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By R. V. Ramani, G. W. Luxbacher

Computer simulation of mine ventilation system is rapidly becoming an essential tool in mine planning and design. This Paper examines the utilization of ventilation simulation techniques to evaluate the number, shape, size and layout of mine entries in a typical coal mining system. Since the mains and sub-mains serve primarily for transportation and ventilation and the ventilation system is critically important to the health and safety of the workers, there exists a great need for optimal designs in this area. Evaluation criteria could include, among others, minimization of power costs, shaft requirements and leakage. Constraints of this optimization problem include health and safety regulations and production and mine infrastructure requirements.

Jan 1, 1980

By Walter von der Linden

A description is presented of the mining conditions of four longwall shield type support installations in the Pittsburgh seam in northern West Virginia and southwestern Pennsylvania. Details of roof control and operating procedures, production and performance data, and equipment description and basic engineering specifications are given for these four longwall installations. The range of mining heights was between 150 and 250 cm (60 and 95 in.). The major accomplishment of the shield supports in all four faces was the provision of an almost 100% availability for coal cutting; i.e., the face-down time due to roof control problems and support maintenance requirements was minimal.

Jan 1, 1978

By J. C. Draper, R. J. Houston, R. E. Pepperman

Duquesne Light Co. and CAI Consultants, Inc. conducted a demonstration program to establish permanent vegetative cover directly on acidic, deep coal mine refuse. Several plots were treated with formulas varying in soil amendment application rates and plant speak. Periodic monitoring of refuse chemistry indicated when maintenance applications of seed and soil amendments were required. To establish drainage control, the site had to be regraded. The most successful experimental formula was used as the bank for the formula applied to regraded portions of the site. Specific treatment for acidic spots has been initiated. Results of the program indicate that adequate permanent vegetation has been established.

Jan 1, 1985

By L. M. Cathles, W. Joseph Schlitt

A mathematical model describing the leaching of low grade industrial waste dumps in developed and solved by finite difference techniques. The leaching behavior of model dumps of different sizes, permeabilities, and waste characteristics, under different operating conditions, is then investigated using the model. It is shown that leaching is fastest for dumps 50-100 feet (15-30m) high, that permeability is very important for the effective leaching of large dumps, that slow leach kinetics of the waste may not be detrimental, and that the leaching of large dumps may be facilitated if leach solutions are preferentially applied to the hot, near-edge portions of the dump.

Jan 1, 1980

By Peter B. Nalle

Over a period of years the Crestmore plant of the Riverside Cement Co. has been supplied with limestone from the Chino limestone bed. The limestone bed dips about 40º and extends 1500 ft along the strike. Thickness of the bed is such that horizontal distance from footwall to hanging wall varies from 400 to 1200 ft. When the new room and pillar mining system was instituted the haulage units used for development were model C Tournarockers. Four of these diesel units were purchased with the idea of using them solely for development work since it was realized that they would have to be supplemented by additional, and perhaps larger haulers.

Jan 4, 1959

By Victor M. Braschi

The railroad history of Mexico began with the first presidential term of General Diaz. Concessions for the building of railroads had been granted in former years; indeed, an exclusive privilege was granted, August 22, 1837, to Francisco de Arrillaga for the construction of a railroad from Mexico to Vera Cruz, with a branch to Puebla, and other concessions were granted from then on at various periods; but the year 1877 was the real beginning of the regular and constant decelopment of the railways of Mexico. The programme laid out at that time by the new government, and responded to by the nation, was to develop its natural ele-

Jan 1, 1902

By M. T. Simnad, G. Derge, Ling Yang

A method is described for using radioactive tracer for the direct determination of ionic mobility in a molten electrolyte. The ionic mobility of Fe" in silica-saturated iron silicate is found to be 0.0009 (*0.0002) cm2 sec ' volt L at 1250°C. eLECTROCHEMICAL studies', ' of molten iron eE oxide and iron silicates have shown some ionic conductivity at all compositions. The current efficiency in electrolysis increases with the concentration of silica to a maximum of 90 pct at about 34 pet SiO,. In the silica-saturated melts the transport number of ferrous ions is near unity, indicating that

Jan 1, 1957

By J. Marshall Downey

The most fortunately situated U. S. potash producer-whether in New Mexico, California, or Utah--once simply took from the ground a mixture of sodium chloride and potassium chloride, crushed it to a maximum of 10 mesh, and separated the two salts by physical methods. He piled the sodium chloride on the desert and sold the potassium chloride to fertilizer mixing companies. Seven companies in the Carlsbad basin of New Mexico now use at least three basic processes for making the separation and at least three more processes have been or are under investigation. In addition, two companies outside the basin use two methods for taking KC1 from natural brines

Jan 12, 1958

A development drilling and bulk sampling program should furnish the following information: (1) geology of the mineralized zone, (2) quantitative data on grade and tons of material within pertinent cutoff limits, (3) physical size and shape of the deposit and areas underlain by waste as well as ore, (4) mineralogical and metallurgical characteristics of the ore, (5) physical characteristics of the ore, (6) bulk samples for metallurgical testing and grade, (7) data on factors that affect mining operations, such as ground water and ground conditions. The method and equipment best suited for a particular drilling job depend upon the geologic features of the mineral deposit to be tested.

Jan 10, 1967

By R. Maddin, N. Ujiiye

ALTHOUGH the cold-rolled texture for body-centered-cubic metals and alloys is well known (see, e.g., Barrett'), the pole figure representing the texture may be interpreted in two ways. It may be regarded as consisting of several ideal preferred orientations with an associated spread (a view which is shared among several investigators2), or it may be regarded as consisting of two sets of continuous preferred orientation also with an associated spread."." Recently, Chen and Maddin7 noted a stable (001) [loo] end orientation for molybdenum single crystals rolled at low rates of reduction provided the initial rolling. orientation" was close to the cube ori-

Jan 1, 1957

By H. W. Young

DEVELOPMENT of high-tension outdoor substations during the past few years has been due primarily to economic reasons. The demand for power in small communities could not be met with the conventional and 1 FIG. 1.-33,000-VOLT STEP-UP OUTDOOR AIR-BREAK SWITCH AND SUBSTATION INSTALLATION OUTSIDE OF A POWERHOUSE GENERATING AT 2300 VOLTS STEPPING UP TO 33,000. TWENTY-ONE COAL MINES ARE SUPPLIED FROM LINES LEADING FROM THIS INSTALLATION. comparatively expensive indoor types unless the rate for service was materially increased. That the various problems incident to development have been solved successfully, it is only necessary to point to the

Jan 9, 1919

By Richard Akerman

(Translated by FREDERICK PRIME, JR., Professor of Metallurgy in Lafayette College, Easton, Pa.) [THE attention now being paid both in this country and Europe to the greatest economy in the working of the blast furnace, and the eagerness with which all thoughtful men in the iron business look for any new information which will tend to throw light on this sub¬ject, is a quite sufficient excuse for presenting this paper to the Amer¬ican Institute of Mining Engineers.] I. It must be borne in mind that when two bodies unite to form a chemical compound, heat is almost always evolved. In order to

Jan 1, 1873

By Herbert Haas

1. INTRODUCTION COPPER matte is now converted into blister copper at a cost of only $5 per ton of copper, or, based on a 40 per cent. matte, $2 per ton of matte, which is the record of at least one large smelting Works; and it seems hardly likely that a further reduction, large enough to warrant, a change in existing practice, could be made in bessemerizing costs. But the new type of converter here described and the new practice proposed are intended, not so much for the treatment of mattes, as for the extension of, the process to the direct reduction in the copper-converter of pyrite ores

Jan 6, 1914

By Bruno V. Nordberg

The high cost of coal in Butte and the development of large amounts of cheap electric power from the Missouri river caused the Anaconda Copper Mining Co. in 1908 to make an investigation as to the possibility of adapt- ing this cheap electric power for the operation of their many large hoisting plants. At this time electric power had already been adopted for practically all other power purposes around the mines, such as pumping, compressing air, etc. The map (Fig. 1) shows the location of the mines of the Butte mining district. These mines are located within a circle of approximately a 1-mile

Jan 1, 1914

A filled stope is one in which the support for walls and men and, at times, for the back of ore, is furnished by waste rock or sand tailings. The filling may be rock sorted out in the stope or from the walls, develop-ent, or the surface. The orebody is mined in sections, each practically an open or timbered stope, filled wholly or in part before adjacent ground is attacked. As a rule, the filled-stope method is limited to overhand flat-back, stepped-face, or rill stopes. The examples given are Copper Range, Iron Cap, Verde district, Zaruma district, Lucky Tiger, and Silver King Coalition.

Jan 1, 1925

By A. E. Anderson, H. J. Hilll

Laboratory data for 155 field muds and 77 .shales have been used to develop correlations to estimate the net streaming potential component of the SP. Analysis of these data and comparison with field tests show that streaming potential corrections must be made to obtain an accurate estimate of the electrochemical potential for use in the determinntion of formation water resi-iiviy. The self-potential curve is related to formation water resistivity, and considerable effort within the oil industry has been directed toward clarifying this relationship. The Schlumbergers and Leonardon1,2 recognized that two types of potentials, electrochemical and electro-kinetic, resulted in the net potential variation in the borehole. Most of the later papers have dealt with the electrochemical component and its controlling parameters. The investigations of Wyllie,2" Salisch' and Moore5 provide the most extensive sources of data on streaming potentials across mud cakes. These authors observed streaming potentials of sufficient magnitude to be of critical importance in SP interpretation, if it is assumed that streaming potentials develop only opposite permeable beds. Streaming potentials across shales have been reported by Schenck and by Gondouin, et al.7 Since SP magnitude is the difference in potential opposite shale and sand beds, these authors suggested that the net streaming potential component may be negligible. The present investigation was initiated to evaluate empirically some of the parameters controlling the magnitude of the net borehole streaming potential and to determine whether useful relations between mud properties and net streaming potential could be established. Field muds were used in this investigation. These muds were characterized by the amount and type of chemical treatment utilized for five days before Sampling. Filter loss, mud resistivity, mud density and filtrate resistivity were determined for each mud with conventional methods and apparatus. Mud filtrate pH was estimated with Hydrion pH paper for the appropriate range. Streaming PotentIals Across MuD Cakes Commercial calomel-saturated KC1 electrodes are subject to potential changes attributed to contamination of the very small fiber-tip bridge by particles of clay from the drilling mud.3 To minimize this difficulty, a large diameter bridge (Fig. 1) was constructed with saturated KC1-agar gel and a filter disc of microporous porcelain. Experiments showed that streaming potentials across this bridge are less than 0.2 mv at pressure dif-

By L. P. Davidson

ThE new electrolytic zinc plant of the American Zinc Company of Illinois commenced operation in April 1941. The simple flowsheet using the standard current density and the economic reasons that dictated it are given herewith. The Evans-Wallower Zinc Co. built an electrolytic zinc plant at Monsanto, Ill., in 1929 and operated it for about two years. The plant stood idle from 1932 and was purchased by the American Zinc Co. in 1940. Because of the condition of the equipment, excepting the motor generator set, a complete rebuilding was necessary. The Fairmont City plant of the American Zinc Co. could treat the leach residues, the purification cake and the skimmings from the melting furnace in its various plants. This possibility permitted a simple flowsheet with good economic results. The flowsheet is shown in Fig. I. The calcined concentrates are leached in mechanically agitated tanks with spent electrolyte and such ferric iron solution as necessary. When the acid has been neutralized and the iron coagulated, the fluid is discharged to settling tanks. The underflow from these thickeners is filtered on a Moore filter; the filter cake leaves the plant for retreatment and the filtrate joins the thickener overflow. Zinc dust is added to this solution until the copper and cadmium are precipitated. The pulp is filtered through Shriver presses, which deliver the purified solution to stor- age tanks, and the copper-cadmium-zinc cake is shipped for retreatment and recovery of these three metals. The purified solution is electrolyzed; the regenerated acid is returned for use in the leaching plant and the cathode zinc, after stripping, goes to the melting furnace, from which it is cast in slabs. The skimmings from the melting furnace are shipped to the Fairmont City plant for reduction to metal in the retort furnaces. The choice of this simple flowsheet was made possible only because of the facilities of the Fairmont City plant. The long leaching pried, with high acid content and high temperature which characterize the high-density process, gives a higher zinc extraction but also dissolves more impurities, which must be removed. The same is true to a lesser degree of the multi-step leaching of the western low-density plants. By the sacrifice of some initial extraction, solutions can be obtained that are relatively easy to purify and give good ampere efficiency. This loss in initial extraction is made up in the retreatment of the residues in the Waelz plant. The impurities that accompany the zinc thus extracted are inconsequential when the Waelz product is treated in a distillation plant. It was recognized that this flowsheet would require a somewhat greater amount of sulphuric acid—-eithcr as acid or as sulphate sulphur in the calcine—because of poorer washing. The sulphuric acid plant at Fairmont City could deliver 60" Bè. acid to compensate for the sulphate loss and the cost would be less than the cost of more intensive washing.

Jan 1, 1943

By V. R. Garfias, R. V. Whetzel, J. W. Ristori

Since the entry of the United States into global war, virtually all data and information necessary for compiling figures on world petroleum consumption have become unavailable. This situation undoubtedly will continue until the world petroleum industry can return to a peacetime basis. During the past 10 years, the authors, by publishing annual estimates of .world consumption, have attempted to emphasize the importance of a yearly world-wide survey of petroleum supply and demand. It is beconling more and more evident that statistics for the United States alone can no longer give a comprehensive idea of the state of the petroleum industry, even within the United States itself. Therefore, when conditions in the industry again become normal, it is the hope of the authors that those bureaus equipped to do so will carry forward the study of petroleum supply and demand on a world-wide basis. Enough data and information are available, however, to attempt a rough estimate of world output of crude petroleum and petroleum substitutes for 1942, which to some extent may reflect the trend of world consumption. This estimate by countries, as compared with the output in 1941, is shown in Table I. The world production of crude petroleum and petroleum substitutes for 1942 is estimated at 2,208,000,000 bbl., or a decrease of 171,000,000 bbl. under 1941. Crude production is believed to have decreased by about 200,000,000 bbl., (about 9 per cent); while petroleum substitutes increased by 28,500,000 bbl., (nearly 20 per cent). The decline of crude output in the United States is estimated at 19,000,000 bb1.—less than 2 per cent; while that in foreign countries is estimated at 180,000,000 bbl., or more than 20 per cent. The marked decline abroad is due largely to losses in Venezuela and Colombia, where the lack of ocean transportation became the controlling factor, and in the East Indies and Burma, where military invasion brought about the destruction of the fields. The production of petroleum substitutes in 1942 apparently reached a new high figure of 7.5 per cent of the total world petroleum output. The important features of petroleum production outside of the United States are the changes that have taken place during the year in the supply of the Axis countries. In Japan the output for 1941 was estimated at 8,800,000 bbl., 5,500,000 of which were petroleum substitutes. It is believed that the output of synthetic oils during 1942 substantially increased, raising the total interior production of Japan to nearly 10,-ooo,ooo bbl. Also, during 1942 Japanese armed forces gained possession of oil fields having a normal peacetime output of about 78,000,000 bbl. per year. The production of these areas for 1942 is estimated at some 23,000,000 bbl., which indicates that Japan is now getting at least 33,000,000 bbl. a year, which exceeds by 8,000,000 bbl. Its

Jan 1, 1943

By Benjamin L. Miller

The essential differences expressed by the different speakers participating in this symposium concern merely the relative emphasis placed on the subjects that are commonly included under the term "geophysics" and the branches of science that form the basis for investigations in this field. In order to appreciate the present situation it may be profitable to briefly refer to a few historical matters. One can find almost countless descriptions of geological phenomena long antedating the introduction of the title of "geology," which has been credited to Richard de Bury in the fourteenth century. Interpretations, when they were offered, were generally pure speculation. Only toward the close of the eighteenth century do we find theories developed as the result of observations and tested by additional observations. It is difficult to select and give proper credit to the individual who was particularly responsible for turning geology into a distinctly observational science. william Smith, who has been called the "Father of English Geology," certainly represents the period when observation was the only method used. As he traveled through the British Isles, "sometimes 10,000 miles in a year," he was continually making notes of his observations. Geikie says: "His plain, solid, matter of fact intellect never branched into theory or speculation, but occupied itself wholly in the observation of facts." William Smith, with others of his time, definitely laid firmly the foundations on which modern geology has been built. Field and laboratory observations can no longer be said to constitute the sole basis for geologic contributions but we have not laid aside the methods of Smith and his followers. It is folly to underestimate the fundamental value of the observational part of geology in the present. The objection to purely observational geology is that it is mainly qualitative and not quantitative, general and not specific. No one can deny this charge and probably there are few who do not welcome every method or process whereby we can put aside generalities for definite established values. Physics is the science that has particularly come to the aid of the geologist in this respect. Contributions of PhYsics It is not the intent of the writer to enumerate or to evaluate all of the contributions to geologic advance in the field of. physics. A few only are used for the purpose of illustration, When Clarence King, Director of the United States Geological Exploration of the Fortieth Parallel, invited Ferdinand Zirkel to study 2500 thin sections of rocks collected from the western United States, the use of the microscope came into general use. Zirkel's report was published in 1876. He was not the first to use transmitted light for microscopic rock determination, some work having been done by Henry Clifton Sorby and others some years earlier, but he was the first to put into general use this method. We may well daim that this

Jan 1, 1946

By Paul A. Beck

IN several recent investigations1 ' considerable evidence was accumulated to show the predominance in various face-centered cubic metals of a certain relative orientation, corresponding to a rotation of 30" to, 40" around a [111] axis, between a matrix with a strong single orientation texture and grains growing in this matrix." This relative orientation was found to occur both in recrystallization and in coarsening, "secondary recrystallization", so that one is inclined to look for an explanation applicable in both cases. The abundance of growing grains in the described orientations proves that suitable "nuclei" are present in the matrix material and that they have the capacity to grow. The scarcity of growing grains in other orientations may be explained in one 'of two ways. Either the number of nuclei or the rate of growth must decrease strongly for orientations deviating from that predominating among the growing grains, Fig. 1. Both the "oriented nucleation" and the "oriented growth" theory found support in the literature. Because the frequency of nuclei as a function of orientation is in most instances not amenable to direct experimental investigation, a definitive decision is difficult to achieve. However, it is now known with great certainty that the rate of boundary migration is strongly dependent on the relative orientation of the two grains meeting at the boundary and that the orientation favored by high boundary mobility closely corresponds to that predominating in most cases of recrystallization and coarsening. Thus, it was found that, in general, the mobility is very low for boundaries between grains of nearly identical orientation, or for coherent twin boundaries. On the other hand, the boundaries between two grains of a relative orientation correspending to a [1111 rotation of 30" to 40" have the highest mobility in face-centered cubic metals. If a large variety of nucleus orientations are produced grow- by means of a highly inhomogeneous local deformation, nuclei close to the above orientation are found to grow fastest.z4 In view of this evidence and of the fact that the preferred orientation relationship is the same in recrystallization and in coarsening, the oriented growth theory appears by far the more promising one. Since the origin of nuclei in primary recrystallization is certainly different from that in coarsening, the occurrence of the same orientation relationship in the two processes would be difficult to explain on the basis of oriented nucleation. other advantages of the oriented growth theory are its capability of accounting for the often observed sharpening of the texture in coarsening, and its suitability for explaining the role in the formation of the ''cube texture,, of the most important variables, such as the degree of rolling, the penultimate grain size, and the time and temperature of the last anneal: No similarly consistent explanation of all these effects has ever been offered in terms of oriented nucleation. An important problem in connection with the oriented growth theory is the following: In the ce-c entered system there are four [111] axes and

Jan 1, 1952