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By Y T. J Kwong

With the recent emphasis worldwide on environmental protection and sustainable development, finding an enriched mineral deposit no longer guarantees mining development. Only if the identified resource can be exploited in an environmentally-friendly manner is it possible that a mine may be developed. Designed primarily to aid with exploring for similar deposits of a particular type, traditional genetic ore deposit models tend to ignore the fact that all mineral deposits are characterised by type-specific environmental signatures. In fact, how an ore deposit can be mined, the commodities of interest extracted and the resultant mine wastes managed are all largely dictated by the geology and mineralogy as well as the environmental setting of the deposit. An environmental ore deposit model integrates such related information to identify the environmental challenges associated with mining an ore deposit of a particular type and facilitates the selection a suitable combination of methods to minimise environmental risks and impacts. Given that environmental management consumes a large portion of the budget for a modern mining project, making informed decisions at all stages of mining development can reduce the overall project cost. Through case examples, this paper demonstrates how environmental ore deposit models may be useful in mine permitting, active mining and in site decommissioning. It is only through an innovative and flexible approach that the mining industry can shed its tarnished image and gain the social license to mine.

Aug 22, 2011

By J Nortier, J Dray

There is no single factor that determines the appropriate capacity for a mining project. It is driven by the size of the resource, the capacity of the market, the availability of capital, the availability of power, the availability of water, and a myriad of other considerations. There is also no single solution to the question of how big the project should be. However, to develop a project, the study team needs to select the configuration options that it regards as the best for the project. To be able to make this selection, the study team should consider the range of available options and do so at a level of detail that gives it confidence in the conclusion but does not lead to multiple detailed design exercises. Having considered the range of options, and with a clear definition of the project owner’s objectives and constraints, the work to be carried into feasibility studies can be focused appropriately. This paper discusses the process of completing strategic mine planning to identify project configuration options to assist in the selection of the processing plant throughput rate (Capacity Study) for a large greenfield open pit mine. The processes described in this paper allow for the basis of design to be set for subsequent studies that meets the objectives at a risk profile acceptable to the owner.

Jun 22, 2022

By R McIlwraith, B Breul

Two case studies are presented in this paper. The first one discusses a roller compacted concrete water supply dam that was constructed in El Mauro in Chile to provide water for agriculture activities downstream of a copper mine during the dry season. The 23 m high dam used a bituminous geomembrane (BGM) as the low permeability upstream facing element on the dam to control seepage through the dam. This is the first time that a BGM has been used in this application. A deep cut-off trench was used to control seepage beneath the dam and through the abutments. This paper briefly presents the design of the dam, including selection of the concrete mix and maximum aggregate size that the use of the Coletanche BGM allowed, and provides details of the construction, quality control and assurance of the installation of the BGM. An ultrasonic apparatus was used as part of the quality control on the BGM seams.The second case study discusses a tailings dam in Cerro Lindo, Peru (near Chincha), where a watertight BGM was installed on the upstream face. Results are presented of the survey done by a consultant on the behaviour of the dam and in particular of the BGM following an earthquake of magnitude 8.1 in Chincha close to the site. These findings on-site were checked by trials in a laboratory in California. Test results are given and explained.CITATION:Breul, B and McIlwraith, R, 2015. Case histories – roller compacted concrete dam waterproofing with a bituminous geomembrane in Chile and a tailings dam in Peru subject to an earthquake of 8.1 magnitude, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 367–372 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By K M. P Singh, K M. K Sinha, G S. Jha, T Gouricharan, K K. Sharma

The majority of the powerplants in India are fed with non-coking coals, with the coals dispatched from their respective mines via wagons loaded by a rapid loading system or pay loader. The usual top size of coal is 200 mm and sampling is carried out manually from wagons. The manual method of wagon top sampling of large size raw coal is not only difficult, but also violates some of the fundamental principles of sampling. As per sampling requirements, samples are to be drawn from the full depth of the wagons, which is impossible to be done manually. Since the ash distribution in the different size fractions is not homogeneous, the results from the samples, which do not reflect the true size distribution of the lot, are likely to be biased. More importantly, sample collection by shovel from the top is a function of human discretion and not governed by the equiprobability rule. In another case, the sample has been collected by a cross belt-type auto mechanical sampler for 200 mm size coal at one of the super thermal power stations. Test analysis shows that coal collected using a cross belt-type mechanical sampler also has significant deviations from stopped belt coal samples of 200 mm size due to size segregation. Studies carried out on wagon top sampling through specially designed experiments reveal some interesting features. The presence of bias in wagon top sampling is apparent when compared with the ‘stopped belt’ sample. In this paper, a comparative study between manual wagon top sampling/auto mechanical sampling with respect to stopped belt sampling has been conducted for coal of size 200 mm. In addition, precision studies have been performed for wagon top sampling/mechanical sampling for Indian thermal powerplants.CITATION:Sinha, K M K, Sharma, K K, Jha, G S, Singh, K M P and Gouricharan, T, 2014. A comparative study of manual wagon top sampling and auto mechanical sampling of 200 mm size coal with respect to stopped belt sampling of thermal coal at Indian super thermal powerplants, in Proceedings Sampling 2014 , pp 43–48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By Ring R. J, Waters D. J, Vautier F. E, Fulton E. J

Laboratory leach tests have been carried out by the Australian Atomic Energy Commission to compare the effectiveness of Caro's acid (permonosulphuric acid) as an alternative oxidant to pyrolusite in the leaching of uranium ores. Results demonstrated that Caro's acid reduced acid consumption in leaching and the lime required for neutralisation of tailings liquor. The uranium extraction was unaffected by choice of oxidant.Following this study, Interox Chemicals Pty Ltd arranged a plant trial using Caro's acid at the Nabarlek uranium mill of Queensland Mines Ltd. The trial confirmed that significant savings in acid and lime usage can be achieved under plant conditions.Plant operations also demonstrated that Caro's acid has a number of significant operating advantages over pyrolusite.Queensland Mines Ltd have recently decided to convert their leaching process from pyrolusite to Caro's acid. The new system is expected to be fully operational by mid 1983.

Jan 1, 1983

By T D. H McGrath, R Byleveld, W P. Staunton, J J. Eksteen

"The Gold Technology Group at Curtin University through the AMIRA P420 series of projects has recently developed the integrated liberation leach model (ILLM) for optimisation of gold plants. The model encompasses recovery by both gravity (batch centrifugal concentrators or BCCs) and leach adsorption (CIP/CIL) circuits. The ILLM essentially combines the Group’s well-known standalone models (ie gravity and SIMCIL) to create a robust simulation package.The ILLM process model provides a tool for sites to determine optimum set points for operations to optimise recovery (eg target grind size). It can also be used to predict the effect on gravity recovery, leach recovery and overall recovery when changes are made to circuit design, either temporarily (eg a leach tank taken off-line for maintenance) or as part of a circuit expansion (eg expanded gravity circuit capacity, or addition of leach tank capacity).This paper discusses the capability of the ILLM process model by highlighting a recent case study. The paper also addresses the test work and plant data required as model inputs, as well as limitations and the application of the ILLM to greenfield projects.Citation:McGrath, T D H, Staunton, W P, Eksteen, J J and Byleveld, R, 2016. Application of an Integrated Liberation Leach Model for Process Optimisation, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 173–178 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By D Giles, A C. Bailey

In the first 20 years of the 21st century, just over 20 per cent of Australian mineral exploration expenditure was dedicated to iron ore, totalling >A$8 billion and >30 million metres of drilling (Australian Bureau of Statistics, 2021). Improvements in the cost, efficiency, safety, reliability and data quality of drilling have the potential to deliver significant productivity improvements, increasing the probability of discovery and reducing the time from discovery to mining. Currently in its third year of research, Mineral Exploration Cooperative Research Centre (MinEx CRC) is focused on a new set of exploration tools and new ways to deploy those tools which recognise the fundamental importance of collecting quantity and quality data from the subsurface, to enable exploration success for all minerals, including iron ore. MinEx CRC is focused on developing more productive, safer and environmentally friendly drilling methods to discover and drill-out deposits. This includes pioneering work on Coil Tube (CT) drilling technology and innovations in Diamond and Reverse Circulation (RC) drilling techniques aimed at improved drilling optimisation and automation. In parallel, MinEx is developing new technologies for collecting data whilst drilling. This is being undertaken in four separate industry-led projects utilising geophysical, seismic, downhole analytical and 3-dimensional (3D) modelling improvements. A National Drilling Initiative (NDI) is also underway, with two drilling programs completed in 2020. The NDI is a world-first collaboration of Geological Surveys, researchers and industry, which undertakes drilling in under-explored areas of potential mineral wealth in Australia and provides a test-bed for new mineral exploration technologies.

Nov 8, 2021

By T A. Carter

In 2010 Agnew Gold Mine (AGM) struggled to produce the required tonnages from its stopes. The longhole rises used to create void in stopes were unreliable and often failed to gain the designed rise height. The number of firings per stope was having an adverse impact on the ground conditions at the stope brows, impeding stope productivity.Through practical experimentation with longhole drill rigs, box hole rigs and development drill rigs as well as trialling new methods in conjunction with reviewing drill hole data, drill hole accuracy was observed to be an issue on-site. Innovative dragging methods such as the reverse drag, combined with a slope instead of a vertical face on the rear of stopes, have improved dragging and a reduction of firings per stope, enabling larger production blasts.The methods trialled and subsequently implemented at AGM have facilitated the mine achieving budgeted targets for six consecutive quarters. This paper documents the use of these methods in a key lode of AGM’s operations to improve drill and blast practices in order to achieve production targets.CITATION:Carter, T A, 2014. Improving production drilling and blasting in the Kim South orebody at Agnew Gold Mine, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 251–258 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By P Esteves, J L. Bechir, R Galery, C Senna, V Souto

The current moment experienced by the mineral industry is marked by a series of economic, social and environmental challenges. Among the main challenges, it is important to highlight the decreasing in ore grades with the gradual depletion of the existing deposits, the high volatility in international commodity prices and the operational inefficiencies in the mine, beneficiation, and metallurgical plants. In this context, mining companies are continuously looking for alternatives that minimize production costs and maximize overall production. In addition, recent tragedies involving tailings dam collapses in Brazil, reinforced the need for a more responsible, sustainable, and conscious mining, such as aiming the preservation and rehabilitation of the land environment. In this scenario, the Sensor-Based Sorting (SBS) technology is currently getting more space into the mining market. This separation technology aims the removal of gangue material in coarse particle size fractions, prior to comminution and concentration stages. As a consequence, the technology allows a smaller consumption of energy, water, chemical reagents and other inputs. Moreover, the sensor-based sorting is a dry processing technology and favors the reduction of fine material to be sent to the tailings. The aim of this paper is to provide information regarding the technical and economical evaluation of SBS technology applicability to a zinc silicate mining in Brazil. The project evaluation was performed in two stages: laboratory test work and the execution of a pilot plant. The execution of a pilot plant allowed the technology optimization, quantification of downstream process effects, such as a proper economic evaluation about the technology benefits. Keywords: Sensor-Based Sorting; Particle Sorting; Ore Sorting; Preconcentration; capital expenditure (CAPEX); operating expenditure (OPEX); zinc; comminution; dry processing.

Nov 10, 2020

By J-P Franzidis, M Esvelt, E V. Manla

The Floatability Characterisation Test Rig (FCTR) is a self-contained, highly instrumented, mobile pilot plant that is able to treat up to 2 tph solids. It consists of a bank of six 130 L WEMCO« SmartCells« and a bank of six 50 L WEMCO« SmartCells«. It was developed as part of the AMIRA P9 Project, primarily to determine ore floatability characteristics and to develop and validate flotation plant modelling, scale-up and simulation methodologies. However, it may also be used to carry out pilot-scale flotation test work. This paper briefly describes the circuit modelling, simulation and scale-up test work performed using the FCTR and the use of the FCTR in pilot-plant test work performed by the metallurgical staff at WMCÆs Kambalda Nickel Operations and Mount Keith Nickel Operation. At both Kambalda and Mount Keith the FCTR was found to be very flexible and straightforward to run, with an easily changeable circuit configuration and stable operation. Testwork was facilitated through having full stream sampling on all streams, and a high degree of instrumentation providing accurate measurement of process variables. The results obtained from the FCTR testwork were highly repeatable. As a consequence of using the FCTR, WMCÆs Kambalda Operation and Mt Keith Operation were able to complete a rigorous programme of pilot plant testwork more quickly than in the past, and with a high degree of confidence in the results.

Jan 1, 2003

For Australian mining projects, sustainable groundwater use is typically defined as a groundwater extraction regime, measured over a specified planning time frame, which allows acceptable levels of stress and protects dependent economic, social and environmental values (DEH, 2004). This principle is compatible with most stakeholdersÆ understanding of our national environmental objectives, yet the application of this policy on a project-specific scale is not always straightforward. Three examples of sustainability issues in the management of groundwater in mining are presented. These examples highlight each of the three dependent values: environmental, economic and social.

Jan 1, 2006

Diversity; what a wonderful topic. Diversity; the condition or quality of being diverse, different, varied to the point that the very word diversity means different things to different people. As one example of diversity the American Science Magazine (April, 1994) contained a light-hearted interview with Dr Noitall who was pushing his case for diversity.

Jan 1, 1996

By B Olsson, B Reynolds, R Norman

An unprecedented growth in demand for coal exports has placed pressure on multi-user coal chains to guarantee that their capacity expansion projects will meet the required demand. These projects, however, are taking place in an increasingly complex commercial and technical environment - competing rail and coal terminal service providers as well as a myriad of competing mine operators, all needing to operate in an increasingly integrated manner to get the most out of expensive shared assets.Increasing system complexity and integration has driven the need for more holistic and sophisticated analysis tools. The capacity of coal chain subsystems, such as mine, rail and port, can no longer be determined effectively in isolation. Understanding the nature of the interactions between these subsystems, their sensitivity to uncertainty and the resultant capacity of the integrated system is the key to both maximising value and minimising risk.Recently, TSG has worked closely together with the Integrated Logistics Company and a number of key stakeholders in the Dalrymple Bay Coal Chain to develop independent system master plans. These master plans have provided a quantitative and rational assessment of coal chain capacity in its current state and a prediction of its capacity once a pipeline of committed capacity improvements is in place. This paper provides an overview of the study and a comprehensive guide to the process required to effectively achieve valuable strategic insights in a challenging multi-user stakeholder environment.CITATION:Reynolds, B, Olsson, B and Norman, R, 2012. Using independent system simulation to mitigate risk in the Dalrymple Bay Coal Chain, in Proceedings Project Evaluation 2012 , pp 77-84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By B Saunders, J Carpenter

PanAust’s Phu Kham copper-gold operation (Phu Kham) in Laos is currently limited by throughput in the Semi Autogenous Grinding (SAG) mill. The ability to accurately predict SAG mill throughput (throughput) is therefore critical to accurately forecast copper and gold production. During the fourth quarter of 2016 the proportion of hard unweathered rocks in the mill feed increased, resulting in a period of lower than expected throughput. These low throughput rates prompted a study with the aim of identifying a practical solution for throughput predictions. The study identified an empirical modelling approach based on actual SAG mill throughput rates. The empirical model was then optimised by linear programming to identify the ideal feed blend of unweathered rocks to achieve a maximum SAG mill throughput.Rock strength was the initial focus of the throughput study at Phu Kham because previous studies had identified a strong link between rock strength and throughput. It was determined that there was insufficient valid data to adequately model but sufficient data to qualitatively characterise rock strength. The data identified that the weathering and lithology had a controlling influence on the rock strength. Complicating throughput predictions were operational improvements (changes to blasting and mill settings) implemented in response to the lower than expected throughput. This created uncertainty with the throughput equations. A self-learning empirical modelling method was developed to predict the throughput by incorporating fundamental rock properties with operational practices and improvements. The method is based on the proportion of mill feed with similar weathering and lithology (a proxy for comminution performance) and the actual mill throughput using the SAG mill as the analytical instrument. The modelling method simultaneously incorporated the sum and interaction of unmodelled influences including blasting, crushing and mill settings. The empirical modelling method worked at Phu Kham because the lithology and weathering has an intuitive and observable controlling influence on SAG mill throughput. The modelling method is described along with a worked example of feed blend optimisation using linear programming.CITATION:Carpenter, J and Saunders, B, 2017. Empirical mill throughput modelling and linear programming for blend optimisation at the Phu Kham copper-gold operation, Laos, in Proceedings Tenth International Mining Geology Conference 2017, pp 291–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

The following paper outlines the types of employment immediately available to graduates following their university degree, a discussion on mine manager requirements, mentions career advancement and time frames to achieve this as well as providing some key information regarding student vacation work. The author hopes to educate present graduates, as well as inform students of characteristics to develop the most opportunities in life.

Jan 1, 2006

By H Kurth

Mining geologists utilise many technologies to map, sample, measure, model and plan before and during the mining process. Predicted ore quality rarely corresponds with feed quality determined by process operators. Objectively measuring conveyed material quality accurately in real time avoids disagreements over mined ore quality and generates opportunities to improve mill feed quality.This paper discusses the well proven PGNAA (prompt gamma neutron activation analysis) technology used in the GEOSCAN-M elemental analyser that is ideally suited to measuring composition of primary crushed conveyed material in real time. Representative, continuous, fully penetrative measurements are unaffected by particle size, belt speed, mineralogy, dust or layering on the conveyor. Material can be directed to processes or stockpiles by utilising measurement increments of typically one to five minutes and then activating diverters to direct increments to the correct location. Waste, low-grade or deleterious material can be rejected to waste dumps or stockpiled for later processing. Material meeting a product specification can bypass unnecessary processing. Paybacks in weeks have been achieved for such applications. Process operators are able to control the blend of ores fed into the mill to improve processing performance and use measurements for ore reconciliation and metal accounting. Utilising the technology to upgrade ore quality after mining and before processing is beneficial in improving plant economics.The technology has been successfully utilised in base metals, ferrous metals and industrial minerals. Mining geologists can determine ore quality being produced in real time and modify the ore quality prior to milling. Ore feed quality measurements are also used by process operators in optimising plant performance. The elemental content can help identify geometallurgical domains as well as other major changes in quality, which may affect processing. This paper outlines proven applications and case studies and proposes some innovative applications.CITATION:Kurth, H, 2017. Measuring ore quality using real-time on-belt elemental analysis – more than grade control, in Proceedings Tenth International Mining Geology Conference 2017, pp 213–220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Y Pan

The recycling of steel is a crucial aspect of the shift toward a sustainable metals industry. The emphasis on steel recycling through the introduction of the scrap based mini-mill concept is also matched with a desire for greater product quality and reduced environmental impact, which, in turn, has generated important innovations. There have been significant advances in the technology for recycling steel over the last 20 years and this paper will provide an overview of these developments and discuss future directions in steel recycling including scrap management, control of tramp elements, electric arc furnace technology and ladle metallurgy.

Jan 1, 2004

By T van Niel, M Trefry, B Baker, I Rea, A Hawdon, D McJannet, D Boadle, R Fandrich, A Littleboy

Many open cut mines extend to depths well below the natural water table level with constant dewatering required to maintain operations. When mining activities cease the groundwater starts to fill the void and pit lakes form. The resultant pit lake is directly connected to the surrounding water table and understanding the hydrological and chemical evolution of these lakes is important for minimising environmental impacts. In Western Australia alone there are currently 1800 mine voids and more than 150 mines operating below the water table (Johnson and Wright, 2003). In conjunction with BHP Billiton Iron Ore, CSIRO has been undertaking research to measure and model rates of evaporation from pit lakes in the Pilbara region of Western Australia. Extreme high temperatures and low humidity ensures that this region experiences the highest evaporation rates in Australia.CITATION:McJannet, D, Hawdon, A, Boadle, D, Baker, B, van Neil, T, Littleboy, A, Trefry, M, Rea, I and Fandrich, R, 2016. Measurements and modelling of evaporation from abandoned mine pit lakes, in Proceedings Life-of-Mine 2016 Conference, pp 106–109 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By E Nettleton, A Melkumyan

A probabilistic system for autonomous tracking of excavated ore in mining would be highly valuable. Currently, mine sites can have a vast array of sensors; examples include excavator load cells, bucket volume estimators and haul truck strut pressures which can be used to gather information about the excavated ore at different locations. These sensors can be utilised efficiently to increase the accuracy of mine estimates by introducing a real-time ore tracking system. This requires the introduction of a probabilistic ore tracking framework to consistently fuse information from any sensor input. Current modelling practices are manually intensive, deterministic (no recognition of the quality of data) and generally not a complete end-to-end system. This paper will provide a novel method for tracking extensive ore properties (mass, volume) and intensive ore properties such as chemical composition (eg Fe per cent, SiO2 per cent, Al2O3 per cent). This method is proved to ensure that correct correlations between states are conserved as material is transferred, combined and/or separated at different locations with any configuration of sensor inputs. This ensures that consistency of estimates is maintained and other benefits such as real-time probabilistic reconciliation can be implemented. A method for combining material of different mass and chemical compositions is also developed to enable accurate and efficient operation of the system. Representative experiments on a small-scale and a larger field trial which mimic the mining processes of excavation, haul and unload to ROM Stockpile will be used to verify the approach.

Sep 26, 2011

By A Bennett, S Arndt

Minerals and Metals Group Pty Ltd (Golden Grove Mine) commissioned a comprehensive study of the life of mine using advanced 3D stress modelling. Essential input into the modelling was the proposed mining sequence, itself the culmination of years of planning and geotechnical experience gained in comparing actual performance to predictions. The modelling approach addressed the whole of mine at a scale of 5 km. There were however several magnitudes of scale to address, from the scale of laboratory testing (0.05 m), to drive size (5 m), extraction size (50 m) and stope size (500 m). Scaling was therefore an integral part of the procedure. The constitutive rock properties in terms of peak and post-peak behaviour varied with the scale. At the laboratory scale, the constitutive relationships for all the main rock units were determined in 3D as well as recovering the in situ stress using the rock memory technique, deformation rate analysis (DRA), whereas at the larger scale the properties were varied to match observations.The modelling, using non-linear analysis to account for rock mass yield and peak-residual strength, demonstrated that if the planned extraction sequence and stope geometry had been pursued there was a high probability of large volumes of excess shear stress being released. However, it was not possible to identify whether the excess shear stress (ESS) will release as one large event or many smaller events. The mining approach was to modify the extraction sequence/stope geometry to manage the hazard. This is where the economic advantage can be realised.Alternatively or in combination with further modelling, the volume identified with the predicted high ESS or energy release could be intensively explored for structures having adverse orientation to the stress change and with sufficient areal extent to release the ESS. The microseismic data can be interrogated for the likelihood of a large event to support the hypothesis of a singular release versus multiple releases of smaller events. If the initial planned extraction sequence had to proceed as designed, changes to dimensioned stopes would be recommended for risk mitigation. Mine planning could as an option, modify the sequence and the extraction could then be remodelled.CITATION:Bennett, A, Arndt, S and Dight, P M, 2014. The economic advantages of detailed geotechnical assessments for extraction sequencing, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 243–250 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014