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By R. D. Nelson, S. D. Dahlgren

The conditions of temperature, strain rate, and total strain favoring deformation by grain boundary sliding, slip, or deformation with concurrent recrystallization were evaluated for alpha plutonium. Grain boundary sliding and slip were studied by examining structures formed on polished surfaces with 4.5 pct compressive deformation. The conditions required for recrystallization were determined from compressive deformation us time curves. At 110" C and at a strain rate of 10&apos;per min, deformation was almost exclusively by grain boundary sliding whereas slip was the predominant deformation mode at -10°C and lo-&apos; per min. Defarmation at intermediate tenzperatures and strain rates produced structures showing mixtures of grain boundary sliding and slip. Recrystallization occurred concurrently with deformation only after a critical strain was reached. About 14, 6, and 3 pct strain was required at 105", llO°, and lZO°C, respectively, before recrystallization started, irrespective of the strain rate in the range of lo-&apos;1 to 10&apos;4 per nzin. L HE temperature and strain-rate dependency of the modes of plastic deformation were evaluated for high-purity as-cast alpha plutonium. The techniques used to study slip and grain boundary sliding were similar to those employed previously for alpha plutonium by Bronisz and Gorum,&apos; and spriet.&apos; Recrystallization was investigated using the methods reported by Nelson.3 Bronisz and Gorum&apos; found that slip occurred on more than one slip system at room temperature, and suggested that grain boundary sliding also contributed to the deformation. spriet2 found that deformation was predominantly by slip at room temperature, and observed one to three orientations of slip traces in individual grains. In addition, he deformed polished samples at 10O° C, but concluded that the deformation character of alpha plutonium at 100° C and at room temperature were not essentially different. Several investigators reported that twinning was only occasionally observed.1&apos;2&apos;4 Nelson3 recently found in creep tests that high-purity alpha plutonium would recrystallize concurrently with compressive deformation at temperatures between 25" and 115°C. EXPERIMENTAL PROCEDURE Electrorefined plutonium having less than 300 ppm total impurities was received from Los Alamos Scientific Laboratory in the form of +-in. diarn cast rods. Major impurities were americium, <I00 ppm, and tungsten, (60 ppm. Less than 25 ppm each of other impurities were present. The rods were cut into right half-cylinders 0.35 in. long and 0.25 in. in diam, and the flat faces along the cylinder axes were metal-lographically polished. To avoid loss of the metallo-graphic polish by oxidation, the polished samples were deformed in a silicone fluid heat treating medium contained in a chamber evacuated to a pressure of lo-&apos; torr. Deadweight loading was used to compress the samples between 4.5 and 20 pct at strain rates between 10"4 and lo- &apos; min-&apos;. Strain rates were determined by dividing the total deformation by the elapsed time of the test, even though the strain rate was not constant during deformation. Curves of strain vs time for samples deformed with a constant compressive stress3 show that the strain rate changes by less than a factor of four during the testing of a given sample, which is small compared to the three orders of magnitude change in strain rate investigated. Two samples were loaded into an ordinary metallographic mounting mold and impacted by striking the mold piston with one blow of a 2-lb hammer. Deformation temperatures for the two impact samples were 25" and 90°C. The samples, following deformation, were washed in carbon tetrachloride and their polished and deformed surfaces were immediately inspected metallographi-cally. Subsequently, the deformation structures were replicated with acetate replicating tape for later electron microscope examination, and the samples were then repolished and etched to reveal the microstruc-tures of the deformed metal. Second-stage carbon replicas were prepared from decontaminated acetate replicas using the procedure developed by Miller, Bierlein, and astel.&apos; Additional samples, which were 0.35 in. long by 0.25 in. in diam, were used to obtain constant load deformation vs time curves. These samples were deformed 10 to 20 pct with loads of 15 and 20,000 psi at 120°C; 30, 45, and 55,000 psi at 110°C; and 20 and 30,000 psi at 105°C. Samples were polished and etched to determine whether or not recrystallization or twinning had occurred during deformation. RESULTS AND DISCUSSION The experiments showed that alpha plutonium deforms by grain boundary sliding, slip, and deformation with concurrent recrystallization. Deformation by twinning was insignificant. Metallographic examination of polished and deformed surfaces revealed grain boundary sliding and slip. The start of recrystallization was ascertained from constant load deformation vs time curves. Deformed surface structures of samples compressed 4.5 pct under four different conditions of temperature and strain rate, Fig. 1, show how the deformation mode changes from predominantly grain boundary sliding to predominantly slip with increasing strain rate and decreasing temperature. Deformation at 110°C and 10" 4 min-&apos;, Fig. l(a), was predominantly by grain boundary sliding. Only a few slip traces can be seen in Fig. l(a).

Jan 1, 1969

By J. L. Brimhall, R. A. Huggins, M. J. Klein

IN a recent paper1 it was shown that small additions of magnesium, copper, and oxygen decrease the stacking fault probability in plastically deformed silver. Correlation of :X-ray data with measurements of the twinning frequency and metallographic observation of slip lines indicated that this effect may be due to an increase in the relative stacking fault energy. It is the purpose of the present note to report experiments on these alloys of known stacking fault probability that relate to the stacking fault contribution to electron scattering in silver. There has been a considerable amount of disagreement in the literature concerning the contribution of dislocations to electrical resistivity in metals. Calculations relating to the scattering of conduction electrons by the dislocation core, its strain fields, and related effects have been made by several authors.2-5 In addition, experimental work on Cu,3,6-10 Ni,11 and Ni-Co alloys1:! has shown that dislocations in those materials exert an anomalously large effect on resistivity, this effect being related to the presence of extended dislocations. The problem of the scattering due to the stacking fault region between partial dislocations has been treated theoretically using several different procedures.13-&apos;0 The results of these calculations show a wide range of predicted values, from rather large to completely negligible, due to the models and the approximations involved. Almost all of this work has been applied to the specific problem of scattering in copper. The more complete theoretical treatments depend rather critically. on the shape of the Fermi surfaces and the effective mass parameters. The scattering from stacking faults might therefore be expected to vary significantly from one metal to another. Unfortunately, sufficiently accurate information is not available .which would allow one to have any confidence in a theoretical prediction of the scattering in the case of silver. Resistivity measurements were made on small wire specimens of vacuum melted high purity silver and several dilute alloys. These measurements were made at approximately 20°C, with great care being given to temperature measurement and corrections. At such temperatures phonon scattering is significantly greater than imperfection scattering. However, the experimental technique was such that measurements on similarly treated samples were reproducible to better than 2.4 X 10-9 ohm-cm, which was satisfactory for this work. Values of the stacking fault probability and the increase in resistivity after severe plastic deformation are given in Table I. The increases in resistivity resulting from plastic deformation agree quite well with previous work on silver.14,21-26 In addition, it has been previously found that interetitials and vacancies in silver anneal out well below room temperature, so that the residual imperfection scattering in these experiments could be expected to be primarily associated with dislocations;. It is seen from the data in Table I that large changes in stacking fault probability are accompanied by differences in resistivity due to imperfection scattering of only a few percent. If the scattering of conduction electrons by extended dislocations is primarily due to the area of the stacking fault region independent of the stacking fault energy, and not the core and strain fields associated with partial dislocations, the resistivity increase should be proportional to the product of the dislocation density and the stacking fault width, as is the stacking fault probability. Therefore, the imperfection scattering caused by plastic deformation of the alloys should be considerably smaller than that found in the pure silver. Since this was not observed, these results sugegest the possibility that stacking faults do not themselves contribute appreciably to the electrical resistivity of silver deformed at room temperature. An alternative explanation of these observations is that the scattering by the stacking fault is roughly proportional to the stacking fault energy, rather than being determined by the total area of such faults. Sufficient evidence is not yet available to separate these two possibilities. This work was supported by the Office of Naval Research.

Jan 1, 1962

By S. R. Balajee, I. Iwasaki

The interaction between British gum 9084 and dode-cylammonium chloride (DAC) at quartz and hematite surfaces was established from coadsorption studies and streaming potential measurements. The cationic DAC interacts with the somewhat anionic British gum 9084, leading to the formation and adsorption of a binary complex of DAC-British Gum 9084 at the interface. The parallel ability to depress quartz along with hematite as a result of the interaction between DAC and British gum appears to be the main reason for the ineffective depressant action of starches and starch derivatives in the cationic flotation of iron ores. Amines are not particularly selective collectors for the flotation&apos; of siliceous gangue from iron ores and, therefore, a suitable iron oxide depressant is needed for a satisfactory separation. Various starches and their derivatives have been extensively tested with oxidized iron ores,&apos;-3 and it has been empirically established that British gums and dextrins are preferable. However, for the flotation upgrading of magnetite-taconite concentrates from 8 or 8.5% Si O2 to about 5% Si 02, British gums, which have been used so successfully on oxidized iron ores, have been found to have no effect and oftentimes are actually deleterious.4 In previous articles,5-7, starches were shown by adsorption measurements, flotation tests, and floccula-tion tests to interact with calcium ions in solution, and it was thought that a study on the interaction between starches and dodecylammonium ions would be able to shed some light on the anomalous flotation behavior described above. In fact, starches are known to interact markedly with paraffin-chain-type surface active agents and, thereby, to precipitate the starch or inhibit the iodine-starch reaction.8 From X-ray diffraction studies and viscosity measurements, the formation of a helical complex between mylose and a surface active agent has been postulated.9 The interaction with other types of hydrophilic colloids, such as synthetic polymers and proteins, has also been investigated and is usually explained in terms of van der Waals&apos; force interaction and/or ion-ion interaction. In the present investigation, the interaction of British gum and dode cylammonium chloride on quartz and hematite was studied by adsorption and streaming potential measurements in an attempt to establish the mutual adsorption behavior of British gum and dode-cylammonium chloride on mineral surfaces and to clarify the anomalous depressant activity of British gum in the cationic flotation of iron ores. All the measurements were carried out at a natural pH of near 7 because dodecylammonium chloride gives maximum selectivity of flotation separation at this pH2 and to avoid any third parameter in the system. EXPERIMENTAL MATERIALS AND METHODS Minerals: The quartz and hematite samples used for the adsorption tests were prepared as described in a previous paper,"J except that the specific surfaces of the samples were increased to 5,860 and 16,000 Sq cm per gm, respectively. For the streaming potential measurements, the 48165-mesh fractions screened out of the original samples were etched with hydrochloric acid, washed repeatedly with water, and stored under water in Pyrex bottles. Reagents:DodecyIammonium chloride (DAC) was prepared1 1 by bubbling dry hydrogen chloride gas through a benzene solution of high-purity dodecylamine supplied by Armour and Co. British gum 9084, received from Corn Products Co., was solubilized by first dispersing it in water to produce a 0.05% solution and then homogenizing it in a blender for 5 min. Distilled water was used in the preparation of the samples and the solutions and for all test work. Adsorption Measurements: The procedure for the adsorption density determinations was also the same as that described in the previous paper.1° The residual concentrations of the British gum and the DAC in the supernatant solution were analyzed colorimetrically by the phenol-sulf uric-acid and amine-picrate methods, respectively. The validity of the mine-picrate method for the colorimetric analysis of DAC in the presence of British gum and the analysis of British gum in presence of DAC were checked by establishing calibration curves between optical density and concentration. Streaming Potential Measurements: The cell assembly for the streaming potential measurements was similar to that described by Fuerstenau.&apos; The streaming potential

Jan 1, 1970

By OTTO HERRES

TITANIUM is estimated to be the ninth most plentiful element, ranking after iron, aluminum, and magnesium, and ahead of copper, lead, and zinc. Vast quantities of titanium are widespread throughout the world in ore deposits and beach sands. Before the war, processing plants were operated in England, France, Italy, Czechoslovakia, Norway, Russia, Australia, United States, and Japan. In spite of its widespread occurrence, however, the U. S. Department of Justice has held the titanium industry to be a world monopoly and action was taken in the Federal court during the summer of 1945 to enjoin international patent and marketing agreements and to restore free competition. Possibly the rather surprising lack of public familiarity with this industry of international importance arises from its astonishingly rapid development and growth in the strong hands of some of the greatest chemical companies in the world, including the important foreign companies, Imperial Chemical Industries (British), Montecatini (Italian), I. G. Farben (German), and Titan Kogko Kabushiki Kaisha (Japanese). The rapid growth of the titanium industry in the United States is indicated by a tenfold increase of ore imports in the 1930 to 1940 decade before the war began to affect shipments from overseas. The fact that the industry formerly derived practically all ore for chemical processing in American plants from foreign sources probably also accounts for lack of general public knowledge of titanium. In 1939, to meet the requirements of increasing demand for the white pigment. titanium dioxide, more than 250,000 tons of titanium concentrates moved to this country, principally from the Travancore coast of India where the ilmenite concentrate from the beach sand runs as high as 60 per cent in titanium dioxide. Global warfare put a stop to shipping and thus gave rise to the development of titanium mining on a substantial scale in the United States during 1941.

Jan 1, 1946

By M. R. Lorenz

Efficient visible light emission from p-n junctions in semiconductors is currently achieved in the four materials, Sic, GaP, ]Ga1-xAs and GaAs1-x,. Recent advances in materials preparation and p-n junction formation are briefly reviewed. The radiative recombination processes in the different materials depend largely on the band structure and the impurity states of each material. The spectral distribution of the emission ranges from the blue in Sic, to green in Gap, yellow in Sic and red in Gap, Ga1-x AlxAs and GaAs1-x Px. The origin of the various processes are discussed. The conversion of the electrical power into optical power and the measurement of the conversion efficiency are reviewed. The currently maximum quantum efficiencies at 300°K are: 3 pct in GaP(red), 1 pct in SiC(yellow), 0.1 pct in GaP(green), 0.2 pct in Ga1-x AlxAs at 66001, and 0.1 pct in GaAs1-x Px at 6800. The brightness and the interplay of the quantum efficiency and the luminous efficiency are given detailed consideration. VISIBLE light generated by the application of a direct current to a semiconductor crystal was first observed by Lossev1 in 1923. Light emission came from naturally occurring junctions in Sic crystals but little was known then with regard to the mechanism of charge transport and light emission. Some nearly 30 years later and with a vastly increased understanding of semiconductors the phenomenon of electroluminescence was studied in more detail, for example in p-n junctions of germanium.2 In these early studies, the efficiency of converting the electron current into a photon current was very low and therefore aroused little interest toward practical application. More recently it became apparent that in certain materials, for instance GaAs, and under certain conditions, the conversion efficiency was not low at all.3 The subsequent discovery of the p-n junction laser4-6 provided the impetus for increased studies of electroluminescence. Light emitted from GaAs occurs in the infrared region of the electromagnetic spectrum and is not visible to the eye. At nearly the same time the use of GaAs1-xPx led to laser action at low temperatures which was visible to the eye.7 Later a red light emitting diode, made from Gap, was reportedS which emitted incoherent radiation at 300°K with an external quantum efficiency of about 1.5 pct. The fact that such efficient devices were obtainable led to a more concentrated effort in the search for highly efficient room-temperature semiconductor light sources. It is some of this later work on p-n junction luminescence with which we will be concerned here. Since our aim is centered on visible light, with hv =1.8 ev ( ?=7000?), only the wider band gap semiconductors are of interest, i.e., Eg 1 1.8 ev. Although many compounds meet this criterion, only a limited number of those are also good semiconductors, i.e. contain low resistance n and p regions. Some of the more promising candidates are listed in Table I. We will only be concerned with light generation from a p-n junction. This limitation excludes essentially the group II-VI binary compounds, although we will briefly review the case of ZnTe and the solid solution ZnTe1-xSex. As we will show they may contain a p-n junction but only of a special kind. Most of the discussion will deal with the four materials, Sic, Gap, Gal-xAlxAs, and GaAs1-xPx. These appear to be at the present time the best visible light emitting semiconductors. In the following sections we will briefly consider: 1) the electrical properties of p-n junctions; 2) some recent advances in materials preparation; 3) the formation of p-n junctions; and then in somewhat greater detail we will consider: 4) the various radiative recombination processes; 5) the measurement and observation of the external quantum efficiency; 6) the luminous efficiency; 7) the brightness of light emitting diodes (LED&apos;S). THE P-N JUNCTION The p-n junction in a semiconductor crystal is the interface between two differently doped regions. More specifically the p region is doped predominantly with acceptor impurities and the n region contains predominantly donor impurities. The energy band structure of a degenerate p-n junction at thermal equilibrium is shown in Fig. l(a). The excess electrons on the n side of the junction are confined to this region by the barrier potential Eg. Similarly the excess holes on the p-side of the junction are confined to the p-region by a similar potential barrier. If we now apply a dc voltage V such that the p region is made positive and the n region negative, the barrier potential EB is reduced by the applied voltage, V and the junction is said to be forward biased. With the barrier potential lowered, electrons and holes can drift toward the p region and n region, respectively, see Fig. l(b). The current voltage characteristics of p-n junctions in most wide band gap materials can be described by the relation: J = Joexp(eV/BkT) [1] where the functional form of Jo is determined by the recombination mechanism. Jo is generally a complicated parameter which depends on a number of different factors including temperature, junction width, bias voltage, and carrier lifetimes. The parameter B also depends on the recombination mechanism but

Jan 1, 1970

C. R. CORNING, Chairman. ADOLPHE E. BORIE, First Vice-Chairman. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. Vie-Chairmen. JOHN H. ALLEN, GEORGE M. COLVOCORESSES, RICHARD M. ATWATER, JR., ROBERT PEELE, GEORGE D. BARRON, CHARLES P. PERIN, A. CHESTER BEATTY, JOSEPH A. VAN MATER, J. PARKE CHANNING, ARTHUR L. WALKER. D. C. Bard, Howard Eckfeldt. Philip N. Moore, W. de L. Benedict, R. C. Gemmell, T. H. O&apos;Brien, John C. Branner, F. Louis Grammer, James J. Ormsbee. Palmer Carter, Ernest A. Hersam, Edward W. Parker, Allen J. Clark, Edwin C. Holden, John B. Porter, F. Crabtree, William L. Honnold, R. DI. Raymond, George G. Crawford, Reginald E. Hore, Robert H. Richards, O. C. Davidson, C. Colcock Jones, LeRoy Slash, E. V. D&apos;Invilliers, Eugene P. Kennedy, Frederick H. Sexton, James S. Douglas, Chester F. Lee, Henry L. Smyth, Walter Douglas, Richard S. McCaffery, F. W. Traphagen, Howard N. Eavenson, James F. McClelland, Elton W. Walker. Milton H. McLean, The Chairman of the Committee on the eve of his departure frog -,he country for an extended stay, addressed the following letter t ,he President of the Institute NEW YORK, N. Y., APRIL 19, 1913.

Jan 5, 1913

COMMITTEE ON INCREASE OF. MEMBERSHIP. C. R. CORNING, Chairman. ADOLPHE E. BORIS, First Vice-Chairman. THOMAS T. READ, .Secretary, Woolworth Bldg., New York, N. Y. Vice-Chairmen. JOHN H. ALLEN, GEORGE M. COLVOCORESSES, RICHARD AL ATWATER, JR., ROBERT PEELS, GEORGE D. BARRON, CHARLES P. PERIN, A. CHESTER BEATTY, JOSEPH A. VAN MATER, J. PARKE CHANNING, ARTHUR L. WALKER. D. C. Bard, Howard Eckfeldt, Philip N, Moore, W. de L. Benedict, R. C. Gemmell, T. H. O&apos;Brien, John C. Branner, F. Louis Grammer, James J. Ormsbee, Palmer Carter, Ernest A. Hersam, Edward W. Parker, Allen J. Clark, Edwin C. Holden, John B. Porter, F. Crabtree, William L. Honnold, R. M. Raymond, George G. Crawford, Reginald E. Hore, Robert H. Richards, O. C. Davidson, C. Colcock Jones, LeRoy Salsich, E. V. D&apos; Invilliers, Eugene P. Kennedy, Frederick H. Sexton, James S. Douglas, Chester F. Lee, Henry L. Smyth, Walter Douglas, - Richard S. McCaffery, F. W. Traphagen, Howard N. Eavenson, James F. McClelland, Elton W. Walker. Milton H. McLean, Meetings of this committee were held at the Institute headquarters on April 18, and May 2 and 15. It was resolved that meetings shall be held monthly on the third Friday of each month.

Jan 6, 1913

THE Institute assembled in the metallurgical lecture-room of Pardee Hall, Lafayette College, at 7 o&apos;clock P.M. on Tuesday evening, October 21st. The session was opened by the President, R. W. Raymond, with an address on Mining Industry as illustrated at the Vienna Exposition. The second session was held on Wednesday morning. The Council reported the following names for election as members and associates. They were unanimously elected. †Ayres, W. S., - Easton, Pa. *Baker, Prof. A. L., - Easton, Pa. †Browne, Thomas Nicholl, - Hamilton, Nev. *Carter, Frank, - Pottsville, Pa. *Davis, E. F. C., - Pottsville, Pa. *Fox, Prof. J. G., - Easton, Pa. *Haight, Ogden, - Etna, Pa. †Hall, Norman, - Sharon, Pa. *Knap, Joseph, - Fountain Mill, Pa. †Miller William McKeen, - Easton, Pa. †Pardee, I. P., - Easton, Pa. *Plater, John E., - Eureka, Nev. *Platt, Joseph L., Jr., - Franklin Furnace, N. J. *Plumb, W. H., - Mauch Chunk, Pa. *Reis, George L., - New Castle, Pa. *Samuel, Edward, - Philadelphia, Pa. *Smith, William Allen, - Trenton, N. J. *Smock, Prof. John C., - New Brunswick, N. J. *Weberling, Charles, - Salt Lake City, Utah. Also the following as foreign members Beaulieu, Ad. le Hardy de, - Brussels, Belgium.. Beaumont, Major Fred., - London, England. Beck, Alexander, - Mons, Belgium. Bodmer, J. J., - London, England. Brassert, Berghauptmann, Dr., - Bonn, Prussia. Brogden, James, - London, England * Members. † Associates.

Jan 1, 1874

By L. R. Smith

BUTANE OPERATED drilling rigs are a recent innovation in the petroleum industry, so extensive data on their operation are not available. However, experience indicates that, within limitations, as much can he accomplished with butane as with steam, at a decided reduction .in expense of installation and cost of operation. Commercial butane is a liquid motor fuel similar to gasoline, but much more volatile, so that it has to be stored under pressure. At 10° F. it is liquid at atmospheric pressure, but at 100° it has a pressure of 70 lb. or more. As soon as the pressure is reduced, it turns to vapor and in that state is far more easily mixed with the air necessary for combustion. Butane occurs as a by-product in the absorption process of natural gasoline extraction from casing-head gas. The product has been used to some extent 10 raise the octane value of gasoline. However, because of its volatile nature, such admixture is stable only to a limited degree. Attempts also have been made to introduce the product in a gaseous form into oil- hearing formations in repressuring work. It has, however, until recently, for the most part been wasted.

Jan 1, 1937

By W. C. Lilliendahl, G. Meister

Uranium metal with a purity of about 99.9 pct was produced on a large scale by fused salt electrolysis with a material efficiency of about 90 pct. The material efficiency depends mainly on bath composition, electrolysis temperature, electrode smothering, and elutriation during washing of the powder. RESEARCH and development work on fused salt electrolysis carried on by the Westinghouse Lamp Div. Bloomfield, N. J., was done under the Manhattan District Corps of Engineers and later under the Atomic Energy Commission for the commercialization of uranium production for the first atomic pile at the University of Chicago in 1942. From the conception of the atomic bomb project it was recognized that metals with impurity levels having little metallurgical significance would be required. Permissible impurity levels were based on neutron absorption. Of particular significance was boron, which could not be present in amounts exceeding 1 ppm. The electrolytic method as developed in 1930 by Driggs and Lilliendahl,1,2 and later improved, yielded uranium of very low boron and other deleterious impurity content. No other method was capable at that time of producing uranium metal of the required purity.&apos; The low boron content of uranium produced by the electrolytic process resulted from the availability of the reactants which were low in boron content, and from the inherent elimination of boron in the fused salt bath. Since the heart of any electrolytic process is the electrolysis cell, this paper will deal with the development of the original bath composition for the efficient production of uranium from a batch process to one of continuous operation. Emphasis also will be placed on other factors which will affect the material efficiency of the process. With the laboratory cell the material efficiency of uranium powder recovery in the early electrolysis was relatively low, about 35 pct based on the ratio of uranium recovered to uranium added. This early process also had other defects. The electro- lytic bath could not be used continuously. After three runs from a freshly charged crucible, the deposit showed a tendency to slip off the electrode as it was raised from the bath. This condition necessitated pouring the charge every fourth run and preparing a new bath. It was assumed at that time that this condition was caused by the increasing fluoride concentration with each addition of uranium salt, which adected the mobility of the uranium ions. Experimental The electrolysis cells differed in size only. They were of the floating cathode type. The laboratory cells were 21/2 in. ID and 6 in. deep and operated at 30 amp and 5 volts. Production was about 150 g metal powder per 8 hr. The plant cells (5 units) were 9 in. ID x 21 in. deep and operated at 1800 amp at 12 volts. The total production unit was designed to produce 250 lb of uranium powder per 8 hr day. Because of the tendency of uranium fines toward spontaneous combustion, material efficiencies were based only on the recovery of useful coarser metal which could be safely handled. The reported efficiencies are of particular significance only as related to the same group of experimental procedures. At the start of the project no changes were contemplated until previous data could be definitely confirmed. Therefore, the first experiments were with the 50 pct CaCl2-50 pct NaCl mixture. The material efficiency of uranium deposition as a function of the number of electrolyses is shown in Table I. In Table I, the decrease in efficiency at 800°C with number of runs is apparent and confirmed the earlier data. Operating at 900°C enabled the number of runs to be doubled, but before pouring the charge the efficiency of recovery became poor. This test indicated that the improved efficiency might have been caused by an increase in the fluidity of the bath.

Jan 1, 1958

By Carroll C. Bailey, William F. Boericke

Mine financing, or providing adequate capital for developing and bringing a mining property into production, is an essential requirement for a successful operation. Today it presents a different picture than even twenty-five years ago. The day appears to be gone when a mining property could pay its own way from grass roots to production. The country has been quite thoroughly combed for surface showings from which sufficient initial profit could be immediately garnered to pay for further development and production facilities. The four M&apos;s for success in mining-mineral, market, management, and money-are still essential; but doubled or tripled wage costs and steep advances in cost of equipment and supplies throw increased emphasis on adequate capital funds for bringing in a prospect and making it a producer. Consequently, the old picturesque, although seldom rewarding, grub- staking procedure where a single venturesome citizen might advance funds to a prospector on a fifty-fifty basis for whatever discovery he might find, has largely disappeared. Its place, to some degree, has been taken by the small syndicate of venturesome members who band together for furnishing funds to a group of prospectors for the same general purposes. Such a syndicate has a definite organization and is usually assured of sufficient initial funds, or flow of funds, to carry on work for several years. It is headed by an engineer-promoter who has had considerable field experience as well as personal knowledge of his prospecting crews. For the owner of a potential mining property who has ample capital, the problem is to determine (1) justification for the necessary investment in exploration and development, and (2) the economics of the enterprise as to size and degree of integration of the final operating entity. If the owner of such a property has little or no capital, he also faces these same basic problems but, in addition, must be able to present the findings of fact and persuade the prospective investor that the enterprise will produce

Jan 1, 1959

By M. Albertson

UNITED STATES petroleum pro-dU6tion during 1937 materially exceeded? that of any previous year. Firm control of the production rate was maintained under State and Federal laws and aided by the&apos; Interstate Compact. During the first ten months," crude oil prices were stable, except for a slight increase early in the year. Toward the end of the year, uncertainty of price structure be-came evident and a sharp reduction in allowable production was under way. Exploration for new pools and development of .pools already discovered continued active throughout the year. Production control agencies in Texas, and to a less extent in New Mexico and Louisiana, appear to have had increasing difficulty in holding crude oil output to allowable limits. The situation elsewhere is less well known but probably the same condition exists in other important producing States whether control is by State commissions or by unofficial bodies.

Jan 1, 1938

The Institute assembled in the metallurgical lecture-room of Pardee Hall, Lafayette College, at 7 o&apos;clock P.M. on Tuesday evening, October 21st. The session was opened by the President, R. W. Raymond, with an address on Mining Industry as illustrated at the Vienna Exposition. The second session was held on Wednesday morning. The Council reported the following names for election as members and associates. They were unanimously elected. Ayres, W. S.,.......Easton, Pa. *Baker, Prof. A. L.,.. Easton, PR. Browne, Thomas Nicholl,.... Hamilton, Nev. *Carter, Frank,......Pottsville, Pa. *Davis, E. F. C.,... Pottsville, Pa. *Fox, Prof. J. G.,...,..Easton, Pa. *Haight, Ogden,...Etna, Pa. Hall, Norman,...Sharon, Pa. *Knap, Joseph,......Fountain Mill, Pa. Miller William McKeen,.... Easton, Pa. Pardee, I. P.,....Easton, Pa. *Plater, John E.,......Eureka, Nev. *Platt, Joseph L., Jr.,.....Franklin Furnace, N. J. *Plumb, W. H.,......Mauch Chunk, Pa. *Reis, George L.,......New Castle, Pa. *Samuel, Edward,. ..Philadelphia, Pa. *Smith, William Allen,.....Trenton, N. J. *Smock, Prof. John C.,..... New Brunswick, N. J. *Weberling, Charles,.....Salt Lake City, Utah. Also the following as foreign members: Beaulieu, Ad. le Hardy de,. . Brussels, Belgium. Beaumont, Major Fred.,..London, England. Beck, Alexander,.Mons, Belgium. Bodmer, J. J.,..London, England. Brassert, Berghauptmann, Dr.,. .. Bonn, Prussia. Brogden, James,.London, England.

By M. C. Manderson

The sharp drop in world phosphate demand that took place in 1975 due to temporarily high prices, now seems to be reversing itself. And prices for both phosphate rock and phosphate fertilizers, which declined dramatically from their 1975 highs, now appear to be bottoming out. This recent price weakness has delayed new mining ventures that had been planned for completion by around 1980. While there is ample capacity to supply near-term rock needs, the stage seems to be emerging for a better supply-demand and price environment in the late 1970&apos;s and early 1980&apos;s.

Jan 1, 1979

By D. C. DERINGER

METALLURGISTS and mill operators appreciate, in a general way, .the economic or commercial relationship between recovery and grade of product but few have correlated in detail fluctuating metal prices with the metallurgy. They know that many factors such as metal price, dedusiions for returning charge, transportation, percentage of metal in head ore, etc.; all affect the commercial relationship between recovery and grade of product. In practically every mill some one at some &apos; time has calculated the amount of recovery that can be sacrificed for each percentage increase in grade of concentrate and from this calculated ratio the commercial or ., economic tail has been established. Such a ratio finally becomes a well-entrenched rule by which the progress of the metallurgy is judged.. When once established, these-, ratios are but seldom corrected to changes of metal prices for each possible grade of concentrate that may be produced. The calculation is tedious when often repeated. Other methods have been suggested and used to correlate the commercial with the metallurgical phase. A factor .derived ,by multiplying the grade of concentrate by recovery is often used, but is of little importance because it does not possess a single commercial quantity. The percentage monetary recovery calculated by dividing the gross value of the ore into the net smelter return gives a good economic index and, is to be commended, but it is difficult to correlate exactly and quickly the work of each day on a commercial basis.

Jan 1, 1931

By Northcutt Ely

This chapter deals with the systems of laws by which governments regulate the exploration for and production of the minerals within their jurisdictions. It is a summary, restricted by necessary space limitations, of material assembled by the author for a publication of the United States Bureau of Mines, "Summary of Mining and Petroleum Laws of the World," (Information Circular 80 1 7, 196 1. ) The present study is organized in three parts, dealing with (1) the historical background of these legal systems, (2) laws of the United States, and (3) laws of other countries of the world. The reader&apos;s attention is invited to the acknowledgments at the end of the chapter, which inadequately express the appreciation due those who have assisted in the collection of this material. Part I. Historical Development of Major Western Systems of Land Tenancy with Respect to the Ownership and Control of Minerals The use of metals in primitive societies was largely confined to the manufacture of weapons for self-preservation. The ruler&apos;s control over copper, then bronze, then iron, was essential to maintenance of his own ascendancy at home and his group&apos;s position against neighbors who had access to similar metals. Ancient societies were thus characterized by the ruling group&apos;s ownership of minerals and metals. The Egyptian civilization, which emerged in the fourth millenium B.C. upon the agricultural subjugation of the lower valley of the Nile, was responsible for extensive development of the upper valley as a source of mineral wealth. The production of gold during the height of that civilization has been estimated at $30,000,000 per year, thus equaling the early placers of California and Australia. The mines of Egypt were the property of the Pharaohs and were controlled at their direction. Greek mining developed a different scheme of land tenancy which more closely resembled modem concepts. Development of mineral resources was

Jan 1, 1964

By A. W. Gauger

DESPITE many handicaps and in the face of many discouragements anthracite and bituminous coal producers continue to supply the needs of the nation now vastly multiplied by the demands of the greatest war of all time, total output being about 620,000,000 tons of bituminous and 64,445,000 of anthracite. The progress made by this industry during the national emergency reflects more credit on all connected therewith than will ever be given. Not only has the industry been called upon to produce more coal than ever before but it has also sent representatives to England to study and advise on methods for increasing production there, and has co-operated with other Allied Nations by welcoming engineers sent to this country to study American practice. One noteworthy development has been the growth of strip mining in the

Jan 1, 1945

By F. B. Plummer

PROGRESS during 1940 in oil-production technology has been confined largely to a steady advancement in practices inaugurated in previous years, rather than the introduction of any new startling process or technique. The usual changes, improvements and additions in production equipment have been introduced. An increased attention to, and interest in, research has been noteworthy, resulting in improved efficiency in operation of oil wells. control, utilization of reservoir energies and reduction of production costs.

Jan 1, 1941

By W. C. PAGE

ALL mine ore here must be concentrated before shipment, which involves selective flotation. Three products are made: lead, zinc, and pyrite concentrates. The equipment and practice are so well outlined in the accompanying flow sheet that only a few amplifying remarks are necessary. After crushing at the mine to approximately 4 in., the ore is carried by aerial tram about 4 1/2, mi. to the mill. From 1800 to 2000 metric tons per day, excluding Sundays, is thus transported. At the mill, the buckets are hand-tipped into the bins. After crushing to pass a ¼ -in. square opening, the ore may be stored in reserve crushed-ore bins or ball-mill feed bins as desired. Total bin capacity at the mill is about 4000 metric tons. The concentrator is arranged in three independent grinding sections, each fed from its own storage bin. Grinding operations follow standard practice, with ball mills in single-stage closed circuit with classifiers, the overflow from which is delivered to the lead circuit rougher flotation machines,

Jan 1, 1936

By Robert M. Weidenhammer

For years before the war, Coal had the reputation of being a sick industry. Currently it is operating at peak production and succeeding pretty well in keeping out of the red. But, says Mr. Weidenhammer, it will have a relapse as soon as the war ends unless (1) working capital can be built up; (2) it gets the support of the people and Congress; and (3) a truly long-range national fuel policy is formulated.

Jan 1, 1943