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By Rick Ellman, Ian Chaney

"The Hampton Roads area encompassing the Norfolk, Virginia Beach and Newport News metropolitan region experiences some of the worst traffic congestion in Virginia. With continued growth of the ports and increasing demand, the Virginia Department of Transportation (VDOT) initiated the Downtown Tunnel/Midtown Tunnel/MLK Expressway Project, a complex undertaking critical to addressing the Hampton Roads area’s transportation needs. The project is a $2.1 billion Design/Build/Finance/Operate (DBFO) endeavor most notably involving the construction of a new two-lane vehicular tunnel utilizing the Immersed Tube Tunnel (ITT) method. The tunnel will pass under the Elizabeth River parallel to the existing Midtown Tunnel between Norfolk and Portsmouth, Va. It will be the largest design-build project constructed in the history of the Hampton Roads District.The New Midtown Tunnel will extend approximately 6,450 ft (1,966 m) along the north side of the existing tunnel where it ties into the existing Midtown Tunnel approaches in Norfolk and Portsmouth. It is being installed in a pre-excavated trench of which approximately 2,250 ft (686 m) required bracing on the Portsmouth side and approximately 1,000 ft (305 m) required bracing on the Norfolk side. The remaining 3,200 ft (975 m) of trench excavation was open cut dredging with laid back side slopes, optimized to reduce dredging, disposal and backfill quantities while also reducing the risk to the existing tunnel. The braced excavation portions of the tunnel alignment were divided into distinct segments which include: Portsmouth Approach Boat Section, Portsmouth Approach Cut-and-Cover Section, Portsmouth Dredge Section, Norfolk Dredge Section, Norfolk Approach Cut-and- Cover Section and the Norfolk Approach Boat Section. All “approach” excavations were performed in the dry and all “dredge” excavations were performed in the wet. Eleven ITT segments are being fabricated in the Sparrows Point Dry Dock facility in Baltimore, Md., and each 14,000 ton (12,700 tonne) segment is being towed approximately 220 mi (354 km) to the site. The ITT segments will extend under the Elizabeth River, with the deepest crossing 90 ft (27 m) at the Federal Navigation Channel. Once beyond the channel limits the ITT rises at an approximate 4.5% slope. Controlled screeding and element lowering operations will be performed primarily from floating barges."

Jan 1, 2014

By Goudschaal Mark R.

"The Museum of Science and Industry U-505 Submarine Relocation project in Chicago, IL consisted of building an underground reinforced concrete vault (37' deep) for the Museum's new U-505 exhibit. This WWII submarine was captured in 1944, had been located outdoors at the Museum since 1954 and was lowered into its new exhibit area in 2004. A unique combination of earth retention, water cut-off and underpinning systems allowed a forty-two foot (42') deep excavation underneath th is historic museum. The museum - originally built in 1893 for the Chicago World's Fair - was closely monitored for building movements throughout construction. The underpinning systems, construction activities and monitoring results are presented herein. IntroductionThe historic U-505 German submarine at the Museum of Science & Industry was restored, moved approximately 1,000' and then lowered into its new indoor home (Figures 1, 2 and 3). The new underground exhibit opened this year celebrating the 61st anniversary of the German submarine's capture on June 4, 1944. On this historic day, Captain Daniel V. Gallery, a Chicago native, led the Navy in the siege of this submarine near the coast of Africa. This U-boat was the only German sub captured by the United States Navy in WWII and the Enigma machines, codebooks and publications recovered from the sub helped the war effort."

Jan 1, 2005

By James Westfield

A brief resume follows of some recent activities of the Division of Coal-Mine Inspection that have had a favorable effect on health, safety, and the reduction of injuries at coal mines: 1. The Federal Mine Safety Code for Bituminous-Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines on July 24, 1946, after consultation with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors during their inspections of bituminous-coal and lignite mines as a basis for determining the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior October 8, 1953, following further consultations with representatives of management and mine workers, and was incorporated by reference in the 1952 and subsequent bituminous-coal wage agreements. The agreement of May 29, 1946, between the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bituminous-coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. The inspectors were active in making prompt investigations of hazardous mines that had been closed by order of the Coal Mines Administrator to determine if enough improvements had been made to allow the mines to reopen. Federal coal-mine inspectors also had temporary authority to close mines they found to be imminently dangerous, but such authority (under Executive Order 9728) was removed on June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1957

By W. S. Sanner

This report describes the commercial application of the launder screen in anthracite-industry fine-coal cleaning operations. No new device, the launder screen has been used since the early part of the present century to size, screen, classify, and deslime the fine-anthracite sizes (Buckwheat Nos. 1 through 5) recovered by "river-coal" men dredging along streams draining the anthracite fields. The launder screen is stationary, has no moving parts, requires ample water for operation, and can be constructed economically on the job. Essentially, it consists of a wooden trough with baffles placed through its width to form a well system. The wells are covered by fine-mesh woven-wire screening. Each well is tapped with a number of orifices, and the hydraulic suction head developed in this manner removes high-gravity fines and slimes through the screening as underflow to waste. Material retained on the screen surface discharges as overflow product.

Jan 1, 1954

By Jason M. Porter, Douglas L. Porter, David L. Olson, Travis W. Koenig, Van S. Blackwood, Brajendra Mishra, Robert D. Mariani

"Traditional alloy theory models have been applied relative to the three solid phases of uranium: alpha (orthorhombic), beta (tetragonal), and mainly gamma (body centered cubic)[l]. The Darken-Gurry and Miedema models, with modifications based on concepts of Waber, Gschneidner, and Brewer have been used to predict the behavior of four types of solutes: 1) Transition associated with alloying in and containment of the uranium fuel 2) Transuranic elements in the uranium 3) Rare earth fragmentation elements (lanthanides) 4) Transition metals and other fragmentation elements. Using these solute map criteria, elemental behavior have been predicted as highly soluble, marginally soluble, or immiscible (intermetallic phase formers) and have been used to compare solute effects during uranium phase transformations. The overlapping of these solute maps are convenient first approximation tools for predicting alloy behavior.IntroductionAn investigation is in progress to determine the role of various solute elements on size and shape of the 'Y phase field range for uranium to optimize the burning and material processing of nuclear fuel is in progress. Traditional alloy theory models based on correlations to elemental electronic and crystal properties are used to predict solubility and micro structural formation. The effectiveness of this model is based on microstructure property correlations. Darken and Gurry, and Miedema models, with modifications based on concepts of Waber, Gschneidner, and Brewer, models have been used to describe solute solubility with respect to uranium based the on correlation between elemental electronic structure and uranium phases. The alpha (orthorhombic), beta (tetragonal), and gamma (body centered cubic) phases have different solubilities for specific alloy additions as a function of temperature. Using the method of Waber, ellipse diagrams classified those solutes that should have broad solubility in the allotropes of uranium[2]. The predictive diagrams are made from four different correlations:"

Jan 1, 2012

Jan 1, 1988

In February 1995, Falconbridge Limited approved the construction of a nickel mining and milling facility on its Raglan property situated in the Nunavik region of northern Quebec, Canada. The construction period successfully terminated with the commissioning and start-up of the plant and concentrator in early-December 1997. The estimated life of the project is 20 years with an annual mining rate of 800 000 tonnes of ore, producing 21 000 tonnes of nickel per year. This paper discusses the subject of æRemote Mining in the Canadian ArcticÆ as it applies to the Raglan mine process and people. During the feasibility stage of the project, many assumptions were made which influenced the design and operating parameters of the facilities and the equipment. Transportation, communication, remote logistics techniques and standard industry practices required to support a æfly-in/fly-outÆ operation were reviewed and either adopted or rejected for use at Raglan. These assumptions were æmade to fitÆ the uniqueness of our planned operation. It was also acknowledged that many of them would ultimately impact on the people required to staff the operation following construction. Therefore, their suitability and applicability were examined from an economic, operational and human perspective. In a continuing effort to improve the quality of life for Raglan employees, as well as the economics of our mine operations, these assumptions are under constant review and scrutiny. There is no doubt that experiences gained, and willingly shared by other North American arctic mining operations, proved invaluable and are a big reason for RaglanÆs overall success thus far. The mining industry is being challenged technically to develop lower grade orebodies at the lowest possible cost. In addition to environmental constraints, serious social, political and moral questions are being asked and added to this list of challenges. Miners throughout the world must improve their operating standards and public image if we want to attract the best possible employees. Remote mining operations provide a unique opportunity to experiment with various human resource concepts as well as demonstrate the industryÆs commitment to environmental and community concerns.

Jan 1, 1998

By P. D. S. St. Pierre

IN REGENT YEARS, blast furnace operators have found it necessary to improve their technology in order to handle increasingly low-grade feed and yet satisfy the demands for greater tonnages of metal. Studies have been made covering several aspects of the problem, and in this connection the slags produced in the iron-making process have been critically examined with a view to discovering the slag with the optimum properties for a given operation. A good slag should combine, as far as possible, the properties listed in Table I. Unfortunately, some of these desirable properties are incompatible. For example, the advantage of the small ?bulk of a low-flux slag is offset by its low desulphurization potential and high viscosity. Similarly, a very fluid slag increases refractory wear. It will be seen, then, that a balance must he struck between these conflicting requirements. In the .present paper only the melting relationships of blast furnace slag ?compositions will be considered in detail. In interpreting the data herein presented, the optimum property requirements listed in Table 1 must strictly be borne in mind. It should also be noted that the discussion presented here always relates to calcined fluxes, since this facilitates reference to the final slag composition. Thus, in making calculations pertaining to the ?burdening of the furnace, due allowance should ?be made for the fact that the fluxes are added as carbonates.

Jan 1, 1956

By Howard N. Eavenson

TWO months ago, just after the coal code hearing in Washington, one of our leading liberal weeklies printed a study of the coal industry made by an economist in the Administration, and on the outside cover bad it featured as "Coal-A Dying Industry." There are, of course, different opinions as to the accuracy of this characterization and I want to present some of the facts about the outlook for the bituminous industry for a short time ahead. In view of what has happened in the industry within the recent past it would be futile to attempt to make any prophecy about what is likely to occur in the future. We all know that a prophet is not without honor save in his own country, but it is likely that anyone undertaking this role about this industry would soon find himself in no man's land. One can, with some slight degree of safety perhaps, outline present conditions and tendencies and draw some inferences as to what the future may hold.

Jan 1, 1933

ENERGY 73 The First International Energy Exhibition will be held in Brussels from 13th to 18th May, 1973. Vllth INTERNATIONAL CONGRESS ON CYBERNETICS This congress will be held in Namur, Belgium, from 10th to 15th September, 1973. GRADUATE SCHOOL OF BUSINESS ADMINISTRATION University of the Witwatersrand The Sixth Executive Development Programme is scheduled to take place from 2nd July to 24th August, 1973. IFAC SYMPOSIUM 1973 Second announcement ofthe International Symposium on AUTOMATIC CONTROL IN MINING MINERALS AND METAL PROCESSING to be held at the University of New South Wales, Sydney, Australia, from 13th to 17th August, 1973. MINERALS AND ENVIRONMENT The effect ofthe mineral industry on the environment and mineral resources The Institution of Mining and Metallurgy, with the co-operation of the Institute of Quarrying and the Institution of Mining Engineers, will hold a Symposium "Minerals and the environment" at the Institution of Electrical Engineers, Savoy Place, from 4th to 7th June, 1974. COLLOQUIUM ON SLlMES DAMS The South African Institute of Mining and Metallurgy have great pleasure in advising members that a two-day colloquium on slimes dams is bei ng arranged for the 14th and 15th November, 1973. INTERNATIONAL SOLVENT EXTRACTION CONFERENCE This conference will be held at Lyon from 8th to 14th September, 1974. Particulars may be obtained from the Secretary: Dr A. Naylor, British Nuclear Fuels Ltd., Windscale and Carder Works, Seascale, Cumberland CA20 IPG, United Kingdom. Competition for Student Members of the South African Institute of Mining and Metallurgy Each year the Institute offers a prize (or prizes should the entries warrant it) of up to RIOO for the best paper or dissertation on a topic appropriate to the interests of the Institute. Proceedings of the Tenth International Symposium on Application of Computer Methods in the Mineral Industry (APCOM) The Proceedings of the APCOM Symposium held in Johannesburg from April 9th to 14th, 1972, have now been published. Members of the Institute may buy the Proceedings at a special price of R12,50 as against the list price of R25,00 to non-members. Verrigtinge van die Tenth International Symposium on Application of Computer Methods in the Mineral Industry (APCOM) Die Verrigtinge van die APCOM Simposium, wat op April 9 tot 14, 1972, in Johannesburg gehou is, is gepubliseer. Lede van die Instituut kan die Verrigtinge teen 'n spesiale prys van R12,50 koop, in teenstelling met die prys van R25,00 vir nie-Iede.

By P. Valicek, M. Farren, R. G. B. Pickering, G. Harrison, P. van Dorssen, W. Joubert, H. J. van Rensburg

Introduction In South African metalliferous mines, stoping operations are largely confined to narrow, tabular orebodies making mechanization extremely difficult. Limited flexibility in terms of stope width has necessitated drilling by means of hand held, pneumatic rock drills at most of our operations. As the largest producer of platinum in the world, we drill in excess of forty million stope blast holes per annum. Cleaning of the broken ore is also done by conventional means—utilizing scrapers and scraper winches. Conventional methods such as these carry high costs in terms of risk exposure as well as labour intensity. The purpose of this paper is to describe the development of a long hole stoping system suitable for the narrow platinum reefs. The new system had to be substantially safer and more cost effective than conventional mining. We selected a site that was conducive to mechanized mining and set out the parameters that we considered would meet our requirements. We then conducted a feasibility study to evaluate the conceptualized long hole stoping system in terms of specific goals. An analysis of the proposed system identified the Key Performance Indicators (KPIs). One of the most critical goals was to be able to create a man-freestope. This would mitigate the safety risk associated with normal stoping operations, as well as the inefficiency cost previously referred to. Other challenges included setting targets for long hole accuracy, stoping width reduction and specific blasting system performance for long hole stoping. We also modelled a critical span that we considered to be inherently safe and to ensure hangingwall stability, throw-blastcleaning and overall system productivity. Anglo Platinum Research and Development and Sandvik Tamrock entered into an agreement for the supply of a specialized long hole-drilling machine. The system was implemented and tested by the mine with the support of the other participants. The results achieved met our expectations. It was demonstrated that with this method of mining it is possible to have a man-free/support-free stope face and to achieve a reduction in shaft head cost per ton whilst reducing dilution. Key performance indicators assessed during the trial •Safety targets •Mining layout •Drill rig •Production targets •Support requirement •Explosives requirement •Services requirement •Ore removal and cleaning requirement •Training requirement Safety targets All persons involved with the project had to adhere to the mine’s safety programme including the zero-tolerance campaign, and were required to report all hazards observed immediately. Mine personnel and Tamrock carried out a full risk assessment on the drill rig before transporting underground. A further risk assessment was carried out when the machine was in position underground. Mining layout See Figure 1 and Figure 2 for a detailed description. Drill rig The drill rig was a combination of a Secoma P-Low LC 10long hole feed and an Axera low profile carrier. The choice of this equipment was made through consultation with Tamrock Sandvik. All relevant design perimeters of the area to be mined were taken into consideration. Production targets

Sep 1, 2001

By R. Owen

An overwhelming amount of data can be collected around the blasting process. This information can include blasting product, pattern design, blast results, and routing. It is only when these data sources are combined in a concise and accurate form that they are of real use in determining the safety and economic implications of each parameter. Two key technological aspects of blasting are drill fleet management (DFM) and size fraction analysis (SFA). As these technologies are integrated as near-real-time measurement and QA/QC tools, the resolution and realization of blasting parameters is significantly increased. The Freeport-McMoRan Morenci Mine has integrated these technologies along with other existing database structures to create a responsive and sustainable tool for reconciliation, forecasting and parameter matching. This ability allows Morenci to customize blast patterns to meet the criteria most critical to each shot, whether the impact is influenced by routing and recovery, equipment maintenance or safety concerns. DRILL FLEET MANAGEMENT The current DFM was stabilized in its current form in mid 2009 after database and hardware maintenance met stability requirements. Currently the system is running on 12 production drills. The system receives pattern layout and is capable of semi-autonomous drilling over the entire district. The fleet is capable of drilling in highly altered intrusive units and hard granites through the range of sedimentary and volcanic units that comprise the Morenci District. The system brings a level of accuracy not achievable with earlier paint-marked patterns. Depth control is also increased along with more consistent wear and maintenance patterns due to semi-autonomous drilling.

Jan 1, 2011

By Albert L. Brautigam, Michael R. Yenchek, Jeffrey Shawn Peterson, James C. Cawley

The National Institute for Occupational Safety and Health investigated how the starting of induction motors may cause nuisance tripping of short-circuit protection on coal mine power systems. This research had a dual purpose: 1) to identify how motor-start waveforms differ from those for short circuits and 2) to devise a method to provide short-circuit protection without intentional time delays to account for motor starts. This technology will help ensure that surface temperatures of energized electrical apparatus will not exceed gas or dust ignition thresholds when short circuits occur.

By D. G. Collins

As part of its effort to develop ways to maximize resource recovery, the Bureau of Mines investigated the extraction of vanadium from Western phosphate beneficiation tailings with H2S04 and/or H3P04. Dissolution of the vanadium was accomplished by digesting a mixture of acid and a 50-pet-solids, tailings-water slurry. In the most effective method investigated, vanadium and phosphorus were leached by digesting the slurry at a constant boiling temperature (1000-1100 C) in a stirred reactor. In batch tests, maximum vanadium dissolution was 95 pet. In continuous-circuit tests designed to further evaluate vanadium dissolution at con-stant boiling temperature in a continuously stirred reactor, vanadium dissolution ranged from 70 to 85 pet. An economic evaluation of the process demonstrated that H2S04 consumption is the major cost factor. Based on the value of the vanadium product with no allowance for a phos-phate product, the cost of producing the V205 is more than twice its value. The potential for profit would depend upon the value of the phosphate fertilizer produced from the impure H3P04 remaining after vanadium extraction.

Jan 1, 1985

Gold mineralisation was first noted in 1983 at the Wapolu Point area of Fergusson Island, Papua New Guinea (PNG) during a follow-up regional reconnaissance program. Subsequent exploration programs through to late 1987 completed 22,147m of costean trench sampling, 553 aircore/RC/diamond core drill holes (16,970.5m total) and metallurgical testwork, predominantly on the Wapolu grid in two mineralised areas.Subsequently in 1988, geostat-istical global and polygonal resources were calculated for the main mineral-ised zones, Didigayagaya and Dagwalala. In 1992, a 'probable total reserve' of 1.9Mf @ 2.4g/t with a 1.2g/t cut-off was calculated for these prospects.

Jan 1, 1994

By Qiang Yu

This paper reports on a research project supported by NSF, which aims at developing a multi-scale methodology for systematic microstructure prediction in thermo-mechanical processing of metals. This methodology is based on combining mesoscopic microstructure models with macroscopic process formulations and involves the following three main steps: (I) based on the given global processing conditions, the gross deformation patternof the entire workpiece is modeled using a continuum-based algorithm, (2) the resulting parameters are then extracted from the continuum-based simulation, post-processed and passed on to the mesoscopic numerical module, and (3) the microstructural changes are finally modeled at the mesoscopic scale. This approach is expected to overcome the disadvantages of current microstructure prediction practice employing empirical relationships between microstructural features and processing parameters. Keywords: Thermo-mechanical processing, Microstructure, Grain growth; Recrystallization; Mesoscopic models; Finite Element Method

Jan 1, 2003

By W. J. Pearson

"""POTASH"" is a term applied to the compounds of the element potassium (K) and when used in agriculture and industry is ex-pressed in terms of potassium oxide (K2O), regardless of the actual com-position of the compound. When a chemical analysis is made of a fertilizer, the amount of K is deter-mined and then calculated to the equivalent amount of K2O. However, the compound K2O does not exist in nature. Most of the world's potash supply is derived from mineral deposits similar to those in Saskatchewan and New Mexico. However, there is some production from concentrated surface brines such as occur in Searles Lake, California; Salduro Marsh, Utah; the Dead Sea; and from well brines in Micl1igan."

Jan 1, 1960

By Marcella Gautê Cavalcante Xavier

As ligas livres de chumbo (Lead-free solder alloys) potencialmente utilizáveis em processos de soldagem branda, tais como as ligas à base de Sn, vêm sendo estudadas como alternativas para substituir as ligas do sistema Sn-Pb. Em vista disto, o presente trabalho, aborda tanto a análise das características microestruturais formadas durante a solidificação transitória das ligas eutética Sn-0,2%Ni e hipereutética Sn-0,5%Ni, quanto a determinação das suas respectivas correlações com os parâmetros térmicos de solidificação: velocidade da isoterma eutética (VE) e taxa de resfriamento (?E). Para tanto, as ligas foram solidificadas unidirecionalmente no sentido vertical ascendente e em regime transiente, e caracterizadas por técnicas de microscopias ótica e eletrônica de varredura. Na liga hipereutética Sn-0,5%Ni, o aumento da quantidade de Ni na liga influenciou tanto o comportamento térmico quanto o espaçamento celular (λC), proporcionando maiores valores de ?E, porém, λC mais grosseiros.O intermetálico NiSn4 formou-se na região eutética de ambas as ligas, enquanto que na liga Sn-0,5%Ni, as fases primárias identificadas por EDS-MEV foram NiSn4 e Ni3Sn4. A transição morfológica celular/dendrítica(?E> 1,2ºC/s) ocorreu apenas para a liga eutética, enquanto que as células regulares da liga hipereutética deram origem as células do tipo placas(?E> 1,4ºC/s).

Oct 30, 2017

By Frederick J. Murrell

No other region of the world is enjoying the tremendous growth of power use that is currently being experienced in Asia. Fortunately for the coal industry — particularly in Asia — the power plants being planned or under construction are designed to use coal as fuel. This has produced a significant increase in the demand for steam coal that, in turn, has encouraged many in the industry to develop new coal mines. Indonesia is a country that has enjoyed substantial growth in coal production. This developing country has 195 million people who live on the nearly 13,000 islands. It has quickly emerged as the third-largest exporter of steam coal, following only Australia and South Africa. Almost all coal in Indonesia is mined by surface-mining methods.

Jan 1, 1996

By Cynara Christ Klippel

A formação de uma escória adequada é essencial para a reação de desfosforação, pois ela deve ser capaz de absorver e reter o fósforo em sua estrutura. Este trabalho tem como objetivo a avaliação do processo de desfosforação de ferro-gusa tomando como base os resultados obtidos na análise química da mistura inicial e escória final, uma vez que as condições finais do metal são determinadas por sua escória. As misturas utilizadas são a base de CaO-FeO e a temperatura de tratamento foi de 1400ºC. Inicialmente o estudo será realizado usando os modelos da literatura e posteriormente com uso de ferramentas de termodinâmica computacional. Será também determinado um modelo para prever a eficiência destas misturas.

Aug 17, 2017