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By F. N. Kissell

The Bureau of Mines has successfully used sulfur hexafluoride (SF6) as a tracer gas to measure mine air flows under conditions where conventional methods have failed. SF6 was employed experimentally to measure accurately recirculation of return into intake air caused by leakage through an old stoped area, to check for potential leakage from an adjacent mine, to trace 10,000 cfm of “lost” air from an intake airway, and to measure transit air time through uranium mines. It proved useful as a means of accurately measuring airflow volumes in airways of large cross section and very low flow velocity, and in determining the recirculation resulting from underground cooling plants.

Jan 1, 1974

By Hon-Chung Ko

This Bureau of Mines report provides the enthalpies of formation of cupric bromide and cuprous bromide as determined by hydrochloric and hydro-bromic acid solution calorimetry. At 298.15 K, the values are -33.10 ± 0.4 kcal/mole for CuBr2, and -25.24 ± 0.25 kcal/mole for CuBr.

Jan 1, 1975

By C. M. Frost

The hydrodesulfurization characteristics of a Venezuelan topped crude oil and a Venezuelan reduced crude oil were determined at temperatures from 740° to 850° F, pressures from 800 to 1,600 psig, and space velocities from 1.0 to 2.0 Vo/Vc/hr. Kinetic calculations showed that under these conditions the desulfurization reaction was first order with respect to sulfur and had an average activation energy of 32.5 kcal/mo1. Catalyst life tests made at 750° F, with pressures of 800, 1,200, and 1,600 psig and space velocities of 1.0 and 1.25 Vo/Ve/hr, showed that the decrease in the relative activity of the catalyst was a logarithmic function of time or volume of oil processed and the amount of vanadium deposited on the catalyst. Comparative tests made with residual fuels prepared from a Wilmington, Calif., crude oil and a Wyoming asphaltic crude oil showed that catalyst life may be extended by processing fuel oil with a low metal content, but it may be shortened by the presence of large amounts of asphalt in the feed.

Jan 1, 1971

By E. Chin

The mineral industry of Bangladesh was totally dominated by natural gas production and its downstream uses. A small amount of cement was produced, and clays were used locally for ceramics and construction materials. Nitrogenous fertilizer was produced from natural gas and a modest, scrap-based steel industry produced steel for local consumption. The country has been developing and using its abundant and inexpensive gas reserves as fast as practical. The population, however, was predominantly dependent on agriculture for its livelihood. The industrial sector accounted for 10% of the economy, and most of the industrial output was directly associated with agricultural products jute, tobacco, and textiles. Industrial expansion, even with the availability of gas, was severely constrained because of limited domestic demand, lack of skilled work force and management, poor infrastructure, and a low rate of domestic savings. To put greater emphasis on the industrial sector, the Government established a National Committee for Industrial Development in July. The Committee instituted policy reforms in the areas of trade and investment. One important step was to move from a positive import list to a negative list, thereby permitting imports of items not restricted or banned. The system for recovering and approving new domestic or foreign industrial investments was streamlined to expedite what had become a cumbersome, bureaucratic exercise. To encourage industrial development in areas away from the crowded urban centers, several economic incentives reportedly were adopted. These included a reduced tax rate on imported machinery, exemption of import license fees, a reasonable debt equity rate, and a 9-year income tax exemption period.2 In the trade sector, imports increased 12% in fiscal year (FY) 19843 mainly

Jan 1, 1987

By K. K. Kershner

Important contributions can be made to conservation of natural resources by recovering mineral values from primary and secondary metallurgical slimes and flue dusts. This applies particularly to ultrafine mineral particles that escape recovery by conventional mineral dressing. In the interest of economy and conservation the Bureau of Mines is investigating fundamental properties of ultrafine mineral values in slimes as a means of developing new or improved methods of mineral recovery. The work described in this progress report was carried on in the Bureau's laboratories at Rolla, Mo., from 1951 to 1953. The mineral material used as a subject for study was tin-ore slimes. DESCRIPTION OF TIN SLIMES The tin slimes consist principally of quartz, with appreciable quantities of tourmaline and sericite mica and small amounts of cassiterite, pyrite, hematite, and arsenopyrite. The tin content is approximately 0.5 percent.

Jan 1, 1954

By Donald W. Mitchell

The fire hazard of neoprene, polyvinyl chloride, and rubber conveyor belts was studied at the Federal Bureau of Mines Experimental Coal Mine. The effects of intensity of ignition source, velocity of the ventilating air, and type of belt were investigated at three levels in small-scale gallery experiments. Studies were made in the mine on the effects on ignition and flame propagation of belt-entry dimensions, belt widths, and belt configuration. Methods for extinguishing belt fires were also investigated under simulated mining conditions, and during these trials coal dust and grease were placed on the belt. The research showed that conveyor belts will burn. Neoprene, polyvinyl chloride, and rubber belts, with and without carcass, ignited and propagated flame. The highest rate of flame propagation was obtained on rubber belt. The fire hazard increased with increase in intensity of ignition source and air velocity. Flame propagated only when air was forced through the test zone; propagation was not obtained when forced ventilation was not used, as would exist in a neutral entry in a mine. Automatic water sprays and high-expansion foam effectively arrested flame propagation; direct application of water and bicarbonate dusts was ineffective.

Jan 1, 1967

By Samuel W. McNary

In August 1984 the U.S. Bureau of Mines conducted a study of the mineral resource development potential of the Badger Canyon-Antelope Creek area, within the Boulder-Pioneer wilderness study area, about 5 miles northeast of Ketchum, 10. The purpose of this study was to investigate in greater detail an area which was designated by the U.S. Geological Survey (USGS) and the Bureau as having a moderate mineral resource potential for zinc, molybdenum, lead, and silver, and a low potential for copper. One hundred twenty-eight soil samples were taken along a 6,2S0-ft traverse on the ridge separating Badger Canyon and Antelope Creek. 5 Five rock samples were collected from old prospect pits and mineralized outcrops. All samples were analyzed for gold. Silver, copper, lead, zinc, molybdenum, arsenic, antimony, vanadium, and mercury. The metal concentrations in the soil samples along the traverse are irregularly distributed. Samples collected near old prospect pits tend to be high in lead and zinc, undoubtedly a reflection of underlying galena-and sphalerite-bearing quartz veins. All of the copper and mercury values in the soils are less than the detection limit, as are most of the lead, molybdenum, and antimony values. Except for lead and zinc values, the metal concentrations in the rock samples are low. Galena and sphalerite were observed in quartz vein samples collected at the old prospects. The results of the study indicate that the galena-sphalerite-bearing quartz veins and veinlets are too narrow, widely-spaced, and low in metal values to be economic. Low concentrations of metals in the soil and rock samples, combined with the lack of major mining activity in the past, indicate that the area has a low likelihood for economic development.

Jan 1, 1986

By W. S. Sanner

A High Splint coal was carbonized in a low-temperature, fluidized-bed sys-tem to study the effects of thermal cracking on the products of decomposition. The coal was fluidized in recycle gas at 485° to 600° C, and the products were cracked at 600°, 700°, and 800° C in a bed of fluidized coke. Yields of tar, pitch, paraffins, and olefins decreased as carbonization temperature increased. Thermal cracking of the tar vapors produced the highest tar yields at 600° C, and light oil yield increased at cracking temperatures up to 700° C. At an 800° C cracking temperature, the yield of light oil decreased.

Jan 1, 1969

By M. J. Ferrante

The Bureau of Mines determined the enthalpies of Ni3S2 relative to 298.15 K to provide new thermodynamic data for advancement of mineral science and technology. Enthalpies were measured with a copper-block calorimeter from 298.15 to 1,197 K. A solid-solid transition was found at 834±1 K, with an isothermal heat absorption of 13.32 kcal/mol. The temperature of this solid-solid transition was accurately measured by differential scanning calorimetry. Because Ni3S2 does not melt congruently, the heat of fusion of 4.70 kcal/mol was obtained by extrapolation of enthalpy measurements from the solid and liquid phases to approximately 1,064 K. Tabulated values are given for the relative standard enthalpy, heat capacity, entropy, and Gibbs energy function between 298.15 and 1,800 K. Enthalpies are also given in equation form and combined with data from the literature to derive values of standard enthalpies of formation and Gibbs energies of formation. Similar calculations were made for the reaction of crystalline and liquid nickel with gaseous diatomic sulfur for Ni3S-2(c, l).

Jan 1, 1982

By Joseph N. Harstead

This Bureau of Mines report provides information on the first 49 water-flood projects (or units) in Nebraska. All injection was in the ?D? or "J" Cretaceous sands of western Nebraska. Specific data presented include location, map, discovery and development, water supply and injection, oil and water production, estimates of oil in place, primary and secondary recoveries. The 49 projects studied) including four dual-zone projects, should recover about 126.5 million barrels of oil. Eighty-six percent of the estimated oil had been recovered by the end of 1966. Abundant water was found near most projects.

Jan 1, 1967

By J. E. Zeilinger

This Bureau of Mines report describes the preparation characteristics of three samples collected from the Kidney seam, in the Northern Field of the anthracite region. Removal of the sink 1.70 specific gravity material from the samples collected would result in greatly reduced ash contents at yields in excess of 90 percent. The Kidney seam, in the locations sampled, proved to be a low-ash anthracite containing an unusually high percentage of float 1.45 specific gravity material.

Jan 1, 1970

By Richard E. Dawes

Physical variables, a principal factor in the economies of mineral production, affect both capital and direct operating costs. By using a revenue-cost system for the framework, the analyses of revenue and cost categories demonstrate the relative importance of groups of physical variables, whether explicitly defined or not, to a lead-zinc mining operation. Physical variables affecting the producer represent about 60 percent of the total system influence as expressed by cost ranking. Other physical variables affect the remaining costs as controlled by the smelter, the transporter, and the landowner. Such resource conservation aspects as mineral losses due to mining method and mineral processing constitute a portion of the total revenue effects of physical variables. The physical variable revenue-cost system presented in this report offers a framework for cost-benefit analysis of mineral related research.

Jan 1, 1969

By M. M. Tilman

The Bureau of Mines conducted research to evaluate superplastic behavior in commercial magnesium-base alloys AZ6IA, ZK60A, ZW3, AZ3IB, ZWI, and an experimental Mg-12 pct Al alloy. Strain-rate sensitivity indices (m-values), maximum elongations, and effects of superplastic elongation on tensile properties were determined on fine-grained sheet. Inert-gas-pressure hemisphere-forming tests were conducted on selected sheet stock of the five alloys. Formability trials on AZ31B alloy sheet were conducted on industrial equipment for comparison with commercial superplastic forming of Zn-AI alloy. Closed-die-forming tests were performed on extruded ZK60A rod. All alloys exhibited well over 100-pct elongation, indicating superplasticity, at temperatures and strain rates near the maximum m-values. Tensile properties were generally reduced following 100-pct superplastic elongation, but not to an extent that would preclude use of the commercial alloys in the superplastically deformed condition. The potential for industrial superplastic forming of AZ31B sheet was indicated by hemisphere forming in the laboratory and substantiated in industrial forming trials.

Jan 1, 1982

By M. Kanda, W. D. Bensema, J. W. Adams

Two different techniques were used to make measurements of the absolute value of electromagnetic noise in an operating coal mine, Itmann No. 3 Mine, located near Mullens, West Virginia. The electromagnetic environment created by 250-volt-dc and 550- and 950-volt-ac machinery in two longwall panels was measured and is reported. One technique measures noise over the entire electromagnetic spectrum of interest for brief time periods. It is recorded using broadband analog magnetic tape, and the noise data is later transformed to give spectral plots. The other technique records noise amplitudes at several discrete frequencies for a sufficient amount of time to provide amplitude probability distributions. The specific, measured results are given in a number of spectral plots and amplitude probability distribution plots.

Jan 6, 1974

By J. K. Whyatt, B. G. White

Various methods of monitoring slip movements on bedding planes, as well as examination of rock burst damage in stopes, suggest that many rock bursts in the Lucky Friday Mine are closely associated with these movements. Slip displacements along bedding simultaneously reduce the physical dimensions of stopes and increase compressive stress along stope margins. Such changes, in turn, contribute directly to sudden failures of rock and cemented sandfill surrounding stopes. We believe that the reduction of rock burst hazards must be based on a clear understanding of the basic mechanisms involved. The current work emphasizes the mechanical role of wall rock movement and seismicity in generating conditions that promote rock burst damage. Based on our interpretations of these mechanisms, we briefly address several hypothetical practices that could influence rock burst hazards in similar mining situations. The overall goal of this research is to advance the NIOSH mission of improving the health and safety of the nation’s workers.

By J. A. Organiscak

The U.S. Bureau of Mines recently conducted an investigation into the amount of respirable and quartz dust generated while mining rock in coal mines by continuous and conventional methods. The study was made at two mines that use both continuous and conventional mining. Results show that continuous mining produces 1.2 to 3 times more respirable dust, and 6.7 to nearly 15 times more quartz dust than conventional mining.

Jan 1, 1989

By T. H. Davis

Twelve laboratories from the Western United States and Canada participated in radon progeny intercomparison measurements at the U.S. Bureau of Mines radon calibration facility in March 1987. The participants intercom pared grab-sampling and automated equipment methods at high and low concentrations of radon progeny and condensation nuclei (CN). The objective of this intercomparison was to determine if the measurement procedures and equipment of the North American facilities are equivalent. The sampling results showed good agreement among all participants. The standard deviation for the working level measurements was less than 3.5% for 1.70 working level (WL) and less than 8.8% for 0.21 WL. This relatively good agreement was achieved by using alpha standards calibrated by National Bureau of Standards (NBS) and by closely checking and monitoring airflows.

Jan 1, 1989

By Linda L. Chasko, Charles P. Lazzara, Ronald S. Conti, William J. Wiehagen

Fire has long been a concern for underground mine workers. A mine fire can occur at any time and can result in a partial or total evacuation of mine personnel and the loss of lives. Fires can grow rapidly. Time is the critical element. Prompt detection, timely and accurate warnings to those potentially affected, and a proficient response by underground miners can have a tremendous impact on the social and economic consequence of a small underground fire. Fire preparedness and response have components of technology and people. These components can work synergistically to reduce the time it takes to bring the system back in balance. This report deals with the preparedness of miners to respond to underground mine fires. It is intended to aid the mining industry in understanding the various roles of emergency responders and the training techniques used to increase their skill levels. The report also presents a technology overview to assist in effective response to mine fires.

By David A. Monaghan, Kenneth R. Maser, Adi R. Gurdar, D. Randolph Berry

8. Field Demonstration of the Remote Mine Sealing System in a Coal Mine 8. 1 Selection of Field Test Site Eastern Associated Coal Corporation (EACC) offered its Federal No. 1 coal mine in Grant Town, West Virginia as the site for field testing of the remote sealing system. The choice of Federal No. 1 mine was particularly appropriate as the first attempt at fire control by remote sealing was done in this mine in 1963. EACC provided the men and equipment required for much of the initial preparation. Considerable assistance, advice, and background on coal mining technology was given by Mr. William Laird, Vice President for Research and Development, EACC, and by Mr. Lawrence Jackson, Resident Engineer at the Federal No. 1 mine. District 3 USBM office, the West Virginia Bureau of Mines, the Technical Support Group of the USBM, and Local 4047 of the United Mine Workers of America also cooperated. 8.2 Preparation of Field Test Site 8.2. 1 Underground Site Preparation The underground site chosen for the field testing was in a non-working portion of the mine within a few hundred feet of the main haulage road, as shown in Figure 80. Known as "Seven Switch, " this area was a 20 minute walk or 5 minute "jeep" trip from the man-trip shaft. Ten years having passed since this area was actively worked, considerable effort was required for gob clearing, roof bolting, rock dusting, and rejuvenating the track from the haulage road to the test area. Three primary borehole locations were chosen for the test program. Borehole No. 1 was in a straight passageway

Jan 1, 1973

By V. E. Erwin, W. W. Adams

"INTRODUCTION This report presents statistics of accidents at coke ovens in the United States during the calendar years as 1933, the twenty-first year for which data of this kind are available, 1913 being the first year for which accident reports were collected from the operating companies by the Bureau of Mines. The present report is presented in mimeograph form because insufficient funds are available for printing it. The first report of the Bureau of Mines that contained statistics of accidents for the coke-mining industry in the United States covered the two calendar years, 1913 and 1914. While the figures presented therein related both to beehive and by-product ovens, the original returns from the operating companies were not classified so as to permit the presentation of accident statistics for each class of ovens separately. Beginning with 1915, the accident reports from the operating companies have shown the general type of ovens to which the reports related; therefore, since that year, separate statistics for each of the two classes of ovens have been given in the Bureau's yearly reports of accidents at coke ovens.The coke-making industry in the United States established a safety record in 1933 almost equal in merit to that which it achieved in 1932, when the accident-frequency rate was the lowest and therefore the most favorable that the industry has known. Credit for the achievement is due almost entirely to companies operating byproduct ovens. (See table 8.)"

Mar 1, 1935