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By M M. Pande, M Ishfaq

The effect of aluminium on nitrogen solubility was investigated by equilibrating melt comprising master alloy of Fe-Al with pure electrolytic iron in a controlled atmosphere (pure argon) at 1873 K. Nitrogen in the samples was measured by sampling technique using inert gas fusion absorptiometry. It was found that nitrogen content decreases steadily with aluminium concentration and gradually, becomes close to 1 ppm for very high aluminium steels. Wagner’s second order interaction parameter formalism has been used to estimate the equilibrium constant and interaction parameters. Scanning electron microscopy (SEM) investigation showed, dual-phase inclusions comprising AlN phase surrounding alumina core. The 3D morphology of inclusions was studied by extracting the sample from the top and the central bottom portion of the solidified ingot. A sparse distribution of nitrogen was found for most of the inclusions which manifested the presence of almost pure alumina inclusions with different morphologies and sizes.

Jun 19, 2024

By C L. McIntosh

The west coast of New Zealand’s south island is host to a large number of placer goldfields that stretch from the Westport area in the north to Gillespies Beach in the south and inland to the foothills of the Southern Alps. This area is host to a large number of alluvial, glacial and strand line deposits ageing in range from Recent to Tertiary. In recent years exploration models have been developed for off shore placer deposits on the continental shelf.Gold mining on the west coast has exploited placer gold resources from the 1860s to present, and with the recent surge in the gold price the industry is currently undergoing a resurgence. The current increase in mining is dominated by small-scale mechanical operations usually involving one to two people at each site; a few larger operations also exist such as the Grey River Dredge.Mining methods range from using floating bucket dredges to small diggers. Some of the mining technologies used are similar to those employed during the great gold rushes of the 19th century. Exploration and grade control techniques can be very rudimentary often relying on previous sampling programs or wide spaced bulk sample drill holes. Some bulk sample drilling is used on the larger operations as a form of grade control, most of the small operations tend not to use any ore control sampling prior to mining. Extraction techniques relying on simple gravity based designs with riffle tables or spirals are the most commonly used. Environmental standards are very high within New Zealand and require operators to return mined areas to preagreed to landforms. The high rainfall experienced on the west coast causes challenges to operators in regard to water quality. Technical issues combined with often limited capital provide for challenges to the operations.

Aug 22, 2011

All large open pits in Australia have been mined, or are planned to be mined well below the local water table. This raises several issues that impact on mine safety, mining costs and regulatory approvals. Some pits will be æwetÆ, where they are mined through permeable horizons and where there will be measurable groundwater inflows. These will require some form of dewatering. There may also be some difficulties in the disposal of excess water. Other pits, may be ædryÆ, where they are mined through impermeable material and there are no measurable groundwater inflows but where there are stability issues related to hydrostatic pressures within the pit walls. These may require some form of depressurisation. Some pits are a combination of both. Effective management of groundwater inflows and groundwater related stability issues and the development of cost effective and environmentally acceptable dewatering and depressurisation systems requires an understanding of site specific hydrogeological conditions and practical experience in what works best for different conditions. The presentation will include an outline of the key hydrogeological factors that impact on large pits, practical methodologies for achieving dewatering/ depressurisation, and some case studies from the Goldfields, Pilbara and North Queensland.

Jan 1, 2003

By G Corder

Even though most major operating companies in the minerals industry have Board-level endorsed sustainability principles and objectives, design engineers typically have no mechanism that allows them to implement those objectives in their work. In addition, the existing project management systems do not readily deliver the innovative solutions needed to address key sustainability issues, such as those related to significantly reduced carbon emissions, minimal environmental impacts, and maintaining the societal ‘licence to operate’. SUSOP® (SUStainable OPerations) is an approach for the integration of sustainable development principles into the design of mineral processes, which has been developed through the Co-operative Research Centre for Sustainable Resource Processing (CSRP). Somewhat analogous to the well entrenched HAZOP (Hazard and Operability) studies, SUSOP® is a holistic, systematic and rigorous mechanism for identifying and assessing sustainability opportunities and risks at each stage of project development - from corporate planning, through design and operation, to decommissioning and rehabilitation – without compromising financial rigour. SUSOP® was developed, tested and enhanced through its application to real case studies in the minerals industry. This development path provided significant insights into the process of identifying and evaluating opportunities for improving an operation’s contribution to sustainability and its long-term business case.This paper will discuss the need for a methodical approach for integrating sustainability principles into mineral processing plant design, present the key elements of SUSOP®, and outline its development path through real case studies. In addition, the reasons why such an approach will have growing importance into the future will be raised.

Aug 8, 2011

The products of Lower Miocene calc- alkaline activity on the east coast of Northland, New Zealand are described and contrasted with coeval rocks of the northern North Island. These rocks, the Eastern Volcanic Belt (EVB), occur in four main centres aligned north-west to south east as either plutonic/hyabyssal bodies or as agglomeratic piles and dyke intrusions. Significantly the plutonic members always occur to the north-west of the volcanic members, probably indicative of differential uplift along faults (upthrown to the north) aligned perpendicular to the EVB. A full basalt-rhyolite (diorite-granodiorite/ adamellite) spectrum is represented, with a temporal progression towards the silica-rich endmembers indicated by cross-cutting field relationships. Modal mineralogy parallels this trend, consisting of two-pyroxene, hornblende, biotite, quartz/alkali feldspar modal assemblages, and with rare occurrences of olivine and garnet-bearing volcanic phases. Chemically the EVB is medium-K, calc-alkaline (with respect to AFM and total-Fe/MgO vs. Si02 indices) and quartz and hypersthene normative. The thirty two available K-Prisotope dates indicate that activity was largely confined to the Lower Miocene (24Ma-16Ma), with an apparent younging towards the south east. Initial B7Sr/e Sr ratios (0.70335- 0.70679) are indicative of a continental- arc-type setting, however it is unlikely that a straightforward tectonic reconstruction for this part, of the Pacific Margin is possible. Evidence from xenoliths, both petrologic and isotope, within EVB magmas and from regional geologic studies suggests that hypotheses pertaining to a volcanic arc sited over a subduction zone may hold little relevance in this case. The review concludes that the EVB developed from the partial melting of a geochemically evolved lower crust as indicated by xenolith evidence. This occurred in response to thickening initiated by a short-lived obductive event in the uppermost Oligocene, and controlled spatially by pre-existing basement structure. Intra-suite chemical and mineralogic variation reflects not only crustal variability, but localized differences in physico-chemical conditions best illustrated by the rare occurrences of olivine and garnet.

Jan 1, 1987

By M Boyd

The University of Wollongong was named University of the Year 2000, for its work in preparing students for the e-world. Computer facilitated learning is being introduced into subjects throughout the engineering course. First year mining engineering students are introduced to computers, e-communication, using the UniversityÆs web based information system, and web based subject delivery. Mining engineering students in the mid-years of the course use programming languages and numerical computation software such as MATLAB, while students in the final years use a range of commercially available professional engineering software such as TALPAC. Most of these subjects are offered as part of the UniversityÆs Learning Online program, co-ordinated by its Centre for Educational Development and Interactive Resources (CEDIR). Learning Online subjects are delivered using the Web Course Tools (WebCT) environment. WebCT allows all resources to be accessed through the web, allows email communication between lecturer and student, and allows discussion groups for the exchange of ideas. Students can submit their assignments through WebCT and receive immediate feedback. This paper describes how WebCT has been used to deliver a first year engineering computing subject, mid-year numerical computation subjects, a mining economics subject and mine planning subjects.

Jan 1, 2002

By G Jones

The Singapore Land Transport Authority (LTA) has been procuring the expansion of their underground mass rapid transit rail network at a prodigious rate since the first line opened in 1987. Four lines (149 km) are currently operating and several more lines are at various stages of planning/construction; one of these is the Downtown line stage 2 (DTL 2).DTL 2 contract C917 was awarded in September 2009 for S$320 M. On 18 June 2013 the original contractor became insolvent, leaving the works incomplete. Following a fast-tracked tender process, McConnell Dowell was awarded the S$254 M contract on 29 August 2013 to complete the works. This contract includes two underground stations constructed by cut-and-cover methods and twin bored tunnels between the stations. Each tunnel is 1400 m long, excavated by earth pressure balanced (EPB) tunnel boring machines (TBM) at an average depth of 20 m and segment lined to 5.8 m inner diameter. The tunnel alignment is located under a busy five-lane road lined with prime residential real estate and congested with utilities.To compound the difficulty the tunnels are located within the notorious Bukit Timah Granite formation. This has a very wide range of strength, from below 1 MPa to over 300 MPa. This strength range is a consequence of six weathering grades, from soil to fresh rock, with the fresh granite causing severe abrasion problems. The various grades can occur within a very short distance of each other. Consequently, the problem of supporting a mixed face exists, particularly in the intermediate weathering grades where intact rock is encountered in the invert and corestones within a loose soil matrix in the crown, which can increase the instability by allowing the ground to flow into the TBM.The focus of this paper will be the excavation of the bored tunnels by EPB TBM used by McConnell Dowell to complete these challenging works.CITATION:Jones, G and Shepherd, J, 2014. Earth pressure balanced tunnelling in a dense urban environment, C917A, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 41–50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

It is hypothesised that increasing the number of loading passes will produce a reduced range of truck payload outcomes compared with four-pass loading. The paper provides analysis to support this hypothesis. It is shown that, hypothetically, loading trucks with five or more passes will result in reduced tendency for overloading and reduced confidence interval for truck payloads that increase the confidence level of containing high end payloads within safe and commercially acceptable limits. Furthermore, increased number of passes provides for more precise bucket load spotting and so improves distribution of payloads within truck bodies. Truck-loading issues examined by the paper include: Improvement in life of driveline components and tyres. Generally tyre costs are relatively moderate; but tyres tend to become an increasingly sensitive performance/cost component as truck scale increases; Reduction of site severity fects flowing on to suspensions, truck frames and structural components generally with potential for reduced long-term repair costs; Less physical body damage due to smaller load increments; Reduced risk of non-compliance with payload limitations for safe braking standards; Increase in loading cycle times tend to increase with scale of loading machinery within the limits of a specific type of equipment (ie rope shovels or hydraulic shovels). Production increase with increased bucket capacity is, to a degree, offset by slower loading cycle times. This is particularly pronounced with front-end loaders but tends to be less noticeable with hydraulic excavators/shovels and electric rope shovels. Decrease in loading time, as a proportion of total truck-cycle time as open pits deepen and dump reaches increase. The production and cost benefits of four-pass loading tend to diminish as truck cycle times increase. The paper also discusses the implications for loading-equipment philosophy to satisfy the future needs of the industry. Cost benefits from upscaling tend to diminish as truck scale increases, so increasing management diligence and close monitoring are required to ensure that expected outcomes are realised. These truck-loading issues have been researched to assess the benefits positive or negative) of four-pass loading in practical scenarios. An attempt is made to determine whether four-pass loading is a æmust-haveÆ or merely a æmythÆ.

Jan 1, 2003

By J Lombardi, M Weidenbach

"OZ MineralsÆ Prominent Hill copper-gold concentrator is located 650 km north-east of Adelaide, 130 km north-east of BHP BillitonÆs Olympic Dam operation and 130 km south-east of the regional township of Coober Pedy, in the Gawler Craton region of South Australia. The concentrator was built in 2008 and commenced commercial production in early 2009. The Prominent Hill concentrator is comprised of a conventional grinding and flotation processing plant with a 10 Mt/a ore throughput capacity, operating well over the design rate of 8 Mt/a. Increased throughput rates have seen a decreased water recovery from the tailing thickener due to operating above design. Subsequently, greater pressure was placed on the site water balance and bore field off-take rates due to increased evaporation losses from greater volumes of water reporting to the tailing storage facility. This resulted in a trade-off between water availability and milling rates as part of the operating strategy.Two projects were implemented to increase the tailing thickener underflow density, thus improving water recovery directly back into the operating plant, reducing water losses via evaporation and decreasing the reliance on the bore field system operating at maximum rates to maintain mill throughput. The two projects were: tailing thickener feedwell redesign implementation of the Manta Cube control system.This paper discusses the background, implementation and benefits attained from these two key projects. Combined they have allowed a two to three per cent increase in tailing thickener underflow density to be consistently achieved, which has allowed greater water recovery. As a result, the processing plant has been able to operate at higher throughput rates when required, with greater water availability in the process plant recirculating system and a reduction in occurrences of the plant being æslowed downÆ due to water supply shortfalls. Both projects have also delivered a significant reduction in flocculant usage.CITATION:Weidenbach, M and Lombardi, J, 2012. Tailing thickener operability and control improvements at Prominent Hill, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 137-142 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 29, 2012

By Linge HG, Klauber C

The key element in the carbon-in-pulp process for gold processing is the loading of dissolved Au(CN)2 from solution onto activated carbon. The mechanism and kinetics of this step have been examined by solution adsorption-desorption and X-ray photoelectron spectroscopy for both coconut derived activated carbon and peat-based activated carbon. The results show that these carbon types have the same mechanism and kinetics of adsorption. There is no contribution to the bonding from carbon-oxygen functionalities on the carbon surface, as has been invariably supposed in all previous theories for the mechanism of the reaction. It is shown that Au(CN)Z is reversibly adsorbed intact on and parallel to the graphitic planes of the carbon with the formation of a weak carbon-gold n-donor bond. The kinetic measurement of carbon gold loading reactivity is discussed and use of the Murdoch equation for this test is critically assessed.

Jan 1, 1989

By M Sandy, A Vakili, J Albrecht

Although rock strength anisotropy is a well-known phenomenon in rock mechanics, its impact on geotechnical design is often ignored. No widely accepted guideline currently exists for its characterisation. Anisotropy can significantly control the failure mechanism and progression of damage into the rock mass, particularly in high-stress conditions. As such, it can play a key role in the stability of underground excavations and subsequent geotechnical design.This paper introduces the concept of anisotropy at both intact and rock mass scales. It then presents guidelines for measuring anisotropy and assigning rock mass strength properties. An improved unified constitutive model (IUCM), which can account for more complex failure mechanisms, is then briefly described. This IUCM is used to better understand the typical responses of anisotropic rocks to underground mining and to develop an improved damage classification scheme for these conditions.The application of conventional design methods in anisotropic conditions is shown to lead to significant errors. Two case histories are then presented, illustrating how the proposed methodology can improve the reliability and accuracy of the geotechnical analysis when compared with conventional design methods.CITATION:Vakili, A, Albrecht, J and Sandy, M, 2014. Rock strength anisotropy and its importance in underground geotechnical design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 167–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By S L. Martin, M Wimberger

The binary indicator coding of assay and lithological data according to a single criterion or multiple criteria is a powerful technique for representing mineralised shapes through the modelling of probabilities. This can be as simple as using a single indicator to model the probability of occurrence of a condition, usually a grade threshold or a lithology, but it can also be used with a number of categories. Case studies are presented to show the power of this approach, where the geological controls on mineralisation or on the distribution of a rocktype or alteration, often coupled with mineralisation, are unclear. The categorical approach is often used as a de facto grade filter in disseminated or stockwork mineralisation. The ultimate expression of the indicator formalism is in multiple indicator kriging (MIK), where a conditional distribution of probabilities is generated for each estimation panel. This has applications in recoverable resource estimation, as the input for continuous or categorical simulation, where the distribution of sample grades is multimodal, or when there are superimposed mineralisation events with different orientations. However, in some cases, MIK is being used as an excuse for ignoring a quality geological interpretation. Examples from the public domain show the abuse of the categorical and MIK approaches to modelling probabilities, together with a plea for greater consideration of the geology.

Mar 22, 2022

By D Wimpenny

Underground infrastructure is often a critical component of transportation and utility schemes. It is characterised by long design lives with limited access for inspection and maintenance. The exposure environment can be difficult to assess since it will often vary substantially between different locations in the same facility and with time during construction and in service. In addition, the specific demands placed upon underground infrastructure are not well covered by the exposure classes and other guidance given within current codes of practice. When problems occur they can be difficult to rectify and involve significant disruption.Given these substantial risks the prudent designer may adopt a systematic ‘durability planning’ approach which:· defines the environment and principal deterioration mechanisms for the various elements and construction materials,· predicts the design life for alternative durability enhancement options, and· recommends associated measures to be adopted during construction and in service.This paper describes the development of durability planning within Halcrow, giving examples of its use from its first implementation on tunnels under the Suez Canal in 1993 to recent projects in the Middle East and Australia. It seeks to demystify the process, identify shortcomings and speculate on its future development within the civil and mining sectors.

Mar 8, 2011

The implementation of robust, reliable and accurate sampling systems is the key to the successful management of any mineral processing plant. The representative sampling of a mineral processing plant is the only way to determine what is coming into the plant, what is going out as fi nal product and what is going to tails. In plants with high gravity gold components, where high recovery effort gravity circuits are installed, the use of a gravity recoverable gold (GRG) sampling system can assist in the online monitoring of the performance of the circuit. The typical installation location would be in CIP or fl otation feed (ie cyclone overfl ow), downstream of the gravity circuit. A GRG sampling system generally consists of the following equipment: true proportional, continuous drive, linear cross cut sampler, secondary vezin sampler operated on a timer, a batch centrifugal concentrator, and sample dewatering module. The operating philosophy of the GRG sampling system is that the primary sampler operates on a continuous basis, generating a constant stream of truly representative sample. Consep's H&S drive system is unique in its ability to be able to operate in a continuous mode, therefore enabling a continuous stream of representative sample to be generated. The primary sample stream reports to the secondary sampler. The secondary sampler operates on an intermittent basis (nominally ten minute interval), resulting in a relatively small sample volume per shift. Normally the sample volume would be ten to 15 L per shift. The secondary sample rejects stream reports back to the batch centrifugal concentrator. The sample generated from the secondary sampler can be dewatered using a Consep H&S dewatering module. This device produces a final sample that consists of separate filter cake and filtrate. These are suitable for taking directly to the laboratory. The continuous stream of truly representative secondary sampler rejects is passed through an appropriately sized Knelson Concentrator, typically a KCMD7, KCCD10 or KCCD12 sized unit. This unit recovers any available GRG from the stream. The Knelson Concentrator is also purged of its gravity concentrate at the end of the shift. This sample, which is nominally around 1 - 2.5 kg of concentrate, is also taken to the laboratory. At the end of the shift the client will have a measure of the gravity recoverable gold content of the target slurry stream, as well as a true representative sample of the complete stream. Through the addition of a Knelson Concentrator to an otherwise typical sample station, it is possible to generate a true measure of the performance of your gravity circuit. This will take the guess work out of the daily variation in gravity circuit gold recovery, as the site knows whether the changes are due to gravity circuit equipment performance, or due to the natural variation of ore GRG contents. Maintenance planning can also be designed around the system, as the site will have a composite sample to measure the performance of the circuit, therefore indicating where performance has dropped and maintenance is needed. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Aug 1, 2010

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 T N. Little

This paper is concerned with the influence of engineering geology on design of Wall Control Blasts. In the Introduction, the Blast Management Framework and the Blast Design Requirements classification system (previously developed by the author) is drawn upon to set the context. Blasting objective for all wall control blasts involves both profile and damage control. Four classes of approaches for blast design are outlined and briefly discussed. Five distinct wall control blasting techniques are summarised. The general relationship between geology and blast design is explored in the paper. Influence of geology on pre-split and post-split design and blasting direction is highlighted. Wall damage modelling from the closest row of blastholes is also introduced using the Analytical Damage Model (ADM). The relationship of rock properties and explosive selection and in particular the Mach wave generation is introduced to assist blast designer in this regard. Finally a Conceptual Model that relates vibration, damage and rock mass condition has been presented along with some applications that have been undertaken by the developer. Eight conclusions have been formulated based on extensive work in this area and the current study.

Jun 22, 2022

By M Thompson

"The Jaguar concentrator, 60 km north of Leonora, Western Australia (WA), consists of a standard closed circuit semi-autogenous grinding (SAG) and ball mill producing a float feed of approximately 60 micron at 70 t/h. Following comminution, separate copper and zinc concentrates are produced by differential flotation. These concentrates are subsequently dewatered by thickening and then filtration.Separate audits of the Jaguar Operation’s copper and zinc concentrate thickeners were conducted to evaluate their performance, following occasions where site personnel had identified unnecessary loss of copper and zinc concentrate to the thickener overflow. The feedwells were identified as the source of the observed problems due to the following issues with their design/duty:lack of retention time in the feedwell as current design is completely opennot conducive to effective mixing required for efficient flocculationdiameter of the zinc concentrate thickener feedwell was undersize for its duty.To improve the performance of the thickeners, it is planned to replace both concentrate thickener feedwells with a high rate design for their respective duties in February 2016. The audits also identified that the feed system requires modifications with particular importance placed on minimising air entrainment of slurry into the thickener feedwell. Minimisation of air entrainment is hoped to be achieved by providing constant head pressure through installation of weir arrangements in the feedboxes and redirecting each feed pipe so that it feeds tangentially into the feedwell. In addition, improvements to the control philosophy of both thickeners will be made with the installation of an ultrasonic bed level probe and bed mass sensor, in order to make real-time adjustments to the underflow pump speed to maintain steady state operation.Following the feedwell replacement and modifications to both thickeners it is expected that losses of recovered copper and zinc will decrease to undetectable levels. Subsequently it is anticipated that a more consistent, homogenous underflow can be produced for downstream filtration.Citation:Thompson, M, 2016. Concentrate Thickeners Feedwell Replacement, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 273–278 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By T McLeod, B Catto

AngloGold Ashanti Australia’s (AGAA) Tropicana gold mine (TGM) geology department seized the rare opportunity of building a new geology department for a new operation: the philosophy, the people and the processes. Not satisfied with the status quo, or simply repeating what was familiar and already known, the vision was for an innovative, agile, multidiscipline, high performance team, capable of delivering on expectations.To achieve this, the geology department has operationalised key components of human resource management (HRM).This paper describes the operational design and implementation of key HRM components: job analysis, organisational design and organisational development. The benefits of this approach are presented in terms of engagement and autonomy in roles, opportunity for role variety and flexibility of the organisational structure. The result is a geology department that provides the functions of mine geology, resource development, regional exploration, survey, data management, geographic information systems (GIS), resource modelling, scheduling, sample preparation, resource coordination and hydrogeology, and even geotechnical engineering for a year!Considerations for application in other geology departments are presented in terms of fundamental requirements and lessons learnt. Fundamental requirements for success have been the sustained support of the general manager, valuing the scrutiny that comes with continuous improvement, high quality HRM systems and tools within the organisation, and a committed leadership group within the department. One of the most important lessons learnt is that a robust process of ‘induction to role’ is critical – the process of familiarising new starters with who we are and the way we work.CITATION:Catto, B and McLeod, T, 2017. Rewriting the rule book – geology organisational design, in Proceedings Tenth International Mining Geology Conference 2017, pp 137–142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By M Steinberg, M Amarant

Upstream Classifier are well-known in the iron ore industry for at least 15 years. At present, more than 60 units are in operation in Western Australia. The advantage of this technology is their capability to produce three products with one equipment – iron ore concentrate, iron ore middlings for further processing and slimes (tailings). The principal of this beneficiation process – upstream classification and upstream separation – will always remain. However, the optimisation of the classification and separation efficiency of the equipment itself is a continuous process driven by enhanced automation and instrumentation, design changes and the use of upstream and downstream information and requirements. Besides efficiency, the safety, maintenance and replacement conditions are very important subjects for the operation of an iron ore mine. The aim of this paper is to present a new allflux® upstream classifier design, which has been developed together with several iron ore producer from Western Australia. The new design benefits from its sustainability approach by dividing the entire equipment into small reusable parts. As a result, maintenance is minor, replacement much faster, lifetime much longer and costs much lower. Furthermore, it demonstrates new features to prevent hazardous working conditions such as confined space as well as new fixing devices to speed up the replacement of certain items and parts.

Sep 18, 2023

By G Hill, D Grant, M Tyler

Located approximately 570km NNW of Adelaide in South Australia, the Olympic Dam mine (OD) is the world’s fourth largest remaining copper and gold resource and the largest uranium resource. Discovered in 1975 and going into production in 1988, the operation consists of a fully vertically integrated underground mine, mineral processing plant, copper smelter and refinery, as well as associated infrastructure. BHP achieved production of 203,000 tonnes of copper cathode plus associated by-products in financial year 2016. The immense size and high-grades of the Olympic Dam resource offer a range of growth pathways, making closure timing estimation and planning a challenge. Current estimates put the OD resource at approximately 79 million tonnes of copper. Major factors influencing the closure timing estimation, as a result of the large resource and grade tonnage profile, include the mining method that may be used and the downstream processing method, ultimately influencing such things as the total disturbance area and the extent of infrastructure to be demolished at the end of mine life. In addition, factors such as the mining and processing method and production rate have a direct impact on larger rehabilitation items such as the total number of tailings cells required.CITATION:Grant, D, Tyler, M and Hill, G, 2018. Olympic Dam mine closure planning process, in Proceedings Life-of-Mine 2018, pp 43–45 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018