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By M I. Roberts

As Australia’s mining industry painfully retrenches, mining executives and managers strive to remain viable by seeking significant productivity increases directly through process improvement and indirectly by improving leadership and workplace culture, the most powerful determinant of productivity. Culture is the combination of people’s attitudes and behaviour, together with leadership values and focus.Comprehensive new and automated data collection and management systems promise much for improving productivity, yet despite rapid advances in measurement and sharing of data, the use of data can reduce productivity unless behavioural aspects are considered and designed as part of implementation. This is because systems drive behaviour that in turn shapes attitudes to determine culture.Experience from many mine sites and other industries in three countries confirm that the most powerful drivers of people’s behaviour are the Measurement-Analysis-Reporting system and business leadership.This paper discusses fundamentals of practical, statistically valid process measurement, analysis and reporting systems before discussing associated leadership considerations for sustained improvement in safety, productivity, employee retention, leadership, accountability and commercial returns.The key to productivity improvement is improving core processes and important support processes. In turn, the key to process improvement is identifying the major process components and their interaction by measuring and then analysing their variation and level of performance. Understanding variation is often neglected yet is usually highly significant. It is essential that the fundamentals of statistically valid yet practical process and data analysis are understood and incorporated into system design to ensure productive, informed behaviour.The design and use of Measurement-Analysis-Reporting systems influences behaviour most profoundly and determines people’s effectiveness. Behavioural aspects are detailed by focusing on six primary drivers of human behaviour and five basic systems for managing businesses. These are integrated in a seven-step process and productivity improvement methodology that combines statistical, analytical, systems and behavioural factors.The paper includes development, implementation and tracking of a project plan for improving management and leadership systems to drive aligned behaviours. This key leadership responsibility is essential for improving performance to get the most from capital while providing people with the opportunity to develop greater autonomy, which is essential for self-discipline, responsibility, initiative and accountability.CITATION:Roberts, M I, 2015. Integrating measurement, systems and leadership to build safe, productive cultures, in Proceedings Third International Future Mining Conference, pp 73–82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M Skead, H Michael, R Chase, A Davidson

Ashanti Goldfields CompanyÆs (AshantiÆs) most recent development is the Geita Project in the Lake Victoria Goldfield of NW Tanzania. It comprises six distinct gold deposits within two mineralised trends: Nyankanga, Lone Cone, Geita Hill (Geita trend) and Matandani, Kukuluma and Area 3 West (Kukuluma trend). Between 1936 and 1966, the Geita area produced an estimated 5.5 M tonnes of ore from five underground deposits at an average recovered grade of 5.3 g/t. The discovery of Nyankanga was made by Ashanti in 1996 from RAB drilling of a +100 ppb Au anomaly in laterite soil above ferricrete cover. The Kukuluma trend was discovered by SAMAX Resources (taken over by Ashanti in 1998) between 1996 and 1997 from RC drilling of a +80 ppb Au laterite soil anomaly. Oxide facies banded iron formation (BIF) of the Upper Nyanzian System forms prominent topographic ridges and is the dominant host lithology for gold mineralisation. The ridges are flanked by felsic tuff units which lie stratigraphically above. Syn-genetic lamprophyre (vogesite) and post-genetic felsic dykes are also seen in the Geita trend. At Nyankanga a granodiorite-diorite suite has intruded as dykes and sills into BIF from a plug centred on a WNW fault and has produced wallrock alteration assemblages similar to those seen in Cu-porphyry systems (potassic, propylitic, etc) as well as sulphide and gold deposition. However, the main ore-grade mineralisation (as in the rest of the Geita trend) is controlled by low-to-medium angle structures dipping north-west and north with numerous splays in the hanging wall. High-grade shoots at Nyankanga plunge to the west and to the north-west, being lithologically and fault-controlled respectively. At Geita Hill the higher grade shoots are controlled by fold noses in BIF dipping to the north. Free gold occurs within fractures of sulphides. The deposits of Kukuluma and Matandani occur on an ancient (possibly Cretaceous) erosional plateau and are related to two WNW to NW trending shear zones, discordant to the local strike of the BIF sequence. Complete oxidation occurs up to 120 m depth and there is a strong supergene component to the gold distribution. Primary gold mineralisation is divisible into two distinct assemblages: arsenopyriteûpyrrhotiteûmagnetiteûchlorite associated with brecciated cherts and pyrite associated with shaley banded ironstones. Area 3W is most likely the fault-displaced extension of the same mineralised trend and comprises thin, intermittent zones of high-grade gold mineralisation occurring adjacent to a ridge in banded cherts and minor BIF. Current resources (measured, indicated and inferred) for the project are estimated at 89.24 Mt at an average grade of 4.17 g/t (11.97 Moz of contained gold) at a 1.0 g/t cut-off grade. Of this 9.83 Moz is within the Geita trend and 2.14 Moz is within the Kukuluma trend. A resource of 2.74 Moz is from an inferred resource at depth at Nyankanga where the viability of an underground operation is being studied. Proven and probable reserves are 49.77 Mt @ 3.46 g/t (5.54 Moz) based on a $325/oz gold price providing a mine life of ten years at an average production rate of 500 000 oz per year. Reserve estimation was carried out using mineable polygons to select resource blocks based on a series of mining and costs parameters. In addition key cost parameters were tested to provide sensitivities for pit optimisations and pathfinders for negotiations with suppliers and contractors. Construction began in March 1999 and first gold is expected to be poured in the second-quarter 2000.

Jan 1, 2000

By I Sherrell, R Jain

Worldwide iron ore feed grades are trending downwards and will continue to do so with the increasing difficulties of upgrading ores. This has led to operations looking for ways to capture current tailings that still contain valuable material. In the past, these were acceptable to dispose of, but this practice is no longer economically feasible. With the increasing trend of re-mining previous tailings deposits that could be decades old, new equipment designs have been introduced to upgrade current or historic beneficiation plants. These designs can effectively upgrade these tailings to saleable products.Outotec conducted test programs for upgrading iron ore tailings from flotation rejects, thickener underflow or tailings dumps on samples provided by customers around the globe. The studies utilised Outotec’s SLon vertically pulsating high-gradient magnetic separator in combination with preprocessing equipment such as low-intensity magnetic separation, screen or scrubber and flotation for downstream processing of the magnetic concentrate. A review of the equipment required to economically process these tailings is provided, along with testing data and industrial implementation examples. The effect of different operational and design parameters on Fe grade and recovery from processing each tailings sample has been highlighted.CITATION:Jain, R and Sherrell, I, 2015. Iron ore tailings reprocessing to maximise ore production, in Proceedings Iron Ore 2015, pp 149–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

The history of mining is rightly proud of its achievements in improving productivity and cost improvements over the years. No matter what measure is used, tonnes per manhour, cost per tonne, etc vast improvements have been made over the last hundred years. In fact over the last ten years in Australian coal mines raw coal output per employee has increased by 60 per cent. When one examines why these improvements have taken place the principal reasons have been technological advancement in mining equipment, excavator and dump truck capacity increases, longwall and continuous miners continually improving in reliability and size. Of course all these improvements are correlated to an increase in capital cost. Even with the above-mentioned advances the pressure for increased performance is as strong as ever. The international mining and mineral-processing sector is currently operating in a recessive market with some traditional commodities, eg gold trading at 20 year lows. During recessive times senior management will demand greater returns on capital employed: the obvious choices being reducing costs or increasing throughput. In addition, head office environments will often place a capital freeze on operational management so the opportunity to take advantage of technological change is not available. The challenge is, therefore, to increase throughput and cut costs without the need for capital. The answer is to optimise the existing labour and plant. If done systematically a result in productivity improvement, in our experience, as high as 45 per cent can be achieved with the average across South East Asia and Australasia being 21 - 23 per cent. The intention of this paper is to present a systematic approach to labour and machine utilisation thereby gaining the greatest possible return on the existing capital base.

Jan 1, 1999

By J Kinal, I Mitchell

Many flotation plants use pH to adjust the pulp chemistry of their system to achieve optimum separation. For example, in a sequential lead/zinc circuit the pH during sphalerite flotation is increased to 10.5 or greater to depress galena and pyrite, thereby improving selectivity for sphalerite. However, maintaining a pulp at a particular pH value does not necessarily provide the operator with an abundance of information regarding the chemistry changes occurring within a plant. This paper provides the reader with a number of pulp chemical observations in several plants, showing that the same trends are noted over time; however, the magnitude of the measured values do change. Further, the changes in magnitude are invariably associated with a change in mineralogy. Thus, is measuring pH enough? Can the Eh, dissolved oxygen and temperature be measured at the industrial scale reliably? And, are these measurements useful?

Jan 1, 2006

The modern Golden Cross mine entered the production phase in January 1992. The project is designed to produce over 100 000 oz/yr of gold and over 300 000 oz/yr of silver during a mine life of eight years. An open pit and an underground mine are operated producing around 850 000 t/yr of ore, to feed a conventional carbon-in-leach processing plant. Golden Cross is owned in joint venture by Coeur Gold New Zealand Limited (80%) and Viking Mining Company Limited (20 %).   Since the start of production several major aspects of the design have altered. The underground mine began as a mechanised cut and fill operation. The cut and fill stoping progresses in 3.3 m flatback lifts with maximum stoping width of 6 m. Where the ore zone is wider than 6 m a post pillar cut and fill method is used. In 1993 a new bench mining plan was introduced between the 270 and 260 levels. Flatbacking continued in the footwall drives in anticipation of variability of the ore width and orientation. The development of levels below the main service 200 level has indicated a possibility of bulk mining the ore block rather than flatbacks. This could lower mining costs but also introduce higher dilution rates. Development is in the advanced stages for trialing this method.

Jan 1, 1994

By S Mundell, J Armstrong, M Evans

"Automation is a common goal within the coal industry for reasons such as efficiency, reliability and sustainability. However, it requires standards and frameworks so business systems can communicate effectively. Automation of sample analysis processes has been difficult to establish due to a lack of direct business system communication between commercial laboratories and mining companies. This has resulted in manual procedures that have contributed to problems relating to analysis instructions, sample identification, results formats and visibility of status.These problems result in loss of data and confidence in data validity, loss of process efficiency and inability to react to issues. An Australian Coal Association Research Program project (Evans, Armstrong and Arboleda, 2014) has addressed these issues through the Coal Quality Data Exchange methodology for direct business system communication between coalminers and commercial laboratories to optimise the transfer of coal quality data.The benefits to the coalminer of the framework are:increased clarity and auditability of what is being sent to the laboratory and what was requestedreduced potential for error introduced through manual transcription tasksincreased speed of loading of analytical results to the customer Geoscientific Information Management Systemimproved turnaround time for analytical resultsincreased knowledge about what took place in the laboratory with respect to the determination of the analytical resultsincreased visibility of the status of a ‘work order’. The benefits to the technology companies and commercial laboratories is a common framework on which to build a sustainable solution that gets away from the multitude of formats catered for today and time consuming manual processes. The common framework significantly advances the future possibilities for the automation of sampling and analysis processes in a production environment.CITATION:Armstrong, J, Mundell, S and Evans, M, 2014. Automating communications between laboratories and mines – a case from the coal industry, in Proceedings Ninth International Mining Geology Conference 2014 , pp 351–360 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By A Giblett, R Dunne, D Appelhans

There are a number of hurdles that must be negotiated in order to design an effective gold ore treatment facility such that the expectations forming the basis of project economics are valid and can be achieved in practice. Selecting samples based on geometallurgical context, performing and interpreting testwork relevant to the selected process flowsheet are essential considerations towards achieving this aim. This paper discusses recent experiences in process development for free milling gold ores giving consideration to frequently encountered challenges of this nature.CITATION:Giblett, A, Appelhans, D and Dunne, R, 2013. Considerations for effective gold process development, in Proceedings MetPlant 2013 , pp 445-454 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By S Adamson

Morphological analysis of alluvial gold recovered from the same segment of a placer by four common commercial methods indicates that gold shape and the presence of quartz intergrowths or sulphide overgrowths substantially influence the recovery efficiency of each method. The amount and types of gold saved by each method varies according to the different hydrodynamic conditions under which each of the methods operates. Reverse circulation drilling has the lowest efficiency and preferentially loses moderate-high flatness gold and intergrown or overgrown gold particles with relatively low density. Gravity riffle, hydraulic riffle, and jigcentrifugal concentrator systems respectively save progressively more of these problematic gold morphotypes, but still lose significant and sometimes substantial amounts (of profit) to the tailings. Because of the differences in recovery efficiency, reverse circulation drilling probably underestimates the grade of most placers and may have resulted in bypassing several economic deposits. Losses to tailings by commercial recovery plants arise from inadequacies in fundamental plant design features. These inadequacies compromise plant efficiency by limiting the ability of plants to simulate the wide range of hydrodynamic conditions necessary to operate effectively throughout placer systems. Incorporation of sand pumps and multiple recovery methods into the more sophisticated plants only partly overcomes these inadequacies. At best, efficiency will be maximised in a few segments of the placer determined by individual plant design, and will decrease progressively upstream and downstream of those segments. Without prior knowledge of the morphological characteristics of the gold to be mined, it is difficult to choose the most appropriate plant design, or to estimate what proportion of the gold will be recoverable by any given plant. If the relevant relationships are not considered beforehand, the recovery plant is likely to lose a significant proportion of the gold, and sacrifice maximum profit.

Jan 1, 2001

The mining industry is the largest source of foreign income for South Africa. It is also the main source of employment in the country and, as an industry; it is also one of the largest. Due to the labour-intensive nature of the industry, labour costs in South African mines make up nearly 50 per cent of the total mine cost. It is thus imperative to have optimum labour planning and labour management systems in place.The focus of this study was to investigate current underground labour-planning models. It is shown that there are serious limitations. The range between an oversupply and undersupply of labour can be as high as ten per cent. A new system was therefore developed to ensure a constant labour demand and supply on a daily basis. One of the main objectives was to determine the existing labour supply range and thus the requirements to fill the undersupply. For this purpose, a specific methodology was designed to capture and process all the relevant information. Mine personnel was involved throughout the entire process to ensure ownership of the new model. This buy-in was achieved through planning workshops, interactive presentations and discussions. The improved frequency of daily blasts validated the new system by providing the correct amount and mix of the labour force. The new labour-planning model was then extended to optimise revenue. Implementation on a mine resulted in increased income of R95 million.

Dec 6, 2010

By E Kasai, T Nakamura, E Shibata

In the present study, formation of PCDD/Fs from carbon particles like æsootÆ, so called de novo synthesis, was experimentally simulated using the powder mixture of graphite and metallic chloride. Composite states of graphite and chloride particles were varied by the preliminary treatment, ie high-energy ball milling for different time or heating at different temperatures. These samples were subjected to the measurement of the rates of weight loss mainly due to the oxidation of carbon, the formation of absorbent organic chlorides (AOX) and the formation of PCDD/Fs at 300¦C. The amount of PCDD/Fs formation increased by applying certain pretreatments. Further, linear relationships were obtained among the formation rates of PCDD/Fs and AOX and the weight loss of sample. These results will give useful information to investigate the mechanism of PCDD/Fs formation from unburned combustible carbon and hydrocarbon in thermal processes.

Jan 1, 2002

By R Wilson, R Williams, B Freeburn

McLanahan RSS14x50 scrubber screens have individually processed over 50 Mt of Pilbara iron ore. The first stage of separation in these plants with abrasive, high specific gravity, large lumps is an extremely arduous duty with high wear rates. With the Scrubber Screen layout this occurs in the attached trommel section. The initial supply of the replaceable trommel panels were of steel-backed rubber with a service life of approx. six weeks. Site Personnel established a goal of 26 week wear life in conjunction with 100 per cent reliability and while field trials were undertaken using a variety of hardened and cast steels that demonstrated wear life to the nominated requirement some unpredicted failures still occurred. With a long evaluation time and challenges to create repeatable conditions with field testing, a purpose built test unit was designed and constructed to allow controlled evaluation of a number of materials and designs. During 2016 tests were conducted with eight different materials, of varying thickness to simulate impact conditions and a number of aperture profiles to evaluate both impact and abrasion effects. From these results two designs were selected for full scale implementation to confirm the nominated goals. This paper will present details of both testing procedures and results of all materials, as well as conclusions of successful field implementation.CITATION:Wilson, R, Freeburn, B and Williams, R, 2017. Trommel panel development for iron ore applications, in Proceedings Iron Ore 2017, pp 251–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By B Davis, A H. Benzer, A N. Mainza, C M. Evertsson, L M. Tavares, M M. Hilden, M S. Powell, C Rule, G Asbj÷rnsson

The Mogalakwena North Concentrator of Anglo Platinum Operations was built with the capability to allow for future projected expansion. Several research groups, currently working with Anglo American on collaborative research over a range of projects, were brought in to review the existing operation, with a view to releasing some specific bottlenecks and providing specialist design input to the potential plant expansion.Based on a thorough review of the high pressure grinding rolls (HPGR) and crushing circuit, a wide range of de-bottlenecking opportunities were identified. This was followed by a series of surveys to provide performance measurements and to model the circuit in detail. From this effort a full simulation of the plant has been developed, including updated models of the HPGR, crusher, bins and screens. These models have been implemented in the researchersÆ Model Development Kit (MDK) version of JKSimMet, and in a prototype dynamic simulator based on the Matlab Simulink software.The observations, measurements and simulations have provided guidance and quantified the benefits of some proposed circuit modifications. Based on these findings a number of upgrades are being planned, with the aim of ensuring full utilisation of the installed equipment. The circuit demonstrates a potential expansion of over 30 per cent through minor improvements, and a 70 per cent increase in capacity with the addition of some strategic equipment.The HPGR-crushing upgrade project demonstrates the potential benefits of nurturing disparate Research groups into a strong inter-disciplinary technical team capable of supporting operational needs while developing future technology.CITATION:Powell, M S, Hilden, M M, Evertsson, C M, Asbj÷rnsson, G, Benzer, A H, Mainza, A N, Tavares, L M Davis, B, Plint, N and Rule, C, 2012. Optimisation opportunities for high pressure grinding rolls circuits, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 81-94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By M R. Stevens, W Mori, G B. Boswell

The Onemana prospect is located on the eastern Coromandel Peninsula, North Island, New Zealand. Systematic exploration involving surface geological mapping, geophysics, rock and soil geochemistry, reverse-circulation and diamond drilling has identified a number of important features of a fossil hydrothermal system at Onemana. This relatively intact gold mineralised system is hosted within a sequence of rhyolitic volcanics and volcaniclastics, overlain by lake sediments, sinters and hydrothermal eruption breccia. The system lies within a graben/half graben bounded by major NE-trending faults which form the approximate boundaries to hydrothermal alteration. Rock and soil geochemistry indicate a broad zone of anomalous gold, silver, arsenic, mercury and antimony. Overlapping elevated rock and soil gold anomalies indicate strongest mineralisation occurs over two zones of hydrothermal brecciation named 'Breccia Knob' and 'Western Ridge'. Geophysical data obtained from Gradient Array Resistivity and Ground Magnetics have been used to produce anomaly maps. The terrain corrected resistivity plot shows a number of well defined linear resistivity anomalies which are believed to represent large silicified and quartz veined bodies at relatively shallow depths. The strongest of these anomalies correspond with 'Breccia Knob' and 'Western Ridge'. Reverse-circulation and diamond drilling targeting these resistivity and geochemical anomalies has confirmed wide intervals of quartz veining, silicification and gold mineralisation. Petrologic data based on drill samples indicates the existence of a laterally extensive gold bearing epithermal system. Hydrothermal alteration is thought to have been caused by strongly convecting, two-phase (boiling), near-neutral chloride fluids which persisted at high temperatures (170 - 220¦C) to the paleosurface. A geological model is postulated of a large, complex, hydrothermal system developed in a shallow lake or marginal lake environment created by rifting and graben development within a recently extinct rhyolitic volcanic centre. Geothermal activity alternated between relatively quiescent periods of unrestricted fluid upflow and sinter development interspersed with violent hydrothermal eruptions caused by near surface silica capping and overpressuring above a major fluid conduit centred under 'Breccia Knob'.  Opportunities for precious metal mineralisation are evident from drilling to date. Upflow of near-neutral chloride fluids to shallow depths favours the presence of strongly mineralised stockworks at relatively shallow depths. Periodic hydrothermal eruptions would have caused fracturing and rapid depressurisation of the hydrothermal system, strongly favouring the precipitation of gold from solution both near surface and within feeder-vein systems at depth.

Jan 1, 1995

By A M. Avis

This paper presents an overview of recent developments in the Environmental Impact Assessment (EIA) process to provide the background for a more detailed analysis of environmental and social constraints that the Heavy Mineral Mining industry has encountered over the past decade. Four cases studies are reviewed to provide a context for further analysis and identification of cross cutting environmental and social issues that either resulted in the projects not proceeding, or in the Australian case study, places existing operations under significant pressure from anti-mining lobbyists. The Xolobeni project, from the Eastern Cape in South Africa, is presented as the primary case study because it is recent, topical, and accessible; and raised numerous issues related to mining in a sensitive environment. A proposal to mine an area adjacent to the Okefenokee swamps in 1997 was also met with strong opposition from various environmental groups in Georgia, USA. This case study is briefly reviewed to further understand what ultimately resulted in the project not proceeding. Opposition to mining at North Stradbroke Island is reviewed to identify current issues more applicable to a developed country. A further review of a strategic assessment undertaken at Wavecrest, Eastern Cape, South Africa is provided in support of possible solutions to the challenges identified in the case studies. Important common themes were identified, including in some cases unfortunate timing of the environmental studies, but in all cases opposition was due to ecological sensitivity, landscape quality and sense of place. In one case study limitations to the EIA process included inadequate detail in the specialist investigations and insufficient information on mitigation. In all cases public participation was a limitation. It was either insufficient; flawed through possible bias; too ‘top down’ and required engagement with mobilised, motivated lobbyists. There was also insufficient investigation of social impacts, particularly amongst rural communities directly affected by a project. Generally alternatives were inadequately considered, a recognised limitation of project level EIA. It is concluded that the EIA process should be started as early as possible (at prefeasibility), and that investigations should be expanded from a typical fatal flaw assessment to one that applies methodologies used in strategic assessment. In particular, opportunities and constraints of the natural and social environment should be assessed in the context of the mining option as well as other options, to allow for a more meaningful assessment of alternatives. Public participation must form an important part of this initial study, despite the potential risks associated with public engagement at an early stage in the project. The application of the IFC Performance Standards; and expanding the scope of the EIA into an environmental, social and health impact assessment will lead to a more rigorous procedure, and result in more defensible products which could successfully unlock the key to the resources in these sensitive areas.

Oct 5, 2011

By D Wyatt, J Domenico, W Kow

Over the past few years developments in heavy minerals processing have concentrated on the mineral separation portion of the business. The best example of this would include new developments in rare-earth magnetic separators and associated flowsheet modifications. Except for some minor modifications in spirals, the æwetÆ side of the separation business has lagged behind the ædryÆ side. Basic concentrator design has not changed in 20 years. Recent pilot trials by Outokumpu Technology have shown the benefits of a new gravity flowsheet that combines density separation and spiral concentration on a variety of heavy mineral deposits. This concept is already well utilised within the iron ore industry. The synergistic combination of these two technologies allows smaller, simpler, and controllable gravity concentrators to be built while providing equivalent or better grade and recoveries of valuable heavy mineral. This is contrasted to the all spiral flowsheet characterised by the diminishing returns of multiple stages of spirals and associated recirculating loads. Examples of the flowsheets and associated benefits will be presented from a variety of cases.

Jan 1, 2001

By T Trott, M Lewis, G Lumley

The analysis of equipment trends in The AusIMMÆs revision of Monograph 19 - Australasian Mining and Metallurgical Operating Practices (AMMOP) (in prep) in the paper by Graham Lumley raised some interesting, and in parts disturbing, trends in the Australian open cut mining industry. According to the Australian Bureau of Statistics (2011) the productivity of the whole mining industry is down by 34 per cent since 2001. In terms of open cut equipment, median output for draglines is down by 15 per cent since 2003, electric rope shovels are down by 41 per cent since 2003, hydraulic excavators are down by 39 per cent since 2008, front-end loaders are down by 39 per cent since 2007 and trucks are down by 41 per cent since 2006. Clearly e boom has not been good for the efficiency of the mines. During this same time, best practice (defined as the average of the top ten per cent by annual output per unit of input) has declined, but not by as much as the median (eg shovels down by eight per cent, excavators down by 19 per cent and FELs down by five per cent). This paper will build on the analysis of AMMOP to understand the differences occurring between median and best practice and identify the factors contributing to the decline in performance. As the industry enters a period of potentially lower prices for commodities and reduced margins, pressure will be brought to bear on mine sites to start moving more with the equipment they have. An understanding of where efficiency has been lost will be a key component in that. The information contained in AMMOP, and the subsequent analysis of that information in papers such as this one, will be crucial to reversing the decline in open cut equipment performance.CITATION:Lumley, G, Trott, T and Lewis, M, 2012. Reversing the trend in open pit mining equipment output, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 75-82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By Q Wang

Net present value (NPV) has been the main criterion in mining project evaluation and production plan optimisation. It is a common practice in NPV calculations to take into account only the tangible cost items in the corporate accounting system. The costs incurred due to damage to the local ecosystem and environment are left out and treated as externalities. Such practice on the one hand underestimates the total cost of a mining operation and, on the other hand, ignores the difference in ecological/environmental impacts between different mine plan alternatives. This paper attempts to measure the ecological costs of mining and to incorporate such costs into the evaluation scheme in mining project evaluation and mine planning. The ecological costs of mining are estimated based on the areas and types of land (eg forest land, grazing land, crop land) damaged by mining activities and the carbon emission from fossil fuel consumption. For the land areas (and their associated ecosystems) directly damaged by mining activities, the ecological costs are measured by the prevention and restoration costs, the lost values of eco-services of the damaged land, including bio-product production, soil erosion control, water run-off control, oxygen release, air pollutant absorption and formation of soil nutrients. The ecological cost of carbon emission from the energy consumption of a mining operation is measured by the cost of cultivating the equivalent forest land required to uptake the emitted carbon. A case study on a large-scale open pit mining project is presented to demonstrate the influence of ecological costs on the mine planning outcome.

Sep 26, 2011

By D Kilkenny, D Nardini, P Kline

This paper is a case study highlighting learnings and success in two areas challenging underground miners: change management and collaboration. It examines the implementation process of a new automated loading system in the bulk stoping area of Telfer Mine in Western Australia, controlling multiple load haul dump machines. Here, the new technology has brought together different functions and different companies to deliver a well performing automation system in a changing and challenging mining environment. The introduction of a new and different technology on site has driven collaboration between all stakeholders to break down the traditional barriers to achieve the sustained performance required. Historically, different teams have operated within silos and not always aligned to deliver a ‘best for project’ solution. Technical teams focus on the mine design, maintenance teams focus on reliability and operations execute the plan. Mining contractors focus on productivity and cost. Manufacturers focus on supply of goods and service. Optimising each silo individually is not guaranteed to provide an optimal mining solution. Involving elements from each team as seen at Telfer, has resulted in an optimal mining solution for the automated loading system. A change of focus from the technical teams to include automation parameters in the mine design; operability and maintainability built into the system design allowing for collective ownership and responsibility resulting in a more resilient solution. The implementation of the new technology was not only a technical change but more importantly, successful management of change. Elements of successful change management such as communication, vision, leadership and planning, are essential to harness a trusting site culture which is responsive to new technology. Learnings and challenges from this change process will also be discussed with the intent to improve the success rate and timelines of technology implementations in the future.

Mar 15, 2021

By T Arena

To maintain copper recoveries and maximise production at the Sepon Copper Operation it is crucial to control the amount of copper entering the leaching circuit. This requires close control of blending of the multiple ROM stockpiles to achieve the desired head grade. Grade variability in the ROM stockpiles can lead to significant variation in the processing plant copper feed grade.Head grade sampling from the milling circuit at Sepon is complicated due to milling in leach solution to preserve the water balance. Copper is present in both liquid and solid forms and copper in the added milling solution has to be accounted for. This leads to difficulties in manual head sampling which also introduces delays due to sample preparation and assay turnaround. On-stream analysis is complex because of the solution and solid copper and the need to account for recycled copper solution.This paper describes the complexity of feed grade management at Sepon and the application of on-belt analyser technology to assist in the control of copper metal throughput.

Aug 8, 2011