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By Glenn C. Reed

The Sheep Creek iron deposits, Meagher County, Mont., were investigated by the Bureau of Mines in 1943 and 1944. Work undertaken included exploratory trenching, churn drilling, petrographic studies, and detailed beneficiation tests. It was determined that the Sheep Creek ores occur both as fissure filling and bedding replacements in thin-bedded shale and arenaceous limestones of the Algonkian Belt series. At least five stratigraphic horizons were found to be mineralized. Metallurgical studies indicate that the ores are not amenable to beneficiation by present-day low-cost methods. Details of geology, sampling, and beneficiation tests are presented in this report.

Jan 1, 1949

By R. A. Guidotti

The Federal Bureau of Mines studied the thermal decomposition of the nitrides of the Group V A metals (CbN, Ta3N5, and VN) with the goal of preparing high-purity metals. Solid-state purification and arc and electron-beam melting were examined. Electron-beam melting proved to be the most efficient means of nitrogen and oxygen removal. Columbium and tantalum of 99.9-pct purity were prepared by this technique; in the case of vanadium, however, nitrogen could not be reduced below the solid-solution level.

Jan 1, 1976

By G. A. Howes

This is one of a series of circulars dealing with the cost of equipping and developing mining properties in the United States and Canada, prepared and published by the Bureau of Mines in cooperation with various mining and exploration companies. This group of circulars is designed to supplement an earlier series which covered the methods and costs of mining and milling at a large number of producing properties. ACKNOWLEDGMENTS The authors desire to thank Robert A. Bryce, president of Macassa Mines (Ltd.), for permission to use the data presented in this paper, and to acknowledge the cooperation of A. J. Keast, under whose direction as manager the plant was installed and equipped and the shaft was sunk to a depth of approximately 2,000 feet.

Jan 1, 1932

By K. C. Dean

During the investigations of the occurrence of manganese in the Western United States, a Bureau of Mines examining engineer collected samples frame two properties in Beaver County, Utah. As the ores were too low in grade to be acceptable by manufacturers of ferromanganese, beneficiation studies were made to determine the amenability of the ores to concentration. The Steelville property is about 37 miles southwest of Frisco, Utah. The deposit is an example of manganese occurring as a replacement of limestone in a bedded vein or as layers in limestone associated with shale and rock decomposition products. The Susie Q deposit, about 33 miles southwest of Milford, Utah, is also a tabular replacement deposit in limestone, apparently of limited extent. Test work was done on representative samples of 2-ton lots obtained by the examining 'engineer from each of the properties mentioned.

Jan 1, 1951

By C. A. Komar

The Bureau of Mines conducted experiments on one synthetic and three natural sandstone samples to investigate the effects of acoustic energy on the flow of brine in porous media. Ultrasonic energy at a frequency of 20 kc per second and an intensity of 55 watts per cm2 was irradiated in the direction of the fluid flow and in the opposite direction for distances of 1/2 and 2 inches between the vibrating device and the sample face and under conditions of suppressed and nonsuppressed cavitation. Forty tests were conducted: 32 with a pressure differential of 0.64 psi across the samples, 2 with 5 psi, and 6 with 15 psi. Acoustic waves altered the rate of flow of the brine through the samples, but this effect was observed only at low differential pressures and from a practical point of view was insignificant. As a result of irradiation, however, the samples exhibited reduced permeability. This reduction was probably caused by the shifting of solid particles dislodged by the acoustic waves.

Jan 1, 1967

By Brinton C. Brown

This paper describes the methods and equipment developed at the Bureau's Experimental Oil-Shale mine near Rifle, Colo., for placing men in position to scale loose rock from the walls, pillars, and roofs of high stopes or rooms. The equipment developed at Rifle has application not only in oil-shale mining but in most of the country's underground limestone mines and in the exploitation of other mineral deposits mined in high stopes by room-and-pillar methods. Equipment in use at Rifle includes: 1. A boom-type scaling rig with a self-leveling platform constructed on a small "cat"-mounted crane. Men working from the platform on this machine can efficiently scale mine walls and roofs 27 feet above the floor. 2. A conventional fork-lift truck modified to provide a remotely controlled working platform from which men can scale to heights 27 feet above the mine floor. The platform on this unit is larger than on the boom-type rig and allows the men to inspect larger areas of the mine wall from a single setting of the machine. 3. A third rig, consisting essentially of a platform mounted on a tele-scoping tower, designed and built to elevate men 65 feet above the mine floor. Versatility of this machine permits men to work from the platform at heights of 5 to 65 feet. In the operating position, the unit requires a minimum clearance of 25 feet. In the nonoperating position the tower of the machine folds to an over-all height of 15 feet 10 inches to permit travel through haulageways. 4. An industrial gun, lightweight scaling bars, and mechanical scalers, which have been tried for removing loose rock from the mine walls with varying degrees of success.

Jan 1, 1950

By C. M. McKinney

This report contains Bureau of Mines routine crude-oil analyses of 20 samples from5 areas on the arctic slope of Alaska. Two samples were condensates from the South Barrow gasfield, Barrow Lakes area. The remaining 18 samples were crude oils from the following areas: Barrow Lakes, 1 seepage sample; Umiat, 10 well samples; Cape Simpson, 1 seepage sample and 3 well samples; Fish Creek, 2 well samples; and Wolf Creek, I well sample. Table 1 summarizes information on the origin of the crude-oil samples, and table 2 summarizes characteristics of the samples. Item numbers in both tables correspond to item numbers of the analyses at the end of this report, and the samples are referred to by these numbers throughout the text.

Jan 1, 1959

By Phillip R. Moyle

A basic precept in mineral exploration is that the best places to prospect are where minerals have already been found. The California desert has many old mining districts once thought to be "played out" that are currently producing more mineral wealth than at any time in the past. Because no "crystal ball" exists that will enable us to predict the Nation's future mineral needs, land management plans must be flexible enough to respond to these often unforeseen needs. MANAGEMENT ISSUES The California Desert Conservation Area (CDCA) (figure 1) encompasses 25 minion acres, nearly one-quarter of the total area of California. Passage of the Federal Land Policy and Management Act of 1976 (FLPMA) launched an intensive program by the Bureau of Land Management (BLM) to study this vast area. Painstaking scientific investigations were made of wildlife and plant populations, soil, air, and mineral resources, range use, and wilderness characteristics, among other environmental concerns.

Jan 1, 1992

By J. E. Chilton

The Bureau of Mines has examined the operation of an oxygen sensor manufactured by the City University, London, England. The sensor produces a current proportional to the oxygen concentration by reacting oxygen at a nonconsumable cathode. The sensor design is unique in that the primary mode of oxygen transport to the cathode is by diffusion through a capillary, The sensor using this design has a stability of 0- to 0.02-pct reading change per day over a 4.7-month test, small temperature coefficient of 0.29-pct reading change per °C, and small pressure coefficient of 0.34-pct reading change per 1,000-ft altitude change, If this sensor were incorporated into an oxygen detector or monitor, this would be a distinct improvement in electrochemical-type oxygen analyzers and would be useful to the mining industry.

Jan 1, 1983

By Charles W. Huggins

DEVELOPMENT of the electron microscope has permitted man to examine many small objects that could not be resolved by the light micro-scope. Diffraction, spherical aberration, and chromatic aberration are the main factors that limit resolution to about two-tenths micron with the light microscope. No matter how perfectly a light microscope is constructed and operated, it cannot possibly resolve points separated by less than two-tenths micron. Rapid development following World War II has produced many electron microscopes capable of 20 A resolution. Fibrous inorganic minerals are well suited for electron microscopic study. Many micrographs of chrysotile have been published, but electron microscopic study of the amphiboles has been somewhat neglected. New techniques in sample preparation have simplified the study of fibrous material. Ultrasonic energy has been very helpful in sample dispersion. This publication contains a representative group of electron micrographs of natural inorganic fibers that have industrial value. These fibers commonly are referred to as the asbestiform minerals. The Bureau hopes that the knowledge gained through electron microscopy and other scientific study of the natural inorganic crystalline fibers eventually will lead to the production of synthetic fibers that will satisfy the requirements of industry.

Jan 1, 1959

By A. J. Kraemer

"During the past several years a great deal of discussion has centered around the question of the permissible limit of sulphur content in fuels for automotive and aviation motors. Under certain conditions of operation, sulphur in motor fuels causes the formation of corrosive substances which attack bearings, wrist pins, and other parts of engines. On the other hand, in making gasoline from certain stocks, the gasoline fraction normally contains a relatively large proportion of sulphur compounds. By the generally used processes of reducing the sulphur content, a significant part of the gasoline fraction is lost as motor fuel, and added expenses are entailed for chemicals, labor, and other process costs. This condition has been an economic burden to some refiners of high-sulphur crudes. In some instances the treating losses have been rather severe and the treating costs relatively high, but the data presented in this paper indicate that the reduction of sulphur content of motor fuel is a problem to a relatively small number of refiners and of little or no concern to the remainder; in fact, more than 90 per cent of the 153 samples analyzed passed the Federal specification requirement, Which limits the sulphur content to 0.10 per cent. 3This report is based upon the results of an examination for sulphur content, Doctor test, copper strip corrosion, and color of the samples collected during January, 1930, for the twenty-first semiannual gasoline survey of the Bureau of Mines. The results of the gravity ad distillation tests of the survey were published as Report of Investigations 2995. The numbering of the samples given in this report is the same as in Report of Investigations 2995; for example, No. 25 of this report is the same sample as No. 25 of Report of Investigations 2995."

Jun 1, 1930

By Jr. Reed

The only known large deposits of talc in Alabama occur near Winterboro, Talladega County. Preliminary examinations were made, and work by the Bureau of Mines was recommended. The deposits were investigated to determine the amount and grade of talc present and to search for new talc deposits in the general area. Seventy-five holes, totaling 3370.4 feet, were drilled with Government-owned core drills from August 1, 1948, to February 11, 1949, and 27 samples were taken for assay. This report presents the factual data disclosed by drilling and the results of beneficiation of the talc.

Jan 1, 1950

By H. Kenworthy

Laboratory experiments were conducted on several materials to determine their suitability for the production of mineral wool. By blending raw charges in the proper proportions and in some instances by adding lime, acceptable wools were made from samples originating in Alaska, Florida, Texas, and Virginia. It was shown that satisfactory wools can be produced from many kinds of raw materials if the ratios of acidic and basic constituents are properly maintained. INTRODUCTION The Federal Bureau of Mines has facilities at the Mississippi Valley Experiment Station, Rolla, Mo., for examining and testing mineral-wool raw materials. Samples are evaluated through small-scale wool-blowing experiments, aided by petrographic, chemical, and physical analyses of the raw materials and finished wools. When enough experimental data have been accumulated they are made public through Government reports and periodicals. This report of investigations follows that published in 19513/ and presents test data on samples received and examined since 1951.

Jan 1, 1956

By I. AITKENS

The opal , long in disfavor because it was considered " unlucky, " has become much more popular in recent years . For variety and beauty of color the precious opal is without a peer . These colors do not come from any chemical constituent but are produced by structural peculiarities , which in varying degrees deflect the light rays entering the stone and give a prismatic play of hues .

Sep 1, 1931

It is now widely accepted that horizontal stress is present nearly everywhere underground. Often it is more severe than the vertical stress. It is a major cause of roof control problems in underground mines. The AHSEM computer program contains two modules to improve mine layouts for control of horizontal stress. For development, the user specifies the orientations of the maximum horizontal stress, the entries, and the crosscuts. Angled crosscuts may be used, and the angles may be different for the right- and left-hand crosscuts. AHSEM then shows the user how the stress condition would vary as the entry and crosscut orientations are changed. The second module is for longwall mining. Severe stress concentrations can make headgate conditions hazardous when the entries are improperly oriented. AHSEM shows whether a particular longwall orientation and extraction sequence places the headgate corner in a stress concentration or in stress relief. It also estimates the magnitude of the stress concentration.

Apr 1, 2003

By R. J. Leary, W. M. Mahan, F. X. Tartaron

A new type of apparatus for prerefining molten blast furnace iron and to reduce the cost of subsequent steelmaking consists of a funnel - shaped device lined with firebrick into which a horizontal stream of molten pig iron is directed tangentially at the top . The rotary motion thus induced causes the stream to flatten itself upon the wall and flow in a spiral path to the outlet ; thus , the device was termed " vortex cone .' Oxygen and other refining agents are impinged upon the flowing metal in the cone where reaction is facilitated by the large metal surface exposed and the turbulent flow pattern . Experiments with water in 1 - foot - diameter funnels provided an idealization of the flow patterns to be expected with molten iron . A brick - lined reactor 3 feet in diameter was built for desiliconizing molten pig iron in lots of 1 to 2 tons . At flow rates of 0.3 to 0.5 ton min - 1 (430 to 720 tons per day ) this apparatus was 64- to 90 - pct effective in desiliconization with oxygen efficiencies of 19 to 41 pct . Detailed experiments to develop basic engineering data are underway , and adaptation of this principle to other reactions and reactants is planned .

Jan 1, 1964

By F. E. Cash

Among petroleum refinery employees and officials throughout the United States there has been marked effort to reduce accident frequency and severity. For the interest and benefit of refineries both in Louisiana and in other petroleum-refining States it has been possible to obtain from five refineries, representing 70 per cent of the production of Louisiana, tae accident experience for the past 3 to 6 years. The companies concerned have requested that their names be not used. For tide reason the four plants listed and discussed are designated as refineries A, E, C, and D. The size of the plant as regards largest to smallest number of employees is indicated by the alphabetical order.

Jan 1, 1933

By C. B. Manula, R. L. Sanford, R. A. Rivell

PART I. FLOW CHARTS

Jan 1, 1974

By E. L. Garton

The United States Bureau of Mines has recently collected samples of crude petroleum from wells in the newly developed Joiner. Kilgore, and Longview fields of Rusk and Gregg Counties in the East Texas district, and from the Van field of the East Central district of Texas.

Jan 1, 1931

By M. R. Yenchek

The U.S. Bureau of Mines has determined a method for calculating coal mine portable power cable thermal life for a specified temperature loading. This work was the culmination of a multifaceted research project involving (1) accelerated life tests of insulation and jacket materials and (2) steady-state and cyclical loading of cables. Composite Arrhenius curves were derived for common insulation and jacket materials to identify the key cable quality that precipitates thermal failure. Plots of temperature rise versus current for popular cable sizes were then referenced to develop a correspondence between cable life, based upon thermal degradation and current loading. Predictions of cable thermal life were made through integration over variable load cycles and, consequently variable operating temperatures. This procedure may have utility for both the U.S. Mine Safety and Health Administration and mining machine designers in determining the appropriate cable size for new equipment.

Jan 1, 1991