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By George M. Enos, Robert J. Anderson

An impoRtant factor affecting the rate and nature of corrosion of metals and alloys is the film, or coating, formed on the surface; and this may accelerate or retard corrosive action once started. The formation of films and coatings is intimately associated with the chemical composition and physical constitution of both the metal and the corroding medium. A film or coating may be either the corrosion product resulting from oxidation; that is, an oxide or salt, or a deposition of suspended matter from the corroding media upon the surface of the metal, or a mixture of both. The coating may adhere tightly or loosely to the surface of the corroded metal. In short, a film or coating is the reaction product of the corroding medium and the metal, which adheres to the surface of the metal and with which may be intermingled material from the attacking media not concerned in the chemical reactions. As the terms film and coating are used by different writers for very different things, distinction is made between the two, by the present writers, on the basis of thickness. Thus, a film is defined as a corrosion product or deposition, on the surface of a corroded metal, that is of such thickness that it cannot be measured by the metallurgical microscope. A coating, on the other hand, is of such thickness that it can be measured. If the resolving power of the 2-mm. (equivalent focal length) apochro-matic oil immersion objective (N.A. 1.4) is taken as the limit of the microscope, the limiting resolution is two lines that are 0.0002 to 0.0004 mm. apart. It is thus possible to measure coatings that are greater than 0.0002 to 0.0004 mm. thick. This thickness is equivalent to 50,000-

Jan 1, 1925

By S. Le Fevre

THE application of electricity to the mining and beneficiation of the magnetic iron ores of the Mineville, N. Y., district, on Lake Champlain, has resulted in economies and enhanced quality of product, without which only a comparatively small quantity of the present output could be marketed. The output of the Witherbee, Sherman & Co. mines is about 700,000 tons per annum, and of this about four-fifths is treated by magnetic separation to increase the iron content and reduce the phosphorus. The use of electricity for the magnetic separation of the ore from the gangue is therefore of primary importance, and makes possible the application of electric power for mining and preparing the ore for concentration: The fact which speaks loudest in favor of the application of electricity is this: It is possible for about 25c. per ton of shipping ore to furnish all the power required to put the ore on cars. This includes mining a hard ore underground, from a depth of 900 ft., hoisting to surface, crushing to 4 or s in. in size, and separating from the gangue. This also includes lights about the works, and all miscellaneous power, such as about the shops. The first plant for the generation of electric power for use at Mineville was completed in 1903, and was one of the first for the application of electricity to mining iron ore. This was a Nordberg compound condensing steam engine, direct connected to a 750-kw. alternating-current generator, 3,300 volts, 3 phase, 25 cycles. All the plants added later use the same-current but with higher voltage. The map, Fig. 1, shows the power plants and the transmission system; Figs. 2 and 3 are views of the shaft houses and the mills.

Jan 6, 1914

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 Henry Rawdon

Cold-working is generally considered as a process of hardening metals. Diamet-rically opposite statements concerning the applicability of the scratch-hardness method in the testing of cold-worked metals, particularly after severe deformation, which exist in the technical literature led to the study of the results which are summarized in this paper. A series of metals, of which copper, iron and tin are used as illustrations here, were cold rolled to a definite degree without any intermediate annealing and the hardness determined by both the scratch and Brinell methods. The results indicate that the metal hardens rapidly during the initial stages of deformation; however, after a certain stage, which corresponds to a rather definite microstructure, the metal becomes softer and in its final form may be softer than the metal in its initial stage. As part of the study of the scratch-hardness method for metals and alloys in cooperation with one of the technical committees of the American Society for Testing Materials, the authors devoted considerable time to the study of the changes in hardness of metals when cold rolled. Various seemingly contradictory statements in the technical literature concerning the applicability of the scratch-hardness method to such cold-rolled materials were among the principal reasons for the investigation, the results of which are in part presented here. The effect of cold deformation, at least in moderate degrees, on the hardness as measured by the Brinell and other common methods is so well known that further reference is unnecessary. Concerning the scratch hardness of cold-worked metals, Martens and Heyn state' that hardness, whether measured by the ball-pressure method (Kugeldruck) or by the scratch method (Ritzverfahren), will be increased by cold deformation. Jeffries and Archer give a seemingly diametrically opposite view. They state,2 that "the sclerometer (indicating scratch

Jan 1, 1924

By H. B. Smith, B. Egererg

In a previous paper1 the authors dealt with the physical properties of cold-rolled and heat-treated Britannia metal of the approximate composition Sn, 91 per cent., Sb, 7 per cent. and Cu, 2 per cent. It was found that cold rolling to more than 50 per cent. reduction produced a continuous softening of the metal when measured by the Brinell machine, whereas the Shore instrument indicated increased hardness; that the strength of the material followed the Brinell hardness and that the metal therefore became weaker the more it was cold-rolled; and further, it was found that hardness and strength could be largely restored to the cold-rolled metal by "baking" for about one hour at any temperature between 200" and 450" F., the melting point. The higher the baking temperature, the more effective was the heat treatment as far as increased hardness was concerned. It seemed to be of little importance whether the metal was soaked or not at the baking temperature for a great length of time and the rate of cooling seemed to be immaterial. The present paper deals with the same alloy and more particularly with the resistance towards various forms of stress — tensile, bend and deep drawing. The metallography of Britannia metal has in part also been covered and an explanation attempted for the abnormal behavior of this alloy. Tensile and Bend Tests Two ingots 73/4 in. wide, 11 in. long and ¾ in. thick were cast from the same pot. One ingot was cold-rolled in one direction to a strip 0.241 in. thick, which furnished the tensile test specimens; the other ingot was rolled in the same way to 0.253 in. and furnished the specimens for the bend tests. The ingots were cast as described in the previous paper and cold-rolled in six passes.

Jan 1, 1930

By T. D. Yensen

I. INTRODUCTION IT is safe to say that of all the different materials that go to make up electrical machinery, iron is the most important. Upon its -magnetic and electrical quality depends not only the efficiency of the machine but, to a very large extent, the cost. Aside from the mechanical strength, there are three characteristics of iron that are of importance in this connection, viz., magnetic hysteresis, electrical resistance, and magnetic permeability. In the homopolar machine, where the magnetic flux is unidirectional, permeability is the only important factor, but in all other machines the flux is reversed in one or more parts and causes losses due to hysteresis and eddy currents. The eddy-current loss depends largely upon the electrical resistance of the iron; the higher the resistance the lower the loss, under otherwise identical conditions. These hysteresis and eddy-current losses cause heating of the machine, and as they depend upon the magnetic density in the iron, this density must be regulated so that the heating shall not be excessive. If the hysteresis and eddy-current Josses and the permeability of the magnetic circuit will permit an increase in the magnetic density, or, in other words, a decrease in the amount of iron, this in turn will mean a decrease in the amount of copper needed, with a consequent decrease in the copper loss. It is thus seen that; indirectly as well as directly, the above characteristics have an important bearing on both the efficiency and the cost of electrical machinery. In general, it may be said that iron for electrical machinery should have the following characteristics: (1) low hysteresis loss, (2) high electrical resistance, and (3) high permeability. These are the characteristics that investigators have been striving to attain since electrical machinery first came into use.

Jan 2, 1916

By N. W. Lord

The process of molten-zone refining is analyzed for long ingots and many zone passages. Formulas are derived which give the resultant impurity distribution in terms of finite series. A comparison with the approximate procedure of Hamming is given. HE physical principles and applications of an extremely physicalprinciple efficient form of metallurgical refinement has been described by Pfann. The purpose of the present paper is to describe a method of analyzing exactly the particular program used which enables the segregation effect to be predicted for any number of molten-zone passages in a long ingot. The method is applied to the particular case of refinement of an ingot whose impurity initially is uniformly distributed throughout its length. A number of molten zones of equal length are passed through the ingot effecting a radical redistribution of impurity. Pfann has indicated an approximate method, due to R. W. Hamming, of calculating the resultant concentration after each successive zone pass for a particular value of the segregation constant defined in his paper. Here a solution will be presented in terms of the number of zone passes and the segregation constant. The expression, though cumbersome, is exact and susceptible to ordinary numerical computation procedures. The results of a similar computation using the procedure of Hamming are presented in a table together with the exact results of the present method. The discrepancy in terms of absolute concentrations is tabulated for the first eight zone-lengths. To establish the notation (which follows that of Pfann1 as closely as possible) and physical basis of the analytical equations, the physical model and principal assumptions may be reviewed. An alloy of two elements, where there is formed a continuous range of solid solutions, usually does not melt as a simple compound. Rather, a temperature is reached where the solid solution is in heterogeneous phase equilibrium with a liquid solution of different composition. The temperature dependence of these equilibrium compositions forms part of the phase diagram. For very small concentrations of a solute B in a solvent A, this usually takes the form of Fig. 1. Sometimes the solidus and liquidus slope upward. This corresponds to a segregation constant (defined below) which is greater than unity. The segregation constant is now defined as k = Cn(x)/CnI(x) [1] where C,,(x) is the impurity concentration in the solid ingot at distance x during the nth passing of a molten zone and Cnl (x) is the impurity concentration of the liquid zone from which the solid at dis- tance x is formed (see Fig. 4 of ref. 1.) C (x) remains the same after passage of the zone. The constant k may be either greater or less than unity in general. Purification in the former case is effected only in a finite ingot and in the portion that is melted last. For k less than unity purification is effected even in an infinite ingot. The method which follows gives, in the former case, the successive increases in impurity concentration and, in the latter case, the successive decreases in concentration. The general case of impurity redistribution will be considered first, and purification will be discussed later on. The analysis rests on the following assumption: The movement of the zone is too rapid to allow appreciable atomic rearrangement in the solid sections and too slow to disturb the uniform impurity distribution in the liquid zone characteristic of equilibrium. Hence, the composition in the solid at the left solidifying interface will be determined by Eq. 1 while the impurity concentration of the liquid zone will be uniform throughout its length. The reasoning which follows closely parallels that of Appendix 11 in Pfann&apos;s paper. It is reviewed here for the case of the nth zone pass in order to make clear the meaning of an operator essential to the present method. Fig. 4 of ref. 1 shows the movement of a molten zone of length 1 in an ingot of total length d. Each Cn(x) can be determined from the condition that the amount of solute added to the zone during an incremental advance, dx, is due to the melting in of a solid portion C(x)dx and the freezing out of kCnl(x), that is d I —r- CnL (x) dx = Cn-1 (x+l)- kCnL (x) dx or, in terms of Cn(x) d k k —— C,(x) +—c.(x) =— Cn-1 (x + l). [2] dx l l This, of course, is derived from the main assumption, the fact that 1 is constant, and that the total impurity content previously present up to x + 1 is constant . A correction has to be made for the region (d — nl) < x < d. This is due to the zone length changing during the passage of the solidifying interface beyond x = d — 1. Since the general solution would be too complicated otherwise, only the region 0 < x < d — nl is considered. The general solution of Eq. 2 is

Jan 1, 1954

By R. C. McFarlane, T. D. Mueller, J. E. Walstrom

In evaluating uncertainty, experiments are usually performed repeatedly and then conclusions are drawn from the distribution of results. With the advent of high-speed electronic computers, it is possible to perform experiments using mathematical models constructed to simulate complex experiments or operations. Statistical methods are then applied to the results of the simulated experiments. This procedure forms the busis of this paper. Demonstrated is the need for properly accounting for uncertainty in petroleum engineering problems. How uncertainty affects solutions is evaluated in three example illustrations. The method used to evaluate uncertainty in petroleum engineering studies is the Monte Carlo simulation procedure.&apos;-" INTRODUCTION The solution to most technical problems may be derived from interrelationships among several quantities called variables or parameters. There may be only a few variables or several hundred. Interrelationships among parameters may be explicit or implicit, well established or only approximate. Some variables that fully or partially depend on the magnitude of others are called dependent variables. Input variables for most practical problems are not precisely known; there is usually an uncertainty in their value. The degree of uncertainty may vary from one variable to another. Variables that are known accurately are called determinates.&apos; For instance, the gravity of crude obtained from a particular pool may be known precisely, and therefore is a determinate. The degree of precision with which a quantity can be determined increases as data describing the pool are accumulated during the development of the field and the producing life of the pool. The uncertainty of a parameter may result from difficulty in directly and accurately measuring the quantity. This is particularly true of the physical reservoir parameters which, at best, can only be sampled at various points, and which are subject to errors caused by presence of the borehole and borehole fluid or by changes that occur during the transfer of rock and its fluids to laboratory temperature and pressure conditions. Uncertainty may also result in attempting to predict future parameter values. This type of uncertainty is particularly evident in investment analyses involving future costs, prices, sales volumes and product demand. Uncertainty in the solution to investment problems is often called risk, and its study is called risk analysis.&apos; Uncertainty also enters into biological and sociological analyses in which indeterminate factors are often important due to limited control of the experimental material. It is customary, in evaluating uncertainty, to perform repeated experiments and to draw conclusions from the distribution of the results of these experiments. With the advent of the high-speed electronic computer, it is possible to construct mathematical models which simulate complex experiments or operations and to perform the experiments repeatedly, utilizing the models. Statistical methods are then applied to the results of the simulated experiments This method forms the basis of the investigation reported here. PROBABILITY DISTRIBUTIONS FOR VARIABLES The uncertainty in the value of a variable may be indicated by a probabilistic description accomplished by expressing the quantity by a probability distribution. Many recognized probability distributions can be used to describe physical quantities. Recent studies used various types of distributions to describe core analysis data.&apos;,&apos; However, for the examples in this paper, the uniform and triangular distributions are believed to reasonably approximate the data used (Fig. 1). The uniform distribution confines the variable between an upper and a lower limit. The variable may lie anywhere between the two limits. This distribution is used when no one range of values for a variable is more probable than any other, but information or intuitive reasoning indicates the variable will lie somewhere between the chosen limits. The triangular distribution is used for a variable when more data are available to indicate a central tendency of distribution. This allows postulating a "most likely" value to the distribution and upper and lower limits. In this case, as for the uniform distribution, the variable is not expected to assume a value less than the lower limit or greater than the upper limit. However, with improved quality of data it can be postulated that the variable will tend to assume a value close to the most likely value, and that there will be a decreasing probability for values away from the most likely value. The area under either of these probability distributions is equal to unity since it is assumed that there is a 100 percent probability that the variable will lie somewhere under the curve. An ordinate erected at any particular value of the variable divides the area under the curve into two parts: the area to the left of the ordinate represents the probability that the value of the variable will be equal to or less than the value of the variable at the position of the ordinate, and vice versa. The probability is zero that the variable will have any specific deterministic value. If two ordinates are drawn for any two values of the variable, the probability that the variables will have a value lying between these ordinates is equal to the area under the curve lying between the ordinates.

By R. C. Craze

During the past 20 years. research and development in the study of reservoir behavior have dealt principally with flow of oil through sandstones. Many reservoir studies of sand fields have proved valuable in promoting recovery efficiency. This paper discusses fundamental principles governing oil and gas production from sandstone and limestone alike and presents the results of investigations relating to the application of analytical techniques used for sandstone reservoir studies to the study of limestone reservoir performance. The characteristics of limestone porous systems, porosity-permeability relationships, distribution and occurrence of oil, and characteristics of flow through such systems are discussed. Recognition is made of the similarities or differences which these factors exhibit in limestone and sandstone systems. Comparisons between operating data for typical limestone and sand reservoirs are presented. It is indicated that the distribution and movement of fluids in and through porous limestones follow the same fundamental principles underlying such processes in sandstones. This fundamental similarity may readily be discernible in the performance of many limestone reservoirs. The volumetric balance and unsteady state radial flow equation, the fluid displacement equation, use of electrical analogue devices, and other analytical techniques to study the behavior of limestone fields appear fundamentally applicable, but do require thorough understanding of the properties of the formation, of the fluids, their behavior during flow, and adequate production operating data. Need for more complete coring and comprehensive examination of core properties is stressed. The results of "active oil" studies, and of flow and interference tests are presented. Well spacing, well completion, and efficient rates of production in limestone reservoirs are briefly discussed. INTRODUCTION Limestone and dolomite reservoirs constitute the largest source of supply of crude oil in the world. an estimated 60 per cent of present production coming from carbonate reservoirs. In many large geologic provinces such as Mexico. the Middle East, and more recently Canada, almost all the oil is found in this type of rock. In the United States, all of the major oil-producing areas except California and Pennsylvania contain oil-bearing carbonate formations. The discovery in recent years of large oil reserves in the Silurian, Devonian, and Ordo-vician formations in West Texas, in addition to the large reserves in the Permian, has accentuated the interest of operators, geologists, and engineers in limestone formations and in the many problems associated with understanding the performance of these reservoirs. The rapid increase in discovery of oil in limestone formations and the present-day position of prominence held by these fields in the production and reserve picture in all parts of the world emphasize the horizons opened to the reservoir technologist in the field of geological and production research. Pertinent to an interpretation of the behavior of limestone reservoirs are the methods of analysis which may be utilized and a possession of full knowledge of the many factors which influence the analytical procedures. During the past 20 years a well-developed science of reservoir engineering has been built upon the research of many workers who studied the fundamental nature of oil reservoirs, characteristics of the porous media, properties and behavior of the contained fluids, and the mechanics of flow. Application of these studies to production practice has resulted in greater recoveries and more efficient field operation. The major portion of this evolutionary process has been founded upon studies of sand fields. The applicability of these more thoroughly developed techniques for studying sand fields to the study of the behavior of limestone fields becomes a factor of technical and practical significance. In the light of the technological background available to the reservoir analyst, this paper discusses fundamental principles governing oil and gas production from sandstone and limestone alike and presents the results of investigations relating to the application of analytical techniques used for sandstone studies to the study of limestone reservoir performance. LIMESTONE RESERVOIR CHARACTERISTICS The characteristics of limestone and sandstone reservoirs are similar in many respects and they both may occur under similar structural conditions. Fundamentally, the distribution and movement of fluids in and through the porous limestone media follow the same basic principles which dictate such processes in sandstones. Herein lies a fundamental similarity, which may readily be discernible in the performance of many limestone reservoirs. In some limestone fields, as in many sand fields, widely varying formation properties and distribution may reveal themselves in deviations in the performance of the reservoir, in the behavior of wells, and in fluid flow through the rock, and make difficult the delineation of reservoir behavior. Only by reservoir studies, core analyses, and coordinated laboratory and field experimentation can the effects of the many influencing factors upon the nature of limestone production be determined. FORMATION CHARACTERISTICS The chief difference between limestone and sandstone, aside from their chemical compositions, is the difference in the geometry and origin of the porous systems in the two kinds of rock. In sandstone the porous system results entirely from the openings among individual sand grains which occur during deposition. The geometry of the openings between the sand

Jan 1, 1950

By K. Brack, G. H. Schwuttke

Annealing properties of subszerface amorphous lavers produced through high-energy ion implantation in silicon are studied. The buried layers are produced through the implantation of ions (nitrogen), ranging in energy from 1.5 to 2 mev. X-ray interference patterns, transmission electron microscopy, and resistivity profiling are used to study the annealing characteristics of the ion damage. The annealing experiments indicate a low temperature (below 700°C) and a high temperature (above 700°C) region. Significant changes occur in the amorphous layer during the high-temperature anneal. Such changes are corre-lated with the re crystallization of the amorphous silicon and the formation of subsurface (buried) silicon-nitride films. TODAY&apos;S main problems in the field of ion implantation are related to the accurate determination and prediction of 1) the distribution profiles of implanted ions, 2) the lattice sites occupied by the implanted ions, 3) the lattice damage produced through ion implantation, and 4) the annealing characteristics of damage centers in the lattice. This paper reports investigations concerned with the problems listed under 3) and 4). EXPERIMENTAL Our investigations cover the energy range of incident ions from 100 to 300 mev and from 1 to 2.5 mev. The emphasis of this study is on the energy range from 1.5 to 2 mev. The experiments are conducted with single charged nitrogen ions. To implant the ions a van de Graaff generator is used as described by Roosild et al.1 Accordingly, a gas containing the desired ion specie is passed through a thermome-chanical leak into a radio frequency activated source. The positive ions are driven into the van de Graaff with the help of a variable voltage probe. Emerging from the accelerator the ions drift into a magnetic analyzing system and here the desired ion specie is bent 90 deg into the exit port. The ion beam leaving the analyzer is defocused and drifts down a 4-ft long tube to hit the silicon target. At this position the 20 pamp ion beam has a circular cross-section of 2.1 cm. N2 is used as a source gas for nitrogen ions. The implantation target is silicon with zero dislocation density, 2 ohm-cm resistivity, (111) orientation, mechanically-chemically polished, and 1 mm thick. The target is mounted on a water-cooled heat sink and kept at room temperature. A fluence of 1015 to 1016 ions per sq cm is used. RESULTS 1) Silicon Perfection after Bombardment. High-energy ion bombardment of silicon has some striking effects on lattice perfection. Some results were reported in detail previously at the Santa Fe conference2 and are here briefly summarized for the benefit of the experiments described in the following. 1.1) Identification of Surface Films on Silicon. After bombardment all samples are found to be coated with surface films. The films on the silicon surface vary in thickness and color; they can be transparent, slightly brown, or opaque. The films are thicker and darker in the high-intensity area of the beam and they delineate the bombarded surface area of the crystal. The films produce electron diffraction patterns characteristic of carbon and of SiO2. Carbon is predominant. The presence of carbon in these films was confirmed by use of the electron microprobe. Formation of the films occurs independently of the ions used and is attributed to a contaminated vacuum of the high-voltage machine. The carbon is most likely the product of the pump oil which is cracked and polymerized under ion impact. The films stick tenaciously to the silicon surface and burn off in a low-temperature Bunsen flame. 1.2) Mechanical Perfection of the Silicon Surface. The mechanical perfection of the bombarded silicon surface was investigated through optical microscopy, electron microscopy in which the replica technique is used, and optical interferometry. No mechanical damage of the surface was visible after bombardment. However, if a bombarded sample is soaked for several minutes in hydrofluoric acid (HF), gas bubbles may develop in certain spots of the silicon surface. It is also noted that in these areas the surface film starts to peel off. Relatively large patches of film come off if the sample is soaked in HF during ultrasonic agitation. After HF treatment, pits may be present on the silicon surface. The pit dimensions are estimated to be as large as 50 µ. The pits appear in the region of most intense irradiation. 1.3) Lattice Perfection After Bombardment. No lattice damage is found on the silicon surface. Electron transmission micrographs and selected area diffraction patterns of the surface show no difference before and after bombardment. Measured approximately 2 µm down from the surface, the silicon lattice throughout this depth is of good perfection. Well-defined Laue spots and Kikuchi lines are obtained from the surface as well as from the indicated area below the surface. However, some radiation damage is dispersed in this top layer. A sharp boundary line separates this surface layer from a highly damaged layer which extends further downward into the silicon. Typical of this

Jan 1, 1970

By W. J. West, T. D. Mueller, J. E. Warren

The authors have presented valuable information on the influence of the interfacial tension and the contact angle on the recovery efficiency of the waterdrive process. It is considered, however, that the following points deserve a closer examination. 1. As pointed out by Wyllie and Spangler1 the displacement pressure PD i.e. the pressure required to initiate the displacement of the wetting phase from the core, is a measure of the maximum pore diameter dmax. If the capillary pressure Pe as a function of the wetting

Jan 1, 1956

By J. A. Retty

HOLLINGER CONSOLIDATED GOLD MINES LTD., through two subsidiary companies, has the exclusive right to prospect in two contiguous areas in central Labrador. This paper presents the results of the mineral exploration that has been conducted in these areas to date. One of the subsidiaries of Hollinger. the Labrador Mining and Exploration Co. Ltd., under an agreement with the Newfoundland Commission of Government, holds an area of approximately 20,000 sq.mi., which comprises the western portion of Newfoundland-Labrador and includes the upper basins of the Hamilton and Naskaupi Rivers. (The main area of the deposits so far discovered may be located on a map at about 67° west longitude and 55° north latitude.) The other subsidiary of Hollinger, Hollinger North Shore Exploration Co. Ltd., has licensed from the Province of Quebec an area of approximately 3900 sq.mi. lying directly north of the Newfoundland-controlled area at the headwaters of the George, Whale, and Swampy Bay Rivers. The M. A. Hanna Co., large iron-ore operators of the Lake Superior region, are participating in the project. With the exception of the years 1940 and 1941, field work has been conducted in the Newfoundland area since 1936, and in the Quebec area since 1939. Hollinger assumed the management in 1942. The field base is at Hollinger Lake, some 300 miles north of the tidewater base at Seven Islands, Quebec, which, in turn, is just west of the mouth of the Moisie River, on the Gulf of St. Lawrence. Air transportation is used exclusively to service the operation.

Jan 1, 1945

"NAME…""Utah"" is derived from the name of the Indian tribe, variously spelled ""Yuta, “Ute"" ""Youta,"" ""Uta,"" ""Eutaw,"" and finally ""Utah."" It means ""in the tops of the mountains,"" or ""on the heights."" The state emblem is the ""Beehive,"" typical of industry. State nickname is ""Beehive State.""AREA…Utah is the tenth state in area. It contains 84,990 square miles, of which 2,806 miles are water. When admitted as a territory in 1850, Utah included all the area from the east line of California to the summit of the Rocky Mountains between the 37th and 42nd parallels, which embraced practically all of the present state of Nevada, all of western Colorado, part of Idaho and part of Wyoming, in addition to the present area of Utah.TOPOGRAPHY…Utah is generally mountainous, with several main ranges and also detached groups of mountains. The valleys are broad and level. The mean altitude of the state is 6,100 feet above sea level, which makes the state the third highest of the Union. The highest point in Utah is King's Peak (13,498) in the Uinta range. The lowest point is Beaverdam Creek (2,000) in Washington county.CLIMATE…The climate is diversified between mild temperate in the northern portion to semitropical in the southern portion. There are four distinct seasons. Snowfall is heavy at the greater altitudes and rare in the southern portion. Rainfall is moderate throughout the state. Extremes of heat and cold are unusual."

Jan 1, 1925

By J. F. Smith, J. E. Davison

The heat capacity of CaMg2 was measured over the temperature interval, 4.8° to 287°K, by the technique of low-temperature adiabatic calorimetry. Heat content measurements were performed with a drop calorimeter over the temperature interval, 273" to 673°K. From these data the thermodynamic functions, (FT - H0)/T, ST - So, and & - Ho, were evaluated. A third-Law calculation of the standard entropy of formation of CaMg2 yields a value of -0.25 * 0.06 cal per (°K g-atom) , and the free-energy function derived from this study when combined with existing equilibria data yields a value for the standard enthalpy of formation which is in agreement with direct calorimetric enthalpy measurements. The accompanying paper&apos; shows that the enthalpy of formation of CaMg2 has been determined with good precision by three different calorimetric techniques.&apos;-= TWO independent determinations of the Gibbs free energy of formation of CaMg2 have also been made; both determinations were based on vapor pressure measurements, being in one case hydrogen vapor pressures over ternary Ca-Mg-H alloys4 and in the other case magnesium vapor pressures over binary Ca-Mg alloys.5 The present determination of heat capacity of CaMg2 below room temperature and of the heat content of CaMg2 above room temperature was undertaken to provide supplementary data. These data are useful in their own right but can in addition be used to evaluate an entropy of formation for CaMg2 which, because of the interrelation of free energy, enthalpy, and entropy, can be used as a check of the self-consistency of the composite of the presently available information. LOW-TEMPERATURE HEAT CAPACITY The heat capacity of CaMg2 was measured over the temperature interval 4.87° to 286.64°K in an adiabatic calorimeter. The physical details of the calorimeter and the experimental procedure for measuring the heat capacity of a specimen have been adequately described by Gerstein et a1.6 The source and purity of the calcium and magnesium are described together with the methods of sample preparation and chemical analyses in the accompanying paper.&apos; Results of chemical analyses of the material which was used in the present investigation are shown in Table I. These analyses show that, on the basis of the published phase diagram,7 the heat capacity sample contained a slight excess of a calcium while the heat content sample contained a slight excess of magnesium. However, in both cases the excess was small, and X-ray diffraction patterns showed reflections which were without exception attributable to CaMg2. The sample which was used for heat capacity measurements weighed 69 g while the sample container and addenda weighed 132 g. The sample was in the form of annealed powder, 50 to 60 mesh, and was sealed into the sample container under 0.1 atm of helium. Copper fins inside the sample container facilitated thermal equilibrium of the powdered Sample. Time intervals of the order of 10 min were required for thermal equilibration, and such times are normal for this calorimeter regardless of the form of the sample. The observed heat capacities were corrected for the small excess of a calcium through use of the heat capacity values tabulated by Hultgren et a1.8 The corrected heat capacities are tabulated as a function of temperature in Table II. The free-energy function and the absolute entropy of CaMg2, which were calculated from the experimental heat capacity data, are listed in Table 111. A smooth curve was fitted to a plot of the experimental values of the heat capacity and in only two instances above 30°K did the plotted points deviate from the curve by more than 0.2 pct. Below 10°K the deviation of several of the points was as much as 50 pct. These large percentage deviations were attributed to the small value of the heat capacity and to the low sensitivity of the platinum resistance thermometer in this temperature range. The deviations in the region of 10°to 30°K were less than 5 pct. Although the percentage deviations of some of the low-temperature measurements are large, the actual value of these deviations is small since the magnitude of the heat capacity in that temperature range is small. The error in the value of the third-law entropy at 298.15°K was estimated to be less than 0.01 cal per (°K g-atom). A value of -0.25 ±0.06 cal per (°K g-atom) was obtained for the standard entropy of formation at 298.15°K from the relation:

Jan 1, 1969

By L. A. Bromley, A. W. Petersen

The van Arkel-deBoer method for producing ductile titanium by thermal decomposition of Til, vapor and deposition on an electrically heated filament is modified by film boiling Til liquid on a heated filament, resulting in similar titanium deposition on the filament and liberation of gaseous iodine. The deposition rate is higher and the energy requirement smaller than in the van Arkel process. Many problems must be solved before the process is commercially feasible. TITANIUM of 99.9 pct purity, called ductile titanium, has been produced by a modification of the van Arkel-deBoer&apos; method. In the van Arkel-deBoer method, an electrically heated wire is suspended from two electrodes, which are placed in a container holding TiI, vapor at a low&apos; vapor pressure (usually <5 mm Hg). The vapor diffuses to the hot wire, usually maintained at 1100" to 1600°C,&apos; and decomposes according to the reaction liberating gaseous atomic iodine and depositing solid crystalline titanium on the wire. Estimations based on the data of Runnalls and Pidgeon,&apos; indicate that the rate-control ling step is the diffusion of atomic iodine away from the wire. There appears to be nearly thermodynamic equilibrium at the wire with TiI, and iodine as the main gaseous species. TiI, is almost certainly an important gaseous species in the cooler regions.&apos; The liberated iodine diffuses to a heated source of crude titanium and reacts to form more TiI, vapor, which again diffuses to the hot wire and completes the cyclic process. The foregoing process may be modified by suspending the hot wire in liquid TiI,, instead of the vapor, and obtaining film boiling. This type of boiling is characterized by the formation of a continuous film of vapor over the wire surface. Since only vapor contacts the wire sul.face, the temperature of this surface may be raised as high as desirable, within the limit of mechanical strength requirements for the wire. By properly adjusting the input voltage. the temperature of the wire may be maintained above U0C"C; and by evacuating the vessel holding the liquid TiI, and maintaining a suitable condenser temperature, the vapor pressure of TiI, may be held low. Thus, the conditions of operation of the van Arkel-deBoer method may be approximated with film boiling; and hence, it is postulated that ductile titanium may be produced by this method. Preparation of Til, There are many methods available for the preparation of TiI,; that used in this research was prepared by the direct reaction of titanium sponge in controlled amounts with liquid iodine. Although no difficulty was encountered with this reaction, it has since been pointed out that this method is sometimes dangerous and should be used with caution. The resulting TiI, was purified by distillation. First Film Boiling Experiments Apparatus: The apparatus shown in Fig. 1 was used for film boiling TiI, on short wire filaments. The current to the filament was supplied through a bank of three 5 kva transformers connected in parallel. The current was controlled by adjusting the voltage over a 0 to 67.5 v range with a 7 kva variable transformer on the low voltage side of the bank of transformers. The current and voltage were measured by Weston meters. The sealed-in-glass tungsten electrodes were hard-soldered to the filament for the film boiling of TiI,. The bottom part of the reactor, containing TiI,, was wrapped with ni-chrome heating wires to maintain the TiI, in the liquid state. An ice or liquid nitrogen trap, for solidifying I, vapor and any TiI, not condensed, was attached to the low pressure side of the air-cooled condenser. A Megavac vacuum pump was used. Procedure: A 0.010 in. diam tungsten filament was hard-soldered to the tungsten electrodes. TiI, was melted (mp 156°C) and poured into the reactor chamber; the top of the reactor chamber, containing the electrodes, was replaced. Freezing of the TiI, was prevented by controlling the current to the ni-chrome wires wrapped around the reactor with a 1 kva variable transformer. The mechanical vacuum pump was started and the system evacuated to about 2 mm Hg TiI, vapor pressure. The current to the filament was turned on and the impressed voltage slowly increased with the variable transformer. A sudden drop in current at nearly constant im-

Jan 1, 1957

By S. C. Sun, John A. L. Campbell

The surface properties exhibited by bituminous coal and bituminous coal lithotypes were ascertained by using streaming potential techniques. The electro kinetic prop-erties wereascertainederties of bituminous coal were found to be similar to those of anthracite. The principle electrokinetic properties of the coal and lithotypes, zero-points-of-charge (ZPC), and potential determining ions, were established. The effects of indifferent electrolytes, hydronium and hydroxyl ion sources, and polyvalent ions (cationic and anionic) were also evaluated. Location of the ZPC&apos;s with respect to pH is discussed in terms of chemical and mineralogical composition of the respective surfaces. To account for the observed electrokinetic phenomena, a generalized surface model and adsorption mechanism are proposed. Surface-dependent processes, such as froth flotation and flocculation, are important or potentially important techniques for combating some of the current major problems in coal preparation. In order to correctly apply or improve a surface-dependent process, it is of paramount importance to understand the interfacial phenomenon, especially the double layer properties, exhibited by the solid. The specific objective of this research was to determine the properties of the bituminous coal/liquid interface by an electrokinetic method, streaming potential, and to relate the findings, wherever possible, to the existing unit operations of froth flotation and floccula-tion tion. The electrokinetic properties of both the whole coal and its lithotypes were investigated. As part of the total investigation, the role played in the double layer by the reagents commonly employed in the surface dependent process was also established.&apos; These data will be presented at a later date. Experimental Procedures The coal samples used in this research and their designations are listed in Table 1. The classical description of humic coal lithotypes as developed by Stopes" was used for the delineation of the lithotype samples. The samples were taken from the working face of a producing deep mine of the Pittsburgh seam in the area of Ellsworth, Pa. To avoid oxidation, only freshly exposed areas were sampled. The normal precautions against contamination were also exercised. Two types of samples were taken, specimens rich in a particular lithotype and a representative channel sample. The latter sample was prepared for analyses by grinding it to —35 mesh. It was screened repeatedly during the grinding to provide the largest amount of 35 x 48-mesh (standard Tyler sieves) material possible. The screened fraction was passed over a magnet and then washed several times with distilled water and finally with conductivity water. The resulting sample now termed "whole coal" was stored under conductivity water in a glass bottle. Pure lithotypes were obtained from the lithotype concentrates by hand picking, and were processed in the same manner as the representative sample. Maceral analyses, employing standard petrographic procedures," were performed on the lithotype samples to determine the purity of the samples. The results are presented in Table 2. Reflectance measurements of the vitrinites and fusinites are also reported in this table. Proximate and ultimate analyses of the samples are given in Tables 3 and 4. The electrokinetic properties of the coal samples were determined by streaming potential methods.&apos;-&apos; All of the chemicals used in the investigation were reagent grade (Baker analyzed). The conductivity water was prepared by doubly distilling the water in a pyrex Yoe-type still and passing the distillate through a mixed bed ion exchange column. Results In general, the electrokinetic properties of the investigated bituminous coal were found to be similar to the results of a previous study of anthracite by Camp-bell bell5 and are in accord with the suppositions of Brown." The zeta potentials of the coal and all the lithotypes were found to be negative in conductivity water. Jowett? in a study of slime coatings on coal also found bituminous coal to exhibit a negative surface. Fig. 1 shows that the negative charges, at neutral pH&apos;s, for both fusain and the gangue are very small, almost zero, while at the same pH, vitrain has the largest negative charge, almost 30 mv. Durain has a negative charge of 17.5 mv. The determination of the affect of pH on the charge of the coal surfaces revealed that hydronium and hydroxyl ions apparently behave as potential determining ions; however, they do not appear to be potential determining for the gangue. These results are illustrated in Fig. 1. As the pH of the solution was decreased, hydronium ions were adsorbed, causing the surface of the coal to reverse polarity and become

Jan 1, 1971

By K. H. Hiller

A rotational viscometer has been designed which perrnits the measurement of the rheological properties of drilling muds and other non-Newtonian fluids under conditions equivalent to those in a deep borehole (350F, 10,000 psi). The important mechanical features of this instrument are described, and its design criteria are discussed. The flow equations for the novel configuration of the viscometer are derived and the calibration procedures are described. The data and their interpretation, resulting from measurement of the flow properties and static gel strengths of homoionic montmorillonite suspensiom at high temperatures and pressures, are presented. Data are also presented for the flow behavier of typical drilling fluids at high temperatures and pressures. The pressure losses in the drill pipe and the annulus depend critically upon the flow parameters of the drilling fluid. This work demonstrates the need to measure these parameters under bottom-hole conditions in order to obtain a reliable estimate of the pressure losses in the mud system. INTRODUCTION The rheological properties of drilling fluids are affected by temperature and pressure, but the extent of these effects on the dynamic flow properties is not well known. Measurements of changes of the flow properties of clay-water drilling muds with temperature have been reported by Srini-Vasan and Gatlin.1 The temperatures reported did not exceed 200F, a limitation imposed by the apparatus used by these authors. The rheological properties of clay suspensions were measured at temperatures up to 100C by Gurdzhinian.&apos; Neither the nature of the exchange ions in the clay suspensions nor the degree of purity were defined in his work, nor were the measurements extended to currently used drilling fluids. The lack of systematic measurements of dynamic flow properties at high temperatures and pressures seems the more surprising since during the last decade the importance of the control of the hydraulic properties of drilling fluids has come to be widely recognized. Very good mathematical treatments of the friction losses in drill pipe and annulus have been developed.3 4 These treatments are based on the assumption that drilling fluids behave as Bingham plastic fluids. Quite often this assumption is justified, while in other cases a power law equation pro- duces better fit than the Bingham model does. For convenience in applying viscometer data to pressure-drop calculations, the Bingham plastic flow equation is preferable and, therefore, has been applied to the data reported in this paper, although other equations may fit these data more accurately. In a Bingham plastic fluid the relationship between the shearing stress 7 and the rate of shear D is given by the following equation: where is the plastic viscosity and 4 the yield point. If 4 = 0, the equation for simple Newtonian flow, 7 = pD, is obtained. Two empirical constants are required for the description of laminar flow of a Bingham plastic fluid, and calculations of the flow behavior at high temperatures and pressures cannot be better than is permitted by the accuracy with which these constants are known. For this reason a high-pressure, high-temperature rhe-ometer has been designed to measure the plastic viscosity the yield point +, and the static gel strength S, at pressures up to 10,000 psi and temperatures up to 350F. The important features of its design will be described. The results of measurements on homoionic clay slurries will be discussed insofar as they are relevant to an understanding of the general flow behavior of clay-water drilling fluids. The results of measurements on some typical drilling fluids will be presented also, and their practical implications will be briefly discussed. DESCRIPTION OF EQUIPMENT MECHANICAL FEATURES A viscometer designed to measure the plastic viscosity, yield point and gel strength of non-Newtonian fluids must permit the measurement of the shearing stress t at any given rate of shear D. This is possible only if t and D are approximately uniform throughout the entire sheared sample. A Couette apparatus is the most convenient method of realizing this condition, as has been pointed out by Grodde." The "high-pressure, high-temperature rheometer" described in this paper is basically a rotational Couette viscometer that is immersed in a cell in which pressure and temperature can be controlled over the range of interest. Fig. 1 shows schematically the important features of the pressure cell and associated equipment. The heart of the instrument is the rotating cup. It is shown more clearly in Fie. 2. which revresents the lower one-third of the pressure cell (below the input drive shaft shown in Fig. 1), and it is shown in detail in Fig. 3. For measurements of dynamic flow properties, the rotating cup is driven by a 1/2-hp electric motor, which operates through a Vickers

By R. J. Wagner, F. F. Craig, H. G. Riley, J. D. Griffith

Peripheral water injection has been underway in the Sholem Alechem Fault Block "A" Unit, Stephens County, Okla., since 1955. In the engineering planning of the flood, it was recognized that maintenance of pressure in the large, dry gas caps was vitally necessary to prevent the loss of an estimated 27 million bbl of oil through saturation of the gas caps by the oil banks moving updip on the peripheral flood pattern. The development of an abundant, low-cost water supply and the rising cost of makeup-gas purchases indicated that gas-cap control by water injection was desirable from an economic standpoint, provided an eflective water barrier could be placed without premature water breakthrough into downdip oil producers. A laboratory model scaled to the existing reservoir conditions was comtructed to evaluate the feasibility of gas-cap water injection. Model studies indicated that (I) water injected at the edge of the gar-oil contact would form a continuous barrier between the oil and gas zones, and (2) water would advance uniformly downdip without segregation due to gravity effects provided a specified, minimum water-injection rate was maintained. The model test results also indicated that it was not necessary to fill the gas cap completely with water. Water injection at the edge of one of the gas caps was initiated in March, 1958, to field test gas-cap water injection. Water breakthrough occurred at a downstruc-ture producing well in April, 1959, after approximately 2.5 million bbl of water had been injected into the gas cap. This was the volume calculated to be required to form the barrier between the oil zone and gas cap. This performance indicates that prevention of oil encroachment into dry gas caps in a peripheral water flood by water injection at the gas-oil contact appears practical and that the model studies provided a valid prediction of field performance. INTRODUCTION The Sholem Alechem Fault Block "A" Sims Sand Unit was one of the fist major waterflood projects in Oklahoma to utilize a peripheral injection pattern. Design of control measures to minimize oil encroachment into the large crestal gas caps was one of the greatest single problems during engineering planning of this flood. Engineering studies indicated that saturation of the gas caps with oil displaced by the peripheral water flood could result in a loss of about 27 million bbl of oil, or over one-half the estimated waterflood recovery. This estimate was based on a residual oil saturation after water flooding of 35 per cent pore volume, compared to the negligible oil saturation initially in the gas caps. The Sholem Alechem Springer field, located in Stephens County, Okla., is an elongated anticline with structural dips varying from 400 to 1,000 ft/mile. The structure contains numerous faults, some of which are sealing. The portion of the field considered in this paper is Fault Block "A", which is the largest of the five major fault segments in the field. A map of the unit is shown on Fig. 1. The unit is bounded on the east and west by major sealing faults, on the north by a water-oil contact and to the south by a deterioration of sand development. Two domes, each having gas caps, exist in the unit and are separated by a north-south fault as shown in Fig. 1. The sands being flooded are the Sims sand members of the Springer series of early Pennsylvanian age. The Sims sands average over 100 ft in thickness in Fault Block "A" and have a porosity of approximately 19 per cent. Core permeabilities average 160 md, with interstitial water saturation of about 23 per cent pore volume. Three different zones can be correlated over most of the area. However, they are commingled in most of the producing wells. The two upper zones, designated as First and Second Sims, are the most important. Both the First and Second Sims have gas caps in the east dome, while only the First Sims has a gas cap in the west dome. These gas caps, whose limits are also shown on Fig. 1, initially occupied nearly 11 per cent of the total reservoir volume. The major concern of this paper is the control of the two gas caps in the First Sims sand. Fig. 2 is a cross section, to scale, across the east dome of this formation. Notable features are the relatively shallow dip, the deterioration of the First Sims sand on the south side of the gas cap and the water-oil contact on the northern edge. The formation dip at the gas-oil contact in this cross section is approximately 5".

By P. Somasundaran, I. J. Lin

There are several methods described in the literature for the determination of the order and the rate constant for the flotation of minerals. These often involve some type of computational or graphical procedures. A relatively simpler method developed on the basis of a technique used by Chang" in chemical kinetics is described in this paper. Chang&apos;s technique, like most others in chemical kinetics," is based on the law of mass action which states that the rate of a chemical reaction is proportional to the active masses of the reacting substances at any given time. Application of this law to the flotation of minerals would involve the adaptation of the terms "flotation" for "chemical reaction" and "floatable amount of the minerals" for "the active masses of the chemical reactants." There are indeed a large number of physical processes controlling the actual flotation rate. The most inefficient one of these could be considered equivalent to the slowest reaction in a series of chemical reactions. If variables such as aeration rate and agitation are kept at constant levels, the rate of flotation under free flotation conditions (i.e., conditions under which the suspension is dilute) will be given by the following equation: where C is the concentration of the floatable minerals in the pulp at any given time t, K is the rate constant, and n is the order of the reaction. If we represent the floated fraction of the floatable mineral at time t as m (0 m - 1) and C at t = 0 as Ca, integration of Eq. 1 yields

Jan 1, 1974

By R. J. Borg, C. E. Birchenall

The self-diffusion coefficients for a iron have been deternzined between 980° and 1167° K using Fe55 as the tracer. With decreasing temperature the diffusivity was found to decrease more rapidly than predicted by the Arrhenius equation in the region of the Curie temperature. The diffusion coefficients obtained well above the temperature of the magnetic transformation are more precise ard differ substantially from all the previously reported values. In the temperature region beginning at least 50" above T,, the diffusion coefficient is given by D = 118 (±2) exp 1 HE self-diffusion coefficients for a iron have been reported previously as the result of four independent investigations The general lack of agreement and the poor precision of most of the previous work prompted the redetermination by the present authors. The possible effect of the onset of ferromagnetism upon the diffusivity5 provided an additional impetus for this investigation. The earlier measurements of Birchenall and Mehl1 gave low values for the diffusion coefficient at temperatures below the Curie temperature, Tc. However, the precision of these measurements is not sufficient to establish an indisputable correlation between the low values and the magnetic transformation. The results of this investigation along with all the previous ones are shown in Fig. 1. EXPERIMENTAL Small rectangular samples, approximately 1 by 0.5 by 0.3 cm, of high-purity iron (Vacuum Metals Corp., "Ferrovac") are first heated in hydrogen at 900°C for24hr in order to remove possible trace amounts of dissolved carbon and oxygen. The small

Jan 1, 1961