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By Nicholas J. Grant, Gordon D. Gemmell

CREEP rupture characteristics of high purity Al-Mg solid solution alloys were studied by Mul-lendore and Grant' to investigate solid solution strengthening of pure aluminum and the accompany- ing effects on deformation and fracture characteristics. This paper presents the results of an extension of that work to A1-Cu and Al-Zn alloys to permit a comparison of the relative effects of the three solute elements on the high temperature strength and on the deformation and fracture characteristics. Experimental Procedure A total of nine alloys was studied. They were all made of ultra high purity aluminum alloyed with high purity copper, zinc and magnesium. The corn-

Jan 1, 1958

By John Wellington Finch

In August, 1927, the writer examined certain copper deposits in New Mexico1 which occur in beds of sandstones and shale, and in connection therewith reviewed the literature upon deposits of this type. Such deposits are known and have been reported upon at various points in Texas, Oklahoma, Arizona, Colorado, Wyoming and Utah, but in New Mexico they have been given more development than elsewhere and apparently occur there more conspicuously than in the other states. Some 25 years ago the writer examined deposits of similar origin in northern Arizona and more recently other deposits in western and southwestern Colorado, and these examinations have led him to realize how widely scattered are the deposits and how generally noncommercial they are. On superficial development, to one without a comprehension of their geologic nature, they are alluring on account of occasional small amounts of high-grade ore and much misplaced capital has been expended upon them. This paper, therefore, aims to present briefly certain theories of genesis, some details of which may possibly be new, and to lead up to practical conclusions which may be useful to other geologists and engineers. A bibliography of the more important literature upon such deposits is given below.2 Coffin's Bulletin upon the Radium, Uranium and Vanadium Deposits of Colorado, published in 1921, is a particularly clear discussion. The most comprehensive recent statement is Butler's.

Jan 1, 1928

By John T. Schamaun

Recent applications of explosives and blasting agents to rubble rock have led to requirements for more elaborate design and analysis methods. In most blasting uses, it is necessary not only to fracture the rock, but also to move the broken rubble in a predictable manner. Many in situ extraction techniques require rubblization to take place in a confined region where rock motion is a predominate factor in creating a permeable broken bed. In this paper, two analytical methods are presented which describe the large rubble motion during blasting. These methods provide the blast designer with a tool for evaluation and further refinement of blasting patterns and timing sequences. In both these methods, the rock medium is represented by a series of discrete, discontinuous regions. The use of discontinuous techniques rather than the classical continuum methods, results in better approximations to the rubble motion. These regions are set in motion by pressure loads from the explosive. The motion of these regions is then calculated numerically using interaction laws between regions in contact. The basis for these models or methods is presented along with the background for selecting explosive pressure loads and rock mass material behavior. Typical examples, including both cratering and bench blasting geometries, are discussed which illustrate the use of these models to predict rubble motion. Such engineering representations appear to provide a practical method for use in predicting rubble motion and a tool for design evaluation of blasting in confined geometries.

Jan 1, 1984

By L. W. Kempf

THE thermal conductivity of aluminum alloys is of considerable indus-trial importance. This is particularly true in such applications as inter-nal-combustion engines where one of the principal reasons for the use of these alloys is their relatively higher thermal conductivity. In spite of this, relatively few data are available on this property of aluminum alloys. The reason is quite apparent to anyone concerned with the experimental determination of coefficients of thermal conductivity. This determina-tion, in theory so simple, is extraordinarily difficult if any high degree of precision is desired. Fortunately, some knowledge of the relationship between thermal and electrical conductivity has permitted the use of the latter physical property in deducing the relative approximate-values of the thermal conductivities of metals. This fundamental relationship, first enunciated by Wiedemann and Franz1 as applying to metallic elements and later shown by Lorenz to be applicable to alloys within a single metallic system, has been of service in the industrial application of metals. The electrical conductivity of metals is easily determined with a high degree of precision. It is, therefore, quite desirable that the relationship between electrical and thermal characteristics be determined with the greatest possible precision. This paper presents data on the electrical and thermal conductivities of a number of aluminum alloys of industrial importance.

Jan 1, 1937

Clarence M. Haight, Franklin Furnace, N. J. (communication to the Secretary*).—In that part of Mr. Wilson's paper describing the Gilman cut-and-fill system, a few features do not appear to be fully explained. In what way is the waste used for filling obtained? The text mentions that if waste is encountered when driving the filling raises, these raises are stopped until the fill is needed; that seems to suggest mining the capping for fill, which might make the backs of the stopes bad as the stopes approach the top of the ore. If, on the other hand, the fill is brought to the raises in cars, are the crosscuts that are necessary in ore or waste? Is the cost of this fill included in the stoping costs given? The second, or lower, series of stopes will present a different problem to that which the first series (under the capping) gave. Although no mention is made in the text, it would seem that the second series of stopes will have to be worked on center lines which are offset half the stope width, 20 ft., from the centers of the stopes above, in order to take advantage of the "rafter" effect of the stringers so named. How is the fill to be introduced into the lower stopes? There are no crosscuts mentioned to provide for this; or is it intended to tap the filled stopes above for the fill? In the latter case the method of control of this fill will be of interest. Ore that will admit of a stoping width of 40 ft. with the lengths mentioned in the description is stronger than any with which many mining men are familiar. Has the practice of starting to mine a second stope before the preceding one is filly completed been tried to any extent? If

Jan 1, 1917

By Gerhard Derge

A series of studies of the corrosion of tin is under way in the Metals Research Laboratory at the Carnegie Institute of Technology. The complete program includes examination of the corrosion properties of high-purity tin and the changes produced in these properties by the addition of varying amounts of alloying elements. Other studies of this subject have been made recently under the sponsorship of the International Tin Research and Development Council, but these researches have been confined largely to the weakly acid environments commonly encountered in the canning industry.' There is little information available regarding the corrosion of tin under alkaline conditions, but such data would be of value, for a large amount of the metal is used under such conditions. The potential measurements to be described were made because they seemed to offer the most rapid method for obtaining a general view of the conditions to be encountered in such service. These experiments will also serve to establish a technique that will be of value in further studies. It must be emphasized that the results reported are those of controlled laboratory experiments and that the conclusions drawn cannot yet be applied to service conditions; rather, they point to the directions in which more exhaustive experimental work may be done to best advantage. Experimental Procedure The first work was devoted entirely to the problem of obtaining reproducible results from a series of potential measurements. Only the methods finally adopted as standard will be described here, except when the variations from these have furnished results of interest. The cell used is shown schematically in Fig. 1. The electrolyte is contained in the vessel A (an inverted bell jar), whose ground top is fitted to the transite-board lid B. The controlled atmosphere can be admitted

Jan 1, 1938

By Colin C. Rae

The absence of paraffin and other oil hydrocarbons in the soil although they are concentrated in extensive deposits in some localities, the common distribution of plant remains through many formations that are not productive for oil, and many other factors, seem to indicate the existence of an intermediate organic compound between the complex plant compounds and the petroleum hydrocarbons; and much evidence points to the humus acids or associated organic compounds, which are probably collected by surface waters and concentrated in certain areas by means of precipitation by electrolytes, which would be contained in sea water or possibly in various inland seas or lakes. Present-day Evidence There are many present-day evidences of the association of petroleum with humus acids. Binney, in 1912, made observations without explanations on the peat mosses of Down Holland, England, where he found petroleum being formed by decomposition in the presence of an infiltration of sea water. The analysis of a typical peat will show its relationship to the humus acids under consideration. Sample No. 1, SamplE No. 2. PXr Cent. PER CENt. Water......................... 20.0 29.6 Ash.......................... 3.0 3.05 Fiber.......................... 47.0 54.95 Humus acids................ 30.0 12.50 J. D. Haseman and others have noted the association of asphalt and hydrocarbons with the swampy, boggy areas, particularly adjacent to the sea. Many of the rivers carry much humus acid in solution, and some tropical rivers carry in the aggregate millions of tons of humus each year. The amount of humus is a variable factor, depending on climatic conditions, and on the salts and alkalies present in the water, also on the density and temperature.

Jan 1, 1923

By M. Albertson

The purposes of this statement are to define a problem that exists in regard to the estimation of developed petroleum reserves, to analyze the problem in an abstract manner, and to discuss it as an introduction to certain papers that follow. The problem is to devise and develop a suitable procedure to permit more accurate estimates of developed petroleum reserves. Part of the problem is to make such estimates available earlier in the life of any particular pool. The problem of securing more accurate estimates of developed petroleum reserves existed prior to curtailment of production. With curtailment, however, the problem became acute, some of the more prominent reasons being as follows: 1. The standard method of estimation depended on production-decline curves. This method is inapplicable while curtailment prevails and available methods arc insufficient. 2. The retarding influence imposed by wide open flow conditions upon overdevelopment is absent. Great losses of capital by overdevelopment can now occur before realization of the true situation occurs, or before effective steps can be taken to stop such wastage. This increases the need for early, accurate estimates. 3. Above-ground stocks have diminished and the equivalent of such supply tends more and more to be retained underground in the natural reservoirs. It becomes increasingly necessary to know accurately the amount of these stocks. To direct attention to an additional point of different nature: improved accuracy of reserve estimation can be obtained only by closer scrutiny of the factors that determine recovery. This examination and the resulting efforts to measure the effect of these factors in terms of ultimate recovery must tend to improve ultimate recovery. The statements regarding the acute nature of the problem also indicate to some extent the importance of the problem and the necessity of finding a solution. Developed reserves of the industry, and of individual opera-tors, are one of the great factors that properly should determine explora-

Jan 1, 1936

By T. B. Counselman

"C" VERYONE who has to calculate cyanide circuits, -¦-' using either thickeners, filters or both, realizes the headaches involved in solving a set of simultaneous equations. When you calculate a large number of these, based on experimental data, trying to arrive at the best flowsheet, you can spend days at the task. T. B. COUNSELMAN, Member AIME, is Manager, FluoSolids Division, The Dorr CO., Stamford, Conn. AIME New York Meeting, Feb. 1950. TP 2783 B. Discussion (2 copies) may be sent to Transactions AIME before March 31, 1950. Manuscript received Aug. 23, 1949. Herewith is presented a short method, equally accurate with the standard simultaneous equation method, and much quicker. Here for instance is the standard simultaneous equation method, for 100 tons per day of $10 ore, with the conditions assumed as below (fig. 1). Conditions Assumed a. 100 tons of ore per day crushed in cyanide solution. b. Discharge from all thickeners with 50 pct moisture. c. $10 value dissolved per ton of ore. d. 50 pct in mill and 50 pct in agitators. e. 400 tons of solution from thickener V precipitated to $0.02. f. Agitation with a dilution of 2 of solution to 1 of solids. g. Let V, W, X, Y and Z represent value in dollars per ton of solution discharged from the resvective thickeners. Equating Out of and Into Each Thickener 1. lOOVplus 400V = 500W plus (0.50 X $10 X 100) 2. 1OOWplus 600W= 500X plus lOOW plus (0.50 X $10 X 100) plus lOOV 3. lOOXplus 500X = 1OOWplus 500Y 4. 1OOY plus 500Y = 1002 plus 1OOX plus (400 X 0.02) 5. 100 Zplus l00Z = l00Y plus 100 tons of water (value $0.00) Simplifying: 1. v = W plus 1.00 2. W = X plus 1.20 3. X = Y plus 0.24 4. Y = 0.2Zvlus 0.064 5. 2Z= Y

Jan 1, 1951

By E. P. Peleider

DIAMOND drill research work was initiated at the School of Mines, University of Minnesota, in late 1949. The Drilling Symposium held in Duluth that spring highlighted the problem of high cost and core recovery and the need for controlled testing. An advisory committee made up of informed representatives of both mining companies and drilling companies was formed to suggest and advise on a program of drill research. A Hy-Mac hydraulic drill unit, see Fig. 1, especially designed for experimental testing, was obtained for this work by the School of Mines through the courtesy of the Carboloy Co. It is an extremely flexible unit, capable of exerting a forward thrust of about 1750 lb and turning at speeds from 650 to 2200 rpm. The feed arrangement is so designed that the advance can be set either at a constant rate or permitted to vary at a fixed Pressure, see Fig. 2. The

Jan 1, 1953

By Raymond Mancha

The use of blower fans and tubina- for auxiliary face ventilation is a somewhat controversial subject. Most authorities agree upon the advantages of this system over the maintenance of line brattice for dead-end ventilation. They also recognize the system's disadvantages. However, there is considerable disagreement as to the proper relation of the advantages to the disadvantages. It is the purpose of this report to present the opinions of four authorities of diversified occupation and permit the reader to form his own opinions on the subject. ORsErvers Carel Robinson is a mining engineer consultant of wide repute, who has a background of operating experience. Thomas G. Fear is a mine operator whose present position is that of chief engineer for the Hanna Coal Co. at St. Clairsville, Ohio. E. H. Denny is chief of the Coal Mine Inspection Division of the U. S. Bureau of Mines, and is a very able engineer whose past experience well qualifies him to appraise this problem. Cloyd M. Smith, editor of the periodical Mechanization, is a ventilation consultant. For a number of years he was a member of the Mining Department of the University of Illinois and has studied mine ventilation for many years. It is Mr. Robinson,s opinion that closely spaced breakthroughs, although conducive to low gas accumulation past the last open crosscut during the driving of entries, are difficult to maintain and are constant Sources of fugitive air. Jute or canvas brattice is suitable for entry driving with

Jan 1, 1944

By E. R. Parker, D. L. Martin

During the heat-treatment of silver specimens for tensile tests it was observed that the bars blistered and became brittle when heated in a hydrogen atmosphere. To check this unexpected result, a wide variety of commercial silvers were heated in hydrogen at 850°C. Only a few of the materials developed blisters, the most severe of which is the tube pictured in Fig. I. The microstructure of a cross section of the tube is shown in Fig. 2. The embrit-tlernent is extremely severe at the edge; the blisters result from the severe deformation of the surface material by large under- lying gas pockets. The effects resulting from hydrogen embrittlement of silver have been observed by numerous investigators over a long time l,2,3 although it was only recently that a clear explanation was offered.4 However, the damage resulting from hydrogen embrittlement has not been generally recognized; and it is of advantage to know more about this phe- 1 References are at the end of the paper.

Jan 1, 1943

By S. G. Bankoff

INCE1 proposed that electrostatic attraction between oppositely charged particles was responsible for slime-coating. Del Giudice2 postulated the metathetic formation of a cementing compound. Wark3 suggested that prevention of slime-coating was related to peptization of the slime. [ ] In the experiments of Table I the technique employed was essentially that of del Giudice, with the difference that the particle was examined under a film of water rather than dry.4 In general, the polished particle was agitated for 2 min. in a pulp consisting of 12.5 grams of the slime (-200 mesh) and 50 c.c. of distilled water, washed in three baths of distilled water, and examined at 220 diameters with the Leitz Ultropak. Observations of Brownian movement were made at 850 diameters with dark-field illumination. Several of these experiments do not jibe with the metathesis theory. According to published solubilities,5,6 the lead salts of the anions in experiments [c] through g are more insoluble than lead carbonate, therefore should prevent the formation of lead carbonate on the galena surface. In experiment [i] the calcium oxalate, which presumably was on the calcite surfaces, should have permitted the formation of a lead carbonate cement by virtue of its greater solubility. Experiments [j] through m show that the addition of lime accelerates the deposition of quartz onto a galena surface. The writer is unable to postulate a satisfactory cementing compound, according to the metathesis theory, to explain this effect. These experiments led to the conclusion that the metathetic formation of a cement-

Jan 1, 1941

By W. J. Nelson, R. B. Nance

Detailed underground geologic mapping at a scale of 1:1200 has been carried out at the Crown II Mine of Freeman United Coal Mining Co., which operates in the Herrin (No. 6) Coal Member. The roof sequence, upward from the coal, includes (1) soft, medium -to dark-gray shale; (2) hard, black, fissile shale; (3) argillaceous nodular- bedded limestone, and (4) fine-pined, shaly, water-bearing sandstone. The first unit is highly lenticular, and any or all may be missing at a given locality. The sandstone has a sheet facies and a channel facies. The Herrin Coal is eroded in channels near the Crown II Mine. Structural features mapped at Crown II include normal and strike-slip faults and limestone "bosses." Less stable roof and wet conditions are encountered where the limestone is thin or missing or where it is broken by natural fractures or by artificial openings that intersect the water-bearing strata above the limestone. Geologic mapping of the underground workings has allowed us to predict faults, fracture zones, and channels ahead of the face for this mine. Some lithologic and structural pattern apparently are random and cannot now be projected. Conventional exploratory drilling is entirely inadequate to map faults or lithology of the roof, but it does indicate the range of lithologic variability, which can be used to project needs for roof supports. Drilling also is useful in locating channels and in mapping regional variation in thickness and facies of the sandstone.

Jan 1, 1983

By N. W. Johnson

Mount Isa Mines Limited (Isamine) has process control computers in the major surface plants -- lead smelter, copper smelter, lead/zinc concentrator, and copper concentrator. HP computers are used to implement the more complex stabilizing control loops and control schemes aimed at optimizing plant performance. The choice of control strategies is discussed with particular reference to long-term performance in metallurgical plants. These control schemes must be understood by the process metallurgists who are responsible for the performance and initial fault finding. Major emphasis has been placed on the ability of the control systems to handle most of the common plant upset conditions as well as providing improved performance under normal operating conditions. To illustrate the approaches adopted, the lead/zinc concentrator crushing system and the process bag- house control system for lead smelter off-gas handling are reviewed in detail. The improvements in both of these areas resulting from control systems implementation are discussed.

Jan 1, 1984

By R. P. Marshall, L. P. Costas

The solid solubility of lithium in aluminum was determined by two independent techniques, electrical resistivity and microhardness, and the results are in close agreement. The solubility limits X-ray diffraction studies of the intermetallic compound LiAl indicate that its composition is nearly independent of temperature when in equilibrium with the terminal solid solution of aluminum. THE investigation of the aluminum-rich portion of the aluminum-lithium system at the Savannah River Laboratory was prompted by the observation that over-aged alloys consistently differed from the equilibrium states predicted by the latest published diagrams. Chemical analyses of these alloys showed their impurity contents to be quite low; therefore, the results obtained should have very nearly coincided with true equilibrium. A survey of the literature disclosed that previous studies had been made with metallographicig or electrical resistivity methods,4'5 but that agreement between results and technique was poor as evidenced in Fig. 1, which also includes the present results for comparison. The discrepancies have been attributed to impurities,3 and this is undoubtedly true in the early work.1'4'5 The latest Studies,''~ conducted with starting materials of higher purity, employed metallographic analysis, a technique that is quite sensitive to local homogeneity and depends strongly on subjective interpretation. In the present work the problem of defining solubility limits was approached in two ways. The first measured a physical property, electrical resistivity, at the equilibrium temperature. The second, a micro-hardness characterization of a diffusion zone, is a room temperature evaluation of a mechanical property under conditions removed from equilibrium. A close correlation between two such basically different approaches would strongly justify confidence in the results. I) MEASUREMENT OF SOLUBILITY OF LITHIUM IN ALUMINUM BY ELECTRICAL RESISTIVITY Experimental Procedure. Alloys for electrical resistivity measurements were made by melting and

Jan 1, 1962

By Donald F. Taylor

TANTALUM and columbium are newcomers in the world of metals. Many of the metals described in this volume had been known and used for centuries before either tantalum or columbium was known to exist. The scarcity of the ores and the comparative difficulty of extraction delayed their technology until specialized methods of processing could be developed. HISTORY Early in the nineteenth century, 1801, Hatchett discovered a new oxide, which he called columbium oxide, and a year later, Ekeberg announced that he had found a new element, which he named tantalum. The preparation of the metal tantalum in impure form was first announced by Berzelius in 1824, but the actual production of ductile metal did not occur until 1903, when von Bolton, of Siemens and Halske, developed a process for the production of tantalum pure enough to be drawn into electric-lamp filament wire. The use of tantalum as a filament wire began to decline when ductile tungsten was introduced in 1909. In 1921, C. W. sake, of Fansteel Metallurgical Corporation, produced the first ingot of tantalum metal in America. The first ingot of columbium was produced in 1927 in the laboratory of the same company. There are several good reasons why tantalum and columbium are often mentioned together. They occur together in their important minerals, are similar in many of their properties, and are

Jan 1, 1953

By E. Teghtsoonian, K. G. Davis

Cobalt crystals of commercial purity have been tested in tension. Their resolved shear stress-shear strain curves are very similar in form to those for zinc, magnesium, and cadmium. There is an initial linear region for shear strains up to around 150 pct, the ratio of work hardening slope to shear modulus at room temperature being about 2 X x This is followed by an upturn, which is, PLASTIC deformation in metal single crystals with close-packed structures has been found strongly dependent on stacking-fault energy. The high stacking-fault energy hexagonal metals magnesium, zinc, and cadmium have been quite extensively tested, but up to now no data have been available for a comparable hexagonal metal with low stacking-fau1t energy' An however, smaller in magnitude for cobalt than for the other metals. Values for the critical resolved shear stress rise from 97 kg per sq cm at room temperature to approximately 170 kg per sq cm at -196 °C. The Cottrell-Stokes ratio is not constant either for variations in the strain rate or for temperature changes, its value decreasing with strain. investigation into the plastic deformation of cobalt, which has a very low stacking-fault energy, has therefore been undertaken. EXPERIMENTAL PROCEDURES Cobalt crystals in the form of rods 0.3 cm in diam were grown in an electron-beam floating-zone refiner at a rate of zone travel of 25 cm per hr. Details of the growing procedure are given in Ref. 1. The zoned cobalt rods had the following analysis:

Jan 1, 1963

By Colin C. Rae

The absence of paraffin and other oil hydrocarbons in the soil although they are concentrated in extensive deposits in some localities, the common distribution of plant remains through many formations that are not productive for oil, and many other factors, seem to indicate the existence of an intermediate organic compound between the complex plant compounds and the petroleum hydrocarbons; and much evidence points to the humus acids or associated organic compounds, which are probably collected by surface waters and concentrated in certain areas by means of precipitation by electrolytes, which would be contained in sea water or possibly in various inland seas or lakes. Present-day Evidence There are many present-day evidences of the association of petroleum with humus acids. Binney, in 1912, made observations without explanations on the peat mosses of Down Holland, England, where he found petroleum being formed by decomposition in the presence of an infiltration of sea water. The analysis of a typical peat will show its relationship to the humus acids under consideration. Sample No. 1, SamplE No. 2. PXr Cent. PER CENt. Water......................... 20.0 29.6 Ash.......................... 3.0 3.05 Fiber.......................... 47.0 54.95 Humus acids................ 30.0 12.50 J. D. Haseman and others have noted the association of asphalt and hydrocarbons with the swampy, boggy areas, particularly adjacent to the sea. Many of the rivers carry much humus acid in solution, and some tropical rivers carry in the aggregate millions of tons of humus each year. The amount of humus is a variable factor, depending on climatic conditions, and on the salts and alkalies present in the water, also on the density and temperature.

Jan 1, 1923

By Eliot Blackwelder

For the purposes of this paper, the boundaries of China and Siberia will be taken as they stood about 1907. Except in the Caspian region, it is doubtful if all the oil ever produced in these countries would equal one day's flow of a good Texas well. Considering the vastness of the regions and the variety of strata, it seems strange that these two countries should have made so small a showing in the petroleum industry. No doubt the condition is caused partly by lack of prospecting and of modern methods of development; in larger measure, however, it is evidently because of unfavorable geological conditions over nearly all of east-central and northern Asia. CHINA The known oil occurrences in China are very few. For many years, perhaps a barrel a day has been obtained by primitive methods from wells near the city of Yenchang in the northwestern province of Shensi. A like amount was obtained from wells bored for salt water in the vicinity of Kiating in southwestern Szechwan. The little oil was separated from salt water by allowing it to stand in jars. The salt wells yield also considerable natural gas, which is used to evaporate the salt and also for domestic purposes. There is evidence that wells were bored in this part of China before the third century. It is said that more than 1200 wells have been sunk in that district to depths of 1600 to 2000 ft. (485 to 610 m.) in connection with the salt industry. The scarcity of petroleum in China may be ascribed to three general geologic conditions: First, China contains practically no marine sediments of Mesozoic or Cenozoic age; second, the Paleozoic sediments are not for the most part of the types that generally contribute petroleum; third, the rocks of nearly all ages have been strongly folded, faulted, and more or less intruded by igneous rocks in all parts of China except certain areas in the west and northwest.

Jan 7, 1922