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By Wilbert J. Huff

The Explosives Division of the United States Bureau of Mines makes certain laboratory and field investigations that deal with explosions, explosives, ignition, and combustion, together with many related problems, such as the cause and prevention of fires, and certain fundamental scientific questions bearing upon the determination of the chemical and physical mechanisms underlying some of the important phenomena encountered. Its work on explosives has been particularly directed toward determination of the chemical and physical characteristics of explosives designed for use in coal mines and in a more limited way to those used in metal mines, tunnels, quarries, and other engineering operations. This testing is handled by two units of the Explosives Division, as follows:

Jan 1, 1937

By John W. Cole

The Bureau of Mines conducted a trenching and sampling project during 1947 on the tungsten-rich granodiorite that outcrops in Henderson Gulch, Montana. During the course of this investigation, interest was attracted to the Sunrise copper-gold mine in metamorphosed limestone in the north slope of the gulch. The mine was examined by S. H. Lorain, Chief, Mining Division, Albany Branch, in May 1948. A trenching and drilling program was recommended to develop a parallel vein indicated by outcrops to lie below the principal productive Queen vein. In the meantime, the Queen Mining Syndicate initiated a trenching program that exposed high-grade lead-copper-silver-gold ore in a nearly vertical vein that strikes N. 600 E. to east. A core-drilling program to develop this vein was initiated in September 1948. This report presents the factual data obtained from the trenching and drilling operations. The Sunrise mine was discovered about 1890. Production has been estimated to be $120,000 in gold from 40,000 tons of ore mined during the period 1892-1903. The tailing from this operation was treated by cyanidation in 1912, with a reported recovery of $3.50 to $4.00 a ton from 15,000 tons of material. Subsequent production of sulfide ore was 7,396 tons treated by smelting, with recovery of 1,569.42 ounces of gold, 10,003 ounces of silver, 352,899 pounds of copper, and 354 pounds of lead.

Jan 1, 1950

By George S. Rice

"The successful use of the gas mask by the American Army it France in combatting the poisonous gases of German .shells caused many Army men to feel that the as masks were proof against any kind of gas which might be encountered. The result has been that from time to time there have been reported in the press, deaths of former army men through using their masks to enter various kinds of gases such as illuminating gas, gasoline vapor, and the gaseous atmospheres produced by mine fire. Such a case has just been reported from a mine, in Copperopolis, California, where a former Army man lost his life in descending a mine shaft filled with the fumes of a mine fire. Another man who, in attempting to rescue him, merely used a dust respirator, lost his life also.While the American type of the Army gas mask was developed by the Bureau of Mines for the War Department, and since the war a section of the Bureau's in¬vestigative force has been developing industrial gas masks for certain specificgases, the Bureau has repeatedly called to the attention of the public the fact that such masks have serious limitations and in no case should a gas mask be used in underground workings for the reason that there may be an insufficient amount of oxygen to breathe, (and the gas mask does not supply oxygen) or there may be present carbon monoxide, which the Army mask will not remove, and there always is some carbon monoxide produced by a mine fire or by a coal-mine explosion, or by a blast of dynamite or other explosive.It is true that the Bureau has been developing a mask which may take care of a small percentage of carbon monoxide, that is, one per cent and under, but in mine fires and after explosions, there may be, and frequently is, a much larger percentage of carbon monoxide in the mine atmosphere. Masks such as these, for small percentages of carbon monoxide and associated gases are for use in connection with industrial surface plants, as for example, on the top of a blast furnace or around gas producers in the open air."

Oct 1, 1920

By N. S. Dalal, Xianglin Shi

"INTRODUCTIONEpidemiologic studies of workers in chromate-ore related industries, 1-3 and stainless steel welding and related occupations4 have shown that they have about 20-40 times higher risk of throat or respiratory track cancer than controls. Although the actual carcinogenic substances were not identified in these statistical studies, Cr(VI) compounds (for example, calcium chromate, zinc chromate, and lead chromate) were implicated as the causative agents, whereas Cr(III) compounds were not suspected as carcinogens. s These suggestions were supporte4 by laboratory studies wherein many Cr(VI) compounds produced sarcomas at the implant or injection sites.1,5 Squamous cell carcinomas and adenocarcinomas closely resembling human lung cancer were induced by intrabronchial implants of calcium chromate in rats, 6·7 whereas Cr(DI) oxide and Cr(lll) sulfate did not induce any tumor formation.6,7While the mechanism of the chromate-induced carcinogenicity is not fully understood, it is generally thought8 that it involves some damage to DNA. Specifically, it has been reported that: a) the chromate ion, henceforth referred to as chromate, can pass through the cell membrane and enter the cell while CR(DI) does not, 9 b) chromate does not interact with either native or denatured DNA 10 while Cr(III) does, 11 and c) the final Cr-DNA complex isolated from cellular reactions of chromate is Cr(III)-DNA, with Cr(III) binding to the phosphate groups.12,13 Thus the important question is: since Cr(DI) cannot pass through the membranes, how does Cr(III)-DNA complex form? For this to happen, Cr(VI) must be reduced to its lower oxidation states, 14 ultimately to Cr(III), by some reductants in the cellular environment. Unless this reduction occurs, the DNA would not be damaged and therefore no chromate carcinogenicity would ensue. Thus the reduction of chromate to its lower oxidation states seems to be a key step in the chromate carcinogenicity .1s One of the major reductants in cellular environments is thought to be glutathione (GSH), both outside and inside the cells.16-lB Some evidence for the role of GSH in the chromate toxicity was provided by recent studies showing that exposure of hamster cells to non-toxic levels of added selemite increases the levels of GSH as well as the Cr(VI)-induced DNA strand breaks,19 and that such DNA strand breaks in hepatocytes also change in direct proportion to the GSH content. 20,21 These observations were interpreted as implying that the reduction of chromate by GSH to some reactive intennediate is an important step in the chromate carcinogenicity. 20.21 In · the present undenaking22 we have used electron spin resonance (ESR) and spin-trap methodology to investigate the reduction of chromate by GSH and find evidence for the involvement of the glutathionyl radical (GS ·) as well as Cr(V)-intermediates."

Jan 1, 1990

By R. L. Grant

The principal official test performed by the Bureau of Mines to determine the permissibility of coal-mine explosives, commonly referred to as the gallery test, has been in use at the Bruceton station for many years (2, 16).4/ In this test the explosive under study is loaded into the borehole of a steel cannon and fired into a flammable mixture of natural gas and air or natural gas, air, and coal dust. To meet the requirements for permissibility, the explosive must not ignite the gas mixture under the conditions of the test. There is little doubt that these tests have succeeded in the main objective, namely, to screen the relatively safe from the relatively hazardous explosives. It has been generally conceded that adoption of permissible explosives by the coal-mining industry in the United States has substantially reduced the frequency of disastrous underground explosions caused by blasting. In recent years, however, research workers planning programs for improving the safety of coal-mine explosives have felt the growing need of a more quantitative method for measuring the incendivity of explosives based on a better understanding of the role of the important variables in the gallery tests, Accordingly, it was decided to apply certain statistical methods and techniques to the gallery test to develop it into a more precise tool for evaluating permissible explosives. One of the first and more important methods applied for this purpose was the up-and-down technique (6,7,17), It was demonstrated (14,15) that the weight of the explosive charge directly affects the ignition probability of the natural gas-air atmosphere and that the curve of ignition probability versus charge weight is a cumulative normal curve. Following these experiments, a program, still in progress, was set up to study how the addition of sodium chloride to various permissible-type ex-plosives affects their incendivity. This program resulted in 3,294 shots,

Jan 1, 1961

By M. B. Shirts

Numerous alternative processes have been proposed as being potentially more economical or less polluting than the traditional smelting of copper sulfide concentrates. One such process as recently developed in the laboratory by the Bureau of Mines is composed of a two-stage fluid-bed, oxidation-reduction roasting followed by ammoniacal leaching, solvent extraction, and electrowinning. A copper-leaching recovery of 97.4 percent was obtained, and electrolysis of the acid strip solution deposited metal assaying 99.99 percent copper. The roaster gases contain over 95 percent of the sulfur at a concentration of 12 percent which is better suited for acid making or elemental sulfur production than conventional smelter gas. When considering byproduct recovery, a preliminary estimate indicates copper production costs are com-parable to the conventional smelters.

Jan 1, 1975

By R. A. Meyer

A table that greatly simplifies determination of metastable transitions in mass spectra has been prepared. All the mathematically possible metastable transitions of any compound whose molecular weight lies between 26 and 150 can be determined from the table without calculation. The method of utilizing the table is described, using selected peaks from the spectrum of normal butane for illustration. In the mass spectrometer, ions are formed in the isatron and accelerated through a series of slits. Most of these ions reach the collector without further change, but a few dissociate in transit to form new ions. These ions appear in the mass spectrum at neither the mass--to-charge ratio (m/e) of the original ion nor that of the new ion. A formula that relates the appearance of these new ions to the ion from which they were formed is: [ ]

Jan 1, 1957

By G. R. Hopkins

One of the largest items in the expense of operating a refinery is the cost of the fuel used in distillation and for miscellaneous purposes such as in the heating of buildings and in the generation of electricity, On a B. t. u. basis, the average refinery consumes approximately one-tenth as much fuel as it produces. Theoretically, the fuel consumption at refineries should be much smaller than this, but furnaces can riot be designed to be 100 per cent efficient' and, in addition, a large part of the waste heat is low-temperature heat which would not pay for the expense of recovering it. Annual surveys of fuel consumption at refineries have been made by the United States Bureau of Mines, beginning with 1925. During the 5-year period, 1925-1929, the refineries made steady progress in fuel economy. This is evidenced by the Computed figures of heat requirement Per barrel of crude oil refined, which show a decline from 829,000 B. t. u. in 1925 to 639,000 B. t. u. in 1929 (see fig. 1). In 1930, however, the trend in fuel economy was reversed and the quantity of heat utilized in refining the average barrel of crude oil rose to 672,000 B. t. u. There were undoubtedly a number of reasons for the apparent decrease in fuel economy at refineries in 1930, chief of which were the tendency to carry the distillation farther instead of merely topping the crude and a gain in the consumption of waste oils, such as acid sludge, which in actual practice yield less heat per unit consumed than has been theoretically assigned to oil. The consumption of natural as fuel at refineries has declined since 1927, but this has been more than compensated by a rapid increase in the use of refinery or still gas. The total consumption of oil as refinery fuel in 1930 was not much below the 1925 total, but the consumption of coal has declined rapidly, so that in 1930 liquid and solid fuels contributed only 56 per cent of the total heat units- utilized at refineries as compared with 77 per cent in 1925 (see fig. 2).

Jan 1, 1931

By D. W. Boley

This report contains the results of an analysis of the Logan oilfield, Hocking County, Ohio, and predicts the recovery of oil from the Clinton sand by waterflooding. Core analyses, electrical and radioactivity well-survey logs, reservoir-fluid analysis, and geologic and production data were used for this study. Considered in the evaluation were the reservoir geometry, depth, lithology, continuity of the rock properties, fluid saturations, fluid characteristics, rock wettability, and relative permeability-fluid saturation relationships. The study indicates that a properly engineered waterflood should recover approximately 135 barrels per acre-foot of effective sand. The predicted recovery warrants the initiation of a pilot waterflood in this field.

Jan 1, 1965

By Jack L. Henry

The monocarbide region of the ternary system U-C-O has been investigated at 1,700° C as the first phase of a more extensive study of a portion of the four-component system U-C-O-N. An area bounded by the following compositional limits in atomic percent was studied: U, 44 to 55; C, 30 to 60; 0, 0.2 to 20. Compacts composed of mixtures of uranium, graphite, and uranium dioxide powders were sintered at 1,700° C under an equilibrium pressure of carbon monoxide to produce uranium oxycarbide specimens having a variety of compositions. Sintered specimens were evaluated by X-ray, chemical analysis, and ceramographic techniques. Solid-solution boundaries and phase relations have been established, and the effects of composition on the lattice parameter as well as the decomposition pressure have been investigated. Oxygen can be substituted for carbon in stoichiometric uranium monocarbide to the extent of about 17 atomic percent at 1,700° C. The composition range of the oxycarbide solid solution extends from about 48 to 51 atomic percent uranium in the low oxygen region. Above 10 atomic percent oxygen the composition range narrows to less than 1 atomic percent uranium. Carbon monoxide exists as a gaseous phase in equilibrium with all compositions which contain oxygen. Five separate phase fields were found bounding the solid-solution area. Other phases within this portion of the system include uranium, uranium dioxide, uranium dicarbide, and uranium sesquicarbide. Decomposition pressures of oxycarbide compositions at 1,700° C have been found to vary from a few microns for stoichiometric and uranium-rich compositions to 35 torr for carbon-oxygen-rich specimens. Lattice parameters were found to depend upon the U to C + 0 ratio as well upon the extent of substitution of oxygen into the stoichiometric monocarbide lattice.

Jan 1, 1967

By Frank D. Lamb

"INTRODUCTION The use of beryllium and its alloys has come into prominence in the last 15 years and increased considerably during the war. In contrast to other light metals, such as aluminum and magnesium, beryllium is relatively hard, has a high melting point (1,285° C.), and other properties that make it resemble steel in many respects. It has a specific gravity of 1.85, is only slightly heavier than magnesium (specific gravity 1.74), and is appreciably lighter than aluminum (specific gravity 2.7). Its lack of ductility prevents its use as a structural material, but this difficulty may be overcome in the future by the use of various alloy forms. The only important commercial alloy in which beryllium is used today is with copper. The addition of small percentages (1/2 to 2 percent) of beryllium to copper imparts properties to the alloy that make it desirable for use in springs carrying electrical current, particularly at high temperature. Many other uses of berylliam are known, and new uses are being found constantly that make the metal of increasing interest.Possibly the main factor preventing the use of more beryllium is the lack of a large source of beryllium ore. Many beryllium minerals are found as minor constituents of natural deposits, some of the more common ones being beryl (Be3Al2(Si03)6), chrysoheryl (Be A1204), helvite (3(Mn, Fe) Be Si04. MnS), and phenacite (Be2Si04). Of the known beryllium minerals, beryl is by far the most common and has been found distributed rather widely throughout the world. It usually occurs associated with granitic rocks and is commonly found as a constituent of granitic pegmatite."

Mar 1, 1947

By Robert A. Jankowski

"Following passage of the Coal Mine Health and Safety Act of 1969 (Public Law 911173), the Bureau of Mines initiated a research program aimed at controlling respirable dust exposures of coal mine workers. Respirable dust is the dust that gets into, and interacts with, the lungs of those who inhale it. It has long been recognized as a severe health hazard to mine workers. This program has been implemented by a team effort consisting of the Bureau's in-house capabilities, the Generic Center for Respirable Dust, and contractors, as necessary. Over the years, Bureau research has addressed principally three areas:o Compliance with the Federal 2.0 mg/m3 dust standard (1970-76).o Dust control for longwall mining (1976-1983).o More stringent respirable dust standards due to quartz dust (1983-1987).In addition, fundamental studies have been conducted by the Generic Center for Respirable Dust, with emphasis on penetration of dust into the lung. Accomplishments have been significant, but problems remain, as noted later.The Coal Mine Health and Safety Act of 1969, established a 2.0 mg/m3 dust standard for all coal mining operations, underground as well as surface. At the time of enactment of this legislation, the industry was averaging approximately 4.0 mg/m3. The Bureau of Mines respirable dust research program played a significant role in identifying and developing effective technology to allow better compliance with this new standard, thanks to industry implementation and Federal enforcement."

Nov 1, 1988

By P. D. Kovscek

The Bureau of Mines has tested a low-thrust water-jet-assisted rotary drill. This work was performed to evaluate the performance of a water-jet-assisted drill operated at thrust levels typical of a handheld manual-thrust operation. Prior work by the Bureau had indicated that using water-jet assist with high-thrust drilling applications would increase drilling rate. Small-diameter holes were drilled in five different types of rock. Thrust and water pressure were varied as the drill rate was monitored. The test results indicate that drilling rates increase with increasing water pressure and thrust. The water jet has more effect on reducing the specific energy when drilling in the harder rocks than in softer rocks. Variation in drill rate for a given rock sample is attributable primarily to the material heterogeneity within the sample. One rock type (Greenwich sandstone) could not be drilled efficiently with the water-jet-assisted drill.

Jan 1, 1988

By S. J. Pearce

There are a number of methods for determining relatively small quantities of sulfur dioxide in air. However, those methods require fairly elaborate apparatus and laboratory facilities. Frequently in industrial hygiene surveys it is desirable to have a simple arrangement to obtain "on the spot" determinations. This has been accomplished for concentrations of sulfur dioxide of hygienic significance by using the midget impinger and decolorizing a starch-iodine solution.

Jan 1, 1948

By D. Eugene Rannels, Sarah E. Dunsmore, Cara Martinez-Williams, Yu-Chen Lee

"Dunsmore, Sarah E., Yu-Chen Lee, Cara Martinez Williams, and D. Eugene Rannels. Synthesis of fibronectin and laminin by type II pulmonary epithelial cells. Am. J. Physiol. 270 (Lung Cell. Mol. Physiol. 14): L215-L223, 1996.Previous investigations demonstrated that type II pulmonary epithelial cells regulate extracellular matrix deposition as a function of time in primary culture. In those studies, the matrix fraction was analyzed as a whole. The present work focused on two components of the type II cell matrix, fibronectin and laminin. These glycoproteins have differing effects on differentiation of type II cells in primary culture. Fibronectin synthesis was quantitated between day 1 and day 6 in the cells, matrix, and medium; laminin synthesis was quantitated only in the cells. Although total fibronectin synthesis was regulated as a function of time in culture, reaching its greatest value on day 2, the average proportion of newly synthesized fibronectin in the cells (35%), medium (50%), and matrix (15%) remained constant over a 6-day interval. Between day 2 and day 6, the relative abundance of fibronectin messenger RNA increased 6.5-fold. Rates of cellular laminin synthesis did not vary with time in culture. These results support a role for differential regulation of fibronectin and laminin synthesis to determine the composition of the type II cell extracellular matrix. INTERACTIONS BETWEEN THE pulmonary epithelium and alveolar basement membrane may play a role in the physiology and pathophysiology of the lung. Pulmonary epithelial cells and the alveolar basement membrane form one component of the blood-gas diffusion barrier. Integrity of this barrier is crucial to normal lung function. Specific domains of alveolar basement membrane components have been proposed to determine localization of type I and type II pulmonary epithelial cells during lung growth and development, as well as during repair of the alveolar surface after injury (13). In the injured lung, the extent of damage to the epithelium and the underlying basement membrane is thought to be a key factor to determine subsequent repair or fibrotic scarring (3)."

Jan 1, 1998

By J. W. Miller

Depletion of coals most suitable for metallurgical fuel has made necessary a general survey of coking coal reserves in the United States. These investigations were begunn 1948 at the joint request of the Munitions Board, Department of Defense, and a number of coal companies. This report, which is one in a series, by counties, describes the preparation characteristics of the coals of Harlan County, Ky. From these data it is possible to determine: (a) Which coals, either as mined or after beneficiation by conventional preparation, are chemically suitable under present standards for producing metallurgical coke, (b) Which coals require special and more intensive treatment in preparation than is now practiced; and (c) Which coals cannot be considered to be potential sources of metallurgical fuel regardless of preparation.

Jan 1, 1955

By James J. Jessop, Richard E. Thill, Michael J. Friedel

As part of an investigation aimed at improving the health and safety and competitiveness of the mining industry, the U.S. Bureau of Mines evaluated the application of common offset radar profiling, using a 250-MHz ground-penetrating radar (GPR) system, for the detection of fractures in igneous rock. A series of radar reflection surveys were conducted to detect and delineate the extent of fracturing at various granodiorite and gabbro quarries and outcrops located in Minnesota. The application of radar profiling for detecting joints, sheeting fractures, shear zones, and depth to water table was demonstrated to be feasible with minimal processing. Radar reflection interpretations were verified by visual inspection of the rock mass and field mapping of local structure. The radar reflection section provides a simple, rapid, and cost-effective means for mapping of shallow (less than 10 m) small-scale fractures (greater than 0.25 cm) in igneous rock masses (characteristic of velocities between 0.061 m/ns for gabbro and 0.125 m/ns for granodiorite). Depth or distance estimates to fractures are within 10 pct of the actual, and time-shift compensation is necessary only when topographic irregularities exceed 30 cm.

Jan 1, 1992

By L. A. Stewart

This is one of a series of reports prepared by the Federal Bureau of Mines on mining methods, performance, and costs at individual mines in the United States. The primary purpose of these papers is to promote development and conservation of our mineral resources by disseminating technological information on methods, practices, and results that may be applied to the engineering analysis and solution of mining problems. This report discusses the highly selective mining methods of the Jaquays Mining Corp. at the Regal asbestos mine, 45 road miles northeast of Globe, Ariz. The milling method at the Globe plant is discussed briefly, and the extraction ratios of the various grades of fiber are tabulated. The proposed flowsheet of a new mill under construction is shown.

Jan 1, 1961

By W. W. Adams

"During the calendar year 1925 the Bureau of Mines received from the operators of several hundred mines and quarries complete accident records covering deaths, permanent disabilities, and “lost time” temporary injuries. Some of the companies, - those that participated in the National Safety Competition-also furnished information showing the number of man-hours of work performed during the year. With these two types of information it was possible to calculate the accident-frequency and accident-severity rates of the different plants. Complete and comparable reports of accidents and Man-hours of “exposure” were received from 34 underground metal mines, 59 underground coal mines, 15 underground mines producing other nonmetallic minerals, and 102 open quarries or open-pit mines. The figures in the table appended to this report show the accident severity rates and other data for each of the 34 underground metal mines and for the group as a whole. It is proposed to publish similar figures for the other classes of mines and quarries at an early date.The 34 metal mines listed in the table are situated in Arizona, Idaho, Kansas, Michigan, Minnesota, Missouri, New Jersey, New Mexico, Oklahoma, South Dakota., and Utah; they employed 5, 925 men, an average of 174 men per mine, including employees above-ground as well as underground. With but few exceptions, 50 men was the minimum number of employees in any mine. The total period of employment or “exposure” at the 34 mines was 14,612,607 man-hours, an average of 2,466 hours per man, or the equivalent of 308 work-days of eight hours for each employee. Accidents resulted in 15 fatalities, 9 permanent disabilities, and 1,950 temporary “lost time” injuries (causing disability exceeding remainder of shift). The fatal and nonfatal injuries represented 132,575 days of disability. Thus the accident frequency rate for the group was 135 accidents per million hours and the accident severity rate was 9.073 days lost per thousand hours of 1 “exposure”. The severity rates ranged from 0.227 to 88.653, while the ·range of the accident-frequency rates was from 16. 6 to 307 .4. In compiling the accident severity rates shown in the table, all accidents caused by explosives were weighted at twice the number of days actually lost, as one of the purposes of the National Safety Competition was to stress the prevention of accidents caused by explosives."

Sep 1, 1926

By J. E. Wilson

A bench-scale expansion tester using 71 grams of coal was developed to determine the practicability of an apparatus of this size to investigate the effect of variables such as oxidation, blending, bulk density, inerts, size consist, petrographic differences, and rate of heating on the expanding properties of coal. The value of this tester is shown by the correlation that exists between its results and those of the larger scale sole-heated oven expansion apparatus used in commercial plants. From tests on 32 coals the standard error of estimate for predicting sole-oven results from bench-scale results is ± 5.3 percentage points. A standard deviation of the difference between pairs of tests in the latter apparatus of ± 2.1 percentage points was determined for 31 samples. In the sole-heated oven test the expansion of a coal at constant pressure is directly proportional to the dry coal bulk density. Tests in the bench-scale tester show a similar relationship between expansion and bulk density. When the blending ratios of high-and low-volatile coals are varied, similar changes in expansion are observed in both the sole-heated oven and the bench-scale tester. Therefore, the effect of other variables on expansion should be similar in the latter apparatus.

Jan 1, 1960