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By Robert C. Stephenson

In 1954, a year when general industrial production declined, it is significant that industrial mineral products continued in high demand. Phenomenal growth of the cement industry, increase in filler-fibre markets such as for asbestos and diatomite, expansion of the gypsum industry, and the increasing production of agricultural raw materials all illustrate the vitality of industrial minerals fields. Pioneer development of new industrial raw materials-wollastonite as a current example-requires keen foresight, hard work, and tremendous intestinal fortitude. The present-day requirements of industry for rigid quality control and uniformity of raw materials have resulted in highly specialized

Jan 3, 1955

By E. Hoek

The stability of a rock structure depends primarily upon the extent to which fracture develops within the structure, The prediction of the extent of potential fracture, the first step in the study of fracture development, involves a knowledge of both the stress distribution in the structure and the criterion which governs rock fracture under various stress conditions. While a great deal of research effort has been devoted to the development of techniques for analyzing the stresses in mining and civil engineering structures1-3 and to the investigation of the fracture mechanism of rock 4-6 relatively little attention has been paid to the application of available knowledge to the solution of practical engineering problems. This paper describes a photoelastic technique for the determination of potential fracture zones in certain types of rock structures. A practical example, based upon a problem which might be encountered in designing the layout of deep-level mine excavations, is given as an illustration of the application of this technique. STRESS ANALYSIS AND ROCK FRACTURE In deciding upon the technique to be used for the solution of a problem involving the prediction of rock fracture it is necessary to consider: 1) What type of stress information is required to satisfy the fracture criterion for rock; anti 2) How this information can most conveniently be obtained. It has been established, both theoretically 4,7 and experimentally 5,6,8that the fracture of hard rock depends primarily upon the relationship between the algebraically greatest and the algebraically smallest of the

Jan 1, 1967

By Henry W. Turner

The following notes were taken on a trip through northern Korea in the fall of 1910. We started with about 19 Korean ponies, and as many Koreans, from Shin Anju, on the railway from Seoul to Antung. We passed through the ancient walled city of Anju, and thence up the valley of the Anju river. We then crossed over to the north into the Kalsan drainage, thence over another divide to the Chasung river, and finally reached the old Korean copper-smelting camp of Tong Jom— in all a distance by trail of about 200 miles. The return trip was made with ponies to Mampochin on the Yalu river, and thence' down the river in a junk to Antung. The route of travel is shown on the sketch map, Fig. 1.

Jan 1, 1913

By David H. Carlson, John H. Johnson

The paper presents background information, a description of mine characteristics that affect air monitoring techniques, and a review of Portable measurement techniques and instruments for gas and particulate matter sampling. A general review of the laboratory and field research being conducted at Michigan Technological University in the area of diesel emissions is presented. The facilities involved with this research are also described. These are the experimental mine, the diesel dilution tunnel test cell, the mine air monitoring lab (MAML), portable instruments, and the production mines used.

Jan 1, 1982

By Louis A. Riley

I DESIRE to submit, for the consideration and information of the members of the Institute, the following data, drawings, and tables, showing what I believe will be interesting information with regard to the diamond drill, and its uses in developing mineral lands. I would first say that the results given have been obtained during the past two years by means of two drilling machines belonging to the Lehigh Valley Coal Company, operating on their coal lands in the Mahanoy, Lehigh, and Wyoming regions. 1st. A tabulated statement, giving location of borings, date, progress, total cost, itemized cost per foot, etc. 2d. Section showing strata bored in Nos. 5 and 10 holes at Mt. Carmel, see Plate VI. 3d. Section showing strata bored in No. 19 hole at Hazleton, see Plate VI. 4th. Photograph and description of drill No. 2. From the first it will be seen that the total number of test-holes bored up to May 1st of this year is 24; 9 of these are in the Mahanoy region, 6 in the Lehigh region, and 10 in the Wyoming region, in all of which cores have been taken for the whole distance. The total distance bored is 9902 feet. The majority of the holes have been put down for the purpose of proving the lower veins of the coal series, and have had to encounter the harder rocks of the coal formation. Much of the distance has been through the lower conglomerates, going in some cases through the coarse egg conglomerate, the foundation of the coal deposit, and to the green sandstone and red shale which underlie it. These lower sandrocks and conglomer¬ates are among the hardest known to geologists, and present a formidable resistance to the exploring drill. This fact must be taken into consideration in comparisons of cost of drilling, and when considered will still further improve the very favorable results I am able to show in my statement of costs. In illustration, I will cite the work of one bit when boring in the upper or softer rocks of the Wyoming region, where 280 feet were obtained without resetting, while in the Lehigh and Mahanoy regions, in the lower and harder rocks, bits set with the same quality of diamonds would only bore from 3 to 20 feet before being worn out. In this connection it may

Jan 1, 1877

By D. L. Katz

The critical phenomena have been studied during the past century but our knowledge of the critical temperatures and pressures of complex hydrocarbon mixtures still is very limited. The critical temperatures and pressures of pure substances have been examined in large num-bers,20 and in great detail.11,17 No experimental determinations of the critical phenomena have been reported on such complex hydrocarbon systems as a reservoir fluid. The critical temperature is defined by Taylor18 as follows: "there is some temperature for each gas above which the gas cannot be liquefied. This temperature is called the critical temperature." The critical pres-sure of a pure substance is the vapor pressure at the critical temperature. It should be noted that these definitions refer to a given substance in the pure state and do not mean that the pure substance cannot be liquefied in the presence of a second constituent. The normal procedure for obtaining the critical temperature of a substance is to heat it in a glass tube 1,20 under pressure until the meniscus between the liquid and vapor phase disappears, although other methods, especially for mixtures, have been used. 11,14 However, when considering oil and gas reservoirs, it is more enlightening to consider a critical phe-nomenon that occurs when a mixture of oil and gas are compressed at a reservoir temperature until the meniscus disappears because the two phases become equal in composition. This conception, along with erroneous applications of the definition of the critical phenomena of a pure substance to that pure substance when it is part of a complex mixture, has caused confusion even among persons familiar with the classical theories.

Jan 1, 1938

By W. E. Bruce, R. J. Morrell, James Paone

This chapter is a partial summary of an investigation by the U.S. Bureau of Mines (USBM) made in response to a recent request by the Assistant Secretary, Water and Power Development of the U.S. Department of the Interior, for a comprehensive review of horizontal boring technology related to underground power-line installation. This review is concerned primarily with 3 to 36-in. diam horizontal holes from several hundred to several thousand feet in length. An electric power system consists of three essential functions: generation, transmission, and distribution. The generation component includes the generating station and step-up substation; the transmission component includes the transmission line and stepdown substation at typical voltage levels ranging from 69 to 345 kv for underground lines and 69 to 500 kv for overhead transmission lines; the distribution component includes the distribution line carrying the commonly used voltages of 120, 208, and 240 v, the distribution transformer, and the line to the service customer.l The Federal Power Commission reports that 1600 miles of underground transmission lines of 60 to 345-kv capacity are now in service in the United States. By 1980, it is estimated that approximately 3000 miles of trans- mission lines will have to be placed underground.2 The cost of burying electric transmission lines underground in metropolitan areas, approximately 30 miles from the center of each of the most populated cities, will exceed $1.5 billion with the methods now available. The wide spread in unit costs of overhead and underground transmission lines narrows as right-of-way costs for overhead transmission in congested areas increase. Improved methods of underground emplacement will certainly reduce this difference in costs and even further favor underground emplacement. Also, in the future, overhead transmission lines will probably not be permitted in highly built-up areas.

Jan 1, 1970

By David H. Browne

One of the most difficult problems in the chemistry of iron-ore, and one, the solution of which, so far as I am aware, has never been attempted, is the distribution, throughout a given vein, of Bessemer ore, and its relation to the formation of the deposit. In those hematite-mines in which both Bessemer and non-Bessemer ore occur, the sorting of the ore as it lies in the deposit becomes a problem of much economic as well as scientific interest. It would seem, from a superficial examination. or, indeed, from any examination not conducted for this especial purpose, as if high- and low-phosphorus ores were mixed in inexplicable confusion ; and a mining-chemist is very apt to fall into a system of adventitious analyses, taking first-class ore wherever he can find it, and overlooking its relation to the formation and position of the vein. I hope that a few notes which I present on this subject may be found worthy of consideration, as throwing a new light upon this obscure topic. During the last three years, while acting as chemist of the Lumberman's Mining Co., I have made some 3000 analyses of iron-ore from the Ludington mine at Iron Mountain, Michigan. These analyses were necessary in order to separate Bessemer and non-Bessemer ore which occurred intermixed in the deposit. During the last year, I attempted in several ways to find some reason or method in the distribution of phosphorus, and have finally become cognizant of the arrangement herein outlined. I have been obliged to confine my attention to our new mine, and, in that, to that portion wherein

Jan 1, 1889

By S. Razi

Injection luminescence of single crystals of rare-earth-activated CdS was investigated. Crystals of CdS:Nd, CdS:Er, and CdS:Yb, grown by the vapor transport technique, were suitably etched and hetero-junctions of Cu2S-CdS were fabricated on one side of the CdS substrate by chemical reaction. The device was then heated to 200°C in an inert atmosphere for 5 min. Static V-I measurements show that at low voltages (V < 1 v) the current is controlled by the junction, while at higher voltages the bulk Properties of the CdS substrate effectively control the current. Because of the large thicknesses no negative resistance was found. Reverse breakdown voltage varied from 5 v, for junctions that were not heat-treated, to 100 v, for diodes that received the proper heat treatment. The rectification ratio, measured in the range of 2 to 10 v, varied from 300 to 3000. Capacitance- voltage measurements indicate a weak dependence of the junction capacity on applied voltage. The capacity was found to increase appreciably with room light illumination. The variation of capacitance with frequency is indicative of a p+-i-n structure. An open-circuit voltage of 0.4 v was measured under an illumination of 100 mw per sq cm. Under forward bias, the bluish-green edge emission characteristic of CdS was observed. No sharp rare earth emission line was observed, which is in contrast to our results using ZnS:Tb, where, under high-voltage excitation, the rare earth emission was dominat over the lattice emission. The absence of rare earth emission implies that either the nature of the rare earth ion is different at the het-erojunction than in the bulk or the probability of energy transfer to the rare earth ion is small. RARE earth elements are playing an increasingly important role in the Synthesis of materials for a variety of purposes, e.g., solid-state lasers, color television screens, and so forth. Interesting systems result when wide-band-gap photoconducting lattices are activated with rare earths. A study of the lumines-

Jan 1, 1969

By M. L. Fuller

OWING to the nature of the die-casting process, freshly cast alloys are undoubtedly not at equilibrium from the standpoint of alloy phase relationships. After casting, therefore, they tend to undergo phase changes, with the ultimate effect of reaching a state of equilibrium at the aging temperature, beyond which no further change takes place. This phase alteration undoubtedly is one of the primary causes of the changes in dimensions and physical properties that zinc-alloy die castings undergo during aging. It is planned to report on this problem in a series of papers of which this is the first. The writers have made a study of commercial zinc die-casting alloys over a period of several years, utilizing the X-ray diffraction technic of determining the phase composition changes in the alloys. Up to the present, two principal phase changes have been observed which are capable of causing dimensional changes: (1) the segregation of secondary constituents from the zinc-base solid solution and (2) the beta aluminum-zinc decomposition. The latter is the subject of the present paper and studies on the former will be reported upon at a future time.

Jan 1, 1934

By C. Chiou, M. E. Fine

While Gunier-Preston zones are growing in Al-4.2 pct Cu at room temperature, Young&apos;s modulus, measured dynamically, increases about 0.4 pct. From the change in modulus with time the exponent of time in the rate equation for growth of the zones was deduced to be %. From a comparison of the rates of increase of modulus at 1, 28, and 42°C an activation energy of 12 to 14 Kcal per mole is computed. These findings support the idea that copper atoms are supplied along dislocation channels to growing zones. In alloys the elastic constants will be functions of the distributions of the atoms. If the degree of ordering or clustering is changed, one expects a corresponding change in the elastic constants. During age-hardening of aluminum-copper alloys at room temperature, the copper atoms cluster on 100-type planes in the aluminum lattice forming

Jan 1, 1959

By Walter H. Ortel, George B. Wallace

INTRODUCTION A greater understanding is required about the factors which control tunneling operations if we are to meet the expected demand for tunnels. Much of the needed information can best be achieved by the proper use of instrumentation and advanced engineering concepts. Tunnel measurements and their analysis may prove to be the key which will give the insight necessary to understand the relationship of rock, tunnel supports, and linings. There are three main areas which can be improved through the use of tunnel instrumentation. First, and of prime importance, is safety for men and the project. When unstable conditions occur, sets become distorted. Even without measurements, it is sometimes possible to tell when trouble is approaching. In effect, the set acts as a load cell. Distortions in the set indicate reinforcements may be required to maintain stability. Additional sets or rock bolts, if they are placed soon enough, may provide this stability. However, when large rock displacements occur in short periods of time, it could be too late. Figure 1 is an example of the difficulties encountered in stopping moving rock. To stop the movement and possible failure, large props were placed above the spring line and the massive concrete gravity buttress was constructed along the legs. Rock bolts from the buttress deep into the rock were also used in an attempt to stabilize the rock mass. However, this work is for a highway tunnel and eventually these props and buttresses must be removed.

Jan 1, 1971

By P. T. Gallagher, W. A. Oates

THE partial excess entropy of interstitial solutes in metals, SXS , has usually been interpreted as being principally vibrational ever since the initial statistical treatment of hydrogen in metals by Fowler and Smith-ells. The vibrational entropy is considered being due to the optical modes of the light interstitial atom. Little attention has been given to the magnitudes of the values of SXS&apos;. Leiser and Witte2 and Ebisuzaki and O&apos;Keeffe3 have noted that for hydrogen in metals Si is approximately constant for different metals. On the other hand if it is assumed that the interstitial solute is an isotopic defect then, as shown by McLellan, SXS should vary from metal to metal as follows: where S is the standard entropy of the solvent and Mi, M, are the masses of the interstitial and solvent atoms. respectively. Fair agreement with this equation was found for oxygen in silver and nitrogen in iron4 and for carbon in iron.= Ln a subsequent analysis of metal- hdrogen systems McLellan&apos; found a variation of $&apos; from metal to metal but not in a manner expected from the isotopic impurity equation. However, a possible correlation between the energy of solution, Ei, and sf was noted. Similar correlations have been noted for certain dilute substitutional solid Solutions 7, 8 and recently Kubaschewski 9 has demonstrated a correlation between integral heats and ex-

Jan 1, 1970

Cycle, automatic, in mine hoists, LV, 17. Cylindrical furnaces, repairing partly collapsed, XXXVI, 215-222. Dacite-porphyry, San Jose, Tamaulipas, Mex., percentage composition, XXXVI, 186. DAGGETT, ELLSWORTH: The Extraordinary Faulting at the Berlin Mine, Nev., XXXVIII, [liii], 297. Daiquiri, Cuba: geology, LIII, 3, 43. iron deposits, LIII, 40. Magdalena mine, LIII, 9, 23, 24. mines, bibliography, LIII, 59. situation of mines, LIII, 42. [ ]

Jan 1, 1918

ALABAMA. Aldrich, Aldrich, W. F. Anniston, Noble, A. E. Auburn, Brown, R. L. Bessemer, Abbott, C. E., Ferguson, V. Birmingham, Aldrich, T. H., Aldrich, T. H., Jr., Allen, A. W., Bowron, J., Burbidge, T. A., Crawford, G. G., Crockard, F. H., Davis, F. H, Dimmick, F: D., Ellis, E. E., Geismer, H. S., Hiller, E., Johnson, G. R, Ludwig, C. P., McCormack, G. B., McCrery, Peters, R, Jr., Phillips, W. B., Pill, J. R., RamSay, E. Coal City, Pattberg, 0. F. E-msley, Wil¬liams, E. P. Helena, Squire, J. Holt, Shook, J. W. Huntsmlle, Moss. Ironton, Hudson, J., B. Lehigh, Toulmin. Bock Bun, Garvin, J. M. Woodward, Wood¬ward, A. H.

Jan 1, 1910

By A. J. Lanza

The prevention of illness among the employees of the mining industry is especially important in view of the importance of the industry, the unsettled conditions of labor, which emphasize the economic necessity for conservation of labor, and for humanitarian reasons. The burden of chronic illness is altogether unwarranted and unnecessary. If the industry is to maintain its labor supply in an efficient manner and keep the standard high, it is essential that it make every effort to keep its labor in good physical condition. The basic principles underlying health conservation are the same for any industry, but they are here applied especially to the mining industry, and more particularly, perhaps, to metal mining, as it is with this phase of the industry that the writer is most familiar, and as it is conceded that metal mining presents more health hazards than coal mining. The first step in the prevention of illness lies in securing employees who are in sound health and free from organic disease. I do not mean that all men who go underground should be physically perfect, but they should be free from organic defects of the heart, lungs, and other organs, or from anatomical defects that would markedly increase their liability to accident. The number of men working underground in mines in this country whose physical condition totally unfits them for such work presents a situation that should not be allowed to continue, and which I believe is not equalled in any other industry in the country. There is but one way to secure men who come up to the required standard, and that is by a thorough physical examination before employment. I am fully aware of the objections felt toward such a procedure by many employers and employees. There is much to be said on both sides, but to any one who is at all familiar with the mining industry as it is today in this country, and who approaches the matter with an unbiased mind, there can be absolutely no doubt as to the necessity for physical examination. As a purely logical proposition this is self-evident, but there remains the further necessity of placing physical examinations on such a basis that they can be administered in a just and equitable manner free from the abuses and suspicions to which they have been subject in the past.

Jan 1, 1919

By Mehl, Robert F.

IT has been shown by numerous studies that the orientations of new metal crystals are determined by the orientations of the crystals in the original matrix, whether these new crystals are formed by recrystalliza-tion, by precipitation from solid solutions, or by transitions in the solid state. The orientations of crystals formed by recrystallization of cold-worked worked metals that bear preferred orientations are occasionally simply related to the initial preferred orientation; often, however, the relation-ship is not simple, but complicated and obscure in origin.1 The orientations of crystals formed by precipitation from solid solu-tions have been shown by many studies in this and other countries to be determined by the orientation of the crystals of the solid solution stable at the higher temperatures, though here again complicated cases have been found and no general theory is available .2 Related to this latter class

Jan 1, 1934

The ten-year "supply-demand relationship" tables in this chapter for various mineral and metal commodities have been adapted from Minerals in the U.S. Economy, compiled by the Bureau of Mines, U.S. Department of the Interior, published in 1975. Acknowledgment is made to the Bureau of Mines for compilation of the tables. [ ]

Jan 1, 1976

By John C. Branner

Inquiries are frequently made concerning the chalk- and clay-beds of Arkansas, usually with a view to the manufacture of Portland cement. The chalk-deposits were first described by Professor R. T. Hill in the annual report of the Geological Survey of Arkansas for 1888, vol. ii., pp. 153-162. Since the publication of that report I have visited localities then unknown, and have accumulated considerable additional information concerning these deposits, dl of which is brought together in the present paper. My report upon the clays of the State has never been published; only a few of the more conveniently available deposits are mentioned in the present paper. The Chalk-Deposits. Stratigraphic Position of the Chalk.—The chalk-deposits of Arkansas belong to rocks of Cretaceous age. The Cretaceous rocks are confined to a single definite area in Southwest Arkansas. Beginning on the Ouachita river, a little northeast of Arkadelphia, its southern or upper margin follows a line about five miles southeast of, and approximately parallel to, the St. Louis, Iron Mountain and Southern Railway from Arkadelphia

Jan 1, 1898

By Clifford S. Wilson

ScReened pipe is designed with the view of restraining the fine, free-running sands of the production zone from entering oil wells. Its successful use is dependent on a number of factors. The nature and effects of some of these factors can be determined through experiment and observation, but some of the elements that have a distinct bearing on the use of screened pipe can be evaluated only by estimate. The important subsurface conditions which affect the use of screened pipe are: 1. Depth of production zone. 2. Extent of production zone. 3. Reservoir pressure. 4. Character and relative quantity of oil and gas. 5. Character of sediments: a. Cossolidation of beds. b. Variation in beds. c. Grain-size gradation of sands. d. Free-running characteristics of sand from different levels. Aside from the use of mechanical equipment and tools, the measures to be taken in the installation of screened pipe involve: 1. Size of liner. 2. Length of liner. 3. Design and mesh of screen. 4. Portion of liner to be screened. 5. Manner of setting liner. 6. Preparation of or washing of the well before or during the setting of the screen. 7. Manner of bringing in the well. 8. Manner of flowing the well. Values applicable to the actual subsurface conditions that exist at any well can only be approximated. The accuracy of the estimate will be measured by the amount and quality of the evidence at hand and the personal factor of ability to interpret the evidence fairly, whether

Jan 1, 1933