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By John V. Beall

With some difficulty we framed the picture of the village on the mountain getting in the railroad bridge and tunnel at the base. It was a charming scene of red-tile roofs on a green mountain in the golden autumn sunshine with the black hole of the railroad tunnel looking like something out of the movie, "The Train." We clicked the shutter, advanced the film and started back to our rented Audi. At which point there was a hail from the other side of the railroad bridge. A man in uniform was brandishing an object in the air which looked suspiciously like a rifle. We peered around. We were the only other persons in view. He must be yelling at us. He was now closing the distance at a brisk, determined gait but was still 100 yards away. The car was handy but the road was straight, paralleling the railroad tracks for some distance. We dismissed the idea of running for it. Who knows, he might shoot. When he came up we didn't have much of a conversation because it had taken us a week to learn three words of Yugoslavian-zhiveli, long life, huhvalla, thank you, and schlivavitza, the national drink (plum brandy). None of these seemed appropriate. We got the Idea that photographs of railroad tunnels and bridges were prohibited. The guard, for such he seemed to be, took the Audi plate number, administered a last scowling reprimand and stalked off. This incident was the only one in a 15-day visit to Yugoslavia which we would have associated with "Iron Curtain restrictions."

Jan 1, 1970

By Finn Ouchterlony

A simple bilinear R-curve description of crack extension resistance is applied to the testing of sub-size rock core specimens. The K-curve consists of a linear sub-critical part and a flat post-critical part. Formulas for the apparent energy rate resistance quantities Gm, Jm, and [R] are developed. Experiments on notched cores of Ekeberg marble, Bohus granite, and Stripa granite are compared with these predictions. The R-curve model gives reasonable results for Gm -data but fails essentially to describe the Jm and [R]-data. Another model with a sharply increasing linear post-critical part could possibly account for the [R]-data, but direct R-curve measurements seem a better approach.

Jan 1, 1982

This study of engineering education arose out of the action of a joint committee on engineering education, representing the principal engineering societies. The committee had gathered so much material that it decided the work could best be carried out by some one trained in applied' science, who would devote his entire attention to the study.. The Carnegie Foundation therefore asked Prof. Charles R. Mann, of the University of Chicago, to undertake the work. After making a thorough study Prof. Mann has made a most comprehensive report. In it he says: The engineering schools of the United States began their work upon a definite teaching plan and one that had at least pedagogic consistency. But during the past half century the course of study has been overlaid with many special studies intended to enable the student to deal with the constantly growing applications of science to the industries. As a result, the load upon the student has become so heavy that there is a feeling that the students fail to gain a satisfactory grounding in the fundamental sciences and do not fulfil the expectations of engineers in d manufacturers in dealing with the practical problems with which they are confronted on leaving school. At present 60 per cent. of those who enter the schools fail to graduate, still many of them persist in engineering and make a success of it. It is evident, therefore, that the present systems of admission are not satisfactory. If a group of schools will take up the careful study of their entrance systems and experiment with objective tests and records of the students' youthful interests and achievements, the percentage of elimination can be reduced to at least a fourth of its present size, with an enormous saving of time, energy, and money for both student and school. The number of required credit hours per week should be less than eighteen, preferably sixteen. The few experiments that have been made indicate that college students do their best work when not more than five subjects are studied at a given time.

Jan 1, 1919

By Lawrence Adler

A lag apparent in the mining engineering field. While mining will continue as an essential industry, a revitalized profession will be required for national well-being. Specific problems facing the profession include: - a conflict between its design, production and management components, which affect the engineers on a daily basis; - a credibility gap in public matters that is so extreme, government action approaches punitive in degree, and - historical decreases in the number of degree-offering departments in the face of an increasing demand for graduates. A turnaround in these areas could result in attracting into the industry, highly creative, capable, and socially concerned engineers. By improving the quality of undergraduate education, the effectiveness of each entering engineer would be multiplied. This is another way to combat the chronic shortage of trained mining engineers. At the same time, it would set a significant example for other professions in the throes of overspecialization. A revival of the mining profession can be accomplished only during the formative training years of its future practitioners. An educator's role would be pivotal in this effort.

Jan 3, 1975

By Arthur Knapp

THE economics of fuel oil must be considered in two aspects; viz., fuel oil as one of a number of competitive fuels and fuel oil as a refined product of petroleum. "Fuel Oil" is usually defined as that product of petroleum which is used in furnaces for the generation of heat by simple combustion. It is true that any product of petroleum used in an internal combustion engine is essentially a fuel oil, but such oils are not included in the class known as "Fuel Oil." FUEL OIL AS ONE OF SEVERAL FUELS For a number of years, the petroleum industry has believed that the petroleum reserves were very limited and that petroleum products would begin to become scarce within a few years. The industry has believed FIG. 1.-DAILY AVERAGE CONSUMPTION OF FUELS BY PUBLIC UTILITY POWER PLANTS. that there would be a gradual but continual rise in prices as a result of this impending scarcity.

Jan 1, 1928

By Monica Mengoli Chaves, Byron S. Gottfried

For the past several years the U. S. Department of Energy has sponsored the development of a computer simulation program that will predict the performance of coal preparation plants under a variety of different operating conditions. Recently a study was undertaken to transfer the simulation logic from the large scale mainframe environment to a small inexpensive microcomputer operating in a highly interactive "user friendly" environment. This paper describes a program that was written for the APPLE II Plus microcomputer which accomplishes these objectives. The program prompts the user for information in such a manner that it can be used by persons other than computer specialists. This makes the program directly accessible to plant managers, designers and operating engineers.

Jan 1, 1983

By W. F. Tanner

A river delivers a given load of sand, and hence heavy materials, into the sea. The load is fixed by drainage basin characteristics and processes. Wave energy available for redistributing that load is fixed in an entirely different way. An equilibrium diagram of these two parameters (load vs energy) pennits a tentative prediction of what will happen to the heavy minerals. Alluvial rivers transport a mechanical load which consists essentially of wash load (finer than about 0.05 mm in particle diam), bed load (coarser than about 0.10 mm) and the transition sizes in between. A few rivers carry no appreciable mechanical load, and are excluded from this discussion. An example of the latter is the Suwannee River of Florida, which empties across an oyster bar into the Gulf of Mexico and does not build a delta despite the absence of significant waves or currents in that part of the Gulf. An alluvial river may deliver its load into a protected sediment trap (such as an estuary, sound or lagoon), onto a low-energy coast (where it builds a delta) or onto a high-energy coast (from which spot the river load is swept away). The nature and disposition of the load depends, obviously, on three sets of factors: 1) drainage basin characteristics and processes, which determine quantity and make-up of the load; 2) coastal structure and geomorphology, which determine the kind of river-sea coupling which

Jan 1, 1962

By Peter N. Calder

This paper deals with the reinforcement of igneous rock slopes at three open pit iron ore trines in northern Canada. The pits involved utilize overall slope angles in excess of 60º with ultimate depths in the order of 250 m. Three case studies are described. The first concerns the reinforcement of a 300,000 Ton undercut rock wedge, approximately 70 m in height. This was accomplished using 20 cm diameter steel bales, installed in 25 cm diameter vertical holes, and a cement-sand grout. The second involves the reinforcement of a 40 m wide diabase dyke which had been continuously failing as the pit deepened. A unique form of rock reinforcement was used in that the entire mass of the undercut dyke was not pinned to the wall. Rather an interlocking effect between individual blocks within the dyke was relied upon. A third concerns the reinforcement of a berm which was undercut by the contact between the ore and waste. This reinforcement was also accomplished using a combination of steel bales, rods and cement grout.

Jan 1, 1982

By Edward C. Morse

The metallurgical history of Republic has been completely reviewed in a paper presented at a previous meeting of the Spokane Local Section by Professor Thomson;' therefore, the present paper will be confined to matters directly pertaining to the San Poil mill: When I came to Republic last fall to look over the situation there was a plant in operation successfully treating the tailings from one of the earlier mills in the camp. I refer to the mill of the Rathfon Reduction Co. This mill was operating in accordance with modern cyaniding practice, and I was given to understand that the work was very satisfactory and profitable, else it would not have been continued as long as it was. At that time I obtained much metallurgical information of value from Harry W. Newton, Superintendent of the mill of the North Washington Power & Reduction Co. I took a number of samples from the San Poil mine, with the view of determining if Mr. Newton's experience with the ores from the other mines applied to the San Poil ores. I made a large number of tests under a variety of conditions, and found that it was possible to extract as high as 98 per cent, of the values from San Poil ore by the laboratory-tests when the ore was pulverized to 200-mesh and treated with a solution of a strength of 5 Ib. of KCN to the ton. A fairly strong solution was required because of the proportion of silver in the ore, which makes it, from a metallurgical point of view, practically

Jan 1, 1913

By M. Gensamer

IT has been suggested by a number of people that it would be worth while for some one to attempt to summarize or condense the proceedings of this symposium. This task has fallen to me as organizer and co-chairman. Its difficulty will be appreciated by anyone who attempts to read the whole proceedings. It is therefore with trepidation that I offer the following digest. In recent years there has been a renewal of interest in America on this subject of the cohesive strength of materials, and a growing appreciation of the need for a better theory of cohesion failure. The theories of elastic action and plastic action are well developed, particularly the former. The theory of plastic action is still in the course of development, but it is well along. Plastic action is terminated by cohesion failure and what is needed is a theory that will tell us when to expect the cohesion failure. In the past it has generally been assumed that cohesion failure will occur when a critical value of the maximum tensile stress has been reached. Many experiments have shown that this is not strictly true, and this symposium concerns itself with the failures of this simple hypothesis, and with the efforts that have been made to devise a more satisfactory theory. The most active contributor in recent years to knowledge in this field is Dr. McAdam, and he was asked to open the symposium with a summary or condensation of his papers and views. Undoubtedly it is presumptuous to attempt a still greater condensation, but perhaps it will be useful, because even his contribution to this symposium contains no summary, no concise statement of just what his contribution has bees. Dr. McAdam makes two main points. The first is that the cohesive strength is not a single valued quantity, but that it is a function of all three principal stresses and hence must be represented diagrammatically by a surface in a three-dimensional figure. Dr. McAdam has attempted so to delineate the cohesion limit, basing his

Jan 1, 1944

By F. C. Newton

REFINERS of lead by the Parkes process have always been solicitous of recovering the zinc used in the desilverization, and justly so, as the loss in zinc constitutes one of the heavy costs in this method of refining. Part of this loss is due to the absorption of zinc by lead, and in the present state of knowledge is not recoverable as metallic zinc. The remainder of the zinc, which finds its way into the precious-metal-bearing crust, is recoverable and naturally engages the operators' most exacting attention. Careful elimination of the impurities in base bullion has enabled the refiner to produce a zinc crust better adapted to retorting, which reflects favorably in the zinc recovery; and to produce a richer crust, thereby lowering the zincking cost, as the increased efficiency of the zinc results in less of it being in circulation. It is obvious that if the ratio of concentration be increased, a lessening of the amount of crust formed will ensue, throwing less work on the retorts and diminishing the amount of retort metal sent to the cupels, thus making an actual money saving in all these operations. In the effort to obtain a rich crust, the metallurgist has increased the heat to a considerable degree, upon the assumption that at the higher temperature the zinc-silver alloy could be squeezed free from the adhering lead. A further possibility for improvement suggested itself in the freezing-point curve of Prof. H. C. Carpenter, upon zinc and silver. Study of this curve disclosed the existence of a definite chemical compound, . Zn3Ag2, with a freezing point of 665° C., a promising compound for practical application.

Jan 2, 1915

By T. F. Witherbee

That the single charging-bell, properly proportioned, is a good all-around device for distributing material in a blast-furnace can scarcely be questioned; yet it is equally true that, in some cases, it has not given perfect satisfaction; as has been demonstrated by the substitution of double bells, at furnaces under the beat management—generally in cases where anthracite, either alone, or with a portion of coke, was used as fuel. The defect of the single bell seems to be that it does not permit, beyond very narrow limits, such changes in charging as may be required by the temporary conditioil of the furnace. Modern furnaces using Connellsville or other good coke and Lake Superior ores seem to be well served with a single bell. At least, up to a certain size, somewhere about 18 by 85 ft. to 19 by 90 feet, these furnaces make low-silicon pig-iron with about 1,800 lb. of fuel, or in some cases very much less. The following instances occur to me, in which other forms of charging-apparatus have been employed with advantage: 1. A charcoal-furnace, 61 ft. high, 11 ft. in diameter at bosh, and 8 ft. 2 in. at stock-line, with a rectangular crucible, 42 by

Jan 1, 1905

By J. E. Pogue

That the domestic consumption of gasoline displays a marked seasonal variation, with a low in the winter and a high in the summer, is well known. It is logical to expect that the nature of the variation has itself been undergoing a change as a result of improvement in roads, general employment of closed cars, and growth of mass haulage; but so far as I am aware the change in seasonal variation has never been investigated and measured. It is the purpose of this paper to present the method and results of such an investigation, undertaken as a contribution to the technique of planning operating schedules now so prominent in connection with the functioning of the industry under a Federal quota system. For the method employed I am indebted to the suggestions and help of Frederick R. Macaulay,1 who kindly looked over the work sheets; and

Jan 1, 1934

By J. F. Myers, R. J. Tower

"THERE is nothing new under the sun." All over the world, mineral-dressing engineers are working at their problems, no two of which are alike. Each encounters equipment and process problems. Many devise simple ways and means of overcoming their difficulties. Many of these problems are quite common in the industry, yet, since no one human being seems capable of thinking of everything, these problems at some plants often are looked upon as necessary evils. The purpose of this symposium is to gather together, from competent engineers, devices and practices that have been useful to them. Most of the ideas contributed are not new, yet there is no plant operator, old timer or youngster, who will not find some idea herein that will give him a suggestion for improving his operation. Space does not permit a complete elaboration on all of the contributions offered. Each item is summarized, but this will be ample for those skilled in the art of mineral dressing. A list of contributors appears at the end of the paper, and the superior number at the end of each item identifies its source. GENERAL EQUIPMENT A signal light to show that a steel bin, containing relatively fine, moist ore, is full, can be made by suspending a copper rod in the bin to a sufficient depth to ensure ample contact with the ore. One wire of a 32-volt circuit should be attached to the rod and one to the side of the bin. Sufficient current will flow to make the signal light burn. A 110-volt circuit could be used, but 32 volts ensures safety.10 Fig I shows a circular bin for crushed ore. It is a concrete structure footed on the ground, using no supporting columns. Tailing from the sink-float was used for aggregate. Cross conveyors for discharging ore are not required, nor is a tripper for filling. Segregation is minimized by drawing from different gates. An exhaust fan on top of the bin eliminates condensation due to temperature of the ore.21 A beam with an adjustable point of suspension near the center permits rigging rolls for removal in a very few minutes. This makes unnecessary the lacing of the cable through the hub bolts on one side, around the shaft on the other, and the trouble of balancing the load.8 The ratchet handle on a Symons crusher may be replaced by a drum with a cable wound on it. When the cable is pulled by a crane or hoist it causes the drum to revolve and thus screws or unscrews the bowl. This reduces handwork and materially shortens the time required for the job.3 To spread ore feed from an apron feeder over a belt conveyor, place a heavy steel bar about midway between the top

Jan 1, 1947

By R. H. King

This paper describes the results of an underground coal mine trial installation of a shielded trailing cable. The cable was a three conductor, round, type SHC-GC and was installed on a shuttle car in a conventional room-and-pillar mining section. The purpose of the study was to evaluate proposed legislation that would require shielding on low-voltage trailing cables. Such legislation would require machine modifications to cable reels, packing glands, and couplers; increase cable splicing complexity; and necessitate additional splicing materials and training. Furthermore, fault location might be more difficult. Even though shielding will cause some problems for the mine operator, it can reduce electrical shock hazard to mine workers. This paper presents information that mine operators can use to solve most of the problems encountered if they are required to install shielded cables. The in-mine evaluation was funded by the US Bureau of Mines; however, the views and conclusions in this paper are those of the author and should not be interpreted as necessarily representing official policies of the US government.

Jan 1, 1982

By Irwin Roman, Thomas C. Serman

It has been known for many years that when a wire is moved in a magnetic field, an electromotive force is developed which is proportional to the rate at which the wire is moved in a direction perpendicular to the magnetic intensity and to the magnetic intensity itself. If the ends of the wire are connected to a current indicator, the current behaves exactly as though the source of electromotive force were a galvanic cell. If a wire is wound circularly and rotated uniformly around a diameter not parallel to the intensity, the current flowing through the wire will be alternating of sinusoidal shape. If, instead of a single loop, there are several turns wound in a short helix, the electromotive force developed will be approximately proportional to the number of turns, the area of the helix and to the speed of rotation. The maximum electromotive force will be developed when the axis of rotation is perpendicular to the field; if this is not so, only the component of the intensity that is perpendicular to the axis of rotation is effective. This is the principle of the usual earth inductor. With a few turns of wire and comparatively slow rotation, it is possible to produce a considerable deflection of a galvanometer. If two similar coils are rotated together at two different points for which the magnetic field intensities perpendicular to the axes of rotation are different, the electromotive forces developed will each depend on its corresponding intensity and be a measure of that intensity. If the intensities are sufficiently different so that the electromotive forces may be compared, the two intensities may be compared. This is the principle

Jan 1, 1934

By D. B. Barker, D. C. Holloway, J. F. Cardenas-Garcia

Tround International Inc. is currently developing a hard rock drill that uses a salvo of three frangible projectiles to prefracture the rock ahead of a conventional tri-cone bit. This paper reports on a series of experiments conducted for Tround to study the fragmentation enhancement possible through the use of an optimally timed and spaced salvo of projectiles. In this study the complex three-dimensional problem was simplified to a two dimensional salvo impact problem in a transparent brittle plate of glass. The use of high speed photography and dynamic photoelasticity was then used to study the development of the impact damage zone and the various interactions of the stress waves.

Jan 1, 1982

PAST AND PRESENT CHAIRMEN OF DIVISIONS Institute of Metals Iron and Steel Mineral Industry Industrial Minerals Year Division Petroleum Division Division Coal Division Education Division Division 1918 W. M. CORSET 1919 " 1920 W. H. BASSETT 1921 " 1922 W. B. PRICE RALPH ARNOLD 1923 E. DEGOLYER 1924 G. B. ELLIOTT 1925 F. JULIUS FOHS 1926 P. D. MERICA 1927 11 JOHN. M. LOVEJOY 1928 S. SKOWRONSKI A. W. AMBROSE RALPH H. SWEETSER ' 1929 " J. B. UMPLEHY G. B. WATERHOUSE 1930 ZAY JEFFRIES C. V. MILLIKAN W. J. MACKENZIE HOWARD N. EAVENSON 1931 SAM TOUR C. E. BEECHER F. M. BECKET 1932 C. H. MATHEWSON EARL OLIVER F. N. SPELLER THOMAS G. FEAR C. H. FULTON 1933 T. S. FULLER W. E. WRATHER JOHN JOHNSTON ELI T. CONNOR " 1934 J. L. CHRISTIE H. D. WILDE, JR. L. F. REINARTZ " T. T. READ 1935 W. M. PEIRCE HARRY H. POWER A. B. KINZEL JOHN T. RYAN SAMUEL H. DOLBEAR 1936 E. H. DIX, JR. HALLAN N. MARSH C. E. WILLIAMS EUGENE MCAULIFFE WILLIAM B. PLANK OLIVER BOWLES 1937 A. J. PHILLIPS M. ALBERTSON FRANCIS B. FOLEY J. B. MORROW " CHESTER A. FULTON 1938 R. F. MEHL G. B. CORLESS J. T. MACKENZIE PAUL WEIR FRANCIS A.THOMSON J. R. THOENEN 1939 R. H. LEACH W. H. GETS J. HUNTER NEAD C. A. GIBBONS " M. M. LEIGHTON 1940 E. M. Wise T. V. MOORE F. T. SISCO C. E. LA WALL W. R. CHEDSEY W. M. WEIGEL 1941 D. K. CRAMPTON E. A. STEPHENSON C. H. HERTY, JR. JULIAN E. TOBEY " PAUL M. TYLER 1942 CARL E. SWARTZ HARRY P. STOLZ E. C. SMITH NEWELL G. ALFORD A. F. GREAVES-WALKER B. L. MILLER

Jan 1, 1943

By Alfred F. Brainerd

Some fifty years ago, iron-ore was discovered near the town of Sheldon, Franklin County, Vermont, in a vein out-cropping on a knoll near Black Creek, which empties into the Missisquoi River a couple of miles away. A short time after this discovery, the owners, Mr. TV. 0. Gadcomb and Hon. Lawrence Brainerd, both of St. Albans, commenced mining (mostly by open cut), and also erected a Catalan forge, from which iron blooms were produced, most of which were worked into bar-iron and used in the neighborhood of the forge, while some were shipped by Lake Champlain to Troy, Albany and New York. But by reason of the lack of any railroad connections, and an insufficient demand for the blooms, this forge was subsequently abandoned, and the material used in its construction removed to other places. Mr. Keith, of Sheldon, used for many years a mixture of this ore with bog-ore from Swanton, in a charcoal blast-furnace, the product of which he consumed partly in his own foundry, shipping, however, a considerable amount to Troy and New York. Accurate data as to this enterprise are not at hand. The same vein has since been traced for some 20 miles, and some prospecting has been done 011 its outcrops at Berkshire, Enosburg and a few miles east of St. Albans; but the vein being small, only a few car-loads of ore were taken out from these places. The commencement of the St. Albans Iron and Steel Works in 1872, and the erection in 1877 of a ten-ton Siemens open-hearth furnace for the manufacture of steel rails, opened a new use for this ore. The furnace-charge consisted of pig-iron, old mils, steel scrap, and magnetic iron ore, added towards the close of the heat. The ore

Jan 1, 1885

By B. Amadei

INTRODUCTION Laboratory studies on the deformability and strength of intact rocks generally involve the uniaxial compression test, the standard triaxial compression test and direct or indirect tension tests. If [al ,a2 ,a3] are principal stresses [(al>a2>a3)] with compression taken as positive and tension taken as negative, the applied stress field for each one of these tests can be represented as shown in Fig. 1. However, for most in-situ conditions, such as those that exist at any point around an underground excavation, the stress field is truly three-dimensional or multiaxial [(al+ a2+a3)] and none of the tests shown in Fig. 1 can be used to predict the mechanical behavior of the rock. There are special cases for which one of the three principal stresses vanishes. Biaxial loading of rocks in-situ takes place, for instance, when rocks deform and fail in plane stress conditions. This can occur in a free unloaded surface of a rock structure such as in the wall of an underground excavation or a rock slope. Parallel to the free surface, the stress field components can be both compressive [(al>a2>0)], both tensile [(O>a2>a3)], or mixed, one component being compressive and the other one tensile [(U~>O>U~)]. The purpose of this paper is to present the results of 25 true biaxial tests that have been conducted on cubical specimens of Indiana Limestone using the multiaxial cell available at the University of Colorado at Boulder. The tests include uniaxial compression and tension, biaxial compression and combined biaxil compression- tension. Flexible fluid cushions and brush bearing platens were used for compressive and tensile loading respectively in order to minimize loading end effects on the test specimens. The paper begins with a review of previous investigations on the multiaxial behavior of rock. Then, test results are presented in terms of

Jan 1, 1984