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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 Robert R. Perron

The U. S. Bureau of Mines is engaged in many diverse programs for improving mine safety. Of particular interest to the Bureau are new and improved means for minimizing the hazard of fire which can be initiated by prolonged low energy electrical faults on trolley line systems. When a high energy fault occurs on a trolley line, wherein the current exceeds the magnitude normally drawn by legitimate loads, such as locomotives, then the circuit breakers at close-by power rectifier sets trip. Tripping of the breakers not only protects the equipment at the rectifier sets, but also disconnects the energy source from the fault and thereby minimizes the fire risk. However, the fault current is frequently of a level substantially below that required to trip the overload breakers. When the fault is a substantial percentage of the set level of the breakers, the energy dissipated by the fault is frequently sufficient to clear the system by rapidly burning itself clear. Such a fault is often short-lived and does not present as serious a fire risk hazard as a prolonged, much lower energy fault, wherein the energy level is too low to clear the system. The breakdown of a trolley line insulator, in which there was a 15 to 30 ampere fault to ground, would represent such a fault or illegitimate load and a substantial fire risk.

Jan 1, 1975

By J. G. Kirby

The number of petroleum refineries in the United States continued to decline during 1954, and according to the Bureau of Mines annual survey there were 326 refineries with a total daily throughput capacity of 8,420,630 barrels, as of January 1, 1955. The increase in capacity for the year was 413,733 barrels daily, while the number of refineries declined 11. The capacity of the average refinery to process crude oil increased during 1954 from 23,759 barrels daily to 25,830. Breaking down the crude-oil capacity increase, by refining districts; 32 percent was installed at refin¬eries located in the Texas Gulf Coast district, 25 percent in the East Coast district, and 13 percent in both the Louisiana Gulf Coast and the California districts. The Appalachian No. 1, Texas Inland, and New Mexico refining districts reported declines in capacity during the year. Additional crude-oil capacity under construction, January 1, 1955, totaled 146,800 barrels daily. Included in this total are 4 new refineries, 1 each in California, Minnesota, New Mexico, and Washington. In addition to the' new facilities, equipment producing 1.49,550 barrels daily is being replaced.

Jan 1, 1955

By David E. Siskind

The Bureau of Mines has studied the fracturing and associated damage occurring in the vicinity of blastholes from five shots fired in the shale pillars in the White Pine copper mine, White Pine, Mich. Four types of explosives (AN-FO, commercial extra dynamite, ammonia gelatin dynamite, and a low-density, low-velocity permissible) were used. Cores were taken from the blast region and examined by ultrasonic and petrographic techniques. Pulse wave velocities were measured across the core diameters, and thin sections showing cracks and changes in lithology were examined in an attempt to establish zones of damage. Cores from the blast regions and areas near pillar free faces were found to have abnormally low pulse velocities. Petrographic study of the thin sections showed that the negative velocity anomalies were caused by cracks in the cores. Crushing and extensive fracturing prevented meaningful measurements on core fragments from the immediate blast vicinities. Compositional, changes and other rock nonuniformities, such as joints and preexisting fractures, tended to mask detailed damage differences among the four explosives; however, the two most energetic explosives (extra dynamite and ammonia gelatin dynamite) produced damage zones two to three times as large as the AN-FO and low-velocity permissible explosives.

Jan 1, 1973

By W. D. Ryan

The organic act passed by Congress in 1910 instituting the Bureau of Mines provided that the director of the bureau should promulgate such investigations as might be necessary to determine the causes of mine accidents and the best methods of preventing them. With the object of accident prevention in view, Director Joseph A. Holmes, and others who were pioneers in the bureau, conceived the Plan of having first-aid and mine-rescue training as one of the major activities of the Bureau. Out of this plan grew the first-aid and mine-rescue contests, which have been featured as an incentive for men to take courses in this type of mine safety training. The first appropriation for mine-accident investigations became available on July 1, 1908, under the jurisdiction of the U. S. Geological Survey, with Dr. J. A. Holmes in active charge. During 1908 there had been some first-aid training in the Pennsylvania anthracite field and a start made in Illinois, although there appears to be no exact information as to when or where first-aid training in the mining industry first became a reality, it is generally conceded that the St. John's ambulance corps of Scotland was one of the first - if not the first - to make the work effective. In 1911, to celebrate the establishment of the Bureau of Mines and the formal opening of the Pittsburgh, Pa., station, a first-aid and mine-rescue demonstration was conducted on Forbes Field, Pittsburgh. President William Howard Taft and many other men notable in public life were 2 resent. This was the first general national contest of the kind held it the United States; and since then there have been a number of nation-wide first-aid and mine rescue contests, as well as some which have been international in scope. There are over one hundred first-aid and mine-rescue contests of various kinds held annually in connection with mining and the allied industries.

Jan 1, 1929

By Lincoln A. Stewart, P. S. Haury

"INTRODUCTION AND RESUME Arizona asbestos mines are the only sources on the American continents of iron-free chrysotile spinning fiber that meets the Navy specifications for asbestos fiber for use in covering electrical cables. Rhodesia normally supplies the bulk of this grade of asbestos at about half the Price of Ari zona spinning fiber. The acute submarine menace in 1942 focused attention on the danger that imports might be cut off and that a sudden demand for greatly expanded production might fall on the Arizona mines to supply the tonnage of this essential material needed for war production.A joint preliminary investigation of Arizona asbestos deposits was made in August 1941 by J. R. Thoenen, senior mining engineer of the Bureau of Mines and A. E. Granger, a geologist of the United States Geological Survey. A more extended investigation of the numerous asbestos mines and prospects, which are scattered over 25 townships of difficult terrain in Gila County, was begun by the senior author in August 1942.The Geological Survey assigned two geologists (Newton Chute and A. F. Shride) a few weeks later to study the geology as an aid in selecting the mines for the Bureau's exploration projects. Six mines were selected for exploratory work because it was desired to prove reserves of ore where production could be started quickly if urgent demand should arise. Acceleration of production is normally slow because of adverse operating conditions. First, the mines are at distances of 35 to 100 miles from Globe, the shipping and supply point, and the roads are few and poor. The mine openings start in steep canyon walls, so that mining supplies usually have to be packed in and the product packed out over 0.5 to 5 miles of burro trail. Second, most of the ore deposits are small, and the ratio of rock broken to spinning fiber recovered is very high, usually exceeding 200."

Aug 1, 1947

By W. P. Yant

The widespread use of toluene in industry and the importance of air analysis in industrial-hygiene surveys have created a need for a simple and accurate method for determining toluene vapor in air. Most of the methods used to determine small quantities of toluene in liquid or vapor form are based on the measurement of its physical properties. Methods based on fractional distillation, determination of specific gravity, use of the interferometer, use of the spectrograph, and sorption on solid sorbents with subsequent determination of gain in weight have been employed. Distillation and specific-gravity methods are not applicable to the small quantities of toluene found in the air, and use of the interferometer, spectrograph, and sorption methods either are not specific for toluene in the presence of other volatile substances or require expensive equipment.

Jan 1, 1936

By R. S. Fowkes

A study was made by the Bureau of Mines of the penetration of selected granular materials in an unconfined state by wedge-shaped tools having dimensions comparable with the dimensions of the particles composing the materials. The output force for larger particles fluctuated radically. A custom-designed integrator was used to obtain work as a function of depth of penetration in the form of smooth curves. The influence of wedge angle, depth of penetration, penetration rate, entry angle, compaction state, and particle size on the force required and the work performed was ascertained. Empirical equations describing force and work as a function of penetration were obtained for each set of experiments.

Jan 1, 1973

By Michael R. Norland

Surface and subsurface stabilization of mining-related wastes through revegetation depends upon the physical, chemical, and biological condition of the waste following mining. Mining disturbances can significantly alter the soil physical, chemical, and biological characteristics of a site, reducing or eliminating mycorrhizal fungi from the soil. Mycorrhizae are economically and ecologically important because they can alleviate environmental stresses caused by lack of proper soil condition and because they are vital to stabilization of mining waste by increasing plant survival and biomass through increased nutrient and water uptake. This report discusses some of the ecological factors that may affect mycorrhizae-plant associations on mining-related wastes and provides general information on mycorrhizae inoculation technology.

Jan 1, 1993

By W. P. Yant

The widespread use of toluene in industry and the importance of air analysis in industrial-hygiene surveys have created a need for a simple and accurate method for determining toluene vapor in air. Most of the methods used to determine small quantities of toluene in liquid or vapor form are based on the measurement of its physical properties. Methods based on fractional distillation, determination of specific gravity, use of the interferometer, use of the spectrograph, and sorption on solid sorbents with subsequent determination of gain in weight have been employed. Distillation and specific-gravity methods are not applicable to the small quantities of toluene found in the air, and use of the interferometer, spectrograph, and sorption methods either are not specific for toluene in the presence of other volatile substances or require expensive equipment.

Jan 1, 1936

By Hillary W. St. Clair

This report describes an experimental method for determining parameters for the rate of reaction of CO2 with solid carbon. The method involves the simulation of a flow reactor by a mathematical model based on a hypothetical multistage reactor which permits calculation of the analyses of effluent gas and carbon consumed as functions of the flow rate and duration of the reaction. The method is applied to experimental data on the reaction of coke with CO2 in fluidized-bed and fixed-bed flow reactors. A method is described whereby two parameters may be determined simultaneously. The method involves a reiterative procedure that finds the values of the parameters that minimize the sum of squares of deviation between calculated and observed analyses of the effluent gas.

Jan 1, 1971

By V. E. McKelvey

Any discussion of growth and future requirements has to begin with people--both their number and their needs. Both have been rising ever since any American can remember. Together, the number of people, which has been increasing rather modestly, and their wants and desires for material things, which have been increasing very sharply, seemed to have comprised a growth imperative in mineral consumption in the United States, especially during the last several decades. While the Nation's birthrate is now well below the replacement rate and still falling, the built-in momentum of the post-World War II population boom will continue to be felt well into the 21st century. Even using the modest projection of a 0.8 percent yearly increase, we are still looking at the possibility of 265 million Americans being around by Year 2000.

Jan 1, 1975

By D. A. Reynolds, R. G. Travis, James J. Dowd, R. F. Abernethy

"1. Reserve estimates have been made for eight coal beds in Monongalia County, W.Va., but only the Pittsburgh, Sewickley, and Upper Freeport beds are important at this time. The Pittsburgh, Sewickley, Waynesburg, and Upper Freeport beds contain the largest recoverable reserves.2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and 1,800 short tons per acre-foot of coal in place, are estimated at 3,526 million tons as of January 1, 1954. Of this total, 3,294 mil¬lion tons is in beds 28 inches and more thick. Areas in each bed except the Pittsburgh were omitted from the estimate because available data relative to the bed characteristics are too meager for making 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, such reserves should be added to the total estimated reserves.3. Recoverable reserves of coal have been estimated in beds 28 inches and more thick. This thickness is about the minimum now being mined by hand loading onto conveyors in the Appalachian region. The weighted average recovery for all beds in Monongalia County, as determined by this investigation, is 47.9 percent. This percentage is based on the total thickness of coal (less partings three-eighths inch thick or more) in the bed rather than on the thickness of the coal mined. Based on the weighted average percentage of recovery for all beds in Monongalia County, the recoverable reserves are estimated at 1,577 million tons as of January 1, 1954.4. Monongalia County coals of the major producing beds are of high-volatile a bituminous rank.5. The Pittsburgh and Lower Freeport beds in this county yield coal that can be used as metallurgical coal, especially when blended with low-volatile coals. The Lower Freeport coal is coked singly and in beehive ovens, and makes good metallurgical coke.INTRODUCTIONThe investigation to evaluate the reserves of coking coal was planned to cover three phases: (1) Estimation of known measured and indicated recoverable reserves of all coking coal; (2) study of methods of upgrading marginal coals through effective preparation; and (3) study of carbonizing properties of coals and coal blends not now widely used for metallurgical coke making."

Jun 1, 1956

By K. K. Kershner

Nickel having a purity of more than 99.99 percent with reference to metallic impurities was electrodeposited at the Rolla Metallurgy Research Center of the Federal Bureau of Mines. The production of high-purity nickel is in keeping with the current trend in technologies for producing metals with lower and lower percentages of impurities. To understand more fully the role to be played by nickel by itself and as a component in many alloys, the element must be in a state of high purity. Procedures are outlined for purifying nickel solutions by precipitating and filtering off impurities. Details are given for using the purified solutions as electrolytes in depositing high-purity nickel. The elecneleposited nickel contained 0.0005 to 0.002 percent each of cobalt, copper, aid iron together with spectrographically detectable traces of aluminum, magnesium, and silicon. The deposits were smooth and dense; the crystalline structure was typical of an electrodeposited metal. Some preliminary experiments for purifying nickel solutions by liquid-liquid extraction are also described in this report. Tests of this type were limited since more encouraging results were obtained by other methods of purification.

Jan 1, 1961

By R. M. Santmyers

Caesium, rubidium, and lithium are sometimes described as the minor or rarer alkali metals. They generally occur together in nature, although, lithium is distributed more widely and is far more abundant than either of the other two. The chemical, and even the physical, properties of these three elements can best be considered In conjunction with the more familiar members of the alkali group, sodium and potassium. The five elements lithium, sodium, potassium, rubidium, and caesium show an interesting gradation properties from member to member with the increase in atomic weights. All are silvery white and soft enough to be cut with a knife. They tarnish rapidly in air and decompose water at ordinary temperatures. The lowest temperature at which the action of the several metals on water can be de¬tected is -98°C. for sodium, -105°C, for potassium, 108°C. for rubidium, and -116°C. for caesium. The chemical activity appears to increase steadily from

Jan 1, 1930

By K. E. Robinson

This study provides an initial indication that mill tailings produced in the Coeur d'Alene Mining District of Idaho can be placed on floodplain areas in a technically acceptable manner without artificial liners and without seriously contaminating the surrounding area. Tests have shown that landfills on these unused areas can result in returning these areas to productive use. The engineering properties of mill tailings permit construction of stable embankments. Designed slope protection inhibits water erosion. Among the environmental considerations in using tailings for landfill construction are the acid and other contamination produced by tailings and wind erosion of exposed tailings surfaces. The initial results indicate that adverse impacts are not as severe as previously thought, and mitigative measures are feasible. Based on the preliminary data, and in accord with existing Federal and State waste management regulations, a conceptual design has been developed for 23 potential landfill sites in the District, which could reclaim 750 acres of floodplain. A cost analysis of landfill construction with mill tailings indicates that the method would be an economically viable means for increasing the valleywide tailings storage capacity, provided construction with slurried tailings is feasible. A Stage H study is proposed to evaluate slurried tailings as a foundation material, as opposed to hauled tailings used in this present study.

Jan 1, 1981

By A. Wahab Khair

"This paper presents an analysis of fracture mechanisms in coal subjected to bi-axial state of stresses, indentation of laterally confined coal specimen. Coal specimens were loaded to failure by the straight wedge indenters at various lateral confinement pressures. Strain distribution and acoustic emission characteristics of coal specimens under stress were recorded. The influence lines of vertical forces acting on the horizontal straight boundary of the coal specimen for each type of wedge indenter have been established using holographic interferometry technique. The effects of wedge indenter angle, confinement pressure, and coal anisotropy on fracture types, failure modes, and post-failure conditions were studied. The results indicated that combined application of holographic interferometry and acoustic emission monitoring techniques is not only suitable ·for studying deformability of heterogeneous and microscopically discontinuous material under stress but it also enhances the mode of fracture during the post failure stage. INTRODUCTIONOne of the relevant processes in the coal cutting technology is the application of indentation theories. Since most cutting tools in the coal industry are wedge shaped most of the indentation research is found for a wedge shaped tool.A wide range of behavior is found in different rocks subjected to the wedge penetration. A rock which is elastic brittle at standard pressure might become elastic plastic at high confining pressure (Gnirk and Cheatham, 1963). It was also observed that some rocks will merely be crushed and indented by a wedge whereas others will crack and form chips, furthermore the existence or non-existence of chips depends mostly on the geometry of the indenter, type of rock and the depth of penetration (Evans and Murrel, 1958). However, coal cutting technology is mostly explained by models which use rigid wedge to penetrate into a brittle material in which both crushing and chipping will occur (Evans and Murrel, 1958, 1962)."

Jan 1, 1988

By D. Harrington, W. J. Fene

That fatalities from mine explosions can be very much reduced from the experience of past years if not wholly eliminated was fairly well demonstrated during the fiscal year ended June 30 , 1934 , there being only 28 deaths in the United States from explosions during this period . This is by far the lowest number of fatalities from explosions in the history of coal mining in the United States insofar as records are available . Although the frequency of occurrence of explosions has not decreased greatly during the past 6 years , there has been a marked decrease in severity , indicating that our coal -mining people are taking more effective precautions to prevent the spread of explosions . Pennsylvania is a good example of what may be done in reducing both the frequency and the severity of explosions ; by the adoption of up- to - date safety measures , Pennsylvania bituminous mines now have the enviable record of only one major explosion disaster in more than 5 years , and the one major explosion which did occur cost but 7 lives although 277 persons were exposed ; their lives were saved because rock- dusting prevented the spread of the flame and violence . Many of our other mining States are making definite progress in working mines without disastrous explosions and fires ; some of these , like Alabama , West Virginia , Indiana , Wyoming, and others now operating with few , if any , explosions , have had anything but a favorable record in the past .

Jan 1, 1935

By Walter Kawa

Coals of various rank were reacted by the Bureau of Nines in plasma jets generated from argon and argon-hydrogen mixtures containing up to 33 volume-percent hydrogen. Average plasma temperatures ranged from about 3,400° to 12,000° C. Products were a solid residue and a gas containing hydrogen, methane, acetylene, diacetylene, and oxides of carbon. The highest yield of acetylene obtained with argon plasmas was 15 percent by weight of moisture- and ash-free coal. The data indicated that acetylene yields of 40 percent or higher can be obtained from the reaction of coal in argon-hydrogen plasmas, although results from these experiments could not be correlated with operating variables because of low recoveries plasma contained sufficient energy to heat the coal to temperatures as high 9,000 or 10,000° C, but complete devolatilization did not occur in any experiment.

Jan 1, 1966

By L. F. Christianson

The presence of salt in crude petroleum has been known for many years, but recently the percentage of chloride salts of calcium, magnesium, and sodium produced with some crude oils has increased to such an extent that the removal of the salty compounds is imperative for some refiners and their presence causes considerable apprehension for others. The exact reason for this increase of salts is not known definitely, but in all probability a combination of factors contributes to the condition. The most important are acidizing of wells, development of new fields producing crude oils of greater salt content, and the depletion of old fields with an attending increase in the production of emulsified brine. Due to handling

Jan 1, 1938