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By E J. B van Etten

Pit lakes may form when open cut mining leaves a pit void that then fills with ground and surface waters. This often replaces terrestrial ecosystems that existed prior to mining with an aquatic ecosystem, affording an opportunity to improve regional aquatic biodiversity values through targeted aquatic restoration (McCullough and van Etten, 2011). Restoration theory provides guidance when restoring disturbed systems towards landscapes that are of regional value and relevance. But how do we identify a restoration target for a novel aquatic habitat that only exists in the new post-mining landscape? This paper presents a process of first identifying and then surveying local representative aquatic systems, to provide a direction for pit lake restoration efforts and achievement criteria for pit lake relinquishment, using a case study from a sand mining operation amongst wetlands in south-western Australia.The company mines silica sands following mechanical removal of topsoil and then extraction of the ore from below the watertable by dredging. Assessment of wetland and riparian vegetation was achieved through the establishment and measurement of temporary monitoring transects across five natural wetlands in the Kemerton area. Several more regional wetlands were also visited and observations made to supplement and validate these data.Distinct vegetation zonation was found across each wetland, although typically wetland basins were unvegetated or filled with younger woody plants with patchy distributions. Fringing riparian vegetation consisted of few species (commonly the paperbark Melaleuca rhaphiophylla and the sedge Lepidosperma longitudinale), but community composition and structure were variable between wetlands. The pattern of vegetation seen across natural wetlands was best explained by topography and soil chemistry, with low lying wetland areas more likely to experience regular flooding and accumulate organic matter and nutrients.In conclusion, where they are available, regional natural waterbodies may constitute the best valid restoration goal. Nevertheless, the goal may need to consist of a range of closure design opportunities, rather than a single target.

Oct 5, 2011

By M Podreka, P Merry, L van den Berg

Anglo Gold AshantiÆs Sunrise Dam operation is located in Western Australia approximately 55 km south of the town of Laverton. Currently, the mine is producing from both its open pit and underground operations and is planning a significant step change in underground production as the pit phases out. The mine ventilation system is arranged in three independent ventilation districts: Astro, GQ and Cosmo. The future ventilation infrastructure requires significant upgrades to keep up with the increased tonnage. In the short term, increased production is planned for the GQ district as well as for Vogue, which is an extension in the Cosmo ventilation district. In the long term, however, Vogue is likely to become the centre of attention for mining activity.This paper explores several ventilation scenarios which include upgrading the existing fan stations, rentals, establishing a common ventilation backbone, and establishing new upcast infrastructure for GQ to support the short-term production increase. These developments were modelled using ventilation network simulation software to determine airflow distribution and fan operating points for each option. For the GQ area, with its short-term increase in production, each option is evaluated for total owning cost by considering capital and operating costs over a three-year period. For Vogue, which is to become the main focus of mining in the future, a different strategy is followed in analysing the ventilation requirements. Instead of considering different short-term options, a number of staged upgrades are considered to achieve the desired production rates.This paper summarises the planning criteria, airflow requirements, ventilation infrastructure requirements, and economic analysis associated with the conceptual ventilation system design. It highlights how the best short-term ventilation infrastructure upgrades can be selected when considered in isolation but highlights that long-term production planning can have an effect on the decisions made in the short-term.CITATION:van den Berg, L, Podreka, M and Merry, P, 2013. Sunrise Dam short- to long-term ventilation planning, in Proceedings The Australian Mine Ventilation Conference , pp 107-114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

By I Swane, R Rait, A Robertson

Geochemical assessment of mine waste materials prior to commencement of a proposed mining operation is a fundamental component of mine feasibility studies and the regulatory approvals process. Static and kinetic geochemical test methodologies are widely used to predict the geochemical nature of mine waste materials and to develop strategies for managing potentially æhostileÆ materials. These data can also be integrated with data from other fundamental studies such as hydrogeology to predict specific environmental outcomes and potential impacts at mine closure and post-closure.A case study is presented for a proposed open pit gold mine in Mongolia, which illustrates how geochemical, hydrogeological and groundwater quality data can be used as part of a geochemical modelling process to predict the final pit lake water quality over time. A series of static and kinetic test geochemical test programs were completed and acquired data integrated with hydrogeological and groundwater quality data provided by the proponent. A widely used geochemical modelling program (PHREEQC) was used to develop the geochemical model and predict water chemistry in the pit void after mine closure. Sensitivity analyses were completed to explore the effects on the model output of groundwater to leachate water ratio, pit wall rock type and climate.Modelling has indicated that pit void water should be pH circum-neutral at mine closure and should remain within Mongolian and World Bank water quality guideline limits under the modelled simulation most likely to occur in the field. Final void water salinity is expected to increase eight fold over 14 years after end of mine life due to a continuous flux of salts (particularly sulfate salts) into the pit lake whilst the pit lake volume will remain relatively constant due to evaporation and a slow recharge rate. Dissolved metal and sulfate salt concentrations in pit water are also predicted to increase over time and could be moderately elevated compared to applied water quality guideline values. Some of the metal concentrations, however, may be lower as these would be expected to precipitate at circum-neutral pH and greater. Recommended additional assessment work on the project when mining commences includes determining the magnitude of adsorption and co-precipitation of metals occurring in the pit void water/sludge system.CITATION:Robertson, A, Rait, R and Swane, I, 2013. Geochemical assessment of mine waste materials and prediction of final pit lake water quality at a proposed gold mine in Mongolia, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 165-170 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By J Jackson, D C. Curry, A C. Keith

Australian Bureau of Statistics (ABS) data shows that since 2006 the balance of capital costs associated with mine development has become weighted greater than 75 per cent to enabling infrastructure and less than 25 per cent on process plant, equipment and machinery. The well-developed mine planning techniques including pit optimisation and scheduling and process plant design and optimisation have typically proceeded in a linear fashion from geology, mine planning, through processing, with some iterations back to the mine. Only then is attention paid to planning and costing of enabling infrastructure in any detail.Optimisation has typically involved developing cut-off grades, mine plans and schedules and ore processing that produces maximum economic ore. Infrastructure has then been sized æto suitÆ the mining and processing core business drivers.What the ABS data, together with global trends, indicates is that infrastructure can no longer be an afterthought if miners wish to achieve robust project value estimates, realistic ore to market costing and resource statements based on achievable economic cut-off grades.In addition, with such a large proportion of the costs originating from non-mining or processing activities, a mining operation can only be truly optimal if these aspects are given due consideration in the mine design stages, based on quality geometallurgical inputs so that the size and cost of enabling infrastructure is optimised to maximise project value.This paper outlines an iterative holistic approach to mining project development, which integrates the geometallurgical approach and enables infrastructure planning into project design and evaluation. It presents case studies showing reduced overall costs, increased net present value (NPV) and reduced project delivery timelines.CITATION:Curry, D C, Keith, A C and Jackson, J, 2013. Is a 2.5 per cent success rate good enough? Traditional mine development methods have the tail wagging the dog, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 113-128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By S Kakara, A Kamaraj, S S. Varanasi, B V. R Mandalika, M B. Shaik

The properties of top slags play a very important role in secondary steelmaking. Fluxes should be chosen based on the ladle furnace (LF) slag requirements like viscosity, melting temperature, sulfide capacity, etc. CaF2 and CaO-Al2O3-based synthetic slags are the most used fluxes in secondary steelmaking to improve slag fluidity and interfacial chemical reactions. CaF2 is obsolete due to fluorine pollution and CaO-Al2O3 based slags have 40–50 wt per cent Al2O3 and 30–40 per cent CaO which is not beneficial for desulfurisation. Yet another drawback is that LF slag disintegrates into fine powder during cooling due to phase transformation C2S (2CaO.SiO2). Hence, there is a need for the development of low melting fluxes with high CaO content and the capability to prevent slag disintegration. The current work studied the effect of 0–9 wt per cent B2O3 on physico-chemical properties and characterisation of LF slags. X-ray diffraction (XRD) analyses were carried out to identify mineralogical phases present in slag and Fourier-transform infrared spectroscopy (FT-IR) analysis was done to understand the changes in bonds of B2O3 added LF slag. The characteristic temperature of slag was determined by a hemispherical method using high-temperature microscopy. Empirical models were used to calculate viscosity, break temperature, and sulfide capacity. FactSage™, ver 8.2 (by GTT-Technologies) simulations were carried out to find the equilibrium phase fractions and percentage of liquid slag at different temperatures. New phases such as Ca11B2Si4O22 and Ca2B3O5 were formed in LF slag with B2O3 addition. Based on the results, 0.5–1.0 wt per cent B2O3 was found to be sufficient to prevent C2S-driven disintegration of LF slag. Also, the melting temperature and viscosity of LF slag were reduced by adding 3–8 wt per cent B2O3 due to the formation of BO3 planar triangular structure and low melting eutectics in slag. Liquid slag started forming at a temperature as low as 800°C when B2O3 is >6 wt per cent. It was found that the sulfide capacity, viscosity, and break temperature of the slag decreased with increasing wt per cent B2O3. Based on the analysis carried out, B2O3 can be a promising fluxing material in secondary steelmaking, for improving the desulfurisation kinetics and valourisation potential of LF slag.

Aug 21, 2024

By J Franz, S Bock, N Hentrich

Artificial ground freezing is the unrivalled method for groundwater control during mine shaft sinking. Moreover, ground freezing may also provide temporary ground support. The fast development of fibre-optic temperature monitoring devices, three-dimensional freeze pipe survey methods and numerical modelling software provide grounds for developing new and reliable tools for ground control during freeze shaft sinking. This paper presents examples of predictive numerical models that are based on back-analysis and calibration of temperature data that covers the complete construction cycle from pre-freezing through to artificial thawing. The back-analyses showed that standard numerical models are not capable of predicting the prevailing thermo-mechanical conditions satisfactorily. This paper describes the development and implementation of new tools for improved consideration of concrete hydration and latent heat, along with the introduction of other algorithms that improve and simplify the efforts of managing complex numerical models. A function is presented that allows for an automated correction of the model’s mesh based on results of three-dimensional freeze pipe surveys. This paper demonstrates that the latter consideration is important, because the often employed assumption of idealised freeze circle geometry in numerical models impacts on the accuracy of such model’s predictions. Subsequently, the verification of these extended numerical models is demonstrated. Due to its flexibility, the FLAC3DTM code was employed for the numerical modelling. This software provides the possibility of implementing additional functions written in internal FISH or Python language into the models. It is concluded that state-of-the-art techniques for freeze hole drilling and surveying, on-site monitoring and advanced numerical analysis provide a significant potential for both the design and the operation of largescale ground freezing measures. The application of the extended numerical models for predictive simulations during construction allows for temporary shaft lining optimisation, for assisting in operational decision making and for compensating temporary loss of monitoring data. Suggestions are made for required future work in order to further improve the developed ground control tools. CITATION:Bock, S, Franz, J and Hentrich, N, 2018. New tools for ground control in freeze shaft sinking, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 393–406 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By P Holtham, K Duffy, B, W Valery, E Tabosa, rade

Pre-concentration has potential to significantly improve Mineral Resource efficiency by removing gangue early in the process, before energy intensive and expensive comminution and fine processing. However, there are numerous options for pre-concentration and the performance and benefits of these are very case specific. To determine the best option for a particular deposit and to successfully integrate it into the overall mining and processing operations requires comprehensive evaluation. This needs to consider orebody suitability, technology capability and economic viability. The in-situ variability of a deposit and how it is influenced by mining methods and the liberation size of gangue are key factors which are generally not well understood. Geostatistical methods provide an insight into orebody variability, and the overall selection of any pre-concentration solution must be an integrated approach between geology, mining and processing. Many pre-concentration evaluations investigate the potential of just one option. Technology selection should start wide and may include: selective mining, pre-screening (with or without selective blasting), sorting (bulk and or particle), coarse gravity separation (e.g. jigging, DMS), coarse particle flotation, magnetic separation, etc. The upgrade performance of these processes is very ore specific and should be determined from testing, with detailed multi-component modelling used to determine the overall process performance. Many of these pre-concentration processes require significant ancillary equipment, feed preparation and materials handling. It is important to realistically estimate all costs to understand overall economics and select the best option. Some examples showing evaluation and comparison of pre-concentration options are presented in this paper. These include assessments of in-situ variability using geostatistical tools, process modelling of pre-concentration options and overall performance, preliminary layouts and cost estimates, and economic evaluations.

Nov 10, 2020

By R Memary

The environmental and economic impacts of a significant dependence on fossil fuels are affecting the future of sectors such as of mining. These impacts are prompting the Australian Government to seek solutions for reducing its dependence on fossil fuels more generally, such developing clean energy and improving energy efficiency. However, limited research has been undertaken to assess the potential synergies between clean energy and mining in an uncertain global future. This paper analyses current energy use by mining in Australia and reviews the drivers and opportunities for energy efficiency and cleaner energy technologies to be coupled to mining under three future scenarios. Linkages between mining and clean energy are investigated for three global scenarios for mining and metals to 2030, developed by the World Economic Forum (WEF), namely Green Trade Alliance, Rebased Globalism and Resource Security. These scenarios are applied to assess how they could change the barriers, opportunities and trade-offs required for the development of a more sustainable energy sources by the minerals industry in Australia.

Nov 22, 2011

By B Howard, M Jones, D Pershke

"Current closure objectives and criteria are often difficult to achieve and are not delivering value for money outcomes at closure. Current mine closure processes tend to focus on rehabilitation and revegetation of landform structures to as close to premining condition as possible, rather than focusing on the functions of those structures and values they provided. Because mining has highly disturbed the environment, premining conditions and vegetation are often not achievable and objectives and criteria aimed at achieving close to these conditions have been shown to be very costly.The authors have developed a broader approach to developing mine closure plans that is based on environmental risk and gaining post-closure social, environmental and economic value. We think the focus should shift from trying to return the original landscape to returning functions and values provided on- and off-site. If it is not possible to return values on-site in a cost-effective manner, investment should be provided to deliver equivalent values elsewhere.This process can provide better stakeholder acceptance, deliver better environmental outcomes on the tenement and within the catchment and significantly reduce costs, whist fulfilling closure obligations.This framework should enable closure teams to: focus on the functions and services that are important to achieve as outcomes post-closure, rather than a focus on revegetation and replacing the premining biophysical structure engage meaningfully with stakeholders regarding closure outcomes and link outcomes to stakeholder values conduct transparent option evaluations that enable stakeholders to clearly understand the costs and benefits associated with each option and to participate in dialogue on option selection.We present examples of how the framework could be applied to identify alternate closure options that achieve equivalent value outcomes while reducing the costs of closing the mines.CITATION:Howard, B, Pershke, D and Jones, M, 2014. Achieving better mine closure outcomes for less money, in Proceedings Life-of-Mine 2014, pp 615–620 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By M Gerards, M Steinberg, T Graham

The quality and quantity of Australia’s secondary deposits, which include tailings streams and tailings dams, are higher than most countries’ primary deposits. In addition, these secondary deposits have already been mined and processed, meaning that the recovery of high-grade product requires low capital and operating costs.The most widely used process for the recovery of these valuable fine and ultra-fine hematite iron particles is the wet high-intensity magnetic separation technique, originally developed by Dr Jones over 55 years ago. Many of the original machines are still working today.The aim of this paper is to demonstrate the capabilities in terms of grade and yield of using sophisticated magnetic separation modules. All results and figures are obtained from test work and design and engineering work with material from the Pilbara. In addition, consideration is given to dewatering of iron ore product and tailings.Two types of tailings have been identified for processing. Firstly, tailings that have already been deposited in a tailings storage facility, and secondly, live tailings streams from an existing wet iron ore beneficiation plant. In both cases, the technical and practical results are shown along with relevant flow sheets and plant layouts. Finally, this paper highlights the total predicted power and water consumption, capital requirements and projected operating expenses.The results show that the operating costs are significantly lower than the mining and processing operations that are required for an equivalent amount of iron ore. The recovery of iron depends on various factors but is within the 30–50 per cent range at an equivalent grade to the mainstream product. Another significant benefit is that the magnetic separation process is water positive, meaning that water is released rather than added in the process.The processing of the Pilbara’s secondary deposits will therefore result in an overall reduction in operating costs, an increase in product yield from a plant, extend the life-of-mine and offer environmental benefits by reducing the tailings footprint and water usage.The quality and quantity of Australia’s secondary iron ore deposits and tailings are such that many other countries would judge these as equivalent to primary deposits. Furthermore, these tailings are already mined, available and liberated to such an extent that the recovery of a valuable product is highly economical in terms of capital expenses and operating expenses.CITATION:Steinberg, M, Graham, T and Gerards, M, 2015. Recovery of iron ore fines and ultrafines from tailings by using wet high-intensity magnetic separation – JONES WHIMS, in Proceedings Iron Ore 2015, pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By M Medina, J Alexander, R J. Longey

Capricorn Copper Pty Ltd (CCPL) are operating the Capricorn Copper Mine located at Gunpowder, Queensland. As current holder of the environmental authority for the site, CCPL have obligations to rehabilitate areas of the mine that are no longer operational and have the potential to cause/contribute to environmental harm. CCPL sought a voluntary Transitional Environmental Program (TEP) to provide an agreed program of works to cap and rehabilitate the former Mammoth Tailings Storage Facility. The voluntary TEP contained conditions that were required to be met, to reduce the potential for environmental harm from the facility. The former Mammoth Tailings Storage Facility commenced use in the early 1970’s, and is an unlined valley in-fill structure, contemporary in design compared with other such approved structures of the era. The decommissioned Mammoth Tailings Storage Facility, now known as the Old Tailings Storage Facility (Old TSF), has been a legacy source of contamination due to the existing capping not meeting modern cover criterion, and allowing oxidisation and infiltration to the underlying acid forming tailings resulting in Acid and Metalliferous Drainage (AMD) from the facility. A cover design for the Old TSF, and other mine waste storages onsite that required clay capping, had been proposed by previous operators. Under the TEP cover design phase, it was identified that a key constraint was the lack of significant quantities of low permeability clay onsite. The lack of available clay prompted the consideration of alternate lining materials for the Old TSF, with a Bituminous Geomembrane Liner (BGM) being adopted as the preferred alternative. The BGM compared favourably with clay-based materials on seepage analysis, and led to other benefits by eliminating the need for borrowing clay off site, reducing the site’s environmental footprint, and reducing construction time. The BGM cover system on the Old TSF is being monitored with the intent to use this as a case study to confirm expected performance, enabling the cover design to potentially be adopted on the remainder of the site’s mine waste storages that require capping.

Jul 1, 2021

I was delighted to be invited to be patron of this Joint Conference, but the challenging task you have set yourselves, and your speakers' depth of expertise, deny anyone, even the patron, the opportunity to be patronizing. Australia's history has been inextricably link- ed with the fortunes of our great mining industry. That link will remain. Just as the gold rushes of the last century, and the discoveries at Kalgoorlie and Broken Hill changed the lives of generations, so the more recent development activity in iron ore, bauxite, nickel, coal, and uranium are having a significant impact on the lives of Australians today. The minerals industry has contributed to Aust- ralia's jobs and prosperity. Mining is not free of problems, but so long as safeguards are strong and appropriate the net benefits the mining in- dustry brings Australia will continue to be enor- mous. We rely on our mining industry to find, prove, develop and sell our minerals profitably, and my Government is committed to maintaining a healthy mining industry.

Jan 1, 1978

With the theme of û æUnderground Ore Handling SystemÆ, Kopanang Mine completed an extensive project on a specific system with technologies for the handling of ore from a dedicated drawpoint to the shaft system. The intended rail haulage tramming system had to be capable of handling the shaft design and Life of Mine (LOM) requirements. Kopanang is an AngloGold Ashanti gold mine situated in the province of the Free State in South Africa. In the Sotho language the name æKopanangÆ means to come together as a team. ItÆs an appropriate name given that 25 companies worked on this project. The future focus at Kopanang is to establish four mining levels between 3 to 4 km south-west of the shaft and two mining levels to the west. The mine has an expected life of almost 20 years and capital was approved in order to access this reserve to establish the infrastructure to handle the ore, hence this exclusive rail haulage tramming system of close to R40 million (SA rands), which took three years to construct. Apart from the fact that this system had to be capable of handling 6500 t per shift at a depth of over 2 km over a length of 3.2 km, some of the major considering factors were: safety, economic factors with improved labour productivity, efficiency and reliability, risk termination, and ergonomics. The system comprises two 20 t locomotives operating in a double header configuration from a dedicated draw point to a dedicated tip area for the reef and waste ore. With the objective of handling high speed and high capacity, this 200 t payload train is capable of running at 35 km/h powered from a 500 volt ac overhead line. Each loco consists of two 90 kW dc motors with ac/dc power conversion on the locomotive. For the system to operate at this speed, the rail system is constructed with Class 1 rails over the entire hauling distance. The tipping mechanism is unique and the span of 11 hoppers each with a load of close to 20 t is capable of tipping the pay load of 200 t in about 20 seconds hands free.

Jan 1, 2005

By P Gomez, R Baumgartner, G Escobar

"The Cerro Corona mine consists of a Cu-Au porphyry deposit located in the Andes of northern Peru. The deposit comprises a typical Cu-Au multiphase porphyry mineralisation that has been overprinted by an epithermal event. This has generated a complex pattern of argillic alteration facies, which was accompanied by a locally structural-controlled Au-Cu mineralisation with the presence of gold and limited Cu sulfides and sulfosalts. These features, along with the porphyry-style mineralisation, produced a multifaceted occurrence of gold.Since the beginning of operations at Cerro Corona in 2008 there has been a continuous improvement of the geological and mineralogical knowledge. All mineralogical studies have mainly focused on host rock types and, to a lesser extent, alteration minerals, but little work has been done on the mineralisation itself. As a consequence, limited mineralogical information was available for use in the process optimisation initiatives.In the last two years, a series of mineralogical characterisation studies were undertaken with two main goals. First, to gain an understanding of the mineralisation genesis and second, to obtain a detailed characterisation of copper and gold minerals to support ongoing process optimisation. The first goal was achieved by conventional optical microscopy while the second required electronic microscopy and other microanalyses due to the necessity of quantifying several minerals of interest for the processing.The results were used to refine pre-existing geometallurgical domains, explain copper and gold losses in the flotation process and to some extent, improve copper and gold recoveries. The mineralogical characterisation is an ongoing work. Mineralogy provides the basis for any optimisation exercise since it looks in detail at the material to be treated and therefore, should be part of all geometallurgical programs.CITATION:Baumgartner, R, Gomez, P and Escobar, G, 2016. Comprehensive Mineralogical Characterisation at the Cerro Corona Cu-Au Porphyry Mine – the Fundamental Key for Geometallurgical Applications, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 221–230 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By U Singh

This paper presents the evolution of the studies and strategic plans to extend the life of operations at the Savage River iron ore project in north-western Tasmania. The current Life-of-Mine (LOM) plan for the Savage River operations is based on a series of open pits. Drilling has confirmed high-grade extensions of the magnetite resource at depths that exceed practical limits for open pit mining. Grange Resources Limited, the owner of the operation, is investigating underground options – not only to extend the LOM plan but also to maintain peak production at a reduced operating cost while reducing greenhouse gas emissions into the future. What makes this project unique is that it requires introducing a productive and cost-effective mining method to exploit a challenging geotechnical and geometrical orebody in an area of high rainfall. To support the study efforts, the development of an exploration decline, underground drilling programs, and an exploratory drive excavated into the orebody for geotechnical investigation was key to providing the necessary data for a pre-feasibility study (PFS). This paper describes the pragmatic approach and processes to developing the underground mining options study through data collection and then integrating these options into the open pit plans to optimise an overall strategic plan for the Savage River operations. The learnings for operators from this experience are how the technical and pragmatic approaches were aligned to develop the strategic plans, and the importance of timely investment in gathering the necessary data.

Mar 29, 2023

By J Mar·n, R Anderson, S Strohma, R Harvey

Xstrata is the operator of both Minera Alumbrera Ltd (50 per cent Xstrata, 50 per cent Wheaton River) and Ernest Henry Mining Pty Ltd, (99.99 per cent Xstrata), both copper-gold deposits, using conventional SAG/ball milling at current capacities of 36 Mt/yr and 10.3 Mt/yr respectively. Alumbrera is located in Catamarca Province, in the north west of Argentina. Ernest Henry is located in Cloncurry, north west Queensland, Australia. Both operations started in late 1997, with commercial production achieved in early 1998. Different designs and equipment are in use for both operations, however the evolution of SAG milling performance, although logically related to their specific features, reflect similar trends of consistent increases in throughput. This paper will discuss the main changes to the SAG mill liners in both operations and the results achieved to date. A summary of the operating strategies will be included.

Jan 1, 2003

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

By A Wanninayake, E Novello, I Gillani

A residue storage facility (RSF) was designed to cater for Davidson Creek Area and Robertson Range Area operations under the FerrAus Pilbara iron ore development project in the Pilbara Region, Western Australia. Annual ore production was about 15 million tonnes over a period of up to 15 years. The RSF was designed to handle a tailings production rate of 2.2 Mt/a over the project life with ability to be expanded at a later date. The composition of tailings was predominantly -45 ¦ material with some spiral reject material. The fraction of solids was expected to be between 40 per cent and 50 per cent solids by weight.The RSF was designed as an above ground storage facility, integrating with a mine waste dump planned close to the selected RSF site. This integration helped to increase the stability of the RSF embankment and to reduce the construction cost. The main source of construction material for the remaining part of the RSF embankment was selected to be mine waste. The RSF was designed to be constructed in stages by considering the availability of mine waste according to the mining schedule. The use of mine waste for construction of RSF embankments has several benefits over use of borrowed material. These include less construction costs and less disturbances to the environment, by minimising borrowed areas and waste dump footprints.CITATION:Wanninayake, A, Novello, E and Gillani, I, 2013. Effective use of mine waste in the design of a residue storage facility, Pilbara region, Western Australia, in Proceedings Iron Ore 2013 , pp 39-44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By M Berry

Consider these four questions:What is the definition of life-of-mine?When should life-of-mine planning seriously commence?When can life-of-mine planning seriously commence?What is the key input to effective life-of-mine planning?Whilst there is likely to be general consensus on the answers to the first three questions, the answer to the fourth question is open to debate. This author argues that understanding and managing risks and opportunities associated with geological uncertainty is the key input to effective life-of-mine planning, at all stages in the life cycle of a mining project.CITATION:Berry, M, ?2014. Effective life-of-mine planning by understanding and managing risks and opportunities associated with geological uncertainty, in Proceedings Life-of-Mine 2014 , pp 183–190 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By M Rea, E O’Connell

Decarbonising explosives manufacturing and catalysing low-carbon mining supply is a significant global challenge. Low-carbon manufacturing precincts – clusters of geographically close businesses across multiple industries that share a goal of adopting firmed renewable energy and decarbonising process emissions – offer one potential solution. In an Australian first, Orica commissioned tertiary catalyst abatement technology in 2023 to mitigate greenhouse gas (GHG) emissions at its Kooragang Island (KI) facility in New South Wales (NSW), Australia. The EnviNOx® technology (ThyssenKrupp Industrial Solutions AG, Dortmund, Germany) used reduces nitrous oxide (N2O), a potent greenhouse gas arising as a by-product of nitric acid manufacture. As a result, mining customers in NSW are now benefitting from ammonium nitrate (AN) products that are almost 50 per cent less emissions-intensive than those Orica previously offered. The $37 million project is a private-public partnership that has involved partners across Federal and State government, global engineering and technology vendors, local community groups and local carbon advisors to overcome financial barriers.

Sep 1, 2024