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By W. H., Bassett

IN January, 1926, the writer began a study of the commercial value of beryllium in its relation to copper. The purpose of the investigation was not to make a mere laboratory study of the characteristics of beryllium-copper alloys, but to determine under mill conditions the behavior of copper when alloyed with beryllium and when other metals were added to such alloys; in other words, it was considered important to know whether the alloy bars could be hot-rolled or cold-worked, and what limits in composition would have to be established for these two methods of working. Consequently, more stress has been placed on the practical application of the alloys in engineering and commercial use than on a discussion of the metallography of the specimens examined, although this part of the matter has not been entirely neglected. Credit should be first given to G. Oesterheld,1 who, in 1916, published the copper-beryllium equilibrium diagram. Fig. 1 has been copied from the original article with the simple substitution of English words. It will be noted from Fig. 1 that alpha solid solutions are formed, up to about 1.5 per cent. Be (10.5 atom.). The freezing-point curve, after falling from 4.2 per cent. Be (23.5 atom.), enters into a very complicated form over the entire beta region. There is a possible compound, Cu2Be, at about 6.5 per cent. Be (32.3 atom.). The pure gamma range extends from 11.2 to 12.2 per cent. Be. (46.5 to 49 atom.), after which the liquidus rises rapidly to 30 per cent. Be. (75 atom.). The delta solution extends from 25 per cent. to an unknown percentage of beryllium. There is a eutectoid point at 575" C., extending from 1.5 to 11.2 per cent. Be., the maximum time interval of which occurs at 6 per cent. Be. Below this line the beta solution is described as breaking up into alpha and gamma. Microscopically, the eutectiferous alloy thus formed closely resembles pearlite, and requires a high magnification for its resolution.

Jan 1, 1927

By J. W. Putman, N. J. Grant, D. S. Bloom

SEVERAL recent determinations of the melting S point of pure chromium have been reported which give values of 1845°C1; 1895°C,² 1930°C,³ 1860°C,' and 1890°C.5 because of this wide spread of values, it appeared desirable to make one additional attempt to obtain a more accurate, reliable figure. bloom and Grantx recently reported a phase transformation in chromium:.--- it was desired to check this, too, in the course of checking the melting point. To accomplish this, a much higher purity chromium was required. Electrolytic chromium containing about 0.5 pct 0 was crushed to a finer size and was then annealed in highly purified, dried hydrogen at 1375°C for 100 hr. This treatment produced chromium with about 0.008 pct 0, 0.002 pct N, and negligible carbon. The balance of the impurities was 0.3 pct Fe, 0.03 pct Si, 0.004 pct S, and less than 0.001 pct Mo. This chromium was melted in a stabilized zirconia crucible under pre-purified argon, using induction heating. Temperature measurements were made with annealed wolfram-molybdenum thermocouples and a Leeds and Northrup Speedomax Recording Potentiometer. The thermocouples were annealed for 1 min in hydrogen at a temperature of about 2400°C. Each leg of the thermocouple was immersed in an ice-water mixture using mechanical connectors to the lead wires. The thermocouple tip was immersed in the molten chromium in a zirconia protection tube which introduces an error of about 3°C as a temperature drop through the walls of the tube. The weight of chromium was about 183 g. The dimensions of the melt in the crucible were about 1.25 in. diam x 2 in. high. The tip of the thermocouple was held about ½ in. from the bottom of the crucible. Two new thermocouples were used with the above set-up giving the results shown in Table I. Since this chromium is purer than that used by Greenaway, Johnstone and McQuillan,' by Carlile et al.,4 and other investigators,²,3 it is believed to be the more accurate. Thermocouple aging effects which are believed responsible for the high value of 1930°C³ were avoided in this work. This value of 1903°C is correct to about ±10°C. The right hand column lists the temperature of the a ? ß transformation on heating and the ß ? a on cooling.3 A sample curve is shown in Fig. 1. The value so determined is 1840°C + 15°C. Fig. 1 gives adequate evidence that there is a transformation in chromium at high temperatures.' References 'H. T. Greenaway, S. T. M. Johnstone, and M. K. McQuillan: High Temperature Thermal Analysis USing the Tungsten-Molybdenum Thermocouple. Journal Inst. Metals (November 1951) 19, p. 109. ²J. W. Putman, R. D. Potter, and N. J. Grant: The Ternary System Chromium-Molybdenum-Iron. Trans. A.S.M. (1951) 43, p. 824. ³D. S. Bloom and N. J. Grant: Chromium-Nickel Phase Diagram. Trans. AIME (1951) 191, p. 1009; Journal of Metals (November 1951). ' S. J. Carlile, J. W. Christian, and W. Hume-Rothery: The Equilibrium Diagram of the System Chromium-Manganese. Journal Inst. Metals (1949) 76, p. 169. 5G. Grube and R. Knabe: Ztsch. Elektrochemie (1936) 42, p. 793.

Jan 1, 1953

By Robert Hoy

If the reader finds that the basic information in a commodity chapter is insufficient, he can consult the appropriate sources in this chapter to find more detailed or more up-to-date information. In these days, technology develops so rapidly that this 4th edition will be somewhat out of date even by the time it is distributed. A comparison of this edition with the 3rd edition (1960) of Industrial Minerals and Rocks will clearly demonstrate how rapidly the scene changes. One of the best sources of new information, of course, is attendance at technical meetings. For example, the papers presented at the national and sectional meetings of AIME usually discuss new developments in the respective divisions of the society. Frequently this information is available in Preprints. In addition some are printed in Mining Engineering and/or the Transactions of the Society of Mining Engineers of AIME. Furthermore, other professional and trade journals contain articles pertinent to the field. A journal introduced in 1967, Industrial Minerals, published by the Metal Bulletin, Ltd., London, is an excellent source of information. The Mining Journal, Ltd., also in London, publishes a weekly journal, a Mining Magazine (monthly), and a Mining Annual Re- view. The latter covers the field from three aspects: (1) by commodities, (2) through technical developments, and (3) geographically. Other useful magazines and periodicals include Engineering and Mining Journal, Pit and Quarry, Rock Products, and World Mining, all published in the United States. In addition many new books related to industrial minerals have been published since the 3rd edition of Industrial Minerals and Rocks. Most of these, of course, are included in the bibliography of each chapter in this volume. Another excellent information source is the proceedings of the Forum on Geology of Industrial Minerals. This group, which held its 11th annual meeting in 1975, is sponsored by a state geological survey or another mineral agency on a rotational basis. The proceedings have been published by the various sponsors and are available as indicated in Table 1. Two major sources of basic industrial mineral and rock data in the United States, and also a good source for many foreign countries, are the U.S. Geological Survey and the U.S. Bureau of Mines. The two agencies publish many reports and maps on a variety of geo- logical and mining subjects. In addition, each agency has an indexed list of all their publications with a free service announcing new publications. (New Publications of the Geological Survey, U.S. Geological Survey, Washington, D.C. 20242) and New Publications-Bureau of Mines, Publications Distribution Branch, U.S. Bureau of Mines, 4800 Forbes Ave., Pittsburgh, Pa. 15213). The U.S. Bureau of Mines (USBM) publishes annually Minerals Yearbooks which provide statistical data on mineral products including production, consumption, imports and exports, as well as information on new developments. Another very useful USBM series is called Mineral Facts and Problems. Editions were published in 1960, 1965, and 1970. Three other major series of publications by the Bureau are Information Circulars, Reports of Investigations, and Mineral Trade Notes. The latter is particularly good for news of foreign developments. A new Professional Paper No. 820 of the U.S. Geological Survey, 1973, summarizes data on the mineral resources of the entire country. The USGS, in cooperation with USBM, other Federal and various state agencies, has also prepared summary reports on mineral and water resources of given areas which include

Jan 1, 1975

By AIME AIME

NO FEATURE of the annual meeting is considered more important at Institute headquarters than the assembly of delegates from the various local sections and divisions. There the president of the Institute and other officials may learn at first hand what the members are thinking and doing in every part of the country, and the delegates, in turn, may find that head- quarters is not a group of more or less cold-blooded New Yorkers whose primary function is to send out annual bills for $15. This year, the section and division delegates required three sessions to thresh out the matters of common interest: Monday morning and afternoon and Thursday afternoon. They were also guests of the Institute at the Directors' dinner on Tuesday night, and at the Directors' meeting afterward.

Jan 1, 1932

By Edwin Hopkins

THE year 1923 started a few days after the Venezuelan Oil Concessions, Ltd., discovered a 140,000-bbl. well at. La Rosa and a well of between 2500 and 5000 bbl. at La Paz, on the opposite side of Lake Maracaibo. These nearly simultaneous events changed, overnight, the general aspect of oil affairs in Venezuela. Up to that time, big things had been expected by the companies then in the district, but many major companies had shown little interest in the country. Within a few weeks the Pure Oil. Co. and the Gulf Oil Corpn. entered the field and acquired large properties. The Texas Co. purchased several concessions and the Standard of California, Atlantic Refining Co., and Mexican Petroleum Co. established offices. Representatives of many other companies visited the district during the first few months of the year. The sudden influx of buyers naturally caused a great rise in prices and this, together with overproduction in the United States, doubtless caused the slowing up of concession transfers in the latter part of the year. The following property transfers occurred: (1) The Gulf Oil Corpn. contract with the Maracaibo Oil Exploration Corpn., whereby the Gulf acquired the right to select 100,000 acres from the Maracaibo's zones. (2) The Gulf Co. purchase of one-quarter interest in seven concessions of the New England Oil Corpn., Ltd. (3) The Gulf Oil Corpn. purchase of several concessions of Kunhardt and others in the Perija district. (4) The Gulf Oil Corpn. purchase of certain portions of the one-kilometer Lake zone that were not covered by parcels or Government reserves (namely the "sobrantes"). (5) Pure Oil Co. purchase of all Government reserves turned back by Maracaibo Oil Exploration Corpn. in the districts of Mara and Miranda. (6) Standard Oil Co.: of New Jersey deal with the British Controlled Oilfields, Ltd., for control of approxi-mately the eastern third of the .district of Buchivacoa, state of Falcon. (7) Royal Dutch deal with the British Controlled Oilfields, Ltd., for the control of the central third of the district of Buchivacoa, Falcon. (8) The Texas Co. purchase of several concessions in Perija and one west of Mene Grande on the east side of Lake Maracaibo. (9) Purchase by the British Equatorial Oil Co., Ltd., of Goverment reserves corresponding to certain Creole Syndicate parcels under the margin of Lake Maracaibo near La Paz. (10) The Lago Petroleum Co. acquired a concession on all of Lake Maracaibo except a 1-Km. strip along the shore.

Jan 3, 1924

By William Hume-Rothery

MR. CHAIRMAN, LADIES AND GENTLEMEN: I need not say how much I appreciate the honor of being asked to lecture to you, and how much I would thank you for your kind invitation. It is encouraging to feel that the abnormal restrictions of the war have been relaxed sufficiently to allow a free exchange of scientists between our two countries, and I hope that some of you will be persuaded to go to England, and to visit us at Oxford, so that I may repay a little of the kindness I have received from you. As this is one of the first lectures since the end of the war, I have thought it well to describe some of the advances in the theory of alloys which were made in the years between the two World Wars. From the point of view of theoretical science, these years have been of outstanding interest in the history of metallurgy. They have been years in which the development of new and more accurate experimental methods has led to the revelation of many new facts. At the same time, the theoretical developments have enabled some of these facts to be viewed as parts of a general scheme, and we may say that some of the foundations of metallurgical science have been laid. This work was naturally stopped by the Second World War, and it can therefore be reviewed as one definite stage in the development of our Science. To illustrate the new advances, I shall deal mainly with the alloys of copper and silver, since these have revealed many of the general principles. SOLID SOLUTION At the beginning of our period, the first steps in X-ray crystal analysis had been taken, and copper had been found to crystallize in the face-centered cubic structure (Fig I). The determination of this structure naturally was of immense importance in the understanding of our subject, because it meant that we were at last in a position to appreciate the underlying structure out of which the crystal of copper was built. The earlier science of metallography had shown that in many alloys of copper the addition of a second metal in not too large proportions resulted in the formation of a homogeneous alloy which was regarded as a solid solution of the one metal in copper. Fig 2, for example, shows the so-called equilibrium diagram of the copper-zinc alloys, and here you will see that there is a solid solution of zinc in copper extending to something of the order 35 to 40 at. pct zinc.

Jan 1, 1947

By G. R. Hodgson, M. P. Lebourg

The introduction in the field of a new type well completion called for the setting of tubing open-ended in the well before perforating the casing. This paper describes a new perforating tool of the shaped charge expendable type, small enough to pass through tubing and powerful enough to perforate the casing. The perforations are produced at an angle and are large enough for optimum production. Performance of this tool in targets and under various well conditions is described. Very often no lifting equipment will be available at the well. In some cases, pressure will exist in the well at the time of the perforating operation (workover wells or multiple trip perforation) ; therefore, new equipment and new technique for the perforating operation were devised. This paper describes this equipment and technique, particularly casing collar recording, sheave support, and cable pull-down device. this last item being necessary for wells under pressure. Results obtained with this tool in the field are given. INTRODUCTION One of the key requirements for the introduction in the field of a new method of permanent well completion was the development of a new perforating method involving the use of a perforating gun small enough to go through tubing and with enough penetrating power to perforate the casing satisfactorily. The equipment described in this paper was basically designed to go through open-ended two-in. tubing and to perforate 5 1/2 in. casing. The equipment is illustrated in accompanying figures. NEW COMPLETION METHOD With the new permanent type well completion, the production string of casing is run and cemented through the potential producing zone. Open-ended tubing is -then run into the well and used to replace the drilling fluid with oil or water. The amount of the oil or water "cushion" can be varied according to the expected bottom hole pressure. Thus, if desired, the hydrostatic head can be greater, equal to, or less than the expected pressure within the zone to be perforated. Mud having been displaced, the tubing is -then positioned so that the end is above the zone to be perforated. The Christmas tree and flow lines are installed and tested. The drilling rig can now be removed from the well since it is not necessary for the perforating operation, thus resulting in a saving in rig tme. The perforating equipment is then moved to the well and the gun lowered through the tubing. After the gun passes out of the open end of the tubing, the depth measurements are correlated with casing collars and the gun placed opposite the zone to be perforated. Upon firing, the gun body is shattered and falls to the bottom of the well. Since the lubricator has been closed before firing, it is possible to withdraw the casing collar locator and head and then open the well immediately to the tanks. DESCRIPTION OF GUN An investigation of two basic types of Perforators, namely a bullet perforator and a shaped charge gun, was undertaken towards the development of a gun to meet the aforementioned requirements. Preliminary tests on various bullet perforator designs within the diameter limitations did not give results encouraging enough to warrant further study. Somewhat better results were obtained by using conventional shaped charges; but, as in the case of the bullet types, the necessarily small overall diameter proved to be a severe limitation and resulted in insufficient penetration. A shaped charge employing a new design was developed which gave excellent penetration. These shaped charges were designed to produce a large hole directed upward at a 45" angle. In order to obtain the maximum space possible for these charges, it was decided to use an expendable carrier made of drillable material, usually aluminum, which would shatter at the time of firing, leaving only harmless fragments at the bottom of the hole. The fixed spacing is five shots per ft. wit11

Jan 1, 1952

By Donald E. Meyer

High current-low voltage EB-gun evaporation in an oil-free ultra-high vacuum system was found to be necessary, though not sufficient, for stability (300°C, 106 v per on) of aluminium gate MOSFET's and MOS capacitors not stabilized by a phosphorous glaze. five characteristics of the equipment used: 1) Vacuum purification of the aluminum charge, 2) Ionization of the evaporant by the electron beam, 3) X-ray formation, 4) Residual gases during evaporation, and 5) Metal film structure were studied as Possibly significant in MOS fabrication. EVAPORATION of contact metals common to the semiconductor industry historically has been accomplished with oil diffusion pump systems and various resistance heated evaporant sources as dictated by the type of metal evaporated. To meet a need for greater reliability of semiconductor devices, other metallization methods were developed. A good example would be application of the moly-gold contact system to integrated circuits with deposition by RF or triode sputtering.' More recently, fabrication of stable metal-oxide-silicon devices and circuits has put new demands on metallization. The purity of the thin metal films composing MOS structures is critical, particularly at the metal-oxide interface, and ultra-high vacuum metallization using sputter-ion pumping and electron beam gun (EB-gun) evaporation are well suited for the task. At this laboratory aluminum has been the most common contact-gate metal for both MOS capacitors and MOSFET's. In the earliest work with MOS capacitors, aluminum was evaporated from wetted tungsten filaments using both diffusion pump and ion pump vacuum systems. In spite of clean oxide techniques these capacitors were unstable under bias-tempera-ture stressing. Only after a switch to EB evaporation of aluminum were stable capacitors produced. Using the same techniques it was possible to make MOSFET's with equivalent stability. Stability data for a discrete MOSFET is shown in Fig. 1. This is a "clean" oxide gate (no phosphorus stabilization or no etch back of a thicker gate) having a thickness of lOOO? thermally grown on the (111) plane. Gate length after diffusion was 0.24 mils, and the devices were hermetically sealed. Stressing conditions were 300°C and 106 v per cm applied alternately as a positive and negative field for 10 min, 50 min, and 4 hr for a total stress time of 10 hr. An initial shift in turn-on voltage of 0.1 v was detected for 10 min of positive bias. All evidence at this laboratory indicated that while EB-gun evaporation of ultra-high purity aluminum was not sufficient for 300°C stability, it did seem to be necessary. There may well then be something inherent in the EB-gun deposition used which enhanced stability, and probably no single factor existed but rather a series of factors. It is the purpose of this paper to report on some of the investigations carried out to learn more about EB-gun evaporation in ultra-high vacuum systems. EXPERIMENTAL DESCRIPTION The EB-gun was self accelerated, had a maximum power rating of 10 kw, and used a water-cooled copper crucible able to hold a 20-g aluminum charge. The electron beam was bent 180 deg and focused by an electromagnet which also provided movement of the beam across the crucible. Normal power conditions in this work were 9 kv and 300 to 600 mamp. The gun can be described as high-cur rent/low-voltage and was quite different in its mechanism of operation from EB-guns with much higher acceleration potentials. An oil-free vacuum system capable of 5 x 10- l0torr, a quartz crystal rate and thickness monitor and a quadruple mass spectrometer completed the evaporation system, Fig. 2. A typical evaporation cycle consisted of a 3 to 4 hr pumpdown to the upper l0-9 range and evaporation at l0? per sec with the pressure in the bell jar not rising above 1 x 10"7 torr. Thickness control was 5 pct or less and could be automatically monitored and controlled. Five phenomena associated with the EB evaporation and considered as possible contributors to Ma performance included a purification effect, ionization of evaporating aluminum, X-rays, constitution of vacuum ambient during evaporation, and film structure dependence upon evaporation rate. These phenomena are now discussed. Vacuum Purification. The design of the EB-gun permitted purification of the aluminum charge by vacuum outgassing. Particular features included an efficiently water-cooled copper hearth with a capacity of over 20 g of aluminum and the capability for sweeping the beam across the charge. Such capacity meant that aluminum had to be added only after about every fifth evaporation. A new charge was not required each evaporation as is necessary with filament evaporation. An oxide "scum" which appeared on the charge could be completely cleared from the top hemisphere of the charge by sweeping with the beam prior to opening the shutter. An indication of the purifying effect was obtained by a series of analytical measurements on incoming aluminum, after melting but with little vacuum out-gassing, after 30 min outgassing, and the evaporated film itself. Either a solids (spark source) mass spectrometer or an emission spectrometer were used for analyzing the aluminum charge. Analysis of the evapo-

Jan 1, 1970

By F. Keller, A. H. Geisler

Some of the important changes that take place in the structure of aluminum alloys are largely submicroscopic in character. This is especially true of the changes that accompany age-hardening and recrystallization. Although improved metallographic practices have been helpful in indicating some of these changes indirectly, results are limited by the resolving power of optical microscope lenses. The electron microscope, however, provides a new and important means for investigating the fine structure of metals in a range not possible heretofore. It is anticipated that this microscope will yield new and useful information to metallurgists when suitable techniques are developed to utilize its very high resolving power. Several unique methods have been devised to permit the examination of the structure of opaque samples by the electron microscope. These are all based on the principle of producing a very thin film that represents the prepared surface of the opaque metal sample, which can be examined in the transmission microscope; however, the available methods fall into three categories, depending on the manner in which the film is obtained. With the oxide-film method developed by Mahl3-17 a very thin surface layer of the metallographic sample is converted into oxide by a thermal, chemical or anodic treatment. After removal from the metal sample by one of the special techniques described by Evans,19 this oxide film is examined in the electron microscope, and is found to portray the structure of the original metal surface. Films formed on aluminum,8,17 nickel,7 iron 3,8,9 and a nickel-beryllium alloy" by heating; films formed on iron 8.9 by chemical action; and films formed on aluminum3-16 by anodic oxidation, have been examined. The other two are more recent methods developed principally in this country; they consist in making the thin film in the form of a mold or replica of the surface contour of an etched sample. With the negative replica method the thin film is made directly on the sample; with the positive replica method it is made on a negative reproduction of the sample. With both methods, variations in the contour of the metal sample, caused mainly by etching, produce variations in the thickness of the surface replica. Because of the direct dependence of the amount of scattering of the illuminating electrons upon the thickness of the film penetrated, only the variations in thickness of the replica are responsible for tones in the electron image. Negative replicas are made by forming a thin film of some suitable material directly on the polished and etched metal sample, and derive their name from the fact that after removal from the sample they have the high and low points in the sample reversed, as shown in Fig. I. Nega-

Jan 1, 1944

By H. Kenworthy, M. M. Fine

The progress made to date in the mineral dressing of complex Arkansas titanium ores is reported in this paper. Concentrates of rutile, a dioxide of titanium, were produced by treating a submarginal ore from the Magnet Cove Rutile Co., Inc., Magnet, Ark. The rutile recovery at present is 45 to 50 pct of the total TiO2 with the possibility of increased recovery with additional research. The work reported herein is part of a general study which will later include results of investigation of other titanium ore bodies in the Magnet, Ark., area. The fragile character of the rutile minerals, the softness of the gangue, the occurrence of pyrite and leucoxene, and the considerable proportion of extremely small size rutile in the presence of montmorillonite- and illite- type clays in the Magnet Cove open-pit mine are the important factors in the mineral dressing of this submarginal rutile ore.

Jan 1, 1949

I;. D. Godshall, Everett, Wash. (communication to the Secretary) : In Mr. Morse's interesting paper several statements occur which seem to require correction and comment. This is the more appropriate, since Mr. Morse has mentioned me by name, and has cited my "Review of the Russell Process,"* so that silence on my part might be taken as indicating an assent which I cannot give. On the first page of his paper Mr. Morse says that the " goingback " of chlorination was " the only difficulty encountered at Aspen," and adds that he has " never seen any explanation " of the cause. The plain inference is that he now fills this complete

Jan 1, 1896

NEW MEMBERS The following list comprises the names of those persons who became members during the period of May 10, 1918, to June 10, 1918. ABEEL, GEORGE H., JR., Cons. Min. Engr., .4111 Lafayette Ave., St. Louis, Mo. ALLEN, CARL A Metal Min. Engr., U. S. Bureau of Mines, Butte, Mont. BECKER P. FRANK Engr., Lightner Min. Co., 35 Nassau St., New York, N. Y. BOCK, JAMES H., Steam Shovel Foreman, Chino Copper Co., Santa Rita, N. M. CARRON, FRANK X., Civ. and Min. Engr Rock Springs, Wyo. CROWE, THOMAS B., Mill Supt., Portland Mill, Portland Gold Min. Co., Victor, Colo. DOBSON, PERCY GRENSIDE, Min. Engr. and Geol., Crow's Nest Pass Coal Co., Fernie B. C., Canada. ESTABROOK, W. H., Capt., 3d Bat. 20th Engineers, A. E. F., Care postmaster, N.Y. FRASER, 0. B. J., Engr., International Nickel Co. of Canada, Ltd., Port Colborne, Ont., Canada. GARRIDO,. MANUEL F., Min. Engr 109 W. Myrtle St., San Antonio, Tex. GRODSKY, VLADIMIR ALEXANDROVITCH, Cons. Engr., Motor Products Corpn., Detroit, Mich.

Jan 7, 1918

NEW MEMBERS The following list comprises the names of those persons who became members during the period Dec. 10, 1916 to Dec. 31, 1916. BOWMAN, Joseph V., Chem., Andes Copper Mining Co., Chanaral, Chile, South America. CALDER, NORMAN L., Min. Geol., Cia. Minera y de Fomento, Watkins, Fomento Prov. de Santa Clara., Cuba. CONRADS, RALPH A., Met. Engr., Magna Plant, Utah Copper Co., Garfield, Utah. FARR, T. H. POWERS, JR. Asst. Assayer, Argonaut Mining Coy Jackson, Cal HAURY, PETER S., Min. Engr ...Alta Loma, Cal. HOULE, ARTHUR, Supt., Shattuck-Arizona Copper Co., Box 2009, Bisbee, Ariz. LEIB, VICTOR E?, Min. Engr 4204 Ave. D, Austin, Tex. LINDSLEY, THAYER, Min. Engr 82 Beaver St.,. New York, N. Y. POTTER, OCHA Supt., Superior Copper Co., Houghton, Mich. ROCCA, BERNARD T.; Engr., Bluebell Mine, Cons. Arizona Smelting Co., Mayer, Ariz. SAFFOLD, RAY P P.'0. Box 436, Douglas, Ariz. THOMS, JAMES EZRA, Asst. Chief, Milling, -Roasting, Acid Depts., Mineral Point Zinc. Co., Depue, Ill. TOMITA, HARUYOSHI, Met. Engr., Mitsubishi Co., Osaruzawa Mine, Akita-ken, Japan.

Jan 2, 1917

By D. L. Rainey, E. R. Goter, W. R. Hudspeth

THE area in which spodumene-bearing pegmatites occur extends from Gaffney, S. C., in a northerly direction to Lincolnton, N. C., a distance of about 16 miles. The zone averages 2 miles in width. Interest in this area was first aroused by the discovery of small amounts of cassiterite in the peg-matites and in greissen which occurs on the walls of some of the pegmatites. Attempts were made from 1880 into the 1920's to mine and concentrate cas-siterite, but there were no successful operations. In 1935 L. M. Williams became interested in the area and began prospecting by trenching and sinking several small shafts. He gradually gained control of a considerable acreage south of the city of Kings Mountain, N. C. Mr. Williams states that he produced some ore from a shaft which he shipped to the Maywood Chemical Co. in the late 1930's. In 1937 G. H. Chambers of the Foote Mineral Co. visited the area and examined several properties, but the lithium market was too small to support the necessary concentrating plant. Early in World War II the Solvay Process Co., encouraged by various federal agencies, acquired the Williams properties and leases and started a drilling program to develop reserves for spodumene mining. A study of this area was also made under T. L. Kesler by the U. S. Department of the Interior Geological Survey. Starting in 1942 a concentrating plant, water supply dams, and shops and other buildings were constructed. The Superior Stone Co., a neighboring crushed stone operator, was awarded a contract to mine and crush the pegmatite ore. Late in 1943 the plant started operations, which were continued until February 1946. A drop in demand for lithium chemicals forced it to close and remain closed for several years. In 1948 the Foote Mineral Co. became interested in assuring itself a source of lithium ore on the North American continent, to be used in the production of lithium ore chemicals, and inspected properties in Canada, South Dakota, and North Carolina. The North Carolina deposits were the most promising. In the fall of 1950 the company leased the Solvay interests with option to buy and acquired additional properties. Renovation of the mill and preparation of the quarry for mining was begun in earnest in January 1951. A new crushing plant was built and construction started in July 1951. The flotation process used was developed in the North Carolina State Minerals Research Laboratory located at Asheville, N. C. Foote is now in the process of expanding its production. The crushing plant is being revamped and much of the old milling equipment purchased from Solvay will be replaced by new. Mining equipment of suitable capacity has been received and is in use. The frontispiece is a general view of the mill. The orebodies consist of pegmatite dikes composed of fine-grained albite and quartz, with varying amounts of mica and spodumene. The latter may amount to as much as 50 pct of the rock, but the overall average is about 15 to 20 pct. Tin, columbite-tantalite, beryl, and other valuable minerals are present in varying small amounts. These dikes, which intruded into the Roan Gneiss underlying most of the Piedmont area, strike approximately N 30 E and dip about 85" to the west. The gneiss has the same strike but dips about 70" west. The dikes lie in a belt extending from Lin-colnton, N. C., to Gaffney, S. C., and passing through

Jan 1, 1954

By J. Burns Read, Charles H. Fulton

A previous article1 by the authors contained a general description of the new roasting furnace herein described but it did not go into detail as to the metallurgical behavior or the results obtained. Believing that such information would be of great value, they have elaborated on the subject and have given many unpublished details. The furnace described applies the principle of roasting finely divided zinc-sulfide ores, now produced in large quantity by the flotation process, in gaseous suspension; that is, the ore particles are carried, in suspension, in a current of air and gaseous products of the roast. The relatively great fineness of flotation concentrate presents difficulties and problems of roasting in furnaces of the ordinary type; the fine ore is forwarded through the furnace in the form of a shallow bed and its very fineness leads to dense impervious bedding which prevents oxygen from reaching the interior of the bed, thus unduly lengthening the time of roasting and preventing the elimination of the last of the sulfur. The fineness of the concentrate, normally, should lead to a rapid and complete roast, for the speed of roasting is a function of the surface exposed to oxygen, which surface is greatest, per unit of weight, in very fine material. The difficulty in bed roasting is to get the oxygen to the particle. If the fine ore, during the roasting, could be freely suspended in oxidizing gases, full advantage could be taken of the great surface conferred by its fineness. This fundamental idea, of course, is not new, for the Stedtefelt furnace, familiar to the older metallurgists, is an example of it; but the manner in which this is accomplished may be new. The numerous efforts to roast in gaseous suspension show that the idea is attractive; in fact, an analysis would indicate that it is the most reason-

Jan 1, 1925

By D. L., Hayes

THE concentration of zinc ore in Wisconsin is a comparatively simple process, although it presents problems that must be overcome in an efficient manner in such a way that installation and operating costs are low. As the ore deposits are small, the first cost of the concentrating plant must be low; while the low margin of profit makes it necessary to have the minimum operating costs. The original mills were copied from those of the Joplin district, as most of them were built and operated by Joplin millmen. These served the purpose well; they made a clean concentrate, which was the chief requirement at that time, as most 'of the mines were' considerably 'richer than the average at the present time, and wages and supplies were also considerably lower. ' The apparatus used at present has changed very little in principle. . The grizzly opening has gradually been increased to 12 in. and sometimes no grizzly 'is used. The crusher, gradually grew in size, the largest crusher has -an opening of about 24 by 13 in. and a 7/8-in. throw on the. eccentric shaft.

Jan 1, 1921

By W. A. Ver Wiebe

The year 1940 was singularly unmarked by sensational developments in Kansas. Routine operations were carried on in a systematic, orderly fashion and the efforts of oil producers were concentrated on extending known fields. In Kansas an arbitrary yardstick for wildcats has been set up. A well drilled mile or more from a known pool or well is now considered a wildcat. A "rank wildcat" is one that is drilled at least 2 miles from any known producer. During 1940, rank wildcats resulted in the completion of 116 test wells, among which 16 were successful in finding new oil pools and the remaining I00 were dry holes. The ratio of successful wells to dry holes, therefore, was approximately I:6. During the year, 1890 wells were completed in eastern and western Kansas. This figure is somewhat lower than that given in several trade journals, because it does not include wells that were deepened or wells that were recompleted in a different geological horizon. About three fourths of these (1423) were completed as commercial oil wells (I220 in western and 203 in eastern Kansas). The commercial gas wells completed number 58 of which 10 are in eastern Kansas and 48 in western Kansas. Of the remzining completions 147 are dry holes in eastern and 262 are dry holes in western Kansas. Based on daily potential capacity, the new discoveries of the year account for a cumulative initial production of 46,000 bbl. in eastern and 2,128,000 bbl. in western Kansas. The state of Kansas attained a new peak in production, with the total of 66,245,000 bbl. for the year 1940, the number of contributing wells being 20,779. Thus the increase over 1939, when about 58 million barrels was produced, is considerable. The previous peak occurred in 1937, when 70,761,000 bbl. was marketed. In another still earlier peak, in 1917, slightly more than 45,000,000 bbl. was produced and sold. The production of gas probably reached a new peak also during 1940, with its total of 85 1/2 billion cubic feet. Between the peak of the year 1908, when over 80 billion cubic feet was produced, and that of 1940, the production dropped to a low point of 16 billion cubic feet in the year 1921. The number of test wells drilled was larger than in 1939; that is, 1890 compared with 1458. The first peak was reached in 1904, when 2782 wells were drilled. The number dropped off rapidly, to 368 three years later, but rose to the second and highest peak in 1918, when 4671 test wells were completed. In the period between 1904 and 1912 more gas wells were completed than oil wells. Between the high peak of completions in 1918 and somewhat lower peak of 1937, the low point was reached during 1931, with the completion of only 470 test wells. In the number of new pools discovered, Kansas again ranks high among the states. The exact number depends somewhat upon the interpretation of a "new" area— whether it should be called a new pool or a long extension of an old pool. Unfortunately, the matter of securing the right kind of production allowable also enters into this question. Often the decision regarding a new pool cannot be made until other wells

Jan 1, 1941

By W. A. Ver Wiebe

The year 1940 was singularly unmarked by sensational developments in Kansas. Routine operations were carried on in a systematic, orderly fashion and the efforts of oil producers were concentrated on extending known fields. In Kansas an arbitrary yardstick for wildcats has been set up. A well drilled mile or more from a known pool or well is now considered a wildcat. A "rank wildcat" is one that is drilled at least 2 miles from any known producer. During 1940, rank wildcats resulted in the completion of 116 test wells, among which 16 were successful in finding new oil pools and the remaining I00 were dry holes. The ratio of successful wells to dry holes, therefore, was approximately I:6. During the year, 1890 wells were completed in eastern and western Kansas. This figure is somewhat lower than that given in several trade journals, because it does not include wells that were deepened or wells that were recompleted in a different geological horizon. About three fourths of these (1423) were completed as commercial oil wells (I220 in western and 203 in eastern Kansas). The commercial gas wells completed number 58 of which 10 are in eastern Kansas and 48 in western Kansas. Of the remzining completions 147 are dry holes in eastern and 262 are dry holes in western Kansas. Based on daily potential capacity, the new discoveries of the year account for a cumulative initial production of 46,000 bbl. in eastern and 2,128,000 bbl. in western Kansas. The state of Kansas attained a new peak in production, with the total of 66,245,000 bbl. for the year 1940, the number of contributing wells being 20,779. Thus the increase over 1939, when about 58 million barrels was produced, is considerable. The previous peak occurred in 1937, when 70,761,000 bbl. was marketed. In another still earlier peak, in 1917, slightly more than 45,000,000 bbl. was produced and sold. The production of gas probably reached a new peak also during 1940, with its total of 85 1/2 billion cubic feet. Between the peak of the year 1908, when over 80 billion cubic feet was produced, and that of 1940, the production dropped to a low point of 16 billion cubic feet in the year 1921. The number of test wells drilled was larger than in 1939; that is, 1890 compared with 1458. The first peak was reached in 1904, when 2782 wells were drilled. The number dropped off rapidly, to 368 three years later, but rose to the second and highest peak in 1918, when 4671 test wells were completed. In the period between 1904 and 1912 more gas wells were completed than oil wells. Between the high peak of completions in 1918 and somewhat lower peak of 1937, the low point was reached during 1931, with the completion of only 470 test wells. In the number of new pools discovered, Kansas again ranks high among the states. The exact number depends somewhat upon the interpretation of a "new" area— whether it should be called a new pool or a long extension of an old pool. Unfortunately, the matter of securing the right kind of production allowable also enters into this question. Often the decision regarding a new pool cannot be made until other wells

Jan 1, 1941

A tentative plan for the Colorado Meeting has been formulated as follows: One day will be spent at Denver, one day at Colorado Springs, one day at Cripple Creek, a trip by automobile to the top of Pike's Peak, one day at Pueblo, one day at Leadville. All the principal mines and mills of the districts mentioned will be visited, including the gold mines in Cripple Creek, the lead, zinc, and steel works. of Pueblo, the production of ferro-molybdenum by electric furnace at Leadville, etc. Special arrangements are being made for the social entertainment of ladies at all points; one evening at Colorado Springs will be devoted to a reception and dance, and the usual dinner will he given on another evening. The following papers have already been accepted for the Colorado Meeting, and some have already been published: Fireproofing Mine Shafts by the Anaconda Copper Mining Co. By E. M. Norris. (March Bulletin.) Air Blasts in the Kolar Gold Field, India. By E. S. Moore. (March Bulletin.) The Use of Coal in Pulverized Form. By H. R. Collins. (April Bulletin.) Coal Mining in Washington. By F. A. Hill. (April Bulletin.) Carbocoal. By C. T. Malcolmson. (May Bulletin.) Gaging and Storage of Oil in the Mid-continent Field. By O. U. Bradley. (March Bulletin.) An Interpretation of the So-called Paraffin Dirt of the Gulf Coast Oil Fields. By A. D. Brokaw. (April Bulletin.) The Theory of Volcanic Origin of Salt Domes. By. E. DeGolyer. (May Bulletin.)

Jan 5, 1918

By D. E. Hawk, R. F. Burdyn, F. D. Patchen

Earlier work on a mud separator for barite recovery is extended to the design and construct ion of a rugged field unit. Problems associated with scale-up for field use include the me of dilution water and its effect on capacity, power requirements and pressures developed. Equations for these quantities are derived and applied in maximizing the beneficial effects of dilution and minimizing the power required. Tests on the full-size rotor show that its performance can be predicted by theory. The completed unit is compact and lighter than current decanting types. Its capacity is from 10 to 22 gal/min with corresponding barite recovery efficiencies of 92 to 86 per cent. INTRODUC'TION In an earlier publication a new type of centrifugal device was described for solid-liquid separations.l In that paper an operating equation was derived, and its validity demonstrated in laboratory scale experimentation. Some of the features apparent in this new device seem particularly well suited to the conservation of barite in field drilling-mud systems, hence the development was extended to the design and construction of a field unit. In the present paper the design problems associated with scale-up are considered. A full-scale, rugged self-contained field unit is described, and test results discussed which verify that the performance of the large field unit can be described by a simple operating equation. PRINCIPLE OF OPERATION OF SEPARATOR In principle, the new device is simply a perforated cylinder rotating within a body of fluid which is contained within a stationary case, as in Fig. 1. The frictional drag generated by the rotating cylinder causes part of the fluid to rotate. At the surface of the cylinder, assuming no slip occurs, the angular velocity of fluid and of the cylinder are identical. If there are suspended particles present of greater density than the fluid, the centrifugal force acting on these particles causes them to move radially away from the cylinder at some velocity vp . Where the Stokes settling equation holds, this velocity may be expressed as:2 d2 ?p rw2 If the case is provided with openings at both ends, a suspension can be pumped in at one end at a fixed rate. Part of the suspension can then be removed at a fixed rate at the other end of the case as underflow, and the remainder forced through the perforations and hollow shaft of the rotor to appear as effluent, also at a fixed rate. The radial component of the flow velocity of this stream as it reaches the rotor surface, is simply effluent flow rate divided by cylindrical surface area: Because up is a function of particle size, for some particular particle size, the velocities vp and v, will be equal in magnitude. This is defined as the critical particle size and represents the size above which all particles appear in the underflow and below which all particles appear in the effluent. For this equilibrium condition at the rotor surface, Eqs. 1 and 2 combined give

Jan 1, 1966