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In open cut gold mining at Mt Magnet and Reedy, grade control sampling is done with inclined RC drilling using one metre samples. In the small open cuts at Rothsay blasthole sampling was successfully used. Underground sampling for gold and copper grades at Rothsay is done using chip sampling. At the Youanmi open pits both Ditchwitch Earthsawing and RC drilling are used.All assay data are interpreted on sections and plans using a customised SURPAC system. Reconciliations of the grade control predictions of tonnes and grade against initial ore reserves, mining production and milling results are carried out monthly.

Jan 1, 1990

By E. C. Truesdale

IN recent years various problems in connection with research work on the preparation and properties of zinc-base alloys have required reliable information concerning the constitution of the zinc-rich portion of the iron-zinc equilibrium diagram. On numerous occasions rather positive indications were obtained that, for example, the solubility of iron in zinc was incorrectly represented on the current equilibrium diagrams. A careful study of all the available literature relating to the iron-zinc system led to the conclusion that much of the early work was unsatisfactory as measured by present standards of experimental accuracy, and as a result it was decided to redetermine the location of the liquidus curve and of adjacent portions of the diagram. Part I of this paper comprises a description of the experimental methods and a summary of the results by means of which the zinc-rich end of the iron-zinc diagram has been revised in the following ways: 1. Measurements of the solubility of iron in liquid zinc by several different sampling methods, leading to a relocation of the liquidus curve. 2. Microscopic, conductivity, and X-ray studies of the solid solubility of iron in zinc, which, together with thermal analyses, have resulted in new values for the solid solubility and the eutectic temperature and composition. 3. Heating and cooling curves, obtained by a refined differential method, leading to new locations for the two peritectic horizontals. In Part II of the paper the attempt is made to review all of the pub-lished work having a bearing on the constitution of the iron-zinc system, and to correlate the present results, and some recently published data

Jan 1, 1935

By S. Korman, S. B. Tuwiner

THE purpose of this study is to investigate the effect of agitation upon the flotation of chal-cocite. It is believed that the concentration of collector which is required to produce a water-repellent surface upon the mineral is determined among other things by the rate of collector diffusion through an impeding film of more or less stagnant fluid. Its thickness depends upon the intensity of agitation. In the first part of this study a method is developed for determining the thickness of the fluid film upon a polished surface of synthetic chalcocite. The film thickness is then determined as precisely as possible under three readily reproducible condi-tions of agitation intensity. These determinations serve as a quantitative evaluation of agitation. In Part 2 it is demonstrated that in solutions of lime at PH 10.5 and in the absence of air or dissolved oxygen the concentration of collector required to develop water-repellency upon the surface in any given time is a function of the fluid film thickness, and that after about 10 min the relation becomes linear. This points to the possibility that the collector ions may be involved in a diffusional process through the fluid film. In Part 3 it is shown that where air is present more collector is required to produce water-repellency than for the case in which air is excluded. Next, it is shown that for the latter case the most minute amount of sodium sulphide suffices to preclude development of water-repellency. Both oxygen and sulphide are in a sense, therefore, depres- sants for chalcocite in a lime solution at PH 10.5. When oxygen and sulphide are present simultaneously there is a region of minimum critical collector concentration for water-repellency which is very markedly lower than the concentration where oxygen alone or where sulphide alone is present. Moreover, this minimum appears to be identical with the collector concentration which is required where sulphide and oxygen are both excluded. This would appear to indicate that in certain ranges of concentration of oxygen and sulphide, each cancels the effect of the other. The range of concentration of solution for this effect in solutions saturated with oxygen is a function of the agitation intensity. Thus we are led to believe that a chemical reaction involving sulphide and oxygen occurs at the surface of the chalcocite. Part 4 of this study is a further development of this idea and some of its consequences from an electrochemical standpoint, while in Part 5 the disappearance of sulphide from pulps of several minerals is noted with an indication that both dissolved oxygen and the mineral are necessary, the reaction being catalytic or pseudocatalytic. Part 1. Determination of Fluid Film Thickness The Fluid Film Concept: The hindrance to the diffusion of collector to the surface of the chalcocite is a barrier of stagnant fluid in the vicinity of the surface. It is the same barrier that limits the rate of transfer of heat, the rate of solution of dissolving crystals, or any of the other rates pertaining to chemical engineering unit operations in which the film resistance to diffusion plays a principal role.' Fluid films are present upon the surface to an extent which varies with the geometry and intensity of agitation. They result from the fact that in the region within the fluid near a surface, motion is entirely parallel to it. From the standpoint of transfer to or away from the interface the effect is as though the fluid were stagnant. Outside of the film, movement of the fluid may be streamline or turbu-

Jan 1, 1951

By Alfred V. de Forest

We are now assembled in this hall for the eighteenth lecture in honor of the memory of our greatest American metallurgist, Henry Marion Howe. Many of his most intimate contemporaries, led, as was fitting, by Professor Sauveur, have described his vital accomplishments in three fields: as a leader in technical industrial development; in theoretical research; and finally as a teacher and source of inspiration for nearly two generations of students. In 1914 Professor Howe had retired from active teaching, but maintained his laboratory at Columbia University under the care of Arthur G. Levy, with whom he published many of the papers that later were incorporated into his last book, " The Metallography of Steel and Cast Iron." My position at the time was that of personal assistant to Professor Campbell—no pay, no duties, but the great privilege of preparing specimens, taking pictures and attending to some of the current consulting work. Whenever possible, I visited Howe's laboratory to chat with Levy and gather ideas about the wonderful field of metallography—in which I was a rank amateur, rescued by the quiet enthusiasm of Donald Smith of Princeton from an instructorship in civil engineering. Levy let me act as a fly on the wall during the Professor's occasional visits. Busy as he was, Professor Howe took the time and trouble to encourage my interest, as he had done for hun- dreds of others. He told me how he went about gathering his own information speculating as to causes, considering experiments, and verifying his conclusions. I ventured to mention some tests I had run on the irregular stretching of wires of different metals. He read the small volume I had prepared of ill-assorted facts and fancies and remarked: "Nobody cares for your theories or the history of your tests. Describe what you found as briefly as possible and perhaps I can help you to publish." Curiously enough, among my discards were some autographically recorded load-versus-electrical-resistance measurements. Taken with inadequate knowledge and equipment, these curves did not reproduce consistently, but if the relationship between strain and resistance had then been explored, the latest type of strain gauge might have been in useful service for the past 25 years. Professor Howe was a gifted teacher, perhaps because he was primarily an ardent and assiduous student. His own eagerness to learn and his willingness to revise and extend his opinions constantly encouraged those of his environment to be diligent and painstaking in the pursuit of knowledge. In honoring his memory, I also wish to bring to mind the kindly, humorous and quiet Levy, and join his name again, as it was for too brief a space in the past, with that of many-sided Henry Marion Howe. Factors oF Impact Strength The subject chosen for the Howe Memorial Lecture by Dr. Gillett last year

Jan 1, 1941

By G. V. Woody, J. D. Price

Many producers of by-product coke have spent considerable time and given considerable thought to the use of a substitute for low-volatile coal as an admixture with high-volatile coking coal for charging high-temperature by-product coke ovens. Generally speaking, there are two principal reasons for this, one being occasioned by the lack, in certain localities, of low-volatile coal delivered at a cost sufficiently low to permit its use, and another being the desirability of finding a substitute product with a delivered cost lower than the cost of the low-volatile coal. It was for the first of these reasons that the Colorado Fuel and Iron Corporation was particularly interested in this subject. This paper deals with the experimental work and the results obtained by that company in producing and using low-temperature char. Overcoming Defects in Coke from Colorado Coals Colorado coking coals are all of the high-volatile type and were all laid down during the Cretaceous period, which makes them something like 80 million or so years younger, geologically, than eastern coals. They behave, when coked alone, something like the Pittsburgh-seam coals. They make a very brittle, highly cross-fractured, fingery coke of fair shatter value but quite low in resistance to abrasion. Mixed with a low-volatile coking coal such as Poca- hontas or certain Oklahoma coals, they make a coke that is equal to virtually any of the eastern cokes. The inferior quality of Colorado coke has long been recognized, and a considerable amount of time, effort and money has been spent upon investigations of means for improving its physical properties. While it has been found that some improvement in quality of coke can be secured by the adjustment and control of such variables as pulverization, moisture content, oven temperature and bulk density of charge, and through the addition of certain inert materials such as pulverized coke breeze, pitch, high-volatile noncoking or semicoking coal, the benefits so gained have been comparatively small. There are no low or medium-volatile coking coals available within a reasonable freight-cost distance. Therefore a substitute for low-vol-atile coal was developed through low-tem-perature carbonization—or, more correctly speaking, through the partial devolatiliza-tion—of high-volatile coals. The blending of this lower volatile char with the high-volatile coking coal distinctly improves the quality of coke made from Colorado coal. There is nothing especially new about this idea. In 1908 a Japanese patent was taken out by Kotaro Shimomura, whose claim was: The method of making a nonfingery coke out of bituminous coals, without using natural coals of low-volatile matter; according to which a certain coal is heated at a temperature between about 300°C. and about 600°C. so as to leave about 15 to 25 per cent volatile matter in the coal; this coal is mixed with the

Jan 1, 1944

By Earnshaw Cook, J. A. Fellows, Howard S. Avery

Heat-resistant alloys of the higher nickel and chromium ranges have been empirically developed through the practical experience of the past two decades to a position of significant industrial importance. Few quantitative metallurgical data have been published, however, that could be related directly to engineering specifications and design. Inadequate information led to the inauguration, in 1934, of a research directed toward a better understanding of the properties and performance of these steels at temperatures between 1400° and 2000°F. Investigation was concentrated upon the 26 per cent Cr:I2 per cent Ni type, which owes its extensive application to an excellent combination of economy, strength and surface stability at elevated temperatures. The requirements of the oil-refining industry have been prominent in influencing the scope and evolution of the program. Creep strength at the maximum allowable deformation ranges has been employed to evaluate the merits of these alloys. Permissible elongation rates vary from 1.0 per cent in one million hours for turbine blades to I .o per cent in ten thousand hours for tube supports and heating-furnace equipment. Throughout this paper, the limiting creep stress (L.C.S.) for a given temperature has been defined as the stress that will produce a uniform elongation rate (stage 11) of one per cent in ten thousand hours as extrapolated from rates per hour for tests of less than two thousand hours duration. Certain current specifications require a minimum L.C.S. of 1600 lb. per sq. in. at I800°F., of 3600 lb. per sq. in. at 1400°F., and include a tensile acceptance test at room temperature, after aging for 24 hr. at 1400°F., as a measure of embrittlement in service. An elongation of 4 per cent is considered satisfactory for general use, while a minimum of 9 per cent is prescribed on occasion. Many differences of opinion concerning the properties and performance of these alloys appear to result from their sensitivity to unappreciated variations of chemical analyses which, for example, may change their L.C.S. from 3500 to 350 lb. per sq. in. at 1800°F. Within broad chemical limits, it is possible to balance the six or more important elements present to attain desirable properties with a number of different combinations. One method for adjusting the composition has been described under the sponsorship of the Alloy Casting Institute,' in which, by maintaining a substantially austenitic* alloy, optimum creep strength and minimum tendency to embrittle after aging are expected. Unless, however, the limits are undesirably close, it has not been possible to ensure a moderate range of strength and of ductility by any chemical specification alone. There is a definite need

Jan 1, 1942

By J. T. Eash, N. B. Pilling

As a group, the alloys of iron, nickel and carbon are, in application, one of the most versatile of the ferrous alloy family, and while many investigations have been made of their properties and structure only a few attempts have been made to show the microstructural relation over a wide range of composition. It is neccssary at once to be clear about the kind of structural relation with which we are concerned. The equilibrium diagram provides quantitative data regarding structural make-up and its variation with temperature, but equilibrium structures often are far different from the technologically significant ones. This is particularly true of steels and cast irons, and some of the most important cornponents of their structure may have no place in the diagram of equilibrium. The fugitive phases that result from transFormation are dealt with in a highly detailed and descriptive manner in. the S-curves originated by Bain. The present effort lies in a still different field, which is to portray the relation between sweeping changes in composition and in resultant structure, under controlled but nonequilib-rium conditions of thermal treatment. The Guilletl diagram presented in 1903 was the initial attempt at such a correlation and frequent references to this diagram can be found in the literature even though later work has shown it to require considerable modification. Kase2 published in 1925 a diagram that was based upon observations of furnace-cooled melts: At low carbon contents this diagram agreed fairly well with experience in showing pearlite to exist in alloys containing up to 6 per cent nickel, and completely austenitic steels at 24 to 28 per cent nickel. At high carbon contents, however, irons were indicated as being martensitic at around 2 per cent nickel and austenitic at 12 per cent nickel; these interpretations are open to serious question. Based upon experience with steels and cast iron, Wickenden3 suggested a diagram that agreed fairly well with Kase's in the steel range but which presented a wide departure from it in the higher-carbon, high-nickel regions. In its broad picture, the Wickenden diagram is an approach to "practical" structures. Reference may be made at this point to the efforts of Marsh5 to construct an iron-nickel-carbon equilibrium diagram by the coordination of scattered data, which are described at length in the monograph cited. None of these preceding attempts has appeared to meet the need for an exposition of the structural sequence that is encountered in traversing the nickel-steel nickel-cast-iron range under what might be called ordinary departures from equilibrium. ExperimentaT. Conditions Since the intent has been to establish structures developed under arbitrary conditions, experimental details have perhaps more than usual importance. Three of these conditions should particularly be noticed: (I) the material was cast and not subjected

Jan 1, 1942

By N. Tiner

The mechanical properties of magnesium-alloy castings are greatly improved by grain refinement, and at present considerable attention is being paid to methods of obtaining fine-grained castings. One method of achieving this end is the use of proper melting and superheating techniques. These have been employed com-rnercially to a great extent, but no comprehensive study of the subject appears to have been published at present. Numerous investigations found in the literature include some reference to superheating techniques,1"4 and Achenbach, Nippcr and Piwowarsky,% ased principally on thermal analysis, ascribe the grain-refilling action of superheating to the influence of solid foreign particles or dissolved gases present in the melt upon the course of crystallization. The primary purpose of this paper is to present the principal facts concerning the cffect of superheating on grain size of magilesium alloys. .ittempts are also made to explain the experimental results in terms of a general hypothesis. The investigations are limited chiefly to common commercial casting alloys. In order to carry on this work, it was necessary to determine the factors influencing grain size and to develop a proper technique for the preparation of samples. Thc preliminary tests made by the author indicated that the grain size of magnesium alloys resulting from the solidification of a melt is determined by alloy composition, presence of impurities, rate of cooling during solidification, thermal history of the melt and to some extent the structure of the charge used. The rate of cooling is in turn dependent upon the mass of the melt, pouring temperature, and dimensions, properties and temperature of the mold into which the melt is poured. The final grain size of the alloys is still further modified by heat-treatment subsequent to casting. It is not within the scope of the present paper to discuss all of these factors, and it would suffice to note here that when equal amounts of magnesium alloys are prepared from the same alloying materials, melted in graphite crucibles under the same thermal conditions, then cast into graphite molds at a constant temperature, the resultant solids have the same grain size. By maintaining all other factors constant, it is thus possible to vary thermal conditions of a melt and to examine the grain size of resultant castings. Preparation of Samples and Grain-size TestiNg The alloys investigated in this paper were taken from ingots made by Permanente the Or or prepared by the author with pure carbothermic magnesium and necessary alloying elements. Melting was carried out under a flux in a graphite crucible heated uniformly by an

Jan 1, 1946

By John O. Farmer

The wire-line tubing perforator is a mechanically operated tool that is run on an ordinary steel measuring line into the tubing of a well, under pressure, to drive into the wall of the tubing, and securely lock in place, a tapered, cylindrical insert containing an orifice. Use of the perforator obviates the necessity of pulling and rerunning the tubing to install jet collars or flow valves, reduces the cost, and simplifies the task, of placing an oil well on gas-lift operation. More important, however, is the use of the tool with a removable check valve and stop, to provide a means of washing drilling mud from the annulus between the tubing and casing, and to complete the well for gas lift operation without exposing the producing formation to the mud column and without moving the tubing string. This paper discusses the origin, development, and mechanics of the wire-line perforator, the various purposes for which the tool was designed, and the method of selecting orifice sizes for any depth, and gives the results obtained thus far in practical application. Origin and Development Several years ago, a tool that could be lowered on an ordinary steel measuring line into the tubing of a well under pressure was designed and constructed for the purpose of punching a hole in the tubing walls above a shale bridge that had completely plugged the tubing of a well in the Long Lake field, East Texas. The well was in a low, swampy area, which excessive rainfall had caused to be in- accessible by car or truck for about four months. The only equipment at the well site consisted of an ordinary steel wire line that had been carried there to measure the depth of the bridge. Since a pulling unit could not be moved to the well site, and as the pressure on the casing was 2100 lb. per sq. in., it became apparent that the only way out of the predicament was to make a perforating tool that could be lowered into the tubing on a measuring line and operated under Pressure. Thus, the first wire-line tubing perforator was designed and built as an expedient, and was not used extensively until it had been redesigned to meet more frequent and increasingly urgent needs. Until recently, it was necessary to pull the tubing to install jet collars or flow the when a well was to be placed On gas lift. Because most companies either maintained or had access to pulling units and crews for this work, little or no thought had been given to eliminating or even simplifying this task. When the manpower and steel shortage became so acute, however, many operators suddenly found themselves without facilities to equip their wells for gas lifting. The wireline tubing perforator already had been tried and proved successful, therefore operators immediately requested its use to punch gas-jet holes in the tubing, to eliminate the pulling and running of tubing strings. The first deficiency revealed by more general use of the perforator lay in the inability to regulate the size of the hole punched through the tubing. The size could not be controlled to any degree of

Jan 1, 1946

By R. T. Tshikhudo

Nanotechnology can provide solutions to many of the world?s socio-economic challenges. The application of nanomaterials for water treatment and analysis, point-of-care diagnostics and targeted drug delivery systems or devices could improve the quality of life for people in developing countries. Gold colloids have a long history (dating back to the 4th century AD) and are particularly well known for their aesthetic appeal and their therapeutic properties. Since Faraday published a report on the synthesis and properties of colloidal gold in 1857, a reasonable insight into the nature of gold sols (nucleation, growth and kinetics of coagulation) has been developed. Considerable attention has been drawn during the past few decades to the development and optimization of methods for the preparation of gold nanoparticles. In nanoscience and nanotechnology today, gold nanomaterials appear to be the most widely used material by both academics and industrialists. This is due to the extraordinary properties of gold nanoparticles (e.g. optical, catalytic, and magnetic?they are also known to act as strong Raman enhancers and may also amplify fluorescence under certain circumstances). Mintek, through Project AuTEK and the DST/Mintek Nanotechnology Innovation Centre (NIC), has been at the forefront of the development of new industrial uses for gold. Mintek?s gold nanotechnology programme focuses on the development of gold-based nanostructured materials and their applications in health, water and other related areas. While few projects use gold nanoparticles for water treatment and analysis, Mintek?s gold nanoparticles are widely used in the health sector. For example, gold nanoparticles are engineered and produced in large quantities as systems for targeted drug delivery. They are also used as tools for advanced rapid diagnostic tests. Both optical and electrochemical rapid diagnostic methods are developed for the human and animal health sectors for point-of-care testing. This paper gives a brief introduction and overview of gold nanotechnology, and desrcibes the development of some of Mintek?s gold nanoparticle targeted drug delivery systems and lateral flow point of care prototype devices.

Jan 1, 2009

By R. I. Jaffee, C. M. Craighead, G. A. Lenning

Hydrogen forms a beta-stabilized system with titanium, with a beta eutectoid at about 300°C and 44 atomic pct H2. 'The solid solubility of hydrogen in alpha decreases from about 8 to about 0.1 atomic pct from 300°C to room temperature. Hydrogen has little effect on tensile properties, but decreases notch-bar toughness to a large degree. This latter effect appears to be the result of increased notch sensitivity. PRIOR to this investigation, only a small amount of information was available on the effect of hydrogen on the mechanical properties of titanium. The effects of the other interstitially soluble elements, carbon, oxygen, and nitrogen, had received detailed study. Jaffee and Campbell1 indicated that hydrogen up to 1 atomic pct did not affect tensile properties deleteriously. Pitler' indicated that 1 atomic pct H, in titanium reduced the impact strength appreciably, but his alloys contained appreciable amounts of oxygen, and it was difficult to attribute the embrittlement entirely to hydrogen. The high temperature portion of the equilibrium diagram for the Ti-H system was established by McQuillan," and his data generally corresponded with the results of Kirschfeld and Sieverts," Gibb and Kruschwitz," Bevington, Martin, and Mathews," and other investigators. The lower concentration limit of the hydride phase varied considerably among investigators, and Gibb and Kruschwitz9 ad shown that small amounts of contaminants in either titanium or hydrogen caused considerable variation in this lower limit. In view of this pronounced effect of contaminants, the extrapolated value of McQuillan's, about 48 atomic pct at the 325°C eutectoid, appeared the most reasonable. McQuillan's lowest experimental value was 54 atomic pct at a temperature of 450 °C. The density of titanium had been shown to decrease with increasing hydrogen content, but discrepancies were noted among the various investigations. The best values indicated that the density was decreased from 4.56 grams per cc at 0.27 atomic pctl to 3.84 grams per cc at 61.3 atomic pct? This investigation was conducted to determine the effects of hydrogen on a titanium, both in high purity and commercially pure metals, and on high purity a titanium alloys. Material and Fabrication The literature indicated that impurities in either the hydrogen or the titanium must be kept to a minimum. For this reason, the initial studies were made with high purity iodide-refined titanium. The vendor's analysis of the iodide titanium and the hydrogen content of the as-fabricated Y4 in. diameter rods are shown in Table I. Two 1 lb ingots were prepared by arc melting under argon in a water-cooled crucible, using a water,cooled tungsten electrode. This equipment has been described.' As-cast Brine11 hardness numbers of 88 and 58 for these ingots were low enough to insure that the high purity of the metal was maintained during arc melting. The ingots were hot forged to % in. diameter rods at 800°C, cleaned by grit blasting, and then cold swaged to Yz in. diameter rods. The rod was then air annealed at 725 "C, ground to remove scale, and cold swaged to Y4 in. diameter (75 pct reduction in area). The material was then annealed for 1 hr in argon at 800°C to develop an equiaxed a grain size of about 0.05 mm. Micro tensile specimens and microimpact specimens were machined from this rod prior to treatment in the Sieverts-type absorption apparatus. Two lots of commercially pure RC-55 titanium were also used in this investigation to determine the effects of hydrogen and the normal impurities on mechanical properties. The commercially pure RC-55 alloy was obtained in the form of % in. diameter rod. The analysis of this material is also given in Table I. The % in. diameter rods were hot swaged

Jan 1, 1955

By P. Pietrokowsky, T. E. Tietz, J. E. Dorn

The amount of solid solution hardening in aluminum alloys was found to be dictated by two factors: the lattice strain, and the change in the mean number of free electrons per atom of the solid solution. To obtain this correlation it was necessary to assume that aluminum contributes two electrons per atom to the metallic bond. WHEN the modern scientific method of analysis was first being formulated, Francis Bacon recorded in his "Essays" (circa 1600) that "an alloy . . . will make the purer but softer metal capable of longer life." During the intervening centuries voluminous data have been reported which demonstrate that the additions of alloying elements do in fact increase the hardness and strength of the pure metals. Nevertheless, the significant details of this problem on the unique effect of each element toward enhancing the mechanical properties of alloys only recently have been subjected to systematic scientific scrutiny. The major objective of this investigation is to determine how minor additions of alloying elements affect the plastic properties of polycrystalline aluminum alloys. By means of such studies it is hoped to provide not only data on the solution strengthening of aluminum alloys, but also a body of facts which will supplement the knowledge already available on the factors responsible for solution hardening in general. A review1"10 and analysis1' of the existing data on the effect of solute elements on the plastic properties of solid solutions reveal that our current knowledge on solid solution hardening is somewhat meager, inconsistent, and inconclusive. Many of the inconsistencies are undoubtedly attributable to the influence of unsuspected factors, such as purity; or uncontrolled factors, such as grain size, on the plastic properties of alloys. Nevertheless the following conclusions might be tentatively accepted: 1. Addition of solute elements invariably increases the yield strength, tensile strength, and hardness of the host element. 2. The rate of strain hardening, in general, increases with the concentration of the alloying element. 3. The strengthening effect in ternary alloys is the sum of the individual strengthening effects of the two solute elements as measured in their binary alloys. 4. The lattice strain is one factor that affects the strengthening of the alloy but it is not the only factor. 5. A second factor might be the difference in valence between the solute and solvent metals. All of the available evidence is in complete agreement with the first conclusion; the remaining conclusions, however, are not in agreement with all of the published data, but, in each case, the major weight of the existing evidence favors these deductions. Additional investigations will be required before most of these tentative conclusions can be accepted without reservation. In the following report an extensive investigation of the plastic properties of binary aluminum alloys is described. This work was undertaken in an attempt to shed more light on the general problem of solid solution hardening. Materials for Test: Aluminum was selected as the solvent metal for the present investigation on the effect of solute elements on the plastic properties of alloys. This choice was made for several reasons: (1) There appears to be little fundamental data in the published literature on the effect of solute elements on the properties of high-purity aluminum alloys. In view of the ever increasing economic importance of aluminum, such data would be of basic interest to the metallurgists concerned with the development of new aluminum alloys. (2) Aluminum is thought to be only partially ionized in the metallic state1' and consequently it might provide more complex relationships of the mechanical properties with the concentrations of the solute elements than more simple fully ionized solvents would reveal. (3) The data on aluminum alloys will provide a broader basis for correlations between the mechanical properties of metals in general and the concentration and atomic properties of the solute elements than is now available. Some complications, however, attend the selection of aluminum: The solubility of the various elements in the alpha aluminum phase are quite restricted, and not always well known. Consequently, only dilute solid solutions are available for study. This, however, may be somewhat advantageous because the dilute solution laws presumably are simpler than those applying to concentrated solutions. In addition, strain-hardened pure aluminum is known to recover at atmospheric temperatures. Very likely its alloys exhibit slower recovery rates. Thus, the secondary factor of effect of alloying elements on recovery might complicate the data. Such compli-

Jan 1, 1951

By T. L. Joseph

It is a distinct privilege to participate in this meeting convened to honor the memory of Henry Marion Howe, a distinguished scientist and metallurgist. Many have added to our rapidly growing fund of metallurgical knowledge but few have made the unique contribution of formulating basic concepts essential to an over-all comprehensive view of the subject of metallography. Of those previously selected to deliver this lecture, several have added a personal touch to their discourse because they were able to refer to their associations with Dr. Howe. It was not my good fortune to know him or to enjoy his inspiring influence. Like most of you, my contact has been with his published works, which are outstanding in that they provide lucid, detailed expositions of the nature and behavior of metals and alloys. His deep understanding and clarity of expression have greatly accelerated our progress in metallography and in the use of metals. The degree to which a man's thinking, experimentation and writing contribute toward an understanding of basic laws and phenomena determines whether his life's work is of transitory or permanent value. This occasion appropriately recognizes the fundamental importance of Dr. Howe's pioneer work in the field of metallurgy.. On two former occasions, gray iron was selected as a subject for discussion. The fact that the production of pig iron has not been discussed before does not reflect any lack of interest on the part of Dr. Howe or former lecturers in the process that underlies the production of steel. Although Dr. Howe's work in his later years centered around metallography, his earlier publications show a considerable interest in the production of iron and steel. He recognized that in the ascending spiral of metallurgical advancement we are not winding a single thread but are weaving a complex fabric. Specific evidence of his interest in the production of pig iron may be found in his book' on The Metallography of Cast Iron and Steel. In explaining why blast furnaces have been in constant use for about 600 years, he says: "The process is economical because it utilizes with extraordinary completeness the calorific power of the coke due to the thorough transfer of heat from the gaseous products of combustion to the charge." This emphasis on heat transfer, overlooked in many more extended and more recent discussions of the blast-furnace process, illustrates Professor Howe's ability to see the essentials. Other distinct advantages of the blast furnace, such as the removal of- much of the sulphur and practically all of the oxygen, were mentioned. It was also stated that although the blastfurnace process is complex in nature, its outward form is comparatively simple, thus permitting large-scale production at small labor costs. All who contemplate the production of metallic iron from its ores by any other process might well consider the

Jan 1, 1947

By Griffith L, Lama RD

West Cliff Colliery mines Bulli Seam occurring at a depth of approximately 480 m. The Seam is intersected by a number of small shear zones and faults. While the faults have caused displacement of the seam, the shear zones are strike-slip structures with small apparent displacement of seam. Outbursts at West Cliff Colliery occur while driving through these shear zones. Few outburst wave occurred where faults have been intersected. In the last 3 years, over one hundred outbursts have occurred at West Cliff Colliery. The size of outbursts varies from a small bump to exceeding 140 tonnes of coal. A number of studies have been undertaken at West Cliff Colliery to control outbursts and predict Outbursts in advance of workings. These include: geological investigations, microseismic techniques, gas adsorption studies and gas drainage. The investigations to date suggest that outbursts of gas at West Cliff Colliery are more a gas phenomenon similar to what occurs in overseas mines. The results of various investigations are reported. West Cliff Colliery is located in the mid- west of the southern coal fields of N.S.W.

Jan 1, 1980

By John O. Farmer

The wire-line tubing perforator is a mechanically operated tool that is run on an ordinary steel measuring line into the tubing of a well, under pressure, to drive into the wall of the tubing, and securely lock in place, a tapered, cylindrical insert containing an orifice. Use of the perforator obviates the necessity of pulling and rerunning the tubing to install jet collars or flow valves, reduces the cost, and simplifies the task, of placing an oil well on gas-lift operation. More important, however, is the use of the tool with a removable check valve and stop, to provide a means of washing drilling mud from the annulus between the tubing and casing, and to complete the well for gas lift operation without exposing the producing formation to the mud column and without moving the tubing string. This paper discusses the origin, development, and mechanics of the wire-line perforator, the various purposes for which the tool was designed, and the method of selecting orifice sizes for any depth, and gives the results obtained thus far in practical application. Origin and Development Several years ago, a tool that could be lowered on an ordinary steel measuring line into the tubing of a well under pressure was designed and constructed for the purpose of punching a hole in the tubing walls above a shale bridge that had completely plugged the tubing of a well in the Long Lake field, East Texas. The well was in a low, swampy area, which excessive rainfall had caused to be in- accessible by car or truck for about four months. The only equipment at the well site consisted of an ordinary steel wire line that had been carried there to measure the depth of the bridge. Since a pulling unit could not be moved to the well site, and as the pressure on the casing was 2100 lb. per sq. in., it became apparent that the only way out of the predicament was to make a perforating tool that could be lowered into the tubing on a measuring line and operated under Pressure. Thus, the first wire-line tubing perforator was designed and built as an expedient, and was not used extensively until it had been redesigned to meet more frequent and increasingly urgent needs. Until recently, it was necessary to pull the tubing to install jet collars or flow the when a well was to be placed On gas lift. Because most companies either maintained or had access to pulling units and crews for this work, little or no thought had been given to eliminating or even simplifying this task. When the manpower and steel shortage became so acute, however, many operators suddenly found themselves without facilities to equip their wells for gas lifting. The wireline tubing perforator already had been tried and proved successful, therefore operators immediately requested its use to punch gas-jet holes in the tubing, to eliminate the pulling and running of tubing strings. The first deficiency revealed by more general use of the perforator lay in the inability to regulate the size of the hole punched through the tubing. The size could not be controlled to any degree of

Jan 1, 1946

By O. C. Baptist

The Umiat oil field is in Naval Petroleum Reserve No. 4 between the Brooks Range and Arctic Ocean in far-northern Alaska. The Umiat anticline has been tested by 11 wells, six of which produced oil ; however, [lie productive capacity and recoverable reserves of the field are subject to considerable speculation because of unusual reservoir conditions and because several wells appear to have been .seriously damaged during drilling and completion. Oil is produced at depths of 275 to 1,100 ft; the depth to the bottom of the permanently frozen zone varies from about 800 to 1,100 ft, .so that most of the oil reserves are in the permafrost Reservoir pressures are estimated to range from 50 to 350 psi, increasing with depth, and the small amount of gas dissolved in the oil is the major source of energy for production. Laboratory tests were made on cores under simulated permafrost conditions to estimate oil recoverable by solution-gas expansion from low saturation pressures. The cores were also tested for clay content and susceptibility to productivity impaiment by swelling clays and increased water. content if exposed to fresh water. The results indicate that oil can be produced fronz reservoir rocks in the permafrost and that substantial amounts of oil can be produced from depletion-drive reservoirs by a pre.s.r~lrr drop of as little as 100 psi below the saturation pressure. Freezing of formation water reduces oil productivity much more than that due to increased oil viscosity: Failure of we1ls drilled with rtuter-base mud to produce is attributed to freezing of water in the urea immediately surrounding the wellbore. Swelling clays apparently contributed very little to the plugging of the wells. INTRODUCTION Naval Petroleum Reserve No. 4 lies between the Brooks Range and the Arctic Ocean in northern Alaska. The Umiat oil field is located in the southeastern part of the Reserve and is about 180 miles southeast of Point Barrow (the only permanent settlement in the Reserve and the primary supply point for drilling of the wells at Umiat). Eleven wells were drilled for the U. S. Department of the Navy, Office of Naval Petroleum and Oil Shale Reserves, between 1944 and 1953 to test the oil and gas possibilities of the Umiat anticline. Six of these wells produced oil in varying quantities and the best one pumped about 400 B/D.' Estimates of recoverable oil range from 30 to 100 million bbl. The main oil-producing zones are two marine sandstone beds in the Grandstand formation of Cretaceous age: these are referred to as the upper and lower sands. Good oil shows were found throughout the sand settions in the first three wells drilled on the structure, but the highest rate of oil production obtained on any 01 the many tests was about 24 BOPD. These first wells were drilled with conventional rotary methods using water-base mud; later wells were drilled either with cablc tools using brine or rotary tools using oil or oil-base mud. These experiments were successful as is shown by comparing the oil production from Well No. 2 with that from No. 5. These two wells are only 200 ft apart and are located at about the same elevation on the structure. Well No. 2. drilled with a rotary rig using water-base mud, was abandoned as a dry hole after all formation tests were negative. Well No. 5. drilled with cable tools and reamed with a rotary using oil, pumped 400 BOPD which was the maximum capacity of the pump and less than the capacity of the well. These field results indicated that the producing sands were extremely "water sensitive" and it was assumed that the cause of this sensitivity was the presence of swelling clays in the sands. Because of the very unusual reservoir conditions and the difficulties encountered in completing oil wells in the permafrost. the Navy asked the U. S. Bureau of Mines to make laboratory studies under simulated permafrost conditions to assist them in estimating the production potential of the field and the recoverable reserves. These tests were designed to determine the cause of the plugging of wells in the permafrost and to test oil recovery from frozen sand by solution-gas expansion with the oil gas-saturated at very low pressures. EXPERIMENTAL METHODS AND PROCEDURES Samples Analyzed Core samples were analyzed that represent the lower sand in Umiat Well No. 7, the upper sand in No. 3. and both the upper and lower sands in No. 9. These sands should be productive in all of the wells because of their location on the structure. Core samples from

"Sedimented hydrothermal precipitates of silica, now fine-grained quartz, are described from a Pb-Zn-bearing vein system. Their discrimination from the wall-accreted fine-grained quartz that is common in the shallow parts of epithermal systems is discussed. Local fine-grained (<0.3 mm) quartz accumulations occur in a suite of veins with otherwise normal drusiform and crustified infills. This sediment may fill the vein above chokes in steep segments (axial plugs), or form continuous layers within the footwall material where the vein is inclined at low to moderate angles. Pads of fine-grained sediment are deposited on the upwards-facing surfaces of wall-rock clasts and of drusiform crystals growing from the vein walls. The asymmetry of these deposits differentiates them from the more common symmetrical, crustified walllining deposits of fine-grained quartz and opaline silica, and requires a gravity-controlled, sedimentary depositional mechanism.Thin section examination shows that much of the fine-grained quartz is present as elongate prisms. The prism habit was present soon after deposition, but it is not possible to identify unequivocally the original sedimented grains. Sedimentation of vein- and wall-rock-derived detritus is also recognized. Deposition of the fine-grained sediment accompanies normal in situ drusiform growth of quartz and other vein minerals. The mammilated and spherulitic textures associated with accretion of amorphous quartz are entirely absent from the Tyndrum veins with sedimented materials. The literature on modern hydrothermal waters and physical chemistry of silica precipitation shows that precipitates of silica suspended in hydrothermal fluids are amorphous and derived from colloidal silica. It is argued that much of the suspended silica was present as quartz at the time of deposition or was converted from amorphous silica almost immediately after deposition.Hydrothermal sediments and their distribution potentially provide information on flow directions and velocity in veins. Plugs of sediment obstruct vertical flow and lead to local flows with large horizontal components. It is shown that sedimentation features occur in other deposits and can involve other minerals. If the features seen here can be scaled up to the size of major veins, they may result in up and downdip variations in mineral assemblages and abundances, which may affect grade."

Jan 1, 2007

By Arnulf Muan, Carlos Landolt

Equilibria involving Cu-Pt alloys, copper oxides, and atmospheres of known ox2gen pressures have been determined at 1000&apos; and 1200 C. The data obtained have been used to calculate activity-composition relations in the alloys. A moderate negative deviation from ideality is found. At high copper concentrations, the results of the present study are in good agreement with those of previous investigators, whereas at low copper concentrations the activities obtained in this investigation are slightly higher than those reported previously. The present study is part of a research program dealing with the determination of phase relations and thermodynamic properties of copper-containing systems at high temperatures. The information available for such systems is very scanty, particularly for copper oxides and their combinations with other oxide components. Platinum is commonly used as a container in studies of oxide equilibria. To evaluate quantitatively the extent of reaction between the oxide and the container, a knowledge of activity-composition relations in Cu-Pt alloys is necessary. Such data are not available for Cu-Pt alloys in the temperature range of particular interest in the present research program, and particularly for alloys low in copper. Studies of various aspects of the systems Cu-Pt and Cu-0 have been reported in previous literature. The system Cu-Pt is known1 to form a continuous solid-solution series above 812.C, whereas ordered phases are present in certain composition ranges at lower temperatures. Thermodynamic data for the system have been reviewed by Hultgren et al.,&apos; who presented free energies of mixing at 65Oo C, mainly derived from electromotive force cell measurements by Weibke and Matthes.3 Enthalpies of mixing at 640°C have been obtained by Oriani and Murphy4 with liquid tin calorime-try. Their results differ considerably from those derived from the temperature dependence of the data of Weibke and Matthes. Thermodynamic data for the disordered alloys have been obtained by Assayag,5 and more recently by Schmahl and Minzl,6 by Myles and Darby,7 and by McCormack, Myers, and Saxer.8 The two latter sets of data7&apos;&apos; became available after the present study was completed. In the system Cu-0+ two oxides are stable at high temperatures, CuO and CuzO+ each having only minor deviations from stoichiometry. Equilibria in the liquidus temperature region of the system Cu2O-CuO have been studied by Roberts and systemsmyth,9&apos;10CuzO-CuO by Vogel and ocher,I1 by Osterwald,12 and recently the the present authors.13 The system is of the eutectic type with a eutectic temperature of 1083.C The composition of the eutectic liquid corresponds to Xcu0 = °.44, and the oxygen pressure of the coexisting gas phase is Po2 = 0.55 atm.13 Equilibrium oxygen pressures for coexistence of solid CuO and solid Cu2O have been determined by Schmahl and Muller,l4 by Gadalla, Ford, and white,l5 by Bidwell,16 and recently by the present authors.13 There is reasonably good agreement among the various sets of data. Free energies of formation of Cu2O(s) from the elements have been derived by Tretyakov,17 by Bidwell,16 by Kiukkola and wagner,18 by Pal&apos;guev and Neuimin," and by Steele and Alcock,20 There is particularly good agreement among the latter three1&apos;-20 sets of data. THEORETICAL BASIS Consider a subsolidus isothermal section of the system Cu-Pt-0, as shown in Fig. 1. Two phase as-

Jan 1, 1970

By Quemard D, Troncoso J

The Gordonstone Project with a capital cost in excess of $500 million will become the largest underground coal mine in Australia. The project development decision was taken on 31 July, 1990 and at 31 May, 1991 construction was approximately 35 per cent complete. The first train of processed product coal will be railed to Gladstone during December 1992. The general theme of this paper therefore will address the planning and development processes at Gordonstone particularly the interrelatedness of technical, production, construction and environmental disciplines to ensure success during operations.

Jan 1, 1991

By Larry Rayburn

Augercast piles evolved in the late forties from the process of pressure grouting open holes backfilled with stone. In 1956, a patent was issued for a cast in situ pile by pumping high pressure grout through hollow-stem, continuous flight auger as the auger is gradually withdrawn from the ground. The patent rights expired in 1973 and the use of auger-cast piles greatly expanded with most large deep foundation contractors now installing augercast piles. At one time augercast piles had a bad reputation, partly because of not having a blow count to give some engineers a confidence factor and there were some quality issues. Over the years the quality issues have been eliminated and I am sure the augercast is the most installed pile in private industry and is now being used by some State Agencies.

Jan 1, 2005