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By Louis A. Mattson, Winthrop A. Rowe, John T. Cumberlidge, Victor M. Mejia

The parent ultramafic of Nickel Mountain is an alpine-peri-dotite. Compositional layering and late stage dunites suggest the intrusive crystallized in the upper mantle or lower crust. The ultramafic mass was fault emplaced in the upper crust, probably during upper Jurassic time. Soil, saprolite and silica boxwork nickeliferous ores were formed over the Nickel Mountain peridotite during the development and later destruction of the Klamath peneplane. A complex fault pattern was produced by irregular gravity displacements along fault surfaces during the relative uplift of Nickel Mountain. The majority of the ores occur in the fractured hanging wall of these gravity faults. Consequently, structure mapping is important for mining purposes. Ore types at Riddle are classified on the basis of MgO, Fe, and Si02 contents as well as textures. The chemical, mineralogical and textural differences of the various ore types reflect differences in weathering histories. Satellitic ore bodies occur peripherally to Nickel Mountain. These are erosional remnants of landslides and large gravity fault blocks from Nickel Mountain.

Jan 1, 1976

By John D. Erickson

The concepts of long-range, open pit planning presented here are not new. The new idea is how the factors that control the location of the final pit limits can be considered altogether as one large, simultaneous equation. The X, or unknown quantity that is being solved for, is a long-range pit design that fulfills the desired objectives. The objectives of a final pit plan are determination of the extent and location of ore reserves, the allowable stripping necessary to uncover the ore, the final pit surface intercept, final pit topography and the contained metal values in both ore and waste.

Jan 4, 1968

By Holbrook Botset

EXPERIMENTS performed in this laboratory on the flow of gas-liquid mixtures through unconsolidated sands have been described and discussed in an earlier paper.4 In these earlier experiments a definite relationship was found between the liquid saturation of a sand and its permeability to the liquid or gas phase. Furthermore, the nature of the sand, the permeabilities of the sands over a range between 17 and 260 darcies, appeared to have a negligible effect upon the saturation-permeability relation. Likewise experiments indicated that the viscosity of the liquid, or the substitution of an immiscible liquid for the gas phase, had only a very slight effect on the permeability-saturation relation. This con-clusion has since been definitely confirmed by the experiments of M. C. Leverett3 on the flow of oil and water through unconsolidated sands. The sands used by Leverett were of very low permeability (between 6.8 and 1.04 darcies), while the oil-water viscosity ratio varied between 90 and 0.057. Since the sands that constitute petroleum reservoirs are largely con-solidated, although of widely varying degrees of consolidation, it was desirable to extend the experiments on gas-liquid mixtures to consolidated sand. In the study of consolidated sands additional variables are involved, but for the initial experiments the only new variable to be intro-duced was the cementing material.

Jan 1, 1939

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Jan 1, 1938

By Charles Catlett

Having had charge during the past year of the operations of the New River Coke Company, the second largest, if not the largest, coke-producer in this district, my attention was called particularly to the yield of coke from the coal as coked in a bank of beehive ovens, as the record showed that this yield, while believed to be well up with the practice of the district, was much lower than the analysis of the coal indicated it should be. The coal is well known to many members of the Institute, and the scope of this paper does not include a discussion of its occurrence and development. It suffices to say that the New River district comprises the mines working on the coals of No. XII. or the Conglomerate Series of the Rogers brothers, which are located on New river and its tributaries, and which find an outlet for their product east and west over the Chesapeake and Ohio Railway. The New river through this section carries the drainage from an extensive peneplain in which it has formed a very striking and stupendous canon, probably the most striking east of the Mississippi river. The only practical access to this territory is by means of this canon and the Chesapeake and Ohio road, and the opportunities for development by other lines may be considered as nil. If it were not for the fact that this road, farther west, reaches and develops entirely different coals, which are found in other measures, the New River district might properly be spoken of (as is now done at times) as the " C and 0. field." For fuller information on the geology of the region, those interested are referred to the ery complete monograph on the subject by Mendenhall and Campbell of the United States Geological Survey. The rocks are the same as those which carry the more widely

Jan 1, 1900

By C. P. Walker

Determining the distance to remote objects by observing the time required for sound to traverse the intervening space is an old practice. Attempts have been made to use this method for determining the fluid level in oil wells but as far as the writer is aware it was not found to be practicable, because vibrations in gas in the audible frequency range do not travel as well and as far as low-frequency pressure waves, which are capable of transmitting a greater amount of energy than can be transmitted by audible waves. Wood, in his book "Sound," states that in a given medium the range of sound transmission will vary inversely as the square of the frequency. The fact that the sound from a whistle having a low tone has a much lower attenuation rate than that from a whistle of high pitch is well known. Also, the pressure waves caused by cannon fire often rattle windows at points so distant that no sound of the cannon is heard. In 1932 P. E. Lehr and H. T. Wyatt, of the Shell Oil Co., experimented with the principle of the concussion, or pressure-wave echo, method of determining fluid levels in oil wells. They released compressed gas into the top of the casing, thereby creating a pressure wave, which traveled down the well and back again. Their experiments proved conclusively that, with the proper apparatus for recording the echoes and determining the velocities at which the waves travel, the method could be used successfully for determining fluid levels in oil wells. Wells are often equipped with from one to three tubing catchers and these together with the top of the liner are frequently above the fluid. Each of these obstructions reflects a part of the pressure wave. In such wells there may be, therefore, as many as five pressure-wave reflections. Thus it is obvious that in order to identify the various reflections and to determine therefrom the fluid level in a well it is necessary to obtain a graphic record of these reflections.

Jan 1, 1937

By W. C. Hauber

Techniques previously published to predict the production performance of a water flood when the mobility ratio is not unity have been primarily restricted to a five-spot well pattern. When other types of well patterns are considered, the prediction of performance has required either a model study or a complex numerical solution of a multiple-fluid system with a high-speed digital computer. Simple methods are developed in this report for predicting the areal sweep efficiency and injectivity history of a water flood for arbitrary well patterns and mobility ratios. The effect of an initial gas saturation can be incorporated into this method of prediction. With the layer superposition concepts published by Prats, et al.,1 these methods can be used to predict the production performance of a water flood in a reservoir having a wide range in permeability. A reasonably good agreement is shown by comparisons of the results calculated by this method with those obtained either by model studies or by complex numerical solution of multiple-fluid systems. Therefore, it has been concluded that a reasonably accurate method has been developed for predicting the production performance of a water flood employing an arbitrary type of well pattern for any given mobility ratio. A medium-speed digital computer can be used in applying this method. INTRODUCTION Production performance of multi-fluid five-spot water floods can be predicted by the techniques published by Prats, et al.1 This technique takes into account the effects of initial gas saturation, mobility ratio and vertical variations in horizontal permeability. A basic assumption in applying this technique is that unit displacement efficiency does not vary with time after the passage of the flood front. Prats, et al. demonstrated that this assumption is valid for normal waterflood applications with small mobility ratios. To extend Prats' technique to other types of well patterns has required either an experimental model study or a numerical solution of a multiple-fluid system to describe the performance of an individual homogeneous layer. Sheldon and Dougherty2 presented an exact numerical solution employing any arbitrary well pattern. This technique is complex to apply, requiring (1) numerical solution of the single-fluid system, (2) conformal mapping of the streamlines and iso-potential lines to form a new grid network, and (3) a numerical solution of the multi-fluid system on the new grid network. A method was developed in this paper to approximate areal sweep efficiency and injectivity as functions of time for an individual homogeneous layer for arbitrary well patterns and mobility ratios. Analytic expressions were derived to directly apply this method to five-spot and direct line drive well patterns. For other types of well patterns, this method is similar to the approach of Higgids and Leighton,6 in that it utilizes the stream tubes and iso-potential lines obtained by the solution of differential equations when the mobility ratio is unity. However, this method is easier to apply than the Higgins-Leighton method since it does not require knowledge of the variation between oil and water relative permeabilities and saturation. Using the relationship between areal sweep efficiency, injectivity and the volume of water injected into an individual homogeneous layer as obtained by the method presented in this paper, and Prats' technique for the superposition of individual layers, one can predict the production performance of any water flood. ASSUMPTIONS GENERAL Basic assumptions made in this report are that fluids are incompressible and the layers are horizontal, homogeneous and uniformly thick. It is assumed that as water is injected into the layer, three distinct regions are formed —a water bank, an oil bank, and an unflooded region. Each region is assumed to displace other regions in a pis-tonlike manner, with only one fluid flowing in each region, so that there is no change in unit displacement efficiency with time after the flood front has passed in the reservoir. Therefore, the residual oil saturation in the water bank and the oil saturations in the unflooded region are constant throughout the layer. The ratio (F) of the bulk volume of a layer occupied by the oil and water banks at any time before oil breakthrough, to the corresponding bulk volume of a layer occupied by the water bank, is given' by the equation BREAKTHROUGH AREAL SWEEP EFFICIENCY To predict the behavior of any type of waterflood pattern, one must know the breakthrough areal sweep efficiency Eb(Mc,o, F) for the pattern for any water:oil mo-

Jan 1, 1965

By M. Van Siclen

THE outstanding fact in connection with dust disease in the United States at present is the growing recognition of its seriousness by state officials and by the more progressive operators of mining, metallurgical and allied industrial plants. The same may perhaps be said of labor in some of its better organized centers, but the average independent non-union workman continues, as of yore, to suffer the toll of disability and even of death from dust inhalation without realization of the source of his ill-being. Progress in the betterment of the handling of sufferers from dust disease and of the conditions creating dust hazards in mining and allied industries is pursuing a course similar to that of the now widespread campaign against accidents, in which the risk is more obvious, more severe, and was naturally recognized sooner. The coming on of dust disease is generally relatively slow and its immediate effects not infre-quently masked by or attributed to other diseases. Marked exceptions to this general rule have occurred in districts where the dust is particularly pernicious, such as the Rand and Joplin; yet such exceptions, unhappy in themselves, opened the eyes of medical men, and of those in other localities charged with the responsibility for the welfare of industry, to the much more widespread if less spectacular hazard existing from the inhalation of dust in all rock-excavating operations and all industrial operations creating inorganic dust, whether it be crushing and grinding, sand-blast-ing, granite-cutting, or what not. Advancement to date in the United States in prevention and treat-ment has been slow, yet the record shows that quantitative methods for determining the degree of hazard and means for decreasing it were being developed as far back as 25 years ago; and that more rapid progress may be looked for from now on. In 1908, in this country, F. L Hoffman?(1) discussed the mortality from consumption in dusty trades, especially brass foundries; and in 1913 E. R. Hayhurst(2) described the effects of inhalation

Jan 1, 1933

By W. Irwin Moyer

Two methods for the rapid valuation of oil properties are in common use. The one best known and most widely used is the "per barrel" value, based on the present daily production of the well, without regard to its past performance or the history of the sand or pool from which it produces. The second method is the "time to pay out," or the length of time required for a well to place itself upon the credit side of the ledger, from which time the returns from its production (less the operating expenses) will be clear profit. The time basis for valuation is also commonly used in the appraisal of an undeveloped lease. In most oil fields, it is not thought good business to invest in production that will not pay out in at least 4 to 5 years. Nearly all buyers (except in certain regions of very persistent production like the deep-sand territory of the Appalachian field) expect wells to pay out in considerably less time than this. Like the barrel per day price, the time necessary for a well to pay out has been determined for each field, so that one frequently hears a field or district referred to as having a certain time to pay out. This is considered the norm for that field or district and the buyer and seller base their value, to greater or less extent, on their belief in the accuracy of this time. The writer long ago became convinced of the inaccuracy of the barrel per day method, except when greatly modified for local conditions, such as the age of the wells, their economic limit, operating conditions in the field, the future price of oil, and the persistence of the sand as a producer. When so modified, this method becomes more of an analytic or predicted probable yield valuation. While the appraiser may not go through each step in a valuation based on future returnable revenue, his knowledge of the field and the local conditions surrounding his leases make it possible for him to estimate a fair sales value that, in many cases, will be a close approximation to the truth. This is quite different from the commonly understood barrel per day value, in that the conditions surrounding the sale of one lease or property at a fair market value may

Jan 1, 1922

By H. T. Mercer, A. C. Paulson

The composition of steel and the theory of its heat treatment have been so ably discussed elsewhere that it is unnecessary to go into the subject here. The purpose of this paper is to describe briefly the method of treating drill steel at the Copper Range mines, giving some of the troubles encountered and the manner in which they were overcome or corrected. To study the matter properly, it was necessary to devise a system of records that would show the actual underground performance of the drills. To illustrate this system, the records of the Champion mine are used, as it is at this mine that most of the work along these lines has been done. Reports from each drill machine are made daily by the shop and mine, and tables compiled from these reports show the footage drilled, steel broken, drills received and sent out at the shop, drills sharpened, and bits cut off. These data show what each machine or party is doing and whether the miners' supply of drills is kept up to date. There have been times when the supply of drills has been short and time lost by the miner in looking for drills. The daily records show the number and condition of drills on hand at all times. Under the old method of sharpening, the drills were heated in a coke furnace, the proper degree of heat being judged by color. Then they were sharpened in a machine, reheated in a second coke furnace where the proper heat was again determined by color, and quenched in water. While this method was fairly successful in the hands of a careful workman and for the solid steel used in the old piston drill machine, the introduction of the faster water machine, using hollow steel, produced changes both underground and in the shop. Much more was expected of the hollow-steel and hammer-type machine, with its improved method of rotation, but troubles due to breakage, burnt bits, uneven tempering, etc., at once appeared.

Jan 1, 1922

By John V. Beall

When the mineral seekers came, they brought romance, excitement and, too often, transitory riches. It has been so for uncounted centuries. While the rich ore lasted, living was high and money flowed-mostly out of town. The whole creation was like a circus. The headframe went up like the center pole of the big top. The reduction works was an ingenious affair; an opportunity for self-expression by the mining engineer on the job. When the high grade gave out or the bottom dropped out of the market, the whole show folded. Machinery was scavenged for the next location. About all that was left were the raw footings, like giantsteps on the hillside; and the headframe above the silent diggings. Mostly, the people went away too. Arizona Territory was like that at the turn of the century. It can still happen. But, in copper, the age-old pattern has been disrupted. From Mineral Park in the northwest to Chino in the east and Cananea in the South, a growing number of companies have emerged-large, stable, productive. Southwest copper is truly a mighty industry, accounting for one fifth of world new copper production. In this period of scientific development, changes are fast, often dramatic. But even mining engineers, or possibly more so because they have an intimate knowledge of the industry, fail to appreciate the evolutionary changes that have shaped Southwest copper into what it is today.

Jan 10, 1965

By Carlton D. Hulin

THE usual concurrence in time and space of intrusive igneous activity, favorable structural disturbance and mineralization, which is so manifest in the mineralized district necessarily indicates a close interrelationship between these events. Evaluation of available evidence leads to the recognition that an appreciable time interval exists between the emplacement of the igneous intrusive and the formation of associated ore deposits. During this interval known portions of the intrusive are completely solidified, highly differentiated magma fades are injected as dikes, and important faulting occurs, which may fracture and shatter the solidified intrusive body. The highly differentiated dike types could only have originated in some deep portion of an underlying plutonic body that had reached an advanced stage of magmatic differentiation. Appearing after these dikes, the mineralizing solutions may likewise be presumed to have originated at great depth. Certainly no source for these solutions can be found in near-by portions of the intrusive igneous body. The association of igneous intrusives and clustering ore deposits must be recognized as resulting from structural control. The emplacement and the subsequent solidification and cooling of the intrusive set in operation forces that are responsible for the favorable structural disturbances that control the mineralized district, The emplacement of the body of fluid magma weakens the crustal rocks to the extent that failure due to strains originally present in the rock body may occur. Faulting of any type and of any magnitude may be the result. Subsequently, owing to the change of state from fluid magma to crystalline granitic rock, volume decreases approximating 10 per cent may occur, with resultant shrinkage and collapse within the rock body. Following solidification, thermal contraction, induced by cooling of the rock body, causes a further volume reduction of 6 per cent. This thermal contraction, extending over a lengthy period of time, results in a succession of minor fault movements. These small fault movements, occurring progressively throughout the period of mineralization, are responsible for maintaining the permeability of the rock body, without which access of the mineralizing solutions and the formation of the ore deposits of the mineralized district would be impossible.

Jan 1, 1945

By William B. Potter

It is a time-honored custom in this, as in other kindred bodies, for the retiring President on giving place to his successor, after a year of official duties which have been the means of directing his attention in a more than usual degree to the work and interests of the Association, to report the results of his observations from this outlook, and the thoughts that may be suggested by the view. In looking out over the many fields of activity within the range of this Institute, the attention may be arrested by special features marking recent progress and development, or such as by their meager outline or lack of important detail stand in less pleasing contrast, or. even form unsightly objects in the view. It may be that the special field and particular work in which one is engaged will, when observed from the more distant standpoint, or in the light of the whole outlook of the profession, assume a different aspect or develop features of new interest and importance. In this way some special object may suggest to the observer a, fitting theme for the occasion. To others, again, an outline of the whole view may seem a more useful subject for study and review. All fields are examined and the wide horizon of the whole profession scanned to note and report whatever is new in knowledge and practice—the new permanent bench-marks that appear near the horizon designating ground definitely located; the stakes which mark reconnoissance into new territory, and even the prominent objects that faintly appear through the mist of the distant atmosphere, and which may serve later on as points of attachment for the advancing lines of survey into the unknown. And besides these, there is the progress of the work in older and nearer fields—what has been attempted, what accomplished,

Jan 1, 1889

By N. S. Stoloff, R. G. Davies

A study has been made of the efject oj different dislocation-precipitate interactions upon the temperature dependence of the flow stress of aged Ni-14 at. pct A1 alloy. It is observed that when the dislocations bow between widely spaced (-20004 coherent Ni3Al particles the flow stress decreases with increasing temperature in the normal way. However, when the dislocations cut closely spaced (-5004 particles the flow stress is independent of temperature from -100 to 600°C, due to a balance between softening of the matrix and an increase in strength of the particles with increasing temperature. The retention of strength at high tempera-tures of commercial nickel-base alloys, which are strengthened by the precipitation of a phase based upon Ni3Al, is thought to be due to the unusual strength properties of Ni3Al. The flow stress of Ni3Al increases continuous1y from -196"C to a maximum at -600"C. It is concluded from a series of thermal-mechanical tests that the sevenfold increase in flow stress over this temperature interval is due to a lattice effect and is not diffusion-controlled. The flow stress of precipitation- or dispersion-hardened materials depends on the resistance to dislocation motion within the matrix and the extra energy required for dislocations to bow between or to cut particles. If the dislocations bow between the particles or if the strength of the cut particles is constant with temperature, then the flow stress of the precipitation-hardened alloy must decrease with increasing temperature due at least to the decrease in elastic modulus of the material. There will be softening also from thermally activated cross-slip or climb, offering an additional degree of freedom for dislocations to avoid particles. For example, in the case of nickel containing a dispersion of thoria,' which most probably deforms by dislocations bowing between particles, the flow stress decreases by about 50 pct between 25" and 650°C. In A1-Cu alloys2 aged to produce the 8" precipitate, dislocations cut the particles, and the flow stress decreases by about 20 pct between -269" and 25°C. However, many commercial high-temperature nickel-base alloys, for example Inconel-X and Udimet-700, exhibit little or no decrease in flow stress with increasing temperature up to about 700°C. A characteristic feature of these alloys is that they are strengthened by the precipitation of a phase based upon Ni3A1. Guard and westbrook4 and flinn' have shown that Ni3Al (and alloys in which a third element such as molybdenum or iron is substituted for part of the aluminum) is unusual in that the hardness and flow stress increase with temperature to a maximum at about 600°C. For the flow stress of a precipitation-hardened alloy to be independent of temperature we propose that the particles must be cut by dislocations moving through the matrix and that the strength of the particle must increase with increasing temperature. Theories of precipitation hardening do not take into account the flow stress of the dispersed particles that are cut during deformation; the only dissipative process usually considered7 is the creation of interface within the particle and between the precipitate and matrix. The purpose of the present investigation has been to study in detail the temperature dependence of the flow stress of a nickel-base alloy strengthened by the precipitation of Ni3Al in two structural conditions such that when deformation occurs it does so by dislocations a) bowing between the particles and b) cutting the particles, respectively. A simple binary Ni-14 at. pct A1 alloy was chosen because considerable information is already available for this system concerning phase equilibria and precipitation reactions and rates.' Dislocation-precipitate interactions in the binary alloy should be similar to those in the more complex commercial alloys. In addition, the mechanical and physical properties of NisAl were studied in detail in the hope of elucidating the mechanism by which the strength increases with increasing temperature up to 600°C. EXPERIMENTAL PROCEDURE For the study of the effect of precipitation of Ni3A1 upon the temperature dependence of the flow stress, an alloy containing 14 at. pct A1 was utilized; a Ni-8 at. pct A1 solid-solution alloy was employed as a comparison material. Vacuum-cast ingots were hot-rolled at 1000°C and cylindrical compression samples, 0.20 in. diam by 0.40 in. high, were prepared from the 1/4-in.-diam rod. Specimens were recrystallized and solution-treated at 1000°C for 1/2 hr and then water-quenched. A preliminary study revealed that, when the Ni-14 at. pct A1 alloy was aged for 1 hr at 700°C, significant precipitation hardening was obtained, and that the structure was free from grain boundary discontinuous precipitation; an overaged condition was produced by annealing the aged specimens at 850°C for 1 hr. To circumvent the difficulties involved in the hot rolling and swaging of Ni3A1, compression samples,

Jan 1, 1965

By R. E. Zimmerman

WITH coal-preparation plants becoming more complex and containing widely diversified types of equipment and processes, it is necessary that considerable control be exercised in their operation. Rising mine costs make it imperative that close check be made of plant efficiencies to assure a minimum loss of coal to the refuse bank. Further, much of the coal sold today is sold on a competitive specification basis, and this makes it necessary to provide frequent analyses and inspections. Many ' plants are required to operate on a two or three-shift basis, and as a con- sequence an efficient organization is required to eliminate down time and provide for smooth low-cost operation. ORGANIZATION Probably the most important item for successful operation of a preparation plant is a capable, properly organized staff, with the individual workers properly informed and well trained for their particular jobs, clear-cut lines of authority among the supervisors and in general a standard operating procedure for most conceivable conditions that may occur. The idea of placing the older, partially disabled and generally incompetent coal miner in the cleaning plant, as was the practice on the earlier tipples, is entirely inadequate in a modern complex cleaning plant. The new plants require intelligent, alert, and reasonably educated men. With perhaps millions of dollars invested in an installation, it is poor business to use other than a well organized, well trained, and properly supervised force. Organizations naturally must vary with the size of the plant and local conditions; whether it is a central cleaning plant at a distance from the mine organization or one of several cleaning plants operated by the company. Smaller operations can be operated by a washery foreman, under the supervision of the mine superintendent or perhaps the "outside" superintendent. Large installations should have a plant superintendent either responsible to the mine superintendent or preferably, where possible, responsible to a preparation manager or engineer. A typical organization chart for companies operating in the anthracite region of Pennsylvania is shown in Fig. 1. Breaker (preparation plant)

Jan 1, 1950

By William L. Fink, Kent R. Van Horn

Aluminum forms not only binary compounds with most of the metallic elements but also forms many ternary or more complex constituents. Several of those occurring in the more important alloy systems have been identified under the microscope and the action of various etching reagents has been carefully studied.' The determination of the structure and composition of these complex constituents is a matter of some difficulty and little information is available. X-ray crystal analysis offers a promising method for the study of such constituents. First, and of considerable importance, is the possibility of recognizing the presence of a given constituent by means more positive than microscopic observation. Evidence can also be obtained concerning the nature and composition of the constituent in question and ultimately it should be possible, at least in some cases, to describe the structure including the relative locations of the various atoms. In this paper some results of an uncompleted study of the constituents of the aluminum-iron-silicon system are given and the methods employed are described. Inasmuch as iron and silicon are the chief impurities in aluminum, the constitutional relations of this system are of fundamental importance in the metallurgy of pure aluminum and its alloys; the system has been studied by several investigators and the more important contributions have been reviewed recently.² Fig. 1 shows the structure of the aluminum-rich alloys after prolonged annealing at 560" C., in accord with one of the most recent investigations.3 The ternary alloys examined in the course of the present investigation were all annealed at 550" or 560' C.; in fact, some of the specimens were the identical ones used by nix and Heath, who kindly supplied them for this work. Since the results

Jan 1, 1931

By W. O. Borcherdt

THE 650-ton underground mill of The Empire Zinc Company of Colorado (a subsidiary of The New Jersey Zinc Co.) serves the Eagle mine at Gilman in the Battle Mountain mining district of Colorado. The topography is rough, the mine and mill being under Battle Mountain and the adit entrance in the north wall of the canyon of the Eagle River, which is here a steel) gorge. The town of Gilman stands on a shoulder of the mountain at altitude 8975 ft., above sea level, along the Pike's Peak ocean to ocean highway and contains the company office and the usual facilities of a modern mining town. The railway contact is at Belden, altitude 8370 ft., at the bottom of the gorge directly below Gilman, where the westbound track of the Denver and Rio Grande Western Railroad is cut along the north bank and the eastbound track along the south bank of the river. A general description of the mine, mill and service facilities, with an account of the geology, character of the ore and methods of mining and milling having previously been published in a series of articles', this paper will discuss with as little repetition as practicable the reasons for building the mill underground rather than as a conventional structure, the methods of construction employed and the experiences gained in what is apparently the pioneer plant of this type and extent. There is a large historical background for underground plant construc-tion. From the dim past caves have been used for dwellings, stables, storage and shops. It was natural that where caves were available their many advantages led to their enlargement to suit convenience and where they were not available but the ground conditions, topography and, drainage were favorable, to the construction of artificial caves. In the vicinity of Epernay, France, extensive underground chambers protect the manufacture and storage of champagne-an intricate and ingenious application of chemical engineering-and in recent years these plants have been mechanized by the installation of conveyor systems. In the

Jan 1, 1937

By R. I. Jaffee, H. R. Ogden

AT the present time, there appear to be two conflicting opinions on the solubility of boron in titanium. P. Ehrlich' has indicated from X-ray diffraction work that boron is soluble in titanium up to TiB0.8 (17.8 wt pct, 44 atomic pct). The X-ray diffraction pattern for titanium was found in compositions up to TiB0.05_0.07 (1.1 to 1.6 wt pct); then, without a phase gap, superlattice lines appeared up to TiB0.8 On the other hand, Craighead, Simmons, and Eastwood' have estimated the solubility of boron in both alpha and beta titanium to be less than 0.1 wt pct, based on results of metallographic analysis. In some recent work done at Battelle, results were obtained which shed more light on the titanium-rich end of the titanium-boron system. Iodide-type titanium and high-purity crystalline boron were used in this investigation. The boron was prepared by hydrogen reduction of boron tri-bromide and deposition on a hot tungsten wire. The alloys were prepared by arc melting in an argon atmosphere of 10 cm Hg pressure on a water-cooled copper hearth. The ingots were hot rolled to strip at 850°C. Alloys containing up to 1 pct B could be hot rolled. Those containing 2 pct or more B could not be hot rolled. Metallographically, it was found that a second phase was present in alloys containing as little as 0.4 pct B, and that the quantity of second phase increased with increasing boron content. This is illustrated in Figs. la and lb, which show the microstructures of a Ti-0.4B and a Ti-1B alloy annealed in argon at 850°C. X-ray diffraction patterns of alloys containing 1 and 5 pct B revealed the presence of extra lines which correspond to the superlattice lines reported by Ehrlich.' However, no evidence was found of a shift in the lattice constants of alpha titanium indicating that there is very little, if any, solubility of boron in alpha titanium. This fact, coupled with the fact that the alloys were definitely two-phase, indicates that the extra lines are not superlattice lines, but are more probably the result of a second phase of a hexagonal structure almost identical in cell

Jan 1, 1952

By J. D. Doherty

That America's great coal deposits eventually will be our principal source of liquid as well as solid fuels is generally accepted. Moreover, the day when synthetic oil from coal will begin to supplement our petroleum supplies does not appear to be far off. The American petroleum industry has not spared effort or expenditure in its attempt to keep pace with the demand for oil, and recent production has exceeded expectations. However, the rapidly rising demand for liquid fuels plus the increasing difficulty of finding and developing the new oil needed even to maintain present production rates make it highly unlikely that oil from domestic wells can fully meet future oil requirements. Therefore, it appears that one or more of the following courses must be followed: 1. Curtail oil consumption. 2. Incr ase imports. 3. Develop new sources such as synthetic liquid fuels. All three courses may well be needed, as it is doubtful that any one of the three alternatives alone can satisfactorily solve the problem indicated by the prevailing trend in demand for oil. Curtailment of oil consumption is not a constructive policy, except where oil is being wasted or coal can be readily substituted as in stationary steam plants. Reduced oil supplies for most uses will curb our economic advancement and, in addition to inconveniencing consumers, will have a pronounced adverse effect on American industry. The oil-burner-manufacturing industry already has been dealt a hard blow. Shipments in the first 5 months of 1948 decreased 70 pct from those in the same period in 1947.1 The effect of a similar cut in the automobile industry can be imagined. A severe prolonged shortage of gasoline could seriously disturb our present economic well-being. It might be pointed out also that even the prospect of a shortage or lack of assurance for the future can discourage buyers of equipment, as occurred in the case of oil burners. An increase in our imports of oil seems to be a necessary expedient for the immediate future. Its advantages are that it will require a minimum of manpower and steel in a time of critical shortages and will conserve domestic reserves. Any major dependence upon foreign sources for our oil supplies should be avoided, however. Other nations are increasing their oil consumption more rapidly percentagewise than the United States and eventually will compete with us for the not unlimited world supplies. In peacetime, foreign countries might restrict ship- ments of oil to this country or impose exhorbitant prices. In the event of war, there is serious danger that such sources would be cut off, and American-developed oil fields overseas might even be used against us. Although synthetic fuels cannot relieve any oil shortage that might develop within the next year or two, an immediate start toward a substantial synthetics industry to supplement petroleum not only could help relieve shortages several years hence but also would help establish the much needed "know-how" for large-scale production. By assuring ample future supplies, such a start would permit sound planning by industries dependent upon oil and maintain or restore the confidence of prospective customers for oil-con-suming equipment. If it is agreed that domestic production of crude oil cannot be expected to meet future domestic demands, that oil rationing in general is undesirable. and that too great dependence on foreign oil should be avoided—and the weight of the evidence supports such conclusions—it is inescapable that commercial synthetic fuel production should be developed to supplement domestic petroleum supplies, which, of course, will furnish the bulk of our requirements for yean to come. Sources of Synthetic Oil The three principal sources of synthetic oil are natural gas, oil shale, and coal. A commercial plant using natural gas is under construction, and expansion of this industry is expected.

Jan 1, 1950

By R. W. Shoenberger, J. A. Grina, R. J. VanPelt

The many alternatives open to coke plant operators for improving overall coke quality and strength are discussed in this paper. Programs undertaken by US Steel research and coal operations during the previous ten years to improve coke strength are described. New techniques in use, or being considered for future use, are also discussed.

Jan 1, 1982