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By G. R. Hopkins

The petroleum-refining industry established a. new record in fuel effieciency at refineries in 1936, when 597,000 B. t. u. of heat mere required to refine a barrel of crude oil, compared with an average of 615,000 B. t. u. in 1935 (see fig. 1). The principal factor in the 'indicated gain in fuel efficiency at refineries in 1936 was an increase in crude runs of 11 percent over 1935. A large part of the heat utilized at refineries is consumed elsewhere than under stills, or in ways quite independent of crude-oil distillation. In other words, as the operating ratio ( crude runs divided by capacity) for re- fineries increases toward tine maximum of 100 percent, the fuel requirements show progressively smaller increases and the average B. t. u. consumption per barrel of crude refined declines.

Jan 1, 1938

By W. W. Adams

Reports received by the Bureau of Mines, Department of Commerce, from State mine inspectors, for November, 1930, showed that 219 men were killed in the coal mines of the United States during the month, an increase of 25 over the previous month and 33 over November, 1929. On the other hand the production of coal decreased, the output of 43,329,000 tons in November being 8,397,000 tons less than in October and 9,005,000 tons less than in November a year ago. The larger number of fatalities accompanied by a smaller output of coal resulted in a higher death rate4 per million tons in November than in the same month last year or in October, 1930. The November rate was 5.05, as compared with 3.55 for November, 1929 and 3.75 for October, 1930. The increase in the rate for the industry as a whole was chargeable entirely to bituminous mines,, as the anthracite mines had fewer fatalities in November than in either of the previous months to which reference has been made. Reports for bituminous mines alone 'allowed that accidents at class of mines resulted in a death rate of 5.12, based on 195 fatalities and a production of 38,122,000 tons. This rate indicated an increase of 55 per cent over the rate for October, of the same year, and 72 per cent over the rate for November, 1929. The October record was 146 fatalities and 44,150,000 tons, and that for November a year ago was 138 deaths and a production of 46,514,000 tons. Twenty-four deaths occurred at anthracite mines in November, 1970: the output of coal was 5,207,000 tons, hence the rate was 4.61 per million tons. During the corresponding month a year ago there were 48 deaths and 5,820,000 tons of coal produced, which indicated a death rate of 8.25. In October, 1930, the death rate was o.34; based on 48 deaths and 7,576,000 tons.

Jan 1, 1930

By N. E. Hanna

[Testing explosives for safe use in coal miner ran boon an important factor in preventing mine explosions. In the United States, explosives that have been approved by the Bureau of Mines are called permissible explosives. A purvey of the history of coal mining since permissibility testing welt, instituted some 4 years ago shown that there is no record of a coal-mime explosion caused by permissible explosives when used in a manner prescribed by the Bureau. To maintain the appropriate standards of quality, the Bureau of Mines conducts a series of examinations and tenth on samples of explosives collected in the field. In what is considered the most crucial test, teat 1, the explosives An fired from a steel cannon into a gallery atmosphere containing a mixture of natural gas and air, In another important test, test 4, the explosives charge to fired into a mixture of natural gas, air, and coal diet. To satisfy the permissibility requirements, the explosive must undergo throe gallery teats without igniting gas or coal duet. Other tests also are required for permissibility, but they do not come within the scope of the present paper, which studies the factors affecting the incendivity of explosives when fired into methane, air, and/or coal-dust mixtures. It in believed that a better understanding of the factors will contribute to the development of safer explosives.]

Jan 1, 1954

By Edward W. Parsons

Conventional rock-bolt anchors often fail when installed in weak formations. The purpose of this work was to develop an anchor that would utilize an explosive charge to secure anchorage in any type of rock. Laboratory work to develop a rock-bolt anchored by explosive forming was initiated using rock-bolt models which had a drilled explosive chamber and were composed of various metals. This was followed by the use of several types of seamless tubing which were expanded with a water-coupled explosive capsule. By attaching a length of solid bolt to the anchor tube, a prototype explosive-anchored rock bolt was made. More than 150 laboratory models were expanded during this phase of development, During two field tests in underground mines (A and B) and one in an open- cut mine (C), 87 explosive-anchored bolts, 9 slot-and-wedge bolts, 2 bolts anchored with expanding grout, and 28 expansion-shell bolts consisting of three types of shells were installed and subjected to pull tests. The field tests were run to determine the effects of variables such as the amount and placement of the explosive charge, design changes in the bolt, and the effect on anchorage of different pull-test techniques. The field tests revealed the following: Mine A. The explosive-anchored rock bolt was feasible, but changes were necessary in bolt materials and in some details of bolt design. Mine B. The design and materials of the bolt gave excellent results in hard fractured rock, but no information was obtained concerning variations in the dimensions of the anchor unit or in the explosive charge. Nine C. Varying the explosive charge to produce a beaded surface on the bolt tube and tightening of the anchored bolt before pull-testing were found to increase significantly the anchorage obtained in soft ground.

Jan 1, 1963

By Robert G. Lundquist

This report summarizes all relevant findings and conclusions regarding capabillty of high-energy projectile impact to operate effectively in an open pit mining environment and to successfully handle secondary breakage and bench scaling problems. A silenced, aimable, mobile projectile launcher was designed and fabricated, utilizing a Government-furnished smooth-bore, 90 mm cannon. The silenced launcher was tested at the contractor's test site prior to shipment to ANAMAX Mining Company's Twin Buttes Mine near Tucson, Arizona. Demonstration tests were conducted at an inactive waste dump in the mine on 39 oversize boulders to determine the relationship between boulder size and projectile energy required for secondary breakage. The high energy projectile impact method (known by the acronym REAM -Rapid Excavation and Mining) was tested on an additional 23 boulders in the working mine and on 31 areas of potentially loose rock high on the pit walls. Most of the secondary breakage tests were successful and acceptable for open-pit mining purposes without producing large amounts of fly rock. Five of the 31 scaling tests were successful with one shot, but most of the remainder required two or more shots, and a few could not be dislodged because they were not as loose as they appeared to be, based on visual examination from a distance. Cost comparisons between the REAM method and conventional methods of secondary breakage and bench scaling are discussed. A film documentary, REAM--Mining Applications of High Energy Projectile Impact, has been produced by the contractor depicting the applications of the silenced cannon.

Jan 1, 1976

By D. Harrington

The coal-mining industry of the United States finds difficulty not only in making ends meet financially but also in operating with anything like reasonable safety. The record to date has not been particularly good as to either finance or safety, but at least in some phases or safety there are indications of better times to come. During the fiscal year ending June 30, 1929, only 139 lives were lost in explosions in our mines as against 342 lost during the fiscal year ended June 30, 1928; this decrease in such fatalities is definitely a matter for satisfaction. During the fiscal year July 1, 1928, to June 30, 1929, the attention of the safety division of the U. S. Bureau of Mines was directed to 38 mine explosions in the United States. Two explosions were in non-coal mines, one in a semianthracite mine, two in anthracite mines, and 33 in bituminous mines. These were not all major explosions - that is, explosions in which five or more lives were lost; in some of the explosions no lives were lost, while in others fewer than five fatalities resulted. Table 1 gives data on the explosions, showing the number of mines using open or closed lights and the number of explosions with resulting deaths, by causes, for each State.

Jan 1, 1929

By P. G. Clites

A laboratory furnace was developed by the Federal Bureau of Mines for use in studying the interrelationships among variables associated with skull melting and casting high-temperature metals. Although additional work is necessary to determine the extent to which the information obtained by using this furnace can be extrapolated to larger furnaces of the same type, many casting characteristics of metals and alloys can be determined on equipment of this size. This furnace is a laboratory-size, consumable-electrode, skull-casting furnace equipped with a water-cooled copper ladle. The ladle, which is a tilt-pour or over-the-lip type, has a volume of approximately 30 cubic inches and provides up to 20 cubic inches of molten metal for castings. Castings of various reactive and refractory metals, including zirconium, titanium, hafnium, columbium, molybdenum, tantalum, and tungsten, have been produced. In addition, castings of iron, chromium, and copper have been made. The simplicity and versatility of the apparatus would make it useful to metallurgical laboratories preparing cast specimens.

Jan 1, 1961

By B. J. Dalton

The Bureau of Mines Helium Research Center has developed a computer program for solving two-phase equilibria data for binary mixtures and for evaluating thermodynamic functions of interest, including all critical points. This computer program was used to calculate equilibrium points on the PVTu surface for the helium-nitrogen system as predicted by the Van der Waals equation of state. Numerical values are tabulated and illustrations are presented for 1,279 equilibrium points and for quantities needed to construct Ponchon diagrams. Equilibrium ratios as a function of pressure at constant temperature and of temperature at constant pressure-are also shown graphically. In addition, saturated partial molal volume and partial molal enthalpy data are given. It is shown that the Van der Waals helium-nitrogen system exhibits retro-grade condensation of the second type for liquid helium concentrations of about 0.07 mole fraction or less and pressures below about 45 atm. It is also shown that the critical point is at a -maximum value of pressure (at constant temperature) and of temperature (at constant pressure).

Jan 1, 1971

By J. Baicker

A two-inch diameter probe containing an intrinsic germanium detector, a canister-type solid cryogen cooling system, cooled FET preamplifier, linear amplifier, high voltage supply, analog-digital converter, microprocessor, buffer memory, bidirectional cable link, and all power supplies has been designed, assembled and tested. A surface support vehicle was designed, built and outfitted. A mini-computer system was constructed and preliminary software developed and tested. A special handling system for a Cf-252 neutron source was designed and has been ordered. The entire system (less the neutron source) is ready for its first field tests. Lab description of the system is presented.

Jan 1, 1978

By C. E. Armantrout, H. Kato, M. I. Copeland

The data collected during this investigation indicate that the chromiumgadolinium system has extensive liquid immiscibility and one eutectic point . Liquid immiscibility occurred at temperatures above the monotectic isotherm , 1,830 ° C , which extended from less than 0.25 to about 85 weight - percent gadolinium . The eutectic was at 96 percent gadolinium and 1,170 ° C. Gadolinium and chromium were the only phases in this system . There was a solid solubility of less than 0.25 percent gadolinium in chromium at 1,730 ° C and less than 0.10 percent chromium in gadolinium at 1,160 ° C. The alloys were prepared by nonconsumable - electrode arc - melting , and the alloy system was investigated by heat treatment , metallography , thermal analysis , and X- ray diffraction . All the melting , heat treatments , and thermal analyses were conducted in a vacuum or in helium because of the reactivity of chromium and gadolinium with the components present in the atmosphere at elevated temperatures .

Jan 1, 1964

By Edward W. Parsons

The explosive-anchored rockbolt was field tested in six mines where rock conditions varied from incompetent shale or mudstone through fairly soft sand-stone to firm sandy shales. The purpose of the testing was to document, under a wide variety of conditions and in comparison to other rockbolt anchors, the quality of the anchorage produced by the explosive-anchored bolt. In addition, the length, strength, and design of the explosive charge necessary to produce positive anchorage up to the yield strength of the weakest component of the bolt were determined. A l4-inch length beaded explosive charge was found to be suitable, in general, in relatively weak strata, and the length can be reduced in more competent strata. Of the 127 explosive?-anchored bolts tested, 118 bolts produced an evaluated anchorage in excess of 17,000 pounds. Only 4 of 43 expansion-shell bolts and 4 of 14 wedge bolts produced anchorage this good. In preliminary tests, properly coupled explosive-anchored bolts did not ignite an explosive gas mixture. Some minor phases included in the investigation were as follows: (1) effect of explosive-anchored rockbolt on surrounding rock; (2) effect of time on anchored bolts based on torque tests; (3) effect of submersion in water on rockbolt anchorage; (4) pull tests to higher loads; and (5) ignition tests.

Jan 1, 1965

By Phillip R. Moyle

In 1985 the U.S. Bureau of Mines evaluated the mineral resources of the Sheep Creek West Wilderness Study Area (ID-111-36A), Owyhee County, ID, for the U.S. Bureau of Land Management. The Wilderness Study Area consists of 11,680 acres centered approximately 20 miles south of Grasmere, 10. It contains no mines, claims, or prospects. No mineral resources were identified; however, a geode occurrence within and adjacent to the Wilderness Study Area, and minor amounts of placer gold along Sheep Creek, may be of interest to rorkhounds and recreational gold panners.

Jan 1, 1986

By C. M. Mason

The current Bureau of Mines active list of permissible explosives includes 95 brands. Twelve are gelatinous and the rest are the more commonly used granular ammonium nitrate type. The list of permissible blasting devices comprises five Cardox models.

Jan 1, 1968

By K. K. Kershner

Sulfide ore concentrates containing cobalt, nickel, copper, lead, and iron were salt roasted and leached on a laboratory scale. More than 95 percent of the cobalt, nickel, and copper was recovered. Heating patterns for salt roasting different concentrates were established. More cobalt, nickel, and copper were recovered from a bulk concentrate composed of a mixture of copper concentrate and iron concentrate. This mixture corresponded roughly with the mixture of these materials in stockpiles in southeastern Missouri. A temperature range of 375° to 400° C. was best for salt roasting. Metal chlorides were leached at a pH of 1 from chloridized charges of concentrates, Although the amounts of cobalt, nickel, and copper extracted were high, the amount of iron dissolved simultaneously interfered with subsequent separation and recovery of these metals. The amount of dissolved iron was reduced substantially by steam treating chloridized charges of bulk concentrate at 300° C. In this way, the ratios of cobalt, nickel, and copper to iron in leach liquors permitted satisfactory separation and recovery of these metals. INTRODUCTION The Federal Bureau of Mines is experimenting with chloridizing reactions.4 5 6 7/ Salt roasting of sulfide ores and concentrates, or their calcines, to form metal chlorides has certain advantages. Chlorides of

Jan 1, 1961

By E. J. Murphy

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

Jan 1, 1967

By R. L. Handy

The objective of this research was to devise and test an apparatus to rapidly evaluate the cohesive and frictional strength of coal in situ, in order to increase the safety and percentage of coal recovery from underground coal mines. During the first year device was designed utilizing the bore-hole shear test principle from soil shear strength testing: Two opposing corrugated plates are forced outward to exert a controlled contact pressure against the sides of a previously bared hole, and then the plates are very slowly pulled along the axis of the hole to cause shearing of coal in contact with the plates. Results with the device are expressed in terms of a friction angle[_] and a cohesion c. The [ ] angles obtained from an Iowa coal arc in close agreement with and fall between results from triaxial and direct shear laboratory tests on the same coal. The measured cohesion was found to be much less than from the comparable laboratory tests. It may be increased by pre-stressing and other techniques to embed the shear plate teeth for the first shear test point.

Jan 1, 1973

By David J. Kusler

This report describes a rapid, reliable, and relatively simple method developed by the Bureau of Mines Pyrometallurgy Laboratory at Bruceton, Pa., for determining lime (calcium oxide) and magnesia (magnesium oxide) in various materials containing these constituents in greater than trace amounts. Optionally, titania (titanium dioxide) may be determined for the same sample. The accuracy of the method, suitable for most purposes, is shown by comparing the Bureau results with those obtained by accepted procedures. The method has been applied satisfactorily to the routine analysis of blast-furnace slags, for which purpose it was primarily developed, and to other calcareous compositions. In the Pyrometallurgy Laboratory it has replaced the standard methods previously used to determine lime and magnesia, and has been in general use by that laboratory for the past several years. The analysis time, generally under 3 hours, is considerably less than required by standard methods.

Jan 1, 1960

By N. S. Dalal, X. Shi

"Electron spin resonance measurements provide evidence for the formation of long-lived Cr(V) intermediates in the reduction of Cr(Vl) by glutathione redtuctase in the presence of NADPH and for the hydroxyl radical formation during the glutathione reductase catalyzed reduction of Cr(Vl). Hydrogen peroxide suppresses Cr(V) and enhances the formation of hydroxyl radicals. Thus Cr(V) intermediates catalyze generation of hydroxyl radicals from hydrogen peroxide through a Fenton-like reaction. Thus the mechanism of Cr(VI) toxicity might involve the interaction between macromolecules and the hydroxyl radicals.C(Vl) compounds have been found to exert serious toxic and carcinogenic effects on humans and animals (1-3). In contrast, most Cr(III) compounds are relatively nontoxic, noncarcinogenic, and nonmutagenic (1,4). Cr(VI) and Cr(III) oxidation states are different in their metabolic pathways: Cr(VI) , ions are rapidly transported across cellular membrane (1,4,5), while Cr[III) moieties do not easily penetrate cells and are not oxidized by cellular constituents (!). Since it is known that the reduction of Cr(VI) ion is required for its reaction with DNA (1), the molecular mechanisms for the intracellular Cr(Vl) reduction has been the focus of current studies but the details are still not understood.Earlier studies on the mechanism of Cr(Vl) reduction include those on the reduction of Cr(VIJ by glutathione (GSH) .0,6-8), ascorbic acid (9), glucose (10), lactose (IO), galacturonic acid (11), microsome (12), and mitochondrial electron transport chain complexes (13). These studies have shown that the Cr(VI) reduction involves the formation of Cr(V)-containing species which are often considered to be the toxic form of chromium. Thus far, however, no information is· available on the subsequent fate of those biologically formed Cr(V) species, in particular employing well defined biochemical systems. In this context, we report here our investigations of the reduction of Cr(VI) by glutathione reductase (GSSG-R). This enzyme was selected because it is ubiquitously present in cellular systems and it has been postulated to be involved in the Cr(VI) reduction (14-17) but the underlying mechanism has not been clarified. We find that the reduction proces·s involves not only Cr(V) but also ·OH radicals. We further investigate the reactivity of Cr(V) and find that it catalyzes generation of OH radical from H2O 2 through a Fenton-like reaction. The role of ·OH in Cr(VI) carcinogenicity is suggested from this study."

Jan 1, 1989

By G. R. Hopkins, E. W. COCHRANE

According to reports received by the United States Bureau of Mines , Department of Commerce , as of January 1 , 1930 , there were 412 completed refineries in the United States with a daily crude oil capacity of 3,755,585 barrels . This compares with 413 refineries of 3,509,540 barrels capacity on January 1 , 1929 , which indicates that whereas the number of refineries was practically unchanged , the total capacity increased 8 per cent during the past year . Of the completed plants as of January 1 , 1930 , 358 plants , of 3,634,825 barrels total capacity , were operating and 54 , with a capacity of 130,760 barrels , were shut down . Compared with a year ago , this indicates a decline in the percentage of the total refinery capacity that is inoperative . There has been a decided decrease in the number of shut-down plants since 1924 and 1925 , when one plant in every three was inoperative . Many of the inoperative plants of 1924 and 1925 were constructed soon after the boom times of 1920. Some of these were operated for a time but were unable to show a profit during 1923 and 1924 , when an overproduction of crude petroleum was accompanied by demoralized markets for refined products . Prices for refined products improved in 1925 and 1926 , but only a comparatively few of the shut -down plants , then partly obsolete , were able to obtain or renew their crude connections and compete successfully with the larger , more firmly established refineries . After five years or more of continuous idleness , a refinery would be rendered practically useless through corrosion and obsolescence . Consequently , most plants now being carried as " shut -down " have operated intermittently since 1923 . struction . A material change occurred in 1929 in the matter of plants under con- On January 1 , 1929 , there were 14 plants under construction , with a potential capacity of 99,000 barrels per day , whereas on January 1 , 1930 , there were only eight plants of 37,200 barrels capacity being built . This decline was due to the fact that the construction program in west Texas , which was at or near its height on January 1 , 1929 , was completed prior to January 1 , 1930 .

Apr 1, 1930

By Webster S. Anderson

The design, development, and testing of hydraulic props to provide a lightweight, high strength, recoverable unit is described. Modifications in design incorporating threaded components resulted in the development of a lightweight hydraulic prop fabricated from aluminum alloy tubing. This new design facilitates interchange and replacement of component parts, and the physical properties of the material are not changed as they are when welding is required. The new prop is 65,000 pounds and has a maximum load capacity of a lower weight-to-load capacity ratio than the hydraulic props now available.

Jan 1, 1967