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By Guy R. Johnson

Like many other similar plants the ore-washer of the Longdale Iron Company has been a growth of years. In its principal features there is probably nothing new, as the type is that of the well-known " log-washer." Some of its minor details may, however, be of interest to those members who have to deal with the washing of large quantities of brown iron-ores, the principal gangue of which is clay. * Until 1883, the ore at Longdale, being of unusual purity, needed no washing, and was charged to the furnaces as it came from the mines—both lump and fine—the only attempt at cleaning being the' picking over a screen of 1½-inch iron bars, 3½ inches from center to center, set in the top of the bins through which the cars for the furnaces were loaded." In 1883 it was no longer possible to win the ore by open cuts, and regular underground work became necessary. It was very

Jan 1, 1895

By Fuad S. Maayeh, Robert J. Evans, Paul M. Yavorsky

A description and capabilities of the Mine Roof Simulator at the Pittsburgh Mining Technology Center is illustrated for testing longwall roof support equipment. This unique Mine Roof Simulator has the capacity to exert 3 million lbs. of compressive force vertically and 1.6 million lbs. of force horizontally to simulate loads on hydraulic supports typically found in longwall mining. The supports that undergo testing are instrumented with strain gauges and photoelastic coatings such that critically strained areas become readily apparent. These critically strained areas are redesigned or retrofitted with appropriate reinforcement and retested. A data base will be accumulated from several support designs that will lead to an optimized design that will have the potential to reduce downtime by malfunctions of supports and thus increase productivity. A typical test procedure and analysis is given for a two leg 350 ton shield along with a description for placement of strain gauges, displacement gauges, and hydraulic pressure monitors for critical sites.

Jan 1, 1982

By T. M. Anderson

Open pit mining at Inspiration began in 1947 after 32 years of underground mining. Two separate pits are included in the operations: the Thornton pit, which measures approximately 2500 x 2000 ft, and the Live Oak pit, which is 1500 x 3000 ft. The geographic centers of the two pits are approximately 4000 ft apart, and at the closest point, the two slopes are only 500 ft apart. Today, much of the open pit mining is being carried out in areas which were broken by earlier underground block caving operations; less than 50% of the total material moved has required drilling and blasting. In the solid or virgin areas, the, material ranges only from soft to medium hardness, thus simplifying drilling, blasting and loading operations. As a result, most mining costs and problems have been centered around truck haulage, truck maintenance and the ever-increasing length of the grade haul.

Jan 3, 1963

By J. H. Scaff, W. G. Pfann

The effects of impurities on the electrical properties of silicon are discussed in a companion paper by Messrs. Scaff, Theuerer, and Schumacher.' It was shown that an ingot of silicon which contained boron and phosphorus in certain concentrations consisted partly of p-silicon and partly of n-silicon2 and that the common boundary between these regions was the source of a photo-voltage. These features were ascribed to the segregation of boron and phosphorus during solidification of the ingot. Because of different rates of segregation the first portion of the ingot to freeze contained a molar excess of boron over phosphorus and hence was p-silicon. The last-solidified region contained a molar excess of phosphorus and was n-silicon. This paper is concerned with the microscopic examination of such ingots. The microstructures are rather unusual in certain respects and their study has helped to show how the segregation of minor elements modifies the electrical properties of silicon. The microstructures of ingots prepared from two lots of silicon, designated 1 and 2, will be described. These lots were obtained from the Electro Metallurgical Co. Both contain 99.8+ pct silicon, but they differ in impurity analysis. For each lot will be shown the microstruc-ture of a slowly cooled ingot, for which the time of solidification is 6 min., and that of a rapidly cooled ingot, for which the time of solidification is 2 min. The ingots were prepared from 45 g charges of silicon. When an alloy freezes a cored structure is generally produced because of insufficient diffusion to remove concentration differences established during freezing. As a result of coring the first portion of a crystal to freeze is usually poorer in solute than equilibrium requires, while the last material to solidify is richer. In a columnar grain, growth is principally unidirectional and coring can produce a concentration gradient along the entire grain. By carrying the picture of the coring process from a single grain to an entire ingot in which columnar grains are aligned more or less radially, one can easily see that a composition gradient could be established between the outside and center of the ingot. This, to a considerable extent, occurs during the solidification of a slowly cooled ingot of silicon. Slowly Cooled Ingot In slowly cooled ingots of both lots of silicon, columnar grains which are approximately radial in direction and longest at the top of the ingot enclose a region in which the shapes and align- ment of the grains are considerably less regular. The central region is last to solidify and contains cavities and inclusions. The sketch of Fig 1 illustrates some of these features, as well as others which will be described below. If a polished section of an ingot is etched in a mixture of 2 parts of 20 pct HF and 98 parts of HNO3 the p-n barrier becomes visible. The overall shape of the barrier in a slowly-cooled ingot is roughly oval, as may be seen in Fig 1. The proportion of n-silicon, that is, the region enclosed by the barrier, is considerably greater in ingots of lot 1 than in those of lot 2. A sample about 34 x 1/8 X 1/8 in. was cut from a slowly cooled ingot of lot 1 with its long direction extending from the top of the ingot to the porous region. Thus its upper half was psilicon, its lower half n-silicon. A longitudinal face was polished and etched in the acid mixture. The areas of interest are identified in Fig 2. A band of parallel markings extends across the sample in the columnar region. These striae are roughly parallel to the upper surface of the ingot and cross grain boundaries with only slight deviations. They are quite distinct in the n-silicon,

Jan 1, 1950

By John J. Borkert, Carl E. Gerity

In situ mining offers a new and proven method of exploiting sedimentary uranium deposits. The feasibility and economic evaluation of exploiting a uranium reserve by either open pit or underground mining should also include a similar study for in situ mining. This report compares the economics of mining several hypothetical uranium deposits at various depths, grades and reserve sizes by open pit and in situ mining. The evaluation process evolved establishing, where possible, common geological and logistical parameters to both methods of mining. The various assumptions that are unique to either open pit or in situ mining were also drafted, where possible, as equal and common functions to be used in each economic evaluation of the reserve models. After the various parameters were defined, they were programmed to an economic analysis of the various hypothetical uranium deposits by the selected mining method. From the vast array of cost evaluations, total capital and operating cost per pound U308 produced, DCF-ROI, and total net profits before State and Federal taxes were selected as the most meaningful results to compare. From the various geologic parameters used, it was determined that the economic viability of a mining venture is most sensitive to a depth-grade thickness ratio. The three selected evaluation products were plotted against the various depth-grade thickness ratios of the hypothetical uranium deposits. The results of the economic cost analyses show in situ mining generally to be a better method to maximize total net profits and to maximize return on investment.

Jan 1, 1979

By W. Kauenhowen

The production of petroleum in Germany during 1932 totaled about 1,608,558 bbl., a slight increase over the 1, 602,517 bbl. produced in 1931. A decline, as shown in Table 1, occurred chiefly in the Volkenroda (Thuringia) field. The total production of the other fields (salt domes), however. reached a new record, about 21 per cent above 1931. Table 1.—Oil Production of Germany by Fields and Oil Provinces, 1928-1932 (Barrels of 42 Gallons)" Salt Dome Province __________________________________________________|_________________________________________________________________________________________________________________________ 1928 274,323 322,742 679 46,319 644,021 644,315 1929 310,891 337,582 10,535 67,578 719,901 720,069 1930 586,404 427,539 100,716 72,485 1,186,969 29,806 1,220,296 1931 506,548 403,634 213,549 116,088 1,242,598 360,885 1,602,517 1932 769,405 366,982 230 979 130,711 1,498,077 110,481 1,608,558 " Official figures published in Germany are given in metric tons. For the above conversion into barrels a factor of 1 metric ton equaling 7 barrels has been used. Includes a very small production from Hcide, Holstein. c Includes a very small production from Tegernsee, Bavaria, and Bruchsal, Baden. Nienhagen-Hanigsen Field In 1932 the Nienhagen-Hanigsen yielded about 51 per cent of the production from the four German salt dome fields. During 1932 the productive area was again extended, chiefly towards the northwest in the so-called north district, to which the present drilling activity is confined almost entirely. Since the discovery of the north district in 1928, about 45 wells have been drilled in it, of which only two were

Jan 1, 1933

By AIME AIME

COUNCIL* PRESIDENT OF THE COUNCIL. JAMES F. KEMP NEW YORK, N. Y (Term expires February, 1913.) VICE-PRESIDENTS OF THE COUNCIL. S. B. CHRISTY BERKELEY, C; L.. R. V. NORRIS WILKES-BARRE, PA.. GARDNER F. WILLIAMS WASHINGTON, D. C.. (Term expires February, 1913.) KARL EILERS NEW YORK, N. Y.. WALDEMAR LINDGREN WASHINGTON; D. C.. BENJAMIN B. THAYER NEW YORK, N. Y. (Term expires February, 1914.)

Nov 1, 1912

By G. K. Dumbauld, B. E. Morgan

Kesults of laboratory investigations of the effects of drilling muds on oil well cements are presented which show that relatively large quantities of untreated muds do not seriously interfere with the setting of cement slurries, but that relalively small quantities of treated muds seriously retard the setting of cement slurries. Laboratory results also indicate that the harmful effects of contamination with treated muds can he counteracted by the addition of activated charcoal to cements. Also described is the successful use of cement containing activated charcoal for the placement of plugs in oPel hole after previous attempts with ordinary cement had been unsuccessful. INTRODUCTION The contamination of cement slurry by dilution with drilling mud has long been considered a cause of failure in oil well cementing. The cement slurry must displace the drilling mud from the annulus between the casing and the walls of the borehole. and it is probable that some mixing of the slurry and the mud occurs even under the most nearly ideal displacement conditions. Hole enlargement, failure to center the casing in the hole, and formation of gel structure in the drilling mud increase the probability of contamination. In some cementing operations, such as the placement of a cement plug in open hole, considerable mixing of the mud and slurry is likely. Many cement failures which can be attributed logically to no cause other than contamination of the cement slurry by the mud attest the need of a better understanding of this problem. Considerable attention was given to the problem of mud contamination of cements about 20 years ago.The effects of field mud upon cement slurries prepared with different amounts of mix water were investigated thoroughly, and the data obtained were invaluable in determining the causes of the high percentage of failure in oil-well cementing at that time and in bringing about improved cementing results. Since then, many aspects of the problem have changed, due primarily to advancements in cement and drilling mud technology. Today, several types of portland cement are used in well cementing and numerous chemical additives are used in drilling muds. An excellent report on the effects of drilling mud additives on oil-well cements was issued during 1951 by the American Petroleum Institute. Data in the report revealed that many mud additives, notably organic materials in relatively small amounts, produce a marked effect on the properties of cements. Prior to this time, little information has been available on the effects of chemicals commonly used in the treatment of drilling muds upon the properties of cements. Another aspect of the problem of mud contamination of cements, which has received no attention heretofore, is the possibility of producing a cement having properties unaffected by a reasonable amount of mud contamination. In view of the need for additional information on the contamination of present-day cements by currently-used drilling Muds, the investigation described herein was initiated Several years ago with a two-fold purpose: first, to determine the capacity of cement slurries to tolerate contamination by both untreated and treated muds without loss of ability to set and develop strength within a reasonable time; and, second, to investigate the possibility of enhancing the ability of cement slurries to withstand mud contamination by incorporating additives in the cement. The data for this study were obtained by mixing drilling mud with cement slurry and testing the resulting slurry-mud mixture for rate of set and development of strength. Also, several materials were tested for their possible improvement of the property of cement slurry to withstand mud contamination; these materials were tested in both contaminated and uncontaminated cement slurries.

Jan 1, 1952

By Helen L. Cannon

BOTANICAL methods of prospecting for metalliferous ores are based on the premise that deposits at depth may be reflected chemically in surface vegetation. For the past several years, on behalf of the Atomic Energy Commission, the U. S. Geological Survey has investigated on the Colorado Plateau the application of botanical methods to uranium prospecting. Results suggest that orebodies may be found under a considerable cover of barren sandstone through the absorption of uranium and associated trace elements by plants growing at the ground surface. Plant physiologists have demonstrated that uranium is a necessary nutrient for plant growth and therefore is present in all plants.' The amount present is small but measurable. The absorption of uranium by plants growing over ore deposits forms the basis, therefore, for a method of prospecting by plant analysis.

Jan 2, 1954

By F. W. Robinson

THE temperature coefficient of electrical resistance of pure metals is high and therefore the resistance increases rapidly with rising temperature. In 1871, Siemens suggested the use of this property as an accurate means of temperature determination. Owing to practical difficulties, particularly the contamination of the metal and consequent permanent change in its resistance and its resistance-temperature relation, this method fell into disrepute as a practical standard until revived later by Callendar and Griffiths, and subsequently by Holborn and Wien, all of whom showed that the earlier difficulties were not inherent in the method but incident to the mode of protection of the resistance coils. Following .the work of these investigators, the problem of temperature measurement by this means has been the subject of careful study and has now assumed an importance second only in practical adoption to the thermo-electric method. It is generally recognized, both here and in Europe, that the standard temperature scale should be the thermodynamic as it permits the evaluation of high temperatures on the basis of the radiation laws of Stefan and Bolzmann, of Rayleigh, and of Wien and Planck, on a scale consistent with that obtained by means of the gas thermometer at low temperatures. Lord Kelvin showed that only. a very small correction, amounting to about +0.7° at 1000° C.-almost within the limits of experimental errors-is necessary to adjust the constant-volume nitrogen thermometer to the ideal thermodynamic scale.

Jan 9, 1919

By W. R. Wardner

During 1928 low prices in the East greatly restricted the Atlantic market for California petroleum. The situation was made difficult by only partial control of production. The month of December is estimated in the figures presented here and it is hoped that the differences in the final figures will be immaterial. Daily averages are used throughout. Production Daily average crude production for 1928 was 633,942 bbl., very little more than 1927. Natural gasoline production was 35,453 bbl. daily and the supply (crude and natural gasoline) was 669,395 bbl. However, potential supply was 785,621 bbl. daily, 47,436 more than that of 1927. This is accounted for by more production being shut in so that 116,000 bbl. daily was conserved in 1928 which would otherwise have been produced. Fig. 1 shows production by months for 1928. It will be noticed that while crude production held fairly uniform from January to October, the

Jan 1, 1929

By E. Gilpin

Any estimate of the economic mineral value of an unvisited district is to the mining engineer largely a comparative one. If he knows that certain minerals characterize any given geological horizon he naturally draws upon his experience of the same ores as met by him cinder similar geological conditions. And if he has not had the personal experience, the investigation of the geology of a similar district as given in a trustworthy report enables him to lay a fair basis for conclusions. In a general way these conclusions are of value, and while they pronounce on the possible mineral fecundity of a given district, they

Jan 1, 1890

By Chi-Yuen Wang, Chaw-Long Chu

The time-dependent volumetric constitutive relation for a San Andreas fault gouge and a consolidated kaolinite are experimentally determined at confining pressures to 200 Mpa, under creep condition and at ultrasonic frequency. At any given pressure, the bulk modulus determined at 1 Mhz frequency is identical to the "elastic" modulus determined at a stepwise change of pressure. After the pressure change, there occur a time-dependent change of volume and thus the effective bulk modulus. The constitutive relations may be modeled by a standard linear viscoelastic medium with pressure-dependent moduli and viscosity. For the San Andreas fault gouge, viscosity increases from 2x10 13 poise, at 17 Mpa, and 10 14 poise, at 100 Mpa. For kaolinite sample, the corresponding values are 3x10 12 poise and 10 13 poise. These results imply that both stress and pore pressure in fault zones may show time-dependent variations in response to a change of state of stress, such as that occurring after an earthquake.

Jan 1, 1982

By Rudolph G. Wuerker

WITH the growing complexity of ore dressing processes and the diversity of equipment, efficiency control has become increasingly important in beneficiation. In the case of iron ore dressing, there have been sporadic attempts1-3 to establish the optimum separation for various ores so that grade and recovery would be readily predictable. But no rigorous statistical analysis and graphical presentation of such tests could be found in the literature of this country. Tests Made with Iron Ores Expanding upon existing methods of plant supervision and efficiency control, an investigation was started in the ore dressing laboratory at the University of Illinois on the applicability of distribution analysis to iron ores. A sample of crude ore was obtained from the Ohio mine of Cleveland-Cliffs Iron Co. at Ishpeming, Mich., consisting mostly of alternating bands of hematite and siliceous gangue, both about ¼ in. wide. The ore was heavily coated with limonite, which often filled the cracks.

Jan 7, 1958

By O. L. Kowalke

During the last few years the use of base-metal thermocouples has increased very considerably in various industries, due to the necessity for more precise control of temperatures. The base-metal couple has the advantages of being robust to a surprising degree, cheap as compared with platinum couples, sufficiently accurate for most operations, rapid in indicating changes in temperature, easily renewed or repaired, and of generating a much higher electromotive force than the noble-metal couples. There are, however, some factors, such as indicating and recording instruments, the insulation on the elements, the constancy and homogeneity of the wires, and the resistance to oxidation in the furnace, that limit the. Usefulness of the temperature-measuring device. It is the purpose of this paper to discuss in what manner these factors affect the usefulness of the couples.

Jan 9, 1919

By F. N. Speller

ASIDE from the Tuesday symposium on gases in metals, the Iron and Steel Division swung into action for the first time on the third day of the meeting with a discussion of iron and steel alloys. Dr. E. S. Davenport opened the discussion on Wednesday morning by presenting the paper written by himself in association with E. C. Bain and W. S. N. wiring on the equilibrium diagram of iron-manganese-carbon alloys. A written discussion by Mr. Scott showed qualitative agree- ment, but some quantitative disagreement. Messrs. Marsh and Sisco discussed the paper at length, pointing out non- agreement of certain conclusions with the phase rule. Dr. Krivobok, although differing with the authors on some points, stated that in his opinion the information collected would be valuable in the practical use of these alloys.

Jan 1, 1932

By A. Thies, A. Mezcer

The Haile mine is situated in Lancaster county, South Carolina, twenty miles south of Lancaster. The topography of the country is characterized by low hills rising generally less than two hundred feet above the many small creeks which traverse the surface. The road from Kershaw, the nearest railroad station, 3 1/2 miles from the mines, leads through woods with sandy soil and cottonfields. In many places it lies on the bare rock and shows that the adjacent covering of soil and earth is usually not more than one foot thick, and often less. This covering is to a great extent sand. Close by a bridge, about one mile from the mine, large round boulders of diabase may be observed. The country-rock seems to be exclusively talcose slate, with a general strike varying from N. 45' E. to N. 70' E. These variations may be seen in the immediate neighborhood of the mines, the large open cuts of which present exposures favorable to such ob-

Jan 1, 1891

By R. E. Hanneman, A. N. Mariano

In conjunction with the need for accurate volumetric data in the Fe-V system for subsequent use in calculating the high-pressure diagrams, room- and high-temperature X-ray diffraction measurements have been carried out. No previous measurements have been published on lattice parameters or volume changes associated with the a transformation for Fe-V alloys. The existing literature on lattice-parameter data for the a and s phases has been reviewed by pearson1 with considerable uncertainty indicated in the data. In order to obtain a good estimate of ?Va-? for thermodynamic calculations of the a D ?(bee D fee) phase stability, high-temperature vacuum X-ray diffraction measurements were made on an Fe-V alloy of 0.92 wt pet V. The term ?Va-? is the difference of molar volumes of the limiting solubilities of the a and y phases at any given temperature; these values can be calculated readily from the appropriate lattice-parameter data. The equipment used was a commercially available MRC (Materials Research Corp.) high-temperature X-ray camera which was fitted to a Norelco diffractometer

Jan 1, 1964

During 1918, the activities of the United Engineering Society, the Library, the Engineering Foundation, and Engineering Council Were deeply affected by the war and much important war work Was done in our building. The endowment of Engineering Foundation was increased to $300,000 by an additional gift of $100,000 from Ambrose Swasey. By bequest of Dr. James Douglas, the American Institute of Mining Engineers received an endowment of $100,000, the income of which Will be expended in the maintenance of its library (now a part of the joint library). The Library Service Bureau has gained steadily; its business for 1918 amounted to nearly $10,000. Indexing of current engineering literature has been undertaken in conjunction With the Founder Societies and the Index is being printed in their publications. This service has been extended to the Engineering Institute of Canada and the Canadian Mining Institute. The expense is borne by the Societies. In this connection the American Society of Mechanical Engineers has purchased the Engineering Index heretofore published by "Industrial Management." In June the Westinghouse and General' Electric Co. donated to the United Engineering Society their Patent Con¬trol Library of about 8000 volumes. Other noteworthy gifts Were a collection of 370 pieces relating to patent litigations, from Jesse M. Smith, and Dr. William Paul Gerhard's collection on gas engineering, transferred by the American Gas Association.

Jan 1, 1923

The Second Pan-American Scientific Congress will be held under the auspices of the United States Government in Washington, D. C., Dec. 27, 1915, to Jan. 8, 1916. The organization officers are John Barrett, LL. D., Director General of the Pan-American Union, Secretary General; Glen Levin Swiggett, Ph. D., Assistant Secretary General; the headquarters of the Congress are the Pan-American Union, Washington, D. C. The program of the Congress is divided into nine main Sections, which are given below with the name of the Chairman of each Section: 1. Anthropology, William H. Holmes, B. S., Smithsonian Institution, Washington. 2. Astronomy, Meteorology, and Seismology, Robert S. Woodward, Ph. D., Carnegie Institution, Washington, D. C. 3. Conservation of National Resources, Agriculture, Irrigation and Forestry, George M. Rommel, B. S., Bureau of Animal Industry, Department of Agriculture, Washington, D. C. 4. Education, P. P. Claxton, LL. D., Bureau of Education, Washington, D. C.

Jan 12, 1915