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By R. O. Dannenberg

A metallic displacement process, utilizing easily available steel wool or steel window screen, was devised and successfully used for the recovery of silver from waste photographic fixing solutions. Laboratory and prolonged commercial-scale testing established that the iron filament type unit will efficiently precipitate silver, as a high-grade sludge, from acidic waste photographic fixing solutions ranging in grade from less than 1 to over 10 grams of silver per liter. Data and design information are presented to facilitate the construction and operation of a practical unit of any desired size. A smelting process for recovering pure silver from precipitated sludge containing 27 to 80 percent silver was devised.

Jan 1, 1968

By R. Burrell, N .. L. Lapp

"Except for asthma and pulmonary infections, the types of lung disease that have been of immunologic interest the longest are the various mineral pneumoconioses. Because of their chronicity, type of pathology produced, and well-known immunotoxic properties associated with the dusts inciting them, the pneumoconioses have long drawn attention to the possibility that the immune system has not only been modulated but that its effectors have possibly contributed to their pathogenesis. All of the mineral dusts reviewed here have definite immunomodulating properties and act on various cellular and molecular components of the immune system. Further, each has an immunotoxic potential to induce either hypersensitivity (as in the case of beryllium) or other types of immune injury. This article reviews the immunologic aspects of the four major occupational minerals that have an immunologic impact on the lung: asbestos (particularly chrysotile), silica or quartz, beryllium, and coal mine dust.These agents have many things in common, yet each is distinctive. Although the possibility still exists that these mineral particles can adsorb intrinsic tissue antigens or extrinsic organic antigens to their surfaces and initiate immune responses to the adsorbed antigens, only one, beryllium, can act as an antigen itself. Silica is a profound macrophage toxin and thereby exerts many effects on those factors controlled by macrophages. Asbestos has undergone the most immunologic studies resulting in a much dearer picture of how it may contribute to immunopathology. Coal mine dust is the agent about which least is known immunologically, partly because there is no such thing as purified coal mine dust or a standard by which coal mine dust can be defined. Indeed, there are studies that use only the dust from the ground coal itself, whereas other studies use the total dust collected from air samples of a working mine in the belief that other types of dusts (e.g., silica from roof bolt drilling, from sand ground on the rails by cars, and from surface drilling) contribute to the disease (Figs. 1 to 5). This properly is coal mine dust and is poorly characterized. Yet, workers exposed to these dusts share similar reactive characteristics and they may be considered collectively as well as individually."

Mar 1, 1992

By P. L. Woolf

Seven evaluation tests with blast furnace iron bearing burden materials are described. The effects of pellet strength, fines in the burden, decreasing slag volume, pellet size, eliminating stone with superfluxed sinter, and eliminating stone by prefluxing the pellets were determined. Fluxed pellets and fluxed sinter made with the same ore fines were compared. The tests were conducted under cooperative agreements between the Bureau of Mines and North American steel companies. The objectives were to improve blast furnace practice, expand and develop understanding of the operation and theory, quantify the effects of changes, and explore the limitations of operability. This work was part of an extensive program of blast furnace research in experimental blast furnaces at Bruceton, PA conducted in the years 1958 to 1967.

Jan 1, 1984

By T. E. Green, E. F. Spano, W. J. Campbell

A combined ion exchange X- ray spectrographic method was evaluated for the determination of 11 metallic elements in high - purity tungsten : Aluminum , calcium , chromium , cobalt , copper , iron , magnesium , manganese , nickel , titanium , and zinc . Copper , nickel , and manganese in the 5- to 100 - microgram range ( 1 to 20 parts per million based on 5 - gram samples of tungsten ) , calcium in the 10- to 100 - microgram range , and cobalt in the 5- to 20 - microgram range can be determined within an accuracy of ± 10 percent of the amount present . Limits of detection of these elements are 0.05 to 0.14 microgram . The overall method was unsatisfactory for the determination of aluminum , chromium , iron , magnesium , titanium and zinc in tungsten .

Jan 1, 1964

By L. C. Marchont

This Bureau of Mines report tabulates data on nitrogen-gas reservoirs and isolated occurrences of inert gases in several Williston basin oilfields. Recoverable reserves of nitrogen gas in the Minnelusa nitrogen interval within the areas of five oilfields on the Nesson anticline in North Dakota are estimated at about 1.27 trillion standard cubic feet, based on computer analyses of logs from over 300 wells. This volume of nitrogen represents a large source of high-pressure inert gas and warrants consideration of possible application in oil-production operations. Drill-stem tests made in two of the fields indicated that nitrogen can be produced at rates up to 28 million cubic feet per day.

Jan 1, 1966

By A. L. Engel

The Bagdad-Chase copper-gold mine south of Ludlow, Calif., was visited by an engineer of the Bureau of Mines in July 1955 to determine the mine's status of activity and to obtain a bulk sample for metallurgical testing. The deposit was discovered in 1903 and has been worked intermittently. It has a production record of about 273,000 tons of ore. The first production of about 150,000 tons was treated in a cyanide plant 2 miles west of Barstow, Calif. The extraction of gold was not satisfactory because of the presence of copper minerals. Since 1910 the ore has been shipped to various smelters in Arizona and California for use as a flux.

Jan 1, 1957

By Jack E. Tress

The Bureau of Mines has been involved for several years in the development of processes for the recycling of solid wastes. As part of this program, a project was initiated to determine the feasibility of producing secondary pig iron from auto scrap. During the test period, 86,000 pounds of shredded auto scrap, along with petroleum coke and fluxing agents, was charged to a submerged-arc furnace of 1-ton nominal capacity. Eighty-eight thousand pounds of pig iron, with an average carbon content of 3.90 percent and an average copper content of 0.2 percent, was produced at an electrical consumption of 512 kW-hr per net ton. A cost estimate of the process showed that the pig, iron might be produced at a cost of $57 per ton.

Jan 1, 1973

By P. L. Sibrell

Electrorefining of Ti in nonaqueous solvents has been studied by the U.S. Bureau of mines as a method for recycling impure scrap Ti. Electrochemical behavior of Ti species was investigated using cyclic voltammetry. Research results showed that Ti metal can be dissolved in polar solvents such as dimethylformamide or dimethyl sulfoxide. However, deposition of Ti from these solvents was not successful. Several solvent systems were investigated for electrodeposition of Ti but no deposits were obtained. Reduction of Ti4+ complexes to Ti3+ proved to be straightforward, but reduction to lower oxidation states could not be confirmed. In dimethylformamide solutions, cyclic voltammetry results demonstrated the reduction of Ti to an oxidation state of less than three, but no Ti metal was identified. In dimethyl sulfoxide solutions containing LiCl, it was possible to deposit Li metal. After adding Ti salts to the solution, electrolysis quickly passivated the electrode. Deposition of Ti was also investigated in solutions of dimethoxyethane and propylene carbonate but, again, no reduction of Ti to oxidation states of less than three occurred. Therefore, the prospects for a nonaqueous electrorefining system for Ti metal do not appear promising.

Jan 1, 2010

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 Robert H. Merrill

This report summarizes the first phase of studies to determine the design and behavior of an unsupported roof in an experimental room in limestone. The selection of a roof horizon and the design of the room were results of an investigation of the geology of the formation, the physical properties of samples from the proposed roof, and calculations from the theory of gravity-loaded beams. The design of the opening, some physical properties of the roof in place, and the behavior of the roof were checked by tests in a full-scale experimental room. The room was instrumented to measure roof deflection, separations in the roof strata, and incipient failure. The dimensions of the room before instrumentation was installed were 10 by 100 feet; the room was widened in successive increments to 40 by 100 feet. Between widening operations periods up to 6 months were allowed to provide a time test of the roof spans. The results of the measurements of deflection and separations showed that the lowest 6-inch layer in the roof became detached as the room was widened. This layer was eventually removed after standing without failure for about 4 months at room dimensions of 40 by 100 feet.

Jan 1, 1957

By Foster Fraas

A comparison has been made between cubes and spheres in the matrix of the high-intensity wet magnetic separator. For two inclined plane surfaces, such as may occur with cubes, the maximum force value, H [dH-dx] is at the point of nearest approach and is much higher than the force resulting from adjacent spheres. Although the maximum force value for cubes is higher, it decreases more rapidly at increasing distances. The maximum force for spheres is at an appreciable distance from the point of nearest approach. At field intensities for magnetic saturation of the iron spheres, the force extends to further distances with greater uniformity approximating that of the constant force or isodynamic field. The force is also independent of the sphere diameter, which permits the scaling of the sphere diameter to provide changes in particle migration distances without changes in force gradient.

Jan 1, 1972

By J. R. Thoenen

During the year 1927 the Bureau of Mines, at the request of a number of quarry operators, undertook to make a study of quarry operating costs in order to determine average costs for certain operating conditions and to suggest a model cost accounting system for quarry operations. A detailed questionnaire was prepared and mailed by the bureau to all quarries on its records as employing ten or more men in 1926.

Jan 1, 1929

By Potter G. M.

Ore-dressing tests were conducted on a sample of ore submitted by the Richmond Hill Mining Co. of Lead, S. Dak. as a part of the Bureau of Mines program for investigating potential domestic sources of manganese. Half of the sample was taken from the 300-foot level and half from surface cuts. The problems involved were liberation and rejection of silica and iron and removal of lead, Silver, and gold from the manganese concentrates. Although a portion of the silica and iron oxides was too intimately associated with manganese minerals for rejection by ore-dressing methods, thus limiting recovery of high-grade concentrates, the Richmond Hill ore was found amenable to simple gravity methods of concentration for producing intermediate-grade products. By jigging and tabling, 73.8 percent of the total manganese was recovered in a product that, when sintered, assayed plus 40 percent Mn. Lead, silver, and gold were successfully removed from gravity concentrates by a chloridizing roasting treatment.

Jan 1, 1948

By W. W. Adams, V. E. Wrenn

"Production of explosives in the United States during the calendar year 1936, as represented by reports of sales by manufacturing companies, totaled 391,604,500 pounds, an increase of 27 percent over the amount produced during 1935. This quantity included 81,698,375 pounds of black blasting powder (granular and pellet), 262,047,106 pounds of high explosives other than permissibles, and 47,859,019 pounds of permissible 5/ explosives.The manufacturers' reports to the Bureau of Mines classify the sales of explosives according to five main classes of work in connection with which the explosives were used.Coal mines used 87 percent of the total amount of black blasting powder sold, bituminous-coal mines 79 percent, and anthracite mines 8 percent; coal mines also consumed 98 percent of all permissible explosives and 9 percent of the high explosives other than permissibles. The coal-mining industry consumed 16 percent more explosives in 1936 than in the preceding year, the increase at bituminous mines being 21 percent and that at anthracite mines 4 percent.Metal mines used 29 percent of the high explosives other than permissibles and less than 1 percent of the black blasting powder and permissible explosives. The total quantity of the three classes of explosives used in metal mining in 1936 was 36 percent more than the quantity so used in 1935."

Jul 1, 1937

By Raja V. Rarnani, Robert L. Frantz

"Mining is one of the oldest of human occupations. The awareness of occupational illnesses associated with mining, even in ancient times, is evident from the writings of Hippocrates (460-370 BC), Pliny and Elder (AD 23-79), and Galen (AD 131-210). Georgius Agricola (1494-1535), in his De Re Metallica, refers to the diseases of miners and the need for their control through good planning and operating practices and responsible management (Schwerha, 1989). Coal workers' pneumoconiosis (CWP), often called Black Lung disease, is an occupational disease which results from inhalation of coal mine dust which usually contains relatively small amounts of free crystalline silica.A pneumoconiosis is best defined as the accumulation of dust in the lungs and the tissue's reaction to its presence [Lapp and Castranova, 1993]. Silicosis is the name given to the fibrotic disease of the lungs caused by the inhalation of dust containing silicon dioxide, primarily in the free crystalline form. Silicosis is the older and more well known of these mineral pneumoconioses. In contrast, CWP was not recognized as different from silicosis until the pivotal work of Collis and Gilchrist [1928].The U.S. Bureau of Mines (USBM) still regards worker exposure to respirable aerosols in mines as the most serious health problem in mining [USBM, 1994]. The National Institute of Occupational Safety and Health (NIOSH) is considering recommending a reduction in the standard for occupational exposure to respirable coal mine dust from 2 mg/m3 to 1 mg/m3 [NIOSH, 1993]. The Mine Safety and Health Administration (MSHA) may require new criterion for sampling procedures in the mine that would evaluate the ambient dust concentration in the mine atmosphere based on a single sample, instead of the current practice of averaging five samples (MSHA, 1992; Ramat* 1993). Several high-production longwall mining faces currently have extreme difficulty meeting the existing dust standards, and some already operate at reduced production levels to achieve mandated levels [USBM, 1993]. The importance of adequately protecting the miners from high concentrations of coal mine dust, as well as of reducing the incidence and severity of the Black Lung disease, cannot be overemphasized. The importance stems, first and foremost, from the humanitarian viewpoint and, second, from the perspective of the overall welfare of the coal industry.The histopathologic hallmark of CWP is the coal macule (Balaan, Weber and Banks, 1993). Autopsy or open lung biopsy reveals the coal macule to be an amorphous mass of coal particles, dust-laden pulmonary macrophages, reticulin, and collagen. No pathognomonic signs or symptoms identify workers with CWP. A CWP diagnosis requires that the worker experienced the appropriate dust-exposure setting (e.g., underground coal mining) and duration (usually 10 years or more) and, has the characteristic chest radiograph. Based upon the International Labour Organization (ILO, 1980) international classification, pathologists and radiologists have established case definitions for characterizing the pathology and the appearance of CWP on chest radiography (Weeks, 1993). CWP appears in two principal forms: simple, with small opacities, and complicated, with opacities larger than 10 mm in diameter. For all practical purposes, diagnosis of CWP in the living miner is wholly dependent upon the chest radiograph interpretation."

Jan 1, 1995

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 C. W. Owings

Available literature published or abstracted in 1953 and 1954 relating to dust prevention and suppression has been summarized and reviewed in this report, and un-published information also is included to outline current practice for those interested in dust control in and around mines, tunnels, and quarries. More and more companies are realizing the value of controlling dust by incorporating suitable methods and devices in the planning stage. In preparation and crushing plants preliminary tests have been made of the fine materials to determine the best type of dust-control equipment to use, and the details of the quantities of air, the number of sprays, the dust-allaying fluids, and the location of hoods or enclosures have been determined in advance. Such planning has paid for itself in more effective control. Similar planning in a tunnel resulted in healthful conditions and low dust concentrations.

Jan 1, 1956

By Edward M. Kawenski

Tests were made in the Bureau of Mines Experimental Coal Mine on stop-pings similar to those used in operating coal mines to obtain information on air leakage through the face and the rupture strength of a stopping subjected to a pressure differential. Block stoppings were made from cinder, slag, and gravel aggregates with and without mortared joints and coatings. Sheet stop-pings were uncoated brattice cloth and nylon or brattice cloth and expanded metal-lath coated with asphalt, latex, mortar, or rigid urethane foam. Limited data were obtained on air through stoppings subjected to simulated roof convergence and to shock forces created by the firing of an adjacent charge of explosive. The pressure differential required to rupture stoppings was determined. shows that coating the face of a stopping effectively reduces ail: leakage. Block stoppings, particularly those with mortared joints, are most resistant to pressure and shock forces than are sheet stop-pings. Where ground movement is a factor, sheet stoppings leak less air than block stoppings.

Jan 1, 1965

By Patrick D. Plumb

The Bureau of Mines (BOM) has begun a project to increase the understanding of the relationships between ecosystem health and its functions, and minerals development. The BOM, Juneau Branch, Alaska Field Operations Center, is providing support for ecosystem based land-management decision-making and the development of ecosystem based regulations by documenting the effects of mining on ecosystems and demonstrating the tools used to assess and analyze those effects. This is done by reviewing the data available on ecosystems and the environment at a mining site, the Greens Creek Mine near Juneau, Alaska, and applying available Geographic Information System modeling tools to assess the impacts of the mine on components of the pristine ecosystem. Habitat Capability Models for wildlife indicator species are used in this examination. Wildlife indicator species are used as indicators of ecosystem health by the U.S. Forest Service and the Alaska Department of Fish and Game, who developed these models for southeast Alaska. Analysis techniques from the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures (HEP) are also used in this report. By applying available models and analytical techniques to the Greens Creek area, the benefits gained through mitigation of potential impacts become apparent. These or similar techniques are useful for cost/benefit analysis of mitigation alternatives. Also apparent from this analysis is that the degree to which potential impacts are observable will depend upon the ecosystem scale considered. This demonstrates the importance of defining the ecosystem and scale before performing impact and cost/benefit analysis. The watershed scale is found to be useful for assessing impacts to ecosystem components at the Greens Creek Mine. Much progress remains to be made in the modeling and prediction of impacts to ecosystems from mining activity.

Jan 1, 1994

By John J. Mulligan

Lead-silver deposits in the Omilak area, on the western slopes of the Darby Mountains, Seward Peninsula, Alaska, were investigated by the Bureau of Mines, during the 1953 and 1954 field seasons, as a part of the U.S. Department of Interior's continuing program for the development of Alaska's resources. The Omilak area was the scene of early day prospecting and mining activity. The Omilak mine, which operated from 1881 to 1890, was the second producing lode mine in Alaska; the first was a small gold mine near Sitka. Several hundred tons of ore were produced at the Omilak mina; as an indication of grade, 41 tons shipped from Omilak in 1889 contained 75 percent lead and 142 ounces of silver per ton. A prominent, nearby occurrence of lead-silver minerals, found but not explored during this period, has since become known as the Foster prospect. Subsequent exploration of this prospect revealed an abundance of massive galena occurring on an outcrop and as float scattered through limestone talus. Evidence of lead deposition, together with the generally high silver content of lead ores previously shipped from the district, indicated that deposits might be found which would be commercially valuable even in this remote area. To investigate the possibility, the Bureau of Mines made a reconnaissance of the Omilak area and did bulldozer trenching, diamond core drilling, and sampling at the roster prospect. Data resulting from the investigation are presented in detail in this report and are summarized in the following paragraphs.

Jan 1, 1962