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By Alexander Bowie

IN many places throughout the Western mountain plateau regions of the United States coal beds in place have been burned over very extensive, areas, the fire evidently originating on the nakedly exposed outcrop of the coal bed and gradually burning its way into the bed for considerable distances under very heavy cover. . The surface evidences of the burned-out coal beds are seen in the calcined and discolored rocks overlying the places of the outcrop. The greater the mass of the burned coal the higher the results of its combustion can be seen in the overlying strata. I have noted many instances of this condition in the States of South Dakota, Wyoming, Colorado, New Mexico, and Arizona. In the lignite fields of Dakota and Wyoming I noted stretches of level country many square miles in extent where the surface rocks were roasted and vitrified by the burning of a great bed of lignite lying nearly level and with a light cover; this is probably the most favorable natural condition for the burning out of a coal bed. The less the depth of the rock covering overlying the coal bed, the better the .chance for a continuous supply of air to the fire; but when the coal bed clips heavily into the ground, or even if level, if it, passes under a hill or mountain which gives the bed a heavy covering of strata, the fire has more chances of being extinguished from natural causes than in the first condition described. The distance which, a crop fire may extend into a coal field is very much influenced by the dip, the thickness of the coal bed, and the nature of the rock covering immediately overlying it.

Jan 2, 1914

By Samuel S. Arentz, Dorsey A. Lyon

Introduction % •................. 789 The Present Sources of Zinc ..:.......... 791 Zinc Ores.................. 791 Lead-Zinc Ores................. 793 Loss oF Zinc at the Mine.............. 793 Present Method oF Extracting Zinc From Ores....... 795 Class oF Ores Suited to Zinc Retort Smelting....... 795 Concentration Processes Used for Treating Zinc Ores .... 795 Hydro-Mechanical Processes............. 795 Electro-Mechanical Processes............. 796 Flotation Processes............... 797 Losses of Zinc in Lead and Copper Blast-Furnace Smelting .. 798 Possible Future Sources oF Zinc Supply.......... 800 The Problem oF the Metallurgist and the Present Status of New Processes................. 801 Introduction A great deal of attention has recently been given to the metallurgy of zinc, and much of that which has been said and written on this subject has been in the nature of a criticism. For instance, we are quite accustomed to hearing it said that the metallurgy of zinc has stood still, that it is antiquahed, out of date, etc. We are, however, inclined to agree with George C. Stone1 when he says that, although there have been no such spectacular and radical changes as were worked in the metallurgy of copper and iron by the introduction of converters, there has nevertheless been a decided and marked progress in the metallurgy of zinc, and especially during recent years. However, it must be admitted that, due to the fact that the chemistry of zinc is so different from that of the other metals, the retort process is the only process by which zinc is produced commercially; and, moreover, that losses which occur in the zinc industry— that is, in the mining, milling, and smelting of zinc ore—are very great, for it is stated2 that probably less than 50 per cent. of the zinc mined, even

Jan 1, 1915

THE record of the development of physical metallurgy since the founding of this Institute embraces by far the greater part of physical metallurgy as this subject is recognized today. Yet it is not to be supposed that the metallurgist interested in the properties and behavior of solid metals at the beginning of this period was without important and even fundamental information. He had an empirical knowledge of the behavior of solid metals which extended backward into prehistoric times and he had the early beginnings of many of the chapters in the science of metals. Industry was burgeoning in many directions, for methods had been developed, especially in the manufacture of steel that provided materials in extremely large tonnages, permitting applications of metallic materials on a very widespread scale. These multitudinous new uses of metals created an increased interest in the behavior of metals, and provided the basis for the rapid development of a science of metals. Indeed, the development of science generally that accompanied the industrial revolution reached a flood tide toward the end of the century, furnishing the metallurgist basic principles in chemistry, physics, mechanics, and crystallography that would shortly be extensively applied to metallic behavior. In this account, the early developments in the wide metallurgical field will be traced, in order that the status of physical metallurgy in 1871, when this Institute was founded, may be clearly seen. The subject of metallurgy in antiquity has been written upon frequently and at length. We shall here no more than indicate the main features that we need to define the position in 1871 and to provide a proper background for discussing subsequent developments. The writings of Pliny,1 23-79 A.D., to which Robex-ts-Austen3 fre-

Jan 1, 1948

By John Fulton

THE increase in the production of iron has been accompanied by a growing demand for an improved quality, and more especially at the present time, in the manufacture of Bessemer steel, which is rapidly becoming an important branch of industry. This has led the makers of pig iron to a careful investigation of the composition of the materials from which their metal is produced, the inquiry being greatly assisted by a cordial alliance of science and practice. Formerly, chemical science was held in abeyance, or admitted in a hesitating experimental way ; but now it is received as a valuable auxiliary, and its decisions are accepted as final and conclusive. It is called on to assist the iron-maker in determining the quality of his stock, and to detect the presence of injurious elements in his fuel, ores, flux, or iron. The object of this paper is to submit the method now in use at the furnaces of the Kemble Coal and Iron Company in the Broad Top coal and iron region, for removing, by a process of crushing and washing, slate and other impurities from coal, designed, when coked, for furnace fuel. It is not contemplated to claim very advanced progress in this work, believing that it is susceptible of improvement, but to show that some progress has been made in a comparatively new field, and it is hoped in the right direction, since coke is probably destined to become the principal fuel in the metallurgy of iron. The Broad Top coal region occupies an isolated geographical position, standing 25 miles east from the Alleghany field. It is associated with the latter by the structure of its coal, and more closely with the Cumberland field by a similarity in the quality of coal.

By Edgar Trask

EACH branch of engineering seems to depend on the cooperation and contribution of some other branches to enable it to produce more efficient methods and appliances for man to use. The purpose of this paper is to show approximately the gain in efficiency of self-propelled merchant ships when steel of greater elasticity is substituted for mild steel in some of the strength members and alu-minum alloy is substituted in some of the parts where strength is not essential. The new steel will have some greater strength and a much greater elastic limit in the as-rolled condition, and must be readily weld-able under ordinary conditions of shipbuilding. Naturally, its cost may be more than mild steel, but if the demand is great that excess cost may be reduced to an amount that will make its use more economical than that of the present mild steel. There appears to be a well defined axiom in engineering today that to use the least power to carry a given load the weight of the carrier must be reduced to a minimum. This minimum must be, of course, consistent with the necessary strength, rigidity and durability and it must not be attained at an excessive cost where the fixed charges of the carrier will exceed the savings in, operating the motive power. Recent railroad equipment is a notable example of this, and in these trains alloy steels and aluminum together with less weight per horsepower of the power plant are reducing the weight of the carrier and hence the total power required for moving the paying load. Before considering the application of these metals to shipbuilding, it is well to explain some of the fundamentals of ship design.

Jan 1, 1936

By A. F. Lucas

Belle Isle, located in the low sea marshes near Atchafalaya Bay, is the southeasternmost of the famous Five Salt Islands of Louisiana. Rising about 80 ft. (24 m.) above the level of the surrounding marsh and being some 800 acres (323 ha.) in extent, it constitutes a striking landmark on the low Gulf coast, and since the eighteenth century, when it played an important part in the operation of the buccaneers, it has been intermittently frequented by man. In 1897, the writer discovered the great mass of salt that underlies the island and shortly afterward published a brief account of the geology of Belle Isle and the neighboring salt islands.' In that paper he described principally the salt, but pointed out also the occurrence of petroleum and of sulphur in the strata above the salt. Since that time the island has been extensively explored by the drill, and the developments up to 1908 have been described by Veatch2 and Harris13 and Knapp.4 The writer's early conclusions as to the probable presence of sulphur in considerable quantity have been confirmed by the later drilling, some of the wells having found quantities of gas containing hydrogen sulphide and a number of sulphur-bearing strata as well. Under the stimulus of the present keen demand for sulphur for war purposes, a syndicate of New York capitalists was recently formed to explore the sulphur resources of the island in more detail. Under the writer's direction, six wells were drilled for this syndicate during the winter of 1916-17: The present paper presents briefly the results of this work and sums up the present knowledge of the geology of this highly interesting locality.

Jan 1, 1918

By Charles H. Fulton

The process of crushing ore in cyanide solution was first used at the Crown mine, New Zealand, in 1897, by Mr. F. R. W. Daw; and, two years later, Mr. John Hinton tried it experimentally at the old Dakota plant, Central City, South Dakota. To Mr. Hinton belongs the credit of introducing this important modification in the Black Hills, this being its first successful application in the U. S., and its results have been so satisfactory that it has become established as the proper manner in which to treat the dense oxidized siliceous ores of this district. Five mills are now crushing ore in cyanide solution, namely, the Horseshoe, 120 stamps (60 in operation); the Dakota, 30 stamps; the Maitland, 40 stamps; the Hidden Fortune, 60 stamps; the Lundberg, Dorr & Wilson, one 6-ft. Monadnock roller-mill; and several others intend to adopt this practice. The dry-crushing process still holds its place for the treatment of the more porous and open siliceous ores; and two mills continue to dry-crush dense siliceous ores. Character of the Ores. The occurrence of the ores of the Cambrian strata in the northern Black Hills has been frequently described.' In practice they are classified, according to their appearance, into " red " and " blue " ores, the former being oxidized and the latter unoxidized. At the present time, usually the red ores only are treated at the mills, although occasionally small quantities of blue ore, which have become intimately mixed with the red in mining, are included. Generally the extraction of values by the direct treatment of raw ore is from 70 to 75 per cent. for red ores, and from 25 to 50 per cent. for blue ores. The ores consist mainly of a siliceous matrix containing, as a +1SOUTH DAKOTA SCHOOL OF MINES, RAPID CITY, SO. DAK.

Jan 1, 1905

By K. P. Gupta, P. C. Panigrahy

The stabilization of the R, a-Mn, and 0-Mn phases have been studied in the Mn-Ti-Fe and Mn-Ti-Co systems. Iron and cobalt both appear to stabilize the (Mn-Ti) R phase to almost the sarne extent. The R-phase region was found to extend from the lowest e/a to slightly beyond the maximunz e/a limit known for this phase. But, while iron appears to stabilize the a-Mn phase, cobalt tends to stabilize the p-Mn phase. In the two systems manganese appears to get replaced by iron and cobalt in each of the mentioned phases. The instability of the a-Mn phase in the Mn-Ti-Co system and the /3 -Mn phase in the Mn-Ti-Fe system cannot be explained on the basis of adverse size effects because atomic diameters for both iron and cobalt (C.N. 12 at. diam) are ziery similnr and not much different from manganese which they replace. Qualitatively, the reason for the stability of the a-Mn and the p-Mn phases can be traced to the more favorable e/a ratio prevailing in the respective systems and to a competing tendency between the two phases. In transition metal alloy systems the o, p,P, R, a- Mn,' and p-Mn2 phases have been claimed as electron compounds. A large volume of work has been done to establish the criterion for the formation of the o phase but until very recently practically no systematic work was done on the a-Mn and the /3-Mn phases. A recent investigation on the P-Mn phase3 indicates the e/a criterion for p-Mn phase stabilization. Since the R phase was first known to appear only in certain ternary systems1 no detailed work was then possible for this phase. The R phase has been recently discovered as a binary intermetallic compound in the Mn-Ti~ and Mn-si~-' binary systems. The existence of binary R phases opens up the possibilities of studying the effect of alloying elements on the stabilization of the R phase. Of the two binary systems possessing an R phase, the Mn-Ti system appears to be more interesting because at a suitable high temperature it is possible to find the three electron compounds, the a-Mn, p-Mn, and R phases, side by side and it is possible to study the effect of a third transition element on these three electron compounds. For the present investigation iron and cobalt, so called B elements for the formation of electron compounds, have been used as the third element to study the stabilization of the a-Mn, P-Mn, and R phases. EXPERIMENTAL PROCEDURE The alloys were prepared by using 99.9 pct pure electrolytic Fe and Mn, 99.5 pct Co, and crystal bar titanium, supplied by Semi Elements Inc., New York and Gallard Schelsinger Mfg. Co., New York. Weighed amounts of the components were melted in recrystal-lized alumina crucibles in an inert atmosphere (argon) high-frequency induction melting unit. Titanium was made into fine chips for easy dissolution and a special charging procedure was adopted to avoid contacts of titanium chips with the alumina crucibles. Up to 20 at. pct Ti, the maximum titanium content in the investigated alloys, there was no visible sign of reaction of titanium with the alumina crucibles. With a careful control of melting time and temperature the losses were minimized and were always found to be below 0.1 pct. Because of such small and almost constant weight losses, the alloys were not finally analyzed. The alloys were wrapped in molybdenum foil and annealed in evacuated and sealed silica capsules at 1000" * 2°C for 72 hr and subsequently quenched in cold tap water. Annealed samples were examined metallographically and by X-ray diffraction. For all high manganese alloys oxalic acid solutions of various concentrations and 1.0 pct HN03 solution were found suitable as etching reagents. Best contrast between the a-Mn and the R phases could be obtained by using freshly prepared 60 pct glycerine + 20 pct HN03 + 20 pct HF solution. For high iron and cobalt containing alloys, especially for alloys containing the a-Fe, y-Fe, and P-Co phases, 15 cc HNOJ + 60 cc HC1 + 15 cc acetic acid + 15 cc water solution was found to be the best etching reagent. All X-ray diffraction work was carried out (using specimens prepared from annealed powders) with a 114.6 mm diam Debye-Scherrer camera using unfiltered FeK radiation at 25 kv and 10 ma. All calculations for X-ray diffraction work were carried out using an IBM 7044 digital computer RESULTS AND DISCUSSION The two ternary systems, MnTiFe and MnTiCo, were investigated near the manganese rich end, Figs. 1 and 2, and show some common features. In both alloy systems large extensions of narrow R phase regions occur at almost constant titanium contents. At titanium contents higher than that of the single phase R-phase alloys, the same unidentified X phase was found in both ternary systems. The extensions of the X phase close to the Mn-Ti binary indicate that this phase could be the TiMns phase. Too few X phase diffraction lines were present in the diffraction patterns to make positive identification of the X phase. In contrast to this similarity the two systems show opposite behavior in the extensions of the a-Mn and 8-Mn phase regions; while iron tends to stabilize the a-Mn phase, cobalt

Jan 1, 1970

Quarrying and crushing 500 tons of limestone plus burning some 240 tons of limestone per day are the two initial phases in the production of borax, soda ash, sodium sulfate and related chemicals at Stauffer Chemical Co.'s plant in Westend, Calif. These processing steps have been upgraded in recent years by the installation of new primary and secondary crushers, an 8 x 340-ft rotary kiln plus kiln feed, control and cooling components-all designed and manufactured by Traylor Engineering and Manufacturing Division of Fuller Co. As a result of this new equipment, a new product- quicklime-has been added to the West End product family and considerable reductions have been realized in fuel and manpower costs.

Jan 1, 1965

[Trans. No.Place Date Vol. Page 1. Wilkes-Barre, Pa.* .... May, '71.. 1 8 2. Bethlehem Pa Aug., '71.. 1 10 3. Troy N. 'l Nov., '71.. 1 13 4. Philadelphia, Pa Feb., '72.. 1 '17 5. New York, N. Y.• ....May, '72 1 20 6. Pittsburgh, Pa Oct., '72.. 1 25 7. Boston, Mass Feb., '73.. 1 28 8. Philadelphia, Pa.' May, '73.. 2 3 9. Easton, Pa Oct., '73.. 2 7 10. New York, N. Y Feb.. '74 2 11 11. St. Louis, Mo' May, '74.. 3 3 12. Hazleton, Pa Oct., '74.. 8 8 13. New Haven, Conn....Feb., '75.. 8 15 14. Dover. N. J.' Mav. '75.. 43] [ ]

Jan 1, 1925

YEAR OF ELECTION 1913. FRANK DAWSON ADAMS, Montreal, Canada. 1921. WILLIAM CUTHBERT BLACKETT Sacriston, Durham, England. 1935. GUILLAUME DANIEL DELPRAT Melbourne, Vic., Aust. 1920. HENRY STURGIS DRINKER Merion Station, Pa. 1933. KARL EIKERS NEW YORK, N. Y. 1922. FEDERICO GIOLITTI Torino, Italy. 1906. SIR ROBERT A. HADFIELD London, England. 1928. JOHN HAYS HAMMOND New York, N. Y. 1921. FRANK WILLIAM HARBORD London, England. 1917. HERBERT HOOVER Washington, D. C. 1905. HENRI LECHATELIER Paris, France. 1931. WALDEMAR LINDGREN Cambridge, Mass. 1921. C. McDERMID London, England. 1913. EZEQUIEL ORDONEZ Mexico City, Mexico. 1935. ROBERT PEELE New York, N. Y. 1911. ROBERT H. RICHARDS Cambridge, Mass. 1934. T.A. RICKARD Victoria, B.C., Canada 1933. ALBERT SAUVER Cambridge, Mass.

Jan 1, 1936

[Trans. No. Place Date Vol. Page 1, Wilkes-Barre, Pa.* .... May, '71.. 1 3 2. Bethlehem, Pa Aug., '71.. 1 10 3 Troy, N. Y Nov.,'71.. 1 13 4. Philadelphia, Pa Feb., '72.. 1 17 6. New York, N. Y •.... May, '72.. 1 20 6. Pittsburgh, Pa..:.Oct., '72.. 1 25 7. Boston, Mass Feb., '73.. 1 28 8 Philadelphia, Pa.' May, '73.. 2 3 9. Easton, a Oct., '73.. 2 7 10. New York, N. Y Feb., '74.. 2 11 11. St. Louis, Mo.* May, '74.. 3 3 12. Hazleton. Pa Oct.. '74.. 38 13. New Haven, Conn Feb., '75.. 3 15 14. Dover, N. J.' May, '75.. 4 3 16. Cleveland, 0 Oct., '75.. 4 9] [ ]

Jan 1, 1925

University of Alabama-University, Alabama, Mining and Metallurgical Society, James W Stewart University of Alaska-College, Alaska, Mining Society of the University of Alaska, Jack R Hoskins University of Arizona-Tucson, Arizona, Miners Society, A E Gorum Birmingham-Southern College-Birmingham, Alabama, Pick and Hammer Club, Daniel D Arden University of British Columbia-Vancouver, British Columbia, G M Dawson Club, A Gunning University of California-Berkeley, California, Mineral Technology Association, Bernard York Carnegie Institute of Technology-Pittsburgh, Pennsylvania, The Metals Club, Gerhard Derge Case Institute of Technology-Cleveland, Ohio, Case Metallurgical Engineering Society, Robert F Hehemann City College of New York-New York, New York, CCNY Student Chapter AIME, Daniel T O'Connell

Jan 1, 1955

NEW MEMBERS The following list comprises the names of those persons who became members during the period July 10 to Aug. 10, 1915: Members ALBERTSON, MAURICE MERTON, Mine Surveyor, Mining Corporation of Canada, Cobalt, Ont., Canada. ARMSTRONG, GEORGE CHANDLER Mgr., Indian Refining Co., Lawrenceville, Ill. BARBER, MAX HAYDEN, Min. Engr Supt., Crosby Mine, Nashwauk, Minn. BARNESON, JOHN Merchant, 310 Sansome St., San Francisco, Cal. BENSEL, JOHN A., Cons. Engr 111 Broadway, New York, N. Y . BORGESON, ANSHELM CYRUS, fin. Engr Shenango Mule, Chisholm, Minn. BROOKS, CHARLES PETER, Min. Engr 228 Dooly Bldg., Salt, Lake City, Utah. BROWN, FRANK HAROLD, U'011',. Min. Engr., Federal Co., Inc., 50 Broad St., New York, N. Y. CLARK, DOUGLAS Kellogg, Idaho.

Jan 9, 1915

NEW MEMBERS The following list comprises the names of those persons who became members during the period Apr. 10, 1916 to May 10, 1916. ALLEN, WILLIAM R.... Pres., Boston and Montana Development Co., Butte, Mont. BARKER, EDGAR EARL, Min. Engr. Mine Supt., Chile Exploration Co., Chuquicamata, Chile, S. Amer. BAYLESS, JOHN Z., Met. Engr Alaska Gastineau Min. Co., Thane, Alaska. BLACKWOOD, ARTHUR E., Mgr., Sullivan Machinery Co., 30 Church St., New York, N. Y. BREYER, FRANK G., Chief Testing Dept., The New Jersey Zinc Co., (of Pa.), Palmerton Pa. CARPENTER, JAY A., Mill Supt... . West End Cons. Mining Co., Tonopah, Nev. CORLESS, GEORGE BRADFORD, Geol., Missouri Bureau of Geology and Mines, Joplin, Mo.

Jan 6, 1916

By D. W. Frommer, M. M. Fine

Mineral dressing research showed that iron concentrates of commercial quality could be produced from the Pea Ridge deposit near Sullivan, Mo. Magnetic separation and flotation, on a laboratory scale, yielded concentrates ranging from 60.0 to 71.4 pet Fe at recoveries of 89.9 to 97.6 pct. Early in 1957 St. Joseph Lead Co. announced discovery of three new centers of iron ore deposition in east central Missouri.' The discovery resulted from exploratory drilling in the vicinity of a magnetic anomaly or high. A deep hole, drilled into the Pre-Cambrian porphyry to determine the cause of anomaly, penetrated a magnetite-rich deposit.' The magnetic surveys that revealed the anomalies were begun by the Missouri Geological Survey in 1929 and were continued into the 1930's.3 At that time an area in Crawford County known as the Bourbon magnetic high was located. A second anomaly, similar in size and intensity, was discovered about six miles to the northeast in Franklin County in the vicinity of Sullivan. This area was not studied in detail until the early 1940's. To determine the cause of the anomalies, the USBM drilled four holes at the Bourbon site in 1943-1944.4 The most productive hole penetrated four mineralized zones having a total thickness of 127.5 ft. These zones contained magnetite in rhyo-lite porphyry at depths between 1600 and 2000 ft. Additional iron ore below 2000 ft was considered a possibility at the time. Some years later, the USGS, Missouri Geological Survey, St. Joseph Lead Co., and others cooperated in sponsoring an aeromagnetic survey of the Bourbon-Sullivan area which resulted in discovery of a third high, about eight miles distant at Pea Ridge. This deposit, with an estimated reserve of 50 to 100 million tons of iron ore, is considered the main find, although other orebodies in the same general area are of definite interest.' When this discovery was announced, St. Joseph Lead also revealed plans to exploit the deposit jointly with Bethlehem Steel Co. A new corporation, Meramec Mining Co., was established, and 1962 was set as the target date for completing physical plant.2 Annual production goals of 2 million tons of beneficiated and pelletized iron ore were proposed. Preparation of the site for shaft sinking was begun in June 1957. Orebody and Character of Samples: Drilling to date has established the Pea Ridge orebody as a crescent-shaped pipe about 300 ft wide. Some drillholes were bottomed at 2800 ft in very good iron ore.6 he orebody is predominantly magnetite, although hematite and a mixture of hematite and magnetite occur in the upper areas and peripheral walls. Drillhole cores representing ore from different areas and depths of mineralization were grouped into composites for testing. These composites consisted of: 1) medium grade mixed hematite and magnetite, 2) high grade mixed hematite and magnetite, and 3) high grade magnetite. The medium grade ore came from three holes with depths of i350 to 1900 ft. The high grade mixed hematite and magnetite cores came from the 1790 to 2812-ft interval of one hole. Partial chemical analyses of the three samples, given in Table 1, reveal that all are excessively high in phosphorus and sulfur, and sample 1 is

Jan 1, 1960

By Ferid Kromer

Geography: The Tagtepe district of the Vilayet of Eskigehir is about 20 miles northeast of the city of Eskigehir (approximately midway between Ankara and Istanbul) in western Anatolia. The area is a mountainous one, the highest peak being Tagtepe Mountain (5200 ft) which is approximately in the center of the district. The mountains drop off to the deep valley of the Sakarya River on the north and to the plain of Eskigehir on the south. FERID KROMER, Junior Member AZME, is a Consulting Mining Engineer and General Manager, Bagtag Turk Maadin Ltd., Istanbul, Turkey. New York Meeting, February 1950. TP 2629 H. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Dec. 29, 1948. For the most part, the watershed is on the northern side of the mountain barrier, draining into the Sakarya River, which in turn empties into the Black Sea midway between Zonguldak and the mouth of the Bosphorus. The approximate area covered by the Tagtepe district is shown in fig. 1. Transportation to shipping points is available via the Istanbul-Ankara railroad. The station on this line nearest the mining district is Alpikoy station, about 20 miles by road southwest of Tagtepe Mountain. Interior roads within the district are poor. Being of dirt, the winter rains and snows render them almost impassable for trucks from about the middle of December until the end of March, thus presenting a considerable transportation problem. However, the roads from the Bagoren and Tagtepe chromite mines to the railroad shipping point at Alpikoy station have recently been repaired and will be maintained for all-weather truck transportation. Detailed climatic data are not available. However, in general the spring, summer, and early autumn months are dry, and good weather may be expected from May until early November. Then the winter rains commence, and heavy snow is usual during January and February. Geology: The mountainous structure of Tagtepe belongs to basic rocks of serpentine (Variscan Orogeny) which is in contact with Paleozoic schists at west, and an Oligocene outcrop of red clays in Margi-Sepetci region (see fig. 1) at southeast. The northwest and southwest borders of Tagtepe district are, respectively, surrounded by Paleozoic schists and pebbly gray and yellow Neogene clays. More recent formations of alluviums overlay the plain of Eskigehir. Dark basic rocks of trachytes with hornblende are visible on Turkmenbaba Mountain, at the west of Tagtepe. Mineral Occurrences: Chromite: the most important mineral found in any quantity in the Tagtepe district. The alignment of the deposits of chromite is in general along the line Bagoren-Tagtepe (see fig. 1). The first mines in the area were those of Tagtepe and Bagoren, which were developed over 20 years ago with Swedish capital. Other deposits of chromite, more recently discovered and so far of less importance, are being worked at Kurucor, Komurcu, Gelinmezari, and Lacin (see fig. 1). Deposits average generally between 46 and 48 pct chromic oxide, with the exception of the Bagoren mine which averages 44 pct. However, a new lode, very recently plotted, in the Tagtepe mine averages 50 pct Cr,O,, 4.6 pct SOz, and 7 pct FeO. Geological character of the chromite occurrences in the Tagtepe mine may be considered typical of most chromite lodes in this area. The indications are that the formations of ore lenses are developed by the segregation of chromite crystals intruded into the serpentinized rock, and exposed later to tectonic movement within the zone of crystallization. All lenticular masses are more or less regular in shape and follow each other in southeast-northwest direction and dip generally 70" NE. Ore lenses do not seem to persist in depth, average depth of two lenses is 60 ft below surface. Three lodes .have been mined as open-pit. The average dimensions of individual lenses are as follows: pitch length, 100 ft; breadth, 27 ft; and width, 20 ft. The lenses and their enclosing rocks are broken by parallel fractures in approximately east-west direction. These joints are filled, except in one lode, with cementing material, which gives to the ore a

Jan 1, 1951

By Ferid Kromer

Geography: The Tagtepe district of the Vilayet of Eskigehir is about 20 miles northeast of the city of Eskigehir (approximately midway between Ankara and Istanbul) in western Anatolia. The area is a mountainous one, the highest peak being Tagtepe Mountain (5200 ft) which is approximately in the center of the district. The mountains drop off to the deep valley of the Sakarya River on the north and to the plain of Eskigehir on the south. FERID KROMER, Junior Member AZME, is a Consulting Mining Engineer and General Manager, Bagtag Turk Maadin Ltd., Istanbul, Turkey. New York Meeting, February 1950. TP 2629 H. Discussion of this paper (2 copies) may be sent to Transactions AIME before Feb. 28, 1950. Manuscript received Dec. 29, 1948. For the most part, the watershed is on the northern side of the mountain barrier, draining into the Sakarya River, which in turn empties into the Black Sea midway between Zonguldak and the mouth of the Bosphorus. The approximate area covered by the Tagtepe district is shown in fig. 1. Transportation to shipping points is available via the Istanbul-Ankara railroad. The station on this line nearest the mining district is Alpikoy station, about 20 miles by road southwest of Tagtepe Mountain. Interior roads within the district are poor. Being of dirt, the winter rains and snows render them almost impassable for trucks from about the middle of December until the end of March, thus presenting a considerable transportation problem. However, the roads from the Bagoren and Tagtepe chromite mines to the railroad shipping point at Alpikoy station have recently been repaired and will be maintained for all-weather truck transportation. Detailed climatic data are not available. However, in general the spring, summer, and early autumn months are dry, and good weather may be expected from May until early November. Then the winter rains commence, and heavy snow is usual during January and February. Geology: The mountainous structure of Tagtepe belongs to basic rocks of serpentine (Variscan Orogeny) which is in contact with Paleozoic schists at west, and an Oligocene outcrop of red clays in Margi-Sepetci region (see fig. 1) at southeast. The northwest and southwest borders of Tagtepe district are, respectively, surrounded by Paleozoic schists and pebbly gray and yellow Neogene clays. More recent formations of alluviums overlay the plain of Eskigehir. Dark basic rocks of trachytes with hornblende are visible on Turkmenbaba Mountain, at the west of Tagtepe. Mineral Occurrences: Chromite: the most important mineral found in any quantity in the Tagtepe district. The alignment of the deposits of chromite is in general along the line Bagoren-Tagtepe (see fig. 1). The first mines in the area were those of Tagtepe and Bagoren, which were developed over 20 years ago with Swedish capital. Other deposits of chromite, more recently discovered and so far of less importance, are being worked at Kurucor, Komurcu, Gelinmezari, and Lacin (see fig. 1). Deposits average generally between 46 and 48 pct chromic oxide, with the exception of the Bagoren mine which averages 44 pct. However, a new lode, very recently plotted, in the Tagtepe mine averages 50 pct Cr,O,, 4.6 pct SOz, and 7 pct FeO. Geological character of the chromite occurrences in the Tagtepe mine may be considered typical of most chromite lodes in this area. The indications are that the formations of ore lenses are developed by the segregation of chromite crystals intruded into the serpentinized rock, and exposed later to tectonic movement within the zone of crystallization. All lenticular masses are more or less regular in shape and follow each other in southeast-northwest direction and dip generally 70" NE. Ore lenses do not seem to persist in depth, average depth of two lenses is 60 ft below surface. Three lodes .have been mined as open-pit. The average dimensions of individual lenses are as follows: pitch length, 100 ft; breadth, 27 ft; and width, 20 ft. The lenses and their enclosing rocks are broken by parallel fractures in approximately east-west direction. These joints are filled, except in one lode, with cementing material, which gives to the ore a

Jan 1, 1951

By J. Chipman, N. J. Grant, R. Rocca

D. E. Babcock (Republic Steel Corp., Youngstown, Ohio)—With reference to eqs 7 and 8, at what temperature do they apply John Chipman (authors' reply)—That was 1600°C. Dr. Babcock—You have l x 10-4 as the component for the lime and 1 or 4x10-. Now, is it by dividing one into the other you get the 400? That is assuming equivalent activity on the part of oxygen, sulphur, and magnesia. Dr. Chipman—Yes, they are calculated for 1600. Now, the first one for CaO was calculated before we had a glimpse of Dr. Rosenqvist's paper." If you take his calculation you get 14,000 cal which is very good agreement, but our calculation would be superseded by Dr. Rosenqvist's new data. Dr. Babcock—The state you assume those to be in is the liquid state, as near as you can measure? Dr. Chipman—Naturally it is based on the solid CaS, but if you add the effect of fusion on both sides it just about balances out, so the ratio would be about the same. B. M. Larsen (U. S. Steel Co., Kearny, N. J.)—If we knew the activity of sulphur in the slag instead of merely the percentage, we might be able to find some conflicting factors that balance one another out, and find that the FeO or oxygen pressure effect is really present over the whole range. Dr. Chipman—I am fairly sure we would. The activity of sulphur in the slag and the activity of CaO in the slag, if we just knew those quantities, would enable us to save a lot of this computation and assumption and all the approximations we are doing now. Mr. Larsen—Two other points perhaps should be included: 1—an independent effect of manganese in helping the desulphurization; and 2—the number of mols of constituents or number of mols of ions or whatever there is in the slag could vary with these compositions in such a way that you get dilution effects. Dr. Chipman—You can figure all that in if you want to and it might improve the degree of approximation a little bit. Maybe enough to justify the labor of calculation, inaybe not, but we did not do it. L. S. Darken (U. S. Steel Co., Kearny, N. J.)—The authors have tackled a very complicated problem in trying to tie together in one picture the desulphurizing problem over the wide range of basicity and oxidation level from that of the open hearth to that of the blast furnace. At the present state of our knowledge of slags such an ambitious undertaking necessarily involves the adoption of numerous hypotheses. Their formulation (eq 11) for the higher FeO range

Jan 1, 1952

By B. N. Bose, M. F. Hawk

SINCE Davenport and Bain' introduced the isothermal transformation technique for the study of austenite decomposition in steels, a new field of investigation has opened up. Extensive research has been carried out on many different steels, but relatively little work has been done on eutectoid transformations in analogous alloy systems. The researches of Smith and Lindlief,² Mack,³ and Klier and Grymko²0 on the beta-phase transformation in copper-aluminum alloys, of Hibbard, Eichelrnan, and Saunders4 and Smith5 on the kappa-phase transformation in copper-silicon alloys, of Chaudron and Forester6 on the decomposition of "FeO," and of Wasserman7 on similarities between the iron-carbon, copper-aluminum, copper-tin, and copper-beryllium systems essentially comprise the field. The iron-nitrogen system, in view of its remarkable similarity to the iron-carbon system, is particularly attractive for the study of eutectoid decomposition. The present investigation is concerned with the study of isothermal transformation, proceeding by the familiar nucleation and growth processes, and of martensitic transformation characteristics of pure iron-nitrogen alloys. The kinetics of transformation and the morphology of the transformation products have been investigated, for these must be the factors determining the properties and behavior of the final product. The Iron-Nitrogen System he binary iron-nitrogen phase diagram has been a matter of considerable disagreement among vari01.1s investigators. However, the phase diagram according to Eisenhut and Kaupp8 and Lehrer10 is now considered essentially correct as reproduced in fig. 1. The important values, 2.35 pct nitrogen and 591°C, for the co-ordinates of the eutectoid point (obtained from this diagram and used in the re- search to be described) were confirmed in a concurrent study of Paranjpe, Cohen, Bever and Floe." The eutectoid decomposition involves the transformation of the ? face-centered cubic interstitial solid solution of nitrogen in iron to the a body-centered cubic interstitial solid solution of nitrogen in iron and the ?' nitride of iron. This nitride is essentially the compound Fe,N; it also possesses a face-centered cubic lattice but a considerably larger one than the ?; the nitrogen atoms in ?' are arranged in an ordered way in the centers of the unit cubes.8,10,11 A martensitic structure has also been reported8,12 in iron-nitrogen alloys and was studied in the research to be described here. Materials and Methods The specimens used in this investigation were prepared by nitriding "pure" iron. This iron was supplied by the Westinghouse Research Laboratories and is the product bearing their trade name "Puron"; it contains about 0.04 wt pct total impurities, the major portion of which is oxygen. Specimens were ribbons several inches long, a tenth of an inch wide, and 0.125 mm thick; this was the

Jan 1, 1951