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Vertical retreat open stoping (VROS) is a variation of sublevel open stoping (SLOS) that has been introduced at Cannington to minimise the influence of subvertical geological structures during stope extraction. The first application of VROS is described, where structures within the stope resulted in a change in firing sequence and the extraction of two complete sublevels in a single blast. The use of electronic detonators is critical to the success of VROS and their application is described. Numerous benefits of using VROS have been identified and are described. To date, eight stopes have been successfully mined using VROS. In addition to the first application of VROS, two further case studies are described.

Jan 1, 2005

By C M. Stewart

Lithium battery electric powered vehicles and machines (BEVs) continue to gain traction inunderground mining use, with predictions they will dominate the underground light and heavy vehicle fleets for some mines within the next decade. There are clear advantages for ventilation systems through reduced heat output and the elimination of harmful exhaust gases and diesel particulates. However, the risks and effects of BEV fire emergencies for underground personnel and ventilationsystems are still largely in the early stages of analysis and understanding. This paper conducts an industry review of a selection of lithium battery fire incidents and research.A research paper review on lihthium fire behaviour, intensity and toxicity will be analysed and comparisons made with equivalent diesel machinery fires for context. Guidelines for mine firemodelling parameters will be offered to assist in predicting the behaviour, heat and emissions from BEV fires, and recommendations and conclusions will be drawn on the specific hazards of lithium battery fires compared to conventional diesel powered machines.

Oct 12, 2022

By P Luo, J E. Danoczi, P Nakutnyy

Sensor-based sorting methods to remove waste or for upgrading ore prior to downstream metallurgical processing is becoming more prevalent for mining operations. X-ray transmission (XRT) sorters are a popular choice for mineral processing plants since they can sort a wide variety of minerals. XRT sorters pass high intensity X-rays through particles to generate images of varying greyscale, based on their effective atomic density. The ore sorter then mechanically separates the particles using algorithms based on the images. A popular test currently used to evaluate the amenability of the ore to XRT sorting is to pass the particles through the sorter and obtain the greyscale images showing mineralogical differences. This test provides information on the mineralogical heterogeneity between ore particles for their separation. However, it does not provide an understanding of the actual mineralogical composition of the ore or information pertaining to which other minerals may respond in a similar manner, nor does it provide liberation information. This paper describes a test that combines high resolution X-ray micro Computer Tomography (CT) combined with QEMScan to obtain information about amenability of ore to XRT sorting and to obtain valuable information that can streamline metallurgical testwork programs. This test also provides information relating to particle thickness and associated X-ray attenuation coefficients, desired mineral presence and mineralogical information relating to associated minerals and clays to assist with developing sorting algorithms. Combining the CT and QEMScan can address many limitations of the current method to determine whether XRT sorting technology is appropriate for particular ores. Mineralogy information from QEMScan can identify incidences of; mineral encapsulation, problematic clays, detrimental minerals as well as calibrate the greyscale values of CT data. Additional 3D CT imaging carried out on cores provides spatial information of the minerals within the ore and mineral grades.

Nov 10, 2020

By M Norbert, D O’Connor

The mainline running tunnels for Legacy Way comprise two tunnel boring machine (TBM) driven tunnels. Both TBM drives commenced at the Launch Portal adjacent the Mt Coot-tha Road. Excessive surface settlement arising from tunnelling would have had a significant impact to the road infrastructure. The geological structure above the tunnel springline is a mixture of fill, residual soil and weak rock. Given the combination of low ground cover and weak ground materials, along with the use of an open face TBM, an oversize pipe umbrella system has been installed above the tunnels. This pipe umbrella system is similar to that commonly adopted in conventional mined excavation support in soft ground except that the steel pipes are substantially larger in geometry and filled with concrete. It is acknowledged that similar systems with oversize pipe umbrella have been adopted elsewhere in the world in other projects. These systems often comprise of a full arch formed by conjoining oversize steel pipes (in contact only). By aligning the pipes in contact, the arching behaviour of the steel pipe would have been enhanced. However, this poses a degree of construction difficulty due to excavation and installation method of the pipes. The Legacy Way pipe umbrella system only consists of a partial arch at the tunnel crown and each pipe is spaced approximately 1200 mm apart with 900 mm diameter pipe, leaving a gap of approximately 300 mm between pipes. A reinforced concrete portal block was used to support the exposed ends of the pipes.This paper reviews the design analysis, the recorded deflections from the pipe umbrellas and surface monitoring during TBM launch and revisits the analysis using the newly available RS3 program, from Rocscience for 3D analysis of geotechnical structures.CITATION:Norbert, M and O’Connor, D, 2014. Starting the journey – launching of the Legacy Way open face tunnel boring machines in mixed face ground conditions, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 307–314 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By W Lunwongsa, S Meffre, S Nuanla-ong, K Zaw, R James, A Salam

Gold and silver mineralisation at the Chatree low sulfidation deposit is hosted in andesitic volcanic and volcaniclastic rocks and characterised by multiple hydrothermal alteration assemblages and quartz-carbonate (chlorite-adularia) replacements, veins and breccias. The ore-bearing veins are influenced by intersecting structures and host rock lithologies. Emplacement of the host succession occurred at 250 ¦ 6 Ma (dated with laser ablation ICP-MS U-Pb zircon techniques), which was closely followed by mineralisation at 250.9 ¦ 0.8 Ma based on the analysis of adularia from coarse-grained quartz-sulfide (chalcopyrite-pyrite- sphalerite) veins using laser ablation Ar-Ar methods. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Bure R

Approximately 2.4 million ounces of gold and 11.3 million ounces of silver have been produced from the Umuna Lode by Misima Mines Pty Limited between June 1989 and the end of Decemeber 1996. Reserves remaining at the end of December were 32.1 million tonnes at 1.0 gram per tonne gold and 9.7 grams per tonne silver. To attain precious metal production of this volume, an estimated K60,000,000 (1996 Kina) was spent on exploration alone. from the 1940s to the present day. Exploration expenditure for the 1996 calendar year was approximately K4,400,000. With such a large investment in exploration, large quantities of data were generated and stored in various forms. To make best use of this data, it was necessary to organise and systematically store this data in a form compatible with a modern Geographical Information System (GIS). The Umuna Lode on Misima Island is a low sulphidation gold- silver deposit dated at 3.5 ¦ 0.2 Ma. The deposit is controlled by the 50 to 100 metre wide Umuna Fault- a moderate dipping, brecciated clay- chlorite- carbonate altered, normal fault zone. There is approximately 230 metres of mostly dip slip offset on this fault, which is measurable by the offset of the Cretaceous schist, marble and greenstone host sequence. Late Miocene microdiorite spatially related to the Umuna Lode does not appear to be genetically related to the gold- silver mineralisation. GIS was introduced to Misima at the end of 1995 and until recently has been mostly used for data storage and retrieval, the over- laying of various data sets to assist in targeting prospective areas, and as a drafting tool. The use of data-driven, predictive data analysis is the most recent effort in maximising the use of the extensive Misima database. By characterising the key controls and properties of the Umuna- type mineralisation, a Weights of Evidence, data-driven analysis produced a prospectivity map of Misima Island. The purpose of this map was to identify prospective areas yet to be explored and to assess the effectiveness of exploration to date.

Jan 1, 1997

By L Thorburn

In 2009, the Queensland Government developed a series of amendments to environmental authorities (EAs) for mines throughout the Fitzroy Basin in response to studies that assessed the cumulative impacts of mine water discharges in the basin. One of the key amendments was the requirement for all mines in the Fitzroy Basin to develop and implement a receiving environment monitoring program (REMP). The intent of the REMPs was to provide baseline information on the condition of the receiving environments of the mines and any impacts resulting from release of mine-affected water. Since this time, the requirement to complete a REMP has been incorporated into new or revised EAs for mines (including metalliferous mines) in other regions, as well as for other industries that discharge to natural watercourses (such as coal seam gas). This paper discusses the approaches that can be used to incorporate biological monitoring and direct toxicity assessments into REMPs. It highlights the importance of collecting biological data using sound experimental design principles to investigate whether releases resulted in environmental harm; and the use of monitoring data, coupled with direct toxicity assessments, for setting more realistic, site-specific trigger values and release limits (compared to the default guidelines such as Australian and New Zealand Environment and Conservation Council (ANZECC), which may not be appropriate to the region). Implementation of a robust REMP can maximise outcomes for both the proponents and the environment.CITATION:Thorburn, L, 2013. Receiving environment monitoring programs - making the most out of biological indicators and direct toxicity assessments for monitoring of aquatic ecosystems, in Proceedings Water in Mining 2013 , pp 143-148 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By D Oliveira

The use of an equivalent continuum for a rock mass is not always suitable for situations where the failure is structurally controlled by discontinuities as in the case of wedges in the tunnel roof. In these instances, discontinuum approaches are usually preferred. Rock joints that are filled with soft infill are likely to be the weakest planes in a rock mass, having a dominant influence on its overall shear behaviour. In this case, the joint material model adopted for the discontinuities should be able to describe important mechanisms, such as asperity sliding and shearing, post-peak behaviour, asperity deformation, and the effect of the soft infilling. The latest version of a soil-infilled joint model is discussed here. It describes more comprehensively than previous models the occurrence of dilation and compression with lateral displacements, and also represents the hardening mechanism related to asperity interference as observed in the laboratory that cannot be readily captured by the existing joint models. An analytical approach for the analysis of rock wedges structurally controlled by soil infilled joints is presented.The analytical approach presented in this paper for assessment of symmetric rock wedges in the roof of a tunnel demonstrates, that the peak shear strength of the joint may not be fully mobilised before detachment of the wedge. The analysis verifi ed that an overestimation of the factor of safety may be observed when an elastic-perfectly-plastic joint model was assumed, whereas the computed maximum factor of safety was considerably less when adopting an appropriate soil-infilled joint model.

Mar 8, 2011

Since early-2001, Kalgoorlie Consolidated Gold Mines (KCGM) has successfully operated an ultra fine grinding (UFG) circuit to supplement its roaster capacity for the treatment of the refractory gold flotation concentrate. A second UFG mill was installed in 2002 taking the total UFG capacity to over 20 tph while grinding to 11 to 12 microns and achieving over 90 per cent gold recovery. A development program in 2002/3 involving plant trials, pilot plants and laboratory testwork resulted in process improvements and a better understanding of the milling and gold leach processes that assisted in narrowing the gap between UFG and roasting. This paper details the operation of the ultra fine grinding process at KCGM as a non oxidative treatment for the extraction of gold from a refractory ores.

Jan 1, 2003

By Jaczkowski B

The lower orebody (LOB) at Chingola Divi- sion of Nchanga Consolidated Copper Mines Limited (NCCM) accounts for approximately 30 per cent of the total copper production for the company. The uniformity of the geology of the orebody lends itself readily to a computer based ore reserve calculation and accounting system. The mining units are physically defined such that a hierarchical type of com- puter file organisation can reflect the existing physical interdependencies. In 1972, a project team consisting of one representative from each of the mine planning, operational research, and computer services departments was formed to investigate and to define the technical mining requirements of the dynamic ore reserve system (DORS). The system was finally implemented in 1975ò

Jan 1, 1977

By L Mariano

Three selected iron ore samples from the major bedded and channel iron deposits of Western Australia were analysed using a scratch test commonly used in the oil and gas industry. The portable commercial equipment dubbed Wombat cuts a groove on the surface of the sample with a cutter under imposed depth of cut and cutting velocity. The normal and tangential components of the force acting on the cutter are recorded with a high degree of precision (about 1N) at fine spatial resolution of about 20 measurements per millimeter.The intrinsic specific energy inferred from the scratch test measurements is found very well correlated with a classical measure of strength such as the uniaxial compressive strength, for over 300 sedimentary rock samples.The results obtained on the iron ore samples are comparable to those obtained on oil and gas sedimentary rocks. This method could provide an objective and semi-automated measurement of material strength and brittleness in iron ores that can possibly be correlated to the lump to fines ratio.

Jul 11, 2011

By A Roseman, T Gruber

Traditional methods for installing gaskets for segmented bored tunnels have relied upon different bonding procedures with adhesives that carry a series of disadvantages to segment producers. Fixation of the gaskets into the concrete segment as part of the casting procedure has been developed over the last 20 years and has emerged as an economical solution to produce high-quality tunnel segments for various technical tunnel applications. This paper investigates the advantages of using anchored gaskets, the different tunnel systems that employ anchor gaskets and reviews the first anchor gasket project; the Lee Tunnel and analyses how segment production efficiencies are gained.CITATION:Gruber, T and Roseman, A, 2014. Use of anchored gaskets in segmented bored tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 253–256 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J Joy, A Bye, G V. Kizil

This paper demonstrates an application of a recently developed Risk-Cost-Benefit (RCB) Framework to environmental risk management in the mining industry. The environmental application of the RCB Framework as part of an ACARP project (Kizil, Bye and Joy, 2012) involved a thorough selection process with site visits and in-depth discussions with the case study siteÆs environmental management team. Under their guidance, the highest risk of environmental impact at the case study site was identified as æroad subsidenceÆ at the time when the project work was undertaken. This paper presents the unique application of the RCB Framework to examine the risk of mining-induced subsidence and its impact on one of AustraliaÆs busiest highways, with a traffic volume of 38 000 vehicles per day (NSW RTA AADT, 2008). The RCB Framework was employed to assess the optimum group of controls for road subsidence risk management to ensure highway availability while mining occurs. Whilst this paper focuses on road subsidence, the methodology employed can be directly applied to other environmental concerns including preparation for mine closure, rehabilitation planning and waste management. The RCB Framework incorporates mathematical modules which were developed to enable complex yet tightly integrated RCB calculations. The process integrates the risk-control effectiveness assessment to determine that the selected safety initiative is financially beneficial to the mine site and company. This concept has been applied to a number of high-risk mining areas targeting safety, productivity and environmental issues. This paper introduces the five-staged RCB Framework, incorporating the RCB tools RCBGEN (Risk-Cost-Benefit Generator) and RCEMETHOD (Risk-Control-Effectiveness Method), and demonstrates its practical application to the risk management of a road subsidence case study. The case study looks at potential pavement damages, in particular, the occurrence of pavement stepping on the surface of the highway as a result of vertical subsidence. This type of road damage was previously experienced at another major inter-city route while underground mining occurred in the region where the case study site is located. The RCB Framework has been successfully applied to the analysis of the road subsidence case study and determined the risk reduction and financial benefits of implementing a range of risk-controls. User-friendly RCB Charts to provide an aid for decision-making were produced. The value of using the RCB charts to achieve balance between risk, cost and productivity in the decision-making process for risk management has been explained. The case study determined that pavement slots and fibre-optic cable monitoring were relatively low-cost and effective controls applied in the mining industry for the first time at a global level.This paper supports the industryÆs ongoing efforts to manage risk to ALARP (as low as reasonably practicable) and achieve æzero harmÆ by providing a new Framework to more effectively establish the adequacy of controls.CITATION:Kizil, G V, Bye, A and Joy, J, 2012. Application of risk-cost-benefit analysis to highway subsidence due to mining, in Proceedings Life-of-Mine 2012 , pp 197-206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By G Clarke

Commissioning of the Cannington processing plant began in October 1997. The nameplate capacity (of 1.55 million tonnes of ore per annum) was achieved relatively quickly. Since then (like many mines) the operation has strived to increase throughput and improve valuable metal recoveries, to offset declining head grades and lift the value of the operation. The processing plant now has the capability of treating over 3.2 million tonnes of ore per annum and in financial year 2005/06 the combined concentrate production exceeded 600 000 wet tonnes, approximately 80 per cent above concentrate output in the first full year of operation (at the design feed rate). This improved performance was achieved by making changes and additions to each of the major unit processes û primary grinding, flotation, leaching, filtering and paste fill preparation. The changes have included: adding a fines flotation circuit, expanding the grinding circuit, adding a pebble crusher, switching from continuous to batch leaching, building paste conveyors and decommissioning the column flotation cleaning circuits. This paper reviews these changes, outlines the current operating practices and discusses the challenges or opportunities that remain.

Jan 1, 2007

By C Parihar, R Garg, A Bhandari, S Bhandari

Blasting can impact the efficiency of entire downstream mining operation. Individual technology solutions for blasting have been available in the industry for many years but all of them only cater for certain aspects of blasting. Many of them are based on individual research and/or experiences. Some of the available software solutions are not suitable to be used in the field as that they need advanced skills or tools. Also, most do not take technology advancements like mobility, advanced data analytics, web solutions and integration into consideration. Hence, no technology platform is currently present in the industry that addresses all potential needs a blaster may need in an integrated manner.This paper presents an integrated solution that takes care of all aspects of blasting – design blasts according to mine plan; collect data after drilling has been carried out (as there is often difference in designed and actual drilled hole locations in the field); predict blast results in terms of fragmentation, flyrock, ground and air vibrations, wave front reinforcement and flyrock distance; and after assessment, allows changes in charging, delay timing and sequence. The technology solution is a secure, cloud-hosted, web-based software-as-a-service solution that can be accessed from anywhere. Also it has a mobile app, which is available for both Android and iPhone/iPad. The mobile app is also integrated with the web-based solution using application programming interface calls to the central data repository.Case studies for two limestone mines are presented where this solution is being used in its initial format. This software platform enabled analysis of the outcome from a previous blast pattern and then subsequently allowed optimisation of blasting operations based on historical data. Uses of this platform have resulted in improved key performance indicators in these two limestone mines. The mobile app as part of this platform enables extensive field blast data capture and analysis and also various predictions before a blast. Data collected include blast parameters, individual hole charging, initiation pattern, videos, photographs and vibration records for analysis/reporting. The key features of the solution are a blast designer, a detailed blast data collection/analysis and a series of environmental predictors. These predictors give blast results in terms of fragmentation, flyrock, ground and air vibrations and wave front reinforcement and take remedial steps before blasting to optimise and control adverse environmental impact. Many features, such as fragmentation predictor and mobility solution, are completely unique features that are not available elsewhere in such a field personnel-friendly manner.CITATION:Bhandari, S, Parihar, C, Garg, R and Bhandari, A, 2015. An integrated technology solution for optimised and environmentally-controlled blasts, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 393–400 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By S C. Barrie

St BarbaraÆs Marvel Loch operations have successfully used longhole open stoping as the primary mining method for a number of years. A transition to Core and Shell mining was implemented in 2009 to recover substantial ore grade resources remaining in sill and rib pillars. The transition to core and shell for the Exhibition lode required continuous waste filling of created voids and thus the removal of the crown pillar at the base of the Exhibition pit by blasting. Access to the top of pillar was denied as the pit was partially rock filled with waste rock from underground development.Beyond the technical challenges of the blasting project, a simple and transparent risk management process was developed to ensure appropriate controls and mitigating strategies were in place to minimise risk to personnel during the pillar removal process.Although failure of the crown pillar was anticipated but with the actual timing unknown, on 25 December 2011 the crown pillar yielded during normal mine operations. Engineered and isolation controls in place at the time were of a sufficiently high standard to ensure limited exposure of the underground workforce and minimal damage to mine infrastructure. Successful risk management through implementation of appropriate controls during the project lifecycle of two years and three months proved to be fundamental to the safe removal of the crown pillar.CITATION:Barrie, S C, 2012. Successful risk management through project life cycle for removal of the crown pillar at the Marvel Loch Underground Mine, in Proceedings International Mine Management 2012, pp 125-134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By De Cuyper J

Laboratory testwork has been performed on ancient residues from the cyanidation of a previously roasted gold-containing pyrite and arsenopyrite ore. By grinding to 95 per cent minus 60 microns, and after a strong aeration conditioning of the pulp, a gold recovery of approximately 67 per cent was obtained by cyanidation. This recovery was brought up to 80 per cent by leaching with thiourea, after a preleaching step with sulphuric acid under severe conditions of acidity and temperature. To avoid excessive capital costs bound to such processes, it was decided to investigate the possibility of applying flotation after grinding at a size similar or finer than the one used for the leaching tests. The method turned out to give interesting results because of the natural flotability observed at pH values lower than two for particles rich in gold present in the residue. After two cleaning steps, a final concentrate, representing around one weight per cent of the feed, was obtained with an approximate gold content of 350 g/t, representing a batch recovery of gold of about 50 per cent. Apart from sulphuric acid, whose addition was very high (flotation slurries at 25 g/l H2SO4), other reagents were not found necessary. Additional flotation tests were carried out to examine whether the recycling of the cleaner tails was justified but the gain observed appeared insufficient.

Jan 1, 1993

By C D. Rose

A review and summary of the results of 120 coal sampling system bias tests is presented. This review supports new methodology using multivariate statistics currently being considered by ISO TC27 SC4. The current difficulties with ISO 13909-8 are explained and the logic behind the current new working draft is discussed in detail. Bias was detected in nearly 36 per cent of tests reviewed, suggesting that much improvement is needed in designing, maintaining and monitoring the performance of sampling systems in order to avoid sampling bias.CITATION:Rose, C D, 2012. Bias testing of mechanical sampling systems for coal - A review of test results and call for use of multivariate statistical analyses, in Proceedings Sampling 2012 , pp 185-192 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By C Xuan, J H. Park, Q Wang, C Shen, D Kumar, W Mu

Dissolution of non-metallic inclusions in the metallurgical slag is of vital importance for cleanliness control of the steel manufacturing. With the development of high temperature confocal laser scanning microscope (HT-CLSM), new insights have been obtained due to its in situ observation characteristics, higher resolution and precise control. However, HT-CLSM measurement has the limitation, eg the slag composition cannot include high amount of transition metal oxides. In addition, it is time consuming for the experimental procedure and not so simple to succeed for every measurement. It is known that digitalisation has made a significant progress in recent years. Machine learning (ML), a sub-domain of artificial intelligence (AI), is the key enabling technology for the digitalisation of the material science and industry. The database for ML model is collected using almost all available HT-CLSM experimental data and subsequently the established database is trained by different ML methods. Unseen data is used as the benchmark of the ML model. Al2O3 dissolution is the main process to be predicted in the current study. A good agreement between the HT-CLSM data and the ML model prediction results show the possibility to apply ML in process metallurgy.

Jun 19, 2024

By A Dal-Corobbo

Traditional acid and metalliferous drainage (AMD) wastewater treatment focuses on the iron co-precipitation/adsorption process as this is a very effective method of reducing heavy metals, including copper, lead, zinc, arsenic, etc, to parts per billion (ppb) levels in AMD wastewater streams. One of the drawbacks to this method however is the large volume of sludge produced and subsequent disposal costs for the mine site concerned.A proprietary metals treatment system called high density sludge (denoted HDS) which significantly reduces the quantity of waste generated is described in this paper. This process generates a dewatered sludge that contains in the order of 50 to 55 per cent solids. This sludge is denser than conventionally dewatered sludge, which typically contains only 20 to 30 per cent solids. This advanced process has a wide range of applications and can be easily retrofitted into existing AMD treatment systems. It has been successfully installed at several mine sites to treat AMD wastewaters. This paper discusses the high density sludge process, its benefits and provides data and operating results from pilot test installations.CITATION:Dal-Corobbo, A, 2013. High-density sludge process for treating metal bearing acid and metalliferous drainage wastewaters, in Proceedings Water in Mining 2013 , pp 217-220 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013