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By AIME AIME

L H. DUSCHAK gave an interesting talk at a recent meeting of the. San Francisco Section, based -011 experimental work with a variety of ores at the laborator of the Treadwell-Yukon Co., in Berkeley, Cal. He was of the opinion that the customary "cut and try" method of flotation testing was still in evidence and that the flotation process was more of an art than an exact science. Propounded theories have enabled investigators to' classify reagents as well as to suggest new ideas both in the metallic and nonmetallic fields, but the application of theory has riot as yet been able to solve many of the unknown factors in operation.

Jan 1, 1932

By Charles Clayton

IN connection with certain coöperative work carried on between the Ordnance Department of the U. S. Army, the U. S. Bureau of Mines, and the U. S. Geological Survey during the year 1918, it was the writers' privilege to make metallographic examinations of a great many test bars and other pieces of nickel-steel gun forgings. The material studied came from many different steel plants throughout the country and consisted both of forgings that had been accepted by the Ordnance Department and those that had failed to pass the specified physical tests. In general, these tests require a minimum tensile strength of 95,000 lb. (42,091 kg.), an elastic limit of 65,000 lb. (29,483 kg.), an 18 per cent. elongation, and a 30 per cent. reduction in area. An average chemical composition of the steel studied is 0.38 per cent. carbon and 2.9 per cent. nickel. The steel was of both basic electric and basic open-hearth manufacture. The object of the metallographic work was two-fold: to assist in detecting defects in the steel and, if possible, to suggest remedies for the same; and to obtain as much information as possible in regard to the relation of the microstructure of the metal to its physical properties. The greater part of the investigation was devoted to defective metal that failed to pass the ordnance specifications. Many types and kinds of more or less serious defects thus came under observation, but most of these were due to the attempts by the manufacturer to meet the enormous demand for ordnance steel with more or less inadequate equipment, and were soon remedied. Two defects, the so-called "flakes" or "snowflakes" and a certain "fibrous" or "woody" fracture, were encountered so frequently and were so disastrous to the steel that the greater part of the study was devoted to them. As a result much information as to their nature and their effects

Jan 2, 1919

By B. A. Stainton, John D. Gill

OUR combined economic activities have as their goal the maximum of individual well-being and national security. In this age of intense international competition the two objectives are closely related. For many decades, the maximum of well-being and ability to maintain national security have moved generally upward. The best single measure-perhaps the only adequate measure -of the level of the rising goal is the per capita real national income (national income corrected for price changes). For centuries before the industrial revolution the income of the world's population changed little from generation to generation. In our country prior to 1800 the growth of national income was hardly measurable from decade to decade. Since 1850, perhaps since the "industrial revolution," the growth of per capita real income has been increasing geometrically. Of major importance is the accelerative growth of the productive ability of our economy. Inadequate consideration of its implications is partly responsible for periodic delays in solving our princi-

Jan 1, 1946

By R. S. Dean

IN THE COURSE of its investigations directed toward providing strategic metals from domestic sources and toward utilizing power from Federal power projects in West, the Bureau of Mines concluded some years ago that the development of a method for producing electrolytic manganese might well be an important step towards both goals. Accordingly, laboratory investigations were undertaken in 1935. Further studied on a relatively large laboratory scale indicated that electrolytic manganese could be made from domestic ores at a cost not out of line with other nonferrous metals. On the basis of these results, the Electro Manganese Corp. Operating under U.S. Patent 2,119,560 issued to S, M, Shelton and assigned to the Secretary of the Interior for administration, undertook commercial production of electrolytic manganese at Knoxville, Tenn, This company has brought the process through the pilot-plant stage successfully, and is now regularly producing approximately one ton a day.

Jan 1, 1941

By W. D. B. Motter

DURING the early development of blasting with liquid oxygen explosives the trend of experimentation was towards increasing the effectiveness of the explosive. Its characteristic of becoming inert after evaporation of the oxygen content made a strong appeal from the standpoint of safety, especially with missed holes. It later became apparent, however, with practical use of this explosive, that LOX lacked certain other safety characteristics. As its effectiveness was increased, it became more subject to detonation by impact. The object of this paper is to show the steps taken by one operating company to achieve greater safety in the large-scale handling of liquid oxygen explosives.

Jan 1, 1933

By Frederick Laist

This paper is a review of Montana reverberatory smelting practice covering a period of approximately fifty years, during which time the small furnaces that had been in use elsewhere for a century or more, without much change in size or method of operation, were revolutionized and were developed into the huge, continuously operating furnaces of today. A study of Montana practice is particularly instructive, since reverberatory furnace smelting for the production of copper matte received more attention there than in other smelting centers and many of the improvements that finally resulted in establishing the preeminence of this type of furnace over the blast furnace originated in Butte and Anaconda. The material in this paper was gathered from original sources, wherever possible, and all of the illustrations were made from original drawings, some of which have been simplified and worked over so as to be better adapted for reproduction. The aim has been to trace the modifications in design and operation which took place during the period in question—the reasons for the changes and the results achieved through them. For developments during the first twenty years, the technical literature of the period was freely drawn upon, but I am particularly indebted to W. M. Kelly, general foreman at the Anaconda Works, whose recollections and personal experience extend back to the early days. I wish to acknowledge the use made of publications of E. P. Mathewson, William Wraith and L. V. Bender, as well as information obtained here and there from friends and associates. The resume of Great Falls practice was compiled from correspondence, notes and drawings found in the files of the old Boston & Montana Co. and the tabulations showing the performance of furnaces at Butte and Anaconda are adapted from plant records and correspondence in the files of the Anaconda Copper Mining Company. The paper deals with some interesting comparisons that were made between furnaces operated under various conditions in connection with the Carson Case, and results obtained when using natural gas as fuel. This part of the paper may be considered original to the extent that these results have not previously been published.

Jan 1, 1934

By Albert Sauveur

THE senior author of this paper has expressed the belief that when gamma iron transforms into alpha iron on reaching the A3 point, each gamma grain does not change bodily into one or more alpha grains but that the alpha phase forms first at the boundaries and along the crystallographic planes of the austenite grains.1 To quote: On cooling through the point A, at about 900° C., iron passes from the gamma condition to a. new allotropic form generally designated as alpha. This transforma¬tion, however, is not instantaneous. There are good reasons for believing that it begins at the grain boundaries and along the octahedral planes of the crystals and that it progresses until each grain of gamma iron is changed into a grain of alpha iron, the resulting structure being similar to that of gamma iron. Were it possible to retain at room temperature pure iron but partially transformed, it seems probable that a Widmanstättian structure, or rather, as later explained, a martensitic structure would be observed (Fig. 1), consisting of alpha iron at the boundaries and at the octahedral planes, and of a groundmass of gamma iron. In order to confirm, if possible, the accuracy of that view, a number of experiments were conducted. Polished samples of electrolytic iron were heated in a vacuum, maintained in the gamma range for several hours and quenched in different media. It was hoped by such means to produce and retain on the polished surfaces a pattern which would reveal the mechanism of the allotropic transformation. The samples were placed in evacuated quartz tubes, heated to 1000° C. and held 2 hr. at that temperature. The tubes were then immersed in the quenching bath. Iced brine and liquid air were used first. The polyhedral austenitic structure existing at the time of immersion was very clearly revealed (Fig. 2). This is generally ascribed to iron volatilizing at the grain boundaries.

Jan 1, 1929

By William F. Boericke

KIRKLAND LAKE and Porcupine in 1931 accounted for more than $41,625,000 of Ontario's total gold production of $43,117,688. For the first time, the younger camp surpassed the older in gold output, producing $21,734,000 against $19,891,000 for Porcupine. Present output of both camps is increasing, and should pass the record figures of 1931 before the year is out. In May of this year, Porcupine mines milled 285,759 tons, with a bullion value of $1,810,009; the corresponding figures for Kirkland mines are 149,188 tons and $2,104,757. A much higher average value per ton for Kirkland ore, $14.10 against $6.33 average for Porcupine accounts for the difference. The two fields are about 100 miles apart by rail, and there are important differences in the character of the ores, which accounts largely for the difference in milling costs and in final tailing values, despite excellent metallurgical work in both the fields.

Jan 1, 1932

Established as a Society February 26, 1957 OFFICERS AND COMMITTEES Wayne E Glenn, President Earl M Kipp, President-elect John S Bell, Past President R A Morse, Vice-President W D Owsley, Vice-President Everett G Trostel, Treasurer Joe B Alford, Executive Secretary 6300 North Central Expressway Dallas 6, Texas

Jan 1, 1960

By LUDWIG VOGELSTEIN

WE are indebted to Mr. Barbour for his valuable contribution to the literature on copper statistics; it is to my knowledge the only intelligent attempt to throw light on a much misunderstood subject. If I should appear to criticize some of his findings and arguments, I do not want to leave the impression that I do not appreciate the article; I think Mr. Barbour has been painstaking, and even where one might not agree with his conclusions, he has opened our eyes and stimulated us in our search for the truth.' It might be well to define the term "secondary copper" and to make a few remarks about the origin and the reasons for the variation of the supply. Mr. Barbour has touched on these points, but not sufficiently to make them clear to those not in the business.

Jan 1, 1931

By Charles B. Henderson

DESPITE the loss, by enemy conquest, of a high percentage of our normal sources of supply for tin, the position of this important metal is easier today than that of rubber and a long list of other strategic materials, many of which are produced in this country. Actually, there is no shortage of tin for essential war purposes, owing to a strict control of its use, to increasing considerably the amount of secondary tin available, and to the foresight of the Government in authorizing the Reconstruction Finance Corp., as early as June, 1940, to acquire and produce certain critical and strategic materials of which tin was one of the most important. The construction of the Longhorn Smelter on the Gulf Coast in Texas is an important part of this program.

Jan 1, 1943

By Verne C. Fryklund, S. Warren Hobbs

The Coeur d'Alene district in the panhandle of Idaho is one of the major lead-zinc-silver producing areas in the world. The value of recorded production to date has exceeded $2 billion. Country rock comprises six formations of the fine-grained, highly siliceous, and slightly metamorphosed Precambrian Belt Series. Small stocks of monzonitic rocks and several varieties of dikes intrude the sediments. The district is at the intersection of a north trending major anticlinal uplift and the west northwest-trending Lewis and Clark line of which the Osburn fault is the dominant feature. The district structure is complicated and comprises folds, some of which are overturned, and a complex of faults of diverse ages and directions of movement. Late Cretaceous stocks but are also probably Cretaceous in age. The productive veins are localized within a series of 12 subparallel, straight mineral belts that trend approximately N65°W and that appear to be controlled by deep fractures in the basement rocks. The mineral belts are in two groups, separated by 15 miles of post-mineralization movement on the Osburn fault. Veins and ore shoots are variously disposed within each mineral belt. Many crop out at the surface, but others apex several thousand feet beneath it. Local controls that influence the position of ore shoots within the mineral belts include the brittle character of host rock attitude of bedding relative to the mineralized fracture, and the amount and direction of movement on faults. Depth appears to have had little effect on the occurrence or type of ore. Ore occurs in a series of steeply dipping replacement veins of relatively simple mineralogy. Six periods of mineralization, ranging from Precambrian to Tertiary in age, are recognized. The productive galena sphalerite-bearing and tetrahedrite-bearing veins-of the main period of mineralization-are younger than the

Jan 1, 1968

By H. V. Flagg

OPERATION of a modern steel plant presents a curious anomaly. Large-scale operations, in which large volumes or heavy weights of materials are involved, are not usually subject to close control or narrow specifications. On the other hand, operations that call for a high degree of precision are usually carried out under carefully controlled conditions with delicate, precise machinery and tools, and production is made secondary to quality. In a modern steel mill both extremes are taken as a matter of course. A strip mill making auto-body sheets must supply its customers with sheets that all come within a tolerance of plus or minus 0.003 in. in gauge at any point from side to side or end to end, and without blemishes either of color or surface. Sheets that were considered par excellence as recently as ten years ago could not even find a market today. Such exacting requirements have made necessary a nicety of control that approaches the watchmaker's art. Notwithstanding this necessity for precision, the scale of operation is stupendous.

Jan 1, 1940

By H. M. Howe

Page 1. Introduction............................514 2. Definitions.............................517 3. Brevity of the Heating........................517 I. THE HARDENING OF THE BORE..............517 4. The Hardening of the Bore.....................517 5. The Thickness of the Hardened Layer.................517 6. Martensitization..........................518 7. The Hardening Repetitive ......................519 8. The Temperature Cycle.......................519 9. The Hardened Layer is the Merged Layer............... 521 10. The Progressiveness of Merging....................521 11. The Progressive Thickening of the Hardened Layer from Round to Round. 523 12. Merging and Hardening are Cumulative................523 13. Three Additional Causes of the Progressive Thickening of the Hardened Layer 525 14. Progressive Roughening of the Bore..................525 15. Avoidance of an Endothermic Transformation.............525 16. Asymptotic Retardation of the Thickening of the Hardened Layer.....527 17. The Troostitic Layer........................ 529 18. The Usual Lack of Martensitic Markings................529 19. The Thickness of the Hardened Layer Should Increase with the Quantity of Heat Taken up by the Walls of the Bore.................530 20. The Decrease of the Thickness of the Hardened Layer from Breech to Muzsle 531 21. Phstic Deformation as a Contributory aCause of Hardening........531 22. In What Way May Plastic Deformation Hasten Hardening?....... 535 23. Possible Need of Coarsening.....................535 24. Carburization as a Cause of Hardening..........:.....536 25. Does Hardening Increase Erosion?..................-538 11. THE CRACKING OF THE BORE ...............539 26. Appearance of the Bore and Cracks in Elevation............539 27. The Cracks in Elevation in the Rear Ring...............539 28. The Cracks in Elevation in the Forward Ring.............540 29. The Copper Network in the Grooves.................540 30. The Cracking of the Lands......................541

Jan 1, 1918

By N. E. Maccallum

(Cleveland Meeting, October, 1912.) ALMOST half a century has passed since the Siemens brothers, after tedious and costly experiments, finally began the manufacture of open-hearth steel. The furnace of that time was very small, having a hearth-capacity of from 3 to 4 tons, and we can appreciate the wonderful development that has taken place in those 50 years by the knowledge that to-day furnaces of 50 times the original capacity are in operation. As the new steel process assumed importance, and furnaces began to grow in number and in size, a question arose, to which no satisfactory answer has ever been given, and that was: ?What is the safe and economical limit of the open-hearth furnace?" Various stopping-places have been suggested, and 20, 30, 40, and 50 tons have each been advocated, but all such arbitrary restrictions have been passed, and 60 tons would probably represent the average furnace, although in a few instances from 70 to 80 tons are regularly tapped into one ladle. The furnaces which are the subject of the present paper have gone far beyond even these limits, and since, in my opinion, they mark another step in the progress of open-hearth steel, they will be considered fairly and frankly, in order that those to whom the matter may be of interest may be able to judge and form their own Conclusions. Short accounts of the work of these furnaces have appeared from time to time in various technical journals, of which the following is a brief résumé. These furnaces are the property of the Phoenix Iron Co., of Phoenixville, Pa., and their distinctive and important feature is, that they charge to twice the capacity of one ladle, and tap simultaneously into two ladles, with a device for controlling the flow into either. In this way the capacity of the furnace is not limited, as formerly, but heats of any size within the capacity of two ladles may be charged.

Oct 1, 1912

By Walter E. Hopper

The Caddo oil-field, shown in Fig. 1, is located in Caddo parish, northwestern Louisiana. The known producing territory of oil is covered by townships 19 N, 20 N, 21 N, 22 N, and ranges 15 and 16 W., shown in Fig. 2. The center of the field may be taken as Oil City, 24 miles north of Shreveport, on the Kansas City Southern railway. Shreveport is the second largest city in the State, and is the connecting point of five railroad-lines. Drilling at the present time, however, is going on all over northern Louisiana, especially in Caddo and the neighboring parishes. During the winter of 1908-09 I spent 'four months in the Caddo field, under the direction of the Louisiana Geological Survey and the U. S. Geological Survey. II. History and Development. Natural gas escaping at the surface is found at numerous places in northwestern Louisiana. At Shreveport, the plant of the Shreveport Ice & Refrigerating Co. has been lighted by natural gas for 20 years. The well was drilled for water, but was abandoned on account of the gas. A test well, put down in 1905 near the western limits of Shreveport, was driven to 1,650 ft., and encountered indications of gas and oil at various depths, but did not succeed in finding enough to be profitable. Attention was first attracted to the Caddo field in 1895 by indications in water-wells from 40 to 60 ft. deep, in which the pressure of natural gas was noticeable. This indication of gas in a shallow well led to the drilling of the first well in the Caddo field, the old Savage Brothers & Morricell, or the Caddo Lake Oil and Pipe Line No. 1. The rig for this well was erected in May, 1904, and drilling began in June, 1904. The well was bailed Mar. 23, 1905, with a small amount of oil. It was deepened July, 1905, and converted into a "gasser" Jan. 3, 1906. It was abandoned January, 1907. In consequence of the finding of oil in the Savage well, drilling-operations were pushed with energy; and in April, 1905,

Jan 1, 1912

By Ralph W. Smith

DEVELOPMENT of the lime industry- in Ste. Genevieve County began in a crude way in 1840. According to information furnished by the Missouri Bureau of Geology, in the early days small vertical kilns built of stone were used, and wood was the fuel. Modern development began in 1904 when one company introduced steel shells lined with firebrick. Within a few years two more companies erected similar plants, and in 1925 a fourth company began operations. Thus there are today four lime companies at Ste. Genevieve, all operating at high capacity and with a gradually increasing production. GEOLOGY The limestone of Ste. Genevieve County, which has the chemical composition and purity required for lime burning, is the upper 80 or 90 ft. of Spergen formation. The Missouri Bureau of Geology, in its geological map of Ste. Genevieve County, gives the Spergen formation a total thickness of 160 ft., but only the upper portion is pure enough for lime burning, with an average raw-stone analysis of 98.7 per cent CaC03; 0.35 Si02; 0.3 R203; 0.35 MgCO3; 0.3 S03. The Spergen, one member of the Meramac group, Iowa series, of the Mississippian system, underlies an area approximately 12 miles long north and south, by 5 miles wide east and west (Fig. 1) in Ste. Genevieve County. The entire eastern two-thirds of Ste. Genevieve County is sedimentary, the formations dipping gently toward the east on an average grade of about 4 per cent, or 2 ½ º. Thus the outcrops of the various sedimentaries run approximately north and south. A line running west from Ste. Genevieve crosses the outcrops of the sedimentaries, ranging from the top of the Mississippian to the Ozarkian geological system in a space of 12 miles. Thus with the gentle dip of 2 ½ º the 160-ft. thickness of the Spergen formation stretches out in its outcrop so that it is approximately one mile

Jan 1, 1938

By AIME AIME

THE John Fritz Medal Board of Award, at its annual meeting on Jan. 21, 1921, awarded its gold medal and diploma to Sir Robert Hadfield for the invention of manganese steel. On June 1, announcement was made that the Board of Award had awarded its gold medal and diploma to Charles Prosper Eughe Schneider for "achievement in metallurgy of iron and steel; for development of ordnance, especially the 75-mm. gun, and for notable patriotic contribution ' to the winning of the war." The award to Sir Robert Hadfield is for the year 1921; the award to Mr. Schneider is for 1922. The latter was made at this time in order that the medal might be presented by the group of American engineers now visiting England and France.*

Jan 1, 1921

By George M. Fowler

EVERY year it becomes more difficult to find new mining districts and new ore deposits. Nearly all of the important discoveries so far can be attributed to surface manifestations overlying the ore deposit. In the future greater skill will be necessary to find ore deposits that give little or no indication of their presence. Mining geology is making progress by broadening its attack upon mineralized regions, by including in its investigations studies of the relation of physical-chemical processes to ore precipitation and various phenomena that heretofore have not always been looked upon as major factors in the problems. Such, for example, are petrographic peculiarities that will help determine structure, aspects of strata or formations favorable or unfavorable to structural deformation or mineralization, and renewed studies of chert and dolomite. This broadening attack is not necessarily being directed to the study of large areas, but rather by doing extremely detailed work in three dimensions in relatively small critical areas to find the key to the structure, reasons for the manner of rock deformation, composition and texture of the rock, and other con¬trolling factors in the larger areas.

Jan 1, 1935

By R. L. Orr, J. D. G. Masse, Ralph Hultgren

The relative partial molar enthalpies of gold and tin in liquid Au-Sn alloys have been measured from Xsn = 0.474 to 0.510 at 696°K, slightly above the melting point of solid AuSn. Within an average precision of 6 cal per g-atom, the data are represented by two smooth curves, which satisfy the Gibbs-Duhem relationship and which do not show any anomalous behavior in the range of composition studied. The results give no support to the hypothesis that atomic associations in the equiatomic liquid alloy resemble those in solid AuSu. LITTLE has been firmly established as to the nature of atomic distribution in liquid metallic phases. A favored hypothesis assumes the existence of atomic groupings in the liquid phase which are similar to those in solid phases occurring at lower temperatures. Beginning with this hypothesis, it is often possible to adjust the values of certain parameters (such as degree of association) so that approximate agreement is achieved with certain features of the X-ray diffraction pattern of the liquid, even though many other possible structures might satisfy the data equally well. Thus, in this manner, the structure of liquid tin has been described as a dispersion of fragments of gray tin in a matrix of metallic tin.1 Four X-ray diffraction studies2"5 have been made of the liquid alloy of composition AuSn at temperatures slightly above the melting point of the solid. Each investigator concluded, on somewhat different grounds, that the liquid consisted to a large extent of arrays of atoms similar to the solid, with admixture of more disordered arrays. Solid AuSn has the nickel arsenide crystal structure: each tin atom has six nearest neighbors, all gold atoms; and each gold atom has six tin and two gold atoms as nearest neighbors. It remains highly ordered to the melting point. The liquid alloy has a large exothermic (?H700° K = -2700 cal per g-atom6) enthalpy of formation, favoring ordering and making the hypothetical molecular association not unreasonable. The possible existence of such solidlike arrays, or of a high degree of order that occurs preferentially at a specific composition in a liquid alloy, might also be revealed by thermodynamic behavior somewhat analogous to that in highly ordered solid alloy phases. The latter often exist over wide composition ranges, within which the highest degree of order occurs at the ideal composition for which the atomic fractions are equal to the fractions of sites which are "right" for each kind of atom. On departing from the ideal composition, the excess atoms occupy "wrong" positions, raising the internal energy and making it progressively easier for additional atoms to occupy "wrong" positions. Thus, on either side of the ideal composition, there should be a pronounced rise in the entropy and enthalpy, which would be shown particularly by the change in the relative partial molar enthalpies, ?Hi, since they depend strongly on d?H/dx. In the one case where accurate measurements have been made, the solid AuCu ordered phase, the structure becomes much less ordered as the composition deviates from the ideal, and relative partial molar enthalpies change sharply as shown by the data6 given in Table I. This suggests the possibility of finding similar pronounced changes in the relative partial molar enthalpies of gold and tin in liquid alloys near the composition AuSn if the postulated solidlike ar-

Jan 1, 1967