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By L Bertoss, D Carvalho

In the last decade, the use of advanced implicit modelling software/algorithms in mineral resource workflows has become a best practice in the mining industry. In most cases, these workflows can easily replicate the level of detail of explicitly modelled geometries, even for very complex deposits. These techniques are flexible and can produce fast results since software is responsible for generating 3D surfaces and solids based on geological and interpretation data. Nevertheless, depending on how unique and complex some deposits are, intense manual editing and input are required to honour the geological context and produce the desired outcome. The current geological modelling workflow at George Fisher Mine (GFM) is based on the semi-automatic built-in tool that generates stratigraphic sequences (stacked lithology layers) based on logging and mapping data. This tool (stratigraphic sequence from Leapfrog Geo™) works for the majority of areas in the mine but fails to capture observed mineralisation pinch-outs in operational areas and at extrapolated boundaries of the deposit. These pinch-outs have the potential to negatively impact grade forecasts if not resolved manually. Using built-in software tools only, the alternative for a more accurate model is to generate each individual layer and adding tens of thousands of manual interpretation points to honour pinch-outs (based on the amount of existing drilling in the mine and number of layers). This approach would require an estimated minimum of two to four years of a full-time employee (FTE) to be exhaustively completed. This study presents an automated approach to generate pinch-out points using a set of Python scripts that only take a few minutes to run. The newly generated points are then combined into the commercial software workflow as interpretation points, honouring observed pinch-outs. The remarkable time difference between approaches removes chance of manual errors and allows mine geologists to spend valuable time in validation and testing of scenarios, ensuring they are more representative of the deposit’s geology.

May 24, 2023

By P Mikula, B Darlington, J Graham, P Young

In underground mines experiencing dynamic events, there is an ever-present challenge to design and maintain a capable ground support system. One key component of ground support systems is surface support, which serves the essential roles of retaining failed rock and transferring forces generated by surface displacement to rock bolts or other support elements. Observations underground show that in many instances, standard mesh panels alone do not provide sufficient dynamic support to retain substantial bulking failures imposing displacement onto mesh, and in such cases Mesh straps and W-straps may be employed. Determining the performance of surface support elements proves to be difficult, with a multitude of variables at play in the underground environment. Quite comprehensive work has been completed on laboratory testing of surface support systems; however, very little work has been conducted on in situ dynamic testing of Mesh straps and W-straps. In 2019 in Western Area’s Flying Fox Mine, in situ dynamic testing was conducted on a series of Mesh straps and W-straps using Sandvik’s in situ Dynamic Test Rig (DTR). The testing regime applied impact energies from 5.1 to 15.3 kJ to Mesh straps and W-straps. The performance of the straps that did not fail was a maximum absorbed energy of 9.3 kJ and 14.2 kJ for the Mesh straps and W-straps respectively. The testing successfully demonstrated the ability of Sandvik’s DTR to test not only rock bolts, but also surface support elements, creating new testing and research possibilities. The testing also provided important design guidance data that is not practicable to obtain using laboratory dynamic testing facilities.

Nov 29, 2022

By F Butler, G E. Batley, A C. Hogan, A R. Butler

The ANZECC/ARMCANZ (2000) Water Quality Guidelines (the Guidelines) are the primary reference used in Australia and New Zealand for managing and regulating water quality. For most mining operations in Queensland, the environmental authority (EA – licence) incorporates the national default guideline values (GVs) for ecosystem protection as trigger levels (TLs). Exceedances of TLs ‘trigger’ further investigation and reporting. A review of the surface water compliance history at a metalliferous mine in North West Queensland identified minor exceedances of the cobalt GV as a common trigger for investigation and compliance reporting.The reliability of GVs is dependent on the availability and quality of ecotoxicology data for the relevant contaminant. The current national default GV for cobalt of 1.4 µg/L is classified as a low reliability GV due to the lack of available data at the time it was derived (ANZECC/ARMCANZ, 2000).The Guidelines are presently being revised and the toxicant GVs will be available as a set of web-based values and associated technical briefs. The new platform will enable the timely revision of existing GVs and inclusion of GVs for additional toxicants. Cobalt was considered a priority toxicant for the Guidelines’ revision, but was not included in the revision process.A preliminary review of the international literature indicated that at least 15 additional chronic cobalt toxicity studies had been published since 2000, sufficient to derive a high reliability cobalt GV using the protocols developed for the revision of the Guidelines (Batley et al, 2014; Warne et al, 2015). This presented an opportunity to improve environmental management by increasing the reliability of the performance measure.CITATION:Hogan, A C, Butler, A R, Butler, F and Batley, G E, 2016. Derivation of high reliability water quality guideline values for cobalt in freshwaters – improving water quality guidelines for better water quality compliance management in mining, in Proceedings Life-of-Mine 2016 Conference , pp 205–208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By V Louchnikov

Ever increasing depth of mineral extraction presents a challenging environment for hard rock underground mines. High in situ stresses and associated seismicity with potential rock burst hazards are the major decisive factors contributing to the choice of a ground support regime. Conventional ground support systems, designed primarily for static loads, are not always capable of providing safe working conditions for underground personnel in seismically active mines. Systems specifically developed to resist dynamic loading and allowing for larger deformations are therefore preferred alternatives. High-tensile chain-link mesh has a proven record of successful use in open cut operations in various rockfall barrier installations due to its high energy absorption capacity. It has also been used in underground operations in various parts of the world. Its application in Australian underground mining, however, is limited due to the high labour intensity. This paper describes a method of mechanised installation of a chain-link mesh as trialled at Golden Grove, a base metals underground mine in Western Australia. A purpose-built mechanised roll mesh handler, developed in Australia, was used in this trial. The handler is compatible with all standard multi-boom underground drill rigs and is operated utilising the hydraulic circuit normally used for the feed arrangement.A number of operational benefits have been identified during the trial, the main two being:•improved safety of underground personnel due to the reduced amount of manual handling, and•increased productivity due to the decreased cycle time (the trial suggests a 40 - 50 per cent reduction in time over the weld mesh installation method).Although the energy-absorbing mesh combined with yielding rock bolts is a ground support system of choice for rock burst prone conditions, the operational upsides recognised during the trial imply that this product can also be competitively used in less demanding ground conditions where customarily weld mesh or shotcrete are used as a primary surface support.

Mar 21, 2011

By Kneisley RO

This paper presents a brief overview of current bump mechanics theories and pillar design methodologies, and relates these concepts to experiences at two mines located in a north- central Utah coalfield where different pillar designs were used to control mountain bumps. Experiences gained at the first mine demonstrated the successful implementation of a two-entry, 9.8 m (32 ft)-wide, yield-pillar design. A U.S. Bureau of Mines field study quantified the timing of chain pillar yielding and resulting load transfer from the gateroad. In-mine pillar response, although apparently sensitive to site-specific conditions, compared favorably to estimates derived using two yield- pillar design methods. A second study conducted at another mine located in the same district, but subjected to different geologic conditions, documents the unsuccessful attempts to employ progressively narrower three-entry pillar designs based on successes achieved at the first mine site. This second mine never achieved a true yield-pillar design. Use of pillar widths ranging between 9.1 m (30 ft) and 27.4 m (90 ft) always resulted in violent bumps in the tailgate pillars. The pillars were either too large to yield, or too small to support peak operational loads. Hypothetical gateroad systems were evaluated using both analytical and empirical approaches for configurations comprised of two rows of conventional pillars, and systems incorporating both yield and abutment pillars. Analysis concluded that yield pillars less than 6.1 m (20 ft) wide and abutment pillars ranging between 30.5 m (100 ft) and 39.6 m (130 ft) square would be required to achieve a stable gateroad design. However, results of a field study conducted on a two-entry, 36.6 m (120 ft)- wide abutment pillar concluded that abutment pressures from the first panel overrode the pillar, and that a still larger pillar may be required to preclude bumps in the tailgate during second panel mining. Without the benefit of a demonstrated in-mine success, it is not clear which design would ensure elimination of gateroad bumps.

Jan 1, 1992

By F Faraj, M Pal, M Haest, M Bradshaw, H Lang, K Hume

MineSense Technologies Ltd. is revolutionising grade control at mining operations by installing ShovelSense® sensors on buckets that measure the grade of every load before it is dumped in the truck. This allows the mine to exploit grade variations at a resolution that was not available before, reducing the amount of ore loss to the waste stream and removing waste from material destined for processing. These changes dramatically improve the profitability and sustainability of mining operations. ShovelSense relies on X-ray fluorescence analysis of the rocks as they flow in the bucket and is integrated with fleet management to direct the trucks to the right destination. Lab simulations of ShovelSense measurements on porphyry copper ores show correlations between predictions and lab measurements at 0.98 r-squared with a coefficient of variation of 10 per cent. Visualisation of copper grade predictions in three dimensions shows a reasonable match with the dig plan, but with local changes in the ore-waste contact due to more accurate contact identification, related to blast movement and other mining factors. Correct delineation of these contacts ensures ore trucks are not sent to the waste dump and waste trucks are diverted from the crusher, creating enormous value for the operation and the environment.

Mar 22, 2022

By R F. Cota, C Freeman, A Heberle

"The Lamego mine is an underground gold mine in the Iron Ore Quadrangle in Minas Gerais state, Brazil. The mine produces 48 to 50 koz per annum, as part of the larger Cuiabá-Lamego Complex. This combined unit is AngloGold Ashanti’s largest gold producer in the Americas, contributing with 310 to 320 koz per annum.The mine started production in 2009, utilising cut-and-fill mining methods.A mining method change was trialled in 2014, introducing open stope methods. The key benefits proposed from this change are considered to be: improved safety by eliminating re-entry mining methods reduced mining costs/increased productivity from utilising bulk-mining operations.The results from the trial were encouraging, and open stoping participation expanded beyond a trial.Production from open stope areas reached 180 000 t (40 per cent of total run-of-mine; ROM) in 2015. While the change in mining method resulted in higher production rates, it also introduced a critical issue in terms of stope recovery rate.Average underbreak (unplanned loss of ore) in the larger open stopes reached 21 per cent in 2015. To manage this ore loss, a project targeting higher recovery was structured with three primary components: analyse current performance to define contributing factors (design process gaps, operating practices) investigate corrective actions apply corrective actions and maximise team engagement to ensure changes become standard practice.Within six months of commencement, a range of contributing factors had been identified, and the majority of the associated corrective actions implemented, including increased team engagement to ensure changes were not ‘once off’ actions.The outcomes show a clear reduction in underbreak (average ~12 per cent for 2016), with further improvement opportunities identified. The challenging target is now to achieve a further reduction to 10 per cent underbreak as the average for 2017. The results contributed 1400 oz and additional US$ 0.5 million to the cash generation profile for 2016.CITATION:Heberle, A, Freeman, C and Cota, R F, 2017. Increasing stope recovery in an underground gold mine by using effective analysis, corrective action and employee engagement processes, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 117–122 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 16, 2017

By T N. Little

The aim of any rock breaking activity is to achieve success by developing designs that are blasting objective-specific and geology-specific, and then implementing such designs. This paper targets mining geologists with the aim of extending their knowledge of the rock fragmentation processes and providing insights to the significant relationships between geology and blasting. There are two main relationships, and if mining geologists appreciate both these relationships, then they can play a key role in optimising production. The business risk continuum is introduced to support this understanding. The first relationship is between geology and potential blasting hazards, and the operational complexity required to manage those risks. The risks associated with eight different ground types are discussed in terms of ground conditions, hazards and controls. These types are: reactive ground, hot ground, geothermal ground, fibrous ground, cavernous ground, combustible ground, pyritic ground and conductive ground.The second relationship is between the bench geology and blasting results. The blasting results discussed include: muckpile characteristics, remaining rock faces and blasting emissions. In this regard, some detailed insights and graphical examples are given for the influence of geology on blasting emissions, in particular, vibration, airblast and flyrock.A detailed description of the geological materials themselves can convey much useful information for blasting operators provided they are able to utilise this knowledge. Geologists are ideally suited to provide this description more effectively if they are familiar with the blasting process and the rock mass properties that influence blasting hazards and blasting results. It is also important to have clear statements of blasting objectives and associated operational targets, and this will maximise the likelihood of achieving the desired outcomes. The main aim of the paper is to highlight that geology is currently not fully utilised in the blasting process. In this regard, geologists are often not entirely aware of the blasting process and how they can contribute. The two significant relationships discussed above are integral parts of this process, and thus they are discussed as separate issues in the main body of this investigation.

Aug 22, 2011

By S Khosrowshahi, A Weeks, W J. Shaw

"To provide an indication of expected performance of the mine and mill, feasibility studies should include an assessment of the expected day-to-day variability in process plant feed. Attempts to do this based on conventional resource models will be flawed as such studies fail to consider and account for the in-built smoothing (averaging) of input data.This can lead to one of two situations: an expensive, over-engineered process plant that can cope with every possible situation, or operational strategies that fail to manage the natural variability within the orebody and the impact of day-to-day operational decision-making.In both cases the value of the project diminishes through excessive capital costs or reduced throughput or recovery during operations.Unlike conventional estimation techniques, the geostatistical method of conditional simulation can reproduce the inherent variability of the deposit. Once a valid model has been developed, it is possible to analyse the model using a transfer function that simulates the proposed mining processes and provides a representation of the likely variation of mill feed characteristics at any time scale.The case study demonstrates how the proposed mining strategy would result in mill feed being considerably more variable than expected, resulting in poor recovery, low throughput and potential breaches of environmental conditions. Mitigation measures included budgeting for additional mining equipment to enable greater flexibility during mining and revised stockpiling and crusher feed strategies.Awareness of the benefits of modelling the variability of geometallurgical parameters will increase the use of this approach in producing more realistic financial models of expected mine performance at the design stage.CITATION:Shaw, W J, Khosrowshahi, S and Weeks, A, 2013. Modelling geometallurgical variability - a case study in managing risk, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 247-252 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

Financial markets are subject to constant change and project finance, as a product within these markets, adapts and will continue to adapt with those changes. A meaningful discussion of these adaptations requires an understanding of differences between non-, limited and full recourse project finance. The reasons sponsors seek and lenders provide project finance are also pertinent in this context. Arranging a project, financing package can be a canplex and time consuming task. An important first step is choosing the right advisor for the assignment and then structuring and tailoring the financing before approaching prospective lenders. The last thirty years has seen changes in the needs of sponsors and the ability of lenders to meet them. These shifts in preference may well be a guide to the future. Several major project financings successfully canpleted in Australia in the last few years and more recent examples are broadly discussed. Project finance will be keenly sought in the future and the form and nature it takes will continue to vary.

Jan 1, 1983

By D Connelly

Magnetite ores can be used to produce very high-grade concentrates that are suitable feed for the direct reduction process route but the high sulfur content of some concentrates can cause substantial environmental issues. Processing of high sulfur magnetite ore is therefore increasingly problematic for the industry. Generally, the industry demands a concentrate with <0.05 per cent sulfur and <2 per cent silica. This paper reports the outcomes of a study to produce a concentrate with the requisite low sulfur content from a sulfur-rich magnetite ore. The main findings may be summarised as follows: if the sulfur is present in magnetite as nonmagnetic pyrrhotite or pyrite, it can be beneficiated using magnetic separation and hence, monoclinic pyrrhotite is magnetic and is magnetically recovered with magnetite leading to a concentrate that is too high in sulfur. X-ray diffraction and QEMSCAN analyses revealed that the magnetite concentrate was liberated at P80 30 microns and was associated with maghemite, pyrrhotite (magnetic), carbonates and hematite with very low amounts of chalcopyrite, sphalerite and arsenopyrite. Sulfur removal using flotation was the first stage of investigation and this required flash flotation in the grinding stage followed by column flotation of the initial concentrate to generate the final concentrate. At the same time, it was observed that oxidation of the pyrrhotite had a negative effect on its flotation requiring copper sulfate to activate it. Bioleaching and concentrate leaching were also considered and achieved over 90 per cent sulfur removal but were deemed unsuitable owing to the production of highly reactive wastes and high CAPEX. Reference is made to a number of operating magnetite producers and how they manage the sulfur in feed.

Sep 18, 2023

By G Corder

Even though most major operating companies in the minerals industry have Board-level endorsed sustainability principles and objectives, design engineers typically have no mechanism that allows them to implement those objectives in their work. In addition, the existing project management systems do not readily deliver the innovative solutions needed to address key sustainability issues, such as those related to significantly reduced carbon emissions, minimal environmental impacts, and maintaining the societal ‘licence to operate’. SUSOP® (SUStainable OPerations) is an approach for the integration of sustainable development principles into the design of mineral processes, which has been developed through the Co-operative Research Centre for Sustainable Resource Processing (CSRP). Somewhat analogous to the well entrenched HAZOP (Hazard and Operability) studies, SUSOP® is a holistic, systematic and rigorous mechanism for identifying and assessing sustainability opportunities and risks at each stage of project development - from corporate planning, through design and operation, to decommissioning and rehabilitation – without compromising financial rigour. SUSOP® was developed, tested and enhanced through its application to real case studies in the minerals industry. This development path provided significant insights into the process of identifying and evaluating opportunities for improving an operation’s contribution to sustainability and its long-term business case.This paper will discuss the need for a methodical approach for integrating sustainability principles into mineral processing plant design, present the key elements of SUSOP®, and outline its development path through real case studies. In addition, the reasons why such an approach will have growing importance into the future will be raised.

Aug 8, 2011

By J Yamatomi, Y Tamanishi, S Miwa

The four-dimensional (4D) network relaxation method, originally developed by Akaike in 1999, uses Lagrange relaxation and is known for its ability to include the price change and possible better outputs, but the computation time is huge. However, the continuous advancement in computer technologies allows the use of higher-speed computers with more memory capacity. Therefore, in this paper the authors have tried to implement the method with adjustments and improvements in its algorithm to suit the current computing system. As a result, the computation time has been drastically reduced and more constraints can be included, which makes the scheduling a more realistic one. The case study of an open pit gold mine with 129 500 blocks can be solved considering the capacity constraints in 71 seconds. In previous case studies, the mined ore had to be processed or disposed of immediately. Now, stockpiling can be included as another option. Since the details of the algorithm are still being improved, the computation time is a little longer than the previous cases without the stockpiling option. However, it is found that scheduling with the stockpiling option is possible in a reasonable time. In conclusion, the 4D network relaxation method has become more useful with advances in computer technologies and provides better results.

Sep 26, 2011

By Elpatyevskaya VP, Arzhanova VS

Main geochemical problems concerning the environment and mining industry interrelation are connected with the transformation of natural water chemistry by mining wastes. The investigation of many mines in Primorye, the southern part of the Russian Far East, showed that their mining waters have high concentrations of heavy metals and aluminium. Water acidity is primarily connected with the amount of acid-forming sulphide minerals in ores and also depends on the neutralising capacity of rocks. Considerable quantity of metals occur in the waters in dissolved form. Metal concentrations in mining waters exceeds the natural levels by 2-5 orders of magnitude and can&apos;t be reduced to the background levels even after multiple dilution. It is necessary to develop and put into practice new technologies so that to reduce the geochemical impact upon the environment.

Jan 1, 1995

By P Aspinall

Safe work Australia (SWA) has a number of proposed amendments to existing Workplace Exposure Standard (WES) values that may dramatically change how mining workplaces using personal gas monitoring instruments will operate. In consultation with leading gas monitor manufacturers and distributors, an assessment of common Australian alarm settings values and analysis of potential frequency of increased alarm likelihoods has been conducted. This assessment explores the relationships between current monitoring practices, using instruments as health and not just safety tools and identify what will be needed to minimise worker ‘alarm fatigue’ and for common tasks to continue safely. This paper provides the necessary information to aid industry and hygienists to be ‘future ready’ given the likely impact that order of magnitude reductions in time weighted average (TWA) values for NO2, SO2, H2S and other common gases will have on current working practices. Reductions to gas alarm values will provide significant challenges to existing work methods and will require, practical application of the pending future values. Improvements and awareness of instrument capabilities by safety and hygiene professionals will better utilise gas monitors real-time data monitoring capacity and no longer be just ‘safe or not-safe’ instruments. The presentation seeks to promote the practical steps required in setting alarms based on risk consequence and likelihood, increase general awareness of the tools and data available in modern instruments and will enable industry professionals to better manage the challenges of any potential future changes.

Apr 16, 2024

By T Sua, B Wright

"BHP Billiton West Australian Iron Ore (WAIO) conducts an extensive geometallurgy program for its iron ore deposits in the Pilbara with the focus on determining the lump yield (the mass percentage of &gt;6.3 mm rocks) and the lump and fines grade for iron ore products. The geometallurgy program provides accurate information to design engineers and technical marketing teams on the performance of different iron ore mineralogies for future deposits. Additionally geometallurgy results are being used to guide short-term production planning with their introduction into short-term geology models and grade control models. The data that underpins this knowledge is from dedicated geometallurgical programs, drilled using PQ (~83 mm) holes. These holes are crushed by intervals that are based on geological definition which provides an indicative lump yield and lump and fines grade. The lump is then subjected to standard dropping and tumbling test stages to produce a simulated lump and fines product. In the past, quality assurance, quality control holes were drilled using HQ (~64 mm) holes for geochemistry purposes. These holes were crushed to provide an indicative lump yield and lump and fines grade and then 100 per cent is sent for assay (with no dropping and tumbling). Utilising data from HQ holes can significantly increase the indicative geometallurgical data available. This paper compares the geometallurgical results from both PQ and HQ holes from a range of bedded iron deposits (Brockman and Marra Mamba). The PQ and HQ data are compared by orebody, stratigraphy and depth to exclude factors that are expected to influence geometallurgical results.CITATION:Wright, B, Sua, T, Robertson, B and Van Dijken, B, 2016. Comparison of Diamond Drill Size on Iron Ore Geometallurgical Results, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 161–166 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By D Hunter, N Cusworth, J Miller

"Recent project failures have called into question the use and relevance of benchmarking and independent reviews, forcing a rethink of traditional processes and procedures.With cost estimates and schedules dramatically varying from lows seen around the global financial crisis to peaks experienced in the recent mining boom, benchmarking has ranged between essential and misleading.Profound shifts are now underway in future project delivery strategies as the market moves away from cost-plus engineering, procurement and construction management. The current trends in project implementation are to utilise more lump-sum design and construct or fixed-price supply and construct contracts. This trend will remove transparency in detailed cost information by reducing the sources and clarity of cost data.Independent peer reviews (IPRs) of studies and investment recommendations performed over the last decade have both failed to prevent flawed or deficient projects from proceeding to approval and funding, and been successful in ensuring that owners did not proceed with doomed investments.In recent times, it has been recognised by some owners, contractors and engineers that traditional benchmarking checks or IPRs, or a combination of both, will not necessarily produce reliable assessments of study conclusions and of the forecasts of project outcomes. To be of value, the benchmarking process now also needs to recognise the highly volatile responses from the engineering and construction industry to the current and future markets for their services.Similarly, reviewers who draw upon benchmarks of past project experiences on an understanding of the things that shaped and influenced their outcomes need to be more aware of how a future dynamic market may impact the outcome of the projects and raise warning flags accordingly.With the commodity cycle currently approaching what is hoped is its bottom, ensuring that benchmarking and independent reviews evolve into reliable, transparent and worthwhile processes becomes even more important. This can only be achieved with more transparent and analytical benchmarking and business-orientated reviews that both recognise and calculate the impacts of dynamic markets on project implementation.CITATION:Cusworth, N, Hunter, D and Miller, J, 2016. The role of benchmarking and independent reviews, in Proceedings Project Evaluation 2016, pp 249–259 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By M Franklin, C Puglisi, S Fitch

Implementation of a well planned and executed Management Operating System (MOS) can result in widespread improvements to operational performance but its success relies heavily on the investment by and engagement of the larger workforce with the project. Over the seven month period of the Telfer MOS project, significant improvements were achieved; a 20% increase in monthly hoisted tonnes from the open stope and sublevel cave operations and a 45% increase in square metres of ore extracted from the narrow vein operation. The Telfer MOS was undertaken with the intention that the project wasn’t solely about producing new tools, it hinged on the investment and behaviours of the personnel affected by these tools and alterations. To ensure that the project ran smoothly, the Byrnecut senior leadership team and their operators were heavily involved in the project’s development. In the initial stage, Telfer’s MOS project determined that the quality and accuracy of the information received in the form of radio calls to mine control and completed operator plods was questionable. This required an overhaul of the data collection and verification process in the form of altered operator plods, which was then cross referenced with the operator’s radio calls to mine control. Once the data collection and verification process was implemented, the Telfer team was then able to produce several tools with the aim of providing visibility to the data being captured and its implications. These tools allowed the mine foremen to determine whether equipment was being under-utilised and where they should focus their production efforts to meet monthly targets. Whilst the initial underground project is now complete, the implementation of MOS across the entire site is ongoing with significant operating improvements occurring.

Mar 15, 2021

The paper focuses on how rock bolts are loaded in different rock masses, as well as in pullout tests. Three analytical models for rock bolts are presented in brief, one for bolts in continuously deformed rock masses, one for bolts in blocky rock masses, and one for bolts in pullout tests. The bolt models are used to interpret measurement data for rock bolts from three sources and to help specify the modes of axial load in the rock bolts. It is found that in continuously deformed rock formations fully coupled rock bolts have only one axial stress peak. The position of the axial stress peak moves towards the far end of the bolts with increasing rock deformation. In blocky rock masses several axial stress peaks may appear in the rock bolt. The position of this kind of axial stress peak does not change during the entire loading process. For rock bolts in pullout tests, decoupling of the interface always occurs first at the loading point. The decoupling front moves towards the far end of the bolt with an increase in the applied pull load.

Jan 1, 2000

By J Coombes

The JORC Code lists the three core principles of Transparency, Materiality and Competency as fundamental to how mineral estimates are publicly reported. But where the principles of Transparency and Materiality can be considered conscious choices underlying decisions at the point of disclosure, Competency is a self-declared position statement based on one’s confidence to defend a technical position (as well as the functional pre-requisites of institute membership and a minimum of five years relevant experience).Developing competency in the mining industry is an ad hoc process, generally left to the individual to chart through a process of osmosis from personal work experiences that lead to a sufficient level of confidence. Companies that actually present professional development programs leading to reporting competency are rare. And even once a person has followed a program, there is no specific outline of what constitutes technical competence.No doubt, there are persons signing off on mineral statements who would benefit from developing and/or updating their technical skills (they may not even be aware of unmastered skills). Equally, there are technical practitioners who are sufficiently competent, but lack the confidence to step up and publicly report their estimates. Confidence in one’s own abilities plays a significant role in deciding when one is ready for the responsibility of submitting mineral estimates for public consumption. In addition, a person’s organisational support, such as the availability of suitable peers and professional development programs, and opportunities to learn from a variety of technical projects contribute to developing relevant experience. Increased exposure in both technical breadth and depth enhance confidence in one’s ability and competence.The mining industry provides numerous opportunities through direct and indirect means to develop the competency underpinning a stable reporting code. This paper examines a theoretical framework and associated processes that could be used to examine how the mining industry, companies and individuals collaborate to develop this vague principle of competency. This paper seeks to initiate research with the express purpose of enabling more effective and efficient development of reporting competency in our industry.

Aug 22, 2011