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By C Bellia, A Maldonado, S Strong, H Baxter

This paper discusses the technical and cost benefits of alternative data collection techniques used to collect lithological information, obtain laboratory testing samples and perform in situ testing. A comparison between diamond coring and sonic coring techniques is made using data from a recent geotechnical investigation for a final pit slope cut-back. The impacts of the coring method on laboratory strength testing results, material character testing and, ultimately, the mass strength parameters and subsequent slope design adopted are compared. The sonic coring method was chosen out of necessity and enabled the collection of tube samples of a clay unit of interest as well as bulk samples for material character and geochemical testing. The sonic coring generated unexpected degradation of clastic units, while cohesive clay-dominated units were recovered well. The likelihood that disturbance due to the coring method would result in lower than expected triaxial strength results was recognised ahead of time, with surplus samples collected and single-stage triaxial strength testing undertaken. This testing compared favourably with historic three-stage testing, where sample degradation occurred during the later stages. Material character testing of fine-grained, clay-dominated units was comparable with historic diamond core testing, while grain size estimates for more clastic units tended to be finer than previous results. The use of sonic coring over non-cored methods enabled the collection of material texture data, geotechnical properties and a full suite of geochemical analyses. This provided a comprehensive understanding of the lithological and geotechnical character of the rock and soil mass. A high-confidence geotechnical model was developed. The end result was the development of a slope design that was more aggressive than was previously designed (5° steeper inter-ramp angle), which has proven to be appropriate to the conditions following excavation. Overall, sonic coring was a cost-effective means of obtaining additional geotechnical data for the site.CITATION:Baxter, H, Bellia, C, Maldonado, A and Strong, S, 2015. Case study assessing alternative data collection techniques and analysis methods to assist with geotechnical slope design, in Proceedings Iron Ore 2015, pp 419–428 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By J Geronimo, P Kumar, Z Yussupova, M Yahyaei, M Powell

This work goes beyond the general perception of how the well-known mine to mill process can be applied, by applying deeper knowledge along the mining chain. Grade deportment and dilution are considered at the mining stage, and modelled with the new SMI blast movement simulator, linking with the block model data. Assessing the shift to a considerably more competent section of the orebody is quantified via substantial milling trials at standard and higher-intensity blasts. These were stockpiled for batch processing through the mill to ensure feed integrity. The trial work included operating the mill at widely different fillings to develop Grindcurve milling responses. Additionally, model informed process control is initiated via a mill prediction tool.It has been found that accounting for blast movement for the higher intensity blasts could generate additional value of around $1.5M per blast. With the high-intensity blast and changing mill control, the plant was easily able to exceed projected mill throughputs with the far more competent Pipeline ore. Strategies to shift the workload and debottleneck the milling circuit were proposed and proven during the milling trials, demonstrating an increase in throughput of 7 per cent despite running at a lower SAG mill speed, and potential of 16 per cent for increasing the SAG mill to standard operating speed. A number of process improvement opportunities have been identified to enhance current productivity and ensure long term capability to process the considerably more competent future ores. All of this is being linked in with the major digitisation program at the Barrick Cortez site, with an objective of linking all the data into a mine-wide process optimisation system, that can embed the processes by providing process-wide data access and production support via the future dynamic models linking ore body knowledge to productivity along the full process chain.CITATION:Powell, M, Yahyaei, M, Geronimo, J, Yussupova, Z and Kumar, P, 2018. The designed approach to mill liner optimisation – experience at Pustynnoye mine, Kazakhstan, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 595–612 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By J W. Glatthaar, M Mavotoi

The occurrence of fluorine in the copper/gold concentrates produced by Ok Tedi Mining Limited has provided a series of challenges to metallurgists since 1988. Although fluorine is distributed throughout the gangue minerals contained within Ok Tedi ores, itsÆ presence in talc and phlogopite (naturally floating fluorosilicates) has proven to be the predominate sources of fluorine in the final concentrate. Initial treatment for the fluorosilicates consisted of the use of a carboxy-methyl cellulose depressant added to the flotation cleaners. This was superceded in 1998 with the installation of a fluorine reverse flotation process for the removal of naturally floating fluorosilicates from the final concentrate when the fluorine content of the final concentrate exceeds smelter-defined trigger points. The fluorine reverse process is similar to by-product molybdenite concentrate production in that sodium hydrosulfide is used to depress copper/gold flotation whilst allowing the fluorosilicates to float. The process was installed in two parallel modules (to match the existing grinding/flotation modules at Ok Tedi), each consisting of a closed rougher/cleaner circuit configuration. Both rougher and cleaner cells are Jameson Cells from MIM Process Technologies, with the selection based on both processing characteristics and available construction space. This paper discusses both the nature of fluorine in-, and its removal from-, Ok Tedi copper/gold concentrates.

Jan 1, 2003

By R J. Beazley, M C. Woods

"The International Cyanide Management Code (the Code) is a voluntary industry program for gold miners and associated cyanide transporters and cyanide producers. By becoming a signatory, a company commits to follow the CodeÆs principles and implement its standards of practice.Signatories are required to undergo an initial certification audit within three years and a recertification audit every subsequent three years. Recertification audits evaluate compliance over the preceding three-year period. This approach presents a number of challenges. Golder Associates has undertaken in excess of 75 initial certification audits and 25 recertification audits; more than any other audit firm. This paper outlines some of the challenges identified and lessons learnt from the recertification audit process. Central to the process is the challenge for organisations to maintain commitment to compliance over the full three-year period and effectively address deficiencies or non-conformances that may have occurred during that period in a prompt manner.The International Cyanide Management Institute (ICMI) provides guidance in evaluating deficiencies or non-conformances, which requires consideration of the æcauseÆ, ædurationÆ and æongoing compliance effortsÆ and an assessment of the concept of ægood faithÆ in response actions. Golder AssociatesÆ experience with the recertification process highlights some common deficiencies with Code compliance programs, such as: system breakdowns (leading to ineffective communication between departments or loss of information) exceedance of discharge limits inadequate inspections, maintenance activities and associated record-keeping.Such deficiencies can be attributed to: personnel changes organisational changes or structures management systems (eg integrated or standalone) awareness and interpretation of Code requirements transparency of management decisions with Code implications.We have identified that ongoing programed assessment is an effective strategy in maintaining Code compliance.CITATION:Beazley, R J and Woods, M C, 2013. Cyanide code recertification - the three-year challenge, in Proceedings World Gold 2013, pp 247-254 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

By P de Caritat, A Davidson, A Mann

Top outlet sediments from the National Geochemical Survey of Australia have been extracted by a partial extraction method for over 50 elements including gold. The partial extraction results from this low-density survey show discrete coherent anomalies for Au in the vicinity of many of AustraliaÆs known goldfields, and in the vicinity of some minor gold occurrences. In several instances catchment outlet anomalies for Au have been recorded from areas not known to contain significant economic gold. Several large economic goldfields are shown to not produce anomalies in catchment outlet samples. A survey of overbank samples in the Swan Avon catchment of Western Australia at double the sampling density shows that low level anomalies (>1 ppb) can be traced back to source using overbank sediments. Follow-up of one of the Au anomalies at Kent River in previously regarded non-auriferous terrain (western Albany-Fraser Belt) indicates a non-economic, but perhaps geochemically significant, Au anomaly with associated pathfinders including palladium. This may indicate that further exploration of the western part of Albany Fraser Belt for Au is warranted. The combination of catchment overbank samples and partial analysis technique has been shown to be effective at locating the source of gold anomalies from initial low-density continental and regional surveys.CITATION:Mann, A, Davidson, A and de Caritat, P, 2013. High resolution soil geochemistry for gold exploration at the continental, regional and prospect scale, in Proceedings World Gold 2013 , pp 167-174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By S M. Stewart

Building and Maintaining Community Relationships   In mining terms, the town of Waihi is distinctive with the Martha mine situated right in the heart of the town. MarthaÆs central location and other mining activity nearby means there is an increased community focus on the happenings at the mine and the effects and impacts of mining. While WaihiÆs proximity to the mine is unique, all mines have a community context that they operate within.   Issues of proximity simply heighten awareness and emphasise the need for building and maintaining good community relationships. In the three years we have been working alongside the Waihi community, we have worked together with concerned and supportive residents, representatives of Newmont Waihi Gold and representatives of Hauraki District Council, to develop a collaborative framework for addressing the economic, social, environmental, cultural and spiritual wellbeing of the people of Waihi. This could not have occurred without the genuine commitment of all participants.   This collaborative focus has resulted in some tangible progress in Waihi which, in part, stems from people taking an interest in the town because the town is taking an interest in itself. As we have worked and learned within the process of building and maintaining a collaborative and sustainable community environment, we have tried to adhere to a philosophy and a set of basic principles. We believe that this approach, combined with a teachable skill set, helped to create the opportunity to develop a truly collaborative community environment which continues to grow. Our paper will describe this philosophy, these principles and the skill set that we have applied.   The application of the process in Waihi has resulted in a series of outcomes unique to Waihi. These outcomes include formation of the Waihi Community Vision committee, the Vision Waihi Trust and the subgroups set up to further the interests of particular groups, for the collective benefit of all the community.   Based on our experience of other situations, and on the way the Waihi process has developed, we believe that the identified principles and skills can be transported and used in other cultures and contexts. While the resultant outcomes may differ, the underlying principles will still apply. Progress will come from creating a sustainable environment within which the community (including residents, industry and regulatory authority) can determine its own internal relationships and the vibrant growing sense it has of itself.

Jan 1, 2006

By J M. Marwan, B Tang

Strain-type rockbursts, or strainbursts, are characterised by a localised violent failure. Their cause is attributed primarily to the sudden release of strain energy, which accumulates in a volume of highly stressed rock as a result of mining activities. Examples of such phenomena are crown/sill pillar bursts created in the mining process, pillar crush in room-and-pillar mining, face ejection in drift development headings at depth, and floor bursts associated with deep shaft sinking. The paper describes a simple method for the assessment of crown pillar bursts in steeply dipping ore deposits which are extracted by the overhand cut-and-fill method. The method is based on a theory previously established by the author to help assess the need for a remedial solution such as pillar destress blasting. Basically, the mining-induced energy storage rate (ESR) in the pillar is compared with the critical strain energy to come up with the so-called burst potential index (BPI).

Jan 1, 2001

By F Shi, W Huang, D Seaman, K Runge

High Voltage Pulse (HVP) technology is a novel process that could potentially be the step-change needed in ore processability in the mining industry. The propensity of high voltage pulses towards mineral-enriched ore particles during treatment makes this technology selective and has the potential to enable ore pre-concentration by size separation. In this study, the potential for pre-concentration of a low grade copper-gold ore sample subjected to HVP pretreatment is investigated and compared to that achievable after mechanical breakage in JKMRC’s rotary breakage tester (JKRBT). The data show that a better pre-concentration result can be achieved after HVP processing than conventional breakage. The gold pre-concentration potential is much better than that observed for copper. 4D HVP pre-concentration characteristic curves were produced to assess the metallurgical performance possible as a function of energy input. The case study shows that when targeting a nominal metal recovery of 90 per cent for gold, the HVP pre-concentration technique can split the low grade ore (0.9 ppm gold and 0.28 per cent copper in the feed size 26.5-37.5 mm) into two components – a low grade oversize material (0.3 ppm gold and 0.15 per cent copper) and a high grade undersize material (1.0 ppm gold and 0.3 per cent copper). The mass split to the low grade is 23 per cent. Under this mass split scenario, gold recovery to screen undersize is 90 per cent and copper recovery is 85 per cent. The HVP treatment of this feed size requires a specific energy (spark) of 2.8 kWh/t.There is further research that would be required before industrial uptake of the HVP pre-concentration technology would be possible. This paper also outlines the research challenges that need to be overcome.CITATION:Huang, W, Shi, F, Antonio, C, Runge, K and Seaman, D, 2018. High-voltage pulse pre-concentration study using a low-grade copper-gold ore, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 327–338 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By G B. Smith

Barrick (Australia Pacific) Limited initiated a trial of Caterpillar’s Minegem autonomous loader technology in 2009 at the Kanowna Belle mine in Kalgoorlie. Autonomous loader technology offers the potential to improve loader productivity, reduce operating costs and improve safety through removing personnel from the mine operating environment. This paper discusses the implementation of the technology at the mine site, the data collected during the trial and quantifies the benefits of using automated loader technology in comparison with teleremote loader operation. The lessons learned from the trial and work planned for the future in respect of this technology is also discussed.

Mar 21, 2011

Laboratory scale flotation tests were done on mineral hematite and aspecular hematite ore using oleic acid and sodium oleate as collectors. The mineral hematite floated strongly in the neutral pH region, with an increased pH range of flotation at higher oleate additions. Concentrates with sufficient hematite grade to meet the paint pigment specification were produced using oleic acid and sodium oleate as hematite collectors on the specular hematite ore. Hematite recoveries of 70 per cent at 60 per cent Fe grade were obtained using stagewise roughing. The interaction between hematite and oleate was confirmed as chemisorption but the exact mechanism could not be determined, as two independent phenomena can be used to explain the fact that the pH of maximum grade increased with increasing oleate addition.

Jan 1, 1999

By I D. Gregson, A Gandhe, A S. Garcia, K M. MacAndrew

"Falls of ground still cause around one-third of all underground mining fatalities. The recent introduction of mechanised room and pillar working into Indian coalmines is an example of the application of new design by measurement and safety monitoring strategies, which can be used to reduce falls of ground risks in mines.Rock Mechanics Technology, now part of Golder Associates UK Ltd (Golder), is providing rock bolt support and pillar design services to the mines using a design by measurement approach. This involves in situ monitoring to confirm support and pillar designs and pillar extraction sequences.Site examples are given of the support designs determined and the monitoring programs undertaken for both design and safety.Routine safety monitoring of roof movement using telltales is also described. A new auto warning telltale has been developed specifically to warn of imminent caving as pillars are extracted.The approach used by Golder has played a major role in ensuring the success of these projects. As a consequence, mechanised room and pillar working is now firmly established in India, and wider application is planned to help meet future demand for coal.The experience confirms that the design by measurement method for this application has important advantages over conventional design approaches using analytical or empirical methods. Firstly, it measures the design performance or outcome rather than trying to calculate or predict it. Secondly, it provides the opportunity for the design to be adjusted to obtain the optimum outcome. Thirdly, it can do this at a local level, so that the support design can be matched to changing conditions to give the most cost-effective design. Finally, it incorporates long-term monitoring of support performance, again at a local level, so that subsequent change can be identified to enable corrective measures to be implemented in a timely manner and to ensure that ground control safety is maintained.CITATION:MacAndrew, K M, Garcia, A S, Gregson, I D and Gandhe, A, 2014. Application of design by measurement for support and pillar design in mechanised room and pillar coal mining in India, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

The mineral processing industry is in boom times. The focus on mill availability and therefore profitability has never been greater, as grinding mill maintenance often dictates the entire plant shut down duration. Advances in mill systemsÆ quality and reliability and the faster, safer relining afforded by RMEÆs Mill Relining Systems have significantly enhanced grinding plant availability and utilisation. Yet relining performance is still affected by the design and planning by a team of stakeholders long before the maintenance team set foot in the mill. For a greenfield grinding plant project, these team players include: 1. project owner, 2. project manager, 3. mill supplier, 4. liner supplier, 5. plant operating personnel, 6. plant maintenance personnel, 7. mill relining crew, and  8. mill reline system supplier (RME). The complex and sometimes competing design demands of mill construction and operation together with the pressure of tight timelines can result in even simple maintenance requirements being overlooked let alone optimising plant design and planning for maintenance. This paper identifies all the involved stakeholders in an effective mill relining 'team' and gives principles and considerations for each to more effectively achieve the goals within their vital roles. This paper is aimed to be a practical guide for grinding mill designers and planners to more fully exploit the advances in Mill Relining Systems and improve their mill profitability.

Jan 1, 2008

Large mining operations need equipment that consistently performs as expected. The most effective way of ensuring this is to have a defined life cycle with an optimised maintenance strategy. The determination of this life cycle is an economic decision, influenced by the construction and utilisation of the equipment. An effective life cycle costing (LCC) tool must be able to process the many variable factors involved.Many factors influence the costs that are associated with a machine over its life. The most variable of these are the costs of maintaining the equipment. Maintenance costs are dependant not only on the utilisation of the machine, but also on the strategy that has been developed to support the machine through its life. A combination of supplier support, component changes, regular servicing and unscheduled maintenance needs to be modelled, based on a variety of drivers. Traditionally spreadsheets have been used to model these factors, but the increasing complexity of the situation can make spreadsheets unwieldy and difficult to manage. A database solution that breaks each activity into its constituent components, links them to an associated mine plan driver and then aggregates the result is the ideal tool to provide a time based cost profile. The evaluation of a number of scenarios, representing different maintenance strategies/life cycles can be rapidly undertaken. Auditability through inbuilt tools is required to provide easy tracing of data. Use of the host company's account structure allows for reporting against the standard chart of accounts.

Dec 6, 2010

By M Orunesu Preiata

The Odysseus Project is part of the high-grade Cosmos Nickel Complex that lies 30 km north of Leinster. The Odysseus definitive feasibility study (DFS) was approved by the Western Areas’ board in October 2018. Early works commenced in January 2019 with rehabilitation of the existing underground infrastructure. In June 2022 Western Areas was acquired by IGO Ltd. The project is now well advanced to meet its target of first concentrate. The project included the construction of a haulage shaft. The design of the hoisting equipment and the shaft barrel evolved from the initial DFS design stage to the final execution, as the data were made available from the initial investigation to the data gathered during execution (although this did not change from its initial concept). The design philosophy for the haulage shaft incorporated, from the beginning a multidisciplinary approach with inputs from three main areas involved in such projects, namely excavation techniques, geotechnical assessments, and infrastructure construction. This interaction is a fundamental component for the success of such a critical project. In fact, each of these three areas influences each other in a cyclical manner, triggering a continuous review of the project inputs and outputs, while maintaining the original project goals: the design of an infrastructure able to deliver the desired throughput. The throughput dictates the infrastructure that needs to be built, which in turn controls the size of the shaft. The key assumption applied to this is that the rock mass can accommodate the excavation void, and the excavation technique with its tolerances and limits that ultimately need to be verified back with the initial assumptions used for the infrastructure design. The aim of the paper is to present a case study of the experience gained with the Odysseus hoisting shaft and to propose a possible logic path for similar projects elsewhere.

Mar 29, 2023

By Fradd WP

South Australia pioneered metal mining in Australia and was the main source of copper for several decades. Gold discoveries and mining also contributed significantly to the development of the Colony. Across the State can be seen the holes, the mullock heaps and, in some instances, the remnants of machinery of the past era. In this, the centenary year of the discovery of the Teetulpa goldfield, considered by some to he the most significant discovery of gold in the State, it is appropriate that we should present a paper on the history of gold mining in South Australia. South Australia has not been a major producer of gold with recorded production a little in excess of 15 million grams (15 t). This represents about 0.25 per cent of the Australian total and ranks last of the States of the Commonwealth. The outstand- ing feature of gold production in South Australia has been the succession of short periods of rela- tively high production immediately following a discovery, with payable dirt being quickly exhausted, a fact clearly illustrated by the graph of South Australian gold production (Figure 1).

Jan 1, 1987

By A Parry, C Fitzmaurice

After conducting laboratory ore sorting testwork on samples of a low grade nickel ore stockpile at Western Areas’ Flying Fox nickel mine, a mobile crushing, screening and ore sorting plant was located adjacent to the stockpile. An initial two month trial of the ore sorter program proved successful and was extended to process the entire Flying Fox low grade stockpile in a further four month campaign. A total of 167 660 t of low grade ore was processed, providing highly upgraded feed trucked 26 km to the Cosmic Boy concentrator. A more than three-fold grade increase was achieved on ore sorter accepts. The moderately upgraded fines that by-passed the mobile ore sorter were also subsequently blended into plant feed. This paper describes the mineralogy of the Flying Fox low grade ore, the mobile ore sorting campaign and provides some commentary on the economic and environmental benefits achieved in the ore sorting campaign. The ore sorting campaign demonstrated the benefits of being able to utilise mobile ore sorting equipment temporarily located adjacent to sub-economic low grade stockpiles in order to effectively treat these stockpiles and produce viable plant feed.CITATION:Parry, A and Fitzmaurice, C, 2018. The upgrading of low-grade nickel ore stockpiles at Western Areas Ltd Forrestania operations, using a mobile ore sorting plant, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 541–550 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By P Clark, P A. Kirsch, R Tapia Rivera

Community members’ sources of information about companies’ social investments are often influenced by the messages in a variety of communication channels, such as newspapers, television and social media. In this sea of communication channels, corporate communications may not always have the desired effect in influencing community perceptions. This paper explores the efficacy of communication between mining companies and communities in Chile through content analysis of corporate sustainability reports and newspaper reporting.Chilean media reporting between 2005 and 2013 is examined to identify community perceptions of corporate social investments made by mining companies. Content within the Chilean newspapers El Mercurio (national) and Soy Chile (regional) is contrasted with content from corporate sustainability reports published by The National Copper Corporation of Chile (Codelco) and Barrick Gold Corporation, Canada (Barrick) for the same period. The objective is to identify differences in the way that corporate social investments are reported by companies in sustainable development reporting and by media in newspapers.Overall, the study demonstrates that the media’s framing and reporting of corporate activities was more negative than positive. Moreover, media outlets tended to focus upon the ‘negative impacts’ or ‘damage’ to communities brought about by mining developments. Conversely, companies’ public communications were largely focused upon direct improvements in livelihoods (health, education, etc) of neighbouring communities. This preliminary study provides a baseline for the development of new formats of effective communication with neighbouring communities. The paper advocates for an increase in participatory mechanisms with affected parties, which could lead towards a greater mutual understanding of the impacts and draw parties closer together.CITATION:Tapia Rivera, R, Kirsch, P A and Clark, P, 2014. Challenging Perceptions? Sustainability Reporting, the Media and Mining, in Proceedings Life-of-Mine 2014 , pp 413–426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By P Mikula, R Geranmayeh, R Carlton, M Ferguson, R Whiting

The concept of using specially designed slot blasts to mine through stress abutments that intersect faults, while controlling fault-slip seismicity, has come of age at Mt Charlotte Mine. Due to the high and adverse stress field and the presence of major faults, the mine is vulnerable to significant fault-slip seismicity. As mining proceeded, advancing stress abutments around various mined areas encroached on several major subvertical faults. If the sequence formed a diminishing pillar between stope and fault, the removal or failure of that pillar daylighted the fault, and often resulted in significant fault-slip seismicity. A new strategy called ‘Tight Slot Blasting’ (TSB) was developed to restrain or dampen this style of fault-slip movement. The TSB has geometric similarities to a conventional cut-off slot used to create stress shadows, but its function is different. Its objective is to trigger and control a sudden shift of the stress state on a fault from an initial stable state, through an unstable transition, to a second stable state. A TSB firing advances a long tall narrow slot through a stressed abutment between a stope void and a nearby fault, using a rapid blast with a low swell ratio, so that the slot substantially and rapidly fills with blasted rock fragments. During the blast process, the stressed rock is rapidly removed and transformed into the fragmented rock fill in the slot. The strategy deliberately allows a fault-slip episode to manifest at a chosen time and place. The tight-packed broken rock in the slot performs an essential shock-absorbing function by controlling the slip amount and rate on the fault, while at the same time the fill becomes compacted by the movement. This controls the dissipation of fault-slip energy, and greatly reduces the seismic response in time and space. A small closure across the slot occurs, with consequent relaxation and destressing of the adjacent rock mass. Stress monitoring data shows that slot creation lowers the abutment stress in the nearby rock mass, while the newly placed fragmented rock fill acts as a shock absorber, providing considerable resistance to substantial fault-slip movement that otherwise could deliver a significant seismic event. First used in 2007, the strategy has been refined to become a routine specialised practice for management of seismically hazardous situations at Mt Charlotte, with 12 successful TSBs conducted to date. Despite mining through multiple high stress abutments, seismic reactions have not exceeded ML 2.1 with any TSB firing, all remaining below the site tolerable maximum of ML 2.3. This paper presents an overview of the strategy, and five case examples of the strategy in critical stressed areas in July 2016, Sept 2017, Dec 2017 and two in Oct 2020. The strategy has successfully managed the seismicity and is expected to remain an essential part of the seismic management plan at Mt Charlotte Mine.

Nov 29, 2022

By A Bax, G Wardell-Johnson, W P. Staunton, J McGrath, J J. Eksteen

Since 2001, the AMIRA P420 gold processing technology project series has been studying the recovery of gold using gravity devices, with particular emphasis on the centrifugal units, Knelson and Falcon concentrators. The work has entailed the surveying of operating gravity circuits in Australia, Africa and North and South America.This paper reviews some of the results and lessons of these studies, including common circuit operating and design factors, which limit gravity recovery; pointers towards effective modelling of gravity circuits; and the contribution of gravity to overall gold recovery.CITATION:Wardell-Johnson, G, Bax, A, Staunton, W P, McGrath, J and Eksteen, J J, 2013. A decade of gravity gold recovery, in Proceedings World Gold 2013 , pp 225-232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By T Bookless, J Pownell, D Meadows

The ever increasing trend of the gold price has meant that ore deposits that were previously considered too complex, or unattractive by virtue of their low gold grade, are now being investigated more closely. These ore deposits present a greater risk of failure than previously was the case. To ensure that the risk of project failure is reduced and the maximum value is derived from the deposit, its mineralogy, as well as other characteristics, should be well understood such that the optimum process can be designed.Quite often the flow sheet design is assembled using individual process components, from various sources, and without consideration of the complete system. Test work programs require careful planning and an open viewpoint in terms of comminution circuit design particularly with respect to ever increasing power costs across the globe. As an example, high pressure grinding roll (HPGR) technology in many cases offers better mineral liberation than the more traditional comminution devices and it does so at a reduced energy input, and yet HPGR test work is often restricted in its scope due to the perceived novelty of the technology and the resultant lack of generally agreed and accepted test work routes.In this paper the authors outline a typical HPGR test work process route driven by the needs of different ore types and illustrate that to optimise the project value, any test work program should start from the premise that thorough understanding of the ore is vital.CITATION:Bookless, T, Meadows, D and Pownell, J, 2013. Enhancing project value through a designed high pressure grinding roll test work program, in Proceedings World Gold 2013 , pp 291-300 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013