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By G Barla

In Europe, a major interest in the infrastructure and tunnelling fields is in the new crossings of Alps in the form of base tunnels, which are important components of the high-speed (for passengers)/high-capacity (for freight) Trans European railway corridors. These tunnels cross the mountain belt at the elevation of the main cities and basins located all around the Alps and are longer (up to 57 km) and deeper (up to 2500 m) than all tunnels constructed in the centuries before. The excavation of the first Alpine railway and road traffi c tunnels could in general be carried out successfully by conventional excavation methods. With the great lengths of the new base tunnels, mechanised excavation by using tunnel boring machines (TBMs) is imperative as it contributes significantly to savings in construction time and costs. Questions are however posed on the adoption of such a systematic tunnel construction method given the severe ground conditions which are some time anticipated along the tunnel alignment, with possible major geological hazards such as water inflow in heterogeneous fractured or karstifi ed rock masses, stress-induced tensile failure of hard rocks, and plastic shear failure and squeezing of weak rocks, etc. This lecture is to briefly review the current state-of-the-art in the understanding and modelling of two such critical hazards as spalling/bursting and squeezing ground behaviour. With the present interest in the design of mechanised tunnelling with TBMs in such conditions, the complex interaction between the rock mass, the tunnel machine and its system components, and the tunnel support is studied in detail by numerical modelling. The research and development efforts presently underway with the intention to provide the designer with a novel three-dimensional (3D) simulator of mechanised tunnel excavation are presented. Case examples are discussed with reference to the Lyon-Turin Base Tunnel design.

Mar 8, 2011

By M P. Sandy, R M. Stephenson

Portals to access underground mines are important infrastructure and their design requires careful consideration. Portals are generally expected to last for the life of the mine. Typically, the exposure of personnel and equipment is high, with many hundreds of movements through the portal per day. Consequently, the risk associated with geotechnical instability must be extremely low. Portals are often established from a boxcut. In areas where the weathering profile is well developed, the design and execution of the boxcut can involve significant effort, with the objective of minimizing the volume of the boxcut, whilst ensuring that conditions at the design depth are suitable for establishing a stable portal. Properly designed site investigations are a critical part of this process. Currently available portal design guidelines have not been updated for decades, however the equipment and ground support systems have changed significantly in recent years. Many mine portals have since been constructed in a relatively short time frame with success, often in challenging ground conditions using some of the more modern approaches to ground support. This is beneficial because delays in establishing a portal will generally delay other critical path activities, and lead to cost overruns.

Mar 15, 2021

By E M. Wightman, C L. Evans

A recent survey of mineral processors undertaken as part of the International Mineral Processing Council (IMPC) Education Commission identified mineralogy as one of the key skills required for mineral processors (the other key areas being comminution, flotation, physical separation, sampling and extractive metallurgy). Past experience in a number of operations has shown what can be achieved when the data outputs from mineralogical tools are coupled with people with the right skills who can transform the data into actionable information. This paper reviews what has been done successfully in plant operations over a period of more than four decades and gives examples of a range of applications with both long and short-term objectives. The examples demonstrate the usefulness of mineralogical data – both basic and complex – in optimising mineral processing operations, whether the data are applied in a simple analysis or in more complex modelling. Similarly, the examples show the range of options available for operations to access the mineralogy information they need – through in-house experts and equipment based in centralised technology centres, through on-site equipment and experts or through external laboratories and consultants.The examples from industry highlight the huge potential benefit of including mineralogy as an integral part of operational best practice and raise the question of why more operations do not utilise what should be readily available data. Successful application of mineralogical data requires skilled people to generate relevant data of the required quality, together with skilled people to interpret the data (this may be the same person). And, as in any project, corporate recognition of the value of this approach to best practice is required to ensure continuing support. With fewer university courses providing courses in process mineralogy to undergraduate mineral processing engineers and chemical engineers, there is an increasing lack of knowledge about what mineralogical information is needed, how to get the required data and, equally importantly, how to turn the data into useful information.CITATION:Evans, C L and Wightman, E M, 2018. Understanding minerals in mineral processing – the basics and beyond, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 363–376 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

The main objectives of this paper are to identify the main sources of coal dust and to investigate measures for minimisation of dust generated at these sources at the Bukit Asam open cut mine, on the island of Sumatera, Indonesia which uses a

Jan 1, 1994

Although the mining of metals was well established by the time of the Roman Empire mining skills did not really advance greatly for many centuries. Miners did not have the scientific knowledge to distinguish minerals, to process them, and to obtain the best recovery. Each mine essentially developed its own methods in isolation, most of them dangerous. However, with the beginning of the industrial revolution in the early 18th century there was a rapid increase in mining activity in Central and Western Europe and an accompanying need to educate professionals in the developing fields of science and technology. There was also a need for specialised schools (for example, Schools of Mines) to accomplish this since the universities of the time, formed as early as the first half of the 12th century, were cloistered institutions, focused on the study of classics, theology and law. The earliest attempts at organised technical education were made in 1702 with the establishment of a School of Mines in Frieberg, Germany (Table 1) to service rich copper mines, and in 1747 with the establishment of a School of Mines in Paris. By this time, the industrial revolution was well under way and other Schools rapidly followed, at Clausthal in the Ruhr region of Germany in 1775; in 1777 at Almanden to service the mercury mines of Spain (later transferred to Madrid); in 1780 at St Petersburg, Russia and at Falun, Sweden in 1819. The academic staff for these new institutions were often trained in the original School at Frieberg.

Jan 1, 2002

TSG Consulting works with many of the major global mining companies using simulation modelling as an integral component in their development teamÆs processes to determine which combination of infrastructure options, operating performance and operating rules best achieve project goals. All systems can be divided into a series of subprocesses. Conventional management and design practices focus on the optimisation of these system components. However, the interaction between subprocesses means that improvements made to the individual components do not necessarily translate into total system performance improvement.TSG Consulting advocates a ætotal integrated system approachÆ to understanding the behaviour and performance of complex interacting systems. In a constraint-based integrated set of processes, the instantaneous system capacity is limited by the subsystem component capacity that is the bottleneck at that point in time. Additionally, real world stochastic and dynamic influences tend to have knock-on effects across subsystem boundaries. This necessitates the requirement for simulation modelling to develop and validate solutions that are sufficiently robust to deliver sustainable outcomes. The key to maximising production is to understand the causes and effects the inherent variability has on component performance, subprocess performance and most importantly, the total integrated system performance. The correct use of simulation modelling techniques allows study teams to evaluate the relative merits of different capacity enhancement proposals. Put simply, when done well, simulation modelling provides a quantitative and rational process to enhance the knowledge and insight needed to make informed decisions.

Jan 1, 2007

By G Burton, S Fityus, J Li, S Vaughan, D Payne

Daunia and Caval Ridge coal mines, owned and operated by BHP, have been co-disposing rejects and dewatered tailings within spoil dumps from the beginning of their operations in 2013 and 2014, with the purpose of minimising environmental impact and geotechnical risk. Following the recent large failures of tailings dams around the world, BHP Coal, through its Coal Tailings Program, plans to transition other coal mines to deliver “dry” tailings and produce mixed plant rejects (MPR) for inpit co-disposal. This will materially reduce future tailings dam risk exposure. Previous laboratory shear strength testing was conducted on rejects with a maximum particles size of 20 mm, and some concerns were raised that this might not represent the mechanical properties of the actual full particle size distribution (PSD) rejects. BHP was also aware that using different technologies to dewater the tailings, such as belt press filters (BPF) and solid bowl centrifuge (SBC), could produce thickened tailings which could significantly modify the physical behaviours of the MPRs, particularly the bonding between particles. Therefore, laboratory testing on both coarse rejects and mixtures of the coarse rejects and dewatered tailings (MPRs), with full PSDs, was carried out. Testing was performed using the large direct shear machine developed by the Australian Coal Association Research Program (ACARP) project C20019 in 2017, as well as a 300 mm diameter triaxial apparatus at the University of Newcastle (UoN). This paper presents details of the laboratory testing program and results for the rejects from the first studied mine of the BHP Coal Tailings Program. It compares the shear strengths measured at full scale with those tested on modified (scalped or crushed) specimens in the past; and discusses the tailings dewatering technique selection from geotechnical aspects based on the testing results, and finally presents some dump and tip head stability analysis results using the testing results.

Jul 1, 2021

Dust emissions from mining, material processing and ship loading operations (fugitive dust sources) are an environmental issue of increasing concern to both government regulators and the community. The main concerns relate to potential amenity, health and environmental impacts from the emissions. Therefore it is imperative that mining/ processing operations, as part of their overall environmental management, reduce fugitive particulate emissions to as low a level as is practicably possible. This technical paper outlines the mechanisms that lead to fugitive particulate emissions, the importance of understanding the exact cause of fugitive emissions, monitoring methods that can be used to quantify the emissions from specific sources, the use of atmospheric dispersion modelling in dust management and innovative dust management strategies including predictive meteorology and proactive management.

Jan 1, 2009

By D Cliff, B Belle

Trigger action response plans (TARPs) are inherent to managing multiple hazards such as high gas content with multiple coal seams, high spontaneous combustion propensity, heat and ventilation. TARPs aim to provide assurance and guidance when the situation deviates from the original plan or there is a change in conditions that could be hazardous. Over the years, learnings from various incidents have continuously required coal operations to revisit the TARP trigger values that were based on historical data or guidance values from the industry. In most cases, the background to the basis of TARP statistical data (ie average, maximum, hourly or daily for the monitoring or sampling location) is unknown. The introduction of real-time monitoring devices to monitor gases and airflows has provided greater understanding of the hazard scenarios and their controls. This paper analyses the carbon monoxide data from operating longwall mines and compares these with the historical trigger values to understand the changes and identify improvement opportunities while setting trigger levels in the TARPs. As an example of setting trigger values, those used during the sealing of a panel are explored in terms of setting values based upon the sampling location and the level of risk. It is envisaged that the learnings shared herein will further enhance the understanding and management of multiple hazards in Australian coalmines.CITATION:Belle, B and Cliff, D, 2015. Improved trigger action response plan development based upon mine-specific data, in Proceedings The Australian Mine Ventilation Conference, pp 73–78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By P K. Wong, D A. F Oliveira, F M. Azad

In situations where foundation piles are located in proximity to existing or future tunnels, it is typical for the tunnel owner to require that sleeving of the piles be carried out to at least the invert of the tunnels to minimise any load transfer to the tunnel lining. In competent rock, this practice may be sometimes unnecessary, thus uneconomical. This paper presents an assessment of the effect of pile loading from one of the multi-storey buildings at Barangaroo South in Sydney on the adjacent future Sydney Metro tunnels. It was originally required by Transport for NSW (TfNSW) that the piles be sleeved below the tunnel invert level; however, the building developer wanted to reduce the pile sleeving depth to achieve a more economical solution due to the large number of load transfer piles being required for the project. To assess this feasibility, a full 3D commercial numerical code, FLAC3D, was used to carry out this complex soil-structure interaction analyses. Based on these assessments, it was demonstrated successfully to the TfNSW that the pile sleeving may be terminated at 2 m above the tunnel invert level. For this arrangement, the investigations found that the loading on the piles should have negligible adverse impact on the tunnel lining design. As a result of such an assessment, the proposed pile sleeving level was approved by TfNSW, thus offering an economical foundation solution for the project.CITATION:Azad, F M, Oliveira, D A F and Wong, P K, 2014. The impact of pile loading on adjacent metro tunnels – Barangaroo South, Australia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 355–360 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

The paper discusses the characteristics of Be-zymianny activity during the last 2500 years. Three periods of increased activity have been identified which are the eruptive cycles lasting for 100-400 yrs. The periods of high activity fall on the fol-lowing time intervals: 2400-1700 yrs ago, 1350-1000 yrs ago and from 1955 ixp to the present time. The 1955-1956 catastrophic eruption after a long period of repose (about 900-1000 yrs) opened a new cycle of activity of the volcano which is continuing to-day. Several decades are distinguished in activity which differ in character and intensity of eruptions.

Jan 1, 1990

By P Elliott, D Pershke

In a minerals processing context, sustainability is about using natural resources more efficiently to achieve maximum economic benefits with minimal environmental impacts. It embodies five overarching themes, which the paper will illustrate with practical examples from Australian minerals processing plants. These are:resource utilisation and materials efficiency,process waste reduction and enhancement of co-product values,reduction of water use and impacts,reduction of energy requirements and greenhouse gas emissions, andenhanced control of minor elements and toxic materials. Sustainability could be embedded profitably in minerals plant design in three dimensions: 1.technology,2.design, and3.operations. This presentation discusses a set of principles that could be applied to minerals processing technologies and provides an outline of sustainability assessment and opportunities evaluation tools. The application of the tools is illustrated through a case study by analysing a suite of nickel processing technology routes. The analysis reveals that current generation of nickel processing technologies do possess real potential to emerge as sustainability champions in integrated processing of nickel ores and concentrates, if they are designed, engineered, and operated for sustainability and adapted effectively to site specific constraints and opportunities. The paper will address data gaps and uncertainties regarding the impact of scaling up of pilot-plant performance, and provides strategies to overcome them.

Jan 1, 2006

By C Mason, A Littleboy

This paper presents the results of a large scale survey of The Australasian Institute for Mining and Metallurgy (AusIMM) membership. This survey aimed to understand and define the key issues and drivers that AusIMM members perceived would shape the development of the Australian minerals industry over the next 20 - 30 years. Nine hundred and fifty-nine participants rated the importance of 11 issues and six drivers (generated from interviews with AusIMM members), and 236 of these participants also provided qualitative descriptions of the future. Issues were defined as problems or opportunities for the minerals industry that may be controlled or influenced by the industry, while drivers were defined as those factors that will influence the direction of the industry that are not within the control of the industry. The quantitative data revealed that the top four issues, in order of their perceived importance to the Australian minerals industry, were: investment in exploration, workforce, health and safety, and innovation. The top three drivers in order of their perceived importance, were: economics of mining, global context and Australian society. While the top four issues were largely consistent across professional groups examined, metallurgy and mineral processing professionals rated water inputs and energy inputs significantly higher than the other professional groups. For the list of drivers, there was strong agreement regarding their ranked order of importance across the professional groups examined. Within the qualitative data, however, a single issue (technology) and a single driver (economics of mining) dominated participantsÆ descriptions of the future. These findings provide important input into a broader program of scenario development for the Australian minerals industry being undertaken by CSIRO and its partners. The results of this study demonstrate the importance of using a mixed methodology in generating these inputs to understand more fully how important stakeholders view the future and the factors that will shape it. The results of this study are also discussed with respect to the role that CSIRO may play in facilitating the exploration of uncertainty around the future of the Australian minerals industry.

Jan 1, 2009

The Prominent Hill copper-gold deposit is located approximately 150 km north west of Olympic Dam, on the southern margin of the Mount Woods Inlier in South Australia. Its discovery in November 2001 resulted from the application of a geological model developed from geological, geophysical and petrophysical data pertaining to the Olympic Dam deposit. The discovery has dispelled the notion the Olympic Dam may be unique, and that another deposit like it is unlikely to be found. The Prominent Hill mineralisation is hosted by haematite-matrix hydrothermal breccias, which have suffered extensive iron-sericite-silica alteration and overprinting. Copper, gold, barium, fluorine, uranium, cerium and lanthanum are all intrinsically associated with the hydrothermal iron. Breccias intrude an east-west striking, fault-controlled sedimentary succession, which is flanked to both the south and north by volcanic complexes. Many similarities between Prominent Hill and Olympic Dam are documented including geological setting, mineralogy, breccia styles, and alteration. Differences relate largely to the nature of the immediate host rocks. The similarities and difference provide key data for improving exploration models for this style of iron oxide copper-gold deposit, both within the Gawler Craton as well as globally.

Jan 1, 2004

By A K. B Opitz, M Becker, J L. Broadhurst

"One of the key drivers of geometallurgy is to define the ore characteristics and their variability to build a geometallurgical model. The inclusion of waste rock properties and their variability is just as important, given that the generation of acid rock drainage (ARD) poses one of the most significant environmental challenges facing the mining industry. Formed through the oxidation of sulfide minerals in the presence of oxygen and water, ARD generation is exacerbated through the regeneration of lixiviates by naturally occurring iron- and sulfur-oxidising micro-organisms. In order to manage the potential risk of ARD pollution, timely, accurate, reliable and robust characterisation and prediction of the ARD potential of waste material is critical from an early stage in the mining process.This study demonstrates the use of the biokinetic-accelerated weathering test developed at the University of Cape Town to characterise the ARD potentials of gold waste rock samples under microbial conditions. These tests are performed in conjunction with standard characterisation tests to provide an indication of the potential for ARD generation under both chemical and biological conditions. Results provided information regarding the relative rates of acid neutralisation and acid generation, with the contribution of specific minerals to the observed behaviour considered through use of a detailed mineralogical assessment. Overall, the addition of the biokinetic test to the current geometallurgical characterisation and prediction toolbox will allow for relatively rapid assessment of the bulk kinetics of ARD generation.CITATION:Opitz, A K B, Becker, M, Broadhurst, J L, Bradshaw, D J and Harrison, S T L, 2016. The Biokinetic Test as a Geometallurgical Indicator for Acid Rock Drainage Potentials, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 183–192 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By S Dunham

A cross-discipline approach combining geology, metallurgy and mine planning, geometallurgy is seen as the next logical advance in improving the design and operation of mining businesses. This rapidly evolving field is focused on realising the value that has often been lost in the chasms between the aforementioned technical silos. When successful, the geometallurgical approach promises the ability to tailor mining and mineral processing development and operational options more closely to the characteristics of the resource with resulting lower costs (both capital and operating), improved recoveries and fewer project failures.As with any technological (or managerial) change, there will be side effects from the success of the geometallurgical approach that will impact areas beyond obvious linkages between geology and processing. Some of these effects have the potential to be beneficial to the resource industry and society in general. Beyond the basic geometallurgical promise of closer alignment between processing design/strategy and the multivariate 3D spatial characteristics of the mineralisation, this paper discusses the broader implications and ramifications of the emergent geometallurgical approach: enhancing exploration and discovery; improving project development success; achieving sustainability in an industry working with non-renewable resources; in a world of increasingly hard won license to operate, improving the management of potentially harmful by-products and waste materials (with knock on effects for proactive management of closure issues); smarter approaches to energy management and thus optimisation of projects with respect to carbon footprint; and potential to re-value assets and thus realise a strategic advantage in the area of acquisitions, divestments, mergers and take overs. The authors strongly believe that companies that actively engage with the above issues (and ensure that technical efforts in the area of geometallurgy are not isolated from the larger value chain activities of the firm) will be able to exploit the opportunities that consequentially arise. These early adopters will gain first mover advantages. Firms taking the broad view of geometallurgy will have an opportunity to maximise stakeholder value and win greater success than their less insightful competitors.

Sep 5, 2011

By T Y. Dube

In this paper current net present value (NPV) based mine valuation techniques that take into account market and private risk are discussed and analysed. Potential pitfalls that arise from the application of a portfolio, market or commodity based risk metric to a mining project are identified. An alternative non-simulative framework for quantifying and factoring market and private risk in NPV calculations is proposed and then applied to a hypothetical case study in an attempt to overcome identified pitfalls. Mathematical proof that a static discounted cash flow (DCF) calculation can underestimate or overestimate mine NPV is presented, the conditions for each are outlined and the degree of underestimation defined.CITATION:Dube, T Y, 2012. How the use of market-based risk metrics can undervalue good mining projects and overvalue poor ones, in Proceedings Project Evaluation 2012 , pp 29-34 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By A Scott, A C. Torrance

Explosive properties are typically summarised on manufacturers’ technical data sheets. The values most commonly referred to are the density of the explosive, the energy it is expected to release and its velocity of detonation (VOD). This information is provided so that blasting engineers can make a considered selection of the most appropriate product for a particular blasting application. As an example, a lower VOD and energy product is better suited to blasting in soft, weathered material. In contrast, blasting hard, competent material generally requires a higher energy product which is usually characterised by higher VOD and energy.A review of the technical information supplied by manufacturers shows a wide range of methods of reporting both VOD and energy. A meaningful comparison between products from different suppliers is almost impossible to achieve based on these data. For a similar product, one supplier may have a VOD range of 2800–5800 m/s and a relative bulk strength of 1.34 while a corresponding product from another supplier is quoted with a VOD range of 3100–6300 m/s and a relative bulk strength of 192. In the end, the user has to rely on the level of confidence available from their experience using a certain type of explosive in the type of rock to be blasted at that mine.This paper reviews some of the technical and supporting information that is freely available in the literature and attempts to provide some clarity as to what the numbers that are reported actually mean for the end user. An alternative approach to the evaluation of the suitability of a given explosive to blast a given rock mass is proposed.CITATION:Torrance, A C and Scott, A, 2015. What is relative about energy?, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 447–454 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By F K. Altuntov

The study presented in this paper is based on the Kiirunavaara underground mine located in the northern part of Sweden. The deposit is mined using the sublevel caving (SLC) mining method. This paper briefly reviews the alternative SLC layouts, as well as presents challenges for the application. In Kiirunavaara currently, the traditional SLC design is employed, however, continuous improvement of material transportation systems used in mines generates a need for investigation of the current and future production area layouts in sublevel caving mines. When identifying the potential benefits of the alternative production area layouts, the production targets and effects must be further investigated to understand the benefits and potential effects. In this study, several different layouts have been investigated and evaluated. The designs include different development configurations and orepass infrastructure moved further away from the orebody and still require further investigation.

Mar 29, 2023

By D Readett

The most critical variable in the successful establishment of the Murrin Murrin Heap Leach plant was the effective agglomeration of the Ni laterite ore. This paper describes the test work undertaken to establish the key agglomeration parameters including state of the art testing and analysis procedures. These parameters were then utilised to establish the key design and operational concepts for the world’s first commercial scale Ni laterite heap leach. Following the technical and economic success of the operation, the actual operational data is compared back to the original test work data.

Aug 8, 2011