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By Richard D. Snouffer

Prime topics of conversation these days are the new concepts of rail haulage for bulk items such as iron ore, potash and coal. We have heard such ideas as the "integral train" and the "unit train" discussed frequently during the past two years at various AIME meetings, and progress reports have kept up a steady appearance in the technical press and in local newspapers. While no railroad has a complete "unit train" in service at this moment, one has 50 fast-discharge cars under construction and the Pennsylvania Railroad has experimented with radio-controlled motive power distributed at intervals throughout the train. To a great extent, however, the promise for greater efficiency and lower costs held out to industry by these new haulage methods is dependent not on greater speed or larger cars or more dedicated equipment alone but, rather, on the utilization of modern practices in the loading and unloading of rail cars. It is the purpose here to examine these two key steps and the up-to-date procedures and equipment they entail.

Jan 7, 1963

By P. Nelson, K. L. Gunsallus, A. R. Ingraffea, J. F. Beech

INTRODUCTION Fracture toughness, KIC, is an intrinsic material property and is a measure of the energy required to create new surface area in a material. Fracture toughness measurements can be made for a wide range of rock types (Ouchterlony, 1980). As a measure of energy of comminution, fracture toughness might be used for more sensitive predictions of Tunnel Boring Machine (TRM) performance than are possible with other index measures in current use. This paper describes part of an ongoing, comprehensive, analytical/experimental program aimed at evaluation of KIC in such a role. The program includes efforts to: 1. Provide a firm analytical basis for a test specimen geometry: the core-derived short-rod. 2. Develop simple, inexpensive testing equipment and techniques. 3. Evaluate the accuracy of the above by testing rock and other materials and comparing the measured fracture toughness with those obtained by other methods. 4. Measure fracture toughness of a substantial number of different rocks from three ongoing TBM projects. 5. Compare fracture toughness results with other strength measures. 6. Compare all test results with observed TBM performance in the three projects. Presented here are summaries of all but the last of these efforts. Comparative evaluation of KIC as a more senstive rock property for TBM performance prediction will be the subject of the oral presentation and a subsequent paper.

Jan 1, 1982

By Lyall Zickrick

EXPERIMENTS of previous investigations have indicated that calcium-copper alloy, when used as a deoxidizer for molten copper, results in a sound copper casting of good physical and electrical properties. Bradenberg and Wiens1 have obtained successful results in casting sound copper using calcium for deoxidizing. Masing2 has obtained deoxidized copper of high density and high conductivity by use of calcium. Pratt,3 in 1907, patented the use of calcium for the deoxidation and degasification of, copper. Schumacher, Ellis and Eckel 4 in 1929, conducted a series of experiments on deoxidizing copper with calcium. They concluded that so long as there is only a small percentage of residual calcium the mechanical and electrical properties of the copper deoxidized are not impaired; and the deoxidation is thorough. For this investigation, a, copper-calcium alloy high in calcium and 10 variously deoxidized copper ingots were prepared. The investigation concerns itself with the casting properties and structure of these variously deoxidized ingots, their working and annealing characteristics, and the resulting physical and electrical properties of the worked materials.

Jan 1, 1932

By William Reynolds

THIS paper deals with the results of a study of the application and development of mining machines for cutting out and removing dirt bands in bituminous coal beds. FACE PREPARATION When one or more dirt bands1 occur in a seam of coal, the problem of elimination of impurities becomes manifest. The degree of complete-ness to which these impurities are removed at the face has an important bearing upon labor costs, haulage costs and outside cleaning costs, and often the ash content of the product is markedly affected. Yet, because the present-day miner is paid for the number of tons he loads he often lacks interest in the quality of the coal. To insure a clean product, a system of penalties for dirty coal is enforced, but control of extraneous impurity content in the loaded coal is often inadequate and ineffectual when coal and banded impurity are shot as one. It seems only logical that to reduce the amount of impurities by proper face preparation before the men are permitted to load the coal is the most efficient method of preparation.

Jan 1, 1936

By D. M. Spratt, O. R. Bell

In Australia's remote northwest are located the operations of Cliffs Robe River, one of the world’s largest iron ore projects. initial project cost was $US300 million and required the construction of a deepwater port, two towns for 3000 people, a 105 MW power station, and 170 km of railroad, all in harsh, arid country over 1300 km from the nearest industrial center. The ore occurs as goethite cappings on scattered mesas and averages 57% iron. All aspects of the project are reviewed from pre-operational research, through project construction to current operation.

Jan 1, 1982

By Lo-Ching Chang, J. Chipman

The perennial and increasing interest in the chemical behavior of steelmaking slags has led to numerous attempts to formulate the thermodynamic properties of these solutions. The classical view is that of a solution of the component oxides in which certain acidic oxides are more or less completely held in combination with basic or metallic oxides, the nature of the interoxide compounds being derivable from the chemical behavior of the slag or from the mineralogy of a solidified specimen. The known electrical conductivity of slags has pointed to the existence of ions in the solution and a number of attempts have been made to account for the observed facts of slag behavior on the basis of a theory of complete ionization of the solution. It is the purpose of this paper to examine, in the light of ionic theory, a number of recently published series of data on slag-metal and slag-gas equilibria, with the purpose of obtaining a more complete or more satisfactory generalization than has been possible on either of the single bases of simple compound formation or complete ionization. The attempt to formulate the ionic constitution of a complex solution is fraught with many uncertainties. An ion is not something that can be plucked from the solution and examined in detail, nor can its true formula be determined with certainty by any single experimental method. In attempting to express the composition of a slag by various ionic formulas it can be expected that alternative hypotheses of essentially equal merit will present themselves. In the present state of early development of the ionic theory of slags, it may be necessary to make some rather arbitrary choices of ionic formulas in the absence of su- cient information to yield complete certainty. Acids and Bases The classification of slag-forming oxides as acidic or basic apparently dates back into the days of Berzelius. It is difficult to see how the concept could have originated in the early twentieth century when it was fashionable to define an acid or a base as an aqueous solution containing hydrogen or hy-droxyl ions. It is, however, entirely consistent with the modern and more general theory of acids and bases. In this theory, as originally formulated by G. N. Lewis,' a basic molecule is one that has an electron pair which may enter the valence shell of another atom thus binding the two together by the electron-pair bond. An acid molecule is one which is capable of receiving such an electron pair into the shell of one of its atoms. The acid, the base, and the product of neutralization may be either ions or neutral molecules. The product of such a reaction may itself be a base or an acid if it is further capable of giving or accepting an electron pair. Thus a base is a donor of electrons, an acid, an acceptor. In oxide slags the typical and ever-present base is oxide ion, 0-—. In behavior and in importance it is analogous to hydroxyl ion, OH-, which is the typical base of aqueous solutions. There is nothing in the chemistry of slags which is quite analogous to the acid H30+ in aqueous solutions. This is not surprising for in slag systems there is nothing which can be designated as a solvent and no ubiquitous positive ion. The chemistry of slags is in fact more complex than the chemistry of aqueous solutions and the concepts which must be evoked in its study are correspondingly broader. In seeking a basis for a classification of slag-forming oxides as basic or acidic it must be remembered that these terms are not absolute but relative. A substance which acts as a base toward a second substance may act as an acid toward a third. This is less likely to happen among strong bases or acids than among the weak ones; there are numerous examples of weak acids which under the influence of a stronger acid behave as weak bases. Such substances are called amphoteric. A classification of the glass-forming oxides has been proposed by Sun and Silverman² and further developed by Sun3 in which the oxides are arranged in order of decreasing acidity or increasing basicity, each substance being potentially capable of acting as an acid toward substances below it in the list and as a base toward those above it. It is based upon the relative strengths of the metal-to-oxygen bond as determined by the energy required to dissociate the oxide into its component atoms.' Data are available for computation of this energy, at least approximately, for the oxides of slags and glasses. In general those oxides from which it is most difficult to remove the positive atom are the strong acids while those in which it is most loosely held are the strong bases. It is in the latter, of course, that formation of oxide ion occurs most readily as, for example, in CaO which in solution ionizes to form the weak acid Ca++ and the strong base O—. The order of arrangement found by Sun is shown in the first column of Table 1, to which have been added the data for

Jan 1, 1950

By S. R. Smith, W. M. Voorhis, J. D. Young

The Tennessee Valley Authority (TVA) has conducted investigations to identify the major causes of coal pile inventory adjustments. This paper describes past and current attempts to improve inventory survey accuracy and reduce costly inventory adjustments. The unique interaction between accountants and engineers is also reviewed. Data and results of a recent field test wing downward-looking radar developed by Ohio State University are presented. These show great promise in determining coal pile depth and density, thus improving inventory accuracy. This electromagnetic remote sensing technique, if successful, would provide an optimum technical and economic method of surveying all 12 TVA stockpiles without costly borehole drilling or disrupting stockout and reclaim activity. The effect of changing coal quality to meet environmental standards has made accurate coal pile density measurement more important than ever in reducing the costs of electric power generation from coal.

Jan 1, 1984

By George Jones

MACHINE mining on the pitch plays an important part in the produc-tion schedule at the Salem Hill Colliery of the Haddock Mining Co. This mine is just outside the city of Pottsville, in Schuylkill County, along the southern border of the Anthracite Region. The entrance to the mine is through a cross-measure tunnel 15 ft. above water level and running north 1500 ft. until it strikes the Rabbit Hole vein, where the machine mining is carried on. The main slope, dipping south, was sunk 1200 ft. in the Rabbit Hole vein with levels turned off at 300-ft. intervals. The vein is from 24 to 30 in. thick on a varying pitch of 20° to 40°. The overburden has differed from 50 to 466 ft., the most recent work having the maximum overburden. Immediately over the Rabbit Hole vein is a seam of soft sand slate from 1 to 4 ft. thick which presents a problem at times because it dis-integrates rapidly when exposed to the air. It will crack up and fall without any audible warning, therefore the workmen must always be on the alert, watching for loose slabs. The main top is sandstone, vary-ing in thickness from 8 to 20 ft. The bottom rock is similar to the top, but is finer grained and subject to a more complete disintegration. The vein has a 3 to 4-in. shelly band along the bottom, and all under-cutting has been done in this soft band.

Jan 1, 1935

By R. E. Grim

With the exception of the extreme northeastern part of the state, Mississippi lies wholly within the Gulf Coastal Plains. The largest structural feature definitely proved is the so-called Jackson structure1 in the central part of the state. This structure is mainly the result of the burial of an igneous ridge on the old sea floor. The ridge trended in a northwest direction from about the town of Jackson in Hinds County into southeastern Arkansas. The present structure is the burial of the ridge. Recent detailed surface work by major oil companies has suggested smaller structures in other parts of the state, but so far they have not been definitely proved. Also considerable magnetometer and seismographic work has been done in the northern and central part of the state. The results of the operation of the seismograph are not yet available, but the magnetometer located many "magnetic highs" in this part of the state. Outside of the area of the Jackson structure, the exact cause for this magnetic variation is not known. In a portion of south Mississippi, considerable seismographic work has been done recently in an attempt to locate salt domes. While the details are not available, it has apparently met with little success. Prospecting by districts during the past year may be summarized as follows: Five wells of importance were drilled in the Amory district of east Mississippi. This district comprises all or parts of Monroe, Lee, Itawamba, Prentiss, .Alcorn and Tishomingo counties. Small gas was discovered at about 2500 feet. Several wells were drilled in the. Jackson district which is located in part or all of Hinds, Rankin, Madison and Yazoo counties. Some of these wells were abandoned and one was shut down most of the year

Jan 1, 1930

By George S. Rice

The extremely valuable papers and discussions on coal-cluat explosions by Bache,' Eavenson, Shurick, Mannakee,* and Raymond are of unusual interest to me, since it has been my duty to carry on investigations on this and allied subjects for the Technologic Branch of the United States Geological Survey during the past year, and to make a series of coal-dust tests in the explosion-gallery at Pittsburg during a short periocl when its use could be diverted from the pressing work of testing explosives. In several of the discussions mentioned, it has been assumecl that the Technologic Branch of the Survey mas not paying attention to certain phases of the general problem, or to the specific question of temperature and humidity of mine-air in its effect upon the explosibility of coal-dust. This assumption is not correct, since from the time of the establishment of the " Mine-Accident Division," with its subdivisions of explosives, rescue-work, and mine-investigation, the mining engineer.; of the last-named section have made the subject one of chief consideration. Their general duties, including mine-sampling for governmeilt purposes, emergency-calls for rescue-work, and esplosion investigations, have prevented undivided attention, but all of them have been supplied with instruments for such determinations, and special report-forms have been in use and a great many observations made in mining-districts to which the mining engineers have gone. With the idea of obtaining a uniform system of reporting these data, and in the hope that the work may be of service to mining engineers in the field, the collecting blanks in use are shown in Forrns 1 and 2.

Jan 1, 1911

By V. E. McKelvey

Some understanding of the United States mineral resource potential is essential for planning and policy making for the future. Reserves of some minerals are essentially lacking and for many others they are sufficient for only short term needs. Estimates of undiscovered resources of many minerals are substantial but are insufficient to support long term requirements, particularly if they continue to increase as they have in the past. Presently, subeconomic resources of some minerals such as aluminum are huge, but their recovery may require increased amounts of energy, which poses problems both as to cost and availability. Beyond these identifiable components of the United States mineral potential, what are the prospects? If they could be identified specifically, of course, they would be included in the above. An unappraised potential of new production and discovery can be expected to exist in known districts, where unproved methods of exploration may yield new discoveries; in new types of ore deposits; in metallogenic provinces as yet unrecognized or poorly explored; in frontier areas and in deeper parts of the crust as yet unexplored; and in presently subeconomic sources that may come within economic reach as the result of technologic advance. Other sources may extend the life of domestic material supplies -- substitution of abundant for scarce materials, recycling and prevention of waste, improved efficiency in recovery and use, and conservation of use.

Jan 1, 1976

By D. B. Grove

THE heavy media separation process plays an outstanding role in the concentration of 4000 tons of zinc ore per day at the Mascot mill of the American Zinc Co. of Tennessee. Of the total tonnage, 72 pct is treated in the heavy media separation plant to reject 56 pct of the ore as a coarse tailing, which has a ready market. Concentrates from this separation are beneficiated further by jigging and flotation. Approximately 25 pct of the total zinc concentrate production is made in the jig mill. Jig tailings are ground and pumped to the flotation circuit where the balance of the production is made. Fig. 1 shows a generalized flowsheet of the mill.

Jan 8, 1951

By J. R. Spencer

When supplies of high pressure mercury or other liquids are required in analytical work, it is convenient to have the source of supply at a relatively constant pressure and available in sufficient volume to satisfy the requirements of the apparatus in use. It is also desirable that the pressuring device be as simple and as inexpensive as possible and convenient to operate. This pump combined with a small storage reservoir containing gas under pressure has the attributes of (1) positive control of the maximum output pressure through the use of a regulator in the low pressure air supply; (2) an increasing capacity as the rate of withdrawal of mercury from the pressured system is increased; and (3) simplicity, requiring only the use of a lathe, drill press, and welding unit in its construction. DESCRIPTION Essential parts of the pump are shown in Fig. 1. In appearance the unlt is similar to the usual steam pump in common use in industrial applications although considerably smaller in size. The main differences lie in the area ratio of the air and mercury pistons and in the design of the air valve mechanism. Approximate diameters of these pistons are 4.25 in. to 0.375 in. respectively, giving an area ratio of about 130 to 1. The air piston (2) is attached to the end of shaft (4), with the mercury piston being merely a reduced extension of the shaft. Mercury intake and discharge to the pump are controlled by high pressure check valves that screw into the ports indicated at (6). Air supply is controlled by the valve assembly mounted on top of the

Jan 1, 1950

By James Cudworth

THE Birmingham district of Alabama has utilized the slag from its blast furnaces consistently since the earliest development of the slag industry. Today there are producers of slag cement who started business in 1900, and who have, under a progressive policy, expanded the number of their products to meet present demands. There are producers of slag aggregates and other crushed slag products who have been successful for periods of over thirty years. There are at the present two companies, Cheney Lime and Cement Co. and the Southern Cement Co., manu-facturing puzzolan cement; three companies, Birmingham Slag Co., Woodstock Slag Co., and Swann Chemical Co., making slag aggregates and by-products; one company, Tennessee Coal, Iron and Railway Co., a subsidiary of the U. S. Steel Corporation, producing ground open-hearth basic slag for soil conditioning. Two companies, the Sloss Sheffield Steel and Iron Co. and the Woodstock Slag Co., make slag concrete in ready-mix plants and one company, the Superock Company, manufactures fine and coarse slag aggregates under a new granulation process. No Portland cement is made with slag as an ingredient, because dolomite is used so extensively as a blast-furnace flux that the magnesium content of the slag is excessive.

Jan 1, 1937

By David C. Yang

INTRODUCTION Over the world, and especially in the United States, there is increasing dependence upon progressively lower grade ore deposits. These lower grade ores are frequently difficult or impossible to process due to complex mineral assemblages being very finely disseminated. Thus, many of the conventional mineral concentration methods are not applicable to these ores. For the last few decades, research in the more exotic mineral processing techniques has been conducted, both in universities and in governmental and industrial laboratories. Since its inception, the Institute of Mineral Research of Michigan Technological University (MTU) has devoted much of its attention to the problems of processing refractory, low grade ores. Recently a new flotation system was developed which shows promise of being applicable to a broad range of ore types. This process has been the subject of two allowed patent applications. This paper describes the details of such a flotation system which is potentially useful for treating ultrafine minerals. Some highlights of the testing program on a variety of iron ores and a group of lithium-bearing ores will be presented. EXPERIMENTAL PROCEDURES Both iron and lithium ore flotation treatments followed the same general procedures, with minor differences in pH and in reagent dosages. The method is rather simple, efficient and economical from the standpoint of recovery and the cost of reagents consumed.

Jan 1, 1979

By H. D. Hoskold

This instrument, shown in Fig. 1, is not generally known, though it has been used in England, and found very practical, handy and useful in work not requiring a transit or theodolite. It is not only a good miner's dial, but a circumferentor as well; that is, it can measure horizontal angles like a theodolite. The magnetic bearings are conveniently read on the inward-beveled upper divided circle; while another circle, graduated on the base-plate, is used for reading the horizontal angles with a vernier. Two leveling spirit-bubbles are sunk in the same base-plate. The vertical divided semicircle is attached to the compact-box by two short axes, which permit the semicircle, with its plain sights, to be turned down to a horizontal position, and rest upon a pin, which relieves the axes from strain. This adjustment gives a clear view of the needle and vernier, and protects the instrument from injury, when carried through low mine-workings. A groove in the semicircle receives a sliding-bridge which carries the plain sights, and a vernier for reading vertical angles. A ball-and-socket-headed tripod is used; but sometimes the instrument is mounted on parallel-plates and level-ing-screws; and sometimes a telescope is attached, instead of the plain sights. The instrument is admirable for all such Mexican surveys as Mr. E. A. H. Tays describes ;l and saves so much time and labor as to be vastly superior to the less accurate hanging-compass called by him a " bully " instrument. If the hanging-compass was ever used in England, it has long since given way to more modern and superior instruments.

Jan 1, 1905

By Raymond Sanford

IT IS difficult to know just when a hoisting rope should be removed from service and a new one substituted. It is desirable to utilize the full life of a rope but, on .the other hand, the damage and possible loss of life, resulting from delay in replacing it may amount to many times the cost of a new rope. In the present methods of inspection the inspector must rely upon accumulated experience and a certain sixth sense or intuition in addition to any rules that may be laid down regarding the number and distribu-tion of broken wires. This condition does not neces-sarily arise from lack of interest among users or makers of rope, but is due rather to the lack of satisfactory or adequate methods for testing ropes to determine their exact condition. The main difficulty in devising a physical test lies in the fact that a number of causes, all operating in different ways, contribute to the deterioration of a rope in service, and affect not only the external conditions but also the inner structure of the material of which the rope is constructed. Wear and broken wires on the outer part of the rope are not difficult to detect, but a test is needed which will clearly indicate the presence of broken wires in the interior portions and the change in strength due to alterations in the structure and properties of the material itself.

Jan 7, 1923

R. L. Bullock (St. Joseph Lead Co., Bonne Terre, Mo.)— The progressive approach of The International Salt Co. as described by Mr. Ryon is certainly commendable as is his paper. St. Joseph Lead Co. has been shooting AN/FO in 13/8 to 1 1/4-in. holes for several months now (as of October 1960) on a trial basis. The results thus far obtained are excellent, but conclusive evidence at this date is premature. One point that he gave should interest even the most ardent skeptic. That is, they are getting a detonation of the 1 1/4-in. ANDO charges in 2 1/4-in. holes. In light of its low sensitivity and critical diameter, this would appear to be one of the worse conditions that one could expect in which to get proper detonation of AN/FO. It has been shown* that partial confinement sometimes decreases sensitivity of a column of explosive because the air space above the explosive becomes highly compressed and in turn compresses the explosive prior to passage of the detonation front. Apparently, this does not happen in their shooting and the poor explosive coupling caused by the 2 1/4-in. holes yields a minimum of overbreak and is an ideal condition for their back.

Jan 1, 1961

By A. Bauer, P. Calder, N. H. Carr, G. R. Harris

Smallwood mine is part of the Iron Ore Company of Canada's Carol Lake operation and is situated in Labrador, 240 miles north of Sept-Iles, Quebec. Last year, 15 million tons of crude ore were crushed to yield 6.3 million tons of concentrate and pellets. This year the figures will be 17 million of crude and 7 ¼ million tons of concentrate and pellets, which is the full plant capacity. Carol Lake ores consist primarily of specularite and magnetite mixed with quartz. Since both rotary and jet piercing drills are used, it is often desirable in planning to know in which regions of the orebody, or new orebodies, a particular drill will be most economic. This makes it necessary to establish a correlation between drillability and pierceability and some physical rock property. For the rotary drills a good correlation was found with penetration rate and grinding factor index. The jet piercers were found to have a reciprocal relationship in the sense that the best rotary ground was the worst jet ground and vice versa. It is also indicated how an economic comparison could be made using these penetration rate versus grinding factor index curves, the hole size distribution curves for single pass and chambered holes, and the mine distribution curve for grinding factor index.

Jan 9, 1965

By John Tyssowski

IN 1925, Harry Howard Stout, then metallurgist for Phelps Dodge Corporation, while investigating the cleaning of cathode copper by various gases at elevated temper-atures below the melting point of the metal, observed in the laboratory that particles of pure copper heated in a closed tube filled with hydrogen seemingly "stuck together." By further investigation he found that there was actual crystal growth across the boundaries of the particles of pure metal; in other words, there was a complete new crystal realignment and growth throughout the newly formed copper mass. It was coalescence, not adhesion; the several parti-cles had become one unit. From this dis-covery has been developed the coalescence process, whereby copper of cathode purity is squirted out in semifabricated form from an extrusion press, by the appli-cation of about 30c0 tons pressure on a 10-in. piston. Stout decided that cathode copper pro-duced by electrolytic deposition was the logical source of the pure copper required for the coalescence process, but as there was no way of reducing the ordinary tough commercial cathodes to the small particles required he was confronted by a serious problem at the outset. Under his direction, this problem was solved by William H, Osborn and Harry Howard Stout, Jr. They developed the process and technique for producing cathode copper in brittle, friable form, and to them must be given the greater part of the credit for this phase of the development program as well as for that relating to the gas cleaning of the cathode particles.

Jan 1, 1940