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By D. J. Carney, E. C. Rudolphy

IT has been demonstrated that inclusion size, distribution, and composition affect the machin-ability of resulphurized steels. Merchant and Zlatinl concluded that large sulphide inclusions aided machining by forming a (lubricating) coating on the tool face. Boulger et al.² and Van Vlack³ noted that the size, distribution, and composition of the inclusions in the steel affected the machinability. Steel specimens containing large globular sulphide inclusions usually exhibited excellent cutting properties, while machinability was adversely affected by the presence of numbers of oxide-type inclusions. Consequently a thorough knowledge of all the factors which affect the inclusions in the final product is desirable. Since almost all the inclusions have their origin in liquid steel, it was necessary to begin a study of inclusions in free-machining steels by studying the inclusions and chemical segregation in the as-cast ingot. Very little information is available on the size, distribution, shape, and composition of inclusions in large, capped, free-machining steel ingots, particularly the B1113 grade. Gregory and Whiteley4 made a general study of the inclusions in a small, high sulphur, free-machining steel ingot. Also, numerous authors have described the solidification and segregation characteristics of the four basic types of steel ingots, namely, rimmed, capped,7 semikilled,7,8 and killed7,9,10 ingots. Most of these studies were made with plain carbon or low alloy, low sulphur steel. It was desirable to study not only the ingot but also the change in size, shape, and number of inclusions on rolling an ingot to a bloom and thence to a billet. This procedure was followed and it is hoped that this study may serve the dual purpose of adding to the general knowledge of ingot solidification as well as contributing to the knowledge of the size, shape, distribution, and composition of inclusions from the ingot to the billet in a high sulphur, free-machining steel. Procedure A 12.000-lb 23x35x75 in. slab ingot of the B1113 grade was cast, sectioned, and studied both macro-scopically and microscopically. An adjacent ingot from the same heat and of the same size was rolled to a 77/8x77/8 in. bloom and thence to a 21/2x21/2 in. billet. These various bloom and billet sections were also sectioned and studied macroscopically and microscopically. Sectioning the Ingot: The ingot herein described was obtained from the United States Steel Corp.'s South Works Bessemer Blow No. 0193, a B1113 mechanically capped heat. The 23x35 in. ingot (No. 2) was teemed according to normal procedures and after stripping and transportation to the rolling mill was not placed in the soaking pit but allowed to air cool in an upright position. When completely solidified, the ingot was cut into sections by means of a powder scarfing torch and further sectioned by saw cutting as indicated in Fig. 1. Cut No. 2 (1x10x12 in.) from sections A through H was cleaned thoroughly, macroetched in a solution of 50-50 water and hot muriatic acid and used to obtain a macrograph of a horizontal section from the surface to slightly beyond the center of the 23-in. ingot dimension. Cuts No. 5 and 3 (lx81/2xl0 in. each) from sections A through H were treated in a similar manner to obtain a macrograph of a horizontal section from the surface to slightly beyond the center of the 35-in. ingot dimension. The composite macrograph of these horizontal ingot sections, which shows a vertical section of the ingot from top to bottom, is shown in Fig. 2. It should be noted that sections No. 2 are normal to sections 5 and 3 in the composite. Drillings for chemical analyses were obtained from selected positions within the above-mentioned ingot sections as noted in Fig. 3. The oxygen content was determined by the vacuum-fusion method. Samples for microscopic examination were cut from

Jan 1, 1954

By E. C. Pechin

Secretary's Note.—Mr. Bramwell was born in 1846, at Liverpool, England, his father being English, and his mother American, of Scotch ancestry. Brought to the United States in early childhood, he was educated at the public schools and graduated from the College of the City of New York. He subsequently studied his profession as a mining engineer at the Royal School of Mines, Berlin, Prussia, and was for a short time in the service of the Prussian government at Konigs hutte. Returning to this country in 1871, he was employed during succeeding years as mining engineer, chemist, and manager at various fnrnaces and iron works in Pennsylvania and the Southern States until, in 1883, he became actively engaged in the development of the Flat-Top coal-field of southwestern Virginia, in which region the town of Bramwell was named after him, in recognition of his services as a pioneer of the great industry which he did so much to promote. After prolonged and fluctuating ill-health, he died, July 13, 1894, at Paris, France. At the opening session of the Bridgeport meeting, the Secretary announced his death, and Mr. Pechin, being called upon, made the remarks reported below.— R. W. R. Widely as Joseph Herbert Bramwell was known, I. think I knew him somewhat better than any one else. After finishing his studies abroad, he came to this country, a very young man, seeking an engagement. This was about the beginning of 1871, as I remem ber, and I was then trying to make iron at Dunbar, at the foot of the Allegheny mountains, in Fayette county, Pa. His engaging manner and charming personnel, combined with his letters of intro duction, made me more than satisfied in securing his services as my chemist. At the outset we lived a sort of pioneer life, and for many months he was practically a member of my family, and the affection then formed remained unbroken to his dying day. I vividly recall the circular of April, 1871, signed by Eckley B. Coxe, R. P. Rothwell and Martin Coryell suggesting a meeting at Wilkes-Barre, Pa., for the purpose of forming the American Institute of Mining Engineers. At the last moment, prevented from going, I sent Bramwell; and I am more than glad that his name appears among those whose sagacity established an Institute that has become illustrious by reason of its numbers, the character of its members, its invaluable papers and its enormous influence for good

Jan 1, 1895

By E. W. Lithgow, E. G. Williams, R. R. Holbrook, B. R. Wilson

The mineralogy and geochemistry of Pennsylvanian shales and underclays were studied to determine their suitability for lightweight aggregate and refractory ladle brick. Eighty percent of the variation in bloating of shales and clays was explained by the variation of Si02, A1203, and fluxes (Fe203, MgO, CaO, Na20, and K20); 60% by variation in quartz, kaolinite, illite, and chlorite. The best bloating was exhibited by marine shales, whereas freshwater shales and underclays experienced little or no expansion. Regional paleogeographic maps o f Pottsville and Allegheny shales permit bloating to be geographically predicted. It was found that clays meeting the specifications for refractory ladle bricks were obtained from underclays having over 34.5% mica, over 40% kaolinite and less than 15% quartz. Underclays of this composition are confined to the lower Allegheney outcropping along the near-margins of the coal basin. The best clay is that underlying the Lower Kittanning coal. Porosity of the first fired brick was found to be inversely correlated with reheat expansion.

Jan 1, 1975

By R. J. Wysor

J. S. UNGER, Pittsburgh, Pa.-On page 22 reference is made to 36 carloads .of dust shipped. Did the material in that last sample come from a; furnace running on pig iron, ferro alloys, or spiegel? R. J. Wysor.-Pig iron; we have not made any ferro alloys; or spiegel at Bethlehem in the last 3 years. J. S. UNGER.-DO you use domestic or foreign ores? R. J. WYSOR.-In regular practice, largely foreign ores. J. S. UNGER.-How much per unit does it cost to produce that? R. J. WYSOR.-You might say it does not cost anything; we do not change our blast-furnace practice at all to obtain the dust. Although it has been a profitable byproduct, I would rather not have it unless we could reclaim it on a large scale, as we would have better working stoves. J. S. UNGER.-Does the trade take it as readily as natural salts? W. J. WYSOR.-The fertilizer dealers have been anxious to get it. This did not happen, however, until the war started. J. S., UNGER.-They have been willing to take anything since the war started. R. J. WYSOR.-Yes. However, we could have sold the material before the war; in fact, about 4 years ago, we had a contract ready to sign, but we did not think it would pay us to bother with it then. W. H. Ross, Washington, D. C.-We of the Fertilizer Division of the Bureau of Soils have been particularly interested in Mr. Wysor's investigations on the possibilities of recovering potash from the blast furnace, and we look upon the results he obtained as among the-most important that have yet appeared on the subject of finding new sources of .American potash. About 5 years ago we undertook a corresponding investigation on the recovery of potash in the cement industry. Representative samples of raw mix and ground clinker were collected from the different cement plants in this country with a view to analyzing each sample for potash. With the data thus obtained and knowing the ratio between the raw mix and the cement produced and the output of the latter, we thought it possible to calculate approximately for each plant the quantity of potash that escapes daily from the kilns. After partly completing the work, however, it had to be abandoned for a time. It was again taken

Jan 4, 1917

By Jay R. Burns

TWO magnesium sand-casting alloys are commonly favored in the United States. These are referred to as H and C alloys (Dow Chemical Co.) or 4Mz65 and AM260 alloys (American Magnesium Corporation). Both are of an aluminum-zinc-manganese type. H alloy contains 6 per cent aluminum and 3 per cent zinc and is characterized by relatively good toughness. C alloy contains 9 per cent aluminum and 2 per cent zinc and is employed where high yield strength and pressure tightness are required. Examination of magnesium castings poured in Europe and England,'J however, demonstrates that H and C alloys are replaced by .%8 and AZ~I, respectively. That is, A8 reprcsents a magnesiurn alloy having superior toughness while A291 is suitable for high yield strength and pressure-tight applications. The basic difference between the .Ameri-can and European alloys is that the foreign alloys employ a somewhat higher aluminum content and less zinc than is found in H and C alloys. The mechanical properties of the alloys, when divided into high and low-aluminum groups, are quite similar, as determined from separately cast foundry-control type test bars ,In this paper the decrease of mechanical properties caused by any given amount of microporosity is measured for H, C, A8, and AZ~I alloys. The relative susceptibility of each of the four alloys to microporosity is also determined. Typical mechanical properties and nominal chemical analyses are reported in Table I. The apparent similarities between the two alloys in each group have led to considerable discussion as to the relative merits of each of the compositions.2 Popular points for comparison between the alloys have been the relative susceptibility of each of the four alloys to microporosity6 and the effect of this microporosity on their mechanical properties. It is primarily intended, in this paper, to show the

Jan 1, 1946

By Jay R. Burns

TWO magnesium sand-casting alloys are commonly favored in the United States. These are referred to as H and C alloys (Dow Chemical Co.) or 4Mz65 and AM260 alloys (American Magnesium Corporation). Both are of an aluminum-zinc-manganese type. H alloy contains 6 per cent aluminum and 3 per cent zinc and is characterized by relatively good toughness. C alloy contains 9 per cent aluminum and 2 per cent zinc and is employed where high yield strength and pressure tightness are required. Examination of magnesium castings poured in Europe and England,'J however, demonstrates that H and C alloys are replaced by .%8 and AZ~I, respectively. That is, A8 reprcsents a magnesiurn alloy having superior toughness while A291 is suitable for high yield strength and pressure-tight applications. The basic difference between the .Ameri-can and European alloys is that the foreign alloys employ a somewhat higher aluminum content and less zinc than is found in H and C alloys. The mechanical properties of the alloys, when divided into high and low-aluminum groups, are quite similar, as determined from separately cast foundry-control type test bars ,In this paper the decrease of mechanical properties caused by any given amount of microporosity is measured for H, C, A8, and AZ~I alloys. The relative susceptibility of each of the four alloys to microporosity is also determined. Typical mechanical properties and nominal chemical analyses are reported in Table I. The apparent similarities between the two alloys in each group have led to considerable discussion as to the relative merits of each of the compositions.2 Popular points for comparison between the alloys have been the relative susceptibility of each of the four alloys to microporosity6 and the effect of this microporosity on their mechanical properties. It is primarily intended, in this paper, to show the

Jan 1, 1946

By AIME AIME

THE Seventh International Petroleum Exposition and Congress to be held in Tulsa, Okla., Oct. 4 to 11, inclusive, in true western spirit promises to be bigger and better than ever. The Exposition has become an established institution. It gives opportunity to petroleum engineers, technologists, and operators to see each year at one place what the tool makers and machinery manufacturers have to offer which is new or better. It has truly become a place "where men, methods and machinery meet." It is also a convenient focus for technical meetings of various kinds devoted to petroleum and natural gas problems. 'The Petroleum Division of the A. I. M. E. has for several years held its chief fall meeting at Tulsa just preceding the opening of the Es- position. This year our meeting will be on Oct. 2 and 3 and it will be held as usual at Hotel Mayo. The Mid- Continent Oil and Gas Association will, as usual, hold a meeting during the Exposition and this year the Petroleum Division of the A. S. M. E. will hold a three- day session, Oct. 6-8, in the auditorium on the Esposition grounds. In all, six technical sessions are planned by this Society, and aside from reports of committees some 20 technical papers are to be presented. Members of the Institute should attend its own meeting and stay over for as many days as possible for the other meeting at which they will hear and see much of helpful interest.

Jan 1, 1930

By H. N. Wolcott

AMONG the many cases of replacement of one mineral by another, that of quartz or silicates by pyrite, or even other sulphides, is not uncommon, but the reverse of this process does not appear to have been recorded, even if it has been observed. It, therefore, seemed to the writer that the case described below was worthy of record. FIG. I.-GROUND MASS OF CHALCOPYRITE (C) CONTAINING ROUNDED GRAINS OF PYRITE (P) SHOWING DIFFERENT DEGREES OF REPLACEMENT BY QUARTZ (Q), AND ALSO QUARTZ VEINLETS CUTTING THROUGH THE PYRITE. (PHOTOGRAPHED BY REFLECTED LIGHT.) The specimens described in this paper were obtained by R. B. Morton of Idaho Springs, Colo., from the Old Town Mine, in Russell Gulch, and are in the collection of Cornell University, where the writer studied them. In the rough, the specimens appeared to consist largely of chalcopy- rite, with some grains of tetrahedrite. The polished surface of some of

Jan 6, 1917

By T. W. Beck

Roof bolter occupations in underground coal mines continue to experience overexposure to respirable dust. One potential source of dust in roof bolting operations is the exhaust from the roof bolter dust collection system. A wet exhaust conditioner (water box) has been developed to reduce dust emissions from the exhaust of the vacuum dust collection system on roof bolting machines. The exhaust conditioner consists of a muffler chamber and a water chamber with four internal partitions to direct airflow over the surface of the water. The National Institute for Occupational Safety and Health conducted a series of laboratory tests to assess the respirable dust capture ability of this device as compared to the standard exhaust muffler. To determine the dust collection efficiency, both devices were placed in the exhaust stream of a simulated roof bolter dust collection system. Gravimetric samplers were operated upstream and downstream of the exhaust conditioner and muffler to evaluate the ability to capture both respirable coal and limestone dust. Researchers observed a 41 % reduction in dust concentrations for the water exhaust conditioner in the laboratory configuration. Significant levels of dust deposition in the sampling chambers may have contributed to this effective capture rate.

Jan 1, 2012

By Dale E. Walker

The Captain mine came into being under the following circumstances: 1) Commonwealth Edison had need for fuel for the generation of electricity in their Chicago service area. 2) Southwestern Illinois Coal Corp. had an ample supply of coal in the Illinois No. 6 and No. 5 seams. 3) The Gulf, Mobile & Ohio R.R. had a one-line transportation system with the capability of transporting coal from the Captain mine to Commonwealth Edison. These fortuitous conditions permitted an effective three-way partner- ship to develop. Commonwealth Edison had built a new generating station at Joliet, Ill., across the Illinois River from the existing station, to supplement their power-generating capacity for the Chicago area (Fig. 1). The annual requirement of the Joliet station is approximately 4.5 million tons of coal. From large reserves of coal in the No. 6 and No. 5 seams, Southwestern Illinois Coal Corp. contracted to supply Commonwealth Edison with approximately 6 million tons annually from its Captain mine. The logical carrier was Gulf, Mobile & Ohio, whose mainline travels through this coal field and also passes by the Joliet station on its way to Chicago. This railroad has been moving Southwestern's coal from the Streamline mine for more than 30 years. The basic ingredients of timing, scheduling, moving, and handling were adopted by the three parties, the precise details being worked out jointly. To do this, each group had to know its requirements exactly. The initial schedule was drawn up and tentatively approved, with each party taking a hard look at its own requirements and commitments to make certain that the schedule could be met on a normal daily basis. With only minor changes, the final schedule was adopted, each participant feeling that it had a sufficient factor of safety to maintain steady operation. Each party agreed to help the other in time of emergency. When a delay occurs in any part of the operation, the other

Jan 1, 1969

By T. L. Joseph, G. Bitsianes

THE layered structure of partially reduced iron ore was described in a previous paper.' Reduction by hydrogen was found to take place at well-defined interfaces between layers of the solid phases. In the present investigation, a detailed study was made of the wiistite phase that had formed during the partial reduction of a cylindrical compact of chemically pure hematite. An unusually wide band of wiistite permitted a rather detailed study of this phase. The specimen was made from Baker's C.P. hematite in the form of a cylinder 1.5 cm in diameter and 1.8 cm long. A dense ore structure with about 6 pct porosity was attained by heating the specimen in air at 1100°C for 3 hr. To confine reduction to the top surface, a ceramic coating was applied to the bottom and sides of the cylindrical compact. The specimen was then partially reduced in hydrogen at 850°C and subjected to a coordinated sequence of macro-, micro-, and X-ray examinations. A section of the partially reduced cylinder is shown in the macrograph, Fig. 1. Four layers consisting of metallic iron, wustite, magnetite, and unreduced hematite are clearly shown. The effort to force reduction to proceed downward in topochemi-cal fashion was only partly successful, as some reduction occurred along one side and bottom of the cylinder. A rather wide layer of dark wustite phase had formed, however, and permitted sampling for X-ray studies as indicated. To supplement previous work and to study the wustite layer in more detail, ten separate layers were removed for X-ray examination. Broad and diffuse patterns were obtained with the as-filed powders, especially with those of iron and wiistite, and the condition indicated a cold-working and variable composition effect within the respective layers. This condition was corrected by annealing the entire series of powders at an appropriate temperature. For the annealing treatment, the ten powder samples were wrapped in silver foil, sealed under vacuum in small quartz tubes, and heated at 750°C for 16 hr. The specimens were then drastically quenched in cold water to preserve the annealed condition. These annealed specimens were X-rayed in turn and the compiled patterns are shown in Fig. 2. The standard patterns for iron and its oxides have been interjected at appropriate positions for purposes of comparison and phase identification. All of the patterns obtained were clearcut and concise so that positive identifications could be made for all of the phases. The outermost layers A, B, and C were composed almost entirely of iron with a small amount of wiistite being detectable at the X-ray limit of phase detection. Layer D from the iron-wustite interface showed both of these phases. The next four layers E, F, G, and H were all in the dark phase band which had been tentatively identified as wustite by the macroexamination, Fig. 1. The diffraction data with their single-phase patterns of wiistite for these layers checked the visual evidence. Continuing the X-ray analyses after layer H, the macrograph (Fig. 1) shows that layer I came largely from the magnetite zone but included some fringes of the wiistite-magnetite interface. The diffraction pattern for the sample confirmed this observation. Layer J came from the unreduced core of the specimen and its diffraction pattern indicated a preponderance of hematite phase. The reduction behavior of synthetic compacts has thus been found to be similar to natural dense iron ore. The previous results were supplemented with measurements of the diffraction films and calculations of the respective unit parameters. These X-ray data are summarized in Table I and offer some interesting correlations as to the compositions of the various phases undergoing reduction. The iron layers that were analyzed gave lattice parameters close to that of pure iron at 2.8664A. Evidently this iron was present in layers A through D as a pure phase with little or no oxygen dissolved in its lattice. With the wiistite layers an entirely different situation prevailed in that there was a definite and

Jan 1, 1955

Discussion of the paper of M. E. Lormbardi,. presented at the New York meeting, February, 1915, and printed in Bulletin No. 9S, February, 1915, pp. 209 to 215. I. N. KNAPP, Ardmore, Pa.-Some years ago I made a swinging spider to carry a string of casing in a way somewhat similar to that described in this paper. The ground I tried it in was too soft for its successful operation. The spider had a central one-flange bushing to carry the slips. Under this flange and on top of the spider was a properly protected ball runway, or ball bearing, which permitted rotating the casing when it was in place and supported by the slips.

Jan 5, 1915

By Walter Miller

ALTHOUGH confident of its ability to meet any demands which may be made, the petroleum refining industry is not complacent about the situation and realizes that the quantities of petroleum products to be furnished are so enormous and so far beyond what was previously estimated that the full co-operative effort of the industry must be exerted. Establishment by the President in May of the Office of Petroleum Coordinator for Defense with Secretary of the Interior Ickes at its head, plus the formation of the Petroleum Industry Council for Defense, in November, provide the channels for united endeavor within the industry and the means for gearing that endeavor within the industry and the means for gearing that endeavor in full harmony with the nation?s needs. Great strides have been made and a rapid understanding of the situation and the magnitude of the task is being attained by all concerned.

Jan 1, 1942

By Blake M. Loring

Recently the S-curves for 30 to 40 alloy steels have been pub1ished.l.2 These steels show individual characteristics, which make each additional S-curve of great interest. There are important differences in the mechanism of the transformation process, the type of transformation product, and the influence of alloying elements. Steels of the same general alloy composition may possess such variable characteristics with regard to the length of time of isothermal transformation that an S-curve for each heat of steel may be desirable. In the present work the isothermal transformation of a steel having the following composition and grain size was studied: 0.29 per cent carbon; 0.21 manganese; 0.026 phosphorus; 0.017 sulphur; 0.056 silicon; 1.45 chromium; 3.25 nickel; austenite grain size, 7. The progress of the isothermal transformation was followed by several different methods, including hardness measurements, dilatometer observations, and examinations of the microstructure. It was not expected that these methods would be in precise agreement.3 Accordingly, the changes in microstructure and hardness were given additional weight in determining the initial stage of transformation and the dilatometer measurements were relied on in estimating the completion of the process. The beginning of transformation was indicated by I per cent of transformation products and the end of transformation by about 99 per cent. The reproducibility of the various methods in the ranges of highest sensitivity was checked by several observations at each time and temperature. The steel used in this investigation was annealed for 24 hr, at 925°C. Macroetching revealed no serious segregation. The specimens for the metallographic and hardness investigations were 1¼ by ½ by ? in. Wires attached to the samples were used for handling. instead of tongs, to avoid chilling. The specimens were heated at 845°C. for ½ hr. and quenched into constant-temperature salt baths held at various temperatures from 205' to 650°C. The time required to transfer the specimens was found to be about 1½ sec., and nearly 5 sec. more was required for them to come to the temperature of the bath. After various lengths of time in the constant-temperature baths the specimens were quenched in water at 2I°C. The specimens were cut in half for the metallographic examination, to provide a surface free from decarburization. To determine the beginning and end of the transformation the percentage of transformation determined metallographically and by hardness was plotted against time. A planimeter was used in the metallographic determination. The hardness and metallographic determinations made at room temperature were confirmed reasonably well by dilatometer measurements taken during the process of transformation at the various temperatures. Two dilatometers were used to

Jan 1, 1942

By Blake M. Loring

Recently the S-curves for 30 to 40 alloy steels have been pub1ished.l.2 These steels show individual characteristics, which make each additional S-curve of great interest. There are important differences in the mechanism of the transformation process, the type of transformation product, and the influence of alloying elements. Steels of the same general alloy composition may possess such variable characteristics with regard to the length of time of isothermal transformation that an S-curve for each heat of steel may be desirable. In the present work the isothermal transformation of a steel having the following composition and grain size was studied: 0.29 per cent carbon; 0.21 manganese; 0.026 phosphorus; 0.017 sulphur; 0.056 silicon; 1.45 chromium; 3.25 nickel; austenite grain size, 7. The progress of the isothermal transformation was followed by several different methods, including hardness measurements, dilatometer observations, and examinations of the microstructure. It was not expected that these methods would be in precise agreement.3 Accordingly, the changes in microstructure and hardness were given additional weight in determining the initial stage of transformation and the dilatometer measurements were relied on in estimating the completion of the process. The beginning of transformation was indicated by I per cent of transformation products and the end of transformation by about 99 per cent. The reproducibility of the various methods in the ranges of highest sensitivity was checked by several observations at each time and temperature. The steel used in this investigation was annealed for 24 hr, at 925°C. Macroetching revealed no serious segregation. The specimens for the metallographic and hardness investigations were 1¼ by ½ by ? in. Wires attached to the samples were used for handling. instead of tongs, to avoid chilling. The specimens were heated at 845°C. for ½ hr. and quenched into constant-temperature salt baths held at various temperatures from 205' to 650°C. The time required to transfer the specimens was found to be about 1½ sec., and nearly 5 sec. more was required for them to come to the temperature of the bath. After various lengths of time in the constant-temperature baths the specimens were quenched in water at 2I°C. The specimens were cut in half for the metallographic examination, to provide a surface free from decarburization. To determine the beginning and end of the transformation the percentage of transformation determined metallographically and by hardness was plotted against time. A planimeter was used in the metallographic determination. The hardness and metallographic determinations made at room temperature were confirmed reasonably well by dilatometer measurements taken during the process of transformation at the various temperatures. Two dilatometers were used to

Jan 1, 1942

By Günter Petzow, Siegfried Steeb

DURING an investigation of the U-Co-A1, U-Ir-A1, and U-Ni-A1 ternary systems, three previously unknown phases have been identified which correspond to the phases UCoA1, UIrA1, and UNiA1, and which be- long to the C22 (Fe2P) type (P 6 2m). In the following the structure determination of the new ternary phases is reported. The alloys have been prepared in an arc furnace under purified argon from 99.97 wt pct U, 99.83 wt pct Co, 99.99 wt pct Al, 99.95 wt pct Ni, and 99.97 wt pct Ir. The pellets obtained were bright and brittle; chemical analyses agreed with the nominal compositions. To obtain equilibrium, the samples were annealed in evacuated quartz capsules at 950°C for 30 hr and then quenched in water. Guinier photographs were processed and evaluated according to a method already described previously.1,2 The hkl's, measured and calculated sin2 6 values, and in the case of UCoAl only calculated and estimated intensities, are given in Tables I to 111. Lattice parameters refined according to the least-squares method and the respective mean-square variations are presented in Table IV. Lattice parameters, especially the c/a ratio, lead to the assumption that the three phases are crystallizing in the C22-type structure. For the calculation of the intensities given in Table I, the atomic positions recently reported by wyckoff3 have been accepted for the C22 (Fe2P) type. The uranium atoms were assumed to be in phosphorus sites; furthermore the scattering amplitudes of the boron atoms have been averaged in the stoichiometric formula UB2 according to atomic percentages; i.e., for these atoms a statistical distribution on the iron sites was assumed. The two smallest distances between a uranium and

Jan 1, 1967

By W. L. Zeigler

DURING the middle 1880s, shortly after the discovery of silver-lead ores in the Coeur d'Alene district of northern Idaho, it became apparent that concentration of the ores would be necessary to obtain a profitable product. Too much siliceous material was present for direct smelting, and the majority of the ores found at depth were too low in metallic content for economic smelting processes at the time. As the ores occurred in quartzite shear zones with siderite and quartz gangue, a large quantity of waste material was present in all the mines. As the galena was not finely disseminated, this made possible relatively good extraction of the argentiferous galena by coarse concentration. The first concentrators consisted mainly of coarse crushing, screening and jigging, principally by Harz jigs, the slimes being treated on buddies. Later Wilfley tables took the place of sand jigs and vanners superseded the buddies. Because of the marketing conditions, no attempt was made until 1900 to effect a recovery on the zinc minerals present, which were found associated in varying amounts with the galena. All through this period, the greater part of the production was obtained from mines containing ore assaying high in lead and low in zinc. Parts of some ore bodies would be reversed in this respect, so that ores high in zinc were left intact. During the decade after 1910, several important mines, The Success and The Interstate Callahan, containing ores high in zinc, were put into operation and were a material aid in the needed zinc production during World War I. Gravity concentration by jigs and tables was used during this period, with bulk flotation increasing in popularity for the treatment of the fine material that had already been treated by ordinary slime concentrating machinery. No extra fine grinding for flotation concentration was thought profitable at the time. TAILINGS DISCHARGED INTO STREAMS From the start of mining and milling operations in this district until 1904, no attempt was made by the various mills in the upper district to impound or stack their tailings. They discharged them directly into the adjacent creeks or streams, to be carried away by high water. The Bunker Hill and Sullivan and the Last Chance mines, both in the relatively flat valley of the district, stacked huge piles of the coarse jig tailings on the near-by river bottom. Rain and snowfall are heavy in the Coeur d'Alene district, as it is on the heavily timbered Pacific slope of the Bitter Root Mountains. A heavy runoff occurs every spring and there is an occasional flood of disastrous proportions when warm "Chinook" winds accompanied by rain

Jan 1, 1947

By L. A. Bromley, A. W. Petersen

The van Arkel-deBoer method for producing ductile titanium by thermal decomposition of Til, vapor and deposition on an electrically heated filament is modified by film boiling Til liquid on a heated filament, resulting in similar titanium deposition on the filament and liberation of gaseous iodine. The deposition rate is higher and the energy requirement smaller than in the van Arkel process. Many problems must be solved before the process is commercially feasible. TITANIUM of 99.9 pct purity, called ductile titanium, has been produced by a modification of the van Arkel-deBoer&apos; method. In the van Arkel-deBoer method, an electrically heated wire is suspended from two electrodes, which are placed in a container holding TiI, vapor at a low&apos; vapor pressure (usually <5 mm Hg). The vapor diffuses to the hot wire, usually maintained at 1100" to 1600°C,&apos; and decomposes according to the reaction liberating gaseous atomic iodine and depositing solid crystalline titanium on the wire. Estimations based on the data of Runnalls and Pidgeon,&apos; indicate that the rate-control ling step is the diffusion of atomic iodine away from the wire. There appears to be nearly thermodynamic equilibrium at the wire with TiI, and iodine as the main gaseous species. TiI, is almost certainly an important gaseous species in the cooler regions.&apos; The liberated iodine diffuses to a heated source of crude titanium and reacts to form more TiI, vapor, which again diffuses to the hot wire and completes the cyclic process. The foregoing process may be modified by suspending the hot wire in liquid TiI,, instead of the vapor, and obtaining film boiling. This type of boiling is characterized by the formation of a continuous film of vapor over the wire surface. Since only vapor contacts the wire sul.face, the temperature of this surface may be raised as high as desirable, within the limit of mechanical strength requirements for the wire. By properly adjusting the input voltage. the temperature of the wire may be maintained above U0C"C; and by evacuating the vessel holding the liquid TiI, and maintaining a suitable condenser temperature, the vapor pressure of TiI, may be held low. Thus, the conditions of operation of the van Arkel-deBoer method may be approximated with film boiling; and hence, it is postulated that ductile titanium may be produced by this method. Preparation of Til, There are many methods available for the preparation of TiI,; that used in this research was prepared by the direct reaction of titanium sponge in controlled amounts with liquid iodine. Although no difficulty was encountered with this reaction, it has since been pointed out that this method is sometimes dangerous and should be used with caution. The resulting TiI, was purified by distillation. First Film Boiling Experiments Apparatus: The apparatus shown in Fig. 1 was used for film boiling TiI, on short wire filaments. The current to the filament was supplied through a bank of three 5 kva transformers connected in parallel. The current was controlled by adjusting the voltage over a 0 to 67.5 v range with a 7 kva variable transformer on the low voltage side of the bank of transformers. The current and voltage were measured by Weston meters. The sealed-in-glass tungsten electrodes were hard-soldered to the filament for the film boiling of TiI,. The bottom part of the reactor, containing TiI,, was wrapped with ni-chrome heating wires to maintain the TiI, in the liquid state. An ice or liquid nitrogen trap, for solidifying I, vapor and any TiI, not condensed, was attached to the low pressure side of the air-cooled condenser. A Megavac vacuum pump was used. Procedure: A 0.010 in. diam tungsten filament was hard-soldered to the tungsten electrodes. TiI, was melted (mp 156°C) and poured into the reactor chamber; the top of the reactor chamber, containing the electrodes, was replaced. Freezing of the TiI, was prevented by controlling the current to the ni-chrome wires wrapped around the reactor with a 1 kva variable transformer. The mechanical vacuum pump was started and the system evacuated to about 2 mm Hg TiI, vapor pressure. The current to the filament was turned on and the impressed voltage slowly increased with the variable transformer. A sudden drop in current at nearly constant im-

Jan 1, 1957

By Strathmore R. B. Cooke

On the basis of experiments con- ducted on quartz using a bubble pick-up method, it was shown in an earlier paper1 that this mineral will preferentially adsorb hydrogen, calcium, or sodium ions, depending on the relative concentrations of those ions in the solution in which the quartz is immersed. For quartz particles ranging in size from 0.2 to 1 mm, it was demonstrated that the concentration of calcium in solution (assumed present as ions) necessary to completely activate quartz for flotation is given by the expression: In this expression, ionic concentrations are in mols per liter. It was further shown that the pick-up method is apparently more sensitive to changes in reagent concentration than the standard captive-bubble method, and that induction times are apparently much reduced. Since completing these earlier tests, a new type of cell has been constructed; this is shown in Fig 1 and 2. In Fig 1, A is a ground joint, B is a ceutral tube reaching to within a few millimeters of the bottom of the cell, and C is a stopper which may be removed for re- agent addition, and serves the further purpose of excluding carbon dioxide from the air during the test. The entire cell is constructed of Pyrex glass, and does not give the trouble experienced with the earlier cell, in which activating ions were released from the glass at high pH values. The only critical factor in the construction of the cell is the clearance between the central tube and

Jan 1, 1949

By F. M. d’Heurle

Films of molybdenum have been prepared by sputtering onto oxidized silicon substrates. The resistivity. lattice parameter, orientation, and grain size were studied as a function of substrate temperature and substrate bias. Under normal sputtering conditions, the resistivity of the films was found to be quite high (600 x 10 ohm-crn). However, with the use of the negative substrate bias of 100 v and a substrate temperature of 350°C, films weve produced with a resistivity of ahout twice that of bulk molybdenum. The lattice parameters measured in a direction nornzal to the surface of the films weve found to be gveatev than the bulk value. This was interpreted as being at least partly due to the presence of compressive stresses. The effects of annealing in an Ar-H atmosphere were studied in terms of diffraction line width, lattice parameter, and resistivity. BECAUSE of its relatively low bulk resistivity (5.6 x 106 ohm-cm)&apos; molybdenum is potentially interesting as a thin-film conductor in integrated circuits. An additional feature which makes it attractive for this purpose is its low coefficient of expansion (5.6 x KT6 per "c),&apos; which is fairly well matched to that of silicon (3.2 x 10 per c). It is possible to deposit molybdenum films by evaporation but generally films produced in this manner have a high resistivity. In order to achieve resistivities close to bulk value, Holmwood and Glang found it necessary to operate in a vacuum of about 107 Torr and to maintain the substrates at 600 C during film deposition. Sputtered molybdenum films have been examined by Belser et a1.7 and, recently, by Glang et al.&apos; This paper describes the results of an attempt to extend some of that work and examine the effects of annealing and getter sputtering on the physical and structural properties of the films produced. SPUTTERING APPARATUS AND PROCEDURE The apparatus used for most of the film sputtering work described here consisted of two "fingers" serving as anode and cathode, respectively, which were mounted within an 18-in.-diam glass chamber. A liquid nitrogen-trapped 6-in. diffusion-pump system was used to achieve a vacuum of about 1 x 107 Torr within the chamber prior to sputtering. The essential features of the equipment are shown in Fig. 1. Cathode and anode fingers are stainless-steel tubes isolated from the top and bottom plates by Teflon collars. In order to limit the discharge to the space between anode and cathode, each finger is surrounded by an aluminum hield, at ground potential, having an internal diameter 18 in. larger than the outside diameter of the finger. The cathode and anode fingers are 6 and 4 in. in diam, respectively. A 116-in.-thick sheet of molybdenum is brazed with a 10 pct Pd, 58 pct Ag, 32 pct Cu alloy to a copper disc which is mounted by means of screws and a large 0 ring onto the lower end of the cathode finger. The disc is cooled during sputtering by water circulation inside the finger. The use of several feet of plastic tubing for the water input and outputg reduces leakage to ground to less than 1 ma when the cathode potential is raised to 5 kv. The upper end of the anode finger is terminated by a brazed-on copper block. A variety of specimen holders can be easily mounted on the upper face of this block. Substrate heating or cooling is achieved by use of an appropriate unit attached to the lower face of the same block. Heating is achieved by means of cartridge-type heaters and cooling by copper coils fed with forming gas under pressure. The inner chamber of the specimen finger constitutes a small vacuum chamber of its own which is evacuated by an auxiliary mechanical pump in order to limit heating element oxidation and heat transfer by convection currents. An advantage of the finger arrangement is the absence of cooling and heating coils and wires within the main chamber. The stain less-steel shutter is useful to establish a discharge for cleaning the cathode at the beginning of each sputtering run. Water cooling of the shutter reduces heating and the out-gassing of impurities which might condense on the nearby substrates. Unless otherwise specified, the substrates used in these experiments were 1-in.-diam oxidized silicon wafe:s, 0.007 in. thick, having an oxide thickness of 6000A. The substrate holders were large copper discs onto the surface of which a number of molybdenum discs, 116 in. thick and 78 in. in diam, were brazed. The wafers were clamped to the molybdenum discs

Jan 1, 1967