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By J Rutter, S Dunham

Technological advances in sensor and material handling technology has enabled a step change in mine operations performance. Sensors capable of monitoring the grade of broken rock mass can be mounted on shovels, truck loading units or conveyors allowing highly precise ore/waste decisions to be made on small parcels of rock, increasing selectivity. This increased selectivity has the potential to remove sub-economic material from the product stream prior to incurring ore treatment costs. Bulk ore sorting is capable of intervening at <10t “pods” on Run Of Mine conveyors, or alternatively at per bucket loading (5-100t) or truck scale (30-350t) parcels of ore. This Grade Engineering technique being developed by CRCORE (Rutter, 2017) can improve mill feed grade, remove deleterious materials and ensure that the high capital intensity ore treatment facility is presented with the best ore feed strategy. While this technology can improve mine economics, estimating the performance of a bulk ore sorting system is challenging. Traditional resource estimation practices such as Ordinary Kriging and Inverse distance weighting (IDW) are based on weighted averages, a process that smooths the grade profile, reducing modelled variance and dispersion. Its purpose is to generate a globally unbiased result but is less suited to generating a model of adequate granularity to enable confidence in local grade heterogeneity. This is an essential component for bulk ore sorting success. Estimating ore sorting performance requires knowledge of the grade-tonnage curve at the scale of the sensor diversion unit (SDU). Evaluation based on an estimator that smooths the SDU distribution will not correctly predict ore/waste separation or economic performance. Alternatives to traditional linear geostatistics have been tested on a variety of mineralisation styles. Additionally, a number of heterogeneity metrics have been developed to assist with evaluation and assessment. The difference between estimation for grade (metal) and modelling for traditional mining block models, versus methods used for predicting heterogeneity and variability are explored.

Nov 10, 2020

Intrusion related Cu/Au mineralisation is localised in Pacific Rim island arcs by arc parallel, termed accretionary structures; or arc normal, termed transfer structures. In Papua New Guinea, NE trending transfer structures, evident on Landsat imagery, represent deep crustal fractures which have facilitated dextral rotation of the mainland during oblique plate collision. Major structures localise intrusion centres, and by rotation, develop ore hosting dilational environ-ments in subsidiary structures. While transfer structures localise the Porgera, Wafi and Yandera porphyry centres, the Frieda Porphyry and associated Nena high sulphidation Cu/Au mineralisation are localised by accretionary structures. The Bulolo Graben, which hosts the Morobe Goldfield, developed during intra arc rifting aided by movement on transfer structures. Crustal thinning has initiated magmatism with which diatreme breccias and fracture controlled mineralisation are associated.

Jan 1, 1994

The modern resource extraction enterprise is a complex capital intensive business operating in a world of constantly evolving social, environmental and economic scrutiny. Investors, government, media and special interest groups expect to see business environmental and social performance respond and deliver increasing corporate responsibility and sustainability. &nbsp; Thorough interrogation of business performance using a multi-disciplinary due diligence approach presents a more sophisticated review and benefits beyond the traditional compliance/conformance &apos;audit&apos; style assessment. &nbsp; Using a due diligence approach allows assessment through a comprehensive lens which examines potential short- and long-term risks including sometimes less tangible environmental and social liabilities, and informs management, investors and regulators of broader business performance. This approach provides information in a form that business can measure performance in a repeatable and enterprise wide sense. &nbsp; This paper provides an outline of the due diligence process applied in this way, drawing from lessons learnt and industry based experiences in the due diligence process and the benefits and tools that can&nbsp; be applied in an environmental and social due diligence business performance assessment

Jun 1, 2010

By G B. French

Post a serious heating event underground, and at the direction of the State Mining Safety Authority, a mining company needed to demonstrate the use of cutting-edge technology to mitigate future events. Yokogawa were contracted to provide a turnkey solution to help the mine achieve this objective. The solution was to use a fibre optic-based Heat Detector that will allow entry into and around the mine considering the potential volatility of the environment, also the need to redeploy as mining activities moved underground and more boreholes are added. Industrial strength fibre optic cable and a robust connector system was chosen to achieve this goal and give the customer the ability to send cable down boreholes of up to +1 km and continuously monitor the temperature ofunderground roadways. Being able to re-deploy the cables into different boreholes and link borehole temperature measurements gave insight into all areas on the mine. The machines deployed on-site were the Yokogawa DTSX1 heat detector incorporating the Ramen Backscatter principle. Being of a robust construction and a low power consumption device, it was easily included into the portable monitoring trailers designed by the customer and built locally.

Oct 12, 2022

In this paper the system of an operative expert estimation of innovative policy of mining enterprise technological development on sustainable development principles, created in the laboratory of economic analysis, planning and management of Mining Institute after D A Kunayev is represented. It is based on application of technology of satellite navigation and global positioning system (GPS). It allows to estimate the geotechnological complex functioning efficiency in the automated mode and on the basis of the obtained results to develop a complex of management measures on the competitiveness increase, realised by means of the automated corporative management system of geotechnological complex. The estimation of complex competitiveness is carried out on such basic aspects, as: technical, technological, organisational, ecological and economic as all of it give certain expenses and influence on complex overall performance. The major difference of the given approach is its realisation within the limits of the automated corporative management system of geotechnological complexes. It is based the fact that data of monitoring of complex&apos;s work will provide a sustainable development of geotechnological complex of mining enterprise.

Dec 6, 2010

By T D. Jolly, L A. Balzan, A R. Harris, Z Bauk

"The availability of real-time data in any process control system is critical for effective management of that system. At MMG LXML Sepon Copper Operation in Lao PDR, controlling the copper grade of the feed to the leaching circuit is paramount for maximising both productivity and copper recovery. Since 2008, real-time analysis data has been available to the process engineers from the Geoscan on-belt analyser installed on the Copper Mill feed conveyor, and highly accurate results on copper grade have allowed the process engineers to strictly control blending to overcome the variability in plant feed grade. The availability of real-time analysis data is crucial, as effective sampling of this stream is both difficult and error-prone, being only a snapshot in time of highly variable ore stockpiles, as well as having significant laboratory turnaround delays. Periodic sampling is used to verify the Geoscan data as accurate. Since its installation, the copper result has been the most critical output of the Geoscan. In recent times, the process engineers have sought to utilise other results from the Geoscan to further improve and control the process. One measurement of particular interest involves the real-time measurement of calcium and magnesium as a gauge of ore feed gangue acid consumption. To satisfy this end, accurate measurement of calcium and magnesium is becoming increasingly more important and has been the subject of ongoing collaboration between Sepon and Scantech, the manufacturer of the Geoscan. This paper discusses this work, describing the calibration process and results obtained, while also providing a basis for Geoscan use in operations to enable enhanced process control for all potential Geoscan users.Citation:Balzan, L A, Jolly, T D, Harris, A R and Bauk, Z, 2016. Greater Use of Geoscan On-belt Analysis for Process Control at Sepon Copper Operation, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 231&ndash;238 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

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

This paper identifies the challenges and opportunities for mining companies and communities in investing in human rights compatible, credible, effective and representative company-community relationships. &nbsp; The paper draws on the work of Professor John Ruggie, Special Representative to the United Nations Secretary General on Business and Human Rights, and his Protect, Respect and Remedy framework for business and human rights, The CDA Collaborative Learning Project, and the experience of Oxfam Australia. This paper begins with the premise that Australian companies commence operations offshore with high expectations and a willingness to work harmoniously with local communities. However, as companies increasingly engage in global operations - particularly in weak governance and conflict zones - the challenge to establish and sustain rights compatible, meaningful, corporate community relationships and grievances mechanisms becomes both more complex and necessary. Establishing trust and honouring commitments made to communities, including legacy issues, is a critical component in good corporate community relations. &nbsp; The second part of the paper will identify some of the impacts and challenges of mining that need to be addressed in corporate community negotiations and consultation. Respect for indigenous people&apos;s rights and their right to give or withhold consent for a project to proceed is increasingly evident, as is the growing global expectations with regard to revenue transparency. As such, key challenges include: grievance mechanisms; free prior and informed consent; transparency and accountability; the gender impact of mining; resettlement, compensation and benefit sharing; and security issues. &nbsp; Finally, the paper will provide practical guidance to companies on how to establish effective corporate community relationships. It will include examples, such as human rights impact assessments, gender impact assessments, and establishing local level grievance procedures. The paper will include an Oxfam Australia case study of a dialogue mechanism at Tintaya copper mine in Peru.

Jun 1, 2010

The Horn Island gold and mineral field produced 194 kilograms of gold in the 4 years subsequent to its discovery in 1894, from an area of shallow workings 1.5 kilometres x 0.5 kilometres. Gold deposits in the adjacent Prince of Wales, Hammond and Possession Islands also drew attention at that time.These islands form part of a Carboniferous sequence of ignimbrites (Torres Strait Volcanics) intruded by the Badu Granite and minor volcanics within the Cape York-Oriomo Ridge. Gold is associated with the epithermal stages of igneous activity. Recent exploration has defined sub-horizontal zones of disseminated gold mineralisation in the sub-surface, as well as reserves in the outcropping sub-vertical structures mined in the past. Released estimates of 170,00 tonnes proven ore and 550,000 probable ore at 4 grams per tonne gold, have been established.Gold is mostly contained in quartz vein stockworks and hydrothermal breccias within the intensely propylitised medium grained granites which form the local host rocks within the coarse grained Badu Granite. Associated vein minerals are sulphides (primarily of lead, zinc and iron) and calcite. Various intrusions of porphyry, aplite and granodiorite occur through the prospect area.

Jan 1, 1986

By Jarvensivu M, Ylinen R, Jamsa-Jounela S-L

The paper presents a new integrated system for control of concentration processes. The system is based on cluster-based modelling taking the ore quality into account and a new on-line particle size analyser capable also for reliable measuring of particle size distribution of concentrate. A metallurgical precontrol audit was performed at the Hitura concentrator in order to design the control strategy of the integrated grinding and flotation control. A new analyser PSI-200, was used to the measurement and control of the distribution of nickel in the total particle size range. An expert control system using the cluster model together with a new control strategy for decision of necessary control actions is outlined. The method has been tested to real data from mineral processes. The results are in good correspondence with empirical process knowledge. KEYWORDS: Cluster analysis, expert control, flotation control, mineral processes, modelling, particle size.

Jan 1, 1993

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

By X Zhang, B McFadzean, C T. O’Connor, S Pikinini

The Platreef in South Africa contains one of the world’s largest reserves of platinum group elements. One of the major platinum group minerals (PGM) components in this ore is sperrylite (PtAs₂), which has been found to be slow floating compared to the other PGMs. In a study aimed at determining the reasons for the poor floatability of sperrylite and to improve its recovery, tests were carried out to determine the interactions of the mineral with a range of standard and novel collectors. Microflotation tests were carried out to determine the hydrophobicity of the minerals before and after adsorption of collectors. In addition, experiments were carried out to determine the enthalpy and extent of collector adsorption on the minerals and to investigate electrochemical interactions between sperrylite and selected standard collectors. The results indicated that poor collector adsorption was the major cause for the poor floatability of sperrylite. Sperrylite had both poor natural (14.5 per cent) floatability and collector-induced flotation recoveries, the highest recovery of 26 per cent being observed using PNBX collector at pH 9. Moreover, the rest potential tests showed that the interaction of sperrylite with standard collectors such as xanthates was poor. The decrease in potential after the addition of the standard collectors ranged from 7.9 mV to 24.9 mV under alkaline conditions. Furthermore, sperrylite rest potentials remained unchanged with a change in pH from basic to acidic, indicating its resistance to surface alteration. Surface alteration of the minerals is key for the chemisorption of collectors to take place on the mineral surface. This was further emphasised by flotation recoveries at low pH, where only certain collectors responded positively to a decrease in pH and these were shown to have undergone a structural change. This work has highlighted the difficulties associated with sperrylite flotation and provides some direction for future research.

Aug 24, 2022

By T J. Callaghan

The Avebury nickel mine in Western Tasmania is a disseminated nickel sulfide deposit hosted in intensely metasomatised Cambrian ultramafic resulting from later Devonian granite related hydrothermal activity.Variable metasomatism of the ultramafic has formed two distinct gangue mineral assemblages. Less metasomatised ultramafic is comprised of fine grained black antigorite with minor disseminated chromite, magnetite and pentlandite. Intensely metasomatised ultramafic is altered to a pale grey or green, coarsely crystalline tremolite/actinolite and diopside assemblage with minor magnetite, chromite and sulfides. Both gangue mineral assemblages are frequently intermixed in ore grade mineralisation.The bimodal gangue of either serpentinite or metasomatised ultramafic presents challenges to drilling, mining, resource estimation and mineral processing as they possess very different physical properties. Mineralised serpentinite has a mean bulk density of 2.8 g/cc and the ultramafic skarn a mean bulk density of 3.2 g/cc. Physically, the ultramafic skarn is hard to break percussively creating difficulties in the crushing circuit and reducing mine development rates. However, it is non-abrasive and grinds readily, resulting in increased diamond drilling rates and increased mill throughput. Conversely the serpentinite gangue is softer and breaks easily resulting in accelerated development rates and crushing circuit throughput. However, its fibrous nature reduces grinding efficiency, increasing bond work indices and reducing diamond drilling rates.Predicting the ratio of serpentinised to metasomatised ultramafic is possible through use of the resource blockmodel, assisting mine scheduling, predicting mill throughput rates, energy consumption and grade control drilling rates.CITATION:Callaghan, T J, 2017. Challenges of bi-modal gangue mineralogy in mining geology, in Proceedings Tenth International Mining Geology Conference 2017, pp 23–26 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By T Kojovic, S J. Windle, J Sullivan

"The Geometallurgical Mapping and Mine Modelling (GeM) comminution index (CI) was developed as part of the AMIRA P843 GeMIII project. Drill core geochemistry samples were passed through a Boyd Crusher with standardised settings and the resulting particle size distribution (PSD) was measured using sieves.Disadvantages of the original measurement were the relatively coarse crush size, requiring a second pass of crushing for geochemical sample preparation, and the limitation of throughput caused by the sieving step. At Antamina, the measurement has been modified to use a 2.2 mm crusher size setting, which permits a single pass. The PSD is measured using a Camsizer, an automated optical sizing instrument. The Camsizer sample is a +180 µm fraction, used to avoid passing too many fines through the instrument and slowing down the measurement. In the sieving step, the weights of the two fractions are recorded and subsequently used to normalise the distribution measured by the Camsizer. In this way, the throughput of the Camsizer can match that of the Boyd Crusher. The PSD data are therefore measured without penalising the throughput of the sample laboratory.The normalised PSD distributions are used to derive modified CI parameters, based on the slope and intercept of the breakage product size distribution, which are indirect measures of the material breakage hardness.Fifty samples were selected as a training set, each sample a composite of five or six individual assay intervals and each with its own measured CI. The average PSDs were calculated for the composites and used to calculate a composite CI. The intact half of the core, approximately 40 kg, was tested to measure the BWi, A*b and crushability. The results were used to develop predictive algorithms for these hardness parameters.A further 50 composites were chosen for lab testing, to serve as a blind test of the algorithms. The paper reports on the test results and the incorporation of the modified CI data and predicted hardness parameters into the Antamina block model.CITATION:Windle, S J, Kojovic, T and Sullivan, J, 2016. Use of a Modified Comminution Index to Predict Bond Work Index and SMC A*b at the Antamina Mine, Peru, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 153–160 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By M Armony, J F. C L Costa, J C. Koppe

Linear kriging methods fail to estimate local grades and local reserves for highly skewed variables due to three reasons: it uses only part of the available data information, it has no physical principles associated with the mathematical proceedings to minimise the problems, and it works with continuous variables while data are discrete because of the limited precision of any equipment. The techniques commonly used up to now to solve the highly skewed variables estimation problems were unsuccessful, unless mathematical rigor is abandoned. Even the method of multiple indicator kriging is not satisfactory. This paper presents a new framework, the field parametric geostatistics (FPG) that transforms noisy variograms into well-behaved variograms and justifies mathematically empirical procedures commonly used, as trimming or capping arbitrarily very high values. The method, when applied to non-skewed variables, yields similar results to classic kriging. The methodology is illustrated in a case study at a gold deposit in Brazil, and compared to results obtained by usual techniques.

Sep 26, 2011

The Cannington silver lead zinc deposit is located near Mt Isa in North West Queensland. This world class orebody is owned by BHP World Minerals (BHP) and is estimated to contain 45 million tonnes of ore at an average grade of 11 per cent lead, four per cent zinc and 500 grams/tonne silver. At BHPÆs planned 1.5 Mtpa extraction rate, the mine life will exceed 20 years. Construction of the underground mine, which commenced in August 1993, was carried out by Peabody Resources Ltd (Mining Services Division) (PRL) for BHP Minerals Pty Limited (BHP) under contract packages totalling approximately $100 M using several innovative techniques to deliver safety, quality and time related project goals. Client/Contractor Partnering, resulting in harmonious working relationships, a combined commitment to the achievement of an excellent safety record, and a seamless transition from the construction phase to operation of the mine, has been a feature of the project.

Jan 1, 1998

We are moving into an era where we experience the consequences of the skills crisis û namely many resource models have been generated by inexperienced people under pressure to deliver high quality resource estimates in unsupported environments, often without technical mentors. These resource models form the basis of our decision to pursue actual mining. This begs the question: how valid are the resource models that form the basis of our mining decisions? This paper presents various model validation tools such as comparison of input and output statistics, swath plots, sectional or bench comparisons between drill holes and models as well as a variety of other approaches. Each model validation tool currently used in industry is examined:how the tool generates results,what assumptions exist,what constitutes a pass/fail in the test, and what interpretations to consider when using the validation tool. Each validation toolÆs suitability and the inherent flaws in the underlying assumptions are also discussed. These are supported with examples of good versus bad validations. Our principles based reporting codes provide flexibility in how models are generated and what approaches and/or parameters are used to generate resource estimates. This flexibility works well when used by experienced practitioners. However, our reporting codes assume a level of experience not always available in the current skills crisis. This paper seeks to provide minimum model validation prerequisites for model acceptance and suitability, regardless of the resource analystÆs experience. As we move forward, our immediate challenge is to ensure our baseline resource models are material, transparent and competent.

Jan 1, 2009

By M Lak, R Amiri, A Haratian, M Asghari, S Haji

Dry magnet separators are used to upgrade and beneficiate a wide variety of minerals such as hematite and magnetite materials. In recent years advances in dry magnetic separators have improved their performance. Fine particle separation is one of the main areas which still remain weak. This paper will present a new design of fine particle drum separators which used for particle size less than 3 mm. A big problem in processing of iron ore is the grade and recovery of mineral values in the fines fraction. The new design high efficiency drum separator is developed to handle fine feeds. In this drum separators both of the drum shell and magnetic yoke rotate in opposite direction. the results showed that when the material feed size was = 1298 μm, drum shell speed was 42.5 rev/min, magnetic yoke speed was 100 rev/min and the maximum intensity of magnetic field was at = 30° the feed grade increased from 50.87 to 65.67 in concentrate box, increase to 60.45 in middle box and tail grade was 24.44. The total achieved recovery for both concentrate and middle box was 81.89 per cent.

Nov 8, 2021

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&apos;s account structure allows for reporting against the standard chart of accounts.

Dec 6, 2010

By A Chandra, P Guj

Only a few complex real options can be valued using closed-form equations, such as the Black and Scholes formula, because these algorithms are restrictive and prevent the construction of practical project evaluation models. Although a binomial lattice method paired with the ærisk-neutral probabilityÆ provides an easier and flexible modelling of exploration and mining projects, it has limitations when projects are complex, long-lived and influenced by the interplay of various market and private uncertainties. In order to overcome these limitations, modern decision tree software using dynamic programming capability can be used for real option valuations. This is a powerful computational tool in which the impact of various sources of uncertainties can be differentiated, so that the optimal decision path can be explicitly displayed visually. There has been significant academic controversy surrounding whether different real option (RO) valuation methods would lead to different real option values (ROV). This paper, using a realistic copper mining example, demonstrates that as long as the same degree of subjectivity and consistency are used in different real option valuation methods, they yield the same result. This conclusion is valid irrespective of whether the cash flow volatility generated by various sources of uncertainties is handled in an aggregated or in an explicit and differentiated manner. This paper compares two choices for an investor either to æbuy now and developÆ a project or to enter into a ætwo-year option to purchaseÆ after the proponents have developed it. It also shows how significantly different net after-tax operating cash flows may be generated by these different choices on the same underlying asset represented by the project. This is due to the difference in the amount and timing of the relevant capital investments affecting the depreciation and amortisation charges and as a consequence, the income tax paid. CITATION:Guj, P and Chandra, A, 2012. Real option valuation of mineral exploration/mining projects using decision trees - Differentiating market risk from private risk, in Proceedings Project Evaluation 2012 , pp 177-188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012