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By John M. Devine

The oxygen bomb-is used extensively for determining sulphur in petroleum, although it has been suspected that the results obtained with this method are somewhat lower than the true varies. In this paper are compared the results given by the oxygen-bomb and Carius methods, the latter being generally accepted as the standard procedure for the determination of sulphur in organic compounds. The Carius determinations given hero were made in connection with a special study of this method.4 Only petroleum oils of the less-volatile type are covered in the present work. Summary and Conclusions. When used with oils containing 2.3 to 0.15 per cent of sulphur the oxygen-bomb method gives results that are consistenly if slightly lower than those obtained with the Carius method. This variation, for the oils used, amounts to 3.1 per cent (on tae basis of sulphur present) for the sample containing 2.47 per cent of sulphur, and gradually increases (as the percentage of sulphur in the oils decreases) to 7.3 per cent for the oil containing 0.15 per cent of sulphur. With the oils studied the presence of ammonium nitrate in the bomb does not influence the results materially.

Jan 1, 1928

By Graham W. Mark

A chemical method of analysis for beryllium was developed recently in Bureau of Mines laboratories. In this method, quinalizarin (1-2-5-8 tetrahydroxyanthraquinone) in N/4 NaOH is used as a colorimetric titration reagent. This solution has a reddish-purple color, whereas the solution containing equivalent amounts of beryllium and the dye is rather blue. In the titration procedure, standard quinalizarin solution is added to the unknown beryllium sample and to two standard beryllium samples of different but known concentrations. Then adjustments in concentrations of BeO in the two known and of quinalizarin in all three are made until the red-violet shade of the unknown is halfway between that of the two knowns. The amount of BeO in the unknown is calculated from the known BeO content of the solutions between which it lies. It is extremely difficult to distinguish the slight differences in shade of these solutions without the use of a proper light filter, especially when the concentration is over 0.1 mg. of BeO, so a study was made of the transmission characteristics of quinalizarin in N/4 NaOH and of the corresponding beryllium complex to determine what filter would give the most contrast.

Jan 1, 1950

By J. B. Gayle

Although heated circuits frequently have been employed in the conditioning stases of certain flotation processes, particularly the flotation of fluorite, the control of temperature is not generally considered economically feasible for the flotation of coal. This viewpoint, although widely held, can neither be substantiated nor refuted by reference to published data. Some evidence is available, however, that temperature is an important variable in the floatability of coal as well as other minerals. For example, Gayle and Swelley4 found that contact angles for coal and related substances were definitely dependent on temperature. Bailey and Whalan5 showed that changes in pulp temperature may exert a pronounced influence on recoveries of coal in batch flotation tests. The present laboratory-scale investigation was undertaken to obtain information about the effects of changes in pulp temperature on coal flotation recovery and also on the selectivity of separation possible using different reagents. The results indicated that flotation recoveries were markedly affected by temperature variations when certain reagents, particularly simple aliphatic alcohols, were used. For other reagents, particularly kerosine, flotation recoveries were substantially independent of variations in pulp temperature. Release-analysis results indicated that temperature variations did not greatly affect the selectivity of separation possible with the reagents tested.

Jan 1, 1961

By M. J. Beus

The Bureau of Mines, under a cooperative agreement with Hecla Mining Co., is conducting a rock mechanics study of the 6,200-ft-deep circu-lar, concrete-lined Silver Shaft in northern Idaho. The objective of the project was to instrument and evaluate lining behavior and rock de-formation when a deep shaft is constructed in a high in situ stress field and anisotropic rock mass. Rock mass displacements were moni-tored with multiple-position borehole extensometers. Liner stress and strain were measured with concrete pressure cells and embedment strain gauges. Field data from the 5,955-ft test level show that rock displacement is controlled by rock mass anisotropy. Liner stress and strain levels reflect the high in situ stress field as well as nearby station and raise construction. Maximum stresses measured in the lining, as a result of shaft excavation, are about one-third of its compressive strength. Subsequent loading pocket excavation resulted in signifi-cantly increased stress and strain levels in the liner. Continued monitoring and preliminary analysis of the data indicate that concrete-lined, circular shafts are stable for the high, unequal horizontal stress fields and rock anisotropy encountered in deep-level mining. Adjacent development work can be expected to significantly alter the initial stress and displacement conditions.

Jan 1, 1984

By H. William Zeller

The Bureau of Mines performed laboratory research into the effects of a barium-based fuel additive (the "postflame" type) on diesel particulate matter (DPM) emissions. The 5.6-L, six-cylinder test engine is typical of types certifiable for use in underground mines. Test parameters consisted of additive concentration and engine loads, speed, and air intake restriction. DPM emissions, including condensed volatiles, were measured gravimetrically. Also measured were gaseous emissions including carbon monoxide, nitrogen oxides, and hydrocarbons. The fuel additive was effective, reducing DPM up to 75 pct, when used at a concentration of 0.09 wt pct (one-fourth of the concentration recommended by the manufacturer). The additive was most effective at the highest fuel-air ratios, reducing DPM from 400 mg/m3 for untreated fuel to 120 mg/m3. At light loads, 25 pct of full rated, no DPM reductions were measured. Based on these results, the additive is recommended for use in diesel fuel, at a concentration of 0.09 wt pct, to power underground mining equipment as long as certain conditions are met: that a beneficial DPM reduction is verified, that the minimum required quantity of additive is used, and that potential adverse effects such as increased nitrogen oxides are checked.

Jan 1, 1990

By L. C. IlsLey

Cooperation between the United States Bureau of Mines and the Safety in Mines Research Board of Great Britain, continuous since 1924, has made possible this and other papers on safety subjects. Grateful acknowledgment is made to representatives of the Board for their assistance in arranging visits to several mine safety stations, and to F. R. Wynne, Deputy Chief Inspector of Mines, for arranging visits to mines in Great Britain and other countries in Europe. During the summer of 1927 the writer had the privilege of visiting the mine safety testing stations in great Britain, Belgium, Germany, and France, in the order named. All of these countries have large coal mines, many of which are rated as gassy. Therefore, when the installation of electrical equipment is contemplated, each of these countries is confronted with the same safety problem as is the United States - the development of electrical equipment that will not ignite gassy atmospheres which through neglect or accident might surround the equipment. The means employed by these countries in safeguarding gassy mines should therefore be of general interest to safety engineers in American coal mines, and it is proposed to give a brief survey for each of the four countries mentioned. The third of these surveys covers conditions in Germany.

Jan 1, 1929

By E. E. Maust

The literature on the activation of sphalerite for flotation by short¬chain xanthates leaves unanswered the question of whether a compact surface film of activator sulfide is necessary or merely sufficient for high flotation recoveries. Studies by Guarnaschelli and Plaksin indicate that xanthate adsorption and flotation of sphalerite are increased with increasing hole/ electron ratio. These results, and the known acceptorlike behavior of many heavy-metal impurities in zinc sulfide, suggest that activation may result from a traditional semiconductor doping effect at the surface. Using the theory of chemisorption states on ionic crystals as developed by Levine and Mark, the Bureau of Mines has carried out A calculation to estimate the surface-state energies of various metals when they are substituted at zinc sites on (110) sphalerite surfaces. Based on a simple Madelung-Born treatment of ionic solids, the calculation indicates that many of the metals known to activate sphalerite for subsequent flotation have lower surface-state energies than nonactivators. The results of these calculations are discussed from the standpoint of consistency with the proposed activation mechanism and observed flotation results. The satisfactory agreement obtained is taken to be support for the proposed mechanism, and further elaboration of a surface-doping model is attempted.

Jan 1, 1976

By G. W. Jones, R. E. Kennedy

"INTRODUCTION In the manufacture, storage, transportation, and use of combustible gases and vapors, explosion hazards, which at times may be present when air becomes mixed with the gases and vapors, become of primary importance. Such conditions are especially dangerous where large volumes of gaseous atmosphere are involved, because an explosion under such circumstances is capable of doing tremendous damage to both property and personnel.Because of its interest in safety in the mining and allied industries, the Federal Bureau of Mines has investigated, and published results dealing with, the explosibility of various types of combutible atmospheres. The explosion hazards of natural gases have received attention, and results giving the limits of inflammability and ignition temperatures in air have been determined and published. 4/ Other investigations have shown how explosions of natural gas-air mixtures may be prevented by the addition of nitrogen and carbon dioxide. 5/Because of the increased demand for crude oil for war purposes, the application of secondary-recovery methods of stimulating oil production have received considerable attention during the last few years. The process consists in the injection of natural gas into partly depleted oil wells to cause the oil in the sands to flow into producing wells and so increase the amount of recoverable oil. 6/"

Feb 1, 1945

By Robert Bottge

When a company develops a mineral property in a remote area of Alaska, it must consider how best to house its personnel. This Bureau of Mines report examines the economics of two options: company towns and company camps. The price required to maintain a 15% discounted-cash-flow rate of return (DCFROR) was derived for hypothetical 1,000-st/d cut-and-fill mines and 50,000-st/d open-pit mines located in three different regions of the State, One set of hypothetical mines utilizes a townsite; the other utilizes a relatively new concept, a fly-in camp or commuting operation, in which two shifts of employees operate the mine and all associated facilities for 1 week before being replaced by a second crew. The study shows that operating costs were higher for mines employing the commuting option than for mines having a company town because of the additional wages paid for overtime hours; however, the price required to obtain a 15% DCFROR for the single-product copper concentrate, f.0.b. the mill site, was significantly lower owing to the lower investment costs for the camp-type operation. The economic advantage for those mines utilizing the camp increases from south to north and from the coast toward the interior.

Jan 1, 1986

By Michael Rieber

Rail cars are referred to as "yellow-balled" when they are sufficiently old or damaged to preclude their efficient operation on long-haul or main line routes. For most coal carrying railroads, their alternative value is salvage. This, however, does not necessarily preclude their effective use, on a limited basis, by small mines located near existing trackage. Because of age, the sizes of these hopper and gondola cars ace currently 50 and 70 tons rather than the 100 tons commonly built at the present time. As a gathering system, yellow-ball rail could provide an alternative, particularly in Kentucky, western Pennsylvania and west Virginia, to coal trucks, conveyor belts and pneumatic pipelines [4, p.17], belts and pneumatic pipelines. Rail service of this type provides a limited alternative to track abondonment, a possible financial return to a railbank [3], a direct contribution to service demand on main lines, and a means by which many small eastern coal mines could retain or regain competitive viability [4]. In terms of energy efficiency, compared to trucking coal, the total direct energy impact (fuel) of yellow-ball rail can be expected to range from 280-990 Btu/ton-mile while that for trucks ranges from 1850-3120 Btu/ton-mile [2].

Jan 1, 1977

By Marilyn Biviano

This analysis was conducted in response to concerns raised by the Chairman of the Energy and Commerce Committee of the House of Representatives regarding the potential impacts on automobile production, GNP and employment resulting from embargoing south African supplies of the platinum-group metals, platinum and rhodium. This analysis should be considered an addendum to the recently released study in which the direct economic costs I of a U.S. embargo on selected South African strategic and critical materials are estimated. The estimated GNP and employment impacts result when a mineral shortage reduces domestic industrial production and are in addition to the direct costs estimated in the earlier study. The direct cost to this nation resulting from a decision to embargo six south African strategic and critical minerals was estimated at $1.85 billion per year during the 1988-1992 time frame of the study. The estimated direct costs include the costs to U.S. consumers resulting from higher strategic mineral prices, lower mineral consumption, and the cost of developing higher cost domestic mineral resources. A large proportion of the costs result from the shortage of the two metals: platinum and rhodium. The average direct annual cost of embargoing is estimated at about $1.4 billion for platinum and $384 million for rhodium.2

Jan 1, 1988

By D. E. Hirsch, J. W. Davis, Norman G. Foster, F. G. Schwartz

This investigation was undertaken to identify nitrogen , oxygen , and sulfur compounds (polar components ) found in catalytically cracked distillate fuel . It is significant that these compounds concentrate in the sediments and gum that form when the fuel is stored . The polar components were divided in three portions by elution from a chromatographic column filled with alumina . After the hydrocarbons were washed through the column with pentane , a benzene eluted extract was removed followed by an ether eluted extract and then an alcohol desorbed fraction . These extracts were individually distilled in a molecular still and the fractions were analyzed by gas chromatography , mass spectrometry , infrared spectrometry , and elemental and functional analyses . Naphthalene and its homologs , phenanthrene and its homologs , and other compounds such as methyl indene , C₂ quinolines , phenyl indan , and the benzothiophenes , appear in the benzene extracts . Quinolines are the major components of the lower boiling fraction of the ether extract , although carbazoles , acridans , and indoles are present in some concentration . Elemental and functional group analyses of the alcohol fraction indicated 10 percent of the distillate portion was nonhydrocarbon , and in this portion the average molecule contained more than one nonhydrocarbon element . Compounds of such complexity are not well known , and standards for positive identification are limited .

Jan 1, 1963

By Robert S. Sanford

Intensive investigations of domestic manganese deposits were conducted by the Bureau of Mines and the Geological Survey during the earlier part of the war minerals investigations when there was doubt that the quantity of manganese needed to produce the greatly increased tonnage of steel demanded for war supplies could' to obtained from its customary sources. Domestic deposits of ores that contain sufficient manganese for direct production of ferromanganese essential in steel Manufacture are generally small, and the bulk of the supply is imported. One of the few large deposits of low-grade manganese ore known in the United States is in the Artillery Peale district in southern Mohave County, Ariz. Manganiforous sediments underlie a very large area. Several large groups of claims, covering the most of the manganese-bearing ground, wore assembled in 1929 and 1930. The greater part of this area was leased by the M. A. Hanna Co. in 1937. Investigations by engineers and geologists for this company revealed that the average content of manganese is very low; but that the Maggio Canyon area, about 180 acres, contains higher-grade material. The company put down 28 vertical diamond-drill holds to explore this ground, under the direction of B. N. Wobbor, geologist.

Jan 1, 1948

By R. S. Dean

A large metallurgical experiment station at Salt Lake City to house the works of the Bureau of Mines in the intermountain area properly has long been projected. It finally became possible when a Public Works Allotment of $300,000 was set aside for building and equipment. With the new building assured, the Bureau of Mines decided to move the headquarters of its Metallurgical Division from Washington, D. C., to Salt Lake City, Utah. It was felt that this move would simplify they administrative work of the chief engineer of the division, as all stations devoted primarily to metallurgical work are west of the Mississippi. These include Rolla, Mo.; Minneapolis, Minn.; Pullman, Wash.; Reno, Nev.; Berkeley, Calif.; Boulder City, Nev.; and Tucson, Ariz. In addition to these stations will groups, of investigators working on metallurgical problem, are maintained at Pittsburgh, Pa., and College Park, Md. Salt Like City was clearly a more central point for the direction of this scattered work than Washington, D. C. The building (fig. 1, A and B) was designed from general plans worked out by the authors of this paper. Contraction was begun in March of 1939, and by the end of the year the Metallurgical Division had moved, into its now quarters.

Jan 1, 1940

By A. B. Hooker

A list of permissible mine equipment, tested and approved by the Bureau r. Mines previous to January l, i-)4, , was published in Bureau c Moines In ornation Circular 7207.3/ The l ,.t c -. that dote was complete as to equipmentthen available and in current Information Circular 7210,?+/ published as a supplement thereto, listed equipment approved during; the calendar 1942. Information Circular72x'3,_/ published as a second supplement thereto, ! listed equipment approved during the calendar year 1943. The present listis. Another supplement covering approvals issued during the calendar year 1c)44. The items are numbered crud to indicate the consecutive order in which each typo of machine or device was approved _.c?. in its particular classification. Thus Information Circular 7207 gave 1,t drills and drilling much fines on the Bureau'sactive.. d active list Ih: additional anal approval: were given in 1942 the three issued in 19 and one issued :n 1944- bring the total to `3. Item 111, under. Loading Machines and conveying appeared in lnformation Circular 7207. It is repeated ',tore to _how that on j,,l was granted Curia 1the optional of this loader when modified .'or 2 0. alt ciruits .]

Jan 1, 1945

By J. B. Littlefield

This study is one of a number conducted to determine the concentration of dust in the air during the complete cycle of operation in wet drilling information as to various factors connected with drilling in mining operations is considered to be of definite value in the control and prevention of air dustiness, and it is particularly desirable to ascertain What features of present-day wet-drilling operations in mine work contribute to dust disease and to remedy deficiencies when they are found. ACKNOWLEDGMENTS A testing alit through rock strata is being developed by the Mining Division of the United States bureau of Mines at Mount Weather, Va., and the tests discussed in this report were conducted there. This experimental alit in rock, constitutes a typo of laboratory where mine conditions can be closely simulated and where many of the variables likely to occur in an actual mine can be eliminated or at least controlled with reasonable effort, thus affording maximum opportunities to secure fundamental data uncomplicated by extraneous conditions. The authors wish to acknowledge the valuable assistance and cooperation of several members of the Mining Division, particularly C. F. Jackson, chief engineer, McHenry Mosier, associate mining engineer, and G. E. McElroy, supervising engineer, mine ventilation.

Jan 1, 1938

By Charles H. Parr

A testing program was conducted to determine the suitability and reliability of adhesives and polycarbonate lenses for extended use in luminaires in mine environments. Polycarbonates were exposed, for periods up to 36 months, to four environments including ultraviolet light, humidity, intermittent water spray, and heat of either 180°F or 407 in various combinations. Rod impact tests on the exposed lens material indicated, that polycarbonate functions well under all 180°F environments and could be used with confidence for periods exceeding the test period, for as long as ten years, with a suit) able safety factor employed in design. The specimens exposed at 240°F showed decreased toughness after 24 months' exposure. Extrapolation of these data was deemed to be risky. A 462-day compatibility test between polycarbonate and six hydraulic fluids was run on stressed PC beams. One fluid caused beam breakage in less than one day, while three caused breakage at intermediate times. Two fluids exhibited essentially no effect on the PC when compared to a control. Epoxy and silicone adhesives were tested as lens adhesives and sealants. Three epoxy combinations tested showed low and erratic failure stresses. A room-temperature-cure silicone adhesive functioned extremely well for time periods up to 36 months and temperatures u2 to 240°F.

Jan 1, 1985

By F. A. Rutledge

Mercury deposits were discovered in 1941 in the sedimentary rocks of the Cinnabar Crook area, near the head of the Holitna River drainage in southwestern Alaska, by Russell Schaefer and Harvey Wincholl of Sloitmut, Alaska. High-grade float was found in both Canary Gulch and Cinnabar Gulch, and indications of other deposits wore found in Aldor and Broken Shovel Gulches. Schaefer and Winchell's exploration in 1942 and 1943 revealed placer deposits of cinnabar along Canary Gulch. During prospecting on Canary Gulch, 3,600 pounds of ore was recovered from the detrital material on the Lucky Day lode at the head of the gulch. When retorted, this ore was reported by the owners to have produced 26 flacks of quicksilver. During the summer of 1943, Wallace M. Cady and Charles A. Hickcox, of the U. S. Geological Survey, spent 4 weeks mapping and investigating the area. Bruce I. Thomas and Harold C. Pierce, mining engineers of the Bureau of Mines, examined and sampled several deposits in September 1943. Following their preliminary examination, in view of the exceptionally high-grade cinnabar present, additional investigation by the Bureau of Mines was recommended. A program of trenching, test pitting, and sampling to delimit the deposits was completed during the summer of 1947 under the direction of the author.

Jan 1, 1950

By W. W. Adams

The quantity of explosives sold in the United States in January, 1931, for domestic consumption, amounted to 368,100 kegs (9,202,500 pounds) of black blasting powder, 4,610;000 pounds of permissible explosives, and 16,533,000 pounds of high explosives 'other than permissible. These figures are based on reports received by the United States Bureau of Mines, Department of Commerce, from nearly all manufacturing companies, and include an estimate of sales by several companies that do not furnish monthly reports. Reports actually received from manufacturers showed soles of 365,977 kegs of black blasting powder (consisting of 220,892 kegs of granular powder and 145,085 kegs of pellet powder), 4,687,900 pounds of permissible explosives, and 15,496,152 pounds of high explosives other than permissible. Sales in January, 1931, were smaller than in January, last year, the decreases being 14 per cent for black blasting powder, 19 per cent for permissibles, and 17 percent for high explosives other than permissible. Sales in January 1931 when compared with soles in December 1930, show increases for all three classes of explosives as follows: 2 per cent for black blasting powder, 16 per cent for permissible explosives, and 7 per cent for other high explosives.

Jan 1, 1931

By W. Beckering

In characterizing tars obtained by the low-temperature carbonization of North Dakota lignite, infrared spectra have been an invaluable aid in both qualitative and quantitative examination. Quite, early in the tar-research program of the Federal Bureau of Mines it became evident that the small number of published spectra available for hydroxy-aromatics would be inadequate for comparative purposes when dealing with the wide range of compounds present in coal tar; therefore, compiling a catalog of spectra was begun as a continuing part of the tar program. Because these spectra should be valuable to other investigators in this and related fields, they are being presented in these reports. This supplement to the original publications presents the spectra (figs, I to 32), representing 32 compounds, largely phenolic materials. The major problem of this project has been the availability of materials for examination. Most of the compounds included in this supplement were synthesized at the Bureau of Mines Lignite Research Laboratory. Some were obtained from commercial sources, whereas the compound 2'-hydroxy-l-phenylnaphthalene was synthesized at the Bureau of Mines laboratory in Bruceton, Pa. The spectrum of 2-ethyl-4-methylphenol, figure 32, is a correction of the spectrum presented as figure 26 in the original reports

Jan 1, 1961