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By A. L. Engel

STRICTLY speaking, ore-dressing does not commence until after the ore is in the mill bins, but where complex ores are treated and their minerals separated to make the best commercial concentrate with the lowest economical tailing, ore-dressing problems begin and often center in the mine itself. This does not refer to the grade of the ore, but rather to the frequent condition in which metallurgical results radically different from customary are obtained because of changes in the character of the ore treated. Different varieties of ore can usually be identified as coming from well-defined depths or zones in the mine, or from known sections of the orebody. Varying degrees of alteration of the ore, inclusions of harmful gangue material, or variations in the quantities of component metallic minerals are often causes of temporarily bad metallurgical results in otherwise successfully operated plants, especially those employing differential flotation to. recover several valuable minerals contained in the ore.

Jan 1, 1931

By Webster, Wm. Reuben

THE greatly enlarged demand for small sizes of seamless copper tube which has recently occurred, due particularly to the rapid growth of the electric household-refrigerator industry, has emphasized the superiority of phosphorized to tough pitch copper for the purpose of producing this commodity. In the manufacture of this material exceedingly heavy reductions by cold drawing are employed, customary practice involving as much as 90 per cent. reduction of cross-sectional area in four runs without intermediate annealing. Although this superiority has long been recognized by tube makers, no quantitative expression of it has heretofore been published. It is believed that the data herewith presented mill serve this purpose. Recent investigators are not in agreement as to the relative mechanical properties of copper containing small amounts of oxygen as compared with copper containing sufficient oxygen to produce that condition known as tough pitch. Hanson, Marryat and Ford1 found that "oxygen has a relatively small effect on the properties of copper." Johnson, on the contrary, states "it cannot be denied that it (tough pitch copper) is inferior to deoxidized copper . . . where severe mechanical manipulation is concerned." These authorities in the reports of their investigations, as might be expected from their conclusions, do not present data of a character requisite to a conclusive determination of the question.

Jan 1, 1927

By AIME AIME

WIDESPREAD interest in the better utilization of coal is indicated by the attendance of over seventeen hundred men interested in the pro- cessing and utilization of coal and its by-products, at Pittsburgh, Nov. 15 to 18. The conference was truly international in scope and of a scientific character, and must be considered a real success. There were dele- gates--official and unofficial-from America, Belgium, Canada, Czechoslovakia, France, Germany, Great Britain, Japan, Mexico, and Sweden. Several Federal and 28 State departments had representatives, also many colleges and universities, and many leading industrial and mining corporations throughout the country. A feature of the sessions was that papers were mostly read in full and attentively listened to, although in some cases they were of a technical nature. The proceedings were opened by the president of Carnegie Institute of Technology, Thomas C. Baker, who spoke of the importance of the conference and felt that without foreign cooperation it could not have been held. There was no need to apologize for the movement of Carnegie Institute of Technology in the matter. Coal is commanding attention in every part of the world; so is power; and coal will remain the chief source of power for generations to come. The coal chemist is working with the engineer, and nobody can forecast what developments there will be in fuel technology. This conference may be the turning point of fuel technology in America. The development and application of these new processes may be of great benefit to Pittsburgh.

Jan 1, 1926

By P. H. Brace, N. A. Ziegler

THE study of the relations between gases and metals is one of perennial interest to all who are connected with the production of high-grade metallurgical products. The data reported here are the outcome of work of which the object is to determine the effects of dissolved gases upon the properties of metals and to gain a more detailed knowledge of the reactions between gases and molten metals, particularly iron, under definitely controlled conditions. We have attempted to reduce our margin of error by dealing with relatively large quantities of metal, from 4 to 13 lb. (2 to 6 kg.), and keeping the ratio of refractories to metal as small as practicable. The ingots produced are large enough to provide adequate material for making determinations of magnetic and other physical properties. In choosing the bell-jar type of furnace we were influenced by the results of considerable experimentation along the same general line which indicated that, for the scale on which we were to work, it was important to have the furnace structure independent of the vacuum enclosure. The use of a bell-jar surrounding the entire furnace accomplishes this and also gives great freedom of observation during operation and ready accessibility for the replacements which are necessary after each run. Our choice of analytical method was made in the light of the results secured by H. M. Ryder, who used a method similar in principle for the analysis of very small quantities of gas extracted from strips of metal heated electrically in high vacuum. We have presented some selected preliminary experimental data as being illustrative of the quantity and nature of the gases which occur in iron of different origins, but do not urge any hypothesis at this time. THE FURNACE Our furnace may be described as "a high-frequency induction furnace of the bell-jar type." It is similar in a general way to that described by Cain and Peterson' though we have introduced certain refinements of

Jan 1, 1928

By JAMES QATLEY

THE atmosphere, which plays such an important part in the manufacture of iron and steel, is the most variable element involved in its several processes; and particularly is this true of the blast-furnace process, which consumes air in large quantities. At no time since the blast-furnace became an important and widely used apparatus-even when it was operated in the most crude manner-have the variations in composition of the raw materials used been as frequent and as great as the variations in humility of the atmosphere. Important, improvements have been made in the blast furnace and its accessories, such as the hot-blast stoves, the increase in size and change in the shape of the furnace, more efficient blowing engines, the increased protection given to the bosh walls, and the careful preparation of' the raw material, all of which have exerted a pronounced influence on the furnace-operations from a metallurgical standpoint. But during the past eight years little advance has been made in this direction; the fuel-consumption has not diminished, nor has there been any material increase in production. Within that period, however, there has been witnessed the greatest development in appliances for the economical handling of material. So complete has been the work in this direction, that, except in isolated cases, in this country at least., a further extension does not hold out much promise of a satisfactory return on the investment required. It seemed that, with the exception of the gas-engine, we had about reached the limit, for like a strong wall, the atmosphere, with its humility as variable to-clay as when first blown into a primitive blast-furnace, appeared to stand as a Barrier to

Jan 1, 1905

By Robert H. Richards

Tuns truly remarkable machine was built on a preliminary scale in May, 1895. The first full-sized table was built by Mr. A. R. Wilfley, and was used in his own mill in Kokomo in May, 1896. The first table sold for installation was placed' in the Puzzle mill, Breckinridge county, in August, 1896. The mill enthusiasts at first hailed it as the cure for all the ills that flesh is heir to in the milling line. A little later it was found to make losses which were serious, and on this account the table succeeded only to a limited extent in displacing the vanners of the gold-mills. Still later, mill-men in a number of districts throughout the country made special studies of the faults of the machine, and devised a number of ways of grouping supplementary machines to overcome as far as possible the losses, and at the same time retain the benefit of the extraordinarily large capacity accompanied by the production of clean concentrates for which the machine has become so justly famous. I hope to make an exhibit of some of these methods in an appendix to my book on ore-dressing which is now in preparation. These experimenters have not written up the subject, and if they possess all the facts they have not given them out for the benefit of the mining profession at large. The object of this paper is to obtain the facts and to pre¬sent them so clearly that their bearing can be seen by all. To this end two complete series-'of tests have been planned. One (the present paper), to study concentration of galena in presence of quartz; the other (to follow shortly), to study concentration of chalcopyrite in presence of quartz. Some authorities claim that the table does its best work when treating natural products; by this phrase I mean products which have been crushed to pass through a limiting

Jul 1, 1907

By Donald T. Hawkins, Ralph Hultgren

The lorsion effusion method has been used to measure the vapor pressure of lead over pure lead and eight Pb-Sn alloys ranging from 9.1 to 87.9 at. pct Pb in the temperature range 950° to 1125°K. The resulting ?H°y 298 = 46,630 ± 200 cal per g-atow for pure lead is in excellent agreement with previous work. Deriued ?Gph values for the alloys were smoothed and correlated with previous heat of formation data to obtain entropies for the liquid alloys. values for the tin component were calculated by Gibbs-Duhem integmtion. Surfhce depletion of these liquid alloys was found to be absent, as shown by the fact that the measured pressure remained substantially constant with time in contrast with previous measurements on iron-rich solid Fe-Mn alloys. The activities and Gibbs (free) energies of the liquid Pb-Sn system are not well known although the heats of formation have been accurately determined by K1eppa.l Vapor pressure determinations of the activity of lead by Voronin and Evseev2 disagree with those of Predel.3 Elliott and chipman4 measured activities by the electromotive -force technique in the ternary Pb-Sn-Cd system. From the resulting values of the activity of cadmium, they were able to calculate the activities of lead and tin for the binary Pb-Sn system at the compositions xsn = 0.33 and 0.67. Atarashiya, Uta, Shimoji, and Niwa5 determined the activity of tin from Hz-H2O equilibrium measurements, but their results are subject to question due to uncertainty in the final state of their samples. To resolve these differences, measurements of the activity of lead were made using a torsion-effusion apparatus. Among other advantages, this apparatus rapidly detects errors caused by surface depletion, which tends to reduce the apparent vapor pressure of the more volatile component. If the measured torques remain nearly constant with time, only bulk depletion is occurring. This contrasts with the rapid decrease in torque found in solid Fe-Mn alloys at high temperatures and low manganese contents.6 EXPERIMENTAL 99.999+ pct Pb was obtained from the American Smelting and Refining Co. and 99.999 pct Sn from Vulcan Detinning Co. Eight Pb-Sn alloys were prepared by melting together weighed amounts of the pure metals in evacuated Pyrex tubes and quenching the melts in water. Loss of weight in preparation was less than 0.02 pct in all cases. The effusion cells were made from high-purity, nonporous graphite. Graphite was chosen because of its resistance to reaction with lead and tin and because it can be accurately machined with precision orifices. Two cells were used with overall dimensions as shown in Fig. 1. The orifices of cells 1 and 2 were, respectively, 1 and 1.5 mm in diam.

Jan 1, 1968

By John D. Price

COAL blending, in the preparation of coal before coke making, is so commonly practiced as to be almost universal. But the reasons underlying this practice, the benefits resulting from it, and the materials used in blending vary widely. This paper will outline the various phases of the subject and present information which may be correlated with work that has been done elsewhere. It will deal entirely with work done on the high-volatile coking coals of the western part of the United States, special emphasis being given to the coals of Colorado and Utah. A surveyL of the 86 coke plants in active operation in the United States during 1949 indicates that only 9 plants, or 10.5 pct of the total, charged one single rank of coal into their ovens, while the remaining 89.5 pcl made use of blending in some form. This report indicated that of these total plants 5 used straight high-volatile coal, 4 used straight medium-volatile coal, 47 used blends of high and low-vola-tile coals, 25 used blends of high, medium, and low-volatile coals, 2 used blends of high and medium-volatile coals, 3 used blends of medium and low-volatile coals. The fact that certain plants operated on a single kind of coal should not be interpreted to mean that no blending was practiced there, for invariably such plants secure their coal from more than one source and in the interest of uniformity do blend the coals as received. The general term coal blending covers two fields, the first of which is the mechanical mixing of a number of coals to secure uniformity. Often it is found necessary to secure coal for coke production from a number of different mines; these coals, though of the same general type or rank, may differ in their chemical composition or in the physical qualities they impart to coke made from them. Again, it is not unusual to find that coal from different sections of the same mine may show variations in quality. Under such conditions it may be necessary, in the interest of a uniform final product, to introduce a system of blending bins, a bedding yard, or other mechanical methods of securing a uniform mixture. Unfortunately this form of blending has received very little attention up to the present time; it has not received the consideration its value merits. The second type of blending, while also for the purpose of coke improvement, deals more particularly with the use of a blending agent differing in character from the base coal: it is this form of blending that will be discussed here. To consider only the western coals, for blending may be found necessary for other reasons with other coals, blending has been practiced experimentally or commercially under the following conditions: 1—When a single coal or mixture of coals of the same rank does not produce a satisfactory coke. For example, a high-volatile coal when used alone is likely to contract when coked so that a comparatively weak coke is formed. Or, if of very low rank, the coal may be deficient in the necessary bitumens required for good coke production. 2—When a product of some special quality is required, for example, when a plant ordinarily producing blast furnace coke must operate at slow coking rate to produce a high-grade foundry coke. Under this condition the reduced daily production of all products which accompanies slow coking time may be undesirable, and the use of some blending agent to increase the size of coke made at faster coking rates may be necessary. 3—When greater yield of coke or its coproducts is needed. Depending upon economic values of the products it may be found desirable to increase the yield of one or the other. 4—When supply of a particular coal must be used, either to protect reserves of high quality coking coal or to utilize a surplus or inferior product not otherwise usable. Many materials have been used for blending purposes, the exact agent to be used depending both upon the condition to be corrected and the nature of the base coal. No universal blending agent that can

Jan 1, 1954

By Dorsey Lyon

I. INTRODUCTION. In presenting, this paper the writers wish to call attention first of all to the fact that the electric furnace was not developed as a competitor of the combustion furnace, but: 1. For the purpose of doing high-temperature work which it is not possible to do in the combustion furnace; and 2. For the treatment of ores from deposits which. are located in regions where fuel is scarce and costly, and where hydro-electric power is comparatively cheap, as is the case in Chili, in Canada, in certain parts of this country and Mexico.. This paper is not presented with the idea of trying to. prove that the electric furnace should replace the reverberatory or the blast furnace as used at present in the smelting of copper ores, but that it may be substituted for their in those localities which are not favorable to them,) and where either of the two following conditions may exist: (a) A district remote from railway transportation. facilities, and where there is a deposit, or deposits, containing sufficient values to warrant their being worked, but which, due to the cost of getting coke in for operating a smelter and of getting ore out to a smelter, have to remain unworked.. And where, on the other hand, there is plenty of water power which call he developed at reasonable cost for the production of electric power, by the use of which for. smelting the ores in an electric furnace, with subsequent Bessermerization if necessary, a concentrated product may be obtained, which can easily stand the necessary transportation charges. (b) Or,. comparatively speaking, the transportation facilities may be all right, but the cost of fuel be too great to permit of the ordinary methods of smelting, whereas,- on the other hand, hydro-electric power can he developed: in the district at a, low cost,, and the ores could be smelted by the electric furnace at a cost. that would make their treatment possible. With these possibilities in mind we have attempted to make a brief comparative study of the problem for the purpose of aiding those interested in the subject, in determining whether it would be possible metallurgically, and feasible commercially; to use the electric furnace-in those localities where, by reason: of excessive fuel costs, the cost, of operating the furnaces for smelting copper-ores. is either excessive or prohibitive. Although the smelting of copper ores in the electric furnace has received considerable attention and more or less experimental work has been done, so far as: we lire: aware there ate no electric furnaces in the United States which are' being worked on copper ores. In Norway, however, trial smeltings of copper ores with an electric furnace of 1,000 h. p. and an estimated producing' capacity of 2,000 tons per annum, have been

Jan 8, 1913

By H. Linder, W. H. Dennen

The graphitic carbon content of soils may be used to detect and delimit subsurface graphitic zones. Spectrographic measurement of carbon in C horizon soils from several areas in the northeastern United States shows good correlation with known graphitic bodies. Bodies of graphite and sulfides are readily located by electromagnetic prospecting methods, but these methods cannot generally discriminate between them. Usual practice, therefore, requires follow-up work on electrically anomalous areas by trenching, drilling, or soil sampling in order to determine the mineralogical nature of the conductor. The efficiency and cost of such follow-up is consequently an important factor in prospecting. The presence of buried sulfide deposits is often reflected in concentrations of metals in the superincumbent soil. Simple chemical tests for such metal concentrations have been developed and applied with considerable success. Bodies of graphite or mixtures of graphite and sulfides are, however, very common and a means whereby buried graphite could be detected by soil testing should provide valuable additional information in the search for ore sulfide and graphite deposits. Graphite is a notably stable substance and should persist in soil above graphite-rich horizons. Microscopic examination of soil samples high in carbon, however, failed to reveal any recognizable graphite fragments indicating a grain size in the clay range. Presumably such small particles would have some mobility in a soil by a translocation mechanism similar to that proposed for the movement of clay particles in a soil profile. Experimental data supports this idea since the boundary between background and anomalous soils carbon values is quite sharp, but the anomalous zone is slightly broader than the graphitic source rock. A simple spectrochemical technique for the determination of carbon in geological materials has been described by Dennen,1 and may be directly applied to soils. A modification of this technique which employs an arcing chamber through which nitrogen is passed is recommended to decrease contributions from atmospheric carbon dioxide. Tests indicate that soils over graphitic zones may be strongly enriched in carbon. The spectrochemical determination of carbon depends upon the formation of the cyanogen molecule (CN) from carbon in a sample and atmospheric nitrogen, under the high temperatures associated with a dc arc. Samples for analysis are dried, lumps broken, and screened. A small portion of the -100 mesh fraction is packed into a copper electrode and excited as the cathode of a dc arc. The band spectra of cyanogen are recorded photographically and the density of the bandhead CN 3883A is measured. The limit of detection of the method is about 0.01 pct C and its coefficient of variation is about 15 pct. Soils, of course, contain carbon in other forms than graphite, and the amount of interference from such sources was examined. The C horizon of several soils from Massachusetts, Maine, and Pennsylvania were found to have a carbon content of 0.3 to 0.5 pct by weight. This content is chiefly due to the presence of carbonates and vegetable matter in the sample and may be readily eliminated, or at least

Jan 1, 1961

By Alexander Coucoulas

FABRICATION of thin-film circuits deposited on glass substrates requires the formation of permanent electrical contacts. Since thin films are in the order of a few thousand angstroms thick and are deposited on nonconductive surfaces such as glass, new methods of lead attachment are being pursued in the microelectronics industry. Ultrasonic welding is being considered in thin-film technology since joining can be accomplished between a wide variety of dissimilar materials.l,' Ultrasonic welding is accomplished by a transducer-coupling-tip system which converts high-frequency electrical energy into mechanical vibrations and delivers it into the weld region. During the process the tip oscillates in a direction parallel to the surface of the weldments, inducing shear stresses in the work pieces which are clamped between the tip and anvil. Though the basic bonding mechanism is not clearly understood, it has been described as closely akin to friction welding. In the course of an investigation concerned with ultrasonic we!ding of aluminum wires to tantalum thin films (1400A) deposited on glass, low weld strengths were related to glass failure. Upon investigating this condition, an improved method of bonding was developed where the aluminum was held at a temperature where a minimum amount of strain hardening occurred during the introduction of ultrasonic energy. Experimental Procedure. Aluminum wires (0.015 in,) were bonded to tantalum thin films with an optimized set of welding parameters (power, time, clamping force) employing a commercial 100-w 60-kc ultrasonic welder. Forty-five degree shear-peel tests, where the lead is pulled at a 45-deg angle with respect to the substrate at 0.2 in. per min, produced a large variation from zero to the strength of the wire, Table I. Inspection of the weld region generally revealed: glass cracking before and after testing; the removal of glass nuggets from the substrate by the lead during testing, Table I; thin-film penetration. In an effort to improve the shear-peel strength, the aluminum between the tip and substrate was heated above ambient temperature through an argon gas media prior to and during welding with the same parameters employed above. With the addition of heat: wire deformation was increased; shear-peel tests all failed at the weld-wire junction, leaving the bonded portion undisturbed; no evidence of glass cracking or film penetration prior to or after testing was observed. In order to prevent failure at the weld-wire junction due to excessive wire deformation, 0.035-in. aluminum wires were welded to tantalum thin films with an optimized set of welding and heating parameters. As

Jan 1, 1967

By Robert Bell

THE " Tar-Sands." is the name which has been given to the extensive horizontal deposit of fine Cretaceous sand, blackened by tarry petroleum, which forms the banks of the last or lowest 130 miles of the Athabasca river before it terminates in Athabasca lake. The Cretaceous strata, to which these sands belong, extend northwesterly from Dakota all the way to this lake and for 500 miles beyond it. The Athabasca river forms the uppermost section of the Athabasca-Mackenzie, one of the great rivers of the world. It rises on the Pacific side of the Rocky mountains, westward of Edmonton, and flows north of east to a point called Athabasca. Landing, 100 miles north of Edmonton, where it turns northward and runs about 280 miles before it falls into the west end of Athabasca lake. The section of this river-system which discharges the lake just named into Great Slave lake, is called Slave river, and below the latter lake it becomes the Mackenzie river. Along the section of 280 miles of the Athabasca river above mentioned, the Cretaceous strata consist of bluish-gray and drab-gray marls, on top, from Athabasca Landing to Drowned rapid, 110 miles down stream; then heavily bedded gray sandstones, 225 ft. in greatest thickness, underlying these, form the banks for about 40 miles further. The strata appear to be horizontal, but they really clip very slightly to the southward. At Drowned rapid, we see the first of the tar-sands resting on almost horizontal beds of bluish-gray limestone of Devonian age. In some places the limestone is associated with shaly or marly bands. Notwithstanding the great hiatus between the two series, the horizontal tar-sands lie conformably upon the almost level upper beds of the limestone wherever the two formations are seen together, all along the river, throughout a

Mar 1, 1908

By Wilfred Walker

With the advent of the New Global Tectonics a coherent pattern of geology is emerging. To the economic geologist this is of vital concern because the type of mineralization in particular environments is predictable. Developments in geological reasoning now take their place beside developments in geochemistry and geophysics. Much is known of the worldwide geography of the Alpine orogenic period because it is now ending its 200 million years of existence, starting with the Jurassic, and we can see the mid-ocean rises and the down flow zones, and between them the stable oceanic and continental platforms. The concepts of mantle cells, the spreading sea floor, and continental drift have gained general acceptance. The oceanographers have demonstrated the uprises like that in the mid-Atlantic. In this paper it is suggested that down flows in the oceans are marked by island arcs, like the West Indies; and down flows in the continents are marked by orogens like the American Cordillera. The number and position of mantle cells is controversial: a total of about 16 cells is suggested in this paper. Certain cells expand, and as they carry continents with them give rise to concepts of plate tectonics. Specific types of mineral deposits are associated with the uprises, oceanic and continental platforms, and down flows. The uprises are accompanied by the currently described Red Sea and Salton Sea deposits, the oceanic parts of the platform have the nodular deposits, and the continental platforms have the post-tectonic deposits. However, most economic metal deposits are associated with the down flow zones in which the stage of geosynclinal development controls the type of deposit: (1) In the initial development stage the simatic upper mantle may be tapped and give rise to the volcanogenic massive base metal sulfide deposits and to the ophiolite suite which characteristically carries nickel, chrome, and cupreous pyrite. (2) In the early geosynclinal stage sialic crust is driven down into the simatic magma of the upper mantle and basic to acidic differentiates give rise to stocks accompanied by skarn and hydrothermal deposits. (3) The intermediate stage of geosynclinal development gives rise to tin-tungsten, lithium, and beryllium deposits as the magma chamber rises above the level of the upper mantle and there is no simatic component. (4) The late stage is one of regenerated deposits. The porphyry deposits are not restricted to stages but only by the time of generation of acid magma. As the geosynclinal system dies, the mantle is again the source of magma, giving rise to gabbro and diabase dykes and sills: in this last, post-tectonic, continental platform environment are found the Mississippi Valley type lead-zinc deposits, the Blind River and Witwatersrand type of sedimentary uranium and gold deposits, and also Sudbury's nickel. The key relationship of major ore deposits generated by downflows is depicted herein on a framework of uprises, platforms, and downflows in the Alpine orogenic period. There is evidence for nine orogenic periods, of which the Alpine period is the latest, having taken place from 3500 million years ago to the present. Each period was characterized by its own worldwide mantle cell system and associated uprises, platforms, and down flows. The cycle of geosynclinal development, including corresponding cycles of mineralization, can be precisely defined in relation to each of these orogenic periods. The development of the Alpine orogenic period therefore can be used as a guide to the study of the earlier orogenic periods which comprise well known periods: Kenoran, Hudsonian, Grenville, and Paleozoic; and less well known: Konkian, Aulian, Belomorian, and Elsonian [(Table 1)]. Each name is used for the period as a whole, and not for the main orogenic event.

Jan 1, 1973

By Fred H. Poettmann

The vaporization characteristics of carbon dioxide in a League City natural gas - Billings crude oil system were studied at three temperatures, 38°. 120°, and 202°F and for pressures ranging from 600 to 8,500 psi. Variation of carbon dioxide concentration up to 12 mole per cent in the composite showed no effect on the equilibrium vaporization ratios (K values) of the hydrocarbon constituents or on the K value of carbon dioxide itself. It was shown that carbon dioxide is more soluble in crudes than in distillates which is contrary to the behavior of methane. A working chart of carbon dioxide K values is presented. INTRODUCTION The study of the equilibrium vaporization ratios of mixtures of paraffin hydrocarbons has been rather thorough.2,6,7,8,9 In the past few years considerable attention has been paid to the vaporization characteristics of the so-called noncondensable gases such as nitrogen, carbon dioxide, and hydrogen sulfide in mixtures of hydrocarbons. since they usually occur to some extent in most crude oils and natural gases.1,3,4,5 Knowledge of this behavior is useful to both the production and refining phases of the petroleum industry. This paper reports the equilibrium vaporization ratios (K's) of carbon dioxide in a mixture of League City natural gas and Billings crude oil, and compares them to those obtained in a natural gas-distillate system. The equilibrium vaporization ratios for the hydrocarbon components in this system had previously been studied by Roland.' In addition to the determination of the K values for carbon dioxide, the K values for methane and ethane were also determined in order to observe what effect, if any, the presence of carbon dioxide had on these K values. The concentration of carbon dioxide was also varied in order to observe the effect of this variable on the carbon dioxide K values. EXPERIMENTAL PROCEDURE The apparatus used in this study cotlsisted of a stainless steel equilibrium cell of about 2 liters capacity. The cell was mounted on trunions permitting rocking in a thermostatically controlled oil bath. Two high pressure valves fitted with steel tubing were mounted on the top of the cell. one was used for sampling the equilibrium gas phase and the other for sampling the equilibrium liquid phase by means of an induction tube within the cell. Stainless steel tubing from the bottom of the cell led to a mercury reservoir and manifold which was connected to a free-piston type pressure gauge manufac- lured by the American Instrunlent Ctr. and to a volumetric. putrip. The temperature of the oil bath was measured by means of a ralibrated mercury-in-glass thermometer. The recorded temperatures are believed to be accurate to ±0.5 °F. The pressures are correct to 22 psi. The crude oil used in this study was stock tank oil obtained from the Wilcox formation in the Billings Field, Noble County. Okla. The natural gas was obtained from the League City Field. Galveston County, Tex. The oil was treated with anhydrous calcium sulfate in order to remove the last traces of water. To insure a supply of constant composition gas at room temperature the cylinders of League City gas were cooled to about 30°F, inverted, and the condensed liquid was allowed to drain from the cylinders. The analysis of the gas and crude are tabulated in Table I. The carbon dioxide came from Pure Carbonic, Inc., and was .stated to have a purity of 99.5 per cent or better. The procedure used to obtain samples of the equilibrium liquid and vapor was similar to that employed by others making use of the rocking type equilibrium cell.6,7,8 The equilibrium cell was evacuated and calculated quantities of carbon dioxide, natural gas, and crude oil were charged to the cell to the desired pressure. In charging the equilibrium cell an attempt was made to maintain the ratio of the natural gas to crude oil as close as possible to that employed by Roland. After the cell was charged, samples of

Jan 1, 1951

By Fred H. Poettmann

The vaporization characteristics of carbon dioxide in a League City natural gas - Billings crude oil system were studied at three temperatures, 38°. 120°, and 202°F and for pressures ranging from 600 to 8,500 psi. Variation of carbon dioxide concentration up to 12 mole per cent in the composite showed no effect on the equilibrium vaporization ratios (K values) of the hydrocarbon constituents or on the K value of carbon dioxide itself. It was shown that carbon dioxide is more soluble in crudes than in distillates which is contrary to the behavior of methane. A working chart of carbon dioxide K values is presented. INTRODUCTION The study of the equilibrium vaporization ratios of mixtures of paraffin hydrocarbons has been rather thorough.2,6,7,8,9 In the past few years considerable attention has been paid to the vaporization characteristics of the so-called noncondensable gases such as nitrogen, carbon dioxide, and hydrogen sulfide in mixtures of hydrocarbons. since they usually occur to some extent in most crude oils and natural gases.1,3,4,5 Knowledge of this behavior is useful to both the production and refining phases of the petroleum industry. This paper reports the equilibrium vaporization ratios (K's) of carbon dioxide in a mixture of League City natural gas and Billings crude oil, and compares them to those obtained in a natural gas-distillate system. The equilibrium vaporization ratios for the hydrocarbon components in this system had previously been studied by Roland.' In addition to the determination of the K values for carbon dioxide, the K values for methane and ethane were also determined in order to observe what effect, if any, the presence of carbon dioxide had on these K values. The concentration of carbon dioxide was also varied in order to observe the effect of this variable on the carbon dioxide K values. EXPERIMENTAL PROCEDURE The apparatus used in this study cotlsisted of a stainless steel equilibrium cell of about 2 liters capacity. The cell was mounted on trunions permitting rocking in a thermostatically controlled oil bath. Two high pressure valves fitted with steel tubing were mounted on the top of the cell. one was used for sampling the equilibrium gas phase and the other for sampling the equilibrium liquid phase by means of an induction tube within the cell. Stainless steel tubing from the bottom of the cell led to a mercury reservoir and manifold which was connected to a free-piston type pressure gauge manufac- lured by the American Instrunlent Ctr. and to a volumetric. putrip. The temperature of the oil bath was measured by means of a ralibrated mercury-in-glass thermometer. The recorded temperatures are believed to be accurate to ±0.5 °F. The pressures are correct to 22 psi. The crude oil used in this study was stock tank oil obtained from the Wilcox formation in the Billings Field, Noble County. Okla. The natural gas was obtained from the League City Field. Galveston County, Tex. The oil was treated with anhydrous calcium sulfate in order to remove the last traces of water. To insure a supply of constant composition gas at room temperature the cylinders of League City gas were cooled to about 30°F, inverted, and the condensed liquid was allowed to drain from the cylinders. The analysis of the gas and crude are tabulated in Table I. The carbon dioxide came from Pure Carbonic, Inc., and was .stated to have a purity of 99.5 per cent or better. The procedure used to obtain samples of the equilibrium liquid and vapor was similar to that employed by others making use of the rocking type equilibrium cell.6,7,8 The equilibrium cell was evacuated and calculated quantities of carbon dioxide, natural gas, and crude oil were charged to the cell to the desired pressure. In charging the equilibrium cell an attempt was made to maintain the ratio of the natural gas to crude oil as close as possible to that employed by Roland. After the cell was charged, samples of

Jan 1, 1951

By C. S. Finney, John Mitchell

On December 31, 1959, there existed in the United States 15,993 slot-type coke ovens capable of producing 81,447,700 net tons of coke. These ovens were concentrated in 74 coke plants in 21 different states. As of the same date, there were 7448 beehive ovens in existence at 45 plants in the states of Pennsylvania, Virginia, West Virginia, and Kentucky. Total annual capacity of the existing beehive ovens was 4,368,800 net tons, but only 5148 ovens with a capacity of 3,131,600 tons were in operating condition. It is interesting to compare the average dimensions of slot-type ovens built during recent years with the 30 ft x 5 ½ ft x 16 ½ in. ovens erected at Syracuse, N. Y. in 1892. A composite oven built according to the average dimensions of all those erected between 1954 and 1958, for instance, would be 39 ft long. 12 ft high, and 18 in. in width. The coal capacity would be 16 tons as against the 4.4 tons which could be charged to the Syracuse ovens. Of the 15.993 slot- type ovens in existence at the end of 1959, by far the greater number were built by the Koppers Co. whose total of 11,280 ovens included 7891 Koppers- Becker and 3389 Koppers ovens. Of the remainder, there were 3260 Wilputte, 1350 Semet-Solvay, 63 Otto, and 40 Simon Carves ovens. By-product coke oven plants are usually classified either as furnace or merchant plants. According to the definitions used by the US Bureau of Mines, the former are "those that are owned by or financially affiliated with iron and steel companies whose main business is producing coke for use in their own blast furnaces. All other coke plants are classified as merchant. They include those that manufacture metallurgical, industrial, and residential heating grades of coke for sale on the open market; coke plants associated with chemical companies or gas utilities; and those affiliated with local iron works, where only a small part (less than 50 pct of their output) is used in affiliated blast furnaces." The annual coke capacity of the merchant plants during 1959 was 10,393,000 tons. However, the by-product oven of today is essentially an appurtenance of the iron and steel industry, rather more than 87 pct of total by- product coking capacity being concentrated at furnace plants. This was not always so. There was a time when the merchant plants played a much greater part in meeting the US demand for coke and gas. High noon for the merchant plants was reached during the early 1930's. By 1932 there were as many by- product oven installations being operated by the merchant sector of the industry as by the coke divisions of the iron and steel industry (44 of each), and in the same year the merchant plants produced 46.5 pct of all by-product coke made in the country. Since that time their contribution has drastically declined. In 1940 merchant plants were responsible for only 23.2 pct of total US production, and by 1950 their number had decreased to 30 plants which turned out 18.5 pct of the total by-product coke made. At the end of 1959 only 20 of the 74 existing by-product oven installations were merchant plants. They ac- counted for 12.5 pct of the year's production, or 6,849,786 net tons. This percentage has remained fairly constant since 1954. There are several reasons for the decline of the merchant coking industry. For example. On the grounds of economy, quality control, continuity of supply, and so on, the iron and steel industry usually prefers to control its own mines and carbonize its own coal at or near to the blast furnace rather than rely on independent operators for metallurgical coke. As the steel companies have enlarged their own coking facilities, so has the need for coke obtained from other sources declined. Furthermore, not only has the steel industry increased in self-sufficiency by building mare coke ovens during recent years, but it has also progressively improved the fuel efficiency of its blast furnaces. During the years 1947-49 the average coke consumption per ton of pig iron was 1892.8 lb. During 1958 the corresponding figure was 1613.4 lb. There are many individual furnaces where still better results are being obtained, and further reductions in the average may be expected. Perhaps the greatest threat to the merchant coking plant has been the fantastic increase in the use of natural gas and petroleum products for purposes which manufactured gas once served. So deadly has the com- petition from natural gas and oil been that it has almost eliminated by-product oven installations owned by public utilities. In the peak years of the early 1930's there were 23 such public utility plants. In 1960 only two were left. One of these, owned by the Citizens Gas and Coke Utility, was at Indianapolis, Ind.; the other was the plant operated by the Philadelphia Electric Co. at Chester, Pa. The non-utility merchant plants have also been sorely hit. With gas sales revenues reduced, domestic

Jan 1, 1961

By R. S. Dean

T HE theory of hardening by heat treatment was, as usual, the most actively discussed phase of metal working theory and in spite of the fact that it is now ten years since the dispersion theory was proposed by Messrs. Merica, Waltenberg, and Scott, it still retains a dominating influence. It is being increasingly recognized. however, that in its simplest form, that is, the purely mechanical effect of very fine crystallites distributed through a groundmass, it is distinctly in- adequate. To explain the observed facts we are obliged to assume some well-defined intermediate stage between supercooled solid solution and conglomerate, however fine be the particles of the latter. This intermediate has been inferred by Gaylor and Preston to be "the rejection of the atoms of the dissolved metal from the lattice of the solid solution accompanied by the possible formation of molecules."' Perhaps this may well be designated as the formation of supersaturated solid solution. Some very definite evidence of such an inter- mediate stage has been found in the hardening of steel where it appears that the very hard martensite may be considered as a supersaturated solution of carbon in a iron. The X-ray spectrometry of drastically quenched steel shows a tetragonal lattice whose parameter changes by tempering at 100" until it coincides with the cubic lattice of iron.? The same gradual change of the tetragonal to the cubic lattice has been observed by Sekito when esamining layers on increasing depth below the surface of a quenched carbon steel.

Jan 1, 1930

By Bengt Helmerson

A new tankhouse was started in January 1959 at the Copper Refinery of the Boliden Co., Skelleftehamn, Sweden. In early 1961 a semiautomatic machine for looping and straightening of starting sheets was introduced to substitute previous manual operations. The machine as well as consequent, racking and handling is described. Finally, economic benefits achieved and new constructions for the future are discussed. HISTORY Tankhouse operations at the Boliden Co. 's Smelter in Skelleftehamn started in 1932 on a scale that since then has been gradually increasing. In order to rationalize the operations, a new tankhouse was erected. It went into production in January 1959 and was designed for a yearly production of 35,000 metric tons at a current density of 16 amps per sq ft. Already from the beginning, however, the tankhouse has been run with a current density of 21.5 amps per sq ft, corresponding to a maximum capacity of 50,000 tons a year. During the time of planning of the new tankhouse, due consideration was given to the possibilities of mechanizing the operations. New ideas could be and were actually tested on full or pilot plant scale in the old tankhouse. In that way we developed a system for the cathode handling including washing, weighing, and transportation. A system using forklift trucks in combination with trailers and overhead cranes has been developed for transportation and racking of anodes and also for handling of anode scrap. With respect to the electrolyte, circulation and temperature control are partly automatic. Special attention was paid to the production of starting sheets, which operation normally requires a great number of man hours, and it was made the object of a particular survey as to the best ways of straightening starting sheets, attaching loops to the sheets, and so forth. As a result, a machine was designed during 1957-58 and built in our own shops. After a period of tests, the new equipment was put in operation commercially on the 10th of April, 1961. Since this date the machine has produced about 2 million starting sheets without interruption and has been the only source of looped starting sheets for the tankhouse. GENERAL DESCRIPTION Fig. 1 shows all the major parts of the system. These parts are: slitting machine with feeding table (I), standard roller leveler, type Ungerer (2), tilting roller table (3), conveyors for sheets and suspension bars (4, 7), storage of suspension bars (51, punching and stitching machine (6), two lift-turn-tilt tables (8) for discharging the starting sheets, two rack conveyors (9) for sheet assemblies. Included are a hy-daulic pump station and panels for pneumatic and electric controls. SLITTING AND STRAIGHTENING The machine is fed by hand by a man sitting in front of the slitting-machine table, Fig. 2. This operator inserts one sheet at a time into the slitter. After being trimmed, the sheet is automatically conveyed to the following step of handling, straightening. The slitting machine cuts away about 8 mm of the upper and lower parts of the sheet (in relation to its original position in the stripper section) for two reasons. The first one is to give the machine sheets of uniform dimensions; the second one is a matter of quality. Normally the starting sheets as stripped have a thick edge at the bottom end. This part would collect anode slimes and might also cause short circuits when inserted in the cells without trimming. The straightener used is of German construction

Jan 1, 1967

By AIME AIME

AT A meeting of the Iron and Steel Institute held in London on May 6, Dr. J. E. Stead was formally inducted into the chair by Dr. Eugene Schneider, the retiring president. After presenting the Bessemer gold medal to Harry Brearley, of Sheffield, England, for his distinguished services to the British steel industry, Doctor Stead delivered his presidential address, a masterly review of iron and steel making progress during the past 50 years, emphasizing economy in production, and pointing out suggestions for future improvement. A considerable portion of the address was devoted to blast-furnace operation.

Jan 1, 1920

By B. J. Guarnera

There have been major changes in the makeup and nature of the uranium exploration industry in recent years. Significant price increases precipitated an increase in exploration activity-according to the Department of Energy, exploratory drilling in 1977, by 140 companies, was almost 8 million m (26 million ft). This represents a 37% increase over the prior year's drilling. Projections for 1978 indicate at least 9 million m (30 million ft) of exploratory holes will be drilled in the US. Exploration expenditures in 1979, including land acquisition, drilling, and other costs, were estimated by DOE at over $236 million. Domestic expenditures for 1978 are estimated at over $250 million.

Jan 10, 1978