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By Jasper L. Stuckey

HISTORY IT is not known when kaolin mining was first begun in North Carolina. Evidence, in the form of excavations and primitive tools, indicates that some of the deposits were worked in prehistoric times. It has been suggested that the prehistoric mining was for mica, but the workings were all in altered or partly altered pegmatite material and the dumps do not represent the amount of material removed. Some of the early openings may have been made in search of kaolin or semi-kaolinized feldspar which was sold to English1 traders along the coast and used in some of the early English porcelains. In 1944,2 an application was made for an English patent to produce porcelain from an earthy mixture obtained from the Cherokee Nation in North America. It is well established, however, that the occurrence of kaolin in western North Carolina was known in England by 1767. In that year, Josiah Wedgewood sent T. Griffiths3,4 to what is now Macon County, North Carolina, to secure a supply of kaolin for use in England. Griffiths diary, now in Etruria Museum, Stokes-on-Trent, contains a most interesting account of his experience. Kaolin was discovered at St. Austell, England, shortly after the voyage of Griffiths, which probably accounts for the lack of further interest in American kaolin. Between 1767 and 1888, there are no records of kaolin mining in North Carolina. In the latter year, however, mining was begun near Webster, Jackson County, and, in the intervening period, has become an important industry. For some 20 years, kaolin mining was carried on chiefly in Jackson, Macon, and Swain Counties. About 1904, it was begun in the Spruce Pine district and for the past 20 years most of the kaolin mined in the State has come from Avery, Mitchell, and Yancey Counties. DISTRIBUTION The kaolins of North Carolina are limited in occurrence to the Piedmont Plateau and Appalachian Mountain area of the State. While kaolins are widespread in the Piedmont Plateau, having been prospected for in Rutherford, Cleveland, Gaston, Granville, Lincoln, Catawba, Iredell, Richmond, Moore, Randolph, and Montgomery Counties, the production from that area has never been important. The known deposits of commercial importance are limited entirely to the mountain area of the State. While kaolins occur widely distributed throughout the mountain area and have been prospected for in many counties of that area, commercial production has come chiefly from two districts. One of these includes Jackson, Macon, Swain, and Haywood Counties. The other includes Avery, Mitchell, and Yancey Counties. GEOLOGY With few exceptions, all the known kaolin deposits in North Carolina contain

Jan 1, 1947

By Albert H. Fay, William B. Plank

In practically all rock-excavation problem there is need for a careful study of the rock structure, its fault, cleavage or bedding planes, and even the texture of the rock itself. These studies should form the bases upon which an excavation method is selected and they should be carefully considered in predicting the amount and extent of the excavation. The need for such studies was forcibly illustrated in the problems involved in a cut made in 1929, along and underneath a 200-ft. high rock projection for a State highway near the City of Easton, Pennsylvania. The rock mass was badly faulted and also contained a number of cleavage planes at approximately right angles to the fault planes. Much of this structure was visible and could have been studied and analyzed before the work was begun. The State had rigid specifications as to finished grade and slope of cut, which apparently were made without reference to the geologic structure. The contractor complied with the specifications, under the close inspection of the State engineers. A tunnel blast was placed in the base of the cliff, with the result that 65 per cent more rock was broken than was intended by the specifications. About four years after the blast, the writers of this paper studied the circumstances surrounding the operation, to determine the cause of this excess excavation. Scope of Work The section of the roadway involved was about 200 ft. long and on a 6' curve. It was necessary to relocate points on the curve, from which all faults and cleavage planes were located and measured by the use of transit and clinometer. A plan (Fig. 1) showing the blasting tunnel, the roadway, and traces of the faults and cleavage planes on the level of the roadway, was prepared; also 13 cross-sections at varying intervals, showing the original face of the hill and the face after the blast. The original and final profiles of the rock face, taken from the plans of the State engineers, are shown in Figs. 2, 3 and 4.

Jan 1, 1937

By E. L. Spain

The deposits described in this paper occur over much of Wayne County and in the southeast portion of Hardin County, Tennessee, and in the northeast and northwest portions of Mississippi and Alabama respectively. The presence of tripoli in this region has been known for some time and descriptions of various occurrences in Tennessee have been made by Jewelll and Miser2, while Hilgard3, Lowe4 and Logan5 have treated the deposits that occur in the adjacent portions of Alabama and Mississippi, but there has not been a 'general survey of the entire field summarizing completely the geology of the deposits with respect to their origin and stratigraphic relationships. During 1934, while engaged in surveys of mineral resources through this region for the Tennessee Valley Authority, the writer collected data with this in mind, and has assembled them in this report. He is indebted to H. S. Rankin and N. A. Rose, of the Tennessee Valley Authority Geology Division, for field assistance. Location of Tripoli Deposits Fig. 1 shows the locations of deposits of tripoli in a long belt that extends from northeast Wayne County southwestward into northwest Alabama and thence passes into Mississippi, where the formations carrying it are finally covered by Cretaceous sand and gravel of the Mississippian Embayment. Occasional deposits occur also in the southeastern corner of Hardin County, Tennessee. While tripoli is found at nearly all points along this axis where the related formations are exposed, the largest deposits are grouped about three different centers. Waynesboro-Collinwood District.—In the area between Waynesboro and Collinwood, in Wayne County, Tennessee, tripoli of various grades outcrops in the valley of Green River and in tributary valleys on either side. This district is roughly 12 miles long in a northeast-southwest direction and has a maximum width of 5 miles at its northern end. Exposures are found in road cuts, highway chert pits, in the beds of some of the streams, and on hillsides. The greatest number of high-grade

Jan 1, 1938

By E. L. Spain

The deposits described in this paper occur over much of Wayne County and in the southeast portion of Hardin County, Tennessee, and in the northeast and northwest portions of Mississippi and Alabama respectively. The presence of tripoli in this region has been known for some time and descriptions of various occurrences in Tennessee have been made by Jewelll and Miser2, while Hilgard3, Lowe4 and Logan5 have treated the deposits that occur in the adjacent portions of Alabama and Mississippi, but there has not been a 'general survey of the entire field summarizing completely the geology of the deposits with respect to their origin and stratigraphic relationships. During 1934, while engaged in surveys of mineral resources through this region for the Tennessee Valley Authority, the writer collected data with this in mind, and has assembled them in this report. He is indebted to H. S. Rankin and N. A. Rose, of the Tennessee Valley Authority Geology Division, for field assistance. Location of Tripoli Deposits Fig. 1 shows the locations of deposits of tripoli in a long belt that extends from northeast Wayne County southwestward into northwest Alabama and thence passes into Mississippi, where the formations carrying it are finally covered by Cretaceous sand and gravel of the Mississippian Embayment. Occasional deposits occur also in the southeastern corner of Hardin County, Tennessee. While tripoli is found at nearly all points along this axis where the related formations are exposed, the largest deposits are grouped about three different centers. Waynesboro-Collinwood District.—In the area between Waynesboro and Collinwood, in Wayne County, Tennessee, tripoli of various grades outcrops in the valley of Green River and in tributary valleys on either side. This district is roughly 12 miles long in a northeast-southwest direction and has a maximum width of 5 miles at its northern end. Exposures are found in road cuts, highway chert pits, in the beds of some of the streams, and on hillsides. The greatest number of high-grade

Jan 1, 1938

By Harold A. Linke

The following article presents notes and data compiled and computed by the writer for use in the determination of: size and slope of mill launders, details of junction boxes and downspouts, and distribution of pulp. It also includes pulp formulas, volume of discharge through bushings, paths of discharging streams, banking of turns and curves. In the design of a concentrating mill, the draftsman usually considers launders to the extent of providing ample "head" for transmission of pulp from one department of the mill to another. The superintendent of construction aims to build his launders wide and deep, and on a slope steep enough to ensure positive flow. So launders are laid generally on too steep a slope, with the result that the repair gang works to maintain launder bottoms and sides against the erosive action of the conveyed pulp. To this end many kinds of liners have been devised: concrete, mastic, white iron, glass, rubber. True, the reduction of slope to the point where a pulp will flow with minimum wear, will minimize labor and expense; but when the desired slope is not predetermined, the millman hesitates to readjust his launder slopes by cut-and-try methods. To the end that the desired size and slope may be found readily, the writer has: (1) conducted experiments with pulps of different specific gravity, screen analysis and dilution; (2) gathered a few graphic data from standard reference works (such as Peele's Mining Engineer's Handbook and Taggart's Handbook of Ore Dressing); (3) computed several tables; and compiled results that have proved dependable for Utah Copper ore. It is quite possible that the following tables and graphs may not be applicable to all ores, but it is hoped that they may prove helpful, even in slight degree, in alleviating a portion of the trouble and migraine of some other millman. Launder Slopes The main object in the study of launder slopes is to provide grade steep enough to prevent "sanding" by a safe margin, and to avoid

Jan 1, 1943

By Harold A. Linke

The following article presents notes and data compiled and computed by the writer for use in the determination of: size and slope of mill launders, details of junction boxes and downspouts, and distribution of pulp. It also includes pulp formulas, volume of discharge through bushings, paths of discharging streams, banking of turns and curves. In the design of a concentrating mill, the draftsman usually considers launders to the extent of providing ample "head" for transmission of pulp from one department of the mill to another. The superintendent of construction aims to build his launders wide and deep, and on a slope steep enough to ensure positive flow. So launders are laid generally on too steep a slope, with the result that the repair gang works to maintain launder bottoms and sides against the erosive action of the conveyed pulp. To this end many kinds of liners have been devised: concrete, mastic, white iron, glass, rubber. True, the reduction of slope to the point where a pulp will flow with minimum wear, will minimize labor and expense; but when the desired slope is not predetermined, the millman hesitates to readjust his launder slopes by cut-and-try methods. To the end that the desired size and slope may be found readily, the writer has: (1) conducted experiments with pulps of different specific gravity, screen analysis and dilution; (2) gathered a few graphic data from standard reference works (such as Peele's Mining Engineer's Handbook and Taggart's Handbook of Ore Dressing); (3) computed several tables; and compiled results that have proved dependable for Utah Copper ore. It is quite possible that the following tables and graphs may not be applicable to all ores, but it is hoped that they may prove helpful, even in slight degree, in alleviating a portion of the trouble and migraine of some other millman. Launder Slopes The main object in the study of launder slopes is to provide grade steep enough to prevent "sanding" by a safe margin, and to avoid

Jan 1, 1943

By R. D. Russell, R. M. Farquhar

ISOTOPIC tracers have become an important aid in following the progress of chemical processes in the laboratory. It has recently been found possible to utilize a system of naturally existing isotopic tracers to obtain information about the geo- logical history of lead ores. Common lead, such as is found in lead deposits, is a mixture of four stable isotopes having atomic weights 204, 206, 207, and 208. Of these, the last three are identical with the lead isotopes produced as stable end products of the radioactive decays of uranium and thorium: the first, lead-204, is not known to be produced on the surface of the earth by any process. Since uranium and thorium occur in the surface regions of the earth in amounts comparable with lead, and since the half-lives of uranium and thorium isotopes are of the same order as the age of the earth, they produce the radiogenic lead isotopes in amounts com- parable to the amount of nonradiogenic lead present. Every significant exposure of a sample of lead to uranium and thorium will therefore lead to the permanent alteration of the lead isotope ratios in that sample.

Jan 5, 1957

By Arthur E. Hall

Tax operation of "softening" in lead refining is designed, as the word implies, to separate from the bulk of the lead the elements that tend to make lead hard. These elements, which invariably are present in argentiferous lead, interfere with the desilverization, and must be almost entirely absent in refined desilverized lead. They are mainly copper, antimony, arsenic and tin. The properties utilized in accomplishing this separation are the low solubility of copper or copper sulphide in lead at its freezing-point temperature, and the greater and selective affinity for oxygen of the other elements at temperatures of the order of 700° to 900' C., or, in the prcsence of sufficient, alkali, at a temperature of about 500' C. The major problems of softening lead bullion lie in the necessary subsequent treatment of the by-products of the primary operation, which contain, either chemically or mechanically, lead or reagents that must be isolated for market or re-use. Therefore an important objective of the primary operation must be the highest practicable concentration of these elements in the by-products. Within the past three decades, during which the writer has been engaged in lead refining, the technique of softening lead bullion has had as many variations as there were lead refineries. This was the result of the variation in composition and character of lead bullion recived. The writer has received for refining shipments of lead bullion varying as widely as indicated by the following table: Sb, Per CEnt As. Per Cent Sn, Per Cent Cu. Per Cent Ag. Oz. per Ton 1.00 0.05 nil 0.05 70 0.50 2.50 2.00 0.50 200 3.50 0.50 nil 0.30 350 At times these have been received uniformly and at other times irregularly with a variation from week to week as wide as those shown. Under such conditions, establishment of a universal softening technique presented many problems. Such variations existed because refinery tolls too often were based on a ton of bullion, whatever its composition, and

Jan 1, 1937

By Paul A. Flinn, Jean-Marie Robert Genin

The MCssbauer effect was used to study the distribution of carbon in Fe-C alloys of high carbon content during room-temperature aging. In freshly formed rnartensite the carbon distribution is approximately random; carbon clustering occurs dun'ng aging. In the retained austete the carbon atoms are isolated, suggesting an efiective repulsion; and no rearrangement during room-temperature aging is evident. The kinetics of the carbon clustering in martensite has been studied in detail at 0" . 10". and 20°C. The time and temperature dependence observed is sinzilar to that reported for a variety of other aging effects, such as resistance change, hardness increase, and recovery of internal friction. The stabilization of the martensite kransformation also appears to be related to the clustering effect. DESPITE extensive efforts since the early days of Reaumur, the mechanism which provides the strengthening of steel remains controversial in many cases for several reasons: 1) The structure of as-quenched martensite is not well-determined. 2) Experimental methods capable of distinguishing between various hardening mechanisms are not well-developed. 3) The temperature of formation of many low-alloy martensites is so high that the martensite formed during quenching may be already tempered to some extent before any observation. Among all the hardening phenomena, the most puzzling one occurs at room temperature, where no structural changes have been detected by the usual methods of X-ray diffraction or electron microscopy. However, a new and more sensitive technique became available with the discovery of the MBssbauer effect. This effect makes possible the detection of changes in the local environment of iron atoms in solid solution. It has been extensively used in the study of substitutional alloy systems, for example, Fe-Al,1 Fe-Si,2,3 Fe-Rh,4 and Fe-Ni.5 Making use of the possibility of obtaining new structural information, we undertook an investigation of the aging of high-carbon Fe-C martensite to follow the structural changes involved in the aging at room temperature. Preliminary results6 showed that a clustering of the carbon atoms occurs with time. A systematic study of the kinetics of the process showed a striking similarity to the kinetics of stabilization of the marten-sitic transformation, thus suggesting further investigation of the relationship. EXPERIMENTAL TECHNIQUE To eliminate difficulties with the aging of martensite prior to the first experimental measurements, we needed an alloy with an M, temperature not above room temperature. Other investigators7 were misled by results obtained on alloys which transformed above room temperature and underwent structural changes prior to the first Mossbauer measurements. Winchell and cohen8 dealt with this difficulty by using a third element, nickel, to depress the MS below room temperature. The presence of nickel did not seriously interfere with hardness or resistivity measurements, but it would complicate the interpretation of the Mossbauer data by increasing the variety of iron environments. We chose, therefore, to obtain the necessary lowering of the M, simply by increasing the carbon content. After the first quench to room temperature, our specimens are retained austenite, which we later quench into liquid nitrogen. The martensitic transformation takes place suddenly, so that the as-quenched condition of the samples is retained, since the temperature is low enough to prevent any carbon diffusion. A Massbauer spectrum at 77°K can be taken and analyzed; after an appropriate up-quenching to the aging temperature, a new Mossbauer measurement at 77°K can be made. Fig. 1 shows a typical cycle of experiments. The samples were foils 25 p thick of high-purity

Jan 1, 1969

By Marc Lemieux

Computer pit design techniques generally make use of models in which the deposit is represented by a regular array of data. Using a regular system, the number of data points required to represent the air, waste and mineralization in a large deposit become excessive. The number of blocks used to describe the deposit is dependent upon the block size. The quality of the pit wall slope design also is dependent upon the block size used and the method of defining the slope. The error associated with reserve calculations becomes greater with increasing block size. A deposit model consisting of variable sized air and mineralized blocks has been developed at the University of British Columbia and improved upon at Climax for pit design work. The method permits put- ting the entire model in core for rapid data processing. This permits the use of a versatile cone generation technique which allows close adherence to variable slope constraints in all directions. The conical shape is approximated by rectangles on each level which equal the area of the ideal conical intersection. The shape of the intersection may vary from approximately circular to elipsoidal. The approximate cone shape is controlled by the slope constraints applicable at the point of intersection on the bench. The overall modeling technique greatly assists the pit design engineer in developing a high quality pit design.

Jan 1, 1977

By Albert B. Horn, J. J. McKetta, O. L. Culberson

Since water is present in natural gas and petroleum reservoirs, it is of engineering value to have accurate experimental data regarding the behavior of water in hydro-carbon systems. Since experimental data of this nature are so scarce in literature, a program is under way at the University of Texas to obtain experimental data regarding the distribution of water in petroleum hydrocarbons. This initial paper is subdivided into three parts: A. The apparatus and analytical procedure are discussed. B. The equipment has been checked by comparing the experimental data with data of literature on the solubility of methane in water at 77°F and pressures to 10,000 psia. C. Experimental data are presented at 100, 160, 220, 280, and 340°F on the solubility of ethane in water at pressures to 1200 psia. As the temperature is increased the solubility of ethane in water first exhibits a minimum and then a maximum solubility. The range of applicability of Henry's Law is discussed. INTRODUCTION Although considerable experimental data have been published on water-hydrocarbon systems in the hydrate region, the information on these systems in the vapor-liquid and the vapor-liquid- 'References are given at end of paper. Manuscript received at the office of the Petroleum Branch August 31. 1949. liquid regions at elevated pressures is extremely scarce. A survey of the literature on hydrocarbon-water systems at elevated pressures was presented by McKetta and Katz12,13,14 showing the systems and phases investigated. In addition to these existing published data, Poettman and Dean" have reported the water content of propane in the three-phase region (only the propane-rich liquid and the vapor phases were studied) and Michels, et al.15 have reported the solubility of methane in water at pressures to 6800 pounds per square inch at 77°F and at pressures to 1500 psia at temperatures to 300°F. It has been shown12,14 that the presence of water will materially affect the phase equilibrium of hydrocarbon systems. In order to make experimental studies on the quantitative effect of the presence of water in naturally-occurring hydrocarbon systems, it is desirable to have data available on binary hydrocarbon-water systems. A program is underway at this laboratory to determine the phase relations of the hydrocarbon-water systems. Initially the investigation will be limited to binary systems with water as one of the components. Later ternary and complex systems will be investigated and reported. EQUIPMENT AND ANALYTICAL PROCEDURE Apparatus In order to avoid a description of the methods employed in each subsequent paper, a description of the apparatus and the analytical procedure will be given here. The apparatus is shown schematically in Fig. 1. The numbered items in Fig. 1 represent the high pressure valves. The equilibrium cell is of the totally enclosed type, with a volume of 550 cubic centimeters. The cell is mounted in an air bath which in turn is mounted on pillow blocks and connected to a rocking mechanism so that the cell and bath will oscillate approximately 30 degrees above and below the horizontal at 35 oscillations per minute. The air bath is heated by two resistance heaters. The first or primary heater is 250 watts and is controlled by a thermoregulator; the second heater is of 500-watt size and is manually controlled to aid in bringing the cell to equilibrium temperature. Air circulation in the bath is accomplished by means of a fan. the shaft of which is concentric to the heaters. The walls of the bath are insulated with 2-in. thick blocks of 85 per cent magnesia. Temperature observations are made with three calibrated thermocouples. One couple is sealed in a well provided within the equilibrium cell, and is used as the criterion of the cell being at the equilibrium temperature. The other two thermocouples are located on opposite sides of the cell to indicate temperature uniformity within the air bath. The thermoregulator, used in conjunction with a relay, gives a variation in the temperature of the air in the bath of plus or minus one degree Fahrenheit. However, since the equilibrium cell weighs approximately 55 pounds, the

Jan 1, 1950

By R. Maddin, A. Lawley

Single crystal Mo-Re alloys (99.99+ purity), grown by electron bombardment floating zone heating, were deformed in tension at temperatures from -196° to +200°C. At -196oC, Mo-6 pet Re and Mo-20 pct Re alloys deform by slip on systems of the type (101) [1ll]. Above-78oC, the operative slip system is of the type (112) [111], (101) [1ll], or (211) [1ll], depending upon orientation. Mo-39 pct Re alloys deform by twinning and slip at all test temperatures with a (112) [111] type twinning system. Critical resolved shear stress for slip and twinning is calculated as a function of composition and temperature, and the mechanical properties compared with those of less Pure polycrystalline alloys. HEXAGONAL close-packed rhenium, c/a = 1.615, is highly soluble in molybdenum. The bee molybdenum-rich solid solution extends to approximately 42 at. pet Re* at 2500°C,' Fig. 1. Recent work on polycrystalline alloys has shown conclusively that the addition of rhenium to molybdenum improves both the fabricability and the low-temperature ductility.2"5 Similar behavior is observed for W-Re and Cr-Re alloys.5 Initially, Geach and Hughes2 found that the Mo-30 pct Re alloy could be cold rolled to approximately 90 pct reduction before the onset of cracking. The remarkable effect of the rhenium was later confirmed by Jaffee et al. 3-5 with an optimum condition of maximum strength combined with maximum ductility at the Mo-35 pet composition. At higher rhenium contents, the ductility was severely impaired due apparently to the presence of brittle tetragonal s phase, Fig. 1. In the Mo-35 pet Re alloy, at least 110 ppm (parts per million) oxygen could be tolerated before cold workability was reduced. By comparison, the corresponding tolerance figure in unalloyed molybdenum is ~ 10 ppm. The effect of rhenium was considered in terms of: 1) a reduction in oxygen solubility in the lattice; 2) a redistribution of intergranular oxide from grain boundary films to isolated spheres; and 3) the promotion of twinning as a further mode of plastic deformation. Paradoxically, twinning is often associated with brittle fracture in iron and the silicon irons.6'7 Work to date has been restricted to are-melted and powder metallurgy polycrystalline material of ~ 99.9 pet purity. The present investigation was initiated for the purpose of determining the mode and crystallography of plastic deformation of a series of bee Mo-Re alloy single crystals over a wide temperature range from -196o to +200°C. Using high-purity zone-melted material (~ 99.99 + pet purity), the specific role of rhenium in the molybdenum lattice may be understood more fully since effects due to grain boundaries and oxide redistribution will be absent. At the same time, the study provides a comparison of single and polycrystalline deformation behavior. EXPERIMENTAL TECHNIQUES A) Preparation and Purity of Single Crystals. Alloys in the form of either are-cast and swaged or sintered and ground bar, 0.120 in. diam, were obtained from the Chase Brass and Copper Co. Alloy single crystals ~ 8-in. long were grown from the

Jan 1, 1962

By Arthur McKee

As HEAT is the controlling factor in all smelting operations, it will be .most helpful to make a new set of calculations on the basis of a .unit of fuel burned at the tuyeres to carbon monoxide. This ties together the only two factors in this operation that seem to be constant with respect to each other-the fuel at the tuyere and the air or its oxygen content. If our usual smelting operations, using natural air heated to reasonably obtainable temperatures, furnish sufficient heat above this critical temperature for the purpose, it is doubtful whether additions of oxygen will be of marked benefit. A unit of fuel will not produce a single heat unit more if burned with pure oxygen than if burned with natural air and less heat will be available per unit of fuel by the amount of heat that is carried in by the preheated nitrogen in the natural air of the blast. This is more readily apparent if considered in connection with a heat balance sheet per unit of fuel at the tuyere. The heat available in the stack, as shown by the committee's report, is less by reason of the lower fuel consumption per unit of output assumed in this calculation. The balance sheet for enriched air shows a shortage of the amount of heat usually carried in with the blast; also a lack in the hearth of sufficient heat to melt the 18 per cent. additional metal and slag and in the shaft to the extent of the shaft heat required to heat the 18 per cent. additional stock to the melting point. These heat deficiencies are provided for by the largely increased conversion of carbon monoxide into carbon dioxide, which is assumed, as shown by the following figures: Calculation for natural air: Carbon dioxide 18.4 per cent. (after having eliminated the carbon dioxide from limestone) and 20.8 per cent. of carbon monoxide. Calculation for oxygen-enriched air: Carbon dioxide 28.4 per -cent. and carbon monoxide 23.2 per cent. (no carbon dioxide from stone as lime is charged instead).

Jan 11, 1924

By E. I. Larsen, F. R. Hensel

According to statements by Guertler1 Smith and Hamilton were the first to study the copper-titanium alloys, but owing to the presence of large amounts of impurities their data are inconclusive. M. A. Hunter and I. W. Bacon later investigated the electrical conductivity and the temperature coefficients at room temperature. The present writers reported their results2 in November, 1930. Recently Kroll published data on copper-titanium alloys3 which agree closely with those obtained by the authors. Material Tested The titanium used was in the form of square sintered rods, the analysis of which runs as follows: titanium, 95.4 per cent; silicon, 0.7; iron,l.8; aluminum, 1.4; copper, 0.1; manganese, 0.05. The ingots were prepared in a high-frequency induction furnace in air atmosphere. Their analyses are given in Table 1. Up to 5 per cent titanium the alloys could be forged. Above that amount they were red short and broke up easily. Owing to their rapid absorption of nitrogen and oxygen from the air, the alloys with the higher amounts of titanium tend to form surface films which greatly increase the casting difficulties, especially when small masses of metal are handled. It was, however, possible to prepare sound ingots up to 25 per cent titanium. Thermal and X-ray Investigation The cooling curves of some of the alloys are plotted in Fig. 1, and R tentative diagram constructed from these data is given in Fig. 2. From this it is evident that the solid solubility of copper for titanium is approxi-mately 4 to 5 weight per cent titanium at 878" C., which is the eutectic temperature. The melting point of copper is lowered gradually by adding

Jan 1, 1932

By C. K. Leith

CERTAIN ideas on iron and steel sanctions to follow originated in a series of conferences held under the joint auspices of the War Department and Brookings Institute in Washington last spring. The views presented may be regarded as those of substantial segments of the steel industry. In view of the fact that steelmaking capacity can be so quickly converted to the production of armament, any effective control must necessarily include the entire steel industry and not solely the parts devoted to the production of implements of war. It must also be exercised all the way from production and shipment of raw materials through their ultimate conversion into finished products and use. Control will be dis- cussed under two main headings: (I) control of raw materials at the source; (2) control of steel capacity within the Axis countries.

Jan 1, 1944

By C. Feng, W. E. Krul

A study was made of the development of texture and the anisotropy in plastic flow of Ti-8Al-1Mo-1V alloy. Based on Pole figure determinations, the shifting of texture induced by rolling at approximately 400°C was found to be due primarily to slip rotation for the major Portion of the material. Grain boundary shear is believed to be an important factor. The anisotropy of the textured alloy was examined in terms of the variations of yield stress under tension and the ratio of bi -axial strain increments µp, in the temperature range 25" to 290°C. The results were related to Hill&apos;s theory on plastic anisotropy. The Schmid factors of (1100)[1120], (1101)[1120/, and (1101)[1120] slip systems were analyzed and found to be compatible with the observed anisotropy. Cross-slip between these planes was proposed as a possible deformation mode. In a number of published articles, considerable interest has been directed to the possible achievement of texture hardening in hcp metals. Following Backofen, Hosford, and Burke,&apos; this phenomenon was related to the yield criteria of the material and was expressed in terms of the biaxial strain ratio, r = d?w/d?l. The higher the value of r, the greater is the expected potential for texture hardening under certain loading conditions. For a given material, r varies with direction. Such variation can be traced to the anisotropy in plastic flow and can be explained within the framework of the various modes of deformation. Hatch2 found that a high r value coincides with a texture whereby the (0001) pole is closely aligned with the surface normal for sheet materials, Based on the analysis of the slip on the {1010}, {1011}, and (0001) planes, Lee and Backofen3 and Avery, Hosford, and Backofen4 concluded that the resistance to thinning is reduced by the operation of the (0001) <1120> slip system; with this reasoning they were able to explain the low r values (i.e., r « 1) observed in magnesium alloy sheets in the rolling direction and in commercially pure titanium in the transverse direction. The general equation, dealing with plastic flow in a polycrystalline aggregate has been used to correlate the plastic anisotropy and texture. In this expression, T and s are shear and normal stresses, and dri and d? are shear and normal strain increments, respectively. Assuming that five slip systems are operative within each grain and applying the principle of maximum work,5,6 one can determine the m value among the available systems. On this basis, Hosford7 and Chin, Nesbitt, and Williams&apos; were able to correlate m with yield stress under plane-strain compression, and Svensson9 was able to predict the variation of yield stress in textured aluminum. These workers made their analyses from materials in which slip operation is known to be associated with plastic flow. Questions remain regarding the derivation of Hill&apos;s theory on plastic anisotropy,10,11 since it was formulated on von Mises&apos; yield criterion.&apos;&apos; Its ability to deal with other forms of deformation has been in doubt.13 Others have discussed the validity of Hill&apos;s quadratic equation relating strain and yield stress.14&apos;15 For hcp titanium, deformation by various modes of slip and twinning operations has been reported.16-20 If all possible modes of deformation operate and contribute substantially to the plastic flow, it is difficult to imagine how the quadratic expression can suitably describe the anisotropic plastic flow of titanium alloys. Backofen and Hosford15 considered that Hill&apos;s is a macroscopic theory and implied that the major mode of deformation by slip mechanism will adequately describe anisotropy of the material. In the present investigation, slip operation will be shown to play the major role in the development of sheet texture induced by rolling of a commercial titanium alloy. Although twinning and other modes of deformation may also operate, their operation is believed to be secondary. The anisotropic properties of the sheet, which can be expressed in terms of directional variation of r, µp = -d?w/d?l and the yield stress will be shown to be governed primarily by slip operation. MATERIALS AND EXPERIMENTAL TECHNIQUES The titanium alloy chosen for the present investigation had a nominal composition of 8 wt pct Al, 1 wt pct Mo, 1 wt pct V, and 0.1 wt pct interstitial impurities. Sheets varying between 0.1 and 0.15 in. thickness were used. The alloy was received in a condition which was prepared by rolling at 900°C and annealing at 700°C. Subsequently, the sheets were subjected to further reduction in thickness by rolling at 400°C. A total reduction in thickness of 65 to 70 pct was obtained by a series of quick passes in a rolling mill with intermediate reheating. Further reduction in thickness was not possible due to cracking developed at the edges of the sheets. X-ray measurements were conducted in a Siemens and a Norelco unit to determine the texture of the sheets. Reflection techniques were used exclusively with CuK, radiation and a nickel filter. The loss of X-ray intensity due to geometric defocusing was calibrated with a technique described previously." The (0001), (1010), and (1071) pole figures were plotted from 0 to 80 deg, and to present the texture elements quantitatively, inverse pole figures were constructed following the technique described by Jetter, McHargue, and Williams.22 Tensile experiments were carried out at 25", 175",

Jan 1, 1970

By Karl F. Peterson, H. K. Najarian, Robert E. Lund

R. E. Powers (Mellon Institute of Industrial Research, University of Pittsburgh, Pittsburgh)—Several of the processing methods at the Josephtown smelter might well be considered by plants producing iron blast furnace sinter. In making blast furnace sinter the objectives are much the same as at Josephtown: To produce a strong yet porous agglomerate which has a size consist in a preferred range. The emphasis however is on production rate rather than on the size or other quality characteristics of the sinter. Therefore the technique is entirely different. Blast furnace sinter plants attempt to make their product in one pass with a minimum recirculating load and without sizing treatment after the sinter leaves the machines. Many plants are beginning to feel that more attention paid to quality characteristics would make the product a more desirable blast furnace material. The pelletizing of very fine material before placing it on the bed is not deliberately done at iron sinter plants, although the installed equipment sometimes gives a simila; action. Such pelletizing seems to be a promising way of accommodating the down-draft sintering Drocess to very fine materials. he recirculating load at Josephtown is extremely high. Two plants&apos; producing blast furnace sinter from raw material of comparable size have a recirculating load of about 100 pct of production. At Josephtown it is notable that the size and the rate of feeding of return fines are under control. This is not the case in most blast furnace sinter plants. The sinter slicer appears to be a worthwhile aid in effecting such control. It is similar in action to rakes and plows used at a number of plants, but it has the advantage that the sinter dislodged is positively removed and not left to the inefficient action of a stationary grizzly screen. Blast furnace size specifications for sinter are not at present so rigid as the Josephtown specifications. If the sizing of blast furnace sinter does become important, then the Josephtown crushing practice, in which a large recirculating load is maintained on the crusher in order that minimum fines be produced, may be of interest. H. K. Najarian (authors&apos; reply)—We note that Mr. Powers appreciates some points that we tried to emphasize in our paper as being of importance in making zinc sinter of good quality and which may well be applied to iron blast furnace sinter. Fig. 2 shows the pelletized nature of the feed going on to a Dwight-Lloyd type sintering machine in our plant. Practically, the entire feed consists of more or less rounded particles which permit more uniform air passage through the charge, while the larger particles in the charge roll on to the surface of the grate, which helps to keep the grate openings from being clogged by excessive fines. An agglomerated charge of this character may preferably be made by rolling action while being mixed in a rotating drum and wetted by water sprays to bind the fine particles together and give the charge the desired moisture content. From our observations of several iron ore and blast furnace flue dust sintering operations, we believe that if the fines from the sinter discharged from the machines were to be recirculated and agqlomerated with the new feed, not only sinter of better quality but larger capacity from the machines may be realized.

Jan 1, 1952

By M. C. Smith, W. V. Green, D. M. Olsen

The creep-rupture behavior of commercial powder-metallurgy molybdenum rod is reported in the temperature range 1600" to 250O°C, at stresses up to 9000 psi and times up to 1 month. The effects of temperature, stress, and grain growth are discussed. Rupture time is fitted to the Larson-Miller parameter and compared to lower-temperature and higher-stress results reported by pugh.1 BECAUSE of its high melting point, molybdenum should retain useful strength to relatively high temperatures. Combined with its ready availability in the United States, this makes it attractive for many applications in missiles, rockets, and so forth—wherever its susceptibility to oxidation can be tolerated or overcome. The mechanical properties of molybdenum rod in the temperature range —200" to 1540°C have been reported by pugh,&apos; Bechtold,&apos; Parke,3 and Carriker and Guard.4 Madden and chen5 have measured the tensile properties of molybdenum single crystals in vacuum up to about 2500°C. As one further step in evaluating its mechanical usefulness, the constant-load creep-rupture properties of commercial powder-metallurgy molybdenum rod have been investigated in the range 1600" to 2500°C. MATERIAL TESTED Creep specimens were machined from 1/2-in. round commercial molybdenum rod, manufactured from powder by pressing, sintering, and swaging. Spectrochemical analysis of the rod showed "traces" (less than 0.01 pct) of silicon, aluminum, chromium, iron, and zirconium, and "faint traces" (less than 0.001 pct) of manganese, magnesium, cobalt, and nickel. Carbon content was 130 to 200 ppm, nitrogen was 110 to 180 ppm, and oxygen 30 to 35 ppm. A typical microstructure of the as-received rod is shown in Fig. 1. Room temperature tensile properties for five specimens strained at about 0.015 in. per in. per min are shown in Table I. CREEP SPECIMENS USED The specimens used for creep-rupture testing are illustrated in Fig. 2. The 1/4-in.-diam gage section was 3/4 in. long, and terminated at shoulders 5 mils high. These shoulders served as fiducial marks for optical strain measurements. Surface finish on the gage section was 16pin. r.m.s. One specimen, for a "long-time" test described below, was modified by dividing the 3/4-in. gage length into three 1/4-in. long sections with individual diameters of 0.250, 0.230, and 0.210 in., each terminating in a pair of fiducial shoulders. TESTING PROCEDURE The constant-load creep-testing machine used has been described by Smith, Olson, and Brown.6 In it the specimen is held vertically on the axis of a cylindrical tantalum or tungsten heater tube by threaded molybdenum or tungsten grips. Both specimen and grips are heated by radiation from the heater-tube, which is heated by its own electrical resistance. The bottom specimen grip is held at its lower end by a clevis pin. The testing load is applied to the specimen through the upper grip by means of hanging weights, a constant force-multiplication lever system, and a pull rod sealed to the chamber lid by a bellows. The incandescent specimen is viewed by an external optical system through slots in the heater-tube and radiation shielding, and an enlarged image of it is projected on a ground-glass screen. Gage-length measurements are made on this image with a pair of cathetometers. Thorium oxide coatings were applied to the threaded ends of most specimens, to prevent diffusion-welding of specimens to grips during testing. Without such a coating welding usually occurred, and grips were often broken by subsequent efforts to remove the tested specimens.

Jan 1, 1960

By E. F. Ketterer, D. B. Collyer, A. B. Wilder

AISI constructional alloy steels are a series of steels in which a numbering system signifies the chemical composition limits. SAE (Society of Automotive Engineers) and AISI (American Iron and Steel Institute) use basically the same numbering system. The steels contain, in part, alloy additions of chromium, molybdenum, nickel, and vanadium. They are used widely in the automotive industry but have not been adopted for high temperature service. The purpose of this investigation was to study changes in microstructure observed in typical AISI constructional alloy steels in the welded and un-welded conditions after exposure for 34,000 hr at 900" and 1050" and, in several instances, 1200°F. The tensile and creep rupture properties after exposure for 10,000 hr were also evaluated. The investigation is a continuation of the work previously discussed. Little was known concerning the existence of graphite in medium or low carbon steels before 1943. It is important to note that continued exposure at elevated temperature is required in order to develop graphite in steels. Interest in the presence of graphite in steel, and also in changes in the properties of steels after long service at elevated temperatures, developed after 1943 when a failure of a welded joint of high temperature piping was associated with the graphitization of a relatively low carbon content steel with 0.50 pct Mo,8,0 Numerous investigations have beeen made in recent years studying the relationship of this type of failure to changes in properties. Attempts have been made to evaluate the performance of a number of steels, particularly in the heat-affected zone of welds. It was the unfortunate failure of a weld-heated zone in high temperature piping in the steam-power industry which focused attention upon possible failures, and upon the need for improved steels for high temperature piping service. Investigation by the National Tube Div., U. S. Steel Corp., Lorain Works, has included a wide variety of steels in an attempt to learn the effects of numerous factors and elements upon the long time performance of steels, although many of the compositions studied will never be used at elevated temperatures.1,4-7 Included were the well established AISI steel series, which offered opportunity to test moderately high carbon content steels as well as observe the effect of nickel, chromium, molybdenum, etc., upon the properties of these well known steels. The properties of the AISI steels were also studied for comparison with the previously reported properties of the Cr-Mo steels, now used by the steam-power industry.5,7 Materials and Testing Procedure The AISI alloy steels in Table I were exposed for 10,000 and 34,000 hr at 900°, 1050°, and 1200°F.

Jan 1, 1958

By Ellen H. Richards

The water-supply of a country may be considered from three points of view: (1) its abundance and availability for agricultural purposes; (2) its chemical properties in their relation to manufacturing purposes; and (3) its quality and quantity as affecting domestic consumption. This paper concerns only those characteristics which may affect manufacturing and domestic uses. The so-called sanitary analyses deal not only with the common mineral elements found in water, but with organic matter and with those substances which, by their presence, indicate changes taking place through the agency of living organisms. Since these living organisms are frequently accompanied by others, capable, as are believe, of causing disease, the products of their action are looked upon with suspicion even when, as in the case of nitrates, that action may have taken place at a time long past. Therefore, upon the quality of the water-supply depends much of the history of a country, when rightly read, as well as much of its promise for the future. Thus, the hardness," or content of calcium and magnesium salts, gives a means of distinguishing at once between the waters traversing only igneous or other siliceous rocks and those coming from calcareous deposits. The presence of decomposing organic matter and intermediate products betrays a use of the water as the public carrier of refuse, which renders doubtful its fitness for domestic supply. In certain regions, one of the most valuable historical records is made by the relative amount of chlorine in the different waters. In the absence of rock-deposits carrying salt,, the chlorine present in rain and snow, and hence in mountainstreams and springs, appears to be derived from the air-borne, finely divided salt spray resulting from the beating of the ocean waves on the coast. If this be true, then the amount of chlorine found in a given water not contaminated with chlorides

Jan 1, 1902