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Project delivery in our current market is not as efficient as it could be. Industry at large (both client and consultant), is diligently following the engineer, procure, construct, manage (EPCM) or engineer, procure, construct (EPC) delivery models and not necessarily appreciating the underlying principles that make them the effective tools they were to start with. We often misinterpret project management with EPCM and end up with a literal and superficial interpretation instead of the disciplined risk reduction and business value capture exercise it is intended to be. One of these underlying principles is the project team as resource or commodity depending on which perspective we follow. Some of us understand this principle only too well and succumb to the temptation to take advantage of the imbalance in the understanding of EPCM by selling bodies and hours. Value and return on investment do not always come into the equation. The latecomers and aspirants are struggling with this as a barrier of entry into this lucrative market, since as we all know - people as commodity was becoming and still is a scarce resource. Clients are also waking up and asking why 1000 engineers on the floor are better than 100, when engineering design in all aspects of industry, new technology aside, is mature. Why is it that we start with a clean sheet of paper with every project or that neighbours in the same industry segment and location just happen to have completely unique conditions and circumstances that require totally original design (Local conditions aside)? The answers to this question appear when we explore the role of the project team and how it is structured. We will need to investigate team culture and levers for success. Then we will formulate a business case for a team to be able to follow traditional project management practices with EPCM delivery models but yet end up with an alternative look, feel and result. An outcome where more input is not necessarily better and the client and consultant both are aligned with success measured in dollars and a win-win outcome for both parties.

Jan 1, 2009

By P Corbett, P Sheffield

Centennial Coal operates the Springvale longwall mining operation which extracts coal beneath the Newnes Plateau in the Western Coalfields of New South Wales. Springvale, and the neighbouring Angus Place mine, have a history of difficult geotechnical conditions where combinations of a relatively high stress regime and weak, laminated roof and extensive geological faulting has led to numerous roof failures throughout the mine’s life. Following development, the mines underground roadways can experience high levels of roof movement which may lead to roof falls. Multipoint wire extensometers are extensively used throughout the mine for roadway condition monitoring, and to reactively drive remedial strata support through trigger action response plans (TARPs).As a result of the use of high-density extensometer monitoring over a long period, the mines have an extensive archive of legacy data. Data processing has evolved over time in order to accommodate the increasing data volume, including direct data entry from the recently introduced hard-wired real-time monitoring instruments. It is likely that telemetric real-time instruments will be introduced in the future, which will cause another step change in data management requirements. This paper discusses the transition to and evolution of relational database management systems for extensometer and associated data.This paper also presents case studies of the use of a new software tool for reprocessing legacy data to enable time-scaled visualisation of monitoring data in the context of longwall and development face positions and installed strata support. The software can be used proactively in the identification of geotechnical risk factors and their interaction with the mining process to allow a more robust geotechnical hazard process. It interfaces directly with the widely used ExtoChart database software and can be presented with scale drawings of geological and geotechnical data to allow correlation of monitoring data results with risk factors.CITATION:Corbett, P and Sheffield, P, 2015. The use of high-intensity monitoring data to better characterise geotechnical properties of a non-homogeneous rock mass, in Proceedings Third International Future Mining Conference, pp 145–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M Revell, B Sainsbury, D Sainsbury

This paper extends the existing knowledge associated with the design and placement of prefabricated pastefill barricades through a consideration of asymmetric drive geometry and conditions. The load capacity of prefabricated barricades and their failure modes are considered in relation to abutment geology and barricade geometry that includes curvature and span and drive geometry that includes abutment angles, haunch angles and misalignment. Design charts are provided for typical barricade sizes to provide general guidance for design capacities and optimising location placement based on asymmetric drive geometry. A recent barricade failure is considered in relation to the drive geometry and the potential impact it had on the installed capacity.

Nov 29, 2022

By N M. Rana, A Take, N Ghahramani, S McDougall, S G. Evans

A critical issue associated with mining operations has been the stability of tailings impoundments. Some breach events have produced catastrophic tailings flows that have caused significant economic damage, mass casualties and long-lasting environmental impact in the downstream environment. This paper reports independently estimated values of runout distance, inundation area and fahrboschung of 16 tailings flows. The adopted methodology involves the geospatial analysis of satellite and aerial imagery to classify each tailings flow into a primary impact zone (Zone 1: main overland flow) and a secondary impact zone (Zone 2: along-creek diluted flow) to characterise runout. Only Zone 1 runout values are reported herein given the greater significance in relation to downstream impact. The fahrboschung is calculated using elevation data from global 30 m digital elevation models (DEMs) and source literature. The results show that all the selected tailings flows travelled long distances (2.4 km to 98.5 km) and inundated large areas (0.35 km2 to 27.0 km2) over very low fahrboschung values (0.04° to 4.8°). This indicates very high flow mobility that is largely governed by the high water content sourced from interstitial waters and, in many cases, supernatant ponds. Scatter plots display poor correlations owing to the complexity and variability in travel path characteristics (confinement, slope angle and obstructions) and the inherent properties of the flowing mass. The slope angle of the travel path exerts a strong control over the flow velocity which has implications on kinetic energy and downstream geomorphological impact. Mean tailings flow velocities may range from ~6 m/s on near-flat, open terrain to over 30 m/s in relatively steeper, channelised travel paths, indicating that tailings flows fall within the extremely rapid and high mobility spectrum of global mass movements. The presented work forms an inceptive part of the CanBreach tailings project, a major component of which is to develop a comprehensive database of case histories to examine the role of geotechnics, failure modes and downstream terrains in influencing tailings flow behaviour.

Jul 1, 2021

By P Hartlieb, M Noeger, M Varelija

Rock bolts are important in underground mining as they provide support to the rock mass around the excavation. They are the most common reinforcement method in mining and civil engineering excavations. The length of the bolts, types and spacing between them can be varied, depending on the reinforcement requirements and the use case (Kolapo, Onifade and Praise, 2022). The rock bolt provides safety and stability for the rock mass in the excavation area and they can be mechanically anchored, grouted, or friction anchored. They normally don’t have a measurement option and there is a possibility that it failed without showing visible signs on the surface, especially in grouted rebar bolts where they can still have some residual strength. Therefore, support functionality can be lost without recognising it. To overcome that, sensors can be installed on all three previously mentioned bolt systems. Intelligent bolts with implemented measuring systems have a function of showing changes and indicating if there is some damage on the bolt. So, it can be said that intelligent rock bolts are regular bolts equipped with additional instruments which are helping us detect potential instabilities inside of the rock mass or malfunction of the bolt itself. Changes in rock mass can be tracked, by measuring rock bolt reaction concerning the excavation response. Rock mass damage and instabilities are therefore measured in terms of rock mass deformation. Moreover, other additional information depending on the type of the sensor device could be collected. Based on such measurements, information about rock mass state can be derived. Different rock bolt types work at different reaction principles. Therefore, limitations on sensor application and information that can be extracted must be considered.

Sep 1, 2024

By Y Li, D J. Williams, E Topal

A mine waste rock dump does not have any intrinsic value, yet is an inevitable structure in surface mining operations. Since the purpose of mining is to maximise profit, possible expenditure reduction in hauling waste rock to the dump, which can represent up to 50 per cent of the total operating cost, is highly desirable. Apart from cost, potential acid mine drainage (AMD), due to seepage from surface waste rock dumps containing reactive waste rock, could threaten the ecological balance, drinking water supplies and irrigation systems downstream from a mine site. In order to minimise these potential risks, selective placement of benign and reactive waste rock, and the encapsulation of reactive waste rock by benign waste rock, need to be carried out during the construction of the rock dump.In this paper, a new methodology, based on mixed integer programming (MIP) is developed to manage waste rock dumping. The model aims to minimise waste rock haulage costs by locating the optimum destination(s) for each waste rock block, while at the same time controlling the placement of reactive waste rock to minimise the potential for AMD. Tests on small-scale virtual data demonstrated that the model is capable of dealing with selective placement of different waste rock types, encapsulating reactive, potentially acid forming (PAF) waste rock, and stockpiling benign waste rock for encapsulation and rehabilitation purposes. The solution time for the MIP model is far less than the traditional manual approach, and the resulting schedule is up to 46 per cent more cost effective.CITATION:Li, Y, Topal, E and Williams, D J, 2012. Mathematical approach for better mine waste rock dumping management, in Proceedings Life-of-Mine 2012 , pp 207-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By R M. Lonsdale, M D. Goodz

"With an ever-increasing dynamic business environment, successful stakeholder engagement is becoming more fundamental to achieving desired outcomes in today’s mineral resource industries. It is imperative to be proactive in correctly identifying all stakeholders and initiating early contact. This builds trust relationships, which are essential to ensure future decision-making processes are streamlined.Often neglected is a company’s obligation to select the correct team to represent its values and mission. The company requires representation that demonstrates an understanding and commitment to its operations and people, the safety and health of the community and environment, and most importantly, represents the decision makers. Stakeholders need to believe that the engagement process is genuine and that the company representatives are aligned towards targeted outcomes that will benefit all stakeholders in some way.Among others, stakeholders include shareholders, staff, families, community, service and supply providers, regulators, land managers and the political/financial framework. Depending upon the mineral product, stakeholders may include ports, international offtake clients and those along the route. New stakeholders continually evolve during mine life, and the engagement process requires an investor–community–public relations (IR/CR/PR) team to anticipate change and actively scan perception and chatter.Successful communication is more than delivering a message; it is about engaging stakeholders and confirming the feedback loop to ensure the correct message is communicated and the relationship is strengthened.The nature of the mining company’s branding and the public’s perception of company intentions will dictate whether there is willingness to allow the company to follow its desired path. This in turn controls the company’s most scarce resource – time. Timing is fundamental to achieving targeted outcomes with minimal cost and delays, marketing in a peak cycle and acquiring critical capital for development and growth.Branding and stakeholder engagement effectively controls and extends to the company its social licence to operate.CITATION:Goodz, M D and Lonsdale, R M, 2016. Stakeholder engagement – who are you, what do you stand for and why? In Proceedings International Mine Management Conference, pp 239-248 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 22, 2016

By B W. Atkinson

Full-stream mechanised sampling apparatus, that collect a full cross-sectional increment from the complete screen discharge, will always be the preferred option for sampling screen overflows. However, the reality is that provisions for automated sampling are rarely, if ever, provided at the discharges of individual screens within beneficiation plants.Sampling from the discharge of high capacity vibrating screens, especially multi-slope screens, is subject to sampling bias, due to the stratification of the ore that occurs on the vibrating screen deck. The stratification in the vibrating bed translates to a stratified falling stream at the discharge end of the screen, typically with smaller particles at the back of the falling stream and large particles at the front of the falling stream (Figure 1).The chemical and physical characteristics of heterogeneous ore (mineral or coal) particles vary significantly with particle size. If samples do not correctly reflect the source material size distribution, they will be biased and the resulting analytical/assay data will not reflect the actual physical nor chemical characteristics of the source material.Prior published data for coal preparation research (Australian Coal Association Research Program) has demonstrated that a bias appears to exist for samples collected from high capacity multi-slope screens.A new form of sampling scoop has been developed with the aim of overcoming this issue.Bias was evaluated at a coal preparation plant by comparing the desliming screen overflow size distribution to that for æreferenceÆ coal preparation plant feed samples collected using the recognised stopped-belt technique. The study procured 20 sets of comparison samples in order to ensure statistical relevance.Two forms of sampling device were employed for the multislope screen discharge.A conventional square aperture scoop was demonstrated to exhibit a significant coarse bias, in that the resulting samples exhibited a significantly coarser size distribution compared to the reference samples. In other words it was evident that the conventional scoop æfavouredÆ material from the front of the falling stream.A new æcollapsibleÆ sample scoop was evaluated in parallel, and its samples were found to exhibit no relevant bias.CITATION:Atkinson, B W and Swanson, A R, 2012. A new method for sampling from high capacity screens, in Proceedings Sampling 2012 , pp 89-94 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By M A. Noppé

"Investors and other stakeholders assessing the risk, opportunity and relative value associated with a resource project need to appreciate the project in its correct context. Errors, omissions, biased reporting or conflicting information in project reporting may lead to a misinterpretation of technical and financial results, resulting in biased estimates or assumptions on project value.This paper provides a simple ‘Resource Project Framework’ for presenting a project’s status that may be readily benchmarked against other similar projects and to illustrate the stages required to advance the project outcomes to higher levels of certainty. The framework draws on definitions and guidelines readily available in various resource industry reporting codes and public company reporting requirements.The framework assesses three key areas for placing a resource project in its correct relative context, namely:the project development stagethe confidence in the Exploration Results, Mineral Resources and/or Ore Reservesthe level of accuracy, precision and confidence in the technical and economic studies supporting the reported results or options for the project.The application of the Resource Project Framework is illustrated using two project examples, one from publicly reported company project releases and the other for two development projects.CITATION:Noppé, M A, 2016. A framework for presenting and benchmarking resource projects, in Proceedings Project Evaluation 2016, pp 260–274 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By V Rodríguez, M Hormaza, R J. Romañach, C Pinzón-de la Rosa

The authors have presented their ideas for developing a powder sampling device in the I-Corps™ program sponsored by the National Science Foundation (NSF). This is an intensive customer discovery program developed to increase the economic impact of the research sponsored by NSF.The I-Corps™ program requires performing at least 100 interviews with potential customers in various industries. These interviews are essential to establish the need for a particular product or solution, and identify potential commercialisation partners and competition. The interviews have revealed the absence of Theory of Sampling (TOS) principles in many companies. The interviews are designed to identify the difficulties associated with current sampling practices that do not meet TOS principles.The I-Corps™ program is a significant challenge for scientists who often avoid discussing a concept in fear of losing their research idea. The program teaches how to obtain information without releasing the important intellectual property related to a product development idea. The I-Corps™ methods have been used to discover the prevailing ideas on sampling in various industries.I-Corps™ also teaches how to present ideas to investors; another significant challenge for a scientist. We are currently learning to present sampling and TOS to investors and business development experts, and will share some of these experiences.CITATION:Pinzón-de la Rosa, C, Rodríguez, V, Hormaza, M and Romañach, R J, 2017. Theory of Sampling meets the National Science Foundation I-Corps™ program, in Proceedings Eighth World Conference on Sampling and Blending , pp 351–354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By D J. Bradshaw, B Lottermoser, A Parbhakar-Fox

"Best practice for acid rock drainage (ARD) risk assessment still relies solely on the geochemical properties of sulfidic rocks and mineral processing products, despite the fact that a rockÆs tendency to produce acid also depends on mineralogy and texture. Consequently, there are a plethora of geochemical tests routinely utilised by the mining industry to predict ARD formation. Due to limitations associated with these tests and their relatively high costs, analysis of recommended best practice sample numbers is rarely achieved, reducing the accuracy of waste management plans. Our research addressed this through examining the application of geometallurgical data for predicting acid formation, and led to the identification of potential environmental geometallurgy indicators.Samples obtained from an iron-oxide copper gold deposit were subjected to the geochemistry-mineralogy-texture (GMT) approach, an improved methodology for classifying acid forming potential. GMT results were compared against geometallurgical and assay data sets to evaluate: relative carbonate content measurements (measured by HyLogger) and identify how these could be used to calculate effective acid neutralising capacity mineral hardness (measured by EQUOtip) to determine application of this data for calculating lag-time to acid formation opportunities to automate the acid rock drainage index (ARDI) using classified images produced by a GEOTEK logger and automated microscopy.Links between the GMT approach and geometallurgical data sets were identified. Classified mineralogy data has application at stage one, HyLogger and EQUOtip at stage two and computer-based ARDI evaluations of classified images at stage three. Through such integration, ARD characterisation costs can be reduced, with value added to geometallurgical data sets. Furthermore, deposit-wide ARD domaining is possible, and acquisition of total-orebody knowledge more likely. Through adoption of this environmental geometallurgy approach, a better informed waste management plan can be formulated, allowing for best practice ARD sampling in a more cost-effective manner.CITATION:Parbhakar-Fox, A, Lottermoser, B and Bradshaw, D J, 2013. Cost-effective means for identifying acid rock drainage risks - integration of the geochemistry-mineralogy-texture approach and geometallurgical techniques, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 143-154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

By M A. Noppé

"Mining is an inherently risky business: from the technical, environmental, social and economic uncertainties associated with advancing an exploration concept to a viable project; to the risks associated with the operating, market, and safety risks and uncertainties attached to a developed mine; and the final mine closure process.Investors and other stakeholders assessing the risk, opportunity and relative value associated with a resource project need to appreciate the project in its correct context. Errors, omissions, biased reporting or conflicting information in reporting may result in a misinterpretation of technical and financial results, leading to biased estimates or assumptions on project value (Noppé, 2016).Simplistically, a project can be assessed on three key areas for positioning the project in its correct relative context, namely: the project development stage the confidence in the estimated quantities and qualities of the resource, reserve and/or product the level of accuracy, precision and confidence in the technical and economic studies supporting the project.In the latter case, the ‘technical and economic’ information includes assessing the necessary social, environmental and commercial/legal/governmental approvals for the project.Responsible management of a resource project through its full life cycle relies on competent and dependable control and direction being effectively provided by the technical, business and board leadership of the organisation. In turn, the project information must be effectively communicated between various disciplines, these disciplines and the company, and the company and its stakeholders.CITATION:Noppé, M A, 2016. Responsible management and transparent reporting across the project life cycle, in Proceedings Life-of-Mine 2016 Conference, pp 5–7 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 28, 2016

By N Kawashima, R St C Smart, A M. Robertson

This paper focuses on a case study at a base metal mine located in a tropical semi-arid area of Western Australia (WA). It is demonstrated that understanding the geochemical nature of the mine tailings forms an integral part of innovative management strategies developed throughout the life-of-mine (LOM) when planning for mine closure. The tailings are currently stored at an above-ground valley fill tailings storage facility (TSF) and one option for long-term management under consideration is leaving the tailings in situ at mine closure and covering using the concept of an enhanced æstore and releaseÆ cover system.Extensive geochemical and mineralogical studies have found that the geochemical behaviour of the tailings in the TSF is significantly more benign than initially predicted. The sulfide content of the tailings is primarily pyrrhotite, which can be acid-forming, acid-neutral or acid-consuming depending on a number of factors including redox conditions. Tailings pore water at depth is pH neutral with excess alkalinity, low concentrations of dissolved metals and elevated sulfate concentration.Recent geochemical tests on tailings samples indicate that a reduction in the acid potential and a corresponding increase in the neutralising potential of the tailings, through partial removal of pyrrhotite at the ore processing stage, has the potential to further reduce the long-term risk of potential impact to the environment from any TSF seepage. The current work program investigates whether partial removal of pyrrhotite is feasible and secondly, whether this approach is necessary to produce a significantly better outcome at mine closure.CITATION:Robertson, A M, Kawashima, N, Smart, R St C and Schumann, R, 2012. Understanding tailings geochemistry - Continuous learning and innovation when planning for mine closure, in Proceedings Life-of-Mine 2012 , pp 287-292 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By J Arola, B Kettunen, W M. Bond

Separation of fine and coarse particles as separate streams prior to flotation, and their differential treatments, could substantially increase recovery and reduce collector consumption. A series of simulations was carried out to quantify the benefits from plant scale implementation of such a treatment at the Ispat Inland flotation circuit (Minorca mine). The study involved detailed plant sampling and sample analysis to generate the data needed for simulation studies. Samples were taken from all the streams from flotation feed to final concentrate, as well as cell lips and cell pulp. Sampling was repeated for the second ore blend that was processed by the plant during different periods of a year. Sample analysis involved sieve analysis and size by size chemical analysis for total iron, magnetic iron and silica. Raw data were mass balanced, and flow rates within the circuit were calculated. Mass balanced data were used to calculate model parameters representing the existing conditions. Usim Pac was used for both mass balancing and simulation studies. Available pilot and bench scale data were utilised to define the modified flow sheet and expected performance. The simulated flow sheet included classification of flotation circuit feed by hydrocyclones. While the coarse fraction followed the existing flow sheet, the fine fraction was sent to a magnetic separator. Magnetic and rougher flotation concentrates were combined to form the final concentrate. Two simulations for each blend were carried out. The first one assumed that there would be no change in size by size kinetic behaviours of both gangue and magnetite due to this modification. This was named as the worst case scenario, in which particles had a longer residence time due to reduced flow rates within the flotation cells. The second scenario anticipated that there would be an increase in recoveries of gangue and magnetite going into froth launder due to more efficient use of collector in absence of fines. Results showed that pre-classification of flotation feed could improve the flotation recovery by 0.3 - 0.5 per cent, with the major benefit being significant reduction (40 - 60 per cent) in the amount of collector used.

Jan 1, 2005

By C Artica

Two quantitative methods for Mineral Resource classification have been applied to a copper skarn deposit beneath a large open pit that is mining a world-class porphyry complex. A drill hole spacing study (DHSS) using the single block kriging method (SBK) and a conditional simulation method (CS) were applied to the skarn deposit and the results compared. Inputs to both processes included the proposed mining rate and stope designs to estimate the likelihood of achieving grade and metal production targets. Mineral Resource classification of the deposit considers the relative precision of tons, grade and metal predictions over quarterly and annual production periods. These relative precision estimates are calculated at 90 per cent confidence interval (CI). The SBK method represented the production period as a single large block. Kriging estimates were performed in the large block for various synthetic drill hole grids, and the estimation errors derived. The error was assumed to be normally distributed due to the large block size and quantity of samples, allowing CIs to be deduced. The CS method followed a conventional sequential Gaussian simulation workflow where grades were simulated with a 5 ft × 5 ft × 5 ft grid node spacing inside mineralisation domains. Each realisation was then averaged up to monthly production volumes represented by a combination of designed stopes, and the coefficient of variation (CV) for the averaged grade was calculated. CI on the relative precision of grade predictions were then deduced from the CVs. The two methods produced similar results; despite being calculated independently. CS results were used to report uncertainty in the proposed life-of-mine plan and highlight areas for additional drilling. SBK results were used as the basis for Mineral Resource classification as this method has been previously applied to the skarn deposit.

May 24, 2023

By M Hedley

Tracking plant and personnel in underground environments provides multiple potential benefits for a mine including increasing safety, better monitoring of production, traffic control, and in the future monitoring and control of autonomous vehicles. The main techniques for wireless tracking are to use radio frequency identification (RFID), signal strength based techniques, and time of arrival (TOA) based techniques. RFID does not provide continuous tracking and signal strength techniques have poor accuracy in the complex radio propagation environment present in mines. TOA based techniques are potentially the most accurate, but most current equipment does not realise the potential of the technique. CSIRO has been developing the wireless ad-hoc system for positioning (WASP) system for wireless tracking in a range of challenging environments including underground mines. WASP has been licensed for sporting applications and has delivered encouraging results in early trials for a surface and an underground mining application. The system utilises a number of ‘anchor nodes’ that are placed at surveyed fixed locations within the mine, and tags attached to plant or personnel to be tracked. The system provides an ad hoc data communication network, thus wired data connections are not required to the anchor nodes. WASP uses transmissions in the 5.8 GHz ISM (instrumentation, scientific and medical) frequency spectrum to perform highly accurate ranging between nodes, hence tracking of tags. The localisation performance of the system depends upon the radio propagation environment, ranging from 0.1 m in low multipath conditions. In this paper we describe the WASP system and provide results of initial testing in an underground mine that shows that the system achieves high ranging accuracy, hence localisation accuracy.

Mar 21, 2011

By G S. C Murray

Major mining projects are developed with the assistance of lending institutions who provide hundreds of millions of dollars in funding over several years, and of course expect those funds to be returned with interest. Two Australian banks have adopted the Equator Principles, an emerging financial industry benchmark for assessing and managing environmental and social risk in project financing. Project financiers have encountered environmental and social issues that are both complex and challenging, particularly with respect to projects in the emerging markets of Asia-Pacific and elsewhere. There are many recent and historical examples of failures by resource companies to effectively manage their environmental, social, safety and security risks, some of which have caused the project to fail completely, and some of which have caused the temporary cessation of production. These events put the financial institutionsÆ funds at risk through inadequate management capacity and non-compliance adversely affecting the ability of the borrowers to repay the loans. They can also reflect adversely on the reputation of the lending institutions. In assessing these risks, lenders are increasingly looking at the track record of the borrower in its country of origin and in other countries where it operates. Lenders are wary of companies that have one standard for operations in a developed country, where the regulatory environment may tightly control what they do, and another standard for operations in countries where the regulatory regime is perhaps less stringent. Lenders may require environmental and social reviews or audits to be conducted on their behalf by competent third parties prior to a loan being approved, and annually over the life of the relationship. The mining industryÆs concept of the unwritten æsocial licence to operateÆ is highly relevant in relation to the delivery of community benefits that are sustainable post-mine closure. This paper provides examples of recent practices that support financial viability and sustainable development, as well as examples of some failures that have put lenders at risk.

Jan 1, 2007

By Q Yang

This paper describes the design and construction of three 7.2 m span access ramp-tunnels to the three level underground car park of the newly redeveloped Top Ryde City Shopping Centre in northern Sydney. The tunnels were to be excavated without significant impact on the overlying Devlin Street, one of the busiest arterial roads in the Sydney metropolitan area and a major link in the Sydney road network. The interpretation of the geological conditions indicated that the tunnels would be driven in a formation of heavily jointed, extremely weathered to fresh Triassic Ashfield shale with some structural features such as dyke, fault and shear zones identified in the available boreholes logs. Both empirical and numerical methods were used to design the tunnels and to predict the ground surface settlements. The design solution, which was influenced by the relatively small scale nature of the work and the current demands on the tunnel construction market, included presupport, initial support and permanent steel fibre reinforced shotcrete (SFRS) lining. The interactions of the driven portals with cut and cover sections and the proposed deep excavation of the new shopping centre were considered at the design development stage and in the construction phase to ensure the safety of the live road. The tunnels have been successfully constructed and are now operational.

Mar 8, 2011

By M Tsai

Tube bundle gas monitoring systems have been used in the mining industry for over 50 years. The initial design was based on four individual gas analysers along with a series of solenoid valves, gas sample conditioning and flow control mechanisms to ensure the correct gas flow stream volume to the analyser. Simtars staff have identified flow control issues when providing operational support to coalmines on numerous occasions. The accuracy of the oxygen analysis is dependent on control of the gas flow to the analyser. Oxygen is one of the parameters used in calculating Graham’s ratio which is used for the detection of spontaneous combustion activity in coalmines. This paper will provide data which identifies the flow control issues by comparing mine site records for the two surface sample lines in the analyser room and the gas cage. Mine sites will be deidentified within the paper. The paper will discuss some of the changes that have been made in modern tube bundle systems and compare the change to the initial design specification developed by the UK National Coal Board, investigate possible operational impacts and provide a technical fix to solve the current flow issues being experienced at some mines.

Oct 12, 2022

By H Kurth

Oyu Tolgoi copper and gold mine in the southern Mongolia holds mineral resources that make it one of the largest known copper and gold deposits in the world. The project is operating an open pit mine on the near surface of Southern Oyu deposit and developing underground block-caving mine at the Hugo Dummet North where 80 per cent of total resources exists. Oyu Tolgoi (OT) commenced open pit mining in 2011 and implemented an industry standard blasthole sampling, and ordinary kriging grade control estimation with block-out process. Since 2017, grade control improvement projects have successfully completed that have led to the implementation of current, improved grade control system. Geological model is updated by blasthole logging on Leapfrog® and used for daily grade estimations. GC estimation is proceeded solely on Vulcan® by running Lava script and integrating with a relational database. Combination of block-out procedure produces GC model which is updated in Vulcan® and as well as in the database simultaneously. Switching to the integrated database eliminated many manual processes such as importing and exporting data and enabled access to the database anytime, anywhere and from any device. Thereby, these improvements allowed to increase an efficiency, create a comprehensive reconciliation system and reduce operational risks. We are looking forward to expanding applications of integrated grade control data stored in the database. This paper outlines how the grade control system was developed at OT’s open pit mine, and how it is integrated into the short range mine planning, mine reconciliation workflow and ultimately enabled development of various automated reporting systems.

Mar 22, 2022