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By Marlion T. McQuinn

This paper will discuss the design, construction, and performance of the support of excavation on the Dulles East and West Automated People Mover Tunnels and Station projects. The elements of the system included drilled soil nails and rock anchors with reinforced shotcrete to the excavated face. We will discuss the geotechnical characteristics, design and construction considerations, loading criteria, construction techniques, schedule constraints, and performance of the support of excavation system. In consideration of the conference theme, there will be a discussion of the application of the real-time instrumentation monitoring program. The project team worked to design and install approximately 710,000 square feet of shotcrete and 19,000 soil nails/rock anchors as well as excavate over 720,000 cubic yards of rock materials within 15 months and in such a manner as to minimize the disruption to airport passengers and operations.

Jan 1, 2006

By P Tzeferis

An exploratory laboratory work was carried out on microbial leaching of poor non-sulphide nickel ores, not amenable to conventional mineral processing operations. The results have shown that domestic low-grade lateritic ores of limonitic or haematitic type are amenable to bioleaching by fungal strains of Aspergillus sp and Penicillium sp. Maximum nickel and cobalt recoveries achieved were 60 per cent and 50 per cent respectively. Losses of soluble nickel in the fungal biomass were found in the range 3 - 11 per cent. Chemical analysis of the leach liquors showed the presence of significant amounts of citric, oxalic and other organic acids, indicating the role which certain metabolic products of fungal activity may play in the process. Possibilities for future investigations are discussed.

Jan 1, 1997

[Council for 1994/95 President J.A. Cruise President Elect D.A.J. Ross-Watt Vice Presidents Senior P.D.K. Robinson Junior Dr N.A. Barcza Immediate Past President Dr H. Scott-Russell Honorary Treasurer D.A.J. Ross-Watt Members of Council J.P.W. Bennie Dr L.A. Cramer Prof. R.J. Dippenaar J.R. Dixon A.A.B. Douglas F.M.G. Egerton Prof. R.H. Eric B.R. Fleetwood Dr M.A. Ford Dr R.V.R. Handfield-Jones P.J. Knottenbelt R.P. Mohring K.C. Owen M.H. Rogers K.A. van Gessel P.M.T. White]

Jan 1, 1995

By William H. Langer

The annual consumption of sand and gravel aggregate in 2006 in the Phoenix, AZ metropolitan area was about 76 Mt (84 million st) (USGS, 2009), or about 18 t (20 st) per capita. Quaternary alluvial deposits in the modern stream channel of the Agua Fria River west of Phoenix are mined and processed to provide some of this aggregate to the greater Phoenix area. The Agua Fria drainage basin (Fig. 1) is characterized by rugged mountains with high elevations and steep stream gradients in the north, and by broad alluvial filled basins separated by elongated fault-block mountain ranges in the south. The Agua Fria River, the basin?s main drainage, flows south from Prescott, AZ and west of Phoenix to the Gila River. The Waddel Dam impounds Lake Pleasant and greatly limits the flow of the Agua Fria River south of the lake. The southern portion of the watershed, south of Lake Pleasant, opens out into a broad valley where the river flows through urban and agricultural lands to its confluence with the Gila River, a tributary of the Colorado River.

Jan 2, 2010

By P. R. Bradley

This paper is one of a series , dealing with mining methods and costs , sponsored and published by the U. S. Bureau of Mines . Papers of this series are written by engineers and executives of mining companies , at the solicitation of the Bureau , and in accordance with an outline prepared by Bureau engineers , for the purpose of securing uniform presentation and conformable data . The property of the Alaska Juneau Gold Mining Co. is situated near the city of Juneau , Alaska , in what is known as the Harris mining district . Wholesale mining operations have been adopted on a large scale and 10,000 to 11,000 tons per day of gold- bearing ore are mined and sent to concentrators near Juneau . In addition to gold , the ore yields 0.6 ounce of silver and 13.0 pounds of lead to each ounce of gold recovered .

Oct 1, 1929

By Alfred Bodenlos

El presente artículo describe la historia geológica pre-cretácica de la Cordillera Negra. En algunos intervalos predominaron los pantanos que dieron lugar a la formación de carbones. Luego, en el Valanginiano superior, la región estuvo sumergida, depositándose calizas delgadas. Los tufos que yacen sobre la secuencia de elásticos indican que hubo actividad volcánica a fines de este intervalo. Parte apreciable de los depósitos marinos del Cretácico medio está formado por calizas bituminosas obscuras.

Jul 1, 1957

By Kot F. Unrug

In the premining stage of engineering design, the only available data are obtained from core drilling. It is often not sufficient for a realistic design of strata control. During the development, an access to the geological formation is created, enabling in situ testing. Obtained data can be utilized accordingly to improve preliminary design. The available methods for testing are described with emphasis on their application for a longwall system. The optimum design ensuring continuous operation of the high output longwalls is critical because their downtime is very expensive. Optimization of ground control measures also has the potential for substantial savings by elimination of unnecessary support.

Jan 1, 1994

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICHARD, Vice-Chairman D M LIDDELL Secretary, 7 Wall St.. New York. N. Y. C. A. BORN, Treasurer JOHN V. N. DORR LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON. Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 12, 1917

By Jacek Paraszczak

L?exploitation rentable des gisements de type filonien constitue un problème important dans le contexte actuel de l?industrie minière québécoise. Les études effectuées depuis 1994 ont indiqué, que la technologie d?abattage mécanique utilisant l?outil hydraulique appelé « éclateur radial-axial » constitue une alternative intéressante par rapport aux méthodes conventionnelles par le forage et sautage. Les essais du prototype de l?éclateur ont prouvé qu?il est en mesure d?abattre les roches dures dans un environnement minier, mais sa performance dans les termes de masse du roc abattu dans une unité de temps a soulevé certaines doutes. Pour cette raison, une étude de préfaisabilité de l?éclatage en tant qu?une technologie d?excavation souterraine a été réalisée. Cet article présente quelques résultats des travaux effectués dans le cadre du contrat octroyé à l?Université Laval par le Ministère des ressources naturelles du Québec. Leur objectif principal consistait à comparer, pour les conditions des gisements filoniens, la productivité et les coûts des méthodes d?exploitation souterraine utilisant l?éclatage par rapport à celles conventionnelles. Deux variantes proposées de cette méthode ont été comparées avec la méthode conventionnelle sur le plan du coût (par tonne de minerai) et de la teneur de coupure de minerai d'or. Les études ont démontré que l?application de l?éclatage représente un potentiel de réduire ce coût, surtout dans les situations où l?abattage sélectif pourrait avoir lieu. Pour le cas de base on a trouvé, qu?il serait possible de réduire la teneur de coupure par la marge d?environ 16 ? 26%. Toutefois, les études de sensibilité ont démontré, que le coût dépend de façon important de la productivité d?éclatage, qui, pour sa part, varie beaucoup en fonction de paramètres du massif rocheux devant être abattu.

Oct 1, 2001

By AIME AIME

THE second meeting of 'the Open-Hearth Committee, 'sub-division of the Iron and Steel Committee of this Institute, was held at the Hotel Cleveland, Cleveland, Ohio; on Oct. 13-15. On Oct: 12, the Open-Hearth Superintendents visited the plants of the Youngstown Sheet and Tube Co. and. the Republic Iron and Steel Co. These men were courteously entertailled by the two companies and every facility for a thorough inspection was furnished. Luncheon was severed at the plant bf the Youngstown Sheet and Tube Co. The meeting was opened Tuesday morning with addresses by J. V. W. Reynders, President of the Institute, and Herbert M. Boylston, Chairman of the Ohio Section of the Institute. E. A. Whitworth, of the Gathmann Engineering Co., presided at the meeting and L. B. Lindeinuth was secretary.

Jan 1, 1925

By Arístides Sotomayor

El presente texto señala la importancia del oro a nivel financiero y minero ya que los inversionistas suelen utilizar este metal para obtener ganancias debido al mínimo riesgo existente en la pérdida de su valor comparado con otras divisas. Así, se estima que en el Perú, existen 480 unidades mineras de oro, de las cuales 28 concentran cerca del 90% de la producción nacional, como la Minera Yanacocha, Minera Barrick, Compañía de Minas Buenaventura, Consorcio Minero Horizonte, Aruntani y Aurífera Retamas. Entre las dos regiones que producen mayor cantidad de oro está: Cajamarca y La Libertad ( 38%) y la tercera región es Arequipa, seguida por Madre de Dios (9%).

May 1, 2016

By Edwin G. Sharp, Frank S. Gaunce, George M. Freeman, Denis J. Kemp, Eric Dulson, Paul Salmon, Ernest R. Hamilton, Carl E. Parden

"THE ECSTALL ZINC PLANT was built for the treatment of the Kidd Creek zinc sulphide concentrates. Construction proceeded throughout 1970-71, with operations beginning in April 1972. The two concentrate types treated differ principally in minor impurity and precious metal contents. Processing flexibility was required to allow efficient recovery of the by-products, especially cadmium, copper and silver. The conversion of the zinc sulphide concentrates to end products follows a sequence of operations that are common to most electrolytic zinc plants and typical of the ""Tainton- Jephson"" flowsheet.1. Roasting in air at an elevated temperature to convert the metal sulphides to soluble metal oxides (calcine) and sulphur dioxide. The sulphur dioxide is converted to sulphuric acid in a contad plant and shipped by train to market.2. Leaching of the calcine in spent electrolyte to effect extraction and recovery of zinc as zinc sulphate solution, leaving an insoluble residue.3. Purification of the clarified zinc sulphate solution by cementation with metallic zinc dust to remove impurities detrimental to the electro-deposition of zinc or detrimental to product purity. The solids from cementation are the starting materials for secondary metal recovery.4. Electrolysis of the purified zinc sulphate solution to reduce the zinc to the metallic state while coincidentally regenerating the sulphuric acid for recycle to the leaching step."

Jan 1, 1974

By S Paciornik

Computer-controlled microscopes with digital image acquisition and analysis led to the creation of the new field of digital microscopy. These techniques not only allow a certain degree of automation but have also brought new possibilities to microstructural characterisation. One of these new and promising possibilities is co-site microscopy, which links different kinds of information obtained from different microscopy techniques. The present work presents the development and implementation of a co-site microscopy methodology that combines images obtained by reflected light microscopy (RLM) and scanning electron microscopy (SEM). This methodology can improve the SEM analytical capacity by adding colour information from RLM. It involves the whole sequence, from image acquisition at the microscopes to the analysis of the phases using pattern recognition techniques. An automatic registration procedure for the two kinds of images was developed, allowing the adjustment of magnification, translation, rotation and pixel size, and the correction of local distortions. Thus, the images from RLM and SEM can be combined to build a multidimensional data set of each field, which can then be used in a pattern recognition approach to discriminate different phases. The methodology was tested with a copper ore sample, aiming at the discrimination of minerals that are not distinguishable with either RLM or SEM.

Jan 1, 2008

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. MI. LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BOHN, Treasurer JOHN V. N. DORR LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology. Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 8, 1917

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, Jr., Chairman EDGAR RICKARD; Vice-Chairman D. M LIDDELL, Secretary, 7 Wall St., New York, N. Y. C. A. BORN, Treasurer JOHN V. N. DORR - LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, -Mass. Inst. of Technology. Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND. Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. 0. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 1, 1918

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. M. LIDDELL, Secretary, 7 Wall St., New York, N. Y. JOHN V. N. DORR C. A. BOHN, Treasurer LEWIS W. FRANCIS Boston Meets first Monday of each winter month. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology, Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman OSCAR LACHMUND, Vice-Chairman LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON S. SHEDD

Jan 9, 1917

By Lawrence S. Darken

STAFF: Editor, Gerhord Derge Cornegie Institute of Technology Schenley Pork Pittsburgh 13, Pa. Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: J. S. Smart, Jr., President; C. C. Long, Past-President; K. L. Fetters, Vice President; T. D. Jones, Treasurer; R. W. Shearman, Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: C. L. McCabe, Chairman; H. L. Bishop, K. L. Fetters, J. J. Harwood, W. A. Krivsky, F. C. Longenberg, R. E. Lund, W. 0. Philbrook, L. L. Seigle, R. L. Smith, and F. L. Vogal. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division: C. L. McCabe, Chairman; R. E. Lund, Vice-chairman; D. H. Baker, Jr., W. A. Krivsky, R. A. Lewis, Paul Qusneau, A. S. Russell, R, E. Shinkoskey, W. W. Stephens, and M. E. Wadsworth. Institute of Metals Division: L. L.Seigle, Chair-man, P. A. Back, J. J. Backer, l.l. Bessen, J. 0. Betterton, Jr., J. 8. Clark, R. S. Davis, A. E. Dwight, R. W. Fountain, R. B. Gordon, C. D. Graham, Jr., R. W. Guard, J. C. Gurland, E. L. Harmon, J. J. Hager, A. A. Hendrickson, M. Harmon, J. N. Hobstatter, H. H. Johnson, Jr., H. 5. Kolish, R. R. Nash, T. N. Rhodin, R. H. Richman, W. Rostokar, P. G. Shawmon, C. W. Spencer, L. Slifkin, J. K. Stanley, C. D. Starr, R. Steinitz, and H. C. Stumpf. Iron and Steel Division: H. L. Bishop, Chairman; 2. E. Boni, F. C. Langenberg, J. B. Wagstaff, and T. V. Wainwright. Published bimonthly by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc., 29 West 39th Street, New York 18, N. Y. Telephone: PEnnsylvania 6-9220. Subscription PetroleumEngineers,$30 per year for non-AIME members in United States and North, South, and Central America; 332, foreign; $5 for AlME members. Single copies, $4.00, single copies foreign, $5.00. The AlME is not responsible for any statement mode or opinion expressed in its publications . . . Copyright 1%1 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address; AIME New York ..Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts.. .Second class postage paid at New York, N. Y., and Ann Arbor, Mich. Volume 221, Number 4.

Jan 1, 1962

By A. Fawcett, B. C. Dyer

Abstract - The basis of the tomographic velocity imaging technique is briefly described and an application of the method to detect and image a cross-section through a chromite pod is presented. Using the chromite application as an example, the relative costs of tomographic data acquisition and processing are compared with those of diamond drilling to obtain similar resolution. A number of different tomographic survey configurations and the potential role of the method in surface and underground exploration are discussed.

Jan 1, 1994

The annual General Meeting of the Branch was held in the St. Helena Club on Wednesday, 4th August, 1971 at 8.00 p.m. Mr N. A. Honnet (Immediate Past Chairman) was in the chair. There were also present Mr V. C. Robinson, President of the South African Institute of Mining and Metallurgy. Nine Fellows: Messrs J. R. F. Handley, C. J. Isaac, J. Lorenzon, J. M. Meyer, C. Mostert, D. A. Smith, S. L. S. Swart, I Thomas and R. G. Williams. Five members: Messrs R. Campbell, A. H. Edwards, K. Pearce, G. P. Rundle and R. B. Sutherland. Five graduates: Messrs J. E. Andrews, E. J. Shillaber, M. H. Smith, T. R. Stromsoe and D. J. van Niekerk. Two associates: Messrs A. Paschalides and D. S. Robinson. Eight visitors. Total present: Thirty-one. MINUTES OF THE PREVIOUS GENERAL MEETING As the minutes of the General Meeting held on the 16th June, 1971, had not been published in the Journal, the Chairman moved that the adoption and discussion thereof be deferred to the next General Meeting. This motion was adopted unanimously. The minutes of the General Meeting held on the 10th February, 1971, were taken as read. The adoption, which was proposed by Mr D. A. Smith and seconded by Mr J. M. Meyer, was carried unanimously. At Mr Honnet's request, Mr V. C. Robinson took the chair during the presentation of the Chairman's Annual Report. CHAIRMAN'S ANNUAL REPORT 1970/71 1970/71 Committee-Office Bearers: Chairman - J. N. Saunders Vice Chairman - G. Y. Nisbet Immediate Past Chairman- N. A. Honnet. Due to the sudden retirement of Mr J. N. Saunders, the committee, at a meeting on the 3rd February, 1971 elected Mr G. Y. Nisbet as Chairman with Mr J. M. Meyer as Vice Chairman. After the transfer of Mr Nisbet to C.D.M., the committee, as a meeting on the 12th May, 1971, decided that Mr Meyer hold the Chair in an acting capacity for the remainder of the year. Committee members: Messrs C. J. Isaac, J. G. Kirchener, L. O. W. Leimer, R. S. Pearson, I. G. Thomas and A. von Holdt. Transfers of several office bearers and committee members resulted in Messrs J. M. Meyer, D. N. Smith and G. C. J. Young being co-opted onto the committee.

U.S. Gold Commission Established. - The President, with the authorization of Congress, has named a gold commission made up of 17 individuals, most of them Government officials, to study U.S. policies related to the role of gold in domestic and international monetary systems and report its findings and recommendations to Congress. U.S. Lead Exposure Ruling. - On June 29, the Supreme Court upheld the Government's right to set lead exposure levels for employees at the workplace. The Court ruled in favor of the Occupational Safety and Health Administration (OSHA) in a challenge by a group that alleged that OSHA had failed to conduct a cost-benefit analysis prior to issuance of the lead standards. It was the Court's contention that Congress did not require such an analysis when it empowered OSHA to establish workplace standards. The petition to the Court was made by the Lead Industries Association Inc., Battery Council International Inc" American Iron and Steel Institute, St. Joe Minerals Corp., and other lead mining and consuming firms.

Jan 1, 1981