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By K Ehrig, V Liebezeit, E Macmillan

The results from metallurgical test programs are used in feasibility studies for design of new plants and brownfield expansions, in long term mine plans, and to make decisions in an operating plant. There are many elements which contribute to a well-constructed test work program. Ultimately, understanding the accuracy and precision of the test work results is critical to ensuring good decision-making at various phases of a project.Every resource drilling and associated assaying program will have a quality assurance / quality control (QA/QC) component, however this often seems to be overlooked in metallurgical testing programs. The principles of “international standard” or “certified reference material” samples and replicate/duplicate testing can be applied to metallurgical programs, although there are metallurgical-specific considerations in both generating and analysing the data.This paper will describe the QA/QC program carried out within the Olympic Dam geometallurgy program. It will present results in the form of case studies from ten years of testing of replicates and bulk reference samples for industry-standard comminution tests as well as laboratory flotation and leaching tests. The Olympic Dam geometallurgy quality control program has enabled quantification of the precision of metallurgical testing and improved our understanding of the best possible modelling results given the underlying dataCITATION:Ehrig, K, Liebezeit, V and Macmillan, E, 2017. Metallurgical QA/QC – who needs it? The Olympic Dam experience, in Proceedings MetPlant 2017, pp 31–44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

The Youga gold mine in Burkina Faso, West Africa, is scheduled to produce first gold in the third quarter of calendar 2007. The project is expected to produce 540 000 oz of gold over 6.5 years, from a conventional open pit carbon in leach mine. The direct capital cost of the project is US$47 M. Etruscan Resources Inc, a Canadian based gold exploration and development company, holds 90 per cent of the project company Burkina Mining Company SA (BMC). The state of Burkina Faso is free-carried for the remaining ten per cent of BMC. RMB Resources Limited, of Melbourne Australia, has arranged a US$35 M project finance facility for BMC (the Borrower) as the majority of funding for the Youga project development. The loan facility was provided by RMB Australia Holdings and Macquarie Bank Ltd (the Lenders) each as to 50 per cent in the lending syndicate. The Lenders also provided a gold hedging facility to guarantee a minimum price for the projectÆs gold production. Burkina Faso is a francophone country, part of the Economic and Monetary Union of West Africa (UEMOA). The project financing is the first such facility to be arranged for a mining project in Burkina Faso, with little or no precedent available in other UEMOA countries. Therefore, while the Youga gold project is forecast to be a robust project applying conventional mining and processing methods, a number of legal, technical, commercial and social issues required identification, evaluation and resolution before the loan could be established. This paper describes that evaluation process and the resolution of these issues. In-house experience and expertise in both the LendersÆ and BorrowerÆs teams has facilitated a greater understanding and æownershipÆ of the issues and hence provided comfort with risks which might not normally be taken in conventional project developments and project financings. As a result, blanket external reviews were not required by the Lenders. A long-standing relationship between Etruscan and RMB Resources also facilitated solutions to a number of issues. Nevertheless, a degree of flexibility by the Lenders, the Borrower and Etruscan was required to successfully close the financing.

Jan 1, 2007

By A He, J Li, J Pan, J Clout

The removal of sulfur from SO2 containing flue gas is improved by adsorbing SO2 into solution with manganese ions as catalyser, however, burnt lime slurry has to be added to modify solution pH and the CaSO3 by-product is of low economic value. In this paper a novel one step process for simultaneous manganese leaching-desulfurisation of flue gas is presented. An investigation of the effect of process parameters included flow rate and SO2 concentration in flue gas, adsorbing time, solution to solid mass ratio, leaching time, and their impact on the oxidation and removal of SO2 from flue gas. The catalysing mechanism of manganese ions on the oxidation and SO2 removal was demonstrated by calculation of the species originating from manganese ions and SO2 in the solution according to solution chemistry. SO2 removal in the adsorbing solution took place at pH 5 - 6, where manganese ions dominantly occurred as Mn2+, and the chain reactions for oxidation of SO2 starting from HSO3- were improved by the presence of Mn2+. SO2 bearing flue gas was effectively desulfurised by leaching rhodochrosite (MnCO3), with desulfurisation of the flue gas and modifying the solution pH being achieved simultaneously, and MnSO4 of high economic value recovered from the leachate. 85 per cent manganese leaching and over 70 per cent desulfurisation of the SO2-bearing flue gas were achieved with only one adsorption stage under optimum conditions.

Jan 1, 2004

By D L. Reid, G Nwaila, J Petersen, J-P Franzidis, Y Ghorbani, M Becker, F C. de Beer, L C. Bam

Traditional methods of gold extraction have involved comminution and processing via cyanide leaching, all of which are associated with energy, cost and environmental implications. Subsequently, numerous opportunities for improvement and optimisation strategies in gold mining and processing have been explored, including heap leaching, which has significantly lowered comminution costs. This paper explores the effect of the more energy efficient high-pressure grinding rolls (HPGR) on the comminution behaviour (especially on the crack density) and cyanide leaching performance of laboratory reactors study on run-of-mine gold ore comprising the Ventersdorp Contact Reef (VCR) and the Elsburg Reefs (ER), sourced from Carletonville in the Witwatersrand Basin in South Africa. The ore was comminuted using HPGR at three different pressure settings (120, 90 and 60 bar). Large (-16/+11.2 mm) and small (-5.6/+4 mm) particles of the HPGR product where then mineralogically characterised using optical microscopy, quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) and X-ray computer tomography (CT) before cyanidation. The results of the leach experiments indicated a correlation between gold extraction, particle size and crack density. Mineralogical characterisation of the ore indicates that the Fe-sulfides present in the VCR are likely to be more reactive than those in the ER, thus having a more favourable influence on gold cyanidation. Overall, the results show promise for the heap leaching of Witwatersrand gold ores prepared using HPGR and demonstrate the value of a multi-disciplinary geometallurgical approach.CITATION:Nwaila, G, Becker, M, Ghorbani, Y, Petersen, J, Reid, D L, Bam, L C, de Beer, F C and Franzidis, J-P, 2013. Morro do Ouro geological model with a metallurgical view, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 75-84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

This paper describes the development of an approach to sustainable development for application at the feasibility study stage for a proposed bauxite mine near the community of Aurukun, south of Weipa on the western coast of Cape York Peninsula, Queensland, Australia. The general environment for development was complex in all dimensions. In particular, the socio-demographic profile of the Aurukun community (population 1200) characterised it as being amongst the most disadvantaged communities in Australia. The traditional owners of the area, the Wik and Wik-Way people, were at the forefront in the efforts of Indigenous people in Australia to secure land rights over the past 30 years, and they had previous experience negotiating an Indigenous Land Use Agreement (the Western Cape Communities Coexistence Agreement) with Rio Tinto Alcan, the operators of the Weipa bauxite mine. Through this they had shown a well-founded sense of entitlement with respect to the development of resources on their traditional land. The Queensland State Government had recently cancelled an existing mining lease over the bauxite resource as the holder of the tenement had not fulfilled the terms of a development agreement that had been in place for 30 years. The Government was anxious to avoid any future æbankingÆ of the resource, and had decided to offer tenure to the resource on an international competitive basis, subject to the requirements of the Commonwealth Native Title Act 1993. This would require a negotiation process with traditional owners and potentially involve companies with whom the traditional owners had no existing relationship (typically developed during the projectÆs exploration phase) and who possibly had no project development experience in Australia. As well, the State Government envisaged an approach to development that drew on the significant work that industry and other stakeholders had undertaken over the previous ten to 15 years, commencing with the mining, minerals and sustainable development (MMSD) process. This work was aimed at rectifying acknowledged deficiencies with industry recognition of stakeholder interests, in particular with respect to environmental management and socioeconomic development. The approach adopted aimed to define the strategic community interests and sustainable development outcomes to which the development of the resource would be expected to contribute, and to embody these within an easily usable management structure that could be applied to each stage of project development from feasibility study through to mine closure. The logical framework (AusAID, 2006; ICMM, 2005) was the management tool utilised to order the identified interests and desired outcomes. The structure included components aligned with the key areas of development interest expressed by the community, and the initial baseline sustainable development plan (SDP) developed established component objectives, outcomes, indicative outputs and activities for the feasibility stage of the project. This established an objective framework to guide potential bidders when developing their response to the State GovernmentÆs Request for Proposal. The paper will describe the evolution of the competitive process and the parallel process for development of the SDP. While the institutional environment was politically and socially complex, the use of simple visual representations of the environment and the analysis and ordering of issues, objectives and criteria through methods such as stakeholder analysis and the logical framework approach, enable the development of a dialogue on the contribution that the development of a mining project can make to sustainable community development, and for the development of an agreed program of community support to capture the contribution. The use of the logical framework was found to have good functionality for plan development. Achieving plan outcomes though, is highly dependent on the skill of key project personnel in facilitation, team building, conflict resolution and leadership, as well as their ability to influence the behaviour of key stakeholders with the capacity and authority to require the integration of local economic development criteria in to key project development decisions.

Jan 1, 2009

By J Caron, M Athayde, F Lavoie, R Joyce

Decarbonisation has become a major challenge for the global steelmaking industry, turning towards new technologies aimed at carbon footprint reduction, which on its own accounts for approximately 9 per cent global emissions. The iron and steel industry represents a ‘hard to abate’ sector, where much of efforts are currently being deployed into initiatives aiming to decarbonise the ironmaking through the use of green hydrogen, carbon capture utilisation and storage and state-of-the-art operation of current technologies, while little efforts being deployed to find carbon-efficient solution to iron ore burden preparation, where high-grade iron concentrate will increase in importance to ironmaking regardless of the chosen reduction route. Quebec Iron Ore (QIO), a subsidiary of Champion Iron Limited (Champion), produces high-grade hematite concentrate with one of the lowest carbon global footprints. Still, QIO is partnering with its clients to the development of burden solutions to minimise CO2 emission, in the seek for a decarbonised steel. In a strong technological partnership, Binding Solutions Limited (BSL) has developed a novel, coldbinding technology to provide a cleaner, more cost-effective alternative to induration. The technology allows miners and steel producers to reduce Capex significantly and reduce energy consumption and CO2 emissions by 90 per cent. QIO and BSL have partnered to adapt the disruptive cold binding technology developed by BSL to QIO’s concentrate to produce a high-quality low emissions iron ore agglomerate. This paper describes the efforts taken to further develop BSL’s cold binding technology and its application to QIO’s high-grade iron ore concentrate to produce a hematite cold bonded briquette (hCBB) showing comparable performances with high quality seaborne fired pellets.

Nov 8, 2021

By C Munro, S Emery, M Flynn, K Tan

"AEROPHINE® 3418A Promoter is a well-known and widely used collector and is an industry standard for its excellent selectivity and efficacy in the processing of complex polymetallic sulfide ores, particularly those containing silver. Until now, however, it has not found widespread use in primary nickel flotation.In an effort to increase nickel recovery without compromising selectivity over iron sulfides, Western Areas Forrestania Nickel operation trialled the use of AEROPHINE® 3418A as a secondary collector at low dosage. A series of ON/OFF trials were conducted, with the finding that a very low dose of AEROPHINE® 3418A increased nickel recovery by 0.6 per cent compared to using xanthate alone.This paper provides a brief operational history and overview of the Forrestania operations, a description of the trial and an analysis of the results.Citation:Emery, S, Flynn, M, Tan, K and Munro, C, 2016. Aerophine® 3418A Promoter as a Secondary Collector to Boost Nickel Recovery at Forrestania Nickel Operations, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 145–148 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

Historically the insurance industryÆs involvement in any project has been relatively late in the process. Often it was a case of the last item to be ticked off the checklist has been to ensure that the insurance is in place. However, in more recent times insurers have imposed more restrictions on the cover they are prepared to provide, which has in some cases necessitated a change in the contracting structure to accommodate the insurance policy(ies). In addition, changing contractual practices have changed the allocation of risk between the various parties involved. This calls for a more proactive approach to the design and implementation of an insurance program for both the construction and operational phases of any resource project. This paper explores how a risk managed approach to the design and implementation of an insurance program for a resource project can align itself with current management approaches to project development. From the authorsÆ experience, this approach is best adopted early on in the project (often in conjunction with the bankable feasibility study) and follows AZ/NZS4360 to objectively examine and compare a wide range of risk exposures of the project in a time-effective manner across the following areas: personnel; environment; general management; compliance û legislation, systems, protocols; asset management; change management; financial impacts to the organisation; products/services; service delivery; and technology. Having identified and then analysed the risk exposures according to common consequence and likelihood ratings the next step is to develop a risk map of all considered exposures. The true value of this approach lies in the development and implementation of a risk treatment plan for identified exposures where the exposure is unacceptable. The plans will lead to the optimal solution to the appropriate risk prevention, risk mitigation and risk transfer options available. This paper also examines other benefits to the project that may arise from adopting a risk managed approach in addition to the ability to design an insurance program which recognises the exposures and the ability of the organisation (and other project parties) to retain risk.

Jan 1, 2007

By T Napier-Munn, E Louwrens, L Keeney

Geometallurgical characterisation of ore deposits is accepted practice in some parts of the mining industry today. Its primary aim is to provide constrained inputs that reflect inherent geological variability and its impact on metallurgical performance for the deposit. Geometallurgy improves project value because it suggests more valuable alternatives for scheduling and processing through an increased knowledge and understanding of the interactions of rock properties and extractive technologies. Lower project cost (both capital and processing) and improved recoveries are the result from closer tailoring of the mining and mineral processing strategies to the characteristics of the resource (Dunham, Vann and Coward, 2011). Tailings storage facilities (TSFs) can be seen as potential resources and it is argued that fundamental geometallurgical characterisation as applied in ore deposit characterisation should also be applied to planning the retreatment of TSFs. This paper will describe a research project at Julius Kruttschnitt Mineral Resource Centre assessing if geometallurgical principles and methodologies can successfully be applied to TSFs as they have been to primary deposits. The project is establishing a new standard method of tailings evaluation which will include a 3D spatial model of the tailings resource. Initial domaining of the TSFs was done using principal component analysis followed by k-means cluster analysis based on chemical assays from drill core samples. The subsequent characterisation of the drill core samples has involved chemical, mineralogical and metallurgical profiling, with a range of metallurgical tests being conducted on the samples. This characterisation step is followed by class-based analysis, predictive modelling and process performance domaining with the ultimate objective of establishing a 3D spatial model incorporating geochemical, mineralogical and metallurgical performance data. This approach, which takes into account processing performance permits a more realistic (as compared to doing limited chemical assays and metallurgical testing) economic evaluation of the potential of reprocessing the tailings material. It is believed that the approach is generic and can be applied to other TSFs being considered for reprocessing. The present case study has also established the gold, copper, magnetite and cobalt deportment for an iron oxide copper-gold deposit tailings resource.CITATION:Louwrens, E, Napier-Munn, T and Keeney, L, 2015. Geometallurgical characterisation of a tailings storage facility – a novel approach, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 125–132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By E N. Sparg, O D. A Deuchar, F Needham

Decline shafts are an attractive option to both new and existing mining operations where there is a need to access an inclined orebody deposit via on-reef development so as to generate a return in the shortest possible time. There are many different technologies that are available to transport men, material and rock in incline shafts. This paper focuses on the applicability of two hoisting technologies for decline shafts, namely endless and direct rope systems. The pros and cons of each system are reviewed. A common concern with direct rope haulage systems is the possibility of generating slack rope during deceleration. This paper illustrates the issues involved in designing a system so as to avoid the possibility of slack rope. In conclusion, the key factors relevant to the selection of endless or direct rope haulages for a particular decline application are reviewed. The paper is a joint submission by FFE Minerals-Vecor and Qualter Hall UK.

Jan 1, 2005

By D Morton, G Wallace

"Evolution Mining is the sole owner of the Mt Rawdon open cut operation, located 75 km south-west of Bundaberg in Queensland, Australia (Figure 1). It is a massive, volcanically hosted, low-grade gold deposit that exhibits excellent characteristics conducive to low cost mining and treatment.In 2014, Mt Rawdon began investigating initiatives to deliver higher mill throughputs without any significant capital expenditure or modifications to the existing processing plant. Various studies have shown throughput increases are possible by applying more blast energy, essentially by reducing feed size through blasting and leaving less work for the comminution circuits (Brent et al, 2013; Ziemski, 2011; Workman and Eloranta, 2003).Given that 53 per cent of energy used on a mine site is consumed by the comminution circuit, with only two per cent being consumed by drill and blast (Smith, 2013), it makes logical sense for a mining operation to align their drill and blast with their processing plant. The term commonly used when exploring this relationship is a ‘Mine to Mill’ program.Over nearly 12 months, various blasting options and Mine to Mill methodologies were tested at Mt Rawdon. Throughout the journey, it was abundantly clear that the Mine to Mill initiative is not as simple as making one technical or physical change and expecting an improvement. Rather, true sustainable improvements demand a paradigm shift across both the mining and processing cultures, where all departments are aligned and working towards the one outcome. This true overarching Mine to Mill mentality, enabled by Vistis™ 250 high energy bulk explosive, ultimately led to a sustained increase in throughput and profitability of the Mt Rawdon operation.Citation:Wallace, G and Morton, D, 2016. High Energy Bulk Explosives and Mine to Mill Focus – the Mt Rawdon Story, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 60–69 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By T Roberts

The transition of mechanical cooling refrigerants from their inception in the 1800s through to the current day has been driven by several factors. Original refrigerants such as sulfur and carbon dioxide, chloromethane and ammonia, whilst effective came with toxicity and/or flammability issues. In 1930 DuPont trademarked a new synthetic refrigerant known as Freon® 12, this development was the introduction of ‘chlorofluorocarbons’ (CFCs).Throughout the 1930s and 1940s additional synthetic refrigerants were developed, namely Freon® 11 and Freon® 22. Due to their non-toxic and non-flammable characteristics, synthetic refrigerants were extensively used for domestic, commercial and industrial applications for the next 60 years.In 1985, one of the first scientific papers suggested a potential mechanism linking CFCs and areduction in the density of the ozone layer. In 1987 the Montreal protocol is ratified; it is the first UN treaty to be ratified by every country on earth. Due to CFC’s ozone depletion potential (ODP), the treaty required the consumption of CFC’s to be reduced by 50 per cent over the next ten years. By 1996 the phase out of CFC’s (Freon® 12) is completed, the phase out of HCFC (Freon® 22) refrigerants comes into effect.On 1 January 2018 the phase down of HFC’s begins. Whilst having zero impact on the ozone layer HFC refrigerants have high global warming potential (GWP). As we transition through the HFC phase down (2018–2035) we are beginning to see the emergence of what some consider to be the fourth synthetic wave, hydrofluoro-olefins (HFO’s). HFO’s and their blends have zero ODP and low GWP’s, ranging from 150 to less than 1. The reduction in GWP with HFO’s typically comes at the expense of flammability, which is not ideal. Each refrigerant has its optimal application, therefor when considering refrigerant choices for mining systems, a complete assessment of the environmental, health and safety, efficiency and commercial impacts should be considered now more than ever.

Oct 12, 2022

By M Flis

The Razorback Iron Ore Project is a high tonnage, low-grade magnetite deposit that defines a new iron ore district in South Australia. Known since the 1960s, the deposit has come into its own as the iron hungry world demands not only larger tonnages, but higher grade and cleaner magnetite concentrate ores that counterbalance the increasingly dirty haematite ores that are coming into production.Razorback is hosted by the Neoproterozoic Braemar Iron Formation, a tillitic unit that is part of the Adelaidean Geosyncline sedimentary sequence. At Razorback, this formation forms the southern limb of the Pualco Syncline, dipping at 42° to the north and outcropping along a prominent ridge. The formation consists of a series of alternating bedded tillitic and interbedded magnetite units that represent cycles of glacial advances and retreats. Seven cycles, resulting in seven stratigraphic members, are recognised. Members B, D, and G are the thickest, at 30 - 70 m each, and are the target of current investigations. While the bedded magnetite has the highest iron content, typically 35 per cent Fe, the tillitic unit, at typically 26 per cent Fe, has similar iron content in the ground mass but is diluted by the inclusion of iron-poor granite and metasedimentary dropstones. The mineralisation forms a simple dipping tabular body with only minor faulting, folding and intrusives. Grades, thickness, dip, and outcropping geometry remain very consistent over kilometres of strike, presenting an excellent mining proposition.Razorback differentiates itself from other Australian magnetite projects in a number of important ways. It is not a banded iron formation (BIF); it will have low crushing and grinding costs; and it is located in an infrastructure-rich area close to open-access, high capacity rail, to a selection of ports and to gas, electricity, labour and engineering services. Royal Resources has announced an Inferred resource of 277 Mt @ 25.9 per cent Fe. The company is targeting a resource of 500 - 1000 Mt to support a 10 Mt per year concentrate production. Davis Tube Recovery work shows that the ore is capable of producing a concentrate of over 68 per cent Fe with very low deleterious elements. Metallurgical testing confi rms the ore is soft, and with near-zero initial stripping ratio the project will have a low opex. With access to existing critical infrastructure, capex will also be low, ensuring Razorback will be a highly competitive iron producer in this emergent mining district.

Jul 11, 2011

By S Doudle

The Iluka Resources Ltd Jacinth-Ambrosia heavy mineral sand mine (South Australia) is located in an undisturbed semi-arid landscape consisting of sparse trees, shrubs and grasses. The soil interspaces are covered with biocrusts, a living soil cover also found worldwide in arid regions. Biocrusts are composed of lichens, cyanobacteria, algae, mosses, liverworts, fungi and bacteria, and live on and within the first few millimetres of the soil surface. Biocrust organisms bind soil particles, sequester carbon and many fix atmospheric nitrogen making them important structural and functional components of ecosystems. Despite their important role in ecological processes, biocrusts are susceptible to disturbance; nevertheless they can recover provided sufficient inoculum is present. Cyanobacteria are the early colonisers and they capture atmospheric and landscape resources and establish conditions that subsequent successional seres can capitalise on. Research conducted in countries including China, Spain and South Africa has been focused on methods to either encourage rapid regeneration of cyanobacterial remnants or to introduce new material from cultured cyanobacteria. We have been investigating the extent and diversity of biocrusts across the 4500 ha mine lease and their potential to improve mining rehabilitation outcomes. Approximately 46 per cent of the soil surfaces are colonised with biocrusts and 33 taxa have been identified. Laboratory experiments were designed to mimic massive soil disturbance and treated with a range of water qualities. Within 22 days, treatments irrigated with fresh water were colonised by new cyanobacterial filaments with a mean surface coverage of 65 per cent. Secondary tests revealed that differences in the photosynthetic yield of the crust were dependent on the salinity levels of the irrigation water used. In 2011 this program is expanding from the laboratory into field scale trials designed to assess both the potential and practicalities of up scaling these techniques to provide crushed biocrusts and cyanobacterial bio-inoculum for use in mine rehabilitation.

Oct 5, 2011

By T Kilpatrick

Managing heat stress on Australian mine sites is a complex and enduring challenge due to the combined and variable contribution of environmental conditions, physical activities, and protective equipment. Inappropriately managed, heat stress can place significant physical strain on workers, leading to serious and chronic health issues. Additionally, excessive heat stress can dramatically reduce productivity, with 30 per cent of workers reporting a loss of productivity due to occupational heat strain. In Australia, due to increased absenteeism and reduced work performance, heat strain is estimated to have an annual economic burden of over $8 billion.

May 5, 2022

By S Gossmann, J Barlow, S Denner

"Unconventional gas resources, including coal seam gas (CSG) reservoirs, can be located above and below aquifers that provide groundwater for agricultural, industrial, urban and other uses. Development of these resources may, therefore, lead to potential impacts on groundwater supply.Management of reservoir/aquifer interconnections necessitates a program of focused data acquisition. For example, groundwater transfer from shallow aquifers to underlying CSG reservoirs may occur where CSG-containing units subcrop beneath shallow aquifers, possibly at significant distances from operating wells.Arrow Energy is undertaking studies of connectivity between aquifers including an investigation in collaboration with the Queensland Office of Groundwater Impact Assessment to evaluate connectivity between the Condamine Alluvium (CA) and CSG-containing Walloon Coal Measures (WCM).The Condamine Valley hosts highly productive agricultural land with groundwater resources heavily utilised for irrigation. Water demand outstrips available supply and groundwater has been subject to restrictions on further development since the early 1970s. Developments that could have an additional impact on groundwater resources in the CA are of major concern to local landholders. This paper describes: planned field investigations at two sites: 1. Stratheden, where pumping from the WCM will be undertaken 2. Daleglade, where pumping from the CA will occur how the data to be collected from field investigations will be used to refine predictions of flux between the CA and the WCM.CITATION:Denner, S, Gossmann, S and Barlow, J, 2013. Planned field investigation of connectivity between the Condamine Alluvium and Walloon Coal Measures, in Proceedings Water in Mining 2013, pp 91-98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By P B. Hills, R J. Walton

Geotechnical instrumentation has been implemented as a key step for monitoring and optimising an engineered mine design for managing seismicity at the Beaconsfield Gold Mine. Measurements of displacement, stress change, ground control element load and seismic response of the rock mass allow for back analysis and calibration of critical parameters for feedback into the engineering design loop. Instrument clusters are installed in strategic locations prior to the commencement of stoping in order to determine the nature of the response of the rock mass to stoping. A selection of instruments including instrumented cable bolts and rod extensometers, resistance wire extensometers, hollow inclusion stress cells, vibrating wire stress meters and resistance wire extensometers are used to gather data through a data logging system. The rate at which data is recorded is adjusted to provide more information during periods of anticipated rapid change such as around stope firings or during periods of high seismic activity, and less information during periods of anticipated quiescence. The twofold purpose of the instrumentation is to calibrate the numerical modelling output which forms the basis of the engineered mine design, and to provide an alert mechanism where the behaviour of the rock mass is not what was anticipated, or where the impact of that behaviour may compromise the integrity of the engineered ground control system. The paper describes the location of instrument clusters with respect to stoping, the type of instruments employed and the method of data acquisition. It provides examples of results obtained and illustrates the way in which that information is used to optimise the mine design and manage seismicity.

Jan 1, 2008

By Jaques A. L, Heinrich C. A

Mt Todd lies towards the south end of the Pine Creek Geosyncline, sandwiched between the Cullen Batholith and the Edith Falls Basin, in an area of regionally metamorphosed sandstones, siltstones and shales. The Batman deposit, some 3 km west of Mt Todd is a sheeted quartz vein system hosted within greywackes of the Palaeoproterozoic Burrell Creek Formation (Finniss River Group). The gold-bearing quartz veins, trending 010¦-020¦ and dipping 60¦-70¦E, are commonly 0.5 to 5 cm wide and occur at intervals which are from 10 cm to 1 m apart. Gold tends to be restricted to the quartz veinlets and immediately adjacent country rock. Grade Control utilises two 4 m 'collar' samples which are collected from each 8 m production blasthole. The irregular distribution of the quartz veins and erratic gold mineralisation has resulted in a disseminated 'salt and pepper' type of gold occurrence, with only a poorly defined footwall. Delineation of ore and waste blocks for mining uses an approach which combines the smoothing effect of kriging with a pragmatic view of the raw data. Large ore blocks with simple geometry help to minimise mining dilution, reduce block variance and give good reconciliations to interpreted ore tonnes and grade. Daily mine face advance is reported against truck counts and provides continual comparison with budgeted production. All data processing uses Gemcom software, together with Lotus spreadsheets.

Jan 1, 1994

The excavation of a tunnel through rock and mixed ground of basalt and silty clays presents a challenge to engineering organisations. Such was the situation facing the Melbourne and Metropolitan Board of Works (MMBW) in constructing the 15.3 km, 5.5m dia. tunnel component of the new Western Trunk Sewerage System. The tunnel geology showed that there were two distinct components to the excavation - rock and mixed ground. By drawing on extensive experience in the use of Tunnel Boring Machines (TBM's) used previously by the MMBW and using techniques developed for predicting TBM per- formance, a comparison of the options of drill and blast versus TBM was made. The conclusion was that TBM methods would provide the best solution to the problem. Tenders were called for the supply of a TBM. A performance specification was used to attract tenders offering designs which re- flected the state of the art on an internation- al level. Particular features required by the MMBW were included in the specification. The excavation planning and operation are described in this paper. The production achieved has shown that the TBM can very adequately handle rock excavation (best weekly production 167.9m). Extreme conditions of mixed ground with heavy groundwater inflows have been handled using an auxiliary thrust system to maintain gripper reaction through the soft ground encountered.

Jan 1, 1987

By Regan R

Appin Colliery mines the Bulli Seam with a gas composition of 98.5% methane and 1.5% carbon dioxide. Relaxation of the strata generally occurs to below the base of the Wongawilli Seam, some 40 m below the Bulli Seam, and approxim- ately 125 m above the Bulli Seam, for longwall face widths of 135 m or more. Previous exper- ience showed that when longwall faces were mined for a distance approximately equal to the face width, the mine ventilation could not provide sufficient dilution due to methane emissions from the underlying measures. Postdraining downholes were drilled to intersect the Wongawilli Seam below the operat- ng longwall. These holes were connected to an underground to surface gas range and various suction levels were applied to improve gas drainage. The resulting gas flow rates and purity from all the downholes were regularly monitored and peak flows in some holes exceeded 160 1/sec. The surface plant drained almost 20 million m3 of gas for the period July 1981 to January 1982 at an average methane purity of approximately 70%. Distinct patterns emerged for different downholes from curves illustrat- ing their variations in flow rate with distance subsequent to passage of the longwall face. The difference between free flow characteristics and those obtained with the application of

Jan 1, 1982