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US 4,190,434 - In the thermal production of magnesium metal, a mixture of calcined dolomite, an iron- silicon-aluminum alloy as a reductant, and residual slag from the production of ferrochromium is smelted to evolve magnesium vapor, which is then condensed. The use of bauxite is lessened or eliminated because of the relatively high alumina content of the residual slag. R. Bonfils, A. Mena, C. Payn, and L. Septier, assigned to Ste. Francaise d’Electrometallurgie (SOFREM). Feb. 26, 1980. 6 pp. (75-10R). Filed: 6-14-78 (915,387). Priority: France, 6-24-77 (77/20,227).

Jan 1, 1982

By Shiou-Chuan Sun

THE fact that coals of different ranks and even of the same rank differ greatly in their amenability to froth flotation is well known. In recognition of the need for an explanation of this phenomenon, two hypotheses have been suggested. Wilkins1 reported that the floatability of coals increased with an increase of the carbon content or rank. This postulate is handicapped by the fact that bituminous coals that possess moderate carbon contents are actually more floatable than anthracite coals that have high carbon contents, as shown in columns 6 and 9 of Table I. Taggart and his associates' implied that the difference of floatability between bituminous and anthracite coal was caused by the variation of carbon-hydrogen ratio. This is not applicable to the relative floatability of other coals and carbons. For example, column 11 of Table I shows that the carbon-hydrogen ratios of low-floating lignitic coal and non-floating animal charcoal are not only smaller than the moderate-floating anthracite coal, but are also similar to the high-floating bituminous coal. Furthermore, according to this hypothesis, high temperature coke-A (464), Ceylon graphite (1238), and lamp-black (357), all possessing extremely high carbon-hydrogen ratios, should be less floatable than other substances having much lower carbon- hydrogen ratios such as high volatile-B bituminous coal (11.9 to 22), anthracite coal (35.7 to 60.5), lignitic coal (15.6 to 33.6), and charcoal (13 to 26.2). However the former group is actually more floatable than the latter group.

Jan 1, 1954

By A. B. Stickney

UPWARDS of 200,000 engineers in this country are sufficiently interested in engineering as a profession to have joined a society, but not over 10% of them belong to any one society. There is a widely-felt need of an over-all organization of all the societies to act as spokesman for all engineers on matters of common concern. On a local basis, over 100,000 engineers in 35 metropolitan areas have organized themselves into local councils, and are doing an effective job of intersocietal co-operation within their sphere of activity. In the last few years much has been said and written about a similar organization on a national scale. Everybody wants iteverybody is talking about it-it's in the air-it's coming-it's inevitable. Although it is no longer necessary to talk about why or whether there should be such an organization, there is no such unanimity about what it should be like. This paper outlines a proposed organization by answering four questions-who, how, what, and who will pay for it.

Jan 1, 1946

By Lyon F. Terry

IN contemplating the prospects of natural gas being transported from the fields where it is produced to such distant points as Philadelphia, New Jersey, New York City, and New England, let us review the advance that natural gas has made and the projects currently scheduled for construction. This may give us a perspective of the point in the long-range development of the natural gas business in which we now find ourselves, and some basis for judging the further expansion of the industry. Authentic statistics of the total marketed production of natural gas in the United States have been compiled by the Bureau of Mines since the year 1906. The growth of the business is indicated by the following data on marketed production for each ten-year interval since 1906:

Jan 1, 1947

By E. R. Johnson

The copper concentrator of the Braden Copper Co. is at Sewell, Chile, on the westem flank of the main Cordillera of the Andes, at an air distance of approximately 50 miles southeast of Santiago, the capital of Chile. The region is mountainous and space is at a premium because of the rough terrain and the danger of snowslides. The ore, a porphyry copper, is mined by a block-caving method in the El Teniente mine. It is hauled to the crushing plant, a distance of 2.6 miles, through a tunnel because of the severe climatic conditions. The usual large, coarsely set, primary reduction machines found in many ore-treating plants are not required because of the mining method employed and the limiting 12-in. spacing of the grizzlies at the head of each ore pass in the mine. It is the purpose of this paper to describe the numerous improvements made in the crushing section of this large flotation concentrator during the past I5 years to increase the efficiency of the plant and to raise the daily output from around 20,000 to 30,000 tons. The reader should keep in mind that all changes were made within the existing building because of the limited space and the high cost of the heavy mill construction required to withstand the snow loads. The present plant, as well as the former, operates on a 24-hr, 7 days a week basis. The crushing plant commenced operations at its present site in 1921, the main equipment being No. 7½ gyratories, followed by 48-in. horizontal Symons disk crushers. Fines were removed by I-in. stationary grizzlies ahead of each unit. In 1924 a third stage of crushing was provided by the addition of 55½-in. rolls in open circuit. During 1925, the Symons disks were replaced by 73½-in. rolls. All the rolls were changed to closed circuit, with elevators and screens to give a final product of 9 pct plus 3-mesh. The flowsheet of a typical crushing section of this period is shown in Fig I. The ore was withdrawn from a common bill serving the five crushing sections in the plant by means of any number up to six 36-in. wide-apron feeders, which discharged onto a common conveyor belt. This conveyor was equipped with a magnetic head pulley and the crusher attendant was stationed near the discharge end to pick out pieces of mine timber that might be in the ore. The ore was discharged over a 13/4-in. spaced bar grizzly and the oversize of this grizzly was crushed by a No. 7½ McCully gyratory crusher set at 13/4-in. opening on the closed side. The grizzly undersize joined the gyratory discharge and was conveyed to a set of 73½ by 20-in. Garfield rolls set at I in. These rolls operated in closed circuit with a bucket elevator and two vibrating screens placed in parallel.

Jan 1, 1949

J. Lainson Wills, Ottawa, Can. (Communication to the Secretary) : The localities of the Quebec and Ontario apatite deposits, and the nature of their occurrence haye been often described in the Transactions and in other publications that are readily available, and I do not, therefore, intend to discuss the many details advanced in Mr. Small's paper beyond the following two points:

Jan 1, 1893

President Howe : It is not so clear to me that the facts which Dr. Waldo brings forward really argue that the nature of the combination between copper and aluminum differs from that of the combination between copper and zinc or copper and tin. As regards electric conductivity, I suppose that the fact, which he thinks points to a special intimate kind of union between aluminum and copper, is that the line in his Fig. 1 is neither straight nor uniformly curved, but that its curvature varies rapidly, not to say abruptly. But we find just such variation in like curves for the copper-zinc and copper-tin alloys. Thus, a slight addition of zinc or tin to copper causes a change in color wholly out of proportion to the quantity added; and, as we add zinc or tin to copper, the tenacity rises very greatly, only to fall off abruptly with further additions of either of these metals. Dr. Waldo : My curve related only to electrical conductivity. The President : If irregularity in one physical property argues

Jan 1, 1895

By George Newton

When Mr. Bailey asked us to present a paper describing our new BOF shop, he requested that we avoid a presentation heavily laden with detail and statistics. Not only have we attempted to do this, but also we have prepared a number of colour slides which, hopefully, will provide you with a graphic conception of the facility. The installation of the BOF facility at the Steel Co. of Canada's Hilton Works was delayed many years because of the remarkable production growth of the oxygen open hearth furnaces in No. 3 shop. However, in mid-1960 it became strongly evident that not only would increased ingot capacity be required, but also that N0.2 shop - with vintage non-oxygen open hearth furnaces - would have to clean its stacks in the near future, or be closed down. A decision to embark on the BOF facility was made in 1967 after an extended period of in-depth planning and assessment of industry trends.

Jan 1, 1972

By Gilbert E. Doan

IN a technical civilization, that is. one whose major difference from past civilizations is its enormous development of technology, in transportation, communication, labor saving, centralized control, and mass production, it is natural that the most critical problems should be those that arise out of technologic advances; it is natural also that a. man who understands these advances should be chosen as the leader to meet these problems. This was done in the selection of Herbert Hoover as President of the United States. Mr. Hoover was a good, and perhaps a great President. But he was not a great politician and that ensured his defeat when a crisis came.

Jan 1, 1939

By W. G. Matteson

The Gulf Coastal plain of the southern United States is that area bordering for a large part, the Gulf of Mexico and extending inland and northward to the main interior highland region. It is more or less V-shaped and includes the States of Florida, extreme southern Alabama, all .of Mississippi and Louisiana, the eastern and southern half of Arkansas, and the eastern, southeastern, and southern portions of Texas. While the contents of this paper apply to. the Gulf Coastal plain in general, they are intended to refer more specifically to that portion of the plain included between the 90th and 97th meridians, and the 29th and 33d parallels, an area that may be described geographically as comprising western Mississippi, all of Louisiana, part of eastern and all of south-eastern Texas. It is within this area that numerous and prolific oil pools have been developed during the last 17 years.

Jan 2, 1918

By C. E. Coleman, D. Hardie, A. E. Wraith

A photoguaplric method of measuring crack velocities has been applied to an examilzation of- the effect of hydrogen on the impact properties of zirconium. Results indicate that the crack in hydrided zirconit travels at about 26 m per sec whereas that in the uacuum -annealed is dependent on the speed of the hammer. RECENT work on the effect of hydrogen on zirconium reveals that when hydrided zirconium is tested in slow bending the crack producing failure can be unstable. The mode of fracture seems to involve the crack linking up broken hydrides by a ductile mechanism in the zirconium matrix.2" In order to compare the fracture of zirconium with that of other metals which show unstable crack propagation, notably steel, the rate of the crack spread must be known. As the methods previously used for measuring crack growth are either unsuitable for the present work5-'' or very costly," a simple technique has been devised in which the maximum crack velocity is derived from a series of crack position-time measurements. EXPERIMENTAL PROCEDURE The experimental arrangement is shown schematically in Fig. 1. The flash unit12 was triggered when the Charpy hammer touched the specimen and the 6-psec flash of the lamp delayed by a preselected time interval in the range 100psec to 10 msec. The camera was left on open shutter during the test. From direct measurement on a calibrated photographic print, Fig. 2, the position of the crack and the specimen was found at a known time after impact and, from a series of such tests using an appropriate range of flash-delay times, the crack velocity was estimated. Preliminary experiments were carried out on mild steel above and below its transition temperature. Vacuum-annealed zirconium, and zirconium hydrided to 100 ppm H were then tested at 20" and 150°C. For comparison, Zr-2.6 pct Nb alloy (in the 0 + transformed /3 condition), vacuum-annealed or hydrided to 100 ppm H, was tested at 20 C. The chemical analyses of these materials are given in Table I. For the high-temperature tests a fine chromel-alumel thermocouple was spot-welded onto each specimen close to the notch. The test piece was heated up to 200°C to allow enough time for preparing the apparatus while the specimen cooled to the testing tem- perature. It was assumed that the specimen cooled uniformly. The accuracy of the flash-delay time was better than i2 pct i 5 psec. The crack length was taken as its maximum distance traveled normal to the length axis of the specimen. Errors in these measurements arise as a result of the uncertainty in the location of the crack tip and the difficulty in defining the exact position of the crack starting point. The latter was due to the bonding and large amounts of deformation at the hammer contact point, especially in the vacuum-annealed specimens tested at 150°C. The maximum error in the measurements was however estimated to be about 5 pct. DISCUSSION OF RESULTS From the trial experiments using mild steel above its transition temperature it can be seen from the plot of crack length against time after impact, Fig. 3. that a reasonable estimate of the maximum crack velocity at the surface of the specimen may be made. Other features of note are the initiation time before the crack is first seen and the slowing down period

Jan 1, 1967

By William T. Folwell

The Lucky Friday mine east of Mullan, Idaho, is an outstanding example of a property in the Coeur d’Alene district where a small and insignificant- appearing silver-lead-zinc vein at the surface has changed at depth into a large vein of great importance. The Lucky Friday vein has little if any surface expression and above the 1200 level the ore shoots are small and discontinuous. Between the 1200 level and 2450 level, the lowest developed level, the main ore shoot has shown remarkable improvement on each succeeding lower level, and today the mine is one of the major lead-silver producers in the Coeur d'Alene district. History: The Lucky Friday property is on the north side of the South Fork of the Coeur d'Alene River in sections 25, 26 and 35, T. 48 N., R. 5 E., Hunter mining district, Shoshone County, Idaho. This is about one mile east of the town of Mullan, which serves the eastern portion of the Coeur d'Alene district. The southern part of the property is crossed by a branch line of the Northern Pacific Ry. and by U. S. Highway 10. This highway is the principal road crossing the panhandle of Idaho and connects the district with Spokane, Wash., on the west and Missoula, Mont., on the east. The main portal and surface plant of the Lucky Friday mine is at an elevation of 3365 ft, only a short distance above the valley floor and a few hundred feet from U. S. Highway 10, so the mine is readily accessible for year-round operation.

Jan 12, 1958

By AIME AIME

EVEN though most of the program of the joint meeting at Easton, Pa., on Oct. 30 to Nov. 1. was devoted to the interests of combustion engineers rather than to coal-mining engineers, nevertheless the A.I.M.E. Coal Division was well represented, with 83, or close to one third of those in attendance giving this as their affiliation. The fuels division of the American Society of Mechanical Engineers had 108 representatives, and an equal number reported no society affiliation. Added to the men's total registration was that of some twenty ladies so the total attendance was in the neighborhood of 325, exceeding that of the last two joint meetings, at Birmingham and Columbus, and equaling the 1938 crowd at Chicago.

Jan 1, 1941

Jan 1, 1897

By H. F. Dunlap, R. R. Hawthorne

A method of calculating formation water resistivities from chemical analyses is presented which is somewhat faster and more accurate than previously described methods. For 26 formation water samples taken from wells in the Texas Gulf Coast, the average deviation of calculated from measured water resistivities was 3.3 per cent, with an average bias of + l.l per cent in the calculated values. This compares with average deviations of 4.6 per cent and 7.8 per cent, with corresponding average biases of +3.2 per cent and -6.3 per cent, for the two methods previously described in the litera-

Jan 1, 1951

By R. R. Hawthorne, H. F. Dunlap

A method of calculating formation water resistivities from chemical analyses is presented which is somewhat faster and more accurate than previously described methods. For 26 formation water samples taken from wells in the Texas Gulf Coast, the average deviation of calculated from measured water resistivities was 3.3 per cent, with an average bias of + l.l per cent in the calculated values. This compares with average deviations of 4.6 per cent and 7.8 per cent, with corresponding average biases of +3.2 per cent and -6.3 per cent, for the two methods previously described in the litera-

Jan 1, 1951

By John H. Schilling

The Gabbs magnesite-brucite deposit is unique in size and is one of two magnesite deposits being exploited in the United States. It is near the town of Gabbs, which is one hundred miles southeast of Reno, in west-central Nevada. The brucite was discovered in 1927; the magnesite was found while exploring the brucite. During World War II, more than 80,000 tons of magnesium metal was produced from about 900,000 tons of magnesite ore mined from these deposits. An additional 5,000,000 tons of magnesite and 1,000,000 tons of brucite have been produced for use in making magnesia refractories and chemicals. Basic Inc., presently the only producer, mines 1.5 ± 0.25 million tons of ore and waste annually using high-selective open-pit rriethods; the ore is up-graded, calcined, and processed into a variety of products. Known reserves of highgrade (less than 5 per cent CaO) magnesite ore total more than 25,000,000 tons, and there are larger tonnages of lower-grade material; brucite reserves are small. The magnesite and brucite are in generally west-dipping dolomite of the upper member of the late Triassic Luning Formation, in the over-riding plate of the Paradise thrust fault. A great variety of dikes and a stock of Cretaceous granodiorite intrude the Luning Formation in the vicinity of the magnesite-brucite deposit. The magnesite bodies are scattered over an area of about a square mile around a prong of granodiorite which extends north from the stock. The brucite is mainly in two bodies in contact with the prong of granodiorite; at the surface and along deeper cracks the brucite has weathered to hydromagnesite and artinite. In the area of magnesite-brucite mineralization, much of the dark, fine-grained, schistose, regionally-metamorphosed dolomite of the Luning Formation has been marmorized to a lighter-colored, coarser-grained, massive dolomite that is intergrown in varying proportions with the magnesite. The magnesite and marmorized dolomite can not be distinguished visually. In addition to the two varieties of dolomite, the gangue in the magnesite and brucite bodies mainly is the various varieties of dike rock, serpentine and a variety of other "contact" minerals, and "post-ore" dolomite and calcite. The magnesite ( and recrystallized dolomite) is believed to have formed by the hydrothermal replacement of the regionally metamorphosed sedimentary dolomite; alternatively it has been suggested that the magnesite is sedimentarv and formed contemporaneously with the dolomite in an embayment of the Triassic sea. Because all the igneous rocks exposed in the immediate vicinity of the magnesite deposits appear to be younger than the magnesite, the ore-forming solutions are thought to be related to a somewhat older granite which crops out elsewhere in the area. The brucite is the result of contact-metasomatic replacement of magnesite during the emplacement of the granodiorite stock.

Jan 1, 1968

By Verne C. Fryklund, S. Warren Hobbs

The Coeur d'Alene district in the panhandle of Idaho is one of the major lead-zinc-silver producing areas in the world. The value of recorded production to date has exceeded $2 billion. Country rock comprises six formations of the fine-grained, highly siliceous, and slightly metamorphosed Precambrian Belt Series. Small stocks of monzonitic rocks and several varieties of dikes intrude the sediments. The district is at the intersection of a north trending major anticlinal uplift and the west northwest-trending Lewis and Clark line of which the Osburn fault is the dominant feature. The district structure is complicated and comprises folds, some of which are overturned, and a complex of faults of diverse ages and directions of movement. Late Cretaceous stocks but are also probably Cretaceous in age. The productive veins are localized within a series of 12 subparallel, straight mineral belts that trend approximately N65°W and that appear to be controlled by deep fractures in the basement rocks. The mineral belts are in two groups, separated by 15 miles of post-mineralization movement on the Osburn fault. Veins and ore shoots are variously disposed within each mineral belt. Many crop out at the surface, but others apex several thousand feet beneath it. Local controls that influence the position of ore shoots within the mineral belts include the brittle character of host rock attitude of bedding relative to the mineralized fracture, and the amount and direction of movement on faults. Depth appears to have had little effect on the occurrence or type of ore. Ore occurs in a series of steeply dipping replacement veins of relatively simple mineralogy. Six periods of mineralization, ranging from Precambrian to Tertiary in age, are recognized. The productive galena sphalerite-bearing and tetrahedrite-bearing veins-of the main period of mineralization-are younger than the

Jan 1, 1968

By Arthur F. Hagner

The titaniferous magnetite deposit at Iron Mountain, Wyoming, is in Precambrian anorthosite. Individual ore bodies are lenses, commonly arranged en echelon, conformable to the platy crystal structure and compositional layering of the anorthosite; a few transect these features at various angles. The ore bodies are on the east flank of the principal anticline in the anorthosite mass. Magnetite and ilmenite, accompanied by spine!, are the ore minerals. The principal gangue minerals are olivine, which was introduced with the ore, and plagioclase, the chief constituent of the anorthosite. The anticlinal region appears to have been a structurally weak zone, and westward-bowing curves of the axis were especially favorable sites for localization of the two largest massive ore bodies. These bodies are synclinal and plunge southeast. The proportion of magnetite-ilmenite to olivine and to anorthosite appears to be related to structural features. Where magnetite-ilmenite is present with olivine, the magnetite-ilmenite is encountered along the most pronounced parts of a fold where anorthite content is highest, whereas olivine is associated principally with more gently folded portions. During granulation and recrystallization of the anorthosite mass, temperature and pressure changes furnished the energy required to release and mobilize iron and other elements that migrated to areas of low pressure, the ore zone. Some iron and magnesium may have combined with silica from partly dissociated plagioclase to form olivine. The ore formed by replacement of anorthosite as indicated by: (1) the marked changes in mineralogy along strike, dip, and plunge of an ore body; (2) the concentration of massive ore in folds and olivine on limbs; ( 3) the halo of low-grade mineralized rock that transects the structure of the anorthosite in the hanging wall; and ( 4) the layering in the large southern ore body, that strikes more easterly than the trend of the body.

Jan 1, 1968

By AIME AIME

ALMOST as many attended the annual dinner this year as last, when the presence of Mr. Hoover was such an attraction that almost two-thirds more than had ever attended before were present. Only by putting the late comers at tables in the balcony could everybody be accommodated. Past President De-Golyer was the toastmaster and in opening the post-prandial exercises referred to the regrettable fact that this was the last of the long series of dinners which have been held at the Waldorf, as the hotel will be torn down to give way to an office building before another year. To the delight of the gathering "Oscar" appeared and, in a delightfully brief but characteristic speech, referred to the long association that had existed and hinted that a new Waldorf-Astoria may arise, where the Institute could continue to gather annually in an enlarged replica of the room they had met in so long. Before taking up the presentation of the medals, Mr. DeGolyer referred to the Institute's "Legion of Honor," the 34 men who have been members continuously for over fifty years. For various reasons only five of them, W. S. Ayres, F. G. Corning, Henry D. Hibbard, A. F. Schneider and Arthur Thacher, could be present. They were all seated at the speaker's table, and W. S. Ayres, 56 years a member, as the dean of the group, was called on to respond for them all. He said: "The introduction I have just received would indicate that this particular group of men to which I belong is considered by the chairman to be a group of real antiques. Possibly you are questioning the accuracy of his judgment. I hope you are, although there may be some first-sight evidences tending to substantiate the view held by the chairman.

Jan 1, 1929