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By Blair J. R

A Train Performance Calculator (TPC) is an essential tool in railway operations, as a means of acquiring quickly a precise measure of the performance of the system. Traditionally the TPC was used in the form of program for a large computer. By employing an efficient integration algorithm and tailoring the program to suit the computer system it is shown that it is possible to devise a TPC for a mini computer. The resulting low running costs and flexibility of operation makes this a useful design tool. This TPC was developed to study problems associated with a single track railway operation. It was applied specifically to study the railway operated by the Mt. Newman Mining Co. Limited in the Pilbara region of W.A. to transport iron ore from the mine to the port. The TPC was used to calculate the effects of changes to locomotive power, to train size, to the track and to the amount of traffic. Its accuracy was checked by comparing its performance with that of the actual trains.

Jan 1, 1977

The proximity of the Town of Kalgoorlie to the Mount Charlotte mine necessitates that charge weight per delay be limited in order to keep surface vibration levels within acceptable limits and to reduce damage to underground workings. The mining system requires that large mass blasts must be used to recover pillars and therefore a large number of separate delays are needed. Until recently all blasting has been done electrically, fired from mains, but with the introduction of large diameter blastholes (165mm diameter) this firing system was inadequate. Various firing systems were considered, but after extensive trials a non-electric sequential firing system was chosen. This system fulfilled all criteria of blast design, was relatively straight forward in charging technique and had a very simple primary initiation system. Although initially designed for large mass blasts, the non-electric firing system is now used for all large hole blasting and in a simpler form for small (57mn diameter) holes.

Jan 1, 1982

By Hampshire MJ

The tailing retreatment project rated at 10 000 t/day commenced operations in October 1982. The operation consists of dredging, feed preparation, cyanide leaching and carbon-in-pulp (CIP) gold recovery followed by Zadra atmospheric stripping and electrowinning. For the first two years the operation was adversely affected by excessive cyanide consumption and low gold extraction. Investigations demonstrated that the very fine, or slime, fraction of the tailing was the dominant consumer of cyanide and dissolved oxygen. The plant flowsheet was subsequently modified by inclusion of 80 - 100 mm dia. cyclones for slimes separation and a 31 m dia. thickener for water recovery. Treatment of deslimed feed in the CIP plant has reduced sodium cyanide consumption from an average 1.85 kg/t to 1.15 kg/t. The reduced oxygen consumption by the CIP plant feed has resulted in higher dissolved oxygen levels, frequently reaching supersaturation after 4 to 5 h contact time. This has allowed much improved gold extraction from the existing CIP plant capacity. Gold extraction from the mixed pyritic siliceous tailing has improved from an average U prior to desliming to a current 57%. Investigations are continuing on the recovery of gold from the discarded slimes.

Jan 1, 1986

By Chapman G. J

Mining operations require detailed and precise methods and procedures for the optimum selection of ore from waste. A fundamental procedure applied to achieve this selection is accurate sampling. The key parameter to accurate sampling is an understanding of the degree of heterogeneity of the key element contained within a sampling mass. This paper will describe the methods applied for the calculation of the fundamental sampling error and the techniques used to achieve a representative sample in the Fimiston Open Pit, Kalgoorlie.The utilisation of Pierre Gy's sampling theory has optimised the blast hole sample quality and quantity for submission to the assay laboratory. This has resulted in reduced cost and optimised assay reliability in statistical terms. Similarly the analysis of exploration drill holes for resource definition has optimised drilling procedures in terms of the drilling method, sample length and sample quantity.

Jan 1, 1993

The paper describes a computer model developed within the State Electricity Commis- sion of Victoria for use in open cut planning. The purpose of the model is to simulate all the typical occurrences in, and influences on, the coal supply and overburden disposal systems in order to be able to assess their performance. The model incorporates much of the long term and day-to-day operations planning logic required for the allocation of resources within an open cut. This logic takes account of power station demands, bunker stocks, plant and crew availability, the balance of reserves between dredgers, planned maintenance, etc. The perfor- mance of plant within the system is simulated using random selections from statistical distri- butions of Time to Failure and Time of Failure for each plant item. The application of the model in selecting a suitable bunker capacity in a notional open cut development is described to illustrate the potential of the model in optimising plant selection.

Jan 1, 1982

By D Kay, M Lovitt

Mass Blasts are generally required at the completion of longhole stoping cycles to maximise the recovery of ore from a specific orebody. During the course of mining, the practice is to leave pillars of ore to support the opening left by extracted ore and to mitigate stresses from working areas of the stope. These pillars usually contain ore that has been included in the resource evaluation and is highly valuable to the mining operation. Due to their stressed nature, the removal of pillars by conventional blasting techniques, through small blasts, can result in pillars being reduced beyond their critical size and ultimately failing, rendering the ore unrecoverable. The AurionGold Kanowna Belle Gold Mine operates a Mine to Mill philosophy. This philosopy requires the fine tuning of blasting to provide the best possibe ore feed at the highest grade for mill productivity. This means that ore to the mill must be well fragmented from blasting that provides high extraction rates from draw points, with minimal dilution from overbreak or fall off, and sized to maximise SAG mill throughput. The AT04 Mass Blast contained significant ore reserves which were required to meet gold production targets. KBGB needed the AT04 Mass Blast to perform as well as if not better than conventional stope blasts to maintain mill production. This paper describes the circumstances, planning philosophy, techniques, including the use of Electronic Initiation Systems and Bulk Emulsion Explosives, and results that provided a highly successful outcome.

Jan 1, 2002

By Schoning W. L

Ore deposit models form the basis for numerous other economic decisions in the mining process. The success of these economic decisions therefore depend directly on the accuracy of the ore evaluation process. The Geology Department at the Sishen Iron Ore Mine is responsible for the generation of a reliable geological computer model of the rock material with predicted grades. This information is then utilised for further ore reserve calculations, mine planning, production scheduling and grade control. Owing to a very complex geological orebody, grades and beneficiation characteristics differ significantly from sample to sample. This means that ore evaluation is a difficult process and great reliance is placed on computer techniques. In 1993, preparation for the ISO 9002 quality certification of the mine motivated the Geology Department to hold formal `problem solving' sessions in order to identify and revise problem areas in operating

Jan 1, 1995

By G M. Jeffress, D C. Arne

There are two discrete aspects to collecting portable X-ray fluorescence (pXRF) data to obtain reliable results and to comply with reporting requirements under the 2012 edition of the JORC Code (JORC, 2012) – sampling method and quality assurance. A robust sampling program is required to obtain representative material for analysis. The appropriate method should be established for a particular project using a small orientation study. A variety of approaches to sampling soils, drill cuttings, rock faces and diamond drill core are discussed. These include using multiple spot analyses, scanning using a single operating beam and the collection of cutting saw pulps. The operator must also be aware of the attenuating effects of analysing through sample bags of different material types for various elements as well as the limitations of current pXRF instruments in reporting reliable data for certain elements. The analysis of the samples must also be accompanied by a quality assurance program in order to generate data that are ‘fit for purpose’. This includes recording X-ray tube resolution on a routine basis, using matrix-appropriate standards for which total elemental concentrations are available, using silica blanks, capturing sufficient duplicate analyses to constrain data precision and obtaining check assays to calibrate pXRF data against laboratory data. Examples of quality control approaches and data are presented. Table 1 of the 2012 JORC Code also recommends that information on instrument make and model, reading times and calibration be provided in any reporting of pXRF data. To this should be added information on operating mode and temperature, software version and moisture content of the samples. A robust sampling methodology with a suitable quality assurance/quality control program should produce pXRF data of sufficient quality for public reporting purposes, provided that the data are presented using appropriate cautionary language and adequate supporting information.CITATION:Arne, D C and Jeffress, G M, 2014. Sampling and analysis for public reporting of portable x-ray fluorescence data under the 2012 edition of the JORC Code, in Proceedings Sampling 2014 , pp 57–64 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By R Engle, R P. McMahan, D A. Bowman, S Schafrik, W Thabet

Preventing injuries and fatalities related to conveyor system use in the mining industry is important and increases uptime while decreasing lost time. The research presented here is funded by the National Institute for Occupational Safety and Health (NIOSH), and intended to accomplish this prevention by the use virtual environments (VEs) to improve training and help miners better understand the hazards of working around conveyor systems. Two conveyor system VEs designed to teach miners about hazards and to safely complete tasks around conveyor systems were developed for this project. The first conveyor system VE, called the instructional tour, gives the miner a semi-automated tour of a conveyor system and teaches the miner about possible hazards (eg, missing guarding) and how to safely fix conveyor problems (eg, a stuck idler) using lock-out, tag-out procedures. The second, called the virtual shift, allows the miner to freely navigate around a conveyor system to detect and avoid hazards. The miner is presented with equipment failures that need to be safely repaired during the virtual shift. If the miner fails to identify and avoid a hazard or fix a failure in a safe manner, an animation of the consequences is shown to the miner, who must start the virtual shift over. The models for the conveyor system VEs were created using 3DS Max. Desktop versions of the VEs were then created using Deep CreatorÖ, an authoring application for creating interactive 3D environments. Later, more realistic versions of the VEs were created for CAVEÖ, a room-sized visualisation system, using DIVERSE, an application programming interface. In initial evaluations of the conveyor system VEs, mining colleagues have indicated great interest in such training tools. According to their feedback, these and similar VEs would provide excellent alternatives to normal classroom training and serve as positive precursors to hands-on experience. These VEs provide new miners a chance to experience hazards associated with working around conveyor systems without being in possible danger.

Jan 1, 2008

By A G. L Pratt

Inclined troughed belt conveyors are more frequently being selected from a range of alternatives, which include shafts and trucks for ore haulage in underground mass mining projects. Belt conveyor haulage systems are being operated with lifts exceeding those normally associated with truck haulage systems and approaching the limits of shaft haulage systems. A belt conveyor haulage system, in this context, incorporates subsystems for: crushing,tramp detection and removal, andhaulage. This paper presents details of recent inclined troughed belt conveyor systems for underground mining operations, and explores the application of inclined troughed belt conveyors for the increasing demands of future underground mass mining projects.

Jan 1, 2008

By S Basu, P M. Midhun

Electro-Slag Remelting (ESR) is a process capable of producing ingots with much lower centre-line segregation and better internal soundness than conventional ingot casting processes, as well as lower inclusion and sulfur concentrations. This process is commonly used for alloyed steels intended for critical applications like components of marine turbines, supercritical powerplants and rocket motor casings. It involves melting a metal electrode using electrical resistive heating in a slag pool and re-solidification of the resulting metal droplets beneath the slag layer, forming an ingot. Conventional ESR fluxes consist primarily of CaF2, Al2O3 and CaO, along with minor concentrations of SiO2, MgO etc. The emission of fluoride vapour from the molten slag causes several environmental and health problems, triggering a need to develop and reduce the fluoride content in the ESR flux. The present study aims to develop low-CaF2 alternatives to commercial ESR fluxes without compromising on productivity and the surface quality of the refined ingot. Thus, the modification in chemical composition needs to satisfy properties like electrical resistivity, viscosity and liquidus temperature, essential for efficient ESR operation. Since electrical resistivity and viscosity are highly dependent on the ionic structure of the molten slag, it is important to understand the effect of compositional modification on the structure of the flux. The present study employs Fourier-transform infrared spectroscopy (FT-IR) and Raman spectroscopy to investigate the structural variations in the modified fluxes, especially the effect of changing SiO2 concentration, in comparison with conventional CaF2-rich fluxes. Additionally, thermal analysis (Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA)) has been carried out to characterise the melting behaviour of the fluxes. The findings are compared with simulations carried out using the FactSage™ software, ver 8.3 (GTT Technologies, Aachen, Germany). Simultaneous analysis of liquidus temperature and the structure is expected to help in identifying the practical suitability of modified ESR flux compositions for industrial implementation.

Jun 19, 2024

By C Pope, M Tannock

Mining exploration and development projects in Australia are being negatively affected by the highly complex regulatory and bureaucratic processes at all levels of government. These processes affect mining companies operating in Australia by impacting on timelines and the cost of developing a mining project. It is not uncommon for the granting of project approvals to take in excess of five years, meaning that mining companies struggle with productivity, efficiency, time frame and cost issues in respect to their projects in Australia. As the mining boom in Australia is moving from the investment to the production phase, it is now more important than ever to maintain a regulatory landscape that facilitates rather than discourages new investment.While one of our key arguments is that there is too much burdensome regulation and red tape in Australia, we are also strongly believe that regulatory intervention is necessary to ensure that appropriate checks and balances are in place to serve the public interest and manage environmental, health and safety, social and other development-related impacts that may arise from a mining project. However, the regulatory intervention in Australia has come to a point where it is excessive and starting to discourage valuable investment in mining projects for nominal return to the public. Excessive regulation or ‘red tape’ impedes productivity and competitiveness, deters investment and innovation and costs jobs, all of which ultimately impact on the growth of Australia and the standard of living of all Australians.This paper aims to examine and compare the federal, state and local regulations that govern mining projects in Australia. It will highlight how these regulations are unnecessarily complex, lengthy and duplicated and how they can be streamlined to reduce red tape. In doing so, the paper will evaluate the recommendations proposed by the Productivity Commission Report on Major Project Assessments released in 2013, which include the recommendation to move to a ‘one project, one assessment, one decision’ regulatory model.CITATION:Pope, C and Tannock, M, 2015. Project development and regulation red tape – a comparative analysis: does it need to be so complex?, in Proceedings Iron Ore 2015, pp 621–630 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By R Carreau

The results of a detailed acid rock drainage (ARD) prediction program were used to revise the waste rock segregation criteria at the Restigouche open pit mine. Waste rock at the site was predominately derived from altered volcanic rocks that hosted a massive sulfide lead/zinc orebody. The program assessed the five years of drainage chemistry from both the potentially acid generating and the non-acid generating waste rock storage facilities in addition to laboratory-based kinetic test results. Material-specific leaching characteristics including relative metal-release rates and neutralisation potential depletion rates were determined from 12 laboratory-based kinetic tests. Solid-phase analyses indicated that, although pyrite was typically the most abundant sulfide mineral in the waste rock, its abundance varied significantly as documented by total sulfur contents ranging from 4.0 per cent. Kinetic test results were used to establish revised waste rock segregation criteria based on total sulfur content and neutralisation potential. The revised criteria maintain that waste material with a total sulfur content 4.0 per cent as potentially acid generating. When present in sufficient quantities, ankerite provided an effective source of neutralisation potential for the range of observed sulfide oxidation rates. Kinetic testing documented that up to 6 kg CaCO3/t was ineffective at neutralising acidity in samples that contained >4 per cent S. The carbonate molar ratio measured from the humidity cells was adjusted to reflect the stoichiometry of the ankerite and applied as an NP/AP criteria for waste rock containing 0.1 <S per cent <4.0.

Jan 1, 2003

By G M. Volkmann

Pipe umbrella support systems – also called canopy tube systems – have been used successfully for tunnelling in challenging ground conditions since the 1970s. Historically, the drilling unit was the limiting factor for pipe umbrella installations – less attention has been paid to pipe couplings and their influence on labour time and load-bearing capacity.This contribution investigates the influence of the type of pipe connection on the load bearing characteristics of a connected pipe and discusses associated influences on design calculations and installation performance. Standard thread connections reduce the effective cross-section and thereby load-bearing capacity in the connection area. To achieve design parameters, over-dimensioning of the un-weakened pipe section is the only way to overcome this limitation. Recently, two new, alternative connection types were designed and developed for connected pipe umbrella pipes. The first one is the nipple coupling, consisting of fitting with a threaded connection that is pressed and welded into the ends of standard tubes. The second type is the squeezed connection, which mechanically connects non-threaded pipe ends, achieved by force-fitted squeezing from the drill rig. Both coupling types have technical as well as operational advantages compared to the common thread couplings, which are the weakest point in the support system.In the following sections significant technical differences are explained, design values given and a site example presented to illustrate the operational advantages of the newly developed coupling?type.CITATION:Volkmann, G M, 2014. Development of state-of-the-art connection types for pipe umbrella support systems, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 333–338 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By M Andrew, H Reynolds, R Mills

As the global mining industry continues to grapple with ‘black swans’ (high consequence / low frequency events) for health, safety and environmental losses, the focus is shifting from risk assessment of these events to risk management using selected purposeful controls that reduce the risk.Fundamental to critical control management (CCM) is a soundly based rationale for selecting the right controls for each and every risk. The approach should be based on a thorough understanding of the dynamics of the event: What causes it? How frequently will it occur? How likely is the consequence to be realised? This is typically done through a bowtie and methodical numerical risk analysis. Core to this step, then, is the structure and content of the bowtie; specifically, the analytic architecture that is used to construct the bowtie. Different architectures yield different constructions, and bowties are no different.Although bowties for operational health and safety (OHS) hazards appear to have a common architecture, they are not generic. It is important to stress that they contain site specific information, are prepared by site based operational teams, and vary from site to site to reflect each site’s operational conditions. They are often a product of the knowledge and understanding of the operational teams involved, may be prone to human error, and potentially miss latent hazards that may have been embedded early in the planning, design or construction phase of a mine or facility, or within the mining equipment. Overcoming these deficiencies through constant re-evaluation of the risks, and challenging the content on the bowtie will help to minimise the chance that something will be missed.This paper will cover key themes in bowtie architecture, introduce the concept of barrier models for high consequence event (HCE) bowties and present a relevant case study to illustrate the issues that determine quality in bowtie construction and critical control (barrier) selection and management.CITATION:Mills, R, Andrew, M and Reynolds, H, 2016. Can we stop a black swan breeding? Advances in bowties and critical control management, in Proceedings International Mine Management Conference, pp 105-114 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By Mikula PA

This paper presents the results of in-situ and laboratory investigations into a mining method which utilises conventional continuous mining techniques to carry out two passes in thick coal seams, resulting in the development of stable pillars with relatively small width dimensions and heights up to 6 m. Geotechnical investigations included structural mapping, brightness logging and standard laboratory testing. Virgin stress was measured using overcoring techniques. Two approaches to pillar design were used in the study. These were; pillar design based on empirical formulae and laboratory testing, and pillar disign using calibrated mathematical models. A trial panel was developed at 300 m depth to study pillar deformation and stress changes due to mining. The extent of rib deformation was studied using borescopes and extensometers. In-situ geotechnical measurements were used to calibrate displacement discontinuity and finite element mathematical models of the coal seam. These models were then used to predict the behaviour of a small panel of pillars which were to be developed to 6 m height. The mining method was shown to be feasible provided adequate rib support was installed. The benefit of rib support was found to be two-fold, in that it increased confinement of the pillar in zones of low horizontal stress, while reducing horizontal stress relaxation in zones of high horizontal virgin stress. The possiblity of roof control by designing the small pillars to yield on retreat is discussed.

Jan 1, 1986

By C Fischer

The introduction of digital communications technologies into the underground mining industry, in both coal and hard rock mining, has enabled high bandwidth applications to be applied in the mining industry. Digital networks based on 802.11 b/g/n open Wi-Fi standards have allowed numerous applications to be run over a single communication backbone. One of the many important applications is the tracking of personnel and equipment via RFID Tags. This tracking application has formed the basis of a Proximity Detection System or Collision Avoidance System (Schiffbauer and Mowrey, 2001; Kent, Fischer and Schiffbauer, 2011) thereby improving safety and increasing control in the mining environment. This paper discusses the growth of digital technology as the backbone for communications in underground mining applications. This growth has allowed the ‘convergence of technologies’ (occurring in the general business world) to be available to mine operators in general and underground mine operators in particular. Mine Site Technologies’ involvement with major mining companies and mining equipment manufacturers (OEMs) in developing and supplying their communication systems is also discussed.The latest technical requirements and specifications for communication systems for underground and open cut mines will be reviewed.

Nov 22, 2011

By S Coward, C Xu, P A. Dowd

"This paper provides an assessment of the current challenges in strategic mine planning and design and suggested approaches for addressing them. The specific challenges covered are: realistic quantification of downstream processes applied to orebody models to provide an integrated approach to mine design and optimisation modelling, estimation and simulation of geometallurgical variables and their integration into resource and reserve estimation and mine planning modelling, estimation and simulation of new variables for new forms of mining – deep mining, particularly block caving, and solution mining flexibility in planning and design to manage risk and minimise its impact information technology (IT) infrastructure and platforms for rapid online data collection, storage, access and processing.Most of these challenges require new types of data, variables, modelling and estimation methods. Foremost among the new types of variables and data are geometallurgical and dynamic rock mass characterisation variables. New types of data and data collection include rapid generation of very large amounts of online sensor data and the consequent need for rapid processing and modelling of these data.This paper outlines the challenges and strategies in each of these areas and uses examples of models and outputs to illustrate approaches and potential solutions.CITATION:Dowd, P A, Xu, C and Coward, S, 2014. Strategies for mine planning and design, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 41–50 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By C Jenkins, J Jasper, Y Suryaputradinata, S Lozyk, M J. Hartmann

The primary objective of mining companies is to function as a profitable business by delivering products that fit customer requirements in a safe and sustainable manner. Optimum resource utilisation is a critical focus area to achieve this objective, and the long-term sustainable business performance of a mining company is determined by the extent to which this is achieved. Technology improvements and/or new technology development could improve resource utilisation. However, adding new projects to a Brownfield operation carries risk. Overall project schedules, tie-in schedules and safety risks normally receive adequate attention, but the introduction and integration of new technology to a Brownfield site also carries the significant risk of failure to achieve design performance (quality or throughput). This risk must be addressed via rigorous design phase risk assessments and piloting. Post commissioning, the effective metallurgical integration of any new technology/circuit/process plant into an existing process plant calls for critical assessment, through circuit performance testing, and optimisation to ensure alignment with design criteria. In addition, this approach provides clear focus areas for further optimisation of the new plant and additional opportunity for overall plant optimisation. Roy Hill recently navigated this process successfully, and this paper provides feedback on the journey that led to improved resource utilisation.

Nov 8, 2021

By C E. Woolley, A Hosseini, J Foster

Northern Star’s Thunderbox Open Pit C-Zone cutback was designed to maximise extraction in a short life excavation; In fresh rock on the western wall this included 20 m to 30 m bench heights with 6.5 m to 10 m berm widths and a 90° pre-split angle. Rock mass quality in this area is generally fair to good, however, there are sections where the dominant foliation runs parallel with the designed pit wall, and more closely spaced, altered, foliation is present: these areas are difficult to predict and prone to failure. Stringent controls and monitoring were required in order to safely access below these areas, in particular the use of slope stability monitoring radar, Trigger Action Response Plans (TARPs), re-entry procedures, visual inspections, drone inspections and day-to-day personnel awareness of the hazard. Robust and comprehensively planned remediation was also required after two significant slope failure events where long reach equipment and rope access techniques were utilised to remediate the areas in question safely, but also in a timely manner, such that expected production targets were impacted as little as reasonably practicable. This combination of rigorous risk management and well planned remediation resulted in a successful and complete extraction of the C-Zone cutback with no impact to operational safety.

Jun 22, 2022