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By G. W. LAAiIBOURNE

FEW mines possess a history of more fascinating interest than the Ontario at Park City, Utah. The famous Bonanza's production record of over $50,000,000; the great extent of its workings; the remarkable character of its mineralization; the fact that recent discoveries have shattered preconceived theories of the geology of the camp practically assuring the half-century old property a future as active and as prosperous as the past make the Ontario one of the unique mines of the world. A mere accounting of the wealth created by this historic property not only exemplifies the great profits

Jan 1, 1925

By M. G. Corson

UNTIL recently, the characteristics of cast copper have seldom been studied and such study as has been made has been inadequate. The prevailing idea seems to be that since pure copper is infrequently used in the cast state, there is no reason for trying to establish precise data regard-ing the properties of the metal in that condition. On the other hand, wrought copper either in the shape of sheets or wire rarely fails in service, except as a result of the action of reducing gases at the annealing tempera-tures, so there is little incentive to study the properties of the cast shapes -cakes, bars, ingots and billets-for-the sake of tracing the causes of failures of the wrought metal to the cast stock. However, about a decade ago, wirebars of American origin often cracked badly while being hot-rolled in mills in Germany. This led to four investigations: by E. Seidl and E. Schiebold,1 by P. Siebe,2 by O. Bauer and G. Sachs,3 and by G. Welter.4 These authors came to the conclusion that failures in hot-rolling were due essentially to the presence .of a wide zone of columnar crystals between the thin layer of fine crystals near the surfaces of the bars and the large but more nearly equiaxed grains of the central core. This macrostructural defect was explained in turn by the probable upward deviation in the temperature of the metal while it was being poured into the molds of the casting machine. More recently, cast shapes of copper were investigated by N. P. Allen5 and by C. Blazey.6 Allen examined vertically cast wirebars and hori-zontally cast wedge cakes of electrolytic tough-pitch copper, but only for the distribution of densities; i.e., porosity. Blazey was interested mainly in the mechanism of the variations in electrical conductivity clue to cold-work and anneal, but gave introductively an account of the composi-tion and average densities of the tough-pitch horizontally cast wirebars used. As far as the present writer can tell, no investigation was under-taken for the sake of presenting a picture of the distribution of mechanical characteristics in the wirebars of copper, tough-pitch or otherwise.

Jan 1, 1938

By Jack A. Kanz, Samuel R. Shortes, E. C. Wurst

Zinc diffusion into GaAs from the vapor phase through reactively sputtered SiO, films Izas been inrestigated for various zinc pressures at 1000"C. Diffusions were carried out in evacuated quartz ampules with elemental zinc and with various Zn-Ga alloys. Sputtered films have proved effective in lowering surface concentrations and preventing surface deterioration during diffusion. Approxin.ate complenzentary error-function impurity distributions were found when surface concentrations were reduced to approximately 3 -—4 x 10" atoms cm'3 or less with dilute zinc sources or by diffusion through SiO, films. Zinc difhsions in GaAs tlzrough SiO, films produced more planar diffusion fronts than were observed with uncoated zuafers under identical conditions. A) Surface Deterioration During Diffusion. Device technolorn-- in compound semiconductors has been hampered by several difficult problems not normally encountered with silicon and germanium. 111-V and 11-VI compound semiconductors generally have volatile constituents at temperatures used for diffusion. To achieve specific junction depths in reasonable lengths of time, or to obtain particular impurity distributions and doping levels, it is often necessary to use temperatures which cause surface deterioration and erosion of the wafer. The resultant surfaces are generally unsuitable for devices. The type and extent of surface damage depends to varying degrees on the particular environment of diffusion and on the particular impurity in question. The most common type of deterioration results from simple dissociation of the gallium and the arsenic during diffusin.' The deterioration process is significantly enhanced by thermal gradients in the diffusion zone, usually resulting in vapor transport and condensation at the cooler portion of the system. The resulting damage sometimes appears as a general haziness over the surface or an array of pyramidal etch pits characteristic of the particular orientation. Occasionally, erosion of the surface occurs uniformly over the wafer so that surface loss is not readily apparent. Workers in GaAs usually resort to the sealed-ampule type of diffusion system3"5 rather than the more conventional open system used for silicon and germanium. Another type of deterioration results from direct interaction of the impurity with the surface. The form of deterioration may vary from surface alloying, as in the case of zinc, to direct chemical attack and vapor transport of the reaction products, as in the case of sulfur. Surface alloying with zinc occurs at higher temperatures and source vapor pressures.4 The process is largely controlled by the amount of free gallium on the surface of the wafer in equilibrium with the arsenic lost to the system. The group-VI elements, sulfur, selenium, and tellurium, are commonly used donor impurities for gallium arsenide. These elements are characterized by high vapor pressures and high chemical

Jan 1, 1964

By P. Nicholls

Patent records show that the attempt to improve the burning of fuel by mixture or pretreatment with chemicals dates back to the early years of the last century. By 1845 English and French patents had included the specific beneficiations of elimination or reduction of smoke, soot and clinker; reduction of the ashes; elimination of sulphur fumes; increase of the rate of burning; increase of the time a given charge of fuel would last; and, in most patents, a saving of fuel. The earlier patents specified additions up to 80 lb. or more per ton of fuel, but after 1860 the quantity was seldom more than 4 lb. There is no record of the extent to which these patents were commercialized, but after 1874 many American patents were assigned to companies specializing in treatment of coal, so it is probable that the products were marketed on a considerable scale at least as early as that date. From 1900 on, many proprietary products were marketed under the general name of "fuel savers," the principal sales being in small packages for the use of householders; savings of from 10 to 40 per cent of the coal were promised. Starting with 1927, the use of proprietary or other mixtures of chemicals was extended to power plants and to treatment of coals at the mines, the claims of saving of fuel being subordinated to those of general improvement and, in particular, to reduction of clinker-ing. Such expectations are attractive and a number of companies experimented with or adopted the practice. There were reports of improved operation, but, apparently, few were confident enough that these improvements were due to the salts to publish the results of tests or their records of operation. There are no data on the yearly tonnage of coal treated but indirect reports suggest that it has been relatively large. Since its establishment in 1910, the U. S. Bureau of Mines has continually received inquiries about these products. At the request of other governmental departments it made tests in 1910, 1916 and 1930, using certain proprietary products applied according to the instructions of the vendors; these tests were made with eastern coals in domestic and

Jan 1, 1938

By P. Nicholls

Patent records show that the attempt to improve the burning of fuel by mixture or pretreatment with chemicals dates back to the early years of the last century. By 1845 English and French patents had included the specific beneficiations of elimination or reduction of smoke, soot and clinker; reduction of the ashes; elimination of sulphur fumes; increase of the rate of burning; increase of the time a given charge of fuel would last; and, in most patents, a saving of fuel. The earlier patents specified additions up to 80 lb. or more per ton of fuel, but after 1860 the quantity was seldom more than 4 lb. There is no record of the extent to which these patents were commercialized, but after 1874 many American patents were assigned to companies specializing in treatment of coal, so it is probable that the products were marketed on a considerable scale at least as early as that date. From 1900 on, many proprietary products were marketed under the general name of "fuel savers," the principal sales being in small packages for the use of householders; savings of from 10 to 40 per cent of the coal were promised. Starting with 1927, the use of proprietary or other mixtures of chemicals was extended to power plants and to treatment of coals at the mines, the claims of saving of fuel being subordinated to those of general improvement and, in particular, to reduction of clinker-ing. Such expectations are attractive and a number of companies experimented with or adopted the practice. There were reports of improved operation, but, apparently, few were confident enough that these improvements were due to the salts to publish the results of tests or their records of operation. There are no data on the yearly tonnage of coal treated but indirect reports suggest that it has been relatively large. Since its establishment in 1910, the U. S. Bureau of Mines has continually received inquiries about these products. At the request of other governmental departments it made tests in 1910, 1916 and 1930, using certain proprietary products applied according to the instructions of the vendors; these tests were made with eastern coals in domestic and

Jan 1, 1938

By John Jermain Porter

The chief purpose of this paper is to indicate the laws governing the fuel-economy of the cupola, to examine the feasibility of some of the proposals for increasing its fuel-economy, and to show that the conditions limiting fuel-economy here are altogether different from those prevailing in the blast-furnace. The two methods available for studying the thermal efficiency of the cupola and determining the factors limiting fuel-economy are: 1, by the determination of the total heat-balance; and 2, by the application of the theory of critical temperatures. The case selected as an example represents a cupola operating under fairly efficient conditions. The data are as follows : Cupola, GO in. in diameter, 15 ft. high to the charging-door, with a 9-in. lining. Bed-charge, 2,000 lb. of coke and 4,000 lb. of iron. Subsequent charges, 400 lb. of coke and 4,000 Ib. of iron. Total number of charges, 20. There was 800 lb. of coke recovered from the drop, hence the total coke burned is 8,800 lb., or 0.11 lb. of coke per Ib. of iron. Coke contains 90 per cent. of fixed carbon and 2 per cent. of moisture. 300 1b. of kindling-wood is used in lighting. 80 lb. of limestone (95 per cent. of CaCO,) is used per charge, or 0.02 lb. per Ib. of iron. Melting-loss, 4 per cent.; distributed thus : Fe, 3.5; Si, 0.25; Mn, 0.25 per cent. Average analysis of top-gases : CO2, 15.1; CO, 10.0 per cent. Average temperature of top-gases, 1,600" F. Temperature of air and stock charged, 60" F. Dew-point of air, 50 F. The items entering into the total heat-balance and their calculation are as follows: 1. Heat of combustion of fuel.—Total heat evolved = 14,580 x lb. of carbon burned + 7,200 X Ib. of wood burned. Hence B.t.u. per lb. of iron charged =

Jan 1, 1913

* The greatest and richest iron ore body in the world was discovered by U. S. Steel in Venezuela in April 1947, and is disclosed for the first time in this issue (p. 178), One solid mountain of ore, Cerro Bolivar, will furnish more tonnage than the famous Hull Rust pit at Superior has, or can produce. Total resources are on the order of 2 billion tons plus. Big Steel is now moving with great speed on construction to bring out this ore, and 10 million tons are scheduled for shipment into Baltimore and Birmingham by late 1952. This ore will arrive at, Pittsburgh at a price lower than present natural ores from Superior. The Venezuelan properties will be completely mechanized. •U. S. Steel and independent companies are embarking on a taconite beneficiation program of tremendous proportions, which must be speeded to completion in the 1950's (see p. 185). By 1960 over $l.2 billion dollars will be spent on Venezuela, taconite, and Labrador to solve the United States iron ore crisis. In addition, U. S. Steel will spend another $300 million plus for a new steel mill at Trenton, N. J., before 1955. •The Deister Concentrator Co. gave $500 to the 1950 Coal Division Scholarship Fund. •Howard N. Eavenson, in analyzing the bituminous coal situation (see p. 193), suggests that anti-trust laws be extended to labor unions, disinterested trustees to administer pension funds, begin pension funds now and stop the collection of all "check-offs" for union dues or funds. •Minerals and metals worth 13.9 million dollars were produced in the United States in 1949, Secretary of the Interior Oscar L. Chapman announced. Although this value was 11 pct less than in 1948, it was the second greatest in history. Nonmetallics was the only major group that in 1949 equaled the 1948 production high. Mineral fuels decreased 12 pct and metals 15 pct. • Prospects for making gas from coal are seen to be unattractive by the Pittsburgh Consolidated Coal Co. because the success of operation depends on price and supply of coal which presently are not attractive. The company has shut down its gasification plant at Library, Pa. * Economic prospects for the immediate future in the United States are good and business probably will continue at its present high levels throughout at least the early part of 1950, Secretary of Commerce Charles Sawyer said in his year-end report to the White House based on his personal survey of business conditions. •A 467-ft well 34 miles north of Rock Springs, Southwestern Wyoming, is said to be flowing a 5 pct solution of nearly pure trona (sodium carbonate) at the rate of 10,000 barrels a day. Trona, natural soda ash, is mined for the chemical trade at Searles Lake, Calif., and from about 1500 ft underground near Green River, Wyo., and has been in short supply. •The AEC is "very much interested" in a discovery of radioactive material that has been made in Baraga County bordering Lake Superior in the Upper Peninsula of Michigan, reported F. G. Pardee, Michigan State mining engineer. The material has been identified as uranium oxide in the form of pitchblende or uraninite. The discovery, made by a geologist of the Jones & Laughlin Ore Co., is the only instance in which the commission has certified samples of Michigan rock.

Jan 2, 1950

By H. S. McQueen

The insoluble-residue method for the examination and correlation of limestones and dolomites, or other sedimentary rocks containing calcium and magnesium carbonates, originated and was developed in the laboratory of the Missouri Geological Survey. The numerous and ever-increasing problems in the field of applied geology, and the need for a tool or aid in the solution of them, led to experimental work with samples collected from deep wells, in the early part of 1924. The success attained, almost at the outset, with this method was so great that the method has now been developed from the state of the experimental to the realm of large-scale, every-day routine. In a previous paper the writer1 described the procedure in detail and the characteristics of the residues obtained from certain Paleozoic formations in Missouri. The purpose of the present paper is to discuss the economic application of the insoluble-residue method. Developmental History Within the Ozark region of southern Missouri the geologic column consists of Lower Ordovician (Canadian of Ulrich) and Upper Cambrian formations, which are composed mainly of dolomite with subordinate amounts of sandstone, shale and limestone. Chert is found to some extent in all except one of the dolomite formations. The stratigraphy of the region is complex because the dolomites have lithologic similarities, fossils are few and often poorly preserved, and identifiable horizons within the comparatively thick formations are not common. Although considerable stratigraphic work of an areal nature had been done for a period of many years by the Missouri Geological Survey, the detailed geologic succession had not, until a few years ago, been systematically worked out. The problems of subsurface stratigraphy were even more complex. This region constitutes the main ground-water province of the State of Missouri and within it wells of varying depths are drilled in order to obtain supplies of ground water. In the work of the State Geological Survey in connection with the drilling of water wells for public supplies * Published with the permission of the Director, Missouri Geological Survey and Water Resources. Manuscript received at the office of the Institute Feb. 20, 1936. Assistant State Geologist of Missouri; Missouri Geological Survey, Rolla, Mo. References are at the end of the paper.

Jan 1, 1937

By R. R. Sayers

TWO serious hazards from coal dust confront the bituminous-coal miner- -a physical or safety hazard and a physiological or health hazard. The first threatens the miner with loss of life from coal-dint explosions, and the second with loss of health and earning capacity from inhaling large quantities of the dust. Studies by the Bureau of Mines have shown that coal dust, except some grades of anthracite dust, is capable of initiating an explosion when no explosive gas is present and that its property of extending or propagating an explosion has been responsible for nearly all the widespread explosions that have occurred in bituminous mines in the United States in the present century. For years many mining people believed that low-volatile coal dust was not explosive but not only is it explosive but if the source of ignition is intense, it is as explosive as the dust of many high-volatile coals because the war is creating increased pressure for greater coal production and because of the trend toward greater mechanization in mines, explosion and health hazards from coal dust are likely !n increase considerably.

Jan 1, 1943

By Robert L. Frantz

Progress and improvement continue to be the bywords of a dynamic coal industry. The industry continues to gain strength and expand its horizons in the face of competition from atomic energy and the problems of restrictive legislation. The direct contribution of coal mining and transportation to the national economy is about $3 billion a year ac- cording to a study made by the National Coal Policy conference. Coal remains the backbone of the power industry producing almost two-thirds of all the electrical energy generated by fossil fuels and one-quarter of all the energy consumed in the nation. Power supplied by electric utilities increased 6.9% last year. The chairman of the Federal Power Commission predicted a 7.5% growth rate until 1980 for the nation's electric output. Some 80,500 MW of fossil fired power plant capacity are on order or under construction before 1974, compared to a present capacity, all sources, of about 290,000 MW. The comparable new additions of nuclear power plants is expected to total about 51,000 MW.

Jan 2, 1969

By A. R. Elsea, E. E. Fletcher

This paper describes a metallographic investigation of the influence of tungsten or molybdenum additions upon the transformation and precipitation reactions occurring in Co-rich Co-Cr alloys. It is shown that tungsten has little effect upon the a-ß transformation temperature range, while molybdenum tends to raise it. Both elements tend to promote the formation of ? phase, molybdenum being more potent in this respect than tungsten. HIGH temperature alloys, that is, alloys which have load-carrying ability at elevated temperatures, have been developed at an increasing rate during the past few years. This has resulted from the requirements in the design of modern aircraft engines. Although many alloys of this type are available, they have been developed on an empirical basis. Metallurgists do not have a clear understanding of the phases or structures that are responsible for these high temperature properties. In order to determine why these alloys possess this particular ability, a project was started at Battelle Memorial Institute with the object of learning more about the fundamental factors which promote high temperature strength in alloys. This study was to include a correlation of microstructure and the high temperature properties of Vitallium, an alloy which is widely used for high temperature service. Vitallium is a complex material both from the standpoint of composition and microstructure. Consequently, it was necessary to obtain informa- tion regarding the phase relationships in this alloy. The Co-Cr binary diagram was determined as the first phase of this investigation.' A second paper described the effects of iron, nickel, or nitrogen on the reactions occurring in the Co-rich end of this system.' The present paper covers a continuation of this investigation in which the effects of tungsten or molybdenum on the reactions occurring in Co-rich, Co-Cr-base alloys were determined. Preparation of 'rest Materials Two series of ternary Co-Cr-base alloys, representing Co-Cr ratios of 80:20 and 68:32 ( Cr x 100 =20 and 32 ) , were prepared containing ( Co + Cr = up to 6 pct W and up to 12 pct Mo. Melting stock consisted of electrolytic Co, electrolytic Cr, 99.9 pct pure W, and 99.9 pct pure Mo. Table I lists the chemical analyses of these materials. The melting furnace was a vertical porcelain tube

Jan 1, 1952

By Richard A. Kesler, W. Michael Reed

Grindability or resistance to fine comminution is the fundamental issue involved in the application and sizing of grinding mills. Over the years, many theories for determining the amount of energy required for size reduction to a specified fineness have been proposed. The first published theory, introduced by P. R. von Rittinger in 1867, stated that the energy required for crushing or grinding is proportional to the increase in surface area produced. The surface area of a ton of particles of diameter (d) is proportional to (1/d), therefore the work input per ton for particles of diameter (d) would be proportional to (1/d). The second significant theory is that of F. Kick published in 1885. Kick said that the work required is proportional to the reduction in volume of the particles concerned. If (f) is the diameter of the feed particles and (p) is the diameter of the product particles, the work input relationship would be: [W =Ioq(f/p) 9] The "Third Theory" of F.C. Bond, introduced in 1951, states that the work required is proportional to the length of the new crack tips produced in particle breakage during crushing or grinding and equals work represented by the product minus that represented by the feed. This takes the form: [W=]

Jan 1, 1982

The American mining industry is vigorous today because it is young. At a time when the ore deposits of central Europe, for example, were being exploited actively, those of the United States were lying practically untouched. The founding fathers of our republic were not interested in mineral wealth because they were ignorant in such matters; their preoccupations were with defence against the Indians, the clearing of the forest, and the starting of agriculture in their new domains. They had no idea of establishing a mining industry. The Indians whom the American colonists dispossessed had no mines; they used only the metal that was to be found lying on the surface of the ground. Their arrows and spears were tipped with flint, which likewise called for little digging, if any. The native copper that glacial action had torn from the lodes of the Lake Superior region and had carried into the valleys of the Ohio and Mississippi was employed in the making of earrings, bracelets, knives, and scrapers. The same useful metal was found in many other places, in Virginia and Carolina, in Vermont and New Jersey, for example, but the Indians did not know how to melt it, much less how to smelt the ore, therefore they shaped it into tools and implements by hammering. Fortunately for them the hammering of the metal caused it to harden and therefore to become serviceable for implemental use. It is doubtful if they obtained the copper by actual mining, that is, by digging or excavating; it is true we find traces of such operations in the Keweenaw .peninsula of Michigan, but we have no

Jan 1, 1932

By Jack C. Haptonstall

This paper describes the analytical characteristics of Western subbituminous coal and the manner in which these characteristics apply to their use in a utility-sized steam generator. It compares these characteristics with those of typical Midwestern coal and Eastern bituminous coal. The paper also reviews in detail the design considerations that must receive attention when various blends of these three coals, or any combinations thereof, are planned to be used. This research paper describes variations in analytical and utilization characteristics when coals from different origins are blended in order to achieve a predetermined sulfur content for the purpose of predicting sulfur oxides emissions as they affect environmental regulations and the resulting alterations in utilization characteristics such blending would cause, and how such blends of coal would affect a utility-sized steam generator.

Jan 1, 1979

By A. A. Collins

H. R. BIANCO*—I should like to ask Mr. Collins if that statement he made about the addition of drosses to the blast furnace slowing down the blast furnace is a result of his own experience or a result of the experience of some older metallurgists; and perhaps I should ask him to define the type of drosses that he means. A. A. COLLINS (author's reply)— That has been my own personal experience with dross. On various occasions at Chihuahua we attempted to incorporate the dross in our regular blast furnace charge and to shut down the dross re-verberatory to try to save some money. As expected, we had very poor results. I think that Ed Fleming will well remember on one occasion, that was back about 1933, when we attempted the first experiment along this line, and as a result of the sulphur addition to the blast furnace to matte out the copper we ended up with hanging furnaces and mushy slags and abandoned the dross experiment, once again turning to the use of the reverbera-tory for handling dross. H. R. BIANCO—Is that dross you refer to from the drossing kettle ? A. A. COLLINS—Yes, the dross that I am referring to came from drossing kettles. Furthermore, to back up my previous assertion, I had occasion in 1943, while up at Leadville, to once again experience the routing of dross through the blast furnace with its sulphur addition, since they had no dross re-verberatory, and to observe that once thf dross was removed, the furnace was speeded up almost 100 tons a day. All of these are personal experiences and I think that Mr. Feddersen also has had a little experience along this line —in fact, I believe all of us have had some experience. H. R. BIANCO—I know at Trail they recirculate considerable dross through the blast furnaces and we also recirculate dross at Herculaneuin and I am not aware that it has done much towards slowing down the blast furnace. A. A. COLLINS—We have always had very poor results. In the first place you have got to add a sulphur addition to pick up that copper and once you do that, that sulphur is apt to combine with some of the zinc and you are going to form a little mush; before you know it you have furnace hangs and a poor working furnace. Now of course that depends on the amount of zinc you have on charge. But in 1943, Leadville had roughly about 7 pet zinc in their slag and it worked very poorly. Previously when they had 4 or 5 pet zinc in their slag it did not matter. B. L. SACKETT* At Tooele we had a great deal of experience with copper. We have always been able to keep a lead well, however, in spite of the fact we have run as much as 5 pet copper and only 15 pet lead on the charge. But regarding the handling of dross, our dross reverberatory furnace is only 7 or 8 years old. Before that we recirculated the dross through the furnace and thought we were doing a pretty nice job. Of course these things are all more or less relative—in other words you establish a certain condition much better than one of a few years ago and possibly as good as any other of which you know and you think you have pretty good results. When we first took the dross off of the blast furnace and put it through the dross reverberatory furnace we immediately found out that we had gained something very real in furnace speed. Since that time there have been occasions when, because of the dross reverberatory being down, we have had to use dross again through the blast furnace and that has checked our original experience in slowing down the furnace very definitely. So we feel that a dross reverberatory is a very valuable asset at the Tooele Plant. A. A. CENTER*—Mr. Sackett's being here reminds me of trying to run with a minimum of lead concentrates the maximum of dross producing electrolytic zinc plant residue. He came up from International Smelting Co. to help us get started on that. We took an old copper blast furnace at Great Falls, Montana, and made a lead furnace out of it by putting a lead well on the other long side which of course is a very unorthodox lead blast furnace. Our aim was to treat the residue from the electrolytic zinc plant, as I said, with a minimum of lead concentrates. That meant a maximum amount of dross. At that time selective flotation was not general practice, so our zinc concentrates ran relatively high in copper and other dross-producing elements; and of course these were largely in the zinc plant residue. I think we might call it muscle metallurgy, but we had an interesting, successful experience there and we ran for over a year thanks to Mr. Sackett's helping us get started. I have the details, but time does not permit. We did well enough so that the A. S. and R. Co. at East Helena kept boosting up the offer to us for the electrolytic zinc plant residue and there was not enough lead concentrate to supply two lead smelters there in Montana, so the matter finally finished up by the A. S. and R. Co. taking all of the residue under long term contracts.

Jan 1, 1950

By AIME AIME

T HE 133rd meeting of the A. I. M. E., opening in New York on Feb. 15, promises to be as successful technically and socially as any in the past. The papers submitted for the various technical sessions are unusually excellent and insure something of interest to every group. Tentative programs have already been issued, and a concise resume of the various sessions, arranged chronologically, appears on page 48. Among the many interesting technical sessions arranged, attention is directed to those of the Petroleum Division, embracing the Symposium on Production that has come to be an annual feature, and new ones on refining practice, transportation and economics. The Institute of Metals program is similarly comprehensive. It includes 15 papers, 8 on copper, 4 on aluminum and its alloys, and one each on magnesium, lead, and fatigue of metals. The Coal Committee offers as a leading contribution its report, prepared under the direction of H. N. Eavenson, giving a new analysis of the capacity of the mines and a comparison of coal with other industries. This will be supplemented by a number of other papers of especial interest to operating men, among which are "Data on Use of Loading Machines in Bituminous Mines," by Graham Bright; "Evaluation of Coal," by R. H. Sweetser; "Selection of Coals for the Manufacture of Coke," by H. J. Rose; and "Relation of Origin and State of Carbonization of Coal to Problems of Low Temperature Carbonization," by S. W. Parr. The Iron and Steel Committee has scheduled seven papers, and there will be a special session on open-hearth practice, in which will be presented the first results of the two conferences, held by the sub- committee at Pittsburgh and Cleveland. A symposium on molding sands will be a special feature of the session on non-metallics.

Jan 1, 1926

By Charles E. Glass

The stabil ity of engineered embankments subjected to earthquakes has received considerable attention in the last 10 years, but most of the effort has been directed toward stability of earth dams. Based upon past performance, earthquake- induced failures on non-impounding mine waste structures will likely correspond to small, local slumps or debris slides, and their stability should be considered as an integral part of mine economic planning. As such, stability considerations should include earthquake hazard, characteristics of earthquake ground motion, dynamic slope stability, and the impact that waste-dump failures have on mine operations. Numerous techniques have been proposed for analyzing the stability of embankments subjected to earthquakes. Before choosing an analysis technique, it is worth noting two important differences between the dynamic response of waste embankments and natural slopes. First, waste embankments respond as structures having unique modes of vibration, which causes embankment motions to differ from nearby ground motion. Second, because of embankment response, accelerations can be different at embankment crests than elsewhere in the structure and occur at frequencies that do not correspond to input ground motion. Because of these factors, embankment response should be calculated prior to slope stability assessment. In this paper several analysis techniques designed to calculate slope stability are evaluated, and conventional pseudostatic techniques are shown to be inappropriate for dynamic considerations. Techniques to calculate dynamic stability should include embankment response, all characteristics of earthquake motion, and roughness along failure planes as input, and should provide a displacement time-history of the slide mass as output. Two techniques satisfy this criterion, and in this paper the LADRS technique is recommended for its versatility and simplicity.

Jan 1, 1985

By C. H. Frick

Before presenting the main topic, as indicated by the title, this paper will give some of the high-spot history of the anthracite industry. Introduction The earliest recorded use of anthracite was in the year 1762, when a company of Connecticut pioneers discovered anthracite near the present city of Wilkes-Barre, Pennsylvania. In the early days of the industry, the coal was used only in large pieces, the smaller pieces being discarded to waste piles. As the output of the industry increased during the nineteenth century, uses were developed for somewhat smaller sizes down to and including pea coal. Early in the twentieth century, sizes smaller than pea, such as No. I and No. 2 buckwheat, were developed and used. Accumulations of piles from current mining operations were still increasing; that is, the smaller sizes were still being discarded. It was not until after World War I that preparation of the so-called steam sizes began commercially. This was largely No. 3 buckwheat, which is screened through a 3/16-in. round-hole screen and over a 3/32-in. or a 1/16-in. round-hole screen. Use of Smaller Sizes The earliest recorded experience in burning the small sizes of anthracite for steam production, other than in a previous small experiment, was in the year 1913, when a size known as "boiler fuel" was introduced—a mixture of rice and barley (No. 2 and No. 3 buckwheat). At that time, there was still no method known for burning the still smaller sizes. At the present time, various sizes down to and including No. 5 buckwheat are being prepared (Table I) from current mining and bank-reclaiming operations. The sizes of No. 4 and No. 5 buckwheat and smaller are generally being used for steam production in large boilers. The Pennsylvania Power and Light Co., following World War I, used 680,000 tons of anthracite per year, burned largely on stokers for production of steam, whereas for the year 1943 it used 1,940,000 tons of stoker sizes and 400,000 tons of smaller sizes for grinding and burning in pulverized form. This company has taken a very large part in the research and development of ways and means of burning these smaller sizes of anthracite, including the grinding of the very small sizes. This paper is particularly concerned with the latter feature.

Jan 1, 1949

By C. H. Frick

BEFORE presenting the main topic, as indicated by the title, this paper will give some of the high-spot history of the anthracite industry. INTRODUCTION The earliest recorded use of anthracite was in the year 1762, when a company of Connecticut pioneers discovered anthracite near the present city of Wilkes-Barre, Pennsylvania. In the early days of the industry, the coal was used only in large pieces, the smaller pieces being discarded to waste piles. As the output of the industry increased during the nineteenth century, uses were developed for somewhat smaller sizes down to and including pea coal. Early in the twentieth century, sizes smaller than pea, such as No. I and No. 2 buckwheat, were developed and used. Accu¬mulations of piles from current mining operations were still increasing; that is, the smaller sizes were still being discarded. It was not until after World War I that preparation of the so-called steam sizes began commercially. This was largely No. 3 buckwheat, which is screened through a 3f 6-in. round-hole screen and over a 332-in. or a M 6-in. round-hole screen. USE OF SMALLER SIZES The earliest recorded experience in burning the small sizes of anthracite for steam production, other than in a previous small experiment, was in the year 1913, when a size known as "boiler fuel" was introduced-a mixture of rice and barley (No. 2 and No. 3 buckwheat). At that time, there was still no method known for burning the still smaller sizes. TABLE I.-Screen Sizes Used for Small Sizes of Anthracite [ ] At the present time, various sizes down to and including No. 5 buckwheat are being prepared (Table I) from current mining and bank-reclaiming operations. The sizes of No. 4 and No. 5 buckwheat and smaller are generally being used for steam production in large boilers. The Pennsylvania Power and Light Co., following World War I, used 680,000 tons of anthracite per year, burned largely on stokers for production of steam, whereas for the year 1943 it used 1,940,000 tons of stoker sizes and 400,000 tons of smaller sizes for grinding and burning in pulverized form. This company has taken a very large part in the research and development of ways and means of burning these smaller sizes of anthracite, including the grinding of the very small sizes. This paper is particularly concerned with the latter feature.

Jan 1, 1946

By AIME

TO say that Milton Fies has been active in promoting the Southern Research Institute is a masterpiece of understatement. He is a director and trustee who was in on the ground floor when plans were first made for the Institute and since it became an actuality early in 1945 his interest and efforts continue. He talked about it at the last regional meeting of the Birmingham Section of the A.F.A. and has talked all over the South-and when he makes a speech he has really prepared it. He does not try to rival a political spellbinder, but his careful, concise English is always well thought out and to the point. Southern Research might be called his present hobby as it has been for the past two or three years. Another major interest has been his encouragement and training of engineering students. Active in the formation of the Student Chapter of the A.I.M.E. at the University of Alabama, for several years he saw to it that the students had a prominent engineer at each monthly meeting, usually taking them down to Tuscaloosa from Birmingham in his own automobile. He has also been keenly interested in the mining engineering activities at Tuscaloosa, both in the Bureau of Mines and the University.

Jan 1, 1946