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By C. C. Merrill

Studies were made to determine the amenability of yttrium to fused-salt electrorefining in a controlled atmosphere. Tests were conducted in a LiCl- YCl3 electrolyte system at 710° C. The major variables studied were the YCl3 content of the electrolyte, from l.7 to 13.4 mol percent, and the initial cathode current density, from 410 to 1,630 amperes per square foot. Vacuum distillation was employed to remove salt from the deposited metal. Metallic impurities, except for lithium, could be reduced to near or below their lower analytical limits, ranging from 10 ppm for Cu to 300 ppm for Ta; reduction of oxygen content, however, was accomplished only in metal produced from electrolytes with 5.4 mol percent YCl3 or less. Initial cathode current density had little effect on the purity of the product.

Jan 1, 1967

By Heine Kenworthy

"INTRODUCTION In 1930 the Shenandoah-Dives Mining Co. near Silverton, Colo., put into operation a newly erected, 300-ton selective flotation plant to mill complex ores from its nearby mine. The operation was a steady producer and was enlarged to treat 600 to 800 tons a day. In 1942 the company opened and started milling an area in the mine containing semioxidized ore. The valuable mineral content of this ore was considerably higher than in, the straight sulfide ore previously handled alone. The mixture of clean sulfide and semi-oxidized ore was difficult to treat; consequently, tailing losses, especially with respect to lead, were high. A few years later, in order to study the possibilities of obtaining higher recoveries by a modification of the mill flow sheet, a 1,200-pound sample of mill, feed, taken over a period of several days by the company, was submitted to the Mississippi Valley Experiment Sta¬tion for testing-. Although this sample proved to contain more than twice as much lead as the average yearly mill feed, the same problem of recovering the oxidized values was present.A résumé of the ore-dressing treatment used in the Shenandoah-Dives mill follows. After crushing, the ore passes through a ball mill, the minus 5-mesh discharge of which is distributed to three tables. A finished lead concentrate is made on the tables, and the table tailing goes to the classifier which is in closed circuit with the ball mill. The classifier overflow is treated -by flotation to obtain a bulk sulfide concentrate at a relatively coarse size. The bulk concentrate is thickened and reground to about 95 percent minus 325-mesh before flotation treatment to separate a lead-copper and a zinc concentrate. A typical monthly average showed that the table concentrate contained about 45 percent lead, 1 percent copper, 4 percent zinc, 12 ounces of gold, and 40 ounces of silver; that the lead flotation concentrate contained '35 percent load, 6 percent copper, 7 percent zinc, 3.5 ounces of gold, and 50 ounces of silver; and that the zinc flotation concentrate contained 2 percent lead, 0.5 percent copper, 60 percent zinc, 0.15 ounces of gold, and 4 ounces of silver. Recoveries in salable products were roughly b5 percent of the lead, 70 percent of the copper, 45 percent of the zinc, 85 percent of the gold, and b5 percent of the silver."

May 1, 1948

By William H. Schiffbauer, Ph. D. Mowrey

Proximity warning devices can improve workplace safety by alerting workers when they are in a hazardous area near moving equipment. Industrial work sites often present extreme challenges to safety-based proximity warning devices. Many commercially available types of proximity warning sensors and systems can be rendered useless when covered with mud, ice, snow, ore, rock, and other material. The list includes radar, ultrasonic, capacitive, and visual types of sensors and systems. Addressing these shortcomings, NIOSH personnel have developed a patented active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) which employs lowfrequency, low-power magnetic fields which are quite impervious to severe environmental conditions. A shapeable wire loop antenna which provides the marker of dangerous work areas, has been mounted on a continuous mining machine and was mounted inside 1.3-cm thick angle iron. This loop antenna was exposed to more than six months of active underground coal production, which included being covered by and scraped over with tons of rock, sprayed by a continuous stream of water, and immersed in thick mud. After six months the loop antenna showed signs of wear, but was still capable of performing its intended function. The HASARD system is now being applied to other industrial applications and is showing much promise, especially in harsh environments. This paper details the system, describes the tests that have been done, and mentions other areas where it can benefit the safety of industrial workers.

By John M. Gomes

The Bureau of Mines investigated two techniques for removing CaO from scheelite (CaW04) prior to electrolysis. In the first technique, a crude tungstic oxide (WO3) containing 0.15-percent lime (CaO) was prepared by digesting scheelite concentrates in hot hydrochloric acid. This oxide was used as cell feed to produce tungsten of 99.9-percent purity. The second technique used a high-temperature, two-phase separation, resulting in extraction of 99 percent of the WO3 in the halide-tungstate phase, while 90 percent of the CaO was retained in the silicate phase. Tungsten of 99.9-percent purity was deposited from the halide-tungstate melt after B203 and NaPO3 were added to form an electrolyte. The two methods were compared with a previously developed technique of depositing tungsten from scheelite concentrate fed directly to the electrolytic cell.

Jan 1, 1971

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 Thomas Fraser, J. D. Davis

"INTRODUCTION Preliminary tests of the Oyon coal constituted part of a wartime exploratory and development program in which many agencies participated. The general objective was to find new and adequate source of fuel and other raw materials for greatly expanded industry.The Oyon coal field, known for at least a hundred years to the mining people of Peru, offers a possible source of high-grade process fuel for the growing metallurgical industries of South America and the Pacific coast. Santolalla 4/ reports that low-volatile coal from this region was used in local smelting operations as early as 1850. It has been mined in very small quanti¬ties for many years and used in neighboring mining camps and villages. Small quantities are regularly used at Oroya for the manufacture of carbide, and in recent years small-scale coking operations in specially designed ovens in the region have demonstrated that these coals will make dense coke.During this long period of desultory operations many small openings have been made scattered over a wide area in this general region, indicating very extensive occurrence of the coal measures, although systematic exploration work has not been undertaken. However, current development work of the Banco Minero del Peru has opened up several substantially parallel highly inclined or vertical beds of workable thickness and has followed these deposits to sufficient lateral extent to prove fairly well the existence of substantial reserves on this property."

Mar 1, 1948

By R. C. Buehl

An experimental iron blast furnace of 3-foot-diameter hearth, producing about 12 tons of metal per day, was operated for 2 weeks with various proportions of anthracite replacing a corresponding amount of coke. The furnace operated well with anthracite in amounts up to 40 percent of the total fuel and produced metal of uniformly low sulfur and normal silicon contents. An increase to 50 percent anthracite during two attempts resulted in poor operation and the charge hung in the s haft of the furnace. INTRODUCTION Anthracite production in Pennsylvania decreased from 84,400,000 net tons in 1926 to 40,600,000 net tons in 1952, and there was a further decline in 1953 to 30,900,000 net tons. Employment in the anthracite industry dropped from 165,000 men working an average of 244 days per year in 1926 to 57,900 working an average of 163 days per year in 1953,3/ which has naturally resulted in considerable unemployment in the region. The industry is actively engaged in promoting new uses for anthracite to increase the demand and thus improve economic conditions in the region. One possibility is the use of anthracite to replace part of the coke for smelting iron ore in blast furnaces. The tests in this report were made to determine whether this use of anthracite would be feasible.

Jan 1, 1955

By E. C. Lane

During the past 15 years the Bureau of Mines has made and published several hundred analyses of typical petroleums and has developed a system of interpreting the analyses and of classifying crude oils. In describing crude petroleum frequent reference is made to the "base" of the oil, a usage the petroleum industry has found convenient. As part of its general study of the characteristics of crude oils, therefore, the Bureau of Mines has developed a system of classifying them according to "base." This system as first published in 1927 was limited to four classes and in its original form is no longer considered adequate. Since the system was first published the Bureau has analyzed a large number of crude oil, including representative samples from nearly every important producing field in the world, and has found that the system of classification could be revised and amplified to advantage. The revised system is presented herein.

Jan 1, 1935

By V. F. Parry, J. B. Goodman, W. S. Landers

"This investigation was conducted: under the direction of A.C. Fieldner, chief, Fuel and Explosives Branch, Bureau of Mines, Washington, D. C. The following members of a Technical .advisory Committee were helpful in advancing the investigation: L. C. Harrington, dean, College of Engineering, University of North Dakota; D. F. Pane, president, Sheridan-Wyoming Coal Co.; Carson W. Smith, president, Consolidated goal & Coke Co.; Durbin van Law, consulting, engineer, Denver & Rio Grande Western Railroad; and C. B. Carpenter, professor of metallurgy, Colorado School of Mines. Coal samples from the Northern Colorado field used in the stoker during 3 years of service were supplied through the cooperation of N. C. Brooks, secretary, Northern Colorado Coals, Inc.This report describes the development and practical tests made on a small stoker-fired system for heating service water automatically. The system was designed to take advantage of the favorable reactivity of low-rank fuels, and the objective was to devise a combination of stoker, heat-receiving, and hot-water storage system Which would be automatic for at least 30 days without attention, while heating service water at minimum cost. The system was developed to a point where coal consumption was less than 10 pounds (or less than 100,000 B.t.u.) per day. The total operating cost of hot water for an average-family-was about $1.00 per month, with coal retailing at $6.00 per ton and electric power at 4 cents a kilowatt-hour. The heating system was designed for the utilization of low-rank fuels, but the general features of the double-tank system can be 'employed fuels, either gas or liquid fuels.The Subbituminous Coal and Lignite Section of the Bureau of Mines began investigations on the utilization of low-rank fuels in domestic appliances during 1939. Tests were made on various devices to find out if they were suitable for the low-rank fuels. Most of the available appliances for burning coal have been designed for the higher-rank fuels, and they are not well-suited for burning the lower-rank coals at maximum efficiency, because subbituminous coals and lignite have high bed moisture ranging between 20 and 40 percent by weight, which lowers heating value to the range of 10,000 to 6,500 B.t.u. per pound. They are noncoking, and the ash content ranges between 4 and 6 percent, with a fusion temperature of about 2,0000 F."

Jun 1, 1946

By Wesley A. Grosh

The Valzinco mine, Spotsylvania County, Va., is a lead-zinc deposit with minor quantities of copper. The property was reopened n 1942 by Panaminas, Inc. The Bureau of. Mines, in an effort to increase the reserves of the deposit to justify greater production, diamond-drilled nine holes totaling 4,213 feet during 1943. Drilling by the Bureau delimited the original ore body and discovered another ore body on the hanging-wall side, which was being developed by the company at the close of the project.

Jan 1, 1949

By E. P. Youngman

This paper is one of a series of digests of foreign mining legislation and court decisions that is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the mining laws of French Indo - China is a translation of an article published by the Department of Mines of Indo - China ; 4 and it is released subject to correction and amplification by the proper American foreign- service officers .

Mar 1, 1933

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Jan 1, 2011

By Charles W. Huggins

Electron diffraction and electron microscopy were used to determine the unit cell parameters of garnierite [(Ni,Mg)3 Si2O5 (OH)4] and to examine its crystal habit. Bundles of ribbons, many less than 200 A. in cross section, make up the bulk specimen of the garnierite Electron diffraction revealed the unit cell to be monoclinic. Unit cell parameters were: a, 5.33 A,; b, 9.23 A.; c, 14.96 A.; and ß, 94°441.

Jan 1, 1961

By L. C. Marchont

This Bureau of Mines report tabulates data on nitrogen-gas reservoirs and isolated occurrences of inert gases in several Williston basin oilfields. Recoverable reserves of nitrogen gas in the Minnelusa nitrogen interval within the areas of five oilfields on the Nesson anticline in North Dakota are estimated at about 1.27 trillion standard cubic feet, based on computer analyses of logs from over 300 wells. This volume of nitrogen represents a large source of high-pressure inert gas and warrants consideration of possible application in oil-production operations. Drill-stem tests made in two of the fields indicated that nitrogen can be produced at rates up to 28 million cubic feet per day.

Jan 1, 1966

By M. S. Seehra, V. S. Babu

"INTRODUCTION The accurate determination of the free silica index in coal mine dusts is an important requirement because severe health hazards are believed to be associated with the inhalation of respirable-sized silica particles.1-6 Free silica refers to the three polymorphs of silica (Si02)viz., quartz, cristobalite, and tridymite-although quartz is usually the dominant form in most mine dusts.6 The free silica index is the concentration in micrograms of free silica in air per m3 of air sampled corrected to standard conditions of 25°C and 760 mm/Hg, the present MSHA (Mine Safety and Health Administration) limit on time-averaged basis being 100 µ.g/m 3 for coal mines. A recent review7 has concluded that quartz, cristobalite, and tridymite particles impart nearly equal long-term hemolytic damage when compared on a per unit surface area basis.At present, two experimental methods-viz., transmission infrared spectroscopy (TIRS) and x-ray diffraction (XRD)-are commonly used for the determination of silica concentrations in mine dusts. In TIRS, which has been adopted by MSHA and is commonly called the P7 method, the silica absorption band near 800 cm - 1 is used for quantification. However the mineral kaolinite, which is commonly present in mine dusts, also has absorption band, albeit weaker, at 800 cm- 1• To correct for this interference, one uses the stronger 915-cm -1 band of kaolinite to determine the concentration of kaolinite, and the kaolinite contribution to the absorbance at 800 cm-1 is then determined from a calibration curve, leading to the determination of silica by subtraction. In the XRD technique, usually an internal standard such as CaF 2 is used to determine the concentration of silica from line intensity measurements. XRD has the added advantage that concentrations of quartz, cristobalite, and tridymite can be determined.8•9 In an exhaustive study on the precision of the techniques ofTIRS and XRD for monitoring worker exposure,9 the conclusion has been reached that both methods measure silica within 253 of the ""true"" value 953 of the time in a single laboratory."

Nov 1, 1995

By Robert Roby

The Mouat copper-nickel deposit in Stillwater County, south-central Montana, was examined by Paul T. Allsman, an engineer of the Bureau of Mines, in 1939. Because of the strategic importance of nickel, a project was executed by John East, Jr., J. J. Naughton, and E. W. Newman, engineers of the Bureau, to further delimit some of the copper-nickel sulfide-bearing bodies that had been discovered by the Anaconda Copper Mining. Co. in 1937 and to investigate the central part of the deposit, which had not been drilled previously. This report is based largely upon the results of the. Bureau of Mines investigation and the results of exploration by the Anaconda Copper Mining Co. In addition, a brief description is given of some other copper-nickel sulfide-bearing deposits along tho Stillwater Complex.

Jan 1, 1949

By P. L. Sibrell

Electrorefining of Ti in nonaqueous solvents has been studied by the U.S. Bureau of mines as a method for recycling impure scrap Ti. Electrochemical behavior of Ti species was investigated using cyclic voltammetry. Research results showed that Ti metal can be dissolved in polar solvents such as dimethylformamide or dimethyl sulfoxide. However, deposition of Ti from these solvents was not successful. Several solvent systems were investigated for electrodeposition of Ti but no deposits were obtained. Reduction of Ti4+ complexes to Ti3+ proved to be straightforward, but reduction to lower oxidation states could not be confirmed. In dimethylformamide solutions, cyclic voltammetry results demonstrated the reduction of Ti to an oxidation state of less than three, but no Ti metal was identified. In dimethyl sulfoxide solutions containing LiCl, it was possible to deposit Li metal. After adding Ti salts to the solution, electrolysis quickly passivated the electrode. Deposition of Ti was also investigated in solutions of dimethoxyethane and propylene carbonate but, again, no reduction of Ti to oxidation states of less than three occurred. Therefore, the prospects for a nonaqueous electrorefining system for Ti metal do not appear promising.

Jan 1, 2010

By J. M. Singer

Flame propagation of lower limit hybrid coal dust-methane-air mixtures in vertical and horizontal flame ducts of 15.2 cm id and 1.8 m length has been investigated to provide information bearing on safety in mines. Fuel concentrations at lower limits of flame propagation and equivalences of coal dust and methane are much higher for continuing flame propagation than for short-span flame propagation in the vicinity of an "overdriving" ignition source. As the energy of the ignition source was increased, the flame speed and the distance of flame propagation from the ignition source increased, whereas the total fuel concentration at the lower limit decreased.

Jan 1, 1968

By B. W. Gandrud, G. T. Bator

The recent introduction of small coal jigs in Alabama to meet the needs of truck - mine operators for cheap and economical cleaning equipment marks another step in Alabama's pioneering record in the mechanical cleaning and preparation of coal . During the past 4 or 5 years a number of these small jigs , with capacity of 5 to 10 tons per hour , have been installed at Alabama truck mines and at a few truck mines in Illinois , Tennessee , and Pennsylvania . Most of the installations have been at mines that specialize in the production of domestic , stoker coal . This report describes three models of small jigs and includes performance data obtained recently on one of the models by the Bureau of Mines, United States Department of the Interior , in cooperation with the University of Alabama, Tuscaloosa , Ala . , for the purpose of comparing it with fullsize jigs on a performance basis . With literally hundreds of truck mines now in operation throughout the country , it has been assumed in preparing this report that there is widespread interest in the availability of small - scale inexpensive preparation equipment for use at such mines in the production of steam and domestic coal and in some instances coal for manufacture of coke . Practically none of the coal from Alabama truck mines is scld to coke - oven plants ; but in some sections of the country truck mines supply a considerable amount of coking coal, and the use of small, inexpensive washers at some of them might be very advantageous during the present war emergency from the standpoint of increasing pig - iron production through improvements in coke quality .

Aug 1, 1943

By Michael S. Miller

In 1984, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied the 34,050-acre Cow Creek Wilderness Study Area (WSA) in order to evaluate its mineral resources. The WSA, located about 60 miles southeast of Havre, MT, contains sandstones, shales, clays, and coal of Cretaceous age. The Cretaceous rocks have been intruded by ultramafic diatremes. Quaternary glacial, stream, and landslide deposits overlie the older rocks. Claims are staked at five of seven sites favorable for diamonds within the WSA and at additional sites nearby. Although the ultramafic diatremes within and near the WSA contain minerals that are indicators for diamonds, no positive evidence of diamonds was found during this study. An abandoned coal mine, the Shellenberger, is inside the southwest boundary of the WSA. Possible petroleum and natural gas at depth are currently of interest; land within the WSA is leased or under lease application for oil and gas. The WSA contains subeconomic clays, zeolites, gold, silver, platinum group metals, and coal.

Jan 1, 1986