Search Documents

By R. W. Coughlin, W. U. Ault

Experiments in laboratory and mine have clearly demonstrated the usefulness of radioactivity detection for directly measuring the potassium content of potash ore as mined. This paper presents the results of these tests and documents the design of a system for automatically grading and sorting potash ore on the basis of radiation detection. It is shown how the experimental results in the subject mine lead directly to the design of this kind of an automatic control system. The system is capable of grading the ore with an accuracy of approximately ±2% K20 content or better. Due to the usual stratification of the ore body, mining potash seldom presents an extreme problem of gangue separation. Nevertheless, it is frequently necessary to transport within a potash mine and even hoist to the surface considerable quantities of halite and other valueless materials. Up to recent times it has been customary to recognize and route these materials by simple visual and manual techniques. However, the work reported here clearly demonstrates that it is now practical and economical to improve upon these techniques by continuous measurement1 of the naturally occurring radioactive isotope, potassium-40. It was the purpose of the work reported here to investigate this technique and assess its applicability. LOCALE OF EXPERIMENTS The work described here was carried out in a potash mine in Carlsbad, N.M. At the working face of this mine the potash ore is freed by blasting; it is then transported a short distance by shuttle car to a moving-belt system which conveys it to the main shaft where it is hoisted to the surface. Quantities of gangue which are also produced in the mining operation are disposed of in mined-out sections of the mine where possible. Otherwise, this material which contains only a small percentage of potassium (as K2O) must also be transported by the conveyor-belt system to the main shaft and then hoisted to the surface and discarded. With this situation, any measuring device for automatic control purposes must be capable of clearly distinguishing between gangue containing insignificant amounts of K2O and ore containing larger percentages of the same mineral. The conveyor-belt system transports the material from the mine face to a rotary crusher and then to temporary storage pits at the main shaft. This is shown in Fig. 1. Upon leaving the conveyor belt the material enters either one of the two storage pits according to the position of a manually operated gate. It was decided that all experiments should be carried out at the conveyor belt between the crusher and gate with a view to the possibility of providing a signal which could operate the gate automatically. THEORETICAL BASIS AND LABORATORY EXPERIMENTS In principle it is possible to grade potassium-bearing ore on the basis of radioactivity. Natural potassium contains 0.012% K40, which is radioactive with a half-life of 1.3 x 10' years. Although about 89% of the K40 disintegrates to Ca40 by beta decay, the other 11% changes to Ar40 by electron capture and the emission of gamma rays. Unlike the ß-rays which are readily absorbed in the first few millimeters of ore surrounding the disintegrating nucleus, the y-ray photons will escape from an ore sample several inches in size. A detector rigidly mounted under a conveyor belt loaded with potash ore will intercept some constant fraction of all the photons emitted from the ore within its field of view. Under these

Jan 1, 1968

By Paul Beck

WHILE the recrystallization properties of most of the practically important metals are known in considerable detail, those of lead are still relatively little known in spite of some valuable contributions in recent years. This condition probably is due to the difficulties involved in applying the usual methods of investigation. The microscopic method of discriminating between the elongated deformed grains of the familiar lenticular shape and the equiaxed recrys-tallized grains is not successful with fully refined lead: lenticular grains cannot be seen under the microscope with any amount of deformation whatever. The probable cause of this phenomenon was recognized long ago. With large deformation the time of recrystallization at room tem-perature is shorter than the period of preparation of the specimen for microscopic examination; with small deformation the deformed grains are not noticeably elongated in the first place. However, with small deformation the migration of the grain boundaries can be observed. The only systematic investigations yet published on the recrystallization of lead, those by R. S. Russell,1-3 make use of the conditions just described. Russell considered recrystallization completed when no further migration of boundaries could be observed. A serious objection to this method arises from the fact that there is no evidence to support the view that grain-boundary migration results only from recrystallization. If such migration does result from other sources after recrystallization is com-pleted-after the deformed grains have been replaced by new unde-formed grains-the "time of recrystallization" as determined by Russell may be too long. Furthermore, the method is subject to the above-mentioned limitation because of the unavoidable period of preparation of the sample. According to Russell, even with the fastest technique 5 min. elapsed before the deformed samples were ready for examination, and consequently no recrystallization time shorter than 5 min. could be measured.

Jan 1, 1939

By F. E. Bash

WHENEVER electric and open-hearth steel men discuss the relative advantages of their respective methods, the question of temperature is always discussed, so that this paper is written in the hope that definite data may settle some of the questions and encourage further investigations along these lilies. The writer has had the opportunity of taking the tapping temperatures of steel from electric furnaces of different sizes in various plants and from a number of open hearths handling the same kind of steel. All temperature measurements were made with the same disappearing-filament type optical pyrometer and the corrections for emissivity applied were those worked out by Burgess,1 which are 0.40 for steel streams and 0.65 for slag. The correction is applied by calculating the curve giving the relation between the true and apparent temperature in the following formula: Log E = CZ log e( 1 _ 1 x \T2 T1) in which E = emissivity; C2 = 14,500; e = base of Napierien logarithms; ? = wave-length of light used = 0.65/4; T2 = true temperature, in degrees absolute; T,1 apparent temperature, in degrees absolute. The curve showing the relation between true and apparent temperature for steel and slag arc given in Fig. 1. For the purpose of comparison of open-hearth and electric furnaces, there are given in Table 1 the tapping temperatures of two 25-ton Heroult electric furnaces and one 6-ton with one 50-ton acid, one 40-ton basic, and one 65-ton acid open-hearth furnace, all making nickel ordnance steel for guns. The two 25-ton Heroult electric furnaces were finishing steel refined by the triplex process and the 6-ton Heroult finished steel that was partly refined in an open hearth.. In this table, the tapping temperature and the temperature of the steel stream into the first ingot

Jan 9, 1919

By AIME AIME

SOME 65 members of the Institute, including most of the Local Section delegates and several Directors and officers, were on hand for the Annual Business Meeting of the Institute held in the Engineering Societies Building on Monday, Feb. 21, at 4:30 p.m., immediately following the second session of the Local Section Delegates Conference. President Mathewson presided. The meeting was largely taken up with the presentation of committee re- ports, discussion of which was invited. F. E. Wormser presented the report of the Admissions Committee ; Philip Kraft, Papers and Publications Com-

Jan 1, 1944

By M. T. Hepworth, T. P. Papazoglou

Hydrogen diffusion in hcp and bcc titanium in the temperature range 610° to 900°C was measured by reacting cylindrical specimens of high-purity titanium at constant temperature with small constant pressures of hydrogen of the order of a few Torr. In the range 0 to 6.7 at. pct H in hcp titanium, the diffusion coefficient D in sq cm per sec is given by: where T is in °K and R in cal per g-atom OK. Only three measurements of diffusivity in bcc titanium were made: at 900' : the diffusivity in ß titanium was found to be 1.8 x 10-4 sq crn per sec. McQUILLAN1 has studied the constitution of the Ti-H system and reported the concentration of hydrogen as a function of pressure of hydrogen and temperature. He found hydrogen absorption was reversible and rapid at temperatures above 500°C in both crystallographic modifications, the a (hcp) phase and the ß (bcc) phase, with the latter phase stabilized by hydrogen additions. Wasilewski and Kehl 2 measured the diffusivity of hydrogen in hcp and bcc Ti-H alloys. For bcc alloys, they reacted cylindrical specimens of titanium with hydrogen gas at 1 atm pressure. They measured the rate of absorption of hydrogen isothermally on specimens ranging from zero hydrogen content when above the transformation temperature to hydrogen contents sufficient to stabilize the bcc phase when below the transformation temperature. By integrating Fick's second law for a cylindrical geometry, assuming a diffusion coefficient independent of composition, they calculated diffusivities as a function of temperature. In the range 650" to 1000°C their results in bcc titanium yielded the expression: where D is in sq cm per sec, T in OK, and R the gas constant in cal per g-atom-OK. Their studies on the hcp a phase were conducted by exposing long cylindrical titanium specimens to hydrogen at a sufficiently high pressure to establish a surface layer of fl phase 80 to 120 u thick for the duration of an isothermal experiment. Concentration profiles were then determined by hydrogen analysis from chips obtained upon machining quenched specimens. The diffusivity of hydrogen was then calculated yielding the expression: The present investigation was undertaken principally to redetermine the diffusivity data on a titanium by a direct absorption from the gas phase at sufficiently low hydrogen pressures to avoid the presence of a surface bcc phase and also to check the diffusivity data at low hydrogen concentrations in the bcc stmcture. EXPERIMENTAL PROCEDURE High-purity electrolytic sponge titanium (99.9 pct) of BHN 91 was arc-melted, forged, rolled, and machined into cylinders of final hardness, upon annealing, of BHN 92. Cylindrical specimens of two sets of dimensions were used: 1.524 by 2.931 cm and 1.905 by 3.663 cm diam and length, respectively. The experimental apparatus used for annealing specimens and for admitting known amounts of hydrogen at constant pressure is shown in Fig. 1. In a typical experiment, a specimen was lightly abraded with fine-grain silicon carbide, washed with water and detergent, and then thoroughly degreased with reagent-grade tri-chlorethylene and acetone. The specimen was suspended by a Chrome1 wire in the center of a quartz furnace tube, without contact with the tube, and heated to 925°C (as measured by a thermocouple adjacent to the specimen, outside the tube) for a period of at least 4 hr under a vacuum of from 10-6 to -7 Torr as measured by an ionization gage. The furnace temperature was then adjusted to the temperature chosen for the particular diffusion study and the specimen allowed to equilibrate thermally. Hydrogen was then ad-

Jan 1, 1969

By John S. Crout

TWENTY-FIVE years ago the training of an engineer was of interest solely to the educator and to the student entering the field. At that time the engineer's position in society was relatively simple. His training emphasized design and operation and he expected to enter industry to handle the engineering problems of raw materials production, mechanical and product design, and the operation of power plants, factories, transportation and communication systems, and similar phases of industrial activity. He was not concerned with or particularly interested in the problems of management, administration, sales, publicity, industrial relations, or of legislation. To a large degree he was content to leave these matters to self-made businessmen, or men trained in law, finance, or commerce. That period in the evolution of the engineer is now history. It is generally conceded that the modern world is dependent upon engineering technology for its day-to-day survival. The continued operation of facilities on which mankind relies is dependent upon the functioning of mines, utilities, chemical plants, and other factories, all of which require the knowledge and the skills of trained engineers. Thus from a purely mechanical point of view, the engineer has become indispensable to

Jan 1, 1947

By E. E. Wark, J. Rogers, I. W. Wark, K. L. Sutherland

SOAPS have been used as collectors for many years, but only in the last eight years have other long-chain paraffin salts been used. It may be anticipated that these newer collectors will be used mainly with nonsulphide minerals, for which the xanthates and similar compounds are of little value. On the other hand, the xanthates are both cheap and effective for sulphide ores and seem likely to retain their present eminence in this field. During 1938 and 1939 two of us (E. E. W. and I. W. W.) commenced a comprehensive investigation of the principles underlying the use of paraffin chain salts as flotation reagents. This research was sponsored jointly by the University of Melbourne and a group of Australian mining companies.[t] A broad, semi quantitative survey was then made of the field covered in the present paper. This was followed in 1940 by further work by one of us (K. L. S.). In 1941 the investigation was taken over by the Division of Industrial Chemistry of the Commonwealth Council for Scientific and Industrial Research, Australia. Discovery of some principles upon which are based the flotation of minerals by paraffin chain salts was followed by their application in the development of processes for the recovery of certain strategic minerals from their ores. Promising results in the flotation of cassiterite from various ores will be described in a subsequent paper. THE PARAFFIN CHAIN SALTS The basic requirements for a "collector" in flotation are that it should form a film over the surface of the mineral to be floated, and that this film should be orientated so that hydrocarbon (nonpolar) groups form the effective surface. When modified in this way, the mineral surface possesses some degree of air avidity. All investigators would agree with Taggart, Taylor and Ince23 that such a film can be produced only if the collector compound contains an active (polar) group to attract it to the mineral surface as well as the nonpolar group. One section of this large class of polarnonpolar compounds is the paraffin chain salts: CH3(CH2) „X where X signifies a polar group that ionizes in aqueous solution. Though the compound can ionize, it may be a weak or a strong electrolyte, and the hydrocarbon chain may be in the cation or the anion (Table I). Many compounds of similar constitution are available, but the usual polar groups are: -CO2Na, -SO3Na, -SO4Na, - PO4Na2, or an aminonitrogen group, the

Jan 1, 1946

By F. Keller, R. H. Brown

BECAUSE of the extensive use of Alclad 24s alloy sheet in aircraft construction, there is much interest in the metallurgical changes caused by heat-treatment of this product.1,2 One of these changes is the result of the diffusion of soluble elements from the core into the coating during treatment. This paper deals with the thermal treatments that may influence diffusion and with the practical effects of diffusion on the serviceability of the product. As is well known, Alclad 24s-T sheet has a core of high-strength alloy combined with surface layers of relatively pure aluminum. The microstructure of a cross section of this product is shown by Fig. I. hot only does the relatively high-purity coating have a high resistance to corrosion, and hence serves as a mechanical barrier between the core metal and the corroding environment, but in addition this coating I exerts electrochemical protection over areas where the core may be exposed, such as cut edges. In addition, the coating affords electrochemical protection to projecting heads of *417S-T, 17S-T and 24S-T rivets, or attached members made from these alloys. Under some conditions of heat-treatment, however, diffusion of copper into the coating will alter the electrochemical relationship between the coating and the core to the extent that only partial protection will be obtained under some corrosive conditions. The reason for the electrochemical protection lies in the fact that the coating layers of pure aluminum are anodic to the alloy core. The addition of copper to aluminum produces alloys in which the potential is lower than that of the pure metal. Moreover, as the amount of copper in solid solution in z4S alloy is increased, the potential of the alloy becomes more cathodic. When heat-treated at 920°F. and quenched in cold water, 24s-T is about 0.16 volt cathodic to pure aluminum. However, copper will diffuse from the core into the coating, and if it reaches the surface the potential will be altered in a cathodic direction. Thus the potential dif-erence between the core and coating may be less than 0.16 volt, depending upon the thickness of the coating, and the time and temperature of heat-treatment. Of the methods available for determining the extent of diffusion of copper from the core into the coating of Alclad 24S-T, two are generally used; namely, the metallographic and the solution potential method.3 METALLOGRAPHIC METHODS Metallographic methods will reveal the progress of diffusion of copper into the coating. For instance, the diffusion zone in the coating intermediate between the coating surface and the core is shown in Fig. I. This photomicrograph is of a polished and etched cross section of 0.040-in. Alclad 24S-T sheet. Diffusion proceeds into the coating more rapidly along the grain boundaries than through the body of the grains. consequently, the diffusion zone is not of uniform width

Jan 1, 1944

By AIME AIME

ON April 7 the twentieth national Open-hearth Conference of the A.I.M.E. will be held in Birming¬ham, Ala., in conjunction with a meeting of the Committee on Blast Furnaces and Raw Materials. At least 300 engineers and operators are expected to attend. Birmingham, the industrial city and iron, and steel center of the South, has been called the "Magic City." Men actively engaged in business in Birmingham today have seen practically every building in the business district erected, have witnessed the establishment of every existing industry, and have hunted birds cm the site now one of the busiest corners of the business district. Incorporated as a town in 1871, the city today has a population of more than 380,000 in its metropolitan area. It is

Jan 1, 1937

Abdul-Ahad. A., Student, Montana School of Mines, Residence Hall Butte, Mont. '39 Abramovits, Charles, Student, Case School of Applied Science Cleveland, Ohio. '37 Abreu, Ovidio M., Student, Univ. of Nevada Reno, Nev. '38 Acker, Voscoe, Student, Agricultural & Mech. College of Texas College Station, Tex. '39 Adams, Albert, Student, New Mexico School of Mines Socorro. N. M. '38 Adams, Charles W., Student, Michigan College of Min. & Tech Houghton, Mich. '39 Adams, Hugh T., Jr., Student, Univ, of Oklahoma Norman, Okla. '39 Adams, Jack L., Student, Univ. of Oklahoma Norman, Okla. '39 Adams, Jack M., Student, Univ of Alaska College, Alaska. '39 Adams, Lewis J., Student, Agricultural & Mech. College of Texas, Box 2514, College Station, Tex. '39 Adams, Robert E., Research Engr., Battelle Memorial Inst Columbus, Ohio. '38 Adamson, George M., Jr.. Student, Univ. of Utah Salt Lake City, Utah. '39 Adkisson, J. F., Jr., Student, Agricultural & Mech. College of Texas, Box 1003, College Station. Tex. '38

Jan 1, 1939

By H. L. Marcus, C. D. Turk

Titanium was physically vapor-deposited by electron beam high rate evaporation. Rates of 50,000 and 85,000Å per min at deposition temperatures of 480°, 535°, and 595°C were used. Deposited thickness ranged front 0.004 to 0.010 in. The evaporated titanium had a high degree of basal Plane texture. The specimens were tested in tension at temperatures ranging from 78° to 520°K. From the data, the yield stress, thermal component of the yield stress, and work hardening characteristics were found as a function of temperature, deposition rate, and deposition temperature. It was found that Taylor's equation, best fit the work hardening data with m = 1/2. MANY investigations have been made on the tensile deformation characteristics of commercial- and high-purity titanium.1"7 The data obtained from these experiments emphasize the fact that the mechanical properties are generally related to the method of production. The correlation of mechanical properties to production history arises from the dependence of impurity concentration on the extraction and melting technique used. Additional effects are derived from crystallographic texturing which can result from fabrication history. Lee and Backofen8 and other investigators9 have shown that crystallographic texturing in titanium sheet has a significant effect on the deformation characteristics. Bunshah and Juntz10 prepared high-purity titanium by high rate physical evaporation techniques. These authors found the deposited material to have a columnar structure with grain sizes ranging from 12 to 104 µ, depending upon the substrate temperature. The room-temperature strengths of the coarse-grained distillate were similar to arc-melted, rolled. and annealed crystal bar titanium. Commercial-purity titanium was also produced experimentally in our laboratory using high rate physical vapor deposition techniques. The commercially pure material has a finer structure than the high-purity distillate,10 and is highly textured. Since the method of preparation and degree of texturing affect the mechanical properties, a research program was initiated to determine the temperature dependence of the yield stress and work hardening characteristics as a function of high rate deposition parameters. This paper relates the results of the investigation. EXPERIMENTAL A) Material Preparation. The titanium was received in the form of commercial-grade 0.096-in.-diam wire which has a composition of 0.016 pct C, 0.0037 pct N, 0.110 pct 0, 0.011 pct H, 0.05 pct Mn, 0.051 pct Fe. balance Ti. The wire was continuously fed into a vacuum evaporation unit as shown schematically in Fig. 1. The deposition chamber was evacuated, purged with argon, and reevacuated to a pressure of 10-5 Torr which was maintained during deposition. A focused electron beam was used to evaporate the titanium from a water-cooled copper crucible. The titanium vapor was condensed onto a preheated titanium substrate. The temperature of the substrate was controlled within ±5°C for the deposition temperatures of 480°, 535°, and 595°C. Control of the input power enabled the use of two deposition rates. 50,000 and 85,000Å per min. The evaporated titanium had a final analysis similar to that of the input titanium, within experimental limits. B) Testing. The evaporated titanium was physically stripped from the titanium substrate and machined into tensile specimens with 1-in. gage lengths. In addition, tensile specimens of as received annealed 35-A titanium sheet with a 20 µ grain size and 45 pct cold-rolled 35-A were also prepared. All specimens were tested in tension in an Instron at a strain rate of 3.3 x 10"4 in. per in. per sec. Proportional limit has been used as a measure of yield strength. Tests were conducted at 78°, 220°, 300°, and 520°K. Metallography, X-ray diffraction, and electron microscopy were used to correlate structure with the deposition parameters and mechanical properties. Room-temperature X-ray measurements were made to determine the phases present. Pole figures and a scans were made to determine deposition texture. Because the vapor deposition was symmetrical about the normal to the substrate, there was no preferred di-

Jan 1, 1969

The following list comprises the names of those persons who became members during the period of Mar. 10, 1918, to Apr. 10, 1918. ADAMS, NOAH- :.. Geol.,. E. N. Gillespie & Co., Box 1875, Tulsa, Okla. ALVAREZ, PEDRO Asst. Met., American Smelt. & Refin. Co., Blue Hill, Maine. BARTRAM, JOHN G., Pet. Geol., Roxana Petroleum Co. of Oklahoma, Cheyenne, Wyo. CHANEY, S. E Supt.., Arizona Binghamton Copper Co., Stoddard, Ariz. CLEVELAND, EARL C Mgr., Deadwood Min. Co., Mogollon, N. M. DENNIS, HOWARD B Min. Engr., Empire Mines, Grass Valley, Cal. FOWLER, ARTHUR A., Partner, Rogers, Brown &- Co., 30 Church St., New York, N. Y. FRIEDMAN, L. A Pres. and Gen'l Mgr., Rochester Mines Co., Lovelock, Nev. GUIBERSON, S. ALLEN, JR 923-24 1. N. Van Nuys Bldg., Los Angeles, Cal. KROHN, ARTHUR Mine Supt., Missouri Metal Corpn., Mine La Motte, Mo. KURSELL, H. A., Mgr., Altai Mines Ltd., Zmeinogorsk, Altai Gov't, Siberia, Russia. LANE, L. RAY Mine Examinations, Galiano 24, Aptd. 1066, Havana, Cuba.

Jan 5, 1918

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

"In the spring of 1927, six members of the American Institute of Mining and Metallurgical Engineers met for dinner at the Chemists' Club in New York to discuss the possibility of setting up a committee within the Institute to further the current interest in the science of steelmaking. Attention to this subject had been crystallized by a symposium held by the Faraday Society in 1925. After a prolonged discussion, ranging from thermodynamics to slag conditioning, it was decided to approach the Institute with the request that a standing committee on "The Physical Chemistry of Steel Making" be set up. This committee proposed to promote scientific and practical papers on the subject, and was designed to cooperate with the Open Hearth Committee of the Institute in bringing scientific developments to the attention of open-hearth operators throughout the country. . . . "As the life of the [Physical Chemistry of Steelmaking] Committee lengthened and general interest in the technical phases of steelmaking grew, it .became evident that there was a distinct need for a book that might serve the open-hearth interests to better advantage than standard texts whose scope is necessarily wide and whose detailed exposition of the open-hearth process is, therefore, somewhat limited. With this thought in mind, the Committee, after some years of consideration and debate, embarked on the venture of writing a manuscript on 'Basic Open Hearth Steelmaking'." The foregoing paragraphs, taken from the introduction by C. H. Herty, Jr. to the first edition, well describe the circum- stances which led to the publication of “Basic Open Hearth Steelmaking” in the spring of 1944. The book consisted of nine- teen chapters contributed by twenty-three authors and edited by the staff of Alloys of Iron Research and T. S. Washburn, H; M. Larsen, and J. S. Marsh with Frank T. Sisco as consulting editor. The Engineering Foundation and the Open Hearth Steel Committee of the Iron and Steel Division, AIME, made financial grants; steel companies and other organizations supported the publication by contributing time and expenses of staff members in their capacity as authors or editors. The volume was sponsored by the Seeley W. Mudd Memorial Fund and appeared under the

Jan 1, 1964

By T. J. Woodside

A. E. LEE*—One question of the flue leading to the tube coolers. What gas velocity is maintained to prevent settling of the finely divided fume ? T. J. WOODSIDE (author's reply)— 30 fps. Of course some fume settles out, but is immediately carried away by the screw conveyors. H. R. BIANCO —How effective are the soot blowers ? Do you have to use any hand lancing? T. J. WOODSIDE Only one point, which is right at the top of the economizer and which the soot blowers do not reach, we occasionally hand lance. But everywhere else the soot blowers have been very effective and no hand lancing has been done. L. V. DAVIDSON*—Do you have considerable variation in the lead content of the fume collected if the lead is higher, and is there greater tendency for the fume to stick on the boiler tubes ? T. J. WOODSIDE—There is very little variation in the lead content. From 5 to 7 pct is the widest range variation we have had and we have noticed no difference in the behavior of the fume. C. R. KUZELL—Mr. Woodside has been quite generous with data pertaining to metal and fuel economics. I think he stated that the coal consumption of the furnace was 21/10 21/10 for a pound of zinc recovered. I take it that that is the gross coal input to the furnace. I wonder what the net fuel consumption in terms of coal might be after crediting the fuel equivalent of the waste heat steam recovered? T. J. WOODSIDE—The fuel value of the waste heat steam is approximately 42 pct of the heat input to the furnace. A very large part of the heat, of course, goes out in jacket water—44 pct. A. D. TERRELL*—I would like to know how much lead is in the deleaded material. T. J. WOODSIDE—It is a little less than 2 pct now.

Jan 1, 1950

By Henry J. Williams

The main difficulty in the determination of silicon in pig-irons containing very high percentages of that element, has been due to their almost complete insolubility in acids, or mixtures of acids. The object of the present paper, which presents no new principle, is to suggest a method of determination which has repeatedly given accurate results, and which obviates completely the tediousness and uncertainty of the usual slow solution in acids. This method has been tried with pig-irons containing from 7 to 14 per cent. of combined silicon, and properly called ferro-silicons. When reduced to an impalpable powder in the agate mortar, an 11 per cent. ferro-silicon was found to resist the action of all acids, or mixtures of acids, with the exception of sulphuric acid of about 1.25 specific gravity. But the action of this acid, even during long continued heating, was very slow, 72 hours being necessary to com pletely dissolve half a gramme of the metal. The complete decomposition of 1 gramme of the metal may, on the other hand, readily he effected in a few minutes by fusion with sodium carbonate in a covered platinum crucible over a blast-lamp —the idea being to dissolve the silicon, leaving the iron in condi tion to be readily attacked by acids. The silicon dissolves as soluble sodium silicate, and metallic iron remains in a very spongy and finely divided condition. The addition of a little hot water

Jan 1, 1889

By Bailey, Lewis Newton

Bailey, Lewis Newton, Master Engineer, Senior Oracle, 4th Regiment, U. S. Engineers, Headquarters Company, died of pneumonia, at Camp Merritt, N. J., on April 30, 1918. Baird, Louis, Lieut., Royal Field Artillery, British Army, died on the battlefield in 1915. Ballamy, John H., Capt., 103d Engineers, killed in action near Fismes, Aug. 9, 1918. Burt, Andrew, died in active service, 1916. Cobeldick, William Morley, Royal Engineers, died from gas poisoning on October 7, 1915. Dougall, Ralph, 4th University Co., Princess Patricia Regiment, killed in action early in the war. Evans, Alfred Winter, Lieut.-Col., New Zealand Rifle Brigade, D. S. 0., D. C. M. killed in action on October 12, 1917. Gorman, Thomas C., Lieut., Canadian Engineers, killed in France, Mar. 18, 1918. Hague, William, 1st Lieut., Engineer Officers' Reserve Corps, died in active service, Jan. 1,, 1918. Hall, William T., Capt., Royal Flying Corps, killed in action, May 19, 1917.

Jan 11, 1918

By J. C. Branner

(New York Meeting, February, 1012.) DURING the past two or three years I have seen statements regarding the first discovery of fullers' earth in this country that seem to require correction or modification. One appears again in the Mineral Resources of the United States for 1909, part II., p. 738, where it is said that ? fullers' earth was first discovered in the United States at Quincy, Fla., in 1893." In this connection the following bit of unpublished history concerning fullers' earth in the State of Arkansas is worthy of attention. In April, 1891, when I was State Geologist of Arkansas, a Swede named John Olsen, formerly a copper-miner in Michigan, but then living south of Little Rock, brought me a sample of what he thought was fullers' earth. He reported that it was from near the town of Alexander, the locality being 1 S. 13 W., section 8, SW. quarter of the SE. quarter. My chemist, Dr. R. N. Brackett, analyzed the material, and reported: Per Cent. Silica, . . SiO2., . 63.19 Alumina, . AL2O3, . 18.76 Iron, . Fe203 7.05 Lime, . Ca0 0.78 Magnesia, . . MgO 1.68 Potash, . K2O 0.21 Soda, . . Na2O 1.50 Loss on ignition, . 7.57 100.74 Water at 110° to 115° C. = 7.84. Another sample from about the same locality, also brought by John Olsen, on analysis by Dr. Brackett gave

Jul 1, 1912

"Acta Metallurgica" Robert Madden, Dec '60 Alfred Noble Joint Prize Committee F B Foley, Dec '61 American Association for the Advancement of Science William L Fink, Dec '60, H K Ihrig, Dec '61 American Geological Institute F C Kruger, Oct '60, Thomas L Kesler, Oct '61 American Power Conference Howard A Herder

Jan 1, 1960

By Clarence P. Linville

(Pittsburg Meeting, March, 1910.) IT is recognized that, in all metallurgical operations, the greatest possible uniformity in all conditions is essential to the best results. It is the constant aim of metallurgists to secure this uniformity, and their success in this respect has been in many cases the cause of great advances in the metallurgical processes themselves. Of all such processes, the production of pig-iron in the modern blast-furnace is perhaps the most complex and the most difficult of control. Notwithstanding the great progress of recent years, there is still great difficulty in obtaining anything like uniform conditions and results in the manufacture of pig-iron. The reason is not far to seek. The ores vary in composition and physical properties, often carrying a varying amount of gangue material, unevenly distributed The coke may vary in composition, cell-structure, moisture, hardness, and other properties. The blast, the weight of which far exceeds that of any other constituent, varies in its moisture-content and consequently in its chemical composition ; and its temperature, by reason of the method of heating, is not uniform, but, besides varying from time to time with atmospheric and other outside conditions, has a maximum and minimum for every changing of stoves. Now, with regard to these variations, the modern demand for uniformity has been greatly aided. Chemical analysis has made it possible to select ores so that the composition of the charge can be kept fairly constant; coal may be obtained from a given field, and coked in the same kind of ovens under conditions which . make the fuel practically uniform ; the Gayley

Mar 1, 1910