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By T. A. Rickard

T HE life and career of Daniel Cowan Jackling constitute a distinctive part of a passing era, marked by the intensive exploration and exploitation of the mineral resources of the western regions of the United States. In the development of his abilities and in the use of his opportunities, he typifies the initiative, the energy, and the skill of a modern captain .of industry. Daniel C. Jackling was born at Hudson, Mo., on Aug. 1.4, 1869. He was the only child of Daniel Jackling, born in England of English parents, and Lydia Jane (Dunn) Jackling, born in the United States, but of Scottish ancestry. His father died a few months after he was born, and he lost his mother less than two years later. The orphan boy was adopted by his aunt. He went to school as soon as he was old enough to walk the two miles, and back, alone. As opportunity offered, he went

Jan 1, 1937

By R. W. Smith

IN the manufacture of portland cement, the basic and fundamental essential is a limestone uniformly rich in calcium carbonate and carrying less than 3 per cent magnesium carbonate. In searching for such a deposit, also having in mind quantity of rock, accessibility and quarrying facilities, the Pacific Coast Cement Co. discovered and developed its present quarry at View Cove on the east coast of Dall Island, Alaska. Dall Island is about 100 miles west of Ketchikan and 650 miles north from Seattle. It is 70 miles in length and 5 to 10 miles in width. The climatic conditions are much more favorable than would be expected. The temperature ranges from zero to 70 degrees. The precipitation is considerably more than at Seattle, although there was less snow during the last season than at Seattle. The island is rugged and mountainous; the vegetation is moss and grass and a large portion is timbered with spruce, hemlock and cedar. Some of this timber has market value. The limestone quarry is about 30 miles north of the extreme southern end of the island. The company acquired 240 acres which contain limestone of remarkable uniformity, the percentage of calcium carbonate being about 95. It is estimated that there is ample recover- able rock on the holdings to supply the cement plant at its maximum capacity for well over 100 years.

Jan 1, 1929

By V. F. Swanson

At the AIME meeting in Tampa in Oct. 1966, an empirically developed equation was presented which allowed the calculation of free settling velocity for any sized particle: 1 [ ] This equation requires the use of two parameters a and p which are coefficients derived from boundary layer theory.2 It was possible to develop values of a and p for several minerals by back calculation of published data. The original equation had one major flaw. When the fluid density exceeds the density of the solids, the solution to the equation becomes imaginary. A flaw was indicated also by the fact that galena and sylvite both having cubic cleavage, did not have similar values for a and b. Galena gave calculated values of a = 1.082 and g = 3.11, while sylvite gave values of a = 1.870 and p = 2.56. These flaws prompted further study of the equation, resulting in the following empirical modification: [ ] It is obvious a real solution of the equation is possible for all values of ps and p. When PL > PS, V is negative, indicating that the particles will rise against the attraction of gravity. The validity of the modification is borne out by the fact that when values of a and p were back calculated for galena and sylvite using the modified equation, both minerals gave values of a = 1.038 and p = 3.01. With the modification shown in Eq. 2, Newton's friction factor becomes [ ]

Jan 1, 1976

By AIME AIME

READERS of a technical paper, or the audience if the paper is presented orally, judge the paper on several counts. The September 1940 issue of MINING AND METALLURGY contained an excellent short article by S. Marion Tucker en- titled "Are You Going to Present a Paper," which considered the general subject of presentation. In it Dr. Tucker referred to the large number of poorly prepared and badly delivered papers that are presented annually before the large number of technical and other societies that meet regularly, and he stressed the point that good delivery, length of paper, content, and composition are of great importance. All of Dr. Tucker's points were well taken; however, good illustrations are equally important in explaining certain phases of some papers.

Jan 1, 1941

By F. O. Garrabrant

Power is furnished to the Climax Molybdenum Co. by the Public Service Co. of Colorado over two 100,000-volt lines to a bank of three 3333-kva. transformers 100/13.8 kv. These transformers are so designed that with the addition of forced cooling their capacity may be increased 331/3 Per cent at 12,000-ft. altitude. Under present conditions, these transformers are operated at 140 per cent of their rating with forced air cooling. On the secondary side of this bank there is a 15-kv., 1200-amp. Westinghouse oil circuit breaker provided with automatic reclosing relays allowing three successive short circuits before lockout. From this breaker 13.8-kv. power is transmitted to a central switching station (Fig. I) where all circuits radiate to the different operations of the property. Each circuit is protected by a 23-kv., 600-amp. oil circuit breaker with by-pass and isolating disconnecting switches.

Jan 1, 1947

By David Turnbull

IN isothermal recrystallization processes, new crystals generally grow into the matrix until they impinge upon other new crystals or an external surface, at constant linear rates G. Before impingement the perceptible course of growth can be described by the equation: 1 = G(t-7) C1I where, G = dl/dt, 1 is a crystal dimension measured in a constant direction, t is the time, and 7, the nucleation period, is a positive intercept on the time axis. Fig. 1 is a schematic representation of I as a function of time for a recrystallizing grain. G is dependent upon temperature, driving energy (strain or surface energy), relative grain and boundary orientations, but is generally independent of time. The frequency of nucleation, fi, (time" volume") can be defined by the equation: N = 1/fV [2] where ? is the mean nucleation period and V is the volume of the specimen that has not recrystallized. The kinetics of primary and secondary recrystallization generally can be described satisfactorily in terms of the parameters N and G only.'-" After recrystallization is complete the average grain size 7 increases with time by "normal grain growth;" didt, the average rate of grain growth, is strongly time dependent and has not yet been precisely related to G for the motion of the individual grain boundaries constituting the system. It has been suggested4* " that the elementary act in grain boundary migration is closely related to the elementary act in grain boundary self-diffusion. Although the distance of atom movement in the two processes may be somewhat different, there is reason to expect that the activated states may be very similar, so that the free energy of activation for grain boundary migration should be of the same order of magnitude as for grain boundary self-diffusion. Therefore, it is desirable to develop a satisfactory basis for comparing data on self-diffusion and grain boundary migration and to make such comparisons where possible. Theory The formal theory of grain boundary migration rates is analogous to the theory for the rate of growth of crystals into supercooled liquids reviewed elsewhere 6-8. Boreliuss has shown that the latter theory describes, within the theoretical uncertainty, the growth of selenium crystals into supercooled liquid selenium. Motto and more recently Smolu-chowski" have derived expressions for the rate of boundary migration in recrystallization. The treatment to be presented is similar to Mott's excepting that the formalism of the absolute reaction rate theory will be used. The atomic mobility, M, in grain boundary migration is defined by: G = -M6p/6x where p is the chemical potential per atom and x is the coordinate measured in the direction of grain boundary movement. Let AF be the free energy difference per gram atom on the two sides of the boundary and k the thickness of the boundary. For RT>>AF the potential gradient across the boundary (6p/6x) is essentially linear and it follows that: SF/8x = - aF/N\ [4] where N is Avogadro's number. According to the Nernst-Einstein equation, M is related to a diffusion coefficient, Do, for matter transport in grain boundary migration by the equation: M = Da/kT [5] Substituting eqs 4 and 5 into eq 3 gives the basic relation between Do and G: G = DoaF/\RT [6] Do values may be calculated from experimental values of G from eq 6 and directly compared with the coefficient of self-diffusion within the crystal, DL, or the grain boundary self-diffusion coefficient D,. However, a more convenient, though equivalent, basis for comparing atomic mobility in grain boundary migration and self-diffusion is through the constants of the absolute reaction rate theory. According to this theory diffusion coefficients may be written:" D = k2(kT/h) exp [-AF,/RT] 171 aFa, the free energy of activation, is related to the measured energy of activation, Q, by the equation: AFA = Q - T aSx - RT [8] where aSa is the entropy of activation. Substituting eqs 8 and 7 into eq 6 gives: G = ek(kT/h) (aF/RT) exp [(AS,,)C/R] exp C-Qc/RTI C91 where the subscript G refers to boundary migration. The relationship between the driving free energy and the free energy of activation in boundary migration is indicated schematically in Fig. 2. Experience indicates that the variation of G with temperature can be described by: G= Go exp [- Qc/RT] [10] where Go and Qc are generally temperature independent over wide ranges of temperature. Comparison of eq 9 with eq 10 gives:

Jan 1, 1952

By R. E. Reed-Hill

The shear continuity conditions under which one mechanical twin may cross another are considered. Twin intersections usually involve various types of slip deformation in addition to twinning. Because the shear of the crossing twin may be partly transmitted through the crossed twin by slip mechanisms, continuity of the twinning shear vectors is not required at a twin intersection. It is concluded that analyses based on twin intersections should not he used as an independent method for deducing twinning elements in newly observed twinning modes. WHEN one mechanical twin passes through another, a twin intersection is said to occur. In the simplest form of intersection, Fig. 1, the crossing of one twin by another is accomplished with the aid of a second-order twin induced, in the twin that is crossed, by the crossing twin. The subject of twin intersections is significant to the field of deformation studies because it has been postulated by cahn1 that twin intersections should occur only under the following continuity conditions: 1) the traces of the primary and second-order twin must be parallel to each other in the plane of the crossed twin; 2) the direction 771 and magnitude, S, of the twinning shear must be identical in the crossing and second-order twins; also, the sense of shear must be the same. If these postulates are valid they constitute a valuable tool for determining twinning elements of newly observed twinning modes in metals. In his classic paper in 1953 on the plastic deformation of a uranium, Cahn1 used these continuity conditions to deduce twinning elements for several uranium modes. However, in the same year, pratt2 showed that both of Cahn's continuity equations were violated for (1012) twin intersections in zinc. Later, Kiho and Maruyama3, 4 showed that Cahn's second postulate was violated in {301) and (101) twinning in tin and (101) twinning in bismuth. In spite of this documentation that Cahn's second postulate is often violated, several recent papers5'6 have been published which have attempted to use the condition of continuity of twinning shear vectors for the evaluation of twinning elements. The primary purpose of this paper is to call attention to the possible ambiguity inherent in applications of Cahn's postulate, and to present additional information concerning the nature of twin intersections.

Jan 1, 1964

By E. Ray Webb

A interest to geologists and to mining and petroleum engineers is a laboratory method for determining the dip and strike of sub- surface structures, as well as the direction of fault planes traversing them. The information is derived by making use of the magnetic properties of borehole cores which must show visible representations of bedding or fault planes. Complete knowledge of these factors aids greatly in the successful exploitation of both ore and petroleum deposits.

Jan 1, 1940

By R. T. ROLFE

IN this critical age, people are not content .with the judgments passed on men and things long ago, but must needs revise them. It is an excellent spirit, so long as we do not start out with the idea that old opinions must necessarily be wrong, and that all ancient malefactors must therefore be whitewashed. That interesting ogre, Gilles de Retz, to whom the process has recently been applied, is no longer with us, so no one will be the worse for it, but the old bugbear8 of the steelmaker, sulfur and phosphorus, still are, and now Mr. McIntosh, in a recent article in these pages, asks us to regard one of them in a new light.' This article is a most interesting one, with much of which one must agree. One of his -statements, how- ever, although correct, is somewhat' misleading, and he rather discounts the fundamental objection of the steelmaker to phosphorus, its dangerous propensity to segregate and the secondary effect on the carbon distribution and therefore on the homogeneity of the steel that is produced thereby. Further, the evidence on which he bases his claim that phosphorus does not lower the impact strength of steel is rather slight. The writer views with the utmost misgiving any proposal to increase the amount of phosphorus in steel, and cannot regard it in any other light than as a prejudicial impurity, to be kept down to as low a proportion as possible. It thus becomes necessary to examine the evidence upon which Mr. McIntosh's claims are based

Jan 1, 1926

By C. V. Millikan

TEMPERATURE measurement in wells is an old practice and geothermal gradients have been of interest to geologists for many years.1,2 Their application to the operation of oil wells is a more recent practice. It has long been recognized that temperature anomalies occur in drilling and producing wells but thermometers that could obtain a satisfactory record of the anomalies were not available.3 The normal geothermal gradient is con-sidered as being about one degree Fahren-heit for each 60 ft. of depth.4 This "nor-mal" gradient varies in different areas, but whatever it may be in an area there is little variation from the surface to as deep as the drill penetrates. The normal gradient is appreciably changed by gas expanding from the reservoir into the borehole or by the movement of fluid through a borehole while drilling, producing, or circulating. It is the resulting anomalies and abnormal gradients from which conditions in wells can be interpreted. Some of the applications of such interpretations are locating the position of oil or gas sands, permeable strata in a reservoir zone, gas-oil contact, source of water, casing leaks, and the top of cement behind casing.

Jan 1, 1940

By Michael S. Koleda

Less than two years ago, the, Congress, with broad bipartisan support, passed the Energy Security Act of 1980. A decade marked by ten- fold increases in world oil prices and two major interruptions in oil flows from the Middle East had ended. An all-out national commitment to transform America's vast tar sands, oil shale and coal resources into conventional fuels had begun. The national synfuels effort was to be public-private cooperation at a scale unmatched in peace time. Private industry would own and operate the synthetic fuels facilities. Government would reduce market uncertainties to acceptable levels. The potential government commitment was substantial. Up to $88 billion would be available through the Synthetic Fuels Corporation, principally in the form of contingent financing. Billions more would be spent through Department of Energy programs. Additional incentives for alternate energy development were contained in the Energy Tax Act of 1978. The Energy Security Act clearly specified national synthetic fuels production objectives: 500,000 barrels per day by 1987 -- 2 million barrels per day by 1992. Finally, said Congress, Uncle Sam was going to do something about rapidly rising oil prices, uncertainties of energy supply, and the resulting disruption to the U. S. economy. Simply put, the purpose of the Energy Security Act of 1980 was to provide government guarantees sufficient to get synthetic fuels projects off the private sector drawing boards and into commercial production. Because of their huge cost, technological uncertainty, and lengthy pay-out period, these projects were always second place to projects of smaller size, known technology and more rapid pay-out. The Energy Security Act was the legal expression of public policy to bring the free-market synfuels timetable into line with the faster paced political timetable in the interest of national energy security.

Jan 1, 1982

By AIME AIME

BUFFALO, Queen City of the Lakes, singularly accessible by land, water and air, will be the mecca for metallurgists throughout the United States and Canada during the week of the National Metal Congress, Oct. 3 to 7. Headquarters during the National Metal Congress will be the Hotel Statler and there on Wednesday and Thursday, Oct. 5 and 6, the Institute of Metals and Iron and Steel Divisions, A.I.M.E., will hold a series of technical sessions, the annual Science Lecture, a dinner and executive committee meetings. The American Society for Steel Treating, American Welding Society, Production Division of the Society of Automotive Engineers, the Iron and Steel and Machine Shop Practice Divisions of the American Society of Mechanical Engineers, the Wire Association and the American Drop Forging Institute will present a carefully planned program extending throughout the week.\

Jan 1, 1932

By AIME AIME

THE United Electric Coal Companies, operating large strip mines at various points in Illinois, pioneered in developing and perfecting the strip method of mining coal by use of large shovels and drag-lines. Coal stripping was first started on the properties owned by this company near Danville, Ill., in 1885. The first mechanical' excavating machine used for the purpose was really a dredge minus the hull, which had been purchased from the Marion Steam Shovel Co. It was erected on a wood frame supported by wheels and was referred to as a dry-land dredge or stripping machine. Wood was used throughout in the construction of this primitive excavator, even for the boom which was 50 ft. long. A single-cylinder vertical steam engine furnished power to hoist the %-yd. dipper arid swing the boom. 400 cu. yd. of overburden moved in a day was a great record.

Jan 1, 1936

By J. Parke Channing

ALTHOUGH the original thought of investigating waste in industry came from a mining engineer, Herbert Hoover, and although the chairman of that committee was a mining engineer (although the real work was done by the vice-chairman, L. W. Wallace), it is an interesting commentary that when the report first saw light, at St. Louis, on the first of June, 1921, some people most violently went up in the air when it was submitted by the representatives of the mining engineers. At the time they resented most markedly the report of the committee that 50 per cent. of the waste in industry, or as Mr. Ingalls in his paper has properly said, inefficiency in industry, was to be laid upon management. The reason for that seems to have been that, as a whole, the mining industry is pretty well organized and is superior to a large number of manufacturing industries including those studied by the Report. However, this very meeting shows that even the min-ing engineers have finally realized that there is waste or inefficiency in mining and that a large proportion of it can, with propriety, be assessed against management.

Jan 3, 1922

By W. S. Ayres

By Robert Laurich

Chuquicamata pit was opened in 1915 with steam shovels and steam locomotives brought down from the Panama Canal excavation project. With expansions in the early years, more steam locomo¬tives were brought into the mine. IMPROVED LOCOMOTIVES During the period 1927 to 1937, electric locomo¬tives were purchased and main line and bench tracks were electrified. Third rail was installed up to the working areas. At first, the locomotives were equipped with batteries for service at the shovels, but charge life was too short and they were con¬verted to use the third rail and a reel with 3000 ft of trailing cable for service in the loading area.

Jan 11, 1959

By James W. Wade

THIS discussion of the future supply of lead refers only to the next ten-year period. Beyond that no prediction can be made that would be of sufficient accuracy to serve any purpose. When any commodity is by an unsatisfied demand forced to a higher price level, and the profits of those who are able to produce the commodity are greatly increased, there is awakened a new interest in the commodity on the part of both producer and consumer. The consumer attempts to reduce his costs by developing substitutes or assisting in the development of new sources of supply. Lead is now going through this stage. The lead producer is increasing development expenditure and searching for new mines. The consumer is developing substitutes as illustrated by the increasing use of zinc oxide as a pigment, and the use of dry batteries in radio sets. The search of the Ford interests for lead, by prospecting in Missouri and Idaho, is induced by the effort to develop a new source of supply. Considering the index figures of the Department of' Commerce, it is evident that lead is on a substantially higher price level. For February, 1926, the index figure of lead is 209, while the general commodity price index is only 156, 100 being taken as the base for 1913.

Jan 1, 1926

By R. S. Bradley

WHAT are known as insulating firebrick are lightweight firebrick with low thermal conductivity designed primarily for use in direct contact with furnace gases. These are a recent development in the refractories industry, and are really an outgrowth of the type of insulating brick suitable for use behind refractory walls developed by the insulation manufacturers. To differentiate between these two types of brick, the manufacturers have recently agreed upon the use of the term "Insulating Firebrick" to apply to the type of brick suited for use in direct contact with furnace gases, and the term "Insulating Brick" for the type suitable for use behind refractory walls. Insulation was applied to steam pipes as far back as 1900. This was a low-temperature insulation, the most common type being magnesia blocks. The next development was applying insulation to the outside of furnace walls, a service which necessitated an insulating material of higher temperature resistance. Natural diatomaceous earth, both in the powdered and brick form, was used; this was efficient and is still used extensively for backing up refractory walls where the inner surface temperature of the insulation does not exceed 1600° F.

Jan 1, 1937

[ ]

Jan 1, 1938

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT M. RAYMOND Membership KARL EILERS, Chairman LEWIS W. FRANCIS J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY,1 Chairman ALEX C. HUMPHREYS2 GEORGE C. STONE2 J. H. JANEWAY4 BRADLEY STOUGHTON1

Jan 3, 1918