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By R Lastra, Y Choi, C Hamilton, P Kondos

Hydroseparation (http://www.cnt-mc.com) was used to concentrate sized fractions (from <38 ¦m to 150 ¦m) of various ore products ahead of carbon-in-pulp (CIP)-treatment. The resulting size-by-size concentrates were mounted as monolayer polished sections and subjected to automated unattended precious metal searches by image analysis (see Lastra, Wilson and Cabri, 1999). Systematic variations in Au-deportment permit quantification of Au reporting as discrete grains from fresh-feed through to pressure oxidation (POX)- and CIP-feed. Application of hydroseparation, image analysis and assays to characterising tailings (from <10 ¦m to 106 ¦m) from four mine sites is also described. Results are encouraging enough to predict that the combination of hydroseparation (HS) and automated image analysis could become a standard methodology for study of precious metal ores and metallurgical products.

Jan 1, 2008

By C Rothfuss, X Wang, S J. Herbert, K Prasad

The extraction of groundwater to produce gas from coal seam gas (CSG) reservoirs has highlighted the opportunity for beneficial uses of groundwater in Australia. This paper presents an assessment of alternate groundwater modelling approaches that can be used for assessment of one beneficial use option, that of injection. This assessment examines the outcome of the use of different simulation methods on predictions of hydrodynamic behaviour.In this paper, a simplified hydraulic concept of a multi-aquifer system within the hypothetical injection field was used to investigate the hydrodynamic behaviour of injection into the Precipice Sandstone. Comparisons were made through the analysis of a Theis 3D analytical solution with 2D and 3D numerical solutions. The paper discusses the different solution methods and the impact of these on predictions of pressure and flux. Differences in 2D and 3D solutions result in implications if planning injection as a beneficial use of water. For example, the 2D solution resulted in faster and higher injection pressure build-up when compared to the 3D solutions. The 2D modelling could result in either plans that require higher capital expenditure for a greater number of wells in order to spread the pressure effect and remain below the maximum injection pressure or a reduced injection rate. Meanwhile, the 3D modelling with sensitivity analysis could result in planning for lower capital expenditure for fewer wells required to spread the pressure effect and remain below the maximum injection pressure. CITATION:Wang, X, Herbert, S J,?Rothfuss, C and Prasad, K, 2013. Assessment of effectiveness of artificial recharge for coal seam gas water management based on numerical modelling, in Proceedings Water in Mining 2013 , pp 67-72 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

The mineral processing industry is in boom times. The focus on mill availability and therefore profitability has never been greater, as grinding mill maintenance often dictates the entire plant shut down duration. Advances in mill systemsÆ quality and reliability and the faster, safer relining afforded by RMEÆs Mill Relining Systems have significantly enhanced grinding plant availability and utilisation. Yet relining performance is still affected by the design and planning by a team of stakeholders long before the maintenance team set foot in the mill. For a greenfield grinding plant project, these team players include: 1. project owner, 2. project manager, 3. mill supplier, 4. liner supplier, 5. plant operating personnel, 6. plant maintenance personnel, 7. mill relining crew, and  8. mill reline system supplier (RME). The complex and sometimes competing design demands of mill construction and operation together with the pressure of tight timelines can result in even simple maintenance requirements being overlooked let alone optimising plant design and planning for maintenance. This paper identifies all the involved stakeholders in an effective mill relining 'team' and gives principles and considerations for each to more effectively achieve the goals within their vital roles. This paper is aimed to be a practical guide for grinding mill designers and planners to more fully exploit the advances in Mill Relining Systems and improve their mill profitability.

Jan 1, 2008

By Drury SA, Williams RD, Nind DC

The Airborne Thematic Mapper is an eleven channel digital scanner which acquires image data in the visible, near infra-red, short wave infra-red and thermal infra-red wave- lengths. A description of the system is presented which includes details of the operating wavelengths and performance parameters of the scanner. Consideration is also given to the aircraft installation requirements. During January 1984 the scanner surveyed the mineral rich areas of Leonora, Laverton and Kalgoorlie in Western Australia. This is a region of intense exploration activity for gold and base metals. Some 30,000 square kilometres were systematically surveyed in a period of ten days. This scanner was flown at 7,000 metres altitude giving a ground pixel size of 17.5 by 17.5 metres. The flight line spacing was 8 kilometres. The overall project took some thirty days from conception to completion. The planning and execution of this operation are described in detail. The resulting magnetic tapes provided 11 channels of digital image data over a 30,000 square kilometre area and a variety of image processing techniques were employed in order to capitalise fully on the results. The imagery provides a powerful tool for the geological mapping of the terrain. The data can also be used to monitor the environmental effects of mining operations.

Jan 1, 1986

By G T. Jemwa, F Rousseau, F J. Wolfaardt, J A. M Rademan, P W. Smit

Mining companies are increasingly faced with the challenge of reducing operating costs while maximising throughput and profitability. At the same time, the grade and quality of treated ores are becoming poorer and more variable, resulting in suboptimal process performance.It is now widely accepted that strategies to drive operational goals must revolve around improving plant availability, reliability and process efficiency. In particular, progress in plant automation and control systems has seen a trend towards unified frameworks for control and optimisation of mineral processing plants. These frameworks seek to seamlessly integrate different roles and tasks involved in process operations - IT, automation, plant maintenance and operations. An integrated solution framework for reducing process variability, increasing process efficiencies and maximising plant availability and reliability is discussed within the context of a typical milling circuit. The framework exploits a real-time analysis ægapÆ evident in production operations that prevents timeous identification of equipment and process failures. This is achieved by leveraging predictive analytics for equipment health monitoring, control loop monitoring and advanced regulatory control solutions towards enhanced process performance, improved asset management and regulatory compliance. The framework provides for early and actionable warnings on equipment and process degradation using real-time operational data.Resolving these problems can potentially avoid unplanned downtimes, process instabilities and other operational surprises, thus ensuring optimal plant throughput and optimal process behaviour for improved recoveries. Integrating control systems and plant automation with advanced analytics to analyse and optimise processes enables operations to achieve reductions in the variability of key process parameters. In addition, early detection of equipment malfunction or suboptimal process conditions leads to improved equipment availability and reliability. Ultimately, these operational gains reflect in profitability because of plant throughput and recovery gains. These benefits are demonstrated using data from a South African gold mining operation, where such an integrated asset and process health monitoring framework for process optimisation has been implemented.CITATION:Jemwa, G T, Wolfaardt, F J, Smit, P W, Rademan, J A M and Rousseau, F, 2013. Towards an integrated framework for asset and process health monitoring and optimisation on a milling circuit, in Proceedings World Gold 2013, pp 137-148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By K Williams, A Lavrinec, V Gurung, D Ilic

The moisture content of iron ore during handling can range from the dust extinction moisture at the point of arrival at the port to the transportable moisture limit at the point of loading ships for maritime transport. Moisture content and ore composition, specifically fines content, have a large influence on ore flowability. Typically, elevated moisture can result in bottlenecks, downtime and lost productivity due to build-up, conveyor carry-back and blockages, increasing maintenance costs. On the other hand, low moisture can result in increased dust emissions influencing the environmental footprint and product losses. Managing the use of water across the supply chain is therefore critical for service life of equipment, productivity, but also has environmental and social impacts, affecting the social license to operate. Previously, experiments have shown that oscillations induced in iron ore during handling and transport can result in movement of moisture through the ore. This kind of moisture migration depends on the nature of these oscillations, such as the undulation of idlers during conveying, the inherent ore properties and the initial moisture content. Moisture has been observed to move either upwards and/or towards the bottom of the burden. These effects can be exploited to remove excess water from the ore influencing handleability and operation, however, the actual mechanisms of moisture migration are currently poorly understood. The study presented herein involves the use of simulation to examine moisture and ore interactions. Simulations using discrete element method (DEM) and coupled with smoothed particle hydrodynamics (SPH) are implemented to investigate the behaviour of moisture in wet ore in the presence of oscillation. This is conducted at a fundamental level first using glass beads and water which is then compared to iron ore at high moisture content. The results of the modelling are discussed in view of experiments conducted.

Sep 18, 2023

By P M. Ashley, M T. Costelloe

The Mary Kathleen tailings storage facility (TSF) contains 7.1 Mt of uranium mill tailings. This waste repository was rehabilitated in the mid-1980s using a multibarrier dry cover. At the time of mine closure, it was predicted that acid mine drainage (AMD) generation would not eventuate and that uranium, heavy metals and radionuclides would be adsorbed within the tailings and not seep from the TSF into the environment. This study reports on the environmental status of the TSF. Gamma-ray measurements indicate an intact dry cover of the waste repository. However, seepage (~0.5 L s-1) of acid (pH 5.71), saline (0.31 per cent), high conductivity (8.8 mS cm-1), slightly oxygenated (DO 2.6 mg L-1), radioactive waters occurs from the toe of the tailings dam into the former evaporation ponds and local drainage system. Seepage waters are calcium-magnesium-sulfate rich with elevated Fe, Mn, Ni, U and Zn values. Oxygenation of tailings seepages causes the precipitation of Fe and coprecipitation and adsorption of other metals (Pb, U, Y), metalloids (As), rare earth elements (Ce, La) and radionuclides (U-235, U-238, Th-227). In contrast, Ba, Ni, Sr, Mn, P, S, Ca, Mg, Na and K as well as Ra nuclides (Ra-226 and Ra-228) remain in solution until pH neutralisation and evaporation lead to their precipitation in efflorescences and sulfate-rich evaporative sediments further downstream. Dry capping of Mary Kathleen uranium mill tailings has resulted in physical containment of the wastes. The dry cover shows no signs of erosion and radiation levels are within acceptable limits. However, the flow rate of surface seepage from the TSF occurs at a much higher rate than predicted. Also, the neutralising potential and adsorption capacity of the tailings and underlying aquifer were overestimated at the time of mine closure. AMD has developed mobilising metals, metalloids, rare earth elements, alkalis, radionuclides and sulfate from the waste repository into surface water seepages.

Jan 1, 2003

By McKay AD

The bulk of Australia's uranium resour- ces was delineated in the last 18 years when a total of $563 million (1984 dollar values) was spent on uranium exploration. Australia's share of the low-cost Reasonably Assured Re- sources in the World Outside the Centrally Planned Economies Area (WOCA) increased from 1.5% in 1967 to 29% by the end of 1984 and its share of the low-cost Estimated Additional Resources (Category I) then stood at 25%. As of December 1984, Australia's uranium resour- ces were estimated by the BMR to be: Cost range US$80/kg U (US$30/lb U301) Reasonably Assured Resources 463 000 t U Estimated Additional Resources(I) 251 000 t U Cost range US$80-130/kg U (US$30-50/lb U308) Reasonably Assured Resources 63 000 t U Estimated Additional Resources(I) 126 000 t U The increases in Australia's resources was sustained by a group of large and rela- tively high-grade deposits which were disco- vered during the period 1969 to 1975. Austra- lia's share of the low-cost resources was also enhanced by a contraction of WOCA's low-cost resource base due to escalation of production costs for smaller low-grade deposits. Most of Australia's uranium resources are contained in the Proterozoic unconformity- type deposits of the Alligator Rivers uranium field and the stratabound deposit at Olympic Dam on the Stuart Shelf. Most of the remain- der of Australia's uranium resources is con- tained in calcrete-type deposits. Less than 10% of Australia's uranium resources are in sandstone-type deposits. Total Australian production to the end of 1984 amounted to 26 241 t U, representing 3.4% of WOCA's cumulative production. Aus- tralia's share of WOCA's annual production has steadily increased from 1.3% in 1977 to 11.2% in 1984 (4390 t U). The increases in Austra- lian production took place in the face of reductions of production in WOCA countries, principally the US, from a record level of 43 988 t U in 1980 to about 39 000 t U in 1984. New low-cost production centres, mainly in Australia and Canada, have partly compen- sated the decline in US production. The Department of Resources and Energy (1985) reported that Australian exports of yellowcake are expected to reach 10 000 t U308 (8480 t U) by 1993/94, representing an in- crease of about 13% oer annum.

Jan 1, 1986

By S Graskoski, S Craig, C Myburgh

Too often in mine planning, maximising revenue-generating material takes precedence over minimising costs. The ability to target both revenue and cost optimisation enables mine plans to fulfil corporate objectives of targeting maximal project net present value (NPV). The state of current mining costs and increasing government regulations in Australia are forcing many mine planners to pay closer attention to cost minimisation. Dumping waste material, which ultimately forms waste landforms, represents a large cost to mining operations. A general mine, with a waste to ore strip ration of 6:1, allocates approximately 32 per cent of total mining costs to waste haulage alone (Gregory, 2003).Most scheduling packages do not dynamically build economic or minimal cost dumps as part of the scheduling process. In most cases, waste dumps are built after a mining schedule has been defined. Automated software is now available which dynamically schedules the pit and waste dumps together. The overall shape of the waste dump is therefore dictated by minimum cost or minimum haulage hours.The purpose of this paper is to compare dynamic pit and waste schedules to traditional methods which apply haulage estimations after defining the mining schedule. This paper includes a case study on the large open pit operation at Tropicana Gold Mine, a joint venture between AngloGold Ashanti Australia Ltd (70 per cent) and Independence Group NL (30 per cent). The operation will focus on mining three large open pits over a 13-year mining life. A total of 397 Mt of waste is mined and directed to multiple destinations including waste dumps, the run-of-mine (ROM) pad and tailings storage facility (TSF) perimeter.Due to these complexities, management of the haulage fleet, especially during the critical period of operation readiness and start-up, is essential. Critical infrastructure such as the TSF and ROM pad will need to be built early and these areas, as well as the sequential development of the waste dump, will need to be developed within the constraints of structured mining fleet build-up.This paper investigates the influences of haulage estimation accuracy and compares traditional approaches for waste planning to automated approaches using EVORELUTIONÖ.CITATION:Graskoski, S, Craig, S and Myburgh, C, 2013. Dynamic pit and waste dump schedule optimisation at Tropicana Gold Mine, in Proceedings World Gold 2013 , pp 121-128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By P Hagan, S Campbell

A study was undertaken using various methodologies to determine the optimum loading and hauling configuration for different haul routes at Callide Mine, a coal mine located in central Queensland. The study involved development of an effective flat haul model that was used to estimate production rates in truck and shovel circuits that employ two excavators of differing capacities then Queuing Theory to construct a capacity constraint model for scheduling purposes to assist in truck allocation and finally a cost model to determine the most cost effective fleet configuration.The model was calibrated using haul road design and performance data of trucks and excavators currently in use at the mine. The study examined the effects of cycle time for different truck and excavator fleet configurations on production rate and costs.The study found haulage cost was directly related to cycle time while production rate reduced with cycle time. The study indicates the approach taken in combining a cost model with a capacity constraint model offers a simple and effective method of scheduling an optimum number of trucks in a haulage circuit.CITATION:Campbell, S and Hagan, P, 2012. Selection of an optimum truck and shovel fleet based on effective flat haul and capacity constraint modelling, in Proceedings Eighth Open Pit OperatorsÆ Conference , pp 19-26 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 18, 2012

By K Smith

This paper presents an assessment of the Robertson (2010a) method within the CPTu inversion parameter framework of Been et al. (1987), using CPTu calibration chamber data presented by Jefferies and Been (2015) and in other literature to assess the validity of the method, with particular focus on applicability of the method to TSFs (i.e. its applicability to loose silts and silty sands). The assessment demonstrates that although the method estimates values of k consistent with calibration chamber data, the method estimates values of m that are generally 1.5 to 2 times greater than calibration chamber data. As a result of this, the method generally overestimates Ψ for values of Ψ less than 0, and underestimates Ψ for values of Ψ greater than 0. This may result in both overly conservative assessment of materials as potentially liquefiable and unconservative predictions of material behaviour for loose materials.

Jul 1, 2021

By Aspinall T. O, Just G. D

Computer software systems have been developed to assist in a wide range of specific mine planning and scheduling applications. In selecting appropriate systems for any mining operation it is apparent that certain features have particular advantages for each mine site. The ideal solution to this problem is to select a range of systems which best relate to sections of each mining operation. This approach raises potential data linking difficulties where output from one system is incompatible with input requirements for other systems. A study at the University of Queensland investigated the problems related to the integration of a number of mine planning and scheduling software systems. The project used data from large scale coal strip mining operations in Central Queensland. Two major computer packages used extensively in the study were the SURPAC mine planning and XPAC mine scheduling systems. Dragline and truck and shovel operations were analysed in the project. Results of the work have been directly applied at the mine site to assist current strip design by effectively automating the design procedure. This enabled sensitivity studies to determine the effects of changing dragline working levels and varying pit dimensions. Coal blending studies and procedures to optimise operations have been investigated using linear programming within a spreadsheet software application. Output from the SURPAC and XPAC programs was directly linked to the linear program for this analysis. The simulation program GPSS/PC was also used in a similar manner to assess optimisation parameters.

Jan 1, 1992

By K C. Runge, E Tabosa, A Jankovic

Flotation recovery in geometallurgical modelling is usually predicted based on relationships developed from batch flotation testing of different ore types. These batch flotation tests are usually performed at a constant set of operating conditions and at a fixed feed grind size P80. Usually the laboratory feed grind P80 is that which is expected to be produced in the full-scale flotation circuit for that particular ore type.Flotation recovery will be a strong function of the valuable mineral particle size distribution, with lower recovery of ultra-fines due to poor flotation kinetics, optimum recovery for the intermediate sized particles and lower recovery for the coarser particles due to poorer liberation of this fraction. This valuable mineral particle size distribution is not characterised by the solids P80 parameter alone. The proportion of material in each class will also be a function of the slope of the size distribution and the degree of preferential grinding of the valuable mineral in comparison to the total mass of the ore.This paper will demonstrate (through example) how these other size distribution parameters can change with a change in grinding technology, the size and operating conditions used in a grinding unit and the characteristics of the classification technology used in conjunction with the grinding unit. Case studies will be presented that demonstrate how this can result in these parameters being very different in laboratory testing to that produced in the full-scale comminution circuit. A rule of thumb that laboratory rod milling rather than ball milling produces a size distribution most similar to that of the full-scale grinding circuit will be challenged. These differences can result in a significant change in flotation recovery. It is therefore important to consider these parameters when developing a laboratory geometallurgical program, to enable more accurate prediction of the flotation recoveries that will be achieved in the full-scale process.CITATION:Runge, K C, Tabosa, E and Jankovic, A, 2013. Particle size distribution effects that should be considered when performing flotation geometallurgical testing, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 335-344 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By J W. Muir, N Bedford

Hong Kong is one of the most rapidly developing cities in the world. With constant population growth and limited opportunities for space, the development of a fast and effective underground public transportation network is essential. Hong Kong’s Mass Transit Railway (MTR) Corporation is currently undertaking several large underground expansions to its existing network. Much of the excavation will be carried out using the drill and blast excavation method.Drill and blast excavation is common in Hong Kong and with the continued development of underground infrastructure the use of the drill and blast excavation method will increase. Although an effective method of excavation, the blasting vibrations caused during construction can have an adverse impact on surrounding structures and impose disruption on the local community.In order to minimise the risks associated with blasting vibrations, and to demonstrate that the impact on local stakeholders will remain within acceptable limits, it is generally necessary for a contractor to submit a blasting assessment report for approval by government authorities before blasting may commence.Continued increases in population density will force more infrastructure to be constructed underground. Tunnels and caverns are increasingly excavated in closer proximity to critical sensitive receivers. This leads to greater potential impacts on the community, tightening constraints on contractors and a higher level of confidence required for approval authorities. Finding a balance between the needs of the community and rising construction costs becomes more challenging.This paper presents a case study on how the blasting assessment report process has been successfully implemented for a major MTR project situated in a densely developed area of Hong Kong. It describes several methods of assessing blasting vibration impacts, innovative uses of blasting for excavation and the mitigation measures employed to provide the best outcome for all project stakeholders.CITATION:Bedford, N and Muir, J W, 2014. Blasting vibration assessment and innovative blasting methods in high-density urban environments, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 9–20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By P Navarra, R Kuhne

Dynamic simulation (discrete event simulation) is the preferred methodology to evaluate the impact of dynamic aspects of processing plants on the overall plant capacity. This tool can be used to: identify bottlenecks in the plant,justify upgrade and expansion projects by evaluating their impact, oroptimise maintenance and operating practices without disrupting the operation. Iron Ore Company of Canada's (IOC) pelletising plant is a complex operation because of multiple products, varying equipment capacity and shifting bottlenecks. Furthermore, with extensive capital requirements for projects and long lead times, a high level of confidence in project outcome is required. Therefore, a model of IOC's pelletising plant in Labrador City was constructed in 2007 by a joint IOC and Hatch team. The model includes both operational and metallurgical aspects in order to better capture the complexity of IOC operation. In this paper, the justification, boundaries, and functionality of the model are described. A comparison of simulation results to historical plant operation is given. It is observed that projects have interactions and that the benefits of combined projects are not equal to the combined benefits of the individual projects. Projects can have synergies that result in greater benefits when combined or can have overlapping benefits that result in lower benefits when combined. The power of the proposed modeling exercise lies in the ability to assess the impact of projects on overall performance.

Jan 1, 2009

The Myra Falls minesite, of Westmin Resources Limited, is located at the geographic centre of Vancouver Island, within the confines of Strathcona Provincial Park. The operation includes two active underground mines, II-W and Lynx, together with a modem 3650 1/d milling facility. Recent exploration successes will lead to the commissioning of a third mining area in late-1993 - The Battle/Gap Mine. These ore deposits are complexly metal-zoned volcanogenic massive sulphides of Devonian age, hosted in the Myra Formation of the Sicker Group volcanic assemblage. Three distinct felsic volcanic units are defined within the 450 metre thick Myra Formation. They are, from oldest to youngest, the H-W Horizon, the LMP Horizon and the Upper Rhyolite Unit. Massive sulphide mineralisation occurs throughout the property in the H-W and LMP Horizons. There are a number of orebody types, including polymetallic massive sulphides, polymetallic disseminated sulphides, zoned pyritic massive sulphides, elastic sulphide zones and stringer sulphide zones. Individual orebodies range in size from 10 000 tonne zinc-rich polymetallic lenses to the ten million tonne, zoned massive sulphide H-W main lens. The property has been in continuous operation for 26 years, producing over 13 Mt of ore averaging 2.2 g/t Au, 64.0 g/t Ag, 1.9 per cent Cu, 0.6 per cent Pb, and 5.6 per cent Zn. Current geological reserves stand at 12.5 Mt at a comparable grade, including 4 Mt of recently discovered high grade ore in the Battle and Gap Zones. Mining and milling methods have evolved over time to enable successful extraction and milling of these complex ores. Change is on-going with the recent conversion of the H-W Mine to large-scale bulk mining methods, and the development of effective computerised ore reserve calculation and mine planning tools. These changes, in concert with successful exploration techniques that led to recent high grade ore discoveries, have breathed new life into the operation and should assure its present and future viability.

Jan 1, 1993

By R Belissont, C Veloso, L Senez, F Vasconcelos, E Kleiderer, J Mesquita, Y Basselin

Mont-Wright mining complex is an important asset of ArcelorMittal located in the province of Quebec, Canada. It is composed by Mont-Wright and Fire Lake mines, operating 365 days per annum, and producing 25 Mtpa of iron ore concentrate with 66 per cent Fe. Mont-Wright concentration plant is composed by seven lines with a flow sheet encompassing AG/SAG milling, primary and secondary classification stages, spiral concentrators (rougher, cleaner and recleaner stages) and dewatering unit operations. In this context, an equation called ‘Wrec’ was developed in 1971 with the objective of estimating the mass recovery of the different blocks in the beneficiation plant and support the mining planning works of Mont-Wright complex. This equation was based on the correlation between the results of heavy liquid tests performed with drill core samples and spiral concentrators pilot scale tests, returning an estimative of concentrator yield. However, since its first development, no updates have been done in the equation, which lead to some deviations from expected recoveries in the last years. This is probably due to the changes in the process and in the ore fed into the concentrator during the period. In this way, the study presented here corresponds to the execution of heavy liquid/spirals pilot scale tests with 26 composite samples collected at Mont-Wright deposit aiming at revising and updating ‘Wrec’ equation. Based on test work results, an updated formula was established to estimate the plant recovery and a comparison performed using industrial data showed that the old formula overestimated the real yield by 5.40 per cent, on average. At the end of the study the new equation was incorporated into the mining planning process.

Sep 18, 2023

By B D. Burford

High intensity stirred milling using the IsaMill has been the enabling technology for many projects by transforming the economics of fine grinding and simplifying circuit design. IsaMill grinding technology was originally developed for large-scale grinding to P80 sizings of 7 ¦m. The IsaMill is a high throughput, high efficiency mill that produces sharp product size distributions in open circuit configuration. The ability to grind in an inert environment, using a wide variety of media types, can give further metallurgical and economic benefits. The high energy intensity results in a small footprint that enhances the ability to distribute grinding power throughout the circuit, applying grinding energy to the minerals that need it. Recent scale up developments in IsaMill technology have enabled the benefits to be extended to large-scale conventional grind sizes, until now the domain of ball and tower mills. This paper will examine the crossover of IsaMill technology from ultrafine applications into the more conventional grinding area (P80 20 - 150 ¦m). Scale-up developments in IsaMill technology that have enabled this are reviewed. The upcoming commissioning of a 3.0 MW M10,000 IsaMill, the most powerful to date, grinding to P80 55 ¦m at PPL in South Africa will be discussed, as will the recent commissioning of a 2.6 MW M10,000 IsaMill at Kumtor. Recent testwork at McArthur River, where an IsaMill is being considered as an addition to the primary grinding circuit to replace the current tower mill will be reviewed. The potential combination of HPGR and IsaMill to transform concentrator grinding economics will also be discussed. Large-scale IsaMill technology has the ability to transform circuit design and energy efficiency for both coarse and fine grinding.

Jan 1, 2006

By R Memary

The environmental and economic impacts of a significant dependence on fossil fuels are affecting the future of sectors such as of mining. These impacts are prompting the Australian Government to seek solutions for reducing its dependence on fossil fuels more generally, such developing clean energy and improving energy efficiency. However, limited research has been undertaken to assess the potential synergies between clean energy and mining in an uncertain global future. This paper analyses current energy use by mining in Australia and reviews the drivers and opportunities for energy efficiency and cleaner energy technologies to be coupled to mining under three future scenarios. Linkages between mining and clean energy are investigated for three global scenarios for mining and metals to 2030, developed by the World Economic Forum (WEF), namely Green Trade Alliance, Rebased Globalism and Resource Security. These scenarios are applied to assess how they could change the barriers, opportunities and trade-offs required for the development of a more sustainable energy sources by the minerals industry in Australia.

Nov 22, 2011

By S Morgan, L C Pagdalian, S Serdzeff, C Malaloy-on

It is widely accepted that mineral deposits are decreasing in metal grades. To remain profitable and meet market demand, mining companies are expanding their operations by increasing the tonnage treated. These expansions may include new concentrators with higher nameplate tonnages or upgrading the capacity of existing ‘brownfield’ operations. In many cases, the brownfield upgrade route is preferred as it is less capital intensive; however, brownfield upgrades are never straightforward and present many metallurgical and engineering challenges.For example, to increase feed throughput at a brownfield site, there will be a requirement to modify the mine development plan. This may result in the ore mineralogy varying beyond the current feed fluctuation range. To accommodate these ore variations, a combination of mineralogical analysis and small scale testwork can be used to develop a new process flow sheet to achieve the product recovery/concentrate grade requirements. In general, however, flow sheet development does not usually consider site specific layout constraints and equipment requirements. At sites where future expansions were never considered, taking this silo approach could lead to project delays and compromise the circuit design.Engaging an experienced technology partner ensures the nominated project team is involved throughout all stages and aspects of a given brownfield upgrade – from conceptual flow sheet development, through to detailed engineering, construction and commissioning. The recent Carmen Copper Corporation (Carmen Copper) circuit upgrade has been completed in technology partnership with Outotec. The circuit upgrade was extensive and included new equipment additions to the comminution, flotation and dewatering circuits. Carmen Copper’s intimate knowledge of the ore characteristics, in conjunction with a trusted, knowledgeable technology partner, facilitated a robust circuit design, and fast-tracked the project execution. This paper deals specifically with the flotation circuit upgrade and highlights the benefits to Carmen Copper of this holistic approach.CITATION:Morgan, S, Serdzeff, S, Malaloy-on, C and Pagdalian, L C, 2014. The benefits of technology partnerships during brownfield upgrades, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 471–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014