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By A Jewbali, R Perry, R Inglis, L Allen

"The use of conditional simulation to characterise mine plan uncertainty is increasing for the assessment of risk in mining projects. While the development of grade uncertainty profiles is relatively straightforward and can be validated using standard geostatistical techniques, the addition of geological uncertainty to evaluate total risk remains problematic. Some of the problems associated with geological uncertainty methods include the clustering of data in favourable geologic units, difficulty in training image definition and the inability to address change of support issues for categorical variables. Despite these obstacles, the importance of geological uncertainty as a contributor to total uncertainty has prompted Newmont to explore and evaluate the use of various techniques (and combinations of techniques) on different deposit types.Two orogenic deposits of different geological complexity were selected for the study: Subika, a shear zone-hosted deposit, and Merian, a deposit containing gold mineralisation associated with quartz vein zones and stockwork within which are found higher-grade quartz breccia zones. Newmont trialled various categorical simulation approaches to determine the applicability of these methods for each deposit type and the effect of parameter choice on the width of the uncertainty interval. Some of the techniques that were trialled include multiple point statistics methods, sequential indicator simulation using local probabilities as well as variations of these methodologies.The goals of this study included: gaining an understanding of which techniques may work best in which deposit types gaining an understanding of the intricacies of each method gaining an understanding of the effect that each method has on total uncertainty analysis.This paper presents a comparison of the various techniques and makes recommendations for their use in uncertainty analysis.CITATION:Jewbali, A, Perry, R, Allen, L and Inglis, R, 2014. Applicability of categorical simulation methods for assessment of mine plan risk, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 85–98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By A Muhairini, M Eggers, J Smith, H Baxter

Detailed geochemical analysis of cored and non-cored drill hole data was used to characterise and model the Cenozoic detrital valleys of several deposits within the southern Pilbara region, Western Australia. The purpose of this modelling was to better characterise and understand the relationships between the various geotechnical units comprising mixtures of rock and soil for the purposes of slope stability and depressurisation studies.This paper presents data from several valleys where geological, geomorphological and climatic processes have resulted in the deposition of heterogeneous detrital rock and soil sequences. Seven primary detrital units are recognised as occurring within all the valleys studied, suggesting that the geological processes involved in the erosion and deposition of the units were widespread. Geochemical assessment of cored and non-cored data suggests correlatable geochemical signatures can be recognised for each of the units; however, local variability in the groundwater history of individual valleys is demonstrated by late-stage carbonate precipitation recognised both in the core and through the geochemical signatures, which has resulted in alteration of the parent rock/soil material. This paper discusses how the carbonate alteration may lead to improvements in rock/soil mass strength of a clay unit by comparing laboratory strength test samples of the same parent material with varying degrees of precipitate alteration to those with no discernible carbonate alteration. Following from this, correlations with geochemical assay results have been derived, whereby zones of more favourable strength conditions may be modelled through assessing areas of analogous geochemistry.The paper demonstrates how geochemical assessment can lead to improved geotechnical and hydrological modelling for a detrital valley system without the need for significant coring and laboratory testing. This in turn leads to improved confidence in the slope design and depressurisation recommendations for a slope.CITATION:Baxter, H, Eggers, M, Muhairini, A and Smith, J, 2015. The effect of carbonate alteration on detrital mass strength and implications for geotechnical slope design, in Proceedings Iron Ore 2015, pp 429–436 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By S Liu, N M. Rana, A Take, N Ghahramani, D Clohan, S McDougall, S G. Evans, H J. Chen

Tailings dam breaches have caused significant life loss, social, economic and environmental damage in recent years. The term "tailings-flow" refers to various forms of tailings outflow movement resulting from the breach of a tailings dam. These flows, comprising a mixture of tailings, water and dam materials, can take different forms, ranging from a debris flood to a flowslide, and can travel long distances and impact large areas. The inundation extents depend on the failure mechanism, tailings dam height, total released volume, sediment concentration (associated with the rheological behaviour of the flow) and downstream conditions (including topography, land cover and presence of a water body). Numerical runout modelling of tailings dam breaches is important for predicting the dynamics and extent of tailings-flows, which are crucial steps in tailings dam consequence analysis and risk management. This paper presents a comparison of numerical simulations of the 1994 Merriespruit tailings dam breach using three numerical models: DAN3D, FLO-2D and MADflow3D. Using compiled site condition information and data from the literature and public domain, model performance was evaluated primarily based on comparisons between the observed and simulated inundation extents. The main purpose of this preliminary model benchmarking exercise was to help us evaluate the capabilities and limitations of each model, and to identify opportunities for future model improvements as part of a broader research initiative known as CanBreach. This exercise also highlights the inherent complexity of tailings-flows and the importance of using judgement to interpret model input and results.

Jul 1, 2021

By Ellson I. G

Advantage has been taken of the need to build the new mining town of Shay Gap to incorporate a new standard of living in an isolated area, which suffers from climatic extremes. The various problems associated with living in the Pilbara area of Western Australia are outlined, together with their effect on the design of Shay Gap.

Jan 1, 1973

By Baohm C, Barker T

There have been significant changes in the Australian mineral sands industry in recent years due to changing supply and demand conditions, new product opportunities and opportunities for rationalisation of operations. Earnings within the industry have typically been volatile and this has been reflected in the share prices of listed mineral sands companies. Apart from the effects of variations in the state of the economy on the industry, share prices have also reflected the extent to which a company's earnings volatility is due to capital structure, the relative proportion of fixed costs to total costs and the nature of th'- sales mechanism. At the time of writing, the high prevailing share prices for industry participants and the current outlook for the industry would suggest that the time is opportune for raising equity capital. The immediate outlook for the industry and its various product segments appears favourable but beyond this the usual uncertainties remain. The new tax environment will cause most companies in the industry to have to rethink their dividend and capital structure policies. Most shareholders will now be concerned to maximize dividend receipts and minimise exposure to capital gains tax. Companies in the industry that have relied fairly strongly on earnings retention to help finance growth in the past will- need to look to increased equity raisings in the Future.

Jan 1, 1986

The traditional form of project financing for resource related projects has involved project financings structured with either recourse to the project sponsor(s) or commercial banks accepting the project's risks, usually after project completion, subject to, inter alia, the nature of the project, geographical location, quality of the projected cash flows and commodity price outlook. However, the concept of commodity-linked borrowings hasadded a new dimension for borrowing opportunities for resource-oriented projects and or companies.

Jan 1, 1985

By M L, G Maddocks, A Ferrier, ers, A Forbes

Evolution’s Mount Rawdon Operation (MRO) produces gold and silver through open pit mining methods. The mining operations are scheduled to be completed in FY24 (Financial Year 2024), after which low-grade stockpiles will be processed until the end of FY27. As part of MRO’s Progressive Rehabilitation and Closure Plan (PRCP), RGS Environmental Consultants (RGS) and Deswik were engaged to develop the final landform surface and a whole of site probabilistic water balance/water quality (WB/WQ) model to evaluate the viability of several closure options with respect to water quality in the various site water storages, particularly the final void which will form a pit lake. This case study details the closure option which included (amongst other things) covering the final landforms and directing water toward or away from the final void post closure. Closure and rehabilitation for MRO had previously been planned and evaluated on a ‘domain’ basis. Furthermore, the rehabilitation plans and final water management plans for the Tailings Storage Facility (TSF), Waste Rock Storage Facility (WRSF) and other domains were not coordinated, possibly resulting in competitive rehabilitation material requirements at the commencement of closure activities. An assumption was that a legacy non-acid forming (NAF) stockpile would provide sufficient material to both supplement ex-pit material for the construction of the TSF embankment raises and to complete all closure activities, but the volumes available and the volumes required to complete the closure activities had not been quantified.

Aug 2, 2023

It is a great privilege to be invited to give this address at this centenary conference. A centenary is a time for recollection, for celebration and for looking ahead. The AusIMM has much to celebrate and many things to recall. I hope in this address to make some useful comments about Australia's future (and mindful of but not forgetting New Zealand), looking ahead for 25 years or so, and the mining industry's role in that future.

Jan 1, 1993

By S Li, Y Lei, X Wu, C Ma, W Q. Zhang

The failure of roof of thin bedrock working face under loose aquifer in a coalmine can lead to water-sand inrush disaster. Based on the accident of water-sand inrush in 30108 working face of a mine in Shaanxi province, China, the mechanism of water-sand inrush is theoretically analysed. The process and critical conditions of water-sand inrush in working face are reproduced by numerical simulation where the bedrock thickness is 20 m, the clay layer thickness is 40 m and the mining height is 6.5 m. The study found that under the condition of thin bedrock and thick clay layer, the characteristics of the clay layer have a significant inhibitory effect on the development of the fractured zone, and the development of the water-conducting fractured zone is incomplete and insufficient. However, in the process of continuous mining of multiple adjacent working faces, the strength of the clay is gradually reduced by the influence of mining and the erosion of water, and the height of the fractured zone is gradually increased. In the subsequent mining process of the working face, the roof is more likely to be cut-off and lead to water-sand inrush. From the initial failure of the clay to the final crack directly through the surface, the shear strength of the clay is reduced by about 52 per cent. Further simulation found that in addition to the characteristics of the clay layer itself, the main factors affecting the water-sand inrush in the working face caused by overburden failure also include the difference in bedrock thickness and strength, and the difference in coal seam mining height. With the increase of bedrock thickness, the development height of the fractured zone increases gradually with increases of bedrock thickness when the cutting failure of overburden rock no longer occurs. With the increase of mining height, the height of water flowing fractured zone also increases, but the cracking ratio gradually decreases. Therefore, it’s of great practical significance to systematically study the mechanism and critical conditions of water and sand inrush in mines and the main influencing factors for preventing similar accidents in mines with similar conditions.

Nov 29, 2022

The paper will review the fundamental policy issues and options that have been considered in the determination of the proposed allocation and pricing (ie royalty) regime for minerals under the Crown Minerals Act 1991. It will consider such influences on the new disposal, allocation, pricing and management arrangements for the Crown's mineral estate as the existence of prior ownership claims, exclusivity in access, the requirement for cost recovery and the treatment of contingent liabilities.

Jan 1, 1993

By D Kubik, K The

The New Zealand (NZ) Transport Agency’s Waterview Connection will complete Auckland’s Western Ring Route, a 47 km north–south motorway alternative to Stage Highway 1. The project is being delivered by the Well-Connected Alliance comprising the New Zealand Transport Agency (NZTA), Fletcher Construction, McConnell Dowell Constructors, Obayashi Corporation, Parsons Brinckerhoff NZ, Beca Infrastructure and Tonkin & Taylor.The project involves construction of 5 km of new motorway, nearly half of it underground connecting State Highway 20 (SH20) to State Highway 16 (SH16). The underground portion of the project incorporates twin 13.2 m inside diameter (ID) tunnels 2.4 km long, each carrying three traffic lanes, one for north-bound traffic and one for south-bound traffic. The tunnels are being driven by a 14.46 m outside diameter (OD) 2400 t, tunnel boring machine (TBM) shield that was assembled and launched at the southern portal. It will be turned and re-launched at the northern portal for the return drive to the southern portal where it will be disassembled. This paper presents two major temporary works elements contributing to the successful launch of the TBM: the TBM assembly crane platform and the TBM shove frame and associated components.Tunnel boring machine shield assembly – crane platformThe TBM shield was delivered to site in subassemblies ranging in weight from 100 to 380 t. It was initially proposed to use a 750 t crawler crane sitting above the tunnel portal headwall to assemble and disassemble the TBM. However, this did not have sufficient capacity to allow the TBM shield to advance clear of the tunnel before disassembly commences. To reduce the crane’s working radius a temporary steel crane platform was developed that is supported on the side walls of the tunnel approach trench. This has enabled a smaller, less expensive, 600 t crawler crane to be used and will allow the TBM shield to clear the tunnel before disassembly.Tunnel boring machine launch – temporary worksTo launch the TBM a purpose built steel frame was required for the TBM thrust rams to react against. The shove frame had to be able to transfer the thrust loads from the TBM shield to the ground below and thrust wall behind. A range of potential thrust loads and jacking patterns were examined to develop the design load cases for the shove frame. The shove frame was used to launch the TBM at the southern portal and to re-launch it at the northern portal. Elements of the shove frame will also be used to support the portal faces during the TBM arrivals.CITATION:Kubik, D and The, K, 2014. Waterview Connection – temporary works for tunnel boring machine?launching, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 281–288 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

Over the past 5 years, Bougainville Copper Limited has undertaken a number of major plant expansions to the copper concen- trate production plant at Bougainville in the North Solomons Province of Papua New Guinea. These projects have scheduled three additional ball mills, three new banks of Outokumpu flotation cells, four additional tertiary screens, two additional tertiary crushers, and more recently four high capacity 24.5m dia. tailing thickeners. The value of the five separate projects totalled more than A$100 million. A requirement of commissioning and bringing on line of each of these projects has been to minimise both operational losses and copper concentrate production. The commissioning has been successfully implemented by detailed planning of the commissioning work in conjunction with the plant operation. Planning has been detailed for each man involved on an hourly basis, highlighting the work required on each commissioning task that is to be undertaken and the time expected to achieve activity Completion.

Jan 1, 1986

My paper presents a discussion of the legislative and departmental requirements in connection with the acquisition of exploration rights for minerals (other than petroleum and coal) in the Independant State of Papua New Guinea, the Solomon Islands and Queensland and he practical problems associated with land entry and land ownership associated therewith. In general there are many similarities in the methodology and philosophy behind the legislation in each country and the contractual requirements established thereby between the exploration company (the explorer) and the government and the mines department or equivalent in each place. There are also a number of differences. I have prepared the paper on the basis that my audience will largely consist of -experienced explorers and the paper is intended to act as a brief refresher and a guide to the philosophy and the practicalities behind the legislation and practices in ground entry in each case. I will deal in turn with New Guinea, the Solomon Islands and then Queensland.

Jan 1, 1987

By Hegedus M

The Hydrogeological Survay of the bauxite mines in Hungary was establisned 30 years ago. The goal of the HS has been to collect the all available date needed to solve the hydrogeological problems of bauxite mines. The results of activity of the HS have been summarized in the annual reports-. This report is going to present a few methods to evaluate the hydrogeological properties of fissured, karstic rock ie. the evaluation of drilling mud losses, the statistics of core samples evaluated by a special computer program for calculation the porosity and permeability of the rocks. An experimental injection test is presented together with the development of a new portable instrument to get signes of the water table change during the injection test in every two second. It can be proved that the flow around the well may be a transient one if the yield of the injection exceeds a definite one (Figure 2.). It was observed that the permeability calculated from the pumping test date may be 1.2-1.6 time higher than it coming from the injection test. A practical example is presented also how to use the results of the HS for designing the dewatering of a new mine together with an analogous computer model to forecast the yield expectable for making the drift tunnel. A suggestion based on the hydrogeological feature has been done for the dewatering without using electric energy (see Figure 3.-6.).

Jan 1, 1988

By A Jha, R Merz

The substantial growth in world demand for Queensland coking coal has seen a number of new coal mine developments in the Bowen Basin in recent times. The Bowen-Broken Water Supply Scheme (BBWSS) is presently based on water supplied from Eungella Dam and storages at Collinsville to two major pipelines. In early 2004, three successive years of well-below average rainfall had left Eungella Dam at critical levels, threatening the regionÆs mines, which rely on it for their essential water supply. SunWater noted that without significant inflows into Eungella Dam, or the development of a new water supply to the region, existing mines would be severely restricted in water supply, and downstream economic impacts to the region would follow. SunWater investigated the opportunities for additional supply capabilities, including combinations of off-stream storages, additional pipelines, and raising Eungella Dam. An off-stream storage (OSS) was selected as being the preferred option to improve the reliability of the system and head off impending falls in announced allocation for the system. The integrated quantity quality model (IQQM) is the Queensland GovernmentÆs preferred model to define and assess total catchment performance against water security and environmental objectives. Modelling of the performance of the water supply system, with and without the proposed OSS, was required to provide justification to the customers of the system that the OSS was in fact required, and also to optimise the configuration of the OSS within time and budgetary constraints. In the case of the BBWSS, no environmental base flows are dictated by the Department of Natural Resources, Mines and Water (NRM&W) at present and the primary reason for applying IQQM was therefore to investigate the trade-offs between supply options and reliability. SunWater produced IQQM outputs for a range of scenarios for the proposed off-stream storage, and these IQQM outputs were then used as input to a decision-support tool based on the GoldSim modelling package. The GoldSim model was then applied to investigate the water supply reliability for high priority users resulting from various existing and/or proposed water supply infrastructure configurations coupled to the hydrologic system. The GoldSim model included the ability to assess the long-term water supply reliability impacts for each of the water supply end-users for a wide range of user-defined scenarios. Non-technical model users were able to change the size of the off-stream storage, pipeline capacities and assumed climatic conditions and test for themselves the relative benefits (in terms of water supply reliability) of different infrastructure configurations under consideration. The decision tool was of significant benefit in assisting the decision process to SunWaterÆs mining customers. These customers needed to decide if they felt that the increased reliability in their water supplies from the system that would be created warranted the estimated increased charges that would require to be levied to recover costs of the new infrastructure with appropriate profit margins. The conjunctive use of IQQM and GoldSim was successful in demonstrating the impact of both hydrological and non-hydrological issues on the future water supply reliability in the BBWSS and resulted in a decision to proceed with the construction of a new OSS.

Jan 1, 2006

The information age has arrived. In every aspect of life, at the end of the second millennium, computers and information technology have made significant inroads. In mining there has been huge growth in the use of digitally controlled systems. From resource evaluation to mine planning to daily operations, information is being acquired, analysed, modeled and presented, using state-of-the-art information technology. Explosives, too, have moved into the information age. Computer controlled trucks and manufacturing plants have been developed and are now a regular feature on many mine benches. The next challenge for the explosives industry as a whole is to integrate blast initiation with information technology. The benefits are there, both to the supplier and to the end-user. Much has been written in the past about the potential for blast improvement but there are other significant advantages to a digital initiation system. These include security from unauthorised use, stock control and minimisation, reliability through testability and ease of use to name a few. So why is it taking so long? Surely the complexity of an electronic initiation system is far less than that of mobile phones that have been around for a long time. The answer, it seems, lies in the level of new technologies that need to be developed. There are enormous technological hurdles to be overcome in order to put into the market a cost-effective, reliable, user-friendly electronic initiation system. The most significant of these are:Safely and reliably initiating an explosive from an electronic device powered by a small capacitor. Prior to the development of electronic detonators primary initiation of explosives was by shock tube spit or by passing large currents and voltages down a pair of wires. Electronic detonators do not have that luxury. For example the energy stored in a æBeethovenÆ exploder is more than 500 times greater than that available to an electronic detonator. Communicating to a multitude of devices over very long cables installed by miners in harsh conditions. The deployment of an electronic detonator system has been likened to building a large telephone exchange in the rain and getting it to work perfectly first time! New communications protocols needed to be developed and tested. Wiring and connection systems have to be designed to survive the mining environment. In spite of these technological hurdles most of the major explosives manufacturers have persisted with electronic initiation systems and we are now, in 1999, starting to see the results of these multi-million dollar efforts. At SMI we are often asked many questions about this technology. The remainder of this paper seeks to answer those most often asked. As with any business linked to information technology todayÆs breaking news is tomorrowÆs archive and we expect the rate of development and understanding to accelerate as these technologies become accepted by the global mining industry.

Jan 1, 1999

The proponents of new mining projects always run the risk that their project is deemed to be not in the public interest. Nothing to be done here except to try and pick it earlyùit is, after all, the approvals process that is supposed to screen such projects out. But there is a second risk, about which much can be done: that inadequate or untimely information confuses the formal assessment of a project and the political context within which the decision is ultimately made. This is environmental impact assessment (EIA) process risk and it has become steadily greater in a changing world, where: miners have lost clout; public trust in institutions has declined; governments follow, as authority pyramids give way to spheres of influence; NGOs are asking the questions people want answered; and stakeholders have become the reference point. This new world deals harshly with yesterdayÆs methods. But it needs to be understood if principles and methods for managing EIA Process Risk are to be advanced.

Jan 1, 2003

By P Sutton

The global goal of Sustainable Development is not achievable without major changes in the way goods and services are delivered and material needs are satisfied, which requires tremendous innovation in the supply chains and life cycles in which minerals and energy processing take part. Values derived from minerals and metals processing need to be delivered with a fraction of current ecological impacts, which means removing technical obstacles to eliminating waste and emissions in the minerals cycle. The challenge is to find economically attractive ways to get there, through eco-efficiency gains in existing operations, capturing regional synergies, streamlining and greening the materials supply chain, and commercialising new process technology and new products. This paper summarises the outcomes of the Sustainable Resource Processing project, which was designed to provide a strategic analysis of what sustainability means for minerals and metals processing and how that can be effectively translated into technical and business innovation.

Jan 1, 2002

The increasing introduction of high capacity mechanical equipment into the coal mines of New South Wales following. tforld War II brought with it problems of roof support. Rapidly advancing headings in difficult country could not be supported with heavy, close,timbering due to the time involved in installation and the reduction of available' space for the movement of machines. _ The installation of low cost, space saving, rapidly installed roof supports became a necessity if the new mechanical equipment wa-s to be allowed to operate at maximum efficiency. As, a result of experience in the United States of America, the system of roof support using steel reinforcing bolts began to find increasing, popularity in the mechanised mines in this State. From the somewhat'crude methods of in- stallation adopted in some of the, early trials, the practice of roof bolting has advanced into a-highly technical operation, requiring care and skill to ensure optimum results.

Jan 1, 1971

The Charters Towers 1:250 000 Gravity Data Set represents a new initiative of the Department of Resource Industries (DRI, formerly Queensland Department of Mines) to provide high quality regional gravity data over areas of the State that have high potential for new mineral discoveries. The Department has adopted a strategy to upgrade geophysical data to complement the ongoing Regional Geological Mapping Program (RGMP) of this Department and in areas where the data would be of most benefit to the mineral exploration industry. Part of this strategy is to ensure that these data are released within 6 months of data collection.The 1989 Charters Towers survey was completed as a joint project with the Bureau of Mineral Resources, Geology and Geophysics (BMR), and is the first regional geophysical data acquisition project undertaken by the DRI. Prior to this survey, the only gravity data in this area dates from the B MR regional surveys carried out between 1960 and 1967.

Jan 1, 1990