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ALASKA Established November 19, 1947 Meets fourth Monday monthly except June through August Term of office ends October Peter O Sandvik, Chairman Denny G Breaid, Vice-Chairman Douglas W Huber, Secretary-Treasurer School of Mines University of Alaska P O Box 337 College, Alaska

Jan 1, 1958

By C. S. Roberts

The creep mechanism and kinetics of fine-grained magnesium have been studied over the temperature range 200&apos; to 600°F. As a result of a photographic study of microstructural changes, transient and steady-state creep components have been correlated with slip, subgrain formation, and cyclic deformation at the grain boundaries. THE approach of this research has been the blend of a quantitative study of the creep strain of polycrystalline magnesium as a function of time, stress, and temperature with direct microstructural observations of the operative deformation processes. The validity of the conclusions is dependent on the condition that the microstructural changes seen on the polished surface qualitatively represent those occurring in the bulk of the metal. The work was intended as much to lay a background to a study of highly creep-resistant magnesium alloys as to provide a description of the behavior of the base metal itself. The spectroscopic analysis of the electrolytic magnesium used in this study is as follows: Al, 0.009 pct; Ca, <0.01; Cu, 0.0011; Fe, 0.021; Mn, 0.012; Ni, 0.0004; Pb, 0.0012; Si, <0.001; Sn, <0.001; and Zn, <0.01. The impurity level is approximately that of commercial magnesium alloys. The original ingot was melted under Dow type 310 flux and cast as a 3 in. diam billet. It was extruded into 1 in. flat stock under the conditions: billet preheat 800°F (1 hr), container and die temperature 800°F, speed 3 ft per min, and area reduction ratio 45:1. The extrusion process was chosen in preference to rolling and recrystallization because it allowed easier grain size control from specimen to specimen. The grains of the extruded metal were fairly equi-axial and uniform in the size range of 4 to 6 thousandths of an inch. The preferred orientation of basal planes about the transverse direction was determined by an X-ray diffraction surface reflection method. A beam of filtered copper radiation was directed at an angle of 17" to both the transverse direction and the surface yet perpendicular to the extrusion axis. Analysis of the (002) diffraction arcs in the resulting photographic patterns gave an approximate intensity distribution along the great circle which extends through the center of the basal plane pole figure and to the extrusion axis poles. Successive layers of metal were removed by macro-etching between exposures. The extruded texture is relatively sharp, but the most significant point is the position of the maximum basal plane pole density and its variation with depth below the surface. Fig. 1 shows that this maximum is rotated 15" from the normal at the surface toward the extrusion direction. Such an inclination has been reported for extruded 1 pct Mn and 8 pct A1-0.5 pct Zn alloys.&apos; The inclination decreases until the maximum splits at about 0.025 in. depth into two elements of equal and opposite rotations from the ideal. The double texture persists to as great a depth as was experimentally convenient to examine. It probably continues to the very center of the extrusion. There is no great change in the sharpness of the individual elements of the texture with depth. A plate of metal about 0.015 in. thick at the surface of the extruded stock was produced by etching. A transmission diffraction pattern was made for the purpose of determining any preferred orientation of a direction in the basal planes. Relatively uniform {loo) and {101) rings were produced. There is little tendency for parallelism of a given direction in the plane with the projection of the extrusion axis on it. The creep specimens were machined from 6¼ in. lengths of the extruded stock. Creep was measured on the reduced section, ½x1/8X2¼ in. long. This section was electropolished on one side for the studies of microstructural changes during creep. An orthophosphoric acid-ethyl alcohol electrolyte was used under the conditions recommended by Jacquet.² Hand polishing was used for previous mechanical preparation. Electropolishing was continued until all mechanical twins had been removed. The electro-polished surface was protected from oxidation during creep testing by a thin layer of silicone oil. All micrographs were taken at room temperature on conventional metallographic equipment and after removal of the oil film. The creep tests were performed with machines which have been described in detail by Moore and McDonald." Five testing temperatures, 200°, 300°, 400°, 500°, and 600° ±3°F were used. Difference in temperature between the two ends of the specimen reduced section was 2°F or less. The testing was done at constant load. Strain readings were taken as frequently as necessary to develop usable creep curves. Tensile Creep vs Time, Stress, and Temperature A definition of terms is necessary. Whenever successive sections of a creep strain-time curve show decreasing, constant, and increasing slope with time they will be termed primary, secondary, and tertiary

Jan 1, 1954

ALABAMA Auburn.-Brown, R. L. Battelle.-Green, G. G. Bessemer.-Abbott, C. E. Dobbs, G. G. Ferguson, V. Birmingham.-Aldrich, T. H. Aldrich, T. H., Jr. Allen, A. W. Bonnyman, J. Bowron, J. Crawford, G. G. Crockard, F. H. Ellis, E. E. Fairbairn, C. T. Gambrill, G. T., Jr. Geismer, H. S. Hiller, E. McCormack, G. B. Maben, J. C.

Jan 1, 1917

By K. A. Lambert

In the Anthracite Region there are considerable areas where the original mining was done 50 or more years ago. In this original mining, the pillars that were left proved inadequate in size for the support of the roof, which has since collapsed as a result of squeezes, and completely filled the original openings. In an endeavor to recover the coal which remains in the pillars in such areas, the reopening cost for development, as well as for pillar recovery, has been excessive in many instances. Various methods have been tried out with a view to lowering the cost, in order that the greatest possible percentage of recovery of the reserve tonnage may be realized economically. Ordinary hand mining necessitates the driving of development road 10 ft. wide in the clear between timber legs, with 6 ft. of clearance over the rail to accommodate mine cars; collars or crossbars on the timber sets have been difficult to maintain in these openings in the heavily caved condition, especially in beds where the overburden is great,. Numerous failures have occurred on these development road timbers because of roof movement resulting from removal of pillars. The actual removal of pillars from this development work has been costly because full-width openings for transporting mine cars to the face have to be maintained by cleaning caved material from alongside the pillars, or skipping up along the pillars where pillars of sufficient width are found. Shaker-chute Methods A method of developing such caved conditions and recovering pillars tributary to this development, utilizing shaker chutes, is being tried out with considerable success at Loree colliery. An outline of the chute and apparatus is shown in Fig. 1, which indicates the location of pillars and caved material. The cost of both labor and material required in the recovery of such coal is considerably less than by ordinary hand methods. In order to try out this method of mining a location was chosen where a tightly caved area had been developed by ordinary hand methods to within 300 ft. of the property line. The original bed height was 12 ft., with an overburden of 325 ft., but on account of the squeezes which

Jan 1, 1931

By Donald H. Yardley, A. Aly Selim

Abstract-An economic simulation model was developed to predict the amount of copper recovered from copper oxide deposits, and the cost of producing it as a function of the deposit parameters. The economic simulation model includes programs for fragmentation design and cost, copper extraction, solution distribution and recovery, effluent solution cutoff grade, and financial analysis. Cost and price indices were also developed to evaluate the economic feasibility of in situ leaching operations as a function of their starting date. Application of the models to various hypothetical properties having the same area and different ore thickness shows that the effluent solution cutoff grade does not vary with the ore thickness nor with its grade. The percent of copper recovery is, however, shown to increase with the increase in the ore thickness and is independent of the ore grade. It is also shown that while the profit per unit of extracted copper increases with the increase in ore grade or ore thickness, the rate of return on total investment does not show any correlation.

Jan 1, 1978

Jan 1, 1947

By Brigitta Hassler

INTRODUCTION In the early 1960&apos;s research was begun in Sweden to improve the agglomeration of our domestic iron ore concentrates (5). Different agglomeration methods that were used in the building material industry were studied under the economic support from the Swedish Technical Council, the Swedish Board of Technical Development and by the Swedish industry. The research work was performed at the Division of Mineral Processing at the Royal Institute of Technology in Stockholm. All known agglomeration methods were reviewed and the methods were developed to produce superior quality agglomerates (6). The term cold bonding (in contrast to sintering) was introduced to describe the induration operation in these processes and this has been accepted internationally. Even though we used it mostly for steam autoclaving methods, it has come to describe a class of processes that use binding methods by pore filling. Schumacher in Germany discovered around 1907 that a strong material can be produced by mixing slaked lime with fine ground quartz and subjecting to a steam atmosphere under pressure at about 185ºC. This started development of lime-sandstone building materials and later on, in Sweden, the light-weight concrete. Schumacher also used the same reaction for briquetting iron ore concentrates by adding silica and lime, and autoclaving. The product seems to have been accepted for blast furnace burden and the process was used on an industrial scale until the 1920&apos;s. The sintering method has a small melting phase as diffusion medium and in the steam-autoclaving method a small quantity of water condensate at about 200°C serves the same purpose. Thus the induration process by the hydrothermal hardening methods is similar to that of sintering or heat treatment.

Jan 1, 1977

By F. J. Dunkerlery, V. Damiano, J. Fulton, F. Pledger

Grain-growth and recrystallization characteristics of a commercially pure zirconium prepared by the iodide process are reported. Grain growth from 640° to 800°C was continuous once initiated and obeyed D = kt". Recrystallization of zirconium occurred at temperatures of 450° to 550°C after deformations of 20 and 50 pct. Hardening from partially soluble inclusions prevented determination of the absolute rates of recrystallization, but the relative rates of recrystallization obtained are useful as a guide in fabrication practice. BASIC information needed as a guide in the hot and cold working and annealing of metals includes recrystallization and grain-growth data. A search of the literature revealed no such information for pure zirconium. This is a report of practical grain-growth and recrystallization results obtained for a commercial grade of pure zirconium on a project sponsored by the Office of Naval Research. In this work, isothermal grain-growth curves were obtained at five temperatures from 640" to 800°C inclusively; while recrystallization curves have been determined at 450°, 500°, and 550°C for the metal at the deformation levels of 20 and 50 pct. In addition to the usual variables of temperature, time, and deformation, distribution of the second phase found in all commercial grades of iodide zirconium is also treated as an important factor in these grain-growth and recrystallization studies. In conducting this work, two properties of zirconium were particularly pertinent in dictating experimental conditions. First, since zirconium undergoes a transformation from the a close-packed hexagonal form to the ß body-centered cubic form at 862°C, no recrystallization or grain-growth studies were made above 800°C. Second, because dissolved gases (oxygen, nitrogen and/or hydrogen) increase the hardness and lower the ductility of the solid metal, all annealing treatments in this investigation were carried out in vacuum or in a helium atmosphere. Materials and Methods The zirconium used in this investigation was prepared by the Foote Mineral Co. by deposition from its iodide. A spectrochemical analysis of the metal showed the following composition in weight pct: Hf, 2.1; Mg, 0.012; Fe, 0.035; Si, 0.095; Ti, 0.023; Al, 0.037; Mo, trace; Ni, trace; Cr, trace; Ca, 0.006. Conventional metallographic procedures involving hand polishing on wet metallographic papers, followed by final polishing on fine, levigated alumina on gamal cloth and a medium speed wheel were used throughout this investigation. Grain boundaries were revealed with modified Tucker&apos;s etch containing 20 parts glycerine, 2 parts hydrofluoric acid, and one part nitric acid. Grain-Growth Procedure: Three lots of zirconium, designated here as series A, B, and C were prepared for the grain-growth studies as follows: Series A was prepared by cold swaging the % in. as-deposited rod to a 3/16 in. final diameter, followed

Jan 1, 1952

By Theodor Knutzen, Charles H. Fulton

The plant of the National Smelting Co., a corporation controlled by the Horseshoe Mining Co., was built during 1901 to smelt the dry siliceous ores of the northern Black Hills, extracting the gold- and silver-values in a matte of low copper-percentage which is shipped to Omaha and Denver for refining. Originally, the plant was designed to collect the values of the siliceous ores in an iron-matte, which mas to be resmelted with lead-ores, in a lead-furnace, the lead-bullion produced to be refined into Doré bullion in English cupelling-furnaces. However, the scarcity of lead-silver ores in the Black Hills, owing to the present non-productiveness of the Galena district, led to

Jan 1, 1905

By J. Pinto, F. Galasso

THE current emphasis in preparing boron fibers by reduction of gaseous boron compounds on a resistively heated metal wire substrate has renewed interest in the borides of those metals which have relatively high melting points and are available as fine wires. A knowledge of the structures and properties of the borides, which are formed when boron diffuses into the metal core during boron deposition, can be of assistance in the understanding of the boron fiber formation process and the fiber properties. Many of these borides are well-known and their properties have been measured. However, when an unidentified boride is found in the core, it may be difficult to establish its composition because of the small amount of material available, the preferred orientation effects on the reflections in its X-ray pattern, and the possible overlap of X-ray reflections if several borides are present in the core. For example. the proper indexing of the X-ray pattern of WB4, which was formed in the tungsten substrate core during boron fiber formation, was accomplished only after small single crystals of this boride were grown and X-ray precession investigations were conducted.&apos; This note presents the results of a study of the phases formed in the core when tungsten, tantalum, and molybdenum metal wires were used as substrates in the boron fiber preparation process with particular emphasis on the identification and characterization of a higher boride of molybdenum analogous to WB,. Boron was deposited on resistively heated stationary 0.0012-in.-diam tantalum, tungsten, and molybdenum wires at 1050°C for various times up to 60 sec using boron trichloride and hydrogen as the reactant gases. After 60 sec of boron deposition the fibers were approximately 0.006 in. in diam. Examination of photomicrographs of fiber cross sections showed that the boron had diffused nearly to the center of the tungsten and molybdenum cores in 15 and 30 sec, respectively, and only halfway to the center of the tantalum core in 60 sec. X-ray diffraction photographs of the fibers indicated that it was also after 15 and 30 sec deposition times that the tungsten and molybdenum metal reflections, respectively, had disappeared from the X-ray patterns of the fibers. The patterns of the boron fibers produced using tantalum wire as a substrate showed that amorphous boron, TaB2, and tantalum metal were present after a few seconds deposition time and remained even after deposition times of 60 sec. Until a deposition time of 15 sec was reached, the tungsten substrate fibers contained amorphous boron,273 6WB, W2B5, and WB4 as well as tungsten metal, while the molybdenum substrate fibers contained amorphous boron, MoBa, Mo2B5, and molybdenum metal for deposition times up to 30 sec. Just before the molybdenum metal pattern disappeared, a pattern similar to that of WB, appeared, suggesting that a phase, MOB,, isomorphous with WB,, was present in the fiber. This same pattern was obtained from the product formed by heating a mixture of molybdenum metal and excess boron powder in a boron nitride crucible at 1960°C in an argon atmosphere. As was the case with the WBn pattern, this pattern could best be indexed on the basis of a hexagonal unit cell rather than the tetragonal unit cell Chrktien and Helgorsky reported for ~0~4,~ see Table I. The unit cell parameters for MoB4 were calculated to be a, = 5.214A, co = 6.358A. Assuming the space group P63/mmc and positions5 2M01 in 2b and 2MoII in 2c found for tungsten in WB~,&apos; a logical structure for MOB, was determined using geometrical considerations to place the boron

Jan 1, 1969

By Walter E. Duncan, Oscar F. Tangel, A. M. Gaudin, Franklin Dewey, R. A. Johnson

Xanthates have been used as collectors of sulfide minerals in the concentration of ores by flotation for over a decade, yet much remains to be done to elucidate the underlying reasons for the remarkable effectiveness of these compounds in this connection. Briefly stated, the known facts concerning the effect of these reagents on the floatability of minerals are as follows: 1. Xanthates are without effect on silicates, silica, and generally on minerals currently regarded as "gangues." 2. Xanthates in very small amount increase enormously the floatability of sulfides of copper, lead, silver, iron and mercury. 3. If zinc sulfides are first &apos;(activated," as by treatment with a copper salt, they are readily floated by xanthates; otherwise not. 4. Elemental copper, silver and gold have their floatabilities increased by xanthates. 5. Sulfides of elements that are not typically metallic—e.g., stibnite, realgar, molybdenit—are not made to float markedly better by treatment with xanthates. 6. Oxidized minerals of lead and copper are floated if treated with large amounts of xanthates, but not so if treated with amounts of the same order of magnitude as required for sulfide flotation. Oxidized zinc minerals are not floated unless xanthates having unusually long hydrocarbon chains (e.g., eight carbon atoms or more) are used. Iron oxides and carbonate are not floated by xanthates. From a flotation standpoint the most striking feature about xanthates is the very small amount required to accomplish startling changes in the behavior of some minerals. The amounts used in practice to effect excellent concentration are frequently of the order of 0.05 lb, of agent per ton of ore; that is, of the order of one part of agent per forty thousand parts of ore. Changes in amount of agent of the order of 0.01 lb. per ton of ore (or 0.002 lb. per ton of pulp, on a 4:l basis) have marked effects on the metallurgical results obtained. Yet these changes represent a variation of but one part per million parts of pulp.

Jan 1, 1935

By Charles Jones

Discussion of the paper of CHARLES COLCOCK JONES, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 105, September, 1915, pp. 1887 to 1898. D. A. LYON, Salt Lake City, Utah.-For some years I have been interested in the iron-ore deposits of the Pacific Coast, and I feel very much indebted to Mr. Jones for the information he has given us on this subject. I think that we are also very much indebted to him for having presented this paper, as he has given us reliable data in shape of facts and figures, which is just what we need in considering whether or not it would be commercially feasible to attempt to establish an iron and steel industry on the Pacific Coast. Personally, due to lack of market, I do not think it is a commercially feasible proposition at the present time. Mr. Jones states that pig iron can be produced on this coast as cheaply as it can be produced in Pittsburgh. Even. so, what can be done, with it after it is produced? To begin with, iron produced on the. Pacific Coast has to compete with iron produced in China. Last year I had occasion to investigate the subject of the market for iron and, steel on the Pacific slope, and found that it was possible for the producers of Chinese iron to sell it for much less than the price for which iron can be produced in the West, and also for less than eastern pig iron is now sold for, even when shipped through the Panama Canal. I was informed that the agents for Chinese iron had instructions to sell it for $1 or $2 less per ton than that asked for other irons on the market. Of course, I realize that the competition of Chinese iron may not be important, but even if it is not, and even though pig iron ,can be produced at the cost given by Mr. Jones in his paper, I do not see any immediate chance of its being so produced, due to lack of market. C. C. JONES, Los Angeles, Cal.-Mr. Lyon is right. It is a fact that Chinese pig is being sold in San Francisco on some large contracts at $18.50 a ton, while $19 is the usual price. We ought to produce iron. on this coast at $14. Personally I do not think Chinese iron is ever going to be an important factor. It is a bugbear out here now. You are not going to have much Chinese pig iron in .this country. Our little friend Japan is going to absorb everything it can. The price of Chinese pig iron at $18 is about as low as it will ever get. If we can show you that we can produce this iron here at the same price as at Pittsburgh, I. think you will have a good opportunity to compete with anything China or India can ever do. Costs there are very low now. They are going to come up by leaps and bounds in the next few years. The labor cost over there may be very low now, but I. have seen some men from there quite recently

Jan 12, 1915

By W. M. Small

Austria.—Austria produced some 430 cisterns of 10,000 kg. each of crude oil of a 0.9428 sp. gr. during 1934. Gosting II well near Zis-tersdorf was placed on the pump in August and at the end of the year was still producing about three cisterns daily. This well is owned by the Erdöl-Produktionsgesellschaft while Gösting I is owned by Raky-Danubia. Only five wells were completed in the republic during the year. These accounted for 1783.5 meters of the 2225 meters drilled. The only producer completed was Gosting 11. At the close of the year, four rigs were in operation and one rigging up. At least 8 or 10 new wells are planned in Lower Austria for 1935. The European Gas & Electric Co. put its 6-km. gas line into operation in May and has sold 12,301,550 cu. m. of gas to the Vienna City Electric Works. A 2-km. pipe line was built from Gösting II to the railway loading rack near Zistersdorf. Hungary.—No oil or gas was produced except a small amount of gas trapped from flowing artesian wells. The Government completed and abandoned a 1500-m. hole at Tisztaberek in northeastern Hungary and is drilling at 967 m. near Bogáes, 120 km. northeast of Budapest. It is unofficially reported it plans to drill two new wells in 1935. The European Gas & Electric Co. has a rig up for a test at Mihalyi in Transdanubia. Czechoslovakia.—In Gbely (Egbell) there were produced 1283 cisterns of 10,000 kg. of 0.935 sp. gr. oil and a small amount of gas used for fuel. This field is operated by the Government; 17 shallow producing wells and three dry holes were drilled, with a total of 3351 m. of hole completed. In Hodonin (Goding) there were produced approximately 1300 cisterns of 10,000 kg. each of 0.91 sp. gr. oil and a small amount of gas used for fuel. The field is operated by the Apollo, which drilled four producing wells averaging 460 m. in depth, one small gas well of 550 m., one small gas well 260, and one dry hole 230 m. Two wells were deepened a total of 80 meters. The Government is drilling below 800 m. in a wildcat test in eastern Czechoslovakia near the Rumanian frontier.

Jan 1, 1935

By D. K. Crampton, H. l. Burghoff, J. T. Stacy

The study of copper alloys of the age-hardening type has received considerable attention, and, among the alloys which the authors have, considered, those containing small amounts of nickel and phosphorus as essential constituents seem especially interesting. Such alloys have attractively great capacity for being hardened and also have relatively high electrical and thermal conductivity in the hardened state. In addition, it has been found that the increase in hardness and strength imparted by aging can be greatly augmented by cold-working, so that excellent combinations of conductivity and strength are obtainnble. In view of the possible importance of the alloys, it was considered desirable to investigate the solubility relationships in the copper-rich portion of the copper-nickel-phosphorus system. This paper present&apos;s some of the results obtained in this investigation to date and also gives propertics of typical alloys that appear to be of commercial interest,. Review of literature Copper-nickel System,.—The binary coppcr-nickcl system has long been known to consist of a series of simple solicl solutions, copper and nickel being miscible at all tempcrat&apos;ures and concentrations. This was establisl~cd by Guertler arid Tammannl in 1907 and confirmed by Tafel2 in 1908. Copper-phosphorus System.—The copper phosporus system has been studied by numerous investigators, so that the copper-rich portion is now definitely known. As most recently determined by Lindlief," his system has a cutectic at 8.38 per ccnt P, cuteetic temperature being 714° C. Components of the cutectic are Cu3P and alpha solid solution. Solid solubility of phosphorus in copper, according to Mertz arid Mathewson decreases from a maximum of about 1.75 per cent at 714&apos; C. to about 0.6 per cent at 300&apos; C.

Jan 1, 1940

By D. K. Crampton, H. l. Burghoff, J. T. Stacy

The study of copper alloys of the age-hardening type has received considerable attention, and, among the alloys which the authors have, considered, those containing small amounts of nickel and phosphorus as essential constituents seem especially interesting. Such alloys have attractively great capacity for being hardened and also have relatively high electrical and thermal conductivity in the hardened state. In addition, it has been found that the increase in hardness and strength imparted by aging can be greatly augmented by cold-working, so that excellent combinations of conductivity and strength are obtainnble. In view of the possible importance of the alloys, it was considered desirable to investigate the solubility relationships in the copper-rich portion of the copper-nickel-phosphorus system. This paper present&apos;s some of the results obtained in this investigation to date and also gives propertics of typical alloys that appear to be of commercial interest,. Review of literature Copper-nickel System,.—The binary coppcr-nickcl system has long been known to consist of a series of simple solicl solutions, copper and nickel being miscible at all tempcrat&apos;ures and concentrations. This was establisl~cd by Guertler arid Tammannl in 1907 and confirmed by Tafel2 in 1908. Copper-phosphorus System.—The copper phosporus system has been studied by numerous investigators, so that the copper-rich portion is now definitely known. As most recently determined by Lindlief," his system has a cutectic at 8.38 per ccnt P, cuteetic temperature being 714° C. Components of the cutectic are Cu3P and alpha solid solution. Solid solubility of phosphorus in copper, according to Mertz arid Mathewson decreases from a maximum of about 1.75 per cent at 714&apos; C. to about 0.6 per cent at 300&apos; C.

Jan 1, 1940

By Thomas T., Read

TWO American students entered the Ecole des Mines in 1856, Joseph Lesley of Philadelphia and Thomas Egleston of New York. Lesley remained there only one year, but Egleston completed the whole &apos;curriculum and received, in 1860, the certificate given to foreign students .in lieu of the official appointment and degree. awarded French students. Returning home he received, in 1861, an appointment by Secretary Henry of the Smithsonian Institution to sort, label, and arrange the collections of mineralogical and geological specimens which had been brought to Washington by the various government exploring expeditions in the West. Thomas Egleston, born in New York City on Dec. 9, 1832, was the son of Thomas Jefferson Egleston, who came to New York from Massachusetts some time before 1829. The first American ancestor of the family had settled near Dorchester. in 1630. T. J. Egleston and Joseph Battell established an iron-merchandizing business* at 166 South St., New, York, which prospered exceedingly; so much so that when Thomas J. Egleston died, July 12, 1861, his estate had a book value of over $500,000. Since an older brother was expected eventually to take over this business, Thomas, who had a liking for science, went to Yale,, where he completed the regular four-year course in 1854, and then remained another year for advanced work in chemistry under Silliman. I One biographer says he went to Europe, . early in 1-856, on account of his health. It was the custom at that time for wealthy young men to make a tour of Europe after completing their academic education. Whatever the precise reason, he began scientific work at the Jardin des Plantes in Paris but soon trans* It still operating as Egleston Bros. Inc., though no direct descendants of its founder are now living.

Jan 1, 1941

By W. W. Weigel

THE mines of the St. Joseph Lead Co. in St. Francois County, Missouri, form a roughly triangular area of about 45 square miles. Locally this is known as the Lead Belt. The four operating mines in the area at present are the Federal, Leadwood, Desloge, and Bonne Terre, in decreasing order of mine area and daily production. Mining began in 1864 and has been carried on in the district continuously since that time. [ ] As a group, the Lead Belt mines now handle 20,000 gal. per min. of water, average head about 465 ft., against a normal daily ore tonnage of 21,200 tons. For a six-day operating week this gives a ratio of 6 ½ tons of water per ton of ore. Total average pumping in 1931 was about 15,000 gal. per min. Since that time a large area of virgin territory has been opened, much of which has had temporary flush flows. About 75 per cent of the water enters in certain restricted very wet areas. Production figures are given in Table I. The figures by divisions for 1931 and 1941 are not exactly comparable, as there were several transfers of pumping loads from one division to another during that period of time. GEOLOGY The basement formation in the Lead Belt area consists of the pre-Cambrian rhyolite porphyry and granite. Overlying this is the La Motte sandstone, of Middle Cambrian age, which offers a good medium for circulation of water. It varies in thickness up to 400 ft. Above this is the Bonne Terre dolomite, approximately 375 ft. thick, which in turn is overlain by the 150-ft. Davis shale. The formations above this, present in the Lead Belt in small areas only, are of minor importance. The ore bodies occur as large, horizontal tabular masses or as long, narrow runs; they are found throughout the Bonne Terre but largely in the lower 150 ft. The rather indefinite contact with the La Motte is a favorite ore horizon. Mining is entirely by open stope and pillar breast systems. To the south, west, and north of the district, sandstone outcrops are few and limited. Heavy faulting bounds the district on those sides and probably there is little if any artesian circulation from those directions. To the east, the La Motte rises to an outcrop area of about 40 square

Jan 1, 1943

By John J. Schanz

INTRODUCTION The two prior Seeley W. Mudd books on mineral economics devoted their final chapters to themes having to do with the future. In 1932, the last chapter in Mineral Economics8 was "The Future Value of Mineral Property" by J. R. Finlay. Both the first edition (1959) of Economics of the Mineral Industries7 and the slightly revised second edition (1964) closed with "Minerals and Man&apos;s Future" by Zay Jeffries. We are not inclined in this third AIME volume on mineral economics to ignore the tradition of the prior volumes. Moreover, it always is fitting and proper to close a book about the mineral industries by examining in a rather general way the challenges and uncertainties that are perpetually strewn in our path as we pick our way into the future. Unlike its predecessor volumes, which were written to acquaint the nonspecialist with the economic characteristics of mineral resources and to provide data about the mineral industries, this edition was also designed with the mineral economics student and practicing specialist in mind. Thus it is anticipated that it will be both a reference as well as suitable for use as a textbook. Consequently, this closing examination of our changing perspectives about mineral resources devotes some space to the past events and current status of mineral economics as a field of study. The fears and forecasts of the past can be a perceptive and usually deflating way to begin an examination of the future. As we look up and down the track of time from the 1975 platform, we find that many of the past views of the future were transient in character, others were imperfect in their prognosis, while others were based on fears that now seemed unfounded. But down through the years some of the observations or expressions of concern have a persistency which perhaps reflects some elemental characteristics of mineral resources. On these "truths" rest our contemporary understanding of the economics of the mineral industries. The uncertainties and priorities for the next 25 or more years, not surprisingly, have a somewhat different mix than those that seemed most compelling to our predecessors in 1932 or 1959. So it is appropriate that we review how the perspective of the mineral economist has changed over the span of a half century. In light of the particular interest of AIME on the role technology must play, it is fitting that we close with some observations on that topic. THE EMERGENCE OF MINERAL ECONOMICS AS A FIELD OF STUDY The publication of Mineral Economics by the AIME in 1932 as a Seeley W. Mudd volume marked the end of emerging interest in

Jan 1, 1976

By W.W. Weigel

The mines of the St. Joseph Lead Co. in St. Francois County, Missouri, form a roughly triangular area of about 45 square miles. Locally this is known as the Lead Belt. The four operating mines in the area at present are the Federal, Leadwood, Desloge, and Bonne Terre, in decreasing order of mine area and daily production. Mining began in 1864 and has been carried on in the district continuously since that time. As a group, the Lead Belt mines now handle 20,000 gal. per min. of water, average head about 465 ft., against a normal daily ore tonnage of 21,200 tons. For a six-day operating week this gives a ratio of 6½ tons of water per ton of ore. Total average pumping in 1931 was about 15,000 gal. per min. Since that time a large area of virgin territory has been opened, much of which has had temporary flush flows. About 75 per cent of the water enters in certain restricted very wet areas. Production figures are given in Table I. The figures by divisions for 1931 and 1941 are not exactly comparable, as there were several transfers of pumping loads from one division to another during that period of time. Geology The, basement formation in &apos;the Lead Belt area consists of the pre-Cambrian rhyolite porphyry and granite. Overlying this is the La Motte sandstone, of Middle Cambrian age, which offers a good medium for circulation of water. It varies in thickness up to 400 ft. Above this is the Bonne Terre dolomite, approximately 375 fl. thick, which in turn is overlain by the 150-ft. Davis shale. The formations above this, present in the Lead Belt in small areas only, are of minor importance. The ore bodies occur as large, horizontal tabular masses or as long, narrow runs; they are found throughout the Bonne Terre but largely in the lower 150 ft. The rather indefinite contact with the La Motte is a favorite ore horizon. Milling is entirely by open stope and pillar breast systems. To the south, west, and north of the district, sandstone outcrops are few and limited. Heavy faulting bounds The district on those sides and probably there is little if any artesian circulation from those directions. To the east, the La Motte rises to an outcrop area of about 40 square

Jan 1, 1943

By W. W. Weigel

The mines of the St. Joseph Lead Co. in St. Francois County, Missouri, form a roughly triangular area of about 45 square miles. Locally this is known as the Lead Belt. The four operating mines in the area at present are the Federal, Leadwood, Desloge, and Bonne Terre, in decreasing order of mine area and daily production. Mining began in 1864 and has been carried on in the district continuously since that time. As a group, the Lead Belt mines now handle 20,000 gal. per min. of water, average head about 465 ft., against a normal daily ore tonnage of 21,200 tons. For a six-day operating week this gives a ratio of 6½ tons of water per ton of ore. Total average pumping in 1931 was about 15,000 gal. per min. Since that time a large area of virgin territory has been opened, much of which has had temporary flush flows. About 75 per cent of the water enters in certain restricted very wet areas. Production figures are given in Table I. The figures by divisions for 1931 and 1941 are not exactly comparable, as there were several transfers of pumping loads from one division to another during that period of time. Geology The, basement formation in &apos;the Lead Belt area consists of the pre-Cambrian rhyolite porphyry and granite. Overlying this is the La Motte sandstone, of Middle Cambrian age, which offers a good medium for circulation of water. It varies in thickness up to 400 ft. Above this is the Bonne Terre dolomite, approximately 375 fl. thick, which in turn is overlain by the 150-ft. Davis shale. The formations above this, present in the Lead Belt in small areas only, are of minor importance. The ore bodies occur as large, horizontal tabular masses or as long, narrow runs; they are found throughout the Bonne Terre but largely in the lower 150 ft. The rather indefinite contact with the La Motte is a favorite ore horizon. Milling is entirely by open stope and pillar breast systems. To the south, west, and north of the district, sandstone outcrops are few and limited. Heavy faulting bounds The district on those sides and probably there is little if any artesian circulation from those directions. To the east, the La Motte rises to an outcrop area of about 40 square

Jan 1, 1943