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By Patrick Granitzki, Alicia Plinio, Janitha Batagoda, Peter Howell

The City of Newark is making a comeback with new mixed-use multi-storied Residential Development projects. The majority of developers tend to use driven H-pile deep foundation systems to support their super-structures. A different approach was recommended for one particular new development near the Passaic River. The surficial geology included glacial deposits consisting of loose to dense sand overlaying relatively soft silt and clay and a lower stratum of medium-dense sand. During a preliminary site investigation for the project, bedrock was encountered at depths ranging between approximately 168 feet to 182 feet below the ground surface. Design capacity required a single pile of 200 tons. Two different pile foundation systems were evaluated in conjunction to the typical driven H-pile system in order to review potential costs and construction schedule impacts. The two alternative pile systems evaluated were tapered tube piles and drilled displacement piles. Theoretical calculations were followed by in-situ load testing. The field testing results indicated the use of drilled displacement piles as the best option for a portion of the proposed building. This paper discusses the different piles systems considered, installation and using drilled displacement piles to minimize cost and optimize construction.

Sep 8, 2021

By Salvatore Fancello, Ferruccio Cribari, Amerigo Tanzi, Mauro D’Angelo, Massimo Lodico, Alessandro Bertero, Eliano Romani, Tommaso Gondolini, Fabio Giannelli

"The new metro line “C” entails the construction and rehabilitation of 24 stations and 21,5 km of metro line, 13 of which carried out underground; the new metro line will improve the transportation system of a congested city such as Rome.The new line “C” of San Giovanni metro station will be constructed adjacent to the existing line “A” of San Giovanni station; the new metro line “C” is deeper than line “A” and will underpass the existing station. The underpass project envisages an Artificial Ground Freezing in order to excavate two new tunnels, while keeping trains running in the safest possible condition.In order to allow trains to regularly run to and from the existing station’s line “A”, a temporary structure for rail support, during excavation of the under-crossing tunnels, was installed and a real-time monitoring system was devised in order to control both soil temperature during freezing activities and the existing station’s behavior. The monitoring system has been one of the key to the success of the project.The excavation of tunnels under the water table, with a hydraulic head of over 10 m in not homogeneous soils having different mechanical properties and permeability and below existing sensitive structures, involves special ground freezing sequences and methods, as well as peculiar drilling systems and operations, such as TDDT (Trevi Directional Drilling Technology).THE NEW “C” LINE OF ROME’S METROThe world’s most complex and extraordinary Metro System is currently being built in the heart of Rome. Its underground route stretches underneath the most important monuments, churches and historical buildings.Rome’s Metro Line C is the longest urban underground railway in Italy and it is the first line in Rome to extend further east to the Great Ring Road, thus bridging the gap between the farthest suburbs and the Historical Centre. It is an original project, carried out mostly underground at a depth of 25/30 metres below road level."

Jan 1, 2016

By R. G. Diale, H. R. Chauke, T. M. Ledwaba, P. E. Ngoepe

FeCo alloys play an important role in soft magnetic materials with a wide range of technological applications due to their high saturation magnetization and Curie temperature. However, these alloys have low ductility at room temperature. The ductility can be improved by the ternary addition of elements such as V. A density functional theory supercell approach was used to generate B2 Fe50Co50-xVx (0 ≤ x ≤ 50) structures and the properties were evaluated at different atomic percentage compositions to determine the ductility at room temperature. The structures were fully optimized to obtain better equilibrium ground-state properties such as lattice parameters and thermodynamic properties for both binary and ternary systems. The stability of Fe50Co50- xVx was evaluated from the heats of formation, elastic properties, and phonon dispersion curves. Furthermore, magnetic strength was evaluated from magnetic moments. It was found that all structures are thermodynamically stable due to the negative heats of formation. The calculated Pugh’s ratio and Poisson’s ratio confirm that alloying with V effectively improved the ductility. It was also found that Fe50Co50-xVx showed a positive shear modulus for the entire concentration range investigated, in agreement with phonon dispersion curves. The ternary addition of V to the FeCo system resulted in reduced magnetic strength due to a decrease in magnetic moments. These findings reveal that B2 FeCo-V alloys can be used as components and actuators for the automotive industry.

Jun 10, 2024

Low-grade, porphyry copper type mineralization at the Moonmera prospect is related to the intrusion of a granodiorite porphyry mass into the Upper Permian "Gracemere granodiorite". Significant copper mineraliza- tion appears to be associated with the alteration assemblage quartz-sericite- kaolinite. The ore shell is surrounded by a zone where montmorillonite and kaolinite are in greater abundance and this assemblage is over- lapped, mainly at depth, by potassium feldspar alteration. Secondary biotite is abundant throughout the mineralized zone. Preliminary sulphur isotope results on the sulphide mineralization are compatible with a magmatic origin for the sulphur.

Jan 1, 1974

By Alfred R. Powell

In another paper the writer has described an investigation in which the forms of sulphur in coke were determined and described. Coke was found to contain four characteristic forms of sulphur- namely, ferrous sulphide, sulphates, ad- sorbed free sulphur, and sulphur held in solid solution in the carbon. While the coke is still in the oven, only two forms of sulphur are present namely, the ferrous sulphide and the sulphur in solid solution in the carbon. During the quenching, however, the sulphur of the coke is subjected to considerable oxidation, a portion of the ferrous sulphide being oxidized to free sulphur and sulphates, while the solid solution form remains unchanged. The coke, however, loses no sulphur during this process, since the free sulphur which is formed ie retained by the coke in an adsorbed form. Since this oxidation of the ferrous sulphide took place so easily, an inves- tigation was undertaken to determine whether this property could not be taken ad- vantage of in some industrial process for the desulphurization of coke. Although it is true that such a roasting process would not touch the solid-solution form of sul- phur, still the removal of the ferrous sulphide sulphur would undoubtedly benefit the coke from the standpoint of the metallurgist. This improvement in the coke would result not only from the decrease in total sulphur, but also from the large decrease in the ferrous sulphide, which is responsible for the contamination of the iron in the upper part of the blast-furnace. The de sulphurization of coke by roasting in air it a new idea, but dates back to the earliest days of coke manufacture. In 1871, Philipparts published the results of some work done by him on the de sulphurization of coke by air, as well as a review of the results of earlier investigators. In the se earlier experiments, nothing was known of the forms in which the sulphur existed in the coke, while the temperature measurements were only approximate, so that altogether the results were not very conclusive nor complete. The de sulphurisation figures given by the se early investigators generally showed a low efficiency for the process, but some extraordinary results were claimed by certain inventors. In the light of our new knowledge concerning the coke sulphur, it seemed to be important enough to warrant investigation.

Apr 1, 1923

By Karen C. Armfield, Gisele R. Passalacqua, Joanna Smith

New York City is an urban environment with a history spanning over 200 years. The coastline of New York has changed over the years. In the East River, old bulkhead and remnant of relieving platforms together with variable bedrock elevations pose challenges in the design and construction of deep foundations. This paper presents a Case History of high capacity deep foundations along the Franklin D. Roosevelt (FDR) Drive on the Upper East Side in New York City. The project consists of a ramp that overpasses the FDR Drive allowing heavy trucks to access the Marine Transfer Station (MTS) facility built over the East River. Large diameter drilled shafts and mini-piles socketed to bedrock were designed and constructed. Remnant of old bulkhead was encountered at the site and a Ground Penetrating Radar (GPR) investigation was completed during the subsurface investigation phase of the design. This paper discusses details of the subsurface investigation program and design methodology of the high capacity drilled shafts and mini-piles. It also describes construction methods and results of Osterberg Load tests documenting the field values of skin friction through the rock socket. Other construction challenges include construction and drilling rock sockets for drilled shafts over sloping bedrock. 1. INTRODUCTION New York City is a renowned urban city that always calls for the most delicate, yet complex, and robust superstructures and most importantly substructure designs. The historic preservation of this large 200 years old city of 319 square miles is ever changing. Shorelines are often extended to accommodate new infrastructure and very often many miscellaneous structures are discovered below the ground surface. The East 91st Street Ramp was constructed to provide access to the East 91st Street Marine Transfer Station over FDR Drive and York Avenue. Another alternative ramp will be relocated to the South Bound (SD) of the FDR Drive at 92nd Street. A subsurface exploration program was completed in accordance with the New York City Department of Design and Construction (NYCDDC) general requirements, Section 4.5, to perform subsurface investigation along the FDR Drive in Manhattan, New York.

Jan 1, 2019

By A. Schippers, S. Hedrich

Chalcopyrite represents the most important copper resource and is currently mainly exploited using pyrometallurgy. Bioleaching is an environmental-friendly and economic alternative to conventional mineral processing technologies. The technical feasibility of stirred tank reactor bioleaching of copper ore concentrates using acidophilic iron-/sulfur-oxidising bacteria is proven, however, often incomplete due to inefficient chalcopyrite dissolution. A decoupling of bacterial growth from bioleaching activity in one bioreactor by adjusting appropriate temperatures for both process steps allows for almost complete chalcopyrite dissolution. Separation of copper and recovery of other metals from the PLS was possible by implementation of different biological and chemical techniques. The Ferredox process has been proposed to treat limonitic laterite ores for cobalt and nickel recovery by means of anaerobic reductive dissolution with autotrophic, acidophilic bacteria. As a modification, aerobic reductive dissolution of laterites with acidophilic bacteria has shown economic and environmental advantages over anaerobic reductive dissolution. The reductive bioleaching technology has the potential to increase metal recovery in existing mines, and transform unexploited ores and limonite stockpiles into valuable resources. Keywords: Biomining, bioleaching, chalcopyrite, laterite, Ferredox process

Jan 1, 2020

By I. Druce, C. Li, T. Qu, J. Dong, W. Y. Xinchao, V. Nkuna

CITIC Heavy Industries has a large installed base of grinding equipment throughout Africa in different configurations, including high-pressure grinding rollers with ball mill and semi-autogenous ball crusher. The total installed power of CITIC’s mills exceeds 430 MW. In this paper, we compare several typical grinding circuits of copper in Africa with about 15 kt/d throughput based on ore properties, process selection, equipment sizing, and key equipment capital and operating costs. Actual operating performance is also introduced. The comparison for the following mine sites provides a general reference for the selection of copper grinding circuits with this approximate throughput: Kamoa-Kakula Copper Mine with high-pressure grinding rollers with ball mill circuit, and Deziwa and Sicomine Copper-Cobalt Mines with semi-autogenous ball crusher circuits

Jan 1, 2023

By Carolina Conter Elgert

O impacto de alguns elementos microligantes no tamanho de grão e nas propriedades mecânicas obtidas em diferentes rotas de processamento foi estudado neste trabalho para uma laminação de barras de aços especiais, special bar quality em inglês, SBQ. Esse estudo compreende as etapas iniciais da metodologia para o desenvolvimento de um modelo capaz de prever o comportamento da microestrutura e as propriedades mecânicas obtidas em processos de laminação de barras, que é pouco difundido para aços microligados. Foram testadas duas variações de aços microligados, com diferentes percentuais de Nb e Ti A rota de processamento mostrou um papel fundamental para a obtenção de melhores propriedades mecânicas nos aços testados – um aprimoramento considerável foi observado quando o material foi laminado seguido uma sequência termo-controlada.

Oct 30, 2017

By Enif Gutiérrez Guerrero

Inclusion deposition is still a standing problem in the continuous casting of steel since the deposition of alumina inclusions inside the SEN affects the productivity and the product quality. The present work studies the factors involved in the inclusion deposition at the nozzle and the effects of inertial, gravitational, buoyant, pressure gradient, and Saffman forces on the inclusion trajectories. The results show that the inclusions reaching the nozzle, only 30% get deposited along its walls mainly at the Upper Tundish Nozzle (UTN). This area of higher deposition is identified close to a low static pressure and a high turbulent kinetic energy dissipation zones where the effects of the gravitational and buoyant forces do not promote a significant inclusion radial movement since these are aligned with the direction of the flow stream lines. In contrast, in this zone, the Saffman force shows an important effect on the deposited inclusions, slowing down the inclusions in the vertical axis and increasing their radial movement.

Aug 17, 2017

By H. Vigil Fernandez, G. Peach

The Musaimeer pump station and outfall project located in Doha Qatar, was designed to collect and manage ground and stormwater and then discharge the treated waters offshore. The project constructed a long outfall tunnel using an EPB TBM with segmental lining, each tunnel ring being 1.35 m in length with an internal diameter of 3.7 m.. The diffuser structure was a 6-arm structure, measuring 294m by 40 m connected to a central manifold in turn connected to the TBM constructed tunnel via a riser shaft drilled from an off-shore barge. This technical paper will discuss the planning, methodology and construction practices employed to connect the TBM tunnel to the diffuser structure 10.2 km offshore.

Jun 13, 2023

By Jean Igor Margem

Nestes dias materiais ecológicos como compósitos com fibras naturais em matriz polimérica estão chamando a atenção de pesquisadores científicos, devido ao seu bom desempenho na substituição de materiais como madeira, polímeros à base de petróleo e outros. Neste trabalho foram avaliadas as propriedades de tração de compósitos de matriz poliéster reforçados com diferentes espécimes de fibras lignocelulósicas. Compósitos reforçados com até 30% em volume de fibras longas, contínuas e alinhadas de malva, sisal e bambu foram testados em uma máquina Instron a temperatura ambiente. A fratura foi analisada por SEM. Os resultados mostraram alterações significativas nas propriedades mecânicas com a quantidade dessas fibras. Estas propriedades mecânicas foram comparados com outros resultados em compósitos testados em ensaio de tração. Como esperado, a análise da fratura revelou uma fraca interação da interface fibra / matriz, o que corrobora o comportamento típico das fibras naturais quando incorporadas em matriz polimérica.

Oct 30, 2017

By Simon D. Strauss

Production and consumption of nonferrous metals in the United States during 1950 were at peak levels for the postwar period, as is shown in Tables I, II, and III. The trend of production was upward through most of the year. At the year end, with the possible exception of the Tri-State zinc-lead district, the large mining operations in the country were running at capacity. The absence of serious labor interruptions during the year was an important contributing factor in the increased out-put of metals, since in each of the previous postwar years there had been a number of major strikes which affected production adversely.

Jan 2, 1951

By Peng Lv, Shiqian Liu, Bin Xu, Qian Li, Yongbin Yang, Tao Jiang

The treatment process of a low-grade refractory gold ore containing sulfide minerals and carbonaceous matters was studied in this work. The gold extraction of this ore by all-sliming cyanidation was only 11.75%. Hence, a pretreatment was necessary. In this paper, a flotation-preoxidation-cyanide leaching process was developed. The concentrate from the flotation procedure was processed using different preoxidation methods. A concentrate containing 34.08g/t of gold with the gold recovery ratio of 81.20% was obtained by flotation. After roasting, microwave heating or alkaline pressure oxidation, the gold cyanidation ratio reached 82.37%, 81.26% and 71.09% respectively. Roasting was an effective, reliable and mature technique to oxidize sulfide minerals and carbonaceous matters. Roasting and microwave heating both produced dangerous environmental pollutants while alkaline pressure oxidation was eco-friendly.

Jan 1, 2015

By Dimas Henrique Barros Andrade, Roberto Abreu Alencar

O algaraviz é uma parte importante do sistema de sopro de um Alto-Forno, utilizado para direcionar o sopro e combustíveis injetados para a ventaneira, por conseguinte o interior do forno. O algaraviz consiste em uma caraça metálica revestida de material refratário com resistência ao calor e uma camada de isolante térmico entre o refratário e a carcaça. Falhas em serviço de algaravizes costumam a gerar grandes danos materiais, financeiros e com grande risco à vida dos operadores, por isso o controle e inspeção da integridade estrutural e térmica dos algaravizes é de suma importância. A inspeção nos algaravizes é realizada a fim de se detectar precocemente pontos quentes que são indicativos de falhas estruturais no algaraviz. Portanto este artigo foi feito um modelo numérico de transferência de calor, a fim de se averiguar as condições do algaraviz, de forma a verificar se o algaraviz em condições normais de operação mantem as condições térmicas. O modelo revelou resultados satisfatórios de forma que em comparação com resultados de inspeções em peças em operação se obteve um erro de cerca de 8%.

Oct 1, 2019

By M Habte

This paper presents a simplified method for the assessment of creep deformations in rock masses containing bands of low strength or soil strength rock. The main impetus for this work was the need to assess the impact of distinct bands of clay and/or low strength rock on the long term deformation behaviour of a rock pillar formed as part of a series of proposed tunnelling works. In particular, the authors were interested in being able to provide criterion which could be used by site personnel to assess the encountered rock conditions against design assumptions.Creep deformation versus time plots are presented for a range of material consistencies. These plots were produced using the hyperbolic creep equation proposed by Mesri et al (1981). This empirically based equation was chosen for its simplicity and practicality. Discussion is included regarding typical input parameter values and the sensitivity of the results to these values is explored. Finally, in the soil strength materials, the secondary consolidation equation is used to check the veracity of the results calculated using the hyperbolic creep equation.

Mar 8, 2011

By C L. McIntosh

The west coast of New Zealand’s south island is host to a large number of placer goldfields that stretch from the Westport area in the north to Gillespies Beach in the south and inland to the foothills of the Southern Alps. This area is host to a large number of alluvial, glacial and strand line deposits ageing in range from Recent to Tertiary. In recent years exploration models have been developed for off shore placer deposits on the continental shelf.Gold mining on the west coast has exploited placer gold resources from the 1860s to present, and with the recent surge in the gold price the industry is currently undergoing a resurgence. The current increase in mining is dominated by small-scale mechanical operations usually involving one to two people at each site; a few larger operations also exist such as the Grey River Dredge.Mining methods range from using floating bucket dredges to small diggers. Some of the mining technologies used are similar to those employed during the great gold rushes of the 19th century. Exploration and grade control techniques can be very rudimentary often relying on previous sampling programs or wide spaced bulk sample drill holes. Some bulk sample drilling is used on the larger operations as a form of grade control, most of the small operations tend not to use any ore control sampling prior to mining. Extraction techniques relying on simple gravity based designs with riffle tables or spirals are the most commonly used. Environmental standards are very high within New Zealand and require operators to return mined areas to preagreed to landforms. The high rainfall experienced on the west coast causes challenges to operators in regard to water quality. Technical issues combined with often limited capital provide for challenges to the operations.

Aug 22, 2011

By J Poniewierski, Varcos D

Efficient blasting requires constant vigilance with respect to the actual layout being used in the field. Objective measurement techniques are required in laying out a pattern as the 'by eye' or 'thumb suck' methods cannot guarantee consistent results in layout. Erratic blast results are the consequence of such an approach. In a case study at Sons of Gwalia mine, it was demonstrated that incorrect front burdens had a snowballing effect on otherwise carefully laid out blasts, resulting in both excessive amounts of boulders caused by preconditioning of bench fronts and tops, and tight digging. Both problems caused lower excavator productivity and excessive excavator damage, as well as making it difficult to set out subsequent blasts correctly. Several field measurement methods are available to aid in determining correct blast layouts and one is described in this paper.

Jan 1, 1994

By P A. Montoya

La Colosa is a world-class porphyry Au project located in Colombia, currently undergoing prefeasibility analysis. As part of collaboration between AngloGold Ashanti and the AMIRA P843A GeMIII Project, the application of emerging geometallurgical characterisation testing and modelling tools has been incorporated in early stages of project development. The aim of the geometallurgical study is to map inherent comminution variability across the La Colosa deposit providing information critical for mine/mill design and optimisation. In this study, site-based data incorporating multi-element assays, quantitative analyse X-ray difraction QXRD bulk mineralogy measurements, EQUOtip rebound hardness data, and routine geological logging information from 59 diamond drill holes has been integrated with a range of geometallurgically specific comminution test (ie GeMCi, A × b, BMWi). The work in this paper demonstrates the integration techniques used at La Colosa to link routine data acquisition methods with comminution test results through the development of proxy support models. The integration incorporates a range of statistical techniques including principal component analysis and regression modelling. By creating proxy models, comminution index estimates can be propagated into the geological database enabling comminution processing domains to be defined. These domains provide the first spatial representation of comminution performance and variability at La Colosa and can be compared against traditional geological domains. This study provides the foundation for ongoing comminution characterisation as the La Colosa project evolves through project cycles into an operational mine.

Sep 5, 2011

By Biswadeep Saha, Meenakshisundaram Ramanathan, Chai Ren, Sivaraman Guruswamy

"Fe-Ga alloys have a large low-field magnetostriction and these alloys are attractive candidates in energy conversion and harvesting applications. Small additions of W also increase the magnetostriction of Fe. In this paper changes in magnetostriction by W substitution for Ga in various Fe-x at.% Ga alloys are presented. Fe-Ga-W single crystals were grown using vertical Bridgman Growth technique. [001]-orientated single crystal samples were prepared with faces within 1 degree off <100> orientation. The samples were annealed at 1150 °C in the alpha-phase region and water quenched. The magnetostriction coefficient (3/2)A-100 measurements were made on these Fe-Ga-W single crystals. The result on the effects of W substitution and annealing on the magnetostrictive behavior of these alloys are discussed.*Support of this work by NSF-DMR under the award DMR-0854166 is gratefully acknowledged.IntroductionMagnetostrictive materials changes their dimension exhibit reversible strains and changes in elastic properties in the presence of an applied magnetic field or the reciprocal effect of changes in the magnetic properties with the application of stress [IJ and are very important in sensor, actuator device, linear motor, magnetomechanical devices, microelectro- mechanical devices, active vibration dampening devices application areas. The discovery of an order of magnitude enhancement in the magnetostriction of Fe with Ga addition coupled with low saturation magnetic fields, and excellent mechanical properties opened up the possibility of obtaining larger magnetostriction values in other low-cost ductile a-Fe phase based alloys with alloying additives that are less expensive than rareearths such as Tb and Dy [2·4l_ The magnetostriction values observed in Fe-Ga single crystals are sensitive to thermal history and composition. The formation of second short range ordering phases and local defects inside crystal structure can also cause a dramatic change to this alloy's magnetostriction behavior [5-9l_"

Jan 1, 2012