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By Y. F. Bulgakov, Y. V. Melnikova, V. S. Zakharov

A new technology of atmosphere in inertization of fire section with the help of gazeous nitrogen is presented in the report. This technology is based on membrane air subdivision into two streams, concentrated with nitrogen (up to 99%) and with oxygen correspondently with subsequent giving them into the place of fire. This technology belongs to environmentally friendly ones and it has a great number of technical, mobile and economic advantages comparing with the rest of well-known methods of fire extinguishing. This technology application in Ukrainian coal mines allowed to reduce the member of isolated places of fire at the expense of their extinguishing efficiency.

Jan 1, 2003

By R. Romano, E. Montalar, J. B. Serón

The SMR geomechanics classification system (adaptation of RMR for slopes) is reviewed with data from 87 actual slopes in Valencia. In a research project, SMR has been applied by a GIS system, as a method to forecast stability problems in future road construction. As a result of this work a methodology for GIS application has been developed. On revient sur la classification geomechanique SMR ( une adaptation du RMR pour talus et pentes) avec les dates de 87 talus existant autour de Valencia. Dans le cadre d’un projet de recherche SMR a été appliquée, avec un système GIS, comme méthode de prévision de stabilité problèmes dans la construction de futures routes. Une méthodologie pour l’application du GIS a été développe. Das Geomechanische Einteilungssystem SMR (eine Anpassung des RMR an Böschungen) wird an Hand der Daten von 87 Böschungen im Gebiet von Valencia überdacht. In einem Forschungsprojekt wurde das SMR in einem Geographischen Informationssystem (GIS) als Methode zur Vorhersage von Stabilitätsproblemen bei zukünftigen Straßenbauprojekten eingesetzt. Das Ergebnis dieser Arbeit ist die Entwicklung einer Methodologie für die GIS-Anwendung

Jan 1, 2003

The paper deals with the importance of design, and of codes of practice, in ensuring safe working conditions in mines. The design principles involved in the design process are dealt with, and the importance of a logical design process is emphasized. The links between the requirements for developing a code of practice, embodied in the existing guidelines for the preparation of such a code, and the design principles and process are considered in some detail. Finally, suggestions are included which may provide improvements to the code and hence, ultimately, lead to further improvement in safe working conditions.

Jan 1, 2003

By Simon Mundike, Muwindwa Lipalile

A scraper based block cave method has been successfully applied to extract the Lower Ore Body at Nchanga since the 1950?s. Since inception, scraper drifts and service ways have been supported using steel arch sets fabricated to a specific design from high strength manganese steel To reduce costs and to improve productivity, trials commenced in 2002 using fibre reinforced shotcrete as an alternative support method. One of the areas; the 2420 8E 1C trial drift was subjected to abutment loading for several months prior to undercutting and cave mining. Shotcrete installed exhibited minor cracking shortly after application but very little deterioration thereafter. Following the success of the trial, the application of fibre reinforced shotcrete was extended to other drifts. This paper describes the application of fibre reinforced shotcrete at Nchanga and outlines design and quality assurance methods employed.

Jan 1, 2005

Professor R.P. King holds a Ph.D. degree in chemical engineering, which he obtained at the University of Manchester in 1963. After that he lectured in the Departments of Chemical Engineering at the Universities of the Witwatersrand and Natal. From 1968 to 1973, he was Leader of the Chemical Engineering Research Group of the National Institute for Metallurgy at the latter University. Mr C.E. Fivaz, Pr. Eng., is Chief Consulting Metallurgist of Rand Mines (Mining & Services) Limited, and is responsible for the metallurgical activities of the Gold and Uranium Division and the Coal and Base Minerals Division of the Group.

Jan 1, 1984

By S. G. Gendler

One of the ways of trauma and occupational diseases level reduction is noted to be the improvement of the labour protection measures planning. As an indicator for prospective trends determination in the labour protection planning improvement sphere economic risk has been proposed to be used. The trauma and occupational diseases analysis based on the correlative and regressive methods has been carried out for the “Vorgashorskaya” mine of Pechora coal basin. Trauma and occupational diseases occurrences frequency and economic losses value have been estimated. Trauma and occupational diseases economic risk distribution analysis has been presented in respect to the different subdivisions and occupational groups of “Vorgashorskaya” mine.

Jan 1, 2003

By A. K. Das, S. Pathak, C. Bhanu, P. K. Tripathy

Ferroalloys are integral part of steel melting process. The purpose of using ferroalloys is three fold e.g. killing of steel, modifying the slag composition and steel alloying. Amount of ferroalloys used for alloying is subject to requirements of steel properties e.g. yield strength, ductility, formability etc. Variety of ferroalloys (some-times pure metal) is used by steel industries depending upon their techno-economic feasibility. Size, chemistry and modes of addition of ferroalloys are suitably engineered to bring in operational consistency and cost benefits. Of late, Tata Steel has tried out a few ferroalloys for the first time with interesting results to meet the specific requirements of high strength interstitial free (IF) and micro-alloyed steels. Some of these ferroalloys have been put into regular use with complete or partial replacement of ferroalloys used earlier. Size of one of the ferroalloys has also been modified without any other adverse effects. This paper summarizes requirements of ferroalloys for the steel industry with special emphasis on recent trials.

Jan 1, 2007

INTRODUCTION This paper was originally presented at the Platinum Adding Value Conference, held at Sun City from the 4th to 6th October 2004. Narrow reef mining may not be applicable to the base metal operations in Zambia, however, it is considered that the methodology used is equally appropriate to the development of technology and mining methods in mining environments other than narrow reef mining. The purpose of this paper is to explore the integration of technology and stoping systems. For the last hundred years the South African narrow reef mining industry has battled to control working costs in a labour intensive industry. It is only through the application of appropriate technology that change will occur. Stoping systems, because it is the stoping method and methodology that is at the heart of the mining system. Introduce a different technology that results in a more efficient stoping system and the mining system will look after itself. The technology applied to stoping in narrow reef mining, over the last 100 years, can be categorised as follows: ? The introduction of pneumatic rockdrills early this century. The cumbersome rig mounted units being replaced by smaller, lighter, hand held units that were then made easier to use with the addition of an air leg. (The so called Swedish method of mining.) As late as the early 1970s some drilling was still being carried out without the assistance of an air leg. ? Scraper winches to replace gravity and shovels to move rock both in the face and the gullies were first introduced in the late 1920s. ? Hydraulic props installed close to the face and capable of applying force against the hangingwall as well as yielding in a controlled manner under dynamic load arrived in the 1960s. In many instances these have now been replaced by yielding elongates fitted with water hydraulic tensioning devices. ? Some people argue that the introduction of tungsten carbide inserts, to improve drilling, was equally important.

Jan 1, 2005

By Li. S., C. Sili

Abstract. Study on nonlinear damage localization process of rocks under water chemical corrosion is a more interesting topic in rock mechanics research world widely. It is very important in estimating long term stability of rock engineering, design of nuclear waste repository and its performance estimation, geothermal and petroleum development. This paper reports that new development of study on the topic, including methodology, results of meso-mechanical test, real-time CT scan test and acoustic emission test, temporal fractal behaviors, neural dynamic modeling and chemical-induced damage law, etc. This paper also discusses the research directions of the topic in the near future. Zusammenfassung. Untersuchung zum durch die chemische Corrosion induzierten Schaedigungsprozess ist einer der Trends im Gebiet der Felsmechanik. Sie ist zugleich ein sehr wichtiges Forschungsprojekt u.a. fuer geotechnische Langzeitstabilitaetsanalyse, Langzeitsicherheit eines Endlagers, Erdwaerme- und Erdoelfoerderung. Dieser Aufsatz stellt die neusten Entwicklungen in den folgenden Teilgebieten zusammen: Untersuchungsmethoden, Laborversuchsergebnisse der Mikromechanik, der Computer-Tomographie und der akustischen Emission, zeitabhaengige Fraktaleigenschaften, Modelle fuer die Nervendynamik sowie Modelle fuer chemie-induzierte Schaedigungen. Zum Schluss werden kuenftige Forschungsschwerpunkte bzw. –richtungen diskutiert. Résumé L’étude du processus de la localisation de l’endommagement du à l’érosion chimique est un thème d’actualité pour la mécanique des roches. Elle est également un sujet de recherche d’importance dans l’évaluation de la stabilité à long terme des ouvrages rocheux, l’analyse du system de stockage des déchets nucléaires et l’évaluation de son comportement, l’exploitation de l’énergie thermique et pétrolifère, etc. Cet article présente le développement actuel dans ce domaine, incluant la méthodologie d’étude sur le processus de la localisation de l’endommagement dû à l’érosion chimique, l’analyse des essais mécaniques avec l’observation microscopique, du balayage en temps réel (CT), et de l’émission acoustique. On aborde ainsi modèle des caractéristiques fractural du temps, le modèle de la mécanique dynamique neural, ainsi que la loi de comportement d’endommagement dû à l’effet chimique. Enfin, les perspectives relatives à ces études sont présentées et discutées.

Jan 1, 2003

By V. Velicka, J. Ptacek, R. Snuparek, P. Konecny, G. Takla

Coal mining in Ostrava-Karvina coalfield is being accompanied by rockbursts. 82 rockbursts occurred within the period between 1990 and 2002. Natural and technological factors from these rockbursts were collected and analysed. They confirmed that rockbursts are complex geomechanical events and that the relations between co-acting technological and natural factors are very complicated. Der Abbau in dem Ostrava-Karvina Steinkohlenrevier wurde von Anfang an durch Gebirgsschläge begleitet. 82 Gebirgsschläge in dem Zeitabshnitt von 1990 bis 2002 erfolgten. Die Angaben über natürliche und technische Faktoren der Gebirgsschläge wurden gesammelt und analysiert. Es wurde bestätigt, dass die Gebirgsschläge komplexe geomechanische Phänomene sind und dass die Beziehungen zwischen den zusammenwirkenden Faktoren sehr kompliziert sind. L´abattage d´houille dans le Bassin houiller d´Ostrava-Karvina est accompagnée par les coups de terrains. 82 coups de terrains s´étaient produit dans la période entre 1990-2002. Les données sur les facteurs naturels et techniques ont été ramassées et analysées. Les résultats ont corroboré que les coups de terrains sont des phénomènes géoméchaniques complexes. Les relations entre les facteurs techniques et naturels coopérants sont très compliqués.

Jan 1, 2003

By Christian Heili

In 1991 the Government of the Republic of Zambia passed legislation providing for the privatisation of Zambia Consolidated Copper Mines Limited (ZCCM). The newly formed Mining Companies, established after nearly a decade of difficult and protracted negotiations on such matters as, cash at close; retained percentage interest by ZCCM; equity investment; future investment commitment and tax concessions, were faced with great internal challenges and a harsh external environment. There was a convergence of a number of negative forces that had and will continue to have an impact on the mining environment in Zambia. The most crucial of these being, the competitive pressures of the global economy, fluctuating copper price and the prevailing HIV/AIDS pandemic. In the short period after privatisation, the Industry has seen the collapse of Binani Industries (Luanshya Mine), the withdrawal of Anglo America Corporation from Konkola Copper Mines Plc and the disposal of Chambishi Cobalt and Acid Plants by Anglovaal Mining Ltd. The objective of this paper is to provide a theoretical and practically researched foundation, which may be used to assist Zambian Mining Companies in making informed decisions on the issue of Strategic Outsourcing and the degree to which this may support the successful and sustainable growth of the Zambian Copper Mining Industry. If judiciously implemented, Strategic Outsourcing has the potential to generate a practical business valuation and process to assist Mine Management in the achievement of their business goals and consequently the return on investment to their Shareholders.

Jan 1, 2005

By V. Labiouse, B. Heidenreich

The rebound phenomenon, which occurs during rockfalls when a rock block impacts with a slope surface, is influenced by several parameters related not only to the slope material but also to the block and the kinematics. The paper presents a small-scale testing campaign undertaken at the LMR (EPFL) to better understand and quantify the bouncing of blocks on granular slopes. The influence of some factors related to the ground material, the block and the kinematics is examined. Bei Steinschlägen wird die Flugbahn eines stürzenden Felsbrockens maßgeblich durch den Abprall vom Hang bestimmt. Der Rückprall hängt von verschiedenen Parametern ab, wobei nicht nur das Hangmaterial sondern auch Blockeigenschaften und Kinematik eine große Rolle spielen. Zum besseren Verständnis dieses Phänomens und seiner Quantifizierung werden am LMR (EPFL) kleinmaßstäbliche Versuchskampagnen auf granulären Materialien durchgeführt. Der vorliegende Artikel stellt die Versuche vor und untersucht den Einfluss verschiedener Boden-, Block- und kinematischer Parameter. Le phénomène de rebond qui se présente lors de l’impact d’un bloc rocheux sur la surface d’un versant dépend non seulement des caractéristiques du terrain, mais aussi de facteurs relatifs au bloc et à la cinématique. L’article présente une campagne d’essais sur modèle réduit entreprise au LMR (EPFL) afin de mieux comprendre et quantifier l’impact de blocs sur des matériaux granulaires. L’influence de divers paramètres relatifs au sol, au bloc et à la cinématique est mise en évidence.

Jan 1, 2003

By B. S. Spottiswoode

Lack of visibility makes it difficult for continuous miner (CM) operators to judge the desired sump depth. The resulting inaccuracies have proven to lead to significant production losses. This problem of measuring the depth of sump has been addressed in the past and a few measurement techniques have evolved. Despite various attempts, a suitable commercial depth of sump sensor does not yet exist. A system using the Doppler effect has been patented, developed and successfully tested. The method is non-intrusive and involves a beam of microwaves being projected obliquely at the roof. The received signal is analysed with respect to the transmitted signal, yielding the desired measure of displacement. Surface tests have revealed an accuracy of a few centimetres. Underground simulation tests on a load haulage dump (LHD) machine have verified the repeatability under the harsh conditions of interest. The system is presently being installed on a CM where it is to undergo a long-term performance evaluation. This paper presents the theory behind such a system, the hardware developed, the signal processing requirements and an analysis of the test results.

Sep 1, 2001

By Frank Johnson

Between 2000 and 2006, platinum production from the South African mines expanded from 206 to 307 tonnes (DME, 2007). Most of this additional metal has come from traditional ?narrow? reef stoping, generally taken to mean stoping in working places with a mining height of less than 1,5 metres. It is well known that narrow-reef stoping presents safety, technological and ergonometric challenges (Pickering, 2007). In planning for the expansion, which is still continuing, the platinum mining industry realized that it could not simply continue with traditional methods of narrow-reef mining. Particular issues identified were: ? High labour-intensivity: caused by use of hand-held rock drilling machines, labour-intensive support installation and stope cleaning; ? Dependence on rock-drillers: this occupation is no longer an attractive one and there is a reducing flow of new recruits; ? Safety: most of the work is performed close to the new faces, where there is the greatest exposure to the hazards of falling rock.

Jan 1, 2008

By X. J. Lyu, Q. Liu, M. J. Lian, X. Q. Cao, X. F. You, B. O. Erdenekhuyag, H. Y. Zang

The slag-tailings based artificial reef concrete (ARC) is made of CaO-CaSO4 activated granulated blast furnace slag (GBFS) as cementitious material and deslimed gold ore tailings as aggregate. In order to investigate the potential application of the material as ARC, the strength development, hydration characteristics and application performance were investigated under different preparation conditions. Results indicated that using seawater as the mixing water can effectively promote the hydration of slag and generate a large amount of hydration products such as ettringite, CSH gel, hydrotalcite and Friedel ’s salt in the early curing period and so render the material with good early compressive strength. Seawater curing can also accelerate the hydration reaction in the early stage of hydration. The hydration reaction of slag and the compressive strength of ARC can be effectively promoted by increasing the specific surface area of slag. The 28-day compressive strength of the slag-tailings based ARC prepared with 30-50% CaO-CaSO4 activated slag and 50-70% tailings can reach to 19.88-42.87 MPa. Also, the material has a low surface pH value, good resistance to chloride ion penetration, and sulfate corrosion. Keywords: Artificial reef concrete, granulated blast furnace slag, deslimed gold ore tailings, compressive strength, hydration characteristics

Jan 1, 2020

The first annual student prizegiving function of the South African Institute of Mining and Metallurgy was held in the Dorothy Susskind Auditorium, University of the Witwatersrand, on Thursday, 26th May, 1977. The address (see opposite page) was given by Dr M. G. Atmore, a director of Anglo American Corporation and Vice-President of the Institute.

Jan 1, 1977

By H. Wagner

During the last few years a large number of pillars in different mines were investigated. Pillar conditions were evaluated using subjective, empirical, geophysical and numerical methods. A critical comparison of the different methods showed some interesting coherence. This paper concentrates on experiences using the p-wave velocities as an indicator of pillar conditions. Während den letzten Jahren wurde eine große Anzahl von Bergfesten in verschiedenen Bergwerken auf ihren Zustand hin untersucht. Hierzu wurden subjektive, empirische, geophysikalische sowie numerische Methoden angewandt. Dieser Vortrag beschäftigt sich mit den Erfahrungen beim Einsatz der p-Wellengeschwindigkeit zur Beschreibung des Festenzustandes. Le condition géotechnique d’une grand nombre des piliers des mines souterraines différentes sont examinées ces dernières années. On a appliqué des méthodes subjectives, empiriques, géophysiques et numériques. Ce rapport occupe aux expériences avec l’application de la vélocité des ondes de compression pour tracer le condition des piliers.

Jan 1, 2003

By G. Wu, S. Liu

In view of the singleness of traditional methods about international petroleum (Brant) price forecast, ten main factors that affect international petroleum price are fully analysed. Based on time series method and multivariate linear regression method, the simulation model with the theory and idea of system simulation is firstly established. And this forecasting system realizes visual operation under the environment of MATLAB/SIMULINK. So this article tries a new way for further exploring petroleum price’s running law and guiding its forecasting practice. Keywords: Petroleum price forecast, system simulation, residual error, physical flows information flows

Jan 1, 2003

By T. C. Alex, K. M. Godiwalla, R. K. Jana

Manganese nodule, available in ocean beds, is a potential resource of the future for copper, nickel and cobalt. Recovering only these metals, containing less than 3% by weight, will result in the generation of large amount of residue. In addition to the material losses, several environmental and ecological problems arise out of this. The present study has been aimed at reducing the environmental and ecological problems associated with massive generation of this residue together with utilization of the resources. Presence of ~ 20% manganese and ~16% silicon in the residue has prompted us to check its suitability as a raw material for silicomanganese production. Lower manganese content and lower Mn/Fe ratio of the residue than that required for silicomanganese production has been corrected in this study by suitable blending. The efficacy of blending and its thermodynamic aspects using FACTSAGE software are discussed. The studies conducted indicate viability of bulk utilisation of the residue through silicomanganese production and thereby reducing the burden on environment to a great extent.

Jan 1, 2007

By I. V. Lunkin, E. B. Muhamedzhanov, A. B. Begalinov, B. R. Rakishev

Almost all the ore deposits of ferrous, non-ferrous and rare metals of Kazakstan, are exploiting by the open-cast method, are the complex-structural, multi-component ones. Their rational working requires precise organization of extracting works. In this connection it is necessary to set up the best intercommunications between drilling-blasting, excavating-loading and transport works. This requires the stable functioning of the quarry for dispatch of ore raw material of required quality with minimum of corresponding expenses. For this purpose, proceeding from the quarry’s ore output and the assumed parameters of the exploitation system, the first problem about rational arrangement of excavating-loading equipment in extracting faces is solved. By solving the problem the model with dynamic, adapting properties had been used. It was solved numerically by the method of statistical tests. By setting up the necessary link between type-sizes of excavating-loading and transport equipment, the minimum prime cost of loading and transportation of 1 ton of mining mass from the face to the receiving station was adopted as the criterion of optimality. Depending on the type of excavating-loading equipment, the efficiency function may be different. By using wheel loaders, their displacement between the faces is possible, therefore, the efficiency function of the problem may include expenses for their displacement. By using excavators like power shovel, the problem’s restrictions must exclude its displacement between the faces. The efficiency function consists of minimum expenses for loading, proceeding from set of volumes of extraction from the faces, satisfying required quality. The volumes of extraction from the faces, satisfying required quality of ore in output stream, are determined by the method of statistical tests. Sample range is given, proceeding from the restrictions for maximum productivity of the excavating-loading equipment. Volumes of extraction, not satisfying required quality, are cut off. The efficiency function meaning is then determined and minimized. Keywords: Excavating-loading equipment, its placing in extracting faces, optimal load-carrying capacity, specific expenses for loading and transportation of mining mass.

Jan 1, 2003