on the commercial value of American petroleums, the United States Geological Survey has for a number of years' been making analyses and other examinations of these oils and their products. In 1907 the technologic branch of the Survey began a study of certain economic problems having to do with the natural mineral oils. The prime object of the investigations was to determine the economic value of the petroleums and natural gases in the United States with special reference to the supplies in the public lands, and to ascertain how these resources could be utilized in the industries withleast waste and greatest efficiency. This work, which is now being conducted by the petroleum section of the Bureau of Mines under authority of the act of May 16, 1910, will include the collection at the wells and refineries of information as to the following details: Facilities for handling and storage at the wells. Facilities for transportation, whether by pipe line, rail, or water. Distance to the nearest port or center of industry and time necessary for delivery. Facilities for storage at such point of delivery. Suitability of the crude oil for fuel, or the treatment necessary to convert itmost economically into the best fuel. Best processes of refining or of converting the crude oil into its many products. The examination of these products. The utilization of the by-products and residues of the refineries. The collection of adequate and reliable samples, and the complete chemical and physical examination ofthese samples in the laboratory.

Jan 1, 1911

By Daniel E. Sullivan

This Bureau of Mines publication examines the potential impact on minerals of the tariff and nontariff agreements that resulted from the Tokyo Round of the Multilateral Trade Negotiations, which were conducted under the auspices of the General Agreement on Tariffs and Trade. These agreements will affect minerals by reducing tariff levels and by changing rules by which they are traded internationally.

Jan 1, 1981

By M. C. Irani

The Bureau of Mines has designed and put into operation a fail-safe control system for use in underground coal mines equipped with methane drainage pipelines. This control system can detect certain unsafe conditions and respond by automatically shutting off the flow of methane from the degasification borehole to the drainage pipeline. Methane flow is shut off when the methane content in the return airways reaches a predetermined level (typically 1.5 pct), when the methane drainage pipeline is ruptured by roof fall, or when there is an electric power failure. The fail-safe control system was designed using commercially available components and a methane analyzer system previously developed by the Bureau. The fail-safe system consists of a unit that combines a shutoff valve and pneumatic valve actuator, and electronic and mechanical equipment designed to detect hazards and effect shutdown. The fail-safe control system was designed to meet regulatory requirements issued by the Mine Safety and Health Administration (MSHA), U.S. Department of Labor, and State regulatory bodies for the safe operation of underground methane pipelines used for mine degasification. MSHA has inspected and tested this system and permitted its use in two mines. The Bureau installed the fail-safe system in two working coal mines, where successful performance has been demonstrated.

Jan 1, 1979

By Donald E. Redmon

This Bureau of Mines report reviews injury experience in the metallic mineral industries for 1966-67. For each of the years, 27 tables summarize disabling work injuries by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

7133. Clewell, D. H. The Gravimeter. Prec. and Trans. Texas Acad. Science 1941, Austin, Tex., vol. 25, 1942, pp. 86-88. Static gravimeters, unastatized and. astatized, are considered to be the most practical for oil exploration. One gravimeter is described using a beam whose moment about a pivotal axis is elastically balanced. Magnetic or electric fields are deemed unsatisfactory for balancing gravitational force because they cannot easily be kept constant. The gravimeter described is capable of detecting a change in altitude of 3 inches and a change in latitude of about 150 feet. V. S.

Jan 1, 1944

By G. E. McElory

"INTRODUCTION The subject of mine and tunnel ventilation has two broad aspects - (1) what atmospheric conditions to obtain in underground openings and (2) how to maintain the desired conditions efficiently. The first relates primarily to quantity requirements of ventilating systems, whereas the second relates more particularly to pressure requirements. Both, therefore, determine power requirements, which is the deciding factor in any system of mine or tunnel ventilation.Both divisions of the subject have received considerable attention from the Bureau of Mines since its inception in 1910 in the form of research, service, and correlation and dissemination of information. Numerous papers on various Phases of the subject have been published, of which a selected list, numbered and arranged in chronological order by type of publication, will be found at the end of this Paper. One of these, Technical Paper 705 (25) 2/ gives a complete bibliography of Bureau of Mines publications dealing with health and safety. As indicated by the selected list of publications accompanying this paper, the health and safety aspects have received most of the attention devoted to this work, chiefly because these have been dominant factors in Bureau policy, but partly because these aspects lend themselves to laboratory research and small-scale field studies. Although considerable attention has also been devoted to the engineering aspects of mine and tunnel ventilation, there has been, in the opinion of the author, who has been engaged on this phase almost continuously for the last 30 years, only sporadic recognition of the vital effect this phase of the work could have on improving health and safety conditions. As a matter of fact, ventilation activities have constituted but a very minor part of the total work of the Bureau of Mines, as, except for a few years in the nineteen twenties, there have been only a few short intervals when more than two or three men were engaged in field work and a similar number in laboratory research directly related to mine gases or mine air."

Mar 1, 1950

By John A. Ruppert

1. It has been proposed that the addition of enough limestone to an open -hearth s lag to give a CaO-3P2O5 ratio of approximately 2-followed by SiO2 firing in an oxidizing atmosphere under the proper conditions of time and temperature will result in a clinker having a magnetic phase containing a preponderance of Mn, Fe, Al, and Mg as oxides and a nonmagnetic phase consisting for the most part of a phosphorus-containing dicalcium silicate. It has been postulated further that the metal oxide phase can be recovered by fine grinding and magnetic separation. These broad principles have been substantiated by numerous clinkering operations made in an electrically fired studio-type kiln, a batch rotary kiln, and a continuous rotary kiln and by magnetic separations made in a Davis -tube separator and a laboratory-size Jeffrey-Steffensen three -roll continuous separator. 2. Quenching the clinker after firing seems to improve its grindability. Microscopic examination of the ground clinker indicates .that the oxide phase grinds down at a somewhat faster rate than the silicate phase. 3. Very fine grinding is necessary to approach liberation, of the oxide phase from the silicate phase. Grinding to ininus-325-mesh, followed by magnetic separation, gave only a rougher concentrate, which had to be reground before final separation. 4. Although the manganese content of the final concentrate was higher, there was some evidence that manganese recovery was lower from a clinker made from a flush s lag than one made from a mixture of tap and flush slags. A possible explanation is that a clinker made from a mixture of slags has a higher iron content and hence is more magnetic and more easily separated.

Jan 1, 1952

By Michael E. Henderson

The U.S. Bureau of Mines (BOM) constructed the Hydraulic Transport Research Facility (HTRF) to investigate the hydraulic parameters relating to the transport of coarse coal. To achieve these goals in a timely and efficient manner, the Bureau contracted to Boeing Services International, Inc. (BSI) the responsibility of operating the HTRF and providing technical support. This data report is a summary of the testing and data results for the period from 6 September to 9 September 1983. The testing covered herein is for coarse 2-in by 0 (minus 50 mm) Pittsburgh Seam run-of-mine (ROM) coal in a 12-in (300 mm) pipeline, at velocities ranging from 8 to 16 ft/s (2.4 to 4.9 m/s) and at concentrations ranging from 15 to 50 pct.

Jan 1, 1985

By Milton B. Hall

This report discusses in detail laboratory and pilot-plant tests conducted from January 1951 until January 1955 at the Northwest Electrodevelopment Experiment Station of the Bureau of Mines, Albany, Oreg., on defluorination and recovery of evolved fluorine from phosphate rock. Results of use tests of defluorinated phosphate rock by cooperating agricultural colleges and the United States Department of Agriculture are also included. In 1954 the consumption of fluorspar, the only domestic fluorine-bearing mineral of commercial importance, was approximately 478,000 short tons; 245,000 tons was from domestic mines. The production of marketable phosphate rock in the same period was about 13,800,000 long tons. Of this total amount, approximately 15 percent was produced in the West. From the viewpoint of conservation and utilization of fluorine as a natural resource, it is interesting to note that the total estimated quantity of fluorine in domestically produced phosphate rock is more than double that present in domestically mined fluorspar.

Jan 1, 1958