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By Laas JJ, Spearing AJS

Considering the capital outlay, running costs and inherent difficulties of backfilling operations at depth the benefits need to be clearly established, quantified and then exploited. Expansion of Vaal Reefs Exploration and Mining Company towards even deeper, highly faulted ground, and the process of establishing codes of practice for the management of rockfalls and rockbursts, required that a sound support strategy be formulated. This paper describes the derivation of an overall backfilling strategy on Vaal Reefs. Use was made of experience gained over some 12 years with backfilling. Numerical modelling was used to estimate potential benefits of backfilling the deepest mining areas still to be extracted. In exploiting a probably unique opportunity, two contiguous mining areas bounded by the same major geological structures, were compared. One was extensively backfilled and the other not at all. Shaft sinking through a backfilled stope added another dimension to the database. Backfilling was introduced in 1985 and several potential spin-offs were expected. These included improved local strata control for fall of ground and rockburst conditions, regional benefits in rock mass stability and mine ventilation optimisation.

Jan 1, 1998

The information age has arrived. In every aspect of life, at the end of the second millennium, computers and information technology have made significant inroads. In mining there has been huge growth in the use of digitally controlled systems. From resource evaluation to mine planning to daily operations, information is being acquired, analysed, modeled and presented, using state-of-the-art information technology. Explosives, too, have moved into the information age. Computer controlled trucks and manufacturing plants have been developed and are now a regular feature on many mine benches. The next challenge for the explosives industry as a whole is to integrate blast initiation with information technology. The benefits are there, both to the supplier and to the end-user. Much has been written in the past about the potential for blast improvement but there are other significant advantages to a digital initiation system. These include security from unauthorised use, stock control and minimisation, reliability through testability and ease of use to name a few. So why is it taking so long? Surely the complexity of an electronic initiation system is far less than that of mobile phones that have been around for a long time. The answer, it seems, lies in the level of new technologies that need to be developed. There are enormous technological hurdles to be overcome in order to put into the market a cost-effective, reliable, user-friendly electronic initiation system. The most significant of these are:Safely and reliably initiating an explosive from an electronic device powered by a small capacitor. Prior to the development of electronic detonators primary initiation of explosives was by shock tube spit or by passing large currents and voltages down a pair of wires. Electronic detonators do not have that luxury. For example the energy stored in a æBeethovenÆ exploder is more than 500 times greater than that available to an electronic detonator. Communicating to a multitude of devices over very long cables installed by miners in harsh conditions. The deployment of an electronic detonator system has been likened to building a large telephone exchange in the rain and getting it to work perfectly first time! New communications protocols needed to be developed and tested. Wiring and connection systems have to be designed to survive the mining environment. In spite of these technological hurdles most of the major explosives manufacturers have persisted with electronic initiation systems and we are now, in 1999, starting to see the results of these multi-million dollar efforts. At SMI we are often asked many questions about this technology. The remainder of this paper seeks to answer those most often asked. As with any business linked to information technology todayÆs breaking news is tomorrowÆs archive and we expect the rate of development and understanding to accelerate as these technologies become accepted by the global mining industry.

Jan 1, 1999

By B BussiFre, J Molson, M Aubertin, G W. Wils

Waste rock piles containing reactive sulfide minerals can serve as long-term sources of acid mine drainage (AMD). Within these piles, many physical, geochemical and biological processes can contribute to the production of AMD. The flow of water, for example, depends on internal pile structure, which depends on the dumping methods used to construct the pile. In this paper, the internal structure and grain size distribution of typical waste rock piles are first reviewed with respect to their effect on internal water flow. A numerical model is then applied to simulate unsaturated flow within a waste pile assuming two primary waste materials, different atmospheric conditions and several geometric configurations. The simulations suggest that water movement can be controlled by introducing fine-grained material layers within the coarser host material. However, these layers should not be horizontal because they can lead to localised high-saturation regions as well as preferential flow favouring the production of AMD. A shallow slope towards the pile boundary may be introduced to force drainage to the outside while maintaining low saturation within the interior, thus reducing the production of AMD.

Jan 1, 2003

By K Luthbom, A Lagerkvist

According to the Swedish Environmental Protection Agency, the number of potentially contaminated sites in Sweden is approximately 40 000. The funding for remediation from the Swedish Government alone amounts to $A 60 - 80 M (300 - 400 MSEK) annually for the period 2003 - 2006. Uncertainties will arise when obtaining samples in field, preparing them in laboratories and analysing them. Different procedures give rise to varying errors. Using data for decision-making that does not truly represent the site could be fatal. Misclassification of soil could lead to unnecessary costs or to risks to human health and the environment. The total uncertainty of an environmental sample can be split into analytical uncertainty and sampling uncertainty. The analytical uncertainty is usually known and reported from routine analysis. The size of the sampling uncertainty is less well known. Hence, the question is how big are the sampling uncertainties for contaminated soil and how big is the analytical error compared to the total sampling error? A scrap yard and two landfills within a workshop area were investigated. An excavator dug trial pits and samples were taken with a trowel from the walls of the trial pits. Samples were put into plastic bags and taken off site for preparation and analysis using XRF. Sample preparation included drying and sieving. The samples were homogenised by kneading the sample bags prior to analysis. The sampling and sample handling were performed in an intuitively way without knowledge of sampling theory. However, Pierre GyÆs sampling theory was used for subsequent evaluation of the data from the site investigation. The theory defines seven sampling errors, which can be applied to sampling of soil. Some errors have a variance that can be calculated or at least estimated, while other errors can give some idea whether the bias is positive or negative. The total sampling error varied over three orders of magnitudes from sample to sample. The single largest contributor to the large variation in error was the contaminant level. When comparing the analytical error and the total sampling error the ratio varies more than three orders of magnitude.

Jan 1, 2005

By A Murphy, D Lauder, J Miranda

Minera Alumbrera Limited operates the Alumbrera concentrator, treating a nominal 80 000 tpd of porphyry gold/copper ore. It is located in Argentina, 1200 km north-west of Buenos Aires in Catamarca Province, at an elevation of 2550 m above sea level. Treatment facilities consist of crushing, SAG and primary ball mill grinding circuits, rougher flotation, ball mill regrinding, gravity recovery and cleaner flotation. It is one of only a small number of concentrators in the world, which uses Jameson Cells alone for cleaner circuit flotation. Plant design was started in June 1995, with commissioning commencing in July 1997. Following a successful ramping up to design tonnages and recoveries, a number of options were reviewed to improve gold and copper recoveries. This paper concentrates on a detailed size by size flotation recovery project, commenced in May 1999. Utilising optical microscopy, scanning electron microscopy and analysis of surface chemistry it has allowed losses by size fraction to be quantified and options for enhanced recoveries to be developed. Coupled with extensive circuit surveys it has also provided an insight into previously unknown properties of Jameson Cell operation. Among these are unique residence time and bubble formation reactions to reagent and pulp flow variations, which has permitted a number of novel changes to the operation to maximise capacity and recovery.

Jan 1, 2000

By D Cotnoir, Q Liu, D Richard, M Ourriban

The difficulty in fine particle flotation has been attributed, among other things, to a low bubble-particle collision efficiency. Many technologies have been developed which aim at increasing bubble-particle collision efficiency, either by generating micro bubbles or by enlarging particle sizes. However, commercial applications of these technologies are limited. Over the last five years COREM has been actively testing fine particle froth flotation technologies with the objective of commercialisation. Several fine particle flotation technologies, such as dissolved air flotation, electro-flotation, floc flotation, selective flocculation-flotation and carrier flotation, were tested on both single minerals and ore samples in order to identify the reasons that prevented these technologies from being used on a commercial scale. It was found that the two most noticeable factors that prevented the successful application of these technologies were: Mechanical entrainment of fine gangue minerals. This was a general problem in fine particle flotation, but was aggravated by these technologies that either generated micro bubbles or enlarged the sizes of hydrophobic particles. Oxidation of (sulfide) minerals that resulted in hydrophilic oxidation product coatings. The oxidised fine particles could not be recovered by these fine particle flotation technologies effectively. Solutions to the two problems, ie gangue entrainment and fine particle oxidation, were proposed and tested. It seems that polymeric depressants with both depression and flocculation functions could significantly reduce gangue entrainment, and hydrophilic surfaces of oxidised fine particles could be modified by high intensity conditioning or controlled sulfidisation, thus increasing the recoveries of fine valuable minerals. The improved fine valuable particle flotation and reduced fine gangue entrainment along with fine particle flotation technologies resulted in much improved flotation separation of fine particles.

Jan 1, 2005

By S Bluhm, R Funnell

Creative mine-designs are constantly being applied in the deep platinum mining industry in South Africa. Recently, this has resulted in deep hot mine-designs including room and pillar, bord and pillar or stall and pillar layouts and the use of in-stope trackless mechanisation. In these mines, the ventilation systems use refrigerated air and high fan pressures and as a result ventilation leakage can have a huge impact. Leakage is a serious impediment to cost-effective operation and potential leakage in future projects is a major factor in judging project viability. This paper describes certain mine layouts and quantifies the extent of the leakage. Based on typical field data, a range of seals from ævery poorÆ to ævery goodÆ was defined and used to estimate overall leakage. Within these mine networks the ventilation pressure, temperature and density all vary significantly and with the multiplicity of leakage paths it was necessary to make use of the VUMA-network simulation package. For the examples examined, the leakage was found to be up to 85 per cent for æpoorÆ category seals and up to 50 per cent for ægoodÆ category seals. The total air flow (and refrigeration) requirements grow exponentially with strike distance due to the compounding effects of higher pressure and more leakage paths. It is shown that beyond certain depths and strike distances the leakage will become so great that it will be impossible to operate cost-effectively û even with ægoodÆ seals. Indeed, in these examples the projects were not considered viable in their original format because of the high ventilation-cooling costs and the mine-designs were modified to include footwall drive systems û the cost of which was justified by the reduced strategic risk to operating ineffectiveness due to leakage.

Jan 1, 2005

By P Oikkonen

Sprayed concrete has played an integral role in underground rock support for nearly a century. However, concrete is also considered to be one of the biggest environmental problems in construction and mining, largely because of the high carbon footprint of cement and aggregates production. This is driving the industry to find ways to cut concrete usage where possible. Improving sustainability by cutting concrete material consumption also reduces application time and costs. Improving concrete properties can make it possible to design thinner linings, but as awareness of safety and longer design lifetimes are driving developments in the opposite direction, it is not realistic to see this as a major factor in cutting concrete consumption. More accessible solutions are focusing on layer thickness control and minimising rebound and wastage. Digital technology and innovation offer excellent tools for improving sustainability while optimising other aspects of the spraying process at the same time. A digital layer thickness control system gives near-real-time information to the sprayer operator with full coverage of the sprayed surface. This enables the operator to achieve consistent layer thickness on the first pass, in comparison to the traditional methods of overspraying with the aim of achieving sufficient layer thickness, probe drilling after the concrete has set, and respraying at a later stage if needed. Operator competence is the single biggest variable in a successful sprayed concrete process, affecting rebound and wastage levels. Unfortunately, the learning curve to become a master sprayer is quite steep and training on a real sprayer and real concrete requires a significant amount of time and money. Training in a virtual reality (VR) environment enables operator training to be carried out in a low-risk environment and provides a way of measuring performance and assessing and certifying the operators. After the VR training period, a novice nozzle operator has the basic understanding to start working on a real sprayer, and an experienced nozzle operator can benefit from the possibility of assessing their performance.

Mar 29, 2023

By M Danišík

Two drill core samples of haematite/goethite from the Robe River (Western Australia) channel iron ore deposits (CID) were dated using (U-Th)/He methods in order to constrain the timing of iron oxide formation and thereby provide a temporal context for CID genesis. (U-Th)/He ages (He ages) from these samples range from the late Oligocene to Late Miocene and despite a high degree of scatter, they corroborate relationships expected from the internal ooidal stratigraphy: For individual ooids, the ages from haematitic core are older than or indistinguishable from the ages of the surrounding goethitic cortex. The goethitic cortices are, in turn, older than the ferruginised wood fragments recovered from the cementing goethitic matrix.The data suggest the following succession of ore formation phases:• Haematitic cores in ooids of both samples formed in the Early to Middle Miocene.• Goethitic cortices of both samples formed in the late Middle to early Late Miocene. This appears to be the age of goethite cortex formation regardless of depth in the core, which does not support the top-down infill model, genetic model proposed by Heim et al (2006).• Wood fragments form a prominent component of the matrix and were ferruginised during the Late Miocene. Thus the data suggest that the unique environmental conditions for the CID formation existed during the Miocene.A methodological implication of this study is that the temperature utilised for He-extraction from iron oxides has a critical impact on the mobility of parent nuclides. The typical ~1100°C laser heating used for crystalline minerals like apatite or zircon induces loss of U and Th and results in erroneously old ages.

Jul 11, 2011

By I M. Platten, Y Xie, B W. Cuffley, S C. Dominy

"Geometallurgical programs require the collection of representative samples for geochemical, mineralogical and metallurgical test work. Such protocols must be designed to suit the style of orebody in question. The distribution, proportion and size of gold particles have a direct impact on the effectiveness of sampling and test work protocols, and the gold recovery processes employed. Characterisation studies focusing on ore mineralogy, and gold particle deportment, size and distribution are required. High resolution X-ray computed tomography provides a non-destructive method for analysing the 3D nature of gold in rock samples. It can be used to calculate the modal abundance, particle size and distribution of gold in the sample volume. This paper presents a case study of the imaging of in situ gold particles in a high-grade gold ore. The Nick O’Time reef system comprises laminated quartz veins, which locally bear extreme grades of up to 100 oz/t gold. The mineralisation has previously been characterised from both a mineralogical and metallurgical perspective. Eight visible gold-bearing vein samples were scanned using X-ray microtomography. Microtomographic data were integrated with previous mineralogical and metallurgical test work outputs.CITATION:Dominy, S C, Platten, I M, Xie, Y, Cuffley, B W and O’Connor, L, 2016. Characterisation of Gold Ore from the Nick O’Time Shoot (Tarnagulla, Australia) Using High Resolution X-ray Computed Tomography, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 241–254 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By W B. Edgar, S C. Dominy

High-nugget effect vein-gold systems are generally considered to be one of the most challenging of deposit types to evaluate and exploit. To potential investors and mining companies, they are viewed as high risk because of the associated uncertainties in the grade estimate and general paucity of Ore Reserves at production start-up. However, despite the well-known risks, these deposits often have a grade upside that makes them potentially attractive. The reporting of resource grade is of importance and perhaps even more so is the reporting of the associated uncertainty attached to the grade estimate. The use of the grade estimate supported by a grade range is recommended to achieve more complete and useful disclosure. The definition of the grade range can be somewhat subjective, ranging from opinion based estimates through to data-based estimates and geostatistical conditional simulation. Whichever method used, the over-riding issue must be the provision of enough data of appropriate quality and full disclosure to the public of relevant uncertainties.CITATION:Dominy, S C and Edgar, W B, 2012. Approaches to reporting grade uncertainty in high-nugget gold vein projects, in Proceedings Project Evaluation 2012 , pp 95-108 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By M Fuchs

Roadheaders were introduced to mining and tunnelling in the early-1960s. Since this period their main field of application has been for roadway drivages in coal mines and for mineral production, for instance in coal, rocksalt, potash and gypsum mines. Their main field of application in tunnelling is in softer and partly friable rock formations, a suitable area for non-blasting excavation. However, in longer tunnel sections excavators with high ripping forces have replaced roadheaders in many situations. The main arguments against roadheaders have been and still are:a sharp increase in excavation cost with increasing rock strength and increasing abrasivity; and greater risks in conditions which have not been, or could not be, investigated to a sufficient extent. These arguments have, to a great extent, restricted practical roadheader application in production mining and in a lot of æstandardÆ tunnel projects. To address these limitations, factors which could make roadheaders attractive for such conditions and could overcome existing technological difficulties have been investigated. Extension of the economic field of application in hard rock was found to be the most important and the most effective step forward.

Jan 1, 2002

By S Larbi-Bram, F Shi, E Manlapig

Mining companies have recognised that characterisation of particle breakage plays an essential role in the design and optimisation of comminution circuits. Recently the JKMRC comminution research team has developed a new breakage model incorporating the effect of particle size, and a new breakage characterisation testing device, called the JK Rotary Breakage Tester (JKRBT), which allows rapid testing of particle breakage under high energy single impact and low energy repetitive impact conditions. The latter is believed to be the dominant breakage mechanism in AG/SAG mills. Existing devices, such as the JKMRC Drop Weight Tester, are not suitable for performing repetitive impacts since they are too time consuming. Positive feedback received from mining company sponsors to the new technology has prompted the JKMRC to further validate the device and the model through a formalised experimental test program on professionally designed and manufactured JKRBT machines. The first JKRBT was installed at the Anglo Research laboratory in Johannesburg in March 2007 and four more major mining companies will participate in the project in 2008, with commercial release expected in early 2009. The JKRBT has the potential to revolutionise ore testing, with applications in laboratory impact breakage characterisation of rock samples, drill cores, coal and other materials. It also stands poised to significantly advance the process control of comminution circuits since it is readily adaptable to on-line ore hardness measurement. Can any mine afford to miss out on this technology?

Jan 1, 2008

By R H. Knight

Uncertainty in prediction and modelling of geological (physical) ore continuity in geometrically complex ore deposits is a key risk factor in mining. Reducing geometric uncertainty of hard-boundary ore/waste contacts and related geological features improves the efficiency of local mineral resource estimation and reserve calculation, mine/stope planning, ore control and in-mine exploration. Detailed underground mapping of serial-level drives provides a continuous record of the characteristics and contact configuration of ore, as well as crucial ore-related geological features that are required to resolve geometrical variability when closely spaced drilling proves inadequate or is cost-prohibitive. The mapping-based approach described in this paper re-establishes the focus on the geology of the orebody by incorporating high-value, detailed geologic mine mapping information. Mapped ore-related configurations and relationships, recorded on a succession of faces or on a series of levels, provide the basis for 3D interpolation and extrapolation of the local geologic continuity of an orebody. Correlative points representing locations of key ore-related geologic features on each face or level are linked by 3D polylines or trajectories forming a coherent geometrical framework. The coherent progression of geometric changes mapped by these trajectories reveals the overall ‘dynamic’ of the geometrical framework, as well as the spatial tendencies of its geological constituents. Distinct sets of ore control trajectories are selected from within the framework and are used in the construction of alternative geological ore continuity models. As mining proceeds, alternative models are evaluated, and are then either refined or rejected. The geometrical framework is used to evaluate theoretical models and practical heuristics, focus exploration targeting and inform and guide all aspects of mine geology in active mines. This approach also lends itself to analysis of global ore continuity in the re-evaluation of mature or abandoned mines. Its use is particularly effective in geometrically complex orebodies such as the West Branch orebody and the orebodies of No 2 mine of the Balmat-Edwards-Pierrepont zinc district, which are used to illustrate the method. CITATION:Knight, R H, 2014. A mapping-based approach to geological continuity prediction using examples from the Balmat-Edwards-Pierrepont Zinc District, St Lawrence County, New York, USA, in Proceedings Ninth International Mining Geology Conference 2014 , pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By R N. Humphries

The aim of this paper is to question the need to develop bespoke monitoring and assessment methodologies and criteria, thereby ‘reinventing the wheel’, when designing and assessing the success of important natural habitat and ecosystem restoration schemes at mine sites in the UK and Australia. It draws attention to the existence and applicability of the Phase I Habitat, National Vegetation Classification (NVC) and Condition Monitoring methods in the UK and similar approaches used in Australia. These are long accepted established methodologies and have published accounts for describing, assessing and managing natural vegetation communities, habitats and ecosystems. They are often used at the environmental impact stage, but seemingly rarely, if at all, in restoration design and management at mine closure. Their application to mine restoration and closure is illustrated and discussed by reference to a surface coalmine in South Wales, UK.It is concluded that the application of a combination of the Phase I Habitat, NVC and Condition Monitoring methods is highly relevant to the expectations of the Convention on Biological Diversity (CBD) and its implementation in the UK, and probably in Australia too. The methodology and criteria described could be incorporated into the guidance and specified in the mining permits so that there is clarity as to the expectations and requirements for monitoring and assessment for bond release. Their use could be of wider application where there is a requirement to assess the success of restored CBD assets and ecosystems.CITATION:Humphries, R N, 2014. Why reinvent the wheel when there are established methodologies to aid the design and assessment of restored natural ecosystems on mined land?, in Proceedings Life-of-Mine 2014 , pp 675–692 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By J-P Franzidis, E V. Manl, K Runge

Over recent years a number of techniques have been developed as part of the Australian Minerals Industries Research Association (AMIRA) P9 project to represent mathematically or measure directly subprocesses occurring in flotation cells. These include the determination of a:machine parameter (bubble surface area flux, Sb); froth parameter (froth recovery, Rf); entrainment and drainage parameters; and ore floatability parameter (Pi). A cost-effective methodology was developed for using these techniques to derive models of flotation circuits. This methodology was applied to derive a model of the flotation circuit at the Western Mining Corporation (WMC) Ltd Mt Keith Nickel Concentrator. The model was used to simulate a number of minor circuit flowsheet changes, the results of which are discussed in this paper. One year later, a second study of this plant was conducted. In this second study, data were collected while operating the plant in the flowsheet configurations that were simulated from the model developed from the first study. The results obtained from the second study showed reasonable agreement with the trends predicted from the first study model; discrepancies can be explained in terms of the model assumptions. This suggests that this simple circuit modelling methodology can be useful in assisting plant engineers to optimise flotation circuits.

Jan 1, 2000

It was Harold McMillan, Prime Minister of England 30 years ago, who used the phrase "The Wind of Change" to describe political events in Africa in his day. So well did this phrase capture the spirit of the time that it echoed around the world, and the echo has never stopped. Change is the constant factor in the society in which we live and everyone of us has had experience of the effect which it has had on our professional and personal lives.Change will not stop, it will continue at an increasing rate and the questions we must answer are how do we prepare ourselves to meet the challenge of future change and how do we take advantage of the opportunities which it will bring?It is these questions which I wish to discuss in this address.There is nothing new about change in the mineral industry, it has been happening for thousands of years and it will continue as long as civilisation exists on earth. One type of change is economic and we are all aware of the rises and falls which occur in the prices of metals and minerals (Figure 1). When these have happened in an orderly manner, and could be predicted and planned for, it has been possible to take advantage of the benefits and minimise ill-effects, but when they were sudden and precipitate, and could not be predicted, the consequences were serious. The extreme example, of course, was the oil price shock of the 1970s which had such disastrous effects on industry and society.Other types of change are social, cultural and political. They have all been important in recent years and will continue to be so in the future.But it is technological change which may well be the most important because its effects are profound and irreversible, and alter irrevocably the way in which we live. So in discussing the mineral industry in a changing world I will talk specifically about technological change.

Jan 1, 1989

By D Guibal, J Vann, M Harley

Many sample value distributions are highly skewed and present variograms with high relative nugget effects and/or short-range structures. In consequence, significant deskewing of the histogram and variance reduction occurs when transforming between sample and block support, where blocks are of significantly larger volume than samples. When making estimates in the mining industry we usually wish to estimate on the basis of block support rather than sample support. The selective mining unit (SMU) refers to the minimum support upon which ore/waste allocation decisions can realistically and practically be made. The SMU is usually significantly smaller than the sampling grid dimensions, in particular at exploration/feasibility stages. In a non-linear estimate, for each large block (by convention called a æpanelÆ) we estimate the proportion of SMU-sized parcels above a cut-off grade threshold. A series of proportions above cut-off defines the SMU distribution. Use of such non-linear estimates reduces distortion of grade-tonnage curves and provides a better basis for mine planning and economic decision-making. At present, Multiple Indicator Kriging (MIK) is the most widely used technique for performing estimation of recoverable resources. MIK is not the only approach available and it has some potentially serious limitations. The MIK technique is described and a number of theoretical and practical implementation issues are examined. In particular: MIKÆs assumptions about spatial distribution of grade; the behaviour of indicator variograms; application of change of support models; order relationship problems; and modelling the tail of the distribution. Some simple tests are described which allow us to determine the suitability of different estimators for a given deposit and criteria to identify a preferred estimator are also examined. Uniform Conditioning (UC), an alternative estimator which may be used instead of MIK, is described.

Jan 1, 2000

By Vink L, Johnson N. W, Mackenzie J, Young M. F, Johnston M, Landmark V

The influence of ore textures on metallurgical behaviour is poorly understood for most ores. An alternative method for characterising ore textures and for determining the resulting implications on ore processing has been developed for the Geor

Jan 1, 1998

By T Napier-Munn, E Louwrens, L Keeney

Geometallurgical characterisation of ore deposits is accepted practice in some parts of the mining industry today. Its primary aim is to provide constrained inputs that reflect inherent geological variability and its impact on metallurgical performance for the deposit. Geometallurgy improves project value because it suggests more valuable alternatives for scheduling and processing through an increased knowledge and understanding of the interactions of rock properties and extractive technologies. Lower project cost (both capital and processing) and improved recoveries are the result from closer tailoring of the mining and mineral processing strategies to the characteristics of the resource (Dunham, Vann and Coward, 2011). Tailings storage facilities (TSFs) can be seen as potential resources and it is argued that fundamental geometallurgical characterisation as applied in ore deposit characterisation should also be applied to planning the retreatment of TSFs. This paper will describe a research project at Julius Kruttschnitt Mineral Resource Centre assessing if geometallurgical principles and methodologies can successfully be applied to TSFs as they have been to primary deposits. The project is establishing a new standard method of tailings evaluation which will include a 3D spatial model of the tailings resource. Initial domaining of the TSFs was done using principal component analysis followed by k-means cluster analysis based on chemical assays from drill core samples. The subsequent characterisation of the drill core samples has involved chemical, mineralogical and metallurgical profiling, with a range of metallurgical tests being conducted on the samples. This characterisation step is followed by class-based analysis, predictive modelling and process performance domaining with the ultimate objective of establishing a 3D spatial model incorporating geochemical, mineralogical and metallurgical performance data. This approach, which takes into account processing performance permits a more realistic (as compared to doing limited chemical assays and metallurgical testing) economic evaluation of the potential of reprocessing the tailings material. It is believed that the approach is generic and can be applied to other TSFs being considered for reprocessing. The present case study has also established the gold, copper, magnetite and cobalt deportment for an iron oxide copper-gold deposit tailings resource.CITATION:Louwrens, E, Napier-Munn, T and Keeney, L, 2015. Geometallurgical characterisation of a tailings storage facility – a novel approach, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 125–132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015