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By Wm. R. Webster

THIS is a contribution for the proposed new discussion on the physics of steel. The former discussion on the subject started with the consideration of five papers presented at the Chicago meeting in 1893, and continued for several years. The Suggested Lines of Discussion, prepared by Doctor Howe, covered a wide field and added greatly to the success of the work. Naturally, the first step in a new discussion will be to remodel and bring up to date the old Suggested Lines of Discussion so as to embody all the important advances in the metallurgy of steel that have a bearing on the physics of steel and keep the papers and discussions within the field of work undertaken. This paper will be devoted to the practical application, in rolling steel, of the effects of carbon, phosphorus, and manganese on its tensile strength, with some suggestions on further research work. Dr. J. E. Stead, in his paper Influence of Some Elements on the Mechanical Properties of Steel,1 gave a complete review of all that had been done during the past thirty years. He gave full credit to all investigators who worked on these lines, also their results, with his views on same, and in many cases his own results. All of this data and much new valuable information were put in convenient shape for reference and study. To do this required a great deal of work, which is fully appreciated by the steel manufacturers and investigators. The variations in the values given by the different investigators for the increase of the tensile strength of steel for each 0.01 per cent. of carbon, phosphorus, and manganese were largely due to the steels they worked on, the large or small variations in the amount of the elements present, and the omission to take into consideration all the factors, from the blast furnace through to finished rolled material, that affect the character of the steel. For instance, a poorly made dirty steel requires considerably more carbon to give the same ultimate strength than a well-made clean steel with the same phosphorus and manganese content.

Jan 3, 1921

PRESIDENT Mrs Oliver Bowles 5000 Massachusetts Ave N W Washington 16, D. C FIRST VICE-PRESIDENT Mrs David Eugene Park 350 East 57th Street New York 22, N Y. SECOND VICE-PRESIDENT Mrs A B. Kinzel 320 Park Avenue New York 22. N. Y

Jan 1, 1952

By Erwin Pink

It has been pointed out in a previous publication' that, for a given strain rate, serrated yielding can be observed only at certain test temperatures. Fig. 1 shows the results obtained for polycrystalline and re-crystallized tantalum, Va group in the periodic table of elements, where serrations in the course of deformation match the decrease of total elongation. However, there was no evidence of repeated yielding when testing molybdenum or tungsten, VIa group, at similar conditions, i.e., annealed and air-cooled samples (serrations have been found in quenched tungsten2). The reason for the observed serrations in the stress-strain curve are dissolved impurities on interstitial sites of the lattice. Of importance is the concentration of oxygen, carbon, and nitrogen, which are in random solution. Two methods to calculate the limiting concentrations for serrated yielding have been evaluated and applied with more or less success in estimating the role of carbon and nitrogen in mild steel.3 J. Friedel4 has given two equations, which determine the upper and lower strain rates i for the appearance of serrations at a certain test temperature: W denotes the binding energy of the interstitial atom, -1 ev for refractory metals;5 e' the portion of continuous strain in the discontinuous stress-strain curve, measured as -3x10-3; b the Burgers vector, c the concentration, see Table 11, in atom fractions; p the dislocation density, -2 X l09 per cm2 at an average stress ?, -15 kp per mm2 at medium strain. k stands for the Boltzmann constant, T for the absolute temperature, and D for the diffusion coefficient. Table I. Eq. [1], for a given strain rate, determines the minimum temperature, and [2] the maximum temperature, below or above which no "dynamic strain-aging" can occur. According to the calculation, which uses the given quantities, serrations should only be observed within the cross-hatched temperature regions in Fig. 1, and this is in good agreement with the experiment. The effect of varying impurity concentrations is indicated schematically in Fig. 2: only Eq. [I] is affected. Setting Eq. [I] equal to [2], one can calculate the limiting concentration cmin which first causes serrations. The second method uses the aging condition by Cottrell and Bilby6,7 \£i/ \ n. a / where n(t) is the number of impurity atoms, which segregate at a dislocation line of 1 cm length after the time t (t in our case is the time between "repeated yield drops" in the serrated curve, or, the time until the above mentioned strain E' is obtained, i.e., -1 sec for medium intensity or serrations). no is the number of impurity atoms in 1 cm3 and A = Qb4ep[(1 + v)/(l - v)], derived from equations given in Ref. 7. p is the shear modulus, 18,800 kp per mm2 for tantalum, 12,200 for molybdenum, AE the tetragonal distortion caused by interstitial impurities in a bcc lattice (approximately 0.4 for both tantalum and molybdenum) and v Poisson's ratio (0.35 for tantalum, 0.30 for molybdenum). From Eq. [3], combined with the condition for a pronounced yield drop as formulated by cottrel16 (at least one impurity atom segregated at the unit length of a dislocation), again a no min, and hence the concentration Cmin can be calculated.

Jan 1, 1970

LIST OF THE MEETINGS OF THE INSTITUTE AND THEIR LOCALITIES FROM ITS ORGANIZATION Transactions Number Place Date Vol Page I Wilkes-Barre, Pa * May, 1871 I 3 II Bethlehem, Pa August, 1871 I 10 III Troy, N Y November, 1871 I 13 IV Philadelphia, Pa February, 1872 I 17 V New York, N Y * May, 1872 I 20 VI Pittsburg, Pa October, 1872 I 25 VII Boston, Mass February, 1873 I 28 VIII Philadelphia, Pa * May, 1873 II 3 IX Easton, Pa October, 1873 II 7 X New York, N Y February, 1874 II 11 XI St Louis, Mo * May, 1874 III 3 XII Hazleton, Pa October, 1874 III 8 XIII New Haven, Conn February, 1875 III 15 XIV Dover, N J * May, 1875 IV 3 XV Cleveland, 0 October, 1875 IV 9 XVI Washington, D C February, 1876 IV 8 XVII Philadelphia, Pat June, 1876, V XVIII Philadelphia, Pa October, 1876 V 9 XIX New York, N Y February, 1877 v 27 XX Wilkes-Barre, Pa * May, 1877 vi 3 XXI Amenia, N Y October, 1877 vi 10

Jan 1, 1910

By W. A. Nagel, R. P. Alger, H. Sherman, J. Tittmann

A sidewall epithermal neutron tool has been developed to substantially reduce environmental effects that have previously complicated neutron log interpretation. Designed for operation in uncased wells, the device provides increased accuracy in both liquid-filled and empty holes. A brief discussion of neutron moderation, diffusion and capture shows that logs using epithermal neutron detection depend on a smaller number of formation-characterizing parameters than those using thermal neutron or capture gamma ray detection. Thus, they come closer to providing an unambiguorls determination of hydrogen content. In this new device a directionally sensitive epithertnal neutron detection system has been incorporated in a side-wall source-detector skid to minimize borehole effects. The effects of variations in borehole size and shape, mud type, temperature and salinity are greatly reduced. Small residual borehole effects are then computationally accounted for in the surface control panel to provide a borehole-corrected neutron log. The log presents a direct recording of neutron-derived porosity on a linear scale. With corrections for borehole effects already applied, this direct recording of porosity simplifies log interpretation. Furthermore, comparison with a linear porosity presentation of a formation density log permits sandstones, limestones and dolomites to be readily identified. Thus, in complex or variable lithology, porosity is determined with greater accuracy and reliability than heretofore. Laboratory data and field results demonstrate the improvements in neutron logging afforded by this new side-wall epithermal neutron logging device. INTRODUCTION The new Sidewall Neutron Porosity (SNP) logging system, designed for use in uncased wells, provides reliability and accuracy never before achieved with neutron logs. The effects of variations in borehole diameter and shape, fluid salinity, mud weight and temperature—parameters that have long complicated neutron log interpretation— are suppressed or corrected for by this sidewall epithermal neutron detection system. Furthermore, to simplify interpretation the SNP log presents a direct recording of computed porosity on a linear scale. The performance improvements achieved by this new system arise primarily from the combination of two im- portant design features. First. though not unique to this new tool, an epithermal neutron detection system is used,',' Epithermal neutron detection substantially reduces the perturbing influences of the thermal neutron absorption properties of rock matrices and water salinity. Second, the neutron detection system is mounted in a directionally sensitive sidewall skid to greatly minimize borehole effects. The purpose of this paper is to explain briefy the advantages offered by the detection of epithermal neutrons, to describe the SNP equipment and the log, to present calibration and correction data and to give examples of interpretation methods made especially convenient by this new system. ADVANTAGES OF EPITHERMAL NEUTRON DETECTION Epithermal neutron detection, of all the neutron methods in current commercial use, provides the simplest determination of formation hydrogen content. Advantages of epithermal neutron detectors, as compared with thermal neutron and gamma ray detectors, are probably best explained by a brief review of the life of a source-emitted neutron. A fast neutron from the source will eventually be cap-tured by the nucleus of an atom. However. before capture is likely to occur, the fast neutron (energy of 100,000 electron volts (ev) or more) will be slowed down until it is in thermal equilibrium with its surroundings. The neutron is then considered to be a "thermal" neutron (average energy of 0.025 ev at 25C). The overwhelming majority of the slowing down thus occurs in reaching epithermal energies (energies just above thermal—0.5 to several ev). After reaching thermal energy. the neutron will "diffuse" through the formation with, on the average, no further energy change until capture. Upon the capture of the thermal neutron, relatively high energy gamma rays arc usually emitted. Hydrogen plays a very important role in the process of slowing down fast neutrons. On the other hand, the absorption effects of water salinity and low concentrations of other strong thermal neutron absorbers—relatively unimportant in the moderation process-—are very important in thermal diffusion, capture and the production of gamma rays. Thus, by detecting only epithermal neutrons with the SNP, spurious effects due to these thermal neutron absorbers are greatly minimized as compared to the effects on tools using thermal neutron or gamma ray detectors. The epithermal neutron detection system affords another important advantage. Log response in various litho-

Jan 1, 1967

By C. A. Heiland, Tripp R. M., Dart Wantland

This paper serves to illustrate the application of geophysics to a virtually abandoned mine properly, an application that led to the discovery of an ore body and thus afforded an Opportunity to cOmpare subsequent geologic findings with geophysical data. The work herein described represents, however: more than mere ''case history." It demonstrates that it is possible to obtain satisfactory results by simple means and relatively inexpericnced personnel. The geophysical surveys were made by students as a part of their field assignments in the course of their regular training, and were supervised by Dart Wantland, J. E. Hawkins and R. Maurice 'Tripp. In the course of several seasons an appreciable amount of material was accumulated, which gave graduate students an opportunity for special studies. In this connection, the contributions by L. Massé, R. C. Hyslop, and J. E. Hawkins deserve special mention. The property owners cooperated wholeheartedly in the work, and special thanks are due messrs. J. F. Johnson and S. E. Zelenkov, of the American Smelting and Refining Co., for their interest and for permission to utilize the results of their development work for this publication. Location and Geology The Malachite mine is situated on the northcrn slope of Bear Creek Canyon, 4 miles northeast of Evergreen, I½ miles northwest of Idledale, and 4% miles west northwest of Morrison, in Jefferson County, Colorado. The location (Fig. I) is north of the center of set. 30, T. 45, R. 70 W., at an elevation of about 7500 ft, above sea level, Near the mine the terrain slopes rather uniformly southward at an angle of about 180 pigs. 3 and 7). The geology of the Malachite mine area has been described by J, underhill,' W, Lindgren,2 and J. Boyd.3,4 A map showing surface outcrops and mine workings appears in Fig, 2. the Malachite mine is in an amphibolite belt enclosed in gneisses and schists of the Idaho-Springs formation (probably early Algonkian age). The highly contorted beds are nearly vertical and strike slightly north of west. A series of granite-pegmatite dikes have been intruded almost at right angles into the gneisses and schists and doubtedless are postmineral. While most of the formations are exposed at the surface, a part of the 'lope is covered by slide rock and float, and in the eastern portion by alluvium and creek fill. A quartz-diorite dike cuts through the amphibolite schists at a small angle with nearly vertical dip. The copper sulphides, developed in this dike by magmatic segregation, occur in lenticular form. As far as the mine workings have revealed, the ore lenses are often discontinuous in depth and

Jan 1, 1946

By Tripp R. M., C. A. Heiland, Dart Wantland

This paper serves to illustrate the application of geophysics to a virtually abandoned mine properly, an application that led to the discovery of an ore body and thus afforded an Opportunity to cOmpare subsequent geologic findings with geophysical data. The work herein described represents, however: more than mere ''case history." It demonstrates that it is possible to obtain satisfactory results by simple means and relatively inexpericnced personnel. The geophysical surveys were made by students as a part of their field assignments in the course of their regular training, and were supervised by Dart Wantland, J. E. Hawkins and R. Maurice 'Tripp. In the course of several seasons an appreciable amount of material was accumulated, which gave graduate students an opportunity for special studies. In this connection, the contributions by L. Massé, R. C. Hyslop, and J. E. Hawkins deserve special mention. The property owners cooperated wholeheartedly in the work, and special thanks are due messrs. J. F. Johnson and S. E. Zelenkov, of the American Smelting and Refining Co., for their interest and for permission to utilize the results of their development work for this publication. Location and Geology The Malachite mine is situated on the northcrn slope of Bear Creek Canyon, 4 miles northeast of Evergreen, I½ miles northwest of Idledale, and 4% miles west northwest of Morrison, in Jefferson County, Colorado. The location (Fig. I) is north of the center of set. 30, T. 45, R. 70 W., at an elevation of about 7500 ft, above sea level, Near the mine the terrain slopes rather uniformly southward at an angle of about 180 pigs. 3 and 7). The geology of the Malachite mine area has been described by J, underhill,' W, Lindgren,2 and J. Boyd.3,4 A map showing surface outcrops and mine workings appears in Fig, 2. the Malachite mine is in an amphibolite belt enclosed in gneisses and schists of the Idaho-Springs formation (probably early Algonkian age). The highly contorted beds are nearly vertical and strike slightly north of west. A series of granite-pegmatite dikes have been intruded almost at right angles into the gneisses and schists and doubtedless are postmineral. While most of the formations are exposed at the surface, a part of the 'lope is covered by slide rock and float, and in the eastern portion by alluvium and creek fill. A quartz-diorite dike cuts through the amphibolite schists at a small angle with nearly vertical dip. The copper sulphides, developed in this dike by magmatic segregation, occur in lenticular form. As far as the mine workings have revealed, the ore lenses are often discontinuous in depth and

Jan 1, 1946

By L. D. Lamont, W. C. Muehlhof

Throughout the anthracite industry's history, the problem of handling and disposing of refuse material has been one of major importance. In the early days of the industry's activities, only the large sizes of anthracite were satisfactory for market requirements and the smaller sizes were deposited as refuse. As time went by, more efficient coal-burning equipment was developed and a market demand was created for the finer sizes of coal. This demand made it possible to recover marketable coal from banks deposited as refuse in the earlier days of mining. The same condition holds good today and we can see a definite trend toward the objective of utilizing the No. 4 and No. 5 buckwheat sizes. Under present conditions, we know that a limited market exists for No. 4 and 5 buckwheat; we know that the finer sizes of anthracite can be burned as pulverized fuel; we know that these fine sizes can be processed and sold as briquettes, and we also know that the heat content of these fine sizes of coal is comparable with that of the sizes now merchandized. Therefore, it should be the objective of the industry to conserve these fine sizes of coal in such manner that if and when processing facilities are developed, and market demands exist, the material can be salvaged and made available to meet these demands. From the standpoint of economical future reclamation, the ideal method of disposing of refuse containing the finer sizes of coal is to deposit it in banks separate and apart from other breaker refuse. By this procedure, the minimum amount of material will be processed in future salvage operations to recover the No. 4 and No. 5 buckwheat sizes. Many collieries in the anthracite region are operated under leases that have a specific term. These lease agreements provide that, upon expiration of the lease by term, exhaustion or otherwise, the ownership of the refuse material reverts to the lessor. Therefore, a question was raised in the minds of these operators: Why should I assume the expense of such procedure when I have no assurance that I will benefit by the future processing and sale of these fine sizes? Under present conditions, the answer to this question is not one of choice but of necessity, as restrictions imposed by legislation make it mandatory on operators of preparation plants to take necessary steps to properly treat silt-laden waters before permitting them to enter the streams. By reason of these restrictions, the disposal of fine sizes becomes a secondary rather than a primary operating consideration, and the procedure for disposing of this refuse becomes a matter of choice governed principally by topographical and geographical conditions. Methods of Handling Refuse There are three principal methods of handling and disposing of fine-size refuse; namely:

Jan 1, 1947

By W. C. Muehlhof, L. D. Lamont

Throughout the anthracite industry's history, the problem of handling and disposing of refuse material has been one of major importance. In the early days of the industry's activities, only the large sizes of anthracite were satisfactory for market requirements and the smaller sizes were deposited as refuse. As time went by, more efficient coal-burning equipment was developed and a market demand was created for the finer sizes of coal. This demand made it possible to recover marketable coal from banks deposited as refuse in the earlier days of mining. The same condition holds good today and we can see a definite trend toward the objective of utilizing the No. 4 and No. 5 buckwheat sizes. Under present conditions, we know that a limited market exists for No. 4 and 5 buckwheat; we know that the finer sizes of anthracite can be burned as pulverized fuel; we know that these fine sizes can be processed and sold as briquettes, and we also know that the heat content of these fine sizes of coal is comparable with that of the sizes now merchandized. Therefore, it should be the objective of the industry to conserve these fine sizes of coal in such manner that if and when processing facilities are developed, and market demands exist, the material can be salvaged and made available to meet these demands. From the standpoint of economical future reclamation, the ideal method of disposing of refuse containing the finer sizes of coal is to deposit it in banks separate and apart from other breaker refuse. By this procedure, the minimum amount of material will be processed in future salvage operations to recover the No. 4 and No. 5 buckwheat sizes. Many collieries in the anthracite region are operated under leases that have a specific term. These lease agreements provide that, upon expiration of the lease by term, exhaustion or otherwise, the ownership of the refuse material reverts to the lessor. Therefore, a question was raised in the minds of these operators: Why should I assume the expense of such procedure when I have no assurance that I will benefit by the future processing and sale of these fine sizes? Under present conditions, the answer to this question is not one of choice but of necessity, as restrictions imposed by legislation make it mandatory on operators of preparation plants to take necessary steps to properly treat silt-laden waters before permitting them to enter the streams. By reason of these restrictions, the disposal of fine sizes becomes a secondary rather than a primary operating consideration, and the procedure for disposing of this refuse becomes a matter of choice governed principally by topographical and geographical conditions. Methods of Handling Refuse There are three principal methods of handling and disposing of fine-size refuse; namely:

Jan 1, 1947

AN announcement of the annual meeting to be held in New York, Feb. 14 to 17 inclusive is being mailed to all members. Particular attention is called to the necessity of asking for certificates when you purchase your ticket in order that all may secure reduced return fares.

Jan 1, 1927

By Walter Herd

Fox the past eight years No. 2 mine of the Cumberland Railway & Coal Co., Springhill, Nova Scotia-a subsidiary of the Dominion Coal Co., Ltd.-has had an unenviable reputation for bumps. As the workings extended in certain directions under a greater cover, these bumps increased in severity and it became apparent that some change in the system of extraction was necessary if the mine was to continue to operate. In September, 1924, following several fatalities resulting from bumps, the Mines Department of Nova Scotia requested from the U. S. Bureau of Mines the services of George S. Rice, Chief Mining Engineer of the Bureau, to report on the conditions then prevalent in No. 2 mine, Springhill. This request was promptly and courteously granted. Mr. Rice made a full investigation and a comprehensive and helpful report, which is embodied in the 1924 Annual Report of the Department of -Public Works and Mines, Nova Scotia. Prior to 1925, the room and pillar method was employed and in January of that year (there being a cessation of work from March to August due to labor troubles) longwall retreating on the west side, on a limited scale, and in a small section on the east side of the mine was started. The major portion of the east side was not operated on this system till August, 1926, as there was developed a considerable area ready for pillar extraction between an arbitrary boundary and a point up to which bumps of any consequence, had not been experienced. In the interval development work for longwall retreating below the 5900-ft. level was vigorously- pushed. This longwall retreating system was suggested by Mr. Rice as a possible remedy and was heartily endorsed by the company officials. This paper describes the conditions and happenings subsequent to Mr. Rice's report and more especially the results with the longwall retreating system of mining under the peculiar circumstances pertaining to mining. No. 2 Seam, Springhill, at depth, and records the 'conclusions which experience with several severe bumps under this mode of extraction would suggest. Except where necessary to make the paper intelligible as an entity any duplication of Mr. Rice's report will be avoided.

Jan 1, 1929

WE the undersigned, being all persons of full age and citizens of the United States, and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 5 of Article I. of said law, the existing unincorporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and file this Certificate for that purpose, and do Certify as follows: I. That the American Institute of Mining Engineers is an unincor¬porated association organized and existing with the object of promoting the arts and sciences connected with the economic production of the useful minerals-and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publi¬cations among its members and associates the information thus obtained. II. That the persons duly appointed or designated to manage the affairs of said association are designated by the rules thereof Members of its Council; that the undersigned are all members of said Council as the same was constituted on the 29th day of December, 1904. III. That on said last-mentioned date a regularly called meeting of said association was held at its office in the Borough of Manhattan, City of New York; that thirty days before such meeting notice of the intention to incorporate said association was given by mail to each member thereof whose residence or post-office address is known; that at said meeting the following resolutions were offered, seconded and duly adopted by the unanimous vote of all its members then present, to wit: "Resolved, That it is the sense of the members and associates of the American Institute of Mining Engineers in general meeting assembled that it is desirable and necessary for the well being of said association and its members and for the furtherance of the objects for which the same has been formed, that said association incorporate under the Membership Corporations Law of the State of New York;

Jan 1, 1923

By Roberts H. Richards

It is nearly twenty years since Dr. Raymond, then U. S. Commissioner of Mining Statistics, wrote the first paper (so far as I have been informed) upon the education of tile mining engineer, as a distinct profession for American youth. At that time nearly all the prominent mining engineers in the country had studied in one or more of the foreign schools, or had reached their high standing through years of experience in the school of life. The paper mentioned five schools in the United States in which some attention was paid to the teaching of mining engineering, but as four of them had barely graduated their first classes, their influence had not begun to make itself widely felt. Two years later the American Institute of Mining Engineers was formed, and it has been a most potent factor in the problem of "disseminating information on mining and metallurgical subjects," so potent that the need of a national school of mines as headquarters for information as well as for instruction is no longer urged. The number of schools also increased, and in 1876 Abram S. Hewitt, in his Presidential address on "A Century of Mining and Metallurgy in the United States,'' gave a list of fourteen. In 1876 the series of discussions, led by Holley's admirable paper, brought the whole subject of technical education before the country. These discussions, while mostly devoted to the engineering professions in general, touched upon the question of mining and metallurgicel training to some extent. Since that time several papers, inspired by the publication of that series of discussions, have appeared in our Transactions, and several notable addresses have been delivered at the opening or at the commencement exercises of various schools. But nothing directly bearing upon the curriculum of the mining and metallurgical schools has ever appeared in our annual volumes. As education is one of the many-sided subjects which cannot be discussed too often, I have ventured to bring it up again. There have been so many good things said upon the subject that one would only need to use the scissors and paste-brush judici

Jan 1, 1887

"The Washoe Smelter is situated about two miles east of the City of Anaconda. The smelter site includes about 240 acres and peculiarly adapts itself in topography to the efficient handling of material. By reason of its being on a hill side it is possible to make the level of delivery of the product of one building the level of the charge floor of the next succeeding one.THE ORES: The ore treated comes principally from the Butte district and is hauled by the Butte, Anaconda & Pacific railway, a distance of twenty-eight miles, in trains of fifty 50-ton bottom-dump cars to the railroad yards at East Anaconda. At this point these trains are• split up according to their destination,—that is, as to whether they go to the concentrator and sampling mill ore bins, or to the storage bins. In each case they are made up into trains of eight or sixteen cars, according to the size of engine to be used, and are carefully weighed before delivery to their respective bills.Some idea of the magnitude of the works may be obtained from the following figures:Amount of ore that can be treated in 24 hours…12,000 tonsLime rock from adjacent quarries…2,300 tonsCoke used…500 tonsCoal for reverberatory use…500 tonsCoal for power use…50 tonsWater, per minute, 35,000 gallons.Men employed in and around Anaconda, 3,000. Monthly payroll for above, $300,000.00."

Jan 1, 1913

By Paul T. Allsman

1.1-1. Current Status. The history of surface mining is essentially that of mining coal, copper, and iron ores, and the nonmetallic minerals--clays, gypsum, phosphate rock, sand, gravel, and stone. Table 1.1-1 is a comparison of the estimated world production of crude metallic and nonmetallic ores and coal with that of the United States for 1964, in short tons. It includes an estimate of the quantity produced by surface mining methods. Two-thirds of the 8.8 billion tons are mined from surface, ranging from a third of the coal, half the metallic ores, and nearly all clays, stone, sand, and gravel. In the United States, production by surface methods parallels that of the world with two major exceptions: 74% of copper ore and 90% of usable iron ore are mined from the surface, whereas outside the country less than 40% of copper ore and only 50% of usable iron ore are mined from the surface. In surface mining of both metallic ores and coal, much waste is stripped, but in mining nonmetallics the ratio between waste and ore is small. Assuming that the stripping ratio for surface mining in the United States will apply equally to world production, it is estimated on a weighted basis that over 21 billion tons of waste, or a total of nearly 27 billion short tons of material, are mined annually in the world by surface methods. Data are not available to confirm the assumption for waste stripping outside the U.S., but the estimate expresses an order of magnitude that is worth noting. Table 1.1-2 shows the materials-crude ore, coal, and waste-mined by surface methods and the relation to total mined by both surface and under- ground methods in the United States during 1964. Eighty-two percent of all crude metallic and nonmetallic ores and coal was mined from the sur- face, including 82% of metallic, 96% of nonmetallic ores, and 35% of coal. Copper and iron ore comprise 83% of the metallic ores mined from the surface, and clays, gypsum, phosphate rock, sand, gravel, and stone

Jan 1, 1968

October 16th, 1872. THE Institute assembled on Wednesday evening at the Western University, and was called to order by President Raymond. Mr. James Park, Jr., of Pittsburgh, made the address of welcome, which was responded to by President Raymond. The Council reported the following names, with approval, for election Ashburner, William, - San Francisco, Cal. Asmus, George, - New York. Baillie, Nathaniel, - Uniontown, Pa. Bowie, A. J., Jr. - San Francisco, Cal. Brown, A. J., - Treasure City, Nev. Butler, J. G., Jr., - Youngstown, Ohio. Chamberlin, J. G., - Leetonia, Ohio. Clark, R. Neilson, - Canyon City, Colorado. Cornell, A. B., - Youngstown, Ohio. De Crano, E. G., - San Francisco, Cal. Engelmann, H., - Salt Lake City, Utah. Faber du Faur, A., - New York. Janin, Louis, Jr., - San Francisco, Cal. Johnson, George J., - Salt Lake City, Utah.. Kent, Joseph C., - Phillipsburgh, N. J. Kent, William St. G., - Phillipsburgh, N. J. Liebenau, Charles von, - Silver City, Idaho. McClintock, A. H., - Wilkes-Barre, Pa. Miller, Thomas N., - Pittsburgh, Pa. Millholland, James A., - Mount Savage, Md. Peters, Ed. D., Jr., - Dudley, Colorado. Reese, Jacob, - Pittsburgh; Pa. Schirmer, J. F. L., - Denver, Colorado. Smith, W. S., - Fairplay, Colorado. Stoelting, Hermann, - Georgetown, Colorado. Sweet, W. A., - Syracuse, N. Y. Tripple, Alexander, - New York. Van Arsdale, W. H., - Swansea, Cal. Willard, Dwight D., - Bordentown, N. J. The following resolution was then offered and passed Resolved, That gentlemen present, not members, be invited to take part in the discussions of the Institute at the various sessions of the present meeting.

Jan 1, 1873

TEE Institute assembled on Wednesday evening at the Western University, and was called to order by President Raymond. Mr. James Park, Jr., of Pittsburgh, made the address of welcome, which was responded to by President Raymond. The Council reported the following names, with approval, for election : Ashburner, William, . . . . . San Francisco, Cal. Asmus, George, . . . . . . New York. Baillie, Nathaniel, . . . . . Uniontown, Pa. Bowie, A. J., Jr., . . . . . San Francisco, Gal. Brown, A. J., . . . . . . Treasure City, Nev. Butler, J. G., Jr., . . . . . Youngstown, Ohio. Chamberlin, J. G., . . . . . Leetonia, Ohio. Clark, R. Neileon, . . . . . Canyon City, Colorado. Cornell, A. B., . , . . . . Youngstown, Ohio. De Crano, E. C., . . . . . San Francisco, Cal. Engelmann, H., . . . . . . Salt Lake City, Utah. Faber du Faur, A., . , . . . New York. Janin, Louie, Jr., . . . . . San Francisco, Cal. Johnson, George J., . . . . . Salt Lake City, Utah., Kent, Joseph C., . . . . . Phillipsburgh, N. J. Kent, William St. G., . . . . Phillipsburgh, N. J. Liebenau, Charles von, . . . . Silver City, Idaho. McClintock, A. H., . . . . . Wilkes-Barre, Pa. Miller, Thomas N., . . . . . Pittsburgh, Pa. Millholland, James A., , . . . Mount Savage, Md. Peters, Ed. D., Jr., . . . . . Dudley, Colorado. Reese, Jacob, . . . . . . Pittsburgh, Pa. Schirmer, J. F. L., . . . . . Denver, Colorado. Smith, W. S., . . . . . . Fairplay, Colorado. Stoelting, Hermann, . . . . . Georgetown, Colorado. Sweet, W. A., . . . . . . Syracuse, N. Y. Tripple, Alexander, . . . . . New York. Van Arsdale, W. H., . . . . . Swansea, Cal. Willard, Dwight D., . . . . . Bordentown, N. J. The following resolution was then offered and passed : Resolved, That gentlemen present, not members, be invited to take part in the discussions of the Institute at the various sessions of the present meeting.

By William G. Pariseau

The extraction ratio approach to pillar design in flat seams is based on a mathematically exact analysis that is a reasonable physical approximation to room-and-pillar layouts in many instances. The essentials of the approach are reviewed and then mathematically approximate formulas for pillar design in inclined seams of arbitrary dip are proposed. Detailed numerical analysis of stress about a typical 5 entry, 4 pillar panel at dips of 0, 15, 30, 45, 60, 75 and 90 degrees at low and high extraction ratios show that the proposed inclined seam extraction ratio formulas for pillar normal and shear stresses, although conservative, have an accuracy quite adequate for engineering purposes. Appropriate pillar safety factors for compressive and shear failure and a safety criterion for overturning are specified.

Jan 1, 1982

By Robert R. Boyd

The gravity discussed here is that of the clean oil produced. Gravities of fluids containing water, free or in the form of emulsion, sand, drilling mud or mineral salts of a nonbituminous nature do not represent the gravity of crude oil as considered in this paper. During recent years it has become a frequent occurrence for operators to be called upon to explain to landowners the reasons for variations in gravity on shipments of oil from wells in which they are interested as royalty owners. In regard to single well leases it has been noted that marked changes in gravity frequently have occurred for no apparent reason. Data collected on the subject and correlated with production methods reveal interesting facts. It is the purpose of this paper to present some of the highlights on the subject. These gravity changes in the natural crude oil are with a few exceptions the result of the liberation under varying conditions of the volatile hydrocarbons from the natural oil-gas solution contained within the pool. The subject of the liberation of gases from natural oil-gas solution has been investigated by Ben E. Lindsly, of the U. S. Bureau of Mines, and the observations recorded here are in the main consistent with his conclusions. Investigators have recognized two methods of liberation of gas from solution—flash and differential. In the latter method the vapors are removed from the liquid as rapidly as formed and have no opportunity to come to a condition of equilibrium with the oil. In flash liberation an equilibrium condition between the oil and the gas exists at the pressure of separation. Mr. Lindsly has found that the method of liberating the gas from the oil has a pronounced effect on the final gravity and that differential liberation results in a higher A.P.I. gravity due to the higher ratio of gasoline producing hydrocarbons left in the oil. Under actual production practices with high velocities in flow strings, it is our contention that conditions of perfect equilibrium between gas and the oil rarely exist, and that gas separation is made under varying conditions, sometimes approaching that of equilibrium and at other times departing from it.

Jan 1, 1937

By E. S. Fisher, L. C. R. Alfred

The elastic anisotropy factors, c4,/c6,, c3,/cll, and c12/cl,, for hcp metal crystals vary significantly among the dgferent unalloyed metals. Significant variations with temperature are also found. The effects of elastic anisotropy on the dislocation in an elastic continuum with hexagonal symmetry have been investigated by computing the elasticity factors for the self-energies of dislocations in fourteen different metals at various temperatures where the elastic moduli have been reported. For most of the metals the effects of the orientation of the Burgers vector, dislocation line, and glide plane are small and isotropic conditions can be assumed without significant error. Significant effects of anisotropy are, however, found in Cd, Zn, Co, Tl, Ti, and Zr. The elasticity factors have been applied in the calculations of dislocation line tensions, the repulsive forces between partial dislocations, and the Peierls-Nabarro dislocation widths. It is predicted that the increase in elastic anisotropy with temperature in titanium and zirconium makes edge dislocations with (a), (a + c), and (c) Burgers vectors unstable in basal, pyramidal, and prism planes, respectively. The probability of stacking faults forming by dissociation of Shockley partials in basal planes also decreases with increasing c4,/c6, ratio, when the stacking fault energy is greater than 50 ergs per sq cm. The widths of screw dislocations with b = (a) in titanium and zirconium increase very significantly in prism planes and decrease in basal planes as c4,/c6, increases. The effects of elastic anisotropy on various dislocation properties in cubic crystals have received considerable attention during the past few years. In the case of cubic symmetry the departure from isotropic elasticity depends entirely on the shear modulus ratio, A = 2c4,/(cl, —c12); i.e., the medium is elastically isotropic when A = 1. Foreman1 showed that an increase in the ratio A produces a systematic lowering of the dislocation self-energy for a given orientation and Poisson's ratio. ~eutonico~, has shown that large anisotropy can have a marked effect on the formation of stacking faults by the splitting of glissile dislocations in (111) planes of fcc and (112) planes of bcc crystals. ~iteK' made similar calculations for (110) planes of bcc metals. Both studies of bcc metals showed that the large A values encountered in the alkali metals tend to reduce the repulsive forces between Shockley partial dislocations. In fcc metals, however, A does not vary over the large range encountered in bcc metals; consequently, the effect of A on the forces between Shockley partials is masked somewhat by the differences in Poisson's ratio between metals. The effect of A on the line tension of a bowed out pinned dislocation has also been investigated for cubic crystals, first by dewit and Koehler5 and more recent- ly by Head.6 In both cases the line energy model is applied and the core energy is not taken into account, thus making the conclusions somewhat tenuous with regard to the physical interpretation. Nevertheless, the fact that a large A decreases the effective line tension is clearly evident and the tendency for large A to produce conditions that make a straight dislocation unstable (negative line tensions) also seem evident. Head, in fact, shows visual microscopic evidence that stable V-shaped dislocations occur in 0 brasse6 For hcp metals the definition of elastic anisotropy is more complex and, furthermore, significant deviations from an isotropic continuum are found among a number of real hcp metals, especially at higher temperatures. The present work was carried out to survey the effects of elastic anisotropy on the elasticity factors, K, that enter into the calculations of the stress fields around a dislocation core. Some isolated analytical calculations have previously been carried out for several hcp metals but they are restricted in the dislocation orientations and temperature.8'9 The present computations are based on single-crystal elastic moduli that have appeared in the literature and consider various orientations requiring numerical computations. The results are then applied to survey the effects of temperature on the dislocation line tension and dislocation splitting in hcp metals. PROCEDURE Anisotropy Factors. The degree of elastic anisotropy in hcp crystals cannot be described by a single parameter, such as the A ratio in cubic crystals. The following three ratios must be simultaneously equal to unity in order to have an elastically isotropic hexagonal crystal: The magnitudes of these ratios at several temperatures, as computed from the existing data for the elastic moduli of unalloyed hcp metals, are given in Table I. There are no cases of complete elastic isotropy, but the large anisotropy ratios encountered in the cubic alkali metals are also missing. There are, however, several significant differences among the hcp metals, the most notable being the relatively small A and B ratios in zinc and cadmium and the differences in the magnitudes and temperature dependences of A. It has been noted that the temperature dependence of A has a consistent relationship to the occurrence of the hcp — bcc tran~formation. For cadmium, zinc, magnesium, rhenium, and ruthenium, A is less than unity at 4'~ and, with exception for rhenium, decreases with increasing temperature. In the case of rhenium, A has essentially no temperature dependence between 923' and 1123"~, so that it is clear that A does not approach unity at higher temperatures. Cobalt is similar to the above-mentioned group of metals in that it also does

Jan 1, 1969