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By G. J. Wolga, W. W. Tyler, A. C. Wilson

THE physical properties of uranium have been reviewed by Katz and Rabinowitch.1 Their review includes thermal conductivity data for ternperatures above 375°K. Recently, Mendelssohn and Rosenberg' have published data on the thermal conductivity of uranium from 2" to 20°K. Our measuremerits indicate the temperature dependence of the thermal conductivity in the temperature interval from 20" to 300°K. Electrical resistivity and thermoelectric power were measured on the same sample. The material studied was normal uranium which had been heated at 700°C in a lead bath for 10 min and then quenched in a water bath held at 50°C. From this material a rod M in. in diameter and 2 1/2 in. long was machined. Two 0.040 in. holes were drilled into the rod 1 3/4 in. apart. Copper-constantan thermocouples for temperature and potential measurements were soldered to copper pins which were pressed tightly into these holes. Details of the equipment and experimental techniques used in making the measurements have been described elsewhere." Fig. 1 shows micrographs of a section of the sample studied. Fig. la was taken with unpolarized light and shows impurity inclusions, probably uranium carbide. Fig. lb, showing the same field, was taken with polarized light and gives some indication of the grain size and twinning within the grains. Experimental Results Thermal conductivity and electrical resistivity data are shown in Fig. 2. Table I shows values of

Jan 1, 1954

By Morris E. Fine, Richard A. Kloske

The stress-strain beha1,ior in tension of Au-Ag alloy single crystals containing nominally 1,3, 5, 95, 97, and 9.9 at. pct Ag was studied uS strain role and lektlperalure down lo 4.2K. A slrain aging yield hob lc,rrs observed on aging under stress in the temperature range 30° lo 75°C. The species diffusing to the dislocation is thought to be a divacancy-solute complex wilh /he. solute then pinning the dislocation by short-Range ovdering and possibly Suzuki locking. At room tempevullcve the critical reso1ved shear stress .follo~c.s an empirical equation of the form tc = A +Bc' where A and B are 90 and 420 ,g per sy mm tor gold base alloys and 60 and 510 g p~r sq )11ttz .tor si1ver base alloys. This strengthening was attributed to a long-range size ejtect. The alloy slrenglliening at i.2'K is greafer than at room temperature. The additional atrloutzf was altribuled lo a uwak skovl-range i?~levacIion between the solute and dislocallon cove. The activation energy .tor deformation a/ 4.Z0h7 decreases on alloying. 11 increases irr other fee systetns. hi the 5 at. pcl Air-Ag- alloy in pmvlicular there is very extensive easy glide and lavge overshooting- of the synmetry line at 4.Z°K. There is also u sharp decrease in the vale of. strain hardenitlg near the widdle of stage II with the new rate bezng abold the sarne as tlzal In easy glide. This uws attributed to a sudden reduction of activity on the pvitrrarg sgstertr. In Au-Ag alloys the critical resolved shear stress Tc. at room temperature is essentially a parabolic function of atomic concentration:' the 50 at. pct Ag-50 at. pct Au alloy is about 10 times stronger than the pure metals. This strengthening occurs in spite of the similarity in valence and atomic size. Solid-solution strengthening in fcc metals is characteristically greater at low temperatures than at room temperature. In Ag-10 at. pct Au and Au-10 at. pet Ag; r, (20.4K)/Tc (300°K) is 2.3 and 2.5. respectively.- compared to 1.2 in pure silver.3 Suzuki' and Flinn5 explained the alloy strengthening at room temperature as a combination of Suzuki locking and short-range order hardening. The agreement between the computed and measured strengthening was very good: however, in Ag base-A1 alloys Hendrickson and Fine6 concluded that Suzuki locking resulted mainly in a yield drop effect. Recent reviews of the solid-solution strengthening in fcc metals by Fleischer2 and Haasen8, 9attributed the strengthening at room tenl-perature to the combined effect of atom nlisfit and change in shear modulus 011 the long-range stress field surrounding a dislocation. The parameter used by Fleischer was The shear tnoduli of Ag-0 to 6 at. pct Au alloys were measured by Pur-wins. Labusch. and Haasen.In While addition of 4 at. pct Au caused an appreciable increase in the C,, elastic constant. there was a decrease on increasing the solute to 6 at. pct Au: C,, and C :: were not measured in the 6 at. pct alloy. The greater solution hardening at low temperatures implies the presence of short-range interactions between the solute atoms and dislocations These include size and electronegativity effects. Whether the extra alloy strengthening at low temperatures is due to locking or friction hardening is still a controversy."".' In the present research the stress-strain behavior of Au-Ag single crystals containing 1 to 5 at. pct Ag and 1 to 5 at. pct Au was measured vs strain rate and temperature down to 4.2' K. Particular attention was paid to yield drop effects. These have not been previously reported. PROCEDURES The alloys were supplied by the Engelhard Industries. Inc.. as strips 0.050 by 0.250 by 12 in. The compositions are given in Table I. Single crystals were grown under static vacuum using a traveling molten zone technique. Crucibles shaped to the size of the strips were made of high-purity graphite prebaked for 24 hr at 1100°C in vacuum. The crucible and its charge were placed in

Jan 1, 1970

By AIME AIME

A CERTAIN area in the State of Indiana seems to be a breeding place for presidents and near president about eighteen miles southeast of Elwood is the little village of Daleville, and there, on April 9, 1890, John Robert Suman, newly elected President of the A.I.M.E., was born. It was not long before he migrated to California, however, where he went to the Los Angeles High School, then for two years to the University of Southern California, after which he went up to Berkeley

Jan 1, 1940

By Charles H. Fulton

(Cleveland Meeting, October, 1912.) I. INTRODUCTION. THERE are comparatively few accurate data on the melting-or the freezing-point temperature of metallurgical slays, or on related physical phenomena, such as fluidity near the melting-point, specific heat, latent heat, etc. With the exception of the work of H. 0. Hoffman,1 and some older work by R. Akerman, P. Gredt, and H. M. Howe, no information is available that is of direct interest to the metallurgist. Hofman's valuable work is the only one that refers to slags produced in the metallurgy of copper and lead. The classic work of J. H. L. Vogt,2 who views slays from the standpoint of physical mixtures (solutions in which the entities are minerals), has opened up a. new field in the study of slags, and has placed the investigation of such properties as melting-temperatures, etc., on a rational basis. The recent work of A. L. Day, E. T. Allen, and W. P. White, of the Carnegie Institution, at Washington, and of European investigators 3 on certain systems of silicate minerals confirms the value of the investigation of silicate series from this standpoint, and it is my aim to apply this method to metallurgical slaws, in order to gain exact data of value in metallurgy. The work recorded in the present paper is the result of an investigation of reverberatory-furnace slags made for a Western smelting company to determine exactly the influence of change in composition, within comparatively narrow limits, on the melting-point. For a general discussion concerning the mineralogical character of slaws and the principles on which this investigation is based, reference should be made to other work,4 for the subject is too large to be stated in this paper, except very briefly in the following outline 1 Trans., xxix., 682 (1899). 2 Die Silikatschmelzlösungen; I. Ueber die Mineralbildung in Silikatschmelzlösungen; II Ueber die Schmelzpunkt-Erniedrigung der Silikatschmelzlösungen (Christiania, 1903-04). 3 Doelter, Handbuch der Mlineralehevu:e (1911) 4 C. H. Fulton, Principles (of Metallurgy. Chapter viii., on Slags, p. 24.5 (1910).

Dec 1, 1912

By R. B. Woodworth

INTRODUCTION IN the sinking of bore holes, there are but two fundamental operations -drilling and hoisting,-which determine in the main the character of drilling mechanism and structures. There are endless ramifications, however, in the execution of these fundamental operations, according to the purposes for which the bore holes are drilled, their maintenance after completion, the protection and convenience of workmen, etc. The three main lines of use for bore holes are in mineral exploration, the sinking of water and salt wells, and the exploitation of petroleum and natural gas. This paper has to do more especially with the last. Here again there are many divergences. Wells may be drilled by either the percussive, the hydraulic, or the abrasive method. Finally, each of these methods, as applied by drillers of diverse nationalities, has followed somewhat different lines of development. The American system of cable-tool drilling has perhaps had the widest application; the hydraulic rotary is also in extensive use; but the Canadian system, the Galician system, and the Russian free-fall system all have their points of recognized merit and are preferred by operators accustomed to their use. These differences in drilling procedure, which rest ultimately on essential variations in geological conditions, are reflected in the chilling structures as well as in the drilling mechanism. The purpose of the present paper is to record those stages in the development of the application of steel to the construction of drilling mechanism and structures with which the writer has been intimately associated, and to contribute to the history of the art of drilling other data acquired in the course of his personal investigations. It is necessarily limited by reason of space to American practice, with especial reference, therefore, to the cable-tool system and the hydraulic rotary method of drilling wells for oil and gas.

Jan 11, 1915

By Louis D. Huntoon

The Porcupine gold area, located on the Hudson Bay slope of northern Ontario, has produced over $100,000,000 in gold and has paid more than $28,000,000 in dividends, since the first real production in 1912. The character of the ore has been studied by the geologists of the Bureau of Mines of Ontario, the geological staffs of the operating mines, and engineers commissioned to examine properties there. What information the Government has is free to everybody; the geological staffs of the several properties also give to the visiting engineer what information regarding ore deposition they possess, and the author wishes to express his indebtedness to the geologists of the Ontario Bureau of Mines and the staffs of the operating mines for their free discussion of geological questions. This paper is based on the examination of several properties, various petrographic reports, not only on specimens from Porcupine but from elsewhere in northern Ontario, and interviews with Government and mine staff geologists. The petrographic work has been done by Prof. R. J. Colony, of Columbia University. Geological History The geological history of the district may be summarized as follows: The outpouring of great floods of lava accompanied by beds of tuff, flow following flow; the contacts of different flows can be seen in various parts of the camp. This period mas followed by an uplift and the production of the Temiskaming sediments by erosion. Later, dynamic action turned the sediments and underlying lavas on edge; this was followed by the intrusion of igneous rocks—in the Porcupine area the quartz porphyry, which is of such great importance in connection with the gold deposits. Doctor Burrows says: "The intrusions of quartz porphyry have in some way influenced the deposition or location of the gold but it is not likely the porphyry has been the source of the gold-bearing solutions." This statement of Doctor Burrows I indorse. The formation of non-gold bearing quartz veins followed the intrusion of the porphyry. These veins occur along or near the contact of

Jan 1, 1923

By Louis D. Huntoon

The Porcupine gold area, located on the Hudson Bay slope of northern Ontario, has produced over $100,000,000 in gold and has paid more than $28,000,000 in dividends, since the first real production in 1912. The character of the ore has been studied by the geologists of the Bureau of Mines of Ontario, the geological staffs of the operating mines, and engineers commissioned to examine properties there. What information the Government has is free to everybody; the geological staffs of the several properties also give to the visiting engineer what information regarding ore deposition they possess, and the author wishes to express his indebtedness to the geologists of the Ontario Bureau of Mines and the staffs of the operating mines for their free discussion of geological questions. This paper is based on the examination of several properties, various petrographic reports, not only on specimens from Porcupine but from elsewhere in northern Ontario, and interviews with Government and mine staff geologists. The petrographic work has been done by Prof. R. J. Colony, of Columbia University. Geological History The geological history of the district may be summarized as follows: The outpouring of great floods of lava accompanied by beds of tuff, flow following flow; the contacts of different flows can be seen in various parts of the camp. This period mas followed by an uplift and the production of the Temiskaming sediments by erosion. Later, dynamic action turned the sediments and underlying lavas on edge; this was followed by the intrusion of igneous rocks—in the Porcupine area the quartz porphyry, which is of such great importance in connection with the gold deposits. Doctor Burrows says: "The intrusions of quartz porphyry have in some way influenced the deposition or location of the gold but it is not likely the porphyry has been the source of the gold-bearing solutions." This statement of Doctor Burrows I indorse. The formation of non-gold bearing quartz veins followed the intrusion of the porphyry. These veins occur along or near the contact of

Jan 1, 1923

By L. A. Geoffrion, R. H. Perkins, J. C. Biery

Densities of cerium metal and several lour-melting binary cerium alloys were measured over the range 25° to 800°C. A rolumeter, using NaK as working fluid, was used to obtain the data. The cerium, Ce-Co, Ce-Ni, and Ce-Cu alloys all exhibited an increase in density on melting, while a Ce-Mn alloy expanded on melting. FOR the proper design of a nuclear reactor, the change in density of the fuel with temperature must be known. This is especially important in a system utilizing molten fuel, such as LAMPRE (Los Alamos Molten Plutonium Reactor Experiment), since a relatively large change in density usually occurs during the solid-liquid transition. The fuel for LAMPRE is a Pu-2.5 wt pct Fe alloy with a melting temperature of 410°C. However, limitations in reactor design with this fuel have led to consideration of other plutonium-containing alloys for use in future generations of this type of reactor. Several ternary alloys containing plutonium and cerium as two components have satisfactorily low melting points. The system that at the present time appears to be most acceptable is Pu-Ce-Co; it exhibits little change in melting temperature with wide variation in plutonium concentration. Other alloys that have received some consideration contain nickel, copper, and manganese as the third constituent. The proposed fuel alloys are difficult to handle experimentally in the 25" to 800°C temperature range since they oxidize readily, react with many solvents, and contain a poisonous fissionable material. In addition, in this temperature range the alloys pass through the solid-liquid transition. Several techniques are available for measuring the densities and volume coefficients of expansion of solids or liquids. However, the only apparatus that appears suitable for measuring expansion coefficients over this temperature range and through the phase transition is a volumeter. In a volumeter, the indicating medium must be essentially inert to and insoluble in the material being studied. It must also possess a low vapor pressure over the operating temperature range, and its coefficient of expansion must be accurately known. One material that is satisfactory in nearly all of these respects is the alloy Na-78 wt pct K, which melts at -10°C and has a vapor pressure of 860 mm Hg at 800°C. This relatively high vapor pressure at 800°C requires an overpressure of an inert gas to prevent boiling. While a volumeter is capable of determining accurately the volume coefficients of expansion of materials, it cannot be used for absolute density measurements. Therefore, a density determination at a known temperature must be coupled with the volumeter measurements to give all the desired data. The weight-loss technique using immersion in bromobenzene at room temperature proved to be satisfactory. The preliminary work that was done on this experimental program involved developing and calibrating the equipment, and measuring the densities and volume coefficients of expansion of cerium and some low-melting binary cerium alloys. The complications that are caused with the introduction of plutonium into the system were avoided until the equipment was proved to be satisfactory and until experience was gained in its operation. It is this first phase of the experimental work that is described in this report. DESCRIPTION OF EQUIPMENT AND OPERATING PROCEDURE The NaK volumeter is shown schematically in Fig. 1. Basically, the equipment consists of two weld-sealed stainless-steel containers of nearly identical volume. One container holds a tantalum crucible and the specimen being measured; the other contains a tantalum crucible and a tantalum specimen used as a control reference material. To avoid temperature gradients, the bombs are located in a copper block inside the furnace. Stainless-steel capillaries of equal length and volume connect each stainless-steel container to a glass viewing capillary. The stainless-steel containers, stainless-steel capillaries, and a portion of the glass capillaries are filled with NaK (22 wt pct Na-78 wt pct K). The NaK/gas interface in the glass capillary is viewed with a cathetometer which is accurate to *0.5 mm. The cathetometer readings are used to calculate the volume changes of the samples during a run. This volumeter is basically the same as that described by F. Knight in Plutonium 1960. 2 However, changes in equipment design and operating procedure were made to eliminate some major operating difficulties. These changes are summarized below. 1) In filling the manometer with NaK, gas was frequently entrained in the system. Evacuation of the system before filling failed to eliminate the en-

Jan 1, 1965

By C. D. Hunter, I. B. Browning, N. W. Shiarella

During the year 1936 improvement in the oil industry in Kentucky continued at about the same rate as shown by that of the year 1935 over the year 1934. The development of several new pools in western Kentucky and the increase in the application of repressuring methods to the old fields of eastern and to a lesser extent of western Kentucky increased the total production to 5,481,227 bbl., as compared to 5,175,054 produced in 1935. The principle sources of this increased production are the Livermore field and the new Bates Knob field in McLean County, in western Kentucky, and the result of repressuring operations in the " Corniferous" pools of Lee, Powell, Wolfe, Morgan and Estill Counties and the "Weir" sand (of Mississippian age) fields of Magoffin, Lawrence and Johnson Counties in northeastern Kentucky. The last named fields have a producing sand especially adaptable to these methods. Drilling No new fields were opened in eastern Kentucky during the year. All new drilling was codned to pressure wells and new oil wells to complete patterns around the intake wells. Owing to the relatively low "initial" or flush production of the wells in this section—even though the ultimate recovery per acre is as large—higher prices for crude will have to prevail before extensive search for new fields is begun; as in northwestern Kentucky, where active exploratory work has been carried on as in the several preceding years, resulting in numerous new and prolific, although comparatively small fields. In this section approximately 500 new oil wells drilled in the Owensboro field, embracing several pools in Ohio, Hancock, Daviess, McLean, Henderson, Webster and Nuhlenberg Counties in the northwestern part of the state. The total oil production for this field during 1936 exceeded by many thousand barrels the 2,821,722 bbl. produced in 1935. In these fields the producing sands range from the middle Missis-

Jan 1, 1937

By AIME AIME

THIS year the Chairman of the Institute's Iron and Steel Division is THIS William Anderson Haven, better known to the membership generally as Bill Haven. The Division Chairman is an individual endowed with a broad perspective of the ferrous metal industry he result of his earlier experiences as a successful operating man in the working and management of blast furnaces and his later experiences as an engineering-consulting executive concerned with the design and erection of and steel works throughout the world. William A. Haven was born to iron steel in the Pittsburgh district on ;. 1, 1888, and in due time--or in 1909 graduated from Penn State with a Bachelor degree in industrial chemistry.

Jan 1, 1944

By Edwin Hopkins

THE year 1923 started a few days after the Venezuelan Oil Concessions, Ltd., discovered a 140,000-bbl. well at. La Rosa and a well of between 2500 and 5000 bbl. at La Paz, on the opposite side of Lake Maracaibo. These nearly simultaneous events changed, overnight, the general aspect of oil affairs in Venezuela. Up to that time, big things had been expected by the companies then in the district, but many major companies had shown little interest in the country. Within a few weeks the Pure Oil. Co. and the Gulf Oil Corpn. entered the field and acquired large properties. The Texas Co. purchased several concessions and the Standard of California, Atlantic Refining Co., and Mexican Petroleum Co. established offices. Representatives of many other companies visited the district during the first few months of the year. The sudden influx of buyers naturally caused a great rise in prices and this, together with overproduction in the United States, doubtless caused the slowing up of concession transfers in the latter part of the year. The following property transfers occurred: (1) The Gulf Oil Corpn. contract with the Maracaibo Oil Exploration Corpn., whereby the Gulf acquired the right to select 100,000 acres from the Maracaibo's zones. (2) The Gulf Co. purchase of one-quarter interest in seven concessions of the New England Oil Corpn., Ltd. (3) The Gulf Oil Corpn. purchase of several concessions of Kunhardt and others in the Perija district. (4) The Gulf Oil Corpn. purchase of certain portions of the one-kilometer Lake zone that were not covered by parcels or Government reserves (namely the "sobrantes"). (5) Pure Oil Co. purchase of all Government reserves turned back by Maracaibo Oil Exploration Corpn. in the districts of Mara and Miranda. (6) Standard Oil Co.: of New Jersey deal with the British Controlled Oilfields, Ltd., for control of approxi-mately the eastern third of the .district of Buchivacoa, state of Falcon. (7) Royal Dutch deal with the British Controlled Oilfields, Ltd., for the control of the central third of the district of Buchivacoa, Falcon. (8) The Texas Co. purchase of several concessions in Perija and one west of Mene Grande on the east side of Lake Maracaibo. (9) Purchase by the British Equatorial Oil Co., Ltd., of Goverment reserves corresponding to certain Creole Syndicate parcels under the margin of Lake Maracaibo near La Paz. (10) The Lago Petroleum Co. acquired a concession on all of Lake Maracaibo except a 1-Km. strip along the shore.

Jan 3, 1924

By Dix, E. H.

THE percentage of manganese used in commercial aluminum alloys is small, and yet this element is an important addition to some very valuable alloys. When used alone with commercial aluminum containing iron and silicon as impurities, the usual percentage in wrought materials is from 1 to 1.5 per cent., whereas castings may contain as much as 2 per cent. An aluminum-manganese alloy containing nominally 1.25 per cent. manganese is much used in sheet form for the manufacture of cooking utensils and other articles requiring a little greater strength and hardness than could be obtained with commercially pure aluminum. It is also used for various purposes in the form of rods, tubes and pipes. The aluminum-manganese alloys, both wrought 'and cast, offer excellent resistance to many kinds of corrosion attack. The U. S. Naval Gun Factory uses an aluminum alloy containing from 1 to 2 per cent. each of copper and manganese, for both castings and forgings. Manganese is also used, up to about 1 per cent., as a minor alloying .element in several of the strong aluminum alloys of the duralumin type. It is felt that the role of this element when thus used has not been fully understood, but it is believed that the results obtained in this investigation will throw additional light on the subject. The earlier work on the system aluminum-manganese was general in nature, and no detailed investigations of the relations existent in the useful aluminum-rich alloys have been reported. Guilletl1in 1902 surveyed the system, and Hendrichs2 in 1908 published an equilibrium diagram which, although based on .few data, is often used in the literature. Fragmentary work has also been done by other investigators."

Jan 1, 1927

By H. M. Ziesemer

PRIOR to 1909 that mountain of porphyry, known as. Sacramento Hill, had remained hardly touched but had always aroused suspicions as to the presence of ore within.. During that year, exploratory work was started by underground methods; drifting and raising continued until 1913. It was proved that a mineralized zone existed, the limits of which had not been determined; so, because of the lower costs of exploratory work and the greater desirability of vertical sections, it was decided to prove the extent of the ore zone by churn drills. Drilling continued until the year 1917, when it seemed almost certain that the horizontal limits of the orebodies had been determined. Ore continued in depth in one direction beyond a point where it was economical to explore by churn drilling; this extension is still being developed by underground methods. The irregularities of the boundaries of the ore zones, together with the variable grades of ore encountered, made it necessary to drill on the corners of 100-ft. squares. Two ore zones were proved, known as the East and West Orebodies. The Sacramento Hill porphyry stock intruded into the Dividend fault. The fault ran roughly east and west with a dip to the south, having pre-Cambrian schists on the north against Paleozoic limestone on, the south. This intrusion was accompanied by a silica breccia on the south periphery, along the limestone contact side. The ore lay in the silica breccia and in the porphyry, some distance from the breccia. No ore was found in the heart of the porphyry mass on the north side, along the schist contact. The West Orebody is elliptic in shape, having a major axis of 1200 ft. (366 m.) and a minor axis of 800 ft. (244 m.); these diminish with depth until, at 300. ft., the axes are 500 ft. and 300 ft., respectively. The ore consists of chalcocite, some bornite, chalcopyrite, and considerable pyrite in a silicious gangue. About 30 per cent. of the copper is caused by

Jan 2, 1922

By G. Van Esbroeck, M. Van Weyenbergh

The copper mines of the Katanga region in the Belgian Congo lie along the same mineralized belt as those of Northern Rhodesia. There are two distinct types of deposits in that belt, the dolomitic and the quartzitic. In the dolomitic type the metallic minerals are found in a dolomitic limestone country rock. Through oxidation and enrichment, large deposits of high-grade oxidized copper ores were formed, some of which are being worked by the Union Minière du Haut Katanga. Such deposits are all in Katanga. The quartzitic deposits are found in Katanga and Northern Rhodesia. Here the primary mineralization occurred in sandstones and quartzites, in horizons stratigraphically lower than the dolomites. These rocks are not favorable to secondary enrichment and the oxidized zone is poorer than the sulphide zone, which alone contains the ore. There are also in Katanga a few ore-bearing veins. One of them is being worked in the Prince Leopold mine at Kipushi. Prince Leopold Mine The Kipushi ore body fills a fault vein and invades the wall rocks more or less extensively by metasomatic replacement. The vein strikes north-northeast and south-southwest and dips to the west. The variable dip averages 60' to a depth of 300 ft., and more uniformly 80' below 400 ft. In the upper section the average width is 200 ft. and below the width is about 150 ft. The length of the ore body is 2300 feet. The eastern side of the vein—the footwall—is dolomitic and contains irregular masses of ore sometimes extending 100 ft. or more from the main

Jan 1, 1940

By M. Van Weyenbergh, G. Van Esbroeck

The copper mines of the Katanga region in the Belgian Congo lie along the same mineralized belt as those of Northern Rhodesia. There are two distinct types of deposits in that belt, the dolomitic and the quartzitic. In the dolomitic type the metallic minerals are found in a dolomitic limestone country rock. Through oxidation and enrichment, large deposits of high-grade oxidized copper ores were formed, some of which are being worked by the Union Minière du Haut Katanga. Such deposits are all in Katanga. The quartzitic deposits are found in Katanga and Northern Rhodesia. Here the primary mineralization occurred in sandstones and quartzites, in horizons stratigraphically lower than the dolomites. These rocks are not favorable to secondary enrichment and the oxidized zone is poorer than the sulphide zone, which alone contains the ore. There are also in Katanga a few ore-bearing veins. One of them is being worked in the Prince Leopold mine at Kipushi. Prince Leopold Mine The Kipushi ore body fills a fault vein and invades the wall rocks more or less extensively by metasomatic replacement. The vein strikes north-northeast and south-southwest and dips to the west. The variable dip averages 60' to a depth of 300 ft., and more uniformly 80' below 400 ft. In the upper section the average width is 200 ft. and below the width is about 150 ft. The length of the ore body is 2300 feet. The eastern side of the vein—the footwall—is dolomitic and contains irregular masses of ore sometimes extending 100 ft. or more from the main

Jan 1, 1940

By Henry R. Piehler

Continuous seven- and nine teen -filament close-packed silver-steel filamentary composites mere tested in tension. For purposes of comparison, the tensile behavior of the composite was predicted from the measured properties of the individual com-ponents. It was assumed that the axial strain is the same in both components and that the contribution of each component to the composite flow stress is proportional to its volume fraction. Good agreetnent was obtained between the observed and predicted tensile behavior. However, the composite elongation at fracture was about twice that observed when the individual steel wires were tested alone. Composites in which the filaments were widely spaced failed by the consecutive fracture of the filaments. In composites with closely spaced filaments, a composite instability preceded frachcre. These effects are explained in terms of a lateral restraint to the necking of the filaments which develops in the deforming composite. TWO-COMPONENT or composite materials are increasingly being developed and used as structural materials. Of all the composite geometries used, the filamentary configuration has proved to be the most successful. Polymer-bonded fiber-glas, the most common of the filamentary composites, has been investigated most extensively to date. One explanation of the behavior of fiberglas1 suggests that the load transfer between the glass fibers and the polymer matrix occurs primarily through friction. Bond separation between the fibers and the matrix is presumed to occur at very low stresses. Subsequently, only frictional bonding can provide for the transfer of load from the matrix to the fibers. The force normal to the fiber-matrix interface which gives rise to this friction is assumed to arise from the matrix shrinkage which occurs during solidification. The behavior of metallic filamentary-composite materials would be expected to differ from that of fiberglas in several significant aspects. Residual stresses resulting from differences in thermal contraction can be kept to a minimum by proper heat treatment. A strong wetted bond is formed between the two phases. In brazed joints,2 for example, the interphase bond is sufficiently strong that the weaker material will fail before separation occurs at the interface. Most metal filaments can undergo appreciable amounts of plastic deformation before failure. Failure by plastic instability or necking frequently occurs in metallic filaments, but not in glass fibers tested at room temperature. Differences between the behavior of fiberglas-polymer and metallic filamentary composites have indeed been observed in composites containing various types of metallic filaments in a silver matrix.3,4 At strains of the order of 10-2 pct, all the deformation was accommodated by the silver matrix. Hence, the strength of the composite depended only on the fiber concentration and not on the nature of the fiber. At higher strains, the strength of the composite increased when filaments with higher work-hardening rates were used. Surface slip line observations on a silver-mild steel composite that had been stretched 4 pct showed that an appreciable amount of deformation occurred in the filaments. Work on tungsten-copper filamentary composites5 has shown that the ultimate tensile strength for varying filament fractions followed a linear mixture rule. Assuming that the axial strains in both filaments and the matrix are equal, this linear mixture rule can be expressed as: The subscripts c, f, and m refer to the composite, filaments, and matrix, respectively. A and V are the area and volume fractions of each component. sc and of are the ultimate tensile strengths of the composite and the filaments. sm is the flow stress of matrix at a strain equal to the elongation at failure of the filaments. However, the tungsten filaments can undergo only a limited elongation before they fracture without an appreciable reduction in area. A composite containing more ductile filaments might indeed deviate from this linear mixture rule for the ultimate tensile strength, since filament failure by necking might be arrested by the matrix. SPECIMEN PREPARATION Specimens were prepared from 0.8 pct carbon steel piano wires of 0.015 in. initial diameter. The wires were given a thin nickel flash and a silver plate varying in thickness from 0.015 to 0.007 in., depending on the filament fraction desired. In order

Jan 1, 1965

By Persifor Frazer

The following notes on the Whopper and adjoining mines in the Gunnison district of Colorado mere made in the spring of this year. The time chosen for the author to visit the region was, unfortunately, the most unfavorable of an exceptionably unfavorable year. About the middle of May all the hill slopes, which at this period of the pear are generally covered with pasture, were thickly covered with snow. The unusually large precipitation of this Tear caused loacal mountain torrents at every few hundred feet, which wore away the oft foothills into gulches, gouged great chasms out of the roads, and transformed miles of usually dry soil into dangerous quagmires. Travel was totally interrupted for weeks, except on horseback or afoot, and even then with great difficulty and some danger. The Whopper mine is situated on the Whopper Mountain, about two miles from the headwaters of Rock Creek, and on the right hank of that stream. The Whopper Creek flows into Rock Creek horn the east, and, by a precipitous descent, offers excellent facilities for its utilization as a source of power. This stream, which pours past the picturesque Whopper Cabin about thirty tons of water a minute, has a fall of 100 feet in 400 yards, and is said to be a stream of some size, even at the seasons of the year when drought prevails. The Whopper claim extends down the hill a distance of about 250 feet to its intersection with the Whopper Creek (on the other side of which is a small tunnel on its extension called the "Teller") and over the steep hill northwest to the limits of the claim about 1250 feet. The part of the mountain in which this mine is situated is remarkable for its splendid forest, the spruce, fir, and quaking asp covering the mountain-sides with a green growth of valuable timber. The distance from Gothic City to this mine is about eight miles along the valleys of East River and Rock Creek, and on the divide which separates them. The elevation of Gothic City is given from the engineer's notes as 9500 feet above sea-level, and the mean of several observations with a Beck watch-barometer made the elevation of Whopper Cabin (which is about fifteen feet above the floor of the Whopper upper tunnel) about 1260 feet above Skiles's Cabin in Gothic City. The record of this instrument must, how-

Jan 1, 1881

By Persifor Frazer

THE following notes on the Whopper and adjoining mines in the Gunnison district of Colorado were made in the spring of this year. The time chosen for the author to visit the region was, unfortunately, the most unfavorable of an exceptionably unfavorable year. About the middle of May all the hill slopes, which at this period of the year are generally covered with pasture, were thickly covered with snow. The unusually large precipitation of this year caused local mountain torrents at every few hundred feet, which wore away the soft foothills into gulches, gouged great chasms out of the roads, and transformed miles of usually dry soil into dangerous quagmires. Travel was totally interrupted for weeks, except on horseback or afoot, and even then with great difficulty and some danger. The Whopper mine is situated on the Whopper Mountain, about two miles from the headwaters of Rock Creek, and on the right bank of that stream. The Whopper Creek flows into Rock Creek from the east, and, by a precipitous descent, offers excellent facilities for its utilization as a source of power. This stream, which pours past the picturesque Whopper Cabin .about thirty tons of water a minute, has a fall of 100 feet in 400 yards, and is said to be a stream of some size, even at the seasons of the year when-drought prevails. The Whopper claim extends down the bill a distance of about 250 feet to its intersection with the Whopper Creek (on the other side of which is a small tunnel on its extension called the "Teller ") and over the steep hill northwest to the limits of the claim about 1250 feet. The part of the mountain in which this mine is situated is remarkable for its splendid forest, the spruce, fir, and quaking asp covering the mountain-sides with a green growth of valuable timber. The distance from Gothic City to this mine is about eight miles along the valleys of East River and Rock Creek, and on the divide which separates them. The elevation of Gothic City is given from the engineer's notes as 9500 feet above sea-level, and the mean of several observations with a Beck watch-barometer made the elevation of Whopper Cabin (which is about fifteen feet above the floor of the Whopper upper tunnel) about 1250 feet above Skiles's Cabin in Gothic City. The record of this instrument must, how-

Jan 1, 1881

By G. T. Jackson

The Alaska Gastineau Mining Co.'s mine is located at Perseverance, about 4 mi. east of Juheau, Alaska. Its property consists of a group of claims, the lode system traversing these claims for a distance of 11,000 ft. (3352 m.). It is shown in Fig. 1. The ore deposits occur in what is known as the Juneau gold belt. This gold belt can be traced for about 50 mi. northwest of Juneau and 40 mi. southeast. It consists of a single band, several hundred feet wide, in which stringers and veins of quartz, carrying gold, occur in a slate formation near its contact with some altered volcanic rock known as greenstone. The Perseverance orebody consists of stringer lodes, having a strike northwest and southeast, dipping about 60° to the northeast. These

Jan 1, 1920

Some 30,000 people attended from 50 countries. Over 600 exhibitors brought with them a billion dollars of mining technology, ranging from tiny high-precision valves to giant off-highway trucks. Twenty-seven technical sessions with more than 100 papers covered the gamut of mining advancements. It was a grand display of industry vitality just to power the huge exhibit area required 22,000 kW of electricity each day, and support services for the exposition created more than 1000 daily jobs for local labor. Unquestionably, Las Vagas knew the miners were in town for the American Mining Congress' International Mlining Show.

Jan 11, 1978