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By Ednlund D. North

Discussion of the paper of Edmund D. North, presented at the Spokane meeting, September, 1909, and published in Bulletin No. 37, January, 1910, pp. 21 to 25. A. SCOTT REID, London, Eng. (communication to the Secretary*) :-As a constructor of several glass mine-models, I have read with much interest the description of the model of the Montana-Tonopah mine-workings by Edmund D. North. As an interchange of ideas and experience is always an advantage, and in view of the fact that such models are coming more and more into vogue, perhaps the following remarks on this subject may prove of interest to mining engineers generally and to Mr. North particularly. In the model of the Waihi gold-mine, New Zealand, which I constructed, a dust-proof case is used. The top, bottom, front, and two ends are of glass; the back only is of wood, painted a dull white, against which the mine-workings show very distinctly. Each mine-level is represented by a horizontal sheet of glass, supported on metal runners fixed to the uprights at each end of the case, in a manner similar to that described by Mr. North. The corner uprights are strengthened by having a metal band screwed to the inside face of each, to which the metal runners or supports for the sheets of glass are screwed in turn. The reason for having this additional strength is that as the mine is developed in depth, and fresh levels are opened, the increasing weight of the glass sheets, added to the model, caused the unsupported wooden uprights to bend slightly, so that the glass sheets-did not fit in with the desired nicety, and co-ordination was, to a considerable extent, lost. Strengthening the uprights in this manner is not important in models of mines in which only a few levels have been opened, or when the sheets of glass are small, but in the Waihi model there are 15 sheets of glass to be supported, and more to be added as development proceeds, and the weight is considerable.

May 1, 1910

By Sherwin F. Kelly

THE principal interest in the meeting sings arranged by the Geophysical Committee this year centered around the many papers dealing with the practical applications of geophysical methods to solving geological problems in many other parts of the world. The program Wednesday morning dealt with work in South Africa, Poland, and South America. Rudolph Krahmann's first paper gave a perspective of the geophysical investigations upon mineral deposits in South Africa. A striking point in his story was the tremendous increase in magnetic work during the last two or three years. This is largely accounted for by the intensive exploration for the extension of the Witwatersrand gold mining area. The author mentioned many surveys in which other methods were used for the search for ores of copper, lead, and zinc, and in the study of water-bearing and oil-bearing structures.

Jan 1, 1935

By G. F. Fix

Oil and gas activity reached a higher peak in Indiana during 1940 than for any like period during the past decade. Major activity, as during 1939, was in the southwestern part of the state, the Indiana portion of the Eastern Interior Coal Basin, where most of the increase was due to field drilling in previously proven areas. The amount of wildcat drilling was about the same as for 1939. No new fields of any apparent consequence were discovered during the year, with the possible exception of the College pool, in southwest Posey County. Only one well had been completed in this area at the end of the year. About 10 ft. of saturated Aux Vases sandstone was drilled in this well and the initial production was I00 bbl. of oil a day. Other discoveries during the year 1940 include: St. Thomas, in southwestern Knox County, where four McClosky wells, ranging from I00 to 300 bbl. a day initially, were com-pleted; Buff kin, in central Posey County, with 11 oil wells and 5 gas wells completed; and new developments in two old areas —Randolph County (part of the old Trenton field) and Gentryville, northwestern Spencer County, where some oil was found many years ago. The St. Thomas field proved disappoint-ing, with very spotty production from the McClosky horizon of the St. Genevieve limestone at a depth of about 1875 ft. The discovery well flowed 362 bbl. a day ini-tially. At the end of the year the field was pretty well outlined by dry holes and some inside locations were dry. The Buffkin pool also proved spotty, with production from shallow Pennsylvanian sands and from the Basal Pennsylvanian Mansfield sandstone, the latter at a depth of approximately I175 ft., with small production from the Cypress sandstone of Chester age. Oil wells in this pool are small, ranging from 25 to 75 bbl. a day. The Randolph County area, on the east side of the Trenton gas field, showed some promise for a commercial gas field, with four completed gas wells having cumulative initial flows of about 1,200,ooo cu. ft. a day. The area appar-ently was not depleted during the Trenton boom at the turn of the century, since casing pressures are about as high as the virgin pressure in the old field. Elsewhere the pressure has dropped as low as 5 pounds. The Griffin field received most of the drilling during 1940, with 163 completed oil wells. This field now covers about 3200 acres on the Indiana side of the Wabash River and is not as yet completely delimited. It produced the major part of Indiana's oil during the year—a total of 3,594,000 bbl. At the end of 1940, there were 253 producing wells in Griffin. New Harmony had five completions for a total of 24. The Rockport field, in Spencer County, continued to be actively developed and had a total of 45 gas wells and 9 oil wells at the end of the year. Oil in commercial quantities had not been found in the field previous to 1940. Total gas production for the year was 394,470,000 cubic feet. In all, 521 wells were drilled in the state during 1940, as compared to 377 for 1939. Of this number 248 were oil wells, 77 were gas wells and 196 were dry. Divided into

Jan 1, 1941

By G. F. Fix

Oil and gas activity reached a higher peak in Indiana during 1940 than for any like period during the past decade. Major activity, as during 1939, was in the southwestern part of the state, the Indiana portion of the Eastern Interior Coal Basin, where most of the increase was due to field drilling in previously proven areas. The amount of wildcat drilling was about the same as for 1939. No new fields of any apparent consequence were discovered during the year, with the possible exception of the College pool, in southwest Posey County. Only one well had been completed in this area at the end of the year. About 10 ft. of saturated Aux Vases sandstone was drilled in this well and the initial production was I00 bbl. of oil a day. Other discoveries during the year 1940 include: St. Thomas, in southwestern Knox County, where four McClosky wells, ranging from I00 to 300 bbl. a day initially, were com-pleted; Buff kin, in central Posey County, with 11 oil wells and 5 gas wells completed; and new developments in two old areas —Randolph County (part of the old Trenton field) and Gentryville, northwestern Spencer County, where some oil was found many years ago. The St. Thomas field proved disappoint-ing, with very spotty production from the McClosky horizon of the St. Genevieve limestone at a depth of about 1875 ft. The discovery well flowed 362 bbl. a day ini-tially. At the end of the year the field was pretty well outlined by dry holes and some inside locations were dry. The Buffkin pool also proved spotty, with production from shallow Pennsylvanian sands and from the Basal Pennsylvanian Mansfield sandstone, the latter at a depth of approximately I175 ft., with small production from the Cypress sandstone of Chester age. Oil wells in this pool are small, ranging from 25 to 75 bbl. a day. The Randolph County area, on the east side of the Trenton gas field, showed some promise for a commercial gas field, with four completed gas wells having cumulative initial flows of about 1,200,ooo cu. ft. a day. The area appar-ently was not depleted during the Trenton boom at the turn of the century, since casing pressures are about as high as the virgin pressure in the old field. Elsewhere the pressure has dropped as low as 5 pounds. The Griffin field received most of the drilling during 1940, with 163 completed oil wells. This field now covers about 3200 acres on the Indiana side of the Wabash River and is not as yet completely delimited. It produced the major part of Indiana's oil during the year—a total of 3,594,000 bbl. At the end of 1940, there were 253 producing wells in Griffin. New Harmony had five completions for a total of 24. The Rockport field, in Spencer County, continued to be actively developed and had a total of 45 gas wells and 9 oil wells at the end of the year. Oil in commercial quantities had not been found in the field previous to 1940. Total gas production for the year was 394,470,000 cubic feet. In all, 521 wells were drilled in the state during 1940, as compared to 377 for 1939. Of this number 248 were oil wells, 77 were gas wells and 196 were dry. Divided into

Jan 1, 1941

By Etienne A. Ritter

INTRODUCTION. THE Evergreen mine, located at Apex, in the northern part of Gilpin county, Colorado, has opened a very peculiar and interesting copper-deposit, in which both bornite and chalcopyrite occur as rock-minerals. The country-rocks are crystalline schists cut by dikes of granulite and of pegmatite. At the Evergreen property they have been cut by a dike of a new kind of eruptive rock, to which I have given the name " Evergreenite" The rock is composed of quartz, alkali feldspars, orthoclase and albite (often interlocked as microperthite), with augite of the aegirine variety and long needles of enstatite and diallage. For reasons stated below, I believe the dike to be of Tertiary age. It is- easily traced on the surface of the ground, from a point in the bottom of Pine creek, about a mile below Apex,. to the top of Nevada hill, 1,500 ft. beyond and 600 ft. above it. (See Fig. 1.) It varies from 3 to 12 ft in width, and is bounded on both sides by contact-zones about 60 ft. wide, in which the crystalline schists have been changed into pseudo-quartzites or pseudo-gneisses, according to the injection of an excess of quartz or of feldspars through the special layer of the schists.. The most interesting feature is the presence of the pyroxenes, which are always found, though in very variable proportions from place to place, in the layers of these' metamorphosed crystalline schists. The dike has torn from its walls a large number of fragments of the wall-rock. It must have been in a viscous state when that happened, because these fragments of the wall-rock do not show any sign of resorption or of assimilation by the magma. In places they are so distinct and so numerous that the rock looks to the naked eye like a pseudo-breccia, of which, never-

Jan 1, 1908

Willet G. Miller, Toronto, Canada (communication to the Secretary): In his interesting paper Mr. Lindgren says: " As to ultimate results, it would seem as if we should be justified in concluding, with Prof. Suess, that the gold-supply of the world will gradually decrease if no further important improvements are made in the processes for the extraction of this metal; but regarding events so far distant no predictions may safely be made." It seems to the writer that no very important improvements require to be made in order at least to keep up the present production for many years to come. In many parts of the world there are large deposits of auriferous material which can be worked if present conditions are slightly changed. In the territory occupied by the Archean protaxis of the Province of

Jan 1, 1903

By S. F. Frederick, G. F. Pittinato

The deformation mechanisms operating in Ti-5Al-2.5Sn at 20°K under uniaxial and biaxial stress fields were determined by using both optical and electron microscopy. In the uniaxially stressed specimens, de-fu~rnation twins were found only in the immediate vicinity of the fracture. Twinning was, however, established as a deformation mechanism under biaxial stress conditions. The same slip systems were opera-tiz,e under both uniaxial and biaxial stress. Prismatic slip was identified as the major slip syslem; however, basal and first-order pyramidal slip also occurred, but to a lesser degree. The interaction of moving dis-locations on intersecting slip planes resulted in the formation of jogs and dipoles. Hexagonal dislocation networks were formed only under biaxial stress conditions. A discussion is given on the formation of hexagonal dislocation networks. IT has been shown that titanium alloys can exhibit unusually high strengths when tested in a biaxial stress field.'-" The high biaxial strengths are a consequence of a strong basal plane sheet texture which results in distinctly anisotropic flow properties. This texture strengthening appears to decrease with decreasing temperature2 and would seem to indicate a change in deformation modes. For example, in a uniaxial tensile test, Ti-5A1-2.5Sn yields isotropically at 20°K but is strongly anisotropic at room temperature. The increase in biaxial ultimate over uniaxial strength at 20°K is also much less than at room temperature. It is known that titanium car] form deformation twins more readily at cryogenic temperatures than at room temperature.4 Since the formation of deformation twins will reduce the degree of basal texture in sheet material,' an accompanying decrease in texture strengthening would be expected. To investigate more fully the nature of texture strengthening at cryogenic temperatures, the deformation modes of Ti-5A1-2.5Sn tested in uniaxial and 1:1 biaxial tension at 20°K were studied by optical and electron transmission microscopy. EXPERIMENTAL PROCEDURE The uniaxial and biaxial stress test specimens were prepared from 0.020-in. thick sheets of Ti-5A1-2.5Sn ELI having the composition shown in Table I. Uniaxial stress conditions were obtained by using flat tensile specimens machined from the sheet material. The longitudinal axis of the tensile specimens was aligned perpendicular to the rolling direction of the sheet. Tile biaxial test specimens were prepared by rolling precut, 19-in.-lengths of sheet into 4-in.-diam cyl- inders. Following longitudinal butt welding, the cylinders were stress relieved at 1000°F for 4 hr. A 9-in. sq "window" was then chemically milled into each cylinder's surface reducing the wall thickness in the milled area to approximately 0.006 in. The testing procedure consisted of pressurizing the cylinders while simultaneously applying a tensile load. Using this technique, a 1:l axial to hoop stress was obtained. Complete details of the specimen and testing procedures are given in Refs. 1 and 2. The biaxial and uniaxial stress specimens were all tested in liquid hydrogen. Specimens for electron transmission microscopy were prepared by first chemically milling to a thickness of about 0.001 in. followed by electrolytic polishing to electron transmission thickness. The chemical milling solution, consisting of 800 ml of water,

Jan 1, 1970

By Arnulf Muan, R. E. Johnson

Equilibrium CO2 /CO ratios of a gas phase coexisting with selected oxide phase assemblages of the system CaO-"Fe0"-SiOz and vnetallic iron have been determined at 1080°C. The data obtained are used to calculate activity-conzposition relations for metasili-cute, orthosilicate, and CaO- "FeO" solid solutions, and to determine a new value for the free energy of formation of C&S&0,. The metasilicate solution is practically ideal, whereas large deviations from ideality exist in the othe,r two solid solutions. BECAUSE of the geochemical and metallurgical importance of the oxides CaO, "FeO", and SiOz, the system CaO-"FeO"-SiO2 has been the subject of several experimental studies during the past 30 years. Following the delineation of phase relations at liquidus temperatures by a group of investigators at the Geophysical Laboratory of the Carnegie Institution of Washington in 1933,1 Chipman and associates in the early forties2,3 determined activities of FeO in liquids of this system. Since that time, many attempts have been made to interpret the data of Chipman et al. in terms of the constitution of the silicate liquids and the interaction parameters among the various constituents of the system (see for instance papers by Richardson4 and by Flood and coworkers5). One of the assumptions made in some of these interpretations4 is that the binary silicate systems CaSiO3-FeSiO3 and CazSi04-Fe2SiO4 mix ideally in the solid state. The objective of the present study is to provide experimental data on activity-com position relations in solid solutions of the system CaO-"FeO"-SiO2. Such data will contribute toward an understanding of the thermodynamics of silicate solid-solution phases in general, and will serve specifically to confirm or refute some of the assumptions made in interpreting liquid slag behavior. PREVIOUS WORK Phase relations in the system CaO-"FeO"-SiO2 in contact with metallic iron were determined by Bowen, Schairer, and Posnjak,1 and additional phase-equilibrium data for this system have been presented by Allen and snow.' A reproduction of the most up-to-date phase diagram for this system is shown in Fig. 1.7'8 Of particular interest in the present investigation are the relations among the various crystalline phases slightly below the lowest solidus temperature in the system, as shown in Fig. 2. The present work will be concerned primarily with some of the composition

Jan 1, 1968

By C. Feng, I. R. Kramer

A study was conducted to determine the influence of the surface on the yield point of fcc metals and high-purity iron. For the high-purity fcc metals, the yield Point produced by restraining a specimen may be eliminated by removing a sufficient amount of the layer. A yield point similar to that in fcc metals was found when iron specimens were pre-strained after a prior deformation. This yield point is not due to an aging effect but is associated with the surface layer. The yield points in age-hardenable aluminum alloy and those connected with "work softening" are not affected by a surface-removal treatment and are, therefore, caused by bulk-type dislocation reactions. The yield point which appears in previously strained fcc metals has been the subject of numerous studies. Several theories have been advanced to explain this "unloading-reloading" yield point. Cottrell and stokes,' from their study on the effect of temperature on plastic properties of high-purity aluminum, considered that it was the result of an avalanche "breakdown" of Lomer-Cottrell sessile dislocations. Haasen and Kelly2 extended this concept of dislocation-dislocation interaction to account for the yield point when unloading and reloading was carried out at the same temperature. On the other hand, strain aging was found to be responsible for the yield point in A1-Mg alloy by Westwood and Broom,3 and in aluminum alloys containing various amounts of alloying elements by Smallman, Williamson, and Ardley.4 In these cases, the yield point is considered to be associated with the locking of dislocations by impurity atoms. Birn-baum and filer5,6 and Takamura and muira7 reported that, when a high-purity copper specimen was prestrained, then held at a lower stress, and finally reloaded at the prestrain temperature, a larger yield point was observed. Such an increase was attributed to the locking of dislocations by point defects. In addition, Bolling8 suggested that both mechanisms, i.e., dislocation-dislocation interaction and strain aging, are responsible for the yield phenomenon, at least in a brass. Thus, there appears to be experimental evidence for both the strain aging and dislocation-dislocation interaction theories to explain the yield point in the fcc metals and alloys. In a previous article,9 one of the authors observed that, if sufficient amounts of metal were electrolti-cally removed after deformation of a high-purity aluminum single crystal, the yield point did not appear upon reloading. Continued pursuit in this area revealed that the effect of the surface on the yield-point phenomenon is not limited to one metal but affects a variety of metals of different lattice structures. Nor is the effect limited to the yield points produced by simple unloading-reloading at constant temperature; the surface exerts an important role on the yield point even when the temperature is changed at some stage during the test. It is the intent of the present article to give additional information regarding the effect of the surface on the yield-point phenomenon and to show the association between the yield point in both fcc and bcc metals and the existence of a heavy concentration of dislocation in the region near the surface of a deformed specimen.10 EXPERIMENTAL Materials. The single crystals used in this study had a nominal cross section of 0.125 by 0.125 in. and a 3-in. gage length and were prepared by a modified Bridgman technique. The initial purity for the metals was 99.997, 99.999, and 99.999 pct for aluminum, copper, and gold, respectively. Bar stock of these same materials was used in the preparation of the polycrystalline specimens of aluminum and copper. The iron specimens were machined from rods of "ferrovac", reported to have a purity of 99.98 pct. In addition, a precipitation-hardening aluminum alloy, containing 1.5 pct Cu, 2.5 pct Mg, and 5.5 pct Zn, was used. The polycrystalline specimens of iron, copper, and the aluminum alloy had a diameter of 0.17 in. and a gage length of 2 in. while the high-purity aluminum specimen had a nominal rec-

Jan 1, 1965

By K. R. Janowski, H. Conrad

As part of a program to establish the effect of crystal imperfections on laser output, a detailed study was made of the dislocation structure of ruby crystals obtained from varioius sources. Using KHSO4 as an etchant, a detailed mapping of the dislocation structure on the (0001) and the (1150) planes was carried out. A less extensive study was made of the rhombohedral planes. The average dislocation density on the basal plane was 1.5 to 3 x 106 cm&apos;2 and on the (1120) planes -5 x 10&apos; cm-2. Howe7!er, considerable variation existed between areas on a given plane. The subboundaries in the basal plane tended to lie along [1100] type directions while those on the (1120) plane tended to lie: a) parallel to the basal plane, b) along truces of the (1101) plane, and c) along normals to the traces of the (0001) planes. The orientations suggest that mang of the dislocations lie on the (0001), (1701), and (1150) planes A Laue back-rellection nnalysis Of c-axis wander in one crystal revealed a gradual increase in misorientation from me end of the crystal to the other, with a maximum variation of 1°35&apos;. Slight etching of a mechanically polished crystal revealed mumerous polishing scratches, suggesting the existence of a plastic flow layer. It is recognized that chromium concentration, lineage, and other crystalline imperfections play a role in the efficiency of ruby lasers.&apos; Consequently, it is desirable to establish in detail the imperfection structure of ruby crystals to be used as lasers. Some exploratory work along this line had already been done by Barnes&apos; and Dils and Martin.&apos;" How- referred to as the morphological system, as described by Kronberg.4 The Miller indices given in the present paper will be based on this morphological system. In this system, the three common growth planes are the (0001), the {1120}, and the {1101}.5 Since these planes are of high stability, it is expected that they are most suitable for study by the etch-pit technique. In the present investigation, a detailed mapping of the dislocation structure was carried out for the (0001) and the (1130) planes. A less extensive study was made of the etch-pit structure on rhombohedra1 planes. An analysis of dislocations in sapphire (the ruby host) was first made by kronberg,4 who postulated that slip on the (0001) plane occurred by motion of dislocations with Burgers vector 1/3 <1150> and that these dislocations might dissociate into quarter partials. An etch-pit technique using boiling phosphoric acid was developed by Scheuplein and Gibbs6, 7 for identifying dislocations intersecting the (0001) planes and the planes near (2021) in sapphire. Al-ford and Stephens8 were able to reveal dislocations on the (0001) and {1120} planes in sapphire and ruby by etching in fused potassium bisulfate (KHS04) at 675°C. The termini of basal dislocations [(000l), <1120>] were revealed by Palmour and Kriegel9 on {1120} and {1010} by thermally etching sapphire. Bond and Harvey10 were able to decorate dislocations in sapphire by adding 1 pet by weight of ZrO2 to the Al2O3 powder used in the growth of the crystals by the Verneuil technique and then heating the grown crystals for 4 hr at 1500°C. They found, using optical transmission microscopy, that many dislocations had straight segments which were parallel to one of the six [1120] directions in the basal plane. Single dislocation lines curved smoothly from one alignment to the other, turning through angles of 60 to 120 deg. Also observed were isolated hexagonal loops, approximately 10 µ in diameter, the sides of which lay along the same directions as did the longer dislocations. MATERIAL AND ETCHING PROCEDURE The ruby specimens used in this study (all containing approximately 0.04 pet Cr) had been obtained from four different sources: Linde Co., Meller Co., Valpey Crystal Corp., and those grown at Aerospace Corp.* For the initial phase of this study, several specimens were cut from the slab shown schematically in Fig. 1 which had previously been cut from a disk boule obtained from the Linde

Jan 1, 1964

By Paul D. Merica

DURING the Dark Ages, when metallurgy was practiced by the alchemists, any unusual or disturbing variation in metallurgical operations was ascribed to the, presence, in the metals or ores, of an evil spirit, and it was necessary to exorcise and drive it out "by suitable incantations. In this day of science and of engineering, things still incomprehensibly go wrong in the metallurgist&apos;s work shop. The metallurgist is even now not unwilling to lay the blame for many such experiences at the door of something which intellectually- much resembles an evil spirit, "gas in the metal." The presence of gases in his metal, he knows, occasions him many very definite troubles which he can clearly distinguish and diagnose-why may it not be also responsible for those which he cannot so well understand?

Jan 1, 1931

By RICHARD L. HUMPHREY

IT IS proper that there should be a brief accounting of the stewardship which was entrusted to the Joint Conference Committee by resolution adopted by the. Organizing Conference on June 4, 1920, in part as follows: RESOLVED, that it is the sense of this Organizing Conference that the Joint Conference Committee should be entrusted with making provision for putting the conclusions of this Conference of engineers into effect, etc. Pursuant to this authority, the Joint Conference, Committee has acted as an Ad-interim Committee has- prepared, a synopsis of the proceedings of the Organizing .Conference, has edited and published the Constitution and By-Laws adopted by this Conference, and. has issued an invitation to become Charter Members of The Federated, American Engineering Societies; to the list of organizations to whom invitations had been extended to attend &apos;the Organizing., Conference. The Committee in connection with this invitation offered to the extent of its ability, such assistance as might be-desired; and arranged in many cases for one or more of its members to be present when the matter of membership in The Federated American Engineering Societies was considered. . .

Jan 1, 1920

E. A. H. Tays, San Blas, Sinaloa, Mex. (communication to the Secretary*):—The results obtained by Messrs. Hofman and Hayward in their experiments, proving that a low percentage of copper sulphate with a variable percentage of salt, depending on the ore, gives the best results, confirm practical mill-work which I did in 1895. I have none of my notes, taken at the time, to refer to, so have to rely solely on memory, which precludes the conciseness that is alway desirable. In 1894 I took charge of the plant of the San Rafael Company, near Chinipas, Chihuahua, Mex., which at that time was treating a very refractory ore carrying about $15 in gold and from 20 to 25 oz. of silver per ton, the bullion being about 300 fine in gold. The silver in the ore was in the form of a sulphide. Although carrying an average of 0.75 oz. of gold per ton, free gold could rarely be seen by panning, but upon roasting a sample of the ore the gold became visible at once—a result which was discovered by chance and used to advantage later. In order to utilize the old mill to the best advantage, it was decided to use pan-amalgamation after roasting. The roasting, done in a lime-kiln, was similar to the ordinary " burning " operation. The roasted ore was trammed to the mill-bins and crushed by 10 stamps to pass a 30-mesh screen. The pulp was de-watered and fed to four 1-ton pans. My recollection is that upon starting the mill-work, the charge contained 1.5 lb. of copper sulphate and 5 per cent. of salt per ton. From the start the extraction was unsatisfactory and the loss of quicksilver was very large. Experiments were then carried out on a working scale. First, the quantity of copper sulphate was increased 4 oz. at a time; then it was reduced

Jan 1, 1910

By James C. Ray

DURING the summer of 1931, I spent four months in a study of the Willow Creek district, Alaska. This work was part of a general investigation of the territory contiguous to the route of the Government- owned Alaska Railroad. It was conducted by the U. S. Geological Survey to determine the real and potential merits of the mineral deposits, to stimulate development of them, and thus to increase the traffic on the Alaska Railroad.

Jan 1, 1932

By F. G. Jaicks

RECOGNITION of the benefits to be gained from the continuous casting of molten steel into finished or semifinished products has been given by scientific minds since the very beginnings of steel plant technology. In fact, Sir Henry Bessemer is credited with the first of a long list of patents&apos; issued by the U. S. Patent Office for a process which would accomplish this desirable end. None of these early ideas attained practical success and, as a result, the conventional method of teeming into ingot molds became an integral part of modern steelmaking operations. This procedure, although refined to keep pace with the changes which have come about in steelmaking and finishing facilities, is recognized to have inherent shortcomings which adversely affect manufacturing costs and steel quality. Interest in the continuous casting of steel persists because the process is directed toward avoiding some obvious weaknesses of conventional ingot casting. It has been recognized that should it be possible to substitute any of the continuous casting techniques under current development for ingot casting, it would no longer be necessary to make large capital investments in primary rolling equipment, the sole purpose of which is to reduce ingot castings to a form rollable on finishing mills. The results reported in the continuous casting of non-ferrous metals and specialty steels indicate that in addition to avoiding the primary rolling mills there is some basis for expecting significant improvements in yield, surface, and internal quality. Recognizing the shortcomings of the conventional procedures, the Inland Steel Co., in cooperation with Atlas Steels Ltd. and the Freyn Dept. of the Kop- pers Co. Inc., embarked upon a program to evaluate certain aspects of continuous casting in order to determine whether the process could be applied practically to an existing integrated steel plant producing &apos;large tonnages of carbon steels. TO assist in this evaluation a study was carried out in which several types of low carbon steel were continuously cast in an existing machine. It is the purpose of this paper to review some of the results obtained in the casting studies and to interpret the information that was obtained so as to indicate factors that must be considered in assessing operating limitations and plant capacities. Despite the early interest in the continuous casting of steel, the actual application to the steel industry is relatively recent. At present, there are about 25 operating plants casting steel, most of which have been built in the past decade. None of these plants could be classified as large in terms of the tonnages that are being processed by the major integrated steel plants. In contrast to the situation in the steel industry, there has been widespread adoption of the continuous process in the casting of nonferrous alloys, particularly aluminum and copper. As a result, much of the basic information that was required to apply the process to steel was developed in the nonferrous industries. In this respect, a most important contribution was the development of the Junghans2 system, which was initially designed for the casting of nonferrous metals and later applied to the casting of steel. Alternative methods for casting have also been proposed by Babcock and Wilcox Tube Co.,&apos;" the British Iron and Steel Research Association,5 and the Gebruder Bohler A. G.13 Each of these methods is now being used successfully for the casting of special steels in small experimental plants or in modest sized commercial steelworks. The Original Junghans process was first developcd in Germany. Further application of the process has been made by Rossi in other countries.&apos;*&apos; The experi-

Jan 1, 1958

By J. H. Bechtold

Tensile properties of annealed molybdenum were investigated from 1000" to—200°C. In the vicinity of room temperature a well-defined transition in tensile properties occurs. Reduction in area decreases from over 80 pct to 0 pct and, simultaneously, the yield strength increases about 60,000 psi. MOLYBDENUM, tungsten, iron, and many other metals and alloys with the body-centered cubic and hexagonal close-packed crystal structures change from ductile to brittle behavior over some relatively narrow temperature range. The temperature at which this transition in ductility occurs depends on chemical composition, microstructure, and method of testing. When fine grained, completely recrystallized molybdenum of commercial purity is tested in uniaxial tension at a slow strain rate, the transition occurs at slightly below room temperature.&apos; Iron2 and tungsten3 tested under similar conditions become brittle at temperatures close to the boiling point of nitrogen, — 195°C and at about 200°C, respectively. A sharp change in ductility is uncommon in metals with the face-centered cubic crystal structure, however, a relatively sharp transi- tion in notched bar impact properties has been observed below room temperature in a face-centered cubic copper-antimony alloy.4 A transition from ductile to brittle behavior is usually explained by the concepts originally developed by Ludwik,5 and discussed and elaborated on by others including Orowan,6 Hollomon and Jaffe,7 and Gensamer8 In brief, there are two aspects to strength, first the resistance to flow and second the resistance to fracture. Both are functions of temperature, strain, strain rate, stress system, composition, and microstructure. With decreased test temperature the flow stress required to initiate plastic deformation increases more rapidly than the fracture strength and brittle fracture occurs at that temperature where the yield strength equals or exceeds a brittle fracture strength. This investigation was conducted to determine the effects of temperature, strain, and rate of straining on the flow and fracture strengths of molybdenum above, through, and below the ductile-to-brittle transition. Other variables were held constant during testing. This information is believed to show

Jan 1, 1954

By S. W. Nabbs, W. D. Bachman, A. W. Last

A study has been made of wet, autogenous grinding of disseminated copper ores, including testing of a large number of samples from. Kennecott Copper Corp.&apos;s Chino mine. The grindability of the various samples was found to vary over an extremely wide range, even among samples taken from diflerent locations within the same ore body. These variations in grindability can be qualitatively correlated with the composition of the rock and the fracturing and alteration that had occurred. Because of the large-scale nonhomogeneity of disseminated copper ore bodies, extensive and careful testing of autogenous grinding is needed. An accurate correlation of the grinding data from various samples with the geology of the ore body and with mining plans will indicate if variations in grinding mill throughput can be avoided in practice by mixing or blending of mill feed and if, therefore, autogenous grinding can be applied successfully. In the past 15 years, comminution by primary autogenous grinding has been investigated and applied economically in the minerals industry, particularly in iron-ore processing. Successful application of primary grinding is described by A. A. Dor,l.&apos; P. B. Dettmer,334 R. R. Turner, and W. F. McDermott." other authors describing the advantages of primary grinding include H. Hardinge,&apos; R. T. Hukki,&apos; D. S. Coyle" and F. C. Bond,"," to mention only a few. For the past several years, Kennecott Copper Corp.&apos;s Metal Mining Div. Research Center has been investigating primary grinding of disseminated copper ores. Both fully autogenous and semi-autogenous grinding has been explored. Ores from three of Kennecott&apos;s western operating properties and from several development properties have been tested. Host rocks include diabase, schist, silicated and argillaceous limestones, shale, granite porphyry, quartzite, and granodiorite. The object of this paper is to supplement the general knowledge in the field of primary grinding by presenting information gained from the studies with the various disseminated copper ores. Data are presented which show that carefully considered test programs are required to determine the practicality of applying autogenous grinding to a specific mining-beneficiation operation. Particularly this is so if more than one rock type occurs within an ore body or if there are wide variations in the degree of rock alteration within a deposit. Extensive sampling and subsequent testing of the ores within a mine are required if serious pitfalls are to be avoided and good engineering data acquired. We hope that this presentation will stimulate studies to increase the understanding of the fracturing process applicable to large pieces of rock, a factor which is important in autogenous grinding. Test Facilities and Procedures Both pilot-scale and full-scale test facilities were used to investigate primary grinding characteristics of the disseminated copper ores. A 6-ft Hardinge Cascade mill, a 24-ft Hardinge Cascade mill, and a 5-ft Aerofall mill were used in the studies. The Cascade mills were operated wet, while the Aerofall mill was operated both wet and dry. The Cascade mills were operated both for fully autogenous and for semi-autogenous grinding; the Aerofall mill was operated only semi-autogenously. Fully autogenous grinding, as the term is used in this presentation, is defined as the direct grinding of coarsely crushed rock by the action of the rock mass. Semi-autogenous grinding is defined as the grinding of coarsely crushed rock with the rock mass supplemented by a steel ball charge. Most of the test work was done using the 6-ft Cascade mill, operated under fully autogenous grinding conditions. Only limited testing was conducted with the 5-ft Aerofall mill and only one ore was tested using the 24-ft Cascade mill. This presentation is concerned, therefore, primarily with fully autogenous, pilot-scale grinding in the Cascade mill. Fig. 1 presents a diagram of the test facilities used with the 6-ft Cascade mill. Principal test equipment consists of a 6-ft Cascade mill, an 18-in. spiral classifier, an elevator, a 2 x 9-ft belt feeder, a conventional integrating kilowatt-hour meter, and a recording wattmeter. In testing, feed charges, adjusted as to weight, were deposited as evenly as possible on the belt feeder every 15 min. The weight of each charge was adjusted to maintain a mill charge of 27 to 30% of mill volume. The classifier was adjusted to obtain the desired size-consist of the final product, generally at 20% + 100 mesh. After equilibrium was established in the circuit, the feed, mill discharge, classifier sand, and classifier overflow were sampled and their size distributions determined. During the sampling periods, the power drawn by the mill was measured to determine the energy consumed in the reduction of the size consist of the ore solids. Fully Autogenous Pilot Grinding Tests on Various Kennecott Ores Typical test results obtained in the 6-ft Cascade mill with samples from Kennecott&apos;s Ray Mines Div., Chino Mines Div., Utah Copper Div., and a development property designated as Mine A are presented in Table 1. As shown, the ores that were ground most easily in the pilot-scale mill were composite mine samples obtained

Jan 1, 1971

By E. L. Anders

The Mile Six pool is located on the La Brea-Parinas Cullcession of International Petroleum Co., Ltd., in northwestern Peru on the west coast of South America. The reservoir pressure in this pool has been maintained within 200 psi of its initial value throughout its history, and gravity drainage has played an important role in the production behavior. It has now produced 95 per cent of its estimated ultimate recovery. It is estimated that this interesting oil pool will ultimately produce 67 per cent of the initial oil in place and that the resulting residual oil saturation may be as low as 19 per cent of the pore volume (29 per cent of the hydrocarbon pore volume). An evaluation of reservoir rock and fluid characteristics and ultimate oil recovery is presented. INTRODUCTION This study of Mile Six pool was made to evaluate its performance according to latest available information. The production performance of this pool has been discussed in various articles in the past. and the reported behavior has been used as an example for application of computation procedures for gravity drainage depletion&apos; and as an illustration of field behavior under gravity drainage or expanding gas cap drive. There have been wide variations in reported values of initial oil in place, reservoir oil volume factor. connate-water sauration, volume of effective sand, and ultimate recovery because of the paucity of reliable basic data. These various factors have been determined as accurately as practicable with the latest available information, and this evaluation is presented herein. The production history of Mile Six is an excellent example of gravity drainage depleion with effective pressure maintenance by gar injection. GENERAL Mile Six pool was discovered by cable-tool drilling in November. 1927. when well 1996 was completed in the Parinas sand. After slow development with cable tools and sporadic production. the pool was opened to continuous pro(iuction in November. 1933. and develpment was completed with rotary rigs. Pressure maintenance was started in December, 1933. by returning gas to upstructure wells. Most of the development was &apos;completed by 1937, but some additional wells were drilled in the period 1939-1947. and several old wells were deepened. A total of 46 oil and gas wells and 4 dry holes were drilled on approximately 7-acre spacing. Of the producers. 21 are now flowing. 2 are pumping. 44 are gas input wells. 3 are abandoned. I is a gas well shut in. and 15 are shut in because of non-commercial production or high gas-oil ratio. The locations of all wells are shown on the map of Fig. I. Total oil production on Dec. 31. 1952, was 30,867,373 bbl: cumulative gas production was 22,023,777 Mcf; and 26,410,946 Mcf of gas had been returned to the reservoir. These figures do not include oil and gas lost ill a blowout in January. 1940. GEOLOGICAL DESCRIPTION Mile Six pool is located on the northern end of a structural spur projecting from the La Brea-Negritos uplift.&apos; The spur is probably a reflection of a basement structure. It plunges gently to the north, i broken into a complex series of fault blocks. and contain.; the Verdun Alto. Section Sixteen. and Mile Six pools. The Parinas handstone (lower Eocene!. which is the producing formation in Mile Six. occurs at an average depth of 2,200 ft in the pool and dips north and east at from 15&apos; to 20". The pool covers an area of approximately 350 acres. Mile Six is downfaulted about 600 ft from Section Sixteen pool to the soutb. and a major fault forms its western boundarv. The north and east boundaries are formed by the intersection of the sand top with the water-oil contact which occurs at approximately 2.440 ft subsea. An original gas-oil contact probably existed at about 1.875 ft subsea. Fig. 1 presents the latest structural interpretation of the pool. and Fig. 2 is an isopach map showing thickness of the total Parinas formation above the original water-oil contact. The heavy lints of Fig. 1 are contours on the sand top, and the fine lines are contours on the fault planes. This type of straight-line structural map was developed 1)) International&apos;s geologists to reflect structural conditions where the bedding planes dip and have no curvature. &apos;The La Brea-Parinas Concession is highly faulted by normal fault.. The beds are flat wherever exposed. The Parinas formation is approximately 635 ft thick. and it is etimated that 62 percent II the formation is effective sand. The original oil zone was about 565 ft thick. Fig. 211 presents an electric log showing typical Parinas sand development ill Mile Six pool. The Parinas band in Mile Six i. a well-sorted. medium- to-coal-se-grained. cross-bedded sand with minor lenses of shale and small lenses and pockets of pebble conglomerate. The sand grains are subangular to rounded and consist chiefly of quartz with feldspars. biotite hornblende, and augite as accessory minerals. Because of faulting of the Parinas- formation to the east and north of the pool. there is probably l possibility of a significant, natural water drive in Mile six. The faults within the pool. as indicated in Figs. 1 and 2. are of smaller disI,laceInent and seem to act only , partial barriers to fluid movement within the reservoir. RESERVOIR CHARACTERISTICS Core analysis data are available from five wells. The data were obtained from three wells (Nos. 3401. 3586 and 3719) at the time of their completion and from well 1996 when the original liner was sidetracked and the well was deepened ill 1946. Data from well 2779 were obtained in 1943 from old cores taken when the well was deepened in 1934. From these core analyses. the average porosity was estimated to be 22.6 per cent. and the average permeability to dry ail. was estimated to be 780 and Measured productility indices varied from 3.1 to 71.4 B/D per psi differential. Specific productivity indices varied approximately from 0.1 to 0.3 B./D per psi per ft of sand.

Jan 1, 1953

By R. F. Yap, N. Arbiter, C. C. Harris

A fully-instrumented driving mechanism has been constructed to study the power, aerating and solid suspension characteristics of several laboratory flotation machines. Machines operating over normal flotation speed ranges give substantially constant power numbers in liquid systems indicating that they operate close to fully baffled turbulent flow conditions. Owing to lack of geometrical scaling, power numbers for different sizes of cells of the same make are different. Even larger differences occur between cells of different manufacturers. For a given impeller, varying the tank size did not significantly affect the power consumption. Tank geometry and baffling has a slight effect on power consumption with shrouded impellers. For a given impeller speed, suspension height decreases while power increases with increasing mass of solids in suspension. While power consumption is hardly affected by particle size and clearance between the impeller and tank bottom, the suspension height significantly increases as clearance increases and as particle size decreases. Aeration was found to affect not only power but also the suspension characteristics of the machine. For closely sized particles, drastic sedimentation occurred when a critical value of the air flow number was exceeded. The critical air flow number decreased with increasing particle size. This effect was less marked with a wide particle size range. The self-aerating capacity of flotation machines increases with cell size at a given speed for the same impeller-shroud system, but decreases in the presence of frother and solids. Equations have been established for correlating all of the studied variables. Data taken from the literature were also correlated with these equations. The modern mechanical flotation machine has, over a period of 60 years, displaced other designs to become the dominant type. Once the correct chemical environmental conditions have been established, the major requirement, selective mineral-air adherence, is essentially a function of two operating variables — impeller speed and air rate. The special nature of this dependence is such that in the same apparatus, but under different operating conditions, adherence can be either prevented or destroyed. Another aspect of this observation is that flotation machines though differing in detail to a considerable extent can produce similar metallurgical results. It must be concluded that having determined the correct reagent levels, establishing the correct operating conditions are at least as important as machine design. Since about 1960, after 30 years of fairly stable circumstances, manufacturers have been developing new types of machines whose major feature is emphasis on pulp flow characteristics by virtue of new im-peller-stator designs. As far as can be ascertained, these new designs necessitate radical departures from accepted impeller speed-air rate values. Performance data are still awaited. Flotation machine development has been empirical, as is selection of operating conditions. The purpose of the work at Columbia University has been to elucidate the fundamentals of the subject so that the purely mechanical aspects of the flotation process can be understood in hydrodynamic terms.1-6 Hopefully, this might lead to intelligent selection of a particular machine and its operating conditions for a specific ore based on a minimum of testing, or even to new types of flotation machines. The present investigation is the most comprehensive to date.7,8 Earlier work, which was largely exploratory, has been repeated and extended and employes the most accurate measuring techniques available. Additionally, sufficient hydrodynamic data were obtained under flotation conditions to delineate the relevant operating ranges. Attention has been given to scaling in that several geometrically scaled tanks and impellers have been constructed and tested; it has been pointed out elsewhere that undistorted geometrical scaling rarely pertains in flotation machine design.5 This paper is divided into sections dealing with relevant combinations of the three phases: liquid, air and solid. Summaries of the literature have been given in previous publications2-4 and will not be repeated here. Recently, several reviews of mixing have appeared, which can be usefully referenced.9-11 It is of interest to note that flotation is not included

Jan 1, 1970

By Lewis T. Wright

(Pittsburg Meeting, March, 1910.) I HAVE long been aware that ferruginous copper furnace slags if fused in the electric arc will yield metallic iron containing copper, and in order to confirm this knowledge, and to obtain further information of the behavior of such slags in the high temperature and reducing conditions of the electric furnace, a number of samples of slag were fused in an experimental electric furnace. The results obtained, given in Table I., show that a very large amount of metallic iron was produced, and that this iron carried with it practically all the copper, gold, and silver, and more than 50 per cent. of the sulphur, of the original slag. The metallic buttons formed in the electric furnace were clean, hard, but not brittle.

Mar 1, 1910