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By David Kellogg

THE electrodeposition of iron has been practiced for many years. The earlier work along this line was directed toward the preparation of pure metal, but later applications were the production of thin adherent coatings as used in the electrotyping of Russian banknotes in 1860. A historical discussion of this subject, however, would require too much space and would be inconclusive. Much has been written on the subject but no two experimenters use the same methods or materials. During the war, the British army repair, shops developed a method for building up worn parts of automotive machinery, aero engines, etc., using the cold surfate . bath and low-current density method.1 The method has been used successfully in commercial work for the production of about 6000 repaired parts, therefore experiments along the same lines have since been made at the Westinghouse research laboratory. The apparatus used was essentially that described in the article mentioned except that the current -used for cleaning was obtained from a 3/4-kw. 60-volt, house-lighting generator, direct connected to a 2-h.p., 870-r.p.m., 440-volt, three-phase, type CS induction motor; while the plating current was taken from the storage batteries at any desired voltage. The anodes were made from 0.036 in. (0.9 mm.) Armco iron made into cylinders 5 in. (127 mm.) long by 8 in. (203 mm.) in diameter with a disk of 1/8 -in. (3.17 mm.) micarta, having a 2 in. hole in the center fitted at each end of the cylinder for stirring. The anodes were hung on a wooden rocker frame driven by a wooden connecting I rod directly connected to a small reducing gear, such as is sold by most of the apparatus supply firms; 3 gal. stoneware crocks were used as containers. The solution used by Thomas, 75 gm. of the crystallized ferrous ammonium sulfate per liter, was tried, using the current density recommended by him; namely, 0.33 amp. per sq. dm. Under these conditions the deposit on a ½ -in.

Jan 2, 1922

By C. A. Hansen

INTRODUCTION It has been the experience of the writer, during some. five years' work with electrolytic zinc, that the zinc cell is perhaps more- sensitive to impurities in the electrolyte than the analytical methods as yet developed for the chemical identification and determination of these impurities; but that, when proper purification methods have been applied to a given solution, the behavior of the cell is quite independent of the original sources from which the zinc sulphate has been derived. It has also appeared that the behavior of the zinc cell is the best and surest check on the correctness and thoroughness of the purification methods used, because it indicates the presence of both current impurities. and cumulative impurities derived from the leaching of the ore; it also in

Jan 3, 1918

By T. B. Counselman

PROBABLY the earliest concentration of iron ore in this country was carried on in the northeastern magnetite areas. Magnetic concentration was relatively simple and gave a concentrate that, after agglomeration, and in spite of being high in phosphorus because of the dry concentrating methods then in use, was satisfactory blast-furnace feed. Production from the northeastern magnetite area languished after the discovery and development of the Lake Superior ores, where there was seemingly an unlimited tonnage of high-grade ore, first the Michigan ores, and subsequently the still larger deposits of Minnesota. For years only the higher grade, direct shipping ores of the Lake Superior district were mined. Those of Michigan, and of the Vermilion Range in Minnesota, were hard ores and came principally from underground mines. The softer ores of the Mesabi came partly from underground mines, but mostly from the enormous deposits that could be worked by open-pit methods. The costs of ore from these open-pit deposits, even with the high initial cost of stripping, were so low that the underground mines of the Mesabi could hardly compete. The so-called Old Range ores, of Michigan and of the Vermilion Range of Minnesota, were hard and lumpy, and opened up the burden in the blast furnace, therefore making possible harder driving with greater output. Also, some of these ores were of such grade and physical characteristics that they were suitable for charge ore in the open hearth. These ores, therefore, commanded a price premium, and could compete with the softer, finer, but cheaper, Mesabi ores. The big tonnage reserves, however, are on the Mesabi, and it is these big open-pit deposits that constitute our stock pile of iron ore, from which we are drawing so heavily during this war period. On the western end of the Mesabi the ore was found to be high in silica, and not suitable as furnace feed. As early as 1902, attempts were made to concentrate this so-called wash ore and by 1910 the first washing plant was put into operation. The process was very simple, consisting essentially of a sizing and washing operation, with scalping screens, logwashers, and tables, which later were replaced by classifiers. Ore particles finer than 100 mesh were deliberately wasted, because these fines were undesirable in the furnace. Fortunately, these tailings were impounded, and already are being reworked. Before long some of the low-grade ores began to require more elaborate treatment than the simple washing operation and, tables having been discarded because of their low capacity, in favor of classifiers, jigs were next introduced. These were able to discard coarser pieces of tailing than classifiers. Jigs are in active use today, various improvements having been made in their design and application. Various other machines and methods of concentration have been tried from time to time, and have in turn been discarded for more improved processes. The latest and most important process that has been

Jan 1, 1943

By Philip D. Wilson

The mines of the Calumet & Arizona Mining Co. are situated in the Warren Mining District, Cochise County, Arizona, between Bisbee and Warren and adjoin those of the Copper Queen Consolidated Mining Co. and the Shattuck Arizona Copper Co. Paleozoic 1imestones.of considerable thickness have been intruded by granite porphyry. A great stock of the intrusive outcrops boldly near the city of Bisbee and is known as Sacramento Hill. From this central core the porphyry has tongued out into the limestone for many thousands of feet as dikes and sills of irregular shape and variable dimensions. Churn drilling has recently developed a large tonnage of secondarily enriched copper ore in the main porphyry mass of Sacramento Hill. While some ore has been found in porphyry in other parts of the district, it is relatively unimportant compared with that which occurs in the Paleozoic limestone as irregular lenses replacing favorable beds near porphyry contacts or associated with well-marked fracture zones often many hundreds of feet away from the intrusive. In a zone extending from Sacramento Hill for a distance of from 1,500 to 3,000 ft., the limestone has been extensively metamorphosed and in this contact metamorphic zone the ore occurs through a known vertical thickness of upward of 900 ft. and individual orebodies often show extension in a vertical direction of over 200 ft. At a greater distance from the intrusive stock, the ore occurs as lenses of greater horizontal than vertical dimensions with an average thickness of approximately 30 ft. An exception to this rule is found in the occasional steeply dipping mineralized fractures, almost true tabular veins, which are found long distances a way from the zone of contact metamorphism. The copper was probably introduced during or slightly later than the porphyry intrusion in the form of chalcopyrite and bornite. These primary copper minerals are always associated with pyrite and often occur as rich lenses in a huge mass or shell of pyrite carrying an insignificant percentage of copper. In many instances the copper-bearing solutions were preceded by siliceous solutions and these latter, often persisting during the period of mineralization, have thoroughly indurated the ore-

Jan 1, 1917

By Fred T. Agthe, Fred C. Bond

When some materials are ground dry in a ball mill, a stage of comminution is reached at which the finely divided particles begin to adhere to the balls and to the mill lining. As grinding progresses, a coating accumulates upon the grinding media, which tends to cushion the impacts and thus retard reduction of the material. and finally becomes so thick that all grinding ceases. At this stage, the characteristic noise produced by the grinding media during normal mill operation changes to a dull, muffled sound. In most instances, the formation of the coating marks the practical limit of size reduction. Industrial requirements for fine grinding frequently meet with this obstacle, and the tendency in many commercial operations to grind materials to a higher degree of fineness than formerly makes the solution of this problem an important one. The phenomenon is of far greater importance, therefore, than the limited amount of research and technical discussion devoted to it implies. In order to learn more about the coating of different materials when ground dry to a high degree of fineness, certain laboratory tests were made from which it was found that different materials form coatings at widely different size distributions. It is probable that most materials will coat if they are ground fine enough; the exceptions have inherent lubricating qualities, like coal and graphite. In general, the softer materials tend to coat at coarser sizes than the harder or more brittle materials. Limestone, as an example, will coat more readily than quartz, even though limestones of different- texture and composition exhibit great differences in coating potentialities. Various materials were tested in the laboratory to show the variation in coating qualities. It was found that in most tests quartz must be ground to a fineness that would permit it to pass through 325 mesh before coating became markedly detrimental to the grinding operation. Siliceous rocks, however, tend to coat more readily than quartz. Granite, which is composed essentially of feldspar, quartz and mica, has been found to start coating at about 92 per cent through 200 mesh, and feld-spathic minerals alone usually show a tendency to coat at the same fineness. Barite has been ground in the laboratory to a fineness of 99 per cent through 325 mesh without showing serious coating of the grinding media. Gypsum coats readily. Apatite and phosphate rock usually tend to coat. Hematite usually coats, although when mixed with charcoal it does not do so. In testing the carbonate rocks and minerals, it has been found that burned magnesite, dolomite, and dolomitic limestone coat, whereas calcite and calcined calcite do not coat so readily. It has been found that commercial glass, slate, talc, steatite and coke have little tendency to coat. The relative tendencies toward coating during grinding operations, exemplified by

Jan 1, 1943

By Fred C. Bond, Fred T. Agthe

When some materials are ground dry in a ball mill, a stage of comminution is reached at which the finely divided particles begin to adhere to the balls and to the mill lining. As grinding progresses, a coating accumulates upon the grinding media, which tends to cushion the impacts and thus retard reduction of the material. and finally becomes so thick that all grinding ceases. At this stage, the characteristic noise produced by the grinding media during normal mill operation changes to a dull, muffled sound. In most instances, the formation of the coating marks the practical limit of size reduction. Industrial requirements for fine grinding frequently meet with this obstacle, and the tendency in many commercial operations to grind materials to a higher degree of fineness than formerly makes the solution of this problem an important one. The phenomenon is of far greater importance, therefore, than the limited amount of research and technical discussion devoted to it implies. In order to learn more about the coating of different materials when ground dry to a high degree of fineness, certain laboratory tests were made from which it was found that different materials form coatings at widely different size distributions. It is probable that most materials will coat if they are ground fine enough; the exceptions have inherent lubricating qualities, like coal and graphite. In general, the softer materials tend to coat at coarser sizes than the harder or more brittle materials. Limestone, as an example, will coat more readily than quartz, even though limestones of different- texture and composition exhibit great differences in coating potentialities. Various materials were tested in the laboratory to show the variation in coating qualities. It was found that in most tests quartz must be ground to a fineness that would permit it to pass through 325 mesh before coating became markedly detrimental to the grinding operation. Siliceous rocks, however, tend to coat more readily than quartz. Granite, which is composed essentially of feldspar, quartz and mica, has been found to start coating at about 92 per cent through 200 mesh, and feld-spathic minerals alone usually show a tendency to coat at the same fineness. Barite has been ground in the laboratory to a fineness of 99 per cent through 325 mesh without showing serious coating of the grinding media. Gypsum coats readily. Apatite and phosphate rock usually tend to coat. Hematite usually coats, although when mixed with charcoal it does not do so. In testing the carbonate rocks and minerals, it has been found that burned magnesite, dolomite, and dolomitic limestone coat, whereas calcite and calcined calcite do not coat so readily. It has been found that commercial glass, slate, talc, steatite and coke have little tendency to coat. The relative tendencies toward coating during grinding operations, exemplified by

Jan 1, 1943

By R. M. Board

This paper will focus on measurement and control of four main aspects of crushing, namely horsepower, bowl level, mantle position and feed rate, and will discuss related sensors and control techniques, some of them designed specifically for crusher control, that have proven successful and reliable in many installations.

Jan 1, 1982

By David A. Summers, Clark R. Barker, Marian Mazurkiewicz

In May 1975 the U.S. Bureau of Mines contracted with the University of Missouri-Rolla, Rock Mechanics and Explosives Research Center to develop a Hydrominer modification to a longwall shearer unit, wherein the rotating pick-laced drums and connecting gear drives are replaced by a water jet cutting ahead. The concept of the water jet cutting head is based on using the high localized energy of the water jets to isolate a slice of coal by cutting a slot under, at the back of, and at the top of the web. The plow blade of the head then advances into the cut and wedges the coal cantilever over onto the conveyor [(Fig. 1)]. There were several potential advantages foreseen for the system; perhaps the most significant were the elimination of coal dust from the working area and the ability, with a variation in nozzle geometry, to cut webs of greater depth with a small increase in haulage horsepower. The University initially designed the head, based on experiments carried out in the laboratory, under an earlier Bureau of Mines contract. The experiments showed that it was more advantageous to work at a pressure of 68.9 mPa (10,000 psi) with an estimated flow rate of 3.15 X 10 - 8 m3/s (50 gpm) than go to the higher pressures and lower flow rates which have been advocated elsewhere.

Jan 1, 1979

By d&apos, L. Berenbaum, F. Heurle, R. Rosenberg

The structure of aluminum films obtained by evaporation was studied by electron microscopy, mostly by replica techniques and X-ray diffraction. The resistivities and stress conditions of the films were also determined. Film properties were studied as a function of source selection, substrate type, residual pressures of oxygen and water vapor, substrate temperature, and rate of growth. The formation of abnormal localized growths and whiskers resulting from annealing treatment subsequent to deposition was investigated. Films deposited onto single-crystal substrates were found to be epitaxially 0riented; for such films, relative orientations between films and substrates were determined. ALTHOUGH wide use has been made of evaporated aluminum films for the formation of conducting lines on semiconductor devices, relatively little has been reported concerning the structural characteristics of such films.1"9 The purpose of this study was to obtain an overall view of the dependence of these characteristics on film deposition and subsequent annealing conditions, which were similar to those used in silicon planar technology. Accordingly, most of this study was carried out using oxidized and bare silicon wafers as substrates, although some work was also done using alkali halide, magnesium oxide, and mica substrates. However, the main concern remained pragmatic. Emphasis was given to the study of the effects of deposition and annealing conditions on film characteristics such as structure, resistivity, and stress. I) EXPERIMENTAL PROCEDURES The films which were investigated in this study were deposited in 18-in.-diam glass chambers which were connected to the usual type of trapped diffusion pumps filled with silicon oil. Through the use of liquid-nitrogen-cooled Meisner traps and titanium sublimation pumps placed inside the deposition chambers, the pressure could be lowered to the lower portion of the 10- I Torr range and little increase in pressure would occur during the deposition cycle. Unless described otherwise, the substrates were 1-in.-diam p-type silicon wafers having a resistivity of 10 ohm-cm. The wafers were oxidized in wet oxygen at 975°C followed by a short dry-oxygen exposure at the same tempertture to a total oxide thickness of approximately 6000A. The wafers, backed by a layer of gallium, were mounted onto molybdenum discs brazed to a copper block.10 The latter was heated by imbedded commercial cartridge heaters. The substrate temperature could be maintained to within +10°C of a prescribed temperature during film deposition. The search for a satisfactory source for the controlled evaporation of aluminum has led to the use of 1-in.-diam crucibles" machined from rods of a commercially available, refractory composite* of Bn and

Jan 1, 1969

By J. J. De Witte, J. G. Cazort

The Paranam plant in Surinam (formerly Dutch Guiana) was built during 1939-40 to supply crushed and dried bauxite for the growing U.S. aluminum industry, supplementing production from the Suriname Aluminum Co.'s Moengo works, which began operation in 1922. A subsidiary of Aluminum Company of America, Suralco's total annual production from these two plants averages 2.55 million dry metric tons of various grades of bauxite. Starting in 1941 with bauxite from mines on the west side of the Suriname River, annual production at the Paranam plant has varied from a low of approximately 450,000 tons to more than 1 million tons in 1949. High production rates during World War II and the late 1940's rapidly depleted these reserves, and in 1950 plans were made to mine the known deposits on the east bank of the river, about five miles downstream from the original Paranam plant.

Jan 11, 1960

By Graham Bright

METAL mines were developed long before coal mines and the early lighting of underground workings was effected by torches and candles. The early coal mines were outcrop workings and little trouble was experienced from gas, but as the mines became deeper and shaft mines were opened it became apparent that an open-flame lamp was exceed-ingly dangerous where gas occurred. No satisfactory way of lighting gaseous coal mines was found until Sir Humphrey Davy brought out his famous safety lamp in 1815. The introduction of the Davy lamp was a great step forward but it was unsatisfactory from a light standpoint because the gauze absorbed a large percentage of the light given out by the flame. Clanny corrected this by the introduction of a cylindrical glass lens, which not only per-mitted a free distribution of the light from the flame but added greatly to the safety by eliminating the possibility of the flame coming in contact with the gauze and by protecting the flame against air currents. A very complete story of the flame safety lamp since its inception is given in the U. S. Bureau of Mines Bulletin No. 227, by J. W. Paul, L. C. Ilsley and E. J. Gleim, published in 1924. A little more recent publication, known as Safety in Mines Research Board Paper No. 4, entitled "The Light Power of Flame Safety Lamps," by R. V. Wheeler and D. W. Woodhead, was published in England in 1927. The flame safety lamp was the-only lamp available for gaseous mines for about 100 years. Although the incandescent electric lamp has been in use over 50 years, it was not found safe to use this lamp from wired circuits in gaseous locations. The storage battery was advocated shortly after the develop-ment of the incandescent lamp but until the introduction of the tungsten filament in the miniature mine-lamp bulb, the battery lamp was not a real possibility because of the excessive weight of the battery necessary to produce a sufficient amount of light. The actual development of the electric-battery type of lamp took place largely between 1910 and 1915. In England and Europe, the development was almost entirely along the

Jan 1, 1935

By J. S. Bryner

INTRODUCTION IN the study of metallographic specimens in the electron microscope, there is need for a method of locating the same field in both the light microscope and the electron microscope. This need arises chiefly from the fact that in the electron microscope the magnification and degree of resolution are so much higher, and the field so much smaller than in the light microscope that it is often difficult, if not impossible, to identify positively what is being observed. The difficulty is increased by the fact that, because a transparent film replica of the metal surface must be used in the electron microscope, micro-constituents can be identified not by their color but only by their texture and contours. For these reasons it is desirable to obtain a series of photographs showing the same field in both microscopes in order that the appearance of common microstructures and micro-constituents in the electron microscope may be identified and catalogued for future reference. The need for a method of locating the same field in both microscopes arises also when it becomes desirable to enlarge in the electron microscope for more detailed study a particular interesting structure observed in the light microscope. Using the standard polystyrene-silica1,2 replica technique, in which the silica film replica is fished from the ethyl bromide on a 1/3 in. diam 200-mesh specimen screen, the possibilities of locating a particular area on the film in the electron microscope are rather remote. The desired structure may be obscured by the wires of the specimen screen or unrecognizable at the high magnification. A solution to the problem would be provided if a specially designed specimen screen, containing an opening which could be absolutely identified and quickly located in the electron microscope, could be fastened to the silica film replica in such a position that the desired field on the specimen would be located at the identifiable opening in the specimen screen. The design for such a specimen screen, a method for producing it, and a technique for fastening it to the silica film replica are described below. DESCRIPTION OF METHOD The Specimen Screen A simple design for a specimen screen containing an opening easy to identify and locate in the electron microscope is one with two lines of openings at right angles in the form of a cross. Such a screen is shown in Fig I. The opening at the center of the cross is identified easily and can be located quickly in the light microscope and in the objective image of the electron microscope. The specially designed specimen screens for this work were produced in quantity by electroforming. On both sides of a polished strip of copper 1 X 3 X 1/8 in., twenty patterns of the cross of openings were punched with a diamond point micro-hardness tester, using a load of magnitude

Jan 1, 1948

By Warren J. Jackson, John L. P. Campbell

Automatic recording of the radioactivity of the earth's formations provides a log of relative intensities that, if properly interpreted, can be applied to oil-field engineering. Production, engineering, and geological departments regard the radioactivity log as a forward step in the securing of more conclusive information for successful well completions. Explanations of the technique, together with some of the problems to which radioactivity logging have been applied, are presented in this paper. Introduction Those responsible for the completion of new oil and gas wells, or with planning workover operations on old wells, have followed closely the development of radioactivity well logging because they are interested in reducing the number of unknowns that usually are present in such work. Many operators have made use of the log, or are acquainted with at least one of the applications, but it is unlikely that any one operator is familiar with all of the many applications that are possible. The purpose of this paper is to present a representative example of each of the many applications, wherever the information has been released by an operator, and to illustrate by hypothetical examples other applications, releases for which have not been given. In this way, it is hoped that a better understanding of the scope of this new engineering tool may be obtained. Although the literature contains many references that describe in detail the theory, development, and application of radioactivity well logging, a brief discussion of the technique may be helpful to those who are investigating the subject for the first time. All rocks contain radioactive material in varying concentrations. In general, shales contain relatively more radioactive material than sandstones or limestones. These radioactive materials disintegrate with time into other materials of lower atomic weight, and in that process of disintegration the rocks are emitting many rays, the most penetrating of which is the gamma ray. The intensity of emission of the gamma ray is proportional to the quantities of radioactive materials present. A higher rate of emission would be observed, therefore, opposite a shale than opposite a sandstone or limestone. Since measurable intensities of gamma rays are capable of penetrating as many as five concentric strings of casing, and as the gamma-ray intensity is relative to the formations, the measurements of variations in gamma-ray intensities offer a means of identifying cased-off formations in their proper stratigraphic sequence. The Gamma-ray Curve The measurement of gamma-ray intensities is accomplished by means of an ioniza-tion chamber that consists of a heavy cylinder, about 3 ft. long, that contains two insulated electrodes and is filled with an inert gas under high pressure. Under normal conditions no current will flow through the gas when an electrical potential is set up between the electrodes, but when

Jan 1, 1946

By John L. P. Campbell, Warren J. Jackson

Automatic recording of the radioactivity of the earth's formations provides a log of relative intensities that, if properly interpreted, can be applied to oil-field engineering. Production, engineering, and geological departments regard the radioactivity log as a forward step in the securing of more conclusive information for successful well completions. Explanations of the technique, together with some of the problems to which radioactivity logging have been applied, are presented in this paper. Introduction Those responsible for the completion of new oil and gas wells, or with planning workover operations on old wells, have followed closely the development of radioactivity well logging because they are interested in reducing the number of unknowns that usually are present in such work. Many operators have made use of the log, or are acquainted with at least one of the applications, but it is unlikely that any one operator is familiar with all of the many applications that are possible. The purpose of this paper is to present a representative example of each of the many applications, wherever the information has been released by an operator, and to illustrate by hypothetical examples other applications, releases for which have not been given. In this way, it is hoped that a better understanding of the scope of this new engineering tool may be obtained. Although the literature contains many references that describe in detail the theory, development, and application of radioactivity well logging, a brief discussion of the technique may be helpful to those who are investigating the subject for the first time. All rocks contain radioactive material in varying concentrations. In general, shales contain relatively more radioactive material than sandstones or limestones. These radioactive materials disintegrate with time into other materials of lower atomic weight, and in that process of disintegration the rocks are emitting many rays, the most penetrating of which is the gamma ray. The intensity of emission of the gamma ray is proportional to the quantities of radioactive materials present. A higher rate of emission would be observed, therefore, opposite a shale than opposite a sandstone or limestone. Since measurable intensities of gamma rays are capable of penetrating as many as five concentric strings of casing, and as the gamma-ray intensity is relative to the formations, the measurements of variations in gamma-ray intensities offer a means of identifying cased-off formations in their proper stratigraphic sequence. The Gamma-ray Curve The measurement of gamma-ray intensities is accomplished by means of an ioniza-tion chamber that consists of a heavy cylinder, about 3 ft. long, that contains two insulated electrodes and is filled with an inert gas under high pressure. Under normal conditions no current will flow through the gas when an electrical potential is set up between the electrodes, but when

Jan 1, 1946

By A. A. Brant

In this presentation, concepts of the formation and evolution of the universe, the earth, and the cyclic civilizations of man are broadly outlined. The 5 billion or more years of the universe and the 4% billion years of the earth are contrasted to the 5000 years of modern society and the 100 years of objective scientific breakthrough. THE UNIVERSE Let us start back as far as possible, to the beginnings of this universe, some 5 billion or more years ago. This is a time interval that can be crudely underestimated by the moon-earth tidal friction effects that have increased the length of the day by about 1/1000 second per century — from a 5 to 7 hour day to its present 24 — and have moved the moon away at 5 inches per year to its present 240,000 miles. The oldest stony meteorites from interplanetary space give an age dating of some 4.6 billion years, approximating the time of formation of our earth. Further, certain stars pulsate, the period of pulsation being related to their absolute brightness. Measuring apparent brightness and comparing, gives the distance away. Thus Hubble and Shapley of Harvard, from 1925 on, were able to show that the universe reached as far as our telescopes could scan. The Doppler shift of the hydrogen red lines could only mean that the nebulae, or galaxies, were moving away away at velocities increasing with their distances, by 180 km/sec velocity increase for every million light year's distance. In short, the universe is expanding like an exploded bomb. Comparing the velocity increase per million light year's distance again indicates a zero time of some 5 billion years' Thus it appears that this universe had a finite beginning. Physical measurements and present theories permit some picture of our universe's birth. We know since Einstein that many forms of energy are equivalent, e.g., mass, and electromagnetic radiation, aspects of which are heat and light. Now with expansion, radiation density or equivalent mass decreases as a length factor to the 4th power, while mass as matter decreases at a length factor cubed. The temperature in outer space is now perhaps 100° absolute and the radiation mass equivalent is but 1/1000 the rarefied interstellar gas densities. Decompressing the universe to a starting point, however, raises temperature more rapidly than mass density, and results in a high radiation mass energy fraction, which since it is proportional to temperature to the 4th power suggests a zero point temperature of several billion degrees, brighter than any sun. "Let there be light and there was light," according to Genesis 1-3. Now what further initial conditions must there be to explain the relative abundance of the elements in the universe, which by spectral analyses of the earth's crust, stony meteorites, and the sun and stars is surprisingly uniform throughout. Some 55% of all cosmic matter is hydrogen, some 44% is helium and only 1% is made up of all the heavier elements in much the same proportions as on earth. These latter decrease logarithmically in abundance up to atomic weight 100, then level out. This consistent abundance distribution of elements in the universe may be generally explained by taking at Time Zero a hot neutron gas of density about 10-3 grams per cc, at a temperature of several billion degrees Centigrade, with a high radiation energy fraction. Generally neutrons break down into positrons and electrons within about ten minutes, but at the initial high temperature and radiation pressure would recom-bine. However, with rapid expansion and decrease of temperature and pressure, the neutron disintegration would run uncompensated and aggregation would result from neutrons and protons uniting in different degrees of complexity. The total calculated element aggregation time would be about one hour while the temperature still remained above one billion degrees. The element abundances formed would depend on density of the nuclear gas, simplicity of the atom formed, and the neutron capture cross section. Thus a higher density

Jan 1, 1964

By R. M. Murray

Although blister copper has been produced at the Mount Lyell Mining and Railway Company's works since 1896, it is only during the past five years that electrolytic refining has been undertaken locally, this having been done previously at customs refineries, at first in the United States, and afterwards at Port Kembla, New South Wales. Left to right: smelter building, converter building, blower building (in which converter-generators are housed), tank house and anode dock. Wire-bar furnace building in background at center. Possessing a hydroelectric power plant capable of generating power considerably in excess of the requirements of its mines and works at the time, the company was in a favorable position to undertake its own refining work, provided this advantage was not offset by the high cost of coal, which would have to be imported from the mainland, and provided also that the capital cost of the plant would not be unduly large in regard to the relatively small amount of copper to be treated. A study of these several conditions led to the adoption of a high-density plant using blister-copper anodes and equipped with an electric boiler to provide any

Jan 1, 1934

By Georges Ranque

THIS paper by. Georges Ranque is an attempt to reason out the conditions of formation and stability of inclusions and to establish an operative process capable of eliminating or minimizing them. The paper consists of two parts; one in which the author considers the laws of physical chemistry and physics that apply to liquid slag-metal systems and one in which he describes a practice based on the theoretical considerations. Such a paper is bound to contain controversial points and it is therefore your speaker's intention to present Mr. Ranque's side of the picture to the best of his ability without regard for any thoughts or criticisms of his own. RISING VELOCITIES OF INCLUSIONS Most nonmetallic inclusions have densities ranging from about 1.7 to s, while liquid steel has a density of about 7. Under these conditions, ferrostatic pressure should cause the inclusions, being lighter, to rise from the bath and be eliminated. This rising tendency is expressed by Stokes' law, from which may be calculated the rising velocity of a spherical particle in a liquid medium whose density and viscosity are known.

Jan 1, 1947

By T. P. Meloy

Economic constraints require that the optimum mineral processing circuit be chosen for a given ore and then the circuit be optimized. Meloy (1983) developed a general methodology for finding the best circuit for a given ore. This analysis, however, did not specify a way to optimize the best circuit once it has been found. To optimize a given circuit, it is necessary to find the optimum set points for each unit operation in the circuit. Developed in this paper is a simple, general equation which, when applied, defines the optimum separation set point for the maximum mineral grade. This general equation, Equation (4), applies not only to simple ores, but also to complex ores containing variable and locked particles. Currently, the optimum set point can be calculated only for heavy media and cyclone circuits, because they are the only unit operations for which the necessary data has been measured.

Jan 1, 1984

By Howard A. Meyerhoff, J. Earl Frazier

It is not known when silica sand was first noticed along the north coast of Puerto Rico, but the first mention of its occurrence was made in 1922, by N. L. Britton,1 who described its presence in isolated patches extending from Loiza westward beyond Manati. Further observations were made in 1925 and 1926 by Meyerhoff,2 who extended the known occurrences still farther westward to the low hill belt in the Quebradillas limestone immediately south of Hatillo. The extraordinary purity of the sands, which in most localities exhibit no contamination from the non-siliceous materials surrounding them, was quickly appreciated, and the feasibility of utilizing them for the manufacture of glass was investigated, initially by the Committee on Mineral Resources3 and later (1936) by the Puerto Rico Recon-structionAdministration and by H. C. Ray, mining engineer of the Insular Bureau of Mines. In 1934 samples submitted to the Hazel Atlas Glass Co., of Washington, Pennsylvania, were reported to have the composition as shown in the table on column two. Appreciation of the quality of the sand prompted geological and quantitative studies of the deposits, as well as cornmercial investigations to determine the feasibility of utilizing it locally or on the mainland for the manufacture of glass containers. Distribution of the Sands The quartz sands consistently lie within the outcrop area of the Quebradillas limestone, the youngest of the Miocene formations in the Tertiary coastal plain that fringes the northern coast of the Island. Many of the deposits are closely associated with limestone outcrops, but some appear to be embedded in lagoonal sediments at some distance from rock exposures, and at least one deposit, near Dorado, has been reworked by waves and littoral currents. With this single known exception, the deposits consist of irregular, patternless patches of white sand, which have sharply defined contacts with the surrounding material. Although patches of sand are present in a 90-km. belt that is not more than 5 km. wide, extending from Loiza to Hatillo, they attain maximum size, purity and number in the north central coastal area between Dorado and Barceloneta. Fifty separate deposits have been mapped in Lago Tortuguero and to the south of it, some as small as 50 ft. in diameter but

Jan 1, 1948

By J. Earl Frazier, Howard A. Meyerhoff

It is not known when silica sand was first noticed along the north coast of Puerto Rico, but the first mention of its occurrence was made in 1922, by N. L. Britton,1 who described its presence in isolated patches extending from Loiza westward beyond Manati. Further observations were made in 1925 and 1926 by Meyerhoff,2 who extended the known occurrences still farther westward to the low hill belt in the Quebradillas limestone immediately south of Hatillo. The extraordinary purity of the sands, which in most localities exhibit no contamination from the non-siliceous materials surrounding them, was quickly appreciated, and the feasibility of utilizing them for the manufacture of glass was investigated, initially by the Committee on Mineral Resources3 and later (1936) by the Puerto Rico Recon-structionAdministration and by H. C. Ray, mining engineer of the Insular Bureau of Mines. In 1934 samples submitted to the Hazel Atlas Glass Co., of Washington, Pennsylvania, were reported to have the composition as shown in the table on column two. Appreciation of the quality of the sand prompted geological and quantitative studies of the deposits, as well as cornmercial investigations to determine the feasibility of utilizing it locally or on the mainland for the manufacture of glass containers. Distribution of the Sands The quartz sands consistently lie within the outcrop area of the Quebradillas limestone, the youngest of the Miocene formations in the Tertiary coastal plain that fringes the northern coast of the Island. Many of the deposits are closely associated with limestone outcrops, but some appear to be embedded in lagoonal sediments at some distance from rock exposures, and at least one deposit, near Dorado, has been reworked by waves and littoral currents. With this single known exception, the deposits consist of irregular, patternless patches of white sand, which have sharply defined contacts with the surrounding material. Although patches of sand are present in a 90-km. belt that is not more than 5 km. wide, extending from Loiza to Hatillo, they attain maximum size, purity and number in the north central coastal area between Dorado and Barceloneta. Fifty separate deposits have been mapped in Lago Tortuguero and to the south of it, some as small as 50 ft. in diameter but

Jan 1, 1948