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By L. I. Gonzalez de Vallejo

SRC rockmass classification have been applied to 25 tunnels in Spain and Italy, for which it was found that much heavier supports than those estimated by the RMR index were required. SRC and RMR indices and other relevant geomechanical data were obtained during the site investigation and construction stages. Data corresponding to in situ stress measurements, analysis of tectonic structures, and instability problems arising during construction were used to asses the state of stress. The relationship between tunnel section convergence and the SRC and RMR indices was also analysed. Support measurements based on SRC and RMR classification were compared with those actually used during construction. These analyses indicate that for most of the tunnels examined, supports estimated using the SRC were much closer to those actually installed than those predicted by the RMR index. Bei der Verwendung des SRC-Systems zur Klassifizierung des Gesteins als Baugrund für 25 Tunnel in Spanien und Italien wurde festgestellt, dass viel schwerere Abstützungen benötigt wurden, als wenn die Beurteilung anhand des RMR-Systems angefertigt würde. Die Klassifizierung anhand des SRC- und des RMR-Systems, sowohl als auch andere wichtige geomechanische Daten wurden während des Ablaufs der Erkundungen und der Bauausführung gewonnen. Die Resultate der Messungen der Spannungen vor Ort, die Analyse der tektonischen Struktur und die Stabilitätsprobleme während der Bauausführung wurden dazu verwendet, um den im Felsgrund vorherrschenden Spannungszustand zu definieren. Das Verhältnis der Messungen der Tunnelkonvergenz zu dem SRC- und RMR-Index wurde auch analysiert. Die durch das SRC- und RMR-System vorhergesagte Grösse der Abstützung wurde mit der Grösse der Abstützungen verglichen, die am Bau letztlich verwandt wurden. Diese Vergleiche zeigen, dass für die meisten der studierten Tunnel die Vorhersage der Abstützungen, die anhand des SRC-Systems angefertigt wurden, viel näher der wirklich verwendeten waren als die Vorhersage anhand des RMR-Systems. SRC rockmass la classification ont été appliqué à 25 tunnels en Espagne et l'Italie, pour laquelle il a été trouvé que des appuis beaucoup plus lourds que ceux évalués par l'index RMR ont été exigés. SRC et des index RMR et d'autres données geomechanical appropriées ont été obtenu pendant l'enquête de site et les étapes(scènes) de construction. Les données correspondant aux mesures de stress(d'accent) in situ, l'analyse de structures tectoniques et des problèmes d'instabilité surgissant pendant la construction ont été utilisées aux ânes(culs) l'état de stress(d'accent). Le rapport entre la convergence de section de tunnel et le SRC et les index RMR a été aussi analysé. Les mesures d'appui basées sur SRC et la classification RMR ont été comparées avec ceux en réalité utilisés pendant la construction. Ces analyses indiquent que pour la plupart des tunnels examinés, les appuis évalués utilisant le SRC étaient beaucoup plus proches de ceux en réalité installés que ceux prévus par l'index RMR.

Jan 1, 2003

The Iscor Board has given its Mining Division the authority to proceed with detail engineering and design for a Heavy Minerals Project which comprises a mine in Northern Province near Gravelote, a mine in KwaZulu/Natal near Richards Bay and a central processing complex with a beneficiation plant and smelter which will be located near Richards Bay and Empangeni.

Jan 1, 1996

By C. Kasatuka

Globalization creates investment opportunities for enterprises around the world. Attracting foreign investment has been a key challenge for economic growth in developing countries. Corruption, political instability, armed conflict, and other internal problems affect foreign direct investment (FDI) inflows negatively. A framework of criteria provides a basis for comparing non-commercial risk (NCR) among twenty-three mineral economies. Countries competing for foreign direct investment inflows are ranked from least to most risky. This study compares Inward FDI Performance Index (IND) with NCR ratings in developing countries and shows that risk is increasingly mitigated by means of appropriately structured insurance. Given the option for countries with similar mineral potential, investors will generally invest in the country that offers lower non-commercial risk. Keywords: foreign direct investment, non-commercial risk, developing countries.

Jan 1, 2006

By C. Kasatuka

Globalization creates investment opportunities for enterprises around the world. Attracting foreign investment has been a key challenge for economic growth in developing countries. Corruption, political instability, armed conflict, and other internal problems affect foreign direct investment (FDI) inflows negatively. A framework of criteria provides a basis for comparing non-commercial risk (NCR) among twenty-three mineral economies. Countries competing for foreign direct investment inflows are ranked from least to most risky. This study compares Inward FDI Performance Index (IND) with NCR ratings in developing countries and shows that risk is increasingly mitigated by means of appropriately structured insurance. Given the option for countries with similar mineral potential, investors will generally invest in the country that offers lower non-commercial risk. Keywords: foreign direct investment, non-commercial risk, developing countries.

Jan 1, 2006

By P. Otto, G. Borm, Th. Dickmann, F. Amberg, R. Giese

Based on many years experience, the well proven Swiss Tunnel Seismic Prediction System TSP has been substantially augmented for online geological prognosis in underground construction. In its latest version, the Integrated Seismic Imaging System ISIS provides high resolution seismic images of the rock mass around a tunnel face via an array of standard anchor rods. These rods contain 3D-geophones at their tips and can be readily installed during excavation work. A further innovative component of the system is the newly developed high-power repetitive source for application in hard rock: a pneumatic hammer with laser triggering to be mounted on construction machinery. A user-friendly software package permits online data acquisition and processing, 3D-visualization, and a first geological interpretation. Tomographic images of compressional and shear wave velocity fields at fault zones in metamorphic rock of the Gotthard Base Tunnel in the Central Alps are presented. Das langjährig bewährte Schweizer Tunnelseismische Vorauserkundungssystem TSP wurde inzwischen wesentlich weiterentwickelt. In seiner neuen Version, dem Integrierten Seismischen Imaging System ISIS, ermöglicht es hochauflösende seismische Abbildungen des Gebirges im Vorfeld und Umfeld einer Tunnelauffahrung mit Hilfe einer Anordnung von Felsankern, die an ihren Spitzen 3-Komponenten-Geophone enthalten. Eine weitere Neuerung von ISIS ist die pneumatische Hochleistungs-Impulsquelle mit Laser-Triggering. Eine benutzerfreundliche, interaktive Software ermöglicht die online Datenerfassung und -auswertung, 3D-Visualisierung und eine erste geologische Interpretation. Tomografische Abbildungen von Kompressions- und Scherwellengeschwindigkeitsfeldern an Störungszonen in metamorphem Gestein des Gotthard-Basistunnels werden gezeigt. Basé sur de nombreuses années d’expérience, le système suisse, bien établit, de reconnaissance sismique à l’avancement des tunnels (système TSP), a été sensiblement amélioré pour obtenir une prévision géologique en temps réel durant l’avancement de travaux souterrains. Sa dernière version, le Système Intégré d’Imagerie Sismique (ISIS), fournit des images sismiques haute-résolution du massif rocheux à l’avant d’un tunnel grâce à un réseau de tiges d’ancrage standard. Ces tiges, équipées à leur extrémité de géophones 3 composantes, s’installent très aisément durant les travaux d’excavation habituels. Le élément d’innovation récente concern le nouvelle source très répétitive et de forte puissance pour les applications aux roches dures: un marteau pneumatique déclenché par un système à laser. Un ensemble de programmes informatiques convivial permet l’acquisition et le traitement en temps réel des signaux et produit une vue 3D ainsi qu’une première interprétation géologique. Nous présenterons des images de réflexion d’ondes de compression et de cisaillement ainsi que des inversions tomographiques de zones de faille dans des terrains métamorphiques obtenues à l’occasion du creusement du tunnel de base du Gothard, dans les alpes centrales.

Jan 1, 2003

Mr R.D. Beck attended Felsted School in Essex (England) and the Royal School of Mines, University of London, where he ob¬tained the degree of B.Sc.(Eng.), A.R.S.M. in mineral technology in 1969. His other qualifications include Pr.Eng. (1976), C.Eng (1975), and M.I.M.M. (1975). He joined Gold Fields of South Africa in December 1969, and worked at Doornfontein Gold Mine, Greenside Colliery, West Driefontein Gold Mine, Zwartkloof Fluorspar, Gold Fields Laboratories, Gold Fields Head Office, Libanon Gold Mine, and Kloof Gold Mine before being appointed Plant Superintendent at East Driefontein Gold Mine in January 1973. In June 1976, he was transferred to Head Office as Group Metallurgist, followed, in November 1978, by his secondment to Black Mountain Mineral Development Company as Plant Superintendent, to take on-site responsibilities for staff training, plant commissioning, and start up. On his return to Head Office in July 1980 as Assistant Consulting Metallurgist, he was responsible for Black Mountain and new metallurgical projects. Then, in January 1984, he was appointed General Manager of the Zinc Corporation of South Africa Limited. He became a member of The South African Institute of Mining and Metallurgy in 1973.

Jan 1, 1985

By P. Muthaphuli

Kumba Iron Ore?s Zandrivierspoort (ZRP) magnetite-haematite project aims to mine and beneficiate a magnetite resource with low contaminant levels to produce from 1 Mt/a to 2.5 Mt/a product, which will be either a concentrate, micro-pellets for direct reduction, or blast furnace pellets. Anglo American Technical Solutions Research conducted a number of piloting campaigns to validate the process design flow sheet, demonstrate process performance, and to generate data for use as a design basis. Secondary to this, the pilot plant was to produce approximately 7 t of magnetite-haematite concentrate with low enough SiO2 to be used as feedstock for pelletizing studies. The pilot plant achieved 34.2% mass yield, at 69.0% Fe, 2.2% SiO2, from an IsaMill grind of 80% -45 µm. This product quality will compare favourably to other leading direct reduction (DR) pelletizing concentrates. However, two-stage comminution to 80% -75 µm and beneficiation of ZRP ore will produce a blast furnace (BF) quality pelletizing concentrate, indicative quality being 67.6% Fe and 4% SiO2, at higher mass yields. An economic evaluation between producing a DR and a BF pelletizing concentrate will have to be conducted prior to finalizing the concentrate production flow sheet..

Jan 1, 2014

By F. M. L. Mulaudzi

Behaviour studies of metal dusting processes and associated filamentous carbon formation were undertaken on Alloys 600, 601, and 800 using a simulated metal dusting environment of 25C0-70H2-5H20 (vol.%) at 650°C. These samples were studied visually and by optical microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDX) and x-ray diffraction (XRD). Visual examination and SEM surface observation showed that Alloy 800 suffered metal dusting attack at an early exposure reaction period. The coke deposit amounts increased significantly with reaction time from 168 hours to 336 hours in Alloys 600, 601, and 800. Alloy 800 showed pitting after 168 hours' exposure, and the degree of pitting increased after 336 hours. XRD showed all these alloys had a common austenitic phase, with Alloy 800 also having ferritic metal particles. Alloy 800 after 168 hours' exposure had a complex phase mixture on the surface, consisting of ferritic Fe and austenitic FeNi phases. For coke deposit, there were also Fe304, Fe3C and graphitic carbon. The existence of Fe, Ni, and Cr metal particles, and also graphitic carbon in coke deposits, was confirmed by EDX analyses.

Jan 1, 2013

By E. Van Der Lingen

This paper provides a review on coloured gold, platinum, andpalladium intermetallic compounds, and discusses the models thatwere developed to obtain these materials. These compounds have acrystal structure of high symmetry, such as the CaF2or CsClstructures, ensuring distinct electron band structures. Variousexamples of coloured gold, platinum, and palladium intermetalliccompounds are provided. More in-depth discussion is provided on thepurple gold (AuAl2) and yellow platinum-aluminium (PtAl2)compounds with CaF2structure, as well as the purplish-pinkpalladium-indium (PdIn) compound with CsCl structure. Precious metal intermetallic compounds are used in jewellery andprovide a new dimension to design. Some of these compounds havealso found use as barrier coatings on turbine blades for jet engines,and more recently, research has been conducted into their potentialuse as catalysts, electro-catalysts, sensors, capacitors, and fordecorative coatings.

Jan 1, 2014

By Dave Deglon, Andrévan der Westhuizen

Objectives ?Survey typical Met Accounting streams at the Zincor refinery ?Determine Precision in Metal Conc?s Measurements for Monthly Met Balance ?Determine the Components of Variance in these Met Acc Values (Sampling, Preparation, Analyses) ??Common plant practice? should be mirrored even though not always in perfect agreement with ?laid down procedures? or ?good practice? ?Mass Measurement and Inventory Measurement was considered in less detail ?not reported here

Jan 1, 2005

By M. Grave

Rock Engineers are required to design safe cost effective support systems and stoping layouts for their respective mines. As each stope has its own unique environment, continual re evaluation is required in all stopes to maximize extraction and achieve value from the support standard. This paper presents numerical modelling used to plan early mining within the shaft pillar and a reevaluation of an existing stope support standard.

Jan 1, 2009

By R. Ajalloian, L. Karimzadeh

This paper describes the engineering properties of Givi dam foundation. Givi dam will be built across the Givi River on the andesitic rocks (Karaj formation) in Ardabil province (northeast of Iran). Geotechnical investigations including drilling, pumping tests, sampling for laboratory testing and discontinuity survey. Physical and mechanical properties of andesitic rocks such as density, water absorption, porosity, uniaxial compressive strength, triaxial compressive strength, durability and direct shear tests are evaluated in this paper. Discontinuity data are process for the determination of dominant sets and for the rock mass characterization in terms of classification systems ( RMR, Q and RSR ). Correlations between these three classifications are discussed. Le barrage doit être construit sur la rivi_re givi qui cou_e sur les andesites (formation de Karaj)dans la province d_ Ardebile situee_ a Nord- Ouest de l_ _Iran. Les études géophsique commesondage, Pompage. Et échantillonnage afin de verifier les discontinutés out éte_ effectuées. Lesproprietés physique et méchanique des roches andesifique ont éte_ verifieés. Les informations concernaüt aux discontinuitiés afin de montrer leur principale direction ont éte_ verifieés, les proprietés des roches dans leurs ensemble ont éte_ etudieés. Les divers classifications(RMR,Q,RSR ) ont éte_ comparés et analyseés. Dieses Schreiben ist zur Erklaerung der Ingenieureigenschaften ueber Baugrund des Givi Deiches.Dieser Deich soll im Givi fluss auf Andesitgesteine (Karaj formation) gebaut werden. Der platzdes Deiches legit im Ardebil Provinz nordwestlich von Iran. Geotechnische Untersuchungen Sind:Bohrungen, pumpen Versuche, Probenentnahme fuer Laborversuche, BrechbarkeitBestimmungen, physikalische und mechanische Eigenschaften der Andesitgesteine wurde hierausgewertet, wie Z.B.: Wasserleitfahigkeit, Porositaet, Scherfestigketswiderstand, Informationenueber Brechbarkeiten der Gesteine wurde gesamelt, und die meisten Brechbarkeiten bestimdamitman die Gesteine besser klassifizieren kann. In Endefekt wrid die Resultate verschiedeneKlassifizierung wie RMR, Q, und RSR besser geachtet und zusammen vergliechen.

Jan 1, 2003

By C. -I. Lee

Since the early 1970s, Korea has constructed many large-scale tunnels and underground storage caverns in response to the rapid industrial development. The rock mechanics engineers have accumulated valuable experiences in the area of underground space technologies. But they still face technical challenges in environmental and safety aspects. To discuss those challenges in Korea, a brief engineering description of underground space projects including oil and gas storage, food storage, pumped storage power plant, transportation tunnels, waterway tunnels, and radioactive waste disposal is presented. Mechanical and hydrological stability analyses of the storage caverns in Korea are also introduced. Depuis le début des années soixante-dix, le développement industriel rapide en Corée a entraîné la construction de nombreuses galeries et cavernes de stockage souterraines. Les ingénieurs de mécanique minière ont donc accumulé des expériences précieuses dans le domaine de la technologie de l’espace souterrain. Cependant, ils font toujours face à de nombreux défis techniques en ce qui concerne les aspects de l’environnement et de la sécurité. Pour présenter ces défis en Corée, l’étude présente décrit les projets d’espace souterrain, y compris le stockage de pétrole et de gaz, de nourriture, centrales de stockage pompé, tunnels de transport, tunnels navigables, et évacuation des déchets radioactifs. Des analyses de stabilité mécanique et hydrologique des cavernes de stockage en Corée sont aussi présentées. Seit Anfang der 70er-Jahre, baute Korea in Folge raschen Industriewachstums viele lange Tunnelsund unterirdische Lagerungsräume. Fachkräfte im Bereich Gesteinsmechanik sammeltenwertvolle Erfahrungen über unterirdische Raumtechnologien. Dennoch stehen sie auch heute nochvor technischen Herausforderungen im Bereich Umweltschutz und Sicherheit. Zur Erläuterungdieser Herausforderungen in Korea folgt eine kurze technische Beschreibung der Projekte zurSchaffung unterirdischen Raumes für beispielsweise Öl- und Gaslagerung,Nahrungsmittellagerung, Pumpspeicherwerke, Straßen- und Wasserstraßentunnels, als auchLagerung radioaktiven Mülls. Mechanische und hydrologische Stabilitätsanalysen derLagerungsräume in Korea werden ebenfalls dargestellt.

Jan 1, 2003

By C. Righi, R. Carli

In modern steel continuous casting technologies mould fluxes are well-known to assure lubrication required by tribological system of mould-solidifying strand shell, and to provide crystalline phase solid film, contributing to control heat extraction between strand and mould wall. Actual cooling rates during normal continuous casting mould operations are far higher than critical cooling rate of the liquid slag. Indeed, DTA measurements point out that even relatively small cooling rates of 30?50 K/min are high enough to give exiguous formation of crystals. In this paper, contribution of devitrification in defining crystalline phase formation of industrial basic mould slag, used in continuous casting of crack-sensitive steel grades, has been investigated by means of non-isothermal experiments study. Devitrification has proved to play a major role in mould flux crystallization in a working environment explaining the higher amount of crystalline phase formed in plant sample in comparison with lab sample from DTA analysis with typical cooling rate of 5?20 K/min. The amount of crystalline phases formed ranks as follow: Cuspidine > Combeite > Gehlenite. Kinetic analysis of DTA non-isothermal experiments has provided kinetic parameters through Kissinger and Ozawa methods, as Avrami constant resulting to be n ?2 and activation energy of Cuspidine crystallization resulting to be EC= 315 kJ/mole. The effect of addition to the parent material of oxides as MnO, TiO2, ZrO2, Al2O3 and Fe2O3near to saturation point has proved to affect, in certain cases, crystallization behaviour of mold flux. In particular, MnO, TiO2, ZrO2oxides produce a relevant dump of crystallization of Combeite and Gehlenite phases, while Al2O3and Fe2O3do not appreciably affect crystallization. Key words: Mould flux, crystallization, devetrification, DTA non-isothermal analysis, Kissinger and Ozawa methods.

Jan 1, 2004

Professor N. S. Budavari holds a Dip!. Min. Eng. from the Technical University of Sopr on, Hungary, and a Ph.D. degree from the University of Newcastle-upon-Tyne, U.K. Mr J. J. Geldenhuys, Pr. Eng., is Divisional Manager Mining of Anglovaal Limited, being in charge of Prieska Copper Mines (Pty) Limited, Loraine Gold Mines, Limited, and Village Main Reef Gold Mining Company Limited.

Jan 1, 1983

By N. F. Mescheriakov

New mechanical and pneumatic-mechanical flotation machines with axial impellers have been developed. Industrial tests show that these machines ensure lower power expenditure (on flotation) by 1.5-2.0 times as compared with reference machines (with the same or improved technological indices). Application of the newly developed axial impeller, with these advantages, is possible in any volume chambers of type OK, Dorr-Oliver, Wemko etc.

Jan 1, 1998

By G. J. McTeer, D. J. Rioux

Teck Metals Ltd operates an integrated zinc-lead complex at Trail, British Columbia, Canada. Since 1997, KIVCETTM flash smelting technology has been utilized for the treatment of zinc plant residues and lead concentrates. Trail Operations’ furnace uses four water-cooled jackets for bullion tapping. This paper provides an overview of KIVCET bullion tapping for the past 16 years, and discusses successes and challenges encountered with respect to operations, training, and monitoring.

Jan 1, 2014

By J. F. Shao, G. Duveau, W. Z. Chen, O. Ozanam

In this paper, we present a sensitivity study for the numerical modelling of hydromechanical coupling around a shaft in partially saturated claystone. Two representative constitutive models have been used: an elastoplastic damage model (IDEPLML) and an elastic perfect plastic model based on the Hoek and Brown failure criterion (H&B). A series of comparative studies have been performed with respect to main parameters involved in coupling process (mechanical, hydraulic and hydric properties). The emphasis is put on the evaluation of induced plastic, damaged and failed zone due to excavation and drying process. Dans ce papier, nous présentons une étude numérique paramétrique du comportement hydromécanique couplé d’une argilite partiellement saturé, lors du creusement et de la maintenance d’un puit L’étude paramétrique porte à la fois sur le type de modèle et sur les principaux paramètres (mécaniques hydrauliques et hydriques) intervenant dans le couplage. L’accent est principalement porté sur l’évaluation des zones plastifiées autour de l’ouvrage lors de la désaturation. In unserem Beitrag geht es um eine digitale parametrische Untersuchung über das hydromechanische Verhalten eines teilweise durchtränkten Tons beim Abteufen und dem Betrieb von Schächten. Die parametrische Analyse konzentriert sich auf den Modelltypus und auf die wesentlichen bei der Verbindung wirksamen Parameter, d.h. die mechanischen, hydraulischen und hydrologischen. Der Schwerpunkt liegt auf der Bewährung der plastifizierten Bereiche des Bauwerkes während der Austrocknung.

Jan 1, 2003

1. Journals Quarterly Journal of tke International Tin Research Institute, edited by Colin J. Evans and published by the Institute, Fraser Road, Greenford, Middlesex UB6, 7AQ, England. Engineering, building and construction law review, edited by P. C. Loots and published every two months by Construction Law Review (pty) Ltd (P.O. Box 78020, Sandton 2146, Transvaal), R63,00 per year. 2. Publications of the Mineral Policy Sector Nepkeline syenite and feldspar by B. W. Boyd Potask by G. S. Barry Selenium and tellurium by D. A. Cranstone Sodium sulphate by G. S. Barry Tungsten byG. G. Law-West 3. Mintek reports Report M114 Analytical methods associated with the recovery of uran~um. Report M117 An assessment of tke merits of various types of balls in tke milling of ores. Report MU1 Tke determinatl:on of trace elements in coal by atomic

Jan 1, 1983

1. New books from The Institute of Metals Physical and elastic characterisation, edited by M. McLean. 1989. 228 pp. £25.00.High nitrogen steels, edited by J. Foct and A. Hendry. 1989. 461 pp. £49.50. Proceedings of the First International Calcium Treatment Symposium. 1988. 116 pp. £15.Design for recyc/ability, by Michael E. Henstock. 1988. 150 pp. £15. Solidification processing. 1988. 549 pp. £45.Proceedings of the First International Calcium Treatment Symposium. 1988. 116 pp. £15.Marine engineering with copper-nickel. 1988. 103 pp. £18.Sir Henry Bessemer: An autobiography. 1989.380 pp. £16.95. 2. Other publishers Occupational safety and accident prevention. Behavioural strategies and methods, by C.G. Hoyos and B.M. Zimolong. Amsterdam, Elsevier, 1988. 218 pp. Dfl. 180.00. Algorithms in real algebraic geometry, edited by Denis S. Arnon and Bruno Buchberger. London, Academic Press, 1988. 274 pp. £15.95.

Jan 1, 1989