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By E. T. Dumble

The history of the several petroleum deposits of Texas and Mexico, or of the sediments in which they now occur, if the deposits are not indigenous to such sediments, is known in a general way only, but it nevertheless casts strong light on the conditions surrounding them and is of great importance in the search for and exploitation of them. The petroleum deposits of Texas are separable into two main divisions: 1. The deposits of northwestern Texas, which are directly connected with the Oklahoma fields to the north, and have no representatives at all in the Mexican area. 2. The deposits of the coastal area, which extend into Louisiana on the east and connect with those of the Mexican coast to the south. Early in the Pennsylvanian period a series of bituminous shales and limestones were laid down over a broad area in Texas, Arkansas, and Oklahoma. These are known as the Bend series in Texas, the Caney shales in Oklahoma, and the Fayetteville beds in Arltansas. Following their deposition an uplift occurred, forming the Lampasas geanticlinal, which runs northeastward from the old Paleozoic land area of the Llano region toward Red River. The Bend series is petroliferous in places and has furnished a few producing wells on each side of the Lampasas uplift. This uplift forms the barrier and dividing line between the two divisions of the Texas petroleum deposits. To the west of it, in waters which were the southcrn extension of the interior continental seas, in connection with the sedimcnts and coal beds of the Pennsylvanian and Permian, great quantities of petroleum were deposited either as oil or as "potential petroleum." These sediments have been subject to very slight disturbance, and only very gentle folds are found, with no signs of volcanic action in any part of the area. The conditions, therefore, indicate that the greater part, if not all, of the oil in this area is indigenous to the beds in which it is found. East of the anticlinal the oldest beds which appear in contact with the Bend are the Trinity Sands of the Lower Cretaceous. No evidence has

Jan 1, 1916

By Sukune Takenouchi

Porphyry copper deposits in the southwestern Pacific region differ in some points of geologic features from those of the United States. The deposits distribute along old or active island arcs and are generally younger in age (1-16 m.y. B.P.). In Japan, however, no typical porphyry copper deposits are yet reported, though the geological situation of Japanese islands is similar to that of the southwestern Pacific. Fluid inclusions in some porphyry copper deposits In the southwestern Pacific region and those in igneous rocks genetically related to the ore deposits In Japan have been studied, and the genesis of ore-forming fluids from igneous rocks are discussed. From the results, the possibility of finding porphyry copper-type mineralization in Japan are considered.

Jan 1, 1976

By Ralph A. Sherman, John Blizard

The experimental investigation described in this paper was conducted to determine the relative combustibilities of different samples of blastfurnace coke when burned in a current of air in a small furnace. It was undertaken in connection with the work done by Perrottl and Kinney2 on the process of combustion in the blast-furnace hearth.3 Reference is often made to the "combustibility" of coke by blastfurnace men, but exactly what is meant by the term "combustibility" is somewhat vague. Brassert,4 in a paper before a meeting of blastfurnace men in 1914, refers to combustibility as follows: The value of the coke in relation to the heat reactions in the furnace is determined not only by the carbon content but even more so by its combustibility. This, in turn, is governed by its size, the physical and chemical composition of the carbonaceous substance forming the cell walls, and the interior and surface structure of the coke pieces. These properties are, in turn, influenced by the chemical and physical properties of the coals used for coking, the density of the cake of coal in the oven, the coking time, temperature and heat regulation of the ovens, and last, but not least, by the method of quenching, screening and handling the finished coke. What principally concerns the blast furnace is the rate of progression of the combustion, which depends not so much on the chemical analysis as on the physical qualities of the coke. It is this rate of progression that we term combustibility, which is the speed at which the carbon molecules in the coke combine with oxygen under given conditions. In general, what the blast furnace requires is a coke which will burn rapidly and with intensity at the tuyeres, yet which has a sufficiently strong structure and hard surface to resist abrasion and solution by CO2 in the upper part of the stack.

Jan 1, 1923

By John Blizard, Ralph A. Sherman

The experimental investigation described in this paper was conducted to determine the relative combustibilities of different samples of blastfurnace coke when burned in a current of air in a small furnace. It was undertaken in connection with the work done by Perrottl and Kinney2 on the process of combustion in the blast-furnace hearth.3 Reference is often made to the "combustibility" of coke by blastfurnace men, but exactly what is meant by the term "combustibility" is somewhat vague. Brassert,4 in a paper before a meeting of blastfurnace men in 1914, refers to combustibility as follows: The value of the coke in relation to the heat reactions in the furnace is determined not only by the carbon content but even more so by its combustibility. This, in turn, is governed by its size, the physical and chemical composition of the carbonaceous substance forming the cell walls, and the interior and surface structure of the coke pieces. These properties are, in turn, influenced by the chemical and physical properties of the coals used for coking, the density of the cake of coal in the oven, the coking time, temperature and heat regulation of the ovens, and last, but not least, by the method of quenching, screening and handling the finished coke. What principally concerns the blast furnace is the rate of progression of the combustion, which depends not so much on the chemical analysis as on the physical qualities of the coke. It is this rate of progression that we term combustibility, which is the speed at which the carbon molecules in the coke combine with oxygen under given conditions. In general, what the blast furnace requires is a coke which will burn rapidly and with intensity at the tuyeres, yet which has a sufficiently strong structure and hard surface to resist abrasion and solution by CO2 in the upper part of the stack.

Jan 1, 1923

By F. R. Hensel

The present paper describes a number of experiments with fine silver, coin silver, silver-cadmium oxide and silver-nickei-copper compacts, prepared by powder metallurgical methods. The test data are of a preliminary nature, since most of the work was exploratory. Fine Silver Eject of Compacting Pressure on Hardness and Density during Cold and Hot Pressing The cold-welding properties of silver have received considerable attention and the welding characteristics are functions of such variables as: cleanliness of metal particles (impurities and adsorbed gases), chemical nobility of particles, plasticity and hardness, particle assortment, particle shape, particle porosity, apparent density, temperature, pressure, time, recrystalliza-tion characteristics. Chemical nobility, plasticity and low temperature of recrystallization after work-hardening are responsible for the excellent low-temperature bonding properties of silver. Several series of compacts were pressed at pressures of 5, 10, 20, 30, 40, 50, 60 70 and 80 tons per square inch, at temperatures of 32°C. (room temperature), l00°, 2000, 300°, 400°, and 450°C. Silver powder of minus 325-mesh, produced by displacing silver from a nitrate solution by means of copper, was used. The density was calcuiated from accurately measured and weighed compacts. The hardness was measured on the Rockwell F scale. The investigation shows that an increase in pressure promotes a higher density and hardness regardless of pressing temperature, up to a temperature of 400° C. The pressure-density curves at various pressing temperatures are shown in Fig. I, the pressure-hardness curves at various pressing temperatures, in Fig. z. The greatest increase in both hardness and density was obtained in the pressure range of 5 to 20 tons per square inch. A compact from each series was annealed at 300°C. in air, for various lengths of time. The hardness values after annealing are shown in Table I. A minimum hardness was obtained after one hour of annealing. No change in density occurred during annealing. The maximum density was obtained at 80 tons per sq. in., and at this pressure the hardness is equal to that of hard-drawn wrought

Jan 1, 1945

By P. K. Koh

Isothermal salt bath annealing of 0.014-in. thick 3 pct Si-Fe sheet was conducted at temperatures ranging from 927" to 1260°C in order to investigate the grain-growth behavior. Within the temperature range studied normal grain growth did not take place; instead nucleated grain growth prevailed. The nucleation frequency was found to increase with the annealing temperature, with corresponding decrease in grain diameter of ultimate secondaries after long-time annealing. Large secondaries grown by low-temperature isothermal annealing are essentially of (110)[001] orientation, and the (110)[001] texture is strong. The relatively small secondaries grown by high-temperature isothermal annealing also have orientations near (110)[001] as an average but widely scattered; thus the amount of (110)[001] texture is found to decxease with isothermal annealing temperature. Grain growth and texture development at various annealing temperatures can be described by families of sigmoidal curves with the time axis. ThE cube-on-edge (110)[001] texture and predominating large secondaries in fully annealed 3 pct Si-Fe are customarily produced by a 1100°C annealing of a primary recrystallized sheet. On annealing the primary recrystallized sheet above the temperature at which secondary recrystalliza-tion starts May and turnbull' have demonstrated that secondary grains decrease in size as the temperature is increased. The phenomenon was attributed to a decrease in the (G/N) ratio where G is the growth rate of secondary grains and N is their nucleation frequency. In addition, the growth of grains in orientations rather far from (110) [0011 occurred. The present investigation is devoted to detailed rate studies of the same phenomenon. Mi-crostructure, magnetic anisotropy, and texture data were obtained on strips of 3 pct Si-Fe isothermally annealed for various lengths of time in a BaC12 salt bath at temperatures ranging from 927' to 1260°C. The texture results are reported elsewhere.2 EXPERIMENTAL PROCEDURE Commercial 0.014-in. cold-rolled silicon-iron strip (3.16 pct Si), prepared by two stages of cold rolling with an intermediate short anneal, was given a decarburizing 3-min anneal at 800°C. Metallo- graphic studies indicated complete recrystallization. In order to provide a protective atmosphere and to obtain a rapid rise to an elevated temperature, a BaC12 and NaCl fused salt bath was used to heat samples isothermally at temperatures from 927" to 1260°C for various lengths of time. Torque magnetometer measurements were made on 1-in.-diam disc specimens before and after annealing, since magnetic torque curves supply information on textures and texture changes. Surface layers of the strip samples were polished and etched to reveal the grain structure. The diameters of grains were measured from micrographs at X100. The average value of diameters of matrix grains was established. Individual grains in the micrograph were cut out separately along grain boundaries. These grains were classified either as matrix grains or growth grains. The percent weight of growth grains in the cut-out patterns was reported as percent growth. Manv of the individual grains in the annealed samples were large enough to be X-rayed with a 5-mil beam for Lauegrams. Complete (110) pole figures were obtained for the primary recrystallized structure and short-time annealed structure with CoKa radiation at 30 kv in the back-reflection range, such as (220) for (110) poles, as described recently by Newkirk and ~ruce.~ Both the X-ray optics and the technique for pole figure differed slightly from those adapted previously.4

Jan 1, 1960

By William E. Ford, Edward Salisbury Dana

1. Normal Class (25) Barite Type 2. Hemimorphic Class (26) Calamine Type 3. Sphenoidal Class (27) Epsomite Type Mathematical Relations of the Orthorhombic System Crystallographic Axes. - The orthmhombic system includes all the forms which are referred to three axes at right angles to each other, all of different lengths. 296 Any one of the three axes may be taken as the vertical axis, c. Of the two horizontal axes the longer is always taken as the b or macro-axis * and when orientated is parallel to the observer. The a or brachy-axis is the shorter of the two horizontal axes and is perpendicular to the observer. The length of the b axis is taken as unity and the lengths of the other axes are expressed in terms of it. The axial ratio for barite, for instance, is a : b : c = 0'815 : 10 : 131. Fig. 296 shows the crystallographic axes for barite.

Jan 1, 1922

By M. P. Board, M. J. Reus

Instrumentation was installed during construction of the Silver Shaft in northern Idaho to evaluate lining behavior and rock deformation. Rock mass displacements were monitored with multiple-position borehole extensometers. Liner stress and strain were measured with concrete pressure cells and embedment strain gages. Rock displacement data from the 5,955-ft level indicate rock mass anisotropy. Liner stress and strain data reflect high in situ stresses and nearby station and raise construction. Continued monitoring and preliminary analysis indicate that concrete-lined, circular shafts are stable for high, unequal stress fields and anisotropy in deep level mines.

Jan 1, 1984

By Charles Fulton

This paper describes experiments carried on at the Case School of Applied Science, together with their results. Their success led to the design of the larger furnace herein described, but which has not been built. A PREVIOUS article' by the authors contained a general description of the new roasting furnace herein described but it did not go into detail as to the metallurgical behavior or the results obtained. Believing that such information would be of great value, they have elaborated on the subject and have given many unpublished details. The furnace described applies the principle of roasting finely divided zinc-sulfide ores, now produced in large quantity by the flotation process, in gaseous suspension; that is, the ore particles are carried, in suspension, in a current of air and gaseous products of the roast. The relatively great fineness of flotation concentrate presents difficulties and problems of roasting in furnaces of the ordinary type; the fine ore is forwarded through the furnace in the form of a shallow bed and its very fineness leads to dense impervious bedding which prevents oxygen from reaching the interior of the bed, thus unduly lengthening the time of roasting and preventing the elimination of the last of the sulfur. The fineness of the concentrate, normally, should lead to a rapid and complete roast, for the speed of roasting is a function of the surface exposed to oxygen, which surface is greatest, per unit of weight, in very fine material. The difficulty in bed roasting is to get the oxygen to the particle. If the fine ore, during the roasting, could be freely suspended in oxidizing gases, full advantage could be taken of the great surface conferred by its fineness. This fundamental idea, of course, is not new, for the Stedtefelt furnace, familiar to the older metallurgists, is an example of it; but the manner in which this is accomplished may be new.

Jan 10, 1924

By A. D. McMaster, M. L. Gimpl, N. Fuschillo

There is interest in the use of rhenium metal films as resistive elements in thin-film circcits, and already some zvork has been done using er)aporated rhenium films. It has been found that rheniim films protected from the atmosphere by an evaporated layer of silicon monoxide show excellent electrical stability. Unprotected films, however, are subject to aging- effects, notably the increase in electrical resistivity as a function of time. This phenomenon can be understood as primarily one of oxidation of the thin films. This paper is concerned with the study of the oxidation and crystallization behavior of such unprotected films. It has been found that the oxidation rates are a function of the substrate temperatures used during the deposition of Lhe metal films. The strictures observed in the films are correlated with the film resistivities and some data are presented to establish the existence of the various types of oxides of rhenium. ThERE is some interest in the use of thin films of rhenium metal as resistive elements in monolithic, thin-film integrated circuits. Some work has been done using evaporated films and it has been found that such films, if protected from the atmosphere by an evaporated layer of silicon monoxide, show excellent electrical stability up to temperatures of 500"." Rhenium films unprotected from the atmosphere tend to age and the electrical resistivity of the films increases as a function of time. Rhenium films, of the order of <100A thick, prepared by electron-beam evaporation techniques are found to oxidize very readily when exposed to dry air at room temperature. It would seem, therefore, that this aging phenomenon could be attributed to the oxidation of the metal films. In this investigation, the oxidation and crystallization behavior of thin films of rhenium evaporated onto silicon monoxide substrates were studied as a function of the substrate temperatures used during the evaporation. The films were examined using electron-microscopy and electron-diffraction techniques. EXPERIMENTAL RESULTS Rhenium metal was evaporated onto suitable prepared substrates which were heated to various temperatures. The evaporations were performed in a vacuum of approximately 5 x 1CT5 torr. The evaporation was carried out at a rate of approximately 10A per omin. The final film thickness was approximately lOOA and the resistance ranged from 5000 to 10,000 ohms per square. The substrates used for supporting the metal films were made by evaporating 75A of silicon monoxide onto freshly cleaved mica. The silicon monoxide film was then floated off the mica by immersing the composite in water. The film could then be picked up on a clean nickel grid. Silicon monoxide substrates were chosen because of their similarity to quartz and glass substrates commonly used for making thin-film resistors. Fuschillo, Gimpl, and McMas-ter have also shown that silicon monoxide films have only minor structural changes at temperatures up to 800°C. This fact simplified the interpretation of any changes observed in the electron micrographs or electron-diffraction patterns obtained from the deposited rhenium films. After the evaporations were completed, the substrates were cooled to room temperature, except where noted differently, before the coated substrates were removed from the vacuum system. All aging of the deposited films was done in a desiccator. The evaporated films were examined in an electron microscope equipped with a hot stage that would permit continuous observations of the samples up to temperatures of 1000°C. RESULTS A series of electron micrographs of the rhenium films deposited on the silicon monoxide substrates are shown to Figs. 1 to 3. In all cases, the metal films are approximately 100A thick and the micrographs were taken 1 hr after the deposition was completed. here was no apparent structure in the films deposited on the substrates held at the higher temperatures. The

Jan 1, 1967

By F. B. Plummer

PETROLEUM ENGINEERING deals with the production, transportation, and refining of crude oil. Refining is chiefly the work of the chemical engineer; production, that of the petroleum engineer. Production engineering only is discussed in this paper. Petroleum production engineering is closest related to and, in fact, is a branch of mining engineering. Formerly, many petroleum engineers were trained as mining engineers or mining geologists. The profession is related also to mechanical and civil engineering to about the same extent that mining engineering is. Petroleum production draws upon the mechanical branch for drilling and pumping machinery and upon civil engineering for the construction of transportation lines, water supplies, and water-disposal plants. Fundamentally, petroleum production engineering deals with the removal of the oil from the reservoir rocks, just as mining is concerned with the removal of ore. The process of oil production demands a specialized knowledge just as distinct from mechanical and civil engineering as mining is distinct from operating a Diesel engine. Even though the chief tools of the petroleum engineer are the drill and the pump, these may be of little avail, and certainly not efficient, if their selection and use is not based on a knowledge of the physical chemistry of oil, the geology of the formations, the structure of the oil sand, the hydrodynamics of the reservoir, and the interrelation of all these many factors.

Jan 1, 1936

By Price E. R.

The coal industry was beset with work stoppages and strikes throughout the year, and there was some loss in markets to oil and gas. These conditions, along with the mild decline in industrial activity, the steel strike, and the reduction in exports, contributed to an unfavorable year for the industry. All coal mines are working three days a week at the time of writing, and in estimating production for the year, it will be assumed that the mines will continue to work on that basis through December. Total production of bituminous coal in 1949 is estimated at 420 million tons, which is 179,518,229 tons under the production in 1948. Anthracite production is expected to reach 39,400,000 tons as compared with 57,139,948 tolls in 1948, a loss of 17,739,948 tons. Coal stocks, as of January 1, 1949, were 69,373,000 tons but at the end of the year will have dropped to approximately 22 million tons. Regardless of the difficulties during the current year, the industry has made substantial

Jan 1, 1950

By Morris Cohen

It has been known for several years that in certain age-hardenable alloys precipitation of finely divided particles occurs simultaneously with the changes in physical properties; while, in other alloys, these changes take place prior to, or without any, precipitation. The silver-copper alloys are generally considered to be the classical example of the first group, and the aluminum-copper alloys (duralumin) are typical of the second group. The two types of aging are explained by the precipilation theory and the knot theory respectively.‡ It is well recognized now that these theories do not conflict with each other; the one used for a given aging system depends upon which way the alloy in question happens to age-harden. However, previous work on the aluminum-copper al1oys1,2 has shown that if the aging temperature is raised sufficiently the hardening will be accompanied by actual precipitation. In fact, it is quite probable that all of the so-called knot-hardening alloys will harden by precipitation at elevated temperatures. Therefore, a combination of the knot and precipitation theories is necessary to give a complete picture of the agehardening of these alloys, and indicates that knot formation and precipitation are not independent processes. To test the generality of this concept, it is necessary to show that the alloys that commonly harden by precipitation will harden prior to precipitation if the aging temperature is sufficiently lowered. For this reason, it would be well to carefully re-examine the aging characteristics of the silver-copper alloys at aging temperatures somewhat below those used by previous investigators. If hardening can be detected prior to precipitation in these alloys, it will lend great weight to the idea that knot forma-

Jan 1, 1937

By Jack D. Webber

The successful use of oil well packers requires, in part: an understanding of the pressures which exist at the packer in various applications and an understanding of the characteristics of the various types of packers. It is with these pressures, the resultant forces, and the characteristics of packers. that this paper is primarily concerned. An oil well packer may be defined as a mechanical device for blocking the passage of fluids in an annular space. In the more usual case, the annular space is that between the tubing or drill pipe in a well and the casing, and packers which block such an annular space are broadly referred to as casing packers. In the other case. the annular space is that between the tubing or drill pipe and the walls of an open hole, and packers for blocking this space are generally called formation packers. While the hydraulics involved are essentially the same for casing and formation packers. a greater variety of conditions are encountered in the use of casing packers and only casing packers will be discussed. After a packer has been set and a pressure seal effected between tubing and casing, the packer is comparable to a piston in a cylinder. Pressures acting upon a piston result in forces which will move the piston unless some means is provided to prevent such movement. In the same manner, pressures acting upon a packer will move the packer unless there is present a sufficiently great restraining force. PACKER CLASSIFICATIONS Packers may be classified according to the pressure conditions under which they are capable of blocking the annular space between tubing and casing. Fig. 1 shows schematically two types of packers in common use. These packers are capable of blocking the annular space against the passage of fluids under a differential pressure of significant magnitude only when the pressure in the annular space above the packing element is greater than the pressure below. It may be seen that in Fig. l-a. slips with teeth which bite into the casing and prevent downward movement are provided. In Fig. 1-h. an anchor prevents downward movement. In each case, there i-only the tubing to prevent upward movement when differential pressures act to move the packers upwardly. Packers which hold only a significant differential pressure acting downwardly have been in use since the early days of the oil industry and will hereafter be referred to as conventional type packers. In many packer applications operating conditions will 1.crult in differential pressures across the packer which will at times act to move the packer upwardly, and at other times, act to move the packer downwardly. For these applications, designs are available which will block the annular space and resist movement in either direction. Fig. 2-a shows schematically a packer of this type which is designed to be run into a well and set, and removed when desired by merely pulling the tubing. It will be noted that two sets of slips are provided-— one set above the packing element to prevent upward movement, and another set below the packing element to prevent downward movement. This packer is built around a mandrel which is essentially a part of the tubing. and which is free to move longitudinally within certain limits through the set packer. Fig. 2-b shows schematically a permanent type packer which is capable of holding pressures from either direction. Here again, two sets of slips are provided to prevenl movement of the packer. This packer is designed to become virtuallv a part of the casing when set and it is made of drillable material so that it may be drilled out when its removal is desired. The seal nipple shown effects a pressure seal between the tubing and the packer. This seal nipple is a part of the the tubing, and the nipple and tubing may be withdrawn from the well without disturbing the packer. It should be noted that these figures are not representative of all available packers which are designed to hold pressures from both above and below. Packers which resist movement in either direction will hereafter be referred to as universal type packers. There is a third type of packer in general use and this type is designed to block the passage of fluids when the pressure below the packing element ii greater than that above. This type is provided with slips which prevent upward movement of the packer and is somewhat similar to a conventional type packer run upside-down. Packers designed to hold pressure only from below are made in a variety of designs and are usually owned and operated by service companies.

Jan 1, 1949

By Jack D. Webber

The successful use of oil well packers requires, in part: an understanding of the pressures which exist at the packer in various applications and an understanding of the characteristics of the various types of packers. It is with these pressures, the resultant forces, and the characteristics of packers. that this paper is primarily concerned. An oil well packer may be defined as a mechanical device for blocking the passage of fluids in an annular space. In the more usual case, the annular space is that between the tubing or drill pipe in a well and the casing, and packers which block such an annular space are broadly referred to as casing packers. In the other case. the annular space is that between the tubing or drill pipe and the walls of an open hole, and packers for blocking this space are generally called formation packers. While the hydraulics involved are essentially the same for casing and formation packers. a greater variety of conditions are encountered in the use of casing packers and only casing packers will be discussed. After a packer has been set and a pressure seal effected between tubing and casing, the packer is comparable to a piston in a cylinder. Pressures acting upon a piston result in forces which will move the piston unless some means is provided to prevent such movement. In the same manner, pressures acting upon a packer will move the packer unless there is present a sufficiently great restraining force. PACKER CLASSIFICATIONS Packers may be classified according to the pressure conditions under which they are capable of blocking the annular space between tubing and casing. Fig. 1 shows schematically two types of packers in common use. These packers are capable of blocking the annular space against the passage of fluids under a differential pressure of significant magnitude only when the pressure in the annular space above the packing element is greater than the pressure below. It may be seen that in Fig. l-a. slips with teeth which bite into the casing and prevent downward movement are provided. In Fig. 1-h. an anchor prevents downward movement. In each case, there i-only the tubing to prevent upward movement when differential pressures act to move the packers upwardly. Packers which hold only a significant differential pressure acting downwardly have been in use since the early days of the oil industry and will hereafter be referred to as conventional type packers. In many packer applications operating conditions will 1.crult in differential pressures across the packer which will at times act to move the packer upwardly, and at other times, act to move the packer downwardly. For these applications, designs are available which will block the annular space and resist movement in either direction. Fig. 2-a shows schematically a packer of this type which is designed to be run into a well and set, and removed when desired by merely pulling the tubing. It will be noted that two sets of slips are provided-— one set above the packing element to prevent upward movement, and another set below the packing element to prevent downward movement. This packer is built around a mandrel which is essentially a part of the tubing. and which is free to move longitudinally within certain limits through the set packer. Fig. 2-b shows schematically a permanent type packer which is capable of holding pressures from either direction. Here again, two sets of slips are provided to prevenl movement of the packer. This packer is designed to become virtuallv a part of the casing when set and it is made of drillable material so that it may be drilled out when its removal is desired. The seal nipple shown effects a pressure seal between the tubing and the packer. This seal nipple is a part of the the tubing, and the nipple and tubing may be withdrawn from the well without disturbing the packer. It should be noted that these figures are not representative of all available packers which are designed to hold pressures from both above and below. Packers which resist movement in either direction will hereafter be referred to as universal type packers. There is a third type of packer in general use and this type is designed to block the passage of fluids when the pressure below the packing element ii greater than that above. This type is provided with slips which prevent upward movement of the packer and is somewhat similar to a conventional type packer run upside-down. Packers designed to hold pressure only from below are made in a variety of designs and are usually owned and operated by service companies.

Jan 1, 1949

By D. D. Porter, H. G. Carlevato

Blasting to prepare orebodies for in situ leaching usually involves extraordinary conditions which sometimes require special and innovative techniques. To date several unusually large blasts have been made for leaching with results that are very encouraging. Among the factors considered when designing these large blasts are orebody shape and depth, rock properties, vibration and damage potential, loading logistics, and safety. All of these factors, and others, are discussed with an effort made to put each of them into its proper perspective.

Jan 1, 1974

By Alexander Squire

ONE of the principal factors that have contributed to the hesitancy of design engineers to use metal-powder parts is the difficulty experienced in the determination of the mechanical properties of compacted components. Because standard test: methods cannot usually be applied in the inspection of such parts, and because adequate special test methods have not been developed, it has been considered desirable to investigate the methods that are applicable. These may then be included in specifications for metal-powder materials&apos; and components in order that the design engineer may be assured that the subject parts possess the desired mechanical properties for satisfactory performance. It is known that direct relationships exist between usually nonmeasurable properties as tensile strength and elongation and shear strength and the angle through which compacts may be plastically deformed before fracturing. These correlations are valuable in the inspection of specific parts, but it is necessary to set up standards before they may be satisfactorily employed. Apart from the use of correlations, the number and character of the inspection methods that are applicable to almost all powder parts is limited to three-chemical analysis, density, and hardness. The last of these may or may&apos; not be a pertinent characteristic, since the indentation hardness of many powdered-metal materials is so low as to have little significance. It is, however, occasionally desirable to use hardness measurements as an indication of the uniformity of the structure of pieces of a given type. Chemical analysis reveals very little about the physical properties of metal-powder compacts, since the unpressed powder is usually of a composition almost identical with that of the finished pieces. Density determinations are simple, to perform and have the advantage of being nondestructive in character. If the dimensions of a machine part are known (and usually they are), the average density may be determined by weighing a given number of pieces and dividing by the calculated volume of the parts. More accurate measurements may be made by the water-displacement method. , It. is recognized that mechanical properties of metal-powder materials are related to their density, but usually these relations are determined for only one type of powder, processed under a given set of conditions. Comparisons of the properties of compacts formed from different types of powders are made on the basis of compacting... pressures instead of density, and for. this reason the results obtained by using powders of different types appear widely variant.

Jan 1, 1947

By Shiou-Chuan Sun

THERE are several postulations for the mechanism of slime-coating. Ince1 proposed the electrostatic hypothesis, del Giudice2 suggested the chemical theory; Bankoff3 reported that slime-coating is inhibited whenever the surfaces of the slime particles are ionized sufficiently for Brownian movement to occur, and is facilitated when they are not. These postulations were examined by experiments involving the Burton tube, the cataphoretic cell, and slime-coating. The techniques involved will be described elsewhere in this paper. The electrostatic hypothesis, supported by migration experiments in a Burton tube, was abandoned by del Giudice.2 Experiments of mineral migration in a Burton tube, after the idea of Ince with modification, indicated that this apparatus was inefficient for accurate observation. A cataphoretic cell was constructed. The experimental data, as shown in this paper, enable the correlation and advancing of this hypothesis. Del Giudice&apos;s chemical hypothesis considered that slime particles are attached to the galena surfaces by a cement formed as the result of a metathetical reaction between the sulphide and the slime particles. Applying this hypothesis, the calcite slime particles were cemented to the galena surface by the formation of a cementing lead carbonate. In a similar way, lead silicate was considered as the cement of quartz slime coating on galena. Experiments verifying this hypothesis were carried out according to the following procedure: Fresh mineral particles selected from the central part of the broken lumps and examined first under a microscope for ascertaining a clean surface were placed in a small beaker (1.5-in. dia. by 2.5 in. deep) half filled with one kind of slime pulp. The dilution of all slime pulp was 4: 1 and the particle size of slime was minus 400-mesh. After agitation for 5 min. the specimen was removed by a sharp-end tong and washed gently three times in three separate distilled water baths. It was dried before a small electrical fan and examined immediately under a microscope. A photograph was made of the observation. With reference to the published solubilities,4 several of these experiments, which contradict the chemical hypothesis, are listed as following: I. The coating of fluorite slime on the galena surface was light but the coating of galena slime on the fluorite surface was heavy. In a similar way, the coating of quartz slime on the galena was fairly light, but the coating of galena slime on the quartz particle was heavy. According to the chemical hypothesis, using the same constituents and regardless of which is the slime, the density of the coating should be expected to be the same. This, however, as shown above, is not true. Moreover, fluorite (CaF2), having a solubility of 16 mg.[4a] per liter of water, should not be

Jan 1, 1943

By H. Q. Golder

INTRODUCTION The stabilization of slopes is not a design problem. A slope is designed before it is made. For a slope to be stabilized it must already exist. The basic problem has existed for a long time. It started with cuts in soil and rock made in the 18th century during the construction of the canals which were developed at that time, and continued into the 19th century with the development of the railways, and in the 20th century with motor roads and lately open pit mining. It is not difficult to stabilize a slope, but certain questions must be asked and answered. These are: i) How much stability is required? ii) For how long is it required? iii) How important is the cost? These three questions indicate the basic problem of Civil Engineering, which is that the solution to any problem is a compromise between safety, cost and time. Stabilization of slopes is no exception. If the slope exists why is stabilization a problem? There are many possible reasons, for instance, a neighbouring and similar slope may have failed, or it may be necessary to change the conditions of the slope, steepen it, increase its height, put weight at the top, or construct a building at the foot in which case added security is required, or guarantee its stability for a longer time. MECHANISM OF FAILURE In order to pick the correct method of stabilization the mechanism of failure must be understood and the immediate cause of failure known. Often to remove the cause is the best remedy. The mechanism of failure has been studied over a period of many years in landslide problems. Pit slope failures are very similar to some types of landslides. (1) (2) (3) (4) In one sense there are many causes of landslides. Terzaghi lists 19. This means that there cannot be a standard solution to a stabilization problem. In another sense, it can be said that there is only one cause, which is gravity. This is a constant, never failing force which cannot be

Jan 1, 1971

By E. C. Dominguez, H. B. Scharf

The Sparrows Point plant of Bethlehem Steel Co., southeast of Baltimore, is the largest Bethlehem plant, with an annual rated capacity of 6.2 million ingot tons. There is considerable diversity of product, but a high percentage is sheet, tin plate, galvanized sheets, and rod and wire. The large amount of light-weight end product requires a number of pickling installations that necessarily consume large quantities of sulfuric acid. In the coking operations sulfuric acid is also consumed in recovery of ammonia as ammonium sulfate and in treatment of recovered light oil derivatives. Total sulfuric acid consumption in the plant is currently approaching 10,000 tons per month, of which 55 to 60 pct is required for pickling. In 1951 the acute sulfur shortage caused grave concern as to future sulfuric acid supply for the Sparrows Point plant. Raw materials for acid making were already at hand in the form of hydrogen sulfide and pyrites sufficient to produce nearly half the sulfuric acid required at that time. It was also known that the Bethlehem mining activities would produce additional pyrites in the future. Late in 1951 Bethlehem management decided to build a 250-ton sulfuric acid plant at Sparrows Point to utilize these raw materials. The plant was built and put in operation in May 1953. The steel plant has expanded considerably since 1951, and it is now necessary to operate the acid plant far over rated capacity in order to supply plant demand. Production of acid in 1954 amounted to 93,000 tons.

May 1, 1956