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By I Canbulat, J Oh, A Mcquillan, D Payne

This paper presents a new risk assessment tool for coal mine excavated slopes. This new empirical-statistical Slope Stability Assessment Methodology (SSAM) is intended for use by geotechnical engineers at both the design review and operational stages of a mine’s life to categorise the risk of an excavated coal mine slope. A likelihood of failure is determined using a new slope stability classification system for excavated coal mine slopes developed using a database of 119 intact and failed case studies sourced from open cut coal mines in Australia. Consequence of failure is based on slope height and stand-off distance at the toe of the excavated slope. Results are presented in a new risk matrix, with slope risk being divided into low, medium and high categories. The SSAM is put forward as a new risk assessment tool to assess the potential for, and consequence of, excavated coal mine slope failure. Unlike existing classification systems, assumptions about the likely failure mode or mechanism are not required. Instead, the SSAM applies an approach which compares the conditions present within the excavated slope face, with the known past performance of slopes with similar geotechnical and geometrical conditions, to estimate the slope’s propensity for failure. The SSAM is novel in that it considers the depositional history of strata in an excavated slope and how this sequence affects slope stability. It is further novel in that it does not require explicit measurements of intact rock, rock mass and/or defect strength to rapidly calculate a slope’s likelihood of failure and overall risk. Ratings can be determined entirely from visual observations of the excavated slope face. The new SSAM is designed to be used in conjunction with existing slope stability assessment tools. CITATION:Mcquillan, A, Canbulat, I, Payne, D and Oh, J, 2018. New risk assessment method for coal mine excavated slopes, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 473–495 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By D Hillier, A Giblett, K Parker, V Ramsell

Kalgoorlie Consolidation Gold Mines (KCGM) operates the Kalgoorlie Super Pit open cut, Mt Charlotte underground mine, Fimiston process plant and Gidji Roaster facility for joint venture partners Newmont Mining Corporation and Barrick Gold. In 2004, the Fimiston plant was upgraded by the addition of gravity concentration to the Fimiston and Mt Charlotte grinding circuits, including the installation of a central intensive cyanidation reactor to process the gravity concentrates. The gravity project was justified after detailed analysis demonstrating an expected increase in overall gold recovery of approximately one per cent, in addition to reduced elution costs and reduced gold inventory in flotation concentrate stockpiles. The gravity circuits were commissioned in August 2004, and have since consistently recovered 10 to 20 per cent of the gold present in the KCGM ore, delivering a reduction in coarse gold losses equivalent to 0.45 per cent additional metal recovery and contributing to improved metal accountability.CITATION:Giblett, A, Hillier, D, Parker, K and Ramsell, V, 2012. The impact of gravity gold recovery at Kalgoorlie Consolidated Gold Mines, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 199-206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By D H. Laubscher

The in situ rock mass rating system û IRMR - leading to the mining rock mass rating system - MRMR - for jointed rock masses has been used (and abused) in mining operations around the world for the past 27 years. Despite the recent development of elaborate design procedures and computer-aided design packages, MRMR remains one of the most versatile and practical mine design systems available. It is important to realise that the rock mass classification system should not be replaced but rather complemented by more sophisticated and detailed design procedures. The classification system is not only the æcrudeÆ method used for initial assessment (as described in some geotechnical literature) but also in many respects a very effective and practical engineering tool. MRMR could, and should be used during the entire stage of mine life as an integral part of the design process. The objectives of this paper are to illustrate using practical case histories from the past decade, some of the pitfalls of the MRMR classification system, to clarify certain misconceptions in its application and update its mining application.

Jan 1, 2000

By K George

The Dugald River lead-zinc-silver deposit is located approximately 60 km north-west of Cloncurry and 87 km north-east of Mount Isa. The development project is expected to turn operational in 2018. The resource is estimated to contain 61.1 Mt at 12.6 per cent zinc, 1.9 per cent lead and 34 g/t silver, with a projected mine life of 25 years. The evolution from exploration project to development project has presented multiple challenges for the technical team. Understanding and modelling the structural complexity of the deposit has been one of these challenges.Historically fault zones were logged as a lithology, with structural measurements recorded in a separate database table. When underground drill programs and development commenced in late 2012, it was recognised the deposit was more structurally complex than had been modelled. The extensive number of fault zone lithologies in core logging, made it difficult to identify fault trends and model faults in 3D software packages.In 2014, a structural project was conducted to produce a fault model for the deposit. The project highlighted that by logging the faults as a lithology, a shortage of fault characteristics was being recorded. Additionally, structural information could not be filtered to identify different fault sets due to the lack of information available to filter on. One of the major outcomes of the study was to change the methodology for the structural logging of drill core.Faults are now logged in a separate structural log. The structural log collects two types of information: interval data and point data. The interval data represents the damage zone of the fault in the surrounding rock and the point data the plane of movement for the fault. The faults are further characterised by their intensity on a scale of one to five, the type of fault structure (fault breccia, fault vein etc), the minerals present on the fault surface and structural measurements when available.The new data set allows fault data to be filtered based on fault characteristics, making implicit and explicit modelling of the faults more timely and accurate. The data set can be used to produce fault wireframes as single surfaces from the point data or hanging wall and footwall surfaces from the interval data. The logging method and how its applied in fault modelling form the focus of this paper.CITATION:George, K, 2017. A new approach to logging and modelling faults at the Dugald River Pb-Zn-Ag deposit, North West Queensland, in Proceedings Tenth International Mining Geology Conference 2017, pp 315–320 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By R Winterberg

Concrete is a well established and reliable construction material for the permanent lining of tunnels, but shows some weak performance characteristics, which can be overcome by the addition of specialised fibre reinforcement. This paper addresses the particular performance design requirements of segmental linings, discussing the improvements of fi bres on concrete properties. Focus is made on the beneficial effects of fibre reinforcement on the cracking behaviour and the toughness performance, providing a safe and durable tunnel lining.Not only the mechanical performance of fibre reinforced concrete (FRC) for segmental linings, but also the durability of the linings has gained growing attention among the designers and consultants. Especially tunnel linings with exposure to media with corrosion potential, such as wastewater sewer tunnels or desalination plant outfall tunnels, have high requirements on their durability. The design of these structures must provide a comprehensive study of durability aspects. Fibre reinforcement can substantially improve the durability of concrete.Research has been carried out on the cracking behaviour of concrete. The beneficial effects of steel fibres on the cracking behaviour reduce the permeability by reducing the flow paths within the concrete. Crack bridging steel fibres create necking effects in bending cracks, leading to earlier closure of the cracks. Further, steel fibres create particular crack formations, which lead to a substantial reduction of the fl ow rates through separation cracks. The results also show that considerable cost savings can be achieved using FRC, as the thickness of the linings can be reduced.The durability design issues will be addressed and underlined by a case history on the Hobson Bay sewer tunnel in Auckland, New Zealand.

Mar 8, 2011

By M Henderson, M Hudyma

Mining-induced seismicity at Junction Gold Mine became a serious operational problem in the late-1990s. Assessing the local seismic hazard is an important step in assessing the risk associated with potential rockbursting. This paper discusses the qualitative and quantitative means of assessing seismic hazard used at Junction. In qualitative hazard assessment, the role of the primary factors contributing to mining-induced seismicity and rockbursting are identified. These factors include: rock mass properties, geological structures, mine development, and stoping. A qualitative seismic hazard map has been developed considering these factors. In quantitative hazard assessment, seismic source parameters from an Integrated Seismic System are used to assess seismic hazard. The seismic source parameters found to be relevant to seismic hazard assessment at Junction are discussed.

Jan 1, 2002

By M Fishwick Tapia

This paper was prepared and translated from the final report of the investigation into the Codelco Chile Salvador DivisionÆs air blast which occurred in the Inca-West area. In this section of the block cave mine, a stable arch formed covering an area of approximately 15 000 m2 . This zone subsequently collapsed producing a massive air blast. The collapse followed a series of planned extraction activities and occurred on 5 December 1999. This paper discusses the cave back arching event and the measures that were taken in order to induce the controlled collapse. This was to minimise risk to personnel, equipment and installations. The results obtained to date are presented.

Jan 1, 2000

Mobile mining equipment presents only a small portion (ten per cent mining project costs but the selected technology will determine to a large extent the mining performance and mine profitability. The actual performance of the selected mobile equipment technology will rely on the support functions, infrastructure, user interface and user acceptance. Optimising the technology to match the circumstances is an increasingly important phase in a mine feasibility study. Smartly done feasibility studies include the possible future needs of changing or building-up of the selected technology. In massive mining applications the machinery faces quite different challenges than in selective or small-scale mining applications. In massive mining applications the efficient and continuous move of large amounts of material has led to the use of increasing degree of automation. This higher degree of automation in a mining application, on the other hand, will be best applied to a smooth and streamlined mining process and operation. Mining methods like block caving support automated operation. Automated mobile equipment needs supportive infrastructure, monitoring and information transfer systems as well as well established working procedures. Too often the user interface and human factor is disregarded during the consideration of automation. Through the available supplier programming tools it is possible to see how much the selected technology provides flexibility in changing production or economical situations, when major rebuilds or replacements are necessary, and view the effects of all these on the mine economy. When adequate technology is available from various sources, the difference becomes from preparing for the future, managing costs and combining the best layout with the most suitable technological solutions.

Jan 1, 2000

By B J. Hutchison, S Gannon, J Chambers, D Oko-oboh

The Kanmantoo copper mine is located in the Adelaide Hills area of South Australia and is owned and operated by Hillgrove Resources (HGO). The mine is a drill and blast, truck and shovel operation mining sulfide (chalcopyrite) ore located in chloritised andalusite biotite schist. The initial Kanmantoo open pit operation occurred in the 1970s, before falling copper prices closed the mine. In 2010 the mine was reopened by HGO and the Kavanagh cutback of the Kanmantoo pit was undertaken. The Spitfire, Nugent and Emily Star satellite pits were also mined through to 2015 before the latest steep wall Giant pit design was developed to take mining out to 2019.There are no major fault structures and only two significant shear zone structures exposed in the open pit walls. The main Garnet Andalusite Biotite Schist (GABS) unit is quite competent so the pit designs have therefore mainly been controlled by four distinct joint sets. This paper is a case study on the influence of the joint regime on the wall stability of the main GABS unit and how a better understanding of the joint regime and the use of rock reinforcement has allowed the steep wall design to be adopted.The paper also describes the remote geotechnical mapping and slope monitoring techniques used to manage the rockfall risks associated with the steep walled slope design.CITATION:Hutchison, B J, Chambers, J, Gannon, S and Oko-oboh, D, 2017. Case study of joint structure and the design and performance of open pit walls at the Kanmantoo copper mine, in Proceedings Tenth International Mining Geology Conference 2017, pp 355–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By J Webb

The mining industry is relatively niche and complex compared to other global industries in its safety and operating environment. Whilst some of the technology required to decarbonise the mining industry will emerge from the mass market (eg batteries, energy storage solutions and renewable power generation) where exogeneous external investment and innovation will drive supply, bespoke applications such as material movement will be constrained by industry limitations. Underground load and haul equipment burns the majority portion of underground mine diesel, and typically 25 per cent of scope one and two emissions. Transitioning away from incumbent diesel engines offers a considerable health benefit to all mine workers, as well as decarbonisation achievements, and through trials there is emerging evidence of more productive equipment and realistic expectations of lower operating costs of fleet. However, new equipment and material movement systems that support these industry goals are currently approached with caution due to the pivotal role they play in delivering productivity goals, and the lack of experiential data and certainty to mitigate the supplier development risk during this technology transition period, where all resources are required to meet a booming industry. A group of mining companies and suppliers have the aligned aim to accelerate the understanding and availability of heavy haulage mobile equipment through collaboratively piloting equipment and working with suppliers and each other to aggregate market demand, encourage investment and resolve the mine design and technology choices through their involvement in the Electric Mine Consortium (EMC). This paper will outline the major challenges the industry must overcome in sourcing and adopting a zero-diesel particulate and zero-emission mine, drawn from cases and insights across ten EMC mining company members.

Mar 29, 2023

By F Musa

One of the main energy efficiency opportunities identified from the majority of mine site energy audits is to optimize the comminution circuit to reduce energy consumption through improved throughput and product size distribution. Typical analysis reviews comminution process efficiency/inefficiency i.e. utilization of grinding mills, process bottlenecks and product vs. target size, to identify instances of overgrinding or undergrinding. From this, it is possible to establish the potential improvement that could be gained through formal plant optimization and what the optimization program would entail. It can also sometimes reveal immediate opportunities for process improvement. This paper presents steps that can be taken to optimize the efficiency of comminution circuits.

Aug 8, 2011

Opening AddressThank you for inviting me here today to open what promises to be a significant conference on the technological aspects of extractive metallurgy. I would especially like. to welcome delegates who have travelled great distances in order to contribute to, and be participants in, this examination of the technical innovations which have always been a crucial part of our industry.

Jan 1, 1992

By J Hartnett, B Tarrant, A Rayner, D O’Toole, P Davies

Since 2009, the Northern Territory and Australian governments have been working under a national partnership arrangement to inform a rehabilitation plan for the former Rum Jungle uranium mine. Part of the rehabilitation strategy is to backfill a flooded former pit (Pit), which extends down to 100m below the current pit lake surface and was historically partially backfilled with uranium tailings. It is proposed to utilise the remaining pit volume below water level to sub-aqueously store Potentially Acid Forming (PAF-I) waste rock which currently occupies large stockpiles across the site. The rehabilitation design and planning process undertaken to develop a strategy commensurate to project objectives and construction constraints involved the establishment of key constraints derived from the analysis of historic data sources and preliminary design efforts. Tabled strategies were balanced against dependent project tasks and project objectives, especially surrounding minimising disturbance of highly contaminated materials within the Pit. Ideas were developed in conjunction with industry input and review of case histories to develop a remediation solution that is constructible within the project timeframe and constraints.

Jul 1, 2021

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 M A. Harrington-Baker, J M. Trudnowski

Sulfate-reducing bacteria (SRB) have the ability to immobilise dissolved metals by precipitating them as sulfides, provided that a favourable biochemical environment is created. Such an environment includes the presence of sulfate, anaerobic conditions and the availability of organic carbon. If such conditions are engineered within a reactive barrier or field-bioreactor, most metals can be effectively removed. To demonstrate this concept, three passive SRB field-bioreactors were constructed in 1998 at an abandoned mine site in the vicinity of Butte, Montana, USA to treat acid mine drainage with characteristic elevated concentration of metals and low pH. Performance of the field-bioreactors, using aqueous samples, was monitored over 32 months until the project was terminated, field-bioreactors were decommissioned and solid matrix sampling of the reactive matter was performed. The most important analytical results are presented in this paper together with conclusions regarding the appropriateness of the field-bioreactors construction features. Only Zn, Cu, and Cd were being removed as sulfides due to SRB activities. Changes in concentrations of other metals (Fe, Mn, Al, As), which do not necessarily precipitate as sulfide, seemed to be affected by SRB only in an indirect manner by responding to increased pH caused by SRB activity. An innovative cellular containment system used for placing organic matter worked very well in preventing settling of the organic matter and ensuring uniform flow of AMD throughout the entire cross-section of the organic carbon with no preferential flow paths This demonstration was funded by the US EPA and was jointly administered by the EPA and the US DOE under DOE contract number DE-AC22-96EW96405. The project was implemented by MSE Technology Applications, Inc, Butte, Montana, USA.

Jan 1, 2003

By Z Gao, D Liao, W Sun, S G. Pooley, J Wang, Z Shi, G Jing, S Ren, Q Chen

Yuanjing processing plant is a scheelite and wolframite plant in southern China. Water shortages and recent environmental regulations mean that the plant must reuse the wastewater that comes from the mining operation. This paper describes the efforts to reuse the mining and ore washing wastewater (MOW) in the processing plant. Initial attempts to reuse the MOW in the strong magnetic separation were unsuccessful because the magnetic media pack was seriously fouled by the micro-fine precipitate generated. The focus changed to reuse the MOW in the scheelite flotation circuit, which includes one roughing, one cleaning and three scavenging steps. Laboratory batch tests showed this would likely be successful because using MOW reliably improved the flotation performance in the laboratory tests. Then a 20 day industrial trial was run in the plant. The trial was very successful with the enrichment ratio of WO3 increasing from 17.4 to 23.6, while the recovery remained around 79.2 per cent. The industrial trial was so successful the company immediately adopted the new scheme, which has remained in use ever since. This technical solution not only alleviated serious water shortages, and satisfied environmental regulations but also improved the plant performance.

Aug 24, 2022

By K Zunica, A R. Penney

The principles of three-dimensional geological modelling are well understood and routinely used. Sample data is collated and geostatistical tools used to ensure that sample data is suitable for its end use, which is typically a block model that is appropriate for mine planning. What has become increasingly apparent is that physical rock properties and geotechnical parameters need to be incorporated into the three-dimensional geological model to create an integrated mine model.The approach to the collection of geotechnical information is not as highly prescribed and controlled as collection of geological data. Commonly, the geotechnical data set is incomplete and inconsistent, with little consideration of what the end use will be by those collecting the data, or how the geotechnical data might relate to the geological data. In some cases, specific geotechnical investigation programs are completed, yet correlation between those programs and previously collected data is rarely undertaken to the same level of diligence as found in the geology field.There are some obstacles that need to be considered when attempting to incorporate geological parameters, such as grade, lithology, and geological domains with geotechnical information such as rock quality designation (RQD), rock mass rating (RMR), rock strength, and geotechnical domains into the same three-dimensional block model. Interpolation or geostatistical estimation methods used for grade estimates might not be appropriate for many components in rock characterisation, particularly search geometries. A number of examples are provided to illustrate issues underlying some of the data collection procedures, and their effects on three-dimensional geotechnical modelling.The example presented attempts to highlight generally observed shortcomings in the collection of geotechnical information, parameters which need to be considered when combining geological and geotechnical data into the same model, and the benefits of having a combined block model from the beginning of a project.CITATION:Zunica, K and Penney, A R, 2014. Integration of geological and geotechnical data for three-dimensional modelling, in Proceedings Ninth International Mining Geology Conference 2014 , pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

Mining and mineral processing makes a vital contribution to AustraliaÆs national export income, and our society today is critically dependent on its products. Despite the importance of this industry, its operations often come under scrutiny because of its high potential impact on local environments û both social and ecological. The challenge for the minerals industry today is to make the most responsible and best possible use of the national resource base, maximising overall resource utilisation.Research efforts and industry implementation of improvements have been moving in this direction for a considerable time already, and the industry has a long history of process innovation and improvement in Australia. Examples range from the early development of gold cyanidation and mineral flotation to more recent work undertaken under the auspices of AMIRA or through the various CRCs and research organisations such as the AJ Parker CRC for Hydrometallurgy, the Cooperative Research Centre for Mining Technology and Equipment and the Julius Kruttschnitt Mineral Research Centre.However, the nature of research and innovation in the mining and mineral processing sector is changing, as the industry itself copes with the pressures introduced by globalisation, industry consolidation and commodity price cycles. Large firms that have historically maintained a tradition of corporate technology and a culture of innovation are moving to outsource their technological and research competencies and are adopting æfast-followerÆ mentalities. At the same time, the challenges of sustainable development that need to be addressed are many-faceted, multidisciplinary, and require a holistic approach for significant achievements to be realised. Many sustainability issues, particularly those pertaining to environmental and safety issues, are shared across large sections of the minerals industry, and are seen as æindustryÆ problems beyond the scope of a single company.In this environment, collaborative research efforts are becoming the dominant mechanisms for building on past innovations and ensuring the continued success of the mining and mineral processing industries within a framework of sustainable development.

Jan 1, 2004

By T A. J Hopper, S Mukkisa, M L. Johns, K T. O’Neill

Technological advances the sensor design and performance for logging while drilling (LWD) instrumentation offer considerable opportunities in iron ore exploration. Here we focus on the development of a nuclear magnetic resonance (NMR) LWD tool. NMR is an advanced geotechnical logging technology capable of providing in situ measurements of the porosity, pore size and permeability of the formation of interest. The ability to provide real-time characterisation of iron-ore systems is beneficial to both drilling operations as well as real-time formation evaluation. The development of an NMR LWD tool for mineral exploration drilling has previously not been achieved due to the significant technical and environmental challenges associated with the design and operation of such a tool. The tool outlined in this work is designed to work in reverse-circulation (RC) drilling systems. As such, the tool needs to be compatible with the RC drill-string, as well as being highly robust to survive the shocks and vibrations experienced during RC drilling operations. The magnetic physics of the probe must be capable of measuring at the appropriate depth into formation whilst being subject to the array of motions experienced during drilling operations. Furthermore, conducting accurate NMR measurements in an iron ore formation is challenging and the measurement methodology must be tailored to characterise the magnetic environment. The tool also requires high-powered electronics capable of operating the necessary pulse sequences for excitation and acquisition. The resultant tool design must therefore optimise the inherent trade-offs which exist between the physical components (ie mechanical structure, magnetic components and electronic hardware) in order to operate appropriately whilst not hindering RC drilling operations. Current experimental analysis of the prototype indicates that the current probe design exhibits the required measurement specifications and is nearing field testing. Future work will look towards commercialisation of the instrument.

Nov 8, 2021

By B Stewart

It has long been recognised that knowledge of the conditions existing in a mine after an incident is essential in deciding whether to deploy responders as part of the incident recovery process. Applying this knowledge in a structured manner to the assessment and the acceptability of the risks likely to be faced by those teams during response activities before authorising their deployment is an onerous task incumbent upon the person controlling the incident response. The Mine Event Management System (MEMS) provides structure and coordination in the management of mine events. It assists with the skills and knowledge for incident control teams to effectively manage any emergency or non-emergency event, be it large or small. In cases where multiple organisations are involved, the MEMS promotes effective joint operations through the use of common terminology and structure to provide seamless communication between agencies at all operational levels. The SQL-based software developed by Queensland Mines Rescue Service (QMRS) assists decision-makers to make considered options; it does not make decisions for you. When set-up, it allows the information that already exists within a mine’s Safety Health Management System that is relevant to the incident to be accessed and considered rapidly within the pressured environment of an emergency. Additionally, the incident specific questions contained within MEMS focuses the management team on gathering and assessing information relevant to the incident as it progresses. The software’s event log can be utilised as an auditable document for post incident investigation. The MEMS provides a process to properly consider the adequacy of the information available upon which decisions have to be made, to consider and acknowledge the hazards of the environments within or adjacent to which responders will need to work and to acknowledge and authorise the entry of responders into or to remain within a mine either during or post an incident occurring, once an acceptable level of risk is achieved.

Apr 16, 2024