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By D Beck, E Jones

The measurement and management of deformation in underground excavations is a key responsibility of geotechnical and mining engineers. A critical aspect of these roles is to ensure there is sufficient ground support capacity for the expected demand.Current methodologies for monitoring deformation and ground support serviceability-limits require measuring displacement at distinct points, or using visual observations. These current methods limit the assessment to a qualitative interpretation of deformation across the entire excavation.Recent advancements of Light Detection and Ranging (LiDar) technology permit a new method for monitoring deformation that allow a full 3D image of extended sections of an excavation to be precisely scanned. The results from the comparison with subsequent scans provide valuable information on the magnitude, direction and extent of regions exceeding the ground support serviceability-limits. This new method now provides a quantitative assessment across the entire excavation being monitored.The implementation of regular scanning has been demonstrated to be highly advantageous not only at mines with swelling or squeezing ground, but also at mines with rapid seismic induced deformation. The use of LiDar technology as a routine deformation measurement tool for geotechnical and mining engineers (and further applications) are discussed in more detail in this paper.CITATION:Jones, E and Beck, D, 2017. The use of 3D laser scanning for deformation monitoring in underground mines, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 267–270 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

By K Li, C Zhang, i, J Oh, S Saydam, H L. Ram

Rock surface roughness plays an important role in excavation engineering projects and applications related to surface support structures, such as shotcrete and thin-sprayed liner (TSL). The morphology of the substrate affects the mechanical behaviour at the interface significantly. Therefore, it is necessary to quantify the roughness to investigate the relationship between roughness and mechanical properties. The joint roughness coefficient (JRC) proposed by Barton and Choubey (1977) is widely used in practice. It initially estimated the roughness by comparing it to 10 standard profiles visually. However, this method has lots of limitations, it is not only subjective but also a two-dimensional parameter with a small lab scale (Beer, 2002). The subsequent research on JRC, from visual comparison with Barton’s standard profiles to measuring the roughness with a profilometer (Weissbach, 1978; Alameda-Hernández et al, 2014). Then, 2D profiles or 3D surfaces by different technologies with higher resolution and accuracy, such as 3D laser or optical scanners (Fardin, 2004; Jiang, 2020, 2021). These 3D scanners are expensive and only suitable for laboratory scales. LiDAR scanners (Lato, 2009; Aubertin, 2022) have been applied in industrial size, but it is difficult to achieve a millimetre-level accuracy, which is mostly used to detect the thickness of shotcrete in practice. Thus, finding a cost-effective surface roughness measurement method with high accuracy is necessary. Photogrammetry is another method to digitalise the roughness of the surface. Similar to 3D scanners, photogrammetry also generates the point cloud of the objective surface and then reconstructs the 3D model of the objects. 3D reconstruction technology is a trendy technology in recent years. The structure from motion (SfM) algorithm (Westoby, 2012) to rebuild the 3D model with a flexible workflow, aligning photos, building dense point cloud, mesh and texture, which has been proved that can rebuild an accurate model in variable fields.

Nov 29, 2022

By M A. Harrington-Baker, J M. Trudnowski

Sulfate-reducing bacteria (SRB) have the ability to immobilise dissolved metals by precipitating them as sulfides, provided that a favourable biochemical environment is created. Such an environment includes the presence of sulfate, anaerobic conditions and the availability of organic carbon. If such conditions are engineered within a reactive barrier or field-bioreactor, most metals can be effectively removed. To demonstrate this concept, three passive SRB field-bioreactors were constructed in 1998 at an abandoned mine site in the vicinity of Butte, Montana, USA to treat acid mine drainage with characteristic elevated concentration of metals and low pH. Performance of the field-bioreactors, using aqueous samples, was monitored over 32 months until the project was terminated, field-bioreactors were decommissioned and solid matrix sampling of the reactive matter was performed. The most important analytical results are presented in this paper together with conclusions regarding the appropriateness of the field-bioreactors construction features. Only Zn, Cu, and Cd were being removed as sulfides due to SRB activities. Changes in concentrations of other metals (Fe, Mn, Al, As), which do not necessarily precipitate as sulfide, seemed to be affected by SRB only in an indirect manner by responding to increased pH caused by SRB activity. An innovative cellular containment system used for placing organic matter worked very well in preventing settling of the organic matter and ensuring uniform flow of AMD throughout the entire cross-section of the organic carbon with no preferential flow paths This demonstration was funded by the US EPA and was jointly administered by the EPA and the US DOE under DOE contract number DE-AC22-96EW96405. The project was implemented by MSE Technology Applications, Inc, Butte, Montana, USA.

Jan 1, 2003

By M Dean, M Nehring, P Knights, M S. Kizil

Integrated continuous mining techniques such as fully mobile in-pit crusher and conveyor (FMIPCC) systems offer inherent labour, energy and environmental benefits to deep pit metalliferous mines. However, before such systems become commonplace, a number of barriers must be overcome.This paper outlines a number of commonly perceived barriers to FMIPCC application, together with a number of suggested solutions. The paper advances a design approach for specifying FMIPCC systems for deep pit metalliferous applications. A novel FMIPCC configuration is advanced using a hydraulic excavator in backhoe configuration. Because of the requirement to minimise belt extensions, a mine planning approach is presented based on a series of parallel and radial belt conveyor moves.The FMIPCC system does not fully replace truck-shovel systems. In the proposed mine plan, sinking is undertaken with truck-shovel systems using a series of box cuts, whereas pit ‘widening’ activities are accomplished via the FMIPCC system. Because of inherent differences in mine sequencing, the net present value derived from the FMIPCC mine will differ markedly from that derived from traditional, nested-pit, truck-shovel mining approaches. Therefore, any comparison of the FMIPCC and truck-shovel approaches must take into account radically different mine planning approaches.CITATION:Dean, M, Knights, P, Kizil, M S and Nehring, M, 2015. Selection and planning of fully mobile in-pit crusher and conveyor systems for deep open pit metalliferous applications, in Proceedings Third International Future Mining Conference, pp 219–226 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

The mining industry has expanded significantly in the Pacific Region over the past two decades through a mix of new developments and brownfields expansions of existing operations. Despite this overall success there are also a number of well publicised examples of less than successful minerals ventures. These problem developments highlight the fact that success cannot be taken for granted and that rigorous planning and attention to detail is essential. The dominant growth has come through expansion of existing businesses, notably alumina, iron ore and coal, achieved through both efficiency gains on existing plant and step change capacity additions such as new mines and/or expanded processing plant. This expansion has largely been linked to increased market opportunities. The major issues are the quality and extent of the host resource, achieving the market targets, and the efficiency of the expansion effort. There can be also a range of site specific issues which need to be addressed. The development of new greenfields operations is often more complex as it can bring a wide range of new issues. Depending on the nature of the development, and the companies involved, these can extend from initial financing through to obtaining a market position. Incorporating major new technology and/or establishing infrastructure and attracting staff to remote locations can also add significant challenges. This paper outlines many of the critical factors which need to be considered prior to proceeding with major expansions or greenfields developments. These will be linked to a number of developments in the region over the past decade.

Jan 1, 2004

By M Forbes, R Jeuken

Brownfields geoscience measurement such as drilling and surface geophysics can be costly and it is often difficult to weigh the cost of data collection and processing against the value it unlocks at the time of extraction. This makes it difficult to prioritise geoscience expenditure and find the optimum intensity of geoscience activity across competing assets. There are multiple options for managing resource uncertainty and spatial variability through mine planning and resource engineering such as varying marketing strategy, adjusting stockpile or other infrastructure design and product blending. Consideration of these alongside increased data collection further complicates finding a comparable value of geoscience programs to determine the right blend of geoscience measurement and engineering controls. Concepts similar to Value of Information (VOI) analysis which is applied to strategic planning can be used to estimate the value of geoscience measurement and pit sequencing at tactical planning and operational timescales. This involves the quantification of resource uncertainty and prediction of how it will affect resource extraction. This paper outlines this process and demonstrates its use to prioritise geoscience at BHP Coal Assets. The value of infill drill programs in enabling operational stability is quantified and compared the value of engineering controls like increased stockpile capacity. This study supports that idea that the application of VOI methods to bulk mining at tactical time horizons has potential to inform geoscience planning and resource engineering not just separately, but as part of a unified strategy for managing resource uncertainty.

Mar 22, 2022

By O Kirtel, A A. Faizan

With the rapid increase and development of high-speed trains (HSTs), the problems such as train-induced ground vibration and its dynamic effects on nearby structures have become a major environmental concern in urban areas. Ground-born vibrations produced by high-speed trains pose a great challenge for engineers to build structures in such areas that is applicable for residents. In order to study the effect of train-induced ground vibration on nearby buildings, an advanced three-dimensional finite element model for train-induced ground vibrations has been developed using PLAXIS 3D Ultimate. The results of the in situ measurements which was previously carried out by the authors were used to validate the numerical model. The field test for ground vibration due to the passage of a high-speed train was carried out on the Istanbul-Ankara high-speed railway in Turkey with a train speed of 250 km/h. An in-depth analysis was achieved to investigate the effect of different soil properties on the train-induced ground vibrations by using the verified model. According to the result of the vibration analysis, the relative vibration response curves in all directions (x, y, z) for different soil conditions were obtained comparatively. The obtained results of the vibration analysis are discussed in order to figure out some useful conclusions.

Nov 29, 2022

By S M. Stewart

Building and Maintaining Community Relationships   In mining terms, the town of Waihi is distinctive with the Martha mine situated right in the heart of the town. MarthaÆs central location and other mining activity nearby means there is an increased community focus on the happenings at the mine and the effects and impacts of mining. While WaihiÆs proximity to the mine is unique, all mines have a community context that they operate within.   Issues of proximity simply heighten awareness and emphasise the need for building and maintaining good community relationships. In the three years we have been working alongside the Waihi community, we have worked together with concerned and supportive residents, representatives of Newmont Waihi Gold and representatives of Hauraki District Council, to develop a collaborative framework for addressing the economic, social, environmental, cultural and spiritual wellbeing of the people of Waihi. This could not have occurred without the genuine commitment of all participants.   This collaborative focus has resulted in some tangible progress in Waihi which, in part, stems from people taking an interest in the town because the town is taking an interest in itself. As we have worked and learned within the process of building and maintaining a collaborative and sustainable community environment, we have tried to adhere to a philosophy and a set of basic principles. We believe that this approach, combined with a teachable skill set, helped to create the opportunity to develop a truly collaborative community environment which continues to grow. Our paper will describe this philosophy, these principles and the skill set that we have applied.   The application of the process in Waihi has resulted in a series of outcomes unique to Waihi. These outcomes include formation of the Waihi Community Vision committee, the Vision Waihi Trust and the subgroups set up to further the interests of particular groups, for the collective benefit of all the community.   Based on our experience of other situations, and on the way the Waihi process has developed, we believe that the identified principles and skills can be transported and used in other cultures and contexts. While the resultant outcomes may differ, the underlying principles will still apply. Progress will come from creating a sustainable environment within which the community (including residents, industry and regulatory authority) can determine its own internal relationships and the vibrant growing sense it has of itself.

Jan 1, 2006

By B P. Micke

Central Norseman Gold Corporation was established in 1935 and has been mining on the Norseman field in Western Australia since then. It is Australia’s longest continuously operating gold mining operation at nearly 80 years, although it has had its periodic challenges in the intervening years.Over the last 40 years, a series of open pit mines around the Dundas Goldfield have supplied lower cost mill feed to the Phoenix Mill at Norseman from time to time but this has largely come to an end for the foreseeable future. Now that underground ore sources are once again the principal mill feed, there are several challenges to be met for an ongoing profitable operation.During the last 20 years, there have been three different owners and this has affected the manner in which the operations were managed quite significantly. These differing approaches are contrasted and examined in some detail from both the operational and financial aspects.Planning of a downsized operation to ensure sustainable profitability in the future in a mining environment where there has rarely been more than two to four years of reserves ahead of the mill for planning purposes has been a significant challenge. Several of the options examined are described, including alternatives for future mine development.CITATION:Micke, B P, 2014. Managing the margin at Norseman, Western Australia – a case study, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 119–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By C T. Dunbar, P A. Walker, G E. LeJuge

A programme of blast improvement was initiated at the Mt Whaleback iron ore mine by BHPIO management in early-1998. One component of that work was the need to improve wall control blasting practices to better achieve the designed pit slope elements. This paper describes the geological conditions in which pit walls are developed, the mine operating equipment, the blast design concepts applied to minimise blast damage, the techniques applied in an assessment of the blast performance and the operational procedures developed to ensure that the blast concepts are effectively implemented in the production environment. Substantial changes have been implemented in both technical and operational aspects of the mining operation in order to achieve the improvements in pit wall condition, in particular recognising the need for a more flexible approach to limits blasting in response to highly variable and complex geology. The benefits to the mine are not only an improved wall condition, but increased confidence on the part of mine management that mine plans may be implemented on design and on schedule.

Jan 1, 2001

By D J. Brake

In most underground mines, the ventilation system is a significant portion of the total mine capital and operating cost and the largest consumer of underground electrical power. The effectiveness of the ventilation system has a major bearing on the safety, health, comfort and morale of underground personnel, and has a critical role in meeting production targets and therefore business revenue. Perhaps the most important component of the primary ventilation system is the primary fan. Correct performance testing of the primary fan during the warranty period is important not only to ensure the mine has obtained the asset that it paid for and can therefore deliver on the fanÆs crucial safety and economic role in the future of the mine, and to provide a justification for releasing final performance warranty payments to the supplier, but also to provide a benchmark or baseline against which to assess future performance issues. As there are at least three potential international standards available to measure fan performance, there has been considerable confusion regarding which of these to use for testing primary mine fans, and also the correct allowances and tolerances to use. This paper provides guidance on which standards to use for different applications, how the standards should be interpreted, what allowances and tolerances are reasonable, and other important issues to be resolved with the fan supplier prior to making a contract award. The paper also discusses practical issues and methodology for in situ primary fan performance testing.CITATION:Brake, D J, 2013. Performance and acceptance testing of main mine ventilation fans, in Proceedings The Australian Mine Ventilation Conference , pp 141-148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

The geologists at the Zinc Mine in Broken Hill have developed a method of logging core using portable MS-DOS computers and LOTUS 123. The computer based logging system has almost halved both the time and cost to produce a completed log. The system is fast, flexible, easy and pleasant to use.

Jan 1, 1990

By Smith J. W, Wilkins R. W T

This paper is a preliminary report of research on the Mount Morgan gold-copper deposit being done at the Division of Mineralogy, CSIRO. Fluid inclusion and sulphur isotope measurements were made on a suite of 11 samples collected by the staff of Geopeko Ltd. This suite contained representatives of the main ore and rock types of the deposit. Homogenization temperatures of fluid inclusions measured on quartz from 8 of the 11 samples, ranged from 172¦C to 276¦C and to this must be added a pressure correction (in this case, up to 50¦C) to obtain the formation temperature of the mineral. Sulphur isotope measurements were made on 34 sulphides from 8 of the 11 samples. The 6S values form a well defined group ranging from -0.5%oto +3.6%owith a mean of +2.4%c. Although the preliminary data do not indicate unequivocally the origin of the deposit they do impose restraints on the wide ranging suggestions that have been put forward. This work is complementary to the paper of Dr G. Gibbons who has described other mineralogical aspects of the Mount Morgan deposit, based on a more extensive suite of Samples.

Jan 1, 1974

By Gillies A. D S

Replies to a comprehensive questionnaire on mine water resource management systems (WRMS), which were distributed to a selection of Australian mining operations in 1991, are analysed. Although the replies cannot be considered fully representative of the industry, they do provide a good qualitative indication of water resource management in the industry at that time.Within Australia's largely arid land mass, a majority of mines nonnally need to conserve water, a few need to dispose of water and a number face a seasonally varying position. An assessment of the importance of WRMS compared with management of ore extraction and processing is given. A risk assessment of failure is given; there is more acceptance of WRMS failure in the mine compared with the mill. An assessment is made of considerations in WRMS design. Managements are generally pro-active in the design of WRMS and in the setting of perfonnance standards. The operational characteristics of mine systems are examined in detail.Companies generally do not appear to allocate sufficient resources for the collection of basic WRMS monitoring data and knowledge of the water budget to efficiently manage the system. This indicates scope for considerable cost savings in most mines.

Jan 1, 1995

By D W. Wall, J P. Vagenas

Questions of sampling precision and accuracy affect every process plant in differing ways and to differing extents. To address these perceived issues, chemists, metallurgists and engineers are often asked to check their results to confirm their reliability. However, it is not possible to achieve the level of detail required to check every sample, especially if the event has already occurred. No operation has the resources to frequently sample every point in the process for the purpose of verification.One way to address this scenario is by generating a sufficiently detailed comparative data set from a dynamic mass balance simulation of the processing plant. This mass balance uses both sample and plant instrument data to model every flow, while also taking inventory changes and process chemistry into account.The mass balance data can be used to identify any bias present in plant sampling and analysis. It can also be used to verify any unexpected assay results by taking a holistic view of the process. Improving the precision and accuracy of sampling data helps support operational decision-?making and understanding. It also improves the accuracy of the dynamic mass balance used in this process, facilitating further improvements.CITATION:Vagenas, J P and Wall, D W, 2017. The benefits of automated metallurgical accounting for plant sampling, in Proceedings Eighth World Conference on Sampling and Blending , pp 203–210 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The paper describes data from test work programs on a range of magnetite ores in Australia and overseas. The analysis looks at the behaviour of material of different sizes fed to the rolls and the change in product size as a result of that, the conclusion being that there is a logarithmic relationship. The paper develops a form of equation to predict the product size from a given feed size distribution. The behaviour of the various magnetite ores is compared to more standard test methods such as crushing work index and unconfined compressive strength.

Jan 1, 2009

By V O’Brien

The suitability of magnetic surveys flown at low altitudes to identify buried heavy mineral (HM) strands has long been accepted. This is despite the low intensity magnetic response often obtained from such strands. The fundamentals of the magnetic survey method dictate that the closer the instrument is to the source the stronger the response. As such the optimal elevation for the magnetometer is at or near the surface. Iluka sought to use a ground based magnetometer to aid in the exploration target generation process and allow accurate targeting of exploration drill holes. Following the initial trial Iluka recognised the potential additional application of data obtained by a ground based magnetometer over known strand deposits. The detail of the ground magnetic images can confirm the assumed strand continuity between cross-sections of close spaced drilling and can aid in the definition of the geometry of different generations of mineralisation. The ability to confidently determine that the deposit has not been truncated by post emplacement erosion of the mineralised deposit may enable reductions in drilling requirements as well as assisting mine planning activities. Iluka intends to investigate advanced modelling of the magnetic data to determine the level of strand geometry and HM content resolution that can be achieved from the ground magnetic survey data and its potential application in the mining grade control process.It is anticipated that the surveying of Iluka’s known resource deposits will provide the ability to correlate the magnetic response from new exploration targets with those from known deposits for a given depth, HM grade and mineralogy suite.

Oct 5, 2011

Sampling protocols and metallurgical flow sheets should be designed to suit the style of mineralisation in question. In support, the a priori need for evaluation programs is the characterisation of the mineralisation type(s) and domain definition. The proportion and size of gold particles has a direct impact on the effectiveness of sampling protocols and metallurgical processes employed. Within the coarse- to-fi ne gold spectrum, the samplability of a deposit ranges from relatively simple for fine-grained disseminated particles, through to difficult for coarse gold mineralisation. Conversely, metallurgical processing may be relatively simple for coarse gold ore and more difficult for very fi ne gold ores. Most deposits contain a proportion of both particle size types. The nature of mineralisation, mineralogy and associated gold particle sizing can only be determined by preliminary sampling to facilitate testing. Mineralogical studies, focussing on ore mineralogy and gold particle deportment, size and distribution are required as part of wider paragenetic and geometallurgical investigations. This paper discusses key issues and presents a methodology for the determination of gold particle size in coarse gravity-gold ores to support sampling optimisation and which also contributes to metallurgical characterisation.

Aug 1, 2010

By H von Blottnitz, J L. Broadhurst

Eco-efficiency has been proposed by the World Business Council on Sustainable Development as an environmental performance indicator framework that contributes to sustainability by assisting corporate decision makers improve the environmental performance of their operations and processes, while also extracting additional economic value. Given that the recent engagement of the minerals industry with sustainability has highlighted the need for requisite tools and methodologies, it is therefore of interest to assess whether eco-efficiency indicators can drive sustainability performance improvement during process design within the minerals industry. Previous work indicates that the choice of sustainability performance indicators to be used for decision making needs to be governed by the decision context; ie the performance indicators need to be fit-for-purpose. Here, the strengths and weaknesses of eco-efficiency indicators are analysed using case studies. First, a more rigorous definition of eco-efficiency indicators for the minerals industry is proposed based on indicators currently offered in the literature. Two case studies are then selected to reflect typical decision situations encountered within minerals process design. For each case study, eco-efficiency indicators are computed and are compared to more traditional graphical representations of the economic and environmental performance of process design alternatives considered. The sensitivity of these indicators to various process design parameters is also investigated. Results confirm that the meaningful application of eco-efficiency indicators is strongly dependent on the decision context in which the process data is generated. Results also show that eco-efficiency indicators can be related to technical process design parameters to allow for richer communication of performance information for various decision trade-offs; however, in some cases, graphical approaches that provide more insights into the environmental-financial trade-offs should be preferred. The research thus contributes to guiding the selection of the appropriate tools for more environmentally sustainable design of minerals beneficiation processes.

Jan 1, 2009

By F Clark, J T. Carswell

Ore definition for final stope planning is often a challenging prospect in underground (UG) gold mines which exhibit high geological and grade variability. Unlike the grade control (GC) scenario in an open pit (OP), the ability for the mining geologist to plan a sampling campaign which effectively characterises the underlying mineralisation is fraught with difficulty. UG sampling patterns are strongly clustered and typically not dense enough to characterise the spatial and statistical properties. Very commonly, sample volumes are not large enough to provide a reliable grade estimate of the surrounding rock. These factors critically affect our ability to accurately map out ore positions and estimate metal quantities.At Sunrise Dam, traditional UG sampling and modelling techniques have proven to be an unreliable strategy for successful stope planning and extraction. The problem was first observed during the final cut-back in the open pit for which the mineral resource model was constructed from UG diamond drilling. Open Pit grade control reconciliations were strongly positive for both tonnage and grade compared to the resource model. Underground workings missed significant quantities of ore which was laterally defined by open pit reverse circulation (RC) GC drilling. Upon examination it was realised that the cause of the problem was one of inadequate sample density and sample support, the implications of which potentially affected the entire UG mine.As part of a broader study into underground grade control procedures, detailed reconciliation of initial stope production from the GQ domain also pointed to inadequate sampling as a major constraint to effective grade control and reserve conversion.To overcome this deficiency, dense 115 mm wet RC grade control drilling and conditional simulation modelling has been successfully implemented with the intent to replicate the grade control process in the open pit. The increase in sample density and sample volume has proven to be a very effective tool for mapping out highly complex mineralisation. A marked improvement in stope definition, reserve conversion and Mine to Mill reconciliations has been demonstrated on the back of an innovative approach to UG grade control.CITATION:Clark, F and Carswell, J T, 2014. Using reverse circulation drilling to improve sampling in a complex underground gold operation – an innovative approach to underground grade control at the Sunrise Dam Mine, Western Australia, in Proceedings Ninth International Mining Geology Conference 2014 , pp 143–152 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014