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By G. E. Blight

Several aspects of the behaviour and properties of backfills consisting of cemented cyclone underflow tailings are illustrated by means of examples, and guidelines are given on the optimization of the performance of cemented fills. The stretch characteristics of the geofabric used to contain freshly placed backfill are described, as well as the relationship between these characteristics and the forces acting on retaining barricades. The properties required to achieve a self-supporting, stable free face in cemented backfill are explored, and a graphic relationship between stable height and shear strength is presented and compared with that for uncemented (classified) tailings. After a description of the characteristics of Witwatersrand quartzite gold-tailings backfill and commonly used cements, the process of drainage and air entry into backfill is outlined. Following this, the early-age gain in strength and the shear-strength characteristics, as well as the compressibility characteristics of cemented backfill, are described. Two phenomena that are potentially damaging to cemented backfill are seismic effects (or blasting acceleration) and the closure that takes place during the curing of cement. Investigations show that neither of these phenomena is actually significantly deleterious to gold-tailings backfill: liquefaction does not Occur as a result of seismicity, and hydration of cemented fill is not significantly impeded by closure.

Jan 1, 1996

By D. M. Meyer, K. Auerswald

The production of electrolytic manganese in South Africa by M. HARRIS, Pr. Eng., B.Se. (Eng.) (Fellow), D. M. MEYER, Pr. Eng., B.Se. (Meeh. Eng.) (Visitor), and K. AUERSWALD (Visitor) The decision to construct the first electrolytic manganese plant in South Africa was important and farreaching. After evaluating the results of the pilot plant operation, the first South African producer, Electrolytic Metal Corporation (Emcor), established a plant in Krugersdorp. Initially, there were many process problems that had to be InvestIgated, and, after these had been solved and many operating parameters had been established, manganese was successfully produced. When the Delta Manganese plant in Nelspruit was planned, cognizance was taken of the fact that, if peak efficiencies were to be maintained, the process must be operated between fairly narrow parameters. Instrumentation was therefore installed to control the process automatically wherever possible. The main features of the Delta Manganese operation are outlined, with a brief description of each stage of the process from ore milling through to electrowinning and packing of the metal. It is concluded that much benefit can be obtained from further research work into process improvements and into the exact effect of certain variables on plant and current efficiency.

Jan 2, 1977

By R. Pipeleers

Recent experience has shown that all underground workplaces in the Campine Coalfield in Belgium will require controlled cooling within three years. Considering the socio-economic and legal importance of the climatic problems underground, IREA has undertaken studies in forecasting the climate of future workplaces, planning the necessary cooling equipment and optimizing efficiency in the existing cooling equipment. These studies are being carried out using the climate forecasting program of Bergbau-Forschung. So far, the German model has been obliged to utilize manually measured data from a few workplaces in the Campine. As the model does not fit very well with these measurements, it has been thought necessary to' develop a system of continuous data acquisition and transmission. This system is being tested in the Beringen mine of the N.V. Kempense Steenkollenmijnen. In the first part of this paper the digital tranmission system is described; in the second the sensors used to collect the necessary climatic data are presented, and in the third some results are given.

Jan 1, 1987

By I. M. Macleod

An adaptive steady-state on-line optimizing regulator is proposed as an integrated approach to the control of autogenous run-of-mine milling circuits. This optimizing regulator continuously estimates an internal model of the controlled process, and, based on this, determines mill fresh solids feed rate, mill water flow rate and sump water addition flow rate such that a circuit performance objective is optimized. The dual -requirement of controlling both the mill pulp load and the load of particles of grinding media size is thus directly and simultaneously addressed. The concept and theory underlying the operation of the adaptive optimizing regulator are discussed.

Jan 1, 1987

By J. Lamb

Project managers must juggle many aspects to bring their project in on time, on budget, and in accordance with the aims of the project owner. Whether the project is a mining feasibility study, a technology implementation or a construction project, it falls to the project manager and his or her team to deal with risk from two standpoints, which may be at odds with one another. First, a project team must deal with risks to the project itself - that is, risks to on-time, on-spec and on-budget delivery against the value promise made to the customer. Second, there is the management of risks within the subject matter of the project, undertaken on behalf of the customer. The project manager cannot dodge this responsibility; yet there is a tendency (particularly in smaller, in-house studies) to avoid digging too deep, possibly for fear of what may be uncovered! This paper investigates the responsibilities of project teams in regard to risk management and reporting. It examines ownership of project risk; the nature of risk management activities undertaken by the team during the course of a project; and outlines some controls to ensure that the two opposing arms of project risk are reconciled for the benefit of both the project team and the project owner.

Jan 1, 2007

Council and Standing Committees, 1977-1978 President: P. A. von Wielligh. Vice-Presidents: Dr M. G. Atmore and D. A. Viljoen. Honorary Treasurer: J. K. E. Douglas. Immediate Past President, Dr M. D. G. Salamon. Members of Council: J. D. Austin, A. N. Brown, A. A. Hazell, Dr P. R. Jochens, Prof. R. P. King, Dr D. G. Krige, Prof. F. Q. P. Leiding, D. G. Malan, J. C. Mostert, H. G. M. Rose, W. T. Ruhmer, A. A. Sealey, R. A. von Maltitz. Chairman, Witbank-Middelburg Branch: T. S. Wilmot. Chairman, Orange Free State-Klerksdorp Branch: A. N. Shand. Past Presidents Serving on Council: R. J. Adamson, H. Britten, J. K. E. Douglas, Prof. D. D. Howat, Dr J. P. Hugo, D. G. Maxwell, Prof. R. P. Plowman, Dr R. E. Robinson, P. W. J. van Rensburg. Standing Committee Chairmen: Membership, D. A. Vil¬joen; Technical Programme - Metallurgy, Dr P. R. Jochens ; Technical Programme - Mining, Dr D. K. Krige ; Vacation School - Metallurgy, Prof. R. P. King ; Vacation School - Mining, Dr M. D. G. Salamon; Awards, Dr M. D. G. Salamon; Excursions, Dr M. G. Atmore; Adjudication, Dr M. D. G. Salamon; Consti¬tution, Rules, and Policy, Dr M. D. G. Salamon; Mines and Works, P. A. von Wielligh ; Education, Dr M. D. G. Salamon; Monograph Series, Dr R. E. Robinson; Phoenix National Committee, Dr R. E. Robinson ; Pyrometallurgical Discussion Group Convenor, Dr J. B. See/Dr D. I. Ossin.

Jan 1, 1979

By R. P. King

The University of the Witwatersrand (Wits) and the minerals industry of South Africa have grown with the city of Johannesburg. The former has provided teaching and research in mining and metallurgy, while the latter has been responsible for the practical training of metallurgists and for the testing and implementation of innovative ideas proposed by the academics. This interplay between inventiveness and industrial application is illustrated by three examples: the establishment of the iron and steel industry as a result of the persistent experimentation undertaken by Professor G. H. Stanley, the first Professor of Metallurgy and Assaying at the South African School of Mines, which later became Wits; the establishment of the research organization that eventually became the Council for Mineral Technology (Mintek) - again through Professor Stanley's faith in the role of research; and the establishment at Wits of physical metallurgy as a discipline in its own right, as first suggested by Professor C. E. Mavrocordatos of Wits against the opinion of his colleagues in the industry. The Department of Metallurgy at Wits has been well supported by the minerals industry. Not only does the industry provide grants for the financial support of students, but it supplements the salaries of personnel in the Department, making possible the recruitment of top-class academic staff. At present the greatest problem is the lack of interest shown by matriculants in the metallurgical industry as a career. However, an enormous effort is being made by the Chamber of Mines, The South African Institute of Mining and Metallurgy, and the Wits Department of Metallurgy to ensure that matriculants receive appropriate information about the career prospects in the minerals industry.

Jan 1, 1983

By Timo Niitti, Antti Rinne, Janne Turunen, Klaus Schommarz, Sami Grönstrand

This paper captures the essential steps employed in developing Outotec?s new FloatForceTM mechanism. The development of a flotation mechanism essentially revolves around the efficient transfer of installed power, or capital cost, to optimum flotation performance. Optimum flotation performance will be achieved if a balance between metallurgical results, operating and capital costs is maintained. The development of the FloatForceTM mechanism was done by careful evaluation of each of these three areas. This paper focuses on how experience, CFD and laboratory equipment, pilot and plant tests are used to test and evaluate a new flotation mechanism. Validated variables include mixing profile, power draw and local air hold-up. Metallurgical and mechanical design considerations are not covered in this paper. Besides using the FloatForceTM mechanism in new flotation equipment, the FloatForceTM mechanism can be used in existing flotation cell installations, thus enabling improvements in the mixing profiles, solids suspension and metallurgical performance of operating flotation circuits. Results of several tests carried out in existing plant operations are presented.

Jan 1, 2007

By Anthony K. Anyimadu, Chris M. Rule

Froth flotation is the primary mineral processing separation step employed in the beneficiation of PGM ore bodies. Anglo Platinum operates a significant portion of the total installed flotation capacity in the PGM industry, which is installed at 20 operating plants across the Bushveld. PGM flotation has undergone a considerable evolution in both the capacity of flotation cells employed as well as in the circuit design configuration over the past thirty years. Certain of Anglo Platinum?s flotation circuits have been in operation for a relatively long period of time, (in some operations installed equipment dates from the 1960?s) and this allows comparative operating performance between various equipment types and circuits to be evaluated. This paper summarizes some aspects of this experience. Research trends in flotation are continuously monitored to incorporate appropriate findings into existing and future circuit designs. Continuous evaluation and monitoring of flotation performance is undertaken to identify opportunities for increasing flotation efficiencies. Mineralogical and fractional analyses of plant composites and survey samples are analysed to interrogate speciation and association data. This analysis has enabled a better understanding of priorities and opportunities for improved metallurgical performance. These opportunities are divided into three improvement areas: stability, liberation, and fines flotation. The paper discusses these, as well as the circuit design improvements required to take full advantage of the opportunities identified.

Jan 1, 2007

If an orebody has been drilled to achieve some level of regulatory compliance, then a number of associated geological databases will exist, representing 10 000 to 100 000 m plus of core intervals. The databases usually contain data about assays, lithology, mineralisation and geophysical attributes. They will also include location information such as collar positions and downhole surveys. Obviously this data is collected by geologists for, predominantly, geologists and mining engineers. However, from a process design viewpoint process engineers usually ignore the geology where possible and rely on a small number of metallurgical test samples. Typically these test samples are sourced from convenient and available cores or from a small number of specially drilled metallurgical holes. One of the worst instances known to the author was the design of a SAG mill using only two SAG specific test results (one for each of the major ore types) while, geologically, the orebody was defined by more than 30 000 m of drilling. This paper sets out a philosophy to maximise the use of the geological data, both for process design and in preparation for the commissioning phase of projects. Geological data is used in the identification of preferred locations for metallurgical test samples, for checking the metallurgical validity of the geological ore-type definitions, where necessary developing new ore-type definitions (geometallurgical domains) and developing mathematical relationships for the estimation of important metallurgical factors across the geological database. If the estimation of factors (for example ore competence) is considered reliable enough then there is also the possibility of feeding calculated data back into the block modelling process to allow the generation of metallurgically relevant outputs in the mine plans.

Jan 1, 2007

By A. V. Z. Brink

This paper describes the development of a monitoring architecture that allows for continuous monitoring of the process of mining, the underground environment, the state of the rockmass and its response to mining. The system is based on an open standard and is non-propriety. It allows for dense sensor arrays in the workplace, wire less communication to the closest power line, and TCP/IP communication to a central server. Continuous monitoring and quantification of the appropriate parameters allows a mine to optimise its mine process; to dynamically access the safety and health risk to people and equipment; and to quantify exposure to potential heath hazards such as dust, gas or noise. Current application examples of continuous monitoring include an application to optimise drilling and blasting thought fragmentation monitoring; an application of wireless sensor network-based monitoring in to provide early detection of potential rockfalls; and a trail to continuously assess the gold grade at the shaft through correlation with radioactivity. It is unlikely that a single monitored parameter will provide adequate knowledge of the assessed risk or even an optimisation approach. Multiple parameters are being combined using cognitive science tools such as Bayesian theory and other statistical methods to improve the accuracy and relevance of, for example, risk quantification. The decision maker is not confronted with massive amounts of raw data but rather with a single knowledge statement such a probability of failure, a human physiological strain index or an optimisation index.

Jan 1, 2008

By W. J. Vlasblom, A. M. Talmon, A. J. Nobel

In initial laboratory tests with a travelling submerged jet on artificially prepared clay it was found that the cavity depth is dependent on the stagnation pressure of the jet and the undrained shear strength of the clay. In addition, it has been observed that the increase in cavity depth with jet pressure is stronger at higher jet pressures. It is assumed that this can be explained by cavitation of the jet at higher jet pressures. At cavitation a cone of bubbles is formed around the jet, which reduces the exchange of momentum between the jet and the surrounding water. This results in a higher jet velocity and a higher stagnation pressure at a specified distance from the nozzle exit. In literature, no relation between the jet pressure of a free submerged cavitating jet and stagnation pressures was found. Additional tests were carried out to determine this relationship. Because practical dredging occurs at relatively large water depths, these tests were performed in a pressure vessel at different pressure levels. It is concluded that the efficiency of a jet (defined as the stagnation pressure at a certain distance divided by the jet pressure), for stand-off-distances smaller than 45 times the nozzle diameter, increases significantly by cavitation in comparison to the non-cavitating situation. However, the jet pressure required for a fully developed cavitation cone increases strongly with water depth. At dredging depths of 20 m and more, the necessary jet pressures are higher than normally applied in dredging practice. Thus in spite of the importance of cavitation in laboratory tests at atmospheric pressure, in normal dredging practice cavitation is of less importance.

Jan 1, 2007

By H. A. D. Kirsten

The structural competence of mesh- and fibre-reinforced shotcrete was investigated in two series of tests on full-scale panels. It was found that uniformly distributed loading was marginally less demanding than point loading, mesh reinforcement was superior to fibre reinforcement, Dramix fibre and Melt Extract fibre were similar in reinforcing characteristics, and 30 mm to 35 mm was an optimum fibre length. Furthermore, the consistency of the fibre content could not be assured on practical mining sites, and an average fibre content of about 1,5 per cent was the maximum that could be obtained for fibre lengths not exceeding 35 mm. Also, owing to its greater flexibility, shotcrete reinforced with diamond mesh was preferable to fibre-reinforced shotcrete in mining excavations subject to squeezing conditions. In view of the difficulties associated with assuring the consistency of the fibre content in mining applications, it appears that the sophisticated attributes of fibre-reinforced shotcrete can be effectively exploited only in civil-engineering applications in which quality assurance is subject to explicit contractual control. Load-deflection curves, together with measurements of compressive stresses in the surfaces of some of the panels, enabled the ultimate flexural strength of reinforced shotcrete to be rigorously formulated, and rigorous design procedures for shotcrete subject to bending and direct thrust to be developed. The application of the procedures is demonstrated in a practical design case in which the moments and thrusts in a tunnel lining are determined in a numerical analysis of the interaction between the lining, the surrounding rock, and the rock-reinforcing system.

Jan 1, 1992

By R. W. O. Kersten

Backfilling is one of the options available to the mining engineer in mine design. The decision as to the type of backfill is dependent on the purpose for which it will be used. For example, in a situation where high-grade, steeply dipping multiple reefs are to be mined, the purpose would be the following: ? to facilitate maximum extraction; a ? to minimize loss of fines; ? to allow closely spaced multiple reefs to be mined; and a ? to create a working platform. The physical properties required which will satisfy the abovementioned requirements can then be defined; the design of the fill plant, as well as the transport of the fill, will be governed by these considerations. The same procedure is also adopted in deciding on backfill in single- reef gold mines. The first question to be asked is the purpose of the fill. It may be to reduce the energy release rate, for environmental reasons, to reduce timber usage, to improve productivity, to reduce stoping costs, to obtain higher mining extraction, and so on. Only after one, or a combination, of these factors has been selected, can the specifications for the fill be decided on, and the plant designed accordingly. The introduction of backfill at Sheba Gold Mine will be used to illustrate the procedure adopted by Anglovaal in determining the type of fill required.

Jan 1, 1988

By T. F. Cho, B .. O. You, K. S. Yoon, K. S. Won

Discontinuity Orientation Measurement (DOM) drilling system capable of retrieving the reference line-marked core log, which can be used for determining the relative positions and orientations of discontinuity planes along the borehole axis, has been developed. Accuracy of the borehole joints data measured from the reference-lined core and, eventually, the significance and applicability of DOM drilling system for site exploration are verified by comparing with the spatial characteristics of joints investigated by implementing borehole image-taking instruments in the same borehole. Enhancement of boring efficiency has been also confirmed by performing twin drilling operations, one with DOM drilling system and the other with a conventional drilling machine equipped with D-3 core barrel, on two neighbouring sites of 5 m apart. Ein DOM(Diskontinuitätsorientierungsmessung)-Bohrsystem, das durch Grundlinien markierte Bohrprobelog extrahieren kann und die relativen Lagen und die Orientierungen der sich im Bohrloch verbreitenden Flächen bestimmen kann, ist entwickelt worden. Die Wichtigkeit des DOM-Bohrsystems und dessen Anwendbarkeit auf die Erforschung auf dem Bohrplatz werden dadurch bewiesen, dass man die Genauigkeit der Daten der Bohrlochsspalte, die durch die die Grundlinie zeichnende Bohrprobe gemessen werden, mit dem räumlichen Eigenschaften der Spalte vergleicht, die durch die Bildaufnahme des gleichen Bohrlochs nachgeforscht werden. Un system de sondage, Discontinuity Orientation Measurement (DOM), capable de récupérer des carottes markés en une ligne de référence a été dévelopé. Il peux être utilisé pour déterminer les positions relatives et les orientations des plans de discontinuité le long de l’axe de trou de sonde. Leur signification et applicabilité pour une caractérisation de site est verifiée par une comparaison de la précision des données a propos des joints mesurés a partir des carottes markés et les carac-téristigues spatiales des joints enquêtés par le camera de sondage

Jan 1, 2003

By M. Berjak, D. M. Hawlins, R. B. MacGillivray

SYNOPSIS The paper describes a method of producing iso line plans using a mathematical technique for interpolating between boreholes, and its computer application. The iso line plans are used for assessing the value parameters of an ore body. The computer programme also produces means and standard deviations to supplement these iso line plans. The mathematical techniques tested for the production of a satisfactory fit of the data were the polynomial, Fourier and moving average technique. The iso line plans are used for assessing the quality of the ore and other salient features such as depth to the floor of the ore body at different points, with a view to deciding how best the ore may be mined. The plans are plotted by the computer to any scale required. INTRODUCTION To assess the economic exploitability of an ore body many tedious and repetitive calculations must be carried out. Observations of borehole or development samples have to be processed yielding measures of ore reserve and quality in each sampled area, and also measures of the worth of the ore body as a whole and of variation in quality from section to section of the ore body. The observations made on the ore (which we shall term 'value parameters') may embrace a variety of characteristics of the ore. Obvious value parameters are those directly related to the economics of mining, viz. assay values, ore body thickness and depth below surface. Other value parameters however may be almost as important. In the case of coal for example a purchasing contract may specify limits of acceptability on other value parameters such as calorific value, ash content or the percentage of volatile matter. In this case, a detailed study of these value parameters will also be crucial. This detailed study must include an assessment, not only of the body as a whole, but also the regional variation in value of the parameter. An obvious and satisfactory way of displaying this variation is by drawing iso lines of constant value parameter on a map of the ore body and supplementing this with the means and standard deviations of the value parameters taken over all boreholes. Such plans, considered together, show up the zones of significance. The relatively stereotyped nature of the operations involved in this process makes it amenable to computer solution. In order to produce iso line plans on the computer we require some mathematical formula for producing a 'valuation surface'-a mathematical

This paper describes DRA?s involvement with the expansions at Tati Nickel, Phoenix Mine, that have taken an initial plant design of 3.6 Mtpa (originally built by Murray & Roberts), up to 5 Mtpa, and eventually 12 Mtpa capacity. Initially, the plant could not achieve the design name plate capacity for the first few years of operation, as a consequence of the notoriously hard and abrasive nickel ore affecting primarily the operation of the crusher circuit. In order to extend the life of mine, Tati? assessed and then redefined the mining plan, choosing to increase the Phoenix mine reserves to a lower cut-off grade. In order to increase nickel units produced, the concentrator had to therefore treat additional tonnage at lower head grades. Site investigations and field tests around the comminution circuits are outlined, indicated that the milling circuit could be increased to 650 tph, from the initial design of 470 tph, for a similar feed grade and recovery. A project was initiated to debottleneck the crusher circuit and achieve the new target throughput. (Project 5M). This was followed by a feasibility study of the impact of pre-concentration by DMS, which after promising laboratory tests, was followed up with the installation of a 200 tph ?demonstration? plant. The success of this demonstration plant provided the impetus to expand the supply to the 5 Mtpa mill from a large preconcentration stage. A gyratory crusher (one of the largest and most powerful) will receive ore directly from the open pit operation, feeding into a secondary-tertiary crushing plant followed by a modular DMS preparation circuit. Four large DMS processing modules have been installed to treat the tonnage, with high expected rejection levels. Finally a review of the DMS process capability on an ostensibly disseminated micro-gabbro nickel ore is given, which shows the remarkable impact that preconcentration can have on an operation, both in terms of profitability and a successful process ?expansion?. The performance of the DMS plant has significantly extended the life of mine, allowing the mine to significantly reduce mine cut-off grades and curb its previously selective mining practice.

Jan 1, 2009

By W. P. Nel

A fuel cell is an electrochemical engine that converts the chemical energy of a fuel, such as hydrogen, and an oxidant, such as oxygen, directly into electricity. The emerging fuel cell industry may represent a major opportunity for the global platinum mining industry. This is because low temperature fuel cell systems use platinum group metals as catalysts. Fuel cell vehicles may become the most important driver of future platinum demand within years of their commercialization. A great number of factors impact on and drive the diffusion of fuel cell vehicle innovation. Such drivers range from energy security to environmental concerns and the technological development of fuel cells and systems. Such factors and drivers of fuel cell vehicle diffusion are combined with the generic ?body of knowledge? on ?technology forecasting? and ?diffusion of innovation? to design a framework that provides a holistic approach to the analysis of this complex enterprise. An attempt is made in this paper to address the following questions: Which types of fuel cells require platinum group metals? Which types of fuel cells will achieve dominant design status? Will fuel cell vehicles diffuse successfully? How big will the impact of successful fuel cell vehicle diffusion be on future platinum demand? How well do fuel cell vehicles compete with incumbent technologies such as spark-ignited and compression-ignited internal combustion engine-driven vehicles? How soon will oil depletion start to drive the diffusion of fuel cell vehicles? How important is hydrogen as a fuel? What impact does the inadequate hydrogen fuelling infrastructure have on fuel cell vehicle diffusion? The paper contains some initial results of a research project that has the aim of producing a schedule of future platinum demand generated from fuel cell vehicles. Keywords: diffusion of fuel cell vehicles, technology forecasting, platinum demand forecasting.

Jan 1, 2004

The development of short- and medium-term mine production schedules in isolation from each other has meant that only a local optimum can be achieved when each scheduling phase is carried out. The globally optimal solution, however, can be achieved when integrating scheduling phases and accounting for the interaction between short-term and medium-term activities simultaneously. This paper addresses the task of integrating short- and medium-term production plans by combining the short-term objective of minimizing deviation from targeted mill feed grade with the medium-term objective of maximizing net present value (NPV) into a single mathematical optimization model. A conceptual sublevel stoping operation comprising 30 stopes is used for trialling segregated and integrated scheduling approaches. Segregated medium- and short-term scheduling using separate models achieved an NPV of $42 654 456. The final scheduling approach involved integrating the two scheduling horizons using the newly-developed globally optimal integrated production scheduling model to achieve an NPV of $42 823 657 with smoother mill feed grade. The larger the stope data set, the larger the difference between the two scheduling approaches is likely to be. At the very least, an integrated approach ensures feasibility across the two scheduling horizons, which cannot always be assumed when using a segregated approach.

Jan 1, 2012

By N. K. Singh

The calculation of resource volumes for large mineral sands deposits is the process of systematically compiling all known data in order to define the volume of ore contained and its intrinsic economic value. Traditionally, this process has been highly speculative in nature, as the variability of the layer thickness, even between closely spaced, boreholes can be highly variable. The issue of horizon continuity is of critical importance in mine modelling and resource definition. Accurate volume estimates are difficult to derive from drilling data alone, as the borehole spacing of an economically viable drilling programme is often greater than the spatial frequency of the variations in profile thickness. The limitations associated with this inferential approach to resource estimation can be mitigated through the use of newly developed ground penetrating radar (GPR) methods, thereby maximizing orebody optimization by reducing contamination and orebody loss. The use of GPR in the mining industry has historically been limited to shallow, high-resolution applications, such as the location of voids in limestone or the mapping of paleo channels for alluvial gold and diamonds (Francke and Yelf, 2003). These limitations have not been technology based, but rather market based, as the vast majority of GPR systems were originally designed for civil engineering applications. A new generation of GPR technology, designed specifically for maximum penetration in sand environments, is now being developed. This technology has been trialled extensively at the Richards Bay Minerals heavy mineral sand deposit in South Africa with optimistic results. The clay base of the mineral sands has been imaged to some 120 metres. Further equipment refinements are expected to yield even deeper profiling and higher resolution. The resolution offered by this technology is unique, allowing individual depositional sequences to be imaged and modelled in three dimensions. This paper will discuss the advances in GPR technology relevant to the mineral sands industry, as well as methods to optimize and integrate GPR data into existing mine models. Also addressed will be approaches to three-dimensional modelling of high-resolution GPR data and subsequent volume estimations.

Jan 1, 2007