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By AIME AIME

FEW indeed are the sections of the country where trained or partly trained workers have not already been hired by a war industry plant or will be within the near future. Yet right in the midst of the heavily industrialized East lies the anthracite area, home of a million people, whose productive power has persistently been by-passed either by private industry or by the Government Plant Site Board. The chief reason given for not locating war plants in the area is that it is not within the strategic zone, but in numerous instances elsewhere this rule has been waived. Furthermore, the anthracite region is well protected on all sides by mountains and is at all points more than 100 miles inland. Continued depression in the anthracite industry and a crippling blow dealt by the war emergency to the production of silk and rayon goods, the chief manufacturing activity of the area, have resulted in a heavy migration, particularly of trained young workers, into near-by industrial areas. At least 50,000 people are currently unemployed, with the likelihood of an increase in coming months, and as many families are on relief.

Jan 1, 1942

By R. W. Raymond

FOUR portraits have recently been hung in the rooms of the Institute, in recognition of four illustrious men with whom we, as mining engineers and metallurgists, may claim fellowship. LUTHER. Martin Luther is often spoken of as a miner's son; but it is less generally known that John Luther, his father, was, in a small way, a metallurgist as well as a miner, and that Martin Luther himself, in his youth, worked in a forge or bloomary established by his father at Mansfeld, Saxony. Since this is the only manual occupation on his part of which we have any record, it is fair to assume that the great scholar and reformer derived from his work in this department the practical familiarity with the conditions of human labor so abundantly evinced in the homely illustrations which accompany even his serious arguments, and in the witty apothegms of his famous "table-talk." At the same time, I must confess that 1 have not been able to find in any of the works of Luther distinct allusions to mining or metallurgy. KÖRNER. Theodor Körner, a student at the Mining Academy of Freiberg, Saxony, threw himself into the German War of Freedom in the first decade of the 19th Century. He was a poet of no mean rank ; and his " Song of the Sword " is one of the great lyrics of literature. This poem was written but a few days before he died in battle. In many respects, Körner may be compared with our American hero Theodore Winthrop, who similarly met a glorious fate, and left behind him prophetic indications of genius, of which his premature death prevented the complete fulfillment. I am informed by a member of the Institute that Körner's admirable collection of minerals is still preserved at Dresden.

Nov 1, 1908

By Ottar Dragge, C. Danielsson, Bo Kalling

THE desulphurizing of pig iron has been accomplished with a number of different additions. The oldest and still most commonly used agent is soda, the extensive use of which commenced about 1925, when it was used principally for cupola furnace iron. More recent experience' seems to show that better results can be obtained with sodium hydroxide. The well-known desulphurizing properties of lime have also been exploited in different technical processes. Another material with even more powerful effect is calcium carbide.' The desulphurizing ability of manganese, when added to the ladle in sufficient quantity, should also be mentioned in this connection. During recent years increasing attention has been paid to the desulphurizing properties of metallic magnesium." An addition of a suitable alloy of magnesium is now in use purely for the purpose of sulphur elimination. Of the desulphurizing agents mentioned, lime is by far the cheapest, provided that the reaction can be brought about rapidly and completely. Therefore, a method that makes full use of the desulphurizing ability of lime may be able to compete with other processes. A method developed at the Dom-narfvet Iron and Steel Works (Sweden) will be described, which enables pig iron to be rapidly desulphurized to very low sulphur contents by using a burnt lime powder. as the desulphurizing agent. Lime in Older Processes In cases where lime has been used for the desul-phurization of pig iron, it has generally not been used alone, but mixed with other substances such as fluorspar, to obtain the formation of a molten slag during the process. This method has been tried by Tigerschiold,' who treated the iron with a lime-fluorspar mixture, the stirring of the iron being brought about inductively with low frequency alternating current. Very good results were obtained. A process of this type has also been suggested by R. P. Heuer, U. S. A. The principles of this method, which has been tested in Great Britain by Newell. Lanener. and Parsons." re that a mixture of lime and fluoispar is added to the hot metal in the ladle, while a powerful stream of nitrogen gas is blown into the bath to produce the required intermixing. The results of the tests were unsatisfactory, however. A similar process has been developed at The Steel Co. of Canada, according to a statement by H. M. Griffith.' Here the tests were carried out in a carbon-lined ladle provided with carbon tuyeres in the side wall for blowing nitrogen into the bath. The addition consisted of about 20 lb of a mixture of burnt lime and fluorspar per ton of pig iron. Good results appear to have been achieved. The sulphur content of the pig iron is stated to have been reduced from 0.025 to 0.050 pct down to 0.006 pct. Various methods of desulphurizing pig iron have been tried using lime powder without fluxing material for fusing. Eichholz and Behrendt7 have experimented with blowing a powdered limeicoke mixture with air into the ladle. Their results were, however, not conclusive and the experiments do not appear to have been continued. Similar experiments have been carried out at Domnarfvet, using nitrogen instead of air in order to avoid oxidation. But these attempts were not particularly successful. It appears to be difficult to achieve the required agitation by this means. The strong cooling effect of the gas on the iron is also a serious drawback. A method in many respects similar to that tried at Domnarfvet was tried by Eulenberg and Krus at the end of the 1930's. Here again desulphurization was carried out with lime alone, brought into contact with the molten iron in a rotary furnace. The temperature was kept at the required level, 1400" to 1500°C, by the introduction of a pulverized coal burner in one end of the furnace. The speed of rotating was not given. A paper by Bading and Krus states that, in one of the first experiments, the sulphur content in 56 tons of pig iron was brought down from 0.186 to 0.035 pct in 117 min, but that a considerable shortening of the time would be possible. According to later reports by Eichholz and Behrendt,' it should be possible by this process to achieve a desulphurization speed of 0.35 pct S per hr for a consumption of 6 to 10 pct limestone and 2 to 3 pct coke, as fuel exclusively. The final sulphur content is, however, not stated. Domnarfvet Method After a number of different procedures had been investigated, the tests at Domnarfvet were directed to desulphurization with lime in a rotary furnace. Before going into the practical details of the method, the theoretical aspects will be discussed briefly. If the pig iron does not contain alloying elements other than carbon, the reaction can be expressed most simply by the usual equation: FeS + CaO + C = Fe + CaS + CO [I] 4H,. ~ 34,000 cal That this reaction can be carried through to a very complete desulphurization of pig iron has been shown by OelsenD in a discussion in connection with the Eulenberg and Krus' method. He mentions two laboratory tests, in one of which the sulphur content in the pig iron at 1400°C was reduced from 0.540 to 0.006 pct after treating with 3.35 pct lime. The pig iron had a low manganese content, but other analysis is th. given. Mention also should be made of the recently published investigations by Fischer and Cohnen'" dealing with the influence of the carbon content of the iron on desulphurization with lime, although in this case fluorspar was added also. The tests show that efficient desulphurization is possible with lime in the steel bath, provided that the carbon content is sufficiently high. The temperature employed in these tests was considerably higher (1620") than that normal for treatment of pig iron. The author concludes that the product S% X C% - 0.011 at the temperature in question.

Jan 1, 1952

By Raymond L. Orr

Calorimetric measurements have been made of the heats of solution of gold axd indium in a number of liquid tin-rich alloys at a temperature of 705°K. Relative partial molar enthalpies of gold were determined as a function of dilute solute concentrations in the binary Au-Sn system and in the ternary Ag-Au-Sn and Au-In-Sn systems. Relative partial molar enthalpies of indium were determined for dilute solute concentrations in the In-Sn, Ag-In-Sn, and Au-In-Sn systems. Through application of the interaction coefficient concept introduced by Wagner and more recently extended by Lupis and Elliott, ualues have been obtained for the Au-Au, Ag-Au, Au-In, and Ag-In enthalpy interaction coefficients in liquid tin. The results are inte@reted in terms of solute atom distributions through comparisons with the predictions of dilute solution models. INTEREST in the thermodynamic behavior of dilute liquid alloys stems from two primary sources. From a practical viewpoint, it is often of importance to know or to be able to predict the effect that one solute will have on the thermodynamic properties of the other solutes in a multicomponent system. Studies of dilute solutions may also be rewarding from the theoretical point of view. Some of the difficulties arising from the more complex interactions possible in concentrated solutions are avoided, leading to easier interpretations in terms of solutibn models and bonding energies. For example, in a binary alloy the limiting values of the partial molar properties of the solute represent the case for which each solute atom is completely surrounded by atoms of the solvent, and no other interactions are possible. Solute - solute interactions in dilute solutions are conveniently treated by the interaction coefficient concept of ~agner.' Using a Taylor series expansion for the logarithm of the activity coefficient, In yi, of a component, i, in a solution consisting of dilute solutes with atomic fractions xi, xj, xk, and so forth, in a solvent, s, and neglecting the second- and higher-order terms, Wagner obtained the expression: Where Wheyz is the limiting value of yi in the pure solvent, s. The interaction coefficients, e:, e:, and so forth, are defined by: Since yi is related to the excess partial molar Gibbs energy of component i by GfS = RT In yi, E: is re- ferred to as the "Gibbs energy interaction coefficient". Lupis and Elliott~ extended Wagner's treatment to the relative partial molar enthalpy, aHi, and the excess partial molar entropy, qS. They defined the enthalpy interaction coefficient as: and the excess entropy interaction coefficient as: leading to expressions similar to Eq. [I]: The three interaction coefficients are related by? The self-interaction coefficients, E:,qf,and at, represent the effects of interactions between atoms of component i in solvent s; €3, q{, and 03 represent the effects of interactions between i and j atoms in solvent s; and so forth. From the Maxwell-type relationships between partial molar quantities, it may be shown1'2 that e{ = ej, r}\ =tj), and ai - crj. Experimental determination of the interaction coefficients requires extremely precise measurements of the appropriate properties as functions of solute concentrations in very dilute regions. Few such data exist for intermetallic alloys, even for binary systems, because of experimental difficulties. This is especially true with respect to enthalpy data for dilute alloys. Examination of the compilation of data for binary alloys by Hultgren, Orr, Anderson, and ~elle~~ reveals that determination of limiting values of &fii(Xi =0) often requires extrapolations to infinite dilution from xi = 0.05 to 0.10. Direct measurements of the enthalpy interaction coefficient, qi, for multicomponent systems are virtually nonexistent. This quantity is of course subject to direct calorimetric measurement, but its determination must be limited to cases where high experimental precision is possible. The heats of solution of gold and indium in liquid tin can be measured with relatively high precision, which makes determinations of 73 involving these metals as the measured solutes experimentally attractive. This paper presents the results of such determinations of the Au-Au, Ag-Au, Au-In, and Ag-In enthalpy interaction coefficients in liquid tin. MODELS FOR DILUTE-SOLUTION BEHAVIOR Random-Solution Behavior. In the quasi-chemical treatment of solutions, only nearest-neighbor bonds are considered, and a composition independent value

Jan 1, 1967

By Howard L. Hartman, Eugene P. Pfleider

The paper relates to the laboratory and pilot plant studies that have been carried out by Sherritt Gordon Mines Ltd., Metallurgical Research Div., in developing the ammonia pressure leach process for extracting Cu, Ni, Co, and S from high grade Ni concentrate produced from Lynn Lake ores and describes in some detail the chemistry of the process. In the leaching stage air, ammonia, and sulphide minerals react in a sequence of inter-related steps to produce soluble amines of Ni, Cu, and Co in a solution containing sulphate, thiosulphate, polythionate, and sulphamate ions and a controlled amount of free ammonia, the iron and other components of the concentrate remaining as an insoluble residue which is separated from the leach solution by filtration. The pregnant solution produced in leaching is further treated by boiling to precipitate and remove Cu as cuprous sulphide, leaving a copper-free solution with a composition suitable fir subsequent precipitation of Ni and Cu by H,. The progress of individual reactions in leaching and copper removal is discussed. The effect of variables such as temperature, pressure, ammonia concentration, particle size, and agitation is outlined and the technique of thionate control in leach solutions is described. Data is given for the physical and chemical reactions involved in precipitating copper from leach solutions as Cu sulphide by boiling.

Jan 1, 1956

Discussion of the paper of Leonard Waldo, presented at the New York meeting, February, 1911, and printed in Bulletin No. 76, April, 1913, pp. 555 to 559. HERBERT HAAS, San Francisco, Cal. (communication to the Secretary*):-Referring to Leonard Waldo's paper on Temperature Conversion Tables, I believe the following formulas can be easily remembered, and by reference to the thermomter scales of Fahrenheit (F.), Celsius (C.), and Réaumur (R.), their derivation and relation are at once understood n° F. = 4/9 (n°-32) R. = (n°-32) C. n° C.=(9/5 n° + 32) F. = 4/5 n° R. n° R.=(9/4 n° + 32) F. = 5/4 n° C. As the freezing point of water is at 32° F., corresponding to 0° C. and 0° R., 32 must be deducted from the Fahrenheit degrees when these are converted into C. or R. degrees. Likewise, to C. or R. degrees converted into F. degrees 32 must be added. The fractions 4/9 and 5/9 and their reciprocals are obtained thus:

Jan 5, 1913

L50 Adirondack L1 Alaska L2 Arizona L58 Arkansas L66 Billings Petroleum L3 Black Hills L4 Boston L5 Carlsbad Potash L6 Central Appalachian L60 Central New Mexico L7 Chicago L8 Cleveland L9 Colorado L57 Colorado Plateau L10 Columbia LII Connecticut L55 Dallas L12 Delta L65 Denver Petroleum L13 Detroit L14 East Texas L15 El Paso Metals L71 Evangeline L45 Florida L54 Fort Worth L16 Gulf Coast L61 Hobbs L62 Hugoton L68 Illinois Pet Basin L17 Kansas L18 Lehigh Valley L52 Lou-Ark L47 Mexico L19 Mid-Continent L20 Minnesota L56 Mississippi L21 Montana L22 Nevada L64 Niagara Frontier L23 New York L67 New York Petroleum L25 North Pacific L24 North Texas L26 Ohio Valley L27 Oklahoma City L28 Oregon L63 Panhandle L29 Penn -Anthracite L30 Permian Basin L51 Peru L31 Philadelphia L32 Pittsburgh L33 St Louis L34 San Francisco L59 San Joaquin L35 Southeast L36 Southern Calif L69 Southern Calif Pet L53 South Plains L37 Southwest Texas L48 Southwest Alaska L38 Southwest N Mex L44 Spindletop L39 Tri-State L40 Upper Peninsula L41 Utah L70 Venezuela L42 Washington, D C L43 Wyoming L49 West Central Texas L46 Philippine

Jan 1, 1956

By C. H. Jr. Herty

IRON oxide .(Fe0) plays an extremely important part in the manufacture of steel. In the open-hearth furnace and the Bessemer converter it is the chemically predominant compound and controls to a large extent both the operation of the furnaces and the composition and quality of their products. Almost all of the refining action is carried out through the medium of FeO, which oxidizes carbon, manganese, silicon, and phosphorus. At the end of any open-hearth or Bessemer heat the steel contains dissolved iron oxide, which must be wholly or partly eliminated. The type of deoxidation product depends on the amount of dissolved iron oxide and on the deoxidizer used. After the heat has been deoxidized and while it is being teemed, iron oxide diffuses from the ladle slag into the metal, causing losses of deoxidizer and increase in iron oxide content of the steel. It is generally believed that non-metallic inclusions are responsible for a great many failures of steel in service and for decreased yield of steel during rolling. The basis of most non-metallic inclusions is dissolved iron oxide. This investigation was undertaken in order to determine the amount of iron oxide that will dissolve in iron under various conditions. Steel-making slags are complex and it has been thought best to determine solubility under simple slags as a first step. The study is being continued under slags whose compositions approach those of operating. slags.

Jan 1, 1928

By R. E. Reed-Hill

A simple accurate graphical method for orienting fcc crystals using (111) slip traces on a single surface is described. Solutions placing the pole of the surface in a unit stereographic triangle are obtained using a Wulffnet, a (111) standard projection showing the four (111) planes, and a (111) standard projection ruled into unit stereogmphic triangles. The multiplicity of solutions is described in relation to this method. AN accurate, rapid single-surface technique for orienting fcc crystals, using (111) slip or twin traces, has been a matter of continuing interest, as evidenced by the periodic appearance of papers on this subject.'-4 This note presents a new method possessing some advantages over those previously reported. It is an analog to the technique for hcp metals5 where the solution is based upon a stereographic rotation of the specimen surface on a (0002) standard projection that contains the planes of the possible features that might account for the observed traces. In the hexagonal solution, the axis of rotation is the basal-plane trace in the surface. In the fcc case, the axis of rotation is one of the observed ( 111) slip or twin traces. It has been observed that the solution is greatly facilitated if the indicated movements of the (111) traces during the rotation of the surface are plotted directly on a paper copy of a Wulff net as shown schematically in Fig. 1. The trace selected to represent the axis of rotation is assumed to fall at the north-south poles of the Wulff net. The directions of the other traces are then plotted as points at the proper angles around one-half of the basic circle of the net. The loci of points corresponding to the movements of these traces (directions) during a 90-deg rotation of the surface, about the polar axis of the net, are then easily and accurately drawn by following the appropriate small circles on the Wulff net. The solutions to the problem are obtained with the aid of a (111) standard projection of the (111) planes, see Fig. 2. This is normally a Xerox copy of a carefully drawn master made on high-quality tracing paper. The (111) standard projection is superimposed over the Wulff net and rotated about its center until the points of intersection of the loci of surface traces, drawn on the Wulff net, and the great circles representing the (111) traces, all lie along a common meridian of the Wulff net as demonstrated in Fig. 3. This latter great circle represents a possible position of the surface. The pole of this plane is then plotted on the (111) standard projection. Its location in a unit stereographic triangle may be readily obtained by superimposing (over the standard projection) another tracing paper (111) standard projection subdivided into unit stereographic triangles. The result of this last operation is shown in Fig. 4. MULTIPLICITY OF THE SOLUTIONS The maximum possible number of (111) traces on a single grain surface is four. Any one may be selected as the axis about which the surface is rotated. Corresponding to each such choice are three possible surface-pole orientations, related to each other by a simple 120-deg rotation about the pole of the (111) basic circle. This is a direct result of the threefold symmetry of the (111) standard projection. Since each of the four rotations will normally give a different set of three-pole positions, there are, accordingly, twelve possible solutions. Each of these twelve solutions places the surface pole in the same relative position in a stereographic triangle so that all are crystallo-graphically equivalent. Accordingly, only a single solution is required to obtain a basic orientation of the crystal. It should be noted, however, that the orientations obtained by reflecting* any of these twelve orien- *The reflected orientations may be obtained by a 90-deg rotation of the opposite sense to that shown in Fig. 1. This rotation places the correspond-ing trace loci in the lower hemisphere of the Wulff net rather than in the upper hemisphere. tations through the surface are also possible orientations that could account for the surface traces. Thus, a given set of four traces always corresponds to a pair of basic orientations related by reflection through the specimen surface. This ambiguity can only be re-

Jan 1, 1967

By W. B. Mather

R. G. Wuerker (University of Illinois, Urbana)—Mr. Mather is to be congratulated for stressing the most urgent need for a program of testing the physical properties of rocks, as they are encountered by the petroleum engineers on their drilling jobs and by the miners on their excavating, roof control and mineral preparation tasks. Another valuable source of information is the Handbook of Physical Constants.22 It stresses the physicist's approach rather than the engineer's procedure. The study of hardness, and rock hardness in particular, is beset with many difficulties. There is no satisfactory definition of hardness yet, and the term hardness is used to describe a number of quite dif- ferent properties. Hardness tests are grouped into static and dynamic determinations. They should be expressed with reference to the mechanical action of the applied force, like indentation hardness, scratch hardness, abrasion hardness, rebound hardness. A discussion of all these various hardness tests and of the special difficulties encountered in hardness testing of such heterogeneous material as rocks is given in the U. S. Bureau of Mines' standard proposal. The more critical student may be referred to the book by D. Landau: Hardness, which is in my opinion the best existing treatise on this subject.

Jan 1, 1952

By John T. Norton, V.G. Mooradian

The diffusion of metal atoms into the crystal lattice of another metal and the assumption of regular positions to form a homogeneous alloy are some of the most fundamental phenomena of structural metallurgy. The mechanism of this process has been the subject of a great deal of study from many viewpoints, but the picture is still far from complete. It is generally believed that if one metal is to diffuse into another, the first must have some solubility in the second1. This means that the solvent must be able to accommodate the stranger atoms, either on points of its own lattice or in the interstices between, without losing its own crystal-lographic identity. It is also a general observation that cold-working is a distinct aid in the diffusion process, causing it to take place with greater rapidity at the same temperature or with the same speed at a lower temperature. There is considerable doubt, however, as to the real significance of the deformation in its effect on the diffusion mechanism. Several factors associated with the cold-working may be responsible for the increased diffusion rate. The plastic deformation causes a distortion of the solvent lattice, which may be an aid in the assimulation of atoms of another kind. There are many references2 in the literature that suggest that some distortion or "loosening" of the lattice is necessary for atomic migration and that diffusion cannot take place in the undis-torted lattice. On the other hand, it may be that the cold-working causes an increase in surface of contact between the two metals through fragmentation or provides a more intimate contact that is necessary for diffusion. If it is true that lattice distortion is an important factor in diffusion, it seems as if there should be some particular relation between

Jan 1, 1935

By V. G. Mooradian, John T. Norton

The diffusion of metal atoms into the crystal lattice of another metal and the assumption of regular positions to form a homogeneous alloy are some of the most fundamental phenomena of structural metallurgy. The mechanism of this process has been the subject of a great deal of study from many viewpoints, but the picture is still far from complete. It is generally believed that if one metal is to diffuse into another, the first must have some solubility in the second1. This means that the solvent must be able to accommodate the stranger atoms, either on points of its own lattice or in the interstices between, without losing its own crystal-lographic identity. It is also a general observation that cold-working is a distinct aid in the diffusion process, causing it to take place with greater rapidity at the same temperature or with the same speed at a lower temperature. There is considerable doubt, however, as to the real significance of the deformation in its effect on the diffusion mechanism. Several factors associated with the cold-working may be responsible for the increased diffusion rate. The plastic deformation causes a distortion of the solvent lattice, which may be an aid in the assimulation of atoms of another kind. There are many references2 in the literature that suggest that some distortion or "loosening" of the lattice is necessary for atomic migration and that diffusion cannot take place in the undis-torted lattice. On the other hand, it may be that the cold-working causes an increase in surface of contact between the two metals through fragmentation or provides a more intimate contact that is necessary for diffusion. If it is true that lattice distortion is an important factor in diffusion, it seems as if there should be some particular relation between

Jan 1, 1935

By Edwin M. Chance

During the past 10 years, the safe and efficient lighting of the coal mines of this country has received an ever-increasing amount of attention. Several States have passed laws attempting to regulate the type of lamp to be used and the nature of the fuel to be burned, and the mining departments of coal-mining States have generally shown a keen and intelligent interest in this subject. The passage of the recent Employers' Liability Act in Pennsylvania has made it necessary for many coal-mining companies to take out liability insurance, and the companies underwriting such insurance have made it desirable for the insured to permit the use of none but illuminants of established worth. While these conditions have not obtained for a sufficient length of time to permit the statement that the illumination of coal mines by portable lamps has been standardized, still, considerable progress has been made and the direction of future practice in this branch of coal-mining technology is very evident. Under these conditions it seemed that a review of the methods now used in coalmine illumination, together with a brief consideration of the principles underlying these methods, might be of some interest. Miners' lamps may be divided into three classes: The open light, the electric cap lamp, and the flame safety lamp. It will be desirable to consider each of these classes separately, as each has properties peculiar to itself and one class is hardly comparable with another. In this country, without question, the open light is the most generally used of all miners' lamps. This fact is explained by the relative freedom of a large proportion of our mines from gaseous conditions, and by the admirable systems of ventilation installed in those that show a tendency toward such conditions. In the metal mines, the miner's candle has had and still has considerable vogue. Because of the small amount of ventilation usually supplied in metal mines, the freedom of the candle from any tendency to produce noxious gases or offensive odors, and the small amount of air it consumes, are valuable assets, while, because of the light color of the rocks in which workings are driven, the meager light is not a serious handicap.

Jan 1, 1918

INTERNATIONAL ENGINEERING CONGRESS This Congress will be held under the auspices of five National Engineering Societies, of whi h the Institute is one. The sessions will be held in 11 sections and the proceedings will be published in 10 volumes of 500 pages each, of which Volume 8 will contain the papers and proceedings on Mining Engineering and Metallurgy. The membership fee of $5 will entitle the holder to the volume of General Proceedings and Index, and, in addition thereto, any other single volume chosen. Other volumes may be subscribed for according to a sliding scale depending upon the number of volumes taken. The Institute will have a meeting in San Francisco during 1915, and it is desirable for our members to join the International Engineering Congress at in early date in order that their support of the enterprise may be given in its early stages, when it is most needed.

Jan 2, 1914

By George Otis Smith

A YEAR ago, ,at the Institute's dinner, I closed my A remarks with the words: "The scientist devotes his life to the advancement of learning; the engineer gives his to the advancement of living." May 1 begin tonight where I left off then and speak first of the distinction between science and engineering? This difference is a difference both in purpose and in method: it is the sharp contrast between theory and practice; it marks the broad gap between dream and attainment. Sometimes it happens that the investigator is also the builder and applies what he discovers, yet the distinction between science and engineering serves to point out the broad dependence of the engineer upon his brother the scientist. You remember .the old - saying that "where there is no vision the people perish" translate this into modern experience and we may say that "where there is no science, the engineer fails."

Jan 1, 1929

By E. A. Gulbransen, K. F. Andrew

Thermodynamic information on the solubility of hydrogen in exothermic metals is limited. Thus, the overall solubility decreased as the temperature rose, which suggests the heat of solution of hydrogen in the metal is negative; yet the terminal solubility in the metal phase increased, which suggests an endothermic reaction. A thermodynamic analysis, therefore, was made of the several equilibria involved when hydrogen dissolved in the metal. Equations were derived expressing the solubility, terminal solubility, and decomposition pressures of hydrogen in terms of the heat, entropy, and free energy of solution of hydrogen in the given phase. The relations between the thermodynamic functions for the a-zirconium and 8-hydride phase were developed. The thermodynamic quantities were determined experimentally by the measurement of the decomposition pressures over a broad composition and temperature range. Two new methods of analyzing the experimental data were developed for determination of the terminal solubility. STUDIES', ' of the impact strength of zirconium at room temperature indicated that small quantities of hydrogen, of the order of 10 parts per million, embrittles the metal. Micrographic' and X-ray diffraction' studies showed this embrittlement to result from the precipitation of a second phase upon slow cooling. These studies suggested that the terminal solubility of hydrogen in the metal phase increased with increase of temperature. This behavior appeared to contradict the effect of temperature on exothermic hydrogen occluders such as zirconium. For these metals, the solubility of hydrogen should decrease with increase of temperature. Before these facts could be understood, a thorough analysis of the several equilibria was essential. It was the purpose of this paper to consider the several equilibria involved when hydrogen was reacted with zirconium from both the theoretical and experimental points of view. Since the overall solubility of hydrogen in the metal has been considered by a number of workers, it was proposed to study the composition range 0 to 6 atomic pct H in detail. Literature Schwartz and Mallett' determined the terminal solubilities of hydrogen in the metallic phase from diffusion studies. They extrapolated concentration-penetration curves to the boundary between the solid solution phase and the hydride phase at the surface. Their results showed values of 2.6 atomic pct at 400°C and 5.2 atomic pct at 500°C. Extrapolations of the data to room temperature suggested very low values for the terminal solubilities. This study confirmed the hydrogen embrittlement results and indicated that the terminal solubilities increased as the temperature was raised. The solution of hydrogen in zirconium over the complete concentration range was studied by Hall, Martin, and Rees3 and by others. The results showed that hydrogen was absorbed up to a maximum composition of 66 atomic pct or ZrH This composition represented the t-hydride phase. The maximum amount of hydrogen absorbed increased with pressure and decreased with temperature. Due to this temperature behavior, zirconium was classed as an exothermic occluder." In 1930 Hägg studied the crystal structures of the Zr-H alloys over a broad composition range. Four hydride phases were found. However, the range of homogeneity of the several phases was not studied. Gulbransen and Andrew" recently studied the phase diagram of this system by X-ray diffraction methods and by a thermodynamic method based on decomposition pressure measurements. The results showed that only two hydride phases existed for low temperatures, the 6 and the .-phases of Hagg.' Both phases had broad regions of homogeneity. The lower limit of the two-phase region of a and d-phases suggested a terminal solubility of 4 atomic pct at 500°C. This value was in agreement with the results of Schwartz and Mallett.' To avoid hydrogen embrittlement at low temperatures, it was necessary to heat the metal in high vacuum at elevated temperatures. To choose the conditions of temperature and high vacuum, it was

Jan 1, 1956

By Gealy W. Wallwork

INTRODUCTION The administrative processes of coal mines are becoming increasingly complex. As society evolves into a more complicated structure with greater emphasis on individuality, government regulations reach deeply into every activity in an effort to force individuals into a standardized mold. These contradictory pressures add an extra burden to the administration of a mining operation. Recent years have brought a substantial change in the skills needed by mine supervisors and managers. As a result, a better understanding of the administrative functions is necessary. The mine superintendent has the overall responsibility for the mine; for effective operation he must be sufficiently knowledgeable to oversee all the complex functions that make up the mine. This chapter does not cover all the administrative requirements because of the variation in mine operation and in company policies and organizational structure. It does attempt to identify the administrative functions that would be required at a large mine with a preparation plant. It is assumed that the mine operation is decentralized with very little duplication of functions at the organizational levels above the mine. Thus each function is assumed to be relatively complete at the mine and under the general supervision of the mine superintendent. EMPLOYMENT PROCEDURES Throughout the mining industry, in deep or surface mining, in union or nonunion companies, the success or failure of an organization is directly related to the caliber of employees who make up the organization. A company is nothing more than a group of people working together with

Jan 1, 1981

By George W. Lower, William A. Hockings, Donald A. Kaczynski

The rate of dissolution of polycrystalline metallic copper in aqueous cupric ammonium nitrate solutions in the non-film-forming region was investigated by the rotating disc method. The investigation was performed in solution concentration ranges applicable to hydrometallurgical processes. This investigation was an extension of a study on the cupric ammonium carbonate system previously reported by Smith, Lower and Hockings, in which the following kinetic model was proposed: (1) Diffusion of cupric ammine ions to the copper surface; (2) Forward reaction - first order reaction of cupric ammine ions with metallic copper; (3) Reverse reaction - disproportionation of cuprous ammine ions to metallic copper and cupric ammine ions ; and (4) Diffusion of cuprous ammine ions from the copper surface. The nitrate system was selected for this study because it simplified the determination of the ionic composition of the solutions. The variables studied were stirring speed and cupric, ammonia, and nitrate concentrations. The dissolution rate increased linearly with at low values of but exhibited increasingly negative deviations from linearity at higher values of m. The rate also increased with increasing cupric concentration but decreased with increasing ammonia and nitrate concentration. Good agreement was obtained between the experimental rate data and the proposed model. Further verification of the model was indicated by the close agreement of the diffusion coefficient calculated from the data and comparable literature values.

Jan 1, 1974

By H. P. Bucker, M. Felsenthal, F. R. Conley

INTRODUCTION In the intensive analysis of core samples from oil raservoirs, there is a recognized need for pore sizc distribution data. Such data, if collected with adequate precision and in sufficient quantity, should contribute to a better interpretation of fluid flow phenomena than is now possible from a knowledge of permeability and porosity data alone. It is hoped, for instance, that pore size distribution data may eventually provide a useful aid for predicting whether a water flood, or other secondary recovery methods. will he successful in a given reservoir.' Apparatus tor measurlng pore size distribution by mercury injection at pressures ranging from 0 to 2,000 psi have been described in the literature.2,3,4 All of these apparatus are somewhat complex and fairly expensive. Furthermore, the callbration of some of the apparatus is not always easy. Great difficulty, for instance, was experienced in obtaining reproducible pressure-volume correction data for the mercury pump shown in one of the references. An apparatus was therefore developed which was less complicated and less expensive than those of previously described designs. This apparatus is, in some respects, an improved version of a previously described low pressure apparatus' (maximum pressure 150 psi) which did not cmploy a mercury pump but instead used a precision bore glass tube for measuring the injected volumes. Tests were performed with the apparatus from vacuum to 2,000 psi and it was observed that the apparatus furnished reproducible pressure-volume correction data. In addition. it was noted that the maximum correction was small. precision of measurement was high. and operation of the entirc apparatus was relatively easy. Although the apparatus was designed exclusively for samples of 1 in. diameter and 1 in, length or smaller, it could be modified without much difficulty for larger samples, if desired. APPARATUS Arrangement of the pore six distribution apparatus is shown schematically in Fig. I. The heart of the apparatus is a steel sample chamber surmounted by a precision bore capillary glass tube. A mercury reservoir is connected to the lower half of the sample chamber. The top of the glass tube is in communication with a

Jan 1, 1957

By M. Cohen, D. Caplan

The scaling characteristics of three Fe-Cr alloys have been investigated by determining their weight gain vs. time curves at 1600° to 2000° F. The scales formed thereby have been examined using the techniques of X-ray diffraction and spectrographic and metal-lographic analyses in an attempt to explain the discontinuities in the curves and to elucidate the mechanism of scaling. DESPITE the considerable number of investigations that have been carried out on heat resistant alloys, the characteristics of the scales formed at high temperatures are not fully known. The research reported here was undertaken in an attempt to ascertain the mechanism of scaling of the stainless steels. Scaling experiments were carried out first, the weight increase of the specimens being followed continuously with time. It was observed that, as well as showing the expected decrease in oxidation rate with time, the oxidation curves showed breaks corresponding to intermediate periods of accelerated oxidation, after which protectiveness again increased. This phenomenon was observed with austenitic stainless steels (types 302, 309, and 330) and with Fe-Cr alloys (types 410, 430, and 446), but only the latter are treated in this report. An examination of the scales was made using the techniques of X-ray diffraction and spectrographic and metallographic analyses in an attempt to obtain a correlation between the nature of the scales and the oxidation curves. A search through the literature revealed only a very few previous reports of such periods of accelerated oxidation. Dunn' found breaks in the oxidation-time curves of some Cu-Si alloys but saw no rational explanation of the phenomenon. Heindlhofer and Larsen2 attributed a discontinuity in the weight gain-time curve of iron at 1290°F to the formation of blisters, the subsequent cracking of which exposed an unprotected surface and permitted rapid oxidation until a new protective scale had been reestablished. They advanced no explanation, however, for what they termed the peculiar behavior of a 27 pct Fe-Cr alloy at 2000°F which gained weight very rapidly in between two periods of very slow weight gain. Portevin, Pretet, and Jolivet3 in describing breaks in the weight gain-time curves of Fe-A1 alloys suggested that they might be associated with the occurrence of localized and deeply oxidized areas on the specimens. Bandel4 in a general discussion of oxidation curves of heat resistant alloys considered that the discontinuities were due to a local disruption of the protective layer by the growth of iron-rich oxides. Day and Smith" in their report on the scaling of a large number of iron alloys noted but did not explain occasional relatively rapid changes in oxidation rate at higher temperatures. Chevenard and Wache6 found breaks, often two per specimen, in the oxidation curves of an 18-8 type alloy. They suggested that the cause might be a depletion in chromium of the surface layer of metal due to its selective oxidation, the resultant high concentration of iron and nickel in the scale leading to a poorly protective scale. McCullough, Fontana, and Beck' explained the breaks in the oxidation curves of types 304, 430, and 410 alloys as due to mechanical ruptures. Experimental Work Table I lists the chemical compositions of the materials used. Cylindrical specimens 1/4 in. in diam and 11/2 in. long were machined from cold rolled % in. rod. After a fine finish cut with a sharp tool, the specimens were abraded while still mounted on the lathe with Nos. 2, 1, 0, and 00 metallographic grade emery papers. A 3/64 in. hole was drilled at a distance of 1/8 in. from one end to permit suspension in the furnace. Specimen Nos. 1, 2, and 3 were tested with this surface preparation. All others, after being similarly prepared, were electropolished in a perchloric-acetic electrolyte, electrical contact being made by pressing a tapered platinum hook into the drilled hole. The specimens were then washed in hot water, rinsed with distilled water, rinsed with methanol, dried at 120°F, and weighed. Thereafter,

Jan 1, 1953