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By T. M. Kegley, J. H. Frye, D. L. McElroy, M. L. Picklesimer, E. E. Stansbury

Measurements of rate of growth, thermodymmic quantities, and partitioning of Mn are reported for high-purity eutectoid Fe-C and Fe-C-Mn steels for the auistenite-pearlite reaction. Evaluztion of the cotnstants of a derived-rate equation with these data indicate that Mn additions cause the decrease observed by increasivg the activation energy and apparent activation entropy or the movenment of complexes at the interface. A diffusion-controlled mechanism is not required. Appreciable partitioning of Mn to cementite occurs entirely behind the austenite-pearlite interface for more than 30°C of subcooling. ThE growth of pearlite from austenite has been extensively studied over a period of years. but the rate-controlling step in the process is not known nor is the mechanisrn of the effect of alloying elements understood. A comprehensive review of the subject has been given by Mehl and Hagel. The present study has been concerned with further considerations of the effects of alloying elements on the rate of growth of pearlite. Analytical relatioriships for the rate of growth of pearlite have been considered by Zener.2 Turnbull,3 Machlin,4 Cahn.5 Frye,6 and Frye et a1.7 The derived expressions in each case involve the free energy of the transformation. the interlamellar spacing. and some rate term of the nature of the diffusion coefficient. mobility or frequency of occurrence of some rate-determining step. The treatments. of course. differ in detail. Further consideration is given in the present paper to the equation of Frye, Stansbury. and McElroy which was derived from modified absolute rate theory without in any way specifying the mechanism of the reaction. This equation is r=c ? T ? F exp -?E*/RT [1] where r = rate of growth in mm/sec c = a constant AT = equilibrium transformation temperature minus actual transformation temperature "C ?F = free energy per mol of austenite minus that of pearlite ?E* = activation energy R= gas constant ?F in Eq. [1] is computed from the following: ?F=?H?T/To - ?T' dT' ?T' ?CdT"/T" [2] To To where AH is the enthalpy per mol of austenite minus that of pearlite at the equilibrium temperature, To, and AC is the difference in specific heat between austenite and pearlite per mol. Subsequently, Darken, Fisher, and Galligan8 have reported that a layer of ferrite separates pearlite from austenite at the growing interface (i,e., the advancing face of Fe3C is in contact with ferrite, not austenite) and the ratio of the thickness of this layer to the spacing of the pearlite has not been found to vary with alloy content or transformation temperature. This observation does not require any alteration in the above equation: however, it may require that a different significance be attached to the factor, AT. The AT term appears in Eq. [I] as a consequence of a factor for the amount of growth per complex transformed at the interface.* It is based *This is not the sole reason for expecting such a relationship. See Ref. 7._______________________________________________________ on a l/2 ?T dependence of the interlamellar spacing. Zener2 has developed a theory which leads to Soa 1/?V where So = the pearlite interlamellar spacing. This relation is as consistent with the data on interlamellar spacing as other relationships, although, as pointed out by Mehl and Hagel,1 the data are not sufficiently precise to consider the relationship as confirmed. The work of Darken, Fisher, and Galligan8 requires that the above be written where f = the thickness of ferrite layer between austenite and pearlite. The present paper is concerned with iron-carbon-manganese eutectoid alloys and reports experimental measurements of the following kinds: 1) the effect of

Jan 1, 1961

By A. F. Witt, A. M. Gaudin, A. K. Biswas

Finite contact angles in the rutile-water-organic liquid system are traceable to contamination or are due to addition of a surface-active agent. Finite contact angles are invariably accompanied by hysteresis.1-7 Besides surfactant concentration and pH, the nature of the organic liquid is found to be a factor influencing the magnitude of contact angle hysteresis. In a recent paper the authors have reviewed principles and applications of measurement methods for contact angles and their hysteresis.22 In this paper, these methods are applied to a system consisting of rutile, an organic liquid (benzene, decane, or dode-cane) and water. Surfactant (dodecylamine hydro-chloride) was used at various concentrations and various pH values. MATERIALS A synthetic rutile crystal supplied by the Linde Co. was used. It is a cylinder 1/2 in. diam, with faces cut perpendicular to the c-axis. The crystal is stated to be alumina-free and to be 99.9% pure. Rutile is a high surface energy solid, its calculated average field strength being 2.7 x 105 e.s.u.,9 its dielectric constant10 is 114. The zero point of charge of rutile was measured11 and found to be at pH 6.0. The atomic distances and bond angles of the tetragonal crystal of rutile have been precisely determined.l2 The organic liquids were specially purified. Reagent grade benzene was repeatedly shaken with concentrated sulfuric acid to remove thiophene, then neutralized with sodium hydroxide solution, rinsed with distilled water, dried overnight over anhydrous calcium chloride and filtered. The refractive index of this chemically purified benzene was 1.4977 (at 25°C) - very close to that of pure benzene (n25 1.4979).13 Both n-decane and n-dodecane were washed with aqueous sodium hydroxide, concentrated sulfuric acid (repeatedly, until the acid layer was colorless) and again with alkali, to free the organic hydrocarbon from fatty acids and unsaturated hydrocarbons. The organic phases were subsequently washed with distilled water and dried over anhydrous sodium sulfate. The filtered hydrocarbons were then distilled under vacuum (9-10 mm pressure). Decane, thus purified, showed traces of unsaturated and of carboxylic compounds. On gas chromatographic analysis the purified n-dodecane showed the presence of two impurities. However, the relative retention times of these components did not change substantially when measured on a polar or a nonpolar column. This indicates that the compounds were probably in the same polarity class, i.e. the components were nonpolar like dodecane. Conductivity water has always been one of the liquids. Conductivity of the water used was 10-6 ohm-' cm". Dodecyl ammonium chloride was prepared from pure amine (supplied by Armour and Co., Chicago), by Li in the MIT Mineral Engineering Laboratory.14 The critical micelle concentration at 25°C is known, 0.0138 mol per liter15 or 3.06 gpl. All our experiments have been done at concentrations lower than the critical micelle concentration. The glass vessels, glass drop holder and the rutile crystal were all cleaned with hot chromic acid followed by distilled water, concentrated hydrochloric acid, and again distilled water, and conductivity water. During the experiments, a nitrogen atmosphere was maintained. For this purpose, commercially purified nitrogen was further purified by passing it over hot copper wire at 450°C, then through columns of acidic chromous chloride solution, concentrated alkali solution and distilled water. APPARATUS AND METHODS Hysteresis was produced by the "captive drop" or constant volume drop method as well as by the "expanding-contracting drop" or variable volume drop method. The image of the drop while it is expanding, contracting or moving is projected on a screen and photographed. The developed film is projected through an enlarger and the contact angles measured with a protractor.

Jan 1, 1964

By Frederick M. Becket

SHORTLY after the Armistice there appeared a few references to numerous attempts that had been made to produce steel without the aid of manganese, or at least with manganese in abnormally low percentage. Some years later, during two consecutive days of train travel, I had excellent opportunity to read Sir Robert Hadfield's book, entitled "Metallurgy-Its Influence on Modern Progress," and also his paper, "The Metal Manganese and Its Properties : Also the Production of Ferro-Manganese and Its History," presented at the spring meeting of the Iron and Steel Institute, 1927. Both the book and the paper are most interesting historically to makers of alloy steels and

Jan 1, 1931

By W. R. Hibbard

It has been proposed1 on the basis of slip and flow that the ideal deformation texture of drawn wire for face-centered cubic metals is a (111) direction parallel to the wire axis. Under these considerations, an intermediate [loo] texture is permissible but should eventually change to the stable [Ill] orientation. This theory does not explain why copper and its alloys containing up to about 30 pct nickel, 5 pct zinc and 1 pct aluminum were found to have a double [Ill], [100] texture, while alloys with at least 8 pct zinc and 2 pct aluminum developed essentially a single [Ill] texture.1,2 It does suggest, however, that the [loo] component of the former alloys should disappear with additional deformation.3 Some evidence exists to support this suggestion. Howald4 reported that annealed copper wire previously drawn 93.8 pct and 98.5 pct developed a single [Ill] texture. Since, in wire, the drawn and annealed textures are similar, these wires probably had a single [Ill] deformation texture before annealing. In addition, although cold rolled polycrystalline copper and 80-20 brass were found to form different types of pole figures,5,6 single crystals of these metals when rolled from the stable (110) [112] orientation were found to produce essentially the same polo figure.7.8 It may be, therefore, that while the addition of solute elements changes the path by which the final texture is obtained, the final texture is not changed. Experimental Results The wires remaining from the previous investigation1 already drawn about 50 pct reduction in diameter were further drawn to 86 pct and then to 96.4 pct total reduction in diameter. The textures were determined after these stages by transmission X ray photograms taken with a copper K-alpha beam rotated 0 degrees toward the wire axis. It was found that the ratio of the [111].] and [100] intensities of the double texture in copper and its alloys containing 0.94 pct aluminum, 30.70 pct nickel, 2.61 pct zinc and 4.99 pct zinc increased from about 3:l for the 50 pct reduction to about 9:l for the 86 pct reduction. After 96.4 pct reduction, these wires exhibited essentially a single [lll] texture. Summary Thus, the drawn wire deformation texture of copper and its alpha solid solution alloys containing aluminum, nickel or zinc is essentially a single [Ill] texture as predicted by theoretical considerations of slip and flow.' For copper and its alloys containing up to about 1 pct aluminum, 5 pct zinc and at least 30 pct nickel, an intermediate [loo] component is found after about 50 pct reduction in diameter, but disappears after about 95 pct reduction in diameter. For alpha solid solution alloys containing at least about 2 pct aluminum and 8 pct zinc the single [Ill] texture is developed considerably more easily and is found after about 50 pct reduction in diameter. No explanation of this compositional effect is apparent. Similar work is contemplated for cold rolled and cold compressed alloys. References 1. w. R. Hibbard, Jr. and M. K. Yen: Trans. AIME 175, 126. Metals Tech., Feb. 1948, TP 2334. 2. W. R. Hibbard, Jr. and D. E. Trout, 11: Trans. AIME 185, 620. Jnl. of Melals, Sept. 1949, TN 18. 3. W. R. Hibbard. Jr.: Disc. of R. M. Brick's paper on Deformation Textures, ASM Symp. on Cold Working of Metals, Oct. 1948. 4. T. S. Howald: Disc. of Ref. 1. Trans. AIME, 175, 126. Melals Tech. Aug. 1948, TP 2449. 5. R. M. Brick, D. L. Martin and R. P. Angier: Trans. ASM (1943) 31, 675. 6. 0. Dahl and F. Pawlek: Zlsch. Melall. (1936) 28, 266. 7. C. S. Barrett and F. W. Steadman: Trans. AIME (1942) 147, 57. 8. J. E. Burke and C. S. Barrett: Trans. AIME 175, 106. Melals Tech., Feb. 1948. TP 2327.

Jan 1, 1950

By J. N. Ong

The oxidation of tantalum is assumed to occur by four simultaneous first-order chain reactions; solution of oxygen in the metal, nucleation and growth of a suboxide phase at the metal surface and two phase boundary processes which give rise to two different modifications of Ta2O5. A rate equation is then formulated which accounts for all principal details of oxidation behavior, unifies and correlatss the results of the principal investigations, and expresses the rate as a function of pressure, temperature, and time. For purposes of practical application, the expressions: may be used below and above 700T respectively to determine the regression rate of tantalum in cm per hr, where T is to be expressed in "K and P in atmospheres pressure of oxygm. The equations will reproduce within a factor of two all reported experimental rates in the temperature range 475" to 1400°C and pressure range 0.000026 to 40.8 atm 0. 1 HE oxidation kinetics of tantalum have been investigated thoroughly in the temperature range 50" to 1400 and pressure range 1.32 x l0-' to 40.8 atm pressure of 0,and as a result, the principal features of the oxidation of tantalum are known and have been described in considerable detail. The exposition of the characteristics of the behavior of tantalum in oxygen has been largely descriptive, with considerable attention being devoted to elucidating the structure, composition, and morphology of the resulting oxide products. The weight change vs time results have usually been reported graphically. With the exception of the linear rate below 700 C and the process of diffusion of interstitial oxygen into the metal,6'9 no effort has been made to characterize the reaction rates in functional form. It is the purpose of this paper to demonstrate that when the fundamental principles of chemical kinetics are rigorously followed, the results of the principal investigations will be correlated and unified and the oxidation rale may be expressed as an analytic function of pressure, temperature, and time. In addition to accounting for the temperature and pressure dependency of the oxidation rate, the following minor features will be accounted for as a result of the basic analysis: the initial period of nonline-arity in rate at low temperatures, which decreases with increasing temperature;3'5'7 the rate vs temperature cusps obtained at constant pressure"5 the concentration gradient of oxygen interstitially dissolved in the metal.5'7 The analysis will also be consistent with the overall chemistry of reaction and with all visual, microscopic, and X-ray observations. DEVELOPMENT OF RATE EQUATION As a fundamental basis for the treatment of metal-oxygen reaction kinetics, it will be regarded that the rate of reaction is determined by the concentration and not the activity or chemical potential. It is further assumed that all metal-oxygen reactions are first order complex chain reactions" whose rate is dependent on the concentration of an intermediate species which is a complex function of the oxygen concentration, or oxygen pressure, only. The basic rate equation is therefore: is the weight of oxygen consumed by the reaction, A is that portion of the area of the metal over which the reaction is occurring (cm2), t the time (sec), kf the rate constant for forward reaction, C the intermediate species concentration and f '([Oz]) and f (Po,) are complex functions of oxygen concentration and Oxygen pressure respectively. Reverse reactions may usually be neglected in metal-oxygen systems since a large negative free energy generally accompanies these reactions. Eq. [I] takes different forms when the rate of reaction is controlled by diffusion into or through a phase or at a phase boundary. For diffusion into the metal phase, the rate is given by1' Di is the diffusion coefficient of species diffusing into the metal phase (cm2/sec), and Q is the corre-

Jan 1, 1962

By Robert M. Yerkes

The following is a brief account of the methods of measuring intelligence especially prepared for use in the U. S. Army, of typical results, and of some of their immediately practical applications. It has been prepared for the assistance of army examiners and for the information of all who are interested in the relations of scientific placement to military efficiency. Purpose of the Intelligence Tests Under the direction of the Division of Psychology, Medical Department, and in accordance with provisions of War Department General Order No. 74, mental tests are given recruits during the 2-wk. detention period. These tests provide an immediate and reasonably dependable classification of the men according to general intelligence. Their specific purposes are to aid: 1. In the discovery of men whose superior intelligence suggests their consideration for advancement; 2. In the prompt selection and assignment to development battalions of men who are so inferior mentally that they are suited only for selected assignments; 3. In forming organizations of uniform mental strength where such uniformity is desired; 4. In forming organizations of superior mental strength where such superiority is demanded by the nature of the work to be performed; 5. In selecting suitable men for various army duties or for special training in colleges or technical schools; 6. In the early formation of training groups within regiment' or battery in order that each man may receive instruction and drill according to his ability to profit thereby; 7. In the early recognition of the mentally slow as contrasted with the stubborn or disobedient; 8. In the discovery of men whose low-grade intelligence renders them either a burden or a menace to the service.

Jan 1, 1919

By AIME AIME

OUR own Institute of Metals and Iron and Steel divisions cooperated with the Iron and Steel Division of the American Society of Mechanical Engineers, the American Welding Society, and the American Society for Steel Treating in a busy week at Cleveland. The morning sessions were held at the Hotel Cleveland and the afternoon ones at the Auditorium, where the metallurgical exhibition under the auspices of the American Society for Steel Treating not only occupied the arena of the Auditorium but completely filled the huge adjacent Annex. In the intervals of sessions the members thronged the exhibits but in the evenings the local attendance was so great that if the crowds had been any larger it would have been difficult to see the exhibits. With so many firms, both producers of metals and of equipment accessory to their production and use, it would be impossible to mention them -all and unfair to single out a few, since no two individuals' judgment would coincide as to relative interest and importance. In any case an exhibit is a thing to be seen rather than described, and these were well worth seeing.

Jan 1, 1929

By E. J. Schmitz

This section was obtained last year during an examination of the iron-ore resources of the Rich Patch Mountain region and along Craig's creek valley. The geological members below the Oriskany and Lower Helderberg are exposed along the gap in a beautiful arch, while the higher formations appear in a more or less disturbed state on both sides of this arch, and are partly covered by dèbris. I have thought it of interest to the Institute to reproduce the drawing of this section at the gap which I made in my note-book at the time of my examination; those parts of the section, which lie at both sides of the arch, are only approximated. I give also a number of notes and measurements, referring to the Clinton formation and especially to the characteristics of the fossiliferous ore-seam opened in the various tunnels along the arch (see section). I. In Tunnel C: For the first 110 to 120 feet to second shute, we find the ore only here and there in small deposits, and interchanging with, or changing into, either a very siliceous limestone or a sandstone. About 10 feet beyond shute we have : Sandstone roof. Clay-slate, 211/2 inches Brown lean ore, 1 inch. Sandy clay, 3 to 31/4 inches. 1. Dark .brown ore, 3 inches. 2. Fossil-ore, changing into sandstone or very siliceous limestone, 2 inches. 3. Brown lean ore, 6 inches. Clay and slate below, 1 foot. 194 feet from entrance : Sandstone roof. Clay-slate, 4 inches. Clay 15 inches. Fossil-ore, 63 to 7 inches. Clay and ore, If inches. Lean brown ore, 2 inchea. Clay to bottom, 2 feet.

Jan 1, 1896

By G. H. Billings

The following data were collected some years since in the course of a series of experiments with oil as a substitute for coal in puddling, the earlier form of the Archer apparatus being employed. While I am not at liberty to give the name of the works at which the tests were made, I can personally warrant the accuracy of the record, and feel justified, therefore, in making this contribution to a discussion in which all trustworthy figures are likely to be helpful. Oil in Puddling. Starting with everything cold, we used 3518 pounds of oil to get the furnace in condition to charge a heat. After charging, we ran until we took out 13,340 pounds of puddled-blooms, using 8437 pounds, or 1333 gal1ons of oil. At 49 cents per gallon, the cost for oil per gross ton of blooms was $10.91; with coal at $4.871/2, and a consumption of 1.5 tons per ton of blooms (the usual quantity is ton for ton), the cost for coal is $7.31. The quantity of oil consumed in heating the furnace to the proper temperature and to make the bottom, is not included in the oil consumption stated. The quantity used was 3518 pounds of oil. Usually, the furnace need only be lighted, but in this case it had been repaired, and it was necessary to make a new .bottom. This required the quantity of oil necessary to make three heats of blooms, or 2109 pounds. Deducting this from the 3518 pounds leaves 1409 pounds of oil as the quantity consumed every week in lighting up.

Jan 1, 1889

The plan for establishing relations of American industry with national labor on a definite basis so closely follows the channels of the efforts of Engineering Council, principally in the classification and compensation work, that it is of special interest to the engineering profession. The principles laid down under the following headings are about to he submitted to a referendum vote of the membership of the Chamber of Commerce of the United States. These principles were prepared by a special committee of the Chamber of Commerce after a long period of study of the entire subject of industrial relations. 1. Industrial enterprise, as a source of livelihood for both employer and employee, should be so conducted that due consideration is given to the situation of all persons dependent upon it. 2. The public interest requires adjustment of industrial relations by peaceful methods. 3. Regularity and continuity of employment should be sought to the fullest extent possible and constitute a responsibility resting alike upon employers, wage earners, and the public. 4. The right of workers to organize is as clearly recognized as that of any other element or part of the community. 5. Industrial harmony and prosperity will be most effectually promoted by adequate representation of the parties in interest. Existing forms of representation should be carefully studied and availed of in so far as they may be found to have merit and are adaptable to the peculiar conditions in the various industries. 6. Whenever agreements are made with respect to industrial relations they should be faithfully observed. 7. Such agreements should contain provision for prompt and final interpretation in the event of controversy regarding meaning or application.

Jan 6, 1919

By J. Ellzey Hayden, Lucien Eaton

The Cliffs Shaft mine of the Cleveland Cliffs Iron Co., located in the city of Ishpeming, Mich., is the largest producer of hard hematite ore on the Marquette iron range. The two shafts, A and B, lying 820 ft. (250 m.) apart on the east-west trend of the ore formation, were sunk in the early eighties, and, except for four years, have been steady producers of iron ore. Their location, on a hill overlooking the general offices of the company on the one side and the city of Ishpeming on the other, has made the shaft houses landmarks. In the spring of 1919, as the old wooden shaft houses had become shaky and out of line, and would soon be unsafe, it was necessary to replace them with the least possible delay. Three plans of construction were, therefore, considered: To replace the old shaft houses by somewhat similar structures made of wood; to use steel and radically change the design; or to build reinforced-conerete shaft houses outside of the wooden structures, completely enclosing them. The first plan was disapproved, because it is anticipated that the mine will have a long life and the proximity of other buildings makes the danger from fire rather great. Delay in receiving material, and the necessity for closing the shafts during erection, were other factors in the situation. The second plan was disapproved on account of the high cost of steel, slow delivery, and interference with hoisting during the period of erection. The presence near one of the shafts of a large bed of hard gravel suitable for concrete made the cost of the third plan considerably less than the second, and little, if any, delay in hoisting was expected. Our expectations in this regard were fully realized. Furthermore, the work could be done by unskilled labor, which was plentiful, and the erection could be quickly started. When the proposition was submitted to W. G. Mather, president of the company, he recommended that, on account of the prominence of the buildings due to their location, an effort should be made to combine in the design as far as practicable something of architectural beauty. Following his recommendation, the original plans were submitted to the

Jan 1, 1922

By J. Ellzey Hayden

THE Cliffs Shaft mine of the Cleveland Cliffs Iron Co., located in the city of Ishpeming, Mich., is the largest producer of hard hematite ore on the Marquette iron range. The two shafts, A and B, lying 820 ft. (250 m.) apart on the east-west trend of the ore formation, were sunk in the early eighties, and, except for four years, have been steady producers of iron ore. Their location, on a hill overlooking the general offices of the company on the one side and the city of Ishpeming on the other, has made the shaft houses landmarks. In the spring of 1919, as the old wooden shaft houses had become shaky and out of line, and would soon be unsafe, it was necessary to replace them with the least possible delay. Three plans of construction were, therefore, considered: To replace the old shaft houses by somewhat similar structures made of wood; to use steel and radically change the design; or to build reinforced-concrete shaft houses outside of the wooden structures, completely enclosing them. The first plan was disapproved, because it is anticipated that the mine will have a long life and the proximity of other buildings makes the danger from fire rather great. Delay in receiving material, and the necessity for closing the shafts during erection, were other factors in the situation. The second plan was disapproved on account of the high cost of steel, slow delivery, and interference with hoisting during the period of erection. The presence near one of the shafts of a large bed of hard gravel suitable for concrete made, the cost of the third plan considerably less than the second, and little, if any, delay in hoisting was expected. Our expectations in this regard' were fully realized. Furthermore, the work could be done by unskilled labor, which was plentiful, and the erection could be quickly started. When the proposition was submitted to Mr. W. G. Mather, president of the company, he recommended that, on account of the prominence of the buildings due to their location, an effort should be made to combine in the design as far as practicable something of architectural beauty. Following his recommendation, the original plans were submitted to the

Jan 8, 1920

By R. L. Smith, J. L. Rutherford

ZONE refining, as developed by W. G. Pfann,1 has been used extensively for the purification of semiconductors. This method has made it possible to obtain the extremely high purity material necessary for the transistor industry. It has also been utilized to some extent for the purification of relatively low-melting-point metals. However, very little attention has been given to reactive, high-melting-point materials, with the exception of silicon. For this element, it has been necessary to use the floating zone technique in order to avoid contamination from the crucible containing the melt. The method is one in which a narrow molten zone is formed in a vertical rod by induction heating. The molten zone is supported between the two solid sections of the rod by surface tension. It is then moved longitudinally along the rod in order to effect a redistribution of solute. This technique has an advantage over the horizontal boat method, since crucible contamination is avoided. It has the disadvantage of being a much more difficult technique than zone refining in a crucible. Furthermore, it is necessarily a slow process, since only one zone at a time can be formed. However, the floating zone process offers a means of obtaining high-purity metals that are either not available, or can only be obtained in powder or pellet form as the result of complex chemical or electrochemical methods. It should be emphasized that the process is not effective in removing all impurity elements. Those that cannot be redistributed in an ingot during zone melting must be removed by some other means. Very little is known of the prope~ties of very high purity reactive metals such as iron, titanium, zirconium, beryllium, etc. It is quite likely that trace elements in such metals can affect their properties drastically. Therefore, one of the primary objectives of this work is to study the properties of metals which have been obtained in the purest form available and then zone refined. Trace elements can be introduced in a variety of ways, such as by inserting wafers between solid portions of the ingot to be melted, by placing the

Jan 1, 1958

Operating Characteristics of Centrifugal Fans and Use of Fan Performance Curve Discussion of paper by. Louis W. HUBER, presented at the New York Meeting, 1926, .and issued, as Pamphlet No. 1542-A, with MINING AND METALLURGY, February, 1926. G. BRIGHT, Pittsburgh, Pa.-Apparently from the pressure curves for a forward-curved-blade fan, in Mr. Huber's paper, practically all ventilation-might be stopped with increased resistance. In order, to discuss the characteristics of a fan we need, some better way to measure the characteristics of a mine. You all know that. the average anemometer is not very-reliable. Sometimes two anemometers, supposed to be recently calibrated, will differ 50 per cent. Either this or some other committee should standardize measuring methods. The characteristic curves of fans, given by Mr. Huber, would indicate that the forward-curved-blade fan would cause trouble in attempting parallel operation, because two machines will not parallel unless they have dropping pressure characteristics. On the other hand, it is indicated that with the backward-curved blade, they could easily be paralleled. But few mines use more than one fan. Mr. Huber said that if the resistance of the mine was considerably more than contemplated, the quantity of air might be such that the efficiency of the backward-curved fan would be seriously affected, dropping say from 70 to 55 or 50 per cent. In such event, could a difference of speed be selected for the fan that would give the quantity desired at a higher efficiency? L. W. HUBER, Pittsburgh, Pa.-The backward-curved-blade fan responds to change in speed the same as any other fan; if' the speed is doubled, the quantity of air is doubled, the pressure is increased four times and the horsepower eight times. One point not mentioned in the paper is that the backward-curved fan is more efficient than the forward-curved or any other type. If the latter were more efficient, it would pay to install that type and keep the resistance of the mine constant, which is hard to do but it can be done with care. But the total mechanical efficiency of a fan with backward-curved blades is from 10 to 20 per cent. higher.

Jan 1, 1927

By A. Adiaddevich

Petroleum has been found in Russia in various localities from north to south, as may be seen from the list given below: (a) In the basin of the Petchora river, Northern Russia. (b) In the basin of the Volga river, in the governments of Samara and Saratoff. (c) In the government of Astrakhan and in the Uralsk territory, close to the northern and eastern coast of the Caspian sea. (d) At Grozny in Northeastern Caucasus. (e) In the Daghestan territory, Eastern Caucasus, on the Caspian sea. (f) On the Apsheron peninsula (Baku and other districts) close to the Caspian sea shore. (g) On the island of Tcheleken in the caspiah sea, also on the island of Sviatoi. (h) In the Transcaspian territory on the Neftianaia Gora (Oil hill) and on the surrounding hills. (i) In the Ferghana valley in Russian Central Asia. (j) On the Kertch-and Taman peninsulas on the Black sea. (k) In Siberia it has been discovered in the Transbaikal territory and on the island of Sakhalin.. ' ' In the above-mentioned districts petroleum has been found to exist under different geological conditions and to vary in its chemical and physical properties. At the present time petroleum is produced in Russia at Baku, Grozny, on the island of Tcheleken, in the Ferghana district, and in the Uralsk territory. The yearly production in 1912 throughout the Russian Empire amounted to 69,400,000 barrels, of which the Baku fields were responsible for 52,000,000 barrels. This shows that the Balm fields on the Apsheron peninsula are the chief oil-producing centers in Russia, being at the same time the oldest of all our oil fields. In this paper I shall discuss the Baku fields only, leaving all the others until a later date. The Apsheron peninsula in the Eastern Caucasus protrudes into the Caspian sea in the shape of a triangle some 47 miles long covering a total area of some 750 square miles. The eastern part of the peninsula is a flat, slightly rolling plain, rising in its highest parts to 140 to 170 ft. above

Jan 1, 1915

Victor G. Hills, Cripple Creek, Colo. (communication to the Secretary): In continuation of the subject of the perform ance of "baby machine-drills," presented by Mr. Thane, I sub mit the following records of work done with these drills in the Cripple Creek district of Colorado. Two years ago, the Anchoria-Leland mine began to use baby drills ; and, to make the experiment more complete, began by purchasing two machines, of the same size, but of different make. The little drills were first used for stoping and up raising, in which they achieved at once an unqualified success. Soon after, they began to be used for the smaller branch-drifts and prospecting cross-cuts, while the large two-man drills were still used for the main drifts. Now they have almost entirely superseded the large drills, since it has been found that they will do any ordinary work in the mine at less cost, both for labor and for powder, per ton of rock broken. The large drills, of course, make more rapid progress; but it is only where time is a specially important factor that they are now used. The Portland mine, where, until within a year, only the large machines were used, is now using some small drills for stoping, and also for drifting. Mr. Thane speaks of having two men to operate a baby-drill; but in this district the baby-machine is always worked by one man without help. Again, in Prof. Christy's postscript, the quoted extract from a letter of Mr. L. T. Seymour, the South African engineer, mentions a " 2 1/2-inch Little Giant," as though that were the smallest machine used in that region. These statements leave some doubt as to just what Mr. Thane means by a " baby-drill." To avoid any such uncertainty as to the present communication, I will say that the large or two-man drill in common use at Cripple Creek has a 3 1/8-inch cylinder; while a few mines employ a 3-inch, and a few, in running large tunnels, a 3 1/2-inch drill. What we call a baby-drill here has a

Jan 1, 1900

By J. D. Shaw, E. B. Gebert, D. O. Noel

It is, of course, expected that manufacture of the various metal powders should involve numerous methods adapted to the specific characteristics of the metals themselves. Several methods for powdering a particular metal may be available, but the physical characteristics of the powder as produced by the several methods may be quite different. In the final analysis, the application of the metal powder dictates the physical properties that the metal powder must possess, and this, to a very large extent, will determine which of several possible methods of manufacture is adopted. Sometimes powder of the same metal is produced by more than one method, each powder having specific characteristics that make it particularly suitable for its application. For purposes of classification, the various methods of powdering metals can be grouped as follows: 1. Machining. 2. Milling (by ball mills, stamps, attrition mills, etc.). 3. Shotting (pouring molten metal into water, air, etc.). 4. Granulation (by stirring molten metal while solidifying). 5. Atomizing (disintegrating by steam, compressed air, etc.). 6. Condensation of metal vapor. 7. Reduction of oxide powders. 8. Chemical precipitation. 9. Electrolytic deposition. 10. Sintering (for producing alloy powders). 11. Formation of an alloy followed by dissolving or otherwise removing one of the alloying constituents. Machining Turnings, cuttings, filings, etc., are, of course, produced as by-products in machine work of various kinds, and find certain applications as metal powders. For example, iron powder so produced is used extensively as a reducing or precipitating agent and as a constituent in certain hard-finish cements.

Jan 1, 1938

By D. O. Noel, E. B. Gebert, J. D. Shaw

It is, of course, expected that manufacture of the various metal powders should involve numerous methods adapted to the specific characteristics of the metals themselves. Several methods for powdering a particular metal may be available, but the physical characteristics of the powder as produced by the several methods may be quite different. In the final analysis, the application of the metal powder dictates the physical properties that the metal powder must possess, and this, to a very large extent, will determine which of several possible methods of manufacture is adopted. Sometimes powder of the same metal is produced by more than one method, each powder having specific characteristics that make it particularly suitable for its application. For purposes of classification, the various methods of powdering metals can be grouped as follows: 1. Machining. 2. Milling (by ball mills, stamps, attrition mills, etc.). 3. Shotting (pouring molten metal into water, air, etc.). 4. Granulation (by stirring molten metal while solidifying). 5. Atomizing (disintegrating by steam, compressed air, etc.). 6. Condensation of metal vapor. 7. Reduction of oxide powders. 8. Chemical precipitation. 9. Electrolytic deposition. 10. Sintering (for producing alloy powders). 11. Formation of an alloy followed by dissolving or otherwise removing one of the alloying constituents. Machining Turnings, cuttings, filings, etc., are, of course, produced as by-products in machine work of various kinds, and find certain applications as metal powders. For example, iron powder so produced is used extensively as a reducing or precipitating agent and as a constituent in certain hard-finish cements.

Jan 1, 1938

C. R. CORNING, Chairman. ADOLPHE E. BORIE, First- Vice-Chairman. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. Vice-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, Milton H. McLean, W. de L. Benedict, R. C.Gemmell, ' Philip N. Moore, John C. Branner, F. Louis Grammer, T. H. O'Brien, Palmer Carter, Ernest A. Hersam, James J. Ormsbee, Allan J. Clark, Edwin C. Holden, Edward W. Parker, F. Crabtree, William L. Honnold, John B. Porter, George G. Crawford, Reginald E.. Hore, R. M. Raymond, O. C. Davidson, C. Colcock Jones; Robert B. Richard's, E. V. D'Invilliers, Eugene P. Kennedy, LeRoy Salsich, 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. Meetings of this committee were held at the Institute headquarters on April 18, May, 3 and 15, and June 19.. At the meeting of June 19, the Secretary reported that letters of invitation to apply for membership in the Institute had been sent to all the alumni of the School of Mines of Columbia University and also to all State Mine Inspectors and their deputies. He also reported the securing of lists of the alumni of the Harvard Engineering Schools, and of the Mining Schools at Houghton, Mich. ; Butte, Mont. ; State College, Pa. ; Seattle, Wash. ; Fayetteville, Ark.; Laramie, Wyo.; Montreal, Canada, and Wor-cester and Rensselaer Polytechnic Institutes. Arrangements were made to invite all these to join the Institute. It was suggested that a. member' of the Institute resident in Australia be appointed to this Committee, also one from Japan. Attention of the members of the Committee was drawn to the fact that letters requesting, others to join the Institute will be written in the offices of the Institute if desired. The applications for membership received recently have been as follows March, 30; April, 02; May, 70; June, 54. The next meeting will be held July 17. THOMAS T. READ, Secretary.

Jan 7, 1913

By Reginald S. Dean

Manganous oxide is readily soluble in concentrated ammonia solutions containing ammonium salts. Lixiviants of ammonia and ammonium carbamate permit ready extraction of manganese from reduced ores and the manganese in such solutions may be precipitated by heating to transform the carbamate to carbonate. THE widespread occurrence of manganese in low grade oxide and carbonate ores not amenable to mechanical concentration has led to extensive investigations of hydrometallurgical methods for producing a pure manganese compound suitable for further treatment. Manganese carbonate is the preferable compound. This product when fully crystalline and of not too fine crystal size is easily filtrable and stable in air. It can be converted to other compounds such as the oxides by heating in air or can be reacted with acids for producing salts. A useful hydrometallurgical process must produce relatively concentrated solutions that can be purified easily, reagents must be cyclically used, and heat requirements must be small. Neither the ammonium sulphate nor sulphur dioxide leaching processes that have been tested extensively fulfill these requirements. Other heretofore proposed processes have obvious limitations and have not been tried on a large scale. The present process is based on the discovery by the writer of a new group of aqueous manganese-ammonia complex solutions highly concentrated in ammonia, which permit rapid solution of manganous oxide to concentrations of 80 to 100 g Mn per liter and from which a fully crystalline, easily filtrable manganese carbonate is precipitated by the addition of carbon dioxide and partial ammonia removal. Although the process may be carried out with many ammonium salts, commercial advantages dictate the use of ammonium carbamate, which is obtained when CO2 is passed into concentrated aqueous solutions of ammonia. If the carbamate is used, the only reagents, ammonia and CO2, are volatile and may therefore be recovered from solutions and residues by heating, thus eliminating washing and extensive evaporation. Impurities are controlled easily as most metal oxides are either insoluble in the lixiviant or fail to precipitate with the manganese carbonate. Others are controlled by sulphide addition. The process has been tested extensively on a small scale on a wide variety of ores, including Three Kids, Artillery Peak, Cuyuna, and Chamberlain, as repre-

Jan 1, 1953