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Jan 1, 1934

By John M. Dale

Sulfur has attractive features as a base material for coating systems. It melts at 246ºF and can be applied as a liquid above this temperature. Its melting point is just above the environmental stress level, 180°F, for most coatings and yet it is low enough to be easy to work with in comparison to many hot melt systems. The viscosity characteristics are such that sulfur lends itself to spray applications. The oxidation rate of sulfur in the atmosphere is very low and sulfur has outstanding chemical resistance characteristics, particularly in acid environments. One of the greatest potentials for these coatings appears to be in the protection of other materials. At one time, most acid tanks and pits were constructed with acid- proof brick and sulfur based mortars. This type of construction is much more expensive than sulfur based spray coatings. An attractive sulfur based coating composed of sulfur, talc, milled glass fibers and dicyclopentadiene,1 developed by the Institute for the Bureau of Mines has excellent acid assistance and can be used to protect concrete from acid attack.

Jan 10, 1973

By Francois E. Heuze

The Crestmore Mine of the American Cement Company lies at the eastern end of the Jurupa Mountains, 50 miles east of Los Angeles. Originally, a quarry was opened in 1908 for "limestone" used in the manufacture of cement. The mining operations eventually went underground employing first a modified system of block caving and later the "room and pillar" scheme. The limestones are relatively small roof pendants preserved in an enveloping and intrusive quartz diorite. They occur as two irregular lenticular bodies roughly parallel at the top and tending towards convergence at depth. Their dip varies between 25 and 30 degrees E. The presently mined lower bed, Chino limestone, is typically composed of alternating bands a few inches to a few feet thick of medium to coarsely granular white crystalline limestone and somewhat yellowish limestone (brucite marble). A "room and pillar" scheme of mining is currently employed in the lower body of the Crestmore Mine. The levels are horizontal and access is provided by a spiraling road starting in the old quarry. The present depth of operations is an average 750 ft below the surface. Fig. 1 gives a three-dimensional general sketch of the mine. The long axis of the rooms is in an E-W direction, normal to the strike of the beds. Fig. 2 is a horizontal map of the 130 level, the deepest level mined presently. It is in this level that most of the in-situ investigations have been conducted. The present investigation was made possible by a non-restrictive grant of the American Cement Company to the University of California. The program included a series of in-situ tests using flat-jacks, plate bearing,

Jan 1, 1968

By E. M. Rogers

In hoisting from shafts of considerable depth, the dead weightdue to the accumulating length of cable is an important element, and has

Jan 1, 1889

By W. Z. Price

The coal lands that the Nemacolin mine is to develop embrace over 8400 acres; the tract is oblong and its eastern edge is along the Monon-gahela river. As shown in Fig. 1, the mine is divided into two parts (the North mine and the South mine) by a 150-ft. barrier, which however, is cut through at intervals by haulageways. Each part is fed from seven main entries—a loaded track, an empty, a manway, and four return air courses. The loaded tracks converge at the shaft bottom but the empty roads maintain their identity throughout their length. With three intakes and four returns on either side, there is ample room for expansion of air and every facility for ventilating is provided. The four south air courses converge into two, crossing the shaft bottom, and then into one at the south side of the air shaft. The four north air courses converge in a similar manner on the west side of the same shaft. This convergence is accomplished by concrete arched

Jan 1, 1927

By J. E. Johnson

The description of the machine which coilstitutes the subject of this paper is best iutroduced by a statement of the conditions which led to its construction, which may be briefly given as follows : The ore handled at the plant to be here described* is of the variety sornetimes called by those familiar with the brown ores of the South, " Mountain," as distinguished from the " Lime-

Jan 1, 1899

By Gerhard Derge

EXTRUSION processes are used in the commercial production of a wide variety of products, as indicated by the review presented a few years ago by D. K. Crampton.1 Most writers have confined themselves to a general description of the equipment and products and the engineer-ing aspects of the process. The few studies that have dealt with the metallurgical side of extrusion have been concerned primarily with an examination of the mode of flow of the metal during extrusion. This has been accomplished by the use of composite billets, by scribing grids on symmetrical sections of billets and observing the change of dimensions in the gridwork, or by examining microstructures in extruded sections.2-8 Another limitation of these original studies is that they were confined to the extrusion of very simple shapes, usually rods having a diameter of about one-fourth that of the billet. Tin is particularly well suited to the extrusion of collapsible tubes and similar shapes in which the extruded section is very small in comparison to the diameter of the billet or slug. In modern production, impact extrusion methods are generally employed, therefore the thickness of the slug is small compared to its diameter. Under these conditions the process differs considerably from the processes that have been most fully described in the literature, and it is known that the quality of the product is very sensitive to slight variations in any one of the many variable factors involved, such as composition and structure of the alloy, rate of extrusion, temperature, shape of punch and die. An exhaustive examination of all of the above-mentioned problems promises to produce so many data that it seems advisable to initiate the reports at this time, even though all of the factors outlined have not been examined fully, and to confine this paper to a description of the apparatus and method. Only tin and its alloys with small amounts of copper have been considered. These are the alloys most commonly used in this country for the production of the type of articles already described.

Jan 1, 1939

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 Theodore W. Robinson

WHEREVER the amount of work renders it practicable the plan of using permanent standard solutions, in connection with the colorimetric carbon test, affords such manifold advantages that it is to be strongly recommended. That it has not attained a wider and more general application, is mainly due to the fact that, as the method is generally employed, the difficulty attending the production of the colors, and their doubtful stability when produced, have been only too evident to those who have undertaken their composition. The old method of using standard solutions made from sugar, coffee, etc., has always been hampered by the tendency of the colors to change upon exposure to the light, and the consequent liability to serious error, unless they are closely watched. Appreciating these difficulties, while recognizing the desirability of permanent colors, Mr. Magnus Troilius, at the suggestion of Prof. F. L. Erkmann, investigated the properties of cobalt, copper and ferric chlorides, with the view of determining their efficacy in the production of standard solutions. His results, as obtained, seem to have been satisfactory, but his treatment failed to eliminate many of the objections that have rendered the use of organic colors undesirable. The

Jan 1, 1888

Jan 1, 1940

By E. H. Crabtree, T. G. Chapman, V. W. Winters

This paper traces the experimental and pilot plant work completed by the authors since 1939 including the various methods which have been developed in applying coarse activated carbon to cyanidation. The methods and results developed by the authors in desorbing gold and silver from carbons are given and the possibilities for the re-use of the desorbed carbons are discussed.

Jan 2, 1950

Jan 1, 1940

By C. A. Shook, W. H. W. Husband, D. B. Haas

Introduction Although previous studies1,2,3 have been made, no correlations for pressure drop have been proposed. This is probably because severe particle breakage occurred and pressure drops changed substantially with time. A quantitative statement of the relationship of pressure drop to the parameters of the system is desirable for lignite since, unlike higher rank coals, lignite slurries are thixotropic. The present investigation was undertaken to quantify the pipeline behavior and required continuous monitoring of pressure drop and size distribution.

Jan 1, 1980

By G. D. Tranter

THE importance of ladle and teeming practice and its relationship to the yield and quality of the product has focused considerable attention on this phase of open-hearth operation. Inherently bad steel cannot be perfected by manipulation during teeming, but through the proper handling of "off heats" serious losses, which in many cases arise, can be greatly minimized. Conversely, good steel can be ruined as a result of poor workmanship in the -pit, and rendered unsuitable for application to orders where exacting surface and physical requirements are essential. Sufficient evidence has been secured to warrant careful investigation of pit operations when an abnormal number of basic defects develop in the semifinished product or are found on the inspection table. This paper is written from the standpoint .of the problems involved in making satisfactory ingots for sheet rolling. Furthermore, since rimming steel is almost universally used for manufacture of sheet, the data presented herein refer particularly to that type of steel. Going back some 30 years in open-hearth .history, the word "pit" properly described the hole into which the ladle was lowered to receive the metal tapped from the furnace. The working space was necessarily limited, and the disposal of slag and metal overflowing the ladle or lost because of breakouts presented a serious problem. The equipment, of course, was rather crude in the light of present-day development. Often no ladle stands were provided, the ladle being hung on the crane beneath the runner. When delayed taps occurred, the ladle was often held in position for many hours, thus tying up pit operations and causing delays to adjacent furnaces. Because of crowded conditions, slag thimbles were not used and a network of cast-steel triangles and old tapping bars, placed before the heat was tapped, was the means for removing slag from the hole. Furnaces of different capacities were used

Jan 1, 1935

By R. M. Board

This paper will focus on measurement and control of four main aspects of crushing, namely horsepower, bowl level, mantle position and feed rate, and will discuss related sensors and control techniques, some of them designed specifically for crusher control, that have proven successful and reliable in many installations.

Jan 1, 1982

By G. M. Wiles

The increasing number of problems of the modem mine manager has led the author to discuss the art of management. He lists the principles concerning selection of personnel, exploitation and development, new equipment, process improvements, new processes, maintenance, operating cost data and public relations. Application of the principles to problems of mine startup, operation and rehabilitation are described. Since D. C. Jackling was famous for his adeptness at organizing and training teams of operating personnel, the subject of mine management is particularly appropriate for a Jackling Lecture. In fact, it is doubly appropriate because in very basic ways Jackling's career changed the nature of the tasks and challenges facing a mine manager. Management of mines, of course, is the art of finding and winning minerals economically from the earth's crust, and it involves the use of all the engineering sciences. But also of prime importance is a skill which is not yet a science - the area of management often referred to as human engineering. Since expenditures on staff and labor may well involve more than 50% of the direct costs of operating a mine, ability at human engineering is just as important as the ability to plan and put into effect the most efficient operating procedures. In addition to his ability to select and train operating personnel, Jackling possessed, to a degree unmatched by many of his contemporaries, broad, analytical powers covering both the economics and operating phases of large scale mineral extraction. His breadth of vision found its greatest expression at the time he analyzed the Utah copper deposit. Fortunately, Messrs. Penrose and Gemmell had enough faith in his analyses to furnish the capital needed to begin operations. The result, as is well known to all of you, was Kennecott's lucrative Utah copper mine — and the beginning of the open pit porphyry copper era. The Utah copper mine, and Jackling's subsequent similar successes in Arizona, New Mexico and Nevada, had one thing in common —all of these large porphyry deposits were worthless until open pit, large daily tonnage schemes were developed for their exploitation. The successful development of such schemes made vast new mineral resources available for economic exploitation. But at the same time, the trend away from smaller high grade operations in favor of the far more complicated operations required to handle large deposits of low grade ore have greatly altered a mine manager's problems. We are all familiar with the saying "mines make managers." There is still some truth in this statement, but far less than there used to be in the days when high grade properties were the rule rather than the exception. When high grade orebodies prevailed, many managers, superficially at least, could not make a mistake because the profits of their mines

Jan 1, 1962

By James R. Stuart

AS the available remaining properties of iron ore reserves on the Mesabi Range are opened up for mining, the various properties located under lake beds are brought nearer an active status. The actual physical problems involved in stripping these properties do not act as a deterrent so much as the legal and political problems that are encountered. When it is proposed to destroy a natural lake that has been used by the public for many years, much local as well as state opposition may be encountered regarding its destruction. Public hearings must be held and some adverse publicity is likely to result. The ownership of the ore under the lake and the rights of the abutting property owners must be settled, and protection from damage caused by a disturbance in surface and subsurface drainage is likely to be demanded by property owners some distance from the proposed mine area. The Embarrass Mine, located near Biwabik, Minn., falls into this classification. A portion of the orebody lies under what was formerly Syracuse Lake, this body of water having been removed in the process of stripping the mine. An additional problem in the case of a meandered body of water is the establishment of a meander line that can be projected downward as mining progresses to form the basis for a satisfactory division between lake bed and upland ore shipments for royalty purposes. Fig. 1 illustrates the complications encountered in maintaining these divisions. A balance point was agreed upon in the center of the lake to make an equable division of lake bed ore to the abutting properties. The entire lake bed has since been adjudged the property of Minnesota. Lake Characteristics Lake bed stripping problems with which this paper is concerned necessarily are limited to a specific type of lake, namely the glacial lakes of the Lake Superior region. One characteristic common to these bodies of water is a deposit of fine black mud or silt on the bottom, frequently underlain by a layer of impervious blue clay. This is also true of the muskeg areas of the region, which present almost identical problems as lakes in stripping. The actual removal of the water and the lake bed material is a routine matter more or less standardized as to equipment, and the period of time required can be estimated easily on the basis of volume and capacity. More important than the foregoing is the execution of preliminary work, and above all, the timing involved. An account could be prepared based entirely on statistical and cost data which would give a very fair picture of the time required and cash outlay needed to effect the removal of a body of water preliminary to stripping the orebody. However, the real interest from the standpoint of the operator and the engineer who carry responsibility for completion of the job lies in the unexpected emergencies and the action of various materials involved in the stripping when the balance has been upset through diversion of water courses and the reduction of the lake level. Runoff and Drainage Lakes are located in natural basins that catch all the rain water and runoff water for a considerable area. Where a lake is involved having an inlet and outlet or a sizeable water course running through it, the drainage area may include a watershed covering many square miles. All available data then must be collected to supply a history extending over as many years for which information can be gathered on the flow of streams, annual rain and snowfall, and most important, the peak flows to be expected. Where the diversion of a stream around the stripping area is a part of the problem, this last factor is of great importance since it controls the cross-section to be selected for the diversion channel and the volume to be removed in its excavation, as well as affecting the hydraulic considerations to be met in the design of the completed channel. Characteristic material in the overburden found at the Embarrass Mine is illustrated in Fig. 2. Well Pumping Pumping from the well holes was started well in advance of the draining of the lake. Fig. 3 shows a gradual lowering of the water table with no noticeable fluctuations during the period in which the lake was being dewatered. Unfortunately, because of tight ground, a maximum flow to the wells was not maintained. This retarded the rate at which the water table was reduced so that in the course of stripping the excavation soon extended below the water table, and the great bulk of the pumping was handled from a system of sumps in the pit itself. Any dewatering program projected by prepumping from wells, a glorified well point system, would have to be started well in advance of the stripping to be of any great advantage. Preliminary drainage of the surface over the mine area is entirely apart from the actual elimination of the lake bed itself. Since the lake is what is called a perched water table because of the impervious character of the lake bottom, the adjoining surface may be dewatered below the surface of the existing lake and the flow will not be affected by the proximity of that body of water. This condition actually has been demonstrated through the establishment of a number of observation holes where a small churn drill was used to put down the holes and a 3-in. pipe was installed for taking water level

Jan 1, 1952

By W. C. Krumbein

Geological problems are approached from a geometrical (space relations) viewpoint, a kinematical (time sequence) viewpoint, or a dynamical viewpoint. The first two require sound training in conventional geology and in field methods. The third approach requires a solid foundation of chemistry, physics, and mathematics. Modern training for geologists should include close integrltion of basic sciences with geological principles. Introduction Our knowledge of the earth has increased tremendously during the last half century. We know more about its surface configuration, the distribution of its natural resources, the proccssion of living forms that inhabited it in the past, the chemical composition of its oceans, the areal distribution of its surface rocks, the movements of its atmosphere, and so on. Not only do we know more facts about the earth, but we have a better understanding of the processes that take place on and within it, such as the nature of earthquakes, the thermodynamics of the atmosphere, the chemical equilibria involved in the formation of igneous rocks, the mechanics of stream flow, the dynamics of the earth's origin, and so on. Many sciences contributed to the sum total of this knowledge, including such established disciplines as geology, geography, physics, chemistry, astronomy, biology. Out of this accumulation of new knowledge grew also a group of new sciences, such as seismology, oceanography, meteorology, volcanology, hydrology. Collectively these latter are known as the geophysical and geochemical sciences, and to a large extent they began as branches of geology. Until the turn of the century, for example, the study of earthquakes (seismology) was a part of geology, although as early as 1846 Mallet, a physicist, had suggested that the subject could be investigated by elastic-wave theory. Comparatively little progress was made along these lines until the seismograph was developed near the turn of the century; since then, additional earthquake data have accurnul~ted rapidly, but more important, the interpretation of these data essentially has kept pace with their accumulation. In similar fashion, meteorology was generally considered a branch of geology as recently as one or two decades ago. Considerable progress had been made in such aspects as weather forecasting, but the science dates its recent rapid rise from the year 1911, when Bjerknes first applied the principles of dynamics to the analysis of air masses. The rapid development of such disciplines as oceanography, volcanology and hydrology was due in part to the application of principles of chemical equilibrium, of dynamics, and of thermodynamics to earth problems, by men who were essentially physicists or chemists by training. The last half century, therefore, and particularly the last two decades, saw the influx of numerous chemists and physicists into the realm of the earth sciences. In the meantime the main body of geology itself showed a marked growth, and

Jan 1, 1946

By W. C. Krumbein

Geological problems are approached from a geometrical (space relations) viewpoint, a kinematical (time sequence) viewpoint, or a dynamical viewpoint. The first two require sound training in conventional geology and in field methods. The third approach requires a solid foundation of chemistry, physics, and mathematics. Modern training for geologists should include close integrltion of basic sciences with geological principles. Introduction Our knowledge of the earth has increased tremendously during the last half century. We know more about its surface configuration, the distribution of its natural resources, the proccssion of living forms that inhabited it in the past, the chemical composition of its oceans, the areal distribution of its surface rocks, the movements of its atmosphere, and so on. Not only do we know more facts about the earth, but we have a better understanding of the processes that take place on and within it, such as the nature of earthquakes, the thermodynamics of the atmosphere, the chemical equilibria involved in the formation of igneous rocks, the mechanics of stream flow, the dynamics of the earth's origin, and so on. Many sciences contributed to the sum total of this knowledge, including such established disciplines as geology, geography, physics, chemistry, astronomy, biology. Out of this accumulation of new knowledge grew also a group of new sciences, such as seismology, oceanography, meteorology, volcanology, hydrology. Collectively these latter are known as the geophysical and geochemical sciences, and to a large extent they began as branches of geology. Until the turn of the century, for example, the study of earthquakes (seismology) was a part of geology, although as early as 1846 Mallet, a physicist, had suggested that the subject could be investigated by elastic-wave theory. Comparatively little progress was made along these lines until the seismograph was developed near the turn of the century; since then, additional earthquake data have accurnul~ted rapidly, but more important, the interpretation of these data essentially has kept pace with their accumulation. In similar fashion, meteorology was generally considered a branch of geology as recently as one or two decades ago. Considerable progress had been made in such aspects as weather forecasting, but the science dates its recent rapid rise from the year 1911, when Bjerknes first applied the principles of dynamics to the analysis of air masses. The rapid development of such disciplines as oceanography, volcanology and hydrology was due in part to the application of principles of chemical equilibrium, of dynamics, and of thermodynamics to earth problems, by men who were essentially physicists or chemists by training. The last half century, therefore, and particularly the last two decades, saw the influx of numerous chemists and physicists into the realm of the earth sciences. In the meantime the main body of geology itself showed a marked growth, and

Jan 1, 1946

By David R. Maneval, Jack M. Campbell

The regulatory process by which governmental authorities acknowledge and, in turn, permit the location, construction, and operation of large scale energy-related facilities has become extremely detailed in recent years. One example of the detail that is entailed in the regulatory process is the number of permits that must be acquired by operators prior to the construction and operation of energy-related facilities. It has been estimated, for example, that 75 permits are required prior to the opening of a new coal mine in Pennsylvania while 50 are required in Kentucky. From the perspective of facility owners and operators the regulatory process often appears overly complex and may be perceived as a constraint to the corporate decision making process. From the perspective of those responsible for administering regulations, the process is perceived as a means by which public desires-pursuant to social objectives such as environmental protection and occupational safety-can be achieved. As a result of conflicting organizational interests, the clash between energy facility owners and operators and their regulators appears to be inevitable. Furthermore, the resolution of this conflict lies in the trade-off between objectives and the costs of regulation. The balance of objectives and costs is a subject of the political process and not a topic of consideration in this paper. This paper is concerned with the actual administration of regulations, that is, the implementation of that which arises from the interplay of organizational interests. The paper assumes that environmental control laws will not likely be repealed, that regulations to implement the intent of these laws are here to stay and thus the paper seeks to assess how regulations are administered at various levels of government pursuant to objectives. The paper hypothesizes that the administration of objectives (or policy) has an impact on decision making which affects energy facility decision making. While recognizing the fact that regulatory policy cannot be totally divorced from administration, this paper proceeds under the assumption that elements of the regulatory process may be examined individually. The subject of this study is limited to the interplay between regulatory agencies and their clientele.

Jan 1, 1979