Search Documents

By Marvin L. Kay

In the spring of 1950, just two years after the inauguration of the domestic uranium program by the U. S. Atomic Energy Commission, the company entered the uranium mining and milling business through a newly formed subsidiary, Climax Uranium Co. This was the first venture into a new field of mining for Climax, which became the first old-time mining company, other than the vanadium producers, to become active in the embryo uranium industry. Twenty-five years earlier, Arthur Bunker, president of Climax Molybdenum, organized and operated the U. S. Vanadium Co. at Rifle, Colo. With this background, he viewed the budding industry of the Colorado Plateau with much interest. Upon its formation, the new subsidiary entered into a con- tract with the U. S. Government and the potential uranium-vanadium properties of Minerals Engineering Co. were assigned to Climax Uranium Co. Funds for the construction of a processing plant and working capital were advanced by Climax Molybdenum Co. The old sugar mill building of the Holly Sugar Co. in Grand Junction was leased to house the extractive plant. Construction of facilities, which were based upon a new process developed for the treatment of both uranium and vanadium ores, was completed and the mill was placed in operation early in 1951. Subsequent to that time several alterations were made and the capacity of the plant increased. In terms of recoveries, the plant has proved to be one of the most efficient on the Colorado Plateau

Aug 1, 1955

By J. H. Frye, S. G. Holder, E. E. Stansbury

Internal friction studies on annealed and cold-worked pure silver and alloys of silver with 4.5 atomic pct each of Cd, Sn, and Sb are reported. Small amounts of cold work, introduced by stretching pure silver, decrease the internal friction; large amounts of cold work, by wire drawing, cause this decreased internal friction to rise. Results of severol anneoling histories on the room-temperature in-ternal friction indicate a rather complex recovery and recrystallization behavior. A rather system-atic alloy effect is observed for the elements of Period V-B in silver in both the annealed and cold-worked states. DURING recent years internal friction measurements at very small stress levels have been interpreted in terms of structural models and mechanisms occurring within the metal or alloy.These measurements have been made over wide ranges of frequency of vibration and of temperature. While the effects of impurities, alloying, and plastic deformation have been studied by numerous investigators, no investigations of the effect of a series of solutes related by their position in the Periodic Table on a given solvent seem to have been reported. The present paper reports internal friction measurements on silver and on certain silver-base solid solutions to determine the values of room-temperature internal friction associated with varying amounts of plastic deformation and after different annealing

Jan 1, 1957

By N. F. Neumann, A. W. Schlechten

Metal chlorides were formed by reacting metal oxides and calcium chloride; the effect of additions to the reaction mixture was studied. It was found that by use of proper additions, metal chlorides could be prepared from mixtures that were not reactive under ordinary conditions. ManY recent metallurgical developments involve the use of chlorine or chlorides as primary reagents; good examples are found in the production of ductile zirconium and titanium by reduction of their chlorides with magnesium. Various methods of preparing metal chlorides are used and many others have been proposed. Some chlorides are formed by the direct combination of a metal or alloy with chlorine. Other processes react chlorine and metallic oxides; carbon or other reducing agents are usually employed to reduce the metal oxides and so promote chlorination. Metallic chlorides have also been produced by the exchange of chlorine between metal oxides and a chloride, such as sodium chloride. This type of reaction was the basis for the old process of chloride roasting in which metal ores were roasted in the presence of salt. Soluble chlorides thus formed

Jan 1, 1959

By R. F. Campbell, R. F. Miller

SIXTEEN steels containing different combinations of chromium and molybdenum, in amounts up to 5 per cent of each element, were examined for microstructure and hardness after air cooling and after furnace cooling from suitable austenitizing temper- [ ] atures. Diagrams summarizing the structures and hardness resulting from these two cooling rates are presented (Figs. 3, 4, 7).† Data were also obtained on the influence of these two elements, individually and in combination, on the depth 0f decarburization observed after furnace cooling (Fig. 8). COMPOSITION OF MATERIAL The chemical composition of the steels investigated is given in Table I. The plain carbon steel was made in a 25-ton Heroult electric-arc furnace, while the alloy steels were made in a 4.5-ton Ajax-Northrup elec- [ ] tric induction furnace. The cast ingots were hot-rolled to I.75-in. bars. AIR-COOLED SERIES The I.75-in. bars were forged to flat plates, 0.25 in. thick, from which specimens 0.5 in. wide by 2 in. long were cut. The specimens were pretreated to improve their homogeneity by heating to I830°F. (1000°C.) for 20 min. and oil quenching. They were then reheated to I740°F. (950°C.) for one hour and air-cooled, after

Jan 1, 1941

By Simon Ash

THE coal-mining districts of Washington are mainly west of the Cascade Mountains; Fig. 1. The mines are on the foot hills of the slope, the lignite fields of Lewis and Thurston counties extending into the valleys west of the mountains. An exception is the Roslyn field, a small but important area on the eastern slope. If western Washington is divided into three areas from north to south, the bituminous coal fields and most of the active operations will be found largely in the middle area. The southern portion contains lignites over a large area. In the northern portion, mining is practically restricted to one mine, the Bellingham, which is working a subbituminous coal seam near the city of Bellingham. The degree of alteration that the coal of a particular field has undergone may be gaged roughly by the position of the field with reference to the Cascade Mountains. The lignites of Tenino, Tono, Mendota, and Castle Rock, on the railway line connecting Seattle and Portland, occur in a region, of low relief, in which the Eocene coal measures have suffered only minor disturbances. Subbituminous coals occur in the foot hills, as at Renton, Newcastle, and Bellingham. Coals high in fixed, carbon are found nearer the mountains, where. the measures have been sharply ,tilted and folded, as at Black Diamond and Carbonado. The two typical anthracite fields are located still higher, in the rugged mountains where outcrops appear both in deep gorges and on ridges at elevations approaching 5000 ft. At. Carbonado is found the only semianthracite seam worked on a commercial basis. The occurrence of this seam in a region of bituminous coal is due to the nearness of an igneous sill, which has changed its character from bituminous to semianthracite.

Jan 3, 1925

By W. D. Keller

THE high-alumina clays of Missouri are interesting for several reasons. They are the only sedimentary deposits in North America of first grade (over 70 pct A1,0,) diaspore and boehmite sufficiently large to be mined commercially. Mineralogically, they are composed of diaspore and boehmite in intimate coexistence, but gibbsite, the common hydrated alumina mineral in bauxite and laterite, is absent, or is exceedingly scanty if present.* Therefore, the Missouri high-alumina clays do not represent typical laterization. The physical chemistry leading to their mineral genesis, and the geolbgical setting for their formation, present important problems for scientific study. The origin of the Missouri high-alumina clays has been discussed in earlier reports by Allen1 (1935) and McQueen 8, 9 (1929, 1943). These investigations were made under difficult conditions, however, because no diaspore deposit had been opened where a Paleozoic (Pennsylvanian) rock cover lay undisturbed over the high-alumina clay. The relationship of the clay to only the underlying rocks could actually be observed. Lacking the guidance of critical postdepositional geologic evidence, undue and erroneous emphasis was placed on the postdepositional leaching of the deposits in the theories on the origin of diaspore and boehmite from clay (hydrous aluminosilicates) . With new geologic evidence at hand, a clearer picture can be made for the origin of the Missouri high-alumina deposits. In this paper the geology of a diaspore deposit whose original Paleozoic cover had not been eroded will be described and interpreted genetically. The close relationship of boehmite and diaspore (also with kaolinite and a chloritic mineral), will be established. A theory of origin for the high-alumina clays, consistent with the new data, will be postulated.

Jan 1, 1952

By Nicholas J. Grant, Raymond E. Cairns

A high-purity chromium, made by solid-state extrusion, and a series of molten, extruded, dilute alloys containing carbon, oxygen, nitrogen, and sulfur were studied to establish the effects of composition, cooling rate, grain size, strain rate, and prior strain on the transition temperature for brittle THE transition from ductile to brittle fracture with decreasing temperature remains of extreme interest especially among the refractory metals, such as tungsten, molybdenum, and chromium, which have relatively high transition temperatures. Fracture, yield stress, and hardness. Tension tests at a strain rate of 0.015 per min were generally utilized. Results are interpreted in terms of the quantity of each element retained in solid solution. Of these elements, chromium has been studied the least, but deserves additional attention because of its superior oxidation resistance for high-temperature use. In the past, impurity elements which have received attention are carbon, nitrogen, oxygen, and sulfur;'-' of these, nitrogen has usually been considered to be the most detrimental. Unfortunately, because of different levels of both specific and total impurity content, and because of the many different test and evaluation techniques used, a clear, definitive picture of brittle fracture in chromium has not been forthcoming. However, many

Jan 1, 1964

By Robert B. Sosman

The chance that a Howe Memorial Lecturer will be able to refer back to a personal contact with the distinguished metallurgist for whom this lectureship is named grows steadily I I did not have the pleasure of his personal acquaintance, but I did receive from him in 1916, quite unexpectedly, a letter commenting On a paper that I had recently published27 On "Types of Prismatic Structure in Igneous Rocks." The paper was written for geologists and petrologists, but it had an application, naturally, to the crystallization of iron and steel in a mold. The letter impressed me at the time, and still does, with the breadth of of Howe's interests and his perseverance in keeping up with the progress of any branch of knowledge that had metallurgical connotations. Scope of the Lecture During several years preceding the date mentioned I had worked in collaboration with Arthur L. Day and E. T. Allen8 at the Geophysical Laboratory, Carnegie Institution of Washington, on the temperature scale as defined by the nitrogen thermometer at high temperatures. Later (1928-1947) I had the opportunity of helping to apply this experience to the pyro-metric problems of the steel industry. Because of the range of its temperatures, the multiplicity of the methods used, and the variety of its purposes, pyrometry in the open-hearth process has always offered a fertile field for both research and development. I am therefore devoting an hour to the subject of temperatures in the basic open-hearth furnace, the furnace that makes most of our steel in the united States. I would direct your attention particularly to the choice of the first two words in the title of the Lecture. One sometimes hears or reads of the ((temperature of such-and-such a furnace," as if it were a single, measurable, characteristic quantity. I need hardly emphasize to any one who has ever operated a furnace or a kiln that " temperature of the furnace " is a meaningless phrase. Even if we confine our attention to the space enclosed by the roof, walls, and hearth of an open-hearth furnace, it is doubtful whether any such space has ever been so uniform in temperature that the phrase would have a meaning. In any furnace, there are many different temperatures, capable of being measured at many different places, and actually being measured for several different purposes. These pyrometric purposes, methods, and results, if given in detail, would expand this lecture into a book on the basic open-hearth process. I must therefore confine myself to a statement of the range of temperatures as they have been observed in various parts of the furnace, indicating in a general way why they are measured, and mentioning the methods that are available without attempting to describe these

Jan 1, 1949

By Robert B. Sosman

The chance that a Howe Memorial Lecturer will be able to refer back to a personal contact with the distinguished metallurgist for whom this lectureship is named grows steadily I I did not have the pleasure of his personal acquaintance, but I did receive from him in 1916, quite unexpectedly, a letter commenting On a paper that I had recently published27 On "Types of Prismatic Structure in Igneous Rocks." The paper was written for geologists and petrologists, but it had an application, naturally, to the crystallization of iron and steel in a mold. The letter impressed me at the time, and still does, with the breadth of of Howe's interests and his perseverance in keeping up with the progress of any branch of knowledge that had metallurgical connotations. Scope of the Lecture During several years preceding the date mentioned I had worked in collaboration with Arthur L. Day and E. T. Allen8 at the Geophysical Laboratory, Carnegie Institution of Washington, on the temperature scale as defined by the nitrogen thermometer at high temperatures. Later (1928-1947) I had the opportunity of helping to apply this experience to the pyro-metric problems of the steel industry. Because of the range of its temperatures, the multiplicity of the methods used, and the variety of its purposes, pyrometry in the open-hearth process has always offered a fertile field for both research and development. I am therefore devoting an hour to the subject of temperatures in the basic open-hearth furnace, the furnace that makes most of our steel in the united States. I would direct your attention particularly to the choice of the first two words in the title of the Lecture. One sometimes hears or reads of the ((temperature of such-and-such a furnace," as if it were a single, measurable, characteristic quantity. I need hardly emphasize to any one who has ever operated a furnace or a kiln that " temperature of the furnace " is a meaningless phrase. Even if we confine our attention to the space enclosed by the roof, walls, and hearth of an open-hearth furnace, it is doubtful whether any such space has ever been so uniform in temperature that the phrase would have a meaning. In any furnace, there are many different temperatures, capable of being measured at many different places, and actually being measured for several different purposes. These pyrometric purposes, methods, and results, if given in detail, would expand this lecture into a book on the basic open-hearth process. I must therefore confine myself to a statement of the range of temperatures as they have been observed in various parts of the furnace, indicating in a general way why they are measured, and mentioning the methods that are available without attempting to describe these

Jan 1, 1949

By C. H. Mathewson, J. A. Collins

The process of plastic extension of face-centered cubic single crystalline rods is so well understood, since the notable studies of Taylor and Elam,1 that the change in orientation of any crystal by slip and rotation may be predicted from the measured elongation. It is customary to assume a very homogeneous deformation, wherein gliding lamellar arc free to rotate so that their slip direction continually approaches the axis of the rod, until a second slip system comes into operation; whereupon conjugate slip proceeds quantitatively to an end adjustment with the [121] direction in the axis of the rod. This process has been checked in malty face.-centered cubie materialsand and readily permits the preparation of specimens that have been subjtvted to various determinable amounts of shearing action. It is elearly of interest to study in such measurably strained speeimens the, development of a recrystallized structure on annealing and if possilble detect the source of nuclei from which the new crystals grow. Strain-:~nneali~ig experiments of this charactcr have been performed by others but not in detail sufficient to permit a study, for example, of the number of recrystallized grains vs. the amount of shear. In the experiments now reported, this was done with a wide variety of orientations covering nearly the entire range of slip on a single system and corresponding to amounts of shear (ratio of shearing distance to distance between lamellae at the conclusion of a test of from 0.08 to 0.57. A particular point wa-made of determining the crystallite rotation, or small angular range. assumed by the octahedral slip plane after these various amounts of shear. The, mechanism of reerystallization and the magnitude and effeet of recovery on the recrystallization process was investigated.

Jan 1, 1940

By J. A. Collins, C. H. Mathewson

The process of plastic extension of face-centered cubic single crystalline rods is so well understood, since the notable studies of Taylor and Elam,1 that the change in orientation of any crystal by slip and rotation may be predicted from the measured elongation. It is customary to assume a very homogeneous deformation, wherein gliding lamellar arc free to rotate so that their slip direction continually approaches the axis of the rod, until a second slip system comes into operation; whereupon conjugate slip proceeds quantitatively to an end adjustment with the [121] direction in the axis of the rod. This process has been checked in malty face.-centered cubie materialsand and readily permits the preparation of specimens that have been subjtvted to various determinable amounts of shearing action. It is elearly of interest to study in such measurably strained speeimens the, development of a recrystallized structure on annealing and if possilble detect the source of nuclei from which the new crystals grow. Strain-:~nneali~ig experiments of this charactcr have been performed by others but not in detail sufficient to permit a study, for example, of the number of recrystallized grains vs. the amount of shear. In the experiments now reported, this was done with a wide variety of orientations covering nearly the entire range of slip on a single system and corresponding to amounts of shear (ratio of shearing distance to distance between lamellae at the conclusion of a test of from 0.08 to 0.57. A particular point wa-made of determining the crystallite rotation, or small angular range. assumed by the octahedral slip plane after these various amounts of shear. The, mechanism of reerystallization and the magnitude and effeet of recovery on the recrystallization process was investigated.

Jan 1, 1940

The writing that is effective is woven with a he texture into an agreeable pattern; it is free from knots, loose threads, and stray fluff. The instrument that weaves this literary fabric, whether it produce a homely sock or a lordly tapestry, a simple story or a learned treatise, is a disciplined intelligence, as sure as a steel needle, as precise as a swift loom. The simile breaks down at this point, for the product of the pen is instinct with the human spirit and therefore transcends in beauty anything made by a mere machine. If words are to be woven into eloquent meaning, they must be well knit. Upon the relation of words to each other and of groups of words to other groups, known as phrases, clauses, and sentences, depends the success of writing as a means of transmitting thought from man to man. To be understood beyond question, you should know not only what your words denote' but how to build your sentences; you must not only choose your words aright but construct your sentences properly. A sentence is a combination of words that makes complete sense; it says something about something. A clause is a subordinate sentence or a sentence within a sentence. A phrase is a group of words without a predicate; it makes sense, but not complete sense. For example: I shall wait for a few minutes before I go home. The whole statement is a sentence; "I shall wait" and "before I go home" are clauses; "for a few minutes" is an adverbial phrase. The orderly arranging of words and of combinations of words is called 'syntax'; and from the original Greek form, [s?ta???] (suntaxis), is derived the Greek name for an editor,

Jan 1, 1931

By Thomas Fraser, H. F. Yancey

BefoRe a new coal-washing plant is installed, or an existing washery is remodelled and improved, considerable experimental work on the coal to be washed should be done. A thorough examination of a coal, to determine whether it can be washed successfully and the best and most economical process for securing a satisfactory grade of washed coal, calls for mine sampling, analytical work, and experimental coal-washing tests which may require several months' time and the expenditure of considerable money. Having collected the required data on the characteristics of the coal and the results secured with different types of machines under different sets of conditions, it is necessary to decide what method of treatment should be used. The interpretation of the experimental data is no small part of the problem. The first step in the investigative work is to determine from the characteristics of the coal and the manner of occurrence of the impurities whether it is possible to separate the dirt from the coal and produce a washed coal of the required quality. Then it is necessary to select the type of washer or the system of treatment that will produce the greatest amount of washed coal of this grade for the least cost. To secure this information, tests may be made at laboratories operated by consulting or contracting engineers, at the testing plants of machinery manufacturers, at commercial washeries, or in an experimental washery erected on the site of the proposed plant. Such tests will produce figures in which every factor, including analyses of raw coal and washed coal and yield of washed coal, may vary widely. To reduce these results to a common basis for comparison is very difficult. A number of plans

Jan 1, 1923

By Thomas Fraser, H. F. Yancey

BefoRe a new coal-washing plant is installed, or an existing washery is remodelled and improved, considerable experimental work on the coal to be washed should be done. A thorough examination of a coal, to determine whether it can be washed successfully and the best and most economical process for securing a satisfactory grade of washed coal, calls for mine sampling, analytical work, and experimental coal-washing tests which may require several months' time and the expenditure of considerable money. Having collected the required data on the characteristics of the coal and the results secured with different types of machines under different sets of conditions, it is necessary to decide what method of treatment should be used. The interpretation of the experimental data is no small part of the problem. The first step in the investigative work is to determine from the characteristics of the coal and the manner of occurrence of the impurities whether it is possible to separate the dirt from the coal and produce a washed coal of the required quality. Then it is necessary to select the type of washer or the system of treatment that will produce the greatest amount of washed coal of this grade for the least cost. To secure this information, tests may be made at laboratories operated by consulting or contracting engineers, at the testing plants of machinery manufacturers, at commercial washeries, or in an experimental washery erected on the site of the proposed plant. Such tests will produce figures in which every factor, including analyses of raw coal and washed coal and yield of washed coal, may vary widely. To reduce these results to a common basis for comparison is very difficult. A number of plans

Jan 1, 1923

By C. A. Hansen

Page Introduction............................206 Power Characteristics in Zinc Sulfate Electrolysis........... 207 Current Efficiency......................... 207 Corrosion Rates..........................216 Voltage Required by the Zinc Cell..................219 Power Requirements of the Zinc Cell ................221 Impurities in Zinc Electrolyte.....................222 Non-cumulative Impurities.....................223 Cumulative Impurities ....................226 Impurities in General........................228 Temperature and the Stability of the Zinc Cell..............229 Practical Expedients for Control of the Zinc Cell...........234 Acknowledgments...........................234 Appendix................................235 Discussion...................:.......... - 236 Introduction It has been the experience of the writer, during some five years' work with electrolytic zinc, that the zinc cell is perhaps more sensitive to impurities in the electrolyte than the analytical methods as yet developed for the chemical identification and determination of these impurities; but that, when proper purification methods have been applied to a given solution, the behavior of the cell is quite independent of the original sources from which the zinc sulfate has been derived. It has also appeared that the behavior of the zinc cell is the best and surest check on the correctness and thoroughness of the purification methods used, because it indicates the presence of both current impurities and cumulative impurities derived from the leaching of the ore; it also indicates whether these impurities are current or cumulative, at least in so far as they are of serious importance commercially.

Jan 1, 1919

By Lawrence K. Jetter, Robert F. Mehl

SOME advances have been made recently in the theory of the kinetics of precipitation from metallic solid solution despite the complexities of the problem, but there is surprisingly little quantitative information available on rates of precipitation with which to test present theory or upon which to build new theory.‡ Attempts to measure rates of precipitation have been beset with difficulties which originate both in the anomalies that attend the changes in the properties selected for measurement, as, for example, in electrical conductivity or mechanical properties, and also in the complexities in the structural changes in some systems, as in the aluminum-copper system. If the functional relationship between the quantity of precipitate and the value of the selected property is uncertain, measurements of that property are obviously of uncertain utility in determining absolute rates of precipitation. If the precipitating system passes through one or more transition stages, the interpretation of measured rates lacks definiteness; in such cases, it is necessary to measure the rate of reaction in each separate stage, if the rate measurements are to have any significance from the kinetic point of view.* These difficulties cannot be wholly avoided, for at least in some measure they are characteristic of the process of precipitation from solid solution, but they can be minimized both by the selection of a simple system and by the use of a method of measurement relatively free from anomalous behavior. The present paper reports dilatometric measurements on the rate of precipitation of silicon from the aluminum-rich solid solution in the aluminum-silicon system-a study that approaches the desiderata of simplicity. The aluminum-silicon system offers advantages from these points of view: there are no known anomalies in the property changes accompanying precipitation; 2.3,4 there are no known transition stages; the precipitate is an element, not a compound, and both matrix and precipitate are cubic, and while the structures are not identical (the solid solution is face-centered cubic and the precipitate is diamond cubic), the system at least approaches the ideal case of a crystal precipitating from a matrix of the same crystal type-the ideal case which Becker5 assumed in treating the precipitation process theoretically. The dilatometric method, while not free from disturbing effects, as the subsequent dis-

Jan 1, 1942

By Ellis Clark

DURING the winter of 1877-78 the Glendon Iron Company, by the advice of the superintendent, Mr. Frank Firmstone, decided to make the experiment of exploding a heavy blast of gunpowder in their limestone quarry at Cedar Hill, Palmer Township, Northampton County, Pennsylvania. The amount of limestone used in the five furnaces of the company is about 60,000 tons per annum, and it was thought that with successful results; this entire amount or more would be thrown down at a single operation, disintegrating the mass to a greater or less extent, and obviating the necessity of blasting and boring the rock from the face of the cliff, both of which operations are slow, and therefore, costly. The rock at the quarry is Auroral limestone, or No. 2 of the old Survey. No fossils have ever been found in the quarry, nor in the immediate vicinity. The nature of the rock varies considerably in

Jan 1, 1879

By Ellis Clark

During the winter of 1877-78 the Glendon Iron Company, by the advice of the superintendent, Mr. Frank Firmstone, decided to make the experiment of exploding a heavy blast of gunpowder in their limestone quarry at Cedar Hill, Palmer Township, Northampton County, Pennsylvania. The amount of limestone used in the five furnaces of the company is about 60,000 tons per annum, and it was thought that with successful results? this entire amount or more would be thrown down at a single operation, disintegrating the mass to a greater or less extent, and obviating the necessity of blasting and boring the rock from the face of the cliff, both of which operations are slow, and therefore, costly. The rock at the quarry is Auroral limestoue, or No. 2 of the old Survey. No fossils have ever been found in the quarry, nor in the immediate vicinity. The nature of the rock varies considerably in

Jan 1, 1879

By R. H. Jacoby, V. J. Berry

When dry gas is injected into a reservoir containing a volatile crude oil, a significant amount of the reservoir liquid phase may become vaporized. The resultant rich gas phase, when subsequently produced, con-tributes to tank oil production. This contribution assumes greater importance, the more volatile the oil in-olved. Oil recovery may be sub-stantially greater than that predicted by conventional frontal-drive methods, which do not consider the vaporization equilibrium between the reservoir oil phase and the injected gas. A calculation method has been (developed to account for vaporiza-. tion of the reservoir liquid phase during gas-injectiorz operations, and for the tank oil production which results from this factor. Recovery performance calculations are presented for a reservoir containing a highly volatile oil. Tank oil recovery is calculated to be about twice that predicted by the use of the conven-rional frontal-drive equations. In contrastto usual pressure maintenance performance results, in which the gas-oil ratio rises at an increasing rate after gas breakthrough, the pre-dicated gas-oil ratio rises rapidly to about 12,000 scf/bhl and then rises much less rapidly. During gas inje-tion, most of the reservoir liquid phase contacted is evaporated by the dry injection gar. The gas-oil ratio during this period is dependent upon reservoir pressure. The higher the operating pressure, the lower the gas-oil ratio. The predicted behavior i., in accordance with laboratory PVT tests made to .simulate the vaporization behavior. In addition to recovery performance predictions, results of the calculation procedure include complete wellstrearn composition data of value in the design of gasoline plant facilities often used in con-rrction with gas-injection operations. INTRODUCTION In the cycling of gas-condensate reservoirs, dry gas is injected to maintain reservoir pressure during wet gas production and to thereby eliminate or reduce ultimate loss of liquids due to retrograde condensation within the reservoir. Gas injected into crude oil reservoirs has a dual function. It displaces oil to the producing wells and at the same time serves to partially or fully maintain reservoir pressure. Oil shrinkage which would occur upon pressure reduction is thereby minimized or eliminated. Accepted calculation methods are available'= for predicting recovery performance of either gas-condensate reservoirs or crude oil reservoirs which are being subjected to gas injection. In gas-condensate reservoirs, any retrograde liquid formed does not flow, and it is necessary to account only for the vaporization equilibrium between this liquid and the injected gas. Conversely, in normal crude oil reservoirs, both the oil and gas phases flow, but it has not been considered necessary to account for any vaporization of the reservoir liquid which might occur upon contact with the dry injection gas. Recently, high shrinkage reservoir fluids known as "volatile oils" have been found in increasing amounts. These oils are characterized by tank oil gravities above 4.5" API, solution gas-oil ratios above 1,000 scf/bbl, and reservoir volume factors above two. Special techniques have been devised for predicting depletion performance of reservoirs containing such oils.74.5.1; One of the characteristics of reservoirs producing volatile oils is that the reservoir gas phase carries a significant amount of oil which is recoverable as stock-tank liquid. This unusual vaporization be-havior implies that an appreciable amount of reservoir liquid would be vaporized upon contact of the oil with dry injection gas. In a gas-injection operation, tank oil recovery would he obtained not only through frontal displacement of the reservoir liquid by the injected gas, but also through production of the rich gas phase. This means that not only are improved methods needed to predict recovery of such oils from reservoirs undergoing gas injection, but it would also be expected that high oil recoveries might be obtained by such operations. When relatively dry gas is injected in to a volatile oil reservoir, phase equilibrium between the injected gas and the reservoir oil will tend to bc established. Initially the most volatile components, such as propane, the butanes and the pentanes, will account for most of the material transferred from the oil phase to the gas phase. As the partially stripped oil phase is contacted with additional dry injection gas, the heavier intermediate components, such as the hexanes, the heptanes and the octanes, will gradually transfer to the gas phase in increasing amounts. This is because the supply of lighter components in the oil phase dwindles due to the stripping action of the injected gas. This stripping action will usually continue to be effective down

By Robert D. Pehlke, Robert G. Blossey

The solubility of nitrogen in liquid cobalt and a number of dilute cobalt alloys Was measured in the temperature range 1550" to 1700°C at nitrogen pressures to 1 atm. At 1600°C and 1 atm nitrogen pressure, the solubility in pure cobalt is 0.0047 wt pct [3.8 cu cm (stp) per 100 g Co]. The standard free- energy change for the solution reaction 1/2 N,(g) = gout pct in Co) is iF - 10,000 + 5.24 T cal per g atom N. The alloying elements Cv, Cu, Mo, Nb, Tu, W, and V increase the nitrogen solubility, while Al, Fe, Ni, and Si decrease the nitrogen solubility. THE solubility of nitrogen in cobalt was studied previously by Sieverts, Busch and Dodd,2 and Schenck, Frohberg, and Graf.3 Sieverts investigated the solution below the melting point of cobalt, and Busch and Dodd worked with the liquid metal; however, neither study found any solubility for nitrogen in cobalt. Schenck et al, reported a solubility of 0.005 wt pct N in cobalt at 1600°C. Seagle et al. 4 reported residual nitrogen in cobalt after electron-beam melting, although no reasons were ventured for the presence of this interstitial impurity. This investigation was undertaken to clarify these inconsistencies, and to provide additional data on atomic interactions in dilute metallic solution. EXPERIMENTAL PROCEDURE This study was well-suited to the Sieverts' method, which has not changed significantly since its introduction by Sieverts. 5 The apparatus was of the same design as that described by Humbert and Elliott, 6 with a reaction bulb similar to that reported by Weinstein and Elliott. 7 The buret was not water-jacketed, but the measured gas volumes were corrected for small changes in room temperature. The melt temperature was measured by a disappear ing-filament optical pyrometer sighted through a prism onto the melt surface. Temperature calibration was made based on a measurement of the melting point of pure cobalt taken as 1495°C. The difference between the reciprocal of the observed and the true temperatures was assumed to be a constant, neglecting the changes in emissivity with small additions of alloying elements. The total error in gas-volume measurement caused by accuracy limitations in reading the mercury level in the buret, variation in ambient temperature, and variation in melt temperature was about 0.5 cu cm. This represents approximately 10 pct of the total solubility, and is a larger relative error than in previous studies6-' because of the small nitrogen solubilities encountered in the present investigation. The source and purity of the materials used are listed in Table IA. Recrystallized alumina crucibles were used throughout the investigation. Examination of the crucibles after solidification of the melts showed no reaction or penetration. Alloying of the cobalt melt was accomplished with the dropping technique described by Humbert. 6 The investigation was started using cobalt from African Metals Corp. in shot form, but this material was not of sufficient purity and did not yield consistent solubility results. Sherritt Gordon Mines Ltd. cobalt was then used throughout the investigation. In experiments involving alloying elements which could react with oxygen dissolved in the melt, the cobalt was further refined by annealing at 1400°C in a dry-hydrogen atmosphere. This treatment, described by Woolley and Pehlke, 8 markedly reduced the oxygen content. The oxygen and nitrogen analyses of the cobalt used in this study are presented in Table IB. RESULTS Hot Volume. The hot volume was measured prior to each run and was 50 to 55 cu cm (stp) at 1600°C. It increased linearly with increasing pressure and decreasing melt temperature. Pure Cobalt. Measurements of the solubility of nitrogen in pure cobalt and the temperature coefficient of solubility are summarized in Table 11. At 1600°C and 1 atm nitrogen pressure, the solubility was found

Jan 1, 1967