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By Avnulf Muan, P. V. Riboud

The effect of Cr2O3 on melting relations of iron oxide at oxygen pressures slightly above those prevailing in contact with metallic iron has been determined. Liquidus and solidus temperatures of wüstite are raised by the addition of Cr2O3, from 1385°C for pure iron oxide to 1420°C at the peri-ledie point where wüstite, iron chromite, liquid, and gas coexist in equilibrium under the atmospheric conditions used in the present investigation (CO2/H2 = 1). It has been shown in a previous investigation1 that the liquidus and solidus temperatures of iron oxide are drastically increased by the addition of Cr2O3 under the relatively oxidizing conditions prevailing in air. This is to be expected in view of the easy substitution of cr3+ for Fe3+ in crystalline oxide structures which are stable at high oxygen pressures, as demonstrated for instance by the completeness of the solid solution series Fe2O3-Cr2O3 at high temperatures (>1000°C). The stable phase of iron oxide at oxygen pressures approximating those prevailing when metallic iron is present is wüstite. This phase, although commonly represented by the simplified formula FeO for sake of convenience, in reality has a defect structure in which a part of the iron ions are present as Fe3+. It is to be expected that at least a limited amount of cr3 ions will substitute for Fe in this structure when Cr2O3 is added to wüstite. Depending on the ease of this substitution in comparison with that of cr3 substitution for Fe in iron oxide-Cr2O3 liquids under the same atmos- pheric conditions, the liquidus and solidus temperatures of wüstite may increase or decrease upon addition of Cr2O3. The methods of establishing these melting relations and the results obtained are presented in the following. I) EXPERIMENTAL METHOD 1) General Procedure. The quenching technique was used in this study. Oxide mixtures were heated at chosen constant temperatures in an atmosphere consisting of equal parts of CO2 and H2 until equilibrium was established among gas and condensed phases. The samples were then quenched in mercury to room temperature, and the phases present were determined by microscopic and X-ray investigation. 2) Preparation of the Mixtures. Starting mixtures were prepared by weighing and thoroughly mixing Fe2O3 and Cr2O3, or wüstite and Cr2O3. The Fe2O3 and Cr2O3 used were "Baker Analyzed" reagent grades, whereas wüstite of composition was synthesized by reducing Fe203 at 1325°C in an atmosphere consisting of equal parts of CG andHz. In order to avoid contact with crucibles, the equilibration runs were made with small pellets suspended from thin (-0.004-in.) platinum wires. Mixtures made from FOs and Cr203 were readily pelletized at a pressure of 500 atm in a 9.5-mm die, whereas mixtures made from wüstite and Cr203 when treated identically were too weak for handling. In order to obtain a stronger product, these pellets were sintered by heating for 2 min at -1200°C in the same atmosphere as was subsequently used for the equilibration runs (CG/H2 = 1:1). During the sintering, these pellets were wrapped in thin (0.0004-in.) platinum foil, which was stripped off before the equilibration runs. In order to reduce the time needed for equilibrium to be attained, preliminary equilibration of relatively large pellets of each mixture was carried out at -1200°C for 4 to 12 hr. Smaller pellets

Jan 1, 1964

By Charles G. Maier

SCIENCE beginning in rational observation came of age, when its devotees first began to measure and count. It has been said that the most striking aspect, of science today is its growing abstraction, and its preoccupation with mathematical symbolism. Technology with specific and concrete objectives in the satisfaction of human wants, cannot conceivably achieve the abstract unification that science seeks, but .the utility of the' scientist's method has been too well proved to require bolstering. Metallurgy is in its scientific infancy.

Jan 1, 1931

Held at San Francisco, Cal., Thursday to Sunday, Sept. 16 to 19, 1915 COMMITTEES Arrangements CHARLES W. MERRILL, Chairman EDWARD H. BENJAMIIN H. C. HOOVER FRED `V. BRADLEY W. C. RALSTON ABBOT A. HANKS G. H. CLEVENGER Excursion and Accommodations ABBOT A. HANKS, Chairman E. T. BLAKE R. H. BEDFORD C. G. DENNIS FREDERICK BRADSHAW C. E. GRUNSKY, JR. EDMUND JUESSEN ARTHUR B. FOOTE F. A. KEITH GEORGE 0. BRADLEY CHARLES JANIN E. N. ENGELHARDT R. S. HASELTINE N. CLEAVELAND

Jan 12, 1915

George B. CoRless, Chairman. Superintendent, Gulf Coast Division, Humble Oil & Refining Co., Houston, Texas. W. H. Geis, Associate Chairman. Geologist, Los Angeles, California. Benjamin C. Craft, Secretary-Treasurer. Associate Professor, Petroleum Enginecring, Louisiana State University, Baton Rouge, La. Executire Committee George B. Corless, Chairman. M. Albertson, Production Engineer, Shell Petroleum Corporation, Houston, Texas. D. R. Knowlton, General Production Superintendent, Phillips Petroleum Co., Bartlesville, Oklahoma. R. P. McLaughlin, General Manager, Dominguez Oil Fields Co., Los Angeles, California. Hallan N. Marsh, Production Engineer, General Petroleum Corporation of California, Los Angeles, California. Theron Wasson, Chief Geologist, The Pure Oil Co., Chicago, Illinois. Production Engineering M. L. Haider, Vice-chairman. Petroleum Engineer, Carter Oil Co., Tulsa, Oklahoma. Joseph Chalmers, DeBataafsche Pet. Maatschappij, The Hague, Netherlands. Emile HugUenin, Deputy State Oil and Gas Supervisor, Los Angeles, California. Carl E. Reistle, Jr., Petroleum Engineering Department, Humble Oil & Refining Co., Houston, Texas. Production J. TERry Duce, Vice-chairman. Geologist, The Texas Company, New York, N. Y. Basil B. Zavoico, Associate Vice-chairman. Geologist, The Chase National Bank, New York, N. Y. Engineering Research R. L. Huntington, Vice-chairman. Associate Professor, Petroleum Engineering, University of Oklahoma, Norman, Oklahoma. Economics Sidney A. SwensrUd, Vice-chairman. Assistant to the President, Standard Oil Co. (Ohio), Cleveland, Ohio. Refinery Engineering Walter Miller, Vice-chairman. Vice-president, Continental Oil Co., Ponca City, Oklahoma. 10

Jan 1, 1938

By A. M. Gaudin, D. W. Fuerstenau, M. M. Turkanis

SOLUBLE silver salts are effective activators for flotation of sphalerite with potassium ethyl xanthate as collector.' Since sphalerite takes up large quantities of silver ions rapidly," investigation of this system appeared fruitful for studying the mechanism of sphalerite activation and deactivation. Experimental data presented here comprise studies of the mechanism and rates of activation and deactivation of sphalerite with silver and cyanide ions. A 20-lb sample of sphalerite from Ottawa County, Oklahoma, was handpicked, crushed, screened, hydrosized to produce a 65/100-mesh fraction, and purified by electrostatic separation. The sphalerite was then leached with benzene and absolute ethyl alcohol to remove possible organic contaminants and with 0.1 M NaCN to remove any copper that might have been picked up during screening. The benzene had been specially purified by grinding with fine sphalerite for 12 hr to remove trace impurities that might have had a specific affinity for sphalerite. Finally, the mineral was washed, dried in flowing nitrogen, and stored in large ground-glass stoppered weighing bottles under a small nitrogen pressure.

Jan 1, 1957

By Ichiro Ito

At present, in Japan, the application of in-place leaching technique to the mined-out stopes has been carried out at two copper mines in a comparatively large scale. These mines are the Kosaka mine and the Tsuchihata mine, both are situated in the north-east district of Japan. At first, the author would like to tell about the in-place leaching operations and their results at these two mines. Then, the problems involved in the application of in-place leaching technique to the Japanese metal mines and the possibility of the future development of this technique in Japan are referred, too. Next, as to the research works, the author would like to explain briefly about some of the important results obtained in the recent studies on in-place leaching as well as on bacterial leaching in Japan.

Jan 1, 1976

By Thomas Leonard Watson

I. HISTORICAL. BARITE has been mined for many years in various parts of Virginia, probably the earliest mining-operations being in Prince William county, within 600 ft. of the Fauquier county line, about 4 miles south of east from Catlett, a station on the Southern Railway. It is claimed that the mineral was mined here as early as 1845. Mining-operations in Campbell and Pittsylvania counties in the Piedmont region, and near Marion in Smyth county, in the southwest Virginia Valley region, were begun about 30 years ago. The mining and milling of barite on a commercial scale in Tazewell and Russell counties are more recent, and commenced about 15 years ago. II. GEOGRAPHICAL AND GEOLOGICAL DISTRIBUTION. Barite occurs in many counties in the State, as shown in Fig. 1, but the industry has been confined to only a few of them. Its occurrence is noted in two of the three major divisions of the State-namely, the Piedmont region east of the Blue Ridge, and the Paleozoic area west of the Blue Ridge. In the Piedmont region the mineral has been mined in the following counties:, Bedford, Campbell, Louisa, Prince William, and Pittsylvania. In the region west of the Blue Ridge, composed of Paleozoic sediments, barite has been mined in Montgomery, Russell, Smyth, and Tazewell counties. Of the counties mentioned, Bedford, Campbell, and Pittsylvania of the Piedmont region, and Russell, Smyth, and Tazewell of the Valley region, have been the principal producers. In 1906, operations were confined to five counties-Bedford, Louisa, Pittsylvania, Russell, and Tazewell-but in the first two counties named there was no production, the work being solely development.

Jan 9, 1907

By Royal Preston Jarvis

The jig, in one form or another, continues to hold a leading place among the machines designed to separate two or more

Jan 1, 1909

By John G. Hall

The pumping operations at the Chief mine have been unique in the respect that for many years the entire flow of water into the mine has been disposed of by pumping into natural underground " caverns" or "sinks." Volumes up to 4000 gpm have been pumped into these caverns with no apparent tendency for the caverns to fill with water, and it has never been proven that any of the water returns to the mine workings. Major pumping operations have been carried on during two periods, the first from 1918 to 1927, and the second from 1942 to the present time.

Jan 1, 1949

By N. G. W., Cook

When an excavation is made underground the original rock stresses are removed from the surfaces of the excavation. These surfaces converge to partially close the excavation and the superincumbent rock mass moves down towards the excavation. If the convergence of the surfaces of the excavation were controlled, energy generated by their motion against the controlling forces could be extracted. Since the total forces in the rock mass are not significantly affected by the excavation, stress concentrations arise around the excavation, which compensate exactly for those stresses no longer transmitted through the excavation. These phenomena give rise to two general principles which provide the basis for analyzing the effects of making any underground excavation. The first of these is that the total force resulting from the stresses across any plane in the rock, including any plane through the excavation, must be the same before and after the excavation is made. The second of these is that energy must necessarily be released as a result of making an underground excavation.

Jan 1, 1969

[Note.—The paper of Mr. W. H. Hoffman (Glen Summit, October, 1891; Trans. xx., 602), on "Practical Results in the Magnetic Concentration of Iron-ore," together with a paper by the same author (Baltimore, February, 1892; Trans. xxi., 126), on "Granulating Magnetic Iron-Ores with thesturtevant Mill atCroton Magnetic Iron-Mines, N. Y.," and also the papers Presented at this meeting,

Jan 1, 1893

By L. Bruce McRae

A programme of work was initiated so that the possibility for the agglomeration of Transvaal chromite-fines by pelletization could be investigated. The use of cementitious binders did not yield promising results, binder additions of up to 10 per cent failing to produce an agglomerate that would be suitable as feed for an electric-smelting furnace. Further laboratory and pilot-plant studies showed that high-quality pellets could be made from chromite bonded with small amounts of bentonite and hardened by heat treatment at temperatures of the order of 1000°C. An investigation was also done into the reduction behaviour of pellets containing amounts of stoichiometric carbon up to that required for complete reduction. The results showed that the maximum degree of reduction that could be obtained was approximately 75 per cent, and that these pellets had the physical properties that would make them amenable to smelting in a submerged-arc electric-smelting furnace.

Jan 1, 1977

In 1910, he was with the Hidalgo Guadalupe, Pachuca, Mexico, and in 1911 was engineer with the Gualcola Mines Co., at Tuquerres, Colombia. In 1913, he returned to the Sout.hwest, and was employed for that yea.r by the Inspiration Cons. Copper Co. at Miami, and in the middle of the following year he became engineer with the Detroit Copper Co., at Morenci. In the autumn of 1914, Mr. Reece, stirred by his English blood, resolved to return to England to take part in the war. At this time he wrote "I think it will be better for me to resign my membership. If I come through all right, I will apply for re-election." The Institute, however, instead of accepting Mr. Reece's resignation, voted him an indefinite leave of absence, and this precedent soon crystallized into the regular procedure, now in force, of remitting the dues of members in active service. On Dec. 17, 1914, he wrote from Montreal that he fully expected to go over shortly in the second contingent from Canada, with Borden's Armored Brigade, operating with armored motor cars. As he said "this will be active enough service to satisfy any enthusiast, as they are used generally for reconnaissance duty." Soren Ringlund Soren Ringlund died suddenly on July 24, 1918, at Fort Logan, Colo., where he was engaged in service with the Medical Department of the U. S. Army. Mr. Ringlund was born in Denmark in 1875. He came to the United States in 1902, and became a citizen in 1908. He graduated as

Jan 1, 1920

By Clyde E. Williams

THROUGHOUT its history the American iron and steel industry has constantly striven to improve the quality and reduce the cost of its products. No one needs to be told how well it has succeeded. Its success in making steel products at such a low cost has been achieved mainly through large-scale production. While costs have gone down as the rate of production and the degree of mechanization increased, quality of product has been actually improved. Thus high-tonnage records are important only in the light of high quality of the steel. Quality is the watchword! Continual improvement in quality has come as a result of research, not only in the laboratory but in the large commercial units in the plant. In fact, so many operations of the industry are on such a huge scale that experimental work must be done under commercial operating conditions so every progressive steel plant is a research laboratory.

Jan 1, 1938

By Waldemar Lindgren

I. Character of the Deposits, 226: Principal Features, 226 (Form, 227; Posi tion, 227 ; Constituent Minerals, 227 ; Exceptions, 228) ; Literature, 228 ; Geo graphic Distribution, 230 ; (California, 230 ; Idaho, 231 ; Arizona, 233 ; British Columbia, 233; Northwest Territory, 234 ; Mexico, 234; Other Countries, 235). 11. Origin oF the Deposits, 236 : Contact-Metamorphism, 236; Caw of Contact Metamorphism, 237 ; Similar Deposits of Different Origin, 240; Genetic Classifi cation, 240 ; Relation of Pegmatite- Veins to Ore-Deposits, 242. I.—Character of the Deposits. 1. Principal Features. In many schemes of classification and description the term contact-deposit has been somewhat loosely applied to all accumu-

Jan 1, 1902

By B. L. Cusack, N. W. Stump

Selected technological developments applicable to lead and zinc mineral processing and changes in Australian concentration practices made since 1770 are reviewed. Laboratory and pilot plant studies of two new ores have been conducted since 1770. These have resulted in final flowsheet proposals which are described. New production capacity since IT0 has been based on plant expansion or the retreatment of oxidised tailings from plants operating pre-1940ts. Major developments in existing plants have come from the application of computer control to crushing, grinding and flotation and the installation of on-stream analysis systems. Flowsheet configurations have been altered in a number of plants. Selected research topics applicable to lead and zinc processing are also reviewed.

Jan 1, 1977

By Donald B. Gillies

THE great source of iron ore for the furnaces of this country has been the Lake Superior district. Ore was first discovered there in 1844, and the first shipments made via the Great Lakes in 1852 to a furnace at New Castle, Pa. The stream of ore from that region increased slowly to exceed a million tons in 1873, and did not reach 10 million tons until 1895. By 1901 it exceeded 20 million tons, and in 1907 over 40 million tons. Total Lake Superior output through 1948 was about 2500 million long tons. Outside the Lake Superior district are the Southern district, including mainly Alabama, Georgia, Missouri, and Texas; the Eastern district of New York, New Jersey, and Pennsylvania; the Western district embracing Wyoming, Utah, and California.

Jan 1, 1949

By J. S. Marsh, T. B. Winkler

THE past year, the first full one of peacetime production, proved that the process of beating swords into plowshares has increased in complexity in step with civilization. Further, judging by various remarks of our distaff departments, the crystal balls of certain radio and magazine oracles must have been cloudy, because we have been in formed from time to time that coveted items such as automobiles and refrigerators did not appear in great abundance. This seemingly extraneous matter is really not out of place here, however; the steel producer and the fabricator exist in a sort of symbiosis: the making of consumer goods produces scrap which is returned to the steelmaker who makes more steel, and so on and so forth. Thus, no abundance of automobiles, no abundance of scrap from this normal source; and other sources had been picked pretty clean during the war. To be short, so was scrap. Since the economy of the steel industry lean; as heavily upon iron from scrap as upon iron from ore, the statement on transformation of swords to plowshares follows. But this is not the whole story: after all, ingot production was a record for a peace year!

Jan 1, 1947

By Tadao Nagai, Masao Sato

Electrochemical measurements have been carried out in an auto- clave to investigate the electrochemistry of hydrogen precipitation of nickel from acetate buffered solution. After having previously obtained the rate equation for this reaction we have now made a concentrated effort to explain the rate equation electrochemically. A saturated NaC1-type Ag/AgC1 reference electrode has been improved so that it can be used in an autoclave. Polarization curves for the reaction, [H2=2H+ + 2e,] on nickel electrode were measured in solutions free from nickel ions at 185°C, and the parallel curves were obtained by changing PH2 and pH for normal and reverse reactions, respectively. Polarization curves in nickel solutions were complex, probably because the potential of hydrogen electrode is close to that of nickel and of the nickel surface altered during polarization. Then the nickel electrode potential and the reaction rate were measured simultaneously during pressure reduction at various hydrogen pressures and at various nickel concentrations. The reaction rates in terms of current density were plotted to obtain the local polarization curves for reactions Ni2+ + 2e ? Ni and H2 ?2H+ + 2e. The anodic and cathodic local polarization curves exhibit potential dependency. Therefore it is likely that the pres- sure reduction can be regarded as a coupled electrodes reaction.

Jan 1, 1973

By H. P. Greenwald

IN the year just passed the Coal Division's Committee on Rock-Dusting reviewed the status of this safety measure in American coal mines and prepared a paper thereon which will be presented at the February meeting of the Institute. This paper supplements one appearing in Vol. 139 of the "Transactions," page 87 (1940). Because that paper will be issued soon, only a summary is given herein.

Jan 1, 1944