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By G Bickert

Australia is currently developing and engineering a range of specialised processing options for rare earth (RE) (Lynas, 2011, Alkane, 2005), zirconia (Alkane, 2005), lithium (Galaxy Resources, 2008) and other special minerals and metals required in high-tech applications. The processing of lithium, zirconium and RE minerals is based on complex leaching processes which require extensive liquor clarification, solid liquid separation and solids washing. The filtration properties for those leach liquors, residues and precipitates are not well understood and differ drastically according to the process route applied. Thus, filtration test work is essential for equipment selection, sizing and design. Similar types of slurries are filtered in laterite nickel, TiO2 and other chemical oriented processes, while more experience is available here as those processes are applied widely for a number of decades. The increasing need for dry stacking of tailings requires advanced tailings filtration with properties differing drastically depending on tailings properties. More traditional mineral processes such as flotation commonly apply filtration. All of these and other cases require proper filtration test work particularly evaluation of vacuum versus pressure filtration and the need for cake pressing and/or air blowing for filter presses. Bench scale test work and/or pilot plant operation is common to determine filtration rates, achievable cake moisture and wash efficiencies and sometimes filtrate clarity. While those values are important, there is much more valid information to be obtained by filtration test work.This paper discusses the intricacy of filter selection and sizing based on driving forces (vacuum and pressure air, compression by mechanical means and slurry) and parameters (cake thickness, forces and times) and different processes utilised in common filtration equipment. It will discuss the in’s and out’s of filtration test work design, planning, and in particular data gathering, processing, reporting, evaluation and filter sizing from recent examples of bench and pilot scale filtration test work for above applications together with methods for predicting filtration performance for example where test work is lacking. One focus will be the realistic extrapolation of test work results towards different parameters utilised in full scale equipment and plants. The conclusion of the paper will contain checklist for filtration test work.

Aug 8, 2011

By D Espinoza, I Rees, J Pocoe, P Collier

P Collier, I Rees, J Pocoe and D Espinoza

Mar 22, 2022

By C Hoffmann

Given that each year, 30–40 per cent of mining industry deaths are attributable to failures of vehicle interaction controls (EMESRT, 2023), the mining industry is now armed with a growing body of knowledge from EMESRT (Earth Moving Equipment Safety Round Table) and ICMM (International Council on Mining and Metals) global vehicle interaction initiatives over the past years, that enables mining companies, OEM’s and technology providers to work together to develop and implement more effective controls and drive the adoption of capable solutions. Leveraging 20 years of experience as a global technology provider of Proximity Detection System (PDS) and Collision Avoidance System (CAS) solutions for surface mining operations, Wabtec Digital Mine Technology shares key insights for ensuring the effective selection, implementation and integration of these technologies into existing mine site controls and mining operations for effectively reducing vehicle interaction risk enabling mines to drive towards ‘zero-harm’ objectives. Topics covered include: alignment with industry best practice for controlling vehicle interaction risk by EMESRT and ICMM, importance of the maturity of EMESRT levels 1–7 vehicle interaction (VI) control framework, managing expectations that PDS/CAS is a ‘silver bullet’, alignment with industry functional – performance – technical requirements, proximity detection versus collision avoidance, sensor performance and fusion and limitations, rules engine intelligence critical to mitigating nuisance alarms during normal operations, system health monitoring and reporting, human factors engineering and operator acceptance, implementation strategy, installation standards and quality control, change management program, training programs, reporting and data analytics with actionable insights and maintenance strategies. Insights will also be provided on the challenges moving from EMESRT levels 7 (operator awareness) and 8 (advisory controls) to level 9 (intervention controls) as it’s a journey not an out-of-box solution, the growing demand for coexistence of CAS and Autonomous Haulage Solutions (AHS), functional safety approach, value added systems integration and the applicability of new emerging technologies.

Apr 16, 2024

By P M. Cepuritis

In hard rock mining, large-scale bulk mining methods such as block or panel caving (BC/PC) and sublevel caving (SLC) typically generate significant surface deformations such as subsidence. Surface deformations need to be considered in the project evaluation and planning stages of cave mines, for example, planning and location of critical underground mine planning infrastructure such as portals, haulage and vent shafts, access roads, or potential damage to existing infrastructure, changes to surface water management, waste dump, stockpile and tailings dam stability, and environmental impacts. Assessing the impact and risks associated with subsidence is a key component in robust mine planning and operations management.

Nov 29, 2022

By S Thomson, G Rigby, J Norgard, D Wilkinson

Bulk explosives provide the energy to move a rock mass and reduce it to an optimal size (fragmentation). The intensity of energy needed depends on several factors including a customer’s geology and end objectives. An energy mapping tool has been developed to help customers to determine their bulk explosive needs based on these objectives.At one end of the energy map dealing with high-energy products, a new range of bulk explosives products for surface mining have been developed. With these products, it is possible to provide blast designs with up to nearly triple the relative bulk strength (RBS) of ANFO, and address primary focus areas for mining operations, including the reduction of drill and blast costs, improvements in production rates, better face advance through improved broken stock management, better drill productivity, improved milling efficiency and lower energy costs in surface mines.In this paper, field trial results from the first level of new high-energy products are presented. These products have an RBS 2.25 times that of ANFO. Industry variations of a smaller diameter (89 mm) pumped product for civil quarrying applications, and for large diameter (311 mm) hard-rock metalliferous mines are presented. For both cases, the run-of-mine fragmentation levels obtained with the new bulk explosives are contrasted with the fragmentation profile generated with the currently accepted product range applied in similar geological conditions. The new products show increased fragmentation across the measured size distribution, with reduction in P50 values of 20 and 37 per cent over the currently used product for the 311 mm and 89 mm diameter blastholes respectively.CITATION:Wilkinson, D, Rigby, G, Norgard, J and Thomson, S, 2015. Higher energy bulk explosives – matching products to rock types using an energy map concept, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 579–584 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By T Sua, B Wright

"BHP Billiton West Australian Iron Ore (WAIO) conducts an extensive geometallurgy program for its iron ore deposits in the Pilbara with the focus on determining the lump yield (the mass percentage of >6.3 mm rocks) and the lump and fines grade for iron ore products. The geometallurgy program provides accurate information to design engineers and technical marketing teams on the performance of different iron ore mineralogies for future deposits. Additionally geometallurgy results are being used to guide short-term production planning with their introduction into short-term geology models and grade control models. The data that underpins this knowledge is from dedicated geometallurgical programs, drilled using PQ (~83 mm) holes. These holes are crushed by intervals that are based on geological definition which provides an indicative lump yield and lump and fines grade. The lump is then subjected to standard dropping and tumbling test stages to produce a simulated lump and fines product. In the past, quality assurance, quality control holes were drilled using HQ (~64 mm) holes for geochemistry purposes. These holes were crushed to provide an indicative lump yield and lump and fines grade and then 100 per cent is sent for assay (with no dropping and tumbling). Utilising data from HQ holes can significantly increase the indicative geometallurgical data available. This paper compares the geometallurgical results from both PQ and HQ holes from a range of bedded iron deposits (Brockman and Marra Mamba). The PQ and HQ data are compared by orebody, stratigraphy and depth to exclude factors that are expected to influence geometallurgical results.CITATION:Wright, B, Sua, T, Robertson, B and Van Dijken, B, 2016. Comparison of Diamond Drill Size on Iron Ore Geometallurgical Results, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 161–166 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By R Hargreaves, T Elkington, W J. Shaw, G W. Booth

Every day, around the world, thousands of tons of ore are loaded onto ships completing the miningproduction process and starting a multimillion-dollar economic transactions process. These transactions are based on the supply of tons of a commodity with certain specifications of assays of the main element (or physical properties) and concentration of contaminants, which are finally verified and evaluated by buyers, and also are considered ‘as true’ during Reconciliation process. On Sample Stations, this ‘true’ is based on a few kilograms of sample, often representing thousands of tons, that are sent to laboratories for further sample preparation and chemical analysis, where finally assay information is obtained from a few grams of pulverised sample, and are used for further production, planning, operational and financial-marketing decisions. Different International Standards (depending on the commodity) are used to establish the methodology to be followed, to set-up and obtain samples from the Sample Stations, and the specifications are visually inspected to give an estimation on the performance of the sampling point. This paper seeks to highlight with examples, the importance of the implementation of a continuously monitored Quality Program (QAQC and QM) on Sample Stations, focused on the parameters that directly affect the quality and representativeness of the samples. By this implementation, a proactive approach and better-informed decisions can be taken for mining companies to: a) quantify/improve production and reconciliation results, and b) to supply the right specifications of shipped ore, increasing the value of the Resources. Finally, laboratory results are normally used as an indication of the quality of the information applied for the economic transaction, but it should be considered, clarified and highlighted that the laboratory will only process and analyse a sample obtained from a Sample Station, and potential problems on bias or precision may occur in stages prior to the laboratory reception. Hence the importance of the implementation of a quality assurance program that protects multi-million dollar decisions.

Mar 22, 2022

By F Kock, Y Sulianto, T Trott, B G. Putland, D Morgan

"Northparkes installed and commissioned a secondary crushing circuit in 2010 to debottleneck the semi-autogenous grinding (SAG) mill constrained grinding circuits. Following further improvements to the circuit (inclusion of a double deck vibrating screen), the project successfully delivered finer feed to the SAG mill. The result of this project was an increase in the milled tonnes from 5.6 Mt/a in 2012 to 6.0 Mt/a in 2013.The increased throughput rates introduced new challenges with the circuit becoming power limited. How to best optimise the available comminution power, while delivering the optimal particle size to the flotation circuit was made the key optimisation objective. To achieve this objective, Northparkes initiated a project that included engaging comminution experts. Recommendations included changes to the SAG mill including mill lifter design, increased grinding media charge levels and reduced grinding media size with aim of producing a finer grind size.Northparkes implemented these recommendations along with some other changes to SAG discharge grates and the mill discharge vibrating screen. This achieved a substantial reduction in the flotation feed particle size distribution (approximately 20 microns) by utilising increased average SAG power utilisation, in turn resulting in a two per cent increase in copper recovery.With power utilisation now maximised, the next phase of optimisation has moved to the throughput-grind-recovery relationship and the cost benefit analysis of installing additional grinding power.Citation:Sulianto, Y, Trott, T, Morgan, D, Bell, T, Kock, F and Putland, B, 2016. Optimisation of Installed Mill Power Post-installation of Secondary Crushing Circuit at Northparkes Mines, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 331–338 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By A Innis, A Bye, B McCarthy, S Glover

Technology adoption in the mining industry has been steadily increasing over the past decade, driven by the need to improve operational efficiency, safety, sustainability, and profitability. As mining companies wish to implement solutions to improve mining safety and productivity, various technologies are being integrated into mining operations to enhance processes, reduce risks, and optimise resource utilisation. Adoption of new technologies such as autonomous trucks requires a strong focus on foundational operational technology (OT) and a systems-thinking approach. OT support is critical however, OT is traditionally not considered or integrated into standard maintenance activities. Consequently, sourcing and applying service support to OT systems in real-time has posed significant challenges to date. Neglecting the monitoring and upkeep of these operational technologies and equipment can lead to a host of adverse consequences. Operating instability becomes more prevalent, necessitating reactive measures, and the vulnerability to cybersecurity threats increases significantly. To address OT monitoring and maintenance challenges, a systems wide mindset and remote support discipline must be utilised. Remote operations support refers to real-time, 24/7 monitoring, control and support of site OT: network, production systems, maintenance systems, enterprise systems and mobile and fixed plant through a single interface remote from site. The presence of a disciplined team, grounded in a systems-oriented approach, is of the utmost importance to remote monitoring, given the intricate interdependencies of OT systems. The ability to understand the relationships among multiple systems, coupled with the capacity to distinguish between symptoms and root causes, assumes a pivotal role in operations. Through diligent monitoring and the astute understanding of system thresholds, remote operations support can actively identify and alleviate constraints, in turn, serving as the enabler for transformative advancements in technology output.

Sep 1, 2024

By D Shuen, R Sales, D La Rosa

Semi-autogenous grinding (SAG) mill control is complex and depends on many dynamic process variables. Good control strategies ensure that a mill is operating as close to optimal as possible, resulting in significant economic benefits to an operation. Pueblo Viejo, a gold mine in the Dominican Republic, has been actively improving their control strategies since start-up in 2012, and one of these initiatives was to install an acoustic monitoring system on the SAG mill. The data from the system is used to optimise the mill’s performance by limiting the time the mill is either running too quiet or too loud. The lower limit is an indication that the charge in the mill is too high for efficient breakage or that the mill speed is too low and grinding media are not striking the toe of the charge. Conversely, when the acoustic emissions from the mill are too high, this can indicate that the balls are striking above the toe of the charge, resulting in inefficient grinding and excessive liner and lifter wear. Adjusting mill operating conditions to keep acoustic emissions in the ‘sweet spot’ between these limits results in more efficient grinding.Pueblo Viejo installed a Metso SmartEar™ to monitor the acoustic emissions of their SAG mill in January 2013. This system has been installed on many mills around the world and is specifically designed for optimising SAG mill control. One system output is the impact counter which measures steel-on-steel impacts on the mill shell. The impact counter uses both frequency and time domain analysis to approximate the number of ball impacts per minute. This method of analysis excludes parts of the sound signal not associated with steel-on-steel impacts and gives an accurate measure of this critical control parameter. After the acoustic system was installed, Pueblo Viejo collected data to determine the upper and lower limits for the impact count variable. The live data is available to the mill operators and it is used as one of the key operating variables to control the mill.Through continuous improvement and the use of advanced technologies like SmartEar™, Pueblo Viejo are improving the control and operation of their SAG mill, resulting in reduced liner wear, more efficient mill performance and optimised energy consumption. This paper discusses the installation of the system, and the measureable benefits obtained by using acoustic monitoring to control their SAG mill.CITATION:Shuen, D, Sales, R, Wortley, M and La Rosa, D, 2014. The benefits of using SmartEar™at Pueblo Viejo, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 297–304 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By A Romanel, M S. Kato, M P. Piermatei, P Artioli

"Brazil is the sixth worldwide producer of aluminum and Votorantim (Metals) has been operating three bauxite open pit mines in a particular way of working. In those the deposits occur on the top of hills, under forest, coffee, eucalyptus plantation or pasture area.The deposits are not large and normally mining takes an average of two months to be completed before starting the rehabilitation process, which demands a good strategy in mining planning to achieve the production goals.The benefit function developed to select feasible areas uses, beyond production costs, fees from the owner by using their area and rehabilitation cost. Both are based on land use and occupation field survey data. In this process each area with different land use receives a specific rehabilitation cost as input into a block model.Once the selection is made the mining schedule begins, taking into consideration the following premise: the orebody needs to be mined in a short period of time because during this time, the surface owners receive from Votorantim a compensation based on the expected profits from their plantation or pasture, plus royalties related to the ore amount existing in their area.Not all operations have waste dumps. Waste is pushed down by bulldozers to the lower part of the ore border. After loading and transporting ore, the waste is handled back to the mined area to fit the topography. With this step concluded, the mined area is directed to the environmental team who, alongside university partners, develop land reclamation to return them to their owners, eg in 2011, 110 ha were rehabilitated of which 29 per cent is native forest.Votorantim closes many mined areas a year and currently the entire mine planning considers this particular way of operation, making profit with minimum interference with the community and the environment.CITATION:Artioli, P, Kato, M S, Romanel, A and Piermatei, M P, 2012. Environmental variables at bauxite mine, in Proceedings Life-of-Mine 2012 , pp 171-178 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By C M. W Boyle, E K. C Phuak, A Lewan, E Ryan, M D. Paine, P H. Mackenzie

"Rio Tinto Iron Ore (RTIO) has an extensive history in the application of geometallurgy to the iron ore value chain. Fundamental to this has been the geological logging of material types which are assigned processing attributes such as lump per cent and density. Initially these were used for product (lump and fines) grade predictions in relation to grade blocks to be used within short-term planning horizons.More recently the predictive reach of the material types and their associated processing attributes has been extended due to their inclusion into geological block models. These predictions can now be used to influence mine plans across multiple planning horizons in such a way that the extremes of geometallurgical properties can be pre-empted and managed thus improving efficiency. Spatial material type domains are also used in the planning of metallurgical drill holes to ensure greater representivity of material than was typically obtained by chemical and/or stratigraphic criteria alone.Material type logging has also been enhanced by the introduction of modern, rapid mineralogical techniques that have complemented visual logging. This has enabled the identification and quantification of contaminant minerals and their relationships with host ore types to be established. This data is used to better manage product grade predictions and identify risks to the short-term plan.Work is ongoing in RTIO to further refine logging based predictions and in addition apply them to new areas of the business. This work requires collaborative and multidisciplinary teams working on an integrated approach combining geology, metallurgy, technology and innovation, mine planning and technical marketing.CITATION:Paine, M D, Boyle, C M W, Lewan, A, Phuak, E K C, Mackenzie, P H and Ryan, E, 2016. Geometallurgy at Rio Tinto Iron Ore – a New Angle on an Old Concept, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 55–62 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By K Vallo, T Haimi, J Pihlasalo, J Hamuyuni, M Lindgren, F Tesfaye

Decarbonisation of the steel industry has recently attracted a lot of research and technological development. Most of the technological developments are centred around the replacement of blast furnace (BF), which has been the main primary smelting furnace in the ironmaking step of steel production. Replacement of the BF is not an easy task because of BF’s many established capabilities over the years, especially its ability to use low-grade iron feed. In this regard, Metso has developed its own technology, Metso’s Outotec direct reduced iron (DRI) smelting furnace, to tackle this problem. The recently developed six-in line electric furnace for DRI smelting can be used for primary smelting of DRI from blast furnace grade iron ore. Unlike the electric arc furnace (EAF), the DRI smelting furnace can handle larger slag volumes that emanate from the high gangue in BF grade DRI. Therefore, fluxing plays an important role in operating the DRI smelting furnace. This paper presents fluxing options and proposes slag quality and operating windows for the DRI smelting furnace. Also, the effect of slag on refractory durability will be discussed.

Jun 19, 2024

By R Dimitrakopoulos, K Kawahata, L Montiel

A method that optimises mining complexes that are comprised of multiple processing destinations, open pits and underground operations is presented. Mining, blending, processing and transportation decision variables are simultaneously optimised while accounting for geological uncertainty. The method uses a simulated annealing algorithm at different decision levels to generate a stochastic-based extraction sequence and processing policies. A case study shows its ability to generate a higher net present value while facing a reduced amount of risk when compared to traditional optimisation methods.CITATION:Montiel, L, Dimitrakopoulos, R and Kawahata, K, 2014. Globally optimising open pit and underground mining operations under geological uncertainty, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 201–212 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By P Dowd, A Adeli, C Xu, X Emery

Geometallurgical modelling is increasingly being incorporated into mineral resource modelling and estimation as a means of increasing efficiency, decreasing operating costs and reducing risk in mining operations. Traditional geostatistical workflows for geometallurgical modelling face several difficulties, in particular, related to the non-additivity of process response variables, to highly heterotopic data sets and/or to preferential sampling designs, all of which may explain why most attempts to estimate geometallurgical response variables from assay data and mineralogy are still based on statistics and machine learning. The aim of the work presented here is to demonstrate the applicability of geostatistics to estimate copper recovery from copper sulfide ores at the Prominent Hill Iron Oxide Copper-Gold (IOCG) deposit in Australia. As recovery is non-additive, the preferred workflow is the joint estimation of the masses of metal in the feed and in the concentrate, both of which are additive variables. While the mass of metal in the feed can be estimated from abundant online assay analyses, the mass of metal in the concentrate can only be estimated from a very limited number of laboratory-scale batch flotation tests. Traditional approaches to estimating the masses of metal in the feed and in the concentrate, such as simple and ordinary co-kriging, are described and discussed. A modified version of co-kriging is introduced, which incorporates linear relationships between the mean values of the input variables, in addition to a spatial correlation model. Co-kriging with related means is shown to outperform traditional simple and ordinary co-kriging in terms of precision, accuracy and consistency of the estimates, and offers a practical and efficient tool to deal with highly heterotopic and preferential sampling designs.

May 24, 2023

It is well known that the ability to influence project value reduces significantly as planning progresses and decisions regarding project parameters are made. However, at the prefeasibility stage in particular, where one of the main aims should be to evaluate a wide range of options in order to select the best for more detailed further study, there is often a reluctance to spend the time and money needed to do this rigorously. This paper demonstrates, by a number of case study examples, how significant increases in value may be obtained by fully evaluating the combinations of alternatives for various project design parameters, including (though not limited to) mining methods, haulage methods, mining rates, processing methods and rates, sequencing of mining, and cut-off grades, with changes and upgrades over time where applicable. The additional value unlocked is typically orders of magnitude greater than the additional cost of the more comprehensive study. The dangers of misuse of simplistic sensitivity analyses and failure to identify how strategies might change in response to changes in external factors are also illustrated, and the importance of selecting the best ægrade descriptorÆ is discussed.

Jan 1, 2007

By M Wortley, J Korteniemi, D La Rosa, L Rajavuori

Geometallurgical modelling of an orebody provides benefits to a mine by gaining a better understanding of the ore characteristics and how they affect the performance of the concentrator. With this knowledge, plant operating conditions can be adjusted to optimise throughput and recovery in advance of the arrival of particular ore types. Therefore, it is extremely important that the origin of the ore being processed is known as accurately as possible. Depending on the homogeneity of the ore characteristics, reliance on assumptions about stockpile residence times, scheduling and material handling can render the best geometallurgical models useless.The solution adopted at Agnico Eagle’s Kittilä mine was to utilise Metso SmartTags™ and in-house expertise to develop a system that continuously and accurately links geotechnical and lab data from the mine to the performance of the plant. This application presented several unique opportunities and challenges. For example, this was the first installation of a SmartTag™ system for geometallurgical modelling in an underground mine. Challenges included the fact that the system installation is routinely subjected to temperatures below -20°C.The system was installed and commissioned in early 2013 and has been operating continuously since. Kittilä has begun to see the benefits of the system, with an increased understanding of how different ores are processed in the concentrator. Other advantages include the ability to alert operators about the arrival of difficult ores and a better understanding of the ore handling systems.This paper describes the installation and use of the system at Kittilä and details some of the geometallurgical relationships that have been developed using the data collected so far.CITATION:La Rosa, D, Rajavuori, L, Korteniemi, J and Wortley, M, 2014. Geometallurgical modelling and ore tracking at Kittilä Mine, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By H Arvidson, V Chamberlain, R Marinho, B Parsons, T Rowl, M Noppé, M Mattera

With the introduction of CRIRSCO (2019) based mineral asset disclosure, Regulation S-K part 1300, 2019 (S-K1300) by the United States (US) Securities and Exchange Commission (SEC), applicable to companies listed on the New York Stock Exchange from 2021, Mineral Resource is now required to be reported Exclusive of Mineral Reserve, referred to here as ‘Exclusive Mineral Resource’ (EMR). EMR is equivalent to reporting Mineral Resource additional to Mineral Reserve, which has been permitted in jurisdictions outside the US for many years. Despite this, there are no practical guidelines in the literature or relevant reporting codes and rules for Competent/Qualified Persons to refer to, which creates a risk that disclosure of EMR estimates across the industry will be inconsistent and potentially ambiguous for analysts, investors, potential investors, and other stakeholders.With the introduction of CRIRSCO (2019) based mineral asset disclosure, Regulation S-K part 1300, 2019 (S-K1300) by the United States (US) Securities and Exchange Commission (SEC), applicable to companies listed on the New York Stock Exchange from 2021, Mineral Resource is now required to be reported Exclusive of Mineral Reserve, referred to here as ‘Exclusive Mineral Resource’ (EMR). EMR is equivalent to reporting Mineral Resource additional to Mineral Reserve, which has been permitted in jurisdictions outside the US for many years. Despite this, there are no practical guidelines in the literature or relevant reporting codes and rules for Competent/Qualified Persons to refer to, which creates a risk that disclosure of EMR estimates across the industry will be inconsistent and potentially ambiguous for analysts, investors, potential investors, and other stakeholders.

May 24, 2023

By E Shilov, R Dixon, L Tovey

BHP Western Australian Iron Ore (WAIO) operations use a suite of slope monitoring systems which are deployed to operational areas based on the ground control risk. Slope Radars are one system used within WAIO, having recently deployed and integrated a network of 22 radar systems across the operations. The integration required the development of supporting network architecture, infrastructure, virtualised hosting, security protocols and a technology support model. This has enabled data transfer between the physical radar systems located in open pits, to on-site offices, a vendor supported remote control room in Indonesia and the WAIO Integrated Remote Operations Centre for data analysis and monitoring of system and displacement alarms 24/7. The typical technical skillset of a Geotechnical Engineer does not include the knowledge and capability to understand and develop the supporting IT infrastructure required for establishing an integrated radar monitoring network. This paper will provide a discussion of the technology considerations for integrating radar systems and highlight the importance of the developed partnerships between internal geotechnical and technology teams and the external vendor team to ensure a reliable, robust and scalable slope monitoring solution.

Nov 29, 2022

By D Reid

Run-out analyses of tailings storage facilities are typically undertaken using methods based on rheological theory. These are reasonable techniques to model the behaviour of tailings that, through significant run-out and possibly mixing with supernatant water, are generally acting in a fluidised manner. Such modelling often follows on from two-dimensional continuum analysis models where, if failure is predicted, grid failure often occurs when deformations begin to increase. This results in a disconnect between the prediction of failure and the modelling of the potential extent of the failure.Recently, rezoning methods have been incorporated into commercially available two-dimensional soil mechanics deformation codes. Rezoning techniques enable large deformations to be modelled within a two-dimensional continuum analysis framework; however, while promising, the use of such tools is not yet widespread, and a consensus is yet to develop on how they should be applied to tailings dam run-out modelling.This paper uses FLAC rezoning techniques to model the flow behaviour of two historic tailings dam failures. The purpose of these analyses is to critically assess the performance of rezoning against some available historic failures. The required data to undertake such an analysis is outlined, along with the inherent limitations and assumptions required. Parametric analyses are outlined to address some of these issues. In general, the analyses undertaken underestimated the flow distance observed in the historic failures by varying degrees; however, in some instances, the analysis reasonably reproduced the qualitative shape of the initial failure zone. A variety of potential reasons for the discrepancy between historical observations and the models undertaken are provided.CITATION:Reid, D, 2015. The use of rezoning techniques to model historic tailings failures, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 201–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015