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The purpose of this study was to investigate the effectiveness of froth fl otation for the recovery of gold from the gravity tailing stream of the former Lihir Gold Limited (LGL) operation in Ballarat. The P80 of the tailings was determined by screen analysis as 1 mm, with test work conducted on as received material along with samples ground to P80 sizes of 47, 78 and 134 microns. Laboratory scale batch flotation tests were conducted at both natural and elevated pH to investigate the impact of pyrite depression on gold recovery. Results indicated that although an increase in grade from approximately 0.7 g/t to 3 g/t was achievable at a natural pH and a P80 of 134 micron, gold recovery was low at just 35 per cent. Finer grind sizes were found to have an adverse effect on both grade and recovery. Future efforts will be focused on the sub 310 micron size fraction of the tailings, which was revealed to contain approximately 85 per cent of the available gold and may be amenable to cyanidation or ultra-fine gravity treatment.

Aug 1, 2010

By G D. Matthews, M E. Haylett, S Khosrowshahi, A Weeks

Effective domaining is fundamental to geostatistical modelling for grade control. Through analysis of lithological, structural and alteration logging data, effective groupings (domains) can be identified and employed for estimation or simulation purposes.The poor definition of domains can adversely affect the grade control model resulting in a misinterpretation of the optimal ore-waste boundary and ultimately reduces the quality of recovered ore. The implementation of an appropriate domaining strategy is therefore expected to improve recovery and reconciliation.A thorough understanding of the geology of the deposit and adequate sample data is required for selecting domains. For new deposits, a resource drill database and resource model may be the only information available. Where extension to a previous operation is taking place, historic grade control, mapping and exposed geology may be used to improve domain selection. Preconceptions about domains, should they exist, need to be re-evaluated and tested to ensure they are fit for the purposes of grade control.While mining progresses, the domain model is re-evaluated to ensure that the previous interpretation is still suitable for the present configuration and geology. The grade control process, being iterative, lends itself to regular review and continuous improvement as further data is collected during the grade control cycle. Regular updates to the geology model, mapping, geostatistical data analysis and review of variography will provide indications of a changing domaining environment.Narrow vein gold deposits, which may have several factors influencing mineralisation, present considerable domaining challenges. By scrutinising the data, sample populations can be grouped into domains, which not only improve ore recovery, but help assist in the development of a mine geology model.CITATION:Matthews, G D, Haylett, M E, Weeks, A and Khosrowshahi, S, 2014. Effective domain selection for grade control in narrow vein gold deposits, in Proceedings Ninth International Mining Geology Conference 2014 , pp 191–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

Visual computing opens the design process to a wider audience and allows rapid communication of mine plans to all stakeholders. The integration of software and hardware technologies that take advantage of a graphical environment will continue to improve both long-term and short-term mine design (Figure 1). A good design must be adaptive to respond to decision changes as the mine develops and more information becomes available. The constraints on mine design predicate careful analysis in order to operate the mine as efficiently and safely as possible.Continuous improvement in mining is assured by developing innovative technologies that target mine survey, drill and blast, modelling, short-term design and pit and stope optimisers. The design life of a mine has to be sufficiently long to ensure the mine is commercially successful, justifying the high start-up capital costs. Being able to execute a plan so that it honours the design realises the rewards of computerised mine planning and the long-term investment in data acquisition.

Sep 26, 2011

The economic viability of many Southern African massive mining operations is threatened by excessive dilution. In many operations currently in progress, some stopes are experiencing as much as 115 per cent waste ingress reporting to drawpoints. This paper examines the magnitude, causes and types of dilution and presents a set of general principles for the control of dilution in massive stoping operations.

Jan 1, 2000

By G Balog, T Ormerod, D Sidea

Carrapateena is a copper-gold sub level caving operation located in the Gawler Craton, South Australia. One of Australia’s largest undeveloped copper deposits, the project will be a 4.25 Mtpa underground operation, with an estimated mine life of 20 years (OZ Minerals, 2017). First concentrate production was achieved in December 2019, within the Iron Ore Copper Gold (IOCG) hematite breccia complex. The Carrapateena orebody is overlain by 500 m of barren sediments of the Stuart Shelf, which hosts two aquifers. The cover sequence is dominated by shales, quartzites and sandstones in order of thickness. The cover sequence presented challenges to the mine ventilation system as a result of highly variable rock strengths. On this basis, the site developed the first vent rise, Vent Rise 5 (VR5), earlier than required as a means to test the empirical stability assessment. Assessment for VR5 was completed in 2017, with the mine yet to develop through much of the cover sequence. Due to the geotechnical data available at the time, it was anticipated that break out would occur within the vent rise walls as a function of the low strength Woomera shales. VR5 was developed to 4.5 mᴓ in late 2018. The timing of the VR5 development enabled the site technical team to calibrate empirical stability factors for the assessment of future vent rises. At the time of writing, four additional vent rises have been successfully developed to a diameter of 5.5 m. No significant overbreak has been observed within any of the vent rises. This paper is intended for geotechnical practitioners designing large-diameter vent rises in geological environments similar to the Stuart Shelf where a similar approach to vent rise design may be warranted.

Mar 15, 2021

By C Mark, Z Agioutantis

This paper presents an empirical design methodology that is based on successful US roof support systems using both primary and secondary support in coal mining entries and intersections. The recent nationwide dramatic reduction of roof fall rates, especially in areas with weaker roof, can be directly correlated to the effectiveness of the roof support systems. A large database of roof fall histories at several mines is used to define the approximate boundaries of three modes of roof support with respect to roof strength as classified by the Coal Mine Roof Rating (CMRR) and in situ vertical stress as indicated by the depth of cover. These roof support classifications are: • Suspension, where roof bolts mainly provide skin control for strong roof. • Beam building or reinforcement, where a roof of moderate strength can be supported by roof bolts only. • Supplemental (secondary) support, where the primary support by roof bolts may be augmented by several secondary support systems, eg cable bolts, trusses, additional roof bolts or standing supports. The Primary Support Rating index (PSUP) captures the capacity of the primary roof bolt system as a function of the actually implemented roof control plan, ie roof bolt length, roof bolt density, and roof bolt capacity, while it does not consider the type of bolt. The actual PSUP value is compared against a suggested PSUP value derived from statistical analysis of US case histories. Where secondary support is indicated, the expected rock load determines the necessary capacity of the secondary support system. A new (free) software package, Analysis of Mine Roof Support (AMRS), implements the design methodology and also allows comparison with other international indices such as the Reinforcement Density Index (RDI), the PRSUP, etc.

Nov 29, 2022

By T Belligoi

Diamond cores and drill chips provide the only direct physical evidence for ore containing rocks. Early characterisation of cores and drill chips is important as it provides critical information for downstream processing. Traditional characterisation techniques include visual logging by a geologist or analytic and spectroscopic methods but they are time consuming and can miss some important textural or geomechanical features.The goal of this work is to evaluate the application of image analysis to iron ore cores and drill chips and to suggest improvements to existing core-scanning and chip monitoring systems. Two samples of massive ore differing by their mineralogy and texture, as well as two different batches of drill chips, have been imaged and analysed. Results are compared in function of the imaging system and the classification algorithms.As a conclusion, despite the necessity for more testing and improvements in calibration and lighting, it is obvious that image analysis technologies can bring a lot of useful information in the perspective of a geometallurgical mapping of the deposit.

Jul 11, 2011

By I D. Gregson, A Gandhe, A S. Garcia, K M. MacAndrew

"Falls of ground still cause around one-third of all underground mining fatalities. The recent introduction of mechanised room and pillar working into Indian coalmines is an example of the application of new design by measurement and safety monitoring strategies, which can be used to reduce falls of ground risks in mines.Rock Mechanics Technology, now part of Golder Associates UK Ltd (Golder), is providing rock bolt support and pillar design services to the mines using a design by measurement approach. This involves in situ monitoring to confirm support and pillar designs and pillar extraction sequences.Site examples are given of the support designs determined and the monitoring programs undertaken for both design and safety.Routine safety monitoring of roof movement using telltales is also described. A new auto warning telltale has been developed specifically to warn of imminent caving as pillars are extracted.The approach used by Golder has played a major role in ensuring the success of these projects. As a consequence, mechanised room and pillar working is now firmly established in India, and wider application is planned to help meet future demand for coal.The experience confirms that the design by measurement method for this application has important advantages over conventional design approaches using analytical or empirical methods. Firstly, it measures the design performance or outcome rather than trying to calculate or predict it. Secondly, it provides the opportunity for the design to be adjusted to obtain the optimum outcome. Thirdly, it can do this at a local level, so that the support design can be matched to changing conditions to give the most cost-effective design. Finally, it incorporates long-term monitoring of support performance, again at a local level, so that subsequent change can be identified to enable corrective measures to be implemented in a timely manner and to ensure that ground control safety is maintained.CITATION:MacAndrew, K M, Garcia, A S, Gregson, I D and Gandhe, A, 2014. Application of design by measurement for support and pillar design in mechanised room and pillar coal mining in India, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

By P Moser, R Ivanova, F Ouchterlony

This paper describes model-scale bench blasts on mortar blocks with distorted drill hole patterns, done in 2013–2014 at the Montanuniversitaet Leoben. The main aim of the project is to see if the fragmentation from and the crack development behind blasts with and without drill hole deviations differ significantly.The dimensions of the test blocks were 660 × 280 × 210 mm (L × W × H). They were mounted inside a yoke that allows the blast waves to escape (see Figure 1). Three rows in each block were shot row by row with a nominal pattern of B × S = 70 × 95 mm. The same nominal delay 73 µs (ie 1 ms per m burden) between holes was used throughout. Blocks with holes of stochastic collar position errors (variations in burden or in burden and spacing but constant row volume) and systematically shifted collar positions (blasts with staggered pattern) were shot. The results were compared to reference blocks without collar deviations.Apart from the sieving analysis, the remaining bench faces were measured with a stereo-photogrammetric method and horizontal roughness profiles for each row were constructed. Sawing slabs from block remains after the third row and use of dye penetrant allowed the study of internal blast damage.The analysis showed that none of the changes in borehole collaring had a significant effect on the sieving curve (median). The sieving results confirm earlier findings though that the fragmentation gets finer with the number of rows shot, implying that blast damage from earlier rows has an influence on the blasting results. The tests demonstrated that the nequiv (equivalent n-value) has increased ten per cent by shooting staggered pattern and decreased by seven per cent by pattern with burden and spacing errors. For the rest of the patterns, the nequiv was roughly the same.The surface roughness investigation showed that a smooth surface was achieved by the staggered pattern. The other deviations patterns did not show a clear trend.The internal blast damage, which was measured in the remaining part of blocks, showed that out of eleven, four crack families seemed to be most affected by blasting. The comparison of the reference and distorted patterns showed that less cracks were apparent for the staggered pattern, ie less damage was introduced.CITATION:Ivanova, R, Ouchterlony, F and Moser, P, 2015. Influence of distorted blasthole patterns on fragmentation as well as roughness of, and blast damage behind, remaining bench face in model-scale blasting, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 693–706 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By R Morrison, R Dunn

In many mineral processing operations, the reported production figures for an accounting period may not make the best use of available data. While most of the mathematical approaches, such as check-in/check-out, mass balancing, used in effective metallurgical accounting strategies are well understood, the sources and magnitude of measurement errors generally are not. As part of the æAMIRA P754-Metal Accounting and ReconciliationÆ project, a study was undertaken at the Northparkes copper/gold concentrator near Parkes, New South Wales to examine the data used in their concentrator metallurgical accounting system. This paper summarises the results of a detailed examination of the mass measurement systems around the concentrator as well as the primary sampling system used for grade estimation. The goal of this work was to develop practical techniques to quantify the error (ie both accuracy and precision) of the measured metal accounting information. With this information, statistical confidence levels for this data can then be calculated. If the errors are small, the effect of error in each piece of measured data can then be propagated to other calculated production figures such as recovery and feed grade using a statistical technique called æthe propagation of errorÆ.

Jan 1, 2007

By A Datar, D Mulligan

The extractive phase of broad-scale mining can have major impacts on landscapes and associated ecosystems. Post-mining ecological rehabilitation typically starts with reconstructing topography. A fairly common industry practice has been to use landform elements such as plateaus, terraces, and gentle slopes for stabilisation purposes. However, this approach can lead to the generation of fairly uniform landforms that do not necessarily reflect natural ecosystems. Previous research in undisturbed and agricultural landscapes shows that ecological attributes and diversity in microclimates is positively correlated with landform heterogeneity. An objective of this study was to investigate if those findings are still valid in post-mining rehabilitating landscapes on North Stradbroke Island, Queensland, Australia. We investigated the relationship between landform heterogeneity and status of ecological recovery. The landform heterogeneity is measured through variance in three landform characteristics (relief, slope, aspect) using remote-sensing data and the status of ecological recovery is represented by ecological indicators measured through field surveys. The results indicate strong correlations between landform heterogeneity indices and native vegetation species richness with sensitivity to the spatial scale of investigation. It is recognised that climate, substrate and rehabilitation practices act as primary drivers of rehabilitation success. However, the results indicate that, in some examples, landform heterogeneity (heterogeneity in relief and slope angles) contributes up to 30 to 50?per?cent of the variance in native vegetation species richness. While the primary drivers of ecological recovery are difficult to control over extensive areas and extended time periods, landform heterogeneity provides a tool to indirectly control the micro-environmental parameters to improve ecological recovery. Reducing the uncertainties in the choice of ecological and landform indices and the degree of landform heterogeneity suitable for particular rehabilitating landscapes would be site specific. The introduction of desired landform heterogeneity may provide a very effective tool for significant improvement in ecological rehabilitation across broad-scale post-mine landscapes, an outcome of benefit to industry, government and local communities.CITATION:Datar, A and Mulligan,?D,?2014. Do we need to change the way we set up the stage?, in Proceedings Life-of-Mine 2014 , pp 29–46 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By N Haque, S Northey

Water in mining, mineral processing and metal production on a life cycle basis has been at the top of agendas for various industries, government agencies, research organisations, academic institutions and communities. As a result, a number of water footprint assessment methodologies have been developed. However, their practical applications in mining and mineral processing industries with specific case studies are still rare.A key objective of the Minerals Down Under Flagship is to contribute to the long-term sustainability of the Australian mining and mineral industries. Researchers in the Mineral Futures theme have developed robust assessment methods to evaluate the impact of mining and minerals technology development on the environment. The future of mining and the mineral industry is strongly linked with its sustainability - better water management strategies will need to be implemented.Life cycle assessment (LCA) has been a recognised method for measuring the environmental impacts of products, processes and services. It provides a scientifically sound method of comparing products and processes using a common basis and identifies so called æhot spotsÆ and opportunities for reducing environmental impacts. The water footprint of mining, mineral processing and metal production using an LCA basis is still scarce in the literature. Research methodology is now being applied in detail for copper, gold and nickel. A primary focus has been the relationship between ore grade and water use for which mathematical models are being developed. These types of models provide inputs for LCA of mining and mineral processing plants and can identify water saving opportunities through scenarios and process route analysis.CITATION:Northey, S and Haque, N, 2013. Life cycle based water footprints of selected mineral and metal processing routes, in Proceedings Water in Mining 2013 , pp 35-50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By J J. Robinson, B N. Noller, D M. Franks, G McIlveen, D R. Mulligan, A T. Soro

Fiji is a developing nation that relies on economic opportunities and recently experienced increased interest in mining and mineral exploration that could potentially benefit the country. In order to understand the lack of, or failure of, past rehabilitation activity, this study applied risk-based approaches to identify the significance of activities or actions applicable to rehabilitation of post-mined land in Fiji. This involved the use of qualitative, semi-quantitative and quantitative risk methodologies, which allow assessment and evaluation of mechanisms of mining administration and practices, as well as rehabilitation methods and approaches that have been applied successfully to post-mined land in other countries with similar environmental and climatic conditions and social and regulatory environments to Fiji. The semi-quantitative risk-based technique followed an earlier approach applied for mine closure by Laurence (2006) and provided a systematic way to assess and evaluate rehabilitation issues that were identified on-site by assessors, who were able to estimate through expert judgement the likelihood and consequences based on conditions, situations observed and circumstances on-site. It demonstrated that experienced professionals could reproducibly score likelihood and consequence of selected items relevant to mine site rehabilitation, despite the wide-ranging issues identified during post mined land rehabilitation. The quantitative risk-based approach was adopted as a method to determine environmental bonds for mining projects using the assessment of consequences and likelihood results from the semi-quantitative approach, then incorporating unit cost of materials or activities for local conditions required to fully rehabilitate each issue at net present value. Application to both an abandoned mine site and a newly opened mine site in Fiji showed that this approach could provide a risk-based estimate for rehabilitation cost and demonstrated potential applicable in the Fijian context.CITATION:Soro, A T, Mulligan, D R, McIlveen, G, Franks, D M, Robinson, J J and Noller, B N, ?2014. Risk-based Rehabilitation Strategies for Post-mined Land in Fiji, in Proceedings Life-of-Mine 2014 , pp 165–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By S McEachern, J Lowe

An important issue currently facing the mining industry in Australia is the management and cost to the industry and other stakeholders of entry into and exit from towns and their communities. These costs can be environmental, social, economic, political or reputational. The ability of companies to engage the trust of stakeholders, including: communities, governments and investors, is critical, and corporate reputation plays a significant role in this. For the industry to secure a long-term and sustainable future, it must have the technical, business and reputation assets to proceed in a cost-effective, environmentally acceptable and socially supportive way. This research assesses reputation as a critical competitive issue for mining companies, as technology and information make mining more predictable; the physical and human assets of mining companies are less likely to be the critical resource in a Resource Based View model of competitive advantage. The proposition is that in mining today, reputation as it facilitates day-to-day operations, regulatory zeal and access to new mine sites will become the rare, inimitable and valuable resource for mining companies. This paper reports on an ongoing research program to evaluate the impact a mining companyÆs reputation(s), with its various stakeholder groups, has on a companyÆs ability to sustain competitive advantage. Integral to this study is to develop an understanding of the relationships between mining companies and their stakeholders, and the importance of corporate citizenship polices to reputation and hence to corporate sustainability. Through the identification of the drivers of reputation for the various stakeholder groups, a model of reputation formation will be developed and also reputation measures for the mining industry in Australia. The preliminary findings of this research, the results of an industry focus group conducted with representatives from regional mining operations, are reported. The industry focus group was designed to enable a better understanding of who are the main stakeholder groups and how they regard mining companies and to inform the second stage of the research project a Delphi Study of the drivers of reputation by stakeholder groups. The aim of this research is to further the understanding of the relationship between corporate citizenship, reputation and performance in the mining industry, thus assisting companies to strategically manage their corporate citizenship investments.

Jan 1, 2006

By C J. Pitzer

The prevention of fatal risks is a key objective for the global resources industry, especially considering poor performance with regard to fatality rate reduction and the continued occurrence of mine disasters globally. However, the industry has a credible history, over several decades, of the development and deployment management systems to control potential Serious Injury, Fatal and Catastrophic (P-SIFC) risks. While these systems have had a significant impact on the thinking and approaches to the prevention of fatal risks, fatal accident rates have not shown the desired reduction. Recent fatal and serious injury events in Australia have led to the establishment of several enquiries to further identify improvements that could be considered. Globally, fatal accident rates remain stubbornly high or plateaued in many jurisdictions, and several catastrophic events have occurred, such as tailing dams disasters in Brazil and South Africa, and the recent coalmine disaster in Turkey. Apart from the apparent lack of progress, it is evident that the deployment of critical risk systems has introduced more bureaucracy, slower response systems and additional burdens on already overloaded middle and supervisory levels of management. Organisations are rarely able to effectively tap into the risk source of risk knowledge of the frontline worker and supervisor, for various reasons discussed in this paper. To establish a valid and valuable channel of critical risk information flow from the frontline employee, Debmarine Namibia instigated the development and deployment of a system called SafeSENTRY, where the focus is on the ‘dynamic identification of dynamic risks’. This paper outlines the system, the principles of the design, the range of risk metrics that can be derived from the observations of the frontline operators, and demonstrates how a range of posited shortcomings in critical risk management is addressed how features of the High Reliability Organization (HRO) have been developed.

Mar 29, 2023

By M J. Newton

As part of the AMIRA P843 project Keeney and Walters (2008) describe how the principal components analysis (PCA) method can be used to identify classes of samples with similar metallurgical characteristics. However PCA does not take account of the location of each sample in 3D space. This paper describes a study to analyse the spatial distributions of the classes and determine appropriate modelling methods to control the estimation of the comminution parameters and mill performance indices into a 3D block model. This includes but is not restricted to geostatistical techniques that are used for grade modelling. The starting point for the study is the class definitions and the regression models for estimating the comminution parameters and performance indices. Each sample is assigned a class and the spatial distribution of each class has been analysed using different techniques including the calculation of variograms. This establishes whether the classes can be used as domain control for estimation into the block model – a procedure similar to using geological rock type domains for controlling the estimation of grades for a resource model. However, standard geostatistical estimation methods such as ordinary kriging assume that the variable being estimated is additive or linear. This assumption is valid for variables such as grade but this is not necessarily the case for the comminution parameters or the performance indices. Therefore the estimation procedure must either use variables that are definitely additive or the effect of potential non-additivity must be tested and accounted for where possible.The results of the study show how performance indices such as recovery, throughput and specific power can be estimated into the block model. This model is then combined with the geological model to provide a multi-parametric model that is used to optimise the mine planning and scheduling activities which can lead to significant improvements in NPV.

Sep 5, 2011

Sheaves are a critical safety component in a winding system and are expected to survive such extreme loading events as rope break. Sheave designs have often been developed and evolved empirically, consequently many existing sheaves are not necessarily subjected to the detailed analyses that are possible using todayÆs design tools. The design philosophy for sheaves is that the rope should be the weakest link in the system so that associated equipment can function safely for any load up to rope break. A number of failure mechanisms must be considered, but buckling is often prominent. During the course of investigating the feasibility of upgrading the hoisting capacity of a winding system, the capacity of all critical components was reviewed. The sheaves in the system were found to have insufficient spoke buckling capacity for the specified rope. A proposal to increase the spoke buckling capacity by connecting spokes together using a simple tie arrangement was evaluated and found ineffective. An alternative tie arrangement concept was developed and evaluated and shown to be adequate. This paper describes the finite element model, analysis approach and results for the original sheave and the two modifications. The contribution of the sheave rim to the total buckling capacity is evaluated. Some practical issues for spoke tie modifications are discussed.

Jan 1, 2005

By B Twidle, D Bertoldi, J Meikle, R Dunne

The Waihi Gold Mine is situated in a high rainfall area (annual average of over 2 m) on the North Island of New Zealand. Water treatment and discharge at the mine has been ongoing for the last 25 years. The first water treatment plant consisted of a æstandardÆ water treatment facility (ferric chloride precipitation) and cyanide detoxification. With time the project has expanded and the volumes of water increased requiring additional treatment methods (reverse osmosis) to meet the water quality for discharge. This paper will provide information on the historical development of the water treatment flow sheets, performance data and operating costs.CITATION:Bertoldi, D, Dunne, R, Twidle, B and Meikle, J, 2013. Water treatment at the Waihi Gold Mine, in Proceedings World Gold 2013 , pp 503-508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By K Williams, T Donohue, W Chen, T Roessler, A Katterfeld

Wet sticky iron ore poses particular difficulties in every aspect of the material handling process. Material hang-ups in bins, pipes and chutes; carry-back and spillage due to insufficient belt cleaning; clogging of screens; malfunctioning of crushers as well as rat holing of gravity reclaimed stockpiles are all predominantly due to the inherent cohesion and adhesion characteristics of the wet, sticky ore (Roberts, 1993). Limited understanding and quantitative measures on the stickiness of such a material significantly lower the mining operation efficiency.This research aims to investigate the cohesion and adhesion characteristics of the wet, sticky ore on physical modelling, experimental techniques and numerical implementation. Initially, the suitable bridging mechanism that contributes to the cohesive and adhesive forces within the iron ore material was identified (Hering, Martin and Stohrer, 1989; Rumpf, 1958). A cohesion/adhesion energy density factor based contact model was then introduced to describe the stickiness of the material. Secondly, an experimental system was proposed to directly test the stickiness of the material. Such a system is able to obtain both the cohesive/adhesive shear force and tensile force of the material at a specific moisture content. Lastly, the implementation of the proposed cohesion/adhesion model into the discrete element modelling (DEM) software was also discussed. A cohesion/adhesion calibration for modelling wet sticky iron ore in DEM was then conducted to ensure the material modelled in the simulation is reflective of the reality.From the study, understanding of the cohesion/adhesion characteristics of the wet iron ore material is significantly enhanced. Experimental and numerical outcomes can be directly applied for better designing or optimising the material handling processes that involve wet sticky iron ore. Consequently, the mining operating costs can be greatly reduced.CITATION:Chen, W, Donohue, T, Williams, K, Katterfeld, A and Roessler, T, 2015. Modelling cohesion and adhesion of wet, sticky iron ores in discrete element modelling for material handling processes, in Proceedings Iron Ore 2015, pp 387–392 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

The cloud transform simulation is a technique used to generate realisations of correlated attributes. The principle of this technique is to partition the scatter diagram between the input attributes into several interval classes and derive for each class a cumulative distribution function (CDF) using only the data pairs of the scatter diagram in that class. The simulation then proceeds like a traditional Monte Carlo simulation but using the derived CDF in each class.The cloud transform simulation has the advantage of being a simple and fast technique that is able to reproduce the uncertainty in the relationship between the two input attributes regardless of whether the relationship is linear or not. However, the technique has three major drawbacks. First, the number of classes has an impact on final simulated results and there is not a robust approach to define such number. Second, simulated results exhibit some saw tooth variations that are unrealistic and third the reproduction of the spatial continuity of the simulated attribute is not guaranteed.This paper presents the use of the quantile regression approach in order to overcome the first two disadvantages of the cloud transform simulation. Details of the technique and how it can be coupled with the cloud transform simulation are presented along with a real case study.

Sep 26, 2011