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By L. L. Wyman

PREVIOUS studies1 by the writer dealing with the embrittlement of copper have been concerned with the behavior of various pure and deoxidized coppers when exposed to an oxidation-reduction cycle, and the consequent evaluation of these materials on the basis of their resist-ance to this action. No attention was devoted to the variations in pene-tration of embrittlement with time, when these copper materials are exposed to a strong reducing gas, such as hydrogen, nor to the variations in oxygen penetration, with time and temperature, into the "pure" coppers. The cause of the embrittlement is the reduction of the oxygen in the copper by the hot reducing gas, so that a consideration of time, tempera-ture, the occurrence of hydrogen and oxygen must be given. For the purpose of differentiating some of "the involved factors, the present work may be divided into two separate series of experiments. The first of these deals with the oxidation of purified coppers under various conditions and then the subjection of these to a standard hydrogen treatment. The second series concerns the reduction, under different conditions, of tough-pitch coppers of several oxygen contents. The resulting data will give the rates of oxidation, and of reduction, for the materials involved. The first series of experiments will reveal how rapidly copper may become oxidized, while the second series will indicate how rapidly embrittlement will penetrate into an oxygen-containing copper when it is exposed to hydrogen at different temperatures.

Jan 1, 1933

By Otto F. Pfordte

The great advance of the last twenty years in the specialization, delicacy and efficiency of ore-concentrating apparatus calls for a finer system of testing both the qualities of ores and the operations of machines in this department. In amalgamation, lixiviation and smelting, the daily employment of physical and chemical tests has been recognized as necessary, and the cost of the necessary laboratories and employees is cheerfully paid. But while much progress has been made in concentration (due, in a large degree, to the study of the subject in our technical schools), it is still too common in actual practice to follow the loose old method of roughly estimating, once for all, that a given ore " concentrates x tons into one," and resting on this assumption so long as that ore continues to be treated, while assays of the tailings from concentration are made from time to time, without exact determination of their quantity. The first step toward accuracy of control must be a more frequent and precise measurement of the quantity of concentrates from a given operation. This should be expressed in pounds per unit of one ton; and the variations shown in frequent determinations will furnish a constant check upon the character of the ore and the performance of the apparatus. But this is only a part of what should be constantly and systematically done to insure the best work upon a material which must vary continually, even though it come from one mine only. If, in any mill, appropriate laboratory-tests were made at least once a week, the labor and expense involved would be amply repaid by increased knowledge and control of the current operations. A small testing-laboratory, provided with a few gold-pans;

Jan 1, 1902

SUGGESTIONS that existing schools give instruction bearing on the mineral industry, or that schools for that purpose should be established in the United States, began to be made early, and it would require too much space to catalogue them all. Some of the more important may be mentioned to indicate their general character. In the "advertisement to such parents as have now (or expect to have) children prepared to be educated in the College of New York," which appeared in the New York Mercury of June 3, 1754, Samuel Johnson, the first president of King's College, the predecessor of Columbia, said that it was the "design of this college to instruct and perfect the youth," among other things, "in the arts of Numbering and Measuring of Surveying, and Navigation and Geography. . . . and in the Air, Water and Earth around us, and the various kinds of Meteors, Stones, Mines and Minerals, Plants and Animals; and in the knowledge of all Nature in the Heavens above us, and of everything useful for the Comfort, Convenience and the Elegance of Life . . . " Though the concept that natural science should be used to enlarge the bounds of human life was thus implicit at Columbia from the , very beginning (John Stevens graduated from it in 1768, James Renwick in 1807, Horatio Allen in 1833, and A. W. Craven in 1899), it was only during the period of Renwick's professorship of Natural and Experimental Philosophy and Chemistry (1830- 1853) that much attention was given to applied science.* Among the Austin papers, published by the American Historical Association,~ there is a draft in Stephen F. Austin's handwriting of a proposed memorial from the legislature of , Missouri to Congress, not only urging "the propriety and utility * See chapter 4 for early interest in this subject in Philadelphia.

Jan 1, 1941

By Wayne L. Dowdey

With proud humility and keen anticipation, I accepted the office of President of the Institute one year ago, and it is with a great deal of pride in you-our membership that I make this report. You are the reason for a productive and prosperous year for AIME. Superior, good or satisfactory results were experienced in 1978 from almost everything we did as a leading engineering technical society. I recognize and pay tribute to the WAAIME organization. Their work is vital to our efforts, and their programs have proven effective. WAAIME can depend upon our continuing support.

Jan 6, 1979

By H. L. Sheakley, D. J. Coolidge

This paper does not deal with all sands used in the glass industry in Missouri; it covers only that used in the plate-glass factory at Crystal City. However, it is probably safe to say that other sands, pro- duced throughout the state for this purpose, are of identical nature. The glass sand used in Missouri is cornrnonly called the St. Peter deposit, which is ascribed to the Ordovician Rock series in the form of sandstone. This St. Peter deposit, aside from a few small outliers, covers a large area of eastern Missouri. It forms, through a broad curve, the northeast margin of the typical Ozark region between Cape Girardeau on the southeast and Mineola, Montgomery County, on the northwest. The belt is extremely irregular, varying from one to ten miles in width; its length is 150 miles in a straight line. The outcrop near the entrance to the Crystal City mine appears in the form of a sandstone bluff approximately 30 ft. high, running along Plattin Creek (Fig. I). Above the sand rock an overburden of Joachim limestone appears, which thickens to nearly 300 ft. and forms the hill commonly called Buck Knob. Test holes where drilled at various points and the drillers' log indicate that the St. Peter deposit ranges in thickness from 63 to 71 feet. Properties of the St. Peter Sand From an analysis of the glass sands of the St. Peter formation in Missouri, the follow-

Jan 1, 1948

By Charles R. Simcoe

The stress-strain curves in the microyield region for various Fe-C solid solutions shown by Davies and Ku are typical examples of parabolic curves defined by the expression a = kEn 111 These data, when replotted on log-log coordinates, as shown in Fig. 9, exhibit three essentially parallel straight lines. It is apparent that carbon increases the flow stresses, but does not affect the exponent n. In other words, the only factor in Eq. [1] affected by in in carbon content is the constant k. As Eq. [1] is written k is the stress at a strain of 1.0. This is unsatisfactory for examining data in the microyield region. Therefore, the equation can be altered to the form: to permit the use of the authors' microyield stress at a strain of 10-6 as k. Extrapolating the curves in Fig. 9 to a strain of 10-6 gives stress values of 2000, 3200, and 5400 psi for 0.008, 0.014, and 0.02 pct C, respectively. These values do not agree exactly with the authors' measured values, but this will not affect the following discussion. The effect of carbon content on the slopes of the stress-strain curves shown in Fig. 2 of the paper by Davies and Ku can be analyzed by differentiating Eq. [2] with respect to strain. Thus: where n is always less than 1.0. Since n is essen- tially constant as a function of carbon content for the data under discussion, the slopes of the stress-strain curves depend only on k and E. If the slopes are examined at various selected Plastic strains. i.e., 10-6, 10-5, and so forth, it follows from Eq. [3] that the dif-ferent slopes for the different carbon contents depend only on the different values of ke=10-6. Thus, the larger ke=10-6, the steeper the linear stress-strain curve will rise with increasing plastic strain. This

Jan 1, 1969

By Frank Firmstone

The piece of spiegeleisen, the analysis of which is given below, was collected by my father, together with various other specimens, while he was manager of the Glendon Iron Works. It bears a label stating that it was taken from a building in the town of Newton, New Jersey, erected in 1765 and torn down in 1863. The building belonged, in 1863, to T. N. McCarter, Esq. The label is in the hand-writing of Mr. McCarter, now deceased, well known as a member of the bar of northern New Jersey. The specimen was, no doubt, given by him to illy father, with whom he had business in 1863 and 1864. It is now in the metallurgical collection of Lehigh University. I know nothing further as to the history of the specimen, but there is no reasonable doubt that it was made from ore from the Andover mine, at the old charcoal-furnace which once stood at the village of Andover, about 5 miles south of Newton, on the Sussex railroad. It was probably broken from one end of a bearer over an open fire-place, is about 6 in. wide by 2.5 in. thick, has been cast in open sand and shows the charcteristic fracture of spiegeleisen rather low in manganese, as shown in Table I. One edge has been white-washed. Table I.—Analyses of Spiegeleisen Made from Andover Ore. 1. 11. Per Cent. Per Cent Graphite,.0.101 0.005 Combined carbon,... 4.529 4.212 Silicon,..0.037 0.294 Manganese,..... 5.760 3.750 Sulphur,.0.003 0.031 Phosphorus,.0.060 0.072 Iron,........ 89.440 91.570 99.920 99.934 I. Spiegeleisen made at Andorer (charcoal) furnace not later than 1765. IT. Spiegeleisen made from Andover ore at Phillipsburg, N. J., anthracire-furnwe, 185-. Both analyses were made by Dr. P. W. Shimer.

Jan 1, 1907

By T. E. Scott, D. H. Sherman, C. V. Owen

It has been established' that vanadium exhibits a ductile to brittle transition temperature which increases with increasing hydrogen content. Optical microscopic examination at room temperature revealed no evidence of hydride precipitate in fractured specimens containing 100 ppm H, but hydrides were present in samples with 800 ppm H. More recently2 the strain rate and temperature dependences of the ductility drop in vanadium containing 6 ppm H were reported. It was argued that the ductile-brittle transition, while dependent on the presence of hydrogen, probably could not be explained by the precipitation of hydride. The bases of the argument were that 6 ppm H would not produce sufficient hydride to alter the ductility to the extent observed and no visual evidence of hydride was obtained. However, the data were not sufficient in these investigations 1,2 to define accurately the ductile-brittle transition temperature. Also, no information was available concerning the terminal solubility of hydrogen in vanadium at the low concentrations employed. westlake 3 has studied the electrical resistivity of vanadium at several hydrogen concentrations. He was able to detect the precipitation of hydride and to extend the hydrogen solvus to the composition and temperature range pertinent to the observed ductile-brittle transition behavior, Westlake compared his

Jan 1, 1968

MANY are the salts produced. by Nature in various regions and parts of the world, as Pliny shows in his History. Likewise, many are the differences among things that are salty and from which salt can be extracted, as, for instance, all the lyes from any kind of ashes and the urine of all animals. But because these are not things that give men the useful elements necessary to life, I shall omit speaking of them in detail with the exception of some of the more notable ones, and I shall tell you that I find that men proceed in only two ways in order to have a sufficiency for their needs. One is that of extracting it from the salty waters of the sea itself, or from springs, with a certain technique [34v] adapted to the places, either by congealing or by evaporation; and the other is that of mining it from the earth. The latter salt is clear and beautiful, and it is mined from mountains, already made by Nature in the form of stone without the aid of art. All these salts have more or less efficacy* according to the fineness or coarseness of their earthy elemental mixture, and according to the provinces and places where they are found generated. All are of an earthy

Jan 1, 1942

By B. L. Seegmiller

Horizontally stratified lithologies of certain open pit or strip mines create unique stability problems for mine operations. Such problems may result when specific lithologies, such as sandstone and shale, exist in final or long-term slopes. Slope instabilities may occur when a sandstone unit directly overlies a shale unit and ground water drains into the mine along the lithologic contact. In essence, the ground water erodes the underlying shales and undercuts the sandstone. Large sandstone blocks fail in a toppling mode and cause safety and cleanup problems. Use of rock reinforcement including chain link fencing, roof bolt mats, rock bolts, rock anchors, and shotcrete offers a possible solution to the problem.

Jan 1, 1985

By L. B. Lindemuth

To those who are in a position to carry the thought to a conclusion; I would like to present a theory for the cause of blisters in galvanized sheets. Blisters that are caused from piping and shrinkage cavities will not be considered because the reason for their formation is entirely obvious. Blisters that occur periodically with no apparent system of ocation, number, size or grouping, and then disappear with no. apparent change in manufacturing method, are the ones to which this theory would apply. Examination of blisters of the latter type has shown that they contain hydrogen gas at atmospheric pressure, and that occasionally traces of oxide or sulfide are found on the inner surface of the blisters. These two characteristics have led to the rather general idea that hydrogen gas generated in pickling, and that iron oxide supposed to be inherent in the ingot and causing weak spots were, in some manner, responsible for the development of blisters in galvanizing. The theory which I wish to advance is that these blisters are caused by moisture that has penetrated the steel after the annealing operation. This moisture comes from the atmosphere, or from pickling or washing and when it is suddenly expanded into superheated steam in galvanizing, the increase in volume is so great that it cannot escape with sufficient rapidity through the small opening where it entered as moisture.The pressure so generated forces the sheet apart along those lines of lamination ;hat may be found in practically all flat sections of steel rolled comparatively cold. The increase in volume. from moisture to steam at 800° F. is 2244 times the original volume of the moisture. The pressure generated by ;he moisture heated to 800° F. and entirely confined would be enough to expand or explode any container. This would explain the source of sufficient pressure to cause a sheet to blister.

Jan 3, 1927

By D. D. Bolstad, S. M. Dar, T. W. Smelser, H. C. Pettibone

The use of roof bolt supports has reduced the number of fatal and nonfatal roof fall accidents in coal mines. Roof fall accidents, however, still occur far too frequently. Roof bolting plans are based almost entirely on trial and error, which inevitably leads to underdesign or overdesign with regard to bolt length, spacing, tension, and bolt type for the specific conditions. Underdesign poses safety problems, and overdesign leads to unnecessary costs. Guidelines are needed to select and design optimum roof-bolt plans that will maximize safety and minimize cost. Despite the use of 100 million roof bolts per year, the theory of roof bolting remains underdeveloped. Underground tests designed to provide this knowledge have been only partially successful owing to the many uncontrollable geologic variables present in underground mining situations. The Bureau of Mines believes that the best approach is to conduct a laboratory model study in correlation with finite-element analysis (FEA) and field verification, where these variables can be tightly controlled and measured. A physical model allows precise performance measurement of different bolt types as a function of a wide range of precisely measured parameters. Although the model being used is idealized and limited in size, it serves as a reliable basis for confirming the mechanism of rock reinforcement by bolting and the accuracy of the computer FEA approach to modeling mining problems.

Jan 1, 1984

By E. H. Lovitt, A. C. Skerl

After nine years of continuous operation it is a good idea to take stock of the geological concepts that guide the working of a mine. This is a welcome opportunity to discuss the Lovitt gold mine, which has been a challenge in both the geological and operational fields. The occurrence belongs to the extensive group of epithermal gold-silver deposits once worked so vigorously in the western states, Hungary, and New Zealand and still producing in Central America and the Philippines. These deposits are characterized by a relatively shallow vertical range up to 2000 ft, and often much less, and by bonanza orebodies of even more limited range. The area in which they occur is frequently widespread, so that exploration must be directed along and across the strike of known favorable structures in search of repetitions.

Jan 9, 1958

By Richard W. Lodge

In the crucible-method of assaying ores for silver a certain amount of litharge is essential to supply sufficient lead to collect the precious metals. The object of this paper is to point out that the use of a large excess of' litharge in the assay of some ores will give results for silver that are uneven as well as low. So far as I know, however, an excess of litharge does not affect the results obtained in the crucible-assay of ores for gold. The main reasons for using, in the crucible-assay, much more litharge than is required to givc the necessary lead button are: 1, its action as a flux; 2, its action as a desulphur-izer; and 3, its action as an oxidizer, especially on metals like copper and nickel, whereby they are forced into the slag as oxides and thus prevented from passing into the lead button. Hence, by the use of much litharge in the crucible-assay more ore call often be taken than in the scorification-process, and a lead button obtained which call possibly be cupelled at once or after a single scorification. The method is specially advantageous with an ore carrying much copper or similar impurity and poor in silver, when the assayer does not wish to resort to a wet-analysis for the determination of the silver. It is well known that some ores give better results when assayed by the scorification-method, while others give better results by the crucible-method. For several years I have noticed that, when much litharge was used with certain sulphide and arsenical ores, the results were considerably lower than when the scarification-method was used. This fact was more forcibly brought out in connection with certain work carried on this year by Messrs. H. A. Frame and

Jan 1, 1908

By J. C. DeHaven, Harry Seltz

InteRmetallic compounds are formed in many binary metal systems. Some compounds are stable to their melting points, and others decompose at lower transition temperatures. Even those of the first class are dissociated in the liquid state, as indicated by the continuous form of their solubility curves at their melting points1. While the lattice structures of some of these compounds have been determined, their thermodynamic properties have not been investigated. In this paper is described the determination of the free energy and heat of formation of the compound CdSb, which is of the first class mentioned above, melting congruently at 455' C. This compound shows a rhombic structure, and the lengths of the edges of the elementary cell containing four molecules are: a = 6.52, b = 8.60, c = 4.16 A.' There are three possible methods of determining the free energy of formation of a compound of this type. The first method, applying the third law of thermodynamics, requires the measurement of its heat capacity preferably to liquid hydrogen temperatures, and a calorimetric determination of its heat of formation. The second method involves the study of the equilibrium of the compound in some gas reaction, such as: CdSb + CO² = CdO + CO + Sb From the known free energies of formation of CdO, CO² and CO the free energy of formation of CdSb could be calculated. The third method measures the electromotive force of a galvanic cell in which the cell reaction is the reversible formation of the compound from the elements. The first method is generally applicable, but requires elaborate experimental equipment. The second method can not be used for compounds melting at low temperatures, owing to the difficulty in establishing equilibrium. The electromotive force method, therefore, seemed to offer

Jan 1, 1935

By H. F. Miller

Fox some years the prejudice against basic open-hearth steel for casting has been gradually decreasing. Yet many consumers and engineers still cling to acid steel for castings, because of their alleged greater freedom from blow-holes and sponginess. Acid steel has been used for this purpose much longer than basic steel; and the melters in acid practice had it well in hand when basic steel was first tried. Then the necessity of learning a new set of laws for the production of satisfactory basic open-hearth steel for castings became evident. The first of these laws, in my opinion, has to do with the furnace construction. The heat should be melted down as speedily as possible so as to prevent excessive oxidation. I have described in another article ' some furnaces designed by me, and having as one of their features the promotion of quick melting. Size of the Furnace. The hearth of the furnace, however, is a decisive factor in the production of solid castings. The manufacturer should know the size of the heats he intends to make constantly, and should have his furnace built for that size of heat. The hearth should differ in dimensions from that of a furnace making ingotr steel. That is, the bath should be deeper and should have less surface-area. A shallow bath permits the slag to come out soon after the steel commences to flow, and thus prevents the additions from going into the steel, or from becoming uniformly distributed in case they have been put in hurriedly. Under this head comes the very poor practice of making small heats in hearths of a much larger capacity. If into a 25-or 30-ton furnace only 12 or 15 tons of metal is charged per heat, the proportion of heats that will be wild, or show signs

Jan 1, 1913

By Walter Miller

Developments in oil refining were so varied during 1938 that a refiner had to be alert or be left behind. The long-talked-of conversion of oil refining into a true chemical industry using petroleum as a raw material was hastened, particularly in the realm of motor-fuel manufacture, by the increased understanding and use of catalytic processes. The petroleum refiner's vocabulary has been extended to include alkylation, cyclization, aromatization, and isomerization. There are other devel: opments of a similar nature, but these are now considered commercially feasible under proper conditions. New Equipment Less expensive equipment and processes encouraged new construction and replacement. Estimates of money spent in the United States on building new plants and remodeling existing installations during 1938 place the sum at not less than $200,000,000, a noteworthy amount in a year marked by a business recession. The commercial application of small-scale catalytic polymerization of refinery gases made one of the latest advances available to the smaller operators, who usually are faced with unit installation and production costs higher than the large refinery enjoys. Competition was thereby fostered. Outstanding in this respect was the construction of two or more polymerization plants in small refineries at extremely low installation costs, with amortization measured in months instead of years. Houdry Processes Bursting like a bombshell late in the year was the disclosure of the extent of the development of the Houdry processes of catalytic cracking, viscosity breaking, gasoline treatment, desulphurization, and polymerization, said to be applicable to almost any raw petroleum stock and yielding gasoline of exceptionally high octane number. This process is claimed to be particularly adapted to once-through cracking of aliphatic hydrocarbons, and when combined with any of the conventional thermal

Jan 1, 1939

Lewis, B. LINDEMUTH, ?New York, N. Y.-I would like to confirm Dr. Howe's supposition that a process could be worked out for steel along similar lines. About 1 ½ years ago, F. D. Carney and myself were working on the elimination of columnar crystals which are particularly evident in nickel steel. We discussed rotation and varying speeds of rotation, but figured that with just rotation the steel would eventually catch-up to the motion of the mold and that the desired effect could not be obtained in that way, so we decided to alternate the direction of rotation. We rigged up in ordinary commercial turntable and on the same mounting attached a blast, furnace and mud gun, which is a simple steam cylinder, and mounted an 18-in. ingot mold on the turntable. The turntable had a stroke of about 10° to 12°, with stops at the ends. The steam cylinder would bang the table against the stops so that the stopping was so violent that it would tend to keep the metal in motion when the mold stopped and thus wash away any crystals that would form. We made quite a few interesting experiments; the results of which were that the columnar crystallization was entirely eliminated. At the same time we cast ingots in a similar mold, allowing the molds to remain stationary; these showed columnar crystals of from 2 to 4 in. in depth. The grain structure of the balance of the ingots, which were rotated, was very much finer than the grain structure of the ingots that were cast and allowed to cool slowly. The experiments were made on a 0.35 per cent. carbon nickel steel, which is probably more susceptible to columnar crystallization than any other. I think that the rolling properties and the forging properties of some alloy steels could be very much improved by a similar method, or some commercial method of casting ingots to eliminate this columnar crystallization.

Jan 5, 1919

The Library of the above-named Societies is open from 9 A.M. to 10 P.M. on all week-clays, except holidays, from September 1 to June 30, and from 9 A.M. to 6 P.M. during July and August. The Library contains about 55,000 volumes, including sets of technical periodicals and the publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library can render valuable service through correspondence; letters requesting information will receive special attention. The Library is prepared to furnish references and copies of articles on mining and metallurgical subjects; to determine the existence of mining-maps, and to furnish general information as to the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be .o interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape. The members of the Institute can be of service to the Library by forwarding copies of mining-reports, maps privately issued, and similar material, which will be classified, indexed, and made available to other members. Suggestions for additions to the Library, either by purchase or personal solicitation as gifts, will be welcomed. It is hoped that members while in the city will use the Library freely, and assurance is given that most careful service will be rendered to them.

Jan 10, 1914

By R. Taggart, R. H. Ericksen, D. H. Polonis

MarTENSITIC a has been observed to form spontaneously from the retained ß phase during the preparation of thin foil specimens of metastable Ti-Cr alloys containing from 6.9 to 20 wt pet Cr. Similar spontaneous martensite reactions have been reported in thin foils of 0 brass' and other alloys.2 4 The absence of retained austenite in iron-based alloys has also been attributed to spontaneous decomposition during thinning.5 The present work indicates that a unique situation occurs during which the spontaneous transformation takes place when the transitional ? phase is present in the as-quenched or partially aged ß phase. Alloys containing 6.9, 7.0, 8.0, 12.0, and 20.0 wt pet Cr were prepared by the levitation melting of "io-chrome" chromium and iodide titanium. The 0.5-in.-diam ingots were vacuum-annealed at 1000oC, and wafers 0.020 in. thick were then cut from the ingots. These wafers were wrapped in molybdenum foil, encapsulated in Vycor under a reduced pressure of purified helium, and then held for 30 min at 1000°C. The specimens were quenched in water to retain the metastable high-temperature ß phase. The quenched alloys were thinned by mechanical grinding to about 0.005 in. thick, then electropolished in a solution of 300 ml methyl alcohol, 175 ml n-butyl alcohol, and 30 ml perchloric acid at a temperature of -40°C. Needle specimens 0.005 to 0.010 in. diam were taken from each ingot and heat-treated with the foil specimens. X-ray diffraction patterns indicated the structure of the 6.9, 7.0, and 8 wt pet alloys to be a

Jan 1, 1968