Search Documents

By E Ruhanen, S Kauvosaari, M Kosonen, C Meintjes

The Yara Siilinjärvi plant is located in the central part of Finland. Siilinjärvi is Western Europe's only apatite mine and annually it produces 1 Mt of apatite concentrate, which creates approximately 10 Mt of tailings.At the beginning of 2017, tailings handling in Yara Siilinjärvi was brought to a new era, by replacing the conventional tailings storage facility with a new tailings treatment plant. The new high-density tailings disposal system with two paste thickeners increased the percentage of solids in the slurry from 45–48 per cent to 66-68 per cent, making it possible to deposit as a paste. This extended the life-span of the current tailings storage facility by 15 years; from 2020 to 2035.This paper presents the storyline of the Yara Paste Plant Project. The project began with laboratory testing and then progressed to pilot-scale thickening and beaching trials. After some successful pilot trials, the final process design was implemented. Process instrumentation and automation played a key role in the project, as the aim of the Yara Project was to make the plant operable remotely from the main plant. An advanced control system is needed to maintain process stability and the desired operation point in various operational circumstances.This paper discusses the results from the Yara site since the new tailings treatment plant commenced. Some of the main points are that the operation has been running consistently with an underflow solids content of 66-68 per cent, with average beach slope angles of 3.5 degrees in the tailings disposal area. This control system additionally facilitates minimum use of flocculant, which delivers significant savings to operating costs. Robust thickener operation also leads to the trouble-free high-density pumping and high availability of the Paste Plant. During the first year of operation, the plant’s availability has been very good, over 97 per cent.Currently, the plant still has its own staff working there during the daytime, but the Paste Plant is now already operated remotely during the night shifts. The long-term goal is to gradually transition into operating the plant completely remotely.CITATION:Ruhanen, E, Kosonen, M, Kauvosaari, S and Meintjes, C, 2018. Optimising the operation of paste thickening at the Yara Siilinjärvi Plant, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 297–310 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By P F. Hodkiewicz, J de Lacey, M Stewart, R Lane

"Implicit modelling is an approach to spatial modelling in which the distribution of a target variable is described by a unique mathematical function that is derived directly from the underlying data and high-level parametric controls specified by the user. This modelling approach may be applied to discrete variables such as lithology (after converting the discrete codes to numeric values) or to continuous variables such as geochemical grades. This paper discusses the estimation of continuous (grade) variables using implicit modelling.One of the underlying engines of implicit modelling for producing this mathematical function description is the radial basis function (RBF). In essence, the RBF is a weighted sum of functions positioned on each data point. A system of linear equations is solved to derive weights and the coefficients of any underlying drift model coefficients. Once derived, the RBF may be solved for any unsampled point or averaged over any volume to provide an estimate of grade. It is possible, for example, to query the RBF on a regular grid to derive an estimate of block grades. Given the ease of creation of an RBF, and its ability to predict grade, the question arises as to how the grades derived from the solution of an RBF compare with grade estimates derived from conventional geostatistical interpolation methods (eg ordinary kriging (OK)).The purpose of this paper is to describe in lay terms: the basic structure of an RBF the role of parametric choice in the solution of RBFs and how this influences the character of the solution the fundamental similarities and differences between RBFs and conventional geostatistical estimators.Using a high-resolution conditional simulation, we show that in many situations RBF and OK estimates are very similar.CITATION:Stewart, M, de Lacey, J, Hodkiewicz, P F and Lane, R, 2014. Grade estimation from radial basis functions – how does it compare with conventional geostatistical estimation?, in Proceedings Ninth International Mining Geology Conference 2014 , pp 129–140 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 18, 2014

By P Ramsaywok

The use of saline water for mineral beneficiation in arid regions is general practice and also the case with Exxaro Namakwa Sands, situated on the west coast of South Africa. Although it is ‘cost effective’ to use sea water for mineral beneficiation, downstream process separation efficiencies may be negatively affected. This is more specific to surface dependent separation techniques such as electrostatic and high tension (HT) separation. If minimal fresh water is available then, proper washing is often neglected. Salt crystals can form on particle surfaces during the drying process before electrostatic separation.This paper describes a study that has been conducted to determine the effect of upfront salt water processing on downstream electrostatic/HT separation. The study indicated that minor quantities of salt can cause the separation efficiency to decrease substantially.

Oct 5, 2011

By L Cain, C Every, S Mirlatifi, J Ashley

This paper presents a geographic information system (GIS) based method for the prediction of ground movement and the associated impact on existing buildings and structures due to tunnelling in the North West Rail Link (NWRL) project. The NWRL is a priority rail infrastructure project for the New South Wales (NSW) Government and includes 15 km of twin tunnels between Bella Vista and Epping, which will be Australia’s longest rail tunnels. The NWRL tunnels will be constructed in an urban environment where the prediction of ground movements induced by tunnelling and the associated impacts to existing structures must be assessed in the early design stages of the project. An assessment process was developed using GIS able to respond to design changes.An iterative GIS analysis methodology was developed to generate ground settlement contours and identify impacted buildings and structures in response to multiple changes in tunnel alignment during design development stages. The GIS analysis undertook to rapidly provide detailed and accurate parameter information including tunnel depth from surface, tunnel separation, diameter and sample point proximity to the tunnel and assess ground movement contours along the project alignment. Determination of the ground surface settlements were based on empirical methods proposed by Peck (1969) and Mair (1993). The control parameters and the relationship between damage categories and risk classifications for impact assessment were based on Burland, Broms and de Mello (1977), Rankin (1988) and Boscardin and Cording (1989) methods.The GIS-based ground movement impact assessment approach adopted for the NWRL project demonstrates an efficient, iterative and robust approach and could provide an initial framework for other similar tunnelling projects where rapid design changes and early understanding of tunnelling impacts are required to bring greatest benefit to all stakeholders.CITATION:Mirlatifi, S, Cain, L, Ashley, J and Every, C, 2014. An iterative geographic information system based approach for the assessment of tunnelling impact to existing buildings and structures, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 647–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J Player, G Sweby, S Webber, E Jones

Seismic systems are a tool for the monitoring and forecasting the rock mass response to excavation. Common issues encountered at mine site audits and reviews are: how to design an effective seismic system, implementation of the design, interpretation of seismic source results and understanding the reliability of the seismic source. These issues are often a function of several items including: • Experience of site personnel in undertaking seismic system design. • Personnel not envisioning multiple phases of system expansion to understand system robustness issues. • System design/expansion occurring in response to damaging seismic activity rather than planned expansion of a system • The mine access development is often localised in comparison to the total orebody being mined hence, planning sensors in longholes in advance of development rather than in short holes close to development will improve the three-dimensional aspect of the network. • Limited site processing of the seismic event data, hence engineers do not see the uncertainty associated with event location, size, source and system layout. Mine site users require a framework to appreciate the challenges and limitations in locating large events. For example, event locations are given as precise measurements (to the nearest centimetre) whereas the volume of deformation resulting in the event often has dimensions of tens of metres or more (as defined by the source radius). A stronger awareness of the uncertainty of rock mass yield within large seismic sources will assist site users in the interpretation of rock mass damage. The encountered design and implementation errors are reviewed and discussed with a practical set of rules presented to provide a robust seismic system that provides consistent results and increases the user’s understanding of uncertainty in source location and size. The authors’ experience across multiple mine sites, seismic systems and damaging seismic events over a 30 year period has been summarised into practical rules for site personnel of all experience levels.

Nov 29, 2022

By X Y. Ma, X G. Tian, P F. Zhang, T B. Zhao, Z H. Li, Z Y. Fu

This study analysed the fracture characteristics and movement process of goaf roofs under the condition of gangue backfilled mining, based on the engineering conditions of Tangshan Mine F5001 gangue backfilled working face. The inclined borehole detection method is adopted to conduct long-term and fixed-point detection of the roof stability. The distribution characteristics of mining-induced cracks in the roof are described quantitatively based on the crack density, and a similar model test method is used to assist the analysis of the roof movement under the control of gangue backfilled mining using stress sensors and digital speckle deformation field monitoring. The results show that under the condition of gangue backfilled mining, structural cracks in the roof typically appear at the boundary of rock strata. The appearance of cracks is related to the rock strata where they are located. Structural cracks appear in the form of single cracks ahead of the working face and develop into structural cracks in the goaf. The roof movement of the coal seam develops in five stages: fracture incubation, crack extension in advance, dense fracture development, steady fracture expansion, and roof stability. Separation forms the primary component of the roof subsidence, accounting for more than half of the subsidence value. The separation generally extends over a long distance along the strike, and vertical crack-intensive areas appear in the roof above the cut-off and stop line. The findings of this study provide a theoretical basis to support designs of backfilled mining and upgrading of hydraulic supports in working faces.

Nov 29, 2022

By M A. González, J A. Romero, D L. Fuentes, C J. Poblete, O Abdrashitova

"Robustness can be defined as the ability of a system to resist change without adapting its initial stable configuration. Robust design methodology, which is widely accepted in the manufacturing industry, allows the establishment of robustness and reliability metrics in scenario analysis.In the mining industry, a mine can be considered as a system with design parameters such as processing plant and mining capacities. Traditionally, a limited number of scenario iterations are performed in an attempt to determine optimal capacity values. An important strategic decision such as process plant capacity in particular is made during the very early stages of a mining study, often based on a low level of information. Lack of time and tools to run and analyse a larger number of possible scenarios for different design parameter combinations are usually the main reasons for not performing a full analysis. In addition, the uncertainty of other mining study input parameters creates more risk in decision-making.With advances in technology, it is now possible to automate the process of generating several thousands of scenarios in an affordable and timely manner. This allows performing the results analysis and assessing robustness and reliability criteria within a reasonable time frame. It is possible to generate a surface of results based on the net present value (NPV) for each scenario. This surface will reflect the efficiency level of the capture of the economic rent for each production scale. In addition, each scenario can be tested under diverse conditions of volatility of other external variables such as prices, costs or recoveries for example.This paper aims to establish a methodology that applies robustness criteria to determine the best scenario on several surfaces of value, which is then assessed with real data from a mining project. Obtained results demonstrate the advantages of using the proposed methodology in dealing with the above-mentioned multidimensional problems. It allows better decision-making on key design parameters and better control of the risks of a strategic mine plan.Citation:Poblete, C J, González, M A, Romero, J A, Fuentes, D L and Abdrashitova, O, 2016. Use of Robust Design Methodology for Production Scale Definition in Open Pit Mining, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 284–291 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By J Theiler, B Beamish

The presence of reactive metal sulfide minerals in waste rock contributes to the hazard of spontaneous combustion in dumps, as these minerals react with air and water entering the dump at ambient temperatures to form various mineral products and significant heat. This reaction series can also be an initiator of self-heating of carbonaceous material present in the waste rocks if sufficiently high temperatures are reached. Characterisation of these reactive minerals has primarily been to assess the risk of acid mine drainage, which is not necessarily an indicator of spontaneous combustion risk. No systematic testing procedure has been adopted by industry to assess the spontaneous combustion propensity of the waste rock. As a consequence, the principal management strategy for spontaneous combustion has been a reactive approach of dealing with events as they arise.Recent advances in adiabatic oven-testing have enabled more definitive assessment of the spontaneous combustion propensity of coals, including the quantification of the accelerating influence of reactive pyrite (Beamish and Beamish, 2011, 2012; Beamish, Lin and Beamish, 2012). This same test procedure has been used to assess the self-heating performance of metal concentrates and is therefore amenable to assessing the metal sulfide oxidation process from low ambient temperatures. The data obtained from such testing can be used to quantify the more prone waste rock sequences of a mineral deposit in advance of mining. This enables appropriate management planning for emplacement and long-term storage of waste rock in dumps.CITATION:Beamish, B and Theiler, J, 2016. Characterising the spontaneous combustion propensity of waste rock, in Proceedings Life-of-Mine 2016 Conference , pp 93–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By F Musa

One of the main energy efficiency opportunities identified from the majority of mine site energy audits is to optimize the comminution circuit to reduce energy consumption through improved throughput and product size distribution. Typical analysis reviews comminution process efficiency/inefficiency i.e. utilization of grinding mills, process bottlenecks and product vs. target size, to identify instances of overgrinding or undergrinding. From this, it is possible to establish the potential improvement that could be gained through formal plant optimization and what the optimization program would entail. It can also sometimes reveal immediate opportunities for process improvement. This paper presents steps that can be taken to optimize the efficiency of comminution circuits.

Aug 8, 2011

By B T. Qin, C Zhu, Y W. Jia, Y Lu, F L. Li, Q L. Shi

Air leakage through rock fractures in coal mining is a major cause of coal spontaneous combustion. In order to overcome the deficiency of the existing fire control technology and prevent coal spontaneous combustion by isolating coal from oxygen, the article proposes a novel technology of inorganic solidified foam (ISF) with high expansion to fill fractures effectively. ISF consists of fly ash, cement, setting accelerator, redispersible polymer powder, water and aqueous foam. For preparing homogeneous and stable ISF, a preparation system with a pore type foam generator, a mixer device installed with a hollow shaft and helical blades, air compressor, slush pump and monitoring instruments was developed, and the working principles of key devices were elucidated. Based on a series of experiments on the different ratios of each component material and technological parameters of the preparation system, ISF with a foam expansion ratio of 8~10 and dry density of 250–400 kg/m3 was prepared. The relationship between elastic compressive strength, modulus of elasticity and density was summarised. Based on the injection experiment for fracture of loose coal pile with high temperature, the characteristics of sealing air leakage, compressive strength, thermal insulation, flow and cooling of ISF in the fresh state were investigated, indicating that ISF can effectively cut off the air leakage and cover the coal sample to reduce the temperature in the earlier stage, and ISF can remain stable and not crack. The ISF was applied to Luwa coalmine to seal small coal pillar pressure fractures and loose coal fractures in goaf. After press-casting the ISF in Luwa coalmine, the pressure-difference of inner-outer increased, meaning the effect of external conditions on the pressure-difference decreased, showing that it could plug the air leakage effectively.CITATION:Qin, B T, Shi, Q L, Lu, Y, Zhu, C, Li, F L and Jia, Y W, 2015. The novel technology of inorganic solidified foam with high expansion for preventing coal spontaneous combustion, in Proceedings The Australian Mine Ventilation Conference, pp 121–126 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Seib W

In cut-and-break rock excavation use is made of the fact that breaking rock in tension towards a free face requires a specific energy of excavation which is small in comparison with that required for rock excavation using conventional tools operating by a process of indentation of the rock.The process of cut-and-break excavation comprises firstly a cutting step in which a groove is cut into the rock surface, followed by a breaking phase in which a tool is inserted into the cut in order to break the rock adjacent to the cut.

Jan 1, 1992

By S Mitra, D O’Dea, N Barrett, T Honeyands, P Zulli

The steel industry continues to explore and demonstrate technologies that decrease its greenhouse gas emissions, especially in blast furnace ironmaking where alternate operating conditions will be required. As the furnace has been optimised over many years, it is approaching the minimum fuel rate possible with coke and Pulverised Coal Injection (PCI). Alternative operating conditions are therefore required to further decrease greenhouse gas emissions. Because of this, hydrogen has been proposed as a reducing agent in the blast furnace. Injection of hydrogen through the tuyeres was assessed using a comprehensive 2D blast furnace global model. The model was calibrated to a blast furnace operating with PCI as a base case and various approaches to hydrogen injection assessed, with a particular focus on displacing PCI. The maximum hydrogen injection rate of 19.5 kg H2 per tonne of hot metal was predicted, limited by decreases in the raceway adiabatic flame temperature and top gas temperature. Internal blast furnace conditions, such as gas composition and reduction degree were also predicted. Holistic analysis was performed to estimate the effectiveness of hydrogen injection on reduction of greenhouse gas emissions. Based on these results, the changes in blast furnace operation and emissions under hydrogen injection are discussed.

Nov 8, 2021

By J Heyes, G A. Maddocks, R J. Stewart, G D. Corder

Mining is an international business and vital contributor to national and global economies. It depends on the trust and confidence of investors and stakeholders for its financial and operational well-being (Committee for Mineral Reserves International Reporting Standards (CRIRSCO), 2016). The Social Licence to Operate (SLTO) is an increasingly multifaceted and multistakeholder risk that can impact investment decisions. Community challenges to broader political and economic decisions have given rise to protest delaying or stopping projects or closing mines and has led to loss of life (Ernst and Young, 2016). Some governments are now giving greater powers to stakeholders to make the final decision on approving mining and metals activities (EY, 2016). With billions of dollars in project investment at stake, ongoing engagement, collaboration and effective communication with stakeholders is crucial and mutually beneficial solutions are increasingly expected (EY, 2016). It is therefore essential that the industry communicates the risks (and opportunities) associated with investment effectively and transparently in order to earn the necessary level of trust with investors and stakeholders to underpin its activities (CRIRSCO, 2016). Despite this need, investor and stakeholder trust in the sector has eroded in recent years.CITATION:Maddocks, G A, Corder, G D, Heyes, J and Stewart, R J, 2016. The social licence to operate and drivers for change – resource reporting and mine material characterisation, in Proceedings Life-of-Mine 2016 Conference, pp 183–187 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By R Hargreaves, T Elkington, W J. Shaw, G W. Booth

Every day, around the world, thousands of tons of ore are loaded onto ships completing the miningproduction process and starting a multimillion-dollar economic transactions process. These transactions are based on the supply of tons of a commodity with certain specifications of assays of the main element (or physical properties) and concentration of contaminants, which are finally verified and evaluated by buyers, and also are considered ‘as true’ during Reconciliation process. On Sample Stations, this ‘true’ is based on a few kilograms of sample, often representing thousands of tons, that are sent to laboratories for further sample preparation and chemical analysis, where finally assay information is obtained from a few grams of pulverised sample, and are used for further production, planning, operational and financial-marketing decisions. Different International Standards (depending on the commodity) are used to establish the methodology to be followed, to set-up and obtain samples from the Sample Stations, and the specifications are visually inspected to give an estimation on the performance of the sampling point. This paper seeks to highlight with examples, the importance of the implementation of a continuously monitored Quality Program (QAQC and QM) on Sample Stations, focused on the parameters that directly affect the quality and representativeness of the samples. By this implementation, a proactive approach and better-informed decisions can be taken for mining companies to: a) quantify/improve production and reconciliation results, and b) to supply the right specifications of shipped ore, increasing the value of the Resources. Finally, laboratory results are normally used as an indication of the quality of the information applied for the economic transaction, but it should be considered, clarified and highlighted that the laboratory will only process and analyse a sample obtained from a Sample Station, and potential problems on bias or precision may occur in stages prior to the laboratory reception. Hence the importance of the implementation of a quality assurance program that protects multi-million dollar decisions.

Mar 22, 2022

By A Jewbali, R Perry, R Inglis, L Allen

"The use of conditional simulation to characterise mine plan uncertainty is increasing for the assessment of risk in mining projects. While the development of grade uncertainty profiles is relatively straightforward and can be validated using standard geostatistical techniques, the addition of geological uncertainty to evaluate total risk remains problematic. Some of the problems associated with geological uncertainty methods include the clustering of data in favourable geologic units, difficulty in training image definition and the inability to address change of support issues for categorical variables. Despite these obstacles, the importance of geological uncertainty as a contributor to total uncertainty has prompted Newmont to explore and evaluate the use of various techniques (and combinations of techniques) on different deposit types.Two orogenic deposits of different geological complexity were selected for the study: Subika, a shear zone-hosted deposit, and Merian, a deposit containing gold mineralisation associated with quartz vein zones and stockwork within which are found higher-grade quartz breccia zones. Newmont trialled various categorical simulation approaches to determine the applicability of these methods for each deposit type and the effect of parameter choice on the width of the uncertainty interval. Some of the techniques that were trialled include multiple point statistics methods, sequential indicator simulation using local probabilities as well as variations of these methodologies.The goals of this study included: gaining an understanding of which techniques may work best in which deposit types gaining an understanding of the intricacies of each method gaining an understanding of the effect that each method has on total uncertainty analysis.This paper presents a comparison of the various techniques and makes recommendations for their use in uncertainty analysis.CITATION:Jewbali, A, Perry, R, Allen, L and Inglis, R, 2014. Applicability of categorical simulation methods for assessment of mine plan risk, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 85–98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By M I. Roberts

As Australia’s mining industry painfully retrenches, mining executives and managers strive to remain viable by seeking significant productivity increases directly through process improvement and indirectly by improving leadership and workplace culture, the most powerful determinant of productivity. Culture is the combination of people’s attitudes and behaviour, together with leadership values and focus.Comprehensive new and automated data collection and management systems promise much for improving productivity, yet despite rapid advances in measurement and sharing of data, the use of data can reduce productivity unless behavioural aspects are considered and designed as part of implementation. This is because systems drive behaviour that in turn shapes attitudes to determine culture.Experience from many mine sites and other industries in three countries confirm that the most powerful drivers of people’s behaviour are the Measurement-Analysis-Reporting system and business leadership.This paper discusses fundamentals of practical, statistically valid process measurement, analysis and reporting systems before discussing associated leadership considerations for sustained improvement in safety, productivity, employee retention, leadership, accountability and commercial returns.The key to productivity improvement is improving core processes and important support processes. In turn, the key to process improvement is identifying the major process components and their interaction by measuring and then analysing their variation and level of performance. Understanding variation is often neglected yet is usually highly significant. It is essential that the fundamentals of statistically valid yet practical process and data analysis are understood and incorporated into system design to ensure productive, informed behaviour.The design and use of Measurement-Analysis-Reporting systems influences behaviour most profoundly and determines people’s effectiveness. Behavioural aspects are detailed by focusing on six primary drivers of human behaviour and five basic systems for managing businesses. These are integrated in a seven-step process and productivity improvement methodology that combines statistical, analytical, systems and behavioural factors.The paper includes development, implementation and tracking of a project plan for improving management and leadership systems to drive aligned behaviours. This key leadership responsibility is essential for improving performance to get the most from capital while providing people with the opportunity to develop greater autonomy, which is essential for self-discipline, responsibility, initiative and accountability.CITATION:Roberts, M I, 2015. Integrating measurement, systems and leadership to build safe, productive cultures, in Proceedings Third International Future Mining Conference, pp 73–82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By J Loeb, J Dampney, P Cameron

Optimisation of Blast Design and Execution must be done right the first time. It is too late after the ore is broken. Consequences of poor design and execution negatively affect productivity from load and haul through the primary crusher to processing and hence reduce mine site profits. Harnessing and utilising ‘big data’ from geology, geometallurgy, drill hole location, powder loading, blast timing, blast movement and fragmentation to close the loop in blast design and optimise the blast increases productivity across the entire value chain from Mine to Mill. As the internet of things and artificial intelligence increases the quantity of data available, being able to capture and utilise this data to advantage is a challenge. Recent advances in software and hardware together with the increased power of cloud computing allows engineers to close the blasting loop to increase mine site productivity. Numerous case studies over the years detail significant gains from implementing the innovative technologies available to Mine to Mill projects. The opportunity is available for all members of the multi-discipline teams at each mine site to actively ensure productivity improvements are realised and maintained not only in their area, or silo of responsibility but across the entire mine site. This paper refers to recent case studies which outline how significant improvements in productivity are available to all mining operations to increase mine site profitability and dividends to shareholders.

Jun 22, 2022

By R Ahola, M D. Henschel, M A. McParland

With the introduction in recent years of third-generation interferometric synthetic aperture radar (InSAR) techniques, monitoring of mine slopes, benches and surrounding areas has benefitted from increased accuracy and coverage. Fundamental research into point and distributed scattering techniques has pushed the use of InSAR to provide higher spatial and height resolution. In this paper we discuss the operationalisation of third-generation InSAR techniques and show its application to active mining operations.This paper will discuss the use of multiple independent measurements of ground movement obtained from operationally-derived InSAR products over a wide variety of deformation areas within an active open pit mining operation (ie pit slopes, dewatering depressions, tailings containment and waste dumps). A technique that shortens the time between observations (increased observation frequency) and provides ongoing estimates of measurement accuracy will be described. The methodology exploits available satellite data by using multiple satellites and multiple beams. The paper will also examine factors in the design of a mine survey with third-generation InSAR and illustrate some of the necessary engineering trade-offs to efficiently monitor a mine from space.Overall, this paper aims to demonstrate the capabilities and advantages of operational third-generation InSAR techniques for ground movement monitoring of mining operations and provide a framework for proper design of a mine InSAR survey.CITATION:Henschel, M D, Sato, S, Ahola, R and McParland, M A, 2014. Designing interferometric synthetic aperture radar surveys for mine monitoring with accuracy assessment, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 233–238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By M Dusci, A Trueman, S Poos, R Baumgartner, M Brittan

The Canahuire epithermal Au-Cu-Ag deposit in southern Peru is a complex and challenging deposit for metallurgical studies. It has issues of gold locking in sulfides and non-sulfides, deleterious elements and acid rock drainage (ARD). From scoping study to feasibility study, there has been considerable improvement in the understanding of the important geometallurgical characteristics that need to be measured and modelled. This paper presents the current understanding and the requirements to continue to provide optimal models for mining studies.Significant effort has been put into understanding the genesis of the deposit. Improved spatial and temporal understanding of lithology, alteration, structure and mineralogy was used to build a geological and alteration model of the deposit.Early metallurgical programs quantified the effect of head grade on process plant recoveries, but the geometallurgical and statistical analyses did not identify other physical characteristics that influence these recoveries. The studies improved the understanding of the nature of locked gold which can occur as minute inclusions (< 5 ¦m) in sulfides (primarily pyrite with lesser arsenopyrite, pyrite being 100 times more abundant than arsenopyrite) and gangue minerals (quartz and carbonates) as well as solid solution in arsenopyrite and pyrite.The presence of pyrite and the limited buffering capacity of waste rocks increases the potential ARD, which will require mitigation costs before, during and after operations. Waste rock ARD potential has been classified and incorporated in the geometallurgical model. The current classification of waste rock at Canahuire, using international classification standards, is limited due to the complexity of the deposit.Complex deposit metallurgy necessitates a complex process flow sheet, including flotation and cyanidation. Economic recovery will be constrained by the relationships between economic variable grade, other elements and mineralogy. These constraints and inter-relationships are difficult to establish throughout the deposit with a single test. A follow-up geometallurgical program is under investigation and will attempt, with the help of additional test work, to map areas of higher and lower recoveries. It is hoped that metallurgical response can be linked to measurable parameters other than head grade. If this is possible, these factors can be incorporated into future geometallurgical models.CITATION:Baumgartner, R, Dusci, M, Trueman, A, Brittan, M and Poos, S, 2013. Building a geometallurgical model for the Canahuire Epithermal Au-Cu-Ag Deposit, Southern Peru - past, present and future, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 51-58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By R Grobler, D Burger, L Alberts

The current climate in the mining industry is allowing mining companies to further broaden their views and investigate technologies to improve the safety, efficiency and cost-effectiveness of their operations. Furthermore, underground mine environments will become more demanding for mining equipment and personnel as orebodies become deeper in weaker ground conditions with more extreme environmental conditions. Loading and hauling can represent significant components of the production cycle of an underground mine and automation of these activities can offer considerable benefits. Sandvik has accumulated a long history and experience in loading and hauling automation in underground mining. Since the late 1980s Sandvik has actively participated in several major research and development automation programs leading to the commencement of the development of an integrated system for semiautomated loading in 1999. Development work was later conducted to expand the capabilities of the system for automated hauling during 2001 and the AutoMine« system became commercially available. The first delivery of the AutoMine« system was completed in August 2004 in South America, where the system continues to operate in a full-scale production environment and is being expanded as the production area enlarges. Further systems have been delivered and are operational in North America, Africa and Europe. This paper focuses on the AutoMine« system deployed in Block 4 at De Beers Finsch Mine in South Africa. An overview of the mine and the process used to acquire the system and the key drivers which led to the selection of an automated solution are described. An overview of the initial system installation, subsequent expansions and future plans are presented. This is followed by a summary of the implementation and operational experiences associated with automated underground operations. The paper concludes by summarising the benefits that have been realised.

Jan 1, 2008