Search Documents

(Under this heading will be published notes sent to the Secretary of the Institute by members or other persons. ) An experienced gold and silver metallurgist. specializing in cyaniding is desirous of obtaining a position in America. Speaks Me icon Spanish fluently. A member, a technical graduate, with four years' experience in railroad work and general construction, two years' on mine examination and geological reconnaissance, and two a half years' drilling exploration in placer work and petroleum, together with prospecting and geological interlope-tion, desires a position as a mining engineer or mining geologist. An experienced mine superintendent, manager, or field engineer, is open for engagement. Ire has had 12 years' experience as superintendent and manager of large mines in the United States and Mexico, and experience in mine examination. A member of the Institute with several years? experience in mining in the Lake Superior copper district, is open for engagement. A member, at present in the Southeast, desires a position as assistant superintendent or assistant. manager with a mining company operating in Washington or Alaska. Experienced assayer and engineer.

Jan 7, 1913

The Empire IV expansion is on schedule for completion in January 1980; Hibbing Taconite's 2.7 million ltpy* expansion should be finished late in 1979; and Reserve Mining's tailing disposal project is on target for April 1980. Erie Mining Co., the first to bring 170-ton haulage trucks to the Mesabi Range, reports excellent operating results, and Inland Steel expects to produce 80% of its pellets in 1979 using coal rather than oil. One Michigan mine has so many inspectors that it has hired a school bus to transport them around the operation; and a contractor reports that mine construction projects of the future may require the training of 15,000 workers. All of this was covered at the 52nd Annual Minnesota Section AIME Meeting and the 40th University of Minnesota Mining Symposium, a joint event held each January in Duluth.

Jan 3, 1979

By Freeman Bishop

Copper production has been under Government scrutiny for many years because it's known as a concentrated industry which in turn creates what many economists label administrative prices. Neither of these conditions is illegitimate, per se, the Federal Trade Commission and the Justice Department have said time and again. But Justice spoke up once more. This time over a Puerto Rican copper development planned by American Metal Climax, Inc., and the Kennecott Copper Corp. Bureaucratic Dichotomy Creates Confusion and Conflict In the Copper Industry Ian MacGregor, chairman and chief executive officer of Amax, said Justice in a recent communique questioned the propriety of the proposal of a joint copper venture in Puerto Rico. At the same approximate time, Dr. Hendrik S. Houthakker, chairman of the President's Commission on Copper, was urging copper producers to expand production to help hold down prices by making more copper available to all consumers. This, Mr. MacGregor said, is creating confusion and conflict, since the Administration from one source is chastising the industry for doing what another branch requests.

Jan 1, 1970

By Jack Fox

On May 16, 17 and 18, 1871, the first meeting of the AIME was held in Wilkes-Barre, Pa. It was then that the objectives of the American Institute of Mining Engineers were set up. The first ones were to enable the Members of AIME, "comprising Mining Engineers and other persons interested in mining and metallurgy, to meet together at fixed periods for the purpose of reading papers upon and discussing subjects which have for their aim the economical production of the useful minerals and metals, and the safety and welfare of those employed in these industries, and to circulate among its members, by means of its publications the in- formation thus obtained." Now, 100 years later, the American Institute of Mining Engineers, which has now grown to be the American Institute of Mining, Metallurgical, and Petroleum Engineers, is still pursuing those objectives. Dues in 1871 were fixed at $10 per year. Now1 100 years later, the dues have risen to $20 per year. But in pursuing the objectives of the Institute, the services to members have vastly increased, as have the general costs of doing business-even "non- profit" business like ours.

Jan 1, 1971

By William Ide Pierce

It is often desirable to work an old mine that has not been in operation for some time arid that is filled with water. This is especially true in Nova Scotia, where no great depth has yet been reached in any of the mines. The following is a description of a self-dumping water-tank which was used by me at Tangier, for draining a mine, and which did the work of a large pump, while the original cost is merely nominal, in comparison with the price of a pump. The tank, A, Pig. 1, is 1 1/3 by 3 feet and 4 feet high, inside measurement, made of 2-inch stuff and securely bound with iron. There are two clacks in the bottom which open as the tank is lowered into the water, and which close and hold the water as the tank is raised. B is an iron rod running through the tank, below and back of the center, and projecting beyond the sides of the tank. C is one of two guides, and D, a movable iron rod in each guide. This rod, attached to an upright, E, is moved forward and close up

Jan 1, 1886

By H. R. Steacy, A. H. Lang

Growth of general interest in uranium during the last ten years has been unparalleled in mining history, outranking the popular gold rushes and mining booms of bygone years. This is not surprising, considering the spectacular advances in nuclear research and the fact that a small amount of uranium can provide great quantities of energy for peaceful purposes. There are, however, a number of misconceptions and exaggerations regarding uranium. Many novices have highly exaggerated ideas of the ease of finding workable deposits, as opposed to mere occurrences, and reports of insignificant discoveries are sometimes given much publicity. Beginning about ten years ago mining for uranium has assumed a major place in Canadian and U. S. mineral industries. Uranium is now high on the list of metals produced in Canada. The gross value of uranium production in Canada in 1958, when additional plants now under construction are operating, will probably exceed 180 million dollars.

Jun 1, 1956

POSITIONS VACANT (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons.) Superintendent for iron mine operated on the sub-level and caving system. Small output, moderate salary. Location, Southern State. No. 45. Chemist to sample and analyze iron ore. Experience in other branches not essential. Location, Southern State. No. 46. ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introducd by members.) Experienced mine superintendent desires position. Several years' experience in practical management of mining and development work. Has also practiced ass consulting engineer and is thoroughly experienced in the examination and development of mining properties. Mexican experience. Will go anywhere for reliable concern. Salary moderate. References. No. 254. Member, mechanical superintendent, wants position. Has had 12 years' experience as master mechanic of smelting plants in United States and Mexico. Also superintendent of shops doing marine, mining, and general contracting work. . Experienced in manufacture of mining tools and equipment. Up to the minute in copper, lead, and zinc smelting. Has learned a learned a great deal, can forget much, and has the inclination and ability to learn more. Best of references. No. 255.

Jan 10, 1915

THE ladle is a small hearth made on a cage of iron bars like a bird-cage, and has a handle so that it can easily be taken from the forge and carried wherever desired. It is a common device and is much used among masters for small castings, but with a large weight you would have difficulty in lifting it by hand even though you were aided by levers and winches. If you should indeed do it, it would be just as if you had lifted the aforesaid hearth by force, and this would be unwise if you could do anything less difficult. A forge is likewise made for this, with a good pair of large bellows that are well covered with cloth. When the small hearth has been made with good clay, baked, and well covered with ashes, it is placed in front of the mouth [of the bellows] and a crown of two or three brick ends is built around it on top of the rim so that the charcoal may be held better and in greater quantity. Then, having lit the fire and heated the ladle and the charcoal, the pieces of material that you wish to melt are gradually put on

Jan 1, 1942

By Robert G. Nisle

In conducting a pressure build-up test on an oil well, it is often necessary to shut-in the well for a short time prior to initiation of the test. The effect of such a short tern shut-in on the resulting pressure build-up curve is derived. The derivation is based on the Kelvin point-source solution and is a straight forward extension of the fundarnental theory. The magnitude of the effect is evaluatecl and illustrated by an example. It is shown that if the production subsequent to the short term shut-in is at least 10 times the duration of the shrct-in, the effect will he less than 10 per cent. INTRODUCTION It often happens that before a pressure build-up test can be made an additional valve must be mounted on the wellhead, or on arrival at the well, it might be learned that the well had been shut-in several hours the previous day because of a shortage of tankage. In such cases the question is How will such an interruption of production affect the results of a pressure buildup test This work explains how to take account of such a short term shut-in in order that the test can proceed without further delay. The solution presented here makes use of the Kelvin point-source solution used by Horne1 in his treatment of the pressure build-up in wells. Use is also made of the super-position theorem. MATHEMATICAL DERIVATION The well is assumed to have been in production at a constant rate for a relatively long time (several days or more). It is then shut-in for a short time, after which it is again placed in production at the previous constant rate. It continues to produce at this rate until shut-in for a pressure build-up test. The Kelvin point-source solution is expressed by Eq. 1. The sequence of production rates is listed in Table I. TABLE 1 — SEQUENCE OF PRODUCTION RATES Time interval Production Rate At time AT the pressure will be the resultant of the sequence of production rates shown in Table 1. An expression for the super-posed effects may be derived from this table. (Effect of + q for T + ? T) + (Effect of - q for T + ?T-t,) + (Effect of + q for T + ? T - t,) + (Effect of - q for ? T) = Resultant........(2) The desired result is obtained by substituting the effect defined by Eq. 1 for the terms in Eq. 2. The result is Eq. 3. When the logarithmic approximation is made for the exponential integrals and the terms collected the result is Eq. 4. Let T — t2 = T = flowing time following short term shut-in t2 — t1 = 6 = duration of short term shut-in Then T - t1 = r + 6 Substitution of these quantities in Eq. 4 gives p(rw ?T) = P,, -When d<<t - AT then d—&apos;-, T— approaches 1. r + AT In this case the effect of the short term shut-in may be ignored. In order to get some idea of the numerical magnitudes involved take the worst possible case, when AT = 0, that is at shut-in. If the error is made less than some maximum acceptable value at this time, it will be less than the maximum for all subsequent times. d + r Let the difference between the value of y-— and 1 be less than 0.1. Then —6+r — 1 < 0.1 S < O.l T Therefore, if the flowing time following a short term shut-in is at least 10 times the duration of the short term shut-in, the error introduced by ignoring the short term shut-in will not exceed 10 per cent of T+AT A T

Jan 1, 1957

By T. A. Read, M. S. Wechsler, D. S. Lieberman

IN the formation of martensite in steel, it has been observed that the habit plane does not change continuously as the alloy content is varied. Instead, it appears that discrete habits correspond to certain ranges of composition. Greninger and Troiano&apos; found that in low-, medium-, and high-carbon steels, the habits are approximately (1l1), (225), and (259), respectively.* The work of Mehl and Van Winkle2 indicated that the change from the (225) to the (259) habit is fundamentally a consequence of the lower transformation temperature rather than the higher carbon content. Also, Otte and Read3 observed that the habit plane orientation for a chrome-carbon steel scattered within a cone of semivertex angle of 5 deg, which was outside of the experimental error in the determination of the habit plane. These observations suggest the importance of investigating what factors in the crystallography of the formation of martensite account for the several types of habit and the inherent scatter in the precise orientation of the habit plane. A theoretical treatment of the austenite-martensite transformation has been given,4 which considers the total transformation distortion to be composed

Jan 1, 1961

By L. C. Campbell

THE purpose of any accident-prevention program is the curtailment or entire elimination of injuries and fatalities. It is a job that is never finished in the coal-mining industry. Day by day, on shift and off shift, men are exposed to injury and death in varying numbers. Seldom is it possible to lock up at the end of the shift and leave a mine plant in the care of a sleepy watchman, as can be done at most manufacturing plants. Even on off shifts there are maintenance and supply crews, coal cutters, pumpers and ventilation men exposed to danger. The prevention program of The Koppers Coal Co. recognizes two primary facts: First, no program can be successful without the full support of the management and complete knowledge of the job at hand on the part of every supervisor. Second, and equally important, is the full cooperation of every employee in observing the safety rules and practices set up by the management. Conscious day-to-day concern for his safety by the indi-vidual worker is the longest stride toward a good safety experience. How to accomplish the education of the individual worker and super-visor for safety is the problem of The Koppers Coal Co. as it is the problem of all coal companies.

Jan 1, 1939

By E. R. Funk, H. Udin, J. Wulff

The surface tension of solid silver is measured by a refinement of the Udin, Shaler, and Wulff technique. The tests were made in a purified helium atmosphere at four different temperatures and various times. The average of the results is y = 1140 + 90 dynes per cm for the range 875° to 932°C. A SUCCESSFUL measurement of the surface tension of solid copper was reported by Udin, Shaler, and Wulff.&apos; They performed experiments on copper held in vacuum within 100°C of the melting point. At these temperatures, the creep rate in 5 and 3 mil copper wires was sufficient to permit determination of a balance between the contractile force of surface tension and the extending force of small copper weights joined to the end of the wire specimens. By suspending a series of variously weighted specimens and measuring the change in a gage length during the test, the balancing applied load could be found. This point of zero strain is a measure of the surface tension. The mathematical formulation of this gives: w = r y [1] where w is the weight for zero strain; r, the radius of the wire; and y, the surface tension. A subsequent note by Udin pointed out that eq 1 applies only to single-crystal specimens. Since the specimens used revealed a "bamboo" structure upon

Jan 1, 1952

By Arthur G. Metcalfe

Arthur G. Metcalfe (SOLAR)—Three explanations to account for mechanical nucleation effects are considered in the paper, viz., theories based on fragmentation, agglomeration, and pressure-wave mechanisms. The authors show that none of these mechanisms will explain the results observed with tin and Sn-Pb alloys. A fourth mechanism of nucleation enhancement was developed during work at Armour Research Foundation on casting of beryllium and, although presented briefly on various occasions, the theory has never been discussed adequately. It is believed that this theory will explain many of the observations. Classical homogeneous nucleation theories assume that embryo nuclei are formed in the melt as a result of compositional and/or thermal fluctuations. Stable nuclei are formed when a critical size is reached such that the decrease in free energy for conversion of this volume of melt to solid offsets the increase of surface, energy. The assumption is made that the average properties of liquid and solid metal can be used. In practice this assumption is invalid and indeed is contrary to the postulation of thermal and compositional fluctuations in the melt. Actually the conditions favoring embryo formation bring the seeds of its own destruction—the thermal and compositional fluctuations leave the embryo surrounded by atoms of higher thermal energies and/or by solute atoms that depress the melting point. Any mechanical method of dispersing this destructive

Jan 1, 1964

By Phillip J. Maddex, Ole Skaarup

The quite diverse backgrounds of the authors and their mutual interest in reducing transportation costs has produced some interesting innovations. A few words about their background will tell the reason for this joint paper. . . One is a shipping executive with a background of shipowning, ship management, ship and cargo brokerage and chartering, and most facets of the steamship industry, both American and International. The other is a chemical engineer, thoroughly brought up in the American chemical and mineral industries, with several top managerial positions behind him. They began cooperating when U.S. Borax was contemplating a change in its export shipping program and studying the freight cost for shipping borax from The mines in the Californian desert to Europe, and eastern U. S. markets. In the 20 Mule Team days, borax was exported in 50 pound bags. In 1960 it was still shipped in 50 pound hags. Three main products were shipped: two were anhydrous, and all three were sensitive to impurities. The products were bagged at the plant in the Mohave Desert, and shipped about 150 miles by rail to the port in Los Angeles. From Los Angeles, shipment was made by Conference steamship lines at Conference rates. Anyone who has shipped bagged material to Europe by steamer knows that the tab is anywhere from $20 to $30 or more per ton.

Jan 1, 1970

Capital, as represented by mineral resources, is being exhausted rapidly without possibility of identical replacement. The public must be discouraged from thinking-why worry about the bank balance so long as there are plenty of blank checks? Instead of each man, woman, and child being owners of a mineral capital of $89,000 as former Secretary Ickes once stated, they are really the guardians of a mineral reserve which, when harvested, cannot be reproduced. The proper use of this material is the basis of modern civilization and military power. The best American institutions cannot be maintained or transmitted to our children unless this trust is guarded. It is unfortunate that more attention has not been focused on the fact that this country is headed for a have-not status in the family of great nations if some- thing is not done to preserve its mineral heritage. It is the privilege of the United States now to champion and implement democracy because it is industrialized and can get at its raw materials. A high price is being paid every day in mineral depletion for the privilege. No one can eat his cake and have it too. The United States still must face world-wide economic competition and, perhaps, World War III. In the final analysis all wealth comes from the ground, whether plant, animal, or mineral. Value is in-

Jan 1, 1950

By Leonard Bernstein, Harry Bartholomew

MANY of the properties of metals and alloys are structure dependent. Not the least of these is the grain structure. For example, in producing alloy bonds between silicon or germanium and gold-alloy foil at temperatures above their eutectics (which are, respectively, at 370" and 356°C) but below the melting points of the individual constituents, it was found that wetting was more complete with a fine-grain structure than with a coarse-grain structure. In cases where the assemblies were held together for long periods of time at elevated temperatures, wetting was not as critically dependent on the grain structure as was the case for shorter periods of time. When liquid phase forms, it first forms in the grain boundaries due to the fact that most of the impurities are concentrated at the grain boundaries and that most impurities tend to lower the melting point of the gold alloy somewhat. In addition, grain boundaries are at high-surface free-energy levels and are thus in a more favorable condition to initiate good wetting. A fine-grain structure will have more grain boundaries per unit area than coarse-grain structure thereby making wetting somewhat easier. To make the grain structure of an alloy sys- tem visible, a satisfactory method for differentiating between the different grains of which the system is composed must be employed. For the alloy bonding system previously described, the grain structure on the foil surface is of primary interest. Conventionally used etchants for the gold-alloy system will not adequately delineate grain boundaries in their structures. For this reason an alternate method is proposed for those cases where such a determination is necessary. Foil between 0.0005 and 0.005 in. thick has been used in this determination. The equipment used in this investigation was described in a previous publication.&apos; Essentially, it employs a resistance-type filament which can be heated up very rapidly and cooled very rapidly. A thin refractory material is placed on top of the heating element. This refractory material may be molybdenum, tantalum, tungsten, or even ceramic but its thickness should be less than 0.010 in. to minimize the temperature gradient across it. The gold-alloy foil is placed on top of this refractory material. The temperature of the heating filament is raised to 900°C and cooled down to below 100°C in 5 to 10 sec. During this cycle, the foil can be observed to plastically deform due to its own weight. With no further chemical etching, this assembly is then viewed under a standard metallurgical microscope and the grain size measured. Fig. 1 is a Au-1 pct Sb alloy at 400X magnification and Fig. 2 is a Au-1 pct Ga alloy at 130X. This technique has proved to be an adequate means for controlling processing conditions in producing large quantities of gold alloy foil.

Jan 1, 1963

By B. Ramaswami

INTERNAL oxidation occurs readily in silver due to the rapid diffusion of oxygen in silver.&apos; It has a marked effect on creep in polycrystalline silver2 and raises the critical resolved shear stress in single crystals of silver.3 However, the effect of oxygen on the work-hardening parameters of silver is not known. It is the aim of this paper to describe the effect of internal oxidation on the work-hardening characteristics of single crystals of silver and an Ag-0.1 at. pct A1 alloy. The materials used were: 99.99 pct Ag from Handy and Harman and 99.993+ pct A1 from Alcoa. Single crystals, 6 mm by 6 mm in cross section of silver and Ag-0.1 at. pct A1 of mo.5 orientation, i.e., the orientation with the Schmidt factor m = 0.5. were grown by the Chalmers technique.4 One set of specimens, referred to herein as oxidized specimens, was annealed at 940°C for 24 hr in a muffle furnace, in air, and furnace-cooled to room temperature. Another set of specimens, referred to as nonoxidized specimens, was annealed in oxygen-free helium at 940°C for 24 hr and furnace-cooled over a period of 7 hr to room temperature. The annealed single crystals were tested at room temperature in a floor-model Instron testing machine. The results are presented in Figs. 1 and 2. A

Jan 1, 1965

Discussion of the paper of L. C. MORGANROTH, presented at the Pittsburgh meeting, October, 1914, and printed in Bulletin No. 93, September, 1914, pp. 2345 to 2352. D. T. DAY, Washington, D. C.-I would like to hear some further detail as to the California deposits. L. C. MORGANROTH, Pittsburgh, Pa.-We have examined the California deposits at various times; I have been over practically all of them myself. These deposits are all of the massive variety. While it is possible that it could be mined and used for metallurgical purposes, it is not feasible because it costs too much. At the present time magnesite which is mined in California is used in the making of plaster, or by the paper trade. Careful figures show that if the California magnesite could be delivered to Atlantic seaports in the crude state at not over $4 a gross ton, and assuming that it would give the same results as the Austro-Hungarian magnesite, it would be cheaper to use the latter. It is also more difficult to dead-burn the massive magnesite, for while it starts to give up its gas readily, the difficulty consists in driving off the last few per cent., and unless this is driven off the magnesite will absorb C02 from the air, so that in a few months it may have 10 or 12 per cent. DAVID T. DAY.-How is the Austro-Hungarian supply at the present time ?

Jan 4, 1915

By Eric Jette

The nickel-chromium alloys form the base f for many industrial heating alloys, so that this system is of considerable practical importance. The literature on these alloys, however, contains much conflicting evi-dence, not only regarding the solubility limits of the terminal solid solu-tions at different temperatures but even regarding, the number of phases existing in the system. Part of the difficulty undoubtedly arises from the fact that chromium of sufficiently high purity has been available only during the last few years. A second and possibly even more impor-tant difficulty arises from the ease with which chromium reacts with silicon and carbon compounds and the atmosphere to form silicides, carbides, nitrides and oxides. Pilling and kihlgren1 in 1929 reviewed the existing scanty information. They did not consider the diagram by which they summarized the various bits of information to be entirely satisfactory. Matsunaga2 investigated the system by thermal analysis, microscopic examination and other means. Electrolytic nickel of 99.9 per cent purity and thermit chromium containing 0.30 per cent al, 0.40 per cent fe, 0.25 per cent si and 0.04 per cent c were used. A tammann furnace with hydrogen flowing through it was used for melting. Sekito and matsunaga3 reported an x-ray, investigation presumably on these same

Jan 1, 1934

By W. V. Kotlensky, H. E. Martens

In an earlier communication, Ref. 1, the authors presented the tensile properties and the changes in crystal structure and microstructure for pyrolytic graphite tested at 2750°C. It was suggested that changes in the structure may have an effect on the tensile properties of this material. Accordingly, tensile tests were run on a series of specimens, from one block of pyrolytic graphite, some of which were hot-worked by being strained at 2750°C, others of which were tested in the as-deposited condition. According to the manufacturer, General Electric Co., the polycrystalline material was deposited at 2100°C on a substrate of synthetic graphite by decomposition of a dilute natural gas mixture. The as-deposited material had a density of approximately 2.19 g per cc, and as shown in Fig. 1 had a structure of medium size growth cones which were regenera-tively nucleated. All specimens had a gage section 0.75 in. long by 0.06 in. wide by 0.1 in. thick with the thickness direction perpendicular to the basal planes. The testing method and equipment used have been previously described, Ref. 2 and 3. For both the hot-working and the testing the load was applied parallel to the basal planes; a cross-head speed of 1.5 x l04 in, per sec was used. All heating was done in an atmosphere of bottled helium.

Jan 1, 1962