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By Franc R. Joubin, D. H. James

Uranium exploration in the North Shore area of Lake Huron goes back to 1847 when J. L. LeConte, a distinguished American geologist, identified a pitchblende-like mineral which he called coracite from specimens sent from a locality north of Sault Ste. Marie. In 1948 a search for the LeConte occurrence resulted in discovery of the Camray field, some 70 miles north of Sault Ste. Marie. Prospecting the Camray field yielded about 30 pitchblende occurrences spread over approximately 200 sq miles. Almost without exception these discoveries consisted of narrow, short, pitchblende-filled fractures, within or along the contacts of diabase dykes cutting pre-Cambrian Archean granite and gneiss. Eight discoveries were diamond drilled and three were explored underground, but none proved to be of economic value. Uranium prospecting at this time spread far afield, and it was in 1949 that radioactive conglomerate was discovered in Long Township of the Algoma district midway between and 90 miles from Sault Ste. Marie and Sudbury. F. Joubin examined this discovery at that time but could not interest capital in its development.

Jun 1, 1956

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its, Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly anti in more usable shape.

Jan 1, 1918

By James K. Greenlee, David W. Wisecarver

It is estimated conservatively that some 14 billion tonnes of coal reserves in the United States exist in beds considered steeply dipping, i.e. at pitches or slopes in excess of 15O - a slope too steep for practical use of mobile wheel or crawler drive mining equipment. Past attempts to mine these steep reserves are limited owing to production difficulties and high costs, an expected result when mining of slopes must be done conventionally and mining on strike with mobile mining equipment is restricted because of limited cross sectional opening and operating room. In Europe, these adverse conditions are countered through the use of the longwall mining method. In fact, longwall mining is employed along pitches up to 55°. However, both operating and administrative - conditions in foreign steep seam coal mines differ from ours in that (1) the mine does not necessarily have to make a profit and (2) single entry development of retreat mining panels is acceptable practice. In the United States development can be done with a minimum of two entries only, provided belt haulage is not used during development.

Jan 1, 1981

The library of the above-named Societies is open from 9 A. M. to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 12, 1918

The library of the above-named Societies is open from 9 A.M. to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in. more usable shape.

Jan 8, 1918

By Cyril Stanley Smith

BeTa brass (consisting of approximately equal atomic proportions of copper and zinc) exists as a random solid solution at high temperatures, hut at low temperature< an ordered structure is stable, with the copper and zinc atoms occupying alternate sites on the body-centered-cubic lattice. On cooling, ordering commences at a temperature of 450° to 470°C., depending on the composition. The degree of ordering progressively increases at lower temperatures until it becomes virtually complete at about 100°C. The electrical resistivity of the alloy illustrates the changes clearly (Fig. I). This type of reaction has been a favored subject for study by physicists. An excellent summary of the theory is to be found in a paper by F. C. Nix and W. Shock1ey.l All published data on electrical conductivity, specific heat and other properties agree in indicating that the ordering reaction in beta brass takes place so rapidly that it cannot be prevented or even retarded by quenching&apos; With most ordered alloys, cold-working induces disorder and

Jan 1, 1943

By G. W. Powell

G. W. Powell (Ohio State University)—Appleton and Bever measured the quantity Es which, for a solid torsion specimen, is basically an average quantity. Es is the amount of energy stored in a solid torsion specimen strained to a surface shear strain of divided by the total number of gram-atoms of alloy in the specimen. It would seem more meaningful and rigorous to deal instead with the quantity which is the energy stored per gram-atom of an alloy uniformly strained to the shear strain . The purpose of this discussion is to demonstrate that as a function of y is readily obtained from the torsion data. radius of the torsion specimen, shear strain at the surface of the torsion specimen density of the alloy, atomic weight of the alloy, and total energy stored in unit length of the torsion specimen. The energy stored in unit length of an elemental tubular section of the torsion specimen is, as given by Appleton and Bever, where E is expressed as calories per gram-atom. The energy stored in unit length of the torsion specimen is

Jan 1, 1963

The Library of the above-named Societies is open from 9 A. M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information, will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will he sent more promptly and in more usable shape.

Jan 8, 1917

By R. D. MacDonald

The search for metalliferrous deposits in the Labrador-Ungava Trough of Canada dates from 1929 when non-ferrous minerals were the main quest of prospectors in this area. Many gossans, resulting from the oxidation of sulfides, were located and examined but none of these led to any orebodies of commercial value. However, such investigations did much to arouse interest in this area and fostered further mapping and prospecting. Since this early period in the history of prospecting in the Trough, the presence of iron ore deposits and potential iron producing sites has commanded the center of attention of exploration personnel. The iron-bearing rocks of southwestern Labrador have in recent years come into prominence as possible sources of iron ore of the beneficiation type. Exploration and development work has been carried on in concession areas granted by the Newfoundland Government to the Labrador Mining and Exploration Co. Ltd. and to the Newfoundland and Labrador Corp. In the course of evaluating its holdings in the Wabush Lake area (Fig. l), Labrador Mining and Exploration Co. has conducted geological, geophysical and diamond drilling programs.

Jan 10, 1960

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 12, 1917

By R. G. Carlson, F. E. Westermann

HOT pressing of powder particles has gained importance recently, since it affords a method in which high densities are rapidly attained. In a recent study on hot pressing of alumina powders, Mangsen, Lam-bertson, and Best1 have shown within the limits of their experiment, the validity the rate equation for densification in hot pressing, originally proposed by Murray, Livey, and Williams.2 i.e., where D = fraction of theoretical density, t = time, P = pressure and 77 is the viscosity, all in appropriate units. This equation was derived from earlier work of Shuttleworth and Mackenzie3 which is based on the closing of spherical pores under the action of surface tension. The integrated form of this equation yields a straight-line relation between log (1 - D) and t. Such conditions were found by Felten4 to be true only after extended periods of pressing. In an endeavor to quantitatively evaluate the exactitude of this equation in the initial sintering stage, i.e., prior to sealing of the pores, spherical anti-

Jan 1, 1962

By Cyril Stanley Smith

BeTa brass (consisting of approximately equal atomic proportions of copper and zinc) exists as a random solid solution at high temperatures, hut at low temperature< an ordered structure is stable, with the copper and zinc atoms occupying alternate sites on the body-centered-cubic lattice. On cooling, ordering commences at a temperature of 450° to 470°C., depending on the composition. The degree of ordering progressively increases at lower temperatures until it becomes virtually complete at about 100°C. The electrical resistivity of the alloy illustrates the changes clearly (Fig. I). This type of reaction has been a favored subject for study by physicists. An excellent summary of the theory is to be found in a paper by F. C. Nix and W. Shock1ey.l All published data on electrical conductivity, specific heat and other properties agree in indicating that the ordering reaction in beta brass takes place so rapidly that it cannot be prevented or even retarded by quenching&apos; With most ordered alloys, cold-working induces disorder and

Jan 1, 1943

Herbert C. Hoover, who became a member of this Institute in 1896 and who is now one of its Vice-Presidents, is the man who in 1914 extended a helping hand to Americans stranded in Europe at the outbreak of the war, and who made it possible for many such travelers to return safely to their homes. When his countrymen no longer needed his services, he turned to the Belgians, whose need of food had been presented to him. Engineers have been among his assistants from the first, and it is because we believe that members of his own profession will still be particularly interested in his work that we thus mention it in the Bulletin. A Minute adopted by the Board of Directors of the Institute, in which the Belgian Kiddies, Ltd., is recommended to the consideration of the members, immediately follows the Proceedings of the Meeting of the Board of Directors. With the thought that members of the Institute may be glad to read Mr. Hoover&apos;s own words in regard to his work, we print in full the speech

Jan 3, 1917

By Jose F. Agapito

This paper describes part of a geotechnical program which was instrumental in obtaining information for the design of large oil shale pillars. The work was carried out during 1971 and 1972 in the experimental mine of the Colony Development Operation. Colony is an oil shale venture formed between Atlantic Richfield Company, Operator; The Oil Shale Corporation, Cleveland-Cliffs Iron Company, and Sohio Petroleum Company to conduct research and development in mining and retorting of oil shale. The property is located in the southern edge of the Piceance Creek Basin in northwestern Colorado, approximately 250 miles west of Denver. Mining was conducted by the room-and-pillar method in a 60-ft high portion of the Green River formation at a depth of 600 to 850 ft. Pillar dimensions are approximately 60 ft by 60 ft. The mine site is in the eastern face of the canyon containing the Middle Fork of Parachute Creek. The distance from the mine to the side of the mountain varies from 500 to 1200 ft, and its height above the stream floor is approximately 700 ft.

Jan 5, 1974

By John D. Ridge, Robert C. Barwick

The quantities and destinations of the metallic ores and concentrates and partially or fully refined metals in international trade result from the interaction of many factors, of which geographic location is only one. How far the processes of concentration and refining are to be carried in the country in which the mining is done and what dictates the destinations to which the more or less completely processed raw materials will move are determined not only by present-day geologic, political, and economic conditions, but also by the patterns set up by these same conditions as they obtained in the past. The first generalization that can be made regarding trade in metal raw materials-one that affects the form in which the material is transported, rather than the patterns followed by that trade-is that concentration is carried out for all low grade ores, nonferrous or ferrous, in the country in which they originate. (Rule 1.) Economic considerations alone almost always require that this be done; only high grade iron, manganese, and chromite ores can be shipped as they are mined.

Jul 1, 1955

By R. H. King

The Automatic Extraction System (AES) was designed and built under a US Department of Energy Contract by the National Mine Service Co. in cooperation with the Lee Engineering Division of Consolidation Coal Co. The Pennsylvania State University, Mining Engineering Section, was contracted as an independent auditor of the AES performance. The AES had a rotating cutter drum like a continuous mining machine. But two hydraulically powered roof supports, four roof-bolting drills, a dust scrubber, a ventilation fan and ducting in the roof supports, semi-automatic control, an extensible chain conveyor, and other innovations led to the distinction "extraction system" as opposed to "miner-bolter" or continuous mining" machine. After design and assembly, the AES was field tested experimentally in an underground coal mine. The in-mine performance audit was preceded by a computer simulation of the potential production for a later comparison with the actual tonnage mined by the AES. This paper describes the results of an in-mine trial and assesses the production potential of the AES.

Jan 1, 1983

By Carlos D. da Gama, Charles R. Nelson

Griffith’s theory of brittle fracture, as modified by McClintock and Walsh to fit rock behavior in cases of failure by compression, has been successfully applied in various fields of rock mechanics. Extension of the Griffith&apos;s criterion to rock blasting problems may also be more representative of rock behavior than the simple consideration of a criterion of failure based on the dynamic tensile strength of the material. If consideration is given to pre-existing cracks within rock structure, occurring not only because of the discontinuous properties of rocks, but also as a result of drilling operations that normally precede blasting, those cracks can be propagated under the action of the dynamic stresses (radial and tangential) induced by the passage of the wave emitted by the explosion. Conditions for initiation and propagation of pre-existing cracks are deduced in terms of rock properties and explosives performance. Influence of the different variables governing the phenomenon is discussed after considering an actual example. Results seem to be well correlated with experimental evidence of radial cracking observed in blasting with high explosives acting within hard rock.

Jan 1, 1971

By W. E. Anderson, T. M. Brady

As part of a larger study to identify factors influencing the practical operating life of wire rope used on large draglines in surface coal mining, field trips to operating surface coal mines were made during late 1975. Wire rope performance information was obtained from personnel at 13 mine sites west of the Appalachians. Seventeen pieces of equipment, utilizing bucket sizes ranging from 30 to 220 cu yd (23 to 168 m), were documented. Draglines at large US surface coal mines can be represented as 120 machines having 60-cu yd (46-m3) buckets, moving 1.8 x 10[9] cu yd (1.4 X 10[9] m3) of overburden during 6650 hours of productive availability per year. Based on the limited field study, the calculated downtime resulting from rope-related causes averages 105.6 hours per year for each typical 60-cu yd (43-m3) dragline. The total loss in production from this source alone is thereby estimated at about 25 X 10[6] cu yd (19 X 10[6] m3) annually.

Jan 11, 1979

By W. H. Tuttle, H. R. Ahlquist, A. J. Carlson

Variations of the EVOP technique are accepted as the foun- dation in the development of Erie Mining Company&apos;s mining, concentrating and pelletizing complex at Hoyt Lakes, Minnesota. The basic one-variable- at-a-time technique served its purpose through the laboratory pilot plant as well as the full-scale production sized pilot plant. However, recognition by Erie Mining Company management of the potential of computer application and statistical experimentation in plant operation and testing led to acquisition of an IBM 1620 computer in 1961. Adaptation of established techniques in statistically designed experimentation and analysis of results is presented in actual case form including the following: 1. Determination and use of variance, standard deviation, standard errors; application of t-test in determining true differences between daily aver ages of product assays; formulation of quality control limits; determining sample size; and application of normality tests will be discussed. 2. Use of mathematical modeling and regression analysis for establishing mill storage conditions based on bin level indicator lights. 3. Polyvariable random balance design of a balling circuit test and resultant identification of primary control variables.

Jan 1, 1969

By H. I. Smith

WHEN Spain established colonies on the North American continent, some of her land grants, in what is now the United States, reserved to the Crown deposits of gold, silver, and mercury. Later mineral rights were reserved under some of the English Crown charters involving land in the eastern part of North America, with provisions for the payment of royalties thereon to the Crown. Reservation of mineral deposits to the United States Government was instituted by an ordinance of Congress on May 20, 1785, which applied to such deposits in the Northwest Territory, then north of the Ohio River and east of the Mississippi River, and provided that there should be reserved "one third of all gold, silver, lead, and copper mines, to be sold or otherwise disposed of as Congress shall hereafter direct." Little was known then of the mineral resources of the country; the Great Lakes copper region had just come into the possession of the United States by treaty and much of the western mineral land still belonged to France and Spain.

Jan 4, 1954