Search Documents

By Weatherhead J, Grounds J

The Nabarlek Uranium Project located in Arnhem Land in the Northern Territory of Australia was a small high-grade deposit which was the first uranium mine brought into operation following the extensive Commissioner Fox Inquiries into uranium mining during the late 1970s. The operation is almost complete and decommissioning plans have been prepared. This paper reviews all phases of the water management and tailings disposal for the project and compares results with design predictions.

Jan 1, 1988

By G Steward

Gravity Leaching of high-grade gravity gold concentrates, such as Knelson Concentrates, with the ACACIA Reactor represents a new generation of concentrate treatment methods. The ACACIA Reactor is a complete packaged plant for the maximising of gold recoveries from gravity gold concentrates. This paper will introduce the process technology and provide process results from the Porgera ACACIA Reactor installation. The advantages of the ACACIA Reactor are many, and justification for installation has been varied. The typical advantages of the process include: increased recovery of gold from the Knelson Concentrate; no return of high-grade table tails, often grading several thousand g/t, into the mill circuit; reduction in tails grades of slow leaching gold; reduction in the requirement for operating staff by the removal of the manual tabling process and replacing with a fully automated treatment system; improved security by removing the tabling step where operating staff come into direct contact with visible gold; improved health and safety, by the removal of the treatment steps for the table concentrate, which often include operators handling corrosive chemicals and the production of sulphur and arsenic compound fumes; and improved metallurgical accounting, by allowing daily head grade calculations. The ACACIA Reactor was developed by Anglogold for Union ReefÆs Gold Plant and has been in production for over two years, and has proven to be a low cost, high recovery, mechanically reliable method for the processing of gold concentrates. Such has been the success of the plant, there are now four full installations of the processing plant, including Anglogold Union ReefÆs, Anglogold Sunrise Dam, PACMIN Carosue Dam and Porgera Joint Venture.

Jan 1, 2002

A research and testing facility has been developed at Simtars to allow the spontaneous combustion testing of coal on a large scale. In this adiabatic reactor, the coal particle sizing is closer to that which could be found in the goaf and therefore the reaction is more likely to simulate the underground situation. This allows aspects of the spontaneous combustion process and methods for detecting a heating to be investigated which cannot be done in an operational mine. Up to 18 tonnes of run of mine or crushed coal is loaded into the reactor and allowed to self-heat while the temperature and gas profiles within the coal pile are monitored. The gases evolved from the coal are analysed using a fixed gas monitor system and gas chromatography to determine which of the common mine fire indicators and ratios can be used to predict the onset and progress of coal heatings. Benchmarking of the inherent propensity of a coal to spontaneously combust at both the large- and laboratory-scale is also possible by comparing the sample against previously tested samples. It has been found that the coal particle size affects both the time it takes for the coal to react and the location of the developing heating. The heatings generate approximately one metre from the inlet but in the crushed coal case do not progress to an advanced heating stage until the æhot spotÆ migrates towards the coal surface where there is an increased oxygen supply. Physical properties such as the compressive strength of the coal also affect the heating size and the time it takes for a heating to develop. Higher strength coals appear to oxidise more slowly and therefore take longer to self-heat as oxidation of the coal is the heat-generating step in the spontaneous combustion process. The best indicators of the state of the heating were found to be CO make and GrahamÆs ratio which are independent of air flow. Investigation of a potential spontaneous combustion should begin as soon as the CO make or GrahamÆs ratio exceed the background levels. The results from the tests undertaken on a number of Queensland and NSW coals are reported here together with the implications for the mining industry.

Jan 1, 2005

By Quast K. B

Laboratory batch rod and ball milling tests were conducted on samples of Heavy Medium Separator (HMS) sinks from Renison Tin Limited. The product size distributions for this heterogeneous material were very different to similarly sized homogenous material previously reported by the authors. The effects of pulp density on product size distributions were only evident at pulp densities greater than 80 per cent solids. At high solids density, the major weight distribution product peak fell and broadened indicating less efficient breakage, particularly for rod milling. Tin distribution in the ground products was also affected by pUlp density, and there was always less cumulative per cent tin than cumulative per cent weight, ie there was no tendency for cassiterite to slime down to 10/lm.

Jan 1, 1995

By G C. Snedden

Tandem row stator arrangements are common in the last stage of multirow, gas turbine compressors. Tandem row stators, or stator and de-swirler vane combinations are used to relieve the loading on the stator but ensure axial flow leaving the compressor. In this paper a standard 40” (1016 mm) ventilation fan in the Air Blow Fan’s range is modified to utilise the plate support struts on the barrel to relieve the aerodynamic loading on the aerofoil stator. Performance maps for both versions of the fan were generated using computational fluid dynamics and are compared across a wide range of rotor setting angles showing a clear advantage of approximately 2 per cent in efficiency for the tandem blade design. In addition, the area of high efficiency that represents the practically usable area of the map extends over a greater area in terms of flow rate and total pressure rise.

Oct 12, 2022

The incidence of colliery disasters has highlighted the need for more centralised and directed coal mining safety research in Queensland, with particular impetus from explosions at Box Flat in 1972, Kianga in 1975 and Moura No 4 in 1986. Inquiries which identified the likely causes recommended measures and, research and two outcomes have been the present Mines Safety Research Advisory Committee and The Safety in Mines Testing and Research Station at Redbank, near Brisbane, dealing with all mining problems, coal and metalliferous. Already, important research into ignition and explosion and other health and safety matters has been accomplished; the Station has become an accredited testing laboratory; and international recognition has been achieved. Now the advisory, testing and research arms are soundly in place to pursue preventive investigations and be ready to provide assistance in any emergencies.

Jan 1, 1991

By H von Blottnitz, A C. Keith

The influence of the life of a mine extends beyond its immediate vicinity both in geographic and temporal terms. Decisions around mine approvals are generally made based on economics, for the mine owner and immediate environmental and social impacts by governments and communities. The value from life-of-mine planning can also be viewed in a holistic frame across the entire value chain from mine to product user. This research examines the Carmichael Coal Mine in light of the holistic benefits and impacts along its value chain from the mine to relieving the lot of energy poor in India.CITATION:Keith, A C and von Blottnitz, H, 2016. Can Australian coal alleviate energy poverty in India – a case study, in Proceedings Life-of-Mine 2016 Conference , pp 52–56 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By C Mason, A Littleboy

This paper presents the results of a large scale survey of The Australasian Institute for Mining and Metallurgy (AusIMM) membership. This survey aimed to understand and define the key issues and drivers that AusIMM members perceived would shape the development of the Australian minerals industry over the next 20 - 30 years. Nine hundred and fifty-nine participants rated the importance of 11 issues and six drivers (generated from interviews with AusIMM members), and 236 of these participants also provided qualitative descriptions of the future. Issues were defined as problems or opportunities for the minerals industry that may be controlled or influenced by the industry, while drivers were defined as those factors that will influence the direction of the industry that are not within the control of the industry. The quantitative data revealed that the top four issues, in order of their perceived importance to the Australian minerals industry, were: investment in exploration, workforce, health and safety, and innovation. The top three drivers in order of their perceived importance, were: economics of mining, global context and Australian society. While the top four issues were largely consistent across professional groups examined, metallurgy and mineral processing professionals rated water inputs and energy inputs significantly higher than the other professional groups. For the list of drivers, there was strong agreement regarding their ranked order of importance across the professional groups examined. Within the qualitative data, however, a single issue (technology) and a single driver (economics of mining) dominated participantsÆ descriptions of the future. These findings provide important input into a broader program of scenario development for the Australian minerals industry being undertaken by CSIRO and its partners. The results of this study demonstrate the importance of using a mixed methodology in generating these inputs to understand more fully how important stakeholders view the future and the factors that will shape it. The results of this study are also discussed with respect to the role that CSIRO may play in facilitating the exploration of uncertainty around the future of the Australian minerals industry.

Jan 1, 2009

By G F. Brent, S Hawke, M Rothery, P Dare-Bryan

Mine-to-mill studies have previously demonstrated downstream productivity benefits from relatively modest increases in blast energy, or powder factor. These increases have up to now been limited by safety and environmental constraints, since excessive blast energy can result in flyrock, unacceptable vibration, airblast and wall damage.Here, a new blasting method that overcomes these constraints is presented. For the first time it is possible to employ powder factors that are several fold higher than conventional blasting. Independent modelling has shown that such powder factors can potentially increase mill throughput by 20 to 40 per cent. The economic implications are substantial, both in terms of increasing production in existing operations and in consideration of capital and plant requirements for greenfield sites. In addition, mill electricity and grinding media consumption and their associated costs and energy and emissions penalties can be reduced.This method represents a step-change in blasting practices. It involves a novel design utilising dual blast layers within a single blast event, all initiated with state-of-the art electronic blasting systems. The energies in the lower layer can be as high as five times the standard energies, providing for intense fragmentation of the ore. Results from blast models have been confirmed in field trials of the method.Open cut gold mining, in particular, stands to benefit from this method. As gold grades decline, milling costs and throughput increasingly become constraints on production that can be alleviated with this new method. Additionally, it opens possibilities for improved recovery. Blast modelling studies show that dilution of gold ore within the blast can be managed with the new method. Furthermore, it has been shown that vibration from the new method is actually lower than from conventional blasting, allowing the use of the technique in proximity to mine highwalls and other key infrastructure such as underground orepasses.It is concluded that this new method could substantially increase gold mine production and profitability while reducing overall energy consumption and associated emissions.CITATION:Brent, G F, Dare-Bryan, P, Hawke, S and Rothery, M, 2013. Ultra-high-intensity blasting - a new paradigm in mining, in Proceedings World Gold 2013 , pp 395-400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By M S. El Salmawy

In order to develop the HF-free flotation reagent system, the main objective of this investigation was to study the possibility of separation of quartz from feldspar using non-ionic surfactants as the collector. The non-ionic surfactants used were polyoxyethyl cethyl ether (PECE) and polyethylene glycol monocethyl ether (PGME). The flotation behaviour of quartz and microcline with PECE and PGME was investigated. Each surfactant was a good selective collector for quartz with its recovery being influenced by pH and surfactant concentration. Quartz is floated favourably by both types of polyoxyethylene non-ionic surfactant whereas microcline was not so much. The floatability of quartz increases as the oxyethylene length of surfactants increases. Zeta potential measurements in the system of PGME/mineral were also carried out. It was determined that in the absence of PGME the points of zero charge for quartz and microcline should be approximately at pH 2.5 and 1.8, respectively. The addition of PGME to the system causes both minerals to become less negatively charged. Differences in the zeta potential value between quartz and microcline, in the presence of PGME, were detected. It can be suggested that the interaction of the oxyethylene group to the microcline surface should not be as strong as that to the quartz surface. In the mixed surfactant system of PGME and dodecylamine acetate (DAA), a small addition of DAA causes drastic enhancement of quartz flotation in the wide pH range of 1 ~ 10. In the mixed surfactant system selective flotation of quartz from microcline would be anticipated at pH

Jan 1, 2005

By M Scoble, A Ostry, J Shandro

Mining companies are not ill-informed on the topic of community health. There have been a number of research studies that have illuminated community health issues associated with mining, especially in the western Canadian province of British Columbia. However, what is missing amongst the literature is the perspective of mine managers and mining executives on this topic. This is important as mine managers and executives face a number of issues related to community health and are under pressure to consider the topic in more detail. This paper presents results from an exploratory qualitative investigation based on grounded theory research techniques into current community health considerations from the perspectives of mine executives and mine managers working in Western Canada. Interviews were conducted between February and May 2012 with 11 mining versus ten mining executives and managers who represented operating mines or mining umbrella organisations in Western Canada. Participants report on general community health issues that are perceived to be important, the perceived role that the mining sector should play?in contributing to community health and how this differs in Western Canada as compared to locations abroad, and?risks companyÆs face in making community health contributions. This paper concludes by drawing attention to pressing health needs that are present in Northern, rural and Aboriginal populations in Western Canada and provides a platform for future research initiatives focused on improving the health and well-being of communities associated with the mining industry. CITATION:Shandro, J, Scoble, M and Ostry, A, 2012. Community health considerations from mining executives and managers in western Canada, in Proceedings International Mine Management 2012, pp 97-104 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By S Rogers, D Stead, E Eberhardt

The last decade has seen a major increase in use of the discrete fracture network (DFN) approach applied to cave mining problems, often integrated within more complex geomechanical simulations. Because the value of the DFN model directly depends on the quality and quantity of available field data, there is the need to apply dedicated mapping procedures to collect sufficient structural data at the required engineering scale. This paper attempts to address several key questions about DFN modelling; for example: are current methods for fracture mapping suitable for DFN modelling? What are the critical parameters that we need to measure and what do we need to change in the current practice? Particularly at the earlier stages of a cave project, engineers may have to account for the lack of appropriate data, which manifests itself in the form of increased uncertainty and the difficulty to characterise variability in an objective manner using a limited set of data. DFN models could in principle be generated using limited data by assuming statistical distributions for the sampled parameters; however, engineers would need to be aware of the implications that such limited knowledge (and increased uncertainty) would have on stability analysis, fragmentation analysis and mine design. When used correctly, a DFN approach offers practitioners the opportunity to:maximise the use of fracture data collected from mapping of rock exposuresgenerate more realistic synthetic rock mass modelsprovide estimates of natural fragmentation that also account for rock mass variability.CITATION:Elmo, D, Eberhardt, E, Stead, D and Rogers, S, 2016. Discrete fracture network modelling – importance of accounting for data uncertainty and variability, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 845–852 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

Over the last 15 years the contract mining concept has developed into an integral part of the Australian mining industry. Today it is a $2 billion per annum industry with the potential to continue to grow at a rate of between ten and 20 per cent. Australian contract miners have also exported the concept overseas where growth prospects are unlimited. The industry today is at a cross-road where both contractors and mine owners must consider the current state of the contract mining industry and where it is heading. To look at the present and the future, it is necessary to look back at the history of contract mining and why it has developed. Current industry concerns can then be summarised and the areas that need to be considered to enable the industry to prosper, reviewed. The ultimate goal is to reach solutions with benefits to both the mining companies and the contractors.

Jan 1, 1996

The excavator selection process is quite complex due to the large number of influencing factors, many of these are variable and difficult to accurately define. The majority of mining companies prepare a tender of general specifications and suppliers will then match a product to those specifications. The mining company will then evaluate the tenders on the basis of the best available deal. In this paper, the importance of open pit excavator selection in terms of its impact on operating costs is analysed and discussed. A rigorous process for selection is then outlined.

Jan 1, 2003

Direct measurements of liquid contents in foams obtained from (x-terpineol a-T) n-pentanol (AmOH) and n-octanol (OctOH) solutions were carried out using a column of special construction. The column enables to determine the liquid contents by cutting-off foam layers of various thicknesses and measuring amounts of liquid contained in the cut-off foam layers. Liquid contents in the whole foam layers, in the top foam layers of thickness 14 ¦ 1 mm and distribution of water alongside foam height were determined. The average liquid contents were high and reached a level of 30, 35 and 40 per cent for foams formed from cc-T, AmOH and OctOH solutions, respectively. The liquid contents in the top foam layers were much smaller. They were of an order of five per cent for a-T and AmOH and 12 per cent for OctOH. On the basis of the liquid distribution alongside foam height some practical conclusions concerning possibilities of minimising amounts of liquid contained in the collected concentrate are presented.

Jan 1, 1993

By C R. Headley, S O. Hille, N P. Jacob

The redevelopment of the Telfer Gold Mine in the Pilbara region of Western Australia was primarily based on the construction of a 17 Mtpa dual train concentrator coupled with open pit and underground mining operations. The unique copper-gold orebody at Telfer requires the application of complex flotation conditions normally reserved for base metal concentrators, where two competing minerals are managed into separate products. This paper describes the commissioning of the flotation circuit, the process modes and the master/slave relationship that flotation has with a variable orebody.

Jan 1, 2007

Open stoping dimensions are typically controlled by a number of factors including production drilling capacity, scheduling, fill constraints, orebody dimensions and host wall rock conditions. Frequently host wall rock conditions are the key control on stope dimensions. As a new mine is brought into production, there is a steep geotechnical learning curve for those associated with the development of the mine. Initially, the experience and observations gained at other mines is used to guide the stope design. As experience is gained at the new operation, site specific techniques can be validated for use. This has been the case at BHP Cannington, where a heavy emphasis has been placed on the validation of empirical stope stability techniques for site specific conditions and experience. A range of empirical and numerical techniques can be applied during the design of open stopes. The empirical techniques are an experience based application of known performance levels during the design of open stopes. The numerical modelling and structural tools can be used to compliment the empirical techniques so that an understanding can be gained of the likely stress and structurally controlled failure mechanisms.

Jan 1, 2000

By C Lower

An unprecedented, quantitative, deposit-scale understanding of major clay mineral distribution throughout the Yeelirrie uranium deposit has been achieved by adapting the existing HyLogger™/HyChips™ analytical technique to measure resource assay pulps. Spectral analysis via HyLogger™ and HyChips™ systems has previously been used as a small-scale geometallurgical research tool, but never before has it been quantitatively applied to an entire resource sample population for the purpose of developing stand alone block models for major clay minerals. Economic uranium mineralisation within the thin but extensive Yeelirrie?palaeochannel?primarily exists within the transition zone between a groundwater-derived calcrete and the underlying clay-quartz regolith. Early geometallurgical investigations identified that certain clay minerals could be deleterious to the efficiency of the uranium recovery process. Accurate calculation of clay mineralogy from resource assays proved too difficult due to chemical similarities between co-existing kaolinite, smectite and magnesium carbonate minerals. A relatively low-cost, efficient and accurate method of quantitative clay mineral analysis was required to measure over 70 000 resource assay pulps. After initial testing and comparison with QXRD, the HyChips™ 3-1 spectral logging system was implemented as a primary method of clay mineral analysis for the Yeelirrie uranium deposit. The resultant spatial data set allowed the interpretation and geostatistical analysis of geometallurgical domains across the deposit. Clay block models were generated and used in geometallurgical resource calculations to benefit the mine planning process.

Sep 5, 2011

By H Rossiter, C Simpson, J Market, P Jeanneau

Downhole Assay tools are a geophysical method to collect an instigated response from the material surrounding a drill hole and deliver a multielement proxy-assay. They were first tested in the Pilbara at the turn of this century, however since 2011 they have seen a more focused testing and implementation regime with multiple companies across multiple Pilbara mine sites. The increase in the volume of data has led to advances in the measurements and significant improvements to the efficiency of the calibration process. Pulsed Fast and Thermal Neutron Activation Analysis (PFTNA) downhole assay tools collect gamma photon spectra which are characteristic of elemental signatures. One of the key components of the technique is calibrating the spectral signatures to lab assays. Each tool is slightly different due to the organic nature of the crystal detector and therefore responds slightly differently. Environment and hole conditions as well as ore characteristics are among other external influencing factors. Thus, a unique calibration is required for each tool. In addition, not all elements are measured directly, but some are actually characterised by proxy, meaning that if the signal-to-noise ratio for an element is small, it may be easier to identify the mineral or geology in which that element is found and thus infer the concentration of the element. These proxies may differ for each site or geology type within a site. There is a large advantage to build a unique calibration per tool at each site rather than a universal one to be used across the whole province. This then delivers the accuracy and precision of measurements that mining companies require for modern operations. Early work with the tool required several thousand metres of calibration data and several weeks of analysis to build each calibration. This process has now been streamlined to significantly reduce the amount of data required and the analysis time to make it much easier to introduce new tools to a site with an existing model or to create new models. This paper details the calibration process, illustrating the increasing accuracy of the models as training data are acquired as well as the methods for transferring a calibration from one tool to another.

Nov 8, 2021

By Stephenson D. B, Burgess J, Burgess F. L, Marshall S. H

A new high intensity flotation process 'FASTFLOT' is explained and its theoretical advantages compared with other flotation systems are discussed. The results of initial FASTFLOT testing on the zinc roughing circuit at Pasminco Mining, Broken Hill South concentrator are presented and compared to recent plant data. The comparison suggests that on roughing duties, the FASTFLOT process yields superior concentrate grade while requiring less than one third the residence time of a conventional mechanical cell plant. Strategies for FASTFLOT deployment are also presented.

Jan 1, 1994