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Jan 1, 1910

By W. P. Sykes

TUNGSTEN serves mankind in two major roles. The first of these is represented by the tungsten filament of the incandescent electric lamp, a common article of commerce. In the field of hard alloys it plays its second substantial part. A fortunate combination of physical properties in this metal ac- counts for its efficient service as a source of illumination. Tungsten melts at about 3400°C, has a relatively low vapor pressure and at the same time sufficient strength, both hot and cold, to serve satisfactorily as filaments, which may range in diameter from 0.060 to 0.0005 in. In the early days of the incandescent lamp, the pioneers realized the importance of using a substance of high melting point for the source of light. The metals osmium (mp approx. 2700°C) and tantalum (mp approx. 2850°C) were both employed to some extent. Tantalum actually attained some commercial importance in this field because it could be drawn into small wires of appreciable length. DUCTILE TUNGSTEN WIRE Before the year 1908, tungsten was considered a nonductile metal, since no one had succeeded in overcoming the brittleness so typical of the unworked metal at room temperature. The methods employed today in producing ductile tungsten wire were developed over a period of years. The process was largely determined by the exceedingly high temperature required to melt this metal. Even today the difficulties involved in producing an appreciable quantity of pure

Jan 1, 1953

By Herbert Hoover

I HAVE been greatly honored as your unanimous choice for President of this. Institute, with which I have been associated during my entire professional life. It is customary for your new President, on these occasions, to make some observation on matters of general interest from the engineer's standpoint. The profession of engineering in the United States comprises not alone scientific advisers on industry but, in great majority, is comprised of the men in administrative positions. In such positions, they stand midway between capital and labor. The character of your training and experience leads you to exact and quantitative thought. This basis of training in a great group of Americans furnished a wonderful' recruiting ground for service in these last years of tribulation. Many thousands of engineers were called into the army, the navy, and civilian service for the Government. Thousands of high offices were discharged by them with credit to the profession and the nation. We have in. this country, probably, one hundred thousand professional engineers. The events of the past few years have greatly stirred their interest in national problems.' This has taken practical. form in the maintenance of joint committees for discussion of these problems and support to a free advisory bureau in ,Washington. The engineers want nothing for themselves from Congress.. They want efficiency in government, and you contribute to the maintenance of this bureau out of sheer idealism. This organization for consideration of national problems has had many subjects before it, and I propose to touch on some of them this evening.

Jan 1, 1920

By M. J. Swan, W. C. Foshee, R. R. Klimpel

The large volume of water used in coal preparation plants makes water recycling a necessity. Economical cleaning of dirty water usually requires flocculation with an efficient organic polyelectrolyte. This paper discusses identification of optimum flocculant systems. Supporting laboratory data with on-site tests and full-scale field trails supplies information necessary for matching the polymer to the plant.

Jan 1, 1983

By B. Paul

1. INTRODUCTION It is known that the elastic modulus of a metal may be considerably increased by dispersing

Jan 1, 1961

By Theodore Marvin

NOW that real progress is being made in building airplanes that can stand up under adverse conditions in isolated parts of the world, utilization of aviation by mining and petroleum companies is proceeding rapidly. This isolation, offering such handicaps to ordinary methods of transportation, also was the thorn in the flesh of aviation until the recent advances in plane and englue design. The accompanying illustration shows one of the six new planes just delivered to the U. S. Government for map making. The planes will be used in Department of Commerce, Coast and Geodetic Survey, Navy Hydrographic, and Insular work. There is a trap door in the bottom of the hull for a Fairchild camera which takes five pictures-vertical, N60°, E60°, S60°, and W60°-at regular intervals. It is manufactured by the Grumman Aircraft Engineering Corp., Farmingdale, N. Y.

Jan 1, 1935

By Paul E. Queneau, H. J. Roorda

Cobalt consumption will increase during the next decade at an average rate at least equal that of nickel. In the past, use of cobalt has at times been curtailed by lack of availability or by high price. In the future, output of cobalt derived from copper ores and iron sulfides will continue to grow and output of cobalt from nickel ores will be greatly increased. There should therefore be an adequate supply of this metal at a reasonable price. Nickeliferous limonites constitute by far the largest known terrestrial reserves of cobalt. A process has been conceived, based upon selective reduction and aqueous chlorination for treatment of such ores. The proposed procedure permits good extraction of the ore's cobalt content, comparable to that of the nickel, and is adaptable to large-scale, automated unit operations. Chlorine leaching of the ore enhances its value as a potential source of iron and chromium. Over four thousand years ago, cobalt pigments were employed for decorative purposes in some glass and glazes of Egypt and Persia, and by 1000 B.C. they were widely used in the Middle East.' " However, prior to 1914, virtually no cobalt was produced as metal and ceramics remained the largest consumer of the element as oxide. During World War I cobalt-containing high-speed steels came into their own and the metal's merit in magnet steels was established.

Jan 1, 1971

THE progress in lead smelting practice in the United States during 1930 has been along previously defined lines. Since most of the material treated is high-grade concentrate relatively high in zinc, practically all the plants have been forced to adopt double sintering. This generally results in there being' no matte fall, and most of the copper in the charge is recovered in the furnace dross. The furnace dross is . smelted with. scrap iron and flux .in small reverberatories, giving a shipping matte or speiss high in copper and low in lead. Details of this reverberatory. furnace practice vary at the different plants. There is a decided tendency toward moreintensive filtration of blast- furnace and sinter fume. Bag capacity has been in- creased by using higher pressures and more frequent shaking.

Jan 1, 1931

By Oliver Bowles

THE most important non-metallic mineral industries from a tonnage standpoint are those that are allied with the construction industries and are engaged in handling sand and gravel, crushed stone, building stone, cement, lime and gypsum. The greatest problem facing a number of these industries at this time is over-production. They have experienced un- usual, and in some instances phenomenal, growth during recent years, stinlulated by extensive highway and building construction, but in some localities expansion of producing plants has far outstripped industrial needs. The cement industry is operating at about two- thirds capacity. Over-production tends toward price- cutting and unprofitable and interrupted operation, involving maintenance expenses for idle plants and disorganization of working forces. This condition has encouraged active efforts toward reducing production costs by the introduction of labor-saving equipment. Also, there is a tendency toward the location of manufacturing plants, wherever possible, near the centers of consumption rather than at points of production of raw materials. In order to reduce overhead expense, or for other reasons, many consolidations of companies into larger units have taken place. An economic study of conditions in these industries is highly desirable. The U. S. Bureau of Mines has taken one step forward in this direction in the issuance of Economic Paper 7, entitled "Economics of New Sand and Gravel Developments." Briefly, this report emphasizes the importance of making a thorough study of all the economic factors involved before undertaking new .enterprises.

Jan 1, 1930

By H. O. Hofman

THE leading antimony mineral is stibnite. In smelting stibnite ore two processes are available, precipitation and roasting-reduction. The former is suited only for high-grade ores. As low-grade ores are more common than high-grade, roasting-reduction is of greater importance than precipitation. In the roasting process the aim may be to leave the oxidized antimony in the ore, or it may be to volatilize as much of the antimony as possible, collect the volatilized oxide as a rich intermediary product and smelt it for antimony, leaving the gangue poor enough to be considered a waste product. Whichever way the roast is conducted certain difficulties inherent in stibnite are encountered. These are: 1. The low melting point of stibnite which; according to Pelabon,1 is 550°C., according to Wagemann2 540°C., and according to Borgström3 546°C. 2. The ignition temperature: According to Friedrich,4 stibnite, if heated in air, begins to oxidize at 290°C. if the size of a grain is 0.1 mm. in diameter; at 343°, if 0.1 to 0.2 mm.; and 430° if 0.2 mm. 3. The fusibility of a mixture of Sb2S3 and Sb203 which in the form of kermesite (Sb2S3)2.Sb203 melts at 517°C.5 4. The volatility of Sb2S3 and Sb203, for which no numerical data appear to exist, although practical experience has shown that they are volatile at low temperatures.

Jan 1, 1916

By Dozier Fircley

SOME nonmetallic minerals and their products, such as portland cement, common brick and hollow tile, sand, gravel, crushed rock, vitrified salt-glaze clay pipe, and the like, are a necessity in every community. They are mineral in nature but the establishment of plants for their production is usually a local and elementary problem. Yet it is probable that an economic study of the problem in every locality will show that such nonmetallic mineral commodities are not always obtained in the most economical way, or in the best quality. Other nonmetallic minerals are of such value that they may be shipped for long distances and sold in sufficient quantities to establish prosperous commercial ventures. Among these are phosphates, barium compounds, borates, nitrogen compounds, magnesium compounds, sulfur, asbestos, and potash. Success in marketing such products depends on quality, production cost, transportation, and similar conditions.

Jan 1, 1932

Discussion of the paper of ALBERT SAUVEUR, presented at the Pittsburgh meeting, October, 1914, and printed in Bulletin No. 93, September, 1914, pp. 2439 to 2449 G. K. BURGESS, Washington, D. C.-This very instructive contribution by Professor Sauveur to our knowledge of that puzzling substance, Hadfield's manganese steel, should not only be read in connection with the paper of Messrs. Hopkinson and Hadfield referred to by Professor Sauveur (Bulletin No. 87, pp. 513 to 530, March, 1914); but one should also have in mind, as throwing much additional light upon the questions raised, two papers recently presented before the Iron and Steel Institute, the one by Sir Robert Hadfield (Journal of the Iron and Steel Institute No. II, 1913) on Heating and Cooling Curves of Manganese Steel, the other by Messrs. Hadfield and Hopkinson (ibid., No. I, 1914) treating of the Magnetic and Mechanical Properties of Manganese Steel. We then have brought together for this substance, the thermal, magnetic, and mechanical properties as well as the resulting microstructure, for the definite heat treatments described, and in particular after long annealing between 500° and 700° C. Sir Robert Hadfield and Professor Hopkinson see in the properties found for manganese steel (of C = 1.25 and Mn = 12.5 per cent.) a demonstration of the untenableness of the allotropic theory of iron, whereas Professor Sauveur reaches the contrary conclusion, that some of the facts observed can be explained only in terms of the existence of beta iron in steel of this composition. There is another possible hypothesis: namely, that these several series of experiments shed no light on the subject of the allotropy of iron, or at least as regards the existence of beta iron. However heretical it may sound, I am inclined to this last belief.

Jan 4, 1915

By David Reger

THE value of carbon ratios in determining the boundaries of possible oil deposits appears to have passed the hypothetical stage. The theory that the ratio of fixed carbon in pure coals is an, invariable index of incipient metamorphism in both, surface and underground rocks and that it may be applied in defining the limits of petroleum, advanced by David White,1 has been received with keen interest by many petroleum geologists. Detailed isocarb maps have been prepared of the Pennsylvanian area of North Texas and Eastern Oklahoma by M. L. Fuller.2 A similar map of the coal-bearing area of West Virginia is given here. An isocarb3 is a line showing an equal fixed-carbon percentage, pure coal basis; the term has been proposed by David White to supersede a less expressive nomenclature. The term carbon ratio is applied to the percentage of carbon in pure coal after water and ash have been eliminated. As a comparatively small number of analyses have been made on this basis, it is usually necessary to compute the ratio by dividing the fixed carbon of the proximate analysis by the sum of the fixed carbon and volatile matter of the same analysis. Many thousands of proximate analyses have been made by the West Virginia Geological Survey, covering nearly every county in which coal is found. Numerous others have been made by the. U.S. Geological Survey and the U. S. Bureau of Mines, but as uniformity of results is

Jan 2, 1921

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

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

Jan 1, 1967

GENERAL GEOLOGIC DESCRIPTION The Escalante silver deposit located in southwestern Utah is an epithermal vein system consisting of a hanging wall and footwall vein, straight along strike and dipping about 1.2 rad (70°). The veins consist of banded quartz and calcite fissure fillings between volcanic wall rock that are silicified for some distance outward from the vein. The walls of the veins are sharp and the silver values are irratically distributed through the various bands within the vein. Only very low grade values are to be found in the wall rock on either side. The portion of the veins above the water table have been somewhat leached, with some secondary enrichment below. The mineralogical zonation is variable due to a fluctuating water table through geologic time. SAMPLE MANAGEMENT AND COMPOSITE ASSAYS Sample data for the deposit was obtained from over 50 diamond drill holes, from channel samples cut at intervals across a drift, and from scattered surface trenches along the out- crop of the hanging wall vein. Fig. 13-1 is a surface plan map showing the vein outcrop and some diamond drill locations. Two cross sections through the vein are shown in Figs. 1 3-2 and 13-3. Nearly all of the diamond drill core of vein material was assayed in 0.3-m (I-ft) lengths, from which weighted composite assays were manually calculated for the horizontal thickness of the vein. The centers of the composited samples were plotted in north and east coordinates and by elevation, and locations and assay

Jan 1, 1980

By Gerald Edmunds, M. L. Fuller

The development of "fiber" or preferred orientations, during the plastic deformation of metals, and the relation of such structures to the anisotropic characteristics of worked metals has become a subject of common knowledge among metallurgists. Very little has been published, however, relative to variations existent throughout the cross-sections of rolled strips,1 and the influence that such variations may have. This paper presents such a study on a rolled zinc alloy.2 The significance of small differences in surface structure is shown in relation to bending properties. Experience with zinc and its alloys has shown that the outer radius of the bend, which is subject to tensile deformation, is the common region of failure. In considering relations of structural characteristics to bending properties it will suffice, therefore, to consider the ease and possible extent of tensile deformation resulting from various orientations. It is necessary in this connection to assume that on the average the individual crystals of a polycrystalline material act substantially as if their movements were unobstructed by the surrounding grains. This assumption is not strictly valid, but the error involved is unlikely to affect seriously the qualitative conclusions derived from its use. The mechanism of the plastic deformation of zinc crystals has been described by Mark, Polanyi and Schmid3 and by Mathewson and Phillips14 and is regarded as being accomplished by block movements or * Investigator, Rolling Mill Section, Research Division, New Jersey Zinc Co. f Investigator, X-ray Laboratory, Research Division, New .Jersey Zinc Co. 1 Variations of structure throughout the cross-section of wire have been reported in the literature. 2 This alloy contained, in addition to zinc, 1.0 per cent copper and 0.01 per cent magnesium. Its crystal form is hexagonal close packed, the sarne as that of pure zinc. 3 H. Mark, M. Polanyi and E. Schmid: Vorgange bei der Dehrlung von Zink-kristallen. Zlsch. f. Phys. (1922) 12, 58. 4 C, H. Mathewson and A. J. Phillips: Plastic Deformation of Coarse-grained Zinc. Proc. Inst. Met. Div., A. I. M. E. (1927) 143. C. H. Mathewson: Twinning in Metals. Proc. Inst. Met. Div., A. I. M. E. (1928) 7. The results of a further study of plastic deformation of zinc as related to twin-

Jan 1, 1932

By M. E. Nicholson

The effect of boron on the austenitic transformation rate of iron is smaller than on low carbon steels. The influence of austenitizing temperature on B-Fe is the reverse of its influence on steels. THERE have been many studies made of the influence of boron on the hardenability of steel, but apparently none has been made of its influence on the y-a transformation of pure iron. There are several facts suggesting that boron should have a pronounced effect on the transformation rate of iron. First, Simcoe et a1.l indicated that boron reduces the nucleation rate of ferrite and bainite. Second, they showed, along with others,&apos;, " that the lower the carbon content of steel the greater the influence of boron on hardenability. If this trend extends to pure iron, the influence on rate of ferrite formation should be considerably greater for iron than for medium carbon steels. According to Rahrer and Armstrong," the multiplying factor for boron in pure iron should be about 2.40, compared with 1.50 in a 0.35 pet C steel. According to an extrapolation made by Grange and Mitchell,&apos; the effect should be even greater, and the multiplying factor should be about 3.5 in iron. Many investigations of the boron influence&apos;.7, 2, 5 indicated that boron is effective only when in solid solution. On the other hand, Chandler and Bredig" suggested that boron increases hardenability by combining with nitrogen, thereby preventing formation of AlN, which catalyzes the decomposition of austenite. If their hypothesis is valid, boron should have no effect on an alloy free from nitrogen. Digges et al." showed that so far as low nitrogen high purity Fe-C alloys are concerned this is not the case. No experiments, however, have been made on low nitrogen iron. To determine whether or not boron has an effect on low nitrogen iron and, if an effect exists, to determine whether it is as large as predicted from the investigations of boron treated steels, the following work was performed. Because of the rapidity with which iron transforms from austenite to ferrite at even a moderate degree of supercooling, it was decided to study the influence of boron on the transformation rate of iron by determining the effect of quenching rate on the temperature of the beginning of transformation. The technique, essentially that used by Greninger&apos; and Duwez,H consisted of heating small specimens, 0.1 in. sq and 0.010 in. thick, in an atmosphere of purified helium with a resistance heater coil, and then quenching the sample in a jet of helium gas. At the time the jet was applied, the heating coil was removed from around the sample. The sample was suspended in the furnace on 30 gage chrome1 and alumel wires, one welded to each side of the specimen, which also served as a thermocouple for measuring the specimen temperature. Specimens were prepared from vacuum-melted iron obtained from the National Research Corp. which was rolled to a thickness of 0.060 in. and then decarburized in wet hydrogen for 51/2 hr at 700°C. This treatment also removed any boron present in the iron. The resulting iron contained 0.001 pet C. 0.0002 pet N, and 0.005 pet 0. One half of the piece was then boronized by surrounding it with 325 mesh boron powder and heating it for about 2 hr at 900°C in H,. The boronized iron was then homogenized at 1100°C for 24 hr. The iron boride case formed by boronizing was removed by grinding 0.010 in. from each side of the plate, and the piece was finally rolled to a thickness of 0.010 in. The resulting alloy contained

Jan 1, 1957

By AIME AIME

WITH the recent increase in the price of gold, its economic recovery at depths formerly considered impractical has become a present possibility. Two important difficulties must be met: pressure bursts of the rock, and the reduced efficiency of human labor subjected to the higher temperatures and the increased humidity at the greater depths. In the following abstract of a paper by J. H. Dobson, presented before the South African Institution of Engineers on

Jan 1, 1935

By L. E. PORTNER

INCREASING military demands on the petroleum industry have brought into bold relief the crude-oil reserves now available to meet combined military and civilian demands, emphasizing the necessity for a greater efficiency in recovery from what has been discovered than ever before, particularly in light of the absence of new discoveries. This situation-and the fact that the industry, as well as members of the Government charged with governing oil production, desire to meet all crude-oil demands made of the industry with the least loss in tangible reserves through production practices-paves the way for increasing application of sound principles of production engineering and conservation.

Jan 1, 1944

By W. L. Zeigler

THE Galena mill of the Callahan Zinc-Lead Co. is of 150 tons daily [ ] capacity and is situated at Lake Gulch, 2 miles west of Wallace, Idaho. (Fig. 1. It was constructed during the summer of 1926, work having been started late in June and the plant placed in operation Oct. 15, following.

Jan 1, 1928