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By S. C. Rhoads

The Bureau of Mines is investigating low-chromium alloy substitutes for type 304 stainless steel (type 304 SS). The purpose of the research is to reduce the chromium content in austenitic stainless steels used for corrosion-resistant applications. Nine Fe-9Cr-12Ni alloys containing additions of 0 to 5 pct Mo, 0 to 2 pct V, and 0 to 2 pct Cu were selected for evaluation. All of the experimental alloys containing 5 pct Mo and an alloy containing 2Mo-2V-2Cu possessed structure and tensile strengths similar to those of type 304 SSe Alloys containing SMo-2V and SMo-2V-2Cu had ac-ceptable welding properties as measured by the Varestraint test. Alloys containing at least 2 pct Mo had cQrrosion resistance comparable to that of type 304 SS in solutions of nitric acid, phosphoric acid, acetic acid, and citric acid. In chlorides, all the experimental alloys were susceptible to localized corrosion and stress corrosion cracking similar to that of type 304 SSe The corrosion properties were established by weight-loss tests, electrochemical polarization tests, and stress-corrosion cracking tests. An Fe-9Cr-12Ni-SMo-2V alloy and an Fe-9Cr-12Ni-SMo-2V-2Cu alloy had a combination of welding properties, tensile properties, and corrosion resistances that were most comparable to those of 304 SS.

Jan 1, 1984

By Steven E. Mischler

The exposure of mine workers to diesel particulate matter (DPM) and gases is an issue of great concern to the underground mining community in the United States. Approximately 30,000 underground miners are potentially exposed to high concentrations of DPM. In January of 2001, the U.S. Mine Safety and Health Administration (MSHA) promulgated rules setting compliance standards for both underground coal and metal / nonmetal mine workers. As industry works to achieve compliance with these standards, mine operators are looking for feasible methods for reducing DPM concentrations in their mines. In addition, the industry needs methods to accurately measure DPM to ensure that the control strategies they adopt are working successfully. The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) conducts research to evaluate control technologies and monitoring instrumentation that can be used to reduce the diesel particulate matter (DPM) exposure of mine workers. An overview of the strategies being utilized in underground US mines to reduce DPM concentrations will be presented. Also, updates on the development of diesel monitoring instruments such as the continuous elemental carbon monitor or the Personal Dust Monitor for DPM measurement will be provided.

Jan 1, 2010

By William C. Cooley

This volume contains copies of the 5 x 8 in. accession card file for all items collected which were judged to be relevant to underground hydraulic coal mining. In many cases, abstracts are included. Abstracts were taken from the source, from other reviews, or from the preliminary screening of Russian documents performed by Dr. A. L. Brichant. No attempt was made to write abstracts for every accession item.

Jan 1, 1975

By T. H. Jeffers

The U.S. Bureau of Mines has developed porous beads containing immobilized biological materials for removing metal contaminants from waste waters. The beads, designated as BID-FIX beads, are prepared by blending biomass, such as sphagnum peat moss or algae, into a polymer solution and spraying the mixture into water. Laboratory studies were conducted to determine bead sorption and elution characteristics. Batch and continuous tests demonstrated that BIO-FIX beads sorbed arsenic, cadmium, lead, and other toxic metals from acid mine drainage waters collected from several sites. Selectivity for heavy and toxic metal ions over calcium and magnesium was demonstrated. The beads exhibited excellent metal sorption and handling characteristics in stirred tanks, column contactors, and a low-maintenance passive system. The sorption process was reversible, and metal ions were eluted from the beads using dilute mineral acids. Cyclic tests indicated that the beads continued to extract metal ions after repeated loading-elution cycles.

Jan 1, 1991

By W. L. Swager

Tramp (undesirable) elements introduced into iron and steel castings via purchased ferrous scrap are evaluated as to their likely degree of future threat to the quality of castings. Conclusions are based on analysis of literature and on nonmail surveys of foundries, scrap processors, trade and technical associations, and others. The existing tramp-element problem is expected to be persistent, but amenable to improved control by foundries and their suppliers. Four recommendations for action are given.

Jan 1, 1981

By Stephan Stecura

Crystallographic modifications and kinetics of solid-state phase trans-formations were determined for five rare-earth" sesquioxides--La2O3, Nd2O3, Sm2O3, Eu2O3, and Gd2O3. Oxides used for crystal modification studies were prepared by thermal decomposition of the following high-purity salts of the five rare-earth elements--carbonates, chlorides, fluorides, nitrates, oxalates, and sulfates. X-ray diffraction patterns of the cubic and hexagonal oxides were indexed by a graphical method and patterns of the monoclinic oxides by Ito's method. The kinetics of crystallographic transformation were determined by high-temperature X-ray diffractometry. The kinetic data were interpreted using a shrinking sphere model. All of the transformations followed first order kinetics. Activation energies were calculated by application of the Arrhenius equation. These solid-state phase inversions were concluded to occur by a reconstructive transformation mechanism.

Jan 1, 1965

By Margaret E. Harris

The formation of nitrogen oxides, the decay of carbon monoxide, and the concentrations of residual hydrocarbons in the secondary combustion zones of propane-air and methane-air flames were studied in three enclosed burners designed to simulate gas appliances such as space and water heaters. The effect of thermally or chemically perturbing the combustion gases above these flames was determined theoretically and by means of factorial experiments. The concentrations of air pollutants and the flame temperatures were measured, and the effects of ingress of secondary air into the primary and secondary combustion zones, flame stability, burner port surface, and simulated recycling of combustion gases were noted. Based on this study, four principles were derived that, applied to gas appliance design, will insure minimal emissions of these air pollutants: 1. Oxides of nitrogen can best be kept low by depressing peak temperatures to about 3,050° F. 2. If this is not possible, then the secondary combustion zone should be cooled rapidly to this temperature. 3. Carbon monoxide concentrations can be limited by rapid induction of secondary air. 4. Hydrocarbon concentrations can be controlled by designing for well-seated, stable flames. In addition, empirical reaction rates were derived that predict the concentrations of nitrogen oxides and carbon monoxide in the primary and secondary combustion zones.

Jan 1, 1970

By Gerald G. Johnson

The use of the Scanning Electron Microscope to characterize Coal Mine Dust has been possible because of two circumstances. First, the imaging process of the SEM allows multiple signals (secondary electrons, back scattered electrons, x-ray emission, etc.) to be viewed. Second, the use of a computer to analyze the signals and perform statistical tests on the results. The parameters described are size, shape, chemical composition, mass distributions, and particle thickness. Although the system is intended for particular systems, those of agglomerates (whether tile same or not) are handled by special aspects of the computer programs. The work on fibers is not completed at the time of this report. This work discusses the hardware (developed especially for this process) and software (both on an IBM 360/370 and a PDP 11/20). The latter system allows direct interaction between the operator of the SEM and computer for maximum information at the least time.

Jan 1, 1979

By Harry Dobroski

Communications with moving tracked vehicles in a rail haulage mine pose a difficult problem. These communications take place from dispatcher to vehicles or from vehicle to vehicle via the trolley line, which is a very poor communications line. As a result, deadspots and high-signal areas can occur anywhere along the line, or signal can decrease simply as a function of distance. An analysis is made of the trolley line as a communications line, and methods of improving its characteristics are discussed. Data from inmine experiments are presented, showing actual improvements in communications. Recent Bureau developments in new hardware are also discussed. These include an adaptive speaker control for existing carrier phones and a new generation of improved carrier phones.

By Francis E. Federspiel

Based on the investigation by the Bureau of Mines, tungsten is the principal metal found in the study area; gold and silver were the primary metals found at one property. Tungsten occurs in tactite zones formed near contacts of calcareous metasedimentary with granitic intrusive rock. Gold and silver were found primarily along quartz veins in granitic rocks; small amounts of those petals also occur in the tactite zones. Since 1856 approximately 200 lode claims or relocations have been recorded, mainly in the southwest corner of the study area. Tungsten production in this part of the area has been inure than 7,800 short ton units (70,800 kg) of tungsten concentrates; about 4,800 short ton units (43,500 kg) were from the Mud Lakes Mine; and 3,100 short ton units (27,200 kg) were from the Rainbow Mine 1/.

Jan 1, 1981

By Larry R. Powell

As part of the Bureau of Mines effort to establish a comprehensive subsidence data base for subsidence technology development, subsidence and related data are being compiled for various mining, geological, and environmental situations. This publication presents data for a longwall mining operation in the Northern Appalachian Coal Region. Vertical displacements and relative faze positions are tabulated for 160 subsidence monuments. Measurements were taken 32 times during the 2 years it took to mine the two panels. Brief physiographic and geological descriptions of the mining site are presented along with a general account of the mining and subsidence monitoring methods.

Jan 1, 1981

To improve the ventilation of large-opening under-ground stone mines by using stoppings made from stone left in place. Background Underground stone mines typically use large room-and-pillar openings with little ventilation control. Stone miners may be exposed to contaminants that include silica dust, diesel particulate matter (DPM), exhaust gases, nuisance dust, and face shot (blasting) fume gases. The health risks from breathing these fine particles and toxic organic materials are well documented. Although contaminants such as dust or diesel exhaust can be some-what controlled at the source, the escaping contaminants are often diluted and removed from work areas using ventilation with minimal controls. In many cases, current mine ventilation practices use trial-and-error techniques to improve ventilation. The growing realization of the importance of a healthy work environment along with increased regulations will require many stone mines to implement new ways to improve ventilation. In-place stone stoppings are one option. Mine air flows from one point to another because of a pressure differential between those points. This pressure differential is established using a mechanical fan in conjunction with separations (stoppings) between high-pressure (intake) and low-pressure (return) airways. The separation of intakes and returns is an important concept that is used in most other types of mines. Normally, air moves through underground stone mines with minimal control technology. Fans are placed in locations where they are thought to be most beneficial, and intakes are not separated from returns. In a few smaller underground stone mines, proper ventilation can be achieved with a few strategically placed fans. However, as these mines increase in size, moving adequate quantities of air through-out the mine becomes harder, and separation of intakes and returns becomes a problem. Building traditional mine stoppings to separate the intake and return airways in entries with a cross-section area often exceeding 800 ft2 is difficult. The stoppings must be able to withstand both the dynamic pressure from face shots and the static pressures created by the fans. Construction and maintenance difficulties, as well as high costs, are the main factors preventing these traditional mine stoppings from gaining wide acceptance by the stone mining industry.

Dec 1, 2002

By Efrem R. Reeves, David C. Byrne

This study was conducted as part of a project involving the evaluation of a new type of noise exposure monitoring paradigm. Laboratory tests were conducted to assess how “nonstandard” dosimeter microphones and microphone po­sitions measured noise levels under different acoustical condi­tions (i.e., diffuse ?eld and direct ?eld). The data presented in this article re?ect measurement differences due to microphone position and mounting/supporting structure only and are not an evaluation of any particular complete dosimeter system. To varying degrees, the results obtained with the dosimeter microphones used in this study differed from the reference results obtained in the unperturbed (subject absent) sound ?eld with a precision (suitable for use in an ANSI Type 1 sound level meter) 1/2 -inch (12.7 mm) measurement microphone. Effects of dosimeter microphone placement in a diffuse ?eld were found to be minor for most of the test microphones/locations, while direct ?eld microphone placement effects were found to be quite large depending on the microphone position and supporting structure, sound source location, and noise spectrum.

By Philip C. Tully

These modifications to the Redlich-Kwong equations for pure hydrogen and neon were developed after an unsuccessful attempt to generalize a modification technique previously developed for helium. New coefficients of the B terms were developed by minimizing the residuals. No changes were made in the coefficients of the A terms. For normal hydrogen, B was changed to [0.08063Tc PcT] for temperatures from 980 to 423° K and pressures up to 1,050 atm. The average deviation in Z was 0.36 percent with maximum deviations less than 1 percent for all but a few low-temperature points. For neon, B was changed to [PCT 0.1025T], for temperatures from 120° to 973° K and pressures up to 1,500 atm. The average deviation in Z was 0.34 percent with maximum deviations less than 1 percent for all but a few high-pressure and low-temperature points. Efforts to attain a lower temperature range to comparable accuracy with this type of modification were unsuccessful. In the range of applicability, these equations should be used with caution when calculating derived thermodynamic functions, such as the isobaric specific heat.

Jan 1, 1968

This briefing was sponsored by the Bureau of Mines to summarize ongoing and recently completed chromium-chromite research and resource assessment activities by the Bureau. Through the series of 18 presentations compiled herein, Bureau personnel covered a wide range of topics including U.S. chromite and chromium trends and usage patterns; foreign and domestic resources; and research activities on mineral characterization and beneficiation, chemical and pryometallurgical processing of chromite and chromium-bearing wastes, new low-chromium alloy and coating substitutes, corrosion- and oxidation-resistant stainless steels, and chromium-containing refractories.

Jan 1, 1986

By A. A. Berk

Other Federal agencies have been coming to the Bureau of Mines for help with the purchase and utilization of fuel, largely coal, almost since the day the Bureau was created in 1910. The requests covered a wide range of fuel-economy problems and included boiler-water treatment after it became apparent that water-formed deposits on heating surfaces acted as insulators, decreasing heat transfer and impairing fuel efficiency. Dr. Ralph E. Hall, a Bureau of Mines physical chemist determined the reactions that cause adhering scale to form in boilers (7)2 and went on to introduce scientific principles into water treatment for scale prevention (8). Widespread publicity of these achievements increased the requests for help from Federal steam-generating plants. Since no other Federal agency (even those which were more directly concerned with testing water) wanted to provide boiler-feedwater service, the Bureau decided to continue to give requested help to Federal agencies, Later, the Congress endorsed such agency cooperation as an economy measure,

Jan 1, 1963

By A. A. Berk

Other Federal agencies have been coming to the Bureau of Mines for help with the purchase and utilization of fuel, largely coal, almost since the day the Bureau was created in 1910. The requests covered a wide range of fuel- economy problems and included boiler-water treatment after it became apparent that water-formed deposits on heating surfaces acted as insulators, decreasing heat transfer and impairing fuel efficiency. Dr. Ralph E. Hall, a Bureau of Mines physical chemist determined the 3 reactions that cause adhering scale to form in boilers (7)2 and went on to introduce scientific principles into water treatment for scale prevention (8). Widespread publicity of these achievements increased the requests for help from Federal steam-generating plants. Since no other Federal agency (even those which were more directly concerned with testing water) wanted to provide boiler-feedwater service, the Bureau decided to continue to give requested help to Federal agencies, Later, the Congress endorsed such agency cooperation as an economy measure,

Jan 1, 1963

By Charles P. Lazzara, Alex C. Smith, Richard W. Pro, Mark W. Ryan

The U.S. Bureau of Mines conducted a study to determine if commercially available automatic sprinklers could withstand the high static pressures in deep underground coal mines without leaking and if exposure to the mine environment affected their leak pressures. New sprinklers and sprinklers exposed to the mine environment were subjected to increasing pressures until leakage occurred. The average leak pressures of the new sprinklers ranged from 640 to 2,300 psig and were significantly different for sprinklers from different manufacturers and for different types of sprinklers. Different for sprinklers from different manufacturers and for different types of sprinklers. Generally, standard-response sprinklers withstood higher pressures than fast-response sprinklers. The results indicated that most commercially available sprinklers would withstand the high static pressures in deep underground coal mines; however, they would not provide the same reliability and safety factor as sprinklers used aboveground at or below their rated pressure of 175 psig. The average leak pressures of the sprinklers exposed to the mine environment ranged from 740 to 1,180 psig. The mine environment affected the ability of 66% of the sprinklers to withstand high static pressure New sprinklers were also evaluated at pressures of at least 500 psig for 30 days to determine their ability to withstand long-term exposure to high static pressures; no leakage was observed.

Jan 1, 1993

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 Anthony T. Xannacchione, Luis E. Vallejo

At present, there is little knowledge concerning the shear strength of clays containing floating rock particles with concentrations from 0 to 30%. In practice, the effect of rock particles is typically disregarded in shear strength analysis The two primary reasons for this are: 1) a lack of agreement concerning the influence of rock particles on material strength, and 2) the expense and difficulty of testing day-rack mixtures with existing laboratory procedures. These factors have impeded the development of successful slope remediation design techniques far colluviums derived from resistant sedimentary rocks or spoil produced from surface mining. This study reviewed 3 1 technical papers which contain analysis of shear strengths for clay and sands with varying mixtures of rock particles. These technical papers, published over the last 40 years, are comprised of field case studies, laboratory evaluations, and theoretical analysis. Evaluation of this body of knowledge ha shown that the shear strength gradually increases with increasing percentages of floating particles in unsaturated clays.