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The recent dedication of Magma Copper Co.'s San Manuel, Ariz., electrolytic copper refinery and rod casting plant marks the culmination of a three year, $250 million expansion-modernization program. The new facilities will eventually permit an annual production of 200,000 tons of marketable copper for direct sale to fabricators. The Newmont Mining Corp. subsidiary will produce and market continuous cast 5/16 in. copper redraw rod, full plate cathode copper and sheared cathode plate under its own brand name. Among the four largest in the nation, the new refinery and plant, was built at a cost of $34 million and will be fully automated. In addition, all materials used in the plant will be recycled and no waste, discard or emissions will occur.

Jan 3, 1972

All the Technical PUBlications and Preprints published in 1932 are available at Institute headquarters. They are also on file in public, university and technical libraries and, when so indicated in the list, may be found in the Transactions. Copies of the Technical Publications have been mailed to those members of the Institute who are registered in the different classes: A-Metal Mining; B-Milling and Concentration; C-Iron and Steel Division; D-Nonferrous Metallurgy; E-Insti-tute of Metals Division; F-Coal Division; G-Petroleum Division; H-Nonmetallic Minerals; I-Mining Geology; K-Mining Administration; L-Geophysical Prospecting. Other members may obtain copies by writing to the Secretary. Copies of Preprints may also be obtained from the Secretary's office. Additional copies are sold at the rate of 1 cent per page; minimum charge, 25 cents. Nonmembers may purchase the papers at the prices mentioned. Metal Mining Technical Publi- Title Author Meeting Trans. cation Volume No. and Page* 484-A.45 Propeller Type Mine Fan at Moose A. S. Richardson New York 102, 88. 95 F.52 Shaft. Butte. Montana (13) Feb.. 1932 487-A.46 Progress in the Improvement of Max H. Barber New York. Methods and Equipment at Feb., 1932 Open-pit Iron Mines on the Lake Superior Iron Ranges (9) Pre. Sand Filling through Pipes and Lucien Eaton New York, 102, 33, 41 Boreholes (9) Feb., 1932 Milling And Concentration 445-B.37 Soap Flotation of the Nomulfides Will H. Coghill New York. H.19 (18) J. Bruce Clemmer Feb., 1932 461-B.38 Principles of Flotation—An Experi- I. W. Wark New York. mental Study of the Effect of A. B. Cox Feb.. 1932 Xanthates on Contact Angles at Mineral Surfaces (48) Iron and Steel Division 447-C.81 Electrochemical Potentials of Nitri- Shun-ichi Satoh New York, fied Steels (31) Feb.. 1932 450-C.82 Reaistanoe of Iron-aluminum Alloya N. 9. Ziegler New York. 100, 267. 670 E.143 to Oxidation at High Tempera- Feb., 1932 tures (8) 451-C.83 Pressure Welding of Low-carbon C. H. Austin New York. Steela with Theoretical Con- W. S. Jeffries Feb.. 1932 siderations on the Mechanism of Such Welding (42) 453-C.84 Inclusions—Tbeir Effect, Solubility C.E.Sims New York, 100, 154, 176 and Control in Cast Steel (24) 0. A. Lillieqvist Feb., 1932

Jan 1, 1932

By Arthur Hockman, Howard W. Jaffe, Howard F. Carl

THE problem of establishing practical techniques for evaluating natural corundum ores arose from the desire to improve the existing purchase specifications for crystal corundum procured by the Federal Government for stockpiling. Such purchase specifications had been developed for a large number of products, including minerals and ores considered to be critical and strategic because of the country's dependence on foreign sources of supply. It will be apparent to anyone considering the subject of purchase specifications that the determination of whether or not a submittal meets the specifications is a prime consideration. Consequently satisfactory specifications for minerals should not only incorporate physical, chemical, and mineralogical requirements that are practical but should also establish the means by which both buyer and seller can be assured that materials meet stated requirements.

Jan 4, 1954

By P. A. Beck

ACCORDING to the traditional definition,1 re-x crystallization is a process taking place upon annealing of cold worked metals, characterized by the appearance of new strain-free grains, growing at the expense of the cold worked grains until ultimately the new crystals completely replace the cold worked structure. In metals like brass this process was observed long ago to take place simultaneously with the return of the mechanical properties to those characteristic of well annealed material. The above definition implicitly assumes that the matrix in which the new grains are growing is essentially still in the cold worked condition at the time it is absorbed by the new grains, i.e., that the energy stored in the metal during cold working is not greatly decreased by recovery, prior to recrystallization. Accordingly, the bulk of this energy is assumed to serve as the driving force for the process of recrystallization. Recently, a great deal of evidence accumulated, indicating that the traditional concept may be considerably in error. Suzuki' found that by far the largest portion of the stored energy of cold work in compressed polycrystalline copper is released in the early stages of annealing, well in advance of recrystallization. Thus, the new recrystallized grains are undoubtedly growing in a matrix which is, at least energetically, no longer in the cold worked condition, but has nearly returned to the annealed state. It is true that in Suzuki's experiments the major hardness changes due to annealing were observed to take place concurrently with the formation and growth of the new grains, but this process apparently involved the release of only a minor residual fraction of the stored energy of cold work. Confirming in this respect the views of Wood," several recent investigations by various techniques lead to the conclusion that the grains of many, if not all, metals in the cold worked condition consist of small, slightly disoriented "crystallites" or "sub-grains".* (After appreciable deformation at room temperature, the subgrain size in copper appears to be about 7.104 cm and in high purity aluminum about 2.10-4 cm.) Recent investigations which demonstrated this phenomenon most convincingly are those of Heidenreich8 with hammered high purity aluminum, of P. B. Hirsch and collaborators7,8 with cold worked polycrystalline aluminum, copper, nickel, iron, gold, etc., and of Warren and Averbach9 with a rolled copper plus 2 pct Si single crystal. In addition to the existence of slightly disoriented sub-grains, the cumulative evidence from these investigations also shows that in the cold worked condition the subgrains themselves are severely strained. With regard to the early stages of annealing, Heiden-reich's results indicate that within the subarains of hammered high purity aluminum the strain gradually disappears, without discernible migration of the subboundaries. This recovery process presumably accounts for the major portion of the energy release

Jan 1, 1953

By C. E. Birchenall, R. H. Condit

THREE surface activity procedures are in com--L mon use for the determination of diffusion coefficients in solids. In the oldest of these' the activity observed at the original surface is compared before and after diffusion, where all the activity is in a thin, plated layer on the surface before diffusion. Partial absorption of the radiations from active atoms which have diffused below the surface reduces the effective activity after diffusion. The formula employed to calculate the diffusion coefficient is where F, is the ratio of final to initial activity at the surface, measured with identical counting geometry; Z=u3Dt, where D is the diffusion coefficient; t is the diffusion time; and u is the absorption coefficient for the radiation in the solid as defined by Lambert's law. This absorption law implies that all the rays are parallel to each other and normal to the specimen surface. This assumption of a collimated beam used by Steigman, Shockley, and Nix has been adopted by all other investigators and, although it gives results which are approximately correct under restricted physical conditions, it does not represent many actual circumstances. It is the purpose of this paper to show the importance of the divergent rays and to indicate a procedure for taking them into account. In the residual activity method the activity is determined on a series of surfaces ground on the specimen at progressively greater depths in the diffusion layer parallel to the initial surface. Gruzin2 has de- rived a formula for this procedure, which may be put in the form where I is the ratio of the activity measured at a newly ground surface at distance k below the initial surface to the activity at the initial surface measured after diffusion, and K= k/2p Dt. A third procedure involves the autoradio-graphic determination of activity on a plane ground at a small angle to the initial interface through the penetration zone. Aut oradiography can be particularly sensitive to the oblique rays. Unlike most counters which detect essentially all ß particles or X-rays which enter the active volume as a single event, the photographic emulsion may be thin enough so that oblique rays with longer path length in the emulsion produce more darkening than rays which move normal to the film plane. Consider a plane containing a source of radiation uniformly spread over a circle and a point counter located on the perpendicular through the center of the circle. As the counter moves along this line, the total angle 6, at the counter subtended by the specimen will vary. For a fixed counter distance, let 6 be angle between the counter axis and the line connecting the counter to a point P on the active plane. If an absorber of thickness X is interposed parallel to the source between counter and source, the ray from point P to the counter will pass through an absorber thickness X secant 6. Exponential absorption is assumed to hold for all rays. If r, is the ratio of intensity at the counter with absorber to the intensity without absorber and a = pX, 1 00 The behavior of this integral, evaluated numerically,

Jan 1, 1957

By William H. Love

ATLAS shaft was sunk to explore at depth a portion of the eastern end of the dry belt, or silver belt, of the Coeur d’Alene mining district. The Atlas mine is a mile east of Mullan and is on the south side of the Osburn fault. Equal partners in the venture are Hecla Mining Co., Newmont Mining Co., New Jersey Zinc Co. and Atlas Mining Co., the financing being equally shared by Hecla, Newmont, and New Jersey Zinc. As outlined the project had as its goal deep exploration of prominent structures developed in the Atlas in upper levels. Plans called for deepening the shaft from the 800 level to the 2400 level with subsequent drifting, crosscutting, and diamond drilling on the 2400.

Jan 11, 1954

By AIME AIME

THE MODEL LAW previously referred to', in these columns several times, prepared by Engineering Council, to be o ered in any state where legislation is introduced for licensing engineers, is given in abstract below. , Mining engineers throughout the country should watch legislation of this sort and see that the draft prepared by Engineering Council is in the hands of any state legislative committee which proposes to frame a licensing law. So far as this office is informed, the mining engineers are a unit against licensing, but if we must be licensed the most innocuous law that has been submitted is the draft prepared by Engineering Council. ABSTRACT OF MODEL LAW -FOR REGISTRATION OF PROFESSIONAL ENGINEERS, ARCHITECTS, AND LAND SURVEYORS

Jan 1, 1920

By Betty L. Gibbs

A company must have an organized approach to effectively sort through the profusion of available software and hardware and find the programs and equipment which fit defined needs. The selection process must build a complete compatible system which includes hardware and software. The methodology presented in this paper helps identify some of the more important considerations. The steps needed for an organized approach to software/hardware selection are: •All involved staff should contribute to an assessment of current computer capabilities and projection of future needs. •Alternatives are analyzed to determine what software and hardware is available and how selections may possibly be merged into the existing computer system. The evaluation process focuses on details of program capability and hardware compatibility. Analysis must be done to determine how closely individual programs fit the established requirements. The final decision is often a balance of needs between program capabilities and hardware availability. Any programs selected must be able to run on existing and newly purchased hardware. Any additional hardware selected must be capable of meshing with the available computer system.

Jan 1, 1983

By Whitmell J. Smithwick, Charles E. Dandois

The first operating unit of the ring or annular shaft kiln as developed by Mr. Karl Beckenbach of West Germany was rated 185 tpd and was installed in 1962. Today, there are approximately 84 units in operation in Western Europe and Japan. Twenty-one additional units are under construction or on order. Sizes range from approximately 100-330 tpd, however, units of over 500 tons are in the design stage. The ring shaft kiln is a single vertical cylinder to which are attached the required service platforms, combustion chambers, injectors and distribution piping (Fig. 1). Auxiliaries such as recuperator, exhaust fan and dust collector are mounted on the appropriate service platform. The charging pan, feed conveyor, etc., are mounted at the kiln top and at the bottom of the kiln is the silo with a vibrator type discharger. Mounted separately is the required blower for injector air and fan for internal cooling.

Jan 4, 1973

By M. G. Cheney

Careful estimates indicate that during 1942 new discoveries and extensions in West Central Texas added oil reserves slightly in excess of the eight million barrels produced. Drilling activity fell 40 per cent below 1941 and 82 per cent below the normal drilling activity of the late 1920's. Total production for the district continued its downward trend, now being less than % of the 42.7 million barrels peak in 1921. Rapid revival of activity is not probable under existing conditions, as costs of discovery, development and operations on the average probably now exceed current market price for the oil, the latter having remained constant since the spring of I941. Costs have advanced materially since the third quarter of 1941, when reports to the Tariff Commission indicated a margin of profit of 13.3 per barrel. Physical as well as economic conditions are holding back the amount of drilling in this district. The lenticular sands are not suited to 40-acre spacing regulations. There is no surplus of experienced oil-field labor. To reduce costs, much second-hand material is used for all except the deeper wells.. Price controls have retarded movement of used equipment by prescribing maximum prices that arc too low for the better grade materizl, thus making , owners reluctant to sell. On the other hand, buyers are unwilling to pay ceiling prices asked by sellers for poor material. Seventeen new oil fields and five new gas fields were found during 1942. Extensions and deeper 'drilling brought favorable results in eight older fields. The most significant new developments appear to have been in Coleman, Jones, Shackelford and Taylor Counties. A 5800-ft. completion in Wise County brought this county into the producing column for the first time. None of these new discoveries can he rated above one million barrel reserve on the basis of present development. Probably the most important development was discovery of a deeper pay (Gunsight lime) in the Wimberly field of Jones County, which shows promise of producing over an area of about 1000 acres. Jones and Shackelford Counties still lead the district in total annual production. Discovery of the Reddin pool, north central Taylor County, is credited to geochemical methods, making one success out of five or more wildcats based on such methods. Geophysical surveying increased decidedly during 1942 and returns from these studies are expected during coming years. Most of the wildcatting in the district is still based on surface and subsurface geological structural mapping, study of log data as to distribution of prospective producing reservoirs, and drilling in proximity to previous showings of oil and gas. Geological debate continues as to the proper correlation of the 100 to 300 ft. of gray lime that has produced more than 100 million barrels in the Parks, Brecken-ridge, Curry, Eliasville, Ibex, Pioneer and other important fields of this district. Fossils indicate that this limestone is younger than the Atoka beds of Oklahoma. On a structural basis most geologists include this formation with the Bend but a number of paleontologists believe it is more properly classified with the Strawn.

Jan 1, 1943

By M. G. Cheney

Careful estimates indicate that during 1942 new discoveries and extensions in West Central Texas added oil reserves slightly in excess of the eight million barrels produced. Drilling activity fell 40 per cent below 1941 and 82 per cent below the normal drilling activity of the late 1920's. Total production for the district continued its downward trend, now being less than % of the 42.7 million barrels peak in 1921. Rapid revival of activity is not probable under existing conditions, as costs of discovery, development and operations on the average probably now exceed current market price for the oil, the latter having remained constant since the spring of I941. Costs have advanced materially since the third quarter of 1941, when reports to the Tariff Commission indicated a margin of profit of 13.3 per barrel. Physical as well as economic conditions are holding back the amount of drilling in this district. The lenticular sands are not suited to 40-acre spacing regulations. There is no surplus of experienced oil-field labor. To reduce costs, much second-hand material is used for all except the deeper wells.. Price controls have retarded movement of used equipment by prescribing maximum prices that arc too low for the better grade materizl, thus making , owners reluctant to sell. On the other hand, buyers are unwilling to pay ceiling prices asked by sellers for poor material. Seventeen new oil fields and five new gas fields were found during 1942. Extensions and deeper 'drilling brought favorable results in eight older fields. The most significant new developments appear to have been in Coleman, Jones, Shackelford and Taylor Counties. A 5800-ft. completion in Wise County brought this county into the producing column for the first time. None of these new discoveries can he rated above one million barrel reserve on the basis of present development. Probably the most important development was discovery of a deeper pay (Gunsight lime) in the Wimberly field of Jones County, which shows promise of producing over an area of about 1000 acres. Jones and Shackelford Counties still lead the district in total annual production. Discovery of the Reddin pool, north central Taylor County, is credited to geochemical methods, making one success out of five or more wildcats based on such methods. Geophysical surveying increased decidedly during 1942 and returns from these studies are expected during coming years. Most of the wildcatting in the district is still based on surface and subsurface geological structural mapping, study of log data as to distribution of prospective producing reservoirs, and drilling in proximity to previous showings of oil and gas. Geological debate continues as to the proper correlation of the 100 to 300 ft. of gray lime that has produced more than 100 million barrels in the Parks, Brecken-ridge, Curry, Eliasville, Ibex, Pioneer and other important fields of this district. Fossils indicate that this limestone is younger than the Atoka beds of Oklahoma. On a structural basis most geologists include this formation with the Bend but a number of paleontologists believe it is more properly classified with the Strawn.

Jan 1, 1943

By J. G. Hadley

IN THE early stages of the depression the Utah Copper Co. realized that an unemployment problem would he created which demanded an intelligent and sympathetic solution. The company recognized that as many men as possible must be kept at work on a basis which would ultimately permit of the most efficient reabsorption of displaced labor. The company therefore determined to distribute available work among the greatest number of men and to that end adopted a system of rotating employees on a part-time basis. An employer requires a certain number of days' or shifts' work during the month. Obviously one employee working thirty days or shifts a month is equal to two employees each working fifteen. In principle, therefore, where two employees equally fitted to do certain work are available the work could be divided between them on an equitable basis and twice as many persons would benefit. A rotation plan on this basis was adopted by the Utah Copper, Co. on Jan. 30, 1930. Some variations of the orig¬inal plan have been made from time to time, the reasons for which will be discussed.

Jan 1, 1932

By Edward Martinez

The literature on the beneficiation of serpentine asbestos ore states that the specific gravity of the rock containing fiber and the fiber itself is the same so that specific gravity cannot be used as a basis for separation. An investigation of particles of asbestos ore ranging in size from 4 mesh to 5 in. revealed that the fiber-bearing particles generally had a lower specific gravity compared to essentially barren particles. The difference in specific gravity was sufficient to make an effective gravity separation of ore particles and reject a low grade tailings product. The results of laboratory tests are described that lead to the running of pilot plant tests with 20-ton ore samples using a heavy media separator. These tests indicated that a large amount of low grade material could be rejected from the raw ore at a coarse size. Although the process used is a wet separation, it can be added to a conventional dry asbestos mill. A gravity preconcentration would allow the mining of lower grade ore, increase the life of the mine, increase the value of the feed to the fiber recovery section, and decrease maintenance costs by removal of low grade tailings early in the flowsheet.

Jan 1, 1975

By C. R. Boyd

In 1874 I received an appointment in the corps organized by Col. William P. Craighill, U. S. Engineers, to survey the New or Upper Kanawha river for the purpose of ascertaining the practicability and

Jan 1, 1895

By J. J. Gilman

Zinc monocrystals, when compressed nearly parallel to their basal planes (within 20), deform in a new way; and certain deformation markings, called "-bands," are typical of this new mode. Characteristics of these bands are described. Mechanical behavior of low angle zinc monocrystals was investigated in some detail. Recrystallization did not occur upon annealing of banded specimens that were free of deformation twins. -Bands do not seem to be the result of nonbasal slip, but rather, a result of a microbuckling mechanism. u-Bands differ qualitatively and quantitatively from ortho kink bands. A dislocation model, consistent with some of the features of u-bands, is described. THE plastic deformation of zinc monocrystals with slip planes (0001) nearly parallel to the stress axis was studied in this investigation. In a previous investigation, it was shown that some low angle zinc crystals (those with slip planes making angles of more than about 2.5+1° with the compression axis), deform by ortho kinking while others (those with slip planes making angles of less than 2.5+1° with the compression axis) deform in a new way.' This new mode of deformation will be described in some detail here. Some of its striking features are: 1—it operates only for compressive stresses, 2—its temperature dependence is anomalous, and 3—it exhibits a new type of "yield-point" behavior. The mode of deformation to be discussed is not new in the sense that no previous evidence of its existence had been reported. The markings that it creates on the cleavage surfaces of zinc crystals have been described by several investigators.'" However, this is the first time that it has been made to operate under controlled conditions so that its response to mechanical variables, temperature, and aging treatments could be investigated and its geometry completely described. Apparently. Jillson' as well as Holden3 and Pratt" believed that the small bands they observed were simply small versions of ortho kink bands. In fact, two of these authors3,6 "alled the markings "micro kink bands." In spite of the precedence, it is felt that this term is not entirely suitable because these bands do not have the same genesis as kink bands, and they are qualitatively different in structure. As will be indicated by later discussion, the bands seem to be related to the tensile deformation bands observed in aluminum. The present author has chosen to call the bands "micro deformation bands," or simply ",ubands," and the deformation process, ''p-banding." Experimental Methods Crystals were grown from 99.999+ pct Zn obtained from the New Jersey Zinc Co. The details of the technique are given elsewhere." It should suffice to say that the crystals were seeded for orientation control, and precision pyrex tubes were used for molding them. About 40 crystals were used, yielding some 130 specimens. Fig. 1 illustrates the typical form of the specimens and shows how the orientation angles are defined. The crystal specimens were usually 1 3/4 in. long and about 150 mil in diameter. The angle between the slip or cleavage plane (0001) and the specimen axis is designated by xo, while a is the angle between the maximum slope of the (0001) plane and the nearest close-packed direction [1210], vary ing from 0°to 30°. The crystals were cut into specimens with a jeweler's saw and the ends were squared by filing (specimens held in V-block). Crystals of this orientation are stiff toward bending, so this procedure introduced only deformation localized at the ends. Then the specimens were polished either chemically in 50 pct HNO³ or electrolytically in 20 pct chromic acid. The mechanical tests were made with an Instron testing machine. This machine weighs by means of electric strain gages on elastic bars and is quite stiff, since the full-load deflection of its load cells is at most 0.002 in. Most of the testing was done at a

Jan 1, 1956

By Clint L. Milliken

The smelter is often considered the flywheel of the copper industry. No other unit can produce such a uniform product from so many starting materials. Direct-smelting ore, concentrate, precipitate, refinery slag, and scrap in almost any combination can be processed into blister or anode copper. Copper smelting practice has advanced little in the last century. It is still basically matte smelting, although the source of matte has changed from the blast furnace to the reverberatory furnace because of changes in smelter feed, and the Great Falls converter has been replaced by the Peirce-Smith converter. This lack of progress has continued because the economic forces required to produce change have not been of sufficient magnitude. Traditionally, the smelting, operation has required only about 10% of the total cost of producing copper from its ores and this minor cost item has not warranted change until recently.

Jan 1, 1971

By C. S. Smith

It is the policy of The Metallurgical Society to provide, in the TRANSACTIONS OF THE METALLURGICAL SOCIETY OF AIME, a prompt and accurate medium for publication of reports of significant new research in both the scientific and engineering aspects of metallurgy. Papers submitted to the Society are judged by competent reviewers according to established criteria for technical merit, accuracy, originality, and presentation. STAFF: Editor, Dr. Gerhard Derge; Editorial Assistant, M. A. Redmyrski; Staff Coordinator, James J. Burke. THE METALLURGICAL SOCIETY: W. R. Hibbard, Jr., President; J. C. Kinnear, Jr., Post-President; John Chipman, Vice President; T. D. Jones, Treasurer; R. W. Shearman, Secretory. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: A. W. Thornton, Chairman- Dennis Carney John Chipman J. C. Fulton J. H. Hollomon H. H. Kellogg, A. E. Lee, R. Moddin, J. D. sullivan, and D.' Swan. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division: T. B. King, Chairman; S. J. Dickenson, R. P. Hermsdorf, R. Schuhmann, Jr., and P. T. Stroup. lnstitute of Metals DM lion: Robert Maddin, Chairman. F. Lincoln Vogel, Jr.. Vice chairman. W. A. Backofen R. W. Boliuffi J. H. Bechtold' M. B. Bever R: S. Busk C 6. Goetzel poul Gordon C. D. Grobom, Jr., Robert F. Hehe-mann R. I. Joffee F. i. Joumot Jr. lrvin R. Kromer, A. J. Leno. Horold Morgolfn, C. J. McHargue, Russell A. Meussner, J. B. Newkirk, H. W. Paxton, G. E. Pellissier, I. S. Servi, Alon U. Seybolt, A. J. Shaler, and Jack Washburn. Iron and Steel Division: J. C. Fulton, Chairman. T. B. King, F. C. Laogenberg, W. O. Philbrook, and T. 0. Winkler. Publishod bimonthl by the American Institute of Mining Metollurgicol and Petroleum Engineers Inc., 29 West 39th Street, New York 16, N. Y. Telephone: PEonylvanie 6-9220. Subscription $20 par yew for non-AIME members in United States and North, South and Control Americo $25 foreign; $5 for AIME members. Single copies, $4.00, single copios foreign $5,00. The AIME is 1958 by the Amarican mode or opinion axpressed in it* publications ... Copyright by the Amarican lnstitute of Mining, MataIlurgicol, and Petrolum Engineers, Inc,. . . Reg. istered cable address AIME New Yark ... Indexed in Engineering Inderx, Industrial Arts ...Index and Chemicol Number5. Absrtracis . . . Second class postage paid at New York,Indor. N. Y., Industrialond Ann Arbor, Mich.

Jan 1, 1959

By Richard E. Chism

The dry methods of assaying mercury-ores and other combinations of mercury all rest upon the volatility of this metal as a beginning. After the separation of the mercury in the form of vapor from the matrix upon which the assay is performed, the mercurial vapors are either condensed upon cold surfaces or received upon a gold plate into which the mercury is absorbed.

Jan 1, 1899

By Joseph F. Shirley, Harry K. Burke

On January 9, 1964, the molybdenite extraction circuit at the San Manuel concentrator was switched from the sodium hypochlorite-ferracyanide process to the present process described in this paper. This moment was the culmination of over three years of laboratory and pilot plant test work. COPPER CONCENTRATOR Even though San Manuel's molybdenite plant begins with the thickened copper concentrates, it is necessary to describe briefly the copper sulfide circuit, because San Manuel's excellent molybdenite recovery actually begins with the primary grinding of the ore.

Jan 3, 1965

* A complete magnetic picture of the Mesabi range is now available for the first time with the release of 21 additional maps based on the aeromagnetic survey of 30,000 square miles made jointly by the USGS and the Minnesota Geological Survey. A potential iron formation with a magnetic pattern remarkably like that of the Mesabi iron range lies buried beneath the glacial drift in a wide belt extending some 30 miles across the northwest corner of Itasca County in north central Minnesota. Identification of three new uranium minerals by the USGS was recently announced. The new minerals, andersonite, swartzite, and bayleyite are, respectively, hydrous uranyl carbonates of magnesium, of sodium and calcium, and of calcium and magnesium. They were first observed by Charles A. Anderson, Survey geologist, in a coating on gypsum on the 300-ft level of the Hillside mine, Yavapai County, Arizona. International Minerals and Chemical Corp. has announced a $4,000,000 expansion and development program in the Polk County phosphate fields in Florida, Plants for the manufacture of multiple superphosphate and phosphate chemicals including dicalcium p osphate for animal feed and chemical purposes, and a sulphuric acid are planned. Office building, machine shop, warehouse, and laboratory are also scheduled for erection. A new type of tramp iron detector is being used on the conveyor belt feeder at the South Agnew stripping operation. It is made of an alloy of aluminum, nickel and cobalt and does not have any electric coils. The alloy, known as Alnico, is remarkable for the permanence and intensity of the magnetism which it retains. The detector was made by Dings Magnetic Separator Co. and it is probable that Alnico will be used in magnetic separators. The American Society of Engineering Education estimates that unless the percentage of high school graduates entering engineering colleges is increased, there is a strong possibility that instead of a large surplus of engineering graduates, which has been propehsied rather widely, there will soon be fewer engineering graduates available than are needed annually by our national economy. This conclusion is reached from a survey that shows that engineering enrollments are only slightly higher than prewar whereas industrial expansion is increasing the need for engineers. * The natural resources of Korea are being investigated under ECA sponsorship. E.J. Longyear has just embarked 8 crews for that country; two drills are scheduled for base metal search while six are slated for development of coal reserves. An innovation in the development work in the iron country has been the adoption of the Drill-Mobile, jumbo-mounted drills on rubber-tired carriage, by Cleveland-Cliffs at the Mather A and B mines. The machine is being used to cut stations in the new Mathed B shaft and for driving development headings at the Mather A.

Jan 5, 1950