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By Charles R. Fettke

In the present day manufacture of glass nearly pure quartz sands are used almost exclusively as the source of the silica, which is the major constituent of all common varieties of glass. Ordinary soda-lime, such as bottle, common tableware, plate, and window glasses, contains from 65 to 75 per cent. of silica. Occurrence Glass sands occur in nature either in the form of loose, unconsolidated sediments or in deposits in which the individual grains have been more or less thoroughly bound together by some cementing agent so as to form sandstones. While deposits of sand and sandstones occur both widely and abundantly distributed, deposits that are sufficiently free from other constituents than quartz grains, so that they can be employed in the manufacture of the better grades of glass, are, comparatively speaking, of rare occurrence. The major portion of the glass sand produced in the United States comes from sandstones. In order to be suitable for glass sand, they should be rather friable. The rock should break down readily along the cementing material between the grains and should not break across the grains rather than along the bond. Some of the sandstones used are so friable that only light shots of slow-burning dynamite are necessary to disintegrate them sufficiently for hydraulic mining, while others have to be passed through crushers in order to disintegrate the rock into its individual grains. MINERALOGICAL COMPOSITION An ideal glass sand is made up entirely of grains of the mineral quartz free from inclusions of foreign substances. Sands containing 100 per cent. silica, however, are not found in nature, although some very nearly approach this composition.

Jan 1, 1926

By J. R. Thoenen

THE consensus of opinion in the published literature on. Grecian magnesite is that it has been formed by alteration of the serpentine, which in turn was itself a product, of metamorphism from the original olivine intrusion. The general opinion seems to be that the magnesite was formed by descending waters heavily charged with CO2. Inasmuch as this opinion is held by engineers far better qualified than I to speak authoritatively on this subject, I hesitate to dispute that theory. However, certain occurrences coming under my observation do not, to me at least, seem to-entirely substantiate this theory. LOCATION Most of the Grecian magnesite comes from the Island of Euboea, although more recently some deposits have been opened on the mainland near the City of Saloniki, which prior to the war was Turkish. The island, comprising a state or province in the Greek political structure, is roughly 110 miles long and varies from 10 to 30 miles in width. It lies off the east coast of the Greek peninsula in the AEgean Sea with its long axis extending in a northwest-southeast direction. It is separated from the mainland by a long narrow arm of the sea known as the Atalanti Canal. Chalkis (Halkis), the capital on the west coast of the island, is the northern terminus of a branch of the state-owned railway and is connected with the mainland by a single-span, movable, highway bridge, roughly 150 ft. long.

Jan 1, 1928

By William Crane

OPERATORS of diamond drills have long been familiar with thread-like markings or riflings on cores but apparently have given but little serious thought to the conditions that are responsible for their production. The opinion generally held by those who have observed the phenomena is that the riflings are produced directly or indirectly by vibration, but so far as the writer is aware no systematic attempt has been made to demonstrate the fact. A careful search through the literature on diamond-drilling practice has been rewarded by only one reference to such markings of cores. J. N. Justice1 writes, "Of the peculiarities met with in the core, I will mention only one. The core from the "H" drill, at about 360 ft. came out rifled and pentagonal. The change from the circular to the pentagonal was sudden, and for 9 ft. this structure was maintained, when suddenly it returned to the circular. I have not been able to find any one who can explain the cause of this change of form. The drill men marveled at it and suggested vibration, six-stone bits, and several other hypotheses Which need not be mentioned." The writer became interested in the matter of core riflings some 10 years ago while in the Flat River lead region of Missouri, where many remarkable examples of "rifled" cores were observed and collected. Since that time similar phenomena have been observed in various localities throughout the United States and Canada, and samples have been gotten together illustrating a large number of variations in form. After a careful study had been made of the material at hand it seemed desirable that certain data should be obtained from the experience of others regarding the normal action of diamond drills in forming cores, portions of which are occasionally rifled, before an attempt was made to draw any conclusions as to their cause.

Jan 5, 1916

By John K. Berry

The handling and disposal of mine water is a much larger problem than is apparent at first glance. Many more tons of water are removed from underground coal mines in the United States each year than tons of coal. In the old anthracite region of Pennsylvania the average was around 36 tons of water for each ton of coal produced, while bituminous mines average about 5 or 6 tons. Water encountered in the mines may come from several different sources. In mines with light cover and without a firm solid roof, rain may seep directly into the workings. This is also true of deeper mines where pillar falls have broken the roof to the surface. The top under creek beds is generally faulty and broken and water comes through the roof at this point. Deeper mines are frequently overlain by water-bearing strata and pillar breaks and faulty top can admit water, while places running to the dip often accumulate water which comes up through the bottom. In all cases, except where passing under a year-round stream, the amount of water made is usually pretty closely connected with the weather-more water during the rainy season, less in the dry, although the deeper a mine is, the longer it is before changes in rainfall are felt. Another source of water, not connected with seasonal changes, is old water, accumulated over a period of time in abandoned workings of the mine, or from flooded adjacent mines. Here the water filters through the coal, the parting, or comes up through cracks in the bottom. Similarly, core holes, drilled to prospect the property, can be a source of unexpected water and modern safety requirements for dust-allaying water at the working faces can turn a pleasant working area into a soggy mess over the weekend if the system is not properly maintained and operated. Why water must be disposed is obvious. If allowed to accumulate, sooner or later the mine will fill up, or at least it will become "roofed" in low places, blocking ventilation and traffic. But it must also be controlled long before it reaches this stage. Water standing in the working faces is unpleasant for the men who have to work there and also cuts down on the amount of work they can do, as they must watch where they step all the time. It is especially unpleasant in low coal.

Jan 1, 1973

By Alfred E. Hunt

Tars paper is suggested by the appointment on the part of the American Societies of Mechanical and of Civil Engineers of committees upon the subjects of " Standard Tests and Methods of Testing," and " Uniform Methods of Tests of Material used in Metallic Structures," respectively, and by a study of the report of one of these committees, and other papers. Moreover, the writer has had frequent occasion to hear the complahts of tnanufacturers who furnish structural material subject to specifications, that in the tests prescribed, the number of tests required, and the methods of making

Jan 1, 1892

By N. J. Grant, K. M. Zwilsky

A series of copper-alumina dispersion strengthened alloys were prepared using three different copper and two different alumina powder sizes. Improvements in strength of up to ten times that of pure copper were found in room-temperature as well as elevated-temperature stress-rupture tests. Conductivity values remained from 70 to 90 pct that of pure copper. The best alloys were based on the finest metal powder (1 p) and contained from 7.5 to 10-0 vol pet of 0.018 or 0,033 p alumina. DISPERSION strengthening of metals consists of strengthening a metal matrix by the addition of oxides or other refractory constituents, followed by strain hardening, in order to reinforce the base material and extend its temperature range of application. Since the discovery of SAP by lrmannl and Von zeerleder2 in 1949, many investigators have reported data obtained on a variety of metal-inert oxide alloys.3-7 The present work deals with the mechanical mixing of copper and alumina powders. While several techniques of introducing the second phase have been investigated to date, mechanical mixing so far has been recognized as the simplest, least expensive, and most universally applicable technique that can be used to obtain an ultrafine dispersion of inert particles. In the present case, the effects of changing the metal particle size, the oxide particle size and the volume percent of oxide were investigated. This work is an extension of a previous study.6 EXPERIMENTAL PROCEDURE The starting materials were three different grades of copper powder and two different alumina powders. The three metallic powders were -74 µ(- 200 mesh) electrolytic copper powder consisting of irregular equiaxed particles having a normal screen distribution and analyzing 99.5 pct Cu, and two powders having a 5-µ and 1-µ particle size, average, respectively. The latter powders were produced by the hydrogen reduction of purified sulfate solutions at elevated temperature and pressure and were furnished by the Sherritt Gordon Mines, Ltd. The alumina used was obtained from Godfrey L. Cabot Co., under the trade name of Alon C, one batch of powder having a particle size of 0.018 µ, the other a particle size of 0.033 µ. The crystal structure of these alumina powders was found to be cubic gamma. Each batch of powder was mixed in a Waring Blendor for a total of 15 min, followed by a low-temperature reduction in hydrogen and vacuum compacting in cylinders which were hydrostatically pressed at 35,000 psi to give a compact that could be handled conveniently. Six of the compacts were hydrogen sintered at 900°C while the remaining four were sintered at 1000°C. Subsequently, all compacts were hot extruded at 760°C with a reduction of area ratio of approximately 20 to 1. Evaluation of alloys included density and resistivity measurements, room-temperature tensile tests, stress-rupture tests at 450°C plus one other temperature per alloy, hardness tests, microstruc-tural examination, X-ray analysis of the dispersed phase after dissolving the metal phase, and oxidation studies on two of the alloys. A vacuum-melted, wrought copper rod was tested together with these alloys for comparison purposes. RESULTS Table I is a summary of the compositions, sintering temperatures, densities and conductivity values of the ten alloys prepared. All alumina additions are given in volume percent, and will be referred to as

Jan 1, 1962

By J. B. Dorsey, T. W. Brinkley

Performance of a high-pressure, vaporizing gas-drive project in a volatile oil reservoir is discussed. The project has been in operation for over 8 years. Present recovery from the over-all displaced portion of the reservoir is 40 percent, and an ultimate recovery of 60 percent is indicated. Calculations reflect an over-all displacement volume of 50 percent for the entire reservoir; therefore, ultimate oil recovery will be 30 percent of the entire reservoir oil originally in place. Laboratory vaporization tests conducted prior to project initiation also are presented and discussed, along with an analytical method of determining stock-tank oil production and gar injection requirements related to over-all volumetric displacement efficiency from these data. Introduction The Shoats Creek field is located in Beauregard Parish, La., in the extreme western part of the state (Fig. 1). Discovered in 1956, the field is productive in three Cockfield sand zones, ranging in depth from 8,000 to 9.000 ft. The upper two zones, 1st and 2nd Cockfield, are condensate-bearing gas reservoirs. The lowest zone, the 5th Cockfield, is a volatile-oil reservoir. Laboratory work conducted on crude oil from the 5th Cockfield zone shortly after field discovery demonstrated that, when contacted with dry gas, signidcant volumes of the oil could be vaporized at reservoir temperature and at an appropriately high reservoir pressure. Further study led to the conclusion that early initiation of a crude vaporization project in the 5th Cockfield zone would be superior economically to other methods of reservoir depletion. Consequently, the zone was unitized and gas injection operations started late in 1958. This paper discusses laboratory work performed in conjunction with the project, and project performance to the present. History of Development The 5th Cockfield zone in Shoats Creek is composed of a thin, very shaly, low-permeability sandstone. Oil accumulation is controlled by a structural trap bounded by faults along the north and west and by a water contact on the southern boundary (Fig. 2). The zone covers a productive area of 1,550 acres at an average depth of 9,000 ft. The net sand section is thin, having a maximum thickness of 10 ft and an average thickness of 5.5 ft (Fig. 3). Average reservoir rock properties, as determined from core analysis are presented in Table 1. Shaliness of the zone is illustrated by the typical electric log of the 5th Cockfield section in Fig. 4. Because of the thinness and poor quality of the sand, the 5th Cockfield was developed on a wide spacing. Eleven completions were made in the zone between 1956 and 1961 for an average density of 140 productive acres per completion, with the majority of wells being dually completed in the 2nd and 5th Cockfield. Average initial potential for producers in the 5th Cockfield was 130 BOPD. Oil from the 5th Cockfield has a stock-tank gravity of 50.5" API; with a bubble-point pressure of 3,515 psia, the oil was highly undersaturated at the original reservoir pressure of 4,675 psia. Pertinent properties of the oil as determined in the laboratory are presented in Table 2. Because of the volatile nature of the crude, laboratory studies of its susceptibility to vaporization, as well as a vapor-liquid phase study, were conducted in addition to a standard PVT analysis. The vaporization study was conducted in a visual cell; a stepwise illustration of this work and laboratory measurements are presented in Fig. 5. Field

Jan 1, 1969

By C. Zener

HE present paper has its origin in an attempt A by the author, extending over the last several years, to understand the influence of the magnetic properties of the constituent atoms upon the various properties of metals and alloys. During this study the author has been impressed by the important role which magnetism plays in the many facets of metallurgy. In writing this paper he has attempted to convey to his colleagues some concept as to the role magnetism will play in the future development of metallurgy. In some of the subjects herein discussed, such as the influence of magnetism upon phase boundaries and upon mechanical properties, only general thermodynamical properties associated with ferromagnetism are introduced. For these subjects, it is not anticipated that any serious differences of opinion will be encountered. A discussion of the other subjects requires the adoption of a quite specific model of the magnetic structure of the metal. This model is discussed under "Magnetic Shells and Their Interactions." The simple model adopted in this paper has been criticized' as being mathematically inconsistent. This criticism has been ably silenced by Dr. W. J. Carr' of this laboratory. The simple model adopted in this paper has been criticized as being inconsistent with observations on magnetic structure using neutron diffraction. This apparent discrepancy has been resolved by Bader3 who has shown that the finite velocity of neutrons prevents neutron beams from detecting the anti-ferromagnetic structure of the type predicted by the simple model adopted in this paper. Magnetic Shells and Their Interactions An electronic shell of an atom is specified by two symbols.' The first symbol is a number and denotes the total quantum number of the shell. The second symbol is a letter and denotes the orbital angular momentum of each electron within the shell. The letters s, p, d, f are used to denote an orbital angular momentum of 0, 1, 2, 3, respectively, in units of h/2a, where h is Planck's constant. As we pass from scandium to nickel in the first transition period, we eraduallv fill the 3d shell. This shell is responsible for ferromagnetism and hence may be called the magnetic shell. The component of the orbital angular momentum along some specified direction must be an integral multiple of h/2~. Thus, for a d electron this component can have any one of the values —2, —1, 0, 1, 2 times h/2a. In addition to its orbital angular momentum, each electron has an intrinsic angular momentum, hereafter called spin, due to a rotation about its own axis. This spin can have either of two components + Yz (h/2a) or — Yz (h/2~) along the specified direction. A fundamental principle of atomic structure, known as Pauli's exclusion principle, is that no two electrons in a given shell may have identical components of orbital angular momentum simultaneous with identical components of spin. The 3d shell thus may have at most ten electrons. Since an intrinsic angular momentum of a charged particle is necessarily associated with a magnetic moment, the spin of an electron may be thought of as referring to either this angular momentum or to the associated magnetic moment. The electron configuration of the ground state of the isolated atoms in the first transition row is reproduced in Table I. The superscript represents the number of electrons in each shell. For the purpose of this paper, the most important principle of atomic structure relates to the manner in which electrons are added to a shell as the atomic number is increased. This principle, commonly known as the principle of highest multiplicity or more simply as Hund's rule, states that within a given shell the maximum number of electrons have spins pointing in the same direction as is consistent with Pauli's exclusion principle. An application of this principle to the d shell is illustrated in Fig. 1, where the spin structure is given for shells containing from 1 to 10 electrons. The physical basis of Hund's rule is the exchange energy discussed first by Heisenberg in 1928. This is a coupling between electrons with parallel spins (spins pointing in the same direction), the coupling

Jan 1, 1956

By Carle R. Hayward

This work was first undertaken in the metallurgical laboratory of the Massachusetts Institute of Technology in 1907 by L. A. Dickinson, E. Phelps, and V. S. Rood, under the author's direction. They attempted to determine the diagram for the system Cu2S-MiS, but several inexplicable results were obtained. The following year, P. H. Mayer with Mr. Dickinson carried on some experiments with nickel sulphide and found that the molten material slowly lost sulphur until it reached a composition corresponding to the compound Ni3S2, established by Bornemann.l At this point the composition remained stable. The freezing points of the mixtures gradually fell off with the loss of sulphur. Since the above facts seemed to explain the erratic results obtained in the first experiments, Mr. Mayer with F. Jaeger attempted in 1910 to establish a correct equilibrium diagram for the Cu2S-Ni3S2 series. They prepared pure Cu2S and Ni3S2 and determined the cooling curves for various mixtures. The fusions were made in a platinum resistance furnace and the temperatures were measured with a platinum-iridium thermocouple connected with a Sullivan galvanometer. The curve was established for mixtures containing more than 40 per cent. Cu2S, but they were unable to determine certainly the direction of the curve beyond that point. Nothing further was attempted with this series until the present year, when the work was carried to a successful conclusion with the assistance of A. Butts, Jr., and E. H. Weil. The results of this work are given in the following pages. Preparation of Cu2S.—A piece of cathode' copper from the Buffalo plant of the Calumet & Hecla Co. was cut into shavings by a shaper and converted into sulphide by heating in boiling sulphur. A porcelain casserole was used for the purpose, the heat being furnished by a Bunsen burner. It was found that after boiling in the sulphur for an hour the copper shavings were completely converted into sulphide. The liquid sulphur was then poured off, leaving the solid sulphide in the casserole in

Jan 1, 1915

By C. Ernest Birchenall, Robert F. Mehl

Application of diffusion laws in the customary form to experimental studies in binary metallic solid solutions has shown the diffusion cocfficient to vary with concentration for all systems investigated. The factors determining this variation have not been ascertained. However, the question of whether the diffusion coefficient would become a constant, independent of concentration throughout a single phase if the concentration gradient in the diffusion equation were replaced by an activity gradient has been an attractive subject for speculation. Wagner¹ derived an expression for the force acting on a diffusing particle in terms of the chemical potential. This was also the approach chosen by Jost2 in his monograph. From a somewhat different point of view, Eyring3 and his co-workers have used activity gradients when dealing with diffusion in concentrated nonideal solutions. The only actual test with experimental data is that given by Darken,4 though this is more qualitative than quantitative. Many others opposed the application in any way of thermodynamic concepts to kinetic phenomena, including diffusion processes. A rigorous examination of this principle requires good data expressing the relationship between activity and concentration for solid solutions for which reliable diffusion work has been done. The literature provides such information only for the interstitial solution of carbon in gamma iron (austenite) and for the substitutional copper-zinc solutions (alpha brass). Activity data for carbon in austenite at 800°C and 1000°C are available from the recent work of Smith5 on the equilibrium of hydrogen-methane and carbon monoxide-carbon dioxide mixtures with gamma iron. Combining these with the diffusion studies of Wells and Mehl6 makes possible a quantitative test for this interstitial solid solution. The vapor-pressure determinations for zinc over brass by Hargreaves7 allowed the calculation of activities in this system over a wide range of temperatures and concentrations. Extensive investigation of diffusion in this substitutional solid solution has been carried out by Rhines and Mehl.8 Activities in Brass9 If the vapor phase of zinc is assumed to behave as an ideal gas, any solid or liquid solutions that are in equilibrium with the same partial pressure of zinc at the same temperature have the same thermodynamic activity of zinc. In order to assign a numerical value to the activity azn, it is necessary to choose some standard reference state to which an activity value of unity is arbitrarily assigned. It is customary to choose the liquid or solid state of the pure material. Then azn is defined numerically by

Jan 1, 1947

By G. R. Gardner, D. H. Davis

INCREASING realization of the importance of dust control, and the recommendations of various agencies, have led the mining industry to become actively concerned with this problem. The background and necessity for adequate dust-suppression measures have been discussed in a number of publications, including those of the U. S. Bureau of Mines, and the use of spray water to reduce dust at the face and on roadways has been recommended. The problem resolves itself into obtaining adequate dust reduction at a reasonable cost. Inasmuch as the term "adequate dust suppression" has never been clearly defined, nor have permissible limits of dustiness (in terms of dust count) been established, it is apparent that any method selected may be required to meet additional demands. Until the industry has been given some indication of permissible limits of dustiness, no permanent solution is possible. Progress will be somewhat handicapped until such information is available. In addition, dust reduction must be obtained without the addition of any excessive moisture to the coal, since consideration must often be given to: I. Quality standards, particularly reduction in heat value. 2. Handling characteristics, particularly in regard to unloading from railroad cars and bins. 3. Application of dry methods of coal cleaning. 4. Necessity for fine screening within specified limits of oversize and undersize. Little detailed information is available as to the advantages and disadvantages of the several methods of water distribution, the location and protection of sprays, operating data on pressure, quantity of water, and so forth, and results obtained. In 1940 an investigation was undertaken to determine and evaluate the principal factors involved. This paper constitutes a progress report on this work and cannot in any way be regarded as complete on any one of the several phases. CLASSIFICATION OF DUST SOURCES The various sources of underground dust may be classified as primary or secondary. A primary source is one associated with appreciable degradation of size, that is, where the greater part of the actual fines capable of becoming air-borne dust are produced. A secondary source may be considered as one in which the greater part of the fines have been produced at some previous operation and are in such condition that they can be dispersed as air-borne dust. These conceptions appear to be of practical significance, as experience indicates that when dust is controlled at the primary sources the importance of secondary sources is minimized. For these reasons, investigations to date have been concerned principally with the primary sources of dust, and this paper is concerned particularly with one of these-namely, undercutting. In accord with the foregoing definitions, the sources to which the following opera-

Jan 1, 1942

By C. Ernest Birchenall, Robert F. Mehl

Application of diffusion laws in the customary form to experimental studies in binary metallic solid solutions has shown the diffusion cocfficient to vary with concentration for all systems investigated. The factors determining this variation have not been ascertained. However, the question of whether the diffusion coefficient would become a constant, independent of concentration throughout a single phase if the concentration gradient in the diffusion equation were replaced by an activity gradient has been an attractive subject for speculation. Wagner¹ derived an expression for the force acting on a diffusing particle in terms of the chemical potential. This was also the approach chosen by Jost2 in his monograph. From a somewhat different point of view, Eyring3 and his co-workers have used activity gradients when dealing with diffusion in concentrated nonideal solutions. The only actual test with experimental data is that given by Darken,4 though this is more qualitative than quantitative. Many others opposed the application in any way of thermodynamic concepts to kinetic phenomena, including diffusion processes. A rigorous examination of this principle requires good data expressing the relationship between activity and concentration for solid solutions for which reliable diffusion work has been done. The literature provides such information only for the interstitial solution of carbon in gamma iron (austenite) and for the substitutional copper-zinc solutions (alpha brass). Activity data for carbon in austenite at 800°C and 1000°C are available from the recent work of Smith5 on the equilibrium of hydrogen-methane and carbon monoxide-carbon dioxide mixtures with gamma iron. Combining these with the diffusion studies of Wells and Mehl6 makes possible a quantitative test for this interstitial solid solution. The vapor-pressure determinations for zinc over brass by Hargreaves7 allowed the calculation of activities in this system over a wide range of temperatures and concentrations. Extensive investigation of diffusion in this substitutional solid solution has been carried out by Rhines and Mehl.8 Activities in Brass9 If the vapor phase of zinc is assumed to behave as an ideal gas, any solid or liquid solutions that are in equilibrium with the same partial pressure of zinc at the same temperature have the same thermodynamic activity of zinc. In order to assign a numerical value to the activity azn, it is necessary to choose some standard reference state to which an activity value of unity is arbitrarily assigned. It is customary to choose the liquid or solid state of the pure material. Then azn is defined numerically by

Jan 1, 1947

By Samuel S. Wyer

The art of natural-gas compressing is now over 25 years old, and has grown at practically the same rate as the increase in domestic natural-gas consumers. There are now over 200 natural-gas compressing stations in North America, aggregating more than 320,000 hp. of compressor capacity and representing a property value of more than $22,000,000, and compressing more than 85 per cent. of all the gas used. The age and magnitude of the art make it evident that the use of gas compressors is a recognized integral part and universal custom of the natural-gas business. The public also is not without its rights and vital interests in this problem. Approximately 1,700,000 domestic natural-gas consumers in North America are dependent upon gas compressors for their natural-gas service. That is, if the use of compressors were to be prohibited, the majority of these consumers would be unable to secure adequate natural-gas service. Each consumer represents between four and five persons, and it therefore follows that the comfort and well-being—as far as natural-gas service is concerned—of at least 8,000,000 persons would be affected if the use of natural-gas compressors should be prohibited. These 1,700,000 consumers have invested, in services, house piping, fixtures, and appliances, an average of about $90 each, or an aggregate of $153,000,000, which is much more than the companies' investment in gas compressors. Furthermore, in all cases where the rate paid by the consumers is fair to the gas company—considering the value of the service rendered by the gas company—the consumers are entitled to continued service and protection of the investment they have made on the faith that the gas service would be continued in the future. Since "Customs adopted and acquiesced in, if not in conflict with federal or State legislation, have the force of positive law,"l and ('Courts will take notice of whatever ought to be generally known withxn the limits of their jurisdiction,"2 there ought to be no question as to the un-

Jan 1, 1916

By W. L. Fink, R. S. Archer

THIS paper describes results obtained on aluminum-beryllium alloys and aluminum-beryllium-copper alloys in the preparation of which aluminum of 99.95 per cent. purity was used. The constitution and structure of the high purity binary alloys are given. The aluminum-beryllium eutectic occurs at 0.87 per cent. beryllium and 645° C. The solid solubility of beryllium in aluminum at 631° C. is 0.05 per cent. beryllium, and at room temperature is less than 0.013 per cent. beryllium. The densities of the alloys are substantially the same as the values calculated on the assumption that the densities of the elements are not changed by alloying. All of the alloys age-harden at room temperature after a solution heat treatment, and the chill cast aluminum-beryllium-copper alloys age-harden at room temperature without a prior solution heat treatment. Hardness and tensile properties are given. Salt spray corrosion tests on sheet specimens are described. It is shown that beryllium does not lower the corrosion resistance of aluminum to salt spray provided the alloy has received a solution heat treatment. COMMERCIAL POSSIBILITIES OF BERYLLIUM ALLOYS Beryllium has certain properties such as low density, high hardness, good corrosion resistance, low thermal expansion and fairly good electrical conductivity, which would indicate that it is worthy of consideration as an ingredient of light alloys. It was not until recently, however, that beryllium could be produced with sufficient ease to encourage research along this line. The production of beryllium by electrolysis from a fluoride bath has now developed to the stage where it could be used commercially if there were sufficient demand for the element. Claims made in certain newspapers and technical articles in regard to the strength and corrosion resistance of the aluminum-beryllium alloys are not justified by experimental results. Moreover, beryllium is an expensive metal ($200 a pound at the time this work was done) and, on account of the nature of its ore and the consequent difficulty of its extraction, it will in all probability continue to be a relatively expensive metal, although the cost would undoubtedly be a great deal less than $200 a

Jan 1, 1928

By W. P. Sykes

SEVEN years ago, Dr. S. L. Hoyt1 presented a masterful discussion of the hard metal carbides and cemented tungsten carbide. His lecture summarized most of the data then available in the field; many of the details relating to the production, properties and structure of cemented tungsten carbide had never been previously published, for, in fact, this information was only then being acquired. During the intervening years, the cemented carbides have assumed a place of real importance in the commercial field, with an ever widening variety of applications due to constant improvement in the control of production technique and the unremitting search for new compositions that might better the performance of the alloys in one or another type of service. The most recent summary of production methods, properties and guides for the successful application of the cemented carbides appears in the 1936 edition of the Metals Handbook. Of necessity, much detailed information relating to structures and physical properties is not included in such a summary, and it is with such details that the present discussion is concerned. STEPS IN PREPARATION While the past 25 years have contributed a valuable store of working knowledge in the field of powder metallurgy, many of the process controls are derived entirely from experience and are not as yet finally explained by a specific physical or chemical phenomenon. For most of the cemented carbides such difficulties are aggravated by our lack of knowledge not only of the complex alloy systems involved, but also by the possible changes in structure and even in composition which may accompany variations in temperature, heating time, and furnace atmospheres. The principal steps in the preparation of these cemented carbide alloys are fairly well known, but to supply a foundation for discussion these steps are briefly outlined as follows: 1. Formation of the metal carbide in the form of powder by heating a mixture of carbon and the metal powder or oxide for several

Jan 1, 1938

By Bruno V. E. Nordberg

Hoisting is one of the earliest endeavors of man with machinery, for hoisting was probably used by the early Egyptians. Treadmills were used for general hoisting until early in the nineteenth century and it was a short step only to attach a Watt steam engine to the rope drum of a hoist. One of the earliest steam hoists was built for a coal mine at Frisne, near Valenciennes, France. It was a remarkable piece of engineering created by James Watt in 1811, using a wooden drum on a vertical shaft. This followed the crude hoist by Holtzhausen in 1803, which used a drum of wood on a horizontal shaft.' In this country there were examples of crude mine hoists, which have been developed into the efficient machines in use today. African and Australian mines show examples of both extremes, and have an array of fine hoisting equipment exemplified in those built by British manufacturers. The influence of both English and American engineering in hoisting is interestingly evident in Canada. The information available to the writer does not reveal this to be true of South Africa, although American-built hoists have been furnished. Mining camps develop their own style of equipment, adapted to local conditions. For instance, the Butte mining district adheres to the straight drum with friction clutches, because of the great number of levels from which hoisting is done or to which men and material are lowered and the necessity for hoisting or lowering unbalanced. The north Michigan copper country uses both straight and cylindroconical drums and hoists continually in balance, so that the drums are not clutched to the main driving shaft. The Joplin mining district, Missouri, has its own peculiar small hoists. Other individual mines or localities in which a number of mines have been developed show individualistic types of hoists, depending upon their particular problems. In each instance, however, the particular problem must be carefully analyzed, as conditions are seldom so near the same that a number of identical hoists can be used to advantage.

Jan 1, 1940

By Robert A. Colten, Frederick C. Hull, Robert F. Mehl

It is known that pearlite forms from austenite by a process of nucleation and growth, and that the rate of formation of pearlite may be described by a rate of nucleation and a rate of growth.l,2 The manner in which these two quantities operate to produce the observed isothermal reaction curve has been analyzed in a paper published in I939.3 Two types of process were described: (I) that in which nucleation occurs at the grain boundaries of the parent phase, with the nodules growing toward the centers of the grains, initially as hemispheres and then after impingement as roughly radial-columnar structures; and (2) that in which nucleation occurs generally, with the nodules growing to full spheres until impingement with other growing nodules restricts growth. Both cases are met in the formation of pearlite from austenite (Fig. I);2,4 the former, occurring near the knee of the S-curve, has been named "grain-boundary transformation," and the latter, occurring at temperatures near Ael, has been named "group-nodule transformation." In developing our knowledge of the factors that determine the rate of formation of pearlite from austenite, it is important1,2 to obtain data on the rate of nucleation and the rate of growth of pearlite. Such data, when obtained near the knee of the S-curve, will furnish information of use in understanding the factors that affect hardenabil-ity; when obtained at higher temperatures, such data will be useful in understanding the behavior of steels that during heat-treatment react to pearlite.2 It is the purpose of this paper to present data on the rate of nucleation and the rate of growth of pearlite in dependence upon composition, grain size, temperature, and the degree of homogeneity of the parent austenite. The studies are restricted chiefly to plain carbon commercial steels." Previous Data on Rate of nucleation and rate of Growth Data on the rate of nucleation and the rate of growth of pearlite have been published by Scheil and Lange-Weise,5 by Mirkin and Blanter,6,7 by Meh1,l and by Dorn, De Garmo and Flanigan.2, It is difficult to interpret the data, for in most cases too little information is given on austenitizing temperatures and times, the state of homogeneity of the austenite (presence or absence of carbide, etc.), austenite grain size, and mode of formation of pearlite at the temperatures given. Except for the approximations of Mehl and the work of Dorn, austenite grain size was disregarded, though it is well known

Jan 1, 1942

By W. H. Bassett

ALTHOUGH brasses and bronzes have been made for ages, a systematic study of their physical properties has been carried out only during the years of the present century. Among these properties may be included those which are to be detected by means of microscopic examination; in other words by the science of metallography. The earlier workers in this field, both in this country and abroad, gave their attention to steel. When the senior author explored the situation in 1902, there was little encouragement to be found in undertaking the study of the non-ferrous alloys. A start was made, and the metallography of the brasses and bronzes, as well as of the copper-nickel- zinc alloys developed materially under his direction. Annealing experiments were begun in 1902, and in the succeeding years the effect of temperature, and the influence of previous working, on the grain size of brass were studied. The conclusions so well known and widely published today were largely reached during those earlier years. In 1905 the first complete annealing series were made. By this it is meant that brass and copper sheet, 5 B & S Nos. hard, was machined into tensile test specimens, then annealed under accurate control for 30 min. at temperatures up to the melting point of the material. Various determinations were made, including tensile strength and elongation in 2 in. There rapidly followed similar series on all of the copper-zinc alloys from 100 to 60 per cent. copper, on the bronzes, cupronickels, and on copper-zinc-nickel alloys. At this point there was published by Grard, in October, 1909,1 the very comprehensive and complete work on the tensile properties of cartridge brass, 90-10 copper-zinc, and electrolytic copper. The excellent photomicrographs in that paper illustrated the changes in structure produced by cold rolling as well as by annealing at different temperatures, but where Grard's work was confined to copper and to two alloys, the investigations in this laboratory have been over the entire fields of the commercial copper-zinc alloys, copper-tin alloys, representative copper-nickel and copper-nickel-zinc alloys as well as aluminum bronzes and others of a more special nature.

Jan 1, 1927

By William Rawles

THIS report is the first of a series planned by The Mineral Inquiry, organized by the American Institute of Mining and Metallurgical Engineers to make factual studies of the world's mineral resources in their political and international relations. The efforts of The Inquiry are directed toward filling certain notable gaps in available information, without duplication of many other investigations touching this field which are being conducted by other organizations, public and private. Much of its work is indirect-suggesting topics for study by other individuals and organizations and aiding in their planning and correlation. The present report is designed to show the nationality of the commercial control of mineral resources, in addition to the geographic distribution of production by nation-in other words, the overlapping of political and commercial control. Detailed accuracy cannot be claimed for the figures presented. For some companies division of ownership by nationality has been very difficult to ascertain, as many companies are reluctant to dis-close the extent of their holdings in other corporations, and the impossi-bility of tracing all stock ownership is obvious. Also there are frequent changes in the distribution of stock control. The percentages given rep-resent only the participation that has been identified definitely, even though it is known in some cases with fair certainty that larger interests exist, as, for instance, American participation in foreign chromite companies. In bringing together these figures we have had the cordial co-operation of the United States Bureau of Mines, the United States Geologi-cal Survey, the Mineral Division of the Bureau of Foreign and Domestic Commerce, the Brookings Institution, and of many specialists connected with the mineral industries covered. The report does not cover the entire list of minerals. Coal, although it is one of the most important minerals, was omitted because, not more than one or two per cent of the world's production comes from mines that are owned by companies foreign to the countries where the coal is produced. Others, such as gold, are omitted because sufficient data have not yet been accumulated. It is hoped that some of these may be covered in subsequent reports. It is not our purpose here to discuss the significance of the figures sub-mitted, but only to point out the general nature of the problems on which they have a bearing.

Jan 1, 1933

By Robert A. Colten, Frederick C. Hull, Robert F. Mehl

It is known that pearlite forms from austenite by a process of nucleation and growth, and that the rate of formation of pearlite may be described by a rate of nucleation and a rate of growth.l,2 The manner in which these two quantities operate to produce the observed isothermal reaction curve has been analyzed in a paper published in I939.3 Two types of process were described: (I) that in which nucleation occurs at the grain boundaries of the parent phase, with the nodules growing toward the centers of the grains, initially as hemispheres and then after impingement as roughly radial-columnar structures; and (2) that in which nucleation occurs generally, with the nodules growing to full spheres until impingement with other growing nodules restricts growth. Both cases are met in the formation of pearlite from austenite (Fig. I);2,4 the former, occurring near the knee of the S-curve, has been named "grain-boundary transformation," and the latter, occurring at temperatures near Ael, has been named "group-nodule transformation." In developing our knowledge of the factors that determine the rate of formation of pearlite from austenite, it is important1,2 to obtain data on the rate of nucleation and the rate of growth of pearlite. Such data, when obtained near the knee of the S-curve, will furnish information of use in understanding the factors that affect hardenabil-ity; when obtained at higher temperatures, such data will be useful in understanding the behavior of steels that during heat-treatment react to pearlite.2 It is the purpose of this paper to present data on the rate of nucleation and the rate of growth of pearlite in dependence upon composition, grain size, temperature, and the degree of homogeneity of the parent austenite. The studies are restricted chiefly to plain carbon commercial steels." Previous Data on Rate of nucleation and rate of Growth Data on the rate of nucleation and the rate of growth of pearlite have been published by Scheil and Lange-Weise,5 by Mirkin and Blanter,6,7 by Meh1,l and by Dorn, De Garmo and Flanigan.2, It is difficult to interpret the data, for in most cases too little information is given on austenitizing temperatures and times, the state of homogeneity of the austenite (presence or absence of carbide, etc.), austenite grain size, and mode of formation of pearlite at the temperatures given. Except for the approximations of Mehl and the work of Dorn, austenite grain size was disregarded, though it is well known

Jan 1, 1942