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By H. H. Richardson, E. H. Dix

Of all the alloying elements used in commercial aluminum alloys, copper stands out as by far the most important, and it is perhaps for this reason that the constitution of the aluminum-copper system has received the attention of a number of experimenters covering a period of approximately 20 years. It would be expected that during this time the equilibrium relations would have been thoroughly and exactly worked out. In a general way this is true, but there is a surprising lack of agreement in the details of the high aluminum end of the diagram, particularly in regard to the solid solubility of copper in aluminum, which has been given variously as 2 per cent. to 5 per cent. at the eutectic temperature. The importance of this is much greater than might at first appear to one unfamiliar with modern commercial aluminum alloys. This is true because, with one exception, the susceptibility of the strong alloys to heat treatment depends, in part at least, upon the solid solubility relations of copper in aluminum. In 1919, Merica, Waltenberg, and Freeman1 published the first detailed information on these solubility relations. They found that the solubility of copper decreases with falling temperature from about 4 per cent. at 525" C. to about 1 per cent. at 300" C. and is apparently still diminishing at lower temperatures. In 1921 there was published a brief account of the results obtained in the National Physical Laboratory, Teddington, England.2 This laboratory, however, reported that 5 per cent. of copper is soluble in aluminum at 540" C., and that this amount decreases to about 3 per cent. at 20" C. In the same year Ohtani and Hemmi3 reported a solubility of 4.8 per cent. copper at 520" C., 2.6 per cent. at 460" C. and 1.5 per cent. at 420" C.

Jan 1, 1926

Jan 1, 1903

By J. V. Gluck

In the present paper," as in earlier publications, V1'2"1 the authors present experimentally obtained relations for the free energy of solution of oxygen in various metals as a function of temperature. The relations are linear and given in slope-intercept form. The authors give values for the "probable error" of the slope and intercept, citing Birge's method17 for obtaining these quantities. Birge discussed these methods as early as the period 1929-32.25726 In Ref. 25 the probable error is defined as "the numerical value which the true error is as likely to exceed as not", i.e., 50 pct probability. Ref. 26 is even more detailed and includes a lengthy discussion of the applicability of the Gaussian distribution to experimental data. However, the use of the "probable error" has come under some question. For example, Ezekiel'~ states that "the use of the probable error tends to make the results appear rather more accurate than the standard error". Moroney28 stated (in 1951) that "the term 'probable error' was used in former times to denote 0.67450 (50 pct confidence using the normal distribution)....the term, a poor one, is now very much obsolescent. It has been said that 'it is neither an error nor probable' ". Bennett and Franklin in 1954" in discussing statistical confidence levels mentioned that "the customary use of the 5 and 1 pct levels is not completely a matter of chance; these levels probably represent a balance between the desire to be correct and the desire to be specific. Also in most people's minds the borderline between something that could possibly happen and something that is not likely to happen is somewhere in this region. Certainly 5 or 1 pct confidence limits are to be preferred to limits such as the 'probable error' which has only a 50/50 chance of including the correct value." It may readily be seen that the 95 pct confidence level, which is given by 1.960 (assuming large sample size), thus corresponds to approximately three times the "probable error". Indeed, limits of one standard deviation correspond only to about 68 pct probability. Even if we triple the tolerances given by the authors in the equations of their Table 111, the deviations do not become excessive and would not detract from their excellent results. It could then be said with a high degree of confidence (95%) that the precision of the slope and intercept values is about *3-5 percent of their absolute levels rather than the 1-2 percent implied in Table 111. This is then compatible with an earlier suggestion of Gokcen~' of a probable accuracy of 5 pct in dissolved oxygen measurements by the technique employed. Alternatively, the authors could have

Jan 1, 1967

By W. T. lsbell

HERCULANEUM, MO., about thirty miles south of St. Louis on the Mississippi River, is the site of the lead smelter of the St. Joseph Lead Co. The lead concentrates come by rail from the Flat River district and from three properties in Madison County, Missouri; from the Balmat division in St. Lawrence County, New York; a small tonnage from the Tri-State district; and occasionally from the Aguilar property in Argentina. The average grade is 67 to 68 percent lead and 1 to 3 oz of silver. The bulk of the material is flotation concentrate, with some gravity or table concentrate. No secondary metals, outside drosses, or any materials high in bismuth, arsenic, or antimony are treated. All concentrate is received in box-caps and is unloaded directly from a trestle into the concentrate bins at the roaster plant. Flux, coke, and any miscellaneous lead-bearing material is either unloaded directly into bins or unloaded with a locomotive crane. All moving and switching of cars is done with two thirty-ton steam locomotives. Shipping facilities for the plant are provided by the Missouri-Illinois Railroad. Water for the plant and for fire protection is obtained from a dam built in a near-by creek. Drinking water both for plant and town is obtained from

Jan 1, 1947

Here, published for the first time, is the group of Anaconda officials (New York office) concerned with the planning and operations of the company's copper properties in Chile.

Jan 1, 1952

By Ross W. Smith, M. E. Wadsworth, T. James Smolik, A. S. Peck

Ross W. Smith (Acting Instructor, Department of Mineral Engineering, Stanford University, Stanford, Calif.) and T. James Smolik (Kennecott Copper Corp., Salt Lake City, Utah) - Professors Peck and Wads-worth have made an interesting contribution to the study of fluoride activation of beryl. We have a few comments to make regarding the paper and a question to ask of the authors. We note that glass containers were used in the study. Hydrofluoric acid should react with glass to produce SiFg2 in quantity which could adsorb onto the beryl surface (onto either beryllium or aluminum sites). The authors propose that individual F- ions actually go into the mineral surface lattice rather than onto the surface by adsorption of siFi2 ions. Based on infrared reverse bands with an untreated

Jan 1, 1969

THE meeting was opened, Tuesday evening, May 25th, by an address from the President, R. W. Raymond. The following persons having been duly proposed for members and associates of the Institute, were recommended by the Council for election. They were unanimously elected MEMBERS. Florian Alexander, - Newark, N. J. Charles A. Ashburner, - Philadelphia, Pa. Phineas Barnes, - Pittsburgh, Pa. J. Y. Bergen, - Chicago, 111. Leopold C. Bierwirth, - Dover, N. J. Charles E. Billin, - Philadelphia, Pa. Jerome L. Boyer, - Temple, Berks County, Pa. William S. Cherry, - Streator, Ill. Thomas Couch, - Salt Lake City, Utah. W. S. De Camp, - Boonton, N. J. Thomas Donaldson, - Boise City, Idaho. H. Firmstone, - Longdale, Va. Franz Fohr, - New York City. Richard George, - Dover, N. J. John M. Hartman, - Philadelphia, Pa. C. W. Kempton, - Newburyport, Mass. James B. Lewis, - Dover, N. J. James F. Lewis, - Amenia, Dutchess County, N. Y. Arthur H. Meyer, - St. Louis, Mo. Edward H. Morrison, - Boonton, N. J. Charles J. Norwood, - Lexington, Ky. John R. Peters, - Dover, N. J. Charles I. Rader, - Vinton Furnace, Ohio. W. M. Rees, - Stockton, Luzerne County, Pa. George Richards, - Dover, N. J. Alexander H. Sherrerd, - Scranton, Pa. W. S. Sweeny, - Easton, Pa. W. J. Taylor, - Chester, N. J. Walter Tefft, - Mineville, Essex County, N. Y. J. Alexander Tyler, - New York City. J. D. Weeks, - Pittsburgh, Pa. William Wheatley, Jr., - New York City. Moses D. Wheeler, - Virginia, Nevada. Henry Woods, - Streator, III.

Jan 1, 1876

By Salinger, Herbert

WITH the large amount of metallurgical re- search work now being done and the constant effort of the engineer to effect economies of operation, I think it is a safe prediction that the next few years will see a great change in the handling of mine products. The well-managed mine, with sufficient ore reserves to warrant the necessary plants, will increasingly call upon the metallurgist and chemist for the solution of its problems. Shipping sorted ore or concentrate to the nearest smelter will not be the course followed. From ore to metal, or at least to a product directly salable to the consumer, will be the practice followed. As a consequence, mine managers will be increasingly interested in metal trade problems. By metal trade I mean the buying, selling, shipping, handling, and all the practices, forms and customs that go to make up the trade.

Jan 1, 1928

By Wheeler North

THE United Eastern Mining Co.'s property is located in the Oatman, Gold Roads mining district of Mohave County, Ariz. The mine and mill are some 26 mi. (41.8 km.) southwest of Kingman, the nearest railway connection. The ore consists of a mixture of calcite and quartz with some andesite. The values, which are mainly gold, alloyed with approximately 34 per cent., by weight, of silver, are extremely fine so that fine grinding is a most important factor in extraction. The milling process, briefly, consists of single-stage, coarse-crushing, two-stage ball milling in cyanide solution, followed by combined mechanical and air agitation, and by straight counter-current decantation. The Merrill zinc-dust precipitation method is used to recover the values, and is preceded by the Crowe vacuum treatment of the solution. The most notable features of the plant are the absence of filters, and the use of short peb mills loaded with steel balls, for fine grinding. As originally designed, the capacity of the mill was to be 200 tons per day, although the grinding end was to be capable of handling double that amount. By adding extra agitators and thickeners and by some alterations to the grinding end, the daily capacity has been raised to 285 tons. This, it is hoped, may be increased to 300 tons during the warm months of the present year. TONNAGE MILLED PER DAY 1917 average 234 Maximum month 272 Minimum month 146 1918 average 253 Maximum month 276 Minimum month 217 As this article primarily deals with plant operations, those interested in the mechanical description are referred to the article by Mr. Otto Wartenweiler,1 the designing engineer, which gives the details and costs of design and construction. The following changes have been made since that article was published:

Jan 8, 1919

By H. J. C. MAC DONALD

THE mining engineer must have a chest of books snug enough for a camelback or to be stowed away in a canoe; at the lowest possible cost, as he needs it the most in those early years when he earns the least; but at the same time one having an unusually wide range, for he may have to cut down a forest, put up a sawmill, build mine towns, construct dams, power houses, power lines, and railroads. In fact he may be called upon for many unexpected accomplishments and all in extension of the characteristically broad demands of his profession. Suppose that an average mining engineer with a thorough theoretical training and a specialized mining education has accumulated, during a cosmopolitan experience, a complete and up-to-date library, but, unfortunately, in accepting a long term assignment to a far country he is forced to discard the greater part of

Jan 1, 1925

By A. P. Cohen, D. W. Fuerstenau

Methods of accounting for the feed size in analyzing the size distribution shift during comminution have been discussed in a number of papers.1,2,3 Based on experiments which charles2 performed with single Pyrex specimens, Schuhmann4 pointed out that the size modulus of an assembly of particles should be determined by the energy expended per unit volume (or mass), independent of the size of particle being comminuted. In this same paper, Schuhmann derived the Charles energy-size reduction relationship by considering that complex comminution operations can be considered to be the summation of many individual comminution events, each of which must be governed by Were 6wi is the mass of a particle receiving the impact, 6Ei is the energy delivered to the particle, ki is the size modulus of the product resulting from the impact, a is the distribution modulus of the assembly of particles, and A is a constant. Recent experiments on the compression loading of Pyrex spheres ranging in size from 1/8 to l-in. diam have shown that the size modulus of the fragments is determined by the strain energy at fracture per unit mass, independent of sphere diameter.' The objective of the present investigation has been to determine experimentally whether the size distribution of the product from such a complex comminution process as rod milling is determined only by the energy expended per unit mass independent of feed size. Samples of each Tyler sieve fraction ranging from 4x6 to 48x65 mesh were prepared from crushed Brazilian quartz crystals. One kilogram of each fraction was ground at 60 pct solids in an 8x9 1/4-in. mill containing 17.5 kg of rods (26 rods, 5/8-in.; 10 rods, 3/4-in.; and 5 rods, 7/8-in. diam). In each test, the mill was run at 77 rpm for 15 min. Size distributions were determined by a wet-dry sieving technique. Table I presents the size distribution of the products obtained by grinding each of the size fractions. Because the size distributions are so nearly alike, they are plotted in Fig. 1 by shifting each size distribution for the different feed sizes one screen fraction to the right. Thus, the lowest point in each size distribution represents 400 mesh and each of the other sieve sizes must be shifted accordingly. A single regression line was calculated by combining the data for the six tests, excluding the coarsest feed and the two finest feed fractions. 6 This regression line, which is given by (Y \0.88 where y is the cumulative percentage of material

Jan 1, 1962

By James K. Stanley

When a plastically deformed mctal is heated to a certain temperature, it undergoes a complete change in microstructure, the consequence of which is a marked alteration of mechanical properties such as hardness, strength and ductility. This change in microstructure occurs by re-crystallization and is a process involving the formation and growth of strain-free nuclei in the deformed matrix. These nuclei continue to form with time and grow until a new grain structure replaces the cold-worked structure. The formation of the nuclei in the deformed sheet of I per cent silicon ferrite is illustrated in Fig. I. If a recrystallization is conducted iso-thermally, a nleasurement of the fraction of the matrix recrystallized plotted against time leads to an isothermal recrystallization curve, first established in 1942.1 Such recrystallization curves are shown in Fig. 4. These curves show that the recrystallization of a cold-worked metal is best considered as a rate process rather than a time independent process such as is suggcsted by the improperly named and misleading recrystallization diagrams involving deformation, temperature, and grain size.2-5 Any study of the rate of recrystallization resolves itself into a study of the component rates of nucleation and growth. The previous paper1 provided an account of the determination of the rates of nucleation; N, the number of nuclei formed per unit time per unit of unre-crystallized area, and growth, G, the radial growth in unit time, in the recrystallization of silicon ferrite (I per cent Si). A method was developed to furnish experimental data for evaluating the effect of the recrystallization variables on N and G. The mathematical analysis for the derivation of the isothermal recrystallization curve was developed for a two-dimensional case (in thin sheets where the diameter of the recrystallized grain is greater than the sheet thickness). The present paper is a continuation of the study of recrystallization of I per cent silicon ferrite begun in 1942.1 In this work the effect of the factors deformation, temperature, grain size, composition, and recovery is studied with respect to the rates of liucleation and grouth. At the same time it is shown how the cooperation of N and G affects the isothermal recrystallization curve. The study of these variables on N and G has a definite bearing on the mechanism of recrystallization and should lay a foundation for a rational theory on the subject. Procedure The procedure used in these experiments was essentially the same as that described previously but in certain details some changes were made in the interests of speed. With few exceptions, the procedure is the same for the study of all the variables. Where the procedure is different from standard manipulations attention is called to this fact.

Jan 1, 1945

Recognizing the fact that the problems of the committee named by the Board to prepare the "official ticket" for officers and Directors of the Institute are various and difficult; and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee. Each year the Nominating Committee is to select "official" candidates for eight places, as follows:, (1) President and Director (2) Vice-President and Director (3) Vice-President and Director (4) Director (5) Director (6) Director (7) Director (8) Director

Jan 1, 1939

By Sherwin F. Kelly

MANY baffling problems of crustal geology-of warping and folding, elevation, subsidence, and great dislocations of the earth's surface-may now be on the verge of yielding to the science of geophysics. Electric, magnetic, gravitational, geothermal, and seismic methods are being turned to the gathering of geological evidence buried by deep layers of rock, or lying beneath the waters of the oceans. In this hope, B. L. Miller expresses the opinion that these geophysical studies will sup- ply useful data bearing-on some of the more theoretical problems of North American geology. Among these for example, is the explanation of how Appalachia disappeared. This ancient land mass is supposed to have foundered beneath the Atlantic Ocean after the close of the Paleozoic era and the question arises, was it warped or faulted downward? The geophysical data, though meagre, indicate that the surface of the dense, basal rocks, the probable remnant of ancient Appalachia now underlying the Continental Shelf, slopes downwards to a depth of some two miles below sea level at a distance of 140 mi. from shore: thus suggesting that the subsidence was the result of warping downward rather than abrupt faulting.

Jan 1, 1938

By J. A. Fellows, Earnshaw Cook, H. S. Avery

THE increased use of heat-resistant alloys (26 per cent Cr, 12 per cent Ni, 16 per cent Cr, 35 per cent Ni, 12 per cent Cr, 60 per cent Ni, etc ) in recent years has been accompanied by continued demands by the consumer for improvement in properties The manufacturers of these materials, of necessity, have resorted to more critical studies of the basic causes of variations in fundamental properties To keep pace with the need for augmented information, previous techniques of investigation have been refined and new test methods and instruments created It is the purpose of this paper to describe the apparatus, experimental technique and precision of measurement that were employed in the exploration of properties of heat-resistant alloy presented in a companion paper† The detailed precautions in experimental procedure essential for attainment of accurate and comparable data at elevated temperatures cannot be too highly emphasized THE CREEP TEST Since the fundamental concepts of creep testing have been recognized for the past 20 years, present interest is restricted to refinements in equipment and experimental procedure The creep-test laboratory constructed for the American Brake Shoe and Foundry Co is designed to permit 1000-hr tests in the temperature range of 1200° to 2200°F with a choice of applied stress extending from 50 to 50,000 lb per sq in in increments of 50 lb per sq in To simplify the calculation of weight combinations, the loading beams (Fig I) are provided with counterweights to eliminate the tare The precision of the knife-edges (10 1 ratio) is such that a 10-gram weight placed on the upper specimen grip will be exactly balanced by a 1-gram weight attached to the loading shackle Check of the loading weights proved the maximum error to be 0 06 per cent Axial alignment is provided by crossed knife-edges in the grip seats The furnaces are similar in design to those of Crane and Company, Battelle Memorial Institute, and the U S Steel Corporation An 80 per cent Pt, 20 per cent Rh No 19 B and S gauge wire is used as the heating element The details of construction are shown in the radiograph reproduced in Fig 2 The windings are held in place on an alundum tube with alundum cement, the distribution of turns is adjusted to give a maximum temperature gradient of ± 1°F over a 4-in gauge length (Fig 3) To avoid sharp temperature differentials at the ends of the test section, the length of the furnace is four times the gauge length Sixteen-inch coupons are used to reduce the temperature of the threaded

Jan 1, 1942

By M. M. Neale

The pottery department has been aptly described as the "heart of the zinc plant," md every operator of a horizontal-retort plant is acquainted with the fact that good retort practice is the keystone of the smelting process. Since retorts and condensers are clay products, it is obvious that improvements in other branches of the ceramic industry should be observed for possible adoption in the pottery process for zinc smelting. Deaeration of clay bodies is one of the improvements that have become fully, established in many brick and pottery plants. Our investigation of a number of these installations always yielded the same answer—improved practice. Improvement in workability, elimination of laminations, less porosity, greater wet and dry strength, were among the claims put forth for this process. All of these features are exceedingly desirable characteristics in the manufacture of a zinc retort. A preliminary test, which involved truck transportation of deaired slugs over a relatively long distance, did show the value of many of these characteristics in forming the retort. Results from the standpoint of , longer retort life in the smelting furnace were not outstanding. The idea lay dormant for several years but was revived again in 1940, when it was decided to make whatever changes were necessary in the equipment for pottery manufacture to fully demonstrate the process. A number of the manu- facturers of machinery for clay work were asked to submit proposals, and the plan finally adopted was extremely simple and economical. Machine FOR DeaeRRATING Selection of the ''Straight-line'' principle for conversion of the "Wettengel" pug mill to a ''vacuum-extrusion" machine preserved some usable parts of the original equipment, such as the drive mechanism, and main shaft. The converted machine consists of a feed hopper, a compression and shredding zone, a vacuum chamber, and an extrusion barrel, as shown in Fig. I. In operation the clay mix travels from the feed hopper into the compression zone, where it is compressed and finally forced around the tapered cone into the vacuum chamber. As it enters this chamber the clay body is shredded into thin plates, for exFosure to the vacuum. The shredder consists of a hub mounted on the main shaft, to which are bolted segmental sections, each of which carries shredder knives. The compression zone and extrusion barrel function as seals for the vacuum chamber and the shredded clay mix is agitated thoroughly during its exposure to the vacuum. A vacuum pump, equipped with a 3-hp. motor, is attached to this chamber, and maintains 25 to 26 in. vacuum during operation of the mill. Changes in Practice Prior to the adoption of the deaeration process, our standard pottery practice called for double mixing in the combination 7

Jan 1, 1944

The co-operation of the members of the Institute is earnestly sought by the Committee on Nominations, recently appointed by the Board of . Directors, in its work of formulating a ticket for officers and places falling vacant in the Board of Directors in February, 1916. The Committee must present the official ticket of nominations to the Board of Directors at its October meeting. Members are, therefore, urged to send promptly their nominations for officers and Directors in order that the Committee may have an opportunity to give them full consideration. The officers to be elected at the annual meeting in February, 1916, are: One officer, known as Director and President. Two officers, known as Director and Vice-President. Five officers, known as Director; The attention of members is called to Articles V and VII of the Constitution, and to By-Law XIII, which reads as follows: "The geographical districts to be considered by the Committee on Nominations shall he as follows, until otherwise ordered by the Board. District No. 1. New England, New York, and New Jersey, excepting New York City and district., which is provided for in the Constitution. (N. B.-New York City and district is designated District 0.) District No. 2. Pennsylvania. District No. 3. Ohio, Indiana, Illinois, Iowa, and Missouri. District No. 4. Minnesota, Wisconsin, and Michigan. District No. 5. Montana, North and South Dakota, Wyoming, Nebraska, Kansas, Washington, Oregon, Idaho, and Alaska. District No. 6. California and Nevada. District No. 7. Utah, Colorado, Arizona, and New Mexico. District No. 8. Louisiana and Texas. District No. 9. Other Southern States and District of Columbia. District No. 10. Mexico. District No. 11. Canada."

Jan 7, 1915

By John Birkinbine

(New Haven 'Meeting, February, 1909.) AWAKENED public interest in efforts to conserve natural resources will certainly be appreciated by the members of the American Institute of Mining Engineers, and a discussion upon conservation may well form a part of one of the Institute meetings, for the records of papers and discussions which appear in the 38 volumes of its Transactions are replete with evidence of effort's in this direction. Every process which reduces the fuel consumed or the power applied per unit of product; every utilization of waste material, or employment of that formerly rejected, to obtain something of value ; every feature of construction or operation which lessens the labor required or increases the output per employee, is an advance in the direction of true conservation. This may not appear from the records of late conferences or from published articles, in which the effort seems to be concentrated upon reducing the consumption and presenting to the people of the country estimates of exhaustion of natural resources. I rejoice in the awakening of public interest in a matter so important for the present and future welfare of our nation; I appreciate the possibility of much good following conferences of the Governors and delegates from various States and from national societies; and I recognize the interdependence, not only of different States, but of contiguous nations. In fact, the marvelous development of transportation by land and by water, and the decreasing rates at which commodities can be moved great distances, have in many cases practically obliterated geographical boundaries, and nearly every country on the globe can either market its product in other lands or draw upon them for raw or manufactured materials ; hence, conservation is an international subject.

Apr 1, 1909

By E. B. BESSELIEVRE

THE great work of Gorgas in stamping out yellow fever in Panama during the construction of the Canal was one of the chief factors contributing to the ultimate accomplishment of the task, two previous attempts having failed largely through the demoralization of workers by epidemics of contagious diseases. Mining camps, rapidly constructed during the boom days of the rushes to new fields, have been frequent sufferers from typhoid when, as so often used to be the case, little or no attention was given to bacterial examination of the water supply or to the method used for disposing of the sewage.

Jan 1, 1930

By A. M. Gaudin

CHANGES in industrial practice, in plant design, and in research methods which are so clearly to be seen on every hand, have affected the mineral industry as well as others. In particular, ore dressing has passed through a revolution in practice brought about by the introduction of flotation and other quasi-chemical methods, until it has ceased to be solely the mechanical preparation of ores. In fact, the term "ore dressing" itself is obsolescent, and "mineral dressing" has been growing in popularity. This assures adequate recognition of the fact that mineral substances other than ores, e.g. coals, clays, and cement rock, are treated by the same general methods. As a result of these industrial changes it was felt that a complete rearrangement of the curriculum and laboratories at the Massachusetts Institute of Technology would be ad-vantageous. Such a rearrangement would allow instruction and research to proceed in wider accord with industrial evolution and the needs of our times.

Jan 1, 1942