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By M Jones

Legacy tailings storage facilities exist within operating mine sites across Australia. These tailings storage facilities are often viewed as rehabilitation liabilities but with considered assessment may prove to be a resource. Extraction of such a resource might add value to operations by providing cash flow during the development of new mines; providing supplementary mill feed for existing mines undergoing step changes in operations; and supporting mine closure activities. Hellyer Gold Mines is successfully extracting and reprocessing sub-aqueous material from legacy tailings storage facilities at their Hellyer operation in north-west Tasmania. The Hellyer tailings storage facilities contain poly-metallic material from the Hellyer and Fossey underground deposits dating back to the 1980s as well as material from tailings reprocessing activities by other operators of the Hellyer site. Hellyer Gold Mines is reclaiming sub-aqueous material using cutter-suction dredgers and reprocessing on-site. Hellyer is the only operation of its type in Australia and few such operations exist worldwide. Key learnings around the estimation of a resource for legacy tailings storage facilities have been acquired at Hellyer that can be applied to the assessment of other tailings storage facilities. The application of dredging as a mining method at Hellyer is delivered through collaboration with experts from outside the mining industry under the direction of a mining engineer. Key elements required for the planning and delivery of safe and efficient dredging inside tailings storage facilities have been identified at Hellyer and are presented to provide a road map to the development of other dredging operations.

Sep 1, 2024

The mining industry has expanded significantly in the Pacific Region over the past two decades through a mix of new developments and brownfields expansions of existing operations. Despite this overall success there are also a number of well publicised examples of less than successful minerals ventures. These problem developments highlight the fact that success cannot be taken for granted and that rigorous planning and attention to detail is essential. The dominant growth has come through expansion of existing businesses, notably alumina, iron ore and coal, achieved through both efficiency gains on existing plant and step change capacity additions such as new mines and/or expanded processing plant. This expansion has largely been linked to increased market opportunities. The major issues are the quality and extent of the host resource, achieving the market targets, and the efficiency of the expansion effort. There can be also a range of site specific issues which need to be addressed. The development of new greenfields operations is often more complex as it can bring a wide range of new issues. Depending on the nature of the development, and the companies involved, these can extend from initial financing through to obtaining a market position. Incorporating major new technology and/or establishing infrastructure and attracting staff to remote locations can also add significant challenges. This paper outlines many of the critical factors which need to be considered prior to proceeding with major expansions or greenfields developments. These will be linked to a number of developments in the region over the past decade.

Jan 1, 2004

By S F. Rogers, P W. Booth

Digital photogrammetry is revolutionising the task of geotechnical mapping of jointed rock masses and has greatly increased in popularity and sophistication in recent years. Modern commercially available digital photogrammetry software systems can provide geotechnical practitioners with a user friendly tool for rapid data acquisition. The data can be acquired remotely from large exposure areas, some of which may be otherwise out of reach due to restrictions on time, access or safety.Photogrammetry is a complimentary technology to discrete fracture network (DFN) modelling because it can provide the large, statistically significant, spatially located geotechnical data sets required to produce the most robust results. It also provides the flexibility to selectively map structures at a range of scales, depending on the focus of the DFN modelling.Integration of the interpreted rock structure data derived from photogrammetry with modern DFN modelling methods really advances the rock engineering process. The ability to generate 3D fracture models driven by the statistical structural data and conditioned to the features observed by the photogrammetry yields a synthetic rock mass on which improved design methods can be applied. The generation of multiple equi-probable conditioned DFN models allows the use of probabilistic methods for assessing kinematic stability, rock block size distribution as well as a range of other applications.CITATION:Rogers, S F and Booth, P W, 2014. Integrated photogrammetry and discrete fracture network modelling for improved rock mass characterisation and engineering design, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 203–208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

This paper reports the advances made during the development of underground mine fill technology from circa 1960 to the present and, in particular, indicates where increased input from process plant metallurgists û mainly milling, but also smelting û can contribute to further advances. Fill types pertinent to the discussion are partially deslimed, partially dewatered mill tailings fill (uncemented, cemented) and paste fill. Pertinent process plant includes hydrocyclones, thickeners, filters, elutriation tanks, holding tanks, mixing mills, pumps and pipes. Control instrumentation is a critical component of each of the process plant units. The impact of smelter practice on filling is not considered in this paper, except to note that some smelter slags are, or have the potential to be, active pozzolans and when ground to the specific surface area of Portland cement can act as partial Portland cement replacements, a factor of economic and operating significance when Portland cement supply lines are considerable and/or tenuous. The important role of process plant metallurgists has long been recognised, with Thomas, Nantel and Notley (1979) including them as one of the many categories of professionals with contributions to make. With the ever increasing sophistication of mine fill practice and its ever increasing acceptance as an essential component of the mining/ milling/waste disposal process, the scope for contributions by the modern breed of highly educated, specifically trained process plant metallurgists is becoming ever increasingly obvious.

Jan 1, 2006

By P F. Hodkiewicz

"Our understanding of mineral resources relies on three basic steps: data capture data interpretation model construction. Until recently, all three of these steps required significant time and manual effort to produce a single resource model for mine planning, typically taking more than a year to progress from drilling to the final block model. Over the past several years, BHP Billiton has been developing innovative workflows in rapid resource modelling projects to significantly reduce these time constraints and make the process more productive by replacing manual activities with automated ones. Rapid resource modelling is the process of combining recently developed off-the-shelf technology with internal technology developments to fundamentally change the way we collect, interpret, model and evaluate geoscience data. Initiatives include automated systems and standardised workflows to make it safer, faster and cheaper to continuously update multidiscipline resource models. Specifically, rapid resource modelling workflows combine: real-time analysis of drill holes and drill samples with downhole tools and hyperspectral scanning systemsautomated interpretation of drill hole intervals based on pattern-recognition algorithmscontinuous modelling workflows using implicit modelling software. This paper outlines technology developments and workflows that provide a more thorough understanding of mineral resources to support faster and more informed strategic, planning and production decisions.CITATION:Hodkiewicz, P F, 2014. Rapid resource modelling – a vision for faster and better mining decisions, in Proceedings Ninth International Mining Geology Conference 2014 , pp 183–188 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By S Chatterjee

The production scheduling of an open pit mine determines the optimal extraction sequencing that significantly impacts a mine’s life as well as net present value. The optimisation of production scheduling of large open pit mines with geological uncertainty is a computationally very intensive process. In this paper, an approximation algorithm is proposed to schedule an open pit mine, where instead of solving the whole problem at once, the production schedule is generated by sequentially solving subproblems. The subgradient method is used to generate the upper bound solution of the Lagrangian relaxed subproblem. If the upper bound relaxed algorithm is not a feasible solution, a mixed integer programming is solved on the generated upper-bound solution. An application at a copper mine with an orebody represented by 16 532 mining blocks is presented using the proposed algorithm. Results show that all constraints are satisfied. The net present values are also calculated and results reveal an 11 per cent higher net present value (NPV) is generated when compared to the NPV generated when the same approach is applied to the deterministic model of the deposit where uncertainty is not accounted for.CITATION:Chatterjee, S, 2014. Stochastic production scheduling – solution through Langrangian relaxation with the branch-and-cut algorithm, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 323–328 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By R Dunne

"Continuous improvement on metallurgical treatment plants is possible only when good data and analysis of the data are available. Good data implies appropriate and accurate mass measurement coupled with good sampling practices and accurate chemical analysis especially when carrying out monthly metallurgical metal reconciliations. Adequate characterisation of key samples (eg tailings, feed, concentrates and others) at timely intervals is an important part of a good continuous improvement program. The data from this will help identify opportunities to improve operation performance and thus profitability. Examples are provided of projects that have led to improved plant performance based on good metallurgical data collection and analysis.Citation:Dunne, R, 2016. Using Metallurgical Data to Drive Continuous Improvement, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 201–206 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By B King

Processing expansion options and mining fleet purchases are major cost items that receive due focus in most cost management analyses. If these items are not needed, they can significantly reduce a project’s short-term capital spend and improve profitability and value to shareholders. When conditions change prior to purchasing equipment, the purchase may no longer represent the best decision for the project.This paper outlines a structured approach for making major cost decisions to improve the value of a project, determining which items should be kept and which should be eliminated.CITATION:King, B, 2014. Cost management optimisation, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 7–12 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By C Czerny, T Elkington, L Lorenzen

The Dutwa Nickel Project is a nickel laterite atmospheric leach project located in Tanzania that has been under development by African Eagle Resources plc (2012). A bankable feasibility study (BFS) has been progressed to evaluate mining of the resource (107 Mt at 0.92 per cent Ni) followed by hydrometallurgical processing on-site to make a mixed nickel-cobalt intermediate product. The unique relatively high silica contents in the Dutwa deposits, as opposed to limonite, which is more commonly occurring in nickel laterites, presented the possibility for beneficiation of the ores to enhance the leach feed nickel grades and provide economic benefits in terms of operating and capital cost efficiencies.Geometallurgical relationships, based on the results of an extensive variability metallurgical test work program for beneficiation and leaching, were developed for the BFS, which resulted in an improved understanding of ore classifications within the deposit and their responses. The geometallurgical information obtained has been instrumental in making key preliminary techno-economic decisions, such as forecasting whether or not mined material should be beneficiated and was ultimately used to drive the mine plan towards the prioritisation of areas within the deposits that delivered the best cost efficiencies and overall project economic outcomes.CITATION:Elkington, T, Lorenzen, L and Czerny, C, 2013. The use of geometallurgical relationships in process route selection and mine plan optimisation for the Dutwa Nickel Project, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 207-216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By M Forbes, R Jeuken

Brownfields geoscience measurement such as drilling and surface geophysics can be costly and it is often difficult to weigh the cost of data collection and processing against the value it unlocks at the time of extraction. This makes it difficult to prioritise geoscience expenditure and find the optimum intensity of geoscience activity across competing assets. There are multiple options for managing resource uncertainty and spatial variability through mine planning and resource engineering such as varying marketing strategy, adjusting stockpile or other infrastructure design and product blending. Consideration of these alongside increased data collection further complicates finding a comparable value of geoscience programs to determine the right blend of geoscience measurement and engineering controls. Concepts similar to Value of Information (VOI) analysis which is applied to strategic planning can be used to estimate the value of geoscience measurement and pit sequencing at tactical planning and operational timescales. This involves the quantification of resource uncertainty and prediction of how it will affect resource extraction. This paper outlines this process and demonstrates its use to prioritise geoscience at BHP Coal Assets. The value of infill drill programs in enabling operational stability is quantified and compared the value of engineering controls like increased stockpile capacity. This study supports that idea that the application of VOI methods to bulk mining at tactical time horizons has potential to inform geoscience planning and resource engineering not just separately, but as part of a unified strategy for managing resource uncertainty.

Mar 22, 2022

By M Watkinson

Tube bundle monitoring systems have come a long way from their first introduction to coal mining in the late 1960s/1970s. Early developments in the United Kingdom (UK) commenced with single gas analysers (carbon monoxide) and quickly moved towards introducing oxygen analysers and methane analysers for improved analysis, in particular the calculation of air-free results. Recommendations were made in the early days as to how and where to run tubes and on the matching of sample pump and purge pump pressures. Current Australian installations are commonly based on a four-gas multianalyser, infrared for carbon monoxide, carbon dioxide and methane, and paramagnetic for oxygen. These systems are controlled with programmable logic controllers (PLC), with component monitoring as an integral part of the software. This paper discusses the development of tube bundle systems from the 1960s to the current date and looks at the advantages and disadvantages of the installations, along with making operational recommendations to be considered with the siting of the analyser building, running of tubes and maintenance of the system.CITATION:Watkinson, M, 2015. Developments in tube bundle gas monitoring, in Proceedings The Australian Mine Ventilation Conference, pp 259–266 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By B Green

With a focus on safe productive tonnes, there has been an ongoing drive to increase the productivity of the mining fleet across BHP Billiton. In response, a team from the Iron Ore business was formed to review all aspects of the end-to-end drill and blast process and to challenge conventional practices that limit production efficiency. As a result of the outcomes of this work, a number of initiatives were identified to improve operational practices that have also delivered significant cost savings.One such initiative was to increase pattern size to a minimum of 1 Mt where practicable, thereby creating ‘megablast’ as a new standard across all mines. To achieve blasts of this size, the team had to overcome the complex problem of integrating wall control into the megablasts.With traditional blasting techniques, the key strategy, which is also historically inefficient but was thought to be integral to having stable, safe walls, was to utilise the trim blasting/modified production blasts technique (ie narrow blasts along the pit wall designed to ‘peel off’ the material while minimising the effects of vibration and charge confinement on wall integrity).Small traditional trim patterns comprise three to four rows of production holes and one or two rows of batter/buffer holes of reduced diameter that require the firing face to be completely exposed before blasting. This is an extremely slow process that requires a lot of resources for very little tonnage while adding additional expense to the final cost per tonne.This paper will show how the megablast approach was developed to control damaging vibration and confinement effects, flyrock and fragmentation while having the largest possible blast that includes wall control. The new practice is based on a theory that involves the initiation point and control row being the second row of holes from the pit wall itself. Adjusted charges in vented batter and buffer holes help to achieve an optimal toe design, and at the same time create a zone of broken ground that absorbs damaging vibrations formed by the attached production blast of any size, whether it is a straight wall or a multi-angled complex pit shell design.Using the new style of blasting has allowed an increase in the size of the patterns from an average of 300 kt to over 1 Mt whilst maintaining pit wall integrity. Case studies will be presented showing drill, charge and tie-in designs with the presentation having additional blast videos, including overall shots of blasts and in-close footage of what happens behind the blast at the crest of the planned catchment berm.The paper will also demonstrate the flow-on effect of using this style of blasting to reduce operational costs associated with other downstream processes, such as the reduced requirements for pattern preparation, an increase in productive digging, reduced maintenance costs and a decrease in fuel burn for equipment.CITATION:Green, B, 2015. Megablasts – enabling technologies in BHP Billiton Iron Ore, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 599–606 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By M J. Dunn

The geotechnical model is the cornerstone of any mining geotechnical design and as such the confidence level and reliability of the geotechnical model is paramount. The geotechnical model confidence level needs to be commensurate with the level of design that is being applied or study that is being undertaken. The geotechnical model is made up of several components and the reliability of the data underlying these components ultimately determines the reliability of the geotechnical model.Data reliability is linked to the quantity of data collected, the spatial distribution of the data collected, quality of the data collection and the interpretation of the data. In a typical project, there is an opportunity to improve data reliability through the scoping, prefeasibility, feasibility and final design and implementation stages.Currently, very little quantitative guidance exists in the literature on assessing the confidence level of geotechnical studies, although there have been attempts by various authors (Haile, 2004; Haines, Swart and Kruger, 2006; Read and Stacey, 2009; Dunn, Basson and Parrott, 2011) to qualitatively describe what level of geotechnical data is required. Recently a number of authors (Read, 2013; Fillion and Hadjigeorgiou, 2013; Thomas, 2013) have outlined methods that could be applied to assess the reliability of some types of geotechnical data that are used in the development of geotechnical models.This paper briefly discusses some of the factors influencing data reliability and the geotechnical model confidence and some of the tools available.CITATION:Dunn, M J, 2014. Geotechnical models and data confidence in mining geotechnical design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 127–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By L Clarkson, D Williams, P Redcliffe, F van der Wal

This research presents a snapshot and insight into the trends, patterns, and common considerations identified in the current standing of real-time tailings dam monitoring practice. Based primarily on information derived from concurrent research by the author (in form of a Catalogue of Real-time Instrumentation and Monitoring Techniques for Tailings Dams), challenges and opportunities when transitioning to a real-time monitoring system are discussed. Learnings and key considerations between different monitoring approaches are explored, including themes of limitations and advantages that were observed consistently through global supplier feedback.

Jul 1, 2021

The Gold Ridge Mine is an open-cut gold mine in the Solomon Islands. The mine is owned and operated by Gold Ridge Mining Limited, a wholly owned subsidiary of Ross Mining NL. At the invitation of the Solomon Island Government, project construction commenced in July 1997 and gold production commenced in August 1998. The mine is the countryÆs first, and represents a major milestone in the development of the Solomon Islands. At the time of project approval and construction, there was a growing awareness in the country of the potential impacts of mining in the tropics, partly due to unfavourable publicity surrounding a number of other mining operations in the Pacific region. The management of environmental impacts was therefore an important consideration in the approval of the project, and continues to receive a high level of attention from the Government and community. Ross Mining did not commit to the Gold Ridge Project until it had satisfied itself that all waste rock and tailings could be safely contained on-site, and that the standards normally expected of a mine in Australia could be met. Ross Mining approached the approval, construction, and operation of the Gold Ridge Mine with a set of operating principles that met Government and community concerns. These were:best practice environmental management; operation of the mine in accordance with standards expected of mining operations in Australia; independent peer review of key technical aspects; on-going consultation with Government and community; and equitable transfer of wealth to landowners and the local community. As a consequence, the Gold Ridge Mine has developed into a successful mining operation with a high level of support from local landowners, the general community and the Central and Provincial Governments of the Solomon Islands.

Jan 1, 1999

By H Jones

The paper outlines the adoption and evolution of ‘sustainable development’ as a concept in tailings management practices in the mining industry over the last 30 years. Over 500 lives have been lost in tailings facility accidents since World War 2. The paper outlines commonalities in many of these accidents, particularly the role of excess water. It considers the role effective tailings management can play in enhancing the social acceptability of mining in the future.Tailings management is a major operating cost at many mines while the cost of successfully closing tailings facilities is also very high. Current tailings management practices in the industry are outlined. The technical and engineering challenges of reducing potential risks associated with tailings by reducing water entrainment are described. The successful development of practical techniques to better manage tailings and reduce water consumption and wastage are described. For example, water removal in the alumina industry to produce a paste for dry stacking is now a reality.The future adoption of these new risk reducing techniques by the industry is discussed and the implications of the adoption or non-adoption of these techniques on the industry’s future ‘social licence’ is considered.

Nov 22, 2011

By H Kurth

Mining geologists utilise many technologies to map, sample, measure, model and plan before and during the mining process. Predicted ore quality rarely corresponds with feed quality determined by process operators. Objectively measuring conveyed material quality accurately in real time avoids disagreements over mined ore quality and generates opportunities to improve mill feed quality.This paper discusses the well proven PGNAA (prompt gamma neutron activation analysis) technology used in the GEOSCAN-M elemental analyser that is ideally suited to measuring composition of primary crushed conveyed material in real time. Representative, continuous, fully penetrative measurements are unaffected by particle size, belt speed, mineralogy, dust or layering on the conveyor. Material can be directed to processes or stockpiles by utilising measurement increments of typically one to five minutes and then activating diverters to direct increments to the correct location. Waste, low-grade or deleterious material can be rejected to waste dumps or stockpiled for later processing. Material meeting a product specification can bypass unnecessary processing. Paybacks in weeks have been achieved for such applications. Process operators are able to control the blend of ores fed into the mill to improve processing performance and use measurements for ore reconciliation and metal accounting. Utilising the technology to upgrade ore quality after mining and before processing is beneficial in improving plant economics.The technology has been successfully utilised in base metals, ferrous metals and industrial minerals. Mining geologists can determine ore quality being produced in real time and modify the ore quality prior to milling. Ore feed quality measurements are also used by process operators in optimising plant performance. The elemental content can help identify geometallurgical domains as well as other major changes in quality, which may affect processing. This paper outlines proven applications and case studies and proposes some innovative applications.CITATION:Kurth, H, 2017. Measuring ore quality using real-time on-belt elemental analysis – more than grade control, in Proceedings Tenth International Mining Geology Conference 2017, pp 213–220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By J P. van Dyk

A new crude ilmenite beneficiation process was recently proposed that allowed for the preparation of a smelter grade ilmenite from ilmenite with elevated chromium content. Magnetising roasting was not utilised in the process. As part of this circuit an ilmenite low susceptible reject stream was produced that had a low magnetic susceptibility. In this article a magnetising roasting process was investigated to beneficiate this material. Tests were conducted on material produced by pilot scale simulations on a typical South African East Coast heavy mineral reserve. The results obtained were compared to those published in literature for crude ilmenite. The small-scale experiments were used to define approximate operational limits for the oxidising roasting of a low susceptible ilmenite low susceptible reject stream, although industrial roasting conditions may differ significantly from those obtained in laboratory units. In a next phase these results will be confirmed on pilot plant scale.

Jan 1, 2001

By P J. Jacobs

FORACO is the third-largest global drilling services company, and recently celebrated its 50th anniversary. The company’s historical roots are in French-speaking West Africa, delivering hydrogeological drilling services to resource companies, villages and regional centres. Today, FORACO operates over 300 drill rigs in more than 20 countries.The Asia Pacific region of FORACO runs a fleet of 37 late model drilling rigs servicing the diamond drilling, reverse circulation, coal, coal seam gas and hydro drilling sectors.FORACO Australia has extensive experience delivering large diameter coring (LDC) samples to the resource community. In the past three years, the company has been involved in six 8? coring projects in a variety of geographies and geologies, including iron ore, coal and uranium. FORACO has developed proprietary equipment and techniques to deliver cost-effective LDC samples with outstanding core recovery.The FORACO LDC sampling system is hands free, with mechanised rod and corebarrel handing to minimise the risk of manual handling injuries. Sample volumes are six times PQ (the common industry standard for large core samples), with core recoveries consistently above 96 per cent in extremely difficult formations.Eight inch coring is a conventional coring system suited to hole depths up to 150 m. For deeper applications, FORACO has recently invested over $4 M in a 6? wireline coring system capable of achieving depths of 300 m.CITATION:Jacobs, P J, 2014. Large diameter core sampling, in Proceedings Sampling 2014 , pp 71–76 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By B Dold

Western Europe is a dynamic region, with an emerging co-operation between the individual nations both politically, economically, technically and scientifically. The European Union, today with 15 member States and with a range of central European States applying for membership, is a catalyst for this Cupertino, using a combination of EU funds, for financing research initiatives, and legislation to enhance development of technology and environmental performance. Europe is a major net importer of metals but with a large potential for own production, in particular in the accession countries. The metals and mining sector is furthermore identified as having a large potential to generate wealth both in todayÆs EU and in the future, widened Union. This paper provides a chart of examples on the many research initiatives presently underway in Europe, addressing environmental issues related to mining. The list of programmes and projects does not claim to be complete; it is rather an illustration on the wideness of the approach, describing various ways for transboundary Cupertino. The approach taken by many of the programmes goes beyond the strict ARD scientific area and therefore only a limited number of the many programmes can be identified as ARD research programmes. Also national programmes, without EU funding, are operating, eg in Sweden, Germany, and UK. The picture is continuously changing with new programmes being commissioned and old ones being completed.

Jan 1, 2003