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By Otto Robert Stein

Erodibility of reclaimed surface mine soils is a subject in need of quantification. Effects of soil erosion from reclaimed areas may damage surrounding areas and the quality of water in nearby streams and lakes. It may also reduce the potential productivity of the reclaimed site. A study was conducted to determine erodibilities of different reclamation treatments and a nearby unmined soil at three Indiana strip mine sites. A rainfall simulator was used to artifically erode plots con¬structed within seven treatment categories and the unmined soil. Soil erodibility was assessed in terms of the Universal Soil Loss Equation (USLE) K factor. Values for K calculated from field data were compared to values predicted from independently measured soil properties. Differences in soil erodibility between treatments were site specific. Unmined soil had the highest calculated erodibility at one site but at two other sites soils having reclaimed A horizons were highest. Shaley overburden treatments had the lowest calculated erodi¬bility. Predicted soil erodibility was usually lower than that calcu¬lated from field data. Site specific slope gradient factors (S) were developed for reclaimed A horizon treabnents. This was done because the USLE S factor overestimated the measured soil loss at steeper slopes.

Jan 1, 1983

By Chas. F. Jackson

This paper is published as a progress report for the first half of 1929 on the study of wining methods and costs in the Eastern and Central States. Data obtained from 25 mines using open-stope methods are correlated and summarized. Some of these mines have been described in considerable detail in reports already published as Information Circulars. In addition to the published reports on individual mines, considerable data have been obtained from other mines which were visited and studied during the course of the investigation. Many of these mines will later be described in detail in separate papers, and when the field has been covered in this manner it is planned to issue a bulletin on open-stops methods of mining which will amplify the subject matter of the present paper. Definition of ?Open-Stops?. - The term "open-stopes" as employed by the Bureau of Mines is applied to all naturally supported stopes; that is, stopes in which the excavated ore is not replaced by support of an artificial nature other than preps or stulls and in which the ore or (and) capping are not caved during the active life of the stopes.

Jan 1, 1931

By N. S. Dalal, A. H. Hoffman, X. Shi, D. E. Banks, J. K. H. Ma, Y. Rojanasakul

Excessive production of reactive oxygen radicals by alveolar macrophages is proposed to play an important role in oxidative lung injury. A major product of oxygen radical formation is the highly reactive hydroxyl radical (•OH) generated via a biologic Fenton reaction. In addition to its known ability to induce lipid peroxidation, recent studies have suggested that the •OH may exert its cytotoxic effect through the alteration of [Ca2+], homeostasis. To test this potential mechanism as well as to investigate the relationship between •OH and Ca" overloading in cytotoxic injury, isolated rat alveolar macrophages were exposed to externally generated radical system, H2O2 (0.01 to 1 mM) and Fe (1 mM) and their [Ca2+] levels and cell injury were monitored using quantitative fluorescence microscopy with the aid of the specific Ca" indicator, Fura-2, and membrane integrity indicator, propidium iodide. Electron spin resonance measurements using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) confirmed the production of the .OH radical by this system. Upon the addition of the radicals, the macrophages displayed a rapid initial rise in [Ca2+] which was followed by a slower but more pronounced [Ca2+], elevation that reached a level 3 to 5 times higher than the basal level. This process preceded cell death as evident by nuclear propidium iodide fluorescence. Depletion of extracellular Ca" inhibited both the [Ca2+], response and cell injury. Preincubation of the cells with the Ca" channel blocker verapamil or .0H radical scavenger mannitol similarly inhibited the [Ca2+], rise and loss of viability. Firefly luciferase assay of cellular ATP content demonstrated that the alterations in [Ca2+], following .0H treatment preceded the depletion of ATP. Changes in membrane potential caused by Na* substitution with K* had no significant effect on either the unstimulated or stimulated [Ca"], levels. Taken together, these measurements indicate that .OH-induced injury in alveolar macrophages is associated with the alteration in [Ca2+], homeostasis. The mechanism of •OH-induced [Ca2+] loading is not due to nonspecific membrane damage or energy depletion, but mainly due to an increase in Ca2+ influx through Ca2+ selective channels. This Ca2+ over-load state as well as energy depletion caused by the oxidant may activate certain cellular degradative processes leading to cell injury and death.

Nov 1, 1995

By R. V. Ramani, C. B. Manula, A. Owili-Eger

PART 1 THE INPUT AND OUTPUT DATA AND THE MINE SCHEMATIC SHOWING THE FLOWS FROM COMPUTER SOLUTIONS FOR APPLICATION I

Jan 1, 1975

Under the Bureau of Mines Research Contract Number H0252071, Foundation Sciences, Inc. has compared the relative effectiveness of roof bolts installed at an angle over the rib with that of bolts installed vertically at the rib side, The information gathered during this investigation was sufficient to supply supplementary information on the mechanics of roof support systems and the general acceptability of field instrumentation methods. During the 140 days of field investigation, 235 bolts were installed, 45 inclined and 190 vertical, in two adjacent intersections. Of these 235 bolts, 30 were in-stalled with load cells and 38 were tested for anchor capabilities. In addition to this instrumentation, the deformation of the opening was measured by convergence meter on 9 lines throughout the two testing areas, and a borescope and photo-elastic gauges were utilized to obtain information on the roof action beyond the surface.

Jan 1, 1977

By S. H. Brooks

"IntroductionThis preliminary report deals with the effect of oxygen pressure on the ignition temperature and combustibility of oils, it is the third of a series which will present the results of an investigation being made by the Bureau of Mines, on oxygen-oil explosions. The purpose of this research is to obtain technical data that will serve as a basis for safety precautions general outline of the problem has been given in the first report (Serial 2507).The present experiments have resulted in (1) a method for determining spontaneous ignition points of oils in an atmospheric of oxygen under pressure; and (2) the determination of these ignition temperatures for three typical oils, one being an animal oil (sperm), one a vegetable oil (linseed), and one a mineral oil (""Moiloil A"").These experiments on explosibility of oil were performed in order to discover the general nature of the phenomenon, especially the order of magnitude of the temperature necessary for spontaneous explosion (120°C. and upwards) and the effect of pressure variation (negligible as regards ignition temperature but important in relation to the violence of the explosion). A continuation oftests should provide a basis for selecting the safest lubricants for high pressure compression of gases particularly air and oxygen; and should be of value when devising new specifications for lubricants, both in the government departments and the compressed-gas manufacturing industry."

Dec 1, 1923

By J. A. Cavallaro

The heats of formation of anhydrous barium carbonate (witherite), strontium carbonate (strontianite), and lead carbonate (cerussite) were determined by solution calorimetry. The solution mediums were hydrochloric acid for barium and strontium carbonates and perchloric acid for lead carbonate. The heats of formation at 298.15° K are as follows: BaCO3 -297.5 ± 0.8 kcal/mole; SrCO3 -294.6 ± 0.5 kcal/mole; and PbCO3 -168.0 ± 0.3 kcal/mole.

Jan 1, 1966

By E. J. Schneider

In view of the current interest in the constituents of low-temperature tar, the Synthesis of three known xylenols and their hydroxyacetic acid derivatives has been undertaken by the U. S. Bureau of Mines. One of these xylenols, the 1,3,2 derivative first reported by Steinkopf and Höpner,4 has been described by Brown and Branting.5 The other two derivatives, the 1,3,5 first reported by Schütz6 and the 1,2,3 reported by Steinkopf and Höpner, have now been studied in greater detail. In the present work the synthesis of 1,2,3-xylenol and 1,3,5-xylenol was repeated, with some improvements in the former. The hydroxyacetic acid derivatives were also prepared, and it was found that while the melting point of the 1,2,3 derivative agreed with that of Steinkopf and Höpner. that of the 1,3,5 derivative was found to be 111° instead of 85 to 86° as reported by Schütz, by Steinkopf, and later by Bruckner. The discrepancy between the melting-point figures is doubtless due to differences in the purity of the xylenols used in the synthesis of the acids. Schütz obtained his 1,3,5 acid by recrystallizing an impure sample obtained from a mixture of xylenols. The difficulty of obtaining a pure acid by starting with a mixture is demonstrated by Bruckner, who despite painstaking efforts was unable to obtain the pure 162.5° melting 1,2,4 isomer from a mixture that persistently melted at 138° C. Steinkopf did not repeat Schütz's work but merely used the latter's figures in compiling a table. Bruckner, on the other hand. apparently also made the acid (by an improved method), and it is difficult to explain his checking Schütz's figure, unless it is that he, too used a symmetrical xylenol obtained from a tar and not prepared synthetically, as was the one reported in this paper.

Jan 1, 1929

By Jack D. Ramsdell

Electrorefined, magnesium-reduced, and sodium-reduced titanium samples were evaluated for recrystallization behavior, effect of cold rolling on tensile properties, and bend ductility. Curves were determined for the softening of 2.5 to 80 percent reduced cold-rolled metal that was annealed over a temperature range of 300° to 800° C. Upon annealing, coarsening of the grains was found to occur for reductions in thickness of less than 20 percent in titanium made by all three processes. The presence of metallic impurities greatly inhibits coarsening for reductions in thickness below 20 percent, but for reductions in excess of 20 percent grain size is essentially constant at each annealing temperature. The three grades of titanium did not harden excessively from cold rolling; both tensile and bend ductility were good for reduction in thickness up to 80 percent. Upon annealing, softening occurs between 400° and 600° C., and, based on microstructure and property studies, full annealing is accomplished after 30 minutes at 700° C. for the magnesium-reduced and electrorefined titanium and at 800° C. for the sodium-reduced titanium.

Jan 1, 1960

By Daniel G. Di Canio

A computer based accident cost indicator model (ACIM) for estimating tangible costs of occupational injuries, illnesses, and fatalities in the U.S. mining industry is described. Studies performed to expand the scope of the ACIM to all mining sectors are presented. Validation of ACIM cost element estimation algorithms with actual costs of mining-related injuries and illnesses are presented. A study of the effect of a fatal accident on production in surface coal and metal/nonmetal mines is presented. The study is based on a sample of 15 fatalities in underground and surface mines. Evidence of significant long- term decline in postfatality production at 6 of 8 underground samples is presented. The average loss is shown to be 1.8% of annual mine production. A study of accident costs in U.S. mining from 1975 through 1981 using the ACIM is presented. The study shows that total annual costs increased from $180,000,000 in 1975 to $379,000,000 in 1981, a 15% annual increase after adjusting for inflation, with mining companies bearing 45% of the total and expected wage losses to mining families accounting for 42%. The study shows total costs of $12,400 per accident and $674,000 per fatal accident for 1981.

Jan 1, 1983

By G. W. Jones

The operation of combustion engines of various types at high altitudes and other combustion processes at reduced pressures have made it desirable to determine limits of flammabilities -under these conditions. Experiments carried out by the Bureau of Mines have shown that although natural gas-air mixtures become more difficult to ignite as the pressure is reduced below atmospheric, with a suitable source of ignition the limits of flammability are as wide at 175 mm mercury absolute as they are at atmospheric pressure.

Jan 1, 1949

By E. B. Kester

In the commercial evaluation of coal tars, a distillation analysis properly carried out is of considerable importance. Close attention must be given to this operation in order to obtain consistent results and to secure the minimum decomposition of the tar compounds, which in many cases are sensitive to undue heat effects. Low-temperature tars in particular contain compounds of this nature, while in the case of tars produced at high temperatures the large proportion of pitch present has an adverse influence during a distillation. If excessive cracking takes place, the composition of the distillate will naturally vary from the normal, with the result that all the analytical criteria subsequently obtained are affected. Where tars, produced over vide ranges of carbonization temperatures are investigated as in the survey of gas, coke, and by-product making properties of American coals nor being conducted at the United States Bureau of Mines Pittsburgh Experiment Station, the method of distillation must necessarily be the sane for all of the tars studied. Also, it must function equally well for both low and high temperature tar, permit accurate fractionation, and reduce adventitious decomposition to a minimum.

Jan 1, 1932

By Joan T. May

The Federal Bureau of Mines investigated the potential for recovering aluminum from copper-dump leach liquors by use of single-contact ion-exchange technology. A strongly acidic ion-exchange resin was used to extract aluminum from a typical dump leach liquor and from synthetic leach liquors. Aluminum was stripped from resin with a HS04 or NaCl solution. Bench-scale experiments indicate that a single-contact ion exchange is technically feasible, but that the process is limited by the relatively low loading capacity of the resin and the excessive amount of stripping agent required. A further limitation is that significant amounts of magnesium and iron are loaded and stripped along with the aluminum.

Jan 1, 1976

By Ronald S. Conti

This U.S. Bureau of Mines report discusses the results of research conducted in the Bureau's experimental mine at Lake Lynn Laboratory on the response of fire sensors to simulated mine fires, which included (1) a slowly developing coal-conveyor belt fire, (2) a rapidly burning liquid fuel-belt fire, and (3) a liquid fuel-belt fire in the presence of diesel exhaust. During these tests, several mine fire sensors were evaluated with respect to sensor placement, spacing, and type. The data indicate that smoke sensors alarm several minutes before CO sensors do; and that, in the presence of diesel exhaust, a prototype diesel-discriminating smoke sensor can successfully function without being sensitive to the diesel contaminants. The vertical placement of sensors in the entry near the fire was also shown to be critical in terms of alarm times. Additional data showed that variations exist in response time and level of response for two brands of electrochemical CO sensor. Results also indicate that early detection of fires will improve the probability of miners' escape, because of reduced smoke concentrations during the incipient stages of the fire.

Jan 1, 2010

By R. M. GRANTHAM, J. H. SOULE

C. R. Keyes, F. C. Schrader , F. A. Jones ( the first director of the New Mexico School of Mines , whose name was given the deposits ) , and N. H. Darton all described the Jones iron deposits within a decade after their discovery in 1902 . The earliest locations now on record were made in 1927. Interest in iron ores was revived during the second World War . Paul E. Pesonen , of the Bureau of Mines , reported on the deposits in December 1941 and proposed an extensive exploratory program . In March 1942 , the deposit was reported upon by C. H. Johnson , also of the Bureau of Mines , and a definite program of exploration was outlined .

Feb 1, 1947

By Joseph M. Pugliese

The U.S. Bureau of Mines has produced a generic in situ copper mine design manual, which contains a computerized cost model for in situ copper oxide mining. The model specifies (1) site-specific parameters, which must be quantified for mine design, (2) a method for minesite design based on those parameters, and (3) a procedure for assessing economic viability for the mine design. The menu-driven computer program performs calculations for developing commercial mine design specifications, as well as capital and operating costs. The default values are based on 1986 dollars, and indices for updating costs are included. The program also provides discounted-cash-flow rate of return (DCFROR) and allows for sensitivity analyses for an in situ mining operation at any specific undisturbed copper oxide deposit. This report is to be used with the 1990 version of the computer program, which has been made user friendly. It describes the flies, tutorial, input phase, help function, and monitor display of all calculated values and of the DCFROR table. The monitor-displayed discounted initial value of investment and annual operating costs are defined. The dual rate-of-return situation and sensitivity analyses are also briefly discussed. Information is provided on obtaining the computer program on diskette.

Jan 1, 1991

By D. H. Desy

The Bureau of Mines studied the properties of copper that had been oxide dispersion-strengthened with 2 vol pct of either yttria or alumina. Compounds of copper and aluminum or yttrium, coprecipitated from aqueous solution, were converted to oxides; the copper was reduced, compacted, sintered, and extruded. For the resulting copper-dispersoid composites, room temperature tensile properties after annealing in hydrogen, elevated temperature tensile and stress-rupture properties, and electrical conductivity were determined. Compared with oxygen-free copper, copper-2 vol pct alumina or yttria had improved strength after annealing between 400° and 1,000° C, and improved elevated temperature strength, with little loss in electrical conductivity.

Jan 1, 1969

By William J. Campbell

This analytical method development and evaluation was undertaken by the Bureau of Mines to provide accurate determinations of eight minor elements in low-alloy steels prepared from ferrous scrap. Fluorescent X-ray spectrography was the principal method investigated. Confirming analyses were made by conventional instrumental and chemical methods. All X-ray data were processed by a timesharing computer. No corrections were found necessary for inter-element effects or overlapping spectral lines. Concentrations were calculated from the least-square fit of a linear calibration equation derived from measurements on three sets of standard steels. These studies show that X-ray spectrographic analysis of lathe-finished surfaces provides accurate determinations of aluminum, copper, chromium, manganese, nickel, phosphorus, silicon, and tin.

Jan 1, 1973

By Robert C. Ellman

Stockpiles containing 2.3 million tons of lignite constructed in the period 1948-56 in conjunction with the construction of Garrison Dam on the Missouri River demonstrate successful stable long-term storage of lignite. Uniform and thorough compaction of each of the I-foot-thick layers by which the piles were constructed produced a bulk density of 70 Ib/cu ft. Air penetration into the stockpiles was restricted to a degree that prevents spontaneous heating or deterioration of the stored lignite, A continuing record of observations beginning with stockpiling operations in 1948 has been accumulated, This includes periodic fuel analysis, analysis of pile gases, and measurement of pile temperatures on the first large stock-pile, pile 5. This report describes the stockpiling method, the changes in heating value, pile gas composition, and pile temperature and summarizes observations from 1953 to 1964, Data accumulated attest to the stability of the stored lignite. The variation of the average heating value of periodic pile-depth samples is only 160 Btu/lb (11,990 to 11,830) on the moisture" and ash-free (maf) basis during almost 10 years of storage. Temperature levels of the pile interior are progressively decreasing. At pile surface, cyclic variations occur with the season. The only problem encountered with the large stockpiles is wind and water erosion of the pile surface. The partially successful control measures used are described.

Jan 1, 1967

By Raymond B. Ladoo

"Domestic Situation:The greatly increased use of lithopone as a base for paints, particularly for interior use, has timulated the demand for barytes to such a degree that the supply cannot keep pace with the demand. Lithopone is an artificially prepared compound composed of about 70 per cent barium sulphate and 30 per cent zinc sulphide, precipitated together. Its most important use is in paint, but it is also used in oilcloth, linoleum, rubber goods, shade cloth, etc.Prior to the war large quantities of barytes were imported from Germany, but during the war imports were negligible, domestic production increased very greatly and is still increasing. Ground barytes as used in paints/ formerly regarded as an adulterant, but now it is generally recognized as a valuable paint constituent. Mile domestic sources have expanded rapidly they have not overtaken the demand and there is need for still greater expansion. Stocks are low, little is being sold on the open market, and prices are high. Since barytes is a gangue mineral associated with metallic ores now being mined in the west, it is suggested that more attention be given to its recovery as a by-product.The following tables compiled from reports of the U.S. Geological Survey and the Bureau of Foreign and Domestic Commerce, indicate the growth of domestic consumption."

Jan 1, 1920