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By J. W. Downey, A. E. Dwight, R. A. Conner

THE MgCu2 type Laves phase has been observed in the thorium-osmium and thorium-iridium systems. Two alloys corresponding to ThOs2 and ThIr, were prepared by arc melting a 5-g charge in a water-cooled copper. crucible. Both alloys were very brittle. X-ray diffraction patterns were obtained using filtered Cu and Co radiation with a Straumanis-type DeBye-Scherrer camera. The a,, values as shown in Table I were obtained by a Nelson-Riley extrapolation. The structure belongs to space group Oh7-Fd3m. Relative intensities for each of these compounds were calculated on the assumption that 8 thorium atoms occupy (a) positions and 16 osmium or irid-ium atoms occupy (d) positions. The calculated intensities are the product of the Lorentz-polarization factor, the multiplicity factor and F', the structure factor, neglecting the absorption and temperature

Jan 1, 1959

By Robert T. Walker

Robert T. Walker and Woodville J. Walker (Walker Engineering Corp., Salt Lake City)-Mr. Kinkel's article embodies, in condensed form, the results of the first detailed and complete geological survey that has ever been made of the long neglected but potentially very important West Shasta Copper-Zinc district, in Shasta County, California. In view of the difficulties of the terrain and the complexity of the geological structure, this represents a notable achievement, and it is with regret, therefore, that the writers find it necessary to differ from Mr. Kinkel's conclusions on two important points. The first has to do with the interpretation of two members of the stratigraphic column of formations in the district; for purposes of comparison, the description of these two members according to Mr. Kinkel is shown parallel to the description of these members according to the writers, see Fig. 14, Mr. Kinkel's nomenclature being used

Mar 1, 1956

By G. W. P. Rengstorff, L. E. Olds

PREVIOUS research has shown that cast molyb-denum has good ductility at room temperature if the metal is sufficiently pure. In practice, however, it is very difficult to reduce the impurity content of molybdenum to a few parts per million—the maximum content of impurities allowable to obtain reasonable ductility in coarse-grained molybdenum. Also, subsequent fabrication may reintroduce enough impurity to damage ductility greatly, unless extreme precautions are taken to protect the metal during working. The major impurities which embrittle molybdenum are oxygen, nitrogen and, to a lesser degree, carbon. It is reasonable to assume that the harmful effects of such impurities might be neutralized by small amounts of alloying additions. The desired alloying elements would be those which might fonn stable metal oxides or nitrides that would not be harmful to ductility, or thosewhich might increase the tolerance of molybdenum for oxygen and nitro-

Jan 1, 1958

J. T. LITTLETON, JR., ? Corning, N. Y. (written discussion?).-This. discussion will add little that has not been brought out but will show how the problems encountered in the Corning Glass Works were overcome. The chief points of consideration in any equipment are, first, the work the equipment is called upon to do; second, the installation; and, third, the man who will use it. These three points should determine the type of apparatus adopted. If only rough measurements, merely a little better than the eye, are desired, the cost of the instruments should be considered; but if accurate temperature control is necessary, the cost of the equipment deserves only small consideration. There is no question that the real problem for any factory is the installation, making sure that the elements really give the temperatures desired; also, the instruments must be so designed that any man can use them.

Jan 12, 1919

By R. L. Curfman

WHEN the Uranium Reduction Co. mill was put on stream in October 1956, one of the many operational problems was that the sand-slime separation circuits could not produce a satisfactory RIP feed, inasmuch as production greatly exceeded de- sign capacity. The original cyclone portion of the circuits consisted of two stages of three 14-in. cyclones in each circuit, as shown in the condensed flowsheet. The high percentage of +325 mesh material in the over- flows of these 14-in. cyclones was not consistent with good operation, and flow rates per ton of ore were high, indicating that not enough of the total solids in the ore was being rejected as sands. It was inferred by members of the metallurgical department that returning the underflows, or sand fraction, from these cyclones back into the drag classifiers was the primary reason for dirty feed.

Jan 7, 1958

BOSTON SECTION R. L. AGASSIZ, Chairman, - JAMES G. CARLETON, Vice-Chairman, E. E. BUGBEE, Sec.-Treas., Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS, G. A. PACKARD. The forty-fifth meeting of the Boston Section was held, at the Engineers' Club, on Tuesday, Nov. 6, 1917. Mr. F. C. Carstarphen, tramway engineer of the American Steel and Wire Co., was the guest of the evening. After dinner, Mr. Carstarphen gave a most interesting illustrated talk on the subject of aerial tramways. The views-showed the various forms of aerial tramways and three' unique installations, one carrying 285 tons of coal an hour, undoubtedly the maximum quantity transported by any tramway up to this time. The second installation is that of a lumber-carrying tramway, 5 miles long, operating in California. The last views illustrated a 13 ½ -mile tramway for carrying salt over the

Jan 2, 1918

By Paul A. Hodges

With plant start-up slated for early 1966, Palabora Mining Co. will take its place among the large copper mining properties of the World. Located near the town of Phalaborwa in the Lowveld area of Transvaal Province, approximately 250 air miles northeast of Johannesburg, Palabora is the result of a cooperative project between Rio Tinto-Zinc Corp. and Newmont Mining Co. Other large shareholders are American Metal Climax, Inc., Union Corp. Ltd., and Selection Trust Ltd. Earliest known mining activity in the area is thought to date back about 400 years, when the Bantu tribes were migrating southward from the great lakes of Central Africa. Old workings and hand tools have been found in numerous places on the flanks of Loolekop, the hill that contains the outcrop of the Palabora orebody. Nearby ruins of small furnaces give added evidence of the knowledge of copper smelting possessed by these natives.

Jan 3, 1966

By A. Blake Caldwell

In 1936 the Ertsberg story began and its development is a classic example of the courage it takes to discover one mining prospect and bring it into production. Truly, the finding and working of this mine is a modern exception to the overwhelming odds every modern prospector must surmount to be successful. Today, it takes lots of time, plenty of money and the tenacity of a bulldog to whip the laws of nature. Ertsberg ("ore mountain" in Dutch) is literally an elliptically shaped plug of magnetite which erosion has exposed for 560 ft above ground level. The deposit has been likened to an ice cream cone with the outcrop the ice cream, which is above ground, and with the cone buried below the surface. Assaying about 2.5% Cu, the 33 million tons of ore also carry 0.025 oz Au and 0.265 oz Ag per ton.

Jan 1, 1970

By Seishiro Hirakawa, Hiroshi Tokunaga, Hironori Nakamura

Two unique processes of reclaiming zinc from various secondary materials were developed and have successfully been operated for years by Mitsui Mining and Smelting Co. These processes were established based on the characteristic and local energy conditions; i.e., (1) at Miike Smelter, located above the largest coal deposit in Japan, a combination of slag fuming and semi-blast furnace (MF)processes takes advantage of using coal and the carbon bearing briquette residue from the vertical retort plant as reducing agents, (2) on the other hand, at Kamioka Smelter, a direct reduction of zinc-bearing lead slag by using electric furnaces is of advantage in view of cheap electric power supply from our own hydraulic power plants. The former also consumes lots of zinc bearing fines and drosses from various steel plants, fabricators and secondary zinc smelters, while the latter, zinc leach residue from its own electrolytic plant

Jan 1, 1976

By R. C. Amero

FULLERS earth is a general name applied to claylike minerals that have high natural adsorptive powers. They are usually distinguished from ordinary clays by a higher content of combined moisture and a lower apparent density. The definition is based on the ancient use of the material for fulling, or cleansing woolen cloth of oil and grease; a more modern definition should mention the ability to decolorize oil and should differentiate between fullers earth, which is naturally active, and certain bentonites which only develop decolorizing power after being leached with strong mineral acids. The distinction between fullers earth and activable bentonite is not a sharp one, since all types of intermediate clays can be found that are more or less naturally active, yet more or less responsive to acid treatment. The differences seem to depend somewhat on the amount of leaching that has been effected by natural ground waters.

Jan 5, 1951

By T. A. O’Hara

SINCE May 1948, when tungsten carbide bits were introduced at the Flin Flon mine, they have been popular with the miners because of their fast drilling speed and low gage loss. The high cost of commercial carbide bits and tipped drill steel, however, prevented their use except for the hardest rock. In an effort to extend the use of tungsten carbide on a basis economically competitive with detachable steel bits, experimental work was begun in 1950 to test the feasibility of making tungsten carbide tipped drill steel in the mine drill steel shop. This work showed that tipped drill steel could be made locally at less than half the cost of the commercial product. The performance of the local tipped drill steel was comparable to that obtained with commercial carbide bits and tipped drill steel and the cost per foot drilled was much lower.

Jan 3, 1954

PROF. Henry Louis, Newcastle-on-Tyne, England (communication to the Secretary): I have read this paper with much pleasure. It presents a very accurate summary of a very interesting district. Like the authors, I was struck by the extreme General View, near French Co.'s Cyanide Works, Showing Horse-Whims, etc. flatness of this region, which looks strange to a gold-miner accustomed to other reef-districts. This prevailing absence_of relief in the contours is shown in Figs. 1 to 4, from photographs taken in August, 1897, some of which also show the horse-whims used here for hoisting. The flatness of contour is due, no doubt, to the fact that the rocks are similar in structure over large areas and are easily decomposed. I am quite at one with the authors in looking upon the so-called " placers " as the result of decom-

Jan 1, 1899

More than 400 members and guests registered for the 146th General Meeting of the Institute held in Mexico City Nov. 9 to 15, inclusive. Of these, 250 came by special train or automobile from 24 states of the Union, and the others were resident in Mexico. Mexican Government officials, headed by Manuel Santillan, Sub- secretary of the Department of National Economy, acting in. behalf of the President of the Republic, and including the Secretary of Foreign Relations and the Governor of the Federal District, were most hospitable in their official welcome and provided splendid entertainment of various kinds. A reception was tendered by Hon. Josephus Daniels at the U. S. Embassy. Among other hosts were officials of a number of large operating companies, including M. H. Kuryla, of the Real del Monte company; Jules Lacaud, of the CompaiLia Minera de Chontalpan; and Harry Wright, of the Consolidated Steel company.

Jan 1, 1937

By I. N. Zavarine

THE observations presented in this paper were recorded during a study of the spheroidizing process. Spheroidization of cementite in steel is either brought about to develop a set of desirable mechanical properties or is an incidental result of mechanical and heat-treating manipulations. Physical properties of steel are materially influenced by the state of the cementite. Conversion of cementite from the lamellar to the spheroidal state is usually accom-panied by a decrease of hardness and of strength and by an increase in ductility. The spheroidized structure is usually considered as an ultimate step in the process of the softening of steel. The unorthodox hardening of a 3.5 per cent Ni steel (SAE No. 2330) after a heat-treatment that previously proved entirely suitable for a complete spheroidization of cementite in carbon steels led to the observa-tions that constitute the subject of the present paper.

Jan 1, 1939

U.S. Signs Pact With Miami Copper Miami Copper Co., of Arizona has agreed to mine lowgrade copper ores in an extension of its Globe-Miami mining district operations at a guaranteed price of 27.35[] per lb, under a contract signed with defense Materials Procurement Agency. Terms of the contract call for delivery of 230 million lb of refined copper between 1955 and 1962. DMPA said highgrade ore in the de posit will soon be exhausted and it is considered advisable to have Miami continue the operation. The Government has an option to buy 120 million lb of refined copper from present production at market prices. Miami will develop the new ore- body at its own expense-estimated at $3 million. If losses under the new contract reach a specified point, Miami may cancel the agreement. The company plans to use the block caving method in the underground operation.

Jan 4, 1953

By F. J. Menzer, E. M. Schern

The Morenci/Metcalf porphyry copper mining operation, located in southeastern Arizona, currently processes approximately 91,000 tonnes of ore per day and has copper ore reserves estimated to be in excess of one bill ion tonnes. Functional groups within the Geology Department (currently staffed with six professional and two support personnel include mine geology, project geology, and hydrogeology. The primary task of mine geologists is daily preblast bench face mapping with grade and mill amenability estimates. Auxiliary duties include detailed in-pi t metal distribution evaluation, mineragraphic work and flux quarry geology. Project geologists conduct exploration and preliminary development projects both within and outside the Morenci district and provide support to ore reserve block modeling and geotechnical work performed by the Morenci mine engineering group. Hydrogeologists handle exploration for and development of groundwater resources and groundwater flow modeling, mine dump leach solution penetration and recovery evaluation, and tailing dam water reclamation.

Jan 1, 1984

By G. W. Mao, A. M. Gaudin, D. W. Fuerstenau

Activation of sphalerite with copper salts has long been thought of as a chemical reaction of the following form: ZnS + Cu++ [=] CuS + Zn++ [ 1 ] Early experimentation1-3 showed that the reaction seemed to be stopped by the coating of insoluble copper sulfide, but since the analytical methods were crude, it was only surmised that the reaction could proceed by diffusion. Probably the most conclusive evidence for reaction (Eq. 1) was obtained by Cooke,4 who found a stoichiometric replacement of Zn++ by Cu" after 50 days' reaction at about 100°C. Cooke also found the sphalerite to be covered with a rather thick coating of covellite, which in¬dicates that activation is a continuing replacement of Zn++ by Cu" rather than diffusion of Cu" throughout the sphalerite lattice. However, the occurrence of diffusion at high temperatures has been observed.5,6

Jan 4, 1959

By S. E. Haszko

SEVERAL new XGa2 intermetallic compounds, Table 1, where X is a rare earth, having the AlB, structure were prepared as part of a continuing study of the magnetic and structural properties of rare-earth alloys.' In this note, the crystallographic results of these compounds are presented. Chart, Eq. 121 for the data in Fig. 1 can be adequately represented by The corresponding standard free-energy change is AF; = -4.576 T log K = -20,900 + 10.20T [5I At low nitrogen concentrations the ratio of mole fraction to weight percentage is a constant so that the mole fraction X of nitrogen is given by X = 0.0392 [%NJ. At low values of X, the activity and the concearation approach each other, hence K, = 0.0392 K,, where K, is expressed in terms of the mole fraction of nitrogen. Hence Eqs. [4]. and [5] become

Jan 1, 1962

By K. Osseo-Asare

The presence of carbonaceous matter in gold ores presents a two-fold problem: (1) The poor release of gold from the carbonaceous matrix and (2) the uptake of dissolved gold by the carbonaceous leach residues. A critical review is presented of the published information from various parts of the world pertaining to the nature of the carbon-containing components of these ores and their different roles in the gold extraction process. Included in this paper are new results based on the authors' research on carbonaceous ores from the Prestea goldfields of Ghana. Methods for isolating and characterizing the carbon-containing materials are given and a discussion is presented of the interaction of the carbonaceous ores as well as the fractionated components with aurocyanide solutions. Emphasis is on basic physico-chemical phenomena, investigated with the aid of X-ray diffraction, infrared spectroscopy, adsorption, and electrophoretic mobility studies.

Jan 1, 1984

By Charles A. Ashburner

The existence of natural gas-springs in Pennsylvania and the adjoining States west of the crest of the Allegheny Mountains was known to the earliest settlers. Possibly the first gas obtained from a well was at Fredonia, Chautauqua County, N. Y., where a well was sunk on the bank of Canadaway Creek, near the Main Street bridge, in 1821, and sufficient gas obtained for 30 burners, the inn having been illuminated by the gas when General Lafayette passed through the village about 1821. In 1858 another well was drilled, which supplied 200 burners. A still larger one was drilled to a depth of 1200 feet in 1871. According to Mr. E. J. Crissey, Secretary of the Fredonia Natural Gas Light Company, the average monthly supply of these wells in 1880 was 110,000 cubic feet. Since 1859, when the drilling of oil-wells in Western Pennsyl-

Jan 1, 1886