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Jan 1, 1970

The income of the Institute is derived from dues, subscriptions to MINING AND METALLURGY and sale of publications. These sources are fortunately supplemented by the interest from invested funds now amounting to over $500,000, a considerable portion constituting endowments for especial purposes. Aside from the medal funds the principal endowments are the James Douglas Fund for support of the Library, the Rocky Mountain Fund and the Seeley W. Mudd Memorial Fund. The income from the two last named is available for the support of research and a variety of other purposes. It is allocated by the Board of Directors upon recommendation of standing committees in each case. An active effort is being made to increase the endowments of the Institute, it being felt that unusual opportunities exist for research and public and professional service through the organization and at a minimum of expense. J. V. W. Reynders is chairman of the Endowment Committee.

Jan 1, 1923

Jan 1, 1967

By AIME AIME

ON THE occasion of the eightieth birthday of Captain Robert W. Hunt, the Iron and Steel Committee of the Institute, desiring to commemorate the great contributions made to the steel industry by Captain Hunt during his long career, conceived the idea of a Hunt Medal to be awarded annually by the Institute for meritorious contributions to the art of making steel. The project was received enthusiastically by all to whom it was proposed, especially by Captain Hunt's partners and employees who considered it their right, and asked for the privilege of -. - raising the necessary funds within their own circle. This was agreed to, and the Institute has received from them $7500 as an endowment fund to provide an annual award, and $1000 for the expenses of providing of medal.

Jan 1, 1920

By E. S. Wheeler

The rapid increase in the use of monel metal and malleable nickel in the form of sheet, rod and tube has resulted in a similar increase in the demand for these metals in the form of castings. These castings range in size from small valves and pipe fittings weighing a few ounces to large centrifugal pumps, gate valves and marine propellers, some of the last weighing as much as 24,000 lb. A group of such castings is shown in Fig. 1. A large nickel agitator is shown in Fig. 2. Monel metal castings are widely used in accessories for steam power plants and in a variety of chemical plant equipment where the corrosion resistance, high strength and toughness characteristic of this metal render it particularly valuable. Nickel castings find extensive use in the construction of corrosion-resistant apparatus, and are often used in conjunction with wrought nickel sheet and tube in the fabrication of equipment for handling a variety of chemical and food products, particularly dairy products. In response to this demand for castings, numerous foundries have undertaken the production of castings of these metals and have met with varying degrees of success. The successful production of castings of monel metal and nickel requires careful attention to molding practice, proper melting equipment

Jan 1, 1930

By P. Sanchez-Mejorada

GEOLOGISTS who are acquainted with the mines of northeastern Mexico realize that the most important lead-silver replacement deposits of the province are confined to a single formation. But since the formation is several hundred meters thick, the author has determined the relative position of the lead mantos in the belief that this information will prove useful in the search for new mines. This article describes the stratigraphic location of lead-silver replacement deposits known in several mines situated in a region comprising part of the states of Coahuila and Nuevo Leon. The area studied extends for 200 km* (125 miles) from east to west and 70 km (45 miles) north to south. Metallogenic Province: The most important metallic deposits of the region have the following common characteristics: 1) The orebodies occur as manto replacements of calcareous sediments. 2) The horizons that have contributed large tonnages of ore are in similar positions in the corresponding stratigraphic columns (as it will be shown later on). 3) Lead is the most important metal in the ores. Silver is commonly present in small amounts. Occurrence of zinc is dependent on the degree of oxidation of the primary sulfides. 4) A large proportion of the total production has been in the form of oxidized ores. 5) The deposits are located on anticlines. Rocks of Cretaceous age crop out over large areas of the states of Nuevo Leon and Coahuila. forming part of a belt that extends to the south along the eastern Sierra Madre. The sediments are cut by a small number of intrusive stocks ranging in characteristics from rhyolite to diorite. The most prominent structural feature of the region is a series of folds trending northwest-southeast. Faulting is not conspicuous in the region, although a major fault zone is found farther East.' The physiography closely reflects structural features, with mountains formed by anticlines and valleys conforming with intermediate synclines. Narrow valleys have also been developed along the axes of many anticlines, where solution of limy sedi- ments and erosion have proceeded along axial tension fractures. Stratigraphy: Rocks of the Upper Cretaceous are exposed in only a small percentage of the total area. Generally they have been eroded away from the mountains and are covered by recent talus and alluvium in the valleys. Humphrey' has published an excellent paper describing the Cretaceous formations of the Sierra de los Muertos, a short distance west of Monterrey. A brief summary of these formations is given below to convey an overall picture of the stratigraphic sequence that prevails just south of the area under consideration. Upper Cretaceous Indidura: Essentially thin shaly sediments. Cuesta del Cura: Limestone in thin wavy beds

Jan 1, 1959

By Arthur F. Taggart

TO all Mineral Dressers, but particularly to those in the Coal and Industrial Minerals Divisions: Ted Counselman, retiring after two years at the helm of the Milling Committee, pointed with pride to the continued growth of that committee, and sang the swan song "Why ain't we a Division of Mineral Dressing?" Our genial Secretary pointed out, handily, that, you see, the way the Institute is divided there are several blocks running across this way here, and one running all the way down here, and another running part way down here, and they all cut across each other like this, and anyway the miners want to be a Division now, so why not you Mineral Dressers be good and not upset the big Institute organizational chart? And anyway again, Divisions have vested interests, and a Division of Mineral Dressing would take something away from Coal and something from Industrial Minerals, and any good institutional man can see that a Division would never give anything up. It was all quite confusing, and apparently not too convincing, because then the Milling Committee went ahead and voted unanimously it is a good idea, let's see what the other fellows think about it as well.

Jan 1, 1944

By Scott Turner

MY YEAR OF SERVICE as president of the A.I.M.E. came at a time when the mineral industry had suffered severely because of disturbed economic conditions throughout the world. The Institute, an integral part of this industry, had been similarly affected. Its membership and revenues decreased; it was confronted by problems of retrenchment at a time when its vigorous operation was especially important to its members, of some moment to the mining industry, and of value to the nation. Throughout the last year, the recession of activity in our industry continued with slight abatement. Your Board accordingly exercised such economy within the Institute as was possible without impairment of essential functions. It endeavored to aid in sustaining the morale of members, their sense of professional unity, and their interest in maintaining research and the interchange of scientific and technologic data upon which the progress of our industry depends. Effort was made to assist in the difficult task of finding employment for needy members; our endeavors have met with some success.

Jan 1, 1933

University of Alabama University, Alabama Mining and Metallurgical Society WILLIAM R. HIGGS, President ROBERT E. MEAD, Secretary J. R. CUDWORTH, Faculty Sponsor MILTON H. FIBS, Counselor University of Arizona Tucson, Arizona Miners' Society LEE BLESSING, President R. W. CORY, Secretary E. P. MATHEWSON, Faculty Sponsor B. R. HATCHER, Counselor University of California at Los Angeles Los Angeles, California Student Chapter, A.I.M.E. ARCHER WARNE, President ROBERT JOHNSTON, Secretary E. K. SOPER, Faculty Sponsor EMILE HUGUENIN, Counselor Colorado School of Mines Golden, Colorado Student Chapter, A.I.M.E. J. Ross REED, President ANDREW PERRY, JR., Secretary J. BURNS READ, Faculty Sponsor A. W. NEWBERRY, Counselor

Jan 1, 1936

By G. Thodos, D. E. Matschke

Cansiderable time and effort frequently are expended to establish, with a degree of confidence, the PVT behavior of pure substances. In particular, a great deal of experimental information contributed by a number of investigators is available in the literature. The data of each investigator, although significant in themselves, cannot be used with a high degree of confidence until they are compared with the continuum of information presented by others. Current interest in thermodynamic and transport properties, for not only the gaseous state but the con-densed state as well, requires that PVT infarmation be presented for both regions. The density dependence on temperature and pressure, when presented as a continuum, is of considerable value in itself, especially since the available equations of state fail to properly account for the PVT behavior in the condensed state. For this reason and to incorporate PVT data recently presented in the literature, this investigation was carried out. In their studies concerned with the thermodynamic properties of methane, Matthews and Hurd in 1946 utilized the data of Kvalnes and Gaddy and Olds, Reamer, Sage and Lacey to establish the PVT behavim of methane in the superheated region and the saturated liquid densities of Keyes, Taylor and Smithl in conjunction with the Clapeyron equation to develop the densities for the saturated envelope. Current activity sponsored by API Project No. 44 under the direction of F. D. Rossini has led to a tabular presentation of compressibility factors for gaseous methane in the superheated region.la These values were obtained by using smoothed residuals, developed from experimental data and the Ben edict-Webb-Rubin equation,' to establish internally consistent compressibility factors for the real gas. This approach offers probably the most precise presentation of PVT information for gaseous methane to date. The PVT behavior of methane also can be represented accurately by equations of state such as the Benedict-Webb-Rubin equation or the Martin-Hoa equation.' These equations, although valuable for analytically representing the PVT behavior, lack precision in the compressed-liquid region. The PVT data available in the literature for methane were utilized to obtain reduced densities that are presented in Figs. 1 and 2 as functions of reduced temperature with parameters of reduced pressure. The critical constants utilized for methane are those reported by Kobe and Lynn." These critical values, T, = 191.1°K, PC = 45.8 atm and p, = 0.162 gm/cc, produce a critical compressibility factor, z, = 0.289. The PVT information, as obtained from the literature, in many instances was not presented in an immediately

By Jay R. Burns

Two magnesium sand-casting alloys are commonly favored in the United States. These are referred to as H and C alloys (Dow Chemical Co.) or AM265 and AM260 alloys (American Magnesium Corporation). Both are of an aluminum-zinc-manganese type. H alloy contains 6 per cent aluminum and 3 per cent zinc and is characterized by relatively good toughness. C alloy contains g per cent aluminum and 2 per cent zinc and is employed where high yield strength and pressure tightness are required. Examination of magnesium castings poured in Europe and England,1,2 however, demonstrates that H and C alloys are replaced by A8 and AZ91, respectively. That is, A8 represents a magnesium alloy having superior toughness while AZ91 is suitable for high yield strength and pressure-tight applications. The basic difference between the American and European alloys is that the foreign alloys employ a somewhat higher aluminum content and less zinc than is found in H and C alloys. The mechanical properties of the alloys, when divided into high and low-aluminum groups, are quite similar, as determined from separately cast foundry-control type test bars.3 In this paper the decrease of mechanical properties caused by any given amount of microporosity is measured for H, C, A8, and AZ91 alloys. The relative susceptibility of each of the four alloys to microporosity is also determined. Typical mechanical properties and nominal chemical analyses are reported in Table I. [ ] The apparent similarities between the two alloys in each group have led to considerable discussion as to the relative merits of each of the compositions.2 Popular points for comparison between the alloys have been the relative susceptibility of each of the four alloys to microporosity5 and the effect of this microporosity on their mechanical properties. It is primarily intended, in this paper, to show the

Jan 1, 1946

By Joseph E. Pogue

The writer visited the Muzo emerald mines in July, 1915, and spent six days in their study. This paper embodies the results of his observations, plus information personally communicated by Robert Scheibe, Professor of Geology in the Mining Academy of Berlin, who at the time of the visit was completing a detailed field investigation of nearly a year's duration of the emerald deposits of Colombia. An elaborate account of this valuable work may be expected at a future date from the pen of Professor Scheibe.

Jan 1, 1917

Low Zinc Prices Close Alcoa Mine Alcoa Mining Co., announced that it will suspend operations at its Hutson mine, near Salem, Ky., because of low zinc prices, January 15. The Aluminum Co. of America subsidiary announced that the low market has made zinc mining un- profitable. About 70 men were employed at the mine, with a production of about 5000 tons of zinc annually. Alcoa said the shutdown would not affect other company operations, with most of the men at Hutson absorbed in the mining firm's fluorspar operations in the same area.

Jan 2, 1953

By John D. Morgan, Sylvain J. Pirson

An instantaneous and continuous analysis of a mineral suspension should be of great value in controlling various mineral preparation processes. Described herein is a method of analysis based on the use of high-frequency alternating current, which, under certain restrictive conditions, could be of use. Theoretical Considerations In a suspension of conductive minerals, the electrical effect primarily responsible for the variations in electric conductivity is the capacitance. In Fig Ia, let an alternating voltage E be applied across two electrodes F and F', between which are two rows (S and T) of mineral particles, all of approximately the same size, immersed in a fluid. Let the number of rows of particles between the electrodes be R and the number of particles in each row be N. If A is the area of a particle, D is the distance separating two particles, and k is a constant depending on the fluid, the capacity, CO, of the particle system will be given by: KRA C°= ND Referring now to Fig Ib, let R, the number of rows, be held constant, but let N, the number of particles in each row (S and T), be increased X-fold. The capacity, C1, of

Jan 1, 1949

By George Mixter

MINING, in contrast to manufacturing, deals with a wasting asset. That which is taken out of the ground is gone, the property is depleted to that extent, and will eventually become exhausted of profitable ore. So the life of a mining company is dependent upon the ability of its management to develop improved methods to permit extraction at a profit of the lower-grade ores which remain, to extend by intelligent exploration the limits of its known ore bodies, and to find and acquire new properties to take the place of those that, for one reason or another, are no longer operated. Its history is a story of constant change, of the working out of properties here and the acquisition and development of properties there, to maintain the vitality of the whole. It is a story of estimating with the tools and the knowledge available the location and extent of hidden ore bodies and of devising the means of extracting

Jan 1, 1948

By H. M. Chance

STRETCHING from New York southwestwardly to Georgia is a great range of hills and mountains consisting of pre-Palaeozic schists, slates, and gneissic and granitoid rocks, known locally by many different names; in Pennsylvaniaa as the South mountains, the Berkshire or Durham and Reading hills, and in Virginia and farther south as the Blue ridge. To the northwest of this range lies the " Great Valley," underlain by Lower Silurian limestones, and known as the Lehigh valley, Cumberland valley, Shenandoah valley, valley of Eastern Tennessee and Georgia and by other local names, but all these are parts of one valley, geologically and geographically continuous from New Jersey to Georgia. Lying upon and along the northern flank of this range of mountains, and dipping northwestwardly under the limestone of the valley, is the Potsdam formation (Primal or No. 1 of the Pennsylvania Geological Survey), which consists of sandstone or conglomerate overlain by slates. The latter are sometimes arenaceous and occasionally are replaced in part by sandstone. This formation varies from a few feet to several hundred feet in thickness. At the outcrop the slates are completely decomposed, oxidized or disintegrated, forming a belt of clay several hundred feet wide occupying the interval between the outcroppings of the sandstone and limestone. This clay-belt includes a more or less continuous series of iron-ore (brown hematite) deposits, which have been, and still are, extensively worked. The belt is more or less continuously mineralized with iron throughout its length, and hundreds of large deposits of ore have been developed and worked, producing many millions of tons of ore.

Sep 1, 1908

Jan 1, 1970

By N. E. Maccallum

(Cleveland Meeting, October, 1912.) ALMOST half a century has passed since the Siemens brothers, after tedious and costly experiments, finally began the manufacture of open-hearth steel. The furnace of that time was very small, having a hearth-capacity of from 3 to 4 tons, and we can appreciate the wonderful development that has taken place in those 50 years by the knowledge that to-day furnaces of 50 times the original capacity are in operation. As the new steel process assumed importance, and furnaces began to grow in number and in size, a question arose, to which no satisfactory answer has ever been given, and that was: ?What is the safe and economical limit of the open-hearth furnace?" Various stopping-places have been suggested, and 20, 30, 40, and 50 tons have each been advocated, but all such arbitrary restrictions have been passed, and 60 tons would probably represent the average furnace, although in a few instances from 70 to 80 tons are regularly tapped into one ladle. The furnaces which are the subject of the present paper have gone far beyond even these limits, and since, in my opinion, they mark another step in the progress of open-hearth steel, they will be considered fairly and frankly, in order that those to whom the matter may be of interest may be able to judge and form their own Conclusions. Short accounts of the work of these furnaces have appeared from time to time in various technical journals, of which the following is a brief résumé. These furnaces are the property of the Phoenix Iron Co., of Phoenixville, Pa., and their distinctive and important feature is, that they charge to twice the capacity of one ladle, and tap simultaneously into two ladles, with a device for controlling the flow into either. In this way the capacity of the furnace is not limited, as formerly, but heats of any size within the capacity of two ladles may be charged.

Oct 1, 1912

By J. M. Uys, T. B. King

WalSH, Chipman, King, and rant' have measured the water content (as hydrogen) of actual steel-making slags. An average water content of 290 ppm was found for basic open-hearth tapping slags and 114 ppm for acid open-hearth slags. Upon equilibration of these slags at 1550°C with a 25 pct H20-75 pct Nz atmosphere, the water content increased to about 410 and 300 ppm for the basic and acid slags, respectively. Walsh et al. concluded that an acid slag was thus relatively far removed from equilibrium, and that basic slags showed a closer approach to equilibrium, with the water vapor in the furnace atmosphere. Herasymenko2 contended that these conclusions were unjustified, as the oxygen pressure used in the equilibration experiments, ;bout 5 x X atm, was quite different from that found in the furnace. Consequently, during the experiments the slag composition would have changed due to oxidation of ferrous iron. As an extension of Walsh's work and to attempt to clarify this matter, the solubility of water in a basic open-hearth slag was measured as a function of oxygen pressure. Similar measurements were also made on synthetic silicates in the "Fe0"-Fe203-SiO, system. The experimental technique has been described previously by Walsh et a1.l and Uys and King.3 Samples of the basic open-hearth finishing slag, contained in 10-cc platinum crucibles, were equilibrated at 1550°C with atmospheres of different oxygen pressure but constant water-vapor pressure, Ph~o = 0.192 atm. Calculations, as well as measurements, indicate that this figure approximates the water pressure of the combustion gases in a steam-atomized, oil-fired open hearth. Oxygen pressures in the open hearth can vary from 10"2 atm in the combustion gases to between l0-' and 10" atm in the steel bath. The former figure depends on the combustion practice and the latter on the carbon content and temperature of the bath. The oxygen pressure of the slag should lie somewhere between these extremes and is expected to be closer to that of the steel bath than that of the combustion gases. Oxygen pressures were therefore varied between 10" and 6 x l0 atm. At the lowest pressure the slag "puffed up" when quenched (indicating possible loss of water) so experiments were not conducted at lower oxygen pressures. The results are shown in Fig. 1, which includes the water content of the slag "as sampled". The results show that the water content of the slag increased appreciably on equilibration with water vapor at 0.192 atm pressure and that the water solubility apparently decreases with increased oxygen pressure. The solubilities found are comparable to those of the Li20-Ca0-Si02 system.3 Work with synthetic slags in the "Fe0"-Fe203-SiOz system was performed at 1500" C, with Ph20 = 0.192 atrn and for oxygen pressures varying between 10"2 and 10-lo atm. Samples for chemical analysis were prepared as described by Larson.4 The results are shown in Fig. 2. Some low-silica melts tested at low oxygen pressures "puffed up" when quenched and analyzed less than 100 ppm water; these results are not included in Fig. 2. The melts containing 40 mol pct silica also showed a tendency to "puff up" during the quench, when they were tested at the lowest oxygen pressure. These results indicate that, at constant silica content, the solubility of water decreases somewhat with increased oxygen pressure. The effect is, however, small considering the wide range of oxygen pressures studied. Also, at constant oxygen pressure (above about lom5 atm) the solubility increases

Jan 1, 1963

Jan 1, 1967