Search Documents

By E. E. Donath

THE coal hydrogenation process is well known as a means for the production of liquid fuels -from coal. In this paper the possibilities of the coal hydrogenation process as a source of chemical raw materials will be discussed. The recovery of chemicals from coal hydrogenation products necessitates some modifications and additions to the equipment used for the production of fuels. The conversion of coal into liquid fuels such as gasoline requires two steps: liquid phase and vapor phase hydrogenation. Intermediate oils obtained in the liquid phase contain oxygen and nitrogen compounds, especially aromatic compounds, since the coal itself is composed mainly of cyclic compounds. These oils are the raw material for the separation of high molecular weight aromatics and of tar acids and tar bases. The relative amounts of heavy and middle oil-boiling above and below, e.g., 325°C-can be influenced by temperature, residence time, and catalyst of the liquid phase hydrogenation. In the vapor phase hydrogenation a solid bed catalyst is used to convert the intermediate oil from the liquid phase operation into hydrocarbons of the gasoline boiling range. Essentially pure hydrocarbons with a low content of sulphur, oxygen, nitrogen, and olefines are obtained. Depending mainly on the catalyst, the high ring compound content of the liquid phase oil can be preserved and gasoline rich in aromatics obtained. However, with other catalysts, these ring compounds can be split into gasoline with a high content of isoparaffins.1 Again, depending on the operating conditions, products of varying boiling range can be obtained. Selection of catalyst and operating conditions therefore makes possible the production of different grades of motor fuel and also variations in the relative amounts of benzene, toluene, and xylene when aromatic hydrocarbons are produced. The schematic flowsheet, Fig. 1, shows the main steps of the coal hydrogenation process, and the product streams used for the recovery of chemicals are indicated. In the liquid phase hydrogenation stage, coal is made into a paste with recycle heavy oil. The coal paste is mixed with hydrogen and preheated at a pressure of 300 to 700 atm in heat exchangers and preheaters. The coal paste and hydro¬gen enter high pressure converters where the liquefaction of coal, conversion of the high boiling liquid materials initially obtained, into intermediate oils is performed at a temperature around 470°C. The reaction products enter the hot catchpot in which lower boiling oil vapors are separated from the residue containing unreacted coal, ash, and heavy oil. This residue, usually called H.O.L.D. (heavy oil let down), is processed to separate solid and liquid material. By thermal treatment of the residue, e.g., a coking process, distillate oil is obtained, which can be recycled as part of the pasting oil. This stream is rich in polynuclear aromatics and can be, and has been, used for the recovery of such material. The oil vapors and hydrogen from the hot catch-pot are cooled in heat exchangers and a cooler, and the condensed oil is separated from the recycle hy-

Jan 1, 1952

Engineers who are in charge of industrial operations, and their number is legion, sense as much as anyone the present feeling of unrest in the' country and more than anyone else realize the present inefficiency of labor. Undoubtedly the two phenomena are closely correlated and no doubt are due to a multitude of causes which it will be impossible to enumerate. From my experience in mining I estimate that the present efficiency of labor is only about two-thirds of what it was under pre-war conditions. In the mining industry, at least, we have not a large surplus of men looking for work and usually under these conditions men are rather more independent and will not work as efficiently and faithfully as if they felt there were plenty of men ready to take their places. Wages in metal mining have advanced more than the increased cost of normal and sane living. The result is that the men often work fewer days in a month and do not seem to have very much interest in their work while actually engaged in it. Then again, they have been listening to the more or less vague propaganda of the I. W. W. and the radical wing of the socialists, who are harping on the fact that the distribution of newly created wealth is unfair and that the laborer really is not working for himself or his fellow laborers but is carrying on his exertions for the benefit of a small and lim-ited class of exploiters. A continued harping on this view is bound to influence the judgment of even a conservative workman who is not a student of economics and who hears little or nothing upon the other side. I am a great believer in the common sense of the American people and in the long run I do not think that they will be carried away by unsafe doctrines. The trouble with so many of these propagandists of industrial in-equality is that they do not differentiate between production and dis-tribution. Even if we admit that distribution is unfair, unless goods are produced there will be nothing to distribute. A great many unthinking people seem to feel that wages are paid out of a pot which is inexhaustible and do not realize that eventually what comes out of the pot can never exceed what is put into it. The workman is not paid in money but is paid in goods, money as we all know being used simply as a measure of value and a medium of exchange, and that all that can be used to pay the laborer is what he produces.

Jan 11, 1919

By C. M. Boss

Throughout the Lake Superior Basin each of the great ironranges, from which vast quantities of iron-ore have been, and are now being mined, presents characteristics differing from each and all of the others. One of the most peculiar of these varying features is found in the dikes of the Gogebic range. From an economical standpoint this feature of the dikes has been studied by our practical mining men more than any other geological phenomena in connection with the deposits of merchantable iron-ore. In the greater portion of our mines these dikes appear to form the riffles in the sluice of the ore formation, against which the particles of iron oxide are deposited in the process of concentration out of the quartzose matrix which is termed the ironbearing formation. In composition these dikes are apparently of a dioritic formation, more or less altered and decomposed, comparatively soft, and sometimes almost steatitic. While frequently showing something of a cleavage in the direction of their pitch, they are devoid of parallel laminæ, and when broken assume the form of irregular angular fragments. They are generally of nil ashy grey color, but sometimes at great depth are found to be quite dark, almost black, and of a very hard massive nature, showing radial or fibrous crystallization. Practically all of the dikes thus far discovered in the iron formation are approximately at right-angles with the dip of the formation, and the greater number of them have an average easterly dip of from fifteen to eighteen degrees. Sometimes, however, they are folded in such a manner as to form long synclinal basins; but while their western or initial extremity is fre-

Jan 1, 1898

By AIME AIME

COUNCIL.* PRESIDENT OF THE COUNCIL. D. W. BRUNTON DENVER, COLO. (Term expires February, 1910.) VICE-PRESIDENTS OF THE COUNCIL. J. PARKE CHANNING NEW YORK, N. Y. FREDERICK W. DENTON PAINESDALE, MICH. JOHN B. FARISH DENVER, COLO. (Term expires February, 1910.) W. C. RALSTON SAN FRANCISCO, CAL. W. L. SAUNDERS NEW YORK, N. Y. H. V. WINCHELL ST. PAUL, MINN. (Term expires February, 1911.)

Mar 1, 1909

By George C. Lipsey

FOR many years the mining of coal and other minerals occurring in sedimentary formation has been planned according to information obtained by diamond drilling. Placer mines have used churn drills for sampling and estimating deposits, and some metal mines have used the method either wholly or in part. The diamond drill method, therefore, although not entirely new, has come into more prominence in the last few years. Several large-scale developments now being planned or in the production stage have used this method in varying degree. This paper will describe the operations of the Howe Sound Exploration Co., Ltd. at Snow Lake, Manitoba, where a gold mine was developed and equipped for mining and milling wholly on the basis of diamond drilling results. The property has been in operation nearly 3 years, so that results can be compared with the estimates and assumptions made from the diamond drilling. In developing the subject it is necessary to outline as briefly as possible the normal method of mining, from discovery to production stage. Table I sets forth these various stages, the methods of financing, the percentage of total cost, and the relative time interval required for each section of the work. The plan presented in this table cannot be applied to all mining developments, but it gives a basis on which to work. In Stages 2 and 3 the investment is moderate, and if the property does not respond favorably the options or interests can be terminated. Stage 4 represents a sizeable investment, and it is more difficult to drop the property after this part of the operation is completed. Stages 2, 3, and 4 may be repeated several times by diflerent groups or companies before Stage 5 is reached, but when Stage 5 has been started the total capital investment must be provided and there can be no turning back. It will be noted that there is a total of 116 units of investment in the overall cost if one company proceeds with Stages 2, 3, 4, and 5 in order. Stage 4, however, consumes time which is important when markets are being considered. Bringing a property into production when metal prices are low is much more difficult than when the prices are high, and if this stage can be set aside production is attained more quickly. When Stage 4 is eliminated the total becomes 86 units of cost for Stages 2, 3, and 5, but an adjustment of 14 units must be added to Stage 5. These 14 units represent the useable value of Stage 4. Thus Stage 4 represents an investment of 30 units if carried on before Stage 5, but 14 units if included with Stage 5. This is accounted for by the fact that development work can be accomplished more cheaply under Stage 5, since everything that is done is planned on a production basis with permanent services. Stage 4 must of necessity be governed by expenditures, and a great many temporary services, including housing and power plants, must be provided. The prospect shaft is a small one, and drifts,

Jan 1, 1953

By George C. Lipsey

FOR many years the mining of coal and other minerals occurring in sedimentary formation has been planned according to information obtained by diamond drilling. Placer mines have used churn drills for sampling and estimating deposits, and some metal mines have used the method either wholly or in part. The diamond drill method, therefore, although not entirely new, has come into more prominence in the last few years. Several large-scale developments now being planned or in the production stage have used this method in varying degree. This paper will describe the operations of the Howe Sound Exploration Co., Ltd. at Snow Lake, Manitoba, where a gold mine was developed and equipped for mining and milling wholly on the basis of diamond drilling results. The property has been in operation nearly 3 years, so that results can be compared with the estimates and assumptions made from the diamond drilling. In developing the subject it is necessary to outline as briefly as possible the normal method of mining, from discovery to production stage. Table I sets forth these various stages, the methods of financing, the percentage of total cost, and the relative time interval required for each section of the work. The plan presented in this table cannot be applied to all mining developments, but it gives a basis on which to work. In Stages 2 and 3 the investment is moderate, and if the property does not respond favorably the options or interests can be terminated. Stage 4 represents a sizeable investment, and it is more difficult to drop the property after this part of the operation is completed. Stages 2, 3, and 4 may be repeated several times by diflerent groups or companies before Stage 5 is reached, but when Stage 5 has been started the total capital investment must be provided and there can be no turning back. It will be noted that there is a total of 116 units of investment in the overall cost if one company proceeds with Stages 2, 3, 4, and 5 in order. Stage 4, however, consumes time which is important when markets are being considered. Bringing a property into production when metal prices are low is much more difficult than when the prices are high, and if this stage can be set aside production is attained more quickly. When Stage 4 is eliminated the total becomes 86 units of cost for Stages 2, 3, and 5, but an adjustment of 14 units must be added to Stage 5. These 14 units represent the useable value of Stage 4. Thus Stage 4 represents an investment of 30 units if carried on before Stage 5, but 14 units if included with Stage 5. This is accounted for by the fact that development work can be accomplished more cheaply under Stage 5, since everything that is done is planned on a production basis with permanent services. Stage 4 must of necessity be governed by expenditures, and a great many temporary services, including housing and power plants, must be provided. The prospect shaft is a small one, and drifts,

Jan 1, 1953

By J. Taffanel

I am very much impressed by this manifestation of international brotherhood; the mining engineers on both sides of the ocean have similar subjects to deal with, meet with the same difficulties, expose themselves sometimes to similar dangers…

Jan 1, 1915

By C. R. Hocott

THE distribution and movement of fluids in oil reservoirs are influ-enced to a great extent by capillary forces, which depend upon the size and shape of the pores in the reservoir rock, the surface characteristics of the rock, and the interfacial tension between the fluid phases. This paper presents the results of an investigation of the interfacial tension between salt water and crude oil containing dissolved gas under reser-voir conditions. APPARATUS AND PROCEDURE In the preliminary phases of this investigation, it was found that a scum formed at the oil-water interface, which made measurement of interfacial tension by either the ring or capillary rise methods unreliable. Accordingly, the drop-weight method, in which a fresh interface is con-tinuously formed, was selected. In this method, a tip through which drops of one fluid can be expelled is immersed in a second fluid. At the instant that the drop becomes large enough to fall, the gravitational force tending to pull away the drop exactly balances the interfacial force tending to hold it. From the size of the drop, the dimensions of the tip, and the density of the two fluid phases, the interfacial tension may be calculated. The apparatus consists of a circulating pump for bringing the oil to equilibrium with gas at the desired pressure, a displacement pump for forming the drops, an interfacial tension cell in which the drops are formed, and a density cell to determine the density of the oil. The density of the water is determined separately in another apparatus. A flow diagram of the assembled equipment is shown in Fig. 1.

Jan 1, 1938

By F. P. Dewey

Recent discussions have furnished to the members of the Institute much information concerning aluminum and its applications. The present paper will be devoted almost entirely to the description of a process by which the metal is produced in the form of alloys. The characters which especially distinguish the Heroult process consist in electrolyzing a mass of molten alumina (Al2O3), and at the same time alloying the separated aluminum with a heavy metal, the heat necessary for the fusion of both the alumina and the alloying metal being supplied by the direct passage through the molten Al2 0, of an electric current of high amperage and low voltage. The process has been in active operation at Neuhausen in Switzerland for about two years. It is also in active operation at Froges in southern France. Both these locations were selected for this purpose on account of the presence of large and desirable water-powers. The apparatus consists of a carbon containing-vessel, which may be a single crucible for small operations, or may be built up of slabs or blocks of carbon for large and industrial operations. When built up of slabs or blocks, the whole is surrounded by an iron casing. In the earlier crucibles this iron casing was cast around the carbon, in order to secure close electrical contact. This, however, has been found unnecessary; and in the later crucibles the casings consist of plates bolted together, while pulverized carbon is packed between the carbon blocks and the iron. Electric conductors are united direct to this iron casing, and the current passes from this through the carbon lining to the interior of the crucible. By this

Jan 1, 1890

By C. E. Cannon, R. C. Craze

This paper discusses the results of a study of reservoir pressures in the Gulf Coast area of Texas and Louisiana, showing the general relation of the reservoir pressure to its subsea depth, as well as excessive reservoir pressures that have been encountered. The latter are particularly important in mud-control work, and the data show why it is necessary to use muds having a relatively high density in many of the deeper wells drilled in this area. Only a comparatively few of the wells drilled in the Gulf Coast that have encountered excessive pressures are discussed, but as far as is known those omitted fall within the range of pressure observed by the writers. Measurement of Pressures The following methods were used to determine the values of the original pressures: 1. Estimation of original pressure from subsequent pressure behavior of fields. This method is not precise, and was used only in a few of the older fields in which better methods of obtaining original pressures were not available. Only normal pressures were determined by this method. 2. Measurement of shut-in pressures soon after completion of the first producing well. With one exception, all pressures measured by this method were normal, this well having a pressure slightly higher than normal. 3. Measurements of pressure in connection with drill-stem tests. 4. Estimates from the maximum hydrostatic head of mud that failed to prevent flow from the high-pressure formations into the hole. This method is not exact, tending generally to indicate low pressures. Normal Pressures All pressure measurements available are plotted in Fig. 1, with original pressure at the water-oil contact as abscissa and subsea depth as ordinate. All producing fields fall close to the solid line, which passes through the origin and has a slope of 0.465 lb. per sq. in. per ft. By way of compari-

Jan 1, 1938

By I. J. Bear, H. W. Paxton

Studies have been made of the method of propagation of yield in iron single crystals in the range of 205' to 295OK by microscopic and X-ray techniques. 'The results show yielding in two stages, of which the second corresponds closely to the Lüders extension in polycrystalline iron. IRREGULAR macroscopic markings On the polished surface of a polycrystalline mild steel test piece during the lower yield extension were first observed by Liiders.' The lower yield stress was not very constant. Sylvestrowicz and Hall2 showed that it was possible to obtain a constant lower yield stress by using a specimen in the form of a moderately flexible thin strip; the macroscopic markings in this case then appeared as a band of deformation (Lüders' band) which propagated steadily from one or occasionally

Jan 1, 1956

By J. F. Pierce, S. M. Enterline

Since January 1959 a zinc refiner of novel design has been in operation at Blackwell, Okla., producing 99.995+ zinc from the output of the Blackwell horizontal retort smelter. The refiner is a continuously operated, pyro-metallurgical unit with principal dimensions horizonhl permitting one floor operation. It is very ruggedly constructed. Furthermore it is not subjected to deterioration from high concentrations of iron in the feed metal because the boiling units are separate from the rectification columns and constructed with silicon carbide brick arches through which the heat is transferred radiantly to the zinc. A zinc refiner of novel design has been in operation since January 1959 at the Blackwell, Okla. plant of the Blackwell Zinc Co., Inc., a wholly owned subsidiary of American Metal Climax, Inc. Developed by the company's technical and operating staffs, the new refiner produces special high-grade zinc (nominally 99.995+ pct Zn) from the prime western1 slab output of the Blackwell horizontal retort smelter. The refiner is a continuously operated, pyromet-allurgical, high-capacity unit employing fractional distillation to separate zinc from its impurities, consisting principally of lead, cadmium, and iron. In prime western slab, these elements may vary in concentration from 0.005 to 1.6 pct. Table I shows the impurities usually encountered in the Blackwell prime western metal fed to the refiner together with their boiling points and vapor pressures at 907oC. The commercial pyrometallurgical smelting processes for extracting zinc from ore include distillation from retorts and a limited degree of refining can be accomplished by redistillation in similar retorts. To achieve special high-grade purity, an impractical number of batch redistillations would be required, however, with an accompanying loss of much metal. A continuously operated and integrated unit is required in which fractional vaporization and condensation can take place in a large number of stages. The first commercial continuously operated unit was developed by the New Jersey Zinc Co.4 In the separation of any two substances the degree of separation is limited if a mixture exists having a constant boiling point. The Zn-cd5 and Zn-pb6 systems contain no constant boiling points and hence these metals may be separated to any degree of purity. Basically, the pyrometallurgical refining of zinc involves three steps: a) iron, copper, and other metals having no appreciable vapor pressures at 907ºC concentrate in the bath when the impure zinc is boiled, b) lead, bismuth, antimony, and other metals having boiling points above but closer to that of zinc are selectively condensed from the vapor boiled from the bath, and c) cadmium and other metals having lower boiling points than zinc are fractionally distilled by reboiling and subsequent condensation of the zinc from the vapor. The boiling and condensation of zinc must be conducted in vessels constructed of materials which are refractory at the temperature involved (907 ºC) and it is highly desirable that they also be resistant to attack by the various metals. This requirement dictates construction from relatively small, simply shaped pieces which limits the pressures which may be employed to avoid leakage through the numerous joints. Stresses induced must be limited essentially to compressive ones and suitable provision must be made to permit thermal expansion of the components in order to minimize these stresses. Where heat is to be added for boiling or removed for condensation, refractory material through which the heat flows must have a high thermal conductivity. Silicon carbide is highly conductive but is subject to attack by iron and is expensive compared to other commonly employed refractories. A hard, dense aluminous fireclay is well suited to contain these metals where high thermal conductivity is not required. Zinc will penetrate the pores of fireclay brick but only to a limited depth in an exterior wall and has little effect other than an increase in weight and conductivity. The design objectives of the Amax refiner were: a) to achieve a long life by heavy, rugged construction and by employing silicon carbide refractories only where required for heat conductivity and not in contact with liquids of high iron concentrations, b) to simplify operation, manning and control by essentially horizontal construction, and c) to obtain high capacity in a single unit. DESCRIPTION Flow of metal through the Amax refiner is shown diagrammatically in Fig. 1 and schematically in Fig. 2.

Jan 1, 1963

SAMUEL L. HOYT.-The question of adding the ferromanganese to the ladle or to the furnace involves both theoretical and practical questions and its discussion might very easily occupy the rest of the day. One of the points to be kept in mind is the desirability of obtaining uniform steel. If ferromanganese is added to the ladle, it is necessary first to melt the manganese and then to distribute uniformly throughout the heat. The only heat available for this purpose is that of the molten steel itself. No doubt sufficient heat is present, but in our desire to pour the steel as quickly as possible there is hardly sufficient time allowed, many times, for the proper distribution of the manganese. In other words, this is an operation which takes a certain amount of time and any undue shortening of the time allowed must affect the quality and uniformity of the steel. Again, this particular method does not lead to as efficient a use of the manganese as might be desired; a contention which is based on theoretical grounds. In concentrated solution, manganese will completely reduce all the ferrous oxide, the presence of which I hypothecate and produce, as the reaction product, manganese oxide. In dilute solution, the manganese only partly reduces the iron oxide, but the manganesee oxide which does form dissolves the iron oxide in simple solution. The dissolution of ferrous oxide in the manganese oxide will result in a more economical utilization of the manganese and an equal purification of the heat. This whole point, at present, has not been definitely proved and its answer will involve very difficult research work. On the other hand, if the manganese is added to the furnace, the heat of the furnace is used to melt the alloy and there is plenty of time during tapping for the manganese to be very uniformly distributed throughout the steel. By distributing the alloy throughout the charge we can secure a better utilization of the manganese than is possible if the addition is made to the ladle. Certain other points, such as the recovery, have been dealt with at greater length in the paper.

Jan 4, 1919

By F. K. Spragins

Growing demand for conventional crude oil in North America in the face of diminishing sup- ply is bringing about increased interest in synthetic fuels. With one commercial plant already in full production, another in the planning and engineering stage and still others being seriously considered, the Athabasca tar sands are proving to be a leading center of interest. Here, and in the closely related deposits, reserves in place total over 700 billion barrels.' When and if fully developed, Athabasca tar sands could make both Canada and the United States substantially independent of all off-shore supplies of crude for many years to come. Its product, a high-quality, low-sulfur synthetic crude, is beginning to enter the market place at a most favorable time. Oil Deposit The main body of Athabasca tar sands, about 250 miles northeast of the city of Edmonton, are centered in an area of something over 12,000 sq mi. The deposit runs as high as 250,000 bbl per acre and the average richness is placed at 100,000 bbl per acre. Of the over 700 billion bbl in place, 400 billion bbl of raw oil are considered recoverable from which 300 billion bbl of upgraded synthetic crude are expected to be produced.' In the deeper zones, thermal stimulation is considered the best approach to recovery, while in the shallow areas several surface mining techniques are deemed practical.

Jan 10, 1972

By AIME AIME

THIS year the Petroleum Division holds its fall meeting at Houston, Texas, Oct. 2 and 3, with head- quarters at the Lamar Hotel. Technical sessions will be held in the morning and afternoon of both days. A smoker on Friday afternoon will afford an opportunity to get together socially. Saturday evening is left free for private parties to the beach at Galveston, where a wide variety of entertainment is available. On Oct. 4 there will be an excursion to Sugarland oil field, with luncheon at Boling and a visit to Boling sulfur mine and plant in the afternoon. There are nine technical papers on the program for Friday. Saturday morning will be devoted to oil production control and it is planned to make the discussion more

Jan 1, 1931

By J. S. Ll. Leach, L. R. Rubin, M. B. Bever

The energies of formation of ordered and disordered solid solutions of composition CusAu and the energy of ordering in this alloy were determined by tin solution calorimetry. The degree of order was measured by X-ray diffraction and electrical resistance and microhardness measurements were made on ordered and disordered specimens. AMONG the phenomena associated with the order-disorder transformation of a solid solution, the change in internal energy is of special interest because of the part it plays in the various theories of ordering. Published values for the decrease in internal energy accompanying the formation of a superlattice from a disordered solid solution of composition CuAu range from —370 to —2260 cal per gram-atom. Some of these values represent calculations based on theory and others are the results of experimental measurements. The distinction between the change in internal energy, AE, and the change in enthalpy, AH, can here be neglected, because they are approximately equal for solid-state reactions at normal pressure. An analysis of ordering by Bragg and Williams' predicts an energy change of —605 cal per gram-atom for the formation of a superlattice in the alloy Cuau from a completely random solution. Peierls" application to Cuau of Bethe'sb earest-neighbor theory yields —560 cal per gram-atom for the formation of a superlattice from a matrix which initially contains short-range order. Cowley' extended the nearest-neighbor approach to include as many as five shells of neighbors; on this basis a change in energy of —500 cal per gram-atom is expected. Eguchi," using a quantum-mechanical treatment, calculated a value of —2260 cal per gram-atom for the difference in the energy of completely disordered and completely ordered Cu,Au. Sykes and Jones- eated a completely ordered alloy and measured its heat capacity as a function of temperature. This measured heat capacity agrees closely with the corresponding value found by the Kopp-Neumann (or mixture) rule up to about 250°C and above this temperature exceeds it, especially near the critical temperature for ordering. The difference between the integrals with respect to temperature of the observed and the Kopp-Neumann heat capacities was considered to be the energy of ordering. By this method Sykes and Jones found a value of —530 cal per gram-atom. This value is not adjusted for the short-range order remaining above the critical temperature. The pres- ence of such short-range order is suggested by the difference between the measured heat capacity and the extrapolated Kopp-Neumann heat capacity immediately above the critical temperature. Values reported by Weibke and von Quadt' and by Hirabayashi, Nagasaki, and Maniwaa were obtained in the course of investigations primarily aimed at other objectives. Weibke and von Quadt measured the temperature coefficient of the electromotive force of a Cu-CuAu cell. They obtained a value of —1010 cal per gram-atom for the heat of formation of the alloy at 500°C, at which temperature there is no long-range order. They also obtained —1380 cal per gram-atom as the heat of formation of the ordered alloy at 370°C. Considering the heat of formation of the disordered alloy to be independent of temperature, they estimated the energy of ordering at 370°C as —370 cal per gram-atom. At this temperature long-range order is incomplete and the degree of order changes rapidly with temperature. Hirabayashi, Nagasaki, and Maniwa," using an annealing calorimeter, investigated an alloy containing 23.4 rather than 25.0 atomic pct Au and thus could not obtain complete order. Thelr value of the energy of ordering was —490 cal per gram-atom. Orianis has recently investigated the Au-Cu system by the galvanic emf technique. He reports values for the heats of formation of Cu-Au alloys, from which the heat of formation at 427 OC of an alloy of composition CuAu may be found by interpolation. This value is —1080 cal per gram-atom. In the work here reported, disordered and ordered alloys of composition CuAu and corresponding mixtures of gold and copper were dissolved in liquid tin and the heat effects measured. These heat effects are small, since the dissolution of gold in tin is exothermic and the dissolution of copper is endothermic. The method, therefore, yields fairly precise values of the heats of formation of disordered and ordered alloys and of the energy of ordering. Experimental Procedure The calorimeter consisted of a long-necked Dewar flask immersed in a constant temperature salt bath and has been described by Ticknor and Bever." The chief changes in this equipment were an improvement in vacuum and the replacement of the mercury thermoregulator by a resistance thermometer control circuit. The solvent, which was maintained at a constant temperature near 350°C, consisted of 500 grams of 99.99 pct pure tin. The solute samples were mixtures of gold and copper in the proportion corresponding to the composition Cu,Au or solid solutions

Jan 1, 1956

By Joseph Jensen

FROM Aug. 31, 1937, until Apr. 30, 1939, there were 40,872,610 bbl. of oil run to storage in California; from Apr. 30, 1939, to Aug. 31 of the same year 5,512,912 bbl. were withdrawn from storage. But from Aug. 31, 1937, to Aug. 31, 1939, the number of producing wells in the state has increased from 17,706, with a potential production of 1,323,202 bbl., to 18,910, with a potential of 2,302,282 bbl. Thus, in a period of two years, during the first 20 months stocks increased over 1/3 and during the following four months stocks decreased 1/30. In the same two years the number of productive wells increased 1/15 and potential increased 3/4. Undoubtedly, the large increase in stocks created the pressure that caused the reduction in stocks that followed; yet this has come about in spite of the larger number of wells and higher potential. Cause of the change was the adoption on May 17, 1939, by the Central Committee of California Oil Producers of a uniform method of oil curtail-ment for all wells throughout the state. Acceptance of the method in the four months following adoption by practically all fields in California indicates that producers generally are convinced of its merit and fairness. True, some operators still overproduce, but the restraint practiced by the remainder of the industry has been sufficient to turn a situation headed for chaos into one of reasonable stability. Credit for this change goes to the industry itself, because it has all been accomplished under voluntary oil curtailment.

Jan 1, 1940

By William D. Carter

When the first Earth Resources Technology satellite (ERTS-A) is orbited by NASA next year, mineral exploration is expected to take a giant leap forward. There are many inherent advantages in going to space to study large regions of the earth, as existing space data have shown. A preview of what can be expected has already been provided by Gemini and Apollo color photographs taken over many parts of the world in the equatorial belt to 30ºN and S latitude. These comprehensive views cover some 100 sq mi, depicting prominent geologic features in a regional context. Placed side by side with mosaics of aerial photographs covering identical areas, the space pictures point up many inadequacies in the present airborne methods of data acquisition. To obtain a regional picture from aircraft, one must piece together many bits of data, and the final result suffers from variations in lighting and photographic reproduction that may obscure features important to the mineral explorer. By contrast, space photographs provide unsegmented synoptic views of large areas as they appear in a single instant under uniform lighting conditions.

Jan 1, 1971

By Hans Neuberger

INTRODUCTION IN our everyday life, visual perception plays perhaps a more important role than any of the other senses with which we are equipped by nature. It is, therefore, quite understandable that the average person associates 'with the term "atmospheric pollution," clouds of dust, palls of smoke or deposits of soot, phenomena which are so familiar to the residents of industrial cities. On the other hand, "air" is usually considered the prototype of the invisible, of the intangible, and any suspensions in the air which do not conform to this concept, are regarded as foreign to the atmosphere and thus as "pollution." According to Webster, the term "pollution" implies uncleanness, impurity, in short, something undesirable. Although the scientist often accepts popular concepts, he is generally inclined to suspect that apparently "obvious" phenomena imply, literally, "more than meets the eye." To show that this suspicion is also justified with regard to atmospheric pollution, is the objective of this discussion. It will be shown that what seems foreign to the air at first sight, is by nature an integral part of it, and that the more important aspects of pollution generally escape attention. THE ATMOSPHERIC CONSTITUENTS We can distinguish two classes of atmospheric constituents: the permanent gases, chiefly nitrogen, oxygen, traces of argon, neon, and others, and the variable constituents which include water in its different states, carbon dioxide, ozone, and various suspensions, either in gaseous, liquid or solid form. These suspensions, known by the collective term "Aerosol,"20 will be considered in detail. DUST There are two general types of aerosols: the first type is represented by the socalled "neutral" particle 3, commonly known as dust and experienced by everyone, as it is the more conspicuous type of suspensions. . It often represents a special problem to the mining engineer, the mechanical engineer, the industrial engineer, and many other professional men. Dust consists of finely divided solids derived from weathering, drilling, handling and preparation of rocks and coal. Dust may also consist of organic or inorganic particles resulting from manufacture of a variety of products such as flour, rubber, lime and steel, from traffic on land be it on the highways, on rails or in city streets, from decomposed vegetation or from volcanic eruptions. Perhaps the most reviled member of this class of suspensions is the soot and fly ashes from coal fires and other combustion processes. The cosmic source of dust, namely the injection of meteoric matter into the atmosphere, is of minor significance because the concentration of particles is exceedingly small despite the relatively large mass of material invades the earth’s atmosphere from space

Jan 1, 1948

By Andrew Hodge

ISSUES IN MINING LABOR The examination of mining labor issues is often confined to health, and safety. There are other issues, including the present state of mining manpower availability and utilization, and the nature of mineral industries' industrial relations, which are worthy of consideration. The state of the labor market for mining skills, the availability and utilization of mining engineers and related disciplines, the state of research and its employment of scientists and engineers, and the condition of mining industrial relations with all these groups, all have an important effect on the viability and economic health of the minerals production sector. PRODUCTION LABOR Why examine an industry's production labor market? People involved in an industry should be aware of what labor supplies will be relative to industry requirements. This advance information allows industry and government to plan ahead to alleviate problems by moving to affect labor supplies or to accommodate production to expected labor supplies. This is less costly and less painful than responding after the fact to labor market changes. Any industry requires some form of labor. Labor is especially important to the mining industry. Mining labor is well paid. Average annual earnings are higher than in manufacturing. Average hourly wages are also higher. Payroll costs form a high percentage of total cost in coal mining and nonmetallic minerals mining. In metal mining the percentage is comparable to the average for manufacturing. Payroll cost in oil and gas extraction is quite low, but a major proportion of cost is in the form of income to proprietors, i.e., unincorporated businesses. Mining labor is worthy of specific attention. The minerals extraction labor is unique in many ways. Mining labor and especially underground miners are differentiated from other "unskilled" labor. Miners cannot be considered as part of a larger labor pool. The mining labor market has exhibited a unique combination of characteristics. Mining is the only large sector of United States employment in which hourly wages are high and continuing to rise, yet employment declines. Although industry has introduced new labor-saving investments, and labor requirements continue to decline, there is evidence of a mining labor shortage. Specific problems have arisen in the mining labor market such as a present labor shortage in nonfuels mining. Understanding the causes and remedies for these specific problems is also important. These various problems and questions may be handled in a unified manner by examining the relationships of certain economic variables. The relationship that exists between changes in output, employment, labor productivity, and hours worked per week may be stated explicitly:

Jan 1, 1976