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Jan 1, 1952

By R. I. Jaffee, F. C. Holden, H. R. Ogden, A. G. Imgram

The tensile and notch tensile properties of four refractory metals (molybdenum, tungsten, niobium (columbium), and tantalum) and one alloy (Mo-0.5Ti) were investigated. All the materials were evaluated in bar form, and the molybdenum and Mo-0.5Ti also were studied in sheet form. The notch sensitivity of each material was evaluated on the basis of several criteria, including the notch-unnotch strength ratio, the ductility transition, and the fracture transitions. USE of refractory metals as structural materials in aircraft and space vehicles may subject them to low-as well as high-temperature environments. At elevated temperatures, the usefulness of a material usually is limited either by strength considerations

Jan 1, 1962

By J. R. CAIN

SAMUEL L. HOYT, ? Nela Park, Cleveland, Ohio (written discussion?). The work that Dr. Cain is doing on gases in steel should have a highly important bearing on investigational work in connection with steel-making practice. We found, for example, in our work in connection with the use of manganese in open-hearth practice that we needed expressions for the manganese efficiency and the "condition" of the steel. To get these figures we assumed that we would need to know the amount of FeO at different stages of the heat and the amounts of the gases present. This required simultaneous analyses of our samples for FeO and the gases and Dr. Cain seems to be the only investigator who has considered the analytical work from this point of view. That he has done so is very encouraging and it is to be hoped that his work will solve the mys-teries now surrounding this neglected phase of steel metallurgy. Those interested in the Ledebur method for use in connection with the efficiency of manganese as a "deoxidizing " agent will he disappointed to learn that more recent work at the Bureau indicates that Ledebur determinations are not reliable. The principal source of error seems to be due to the partial reduction of the ferrous oxide by the carbon present in the steel. However, it seems like an unnecessary criticism of the Ledebur method to state (p. 1319) that it proved of little value because it showed little differences in oxygen for a series of steels treated with ,various reagents and showing variations in physical properties and free-

Jan 12, 1919

By Albert Sauveur

To understand this paper properly, the reader must have a clear conception of what is meant by the " critical points " of iron and steel; * and in order to avoid the necessity of tedious references to previous publications on the part of those unfamiliar with the subject, it is here briefly recapitulated. Critictl Points.—If a piece of steel containing, say, 0.50 per cent. or more of carbon, be heated to a high temperature and then allowed to cool slowly, the cooling proceeds at first at a uniformly retarded rate until a temperature of about 700° C. is reached, when there is a sudden " retardation " in the fall of

Jan 1, 1897

By P. Dayal, L. S. Darken

THE migration of carbon in austenite under the influence of an electric current has been observed qualitatively several times.14 Lebedev and Guterman5 recently have reported quantitative measurements; their method consisted of welding a low-carbon to a high-carbon wire, passing current, and later estimating the carbon distribution metal-lographically. We believe the method reported in this paper is superior in principle since electrolytic migration and ordinary diffusion are not necessarily coupled as in the weld method; also for the first time the extent of migration is determined by combustion analysis for carbon. A uniform tubular specimen (S.A.E. 1045 or 1095) was mounted as illustrated in the figures. the whole assembly being in an atmosphere of purified nitrogen. Direct current (129 to 226 amp at 0.65 to 1.0 v) served as source both of heat and of potential gradient for carbon migration. The duration of experiment was 7.5 to 12 hr, during which time the temperature was controlled (±10°C) manually. The experimental conditions are indicated in the first five columns of table I. With this experimental arrangement, the temperature initially has a maximum value at the central plane. Also, in this vicinity (by virtue of the symmetry), the carbon entering any volume element is equal in quantity to that leaving; the loss or accumulation of carbon occurs near the electrodes since the carbon moves uniformly near the center and is "frozen" at the cold ends. Hence, providing the time of experiment is not sufficiently long to seriously influence the conditions at the central plane, carbon crosses this plane only under the influence of the electrical potential gradient and not under the influence of temperature or concentration gradient. The amount of carbon which has crossed this plane was determined by combustion analysis of the two halves of the specimen. The results of these analyses are shown in the sixth and seventh columns of table I. It will be noted that substantial amounts of carbon migrated from the anode portion to the cathode portion (except at 920°C, which temperature was too low to exhibit the effect in the allotted time). In spite of precau-tions taken, considerable decarburization occurred as may be seen by comparing cols. 8 and 5. In three cases (indicated by asterisks in table I) the specimen was ground on one side, polished, and examined metallographically before analysis. One specimen was normalized and re-examined. Micrographs of selected areas in specimens 4 and 6 are shown in figs. 1 and 2, respectively. Evidence of carbon migration from the anode toward the cathode is quite apparent. Fig. 2 shows abundant graphite as well as cementite in a region near the cathode. The temperature of this zone is estimated at about 800°C. In fig. 1, particularly in the micrograph on the extreme right (the right side of which is of unaltered carbon content), there is evidence of slight depletion of carbon in the immediate vicinity of the cathode as contrasted to the general increase in carbon of the cathode half of the specimen. Although this may be attributed in part to decarbur-ization, it is believed that it is occasioned also by thermal diffusion—migration (of carbon) from a cool to a hot zone4—a phenomenon superimposed upon the electrical migration. Evidence of carbon migration was visible particu-larly during the course of the high-temperature,

Jan 1, 1951

Jan 1, 1954

By J. C. Kerkering, P. M. Daling

This paper discusses a study performed to evaluate the feasibility of transferring formal system safety assessment technology to the mining industry. A representative listing of formal techniques was evaluated to select the most useful methods for the mining industry to implement. Criteria for selecting methods included the interests, needs, and requirements of mine safety officials. This paper describes one of the selected methods, preliminary hazards analysis (PHA), and illustrates the analysis procedure for a mining example. This study also includes an assessment of the adaptability of selected methods to a user-interactive computer system for use by mine safety personnel. This paper includes a description of a conceptual computerized PHA-type safety program that facilitates performance of the safety analysis and can accommodate updates and revisions as necessary.

Jan 1, 1983

From 1917 to 1926 mining at the Climax Molybdenum Co. property was confined to the Leal and White levels at elevations of 12,145 and 11,935 ft respectively and to surface outcrops above the Leal level. At present the production is coming from the Phillipson and Storke levels at elevations of 11,465 and 11,168 ft. Until 1926 when B. S. Butler recognized the relationship existing between the orebody and a central core of fine-grained hydrothermal quartz, the orebody was believed to be tabular in form. The orebody lies within the pre-Cambrian granites and schists and another rock type designated as the Climax porphyry and surrounds a highly silicious core, the mineable portion of which varies in thickness from 250 to 400 ft.

Aug 1, 1955

W. A. SCHLESINGER,* Denver, Colo.-Two problems are of great interest to the radium manufacturer at the present tine: The first is to perfect a process, more efficient and more economical, which is capable of treating a greater variety of ores. . Practically all the radium now manufactured in the United States is extracted from carnotite ores and these vary a great deal according to their location. The amount of sulfates contained in the ore is of particular importance, and any straight acid-leaching method, such as developed by the Bureau of Mines, becomes prohibitive when the ore contains more than 0.5 per cent. of sulfates, as the sulfates go into solution and naturally precipitate the radium as insoluble radium sulfate. Since the amount of ore obtained from any one claim is usually comparatively small, it is necessary to work a number of claims in different localities, and a process, in order to be commercially satisfactory, should handle all of these ores. In other words, it would be entirely unprofitable for radium manufacturers to employ any process which cannot treat any but sulfate-free ores. He must deal with carnotite containing appreciable amounts of sulfates, and must be able to work this in with the other ores. Carbonaceous ores from certain sections in Utah; which are known to contain as pinch as 1.0 per cent. and more of volatile matters, are prone to a, nitric acid-leaching process. The second problem relates to the treatment of concentrates. There is no doubt that a very large amount of low-grade ore, containing less than 0.75 per cent. uranium oxide, is available. It has been demonstrated that these ores can be concentrated, but there is still room for research

Jan 11, 1918

By Donald L. Everhart

SOONER or later intelligent exploration for uranium leads to these questions: Where did the metallic ions that formed the orebodies come from? What processes and geologic factors were involved in ore replacement? These matters, of course, make a big difference in how best to look for orebodies. Before these questions are discussed it might be well to point out other factors bearing on the subject. The whole business of uranium exploration is only a little over ten years old, participation by the public is only about six years old, and real interest and activity by more than a few large mining companies has arisen only in the past two or three years. Throughout this short period, uranium exploration has been affected by the unique influences of necessary security measures and by division of the over- all job into individual projects by a large number of specialists in diverse fields. This has meant that a normal interchange of information on the nature of uranium deposits has really only just begun. Com- pared to the vast amount of published studies on iron, copper, lead, zinc, and gold deposits over the past 50 to 75 years, current knowledge of uranium deposits is in its infancy and much of the pertinent information is still scattered about in a number of unpublished sources. The volume of reports on all phases of uranium exploration is now beginning to mount at a remarkable rate, and geologists with widely varying specialized backgrounds in uranium geology are engaging in spirited debates over the origin of uranium and the relative importance of geologic controls of various deposits.

Jan 9, 1954

ALABAMA Altoona.-Cain, J. America.-Foreman, J. T. Anniston.-Cowie, L. K. Foster, R. N. Ashland.-Sturdevant, J C Bessemer.-Ball, E. M. McKenzie, W. C., Jr Birmingham.-Abbott, C. E. Aldrich, T. H. Aldrich, T. H, Jr. Ashton, J J. Ball, T. L. Blair, C. S. Brown, T S. Bush, M. W.

Jan 1, 1923

By AIME AIME

ANNOUNCEMENT on August 6 of the historic event of dropping an atomic bomb on Hiroshima, Japan, was more dramatic even than V-E day, since that had so long been forecast whereas the bomb production had been the best-kept secret of the war, even though at one time more than 100,000 people had been at work in connection with its production, and some two billion dollars had been spent on the project. Mining men had long been aware of an unexplained abnormal interest in uranium production, and suspected that something of the sort was on foot, while metallurgists were aware that various men of their acquaintance were engaged in some top secret research. The first announcement was soon supplemented by other official releases which told more about the research laboratories for theoretical and pilot studies, and the plants in Tennessee and Washington, but none of them made clear what the modus operandi is of these terrific bombs. Inquiry at Colum. bia University, where Dr. Dunning and his associates had succeeded in 1939 in splitting the uranium atom, and where laboratories known only as SAM have been feverishly active since the beginning of the war, was unproductive, since none of those officially connected with the project could give out anything beyond the official releases.

Jan 1, 1945

By J. T. Ryan

SiR Humphry Davy's epoch-making treatise delivered on Nov. 9, 1815, before the Philosophical Society of London, first announced and demonstrated a flame safety lamp for detecting methane in mine air. Coal mining was known in England as early as 1180, more than 600 years before the advent of a safe lighting and gas-detecting appliance. Mining, no doubt, took place first in outcrop coal, and danger from gas did not become apparent until the workings became deeper and more extensive. Davy's lamp did much to increase the safety of miners, and a modified Davy lamp is still widely used for detecting the presence and approximate amount of combustible gas in mine air. No factor in coal mining has improved more rapidly during the past 15 years than safety measures. This progress came about not only as a result of the workmen's compensation laws now in force in most of the states of the Union, but because the research work of the U. S. Bureau of Mines had demonstrated some dangers incident to coal mining which were not considered to be serious matters prior to that time. Electric power and explosives are necessary but potential hazards in American coal mines. A general mechanization program is now under way, while the mines are growing deeper and more extensive. Consequently ventilation problems are more complex and a demand has been created for positive detecting devices for carbon monoxide as well as methane. Scientists and manufacturers, working hand in hand during the past 10 years, have invented and developed appliances which make systematic and effective examination of mine air possible. The object of this paper is to describe briefly the approved testing devices in use today, with the hope that they may lead to the saving of life. Two Groups of Dangerous Coal Mine Gases Dangerous coal mine gases may be placed in two groups: (I) those that are dangerous because of their explosive properties, and (2) those that are dangerous because of their toxic properties. Methane (CH4) is the important gas of the first group, and in so-called gaseous mines constantly exudes from the coal and rock; it may accumulate and form an explosive mixture. The explosive range of methane-air mixtures is well defined. The low limit is 5 per cent., the high limit 15 per cent., and the most explosive

Jan 1, 1927

By H. H. Stoek

(Wilkes-Barre Meeting, June, 1911.) THE origin of the Mine-Rescue Service of the State of Illinois can be traced to two distinct sources, the work of the Rescue Station at Urbana and the Cherry disaster. During the early part of the year 1909, the Technologic Branch of the U. S. Geological Survey, now the Bureau of Mines, in connection with the Illinois Geological Survey and the College of Engineering of the University of Illinois, established at the University of Illinois, in Urbana, a branch rescue-station to supplement the work of the Pittsburg station of the Geological Survey. As a result of the work of training at the station in Urbana by R. Y. Williams, mining engineer, and James Webb, foreman of the Bureau of Mines, and the use of the helmets at several mine-accidents in the State of Illinois, . the people of the State were somewhat familiar with oxygen-helmets when the Cherry disaster occurred, in November, 1910. The oxygen-helmets were successfully used in connection with that disaster, and upon the recommendation of the Illinois Mining Investigation Commission, the Legislature of the State, assembled in special session during the winter of 1910, passed a bill appropriating $75,000 for the erection and maintenance of three rescue-stations, stipulating that they should be located in the northern, central, and southern parts of the State. The Act also provided that the stations should be in charge of a Commission of seven, two representing the United Mine Workers of Illinois, two the mine-operators, one the Federal Bureau of Mines, one the State mine-inspectors, and one the Department of Mining Engineering of the University of Illinois. This Commission was called together by the Governor of the State, Aug. 2, 1910, and since that time three stations have been located, built, and equipped: at La Salle for the northern

Dec 1, 1911

FRANCIS B. SILSBE,* Washington, D. C. (written discussion?). ?This paper is an interesting example of the -solution by the methods of metallography of what seemed at first a purely chemical problem. The authors have shown: in detail, how the well-known corrosion of spark-plug terminals is due to the dropping out of the individual crystals of the metal as it becomes surrounded by an oxide film. This corrosion is usually quite slow but in special cases may become a serious factor in limiting the life of spark plugs. There still remains the problem for the metallurgist to produce a material that will be entirely free from, this trouble. One of the most startling results of the work is. the demonstration that it affords of the deleterious effect of a mechanical stress continuously applied to material that is at the same time subject to adverse chemical or thermal conditions. The particular style of spark plug shown in the illustration, and in which serious trouble was caused by this corrosion, has the side terminals fastened at both ends and the method of assem-bling is such that a considerable initial tension is applied to the wire. It is without doubt this superimposed tension that causes the inter-crystal-line network to line up, as it were, into a few continuous and deeply penetrating transverse fissures instead of forming a great number of shallow surface cracks. This result is clearly shown both in the case of

Jan 11, 1919

By C. C. McDermond, Others, B. N. Zavoico

Production of crude oil in Venezuela for the year 1937 was 186,653,-916 bbl., as compared with 155,228,982 bbl. produced in 1936, an increase of almost 31,500,000 bbl. The oil-field strike, which started on Dec. 14, 1936, lasted until Jan. 25, 1937, when a total of 10,000,000 bbl. of production was estimated to have been lost (5,750,000 bbl. in 1936 and the remainder in 1937). Of the total of 186,653,916 bbl. produced in 1937, the Lagunillas field contributed 45.6 per cent, a drop of approximately 10 per cent under 1936 figures; Tia Juana, 14.3 per cent; Quiriquire field, 14.0 per cent; La Rosa area, 13.3 per cent and the Mene Grande field, 7.6 per cent, these being the five leading contributors of the year's production. Detailed production figures by fields and by companies are shown on Table 1. Of the total production of Venezuela the following four major companies accounted for the greater proportion: Standard of Venezuela and Lago Petroleum Corporation together, 48.3 per cent; Shell, 37.4 per cent and Venezuela Gulf, 14.0 per cent. At the end of the year, 2491 wells were producing, of which number 1291 wells were pumpers, or about 52 per cent. Production The accompanying statistics of production record of Venezuela oil fields from its inception to Dec. 31, 1937, shown on Table 2, indicates that the cumulative production reached 1,503,283,228 bbl. In order of importance, Lagunillas leads all the fields, having accounted for about 50 per cent of Venezuelan production, followed by La Rosa area, which produced about 21 per cent; Mene Grande, which produced about 13 per cent, and Quiriquire, which produced 6.5 per cent. Table 3 shows the age of each field. Mene Grande is the oldest, having produced for 24 years; Tarra is next, 21 1/2 years old, and El Mene third, 171/2 years. The gravity of the crude from the various fields, also shown on Table 3, remained unchanged, the only addition being the new Tia Juana field, which averages 15.6' A.P.I. Table 4 shows the method of production by fields as of Jan. 1, 1938; at the end of the year 2491 wells were producing, compared with 2005 wells producing at the beginning of 1937, or an increase of 486 wells. The completions for the year reached 512. Of the 2491 wells producing crude oil, 1291 wells, or approximately 52 per cent, were pumping, 925 (approximately 37 per cent) were flowing naturally and 275 (11 per cent) were on

Jan 1, 1938

By Paul M. Tyler

MINOR industrial minerals included in this chapter are: the alum minerals, bromine, calcium chloride, epsomite and other natural magnesium salts, iodine, meerschaum, quartz, industrial crystals other than quartz (Iceland spar, tourmaline, fluorite, selenite, mica), and nonfuel gases (air, helium, carbon dioxide). ALUM MINERALS The alums comprise a series of double sulphates (or selenates) isomorphous with potash alum, which, according to a ruling of the Pennsylvania courts, is the only product commercially described simply as "alum." Common alum occurs in nature as kalinite (K2SO4- A12 (SO4) 324H2O). The mineral mendozite (Na2S04) 3.A12 (SO4)3- 24H2O) is soda alum; tschennigite (NH4)2SO4.Al2 (SO4)3.24H2O) is ammonium alum; and there are about a dozen other native alums and related double sulphates. Alunite (alumstone or alum rock) has the formula Al2(SO4) 3.K2S04.4A1 (OH)3 and alunogen, Al2(So4) 3.18H20. Saline residues, found wherever natural water is evaporated, may contain sulphate of alumina, which for most uses is the essential ingredient of alum. Mineral wells and springs that emerge from beds of pyritiferous shale are typically astringent and at times form local deposits of alum, generally as incrustations. Acid waters acting upon aluminous rocks may form sulphates of alumina. The alums of commerce, as well as aluminum sulphate (concentrated alum), are produced principally by treating bauxite with acid, but they have been made also on a substantial scale from clay, cryolite, pyritic slates, schists, lignites, alunite, and leucite. Alum shale-chiefly clay, pyrite, and (usually) carbonaceous matter-was extensively used in England as a source of alum for more than two centuries. In France, pyritic lignites mixed with sand and clay were burned in heaps to red ash, the leach Liquors from which, after treatment with ammonia, yielded alum and copperas. Processes have been developed for making alum or aluminum sulphate from such diverse materials as feldspar, aluminous phosphate minerals, greensand, and mixtures of mica and

Jan 1, 1949

By Hjalmar Sjögren

Introduction.............767 Group I. The Ores of the Archean Crystalline Schists.... 770 Distribution............. 770 The Rocks.............770 Structures............772 The Rocks of Norrbotten..774 The Ores.............775 Type A. Apatite.Ores..........776 Type B. Mixed Hematite and Magnetite..777 Type C. Quartz-Banded Ores....777 Type D. The "Skarn" .Ores l..778 Type E. Limestone-Ores,..779 The Origin. of the Ore-Deposits......... 779 Arguments against the Sedimentation Theory,... 780 Concentration and Transformation within the Deep-Seated (Ana-morphic) Zone........783 The Chemical Changes.......784 Transformations in the Surface.Zone....789 The Graingesberg and Norrbotten Deposits,.....791 Analogous Deposits........794 Group II. The Ores of the Porphyries (Keratophyres) ... 796 Kiirunavaara. Luossavaara and TuoIlavaara....797 The Syenite.........799 The Porphyry of the, Foot. Wal1 .....799 The Porphyry of the Hanging-Wal1 ....799 The Ores.........800 The Forms and Dimensions of the Ore-Bodies ..802 Contact-Zones........803 The Genesis of the Deposits .......804 Mertainen and Painirova.......806 Ekatrömsberg..........808 Analogous Deposits,........808 Group 111. Magmatic Seregations in Basic Eruptives,... 809 Taberg in Smaland,.........811 Segregations in Diabase Younger than the Dala Sandstone, . 814 Iron-Ore in Nepheline. Syenite.......815 Ekersund and Soggendal in Norway......816

Jan 1, 1908

By W. L. Austin

The advance made in recent times in this branch of metallurgy is indicated by the attention the subject is receiving from important American copper-producing companies. Reference to the files of publications devoted to the mining industry discloses that some 20 American companies are actively investigating the amenability of their ore, or other material, to leaching methods, and that plants of varying capacities up to 10,000 tons per day arc under construction or are projected. Several leaching works are in commercial operation. It has been frequently pointed out that no method of leaching is universally applicable, for the reason that each ore differs in some particular from apparently similar ore found elsewhere, and also because local conditions are rarely the same even where the ore closely approximates in character that being worked at some other point. For this reason the older companies are approaching the matter in a conservative manner, experimentally determining for themselves the salient features in each instance. In considering a leaching proposition three factors at once fix the attention: (1) disengaging the metal from mineralized forms in which it is found in nature; (2) recovering the metal in a commercial state after it has been dissolved; (3) the apparatus best adapted to carrying out the several operations. Bringing the Metal into Solution This feature.has been found to present no serious difficulties. Numerous solvents for copper are known, and it has been repeatedly demonstrated on a commercial scale that from 80 to 90 per cent. of the metal contained in an ore can be rapidly brought into solution. It is interesting to note, however, that all of the companies above referred to have selected sulphuric acid as the basis for a lixiviant. Where oxidized ore practically free from precious metals is treated simple leaching with

Jan 1, 1915

By R. L. Dietrich

[ ] We at The Dow Chemical Co. have recently done some work on the deformation of magnesium alloys and although it is far from complete there have been a few observations which may be of interest in connection with this paper. In the first place, I should like to point out that the deformation of polycrystalline magnesium alloys has not been completely explained by the work on single crystals. Bakarian and Mathewson found slip on the ( 101) and {002) planes, and (102) twinning as the deformation mechanisms in magnesium single crystals, but in compression when the (002} planes were within ii° of parallel t0 the compression surfaces, fracture occurred at all temperatures up to 340°C (644°F). In commercial working processes, particularly in rolling, an orientation is quickly produced which should be unfavorable to further deformation by the three established mechanisms. The first few reductions in rolling quickly produce an orientation having

Jan 1, 1947