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By John Rudolf

Metropolitan Washington Airport Authority is currently undertaking the first Phase of Metro?s Extension to Northern Virginia. A wide range of tunnel options was considered for the Tysons Corner segment that involves about 20,000 feet of track and four stations. After consideration of many options that involved EPBM single track tunnels, NATM tunnels and large bore tunnel concepts for the entire Tysons alignment, the design now being progressed into construction involves two 520 meter (1,700 feet) long soft ground NATM tunnels with several hundred feet of cut-and-cover construction. The paper discusses the process that led to selection of the short NATM tunnels as the most feasible of the options considered for Tysons.

Jan 1, 2008

Adverse ground behavior events, such as convergence and falls of ground, are some of the most significant challenges and hazards in underground mines. Our goal is to work toward mine-wide, digital, and real-time three-dimensional geotechnical situational awareness and predictive capabilities in complex underground mining operations. This will benefit operators, engineers, and management by enabling them to develop a more proactive approach to ground control. To this end, and inspired by research in the field of remote sensing and autonomous robotics, this paper assesses the potential of mobile light detection and ranging (LiDAR) data acquisition for high-frequency, high-accuracy monitoring tasks in Global Navigation Satellite Systems (GNSS) deprived underground mines. Limitations of current monitoring practices are reviewed. Relevant academic and commercial developments in the fields of indoor mobile mapping systems (MMSs) and simultaneous localization and mapping (SLAM), robust autonomous robotic platforms, and automated remote sensing data processing are highlighted, and their current shortfalls are evaluated. To conclude, the ramifications of this work for the development of future autonomous underground mine monitoring solutions are discussed.

Jul 28, 2020

By T. P. R. de Jong, H. Harbeck

"This contribution reports recent mineral sorting experience and lists the opportunities of the newest generation of automatic sorters with a special focus on electromagnetic detection and Xray transmission. With the available sensor resolutions and actuator systems that are available today sorting of minerals down to 2 mm size and up to 250 mm lump size is technically feasible. In industry, ore as well as coal is still hand-picked and current automation potential only utilised in a handful of specific applications. Recently a number of technological developments took place that may increase sorting potential, save mill costs and lead to lower overall tonnage costs.They are:??High speed and high resolution sorting systems based on X-ray transmission imaging??High speed on-line image processing and further development of advanced data processing??Modular multi-sensor automatic sorting units (using one or more sensors such as colour, electromagnetic and X-ray in a single device)??Sensitive electromagnetic sensors for sorting based on differences in magnetic susceptibility and electric conductivityThe above enables compact dry separation, insensitive for moisture fluctuations and at high separation sharpness, as well as “electronic” high gradient magnetic separation for larger particles. Besides conventional X-ray transmission (XRT), dual-energy XRT (DE-XRT) is now being redesigned to meet the requirements of the mining industry. The mentioned technologies provide automatic dry separation of minerals and rock as alternative for conventional processing."

Jan 1, 2005

RMCMI members were welcomed at 12:30 p.m. by President McKeever. Following the luncheon held at the Conference Center, McKeever introduced Mr. Brooks Mitchell who is President, Human Resources Management, Inc. in Richardson, Texas. His topic was "Perspective on the Last Five Years. " The RMCMI Championship Tennis Tournament was held at the Marriott's Mark courts under the direction of Chairman Alan W. Czarnowsky and his committee members Mary Kay Aisenbrey and Jon Pratt. EVENING Tuesday, June 29, 1982 From 6:00 to 9:00 p.m. a Mini-Banquet was held for the young people of RMCMI members in the East Room of Lionsquare Gore Creek Lodge. The 6:00 p.m. time found RMCMI members gathered for a social hour at Marriott's Mark poolside, The Annual Speechless banquet followed at 7:00 p.m. in the Conference Center. After the dinner, President McKeever introduced the Golf and Tennis Chairmen who announced the prize winners. Robert W. Wilson, Chairman of the Nominating Committee, presented the following slate of officers for 1982-83: President, Vernal Mortensen; Vice Presidents-Colorado, Charles W. Margolf; Montana, Art K. Neill; New Mexico, Robert Diederick; North Dakota, James A. Brown; Utah, Bernard Bernstrom and Wyoming, John T. Goodier. It was moved by Loren V. Linville, seconded and carried that the elective ballot of RMCMI be cast for the officers as nominated. Mr. Wilson advised RMCMI that a successor to Mrs. Whiteside would be selected at a later date by the Committee and Executive Board inasmuch as Mrs. Whiteside's resignation had been received only ten days earlier and there had been no time for interviews. There being no further business, the meeting was adjourned at 9:30 p.m. MORNING SESSION Wednesday, June 29, 1982 President McKeever called the meeting to order at 9:30 a.m. in Salon A of the Marriott's Mark. New business included a report of the Auditing Committee and it was moved by Chairman Paul Hronich, seconded and carried that the Financial Report as prepared by the Treasurer, Mrs. Augusta Whiteside, be approved as submitted. The report of the Resolutions Committee was presented by Chairman Ed Ziolkowski who moved that certain resolutions be approved. The motion was seconded, carried and the resolutions follow: 1. RESOLVED, WHEREAS, in the year since the last convention of The Rocky Mountain Coal Mining Institute, the Institute and the coal industry have suffered the loss, through death, of the services of: John Chrystal Richard R. Fenner G. D. Grayer Albert M. Keenan C. E. Osborn Stanley C. Shubart George Sumers Cal Witmer NOW THEREFORE, BE IT RESOLVED, that there be recorded in the minutes of The Rocky Mountain Coal Mining Institute recognition of the passing of these members, who have so greatly contributed to the advancement of the industry, both nationally and in the Rocky Mountain area, and that a copy of this resolution be sent to the next of kin as evidence of the sincere and deep regard and sympathy of the members of the Institute. 2. RESOLVED, that in recognition of the faithful service to the coal industry generally, and to this Institute in particular, the status of Life Membership in The Rocky Mountain Coal Mining Institute be hereby conferred upon these members: John T. Leech George C. Lindsay A. George Setter

Jan 1, 1982

By B. E. Burakov, S. D. Lupal, O. A. R. Thalhammer, B. Saini-Eidukat

Electric-pulse disintegration is a mineral separation technique that liberates all mineral grains from any igneous or metamorphic rock irrespective of its lithology or grain-size distribution. The normal mechanical crushing of whole-rock samples is replaced by the rending effect of an explosion, produced by applying an electric current from a high-voltage power source. A voltage greater than the 100 kV necessary for the electrical breakdown of rock samples is achieved by using capacitors charged in parallel, but discharged in series. The sample sits in a water bath and the rapid distribution of electric pulses leads to an explosion which occurs preferentially along grain boundaries of the sample. Individual, undamaged mineral grains can be recovered in their original shape and form regardless of grain size. Examples are given of the liberation and concentration of important accessory minerals from different rock types. The examples show the recovery of diamond from two types of non-kimberlitic host rock in Popigai and Kumdykol in Kazakhstan and platinum group minerals associated with chromitites from the Konjdor intrusion and sulphides from intrusions in the Kola Peninsula in Russia

Apr 1, 1995

By I. A. Mutemererwa

This paper investigates the role of vertical integration between chrome ore mines and ferrochromium smelters in the location of ferrochromium production capacity in South Africa and Zimbabwe. Vertical integration is important in understanding the increasing competitive position of these two countries as observations show that an increasingly larger share of the global market has been coming from integrated producers. The paper argues that the increased vertical integration between mines and smelters in South Africa and Zimbabwe has led to a lower cost of chrome ore as an input compared with other producers. Underlying this hypothesis is the basic tenet that, more likely than not, production will take place where the costs are lowest. The paper concentrates on high carbon ferrochromium (HCFC) production in market economy countries (MEC). Using an ordinary least squares model, the study tests the relationship between low chrome ore costs and vertical integration shows a statistically significant relationship. These findings partially support the view that the control of sources of chrome ore is a major source of competitiveness. Keywords: competitiveness, ferrochromium (ferrochrome), ordinary least squares, dummy variables, vertical integration, southern Africa.

Jan 1, 2000

By D. C. Dahlin, W. K. O’Connor, G. E. Rush, C. A. Summers, S. J. Gerdemann

The Albany Research Center (ARC) conducted studies of mechanical activation by conventional and ultra-fine grinding techniques to enhance olivine reactivity in mineral carbonation reactions. Activated olivine is one of several solid feed materials used at ARC in reactions with carbon dioxide to form carbonate minerals. This paper compares grinding techniques via energy demand data and product characteristics, including particle size distributions, surface areas, full width at half maximum (FWHM) XRD analyses, and particle morphology by SEM analyses. Reactivity was gauged by percent conversion to carbonate in subsequent carbonation tests.

Jan 1, 2004

By L. J. Cabri, J. M. D. Wilson, R Lastra

An image analysis program can search for gold minerals in polished sections by scanning about 100 x 100 back-scattered electron images at a magnification of x400, allowing gold grains as small as 1 micrometre in diameter to be detected. Typically, a c.15 h overnight search of a product smaller than 45 micrometres will scan c.1 500 000 particles, providing data that are not easily obtained through manual operation of an optical microscope. The program locates grains of the correct brightness, acquires gold X-rays from them by wavelength-dispersive spectrometry, filters the data to remove artefacts and record the images and stage locations for subsequent retrieval. At the end of the run, the program allows the operator to verify and identify the grains found. Industrial studies at Canmet have included determining the nature of gold in cyanidation tailings, checking the mineralogy and size of gold grains in samples from an Indonesian Cu-Au concentrator and locating and measuring gold liberation and grain sizes in an ore

Jun 21, 1905

EXECUTIVE COMMITTEES OF LOCAL SECTIONS New York L. W. FRANCIS, Chairman, WILLARD S. MORSE, Vice-Chairman. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. P. A. MOSMAN, Treasurer. LOUIS D. HUNTOON. WILLIAM A. POMEROY. Boston HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. ROBERT H. RICHARDS, ALBERT SAUVEUR. Columbia F. A. THOMSON, Chairman. GEORGE W. RODDEWIG, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. R. S. McCAFFERY, S. H. RICHARDSON.

Jan 11, 1914

By S. Fuentes, J. Cáceres

"During the past fifteen years, mines utilizing the block caving method have improved performance and systematically reduced total mining costs.This paper describes improvements in mine design, mine planning, and mine management, including methods enabling the Chilean and international mining industry to ensure cost savings and productivity growth while using the block caving method. These improvements have encouraged the re-evaluation of underground operations at operating and closed open pits, and challenge surface mining applications as the only low-cost mining method. This paper describes a strategy to estimate the optimum open pit to underground transition time during the life of a mine. IntroductionDuring the last fifteen years, block caving mines have experienced huge changes in designs, planning and administration. These changes have permitted operators to drastically reduce costs, improve equipment productivity, and improve overall business performance. As a consequence of this situation, the block/panel caving mining system is challenging actual open pit operations to maximize the net present value (NPV)."

Jan 1, 2004

By J. Engelbrecht

South Africa?s re-entry into the fast moving and competitive global economy calls for some careful strategic planning and a good deal of co-operation between suppliers and end-users. The issues that need addressing are generally well known and include: ?South Africa was ranked 45th out of 46 i.r.o. productivity ?SMMEs contribute 1% to exports compared to 40-60% for the ?tigers? ?High unemployment ?Limited skills of the majority of workers ?Slow growth rate of the economy ?The vast majority of suppliers are not world-class ?The vast majority of suppliers are not export or marketing orientated. In order to survive, all parties, i.e. government, labour and business, will have to play their part.

Jan 1, 1999

(Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members) Members and guests who called at Institute headquarters during the period Feb. 10, 1917 to Mar. 10, 1917: F. H. Armstrong, Vulcan, Mich. G. Komar, Staten Island, N. Y. Franklin Bache, Philadelphia, Pa. H. M. LaFollette, LaFollette, Tenn. R. A. Bingham, W. Orange, N. J. H. Mortimer-Lamb, Montreal, Canada. G. S. Blair, Pittsburgh, Pa. J. S. Lane, New York, N. Y. Graham Bright, Pittsburgh, Pa. D. H. McLaughlin, Cambridge, Mass. C. A. Burdick, New York, N. Y. F. J. McMahon, Wilkes-Barre, Pa. Frederick P. Burrall, Dawson, Y. T. F. Oskar Martin, San Francisco, Cal. William Campbell, New York, N. Y. C. Mentzel, New York, N. Y. G. L. Carlisle, Jr., New York, N. Y. T. C. Merriman, New Haven, Conn. J. Murray Clark, Toronto, Canada. K. -A. Pauly, Schenectady, N. Y. Wayne Darlington, Philadelphia, Pa. , Francis R. Pyne, Elizabeth, N. J. Ralph W. Deacon, Elizabeth, N. J. C. S. Robinson, Youngstown, O. P. St. Jon Dixon; So. Porcupine, Canada. W. A. Scheuch, New York, N. Y. A. E. Drucker, New York, N. Y. Jesse Scobey, New York, N. Y. Lucien Eaton, Ishpeming, Mich. Dunbar D. Scott, Rochester, N. Y. W. E. Goldsborough, New York, N. Y. W. C. Smith, Elizabeth, N. J. C. Marshall Gravatt, Port Royal, Va. Charles Spearman, Mt. St. Patrick, Can. C. N. Hickok, Cleveland, O. . - Harold C: E. Spence, Duncan, Ariz. C. Vey Holman, Rockland, Me. M. M. Thompson, Morsemere, N. J. W. F. Jahn, Kirkland Lake, Canada. Benjamin F. Tibby, Salt Lake City, Utah. F. E. Johnesse, Boise, Ida. J. S. Unger, Pittsburgh, Pa. E. C. Johnson, Chicago, Ill.

Jan 4, 1917

By K. Short

Today?s modern mining operations have literally dozens of applications and systems generating data whose information very often, are not crossed or centralized for operational decisions. In remote locations, the information and situation awareness is typically limited to the location itself. In addition, access to that information is limited to a small, select group of personnel that have received training on how to interpret the results. When the situation affects another area of the mine then information is relayed to the applicable areas involved. Few workers have time to analyze the situation thoroughly, to see how it affects the mines symbiotic relationship within all areas of production. If the capability to correlate and measure events and situations that affect your overall key performance indicators are not in place, the opportunity to identify process improvement becomes more difficult.

Feb 27, 2013

By N. A. Eilertsen

This paper presents the results of intermittent study begun in 1956 by the Federal Bureau of Mines of yieldable steel arches and yieldable steel ring sets installed for support of development openings in metal mines. Observations were made of this type of support in several iron mines in the northeast and north-central states. The sets, both arches and rings fabricated in the United States, are made from a hot-rolled, cold bent, structural U-shaped steel section in two weights, 15 pounds and 21 pounds per foot. The lighter section is generally used, It is 4.41 square inches in cross section area, and the calculation is that a 6-foot length of this structural shape installed as a supporting column, will safely carry the same load as a Douglas fir post of the same length but of 22 times the cross-sectional area of the steel.

Jan 1, 1962

By C. E. Zebula, F. F. Aplan, R. S. Datta

The hydrophobicity of oil shale was found to follow the sequence R-5 > Mahogany >> Eastern. Further, hydrophobicity was found to correlate with the total organic carbon (TOG) content, decreasing with increasing specific gravity of raw oil shale pieces. Differences in hydrophobicity from piece to piece indicate that gravity preconcentration would be much more effective for Western than for Eastern oil shales. Purified kerogen concentrates and low specific gravity fractions (<2.0) of raw Western oil shale samples show critical surface tension of wetting values of [y]c = ~35 mNm -1, and for a kerogen concentrate from an Eastern oil shale [y]c = ~46 mNm-l. This infers that dust from oil shale mining operations can be suppressed by surfactant solutions similar to those used to suppress coal dust.

Jan 1, 1988

By Craig H. B. Leitch

"In describing the alteration of porphyry systems, the term ""secondary K-feldspar"" appears to be an oversimplification. A better term would be ""alkali feldspar"" alteration, because in actual fact the replacement feldspars show gradational changes from an albite, which is important in some systems, to an alkali feldspar containing minor orthoclase molecule, to true orthoclase.There are several textural varieties of secondary alkali feldspar present in the porphyry systems studied from British Columbia, Australia and New Zealand. These include, in apparent increasing order of alteration intensity: clear albite (An10); patchwork albite (Ab5-10); chessboard albite (An0-10) "" irregular albite "" (An0Ab100 to Ab90r10); untwinned "" anoralbite"" (Ab90Or-Ab70Or30); and orthoclase (Ab440Or60-Or100)·The exploration significance of these varieties of alkali feldspar is that their gradation in composition, from sodic to potassic, may be linked to a corresponding increase in intensity of alteration. Thus, there is a tendency for more sodic alteration feldspars to characterize weak, sub-economic deposits, or the fringe zones of stronger deposits; the more potassic alteration feldspars may provide an exploration vector toward more highly mineralized zones."

Jan 1, 1981

By Jason J. Crowder

Presentation Outline ? Introduction ? Costs of ground support and rehabilitation ? Why post-failure rock mass properties are necessary ? The Rock Mechanics Problem ? Present State of Modelling and Instrumentation in Mining ? Case Study Background ??Williams Mine ? Deriving Parameters for Modelling from Instrumentation ? Results from Case Study ??Back Analyses ? Discussion of Research Impact t Summary

May 1, 2006

EXECUTIVE COMMITTEES OF LOCAL SECTIONS New York L. W. FRANCIS, Chairman, WILLARD S. MORSE, Vice-Chairman. THOMAS T. READ, Secretary, Woolworth Bldg., New York, N. Y. P. A. MOSMAN, Treasurer. LOUIS D. HUNTOON. WILLIAM A. POMEROY. Boston HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. ROBERT H. RICHARDS,. ALBERT SAUVEUR. Columbia F. A.. THOMSON, Chairman. GEORGE W. RODDEWIG, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. R. S. McCAFFERY, S. H. RICHARDSON.

Jan 12, 1914

By A. M. Hearn, J. G. Roos

Energy consumption, being a large proportion of the input of the ferroalloy production process, can be measured in terms of the efficiency with which the energy is utilized and the effectiveness with which it is used. The efficiency of the usage of energy revolves around the specific consumption of the energy for the production of the alloy, which encompasses the thermodynamic aspects of the process and is more of a metallurgical function that will not be addressed further in this paper. The effectiveness with which the energy is utilized is determined by the optimisation of the electricity supply from the utility (in this case Eskom). The South African electricity supply industry is on the brink of considerable restructuring, implying changes in ownership, structure and regulation. In other countries, however, restructuring has often seen higher prices. Owing to the diversity of growth prospects in South African markets, Eskom is turning to new market management and generation strategies. In future, Eskom will develop pricing strategies to increase demand from attractive customer segments such as paper & pulp, iron & steel, aluminium, and other metallurgical industries. There will be a broader spectrum of product offerings, including dynamic pricing options and demand-side management incentives. In a future electricity market that will become more dynamic and demanding, it will become increasingly important for electricity consumers to optimise their electricity supply. There are many facets in optimising the electricity supply, which include optimal utilisation of the tariff, integrating energy cost management into the production planning process, implementation of demand-side management actions, modelling, scenario planning (.what-ifs?.), optimisation, maintenance scheduling coordinated with the tariff periods, etc. This paper gives consideration to the status of the development of technology at the manganese alloy works of Samancor at Meyerton, South Africa in order to increase the effectiveness with which energy is utilized.

Jan 1, 2004

COMMITTEE ON INCREASE OF. MEMBERSHIP. C. R. CORNING, Chairman. ADOLPHE E. BORIS, First Vice-Chairman. THOMAS T. READ, .Secretary, Woolworth Bldg., New York, N. Y. Vice-Chairmen. JOHN H. ALLEN, GEORGE M. COLVOCORESSES, RICHARD AL ATWATER, JR., ROBERT PEELS, GEORGE D. BARRON, CHARLES P. PERIN, A. CHESTER BEATTY, JOSEPH A. VAN MATER, J. PARKE CHANNING, ARTHUR L. WALKER. D. C. Bard, Howard Eckfeldt, Philip N, Moore, W. de L. Benedict, R. C. Gemmell, T. H. O&apos;Brien, John C. Branner, F. Louis Grammer, James J. Ormsbee, Palmer Carter, Ernest A. Hersam, Edward W. Parker, Allen J. Clark, Edwin C. Holden, John B. Porter, F. Crabtree, William L. Honnold, R. M. Raymond, George G. Crawford, Reginald E. Hore, Robert H. Richards, O. C. Davidson, C. Colcock Jones, LeRoy Salsich, E. V. D&apos; Invilliers, Eugene P. Kennedy, Frederick H. Sexton, James S. Douglas, Chester F. Lee, Henry L. Smyth, Walter Douglas, - Richard S. McCaffery, F. W. Traphagen, Howard N. Eavenson, James F. McClelland, Elton W. Walker. Milton H. McLean, Meetings of this committee were held at the Institute headquarters on April 18, and May 2 and 15. It was resolved that meetings shall be held monthly on the third Friday of each month.

Jan 6, 1913