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By W. T. Lankford, Low J. R., Gensamer M.

The problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War 11, it became apparent that mass production methods of forming would bc required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet meta1s under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By Low J. R., Gensamer M., W. T. Lankford

The problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War 11, it became apparent that mass production methods of forming would bc required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet meta1s under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By J. B. Mudd

Introduction It is difficult to think of any activity on which mankind has been more dependent than mining, and certainly there is much evidence in almost every part of the world of old workings that clearly demonstrate that man from earliest times has dug and toiled to take from the earth precious stones, metals and materials that from time to time have been essential or of value to him. In step with social development and industrial and technological advances the tempo of mining activity, regulated only by the laws of supply and demand, has quickened and in this century has accelerated rapidly in keeping with its dramatic development. Indeed, the rate of change of events has been such that if it were to continue to accelerate as fast as it has over the past decade there is reason to wonder how the insatiable demands for metals and minerals are to be met in the years that lie ahead. Shallow mines containing high-grade ore deposits either have been or are being rapidly mined out and their place can only be taken in general by ore lying at greater depth, or by ore of low grade, situated for the most part in remote and in underdeveloped areas. The cost of exploration and development is rising at an alarming rate, with the result that the expenditure now required to bring a mine to production far exceeds anything previously contemplated. It is estimated that the total capital required to maintain existing operations and develop new ones during the next 5 years will be of the order of $50,000 million and of this, new capital to bring new mines to production will be of the order of $3,000 million. Today no single mining finance company can, from its own resources, find all the money for a major mining development, and as a consequence there has been a strong trend toward joint ventures and to the formation of multinational consortiums. International lending institutions already play an important part in financing many new mining projects and their participation provides the financial umbrella under which other lenders can invest with greater security. There is little doubt that to finance the costly ventures in the future, governments and international lending agencies, banks and finance

Jan 1, 1971

By H. W. Gillett

WE hear much in these days about "tailor-made" steels. Farseeing executives have sensed the demand for metals of improved and special properties, with those properties deliberately built into the steel in order to fit it for a particular use or group of uses. They have set their metal-lurgists at work to produce what the customer needs, even though the tonnage required may not, at least at first, be great. As the metal-lurgists bring out such metals, the products are advertised and the customer becomes increasingly conscious that he no longer has to take "ready-made" steel as the only thing available, whether it fits his needs or not, but that there are plenty of steelmakers ready to serve his specific needs with a tailor-made steel. Of course this is nothing new in the realm of rather highly alloyed steels to be heat-treated. The automotive industry demanded and got such steels long ago. Indeed, one could not design a modern car using only non-heat-treated carbon steel, since an engine of present horsepower would be so heavy that the gasoline required merely to lug the engine itself around would be absurd. Many different alloy steels and many different heat-treatments are required to produce the fine gradations of properties and the strength per unit weight that are needed in each particular part. Aircraft designers, of course, count a high strength-weight ratio in the materials used as Article I in their constitution, and they too, and in outstanding degree, require tailor-made alloys. Aircraft and automobiles may be considered as the tail coats and Tuxes of the metallurgical tailors. Nowadays there is also a demand for business suits, in the form of high-strength alloys to reduce dead load and so increase payload, all through the transportation industry. We hear most about weight-saving design and materials in respect to the railroads, with the spectacular new high-speed passenger trains and the prosaic freight car. The latter sounds especially sweet to steel-mill ears, because it means tonnage. While most of us think of these developments, and of the engineering acceptance of high-strength materials as "new," the fundamentals are of almost hoary antiquity. It is the widespread availability of a variety of materials and their general acceptance that are new.

Jan 1, 1936

By J. R. Low, M. Gensamer, W. T. Lankford

THE problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War II, it became apparent that mass production methods of forming would be required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet metals under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By R. E. Zimmerman

ALTHOUGH flotation of coal is considered relatively new in the United States by coal-preparation engineers, actually it has been practiced to some extent for the past 30 years, It is practiced much more widely in Europe than in the United States. Commercial plants are operating in nearly all major coal-producing countries of the world. A froth flotation plant has been operating since 1930 at the Champion No, 1 preparation plant of the Pittsburgh Coal Co. Unfortunately the term flotation is widely used in the United States by coal-preparation engineers to designate dense medium processes of coal cleaning. As used here, flotation means those processes for cleaning fine sizes of coal in which the coal is collected in a froth or matte at or near the surface of a pulp. The refuse particles remain in the pulp. Two distinct types of flotation are practiced: froth flotation and agglomeration. FORMS OF FLOTATION The theory of the principles of flotation and of the physicochemical foundations surrounding this process has become a complex and scientific field and coal-preparation engineers contemplating use of flotation processes would do well to study the works of Gaudin, 2, 5 Taggart, 3 Zimmerman, 4 Wark, 6 Ralston, 7 Petersen. 8 Bulk Oil Flotation.-In this process the separation of mineral from gangue is accomplished by virtue of the fact that minerals of metallic lustre, as sulphides, or hydrocarbons, as coal and graphite, are wetted preferentially by oil in the presence of water and consequently pass into the interface between oil and water; while gangue or rock is wetted by water and remains in the medium. Beginning in 1860 with Haynes and later between 1897 and 1907, at least 25 patents were granted for bulk oil flotation. Large quantities of oil are required, generally 3 to 25 per cent by weight of feed, and recovery of such oil is a major problem. The Elmore process 3 (1901 and 1902) is an example of a bulk oil process, The Trent process (1902-25) has been used for the cleaning of coal on a commercial scale, According to E. W, Davidson 9 there were five such plants operating in the United States by 1925. They have since been abandoned.

Jan 1, 1950

By Howard C. Pyle, John E Sherborne

Core analysis is a recent development in the field of petroleum technology. The earliest work on this subject was done in connection with evaluating and planning secondary oil recovery by water-flooding. Present-day analysis of sands of flush fields requires new and independent interpretations of the data provided by cored material. Particular attention is being paid to the development of rapid, routine methods for measuring physical characteristics of sandstone, such as permeability, porosity and grain size, as well as the sand's fluid content. Permeability may be defined as the fluid-passing capacity of a rock. For a sandstone to be permeable it must be possible to pass a measurable quantity of fluid through the material in a finite period of time. The common unit of permeability is the darcy, which may be defined as the rate of viscous flow, in milliliters per second, of a fluid of one centipoise viscosity through a porous medium having a cross section of one square centimeter, under a pressure gradient of one atmosphere (76.0 cm. Hg) per centimeter.' For convenience the subunit millidarcy, or one-thousandth darcy, is often used. Porosity is defined as the fluid-containing capacity of a rock and is usually expressed as a percentage ratio of the total pore volume to the rock or bulk volume. Since measurement of only the effective or communicating pore volume is often made, porosities are distinguished as total or effective.2,3 Net effective porosity is defined as the net pore volume available for oil and gas. Oil and water content of sand is measured and expressed either as the percentage saturation of the total pores or of the bulk rock. The oil content may also be expressed as the percentage saturation of the net effective pores. In connection with water-flooding, methods of core analysis were developed to furnish data that could be used in determining the quantity of recoverable oil14-6 and the probable rates at which various sands or divisions of a sand open to the wells would take water or produce oil. In flush fields, the analytical data are used to predict the productivity of a cored interval. They indicate the presence of oil, gas and water and may

Jan 1, 1939

By Howard C. Pyle, John E. Sherborne

Core analysis is a recent development in the field of petroleum technology. The earliest work on this subject was done in connection with evaluating and planning secondary oil recovery by water-flooding. Present-day analysis of sands of flush fields requires new and independent interpretations of the data provided by cored material. Particular attention is being paid to the development of rapid, routine methods for measuring physical characteristics of sandstone, such as permeability, porosity and grain size, as well as the sand's fluid content. Permeability may be defined as the fluid-passing capacity of a rock. For a sandstone to be permeable it must be possible to pass a measurable quantity of fluid through the material in a finite period of time. The common unit of permeability is the darcy, which may be defined as the rate of viscous flow, in milliliters per second, of a fluid of one centipoise viscosity through a porous medium having a cross section of one square centimeter, under a pressure gradient of one atmosphere (76.0 cm. Hg) per centimeter.' For convenience the subunit millidarcy, or one-thousandth darcy, is often used. Porosity is defined as the fluid-containing capacity of a rock and is usually expressed as a percentage ratio of the total pore volume to the rock or bulk volume. Since measurement of only the effective or communicating pore volume is often made, porosities are distinguished as total or effective.2,3 Net effective porosity is defined as the net pore volume available for oil and gas. Oil and water content of sand is measured and expressed either as the percentage saturation of the total pores or of the bulk rock. The oil content may also be expressed as the percentage saturation of the net effective pores. In connection with water-flooding, methods of core analysis were developed to furnish data that could be used in determining the quantity of recoverable oil14-6 and the probable rates at which various sands or divisions of a sand open to the wells would take water or produce oil. In flush fields, the analytical data are used to predict the productivity of a cored interval. They indicate the presence of oil, gas and water and may

Jan 1, 1939

By T. Wasson

Midland and Isabella counties have been the centers of activities for the year 1932. The major part of the 6,967,000 bbl. produced during the year was obtained from the old Mt. Pleasant field and the Eastern Extension field. The total production to the end of 1932 for Michigan, from all fields since discovery, is 20,679,600 bbl. Production in the Eastern Extension field was obtained from Dundee limestone of Devonian age, at a depth of about 3600 ft. As a result of the year's activity in this area, the limits of the Eastern Extension have been defined. No new fields have been discovered. A number of prospective areas have been drilled and condemned by dry holes. Probably the most outstanding development of the year was the discovery of oil on the Yost farm, in sec. 35 of Greendale Township, Midland County, by the Pure Oil Co., in the early part of December. Production is from the Dundee limestone similar to that in the Eastern Extension but is 4 miles south of that area. The first well has averaged about 500 bbl. per day since completion. It is near the center of a solid block held by the Pure Oil Co., so that rapid development due to competitive drilling is not expected. During the early part of the year the Midland-Isabella area was under proration, but on May 17 proration restrictions were discontinued and remained so until the end of the year. While the Eastern Extension saw the principal activity, some work was done in other fields of Midland and Isabella counties, but very little new production was added. The Vernon field on the north showed a slight increase in production over 1931. The Leaton field decreased. The well in Porter Township, Midland County, is still kept in the production ranks but very little drilling was done in that area. The old Saginaw field, Saginaw County, still remains the only spot in the state where commercial production is obtained from the Berea sand. It showed a slight decline over 1931 with no new producers for the year. The Muskegon field on the west side of the state showed a considerable decline over 1931, but owing to the rejuvenation of some wells by the use of acid this drop was not as great as might have been expected. Only two new producers were drilled in that area.

Jan 1, 1933

By Howard Pyle

CORE analysis is a recent development in the field of petroleum technology. The earliest work on this subject was done in connection with evaluating and planning secondary oil recovery by water-flooding. Present-day analysis of sands of flush fields requires new and independent interpretations of the data provided by cored material. Particular attention is being paid to the development of rapid, routine methods for measuring physical characteristics of sandstone, such as permeability, porosity and grain size, as well as the sand's fluid content. Permeability may be defined as the fluid-passing capacity of a rock. For a sandstone to be permeable it must be possible to pass a measurable quantity of fluid through the material in a finite period of time. The common unit of permeability is the darcy, which may be defined as the rate of viscous flow, in milliliters per second, of a fluid of one centipoise viscosity through a porous medium having a cross section of one square centimeter, under a pressure gradient of one atmosphere (76.0 cm. Hg) per centimeter.1 For convenience the subunit millidarcy, or one-thou-sandth darcy, is often used. Porosity is defined as the fluid-containing capacity of a rock and is usually expressed as a percentage ratio of the total pore volume to the rock or bulk volume. Since measurement of only the effective or communicating pore volume is often made, porosities are distinguished as total or effective.2,3 Net effective porosity is defined as the net pore volume available for oil and gas. Oil and water content of sand is measured and expressed either as the percentage saturation of the total pores or of the bulk rock. The oil content may also be expressed as the percentage saturation of the net effective pores. In connection with water-flooding, methods of core analysis were developed to furnish data that could be used in determining the quantity of recoverable oil,4-6 and the probable rates at which various sands or divisions of a sand open to the wells would take water or produce oil. In flush fields, the analytical data are used to predict the productivity of a cored interval. They indicate the presence of oil, gas and water and may

Jan 1, 1939

By Franklin J. Kay

Introduction The methods used in surface, mining vary throughout the world, depending on many variables such as: the types of over- burden materials, the depth of the overburden, the thickness of the seam, and other operational choices, both financial and functional. However, the stripping machines are typically draglines, stripping shovels, excavators, scrapers, loaders, and bulldozers. In all cases the economic feasibility of mining thin seams depends on the market needs, the market location, the equipment used, the mine management, the quality of the coal, and the labor market. Slight negative combinations of these parameters have closed many mines while positive combinations allow others to exist. The limited mobility or slow movement of large stripping shovels, draglines, and bucket wheel excavators make them more economically fitted to areas where large quantities of overburden are to be moved. This is necessary to keep the transfer and setup time between pits a negligibly small percent of the total operational time. Equipment such as the scrapers, loaders, backhoes, trucks, and bulldozers that are either very mobile or can be trailered is more versatile and can be used in the smaller area mines.* Mobile equipment is also more practical in areas with shallow overburden because of the constant movement required while removing overburden. In thin coal seams the equipment is usually paired such that the operational equipment can be listed as: (1) dragline-loader, (2) shovel-truck- loader, (3) scraper-loader. (4) loader-truck-loader, or (5) loader-loader. In these operations the overburden is removed with the first machine(s) of the pairing and the loader or loaders are used for coal production. Recent articles in Coal Age (Chironis, 1978) and Mining Engineering (Wiebmer, 1978) have discussed varying philosophies in mining similar seams of coal. One operator uses draglines for competitive mining while the other uses scrapers for the same purpose. Both cite strong cases sup- porting their choice of equipment as good sound economic decisions and their success supports their choices. The drag-line operation is adding new larger draglines to decrease the cost of mining, rather than to increase coal production. The scraper operation has also gone to more and larger scrapers for basically the same reasons. These operations and all

Jan 1, 1981

By D. P. Mitchell

Western Australia is the home of much that is new and interesting in the gold-mining industry. Some of the gold deposits are outranked for size and value by nothing yet discorered, while the value of the ores is, in many cases, rivaled only by their complex character. As in all parts of the world, many of the ore-bodies occur in ways which tax the skill of the miner in following them; and among these the writer considers the case of the East Murchison United more interesting than the average. This is one of the leading gold-mines of the colony in point of production, and is situated near the town of Lawlers, in the East Murchison district. The country for several miles around the mine is mainly granite, and the line of outcrop on which this mine is located can be traced for a long distance. As will be seen from the accompanying plan (Fig. I), there are, at the water-level, two nearly parallel veins running slightly north of west. Structural Features.—The most striking peculiarity of these veins, and the hardest to understand, is their tendency to send out horizontal stringers or side-veins. These vary in size from a veinlet an inch thick to a veil] several feet in width, and they extend with great persistence into the wall-rock on either side of the vein. This tendency is shown in Figs. 2 and 3. The usual signs of a movement of the wall-rocks, such as a ribbon-structure of the quartz and a well-defined gouge or seam of clay along the walls, are in many places lacking, while in other places they appear strongly marked. They seem more in evidence below water-level than above. It is a commonlly accepted idea that when a gold-bearing vein loses in width, it often gains in value. In this instance, however, the direct opposite is the case; for in many stopes it has been possible to leave the narrow portions of the vein to act as pillars, and to extract only the wide portions, which are

Jan 1, 1900

By E. W. Davis

Iron-ORE beneficiation methods are determined largely by blastfurnace requirements. There are still many millions of tons of direct furnace ore in the Lake Superior district and blast furnaces are designed and operated for the most efficient use of this material. Beneficiated ore must be so prepared that existing furnaces may use it without alteration in design or radical changes in practice. Many attempts have been made to develop new furnaces or processes for smelting iron-ore concentrate not suitable for blast-furnace use, but these processes have gained little importance. It is, therefore, the endeavor in beneficiating iron ore to make a product that will give at least as good results as direct furnace ore in existing blast furnaces. The term "beneficiation," as applied to iron ore, does not necessarily mean concentration, but more accurately means "dressing up" the ore so that it is more acceptable to the blastfurnace operators. In modern blast-furnace practice the structure of the ore is quite as important as the chemical analysis. Certainly, the higher the iron content and the lower the silica, phosphorus and sulfur, the more desirable the ore bccomcs; but if the structure is bad, that is, if the blast-furnace gases can penetrate the charge only with difficulty, the ore is undesirable regardless of its analysis. This means that the ore should be as uniform in size as possible and free from fines, and also that the individual particles of ore should be pervious to the reducing gases of the furnace. Structure and purity are the primary requirements for a furnace ore and structure is just as important as purity. Iron-ore beneficiation processes can be divided, therefore, roughly into two main classifications: (1) processes that primarily improve the structure, and (2) processes that primarily improve the chemical analysis. During the past 10 years approximately 25 per cent of the ore shipped from the Lake Superior district has been beneficiated. Of this about half has been crushed and screened, a simple operation that primarily improves the structure but in some cases also improves the analysis slightly. The other half of the shipment of beneficiated ore, amounting to an average

Jan 1, 1935

YEAR OF ELECTION 1922. FEDERICO GIOLITTI Torino, Italy. 1917. HERBERT HOOVER Washington, D. C. 1941. DANIEL COWAN JACKLING San Francisco, Calif. 1939. HENRY KRUMB New York, N. Y. 1942. Essington Lewis Melbourne Vic., Australia 1921. C. McDERMID London, England. 1942. PAUL DYER MERICA New York, N. Y. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1938. A.M. PORTEVIN Paris France 1937. JOHN V.W. REYNDERS, New York, N. Y. 1937. GEORGE S. RICE Washington, D. C. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1934. T.A. RICKARD Victoria, B.C., Canada

Jan 1, 1943

By Joseph P. Kittredge

At the time this matter first came up in 1912, the National Malleable and Steel Castings Co. had seven basic-bottom open-hearth furnaces in its plant at Sharon, Fa., using fuel oil, then costing about 2½¢ per gallon. The fuel was satisfactory but its cost fluctuated widely, therefore the use of pulverized coal, which had been successful in the cement industry and in some metallurgical furnaces, was suggested. After a thorough investigation, and an actual trial on one of the open-hearth furnaces, to be certain that the siliceous ash in the coal would not seriously affect the basic slags, the management of this company approved its adoption and a complete installation was started. The conclusion had been reached that the success of the operation depended on pulverizing the coal to greater fineness than had thus far been accomplished, and all equipment was chosen with this in mind. A coal drier was deemed essential, and one of ample capacity and efficiency was selected, which has done all that was expected of it, working without failure and with very small maintenance cost, and is still in operation. Pulverizers The company demanded a pulverization of at least 90 per cent through a 240-mesh screen, with consistent results, and a machine was chosen that was grinding other materials than coal to the fineness desired. The control of fineness was obtained through a vacuum separator, and was governed by the size of the separator and the number and construction of the valves necessary to expand and direct the air current. These valves can be set to obtain any degree of fineness desired, and the result is consistent. Two machines were installed, each capable of producing 2½ tons per hour, 95 per cent through 240 mesh. These machines have done everything expected of them, have run continuously, and are still in operation. An examination of some of our pulverized coal by elutriation and microscopic measurement disclosed that a 1-lb. lump of bituminous coal,

Jan 1, 1940

By Joseph P. Kittredge

At the time this matter first came up in 1912, the National Malleable and Steel Castings Co. had seven basic-bottom open-hearth furnaces in its plant at Sharon, Fa., using fuel oil, then costing about 2½¢ per gallon. The fuel was satisfactory but its cost fluctuated widely, therefore the use of pulverized coal, which had been successful in the cement industry and in some metallurgical furnaces, was suggested. After a thorough investigation, and an actual trial on one of the open-hearth furnaces, to be certain that the siliceous ash in the coal would not seriously affect the basic slags, the management of this company approved its adoption and a complete installation was started. The conclusion had been reached that the success of the operation depended on pulverizing the coal to greater fineness than had thus far been accomplished, and all equipment was chosen with this in mind. A coal drier was deemed essential, and one of ample capacity and efficiency was selected, which has done all that was expected of it, working without failure and with very small maintenance cost, and is still in operation. Pulverizers The company demanded a pulverization of at least 90 per cent through a 240-mesh screen, with consistent results, and a machine was chosen that was grinding other materials than coal to the fineness desired. The control of fineness was obtained through a vacuum separator, and was governed by the size of the separator and the number and construction of the valves necessary to expand and direct the air current. These valves can be set to obtain any degree of fineness desired, and the result is consistent. Two machines were installed, each capable of producing 2½ tons per hour, 95 per cent through 240 mesh. These machines have done everything expected of them, have run continuously, and are still in operation. An examination of some of our pulverized coal by elutriation and microscopic measurement disclosed that a 1-lb. lump of bituminous coal,

Jan 1, 1940

[PRESIDENT E. DEGOLYER, District 0 NEW YORK, N. Y. PAST PRESIDENTS J. V. W. REYNDERS, District 0 . NEW YORK, N. Y. SAMUEL A. TAYLOR, District 3 PITTSBURGH, PA. FIRST VICE-PRESIDENT GEORGE OTIS SMITH, District 4 .WASHINGTON, D. C.]

Jan 1, 1928

By P. Greenfield, P. A. Beck

The phase is a hard and extremely brittle material with a tetragonal crystal structure, containing 30 atoms per unit cell' It occurs in many binary and ternary alloys of the transition elements. The existence of twelve a phases has been reported in binary alloys of metals from the group vanadium, chromium, molybdenum, and tungsten with metals from the group manganese, iron, cobalt, and nickel. It is a characteristic fact that the composition of the o- phases in the various binary systems is not the same. Rather, there is a gradual shift in composition, for instance in the series of chromium a phases, approximately as follows: CrMn,, FeCr, Cr3Co,. In recent years several ideas have been put forward to account for this variability of composition. SullyZ proposed that a was a type of electron compound, characterized by 1.7 electrons per atom in excess of the number required to fill the Pauling atomic orbitals. These excess electrons were supposed to just fill the first Brillouin zone of the u structure. However, later work indicated that the phase is ferromagnetic at low temperatures, so that a- is unlikely to be a full zone compound.~ Another proposal,* which is also based on the structure of the transition elements advanced by Pauling, and in fact leads to essentially the same a compositions as Sully's theory, suggests that the u phase is characterized by a constant number of electron vacancies per atom. The electron vacancy numbers N,. used were originally the same as those in the Pauling theory, but were later modified empirically vn order to bring about better agreement with data for the p phase in certain ternary systems. For alloys, N,, was calculated on the assumption of simple additivity from the electron vacancy numbers of the components, as follows: N,. = 4.66 (Mo + Cr + V) + 3.2 (Mn) + 2.2 (Fe) + 1.71 (Co) + 1.6 (Ni). On this basis a reasonably constant value of N, = 3.4 was obtained for all of the binary u phases and a fairly constant value of N,, = 3.1 for the various p phases. More recently, Bloom and Granta pointed out that a similar correlation with the total number of 3d and 4s electrons per atom is also fairly well fulfilled and concluded that no reference need be made to the Pauling theory. This proposal does not lead to the same binary a compositions as the one described above, so that the relative merits of the two proposals may be determined on the basis of direct comparison with experimental composition data. The purpose of the present paper is to provide such a comparison. Since the experimental data for the composition ranges of several of the known u phases were rather incomplete, it was decided to carry out new experimental determinations for many of the binary systems. Experimental Procedure The alloys were prepared by induction melting in recrystallized alumina crucibles, either in vacuum or in helium atmospheres. Some aluminum was picked up from the crucibles in the alloys of high vanadium content, but this was minimized by keeping the alloys in the molten state for as short a time as possible. The maximum aluminum impurity was 0.13 wt pct by chemical analysis, in an alloy containing over 50 wt pct V. In general, the as-melted compositions agreed accurately with those obtained by chemical analysis. In the case of manganese, however, losses inevitably occurred; consequently all manganese alloys were analyzed. Specimens of all alloys were annealed at temperatures ranging from 1000" to 1300°C in an atmosphere of purified 92 pct helium and 8 pct hydrogen mixture. All manganese alloys were sealed in quartz tubes under vacuum before annealing. The specimens were held at temperature for between four and eight days before being quenched into cold water. Alloys were prepared for microscopic examination by mechanical polishing, usually followed by electrolytic etching. X-ray diffraction specimens were prepared by crushing the homogenized alloys, and by reanneal-ing the obtained powders in evacuated quartz tubes for a few hours at the temperature of the lump anneal. X-ray diffraction patterns were made with unfiltered chromium radiation, using an asymmetrical focusing camera of high dispersion. Using microscopic and X-ray techniques jointly, the accuracy

Jan 1, 1955

By David B. Reger

The exhaustion of oil and gas in the United States is proceeding at a rapid pace. This is especially true in fields where the light oils that furnish the most fuel for internal-combustion engines arc found, leading to a late estimate by Arnold that the petroleum resources are 36 per cent. exhausted.l The further remark by Dr. David T. Day at the New York meeting of the Institute, in February, 1916, that the operators of the country are now scarcely able to supply the ever-increasing demand for gasoline, leads the writer to believe that a determined effort will soon be made to secure deeper producing horizons in those regions that now furnish high-grade oil, and in which pump stations and pipe lines offer convenient means for the economical handling of new production. A study of Arnold's table shows further that the States that produce paraffin oil exclusively are 45 per cent. exhausted, this figure being much higher than the average of paraffin and asphalt States altogether. The most extensive of all the paraffin-oil-producing areas is the Appalachian Field, extending with the Appalachian Geo-Syncline from western New York southwestward through western Pennsylvania, western West Virginia, Ohio, Kentucky, and Tennessee, where oil of high gravity is always secured. Of these States, Pennsylvania and West Virginia rank highest in the quality of their product. In West Virginia, the oil sands dip to a lower level than in any other locality in the Appalachian Geo-Syneline, the Pittsburgh Coal of the Pennsylvanian being only 50 ft. above sea level along the Nineveh Syneline at Wileyville, Wetzel County.² The very significant fact that the sands of the Mississippian and Upper Devonian Measures furnished the richest oil pools of the State along this

Jan 1, 1917

RESEMBLING in some respects the enterprise at R Chuquicamata is that of the New Cornelia Copper Co. at Ajo, Arizona. Controlled from its inception by the Calumet & Arizona Mining Co., New Cornelia became a unit of the Phelps Dodge Corporation when the latter absorbed the Calumet & Arizona company in 1931. Both Ajo and Chuquicamata are situated in low mountains in extremely arid desert country. Both ore deposits consisted-the past tense is used advisedly because the oxidized ore has nearly all been mined at Ajo-of a horizon of leachable oxidized ores overlying sulphide or concentrating ore. The principal technical problem in each case was the development of a method for treating the oxidized ore. In both instances the capping of waste rock was comparatively thin and power-shovel mining in open cuts was the obvious method of exploitation. Nature had smiled on neither place in the matter of climate. Though Ajo does not have the persistent winds for which Chuquicamata is notorious, the comforts of living are largely artificial. And it is only fair to emphasize that at each place the mining companies have achieved remarkable success in providing these comforts. Of course, in point of size New Cornelia must be content with the inferior role. From May, 1917, when production was started, to the middle of June, 1930, the company leached 16,368,000 tons of oxidized ore, thereby virtually exhausting the ores of this class. Up to the same date, about 15,000,000 tons of sulphide ore had been mined, and a rough estimate gives 170,000,000 tons remaining in reserve. The total tonnage does not loom very large in comparison with Chuquicamata's billion tons; but it is exceeded by similar figures for only four of the Porphyry group.

Jan 1, 1933