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By Loren R. Anderson

This volume documents the use of the probabilistic slope stability program PROBISH. The probabilistic slope stability program is an interactive program and is essentially self-tutorial. It prompts the user for the required input data as it is needed, and allows the user to correct mistyped data before analysis is initiated. The program computes safety factor probable Width of failing and probability of failure for a given circular failure surface. Four example problems are included to illustrate its use.

Jan 1, 1982

By N. S. Dalal, V. Castranova, X. Shi, W. Wrr, V. Vallyathan

"SUMMARY Data presented here indicate that freshly fractured silica exhibits surface characteristics and biologic reactivity distinct from aged silica, and on this basis we propose that these surface features may lead to enhanced manifestations of lung Injury. Grinding of silica produces ~10"" Si and SI-O (silicon-based) radicals per gram of dust on the particulate surface which are characterized by an electron spin resonance (ESR) spectrum centered around g = 2.0015. These silicon-based radicals react with aqueous media to produce OH radicals, which are demonstrable using a DMPO spin trap. The concentration of silicon-based radicals in silica decreases with aging in air and exhibits a half-life of ~30 h, whereas its ability to generate OH radicals in aqueous solution decreases with a half-life of ~20 h. However, on storage in aqueous media, the concentration of silicon-based radicals end the dust's ability to generate OH radicals decrease significantly within a few minutes. Freshly ground silica is also more biologically reactive than aged silica, because freshly crushed silica activates a greater respiratory burst In alveolar macrophages than aged silica, i.e., storage of ground dust in air decreases silica-Induced superoxide anion secretion, hydrogen peroxide release, and NBT reduction by 25%, 68%, and 43%, respectively. Furthermore, compared to aged silica, freshly ground silica exhibits a greater cytotoxic effect on cellular membrane Integrity, i.e., a 1.5-fold increase in LDH release from macrophages, a 36-fold increase in hemolytic activity, and a three-fold increase in the ability to induce lipid peroxidation. Because acute silicosis is frequently associated with occupations in which freshly fractured crystalline silica of respirable size is generated, the present study suggests that fracture-generated silicon-based radicals may play a significant role in the pathogenesis of this disease. AM REV RESPIR DIS 1955; 133:1213-1218IntroductionOccupational exposure to crystalline silica can be associated with either chronic or acute pulmonary disease. Chronic silicosis becomes manifest 20 to 40 years after first exposure and is characterized by development of concentric hyalinized nodular lesions in the lung with the de-velopment of dyspnea over a period of several decades. Acute silicosis, on the other hand, is manifested by a rapid on-set after exposure and is characterized by the accumulation of an amorphous granular lipoprotein exudate in the airspaces and rapid development of respiratory disability within a few years (1-3).Information is growing concerning the etiology of chronic silicosis. Studies sug-gest that several mechanisms may be in-volved in the development of fibrosis. Lung injury may result from silica-induced release of lysosomal enzymes from alveolar macrophages (4, 5). In ad-dition, silica-induced activation of su-peroxide anion and hydrogen peroxide release from alveolar macrophages may result in oxidant-induced damage to lung parenchyma (6). Silica exposure can also result in the release of mediators from alveolar macrophages which enhance the proliferation of fibroblasts and the syn-thesis of collagen by these pneumocytes (7, 8)."

Jan 1, 1988

By T. L. Johnston

A review of technical literature of the last quarter century discloses that much experimental work has been carried on in an effort to develop commercial processes for making sponge iron. In addition to the work that has been recorded, other work has been done the results of which have not been published. The degree of success or failure of these investigators does not detract from the fact that the problem has its challenging aspects and practical possibilities that encourage further investigation. The purpose of this report is to record information derived from recent experimental work that .had its 'objective the development and demonstration of one method of producing sponge iron. Work of other investigators was studied and applied wherever possible.

Jan 1, 1948

By D. W. Frommer

Mineral dressing research was conducted by the Federal Bureau of Mines under a cooperative agreement with the St. Joseph Lead Co., on three samples of iron ore from the Pea Ridge deposit in central Missouri. The objective was to provide information on how to upgrade these submarginal ores and produce marketable concentrates. Samples were prepared from drill-hole cores of similar composition and character to produce (1) a medium-grade mixed hematite and magnetite, (2) a high-grade mixed hematite and magnetite, and (3) a high-grade magnetite. In all three ores phosphorus and sulfur constituted objectionable impurities; excessive amounts of silica were also present in the medium-grade ore.

Jan 1, 1960

By R. V. Ramani, P. M. T. White, D. Sutton

Appendix I. Part 1: Description Of Geology & Reserves System Introduction The Ore Evaluation and Reserve programs have been developed to aid in the evaluation of coal deposits, both qualitatively and quantitatively. The "Weighted Moving Average" technique used provides considerable flexibility in dealing with diverse parameters with differing distribution characteristics. Determination of Model Constants "a" and "k" - Unit 1 The flexibility of the method in dealing with diverse value parameter distributions lies in its ability to cater to the individual characteristics of each. These characteristics are embodied in the values determined for constants "a" and "k", namely, local and regional variations in value distributions, respectively. The empirical method used attempts to optimize the "a" - "k" combination. Realistic values for "a" and "k" are entered into the program together with sample values for the required parameters and their respective coordinate location values. All the values within a specified radius from the point being evaluated are used to interpolate a value at that point. (Note, the interpolated point is the location of one of the boreholes, values of which are not used in the calcula¬tion.) 3n a similar manner, interpolated values are calculated for each borehole location and for each parameter. This is done for each possible combination of "a" and "k".

Jan 1, 1974

By Kenneth J. Miller

The Bureau of Mines two-stage coal-pyrite flotation process was modified to provide a more concentrated final clean coal slurry underflow which could be dewatered economically by filtration or centrifugation. This was accomplished by doing the first-stage coal flotation step in the conventional manner with a slurry of about 8 percent solids, but running the second-stage pyrite Flotation step with undiluted coal froth concentrate containing about 25 percent solids. The final clean coal underflow produced by the new technique contained between 26 and 30 percent solids; this pulp was sufficiently concentrated to be filtered industrially without further thickening. Sulfur removal was equal to that obtained using dilute second-stage pulp,

Jan 1, 1975

By E. V. Potter

"INTRODUCTION The oscillator and amplifier system described in this paper was developed specifically for driving sound generators of the type developed by H. W. St. Clair and described by him in an article 3/ published several years ago in the Review of Scientific Instruments.Nevertheless, with little or no alteration it can be used to drive any vibrating system in which the vibrating member must be driven at its resonant frequency; the only restrictions are that the driving mechanism be electrical in nature and that the vibrating member be accessible so that some type of pick-up can be coupled to it. Operation of the automatic frequency-control element in the oscillator, however, depends entirely on the operating characteristics of the vibrating member; therefore, in order to completely explain the operation of the circuit, it will be necessary to describe the construction and operation of the vibrator used with it. Only the essential features and characteristics of the vibrator will be described in this article, and the reader is referred to St. Clair's 4/ report for further details."

May 1, 1943

By D. W. Blaylock

I. The Lower Kittaning bed is the most important bed in Clarion County from the standpoint of present production, but the Clarion bed has the largest recoverable reserve. 2. Known measured and indicated reserves in all beds, based on a minim thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 1,210 million short tons as of January 1, 1952. Of this total, 790 million short tons is in beds 28 inches and mare thick. Areas in some beds were omitted from the estimate because available data relative to the bed characteristics are too wager for ding an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, they should be added to the total estimated reserves.

Jan 1, 1956

By W. H. Kerns

The Taylor Creek lead-zinc deposit is on Taylor Creek, approximately 1-1/2 miles from tidewater, at the head of Duncan Canal, on the east side of Kupreanof Island, Petersburg district, southeastern Alaska. The property was located in 1903, and a 30-foot discovery cut was put to the west tank of the creek. Very little prospecting end developing has been done since that time. The property was examined by J. C. Roehm, associate mining engineer, Territorial Department of Mines, Juneau, Alaska, in June 1946. From exposure n the creek, a mineralized zone with possible dimensions of 1,700 feet by 1,000 feet was indicated. The general strike was northwest, and the dip was low and variable to the northwest. During September through November 1948, the Bureau of Mines conducted a project on the property. Four diamond-drill holes, totaling 770.5 linear feet, were drilled from the surface and 280 lineal feet of hand trenching done. The mineral deposit was found to occur as patches that appear to be a replacement in dolomitic limestone. The patches of mineralization are small, irregularly shaped, and irregularly distributed. Maps showing the location of the drill holes and trenches, analyses of the cores from the drill holes, and anal lee of the samples from the trenches accompany this report (see, also, appendixes A, B, and C).

Jan 1, 1950

By Khamis Y. Haramy

This U.S. Bureau of Mines report describes the use of Bureau-developed flat and cylindrical hydraulic borehole pressure cells. A brief description of the fabrication, installation, and pressurizing equipment is given and pressurizing procedures are discussed. Theories available on evaluation of data from the flat and cylindrical pressure cells and examples of data analysis and stress evaluation are also presented.

Jan 1, 1991

By Donald E. Redmon

This Bureau of Mines report examines the injury experience in the quarrying industry for the years 1968-69. Twenty-eight tables for each year are presented in which disabling work injuries are summarized by department, source of injury, extent of disability, part of body injured, and nature of injury. Correlative information on employment, worktime, and operating activity is also presented.

Jan 1, 1973

By Paul Hatmaker

Pumice and pumicite are siliceous volcanic substances quite similar in chemical composition , but somewhat different in physical properties , manner of formation , and mode of occurrence . Production in the United States has increased from 23,271 tons valued at $ 94,943 in 1910 , to 56,843 tons valued at $336,099 in 1930. Both pumice and pumicite are included in these figures as it has been impractical to collect statistical data on the separate commodities .

Mar 1, 1932

By E. L. Garton

The Bureau of Mines for a number of years bas been conducting an investigation of crude petroleum from producing fields in the United States and the Western Hemisphere and has published a series of reports on these fields. Analyses of crude-oil samples from many oil fields of Oklahoma are given in Bulletin 2915. Analyses of 21 representative crude oils from various producing zones of the Oklahoma City field are given in this report. A close study of the analyses reveals very few differences in the general characteristics and chemical properties of these oils.

Jan 1, 1932

By George H. Popper

The Bureau of Mines has evaluated the extent of phosphate resources available for recovery by the experimental borehole mining method in the Southeastern Coastal Plain of the United States- Phosphate re- sources at overburden depths greater than 30 m are as a rule currently unsuitable for recovery through conventional mining methods because of economic, environmental, or technical considerations. In the identified deposit areas, borehole mining operations are projected to yield a more favorable rate of return and to be environmentally more desirable than conventional surface mining. Borehole mining resource estimates presented in this study are preliminary and designed to serve as a basis for future resource evaluations, as the current data base is relatively sparse and incomplete. The resulting resources have, therefore, been classified as hypothetical and speculative and are subject to up- dating as additional exploratory data become available. Hypothetical and speculative resources amenable to borehole mining are estimated to total about 385 billion metric tons (rat) of phosphate matrix with a minimum in situ grade of 5 pct P205. With projected borehole mining capabilities and current conventional beneficiation procedures, this resource would make available approximately 64 billion mt of phosphate rock product at an estimated grade of 30 pct P205.

Jan 1, 1985

By George L. Gates

This report presents is an evaluation by the Federal Bureau of Mines of the effect of clay-water, brine, and oil-base drilling fluids on the productivity of test wells drilled on the Umiat anticline in U.S. Naval Petroleum Reserve No. 4 in northern Alaska. Eleven, wells were drilled on the Umiat structure as part of the U.S. Navy's extensive exploration of the Reserve during 1944-53 to determine the possibilities for oil production. The Federal Geological Survey cooperated in the exploration program and has published a comprehensive report3/ on the geology of the area and case histories of the wells. The re¬port also includes the results of special studies by the Bureau in connection with the drilling and coring of well 9 with oil-base mud in hole and was the source of much of the information used in preparing this publication. Of the eleven wells, four were drilled with rotary tools and water-base mud (one of the water-base muds was an oil-in-water emulsion mud), five were drilled with cable tools with brine in the hole, one was drilled with cable tools with brine in the hole and later reamed with rotary tools and crude oil, and one was drilled with rotary tools and oil-base mud. Although all of the wells penetrated sandstones that contained oil and gas, some were productive and others were not. The latter two wells, one completed with crude oil in the hole (with some added brine) and the other with oil-base mud, had the greatest productive capacities. The wells drilled with cable tools and brine in the hole had lower productive capacities. In contrast, two of three wells completed with rotary methods and fresh-water drilling mud and the well com¬pleted with rotary and emulsion mud were unproductive.

Jan 1, 1960

By R. A. Cattell

The Bureau of Mines recently observed its fortieth anniversary, and with the close of the fiscal year 1950 it completed 36 years of close cooperation with and helpfulness to the petroleum and natural-gas industries, whose technical problems it studies. Petroleum people likewise observed the ninetieth anniversary of the start of this truly American industry when "Colonel" Drake drilled the first well at Titusville, Pa., in 1859 (see fig. 1). Throughout the period, during which there have been many changes in the fuel and related economy of the country, this work has been carried on systematically by an organized entity of the Bureau first known as the Petroleum Division and in recent years as the Petroleum and Natural Gas Branch. Changes in the industries have been brought about partly by economic forces, partly by advances in technology, and in some measure by the impact of two world wars. As the needs of industry and the Nation have changed, so have the studies of the Bureau changed to meet these needs. Consistently, Bureau technologists and scientists have tried to keep in step with progressive movements; frequently, in fact, have taken the lead. Wherever possible, they have looked far ahead in their program of research, at the same time recognizing the needs of the hour.

Jan 1, 1951

By John J. Mulligan

Since 1941 the Federal Bureau of Mines has been conducting an intermit-tent program of placer and lode investigations to evaluate the potential tin resources of the western Seward Peninsula tin belt. Previous investigations were made in the Potato, Cape, Brooks (Lost River), and Ear Mountain areas. As part of this program the Bureau made a reconnaissance of reportedly tin-bearing stream gravels in areas adjacent to the previously worked tin deposits at Lost River and Potato Mountain. The objective of the reconnaissance was to determine if additional areas might be favorable for lode or placer exploration. The work was begun late in the fall of 1956 and completed during the following summer. The streams sampled were the Lost River and York Creek in the Brooks Mountain area and the Anikovik River and Kigezruk and Baituk Creeks in the York area. Samples were obtained by churn-drilling methods employing conventional placer-evaluation procedures. Holes were drilled at wide intervals at sites chosen as being representative of drainage areas rather than of individual gravel deposits. Minor to trace amounts of tin were found in the gravels of all these streams, but the highest grade was 0.35 pound of tin per cubic yard in the gravels of Lost River below the mouth of Tin Creek. Small amounts of gold were found on Baituk Creek and in one hole on the Anikovik River; the highest grade did not exceed 10 cents per cubic yard. Traces of scheelite and barite were found on York Creek, chromite was encountered in one hole on the Anikovik River, and minor amounts of titanium minerals (probably derived from basaltic intrusives) were found in the York area.

Jan 1, 1959

By R. R. Wells, G. M. Potter, A. O. Ipsen

This paper gives results of laboratory and pilot - plant investigations of concentration of western manganese ores during the Bureau of mines manganese-development program initiated in December 1940. The data summarize results obtained from laboratory investigation of concentration of ores from three properties in southeastern Arizona . The high - grade Gray - claims lot B ore , a product of hand sorting , is marketable directly or after sintering treatment . Intermediate - grade lot A selectively mined ore would be marketable after sintering as a plus 35 percent manganese produce , but gravity concentration methods were employed effectively to produce high - grade manganese concentrates with over 80 percent recoveries . Complex association of fine - grained manganese oxides , calcite , and fluorite in a siliceous ground mass limited the recovery of high-grade manganese concentrates obtainable from the low-grade Pyrolusite -group ore . A recovery of 63.7 percent of the manganese was made by flotation in a concentrate that sintered to plus 48 percent manganese grade . The low-grade Davis ore contains iron and manganese oxides too intimately associated to permit production of marketable manganese products . However , good rejection of calcite gangue was obtained by flotation , and the enriched manganese - iron product might have value as a spiegeleisen ore .

Feb 1, 1946

By J. M. Kuchta

The Bureau of Mines investigated four simulated coal gob fires to obtain a more reliable data base for defining the state of a sealed mine fire and to evaluate the performance of various fire detectors. The fires were conducted in a multiple-entry section of the Bruceton Experimental Mine by heating 4,000 to 21,000 pounds of rubblized bituminous coal to ignition and monitoring the temperature, gas emissions, and smoke under ventilated and sealed combustion conditions. Product gas concentrations depended upon the coal bed size, coal temperature, heating rate, and oxygen concentration or ventilating condition but varied little after the fires were sealed. Expressions are given that define the temporal variation of CO and O2 after sealing when the coal temperature decreased rapidly. The CO/C02 ratio is a more sensitive fire indicator than the CO/?02 ratio, although the latter is universally used for detecting the incipient state of a coal fire. In comparison, the Jones-Trlckett ratio [ CO2 + ¾ CO ? ¼ H2 ?O2] is less reliable for this purpose. The best detector for determining the state of a mine fire after it has been sealed was a prototype submicrometer smoke particulate sensor. Limitations of the various detector systems are also discussed.

Jan 1, 1982

By Robert W. Ageton

Optimal planning for mining the deep, lead-zinc-silver deposits of the Coeur d'Alene mining district, Shoshone County, Idaho, could be facilitated by a knowledge of the magnitude and direction of the pressure acting in the virgin rock. The distribution of primary stresses should be considered in order to prevent possibly destructive mining-induced stress concentrations. This particular investigation was concerned with determining stress in a zone 4,000 feet below the surface and known to be ender stress concentrations due to mining operations. Disking of the stress-relief cores obtained in a vertical down hole permitted qualitative evaluation from visual observations; the results indicate that a high lateral stress existed at the time the measurements were made. Stress-ellipsoid determinations gave a compressive principal stress of -13,000 psi oriented about N 45° W and nearly horizontal, a compressive principal stress of -11,000 psi oriented about S 45° W and abut 60° off the vertical pointing away from the vein, and a compressive principal stress -5 -7,000 psi oriented N 45° E and about 60° off the vertical, pointing toward the vein. Subsequent to the overcoring stress-relief drilling, a rock burst occurred about 100 feet northwest of the test site.

Jan 1, 1967