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By R. L., Fullman

During the past year there have been a number of significant investigations that have furnished evidence on the driving forces governing grain growth and on the role played by boundary impurities. Thus Burke has shown that in high purity alpha brass the rate of grain growth in the earliest stages is approximately inversely proportional to the existing grain size. This relation agrees with one derived by Zener assuming that surface energy was the driving force in grain growth. Also in confirmation of the surface energy hypothesis, Burke found that growth virtually stopped when the grain boundaries or even only the grain corners were melted.

Jan 1, 1949

By W. F. Flanagan, D. H. Polonis, S. D. Dahlgren

Rotation diffraction patterns of Cu-4.84 wt pct Si polymystalline samples were taken during the course of isothel-ma1 affing of the suPersaturated a phase, a diffraction spots were obserzled to streak during the initial stages of aging, and this streaking was similar to the streaking of a spots observed earlier by Barvett with deformed super saturated samples of the same composition. Although it was suggested that stacking faults were the sole cause of styeaking in the deformed samples, the present study has shown that plates with one small crystallite dimension can also contribute to the streaking when there is lattice coherency across close-packed planes. THE decomposition of the supersaturated a phase in Cu-Si alloys has been reported to occur by means of both thermal and stress activation.1-4 According to the Cu-Si phase diagram,3 Fig. 1, the supersaturated a phase (fcc) is expected to transform during aging by the precipitation of the y phase. The results of earlier studies2,4 have indicated that metastable k phase (hcp with nearly ideal close packing) forms initially at temperatures below the eutectoid temperature, after which the k transforms to the a and y phases. Hof-mann et al.4 have proposed a metastable version of the phase diagram, showing the approximate boundaries for k formation below the eutectoid temperature. In view of the close-packed nature of both the a and k phases, it is essential to consider the role assumed by stacking faults in the transformation. Streaking effects have been reported by Barrett 1 in the rotating crystal X-ray patterns of strained Cu-Si alloys and were attributed to stacking faults rather than particle size effects. This deduction was based on the observation that streaks in the diffraction patterns did not occur tangent to the 220fee Debye ring. It is known that the atom movements involved in faulting leave some X-ray reflections unaffected while others are broadened,' and, in particular, it has been shown that faulting will not cause streaking of 220fee reflections tangent to the 220fee Debye ring as would be expected if all the reflections were broadened.' The formation

Jan 1, 1967

By C. H. Herty

AN earlier paper on absorption of sulfur by the slag in the basic open-hearth furnace included a brief discussion of the absorption of sulfur during the melting period. The data available at that time showed that the amount of sulfur absorbed by the melting scrap was proportional to the sulfur content of the furnace gases, and the following statement was made: "The conclusion may be drawn from these results that if a gas entirely free from sulfur were used during the melting, any iron in direct contact with the gases would be completely, or nearly completely, desulfurized before it reached the bath proper." The experimental work discussed herein deals with absorption of sulfur by the melting scrap when fuels with both high and low-sulfur content were used. Before taking up the experimental work let us consider the process as a whole as to the "flow" of sulfur. The input of sulfur occurs in: 1, the hot metal charged; 2, the scrap; 3, the stone or lime charged; 4, the ores charged; and 5, the gas. Sulfur goes out of the furnace in the steel, the slag and the gas. The distribution of sulfur in the furnace depends on the sulfur concentration in each of these materials and on the equilibrium conditions between them.

Jan 1, 1926

By E. H. Rose

IN the realm of ore dressing the most pregnant feat of all time was announced in 1945: the winning of the mineral raw materials which made the harnessing of atomic energy possible. Lost in the stupendous implications of the end result, in the two billion dollar hugeness of the project, and in the famous names attached thereto, the fact that crude uranium ores had to be concentrated received relatively little notice in the press. Only the final link in the concentrating chain was publicized-ether extraction of uranyl nitrate, developed by Hoffman and carried on by the Mallinckrodt Chemical Works, or methods developed by the Ames group under Spedding. Some of the earlier links represented less glamorous but equally difficult and exacting research. One may only speak a word of admiration for those who worked hard, accomplished much, and said nothing. The universal lament for most of the year was "man shortage." A group of Canadian engineers expressed it as "being so short of labor that no labor was available to develop laborsaving devices." . Despite this, an outstanding amount of mineral-dressing progress was made in 1945. Necessity allowed no alternative. The insatiable demand of war for minerals forced the exploitation of lower and lower grade ores, and of others not before considered of commercial character or use, requiring the mineral dresser to fight for and win new bridgeheads on the home front.

Jan 1, 1946

By S. A. Falconer

Much attention and publicity has been given, during recent years, to grinding, classification, flotation, and thickening. The various technical papers, and symposiums held to discuss these important phases of milling, have contributed to a better under- standing of the fundamental principles and operating variables involved. Another important part of milling- to the flotation operator-is a treatment step to which frequently too little attention is given-" conditioning," or the treatment the ground mineral pulp receives before it enters the flotation machines. Conditioning" is a hackneyed and frequently misused term, commonly employed to describe the pretreatment of surfaces of minerals in ore pulps or mill pr6ducts prior to froth flotation. In general, such pretreatment is for the purpose of changing the flotation characteristics of these mineral surfaces to enable them to respond in some desired predetermined manner when subjected to flotation. Taggartl states that the function of conditioning is "either to insure selective collector coating of one mineral species while another species is not; or to take such steps as will compensate for departure there from."

Jan 1, 1949

By G. W. Phelps

The field of industrial minerals is concerned with both sieve size and distribution of sub-sieve particles. A great deal of work has been reported on the techniques designed to provide information of this work. The term sub-sieve is here considered to include particular material that will pass a 325-mesh testing sieve. Plant men require rapid, precise and simple testing techniques that are, if possible, inexpensive with respect to equipment and manpower. A number of particle-size procedures have been developed, based on the Stokes equation for streamline movement of a particle of diam D, moving at velocity V through a liquid of viscosity n. 1 Particles are considered to be rigid, smooth spheres, completely dispersed at low concentration and moving at low velocity through the suspending medium with no slippage between particle and liquid. In particle size determinations the particle moves either from natural gravitational forces or those provided by centrifugal means. The diagram of Fig. 1 shows a spherical particle of density S and diam D moving downward at velocity L/T (or V) through a liquid of density So and viscosity n. The forces of gravity G (natural) or Gc (centrifugal) cause the particle to move through the liquid, thereby creating a viscous drag F or Fc. Within the streamline flow

Jan 1, 1967

By Frank B. McKune

This is something new in my life. A lot of you men here today I do not know, and some I do know. So if you have any remarks to make, I wish you would give your name and the name of your company. This is the first Acid Meeting which has been held under the auspices of the National Open-Hearth Steel Conference, and I hope it is a success. Whether it is a success or not depends entirely upon the support we get. If it does get good support, I have the idea it will be continued as a regular feature of the National Open-Hearth Steel Conference. We all think we have pretty good practices. But we can all learn and I hope that you, gentlemen, who take issue with the things someone else has said will stand up and give your opinions. Otherwise, the meeting will fall rather flat, and we won't get a great deal out of it; and there will not be enough interest shown by the National Committee to continue to place the meeting on the regular yearly program.

Jan 1, 1940

By Thomas H. Leggett

IN speaking of the mining and economic conditions prevailing at the present time on the Rand, it is not my intention to go into the details of the mining-practice, since this has been already well described both in the Transactions1 and elsewhere,2 but rather to take a more comprehensive view of the industry and its surroundings as a. whole, marking its general development and the lines of its future progress. In a. paper entitled Deep-Level Shafts on the Witwatersrand, with Remarks on a Method of Working the Greatest Number of Deep-Level Mines with the Fewest Possible Shafts,3 presented to this Institute in August, 1900, I drew attention to the great cost of sinking the very deep vertical shafts that were then being seriously proposed as necessary for the development of the deeper areas, pointing out the strong advisability of working this ground by means of inclines to be sunk from the existing shafts of from 3,000 to 4,000 ft. in vertical depth. In this paper it is stated (1:). 975): "In short, practice upon the Rand now tends towards fewer vertical shafts and more underground inclines, especially for the very deep mining about to be undertaken." In consequence, the 6,000-ft. vertical shafts, at one time so much discussed, have never been started, and they do not now seem likely ever to be. The necessity of placing all deep shafts further apart in order to make them control and exhaust larger areas was also dwelt upon. This economy was vitally necessary for both 1 Gold-Mining in the Transvaal, South Africa, John Hays Hammond, xxxi., S17 to 855 (1901). R Engineering and Mining Journal, vol. lxxxv., p. 53 (1908). ' Trans., xxx., 947 to 987 (1900).

Jan 5, 1908

By E. W. Davis

THIS nation has been depending upon the Lake Superior iron ranges for most of its iron ore requirements for over half a century. Furthermore, it can continue to draw the major portion of its ore requirements from the same source for another century or more, but to accomplish this, great changes must take place in the present ore mining industry. Preliminary preparations for these changes are now underway and in the next few years decisions of far-reaching importance must be made. But to understand the situation, it is first necessary to know something of the nature and occurrence of the Lake Superior iron formation. So far as is known, the merchantable grades of iron ore remaining in the various Lake Superior ranges are as shown in Table 1, which shows that

Jan 1, 1947

By A. N. Rogers

Jan 1, 1883

By Mark Malamphy

MOST igneous rocks, and particularly those of the basic type, con-tain relatively high percentages of magnetite and other iron oxides, which give them moderately high magnetic susceptibilities and make them responsible for an important percentage of the magnetic anom-alies observed during the course of geophysical surveys by the mag-netic method. The irregular form and high susceptibility of the igneous rocks make them readily polarizable and the position and strength of the magnetic poles formed are not always explicable by theoretical calculations of anomalies due to certain assumed forms in the normal magnetic field of the area under study. During the last four years our field work has permitted us to make detailed observations of anomalies due to igneous rocks in all the states of south Brazil. The form and position of the igneous rock at some places were fairly accurately known, which made it possible to calculate theoretical anomalies and compare them with the observed data. Some of the data we obtained have been published and additional cases are now awaiting publication. In this paper, we will present a few specific cases where the geology is moderately well known and which we believe to be of considerable value as representing typical magnetic anomalies in the south magnetic hemisphere, where the inclination of the magnetic field is very low. Although the vertical intensity is negative in the Southern Hemis-phere, we have adopted the convention of plotting increase in intensity (negative) as a positive anomaly; i.e., above the x axis. This conven-tion facilitates comparison with anomalies in the north.

Jan 1, 1936

By L. T. Larson

The spectral reflectivity of zirconium in light of 441 to 668 nanometers (nm) wavelengths and air immersion has been determined. Bireflectance and apparent-angle -of-rotation measurements show zirconium to be optically isotropic when examined in light of approximately 484 nm wavelength. There is a direct relationship between bireflectance and the tilt of the basal pole of zirconium from the surface normal. This relationship allows the determination of the spatial orientation of the basal pole of an individual single crystal within a coarse-grained poly crystalline section to within± 2 to 3 deg for angles of basal pole tilt from 0 to 90 deg. In recent years considerable attention has been given to the quantitative determination of optical properties of opaque minerals by use of vertically incident, plane-polarized light. In particular, Cameron' and Cameron et a1.2 have developed criteria for the identification of a large number of anisotropic ore minerals based upon measurement of the apparent angle of rotation and the ellipticity or phase difference of the reflected light. It was shown by Larson and Pickle-simer3 that apparent-angle-of-rotation measurements may also be used to determine crystallographic orientations of grains of noncubic metals. In particular, it was shown that the basa.1 pole orientation in space of zirconium grains can be determined to ±3 deg for those grains with basal pole tilts of 10 to 90 deg from the plane of the section. Another, even more widely studied, optical property is reflectivity. cameron4 has commented upon measurement of the reflectance of plane-polarized, vertically incident light and Bowie and Taylor5 have made such measurements an integral part of their system of ore-mineral identification. Leow6 has reported on the spectral reflectivity of molybdenite and has used reflectivity values to calculate refractive indices and absorption coefficients. Cameron7 has made use of reflectivity values to ascertain aniso-tropic ore mineral symmetry and Piller and v. Gehlen8 have evaluated sources and importance of errors in reflectivity measurements as applied to calculation of optical constants. cambon9 has shown that reflectivity measurements using vertically incident, plane-polarized light are useful in the investigation of metals and in the identification of phases present in alloys. Bronson10 has made preliminary measurements on the optical anisotropy of beryIlium and Mott and Haines11 have published qualitative data on the intensity of light reflected from sections of bismuth, tin, and aluminum when these metals are microscopically examined under crossed polarizing plates. Koritnig12 has correlated the reflectivity of homogeneous solid solutions with their chemical compositions. From the above work and investigations in progress by this author, it is apparent that accurately determined values for the reflectance of vertically incident, plane-polarized monochromatic light from carefully polished surfaces of noncubic metals can prove useful in identification, composition determinations, and crystallographic orientation applications. Finally, reflectivity values, when measured in two media of differing refraction index and related to standards whose spectral reflectivities in these media are known, can be used to calculate optical constants such as refractive index and absorption coefficient. These constants may prove of use to those concerned with problems of electron band configuration. This paper reports the spectral reflectivity of zirconium measured in light of 441 to 668 nanometers (nm) wavelengths and air immersion. It also gives maximum bireflectance values for a prism section of zirconium in these wavelengths and shows how bire-flectance may be used to determine the crystallographic orientation of zirconium single crystals. Because of the lack of information on the reflectivities of the standards in oil immersion, no attempt is made to calculate the refractive indices or absorption coefficients although it is recognized that such values may be of fundamental importance. METHOD Single crystals of zirconium were cut by electro-discharge machining from a single-crystal rod grown from iodide bar by an electron-beam zone-melting process.13 The crystal sections were mounted in cold-setting epoxy resin and mechanically polished to a plane, uniform, bright surface. Each crystal was then chemically polished in a 26/26/43/5 mixture (by vol) of water, nitric, lactic, and hydrofluoric acids to remove the mechanically damaged and smeared surface layer. Final polish was obtained by electropolishing at 30 v in a bath of methyl alcohol and perchloric acid (98/2 by vol) at -70oc.14 Reflectivity measurements were made using a photometer system designed and developed at Oak Ridge National Laboratory and described in detail by Larson.15 Briefly, the reflectivity measuring system consists of a reflecting microscope; a double-beam, null-balancing photometer array; a mechanically driven microscope stage; and a direct X-Y readout of the reflectivity of the specimen relative to its orientation on the microscope stage. The measuring photometer receives its signal from the specimen through a slotted Wright occular placed on top of the photovisual head of the microscope. The reference photometer receives light through a flexible glass "light pipe" from a mirror in the reflecting system of the microscope. Monochromatic light is attained through use of interference filters (15-nm half-peak width pass bands) placed in front of a stabilized Vickers 12 v, 100 w, tungsten-filament, quartz-iodide lamp.

Jan 1, 1970

By Charles Will Wright

ALTHOUGH the United States has long led all other countries in both the production and consumption of mineral products, the trend seems definitely toward an increasing dependence upon foreign sources of supply. This is not to take the position that we are either a have or a have-not nation. For years we shall continue to secure a large proportion of our needed minerals: from our own mines, but we must face the fact that this century has seen "a more thorough and intense development of the mineral resources of the United States and a greater depletion of its irreplaceable mineral reserves than has occurred in most other countries. An audit of our mineral production given in the attached charts discloses the extent of our deficiencies. Because of these facts, low-cost foreign sources offer a promising field for the investment of a portion of our mining capital and an opportunity to obtain for the United States a greater supply of strategic metals and minerals. How. ever, to reach this end, the industrialist investing in the foreign field must have the full co-operation and strong backing of the Federal Government and the involved Federal agencies.

Jan 1, 1947

By Paul Gemmill

Production was first recorded from the Pioche district in 1864, and it has continued to show an inherent ability to take on new life after periods of depression in the metal markets. Production from replacement leadsilver- zinc sulfide ore bodies in limestones of Cambrian age now accounts for several times the gross value of silver production from rich fissures in Lower Cambrian Quartzite. Aggregate production of some 6 million tons represents a gross value over $100-million. Future output is expected mostly to be from limestone replacement deposits of which the most productive are "channels" of ore up to several hundred feet wide and several thousand feet long with thicknesses from a few feet up to 50 feet. Such channels are restricted to the lowermost limestone bed of the district, about 250 feet above the basement quartzite. The "blotter-like" characteristic of this highly productive Jimesto~e bed in absorbing mineralization is believed to be, at least in part, due to lithology, including free carbon in the bed, which has created a unique set of conditions for delicately balanced mineralizing solutions that rejected any tendency to replace siliceous wall rock and were properly constituted for replacement of Limestone. All recognizable orogenic history is considered to be related to the Basin and Range faulting that created the mountain ranges. The faults developed after mid-Tertiary time and after widespread extrusives that are themselves involved in the faulting. Flat faults, formerly believed to be part of regional thrust faulting, are now interpreted as gravity slide faulting that can be shown to be large in magnitude and not simply local landslides. Large slide faults generally have concealed the great magnitude of mountain-bordering faults. Mineralization that accounts for ore is later than the faulting. Most faults are pre-mineral since they influence the shape of ore bodies, and some clearly have been offset by fault fissures containing ore. Post-mineral movement probably has been an important component of some large, initially pre-mineral faults. A single period of mineralization was begun by the introduction of large quantities of ironmanganese carbonate, and, in places, carbonate manganese with minor values in sulfides. Closely following the carbonate invasion, massive sulfides were brought in, usually replacing part of the carbonate body though in some places the massive sulfides replaced limestone that was not previously mineralized. Manganese mineralization is not a "halo" but leaks of manganese to higher formations and to the surface are the most significant exploration guides. The Pioche district is expected to be long lived with technological developments in ore treatment being important to the exploitation of low-grade manganiferous ores, while aggressive exploration is expected to find important quantities of bedded lead-silver-zinc ores of the massive sulfide type.

Jan 1, 1968

Thomas T. Read, New york, N. Y. (communication to the Secretary *):—At the meetings of English technical societies it not infrequently happens that, during the discussion of a paper, someone will arise to say that although he highly appreciated the material presented, nevertheless he believed it would have been better if some other phase of the question had been more highly emphasized. Assuming that this form of discussion is permissible in the Institute, I should like to reiterate the point made by Prof. A. J. Moses that conclusive proof of the identity of the minerals in question is an essential feature of the study of ores in this way. This is also expressed by Paul Krusch in his recent valuable paper on the sulphide ores (in which he arrives at conclusions diametrically opposed to those of Mr. Graton), as follows: "The diagnostic properties of the various ore minerals are known to but a limited circle of investigators." Many earlier investigators began the study of ores beneath the microscope by reflected light, but discontinued their work, in most cases, because they were unwilling to undertake the great amount of preliminary work necessary to securely establish a basis for their inferences. It is evident that Messrs. Graton and Murdoch realize that the promised later paper on diagnostic characters will be the more important of the two, but the point should be emphasized to forestall a flood of literature from other investigators who may gain the impression that the brief survey of polished specimens is a vade mecum to incontrovertible conclusions as to any given ore deposit.

Jan 1, 1914

By W. R. Ingalls

IF, in this study of the outlook for the copper industry of the United states, I find myself assuming to be prophetic in some respects I shall express myself with hesitation and with the foresight that after the end of the war with Germany the war with Japan may continue; anyway there is sure to be an uneasy period before copper and the other metals begin to flow smoothly through the natural channels of consumption. It is mainly my purpose to survey conditions and suggest some probabilities, or possibilities, rather than to prophesy. In interpreting them it will be necessary to make certain aasurnptions, among which will be (1) expectation of a rise in the general price level,, which so far has been one-sided; (2) continuance of the k. tariff on copper imports; and (3) lock-up of government-owned copper as a military re- serve. Of these assumptions the first is indicated by the lessons from economic history, and by current symptoms. The second and third depend upon political action by Congress.

Jan 1, 1944

F. E. Bachman, Port Henry, N. T. (communication to the Secretary*):—In discussing Mr. o.o.Laudig's paper, the Action of Blast-Furnace Gases Upon Various Iron-Ores,' I took the ground that Mesabi-ore explosions were entirely mechanical; but more observation and later experience has caused me to

Jan 1, 1905

By E. J. Eisenach, W. E. Jones

SAFETY and industrial hygiene have always been recognized as highly important in company policy, and the co-operative support of the company officials and entire plant personnel has contributed largely to the present success of the Company's program in this field. Growth has necessarily been slow, and dependent, at times, on trial and error but the program in its present form combines the regulations, working methods, and equipment that have proved their value under actual operating conditions. Every effort is made to keep the program on a practical basis. Continuous experimental work is carried on in conjunction with the health and safety program, with resultant periodic changes for improvement. As a proof of accomplishment, in 1945 the frequency and severity rates for accidents were the lowest in the history of the operation. A full-time safety engineer was employed in 1933 and an assistant safety engineer in 1936. During the following year a stenographer was employed in the office and a safety inspector was added for the mine. During the gradual expansion of operations that was climaxed by

Jan 1, 1946

By David R. Maneval, H. B. Charmbury

At the turn of the century, iron and coal were the keys to industrial prosperity. At that time, Pennsylvania was the leading mineral producer in the Country, producing 200,000,000 tons of coal in a typical post-World War I year. Close to 90% of the Nation's energy was generated by coal. Today, coal accounts for but 22% of the energy generated, leading to a drastic reduction in Pennsylvania coal output. In contrast with the post-World War I days, 1964 figures showed a drop in production to 93,846,480 net tons. This huge decrease has created a serious economic problem in a state so much dependent on the coal industry. Along with the reduction in coal production, employment has dropped considerably through these years (the number of miners alone has gone from 280,011 to 43,149), thus causing a heavy burden of supporting the unemployed on the taxpayers. As far back as 1939, coal operators and economists saw the problems on the horizon and the need for improvement. Realizing that research was a way to improve and stabilize the industry they demanded legislative action. The Legislature reciprocated with a small grant to The Pennsylvania State University with the provision that each State research dollar be backed with one from the industry. This initial grant laid the foundation for the further growth in coal research.

Jan 3, 1966

CONTENTS PAGE BAIN, EDGAR C.-The Nature of Martensite. Discussed by Ancel St. John, Henry S. Rawdon, Jerome Alexander, Howard Scott 1 FEILD, ALEXANDER L.-Effect of Zirconium on Hot-rolling Properties of High-sulfur Steels and the Occurrence of Zirconium Sulfide. Discussed by Beram D. Saklatwalla, Bradley. Stoughton, Andrew M'Cance, George F. Comstock, Alexander L. Feild 12 SAUVEUR, ALBERT and KRIVOBOK, V. N.-Use of Sodium Picrate in Revealing Dendritic Segregation in Iron Alloys. Discussed by George F. Comstock, John H. Hall 17 KINNEY, C. L., JR.-Economic Significance of Metalloids in Basic Pig Iron in Basil Open-hearth Practice. Discussed by V. J. Pazzetti, George B. Waterhouse, C. L. Kinney, Jr 19 NEAD, J. H.-Absorption of Sulfur from Producer Gas in Open-hearth Furnaces.. Discussed by George B. Waterhouse, C. L. Kinney, Jr 26 PRIESTLY, WILLIAM J.-Effect on Steel of Variations in Rate of Cooling in Ingot Molds. Discussed by Emil Gathmann, Paul E. McKinney, George A. Dornin. 27 MONYPENNY, JOHN H. G.-Stainless Steel, with Particular Reference to the Milder Varieties (Stainless Iron). Discussed by P. A. E.-Armstrong, Beram D. Saklatwalla 33 ROYSTER, P. H., and JOSEPH, T. L.-Effect of Coke Combustibility on Stock Descent in Blast Furnaces. Discussed by Ralph H. Sweetser,. Richard Franchot, Sidney Cornell, T. L. Joseph 41 DAVIS, F. W., and BOLE, G. A.-Observations on Requirements of Refractories for Open Hearth. Discussed by C. L. Kinney, Jr., L. F. Reinartz, P. E. McKinney 46

Jan 5, 1924