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By James F. Kemp

Jan 1, 1914

By Kenneth K. Humphreys

INTRODUCTION What is automation? Why automate? Webster's New Collegiate Dictionary defines automation as "the automatically controlled operation of an apparatus, process, or system by mechanical or electronic devices that take the place of human organs of observation, effort, and decision." This definition gives an implied answer to the second question, "Why automate?" Automation, automatic control devices, and process control equipment receive their justification in supplementing or replacing manpower, which results in decreased operating costs. In the past, processes were operated with the minimum amount of instruments needed merely to guide operators. Processes were manually con- trolled by the operator on the basis of simple temperature, pressure, flow, and level indications on a panel. Today the tendency is to design a new plant to operate in a fully automatic manner according to a preset pro- gram utilizing a minimum of manpower. In addition to this direct cost reduction in manual labor, increased equipment capacity results from uniformity of flow and uniform control of process variables. This control eliminates or minimizes surges and permits equipment to be operated at or near its ultimate capacity and, for a given material throughput, permits the use of smaller process equipment. Automatic control, therefore, be it in the field of coal processing or in any industrial field, is simply a problem of economics. Control equipment is justified in terms of its contribution toward increasing productivity, increasing profit margins, or producing a new and salable product at a profit. Instruments and control devices can be divided into two general groups: (1) units which measure and (2) units which both measure and control a process variable.

Jan 1, 1979

By M. M. Singh, J. W. Brown

Three rocks of highly varied physical properties are selected for the first reported experimental study concerning microseismic activity of rock under tension to determine the effects of static fatigue, loading rate, repeated loading and rock anistropy compared to compression and bending loads. The microseismic method of detecting rock under deformation may be a great potential tool in surveillance and location in situ of dangerously stressed strata, as well as predicting rock failures. Noises emitted under load or the rate of energy (energy of noise pulses generated per unit time) are computed for varying conditions. The tests are conducted at constant load on a dead weight loading machine to eliminate all possible extraneous noises — an indispensable precaution — at various load levels. Experimental results are reported including the relation of total energy emitted to tensile strength of rock and the possibility of simulating a phenomenological model for microseismic activity. Plots of some of the experiments are included. INTRODUCTION Rock failure, whether on a large scale faulting in the earth's crust and rock bursts in mines, or on small scale ruptures of laboratory test specimens, generates transient vibrations in the rock mass. Mechanisms of intermittent deformation, such as twinning and cracking through and between mineral grains, also produce similar vibrations, but of very small amplitude. Such vibrations from both deformation and failure are referred to as microseismic activity, rock noise, or occasionally seismo-acoustical activity. An individual rock noise is sometimes

Jan 1, 1967

By K. P. Fournier

This report describes work on the problem of predicting oil recovery from a reservoir into which water is injected at a temperature higher than the reservoir temperature, taking into account effects of vis cosity-ratio reduction, heat loss and thermal expansion. It includes the derivation of the equations involved, the finite difference equations used to solve the partial differential equation which models the system, and the results obtained using the IBM 1620 and 7090-1401 computers. Figures and tables show present results of this study of recovery as a function of reservoir thickness and injection rate. For a possible reservoir hot water flood in which 1,000 BWPD at 250F are injected, an additional 5 per cent recovery of oil in place in a swept 1,000-ft-radius reservoir is predicted after injection of one pore volume of water. INTRODUCTION The problem of predicting oil recovery from the injection of hot water has been discussed by several researchers. l-6,19 In no case has the problem of predicting heat losses been rigorously incorporated into the recovery and displacement calculation problem. Willman et al. describe an approximate method of such treatment. 1 The calculation of heat losses in a reservoir and the corresponding temperature distribution while injecting a hot fluid has been attempted by several authors.7'8 In this report a method is presented to numerically predict the oil displacement by hot water in a radial system, taking into account the heat losses to adjacent strata, changes in viscosity ratio with temperature and the thermal-expansion effect for both oil and water. DERIVATION OF BASIC EQUATIONS We start with the familiar Buckley-Leverettg equation for a radial system:* This is sometimes referred to as the Lagrangian form of the displacement equation. If the injection water is at some temperature Ti which is above reservoir temperature TR, then lw, the flowing fraction which is water, is a function of both water saturation and fluid temperature at any given time and position in the reservoir. The temperature dependence of lw results from the temperature dependence of the viscosity ratio µo/µm of which lw is a function. Thus:

Jan 1, 1966

By R. E. Hummel, J. W. Koger

IT is generally accepted that the martensitic start temperature (Ms) can be determined by resistivity measurements and is that temperature where the resistivity vs temperature curve on cooling first deviates from a straight line.1-4 Both Titchener and ever' and pops5 have used resistivity measurements to follow the martensitic transformation in b1 Cu-Zn and ternary Cu-Zn-based b-phase alloys, respectively. Actually because of the nature of their measurements the temperature of minimum resistivity (M) was used by these authors to determine "Ms" . Also, due to experimental difficulties in detecting M, with resistivity measurements, Pops and Massalski 8 determined M, by optical microscopy. The present communication is concerned with high-precision, low-temperature resistivity measurements which reveal a definite M, temperature which differs from the temperature of minimum resistivity (M). It is also shown that M is merely the result of the geometry of the percent-transformation curve and the temperature coefficient of resistivity of the alloy. In other words, it will be demonstrated that M has no apparent significance (except that it denotes a temperature at which some percent of martensite can be detected in a given alloy). Alloy specimens were made by melting 99.999 pct Cu and 99.9999 pct Zn in sealed and evacuated quartz tubes and homogenizing them at 601PC for 300 hr. After the alloy was cold-rolled into foils suitable for resistivity measurements, it was quenched in ice water from 871PC. The chemical analysis showed a zinc content of 38.8 wt pct. The cooling rate during the martensite transformation was 1°C per min and was controlled with a thermistor. Electrical resistivity measurements were made using a K-3 type potentiometer; the reproducibility of the resistivity values was better than 0.03 pct. Temperatures were measured with a thermocouple to an accuracy of better than 0.2° C. Fig. 1 shows the resistivity vs temperature curves of the martensitic transformation in B1 Cu-Zn for both cooling and heating. The starting point of the martensitic transformation (M,) was taken as that

Jan 1, 1968

By N. A. D. Parlee, M. M. A. El-Naggar, G. 8. Horsley

The apparatus was of a modified Sieverts type1&apos;2 with a reaction tube designed to function also as the cell component of an oxygen pressure gage. The reaction tube assembly is shown in Fig. 1 and described in Table I. The main body is a 1-in.-OD 15 mol pct calcia-stabilized zirconia tube. The ground-glass joint, g, the male part of which carried a prism for optical pyrometer use, was connected to the remainder of the Sieverts apparatus. The calibration of the cell (at its 1000°K operating temperature) for internal oxygen pressures (PO2in) in the range 0.2 to 10 9 atm was made against internal air pressures measured by mercury manometer and McLeod gage. At very low po2in values down to l<Tn atm the performance was checked by comparing pQ calculated from electromotive force measurement when the apparatus was filled with a) pure CO gas and b) a CO-CO2 mixture of the ratio CO-CO2 = 1:0.398, with Po, values calculated from the equilibrium constants of the following reactions at 1000°K:

Jan 1, 1968

By B. N. Das, P. A. Beck

THE o phases have a complex tetragonal structure with Lo/ao = 0.52 and 30 atoms per unit cell.1 A large number of such phases are now known to occur in various binary systems of the transition elements and they exhibit the following typical features: 2,3 The composition of binary o phases is variable, ranging from approximately A4B to ABI. With only a few exceptions, in the o phases the A-ele-ment comes from the V- or Cr- group of the periodic table, while the B-elements are from the Mn-, Fe-, Co-, or Ni- group. In the first long period the corresponding o phases of the V- and Cr-series have approximately the same compositions. However, as the B-element changes from Mn to Fe to Co to Ni, the mean composition shifts monotonously toward higher A-contents.2-4 For example, if the mean compositions of the various o phases with vanadium are compared with each other, the composition shift mentioned above becomes plainly visible: V 30Mn0 80 Vo.45Feo..,, Vo .,Coo. 45 and Vo.5Nio.3. Similiar composition shifts, although not the same composition values, were observed in u phases formed by second and by third long-period transition elements.3&apos;4 This behavior, very characteristic of o phases, is in rather sharp contrast to the usually quite well-behaved stoichi-ometry of the Laves phases. In the latter, the AB2 stoichiometry predominates, with A the large atom and B the small atom.= The p phase occurs in the four binary systems of Mo or W with Fe or Co. On the basis of their crystal structure determination, Arnfelt and westgren6 ascribed to the p phase in the Co-W system the ideal composition W,Co7. Since all four binary pphases have nearly the same composition, it would seem quite plausible that some definite stoichiometry such as A6B7, might be characteristic of this phase, as AB2 is of the Laves phases. On the other hand, it has been noted,7 that the phases occur at average electron concentrations near to those at which the various cr phases are found. Also, it has been pointed out by Shoemaker and associates8 that structurally the a phases and the p phases are somewhat related to each other; both of these structures may be described in terms of suitable stackings of quasi-hexagonal layers&apos;of atoms. By studying a suitably chosen ter- nary phase diagram, one might expect to be able to find out which one of the two conditions, the analogy with the o phase or the constant ratio between the number of large atoms and the number of small atoms in effect governs the behavior of the p phase. Several isothermal sections of ternary systems containing o phases have been investigated. In all cases where two binary o phases occur, these were found to be connected b a more or less straight ternary o phase field.7&apos; &apos;10 Such elongated o phase fields were also found in ternary systems in which only one of the limiting binaries is known to contain o phase. In this manner a latent o forming tendency could be detected and the virtual composition of a "binary o phase", which does not actually occur as such was approximately determined by extrapolation. The behavior of the phases, including their composition shift, is analogous to that of the classical electron compounds, as described by Hume-Rothery.11 In order to decide whether the p phase is essentially a "size compound" like the Laves phases, where a fixed stoichiometric ratio is quite generally maintained between the "large atoms" and the "small atoms", or whether the p phase is typically an "electron compound" in the same sense as ois, it was decided to investigate an isothermal section of the Mo-Mn-Co system. The Mo-Co system12 and the Mo-Mn system13 each are known to have a binary o phase. It could be therefore expected that a ternary o phase field will connect these two binary cr-phase fields. The p phase is known to occur in the Mo-Co system. If the p phase should turn out to form an elongated phase field extending deep into the ternary system, the following considerations mighto apply. The atomic radius of manganese (1.314for C.N.12) is between the va,lues for Mo (1.40Afor C.N.12) and for Co (1.26Afor C.N.12). If it is assumed that p is a "size compound", and that Mn is substituting for the smaller Co atoms in the p-structure in the ternary system, the y-phase field might be expected to extend parallel to the Mn-Co binary line. If Mn is substituting for the large Mo atoms in the p-structure, the p-phase field may be expected to extend parallel to the Mn-Mo binary line. On the other hand, if the p-phase turns out to be an "electron compound" like o, the ternary p-phase field should extend parallel to the ternary o -phase field connecting (Mo,Mn)owith (Mo, Co) a

Jan 1, 1961

By L. W. Pommier, F. B. Brien, A. K. Bhasin

In the field of mineral processing, although many operations are applied to suspensions of ore particles in fluids, there is a lack of fundamental knowledge relative to the flow resistance encountered by immersed bodies moving through solid-liquid suspensions. Previously proposed equations, based on the Ostwald-de Waele (power-law) model for non-Newtonian fluids, are exam ined in the turbulent flow region relative to a number of pertinent variables and their effects on the movement of immersed bodies. As more knowledge is acquired in regard to the effects of suspension variables on the rheological properties, useful relationships may be proposed to allow predictions of conditions to achieve optimum results for engineering purposes. In the field of minerals processing, many operations are applied to suspensions of ore particles in fluids. The differential movement of solids of various sizes and densities in suspensions is of utmost importance to gravity concentration, wet classification, flotation, hydrometallurgy, and pipeline transport of solids. The subject is also of importance to other branches of engineering; for example, those involved with soil mechanics, ceramic slips, and oil-well drilling fluids. There is a lack of fundamental knowledge relative to the flow resistance encountered by immersed bodies moving through solid-liquid suspensions. The problems encountered in the direct application of the well-known Stokes and Newton&apos;s Laws to non-Newtonian systems have been examined in a previous paper.&apos; Equations were proposed based on the Ostwald-de Waele (power-law) model for non-Newtonian fluids. This present paper examines these equations in the turbulent flow region relative to a number of pertinent variables and their effects on the movement of immersed bodies. It is thought that, as more knowledge is acquired as to the effects of suspension variables on the rheological properties, useful relationships may be proposed to allow prediction of conditions to achieve optimum results for engineering purposes. The purpose of this paper is to make an initial assessment of the nature and magnitude of pertinent suspension variables. In order to avoid too voluminous a document, the examination of kinetics and mechanisms will be omitted at this time. THEORY A Newtonian fluid is defined as a fluid in which the stress is proportional to the rate of strain, 2 i.e.: H = viscosity; see Table I. for list of symbols The following equations are conventionally used to assess the motion of spherical particles moving under laminar and turbulent flow conditions through Newtonian fluids: When these relationships are applied in practice to suspensions, the liquid density is substituted by a composite suspension density, and viscosity is usually taken as that of the suspending liquid or an approximated "apparent viscosity." However, suspensions are non-Newtonian in character3 and thus, more than one viscosity parameter is required to describe their behavior. A number of models have been proposed for non-Newtonian fluids;2,4 among these the simplest is the Ostwaldde Waele or power-law model for incompressible fluids which for one dimensional flow may be reduced to:

Jan 1, 1970

By John Freeman

THIS paper relates entirely to the casting of brass under fluid pressure in steel dies. Die castings of metals and alloys of low melting point have been available for many years but the development of brass die castings has been relatively recent, occurring within the past five years. The successful development of brass die castings has resulted from the availability of alloy steels that would give satisfactory life as dies and the development of suitable die-casting machines. The melting point of copper is 1084° C. (1983° F.) and of a high brass about 900° C. (1652° F.), as compared to 327.5° C. (621.5° F.) for lead, 419.4° C. (786.7° F.) for zinc and 658.7° C. (1217.7° F.) for aluminum, temperatures that are indicative of the casting temperatures required for the various types of alloys, of which the melting points are somewhat lower than those of the pure metals.

Jan 1, 1935

By L. Moyd, P. Moyd

The first commercially available portable gamma ray-neutron beryllium detector, the Rerylometer, was developed by the same group that developed the first practical portable scintillation counter, the Scintillo-meter. This group includes Professor George Brownell, of the Geology Department of the University of Manitoba in winnipeg, and his associates, K. I. Roulston, R. w. Pringle, and R. L. Funt, of the Physics and Engineering Departments of the University of Manitoba. A prototype model was tested in the field by Dr. Brownell during the summer of 1958. Commercial production was undertaken shortly thereafter by Nuclear Enterprises Ltd., of Winnipeg, and a license for manufacture and distribution in the U.S. was granted to Isotopes Specialties Co., of Burbank, California, a division of Nuclear Corporation of America. Early in 1959, we were retained by the &apos;Mining Division of Minerva Oil Co. to Legin a search throughout North America for minable deposits of beryllium, and to train members of their permanent staff to continue the program. The project included literature sur-veys, interviews with members of various federal, state, and provincial agencies, scanning of our own collection of suites of specimens from various mineral occurrences, and the examination of deposits in the field. The value of a beryllium detector to this program was obvious and arrangements were made to procure one as soon as possible, which resulted in our obtaining and using the first instrument that was produced commercially in the U. S. In addition to the commercially available Berylometer, Mr. William Vaughan and his associates, of the U. S. Geological Survey Geophysics Division, in Denver, have developed and tested several experimental instruments based on the same principles. DETECTOR Principles The detection of beryllium is based on the fact that "hard" gamma rays (1.6 MEV and geater), such as those produced by Antimony convert ordinary beryllium (Be9) to Be8 , with the release of a neutron. The neutrons are counted by a scintillator designed to favor neutron responses while suppressing those of gamma rays. &apos;The instrument is completely selective for beryllium. No other element can interfere. Instrunlentation The Rerylometer itself, which is cylindrical, is about 8 inches in diameter, 13 inches high, and weighs about 11 pounds. (Figs. 1, 2). The principal components include: 1. A disc of wax to moderate (or "thermalize") neutrons. 2. A boron-enriched polyester-zinc-sulphide fluorescent screen. This material produces strong flashes when struck by thermalized neutrons but only weak flashes from gamma rays. 3. A photomultiplier tube. 4. An electronic circuit, complete with one srnall 71/2-volt dry battery. The photomultiplier tube and electronic circuit convert neutron flashes to electrical impulses, but gamma ray effects are almost

Jan 1, 1961

By A. Moskowitz, L. S. Redmerski

The corrosion resistance of stainless steels can be strongly affected by surface treatments. Changes in corrosion resistance can relate to surface composition, integrity and stability of the passive film, and to surface profile (roughness). Operations producing oxidation at the surface, such as annealing, heat treating, and welding, can result in a chromium-rich scale and a chromium-depleted metal surface. In order to restore full corrosion resistance, chemical or mechanical clean-up techniques must remove not only the oxide, but also a very thin layer of metal. Laboratory and field test studies show that these factors are particularly significant in less highly alloyed steels. Annealing stainless in a reducing atmosphere (bright annealing) avoids chromium depletion, but as-bright-annealed material does not display optimum corrosion resistance in certain environments. Electro passiva-tion can be applied to improve pitting resistance without significantly changing bright surface appearance. Potentiometric studies show that electropassivated material also displays significantly greater resistance to breakdown of passivity in acid solutions. The application of special surface finishes for appearance purposes can affect corrosion resistance. Roughness is a key factor. Samples of related appearance but with different surface profiles can show significant differences in corrosion resistance. Thus nonreflec-tive stainless with a relatively smooth surface produced by a special rolling process is much superior to material chemically etched to a similar low reflectivity. THE corrosion resistance of a stainless steel is affected by other factors in addition to its bulk composition and metallurgical structure. These other factors include those relating to the specific chemical and physical condition of the steel&apos;s surface. This paper will consider certain aspects of surface condition in relation to corrosion resistance. In particular, studies will be described on the effects of oxidation encountered in heat treating or welding operations, of passivation after bright annealing, and of different surface finishes. EFFECTS DUE TO OXIDATION When stainless steels are exposed to high temperature in an oxidizing environment, as in annealing or welding, the oxides formed are relatively rich in chromium. As a consequence of oxidation, the metallic layer directly beneath the scale may be low in chromium to some very thin but finite depth.1"8 Such a change in chromium content could lower the corrosion resistance at the surface, whether or not the oxide layer is removed. Studies were performed relating to the effect of oxidation and chromium depletion produced during annealing and welding on the corrosion resistance of stainless steels. The nominal compositions of steels used in this study and others are given in Table I. A) Annealing Studies on 17 pet Cr Steels. 1) Effects of Pickling Treatments. Studies were performed to investigate the corrosion resistance of air annealed type 430 stainless as a function of the amount of electrolytic pickling after annealing. The material used in this study had been air annealed and electrolytically pickled in the mill. All scale had been removed, and yet the material showed unusually poor corrosion resistance. Laboratory electrolytic pickling studies were performed to determine whether additional metal removal from the surface would improve corrosion resistance. Electrolytic pickling was performed in a sulfuric acid bath using various conditions of bath acidity, temperature, time, and current density. The samples were then rated for corrosion resistance in a ferric chloride spot test. For this spot test, a solution was prepared by dissolving 10 g of FeCl3 . 6H2O, 5 g of NaCl, and 2.5 ml of concentrated HC1 in 200 ml of water. An area on a specimen was cleaned and a drop of test solution was placed on the prepared area. After 5 min, the drop was rinsed off and the area wiped dry. The spot was then rated between 1 and 5 by visual comparison with standard spots. The numerical rating of the standard spots can be described as follows: 1—No clouding of surface; 2—very slight clouding of surface; 3—slight clouding of surface; 4—moderate clouding of surface; 5—strong clouding of surface. A rating of 1 or 2 was considered to have passed the test, a rating of 4 or 5 represented failure, and a rating of 3 was considered borderline. The severity of etching in this test has been related to the actual chromium content at the surface.4 Etching (clouding) occurs on type 430 stainless (rating of 4 to 5) when the surface chromium content is 14 pct or less. The effects of current density and retention time when electrolytically repickling this material in 6 pct sulfuric acid are shown in Fig. 1. Increasing the cur-rent density or retention time improved corrosion resistance as measured by the spot test. Similarly, increasing acid concentration of the bath or bath tem-perature was found to improve corrosion resistance. The conditions making for improved spot ratings resulted in increased metal removal, regardless of specific pickling conditions used, Fig. 2.

Jan 1, 1970

By H. E. Hawkes, D. A. Barr

Time variations in the copper content of the sediments of streams draining mineralized areas were studied in two areas of contrasting climatic environment, one in northern and one in southern British Columbia. In each area, samples were collected and observations made of rainfall, stream discharge and air and water temperature at intervals throughout the summer season. Samples were analyzed for total and cold-extractable copper. Results showed a weak inverse relation between cold-extractable copper and discharge in two out of the three test sites in the southern area, and a decrease in ratio of COld-extractable to total copper over the duration of the test period at a highly anomalous site in the northern area. In suspended rock flour resulting from glacial erosion of mineralized rock in the northern area, virtually all the copper was found to be soluble in cold, dilute hydrochloric acid. None of the variations observed is sufficient to cause serious problems in geochemical sediment surveys. Systematic collection and trace analysis of stream sediments has seen wide application in recent years as a method of primary prospecting in primitive areas. Common practice is to collect fine-grained samples of sediment either from the active channel or from the flood plain near the channel. Samples are dried, sieved and the -80-mesh fraction analyzed after breakdown of the sample by a relatively strong attack, such as by fusion or by treatment with hot perchloric acid. Drying, sieving and rigorous chemical attack requires established facilities, either in a well equipped central laboratory or in base camp. Thus analysis for total metal involves a substantial delay from the time the samples are collected until the analytical data can be reported. An alternative system uses a cold aqueous extrac-tant in place of the hot acid or flux.4 Advantages of the cold-extraction techniques are that kits can be prepared for use directly at the sample site and that, in some problems, the patterns in cold-extractable metal, usually abbreviated cxMe, are more useful as ore guides than the patterns in total metal.&apos; In the course of operational geochemical sediment surveys, a problem that has come up repeatedly is failure to reproduce anomalous values or patterns by resampling the same areas. The mystery of the vanishing anomaly has led to speculation as to whether there is a significant variation in the metal content of sediment samples with the weather or with the time of year. Review of the published literature shows that a number of experiments have been carried out on time variations in the metal content of stream water.1,2,5,7-9 The only published report on time variations in stream sediments that has come to the authors&apos; attention, however, is by Govett,3 working in Northern Rhodesia.

Jan 1, 1963

By Charles D. Walcott

Jan 1, 1901

By Carl Henrich

Jan 1, 1893

By Johannes Moeljono, Werner Wenzel, Heinrich Wilhelm Gudenhau

As an important mechanism for increasing production of the suction-draft-sinter process, it has been shown that gas permeability through the sinter layer plays an important role. Methods to increase production rates have been indicated and suggestions for carrying out the process have been made to improve the rate of production, reduce the fuel consumption, and at the same time obtain a uniform sinter. Laboratory experiments were conducted at the Institute for Ferrous Metallurgy of the Technical University at Aachen to illustrate these methods. Methods of Increasing Gas Penetration Through Sinter Layers The following are of fundamental importance in determining the process cycle during the sintering of iron ores: 1) Generation of maximum temperature, since its form and range determine sinter quality. 2) Propagation velocity of the temperature maximum which controls the attainable output. 3) The convective heat transfer which influences the velocity of travel of the temperature maximum.

Jan 1, 1974

By E. Northcott, F. N. Oberg

By electrostatic separation, course Florida pebble phosphate, too lou-grade to find a ready market, can be upgraded to a satisfactory saleable product. Pebble running from 60 pct bone phosphate of time may be upgraded to 73 to 77 pct BPL depending on the mineralogical. structure of the pebble and the nature of the silica innpurity. High-grade concentrates from Florida pebble phosphate deposits have long been recovered by wet methods. When work was begun in the field, only the coarse pebble (generally +1 mm) was re- covered. In the 1920&apos;s a froth flotation process was developed to separate quartz from the finer phosphate fractions, but this method proved unsatisfactory for treating the intermediate fraction (—1 mm +35 mesh). Consequently various other processes were adapted, including agglomerate tabling and spiral separation of reagentized feed. Today the three processes are used—washing and screening for coarse pebble, tabling or spiraling for intermediate sizes, and flotation for —35 mesh material.

Jan 1, 1959

By Charles Hart

In this paper it is the author&apos;s intention to show the extent and character of foreign ores now known to be available; these deposits may be in active production or held in reserve until economic conditions may make them active. He hopes to show the relation existing between these ores and the American supply, and which of the former are now producing or will in turn come into production when our better ores have been exhausted. This phase of this discussion must of necessity include some data as to the present rate of consumption and a study of the changes we may expect here and abroad in the general steel trade and its sources of supply in raw materials. It is obvious that the occurrence of coal, ore and limestone in relation to one another and the proximity of a market are the elements in control of this feature of the problem. If the foregoing situation is favorable, all the other questions may be solved, for it is clear that with proper basic conditions finance, labor and operations will fall in line. We present a short outline of the present methods of carrying on the foreign iron ore trade, believing that it is of general interest in comparison with our own highly specialized methods, and that with the exhaustion of our better ores we will be compelled to seek a part of our supply abroad. A partial list of iron ores, with incomplete analyses (Table I), is added, to give a better understanding of the general situation and explain to some extent the reason for things being as they are in the iron and steel trade of the world and to help in bringing this paper to an informing conclusion. The question of the world supply of iron ores has been a subject for study on the part of geologists and engineers for many years, and found its best results in the Eleventh International Geological Congress, appropriately held at Stockholm, Sweden, in 1910. The proceedings are published in two volumes and are undoubtedly the best records available on this subject at the date of publication. It should be borne in mind, however, that much has happened in the 20 years since these figures were assembled. There is just as much known ore at present as at that time, minus the quantity consumed, plus newly discovered reserves. The World War had great effect upon this situation; during that time explorations were greatly reduced and the settlements after the

Jan 1, 1929

By Thomas H. Sheldon

IN the zeal for opening up new ore-bodies, or for. extracting the ore from attractive bodies gal ready opened up, we very often lose sight of the fact, that, after all, the operation of a mine is a business proposition, pure and simple; and for the best working-results should be treated upon a strict business basis. Of course, in every mine of consequence a record is kept of expenditures and receipts, and such glittering generalities as "gross receipts," " net receipts," " mining expenses," .and " per cent. profit," can be told to the cent; but does this . record show economy of management, either as compared with the same record of other months, or as compared to the record of other mines of the&apos; same class ? Moreover, if such a record shows that the cost of mining is high, does it in any way en¬able the manager to put his finger on the leakage? Does it necessarily follow that a mine which makes a profit of, say, 40 per cent on 25-dollar ore, is doing less economical mining than one which saves 60 per cent on 80-dollar ore ? Of course the figures in the latter case look the more attractive, but when it comes to a point of saving everything which can be saved, and of cutting down expenses to the lowest possible cost of operation, the former mine is doubtless on the most firm and economical financial basis. But as the relative merits of the system of mining in the two cases, nothing could be decided without a basis of detailed comparison ; if one system is more economical than the other, why is it so, and wherein does the advantage lie ? This can be shown only by keeping accurately the cost of each mining operation. And no matter how dissimilar two mines may be in character and operation, yet there are a few general heads common to all mining operations. In the first place, it is necessary to break the ore from the solid ground ;

Nov 1, 1905

By A. N. Holden, W. E. Seymour

DURING the last several years, the U-Zr system has been studied at many laboratories as one of the research programs sponsored by the Atomic Energy Commission. The equilibria in part of this system have been difficult to determine, although the phase diagram from 0 to 60 atomic pct Zr has been established with reasonable certainty. Existing diagrams of the system vary appreciably beyond 60 atomic pct Zr, particularly with regard to the existence of an intermediate phase. Most existing diagrams show a transformation or reaction horizontal near 600°C. In 1955, a collection of uranium phase diagrams&apos; was prepared at the Battelle Memorial Institute and the U-Zr diagram in that collection contained a questionable region in the vicinity of 60 to 80 atomic pct Zr. Summer-Smith" has published a phase diagram of the system that shows no intermediate phase. Summer-Smith did his work with powders and found only the uranium and zirconium eutectoid mixture from X-ray patterns of material annealed below 600°C. Mueller3 at Argonne National Laboratory did similar work with filings, and he found that initially there was a pattern of an intermediate phase, but on long-time annealing

Jan 1, 1957

By B. C. Blake

IN general, billet-type or long slender ingots are used when it is desired to produce directly from the ingot in one conversion a product of medium or small cross-sectional area. They are designed to eliminate the blooming and billet-mill stages of the usual procedure. As used at Connors, they constitute a means of keeping a continuous rolling mill busy in the production of high-quality small rods, small angles, hoop stock, baling ties and concrete reinforcing rods without the need for a blooming or billet mill. They represent sound steel with the best surface that is commercially practical to use in the rolling of small continuous mill products.

Jan 1, 1947