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By J. M. Benson

Metal powder compaction offers unique advantages in the manufacture of net-shape components using techniques such as laser sintering, conventional press and sintering, metal injection moulding, direct rolling, direct forging, and hot isostatic pressing. If the output from the primary metal production process is in powder form, then considerable cost and energy savings can be realized by direct conversion to semi-finished or final shapes. This possibility exists for titanium and possibly also for Ta, Zr, Hf, and Nb metals. However, these attractive benefits are associated with some significant risks. The high surface-to-volume ratio of powder particles coupled with the reactive nature of these metals means that special care must be taken when handling them. Powder explosions are unfortunately still a regular occurrence internationally and these often result in serious injury and loss of life. Even seemingly 'safe' compounds such as sugar, flour, and grain can be extremely hazardous when handled or milled and dust clouds are produced. In addition, exposure to airborne particles can have adverse effects on the human body, especially when particles are inhaled on a regular basis. Furthermore, the medical consequences of these are not fully understood, especially in the case of nanoparticles. The impact is often not observed immediately and debilitating illnesses may emerge only years or decades later. As far as is known, there are no South African guidelines for handling of metal powders. This paper attempts to provide an awareness of the risks associated with metal powders (including those produced indirectly by other metalworking/finishing operations) as well as some guidelines for their safe handling, based on international best practices.

Jan 1, 2012

By M. Reuter, U. Boin

The target of the current metallurgical industry is to recycle and utilize all their by-products, so as to close the sustainable production loop. Slags are the important wastes and by-products of metallurgical industry, which have been treated, recycled and used worldwide. The present paper summarizes the current status of utilization of the various slags from ferrous and non-ferrous metal production, as well as waste incineration, and recycling of salt fluxes in secondary metal production. In addition, the environmental issues of the metallurgical slags are addressed. The metallurgical oxide slags have stone-like properties and, thus, their major applications are in civil engineering field. The slags should be recycled, modified and processed in a proper way, by taking the environmental impact into consideration. With the treatment of salt slags for melting aluminium scraps, as an example, the recycling and elution properties of the salt slags are discussed. Our research indicates that the viscosity of the salt flux is increased with addition of non-metallic components, that a certain percentage of fines remain in suspension, which determines the viscosity, affecting the settling of heavier materials. High slag viscosity will lead to more fine aluminium metal entrapped in the salt slag (may also be seen as a high temperature slurry), and thus increase the load of salt slag recycling. Keywords: recycling, environment, metallurgy, slags, fluxes, salts.

Jan 1, 2004

By Simon St J Tose

The objective of this paper and presentation is to review the different criteria and methodology used by AEL and other organisations to create a pre-split design which delivers a stable highwall for the life of that part of the mining operation. It will look at the need to adapt and change the way, size and direction of the production blasts as the mining phase approaches the highwall position for which a pre-split has been created. Key Words: Pre-split: Design; Highwall; Perimeter

Jan 1, 2006

By S. Fletcher, C. Calle, K. Constanti-Carey, R. Ruzbacky, M. D. Horne

Laboratory test-work has established that two classes of redox catalysts based on anthraquinone and bipyridinium derivatives are effective in accelerating the rate of removal of metallic iron from reduced ilmenite (RI) in the aeration step of the Becher process. Two water-soluble anthraquinone derivatives are efficient: 9,10-anthraquinone-2,6-disulfonicacid, disodium salt (catalyst AQ-2,6) and 9,10-anthraquinone-2-sulfonic acid, monosodium salt(catalyst AQ-2). When 0.2 per cent w/v of either was added during aeration the rate of metalliciron removal was accelerated by two to three times. Furthermore, the addition of either compound resulted in magnetite (Fe3O4), the iron oxide phase preferred in commercial practice, being formed. However, both AQ-2,6 and AQ-2 were rapidly lost from solution during aeration although their catalytic activities persisted even when their concentrations in solution were low(<0.05 per cent w/v). The negatively charged anthraquinones were lost from solution most probably by adsorption onto the magnetite that has a net positive charge at the pH values encountered during aeration. To address this problem, the catalytic activities of positively charged bipryridinium derivatives were tested. Two water-soluble bipyridinium compounds, paraquat (1,1’-dimethyl-4,4’-bipyridinium dichloride) and diquat (6,7 dihydrodipyrido [1,2-a:2’,1’-c] pyrazinediiumdibromide), were found to significantly accelerate the rate of removal of metallic iron from reduced ilmenite, and both gave magnetite as the oxide product in the laboratory tests. Moreover, recycle tests showed they were not lost from solution as quickly as were the anthraquinone derivatives. Results in larger scale plant laboratory reactors also showed a significant increase in aerationrates when diquat was added and magnetite was again the oxide formed. However, the oxygensupply to the reactors was insufficient to achieve the maximum effect of the catalysts on theaeration rates. The limited supply of oxygen in a full scale aerator may prevent the application ofthe catalysts in a commercial Becher operation. Keywords: Becher process, aeration, anthraquinone, bipyridinium, redox catalyst, reduced ilmenite

Jan 1, 2003

Historically, mine ventilation practices as it was referred to then and which was enforced by legislation of those days, focused primarily on the conditions in the working place and little attention given to actual exposures of workers to contaminants in the working environments. With the advent of the Leon Commission of Inquiry into Safety and Health in the South African Mining industry in 1994, findings in the report indicated that more attention should be given to occupational health of workers. The upshot of this report resulted in the promulgation of the new Mine Health and Safety Act (MHSA) with certain sections of it devoted to all the aspects of occupational medicine and occupational hygiene. This paper describes the present situation with regards to statistics on occupational hygiene performance and compensation paid out to persons who have contracted occupational diseases, as well as the way forward in terms of legislation implemented in September 2002 on the chronic and acute issues affecting the mining industry in SA.

Jan 1, 2003

By C. Tan, C. Detournay

Wellbore stability is a major concern for drilling in naturally fractured formations. The infiltration of drilling mud into the fractures is a factor, which may compromise wellbore integrity due to the loss of strength experienced by the fractures. The reduction in the fracture frictional and cohesive properties is attributed to weakening of the infill materials and lubrication of fracture asperities by the mud filtrate. One way to investigate the influence of mud infiltration on wellbore stability in fractured formations is to use a numerical modeling approach. A requirement for the numerical model is the ability to predict the region of mud infiltration. This paper describes a numerical technique to model the extent of mud infiltration for application in coupled fluid-mechanical simulations in densely fractured rock masses using the computer code, UDEC. Several factors are considered including fracture pattern, in-situ stresses, reduction in joint frictional angle and cohesion, viscosity of the mud filtrate and fracture plugging. Results of numerical simulations are presented to illustrate the technique and show the influence of these factors on the extent of mud infiltration. Un des problèmes importants posés par le forage en milieu fissuré saturé, est celui du maintient de la stabilité du puit. L’infiltration de boue de forage dans le massif peut avoir pour effet de réduire les propriétés frictionnelles et cohésives des fractures et de compromettre ainsi la stabilité du puit de forage. Le radoucissement des propriétés des fractures est attribué à la dégradation du materiau de remplissage et au pouvoir lubrifiant des boues. L’analyse numérique offre un moyen d’investiguer l’influence jouée par l’infiltration de boue sur la stabilité du puit. Un des critères de sélection du modèle numérique sera son pouvoir de prédiction du domaine d’infiltration de boue. Cet article décrit une technique numérique permettant de modéliser l’infiltration de boue de forage dans le cadre de simulations hydro-mécaniques, en milieu à haute densité de fractures, effectuées avec le logiciel de calcul UDEC. Parmis les facteurs tenus en compte, on trouvera la nature du réseau de fractures, les contraintes in-situ, le radoucissement en friction et cohésion des joints, la viscosité de la boue et le bourrage des fractures. Des résultats de simulations sont présentés pour illustrer la technique et montrer l’influence de ces facteurs sur la taille du domaine d’infiltration de boue. Bohrlochstabilität ist ein wichtiger Aspekt für das Bohren in geklüfteten Gebirgsformationen. Das Eindringen der Bohrlochstützflüssigkeit in die Klüfte kann die Bohrlochintegrität wegen des Verlustes der Festigkeit des Kluftsystems gefährden. Die Reduktion der Reibung und kohäsiven Eigenschaften ist der Schwächung der Kluftfüllung und der Schmierwirkung der eingerungenen Stützflüssigkeit in Bezug auf die Kluft-Asperities geschuldet. Numerische Berechnungen sind ein Weg zur Untersuchung des Einflusses der Infiltration der Bohrlochstützflüssigkeit auf die Bohrlochstabilität in geklüfteten Gebirgsformationen. Eine Voraussetzung für numerische Modelle ist die Fähigkeit den Bereich der Infiltration der Stützflüssigkeit zu prognostizieren. Diese Publikation beschreibt ein numerisches Verfahren, um die Reichweite der Infiltration von Stützflüssigkeiten mittels fluid-mechanisch gekoppelter Simulationen im engständig geklüfteten Gebirge mit dem Programm UDEC zu modellieren. Verschiedene Faktoren, wie Kluftmuster, Gebirgsspannungszustand, Reduktion von Kluftreibungswinkel- und kohäsion, Viskosität der Stützflüssigkeit und Rissabdichtung wurden untersucht. Ergebnisse numerischer Simulationen werden präsentiert, um die Vorgehensweise zu illu

Jan 1, 2003

By N. Kinoshita, Y. Inada

The authors have proposed and discussed storage of low temperature materials such as LNG, LPG and frozen food in rock caverns. In this case, as the rock mass around the caverns will receive effects of low temperature, it is necessary to consider the thermal behavior and the stability of caverns. In this study, strength and deformation characteristics obtained by the uniaxial tension test and the compression test at low temperatures were discussed. Using the results, temperature and stress distribution around caverns when LNG was stored, were analyzed. Then thermal behavior of the rock mass around caverns was discussed. Die Autoren haben Lagerung von Niedertemperatur-Materialien wie LNG, LPG und tiefgefrorenen Nahrungsmitteln in Felskavernen vorgeschlagen und diskutiert. Da in diesem Fall die Felsmasse um die Kavernen den Effekten der niedrigen Temperatur ausgesetzt ist, ist es erforderlich, das Thermalverhalten und die Stabilität der Kavernen zu berücksichtigen. In dieser Untersuchung wurden Stärke-und Deformationseigenschaften, die durch ein-axialen Spannungstest und Kompressionstest bei niedrigen Temperaturen erhalten wurden, diskutiert. Mit diesen Ergebnissen wurden Temperatur- und Stressverteilung um die Kavernen bei Lagerung von LNG analysiert. Dann wurde das Thermalverhalten der Felsmasse in der Umgebung der Kavernen diskutiert. Les auteurs proposent et discutent l&apos;entreposage de matériaux à basse température, tels que le GNL, le GPL et des aliments congelés, dans des cavités rocheuses. Comme, dans ce cas, la masse rocheuse entourant la cavité subit les effets des basses températures, il est nécesaire d&apos;étudier le comportement thermique et la stabilité des cavités. Dans cette étude, les auteurs discutent des caractéristiques de résistance et de déformation, obtenues par essai de tension uniaxial et essai de compression à basse température. En se servant des résultats, ils analysent la répartition de la température et des pressions autour des cavités, lors du stockage de GNL. Ils discutent ensuite le comportement thermique de la masse rocheuse autour des cavités.

Jan 1, 2003

By M. Suzuki, T. Shiomi, M. Nakada, K. Tsutsumi

Mold powder plays an important role in the continuous casting process for high quality steel production. It is well known that mold powder entrapment causes surface defects in steel sheet and the high viscosity of mold powder prevents the entrapment of mold powder in molten steel in ultra low carbon steel. This paper deals with the entrapment of mold powder caused by suction by Karman?s vortex in a laboratory experiment. At first the effect of the viscosity of oil and interfacial tension between water and oil was investigated in a water model experiment. Then hot model experiments were carried out by mold powder and molten steel. The amount of mold powder entrapment was affected by the viscosity and the interfacial tension between molten steel and mold powder. As a result, the following equation of the mold powder entrapment was obtained. m=1.06*107?-0.255?m-s-2.18 The amount of mold powder entrapment decreased when the viscosity and interfacial tension increased. But the effect of viscosity was larger than that of interfacial tension in the case of the industrial mold powder when the viscosity was under 0.5 Pa.s, interfacial tension was from 1200to 1300 mN/m.

Jan 1, 2004

By M. Tanaka, K. Aoki, T. Mori, H. Morioka, K. Iwano, T. Kanagawa

To estimate the detailed characteristics of the rock around the cavern during excavation, new monitoring technique for dynamic properties of the rock has been applied. In this paper, micro-seismic monitoring and AE monitoring technique are applied to the excavation of large underground rock cavern and the result was discussed to clarify the acutal behavior of EDZ around the cavern. Zur Einschätzung der Gesteinseigenschaften um die Ausschachtung herum haben die Autoren eine Technik eingesetzt, mit der die physikalischen und dynamischen Änderungen im Gestein um den Schacht während der Ausschachtung beobachtet werden. In der vorliegenden Studie wurde zur mikroseismischen Überwachung ein AE Überwachungsverfahren eingesetzt und die Autoren berichten über die Veränderungen in den Gesteinseigenschaften um die Ausschachtung herum. Dans le but d&apos;évaluer en détail les propriétés des roches qui forment les parois des cavernes creusées, les auteurs ont utilisé une technique de mesure permettant d’observer les modifications physico-dynamiques des roches aux alentours de la caverne pendant son excavation. Dans le cadre de cet article, une technique de surveillance de l’agitation et du bruit microséismiques a été mise en œuvre et les auteurs font état de la modification des propriétés de la roche environnante.

Jan 1, 2003

By R. Zivojinovic, S. Vujic

The structural age of the capital mining machinery, representing a part of the system of the Electric Power Industry of Serbia, has been dictated by the initiation and development of open pit coal mines. For example, the oldest bucket wheel excavators were installed some thirty-four years ago, and the average life of the relevant machinery exceeds twenty-two years. Operation of both capital equipment and machinery has direct effects on economic and business activities of open pit mines, and consequently forced us to make a decision and study thoroughly the problem of establishing the optimum exploitation life of capital mining equipment at the open pit coal mines of the Electric Power Industry of Serbia. The aim of this paper is to define and discuss the relative problems as well as to find out the possible solutions and establish the methodology for estimating the optimum exploitation life of machinery. The study was successfully carried out by a team of scientists engaged from and coordinated by the Department of Computer Science of the Faculty of Mining and Geology, University of Belgrade. This paper presents the key observations covering the subject problem. Keywords: Mining, Opencast exploitation, Coal, Optimization, Exploitation life, Capital machinery, Electric power industry, Dynamic programming.

Jan 1, 2003

By R. Abela

In over ninety per cent of mineral sand plants, the most commonly used equipment is the spiral concentrator. The tonnage treated over typical spiral plants can range from as low as 200 ton per hour up to 6 000 tons per hour. Due to the limited capacity of each spiral, plants consist of multiple spirals assembled into banks. The mixture of minerals present in the sand feed requires several spiral stages to achieve the desired mineral recovery. Due to the complexity of the spiral circuits, there are always some design and operating problems that present themselves in plants. These range from slurry distribution, spirals operating at incorrect design parameters and feed variations. The material being treated is difficult to maintain in suspension due to its high density, resulting in segregation and preferential flow in pipelines, distributors and sumps. The objective of this paper is to highlight common problems associated with spiral installations to designers and operators of plants. Practical solutions are recommended in order to prevent and minimize these mistakes in the design. These solutions may be used to improve performance on operating plants.

Jan 1, 2003

By D. R. Hack

The complexity of commercial mining software has gained rapidly over the past decade as hardware developments have surpassed software capabilities at a staggering rate. Software users, recognizing the limitations of off-the-shelf applications, have adapted embedded scripting languages. Custom programming has always had a vital role in mine computing innovations, yielding a dynamic research environment in industry and academia. Fields such as industrial minerals can benefit from customization of existing software, since the majority of mine planning software was designed for large metal mines. Different customization approaches utilizing embedded scripting languages are presented, with examples of sand and gravel applications in development. Following implementation by Surpac and development of the Surpac Command Language, Tcl has been widely applied. Mintec introduced Python, also extensible and portable amongst various operating systems, for use in their MineSight products. In early 2000, Gemcom introduced the use of Microsoft Visual Basic for Applications, widely used customization tools for a decade. Datamine implemented a flexible multi-language approach, with all program commands and processes available through the COM Server Interface. This extends customization from the existing macro language to scripting in HTML, JavaScript, or any language that supports COM.

Jan 1, 2003

By H. T. Ozkahraman

It is important to know the breakage mechanism in materials since this knowledge influences the results of subsequent grinding operations. There are two distinct failure mechanisms in breakage: one is tensile micro crack generation at low stresses, which leads to macroscopic failure by disintegration, and the other is formation of shear zones under heavier dynamic impact forces, which generates more fines as seen in crush zones in blasting. Tensile fracturing simply breaks the material into fragments. It is seen as the disintegration of the specimen into two or more separate fragments. This happens under the absence of lateral stresses and the material is free to expand. On the other hand, compressive-shear breakage produces finer fragments due to shear stresses. The first mechanism is observed in laboratory tensile and bending strength tests and the second mechanism is observed both in laboratory brittleness tests and in situ blasting operations under dynamic impact forces. The friability of rocks and ores can be determined by a brittleness test. A test apparatus to determine the friability value has been designed to suit limestone strength characteristics used in cement production. The friability and stored strain energy values of barite, marble, limestone and bauxite have been determined and compared with the corresponding Bond work index (Wi) and grindability index (G) of these materials. The physico-mechanical properties of the tested materials have also been determined to investigate their effect on friability and grinding. The relationships obtained between the indices were in surprisingly good agreement, with high correlations (0.99 and 0.97). The Bond work index and grindability index can therefore be estimated from the friability value, which can be determined more rapidly than the Bond test. But for certain rock types such as andesites the relationships does not hold. Key words: comminution, tensile stress, shear forces, brittleness test, strain energy.

Jan 1, 2010

By T. Ertekin, X. Dong

This paper identifies the need for the development of specialized inverse solution techniques for the analysis of pressure transient data for the characterization of the transport and sorption properties of coal seams. Central to the proposed inverse solution technique is a specially structured artificial neural network (ANN). The most important transport and sorption characteristics of coal seams are butt and face cleat permeabilities, macropore porosity, Langmuir volume constant, Langmuir pressure constant, and sorption time constant. Conventional methods, such as type curve matching techniques and laboratory-derived measurements are handicapped in terms of being representative over the entire domain of interest. In this paper, we utilize analytical forward solution techniques for various combinations of characteristics of coal seams to generate training and testing patterns. These training patterns are shown to an ANN structured to learn the ubiquitous non-linear relationships that exist between coal seam properties, input conditions and the pressure transients measured. The trained networks are then extensively tested to ensure that they have effectively learned the training patterns. In the final stage of the development, the networks are run in the prediction mode. The responses of the networks are found to be in agreement with the input data. The developed networks are able to generate results generally within 5% error margin for permeability and porosity and 20% error margin for the sorption characteristics of coal seams. A number of examples highlighting the capabilities and degree of effectiveness of the network in characterizing the coal seams areincluded. Keywords: artificial neural networks (ANNs); coal seam characteristics; pressure transient analysis

Jan 1, 2003

By Hao Li, Allan Moss, Richard K. Brummer

At the Palabora Mine, the transition to caving 400 m below the bottom of the 800 m deep pit resulted in a slope failure of the North wall that began in 2003, and is still mobile. This failure can be explained by the daylighting into the cave zone of a prominent joint set. The failure was modelled by the 3-dimensional code 3DEC, which is capable of modelling the nonlinear behaviour of discontinuum materials with large displacement.

Jan 1, 2006

By D. Xie, S. Sun

An overview of recent development of CSIRO?s Multi-Phase reaction models will be presented with examples comparing the calculated physico-chemical properties of metallurgical slags with the existing experimental data. The paper will also outline the development of a kinetically based model for molten bath reactors and its application to submerged combustion of coal in a slag bath as well as the reaction between the slag and injected coal particles. The plume model combines established models for the combustion of pulverized fuel with models for the growth and rise of bubbles from a lance or tuyere. This model predicts the extent of de-volatilization and combustion of the coal in the plume, the utilization of oxygen and the exchange rate of oxygen between the gas and the bath as well as the heat transfer rate between the gas bubbles and the bath. The slag reduction model brings together the recently measured rate data and fundamental understanding of the kinetics of CO-CO2reaction with iron oxide containing slags and predicts the changes resulting from injection of coal particles into molten slags. The top-space model covers reactions between gases and molten droplets in the post-combustion zone, where heat and mass transfer between phases results in higher utilization of the fuel values in the partly oxidized gases and transfer of heat to the molten bath. Keywords: Phase equilibria, viscosity, electrical conductivity, slags, kinetics, reaction rate.

Jan 1, 2004

By J. -Y. Jia, G. -B. Qiu, C. -G. Bai, D. -F. Chen

Due to the great importance of the smelting process, it is essential to establish a calculation model on the viscosity of the slag system containing titania. In this paper, the calculation models of mass action concentrations and viscosity for the CaO-SiO2-TiO2slag system have been established according to the coexistence theory of the slag structure, as well as the referenced viscosities ofCaO-SiO2-TiO2at different temperatures and TiO2compositions. With the two models, corresponding calculated programs are made by means of programming language Matlab5.3, and the curves of viscosity of the TiO2concentration (?TiO2/%) at 1400°C, (R=0.9~1.0) are plotted. The results show that mass action concentrations of TiO2increases with increasing percentage ofTiO2, while the viscosity of CaO-SiO2-TiO2system is decreased. The results show that the models are in good agreement with the experimental and referenced data. They also shows that the models are reasonable for the CaO-SiO2-TiO2slag system. Keywords: coexistence theory; CaO-SiO2-TiO2slag system; viscosity ; calculation models.

Jan 1, 2004

By H. Hu, T. S. Golosinski

The paper reports on use of neural network algorithms to model performance and condition of mining trucks. The model inputs are selected digital data streams collected by truck Vital Information Management System, VIMS, during its operation in a mine. The models built as the result of this work allow for projection of truck condition and performance into future. As such they facilitate more efficient management of mine truck fleets. Keywords: Modelling, modeling, neural networks, mining equipment, Vital Information Management System, Intelligent Miner, mining truck

Jan 1, 2003

Poorly designed sampling protocols generally result in high project risk by artificially increasing grade variability (ie the nugget effect). Sample collection, preparation and assay protocols that suit the ore type, together with QA/QC systems, will reduce this risk. All reporting codes (eg JORC, 2004) require the Competent Person to consider the quality and implication of sampling and assaying programs. High sampling errors beget higher project uncertainty; despite this fact, sampling does not receive the attention it deserves. The case studies presented show that many sampling issues frequently go unrecognised or unaddressed, resulting in poor project decisions during exploration through to feasibility and production. The overall conclusion is that correct sampling is critical to mining project success and that there is often a need for its optimisation.

Jan 1, 2007

By A. V. Z. Brink

Rock engineering risk is defined in this paper as a function of the potential ground motion; the vulnerability of the workplace; exposure of people; and a general term – quality of information. The paper describes the development of prototype software that is a combination between an expert system approach for determining overall risk assessment, a risk control recommendation and a basic GIS (Graphic Information System) approach for graphically overlying input parameters and the output risk. The expert system uses a Bayesian probabilistic approach to combine various workplace-related information, a quantified seismological environment and the exposure of underground staff to provide an overall RE risk rating. The risk assessment is dynamic in that it is recalculated each time that any of the input parameters change, for example each time a seismic event is recorded in the area of interest. The code was tested on a data set from Savuka Gold. As risk assessment is not an absolute prediction of a specific outcome, it is therefore not possible to relate to individual case studies and the reliability of this method would only be determined after an extensive period of use with appropiate back-analysis. Le risque dans le génie minier est défini dans cette étude comme une fonction du mouvement potentiel de terrain ; la vulnérabilité du lieu de travail ; l’exposition des personnes ; et un terme général – la qualité de l’information. L’étude présente décrit le développement d’un logiciel prototype qui est une combinaison entre une démarche de système expert pour déterminer une évaluation générale du risque, une recommandation pour le contrôle du risque, et une démarche de SIG (Système d’Information Géographique) pour superposer graphiquement les paramètres d’entrée et le risque de sortie. Le système expert utilise une méthode de probabilité bayésienne pour combiner des informations variées sur le lieu de travail, des données quantifiées sur l’environnement sismique, et l’exposition du personnel travaillant sous terre, pour finalement produire un classement général de risque minier (RE). L’évaluation du risque est dynamique en ce sens qu’elle est recalculée à chaque fois qu’un des paramètres d’entrée change, par exemple à chaque fois qu’un évènement sismique est enregistré dans la région. Le code fut testé sur un ensemble de données obtenues de Savuka Gold. Comme l’évaluation du risque ne constitue pas une prédiction absolue d’un résultat spécifique, elle est par conséquent difficile à rattacher à des cas individuels et la validité de cette méthode ne pourrait être déterminée qu’après une longue période d’utilisation avec analyse rétrospective appropriée. Das Gesteinstechnikrisiko wird in dieser Arbeit als Funktion einer möglichen Bodenbewegung definiert; die Anfaälligkeit des Arbeitsplatzes; das Ausgesetztsein der Belegschaft; und ein genreller Begriff - Qualität der Informationen. Das Papier beschreibt die Entwicklung einer Prototyp-Software, die eine Kombination zwischen einem Expertensystemzugang für die Bestimmung der gesamten Risikobeurteilung ist, eine Empfehlung zur Risikokontrolle und eines fundamentalen GIS (graphisches Informationssystem) Zuganges für graphisch darüberliegende Eingangsparameter und das Outputrisiko. Das Expertensystem verwendet eine bayesische Wahrscheinlichkeitsannäherung, um verschiedene mit dem Arbeitsplatz in Verbindung stehende Informationen, ein quantitativ bestimmtes seismologisches Umfeld und das Ausgesetztsein des Untertag-Personals zu kombinieren, um eine gesamte RE-Risikobewertung zur Verfügung zu stellen. Die Risikobeurteilung ist insoferne dynamisch,daß sie stets nachkalkuliert wird wenn sich irgendeiner der Eingangsparameter ändert, z.B. jedesmal wenn ein seismischer Fall im Interessensbereich aufgezeichnet wird. Der Code wurde auf einem Datenbestand von Savuka Gold geprüft. Da die Risikobeurteilung nicht eine absolute Vorhersage eines spezifischen Resultates ist, es ist folglich nicht möglich, sich auf einzelne Fallstudien zu beziehen und die Zuverlässigkeit dieser Methode könnte nur nach einer umfangreichen Benutzungsdauer mit geeigneter Postanalyse bestimmt werden.

Jan 1, 2003