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Univ of Alabama-University, Alabama-Mining and Metallurgical Society William L Mason, Faculty Sponsor, E C Wright, Dept Head Univ of Alaska-College, Alaska-Mining Society of the Univ of Alaska Douglas W Huber, Faculty Sponsor, E H Beistline, Mining & Metallurgy Dept Head, Troy L Pewe, Geology Dept Head, James Crawford, Chapter Counselor Univ of Arizona-Tucson, Arizona-Miners Society Willard C. Lacy, Faculty Sponsor, J D Forrester, Mining & Metallurgy Dept Head, F. W Galbraith, Geology Dept Head Univ of California-Berkeley, California-Mineral Technology Association H E Hawkes, Faculty Sponsor, Joseph A Pask, Dept Head Carnegie Inst. of Technology-Pittsburgh, Pa -The Metals Club William R Bitler, Faculty Sponsor, Robert F Mehl, Dept Head

Jan 1, 1960

By H. M. Chance

The Taviche district is about 12 miles from the town of Ocotlan in the State of Oaxaca, and about 250 miles south of the City of Mexico. Its altitude rises to something more than 5,000 ft.; and although within the tropics (latitude about 17° N.) the climate is mild and salubrious, neither excessively hot in summer nor cold in winter. The phrase, "perpetual spring," which has been applied to it, aptly describes the weather during my stay. Sugar-plantations, bananas and other tropical and semitropical fruits flourish in the valleys, while the hills

Jan 1, 1905

Jan 1, 1916

[Appalachian Petroleum Section: Chairman: Robert H. Edele, 1st V.C.: Robert Vutech, 2nd V.C.: Robert Tullis, Sec.-Treas.: Frederick T. Solomon. Meets last Tuesday of each month in Charleston, W. Va. Balcones Section: Chairman: Dr. Frank W. Jessen, 1st V.C.: Gilbert M. Andreen, 2nd V.C.: Lloyd N. Johnson, Seo.-Treas.: W. C. Vercellino. Big Horn Basin Subsection: Chairman: B. E. Yester, 1st V.C.: Robert J. Woodhall, 2nd V.C.: Herbert A. Koch, Secretary: Dean Costello, Treasurer: Thomas W. DeLong. Meets 2nd Wednesday; alternating between Cody and Worland. Billings Petroleum Section: Chairman: George O. Ellis, 1st V. C.: Robert L. Spottswood, 2nd V. C.: Robert M. Watkins, Sec-Treas.: Joseph H. Bato. Meets 5:30 p.m., 3rd Tuesday at Billings Press Club.]

Jan 1, 1961

By Joseph B. Darby, Paul A. Beck

IN isothermal sections of several ternary systems, the a-phase was found1 to extend in the form of a relatively narrow elongated field, connecting the U-phases that are present in the adjoining binary systems. This was interpreted in accordance with the conception that the U-phase is an electron compound and the ternary U-phase fields were shown in several systems' to extend approximately in the direction of constant average d-shell electron vacancy number per atom. ' However, in the various isothermal sections of the Fe-Cr-Mo system" the ternary a-phase field was

Jan 1, 1958

By F. H. Buttner, E. R. Funk, H. Udin

A. P. Greenough (University College, swansea, Great Britain)—I have recently made some experiments on the deformation of silver wire at high temperature in an atmosphere of oxygen-free nitrogen. The observa-tions which 1 made confirm the main conclusion of this paper, that the most satisfactory mechanism so far suggested to explain the deformation which takes place

Jan 1, 1953

By Etienne A. Ritter

The Evergreen mine, located at Apex, in the northern part of Gilpin county, Colorado, has opened a very peculiar and interesting copper-deposit, in which both bornite and chalcopyrite occur as rock-minerals. The country-rocks are crystalline schists cut by dikes of granu-lite and of pegmatite. At the Evergreen property they have been cut by a dike of a uew kind of eruptive rock, to which I have given the name " Evergreenite." The rock is composed of quartz, alkali feldspars, orthoclase and albite (often interlocked as microperthite), with augite of the ægirine variety and long needles of enstatite and diallage. For reasons stated below, I believe the dike to be of Tertiary age. It is easily traced on the surface of the ground, from a point in the bottom of Pine creek, about a mile below Apex, to the top of Nevada hill, 1,500 ft. beyond and 600 ft. above it. (See Fig. 1.) It varies from 3 to 12 ft. in width, and is bounded on both sides by contact-zones about 60 ft. wide, in which the crystalline schists have been changed into pseudo-quartzites or pseudo-gneisees, according to the injection of an excess of quartz or of feldspars through the special layer of the schists. The most interesting feature is the presence of the pyroxenes, which are always found, though in very variable proportions from place to place, in the layers of these metamorphosed crystalline schists. The dike has torn from its walls a large number of fragments of the wall-rock. It must have been in a viscous state when that happened, because these fragments of the wall-rock do not show any sign of resorption or of assimilation by the magma. In places they are so distinct and so numerous that the rock looks to the naked eye like a pseudo-breccia, of which, never-

Jan 1, 1908

By Richard A. Sheppard

Zeolites-crystalline hydrated aluminosilicates of the alkalis and alkaline earths-are important rock-forming constituents in sedimentary rocks and are potentially valuable industrial minerals. They have a framework structure that encloses interconnected cavities occupied by the relatively large cations and water molecules. The cations, chiefly sodium, potassium, and calcium, and the water have considerable freedom of movement within the structure and give the zeolite their cation- exchange and reversible-dehydration properties. Some zeolites have essential contents of barium, strontium, or magnesium. The basic structure

Jan 1, 1975

By Charles H. Morgan

Jan 1, 1905

By Frank Firmstone

IT is often desirable to obtain one or more accurate horizontal sections of a blast furnace after blowing out. Wishing to do this, last April, in the case of No. 4 furnace at Glendon, which had worn in a very remarkable manner, the method described below was employed, with very good results. A scaffold was fixed in the furnace, and on it was placed a drawing- board, covered with paper, the top of which was made level at exactly the height at which the section was to he taken. (Fig. 8.) The centre of the furnace (which had previously been found, and marked on a plank across the top) was laid off on it by dropping a plumb-bob from above, and a strong needle was driven into the board in the centre. By means of a straight-edge and two plumb- bobs, the line passing through the centres of the front and back arches was also drawn on the board. A pencil was fastened to a light wooden straight-edge at a known

Jan 1, 1875

By R. B. Toombs

The national and international importance of Canada's minerals and metals producing industry is reported. The growth of the Canadian industry is traced from 1945, through the period of rapid development of the early 1950's, to the consolidation and expansion activities of the late 1950's and early 1960's. Mineral production in Canada during 1963-including steel, nonferrous metals, and fuels -is reported. It is estimated that by 1970 the Canadian industry will produce $3.9 billion worth of metals, nonmetals, and fuels.

Jan 8, 1964

The members of the Institute living in the lower Mississippi Valley, I extend a hearty and cordial invitation to their fellow-members to meet with them nest October, in St. Louis. They believe that it will be a meeting of singular interest, inasmuch as the district in question can show in active production almost all of the more useful metals and non-metals. Perhaps too few know that the Southeast Missouri District, about 80 miles south of St,. Louis, and to which a special trip is planned, is the largest lead district in the world. It was that before-the European war, and, now that the production of lead has greatly increased abroad, and has correspondingly increased in the United States, this is one of the most interesting of all lend districts. In 1913, the production of the world was 1,270,000 tons, the last world figures obtainable. In that same year the production of the United States

Jan 5, 1917

By Frank Firmstone

It is often desirable to obtain one or more accurate horizontal sections of a blast furnace after blowing out. Wishing to do this, last April, in the case of No. 4 furnace at Glendon, which had worn in a very remarkable manner, the method described below was employed, with very good results. A scaffold was fixed in the furnace, and on it was placed a drawingboard, covered with paper, the top of which was made level at exactly the height at which the section was to he taken. (Fig. 8.) The centre of the furnace (which had previously been found, and marked on a plank across the top) was laid off on it by dropping a plumb-bob from above, and a strong needle was driven into the board in the centre. By means of a straight-edge and two plumbbobs, the line passing through the centres of the front and back arches was also drawn on the board. A pencil was fastened to a light wooden straight-edge at a known

By R. M. Brick

Segregation can occur only in cast alloys that solidify over a range of temperatures with a difference in composition of liquid and solid phases within this range (ignoring monotectic systems and chemical reactions as in rimming steels). Thus a pure binary eutectic alloy should show no segregation unless undercooling occurs for one of the solid constituents of the eutectic; e.g., chill-cast Al-I2 per cent Si alloys. The phasial condition implicitly described above—solidification over a range of temperatures with a compositional difference between solid and liquid—is found in nearly all solid solutions or combinations of solid solutions and eutec-tics, Metastable conditions of solidification of these types of alloys cause coring; i.e., a difference in composition between the center of a dendrite and its periphery. This composition gradient can be detected usually only by microscopic examination of etched structures; it is a "micro" effect. The gradient of more immediate industrial concern is that between the center of a cast section and the surface layers. This gross (macro) effect is usually deter-minable only by sampling of the casting at different points, with chemical analyses of each sample. If the compositional difference is of the same type as in coring, the first parts to freeze being enriched in higher-melting-point constituents, and vice versa, the effect is called normal segregation. When what is apparently the first part of the casting to solidify shows a higher concentration of low-melting-point constituents, the effect is called inverse segregation. These macro effects are quite separate from the micro effect, coring, yet the latter must be described first because it is an essential part of the picture. Coring Solid Solution, Ni-Cu The nickel-copper phase diagram is reproduced in Fig. Ia, in which the solid lines represent the equilibrium liquidus I, 3, 7 and solidus 2, 5, 8, and where the vertical I, 4: 8 represents a 55 per cent Cu alloy. Upon moderately rapid solidification, the first dendritic axes of composition 2 (see Fig. Ib) start to form at a temperature somewhat under I. Solidification continues by growth of the dendritic nuclei, but at temperature 4 the increment solidifying is of composition 5. The rapidity of this crystal growth prevents diffusion of nickel and copper atoms from adjusting the composition of the entire dendrite at 5, which it would be under equilibrium conditions. The average composition of a specific dendrite, or the entire solid phase, at temperature 4 might be that indicated

Jan 1, 1945

By H. W. Rogers

THE first steam shovels used in this country were built by the Otis Company, of Boston, about 50 years ago, but as they were of very crude construction and rather unsuccessful only a few were built. For possibly 10 years prior to 1884 successful steam shovels were made and used on certain classes of work, but it was not until that time that they were manufactured in quantities and began to play an important part in all classes of excavation. From that time up to the present day there have been gradual but continuous improvements on the original shovel, not only in the mechanical construction, but also in the design of boilers and engines which are best adapted to this class of service. In proposing a change from steam to electric operation we have to deal with a steam equipment which has not only proved its worth but has probably reached its highest stage of development and efficiency. That the electric shovel is a possibility cannot be denied, as at present from 12 to 18 shovels are in operation in this country. These shovels may be divided into three classes: the friction electric, which is operated by a single constant-speed motor with friction clutches; the three or four motor direct-current equipment, and the three or four motor alternating-current equipment. It is the second and third classes that I wish to deal with, as the first class does not compare favorably with the steam shovel so far as speed is concerned, although it may be operated as cheaply. There is probably no other class of machinery that presents a duty cycle as severe as that of the shovel, which is very short, varying from 7 to 12 sec. on the hoist, from 7 to 12 sec. on the thrust, and from 10 to 18 sec. on the swing, making a complete cycle in from 17 to 30 sec., and the motor to meet these requirements must have a sufficiently low armature inertia to permit of rapid acceleration and quick reversals under small power. It should also be a motor of rugged design, as it must be subjected to severe overloads and shocks and frequent reversals. This is especially true of the hoist motors and, to a lesser degree, of the swing motor; the thrust motor being practically stalled during the digging operation, although it may revolve or overhaul, according to conditions, and is operated at full speed only after the hoisting operation is completed.

Jan 2, 1914

The total estimated production of coal in the United States during the first century and a quarter of mining is shown in Table 20. This is the total of the production of the various states already shown in the various tables, and is believed to be the first statement of this sort made. No such table prepared from limited data can be accurate, but it is the writer's opinion that the totals shown are less than those actually produced. It was thought that this study would enable a reasonably accurate account of the movement of coal down the Ohio and Mississippi Rivers to be written. The searches made have shown that at this time the data do not exist from which such a study can be made, but some of the facts collected may be useful to future students.

Jan 1, 1942

By P. W. Bridgman

Flow and fracture are admittedly complicated phenomena of which we are yet only partially masters. There is not even nni-.persal agreement as to the details of the language best adapted merely to describe the phenomena, to say nothing of any theory. Certain points of view, however, are widely held, and there are certain general expectations as to what sort of procedures will prove permissible. A complete description of any situation involving fracture would demand a complete history of all the variables in the control of the experimenter. The experimenter endeavors so to choose his independent variables that they are adequate to determine completely the situation in the sense that when an experiment is repeated on the same initial material and with the independent variables running through the same sequence, all the other measurable properties of the system will also run through the same course. It is, I think, the universal conviction that when we are dealing with phenomena of flow and fracture, the most important of the necessary variables are the external forces acting on the various parts of the body; when the force history repeats, with certain obvious restrictions such as that temperature must be constant and non-mechanical forces, such as magnetic field, must be small enough to be ineffective, then the history of all measurable properties will repeat; in particular the alteration of geometrical shape due to flow will run through the same course, and when fracture comes, the character of the fracture will be reproduced. Complete mastery of merely the descriptive aspects of flow and fracture would demand the ability to predict the entire course of flow and complete characterization of the final fracture for every possible combination of forces, varying in time in all possible ways, when applied to bodies of all possible shapes. This full situation is obviously of prohibitive complexity. The first stage in reduction to manageable simplicity is to resolve the total situation into the sum of contributions made by small elements. Our thesis is that if each of the elements is adequately characterized, the behavior of the whole system is fixed. The element is usually taken of a simple geometrical shape, suggested by the mathematics best adapted to the particular situation. The forces acting across the faces of the elements are ultimately determined by the forces acting across the free faces of the whole system. The detailed process of finding the precise forces on the faces of all the elements in terms of the external forces involves the use of a special mathematical invention, the stress, a constructional quantity consisting of six components. The stress at any point in the body is determined by both the external force system and by the physical properties of the body at all points; quite different stresses prevail at the interior of bodies of the same shape under the same external forces in the elastic and plastic ranges. The forces on the faces of any element are, however, uniquely determined by the stress system at the element. Our fundamental thesis

Jan 1, 1945

Jan 1, 1879

By R. W. Smith, Z. Sadowski

The stabilities of finely divided mineral suspensions were determined as functions of pH and concentrations of polyethylene oxide, sodium ligninsulfonate, sodium dodecybulfate, and sodium oleate. In addition, the electrokinetic potentials of the minerals were determined under identical pH and additive concentration conditions. Flocculation or dispersion of the suspensions is discussed in terms of both the amount and manner of adsorption at the appropriate solid-liquid interface as it is influenced by additive concentration and pH.

Jan 1, 1986

Jan 1, 1894