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By R. F. Domagala, D. J. McPherson

Iodide zirconium was combined with calculated amounts of ZrO2 or master alloys and arc-melted. Annealing treatments were carried out at 21 temperature levels. Metallographic examination of the heat treated specimens permitted construction of the binary phase diagram from zirconium to ZrO2. Oxygen additions to zirconium raise the transformation temperature as well as the melting point. Features of the diagram include the peritectic formation of beta, the formation of alpha directly from the melt, an intermediate phase ZrOB with a' range of homogeneity, and a eutectic between alpha and Zr02. PHASE relationships in the Zr-0 system were determined in the range 0 to 66. 7 atomic pct 0 (ZrO,). Arc-melted alloys were annealed at temperature levels between 600" and 2000°C. Determination of the phase boundaries was accomplished by metallographic evaluation of specimens quenched from the various temperatures. Incipient melting techniques were used to determine solidus curves, and X-ray diffraction work was employed to study the lattice parameters of the a solid solution and the phase ZrO,. Experimental Procedures Westinghouse "Grade 1" iodide zirconium crystal bar (approximately 99.8 pct pure) was employed for the investigation. This material is substantially free of the impurity inclusions characteristic of most zirconium metal. Previous work has shown it to be the most satisfactory grade for phase diagram studies. The zirconium crystal bar, as-received, was coated with corrosion product from autoclave tests by which its grade designation is determined. The bars were sand blasted lightly, pickled for 1 min in a 20 pct HN0,-5 pct HF aqueous solution, rinsed in water and acetone, and dried. The bars were rolled to about 1/32 in. strip, cut into 10 in. lengths, and pickled again. The material was sheared to approximately Y4 in. squares, cleaned with acetone, and stored for use. Two pounds of specially prepared "chemically pure," and 100 grams of spectrographic grade ZrO, were obtained for the preparation of alloys. The "Specpure" ZrO, was obtained from Johnson, Mat-they Co.. Ltd.. and Titanium Alloy Manufacturing Div. of National Lead Co. supplied the other grade of oxide. The "chemically pure" material (henceforth referred to as C.P. ZrO,) was used for the preparation of all alloys employed in the determination of phase relationships. A limited number of alloys were prepared with the "Specpure" oxide to recheck certain phase boundaries. Analyses of the two grades of oxide are given in Table I. The C.P. ZrOI was received in powder form, not suitable for arc melting. Therefore, this material was compressed to wafers 1 in. in diameter and about Vn in. thick. These were segmented and stored for use. The "Specpure" material, in the form of small granules, was suitable for use in the as-received condition. A nonconsumable electrode arc-melting furnace was used to prepare alloys. A water-cooled copper crucible and tungsten-tipped electrode were employed. The material was placed in the crucible and rapidly melted under a protective atmosphere of helium gas by striking the arc on a tungsten stud and directing it upon the charge material. Details of operation, including drawings of this type furnace, have been published.'

Jan 1, 1955

By M. J. Salkind

In discussing the possible contribution of plastic deformation to neck growth during sintering, Wilson and Shewmon State that Lenel, Ansell, Salkind, and Early34, 35 concluded that dislocation flow is the rate-controlling process in sintering under zero external load. The experiments cited34, 35 were done with applied external loads, and the conclusions were that the same kinetics could be controlling sintering due to the force of gravity with no additional applied load. The effect of gravity on sintering behavior was previously cited.34, 31 In addition, Wilson and Shewmon argue that the conclusions of Refs. 34 and 35 are doubtful because the strain rate is proportional to stress for plastic flow. This assumption is true only for certain kinds of plastic flow such as Nabarro-Herring Microcree38 As Early, Lenel, and Ansell point out3' plastic flow, based upon dislocation movement, can exhibit strain rates which exhibit a power law relationship to the applied stress.39, 40 Wilson and Shewmon also doubt the results of Refs. 34 and 35 because the stresses in the necks are too small for x/a > 0.1. This is true, and the experiments described in Refs. 34 and 35 were done for small values of %/a. The conclusion was that plastic flow by dislocation movement was important during the early stages of sintering when x/a is small.

Jan 1, 1968

By T. L. Joseph

It is a distinct privilege to participate in this meeting convened to honor the memory of Henry Marion Howe, a distinguished scientist and metallurgist. Many have added to our rapidly growing fund of metallurgical knowledge but few have made the unique contribution of formulating basic concepts essential to an over-all comprehensive view of the subject of metallography. Of those previously selected to deliver this lecture, several have added a personal touch to their discourse because they were able to refer to their associations with Dr. Howe. It was not my good fortune to know him or to enjoy his inspiring influence. Like most of you, my contact has been with his published works, which are outstanding in that they provide lucid, detailed expositions of the nature and behavior of metals and alloys. His deep understanding and clarity of expression have greatly accelerated our progress in metallography and in the use of metals. The degree to which a man's thinking, experimentation and writing contribute toward an understanding of basic laws and phenomena determines whether his life's work is of transitory or permanent value. This occasion appropriately recognizes the fundamental importance of Dr. Howe's pioneer work in the field of metallurgy.. On two former occasions, gray iron was selected as a subject for discussion. The fact that the production of pig iron has not been discussed before does not reflect any lack of interest on the part of Dr. Howe or former lecturers in the process that underlies the production of steel. Although Dr. Howe's work in his later years centered around metallography, his earlier publications show a considerable interest in the production of iron and steel. He recognized that in the ascending spiral of metallurgical advancement we are not winding a single thread but are weaving a complex fabric. Specific evidence of his interest in the production of pig iron may be found in his book' on The Metallography of Cast Iron and Steel. In explaining why blast furnaces have been in constant use for about 600 years, he says: "The process is economical because it utilizes with extraordinary completeness the calorific power of the coke due to the thorough transfer of heat from the gaseous products of combustion to the charge." This emphasis on heat transfer, overlooked in many more extended and more recent discussions of the blast-furnace process, illustrates Professor Howe's ability to see the essentials. Other distinct advantages of the blast furnace, such as the removal of- much of the sulphur and practically all of the oxygen, were mentioned. It was also stated that although the blastfurnace process is complex in nature, its outward form is comparatively simple, thus permitting large-scale production at small labor costs. All who contemplate the production of metallic iron from its ores by any other process might well consider the

Jan 1, 1947

By T. L. Joseph

It is a distinct privilege to participate in this meeting convened to honor the memory of Henry Marion Howe, a distinguished scientist and metallurgist. Many have added to our rapidly growing fund of metallurgical knowledge but few have made the unique contribution of formulating basic concepts essential to an over-all comprehensive view of the subject of metallography. Of those previously selected to deliver this lecture, several have added a personal touch to their discourse because they were able to refer to their associations with Dr. Howe. It was not my good fortune to know him or to enjoy his inspiring influence. Like most of you, my contact has been with his published works, which are outstanding in that they provide lucid, detailed expositions of the nature and behavior of metals and alloys. His deep understanding and clarity of expression have greatly accelerated our progress in metallography and in the use of metals. The degree to which a man's thinking, experimentation and writing contribute toward an understanding of basic laws and phenomena determines whether his life's work is of transitory or permanent value. This occasion appropriately recognizes the fundamental importance of Dr. Howe's pioneer work in the field of metallurgy.. On two former occasions, gray iron was selected as a subject for discussion. The fact that the production of pig iron has not been discussed before does not reflect any lack of interest on the part of Dr. Howe or former lecturers in the process that underlies the production of steel. Although Dr. Howe's work in his later years centered around metallography, his earlier publications show a considerable interest in the production of iron and steel. He recognized that in the ascending spiral of metallurgical advancement we are not winding a single thread but are weaving a complex fabric. Specific evidence of his interest in the production of pig iron may be found in his book' on The Metallography of Cast Iron and Steel. In explaining why blast furnaces have been in constant use for about 600 years, he says: "The process is economical because it utilizes with extraordinary completeness the calorific power of the coke due to the thorough transfer of heat from the gaseous products of combustion to the charge." This emphasis on heat transfer, overlooked in many more extended and more recent discussions of the blast-furnace process, illustrates Professor Howe's ability to see the essentials. Other distinct advantages of the blast furnace, such as the removal of- much of the sulphur and practically all of the oxygen, were mentioned. It was also stated that although the blastfurnace process is complex in nature, its outward form is comparatively simple, thus permitting large-scale production at small labor costs. All who contemplate the production of metallic iron from its ores by any other process might well consider the

Jan 1, 1947

By V 7. 0 / 300 dpi

WHEN the copper smelters were built, in Montana, all of the refractory products which were used in their construction were shipped in from Eastern factories. It was apparent that if a material suitable for the manufacture of these products could be found within the State, a saving of freight could be effected and a new industry built up. Prospecting for such materials was started and experiments were made with samples from numerous deposits. Considerable effort and funds were expended in an attempt to manufacture silica brick from Dillon quartz, a light colored sandstone that is found near Dillon, Mont., on the Oregon Shortline railroad. As a brick material the Dillon quartz was a failure, but it has proved very satisfactory as a silica cement. It is now being used in laying silica brick and for reverberatory furnace bottoms. A bed of quartzite that is particularly suited to the manufacture of high-grade silica brick -was finally discovered at Browns Spur, 6 miles west of Anaconda. The material from this deposit is now being used in the manufacture of the Anaconda silica brick, which have gained a wide reputation for heat-resisting and lasting qualities. The analysis of all average sample of this quartz is: SiO2,, 96.7; Fe203, 0.3; Al203, 2.5; CaO, 0.3 per cent. The very low percentage of fluxing ingredients makes this a most refractory material. All of the Anaconda silica brick are hand molded. Various types of brick machines have been tried, but the hand-mold process proved the best suited to the manufacture of silica brick from this material. The silica is first put through a jaw crusher and is then clumped into wet pans, where 4 per cent. of lime paste is added, to produce a bond. Without the lime the. material would not be plastic enough to mold. After a few minutes' grinding in the wet pans the material is conveyed to the molder, who forces it into the molds by hand. The brick are then dumped on pallets and placed in the drier, where they are left until dry enough to be set in the kilns. Some of the brick are re-pressed before being dried. They are burned about five days, in round down-draft kilns. It is not necessary to have as much heat in the kilns as the brick will be subjected

Jan 9, 1913

By A. E. Harnsberger

IT is obvious that details such as the physical and chemical properties and methods of heat-treating of the materials mentioned must be omitted in a paper on the subject of materials used in oil-refinery pumps1. Only sufficient identification is given to enable the reader to find additional information from already published data. Also, the subject covers many operating conditions, but only the most important services can be discussed here. To the oil refiner, the pumping equipment is of vital interest. Practically every refinery operation, from the charging of crude oil to a distillation unit to the shipping of refined products, involves some form of pumping machinery. Intermediate refining stages involve a great variety of pumping machinery to carry out successfully the aims of the refinery technologist. Temperatures at which oils are handled vary from -50° F. to 900° F. Pressure may vary from subatmospheric to 2000 lb. per sq. inch. The selection of the proper materials involves a careful consideration of the conditions under which the particular pump must operate. The four, most important considerations are temperature, pressure, corrosion, and abrasion or wear. Consideration of temperature may be divided into three parts: (1) extremely low temperatures of the order of -50° F.; (2) temperatures at atmospheric or slightly above; .(3) temperatures from 200° to 900° F. Pressures fall into two groups: (1) pressures reached by ordinary trade pumps of the order of. 200 lb. per sq. in., (2) extreme pressure conditions involving pressures as high as 2000 lb. Noncorrosive and corrosive oils can be treated differently. Under the latter falls corrosion in the presence of water, which will occur up to 250° F. The second type of corrosion occurs in high-temperature pumping equipment, with temperatures from 450° to 900° F., largely caused by sulfur compounds. There are also other corrosive conditions met with

Jan 1, 1935

Jan 1, 1962

By Edward S. Cook

For several years past, dating particularly from the days of serious "ore-dirt" complications at the Warwick furnace, I have been desirous of providing some safe, quick and easy method of relieving the tuyeres of slag, when the cinder- and iron-notches are chilled through loss of heat in the clucible or when, from dropping or jumping of stock, the molten slag is forcibly driven into the bellyand leg-pipes. Various methods were proposed, but objections of one kind or another always presented themselves, and the subject was postponed to a more convenient season. In the summer of 1887, while running on anthracite alone, 1 found the various expedients in use to be so utterly valueless, that the importance of a practicable tuyere slagging-valve impressed me more forcibly than ever. The holes left in the cast-iron jacket at one side of the bottom of the water-blocks were found to be of no value whatever. The swinging or hinged cap on the elbow of the belly-pipe, while convenient to permit the removal of lag after the belly-pipe was partially or wholly filled, could not be adapted to discharge the slag before solidifying, except at great risk to the men and loss of time just when the constant running of the engine and the keeping of blast on the furnace was of the utmost importance. By removing keys from the caps and holding them in place with props, the slag could be discharged through the tuyeres and belly-pipes, with the engine running, by knocking the props away at a given signal. This method is extremely hazardous to life and limb, and I have always hesitated to make use of it. When the furnace is in such condition as to require the adoption of some method of the kind, the stoppage of the engine, cooling the blast and the contents of the crucible, always aggravates the trouble. When the caps are blown open and the slag is discharged by removal of the props, it is necessary to stop the engine to replace them. An hour or more will elapse before this can be done, as the slag must be partly removed before the tuyeres can be approached by ordinary mortals, and the caps handled and fastened in place again. Any movement of the stock is liable to burn the workman, as he stands, securing the cap in front or at one side of the open belly-pipe.

Jan 1, 1889

By J. V. W. REYNDERS

THE principal manganese deposit of Russia, I one of the four principal sources of the world's supply, lies on the southern slope of the Caucasus Mountains, in what is now the Republic of Georgia, district of Sharopan. Tchiatouri, the principal town, is midway between Tiflis, the capital of Georgia, and Poti, the shipping port on the Black Sea, about 130 " miles distant. The deposit can be most easily visualized by thinking of a nearly horizontal coal seam about 6 ft. thick, outcropping on the slopes about 600 ft. above the Kvirila River. One of the accompanying illustrations shows the river, which nearly bi- sects the district, of approximately 50 sq. miles in area, and with its tributary streams makes the topography rugged, while in the background are the snow-capped peaks of the Caucasus range. Another of the illustrations gives a closer view of the outcrop. The roof and floor of the deposit are good, so the methods of working are quite similar to working a coal seam, especially as most of the mineral is soft enough to be mined with a pick. Little machinery is used, except small cars for underground transportation.

Jan 1, 1926

By Kenneth K. Humphreys, Joseph W. Leonard, Robert L. Llewellyn, William F. Lawrence

INTRODUCTION Cleaning fine coal sizes utilizing air currents in machines as the primary separating medium is called dry concentration or pneumatic cleaning. In 1947 approximately 18 million tons (16.38 million mt) of bituminous coal were cleaned by air machines; in 1965, 25.4 million tons (23.1 14 million mt); but in 1975, only 7 million tons (6.37 million mt). Table 11-1 shows the tonnages cleaned of bituminous coal and lignite in the United States by various types of equipment from 1938-1963. Table 11-2 shows only tonnages cleaned by pneumatic methods from 1964-1975. The decrease in tonnage to approximately 7 million tons (6.3 million mt) is due to a higher moisture content in the mined coal and the greater difficulty in cleaning the coal by air. There also was a definite trend to load raw coal at the mines, especially the slack which is the most expensive to clean due to the dewatering and drying requirements. While there have not been any applications of pneumatic cleaning in the anthracite field, its use has not been fully explored. The same is true for lignite and subbituminous coals.

Jan 1, 1979

By L. G. Austin

If S (x) is the specific rate of breakage of size x and B (x, y) (see Table 1 for Nomenclature) is the cumulative breakage distribution function, the Herbst Fuerstenau2 assumption is that Inserting this assumption into first-order grinding equations it has been shown" that there are then simple analytical solutions to the grinding equations, as shown in Table 2. In this context "plug flow" is defined as all material passing through the mill in the same length of time, the residence time t. The term "n fully-mixed" means that the mill has a residence time distribution" which can be treated as if the mill were n equal fully mixed sections in series. In addition it has been shown that the assumption of Eq. 1 also leads to simple analytical solutions for closed-circuit, steady-state grinding with an ideal classifier at the mill exit returning oversize to the mill feed. The solutions are also given in Table 2, with µ as the ideal classifier cut size, C the circulation ratio, and Q (x) the size distribution of the circuit product. The specific surface area of these size distributions is where the density-shape factor k. is assumed to be constant with size. In practice, most methods of size analysis or area [ ] measurement have a finite lower limit, so that the integration is really performed from xm, to xm, For a realistic degree of grinding the value of So is dominated by the fine sizes because of the 1/x factor. Consider batch grinding of a feed of size y to y + dy. The batch grinding solution given in Table 2 is then [ ] The fresh surface area produced is the area of the fines plus the area of the original material remaining minus the area of the original material, [ ] Little error is introduced by neglecting the last term on the right-hand side since at t = 0 it is zero, and when t is significant the first term dominates because of the fine sizes produced. In addition, the form of P (x, t) for [ ] realistic values of S (x) 2t ax° is such that the major fraction of fresh surface produced is contained within the bottom 10% of weight of broken material, that is, for sizes for which P(x, t) < 0.1 (providing y is not near x.,). Thus for surface area purposes Eq. 3 can be approximated by [ ] becomes providing again that the feed sizes are coarse relative to xmi. Then the fresh area production is and W is the mass in the mill. The rate of surface production is WK, and the specific surface is Kt. From Table 2, the specific energy is mt/W so surface production per unit energy is [ ] Surface produced per unit energy input = KW/m (8) where m is the energy input of the mill. Clearly, identical reasoning applies to open-cycle, plug-flow grinding, with t replacing t, and Eq. 8 is obtained again. Considering open-cycle, fully mixed grinding, similar reasoning gives P(x) - t S(x) for surface area purposes, and

Jan 1, 1974

By R. O. Williams

A recent article by Chernock, Singer, Mueller, and Beck 1 which supports the use of the integral of I sin $ d$ for comparing fiber texture data does not settle what happens to I sin ø as ø approaches zero, where I is the diffraction intensity for poles oriented 0 deg from the fiber axis. They indicate that they believe that it should approach some constant value (that is, I increases without bound) and the fact that in reality it does not was a result of the diffraction

Jan 1, 1960

By Cornelius F. Kelley

SEVENTY-FIVE years ago, in Wilkes-Barre, Pennsylvania, 22 men of vision banded together to initiate this great organization. Ideals and emotions mingled and united in the declaration of a twofold purpose: first, the more economic production of minerals and metals, and second, the promotion of greater safety and welfare for each man so employed-tacit recognition of the inseparability of humanitarian and utilitarian concepts of world progress. The members and honorary members then, as now, were mining engineers and associates from allied walks of life. Under the able guidance of David Thomas, our first president and outstanding ironmaster of the time, there were elected 46 members and associates, and the foundations of the Institute were laid. Conceived in a turbulent postwar era, the problems then faced had some similarity to those we face in this time of war-bashed uncertainty. With a Civil War behind them and once again dedicated to a spirit of national endeavor, they surveyed the landscape, then surged ahead toward a beckoning industrial horizon. That effort has never been relaxed. Poised upon the threshold of a new century, rancher, banker, engineer and businessman paused to contemplate and evaluate his natural endowments. Surrounded by immeasurable God-given wealth, necessity inspired

Jan 1, 1947

By E. P. Mathewson

W. W. (Pop) Adams&apos; contribution is short and to the point. "I went to Pueblo about March, 1881, and started working for the Pueblo Smelting & Refining Co. in the sampling room, going from there to the assay and chemical departments, and ending in charge of the lead refinery on the night shift. I was there about two years, returning to California in 1883. The plant was under the management of Mather and Geist, plus Charley Ballard; Herman Schlapp was the metallurgist. Herman Schlapp&apos;s name remains prominently in my recollection of Pueblo for his never-failing kindness and charity to the young men who were trying to learn the Pb. game. John Allen, Walter Koehler, George Westcott, Charley Molson, and Alfred de Ropp were there with me. Schlapp and Koehler I have never seen since I left Pueblo; the others I have met often. , Alfred de Ropp I have often met-here, as he was manager of the Selby Smelting & Lead Co. of San Francisco, for years. &apos;He tells me that I gave him the rudiments. of American profanity at Pueblo; an apt pupil, for since then, by his own efforts, he has added largely to his vocabulary..

Jan 12, 1923

By William D. Klopp

A study was conducted of the tensile and creep properties of are-melted and electron-beam-melted tungsten over the temperature range 2250° to 4140°F. The tensile and creep strengths vary with pain size, the finer -grained materials being stronger. The activation energy for transient creep at 2250° to 3500°F is 95,000 cal per (g)(mole), while that for steady creep at 3300o to 4000°F is 141,000 cal per (g)(mole). At 2875o to 3300°F the apparent activation energy for steady creep decreased with decreasing temperature. It is suggested that cross slip is rate controlling during transient creep, while dislocation climb is rate controlling during steady creep above 3300° F. ALTHOUGH considerable data have been generated on the high-temperature tensile properties of powder-metallurgy tungsten,1 relative few data have been published on the properties of are-melted2 or electron-beam melted tungsten.3 Furthermore, the available data show a fairly large amount of scatter at high temperatures. The effects of structure and purity have not yet been defined, aside from observations that high-purity electron-beam (EB)-melted tungsten3 and single-crystal-plasma-flame tungsten4 are weaker than less pure powder-metallurgy tungsten. The creep behavior of powder-metallurgy tungsten has been studied, but no data are available on the creep behavior of tungsten consolidated by melting. Green5 found that powder-metallurgy tungsten exhibited linear creep at 4082° to 5072°F with an activation energy of 160,000 cal per (g) (mole). The similarity of this activation energy to that of 153,000 cal per (g)(mole) for volume self-diffusion6 suggests that recovery of strain hardening by dislocation climb is rate controlling in this temperature range. In studies at 4800°F, Sutherland and Klopp7 concluded that grain size significantly affected the creep behavior of commercial powder-metallurgy materials. This grain-size effect was suggested by sherby,8 although the opposite relation had been reported for aluminum.&apos; The purpose of the present study was twofold: first, to provide baseline data on high-temperature tensile and creep properties of are-melted and EB-melted tungsten for concurrent tungsten alloy studies, and, second, to determine the phenomenolo-gical effects of structural and purity variables on the high - temperature mechanical properties of tungsten. EXPERIMENTAL The are-melted tungsten materials were prepared by melting sintered 1-1/4-in.-diam electrodes into 2-1/2-in.-diam by 5-in.-long ingots. The are-melting facility has been described previously.&apos; Eight ingots were melted, machined, and hot-extruded at

Jan 1, 1965

By I. R. Kramer

Studies of the effect of size of the specimen on the change of slopes of Stages I and 11 by surface removal showed that the change of Stage I was independent of size with respect to the polishing rate; however, the change in the slope of Stage 11 with polishing rate increased directly in proportion to the surface area. The removal of the surface during the test affected the plastic deformation characteristics of gold, aluminum, and zinc single crystals and polycrystalline aluminum. The apparent activation energy of aluminum was found to be decreased markedly by removing the surface during the deformation process. In previous papers1-3 it was shown that the surface played an important role in the plastic deformation of metals. By removing the surface layers of a crystal of aluminum by electrolytic polishing during tensile deformation, it was found that the slopes of Stages I, II, and III were decreased and the extents of Stages I and II were increased when the rate of metal removal was increased. By removing a sufficient amount of the surface layer after a specimen had been deformed into the Stage I region, upon reloading, the flow stress was the same as the original critical resolved shear stress and the extent of Stage I was the same as if the specimen had not been deformed previously. The slope of Stage I was decreased 50 pct and that of Stage 11 decreased 25 pct when the rate of metal removal was 50 X 10"5 ipm. These data show that in Stage I the work hardening is controlled almost entirely by the surface conditions, while in Stages 11 and III both surface conditions and internal obstacles to dislocation motion are important. It appears that during the egress of dislocations from the crystal, a fraction of them becomes stuck or trapped in the surface regions and a layer of a high dislocation concentration is formed. This layer would not only impede the motion of dislocations, but would provide a barrier against which dislocations may pile up. In this case, there will be a stress, opposite to that of the applied stress, imposed on the dislocation source and dislocations moving in the region beyond this layer. It has been found convenient to refer to this layer as a "debris" layer. The "debris" layer may be similar to the dislocation tangle observed by thin-film electron microscope techniques.4 Reported in this paper are the results of studies on the effects of removing the surface during plastic deformation on aluminum crystals of various sizes. The effects of the surface on the yield point behavior of gold and high-purity aluminum crystals as well as the creep behavior were also determined. The effects of surface removal on polycrystalline aluminum (1100-0 and 7075-T6) are also reported. EXPERIMENTAL PROCEDURE For those portions of the investigation involving creep and tensile specimens, single crystals, having a 3-in. gage length and a nominal 1/8-in. sq cross section, were prepared by a modified Bridgman technique using a multiple-cavity graphite mold. The single crystals were prepared from materials which had initial purities of 99.997, 99.999, 99.999, and 99.999 pct for Al, Cu, Zn, and Au, respectively. The aluminum specimens for the size effect studies were prepared through the use of a three-tier mold in which crystals having a cross section of 1/8, 1/4, and 1/2 in. were grown from a common seed. The mold design was arranged so that one 1/2-in. crystal, two 1/4-in. crystals, and four 1/8-in, crystals of the same orientation could be cast. With this technique, it was possible to obtain only one set of crystals with the same orientation. Because of this limitation, it was not possible to determine both the changes of extent and slope of the various stages since a large number of crystals of the same orientation would have been required. Instead, only the change of slope as a function of the rate of metal removal was studied by abruptly altering the current density of the electrolytic polishing bath at various strains within the regions of Stages I and 11. The experimental techniques used for the tensile studies were essentially the same as those used previously.1,3 The specimens were deformed in a 200-lb Instron tensile machine, usually at a rate of 10-5 sec-5. A methyl alcohol-nitric acid solution was used as the polishing bath for aluminum. The temperature was maintained constant within ±0.l°C by means of a water bath. The tensile machine was

Jan 1, 1963

By J. Murray Riddell, George A. Morrison

This paper is a companion to the one by George A. Morrison on Mining a Deep Limestone Mine in Ohio.‡ Barberton is 8 miles west of Akron, Ohio, and 23 miles south of Cleveland. The underground mining of limestone at Bar-berton constitutes the world&apos;s deepest limestone mine. The stratigraphy is as follows: 0-20 ft. Loam, clay, sand and gravel. Water bearing. 2-40 ft. Fractured sandstone. Water bearing. 40-110 ft. Sandstone with interbedded shale, slightly fractured. Water bearing. 110-314 ft. Sandstone with interbedded shale, slightly fractured. Water carrying. 314-2197 ft. Shale with occasional seams of sandstone, which varies in thickness from a few inches to 4 feet. Dry. 2197-2247 ft. Limestone. Dry. 2247-2742 ft. Dolomitic limestone. Dry. 2742-2767 ft. Salt. Dry. 2767- Dolomitic limestone. Dry. All of the strata dip to the southeast, about 0.5 per cent from the horizontal. The top 110 ft. of the crust is water-bearing. The rock strata are naturally fractured to a depth of 314 ft., sufficient to allow the passage of water. In the shaft-sinking operations, a stra- turn of oil-bearing sandstone one foot thick was encountered at a depth of 520 ft., and flows of methane gas were pierced at depths of 1350 and 1952 feet. Specifications for the mine plant called for, in part, the sinking of two vertical shafts and a hoisting plant capable of producing at the rate of 300 tons per hour. No. I shaft is 550 ft. west of No. 2 shaft. Each shaft measures 8 by 17 ft. outside of steel. General features of the design (Fig. I) are: Principal set members, 6-in. H-section; connecting angles (studdles), ? by 4 by 4-in. angle irons; spacing of sets. 8 ft. centers; spacing of bearer sets, generally, 160 ft.; bearers, of 12-in. I-beams. Each bearing set featured a concrete ring about the periphery of the shaft, steel to rock, and 8 ft. in height; permanent guides, 6 by 10-in. long-leaf yellow pine, 85 per cent heart. The Shaft-sinking Operation The preliminary shaft-sinking work consisted of driving interlocked steel piling about the exterior of the shafts to depths of 35 and 32 ft., respectively, and of such horizontal dimensions as to ultimately permit the pouring of a concrete collar 2 ft. in horizontal thickness. Following the pouring of a shaft collar, a temporary wooden headframe for shaft-sinking purposes was erected. The head-frame, while ordinary, featured: (1) a storage pocket of 300 cu. ft, capacity with truck servicing facilities, and (2) pneu matically operated dump doors, which mere actuated by the hoistman, thus caring

Jan 1, 1946

By D. O. LIVINGTON

(Presented by invitation at a meeting of the Spokane Local Section of the institute, Feb. 17, 1912.) THE Pilares de Nacozari mine is located in Sonora, 75 miles south of Douglas, Ariz. The town of Douglas is on the International Boundary and is the place at which the ores from the Bisbee mines are smelted. The Moctezuma Copper Co. owns the mines at Nacozari, and the copper-concentrates shipped to the Copper Queen smelter, at Douglas, make a good smelting-mixture with the Bisbee ores. The Moctezuma Copper Co. and the Copper Queen smelter at Douglas, as well as the railroad from Douglas to Nacozari, are owned by the Phelps Dodge Co. The ore-deposit occurs in the form of a large ellipse with a major axis of approximately 2,000 ft. and a minor axis of about 600 ft., the major axis bearing about 90 W. of N. The whole of this ellipse is more or less mineralized; the surface being principally an iron gossan with some occasional copper-stains. Below the oxidized zone, which is not more than 50 ft. deep, the minerals are pyrite and chalcopyrite, with occasional seams of chalcocite, the latter being rare. There appears to be no well-marked zone of secondary enrichment, the oxidized gossan over the greater part of the deposit changing suddenly to what is apparently the original unaltered ore. The copper-values are concentrated around the perimeter of the ellipse, and it is principally around this perimeter that the mining is done. The ore mined averages a little more than 3 per cent. of copper, with a small amount of silver, less than an ounce per ton. Some ore of considerably higher grade than this has been shipped, however, but the above average is of the mill-run. The ore is wider near the two ends of the ellipse than along the sides, and is mined in some cases to a width exceeding 200 ft. The country-rock for the first vertical 500 ft is a volcanic acid breccia, probably rhyolitic; below

Sep 1, 1912

By Dale A. Vaughan, Oliver M. Stewart, Charles M. Schwartz

A. U. Seybolt (General Electric Research Laboratory)—The authors should be commended for adding some important information to our knowledge of the solubility of interstitial elements in metals. It is becoming increasingly evident that the effect of even traces of such elements have very far-reaching effects upon the mechanical properties of the body centered cubic metals. Those who have worked in this area know that the accurate determination of the small solid solubility limits in systems of the type reported by the authors is a quite difficult task, and it is therefore not surprising that frequently the results of different workers are not in agreement. It is instructive, and usually helpful, to plot the solubility results on log weight or atomic percent -1/T coordinates to find out if a straight line is obtained. A straight line is expected because in systems displaying solubilities of the order of 1 to 3 at. pet or less, Henry&apos;s law is usually obeyed—or at least well enough obeyed so that the deviation from linearity is not very appreciable. If Henry&apos;s law is obeyed, one canthen use the Van&apos;t Hoff Equation in the form In N = ?H/RT + C, where N is mole fraction, at. pet, or wt pet for small values, and AH is the partial molal heat of solution of the solute. R and T have the usual significance, and C is an integration constant. If one plots the reported nitrogen solubility values as indicated above, the three points fall reasonably well on a straight line. The oxygen values for the two upper temperatures fall very closely to the nitrogen values as shown in the authors&apos; Fig. 15. However, the value at 500°C departs widely from the straight line established by the data at 1500" and 1000°C. It is, of course, true that one cannot place too much emphasis on the significance of a line established by only three points, but in the absence of reasons for anticipating deviations, data exhibiting wide departures from linearity should at least be examined closely. Fig. 16 shows the log at. pct -1/T plots for the authors Ta-O and Ta-Ndata including a solid circle point at 500°C and 1.8 at. pet for Ta-O, which is simply extrapolated from the two higher temperature points. In addition, the data of R. P. Elliott9 for Nb-O are shown. These points were picked off his curve and are not very exact, but as can be seen they line up well on a straight line. It is interesting, and probably significant, that the slope of Elliott&apos;s results is not far from those of Vaughn, et al. This is probably to be expected because one would anticipate that the partial molal heats of solution of oxyten in these two very similar metals should be not too far apart. AH for Ta-O is about -1900 cal per mol, while for Nb-O it is near -2300 cal per mol. Hence, this lends some support to the thesis that the point at 500°C for Ta-O is much too high. The data of Gebhardt and Preisedanz10 are also plotted, and it is seen that their data while lying on a linear plot, have an appreciably steeper slope. The possible reasons for this will not be discussed here except to point out that their pressure-composition data show anomalies which suggest that they may have been dealing with a different equilibrium from that being discussed. There is another consideration which would also suggest that the solubility at 500°C is lower than shown. The solubility values were obtained by the classic method of first establishing a lattice parameter-composition curve. This the authors did, and there is probably little doubt that it is quite accurate. Such a plot is generally almost error-free because it has a self-correcting feature in that any deviation from linearity makes a data point immediately suspect, and subject to confirmation. Unfortunately, this is not true with respect to the actual solubility values. These are obtained ordinarily by taking an alloy containing more solute than is soluble at some temperature and then thermally

Jan 1, 1962

By William Vietti

WEST TEXAS and New Mexico has been overshadowed by the develop-ment in East Texas to such an extent that the area has been placed on a settled production basis by most of the operators. Considerable develop-ment work on both proven and unproven acreage remains to be carried on, but the incentive, a ready and profitable market, has been lacking. The main characteristics of the fields in this area are so well known that they are not described again in this paper, which thus resolves itself into a statistical review of the more important production features of the area. Proration has been in effect during the year and has been rigorously applied with the full cooperation of all producers. Proration in West Texas and New Mexico is based in the more pro-ductive fields on a potential and acreage distrbution of the allowance to the individual wells or acreage units. Potentials are determined generally by a short production test of from 1 to 4 hr.; and the hourly rate is multiplied by 24 to obtain the 24-hr. production or rated potential of the separate wells. The potential values thus set up have been questioned by many production men who are not willing to concede that the instantaneous (hourly) capacity of a well to produce is its potential capacity for a day with all other wells in the pool producing at their capacity. However, the potential of a well determined as above remains its chief rating as a measure of the permeability in place and as an indication of the possible reserve feeding that well. , The acreage factor has made it unnecessary to overdevelop properties in order to obtain an allowance proportionate to neighbors who are willing to drill an excessive number of wells on a piece of acreage in the hopes of a quick drainage and a corresponding profit. Proration has resulted in an orderly development of many of the pools in this area on the base as out-lined above, resulting in more reasonable spacing of wells and the more even withdrawal of oil and the ensuing expectation of high recoveries.

Jan 1, 1933