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By C K. McKenzie, P Popov, B E. Papillon, I Kharitonenko

Flyrock produced by blasts in surface mining and quarrying is a major hazard that can result in serious injuries or property damage. This paper presents a fully integrated and automated approach for reviewing blast outcomes from a wide variety of rock blasting environments from the perspective of flyrock safety associated with blasthole collar ejections. The process is applied at a corporate level for an explosives service provider handling up to 100 blasts per day from mines, quarries and construction sites throughout the US.Flyrock risk minimisation has inspired research and the associated development of a reliable flyrock model to estimate flyrock ejection velocities and the resulting maximum projection distances of fragments. In spite of significant achievements in this area, flyrock incidents continue to occur, mostly due to implementation mistakes. An efficient preventive measure is continuous blasting process improvement that relies on on-site video recording, storage, automatic analysis and classification of the recorded blasts followed by the automatic generation of reports.In this paper, a novel blasting video analysis system that is capable of processing a large quantity of video records is presented. Blast analysis and parameter measurement are fully automated and are carried out using videos recorded with a conventional consumer camera. The blast video recording process does not require the use of surface markers, range poles or objects of a predefined size for scaling purposes.Although automatic video analysis is commonly used in many application areas, such as video surveillance, traffic monitoring and robotics, the algorithms that have been developed to recognise and track solid objects with well-defined shapes, textures and colours are not efficient at dealing with blasts, which, by their nature, have dynamically changing parameters. Moreover, very strong camera vibration caused by blasts that cannot be totally compensated by camera image stabilisers may cause conventional computer vision algorithms to fail.This paper presents novel computer vision methods developed for automatic tracking of the trajectory from a blast ejection point to the highest point reached by blast particles and the ejection velocity. The system also uses colour and motion analysis to detect the emission of toxic fumes during a blast. The solution is vibration tolerant and can differentiate foreground and background data, even in the presence of camera vibration. Moreover, the blasting video analysis method can automatically categorise correctness of the measurements and therefore indicate cases when additional visual inspections may be required to verify reports generated automatically.CITATION:Kharitonenko, I, McKenzie, C K, Papillon, B E and Popov, P, 2015. An automated system for flyrock and fume monitoring of blasts, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 417–424 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Peck W

The tunnel alignments investigated for the Gosford Regional Sewerage Scheme are located in the Terrigal Formation and are covered for most of their length by a thick blanket of soil and weathered rock. The following techniques were found to be most effective in geotechnical investigations for tunnelling in this area: air-photo interpretation, seismic surveys to pinpoint drilling targets, in-situ measurements of strength,deformation modulus and permeability in cored holes, and the construction of rock- mass models. Cross-hole seismic modulus measurements, surface resistivity soundings and electric well-logging techniques were found to have limited applicability due to adverse local conditions.

Jan 1, 1976

By L J. Strachan, O J. Hawes, S W. Crossen, R C. Roberts

The Albany Conglomerate is a widespread geological unit found in northern areas of Auckland, New Zealand. It has previously been described as part of the early Miocene Waitemata Group which underlies most of Auckland. Much of the Waitemata Group comprises weak interbedded sandstones and mudstones, but also includes conspicuous conglomeratic units such as the Albany Conglomerate. The Albany Conglomerate comprises a well-cemented mixture of hard pebbles, cobbles and boulders of igneous and metamorphic derivation in lenticular beds. A number of tunnelling projects are planned for the near future in Auckland. Recent experience has shown that the variable features associated with the Albany Conglomerate can make selecting appropriate construction methods very challenging. This paper explores the engineering geological and sedimentological features of the Albany Conglomerate with respect to other conglomerates within the Waitemata Group and the potential implications on tunnelling projects in Auckland. Consideration is given to the extent of proposed geotechnical investigations and the production of geotechnical baseline reports.CITATION:Roberts, R C, Hawes, O J, Crossen, S W and Strachan, L J, 2014. Underground construction challenges associated with the Albany Conglomerate in Auckland, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 195–202 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Wilkins L. G

Ore recovered by North Broken Hill Limited as a result of mining operations at its Broken Hill leases is obtained, at the present scale of working, in the proportions of 80% from the North mine and 20% from the British mine sections, and is composed mainly of a silver bearing, sulphide lead and zinc mineral, in association with the gangue materials mentioned later in the text.The lead-zinc sulphide lode at the North mine is deposited in folds in pre-Cambrian sedimentary schists. These folds pitch north-east at approximately 40° and dip north-west at approximately 60°. In plan the deposit appears as two lenses designated on the mine as the "Southern" and "Northern" ore-bodies.The Southern ore-body yields the main tonnage of crude ore. The sulphide mass here overlies a heavy layer of rhodonite which persists with the pitch of the lode. In the central section of this ore-body the sulphide zone is coarse grained and of high grade with a wide range of minerals in the gangue dilution. Quartz, garnet, ftuorite, rhodonite, and felspar are common, whilst chalcopyrites, pyrites, pyrrhotite and green felspar are often present. The Northern ore-body is dolomitic to siliceous in nature. Crude ore obtained from the British section is predominantly...

Jan 1, 1940

By C Augustin, M Hahn, K Nienhaus

Operators of mining machinery like haul trucks or excavators have very limited information about the exact distance to other equipment as well as to the natural boundaries like berms, walls and structures such as crushers. The industry is seeking solutions to provide safety and positioning. The authors have developed a solution approach which is being used in several installations. This solution consists of three parts: first robust and compact two-dimensional (2D) radar scanners that provide range and angular information of the environment especially under difficult conditions like dust, rain, snow and fog; second an intelligent data processing framework flexible enough to adopt to different machines and operation modes like speed, inclination, visibility, tire friction, GPS position, orientation and acceleration; and third a high quality and easy to use interface giving highly condensed data to the operator, not blinding the operator at night and being sunlight readable. The truth of present proximity detection sensors is that they not only have a high false alarm rate but furthermore cover only a fraction of the possible scenarios. This makes them unsuitable for stand-alone collision avoidance systems. On the other side, mine dispatch systems only deliver database and GPS information, but no information regarding the real environment. The indurad company and its Australian partner CTS (http://www.cts.com.au) addressed these aspects by developing smart productivity enhancement driver assistance tools like lane and crusher dumping assistance.An innovative driver assistance tool developed in cooperation with the coal shearer manufacturer Eickhoff and the RWTH Aachen University has been awarded with the annual research award of its customer RAG, being the largest German hard coal producer, as well as with the bauma Innovation Award in 2010.

Sep 26, 2011

By C E. Woolley, H Jebaliya, J Foster

The East wall of the Kalgoorlie Consolidated Gold Mines Fimiston Open Pit (KCGM Superpit) has a history of wall instabilities impacting mining operations; the most significant of which occurred in May 2018, when more than 1 Mt of rock dislodged over six, 30 m high bench stacks and impacted the pit floor. Since 2011 approximately 1.250 Mt of material has fallen from the East wall at Fimiston Pit across three failure events (2011, 2018 and 2020). Each failure has been associated with major structures intersecting the pit walls: the Fiji Fault, the Australia East Secondary Splay Fault and the EWD3 Fault. In each instance the trigger for failure has been transient pore pressure in the pit walls. Northern Star will mine a cut back behind the failure area over a vertical distance of 180 m. Cut back mining will include the extraction of a remaining in situ wedge, which is assessed as kinematically able to fail, and a subvertical failure backscarp in Stage 1. A substantial amount of rill material from the 2018 and 2020 failures will be extracted in Stage 2. This paper presents the methodology in use to mine Stage 1 of the cut back, safely, through this potentially high-risk area, detailing the specific mining methodology employed, the controls put in place and the monitoring required. Day-to-day monitoring will be undertaken using the already installed slope stability radar and will feed into a daily assessment of activities which may be undertaken in the cut back area. Initial activities will focus on eliminating the potentially unstable wedge and vertical backscarp with use of innovative drill and blast techniques/products and the extensive use of remote capable equipment to limit personnel exposure.

Jun 22, 2022

By C Jacobsen, N Harries

Assessing and managing instability hazards is an essential activity when working with unstable natural slopes and excavated open pit mining slopes. Slope monitoring has become the standard technique for the management of geotechnical risks associated with mine slope instability hazards. In recent decades, a proliferation of new monitoring techniques such as terrestrial radar, satellite InSAR and LIDAR have become standard operational tools, complementing conventional survey-based monitoring solutions. A reliable monitoring system should identify and record incipient anomalous slope movement. Although the most obvious purpose of a monitoring system is safety related, slope deformation and performance monitoring also enhance the understanding of slope behaviour and assists in improving system design and implementation. For a monitoring system to be considered an effective early warning tool, it needs to operate in real-time and should be linked to the mine’s emergency communication systems. Terrestrial radar systems have been developed that can provide near real-time measurements, at a high level of precision and covering broad areas in all weather conditions. This has had a positive impact on the management of geotechnical risks in operational conditions. The technology adoption of RADAR in mine monitoring has significantly progressed in the last 20 years from technology enthusiasts, to visionaries, to pragmatists to conservative users. However, the increasing adoption of RADAR cannot reduce or remove other monitoring techniques that often have important benefits; even if these technologies cannot be used as a real-time operational tool. An increasing awareness on the importance of combining data from different monitoring techniques to develop a holistic picture of all possible geotechnical hazards is a current industry trend. This is proving to be an excellent foundation for managing hazards associated with slope instability in open pit mines, and is only expected to improve with time with the adoption of new technologies based on big data and Artificial Intelligence (AI).

Nov 29, 2022

By Ariti J

The mineralogy and extractive metallurgy of platinum and palladium in ores and residues is examined and the relative reactivity of Pt, Pd, PtS and PdS in cyanide and chloride media at 20¦C is discussed. Electrochemical measurements establish that Pd is readily leached in chloride media but more slowly in cyanide media due to a passivating PdO film. The passivating oxide film on Pt prevents leaching in either system at ambient temperatures. The results of leaching Au, Pd and Pt from an iron oxide residue obtained from the Sherritt Gordon Process using CN/air and Cl-/H202 are compared. It appears that passivation is overcome either by roasting at ?600¦ or by leaching at >_100¦C.

Jan 1, 1991

By Stump NW

Until a year ago all isotope on-stream analysis utilised flow cells similar to those designed for conventional X-ray on-stream analysis. These systems incorporated a fairly complex sampling system necessary to present a representa- tive air-free sample of the main process to the flow cell. Maintenance costs and capital costs associated with flow cells and sampling systems have been generally high. Costs can be greatly reduced and reliability greatly increased, by using isotopes incorporated in immersible on-stream analysis probes which actually dip into the main process stream eliminating the need for sampling. A bonus of other advantages associated with immersible probes includes temperature stability and ease of calibration. This paper discusses details and results of the probe systems, justifica- tion for installing on-stream analysis, comparison of conventional X-ray and isotope techniques, and a brief survey of methods of analysis using radio- isotopes in on-stream elemental determinations.

Jan 1, 1971

By M L. Muller, A R. O’Donnell

The Mount Isa Mines (MIM) Copper Concentrator has an extensive history of reagent trials, with different reagents coming in and out of favour over the years. The research and use of carbon depressants is particularly prevalent, as carbonaceous pyrite is a major source of concentrate dilution. Years of research led to the use of naphthalene sulphonate due to its excellent carbon depression properties. However, due to rising reagent costs carbon depression ceased in the late 1990s. This led to the loss of knowledge about the use and value of naphthalene sulphonate. Cyanide is used at the Copper Concentrator for the sole purpose of pyrite depression and over the years multiple projects have been devoted to finding alternatives to it. In 2012 the neighbouring MIM Lead-Zinc Concentrator replaced cyanide with naphthalene sulphonate which resulted in cost savings and the elimination of a hazardous reagent. In 2013, plant trials were conducted at the Copper Concentrator in hopes to replicate the outcomes obtained at the Lead-Zinc Concentrator. The results of the trials conducted at the Copper Concentrator showed that naphthalene sulphonate could not replace cyanide and this work was set aside to pursue more promising projects. Further research conducted in 2014 found that mineralogy and a better understanding of the depressing mechanism of naphthalene sulphonate held the key to improved pyrite depression at the Copper Concentrator. The findings showed that Mount Isa copper ore contains two forms of pyrite; euhedral pyrite (cubic pyrite) and framboidal pyrite (carbon rimmed spheres of pyrite), both of which require different reagents to sufficiently depress them. Naphthalene sulphonate was found to be an excellent carbon depressant, suitable for depressing graphite and framboidal pyrite, whilst cyanide specifically targets euhedral pyrite.In 2015 laboratory test work was conducted to examine the use of naphthalene sulphonate in conjunction with cyanide to selectively target both forms of pyrite. This work led to a full plant trial, the results of which showed a significant increase in plant performance, with higher copper concentrate grades and recoveries being achieved. This paper aims to focus on the benefits and importance of understanding past work and linking a detailed knowledge of feed mineralogy to reagent selection for improved plant outcomes.CITATION:O’Donnell, A R and Muller, M L, 2018. Selectively targeting hydrophobic gangue minerals at the Mount Isa Mines Copper Concentrator, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 413–421 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

The Southern Mines Rescue Station (S.M.R.S.) has been established for 55 years and in the past 15 years has had only 4 major call-outs. Whilst the mines rescue training program has continued to expand, the Station has become involved in other work which includes mine worker training and limited research. Notwithstanding, the prime role of the Mines Rescue Station has not been overlooked and the Station has only advanced with the many changes that have occurred in the coal industry. The Rescue Station activities are financed by contributions from Colliery proprietors and the aim of the S.M.R.S. Committee is to provide a service in which colliery management and mine workers will have a high degree of confidence.

Jan 1, 1981

By L Mikhael Gurieff, D Baas

The Phu Kham Copper-Gold Operation (Phu Kham Operation) is located in the Lao People's Democratic Republic and is owned and operated by the Lao-registered company, Phu Bia Mining Limited (PBM). Australian-headquartered copper and gold producer, PanAust Limited holds a 90 per cent interest in PBM; the Government of Laos owns the remaining 10 per cent. The Phu Kham Operation was commissioned in 2008 with an initial concentrator nameplate throughput of 12 million tonnes per annum (Mt/a). Subsequent improvement projects, including the Phu Kham Upgrade Project (PKU), completed in 2012, and the Phu Kham Increased Recovery Project (IRP), completed in 2013, increased the design throughput to 18 Mt/yr. In 2016, the actual mill throughput exceeded 19 Mt/a, this throughput is budgeted to be maintained until the end of 2020.The concentrator flotation circuit upgrade, completed during the IRP, called for a non-selective bulk sulphide concentrate to be generated from the rougher circuit. This in turn caused the mechanical flotation cells in the cleaner circuit, particularly those in the second cleaner bank, to become volumetrically overload. The overload reduced the cleaner circuit performance to approximately 92 per cent copper recovery at a 23 per cent copper concentrate grade, below the expected 95 per cent recovery. This bottleneck restricted copper units entering the plant to approximately 14.5 tonnes per hour (t/h) due to uncontrolled recirculating load build-up in the mechanical cleaning circuit.Maintaining the operating methodologies would have led to a copper production shortfall beyond 2016, to address this shortfall the Phu Kham Operation looked to optimise the Jameson Cell and mechanical cleaner circuit performance. The work included fundamental application of flotation practice and modelling, mineralogical analysis, bubble size analysis, plant surveys and test work. The results were used to develop and implement an innovative automated control system strategy incorporating flotation theory and operating strategies. The automation has the ability to quickly adapt to disturbances in the circuit and maintain optimised performance with little or no intervention by flotation operators.Upon completion, cleaner recovery increased to 95 per cent at a final concentrate grade of 23 per cent copper, and copper units entering the plant increased to 17.5 t/h.CITATION:Baas, D and Mikhael Gurieff, L, 2018. Developing flotation circuit control and automation for the Phu Kham Copper-Gold Operation concentrator, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 37–58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

In 1980 Pancontinental Mining Limited decided that while the Jabiluka uranium project was still a major focus of the company's efforts some diversification was necessary. At this time it was decided to include precious metals in Pancon's exploration and acquisition objectives. As a result the now Paddington Gold tenements were acquired, explored and developed. Today, it rates as the 6th largest gold mine in Australia and at an expanded throughput of 1.2 million tonnes per year of ore it will produce about 110,000 ozs of gold per year. Following extensive exploration activities by Pancon's Exploration Division the Operations Division continued with development drilling finally proving up a reserve of about 8.4 million tonnes at an average grade of 3.2 g/t. An in- house preliminary feasibility study was followed by a two phase feasibility study by Davy McKee. This resulted in a recommendation to the Pancon Board of Directors to develop Paddington with an annual throughput capacity of 875,000 tonnes. This paper describes the acquisition, exploration and development of the Paddington project. It goes on to

Jan 1, 1986

The need to schedule ore production to make maximum use of the strength gained by cem- ented fill during curing is discussed, to show how cement content and hence fill cost can be kept down for any particular operation. Results from laboratory testwork on Isa Mine fill conducted by the author while employed by Mount Isa Mines Limited form the basis of the Discussion

Jan 1, 1973

By D Sibthorpe

The employment of a tunnel boring machine (TBM) is the default delivery method for the realisation of traffic, utility and primary resource underground space worldwide, with hundreds of kilometres completed safely each year. This is not yet the case for the mining sector in Australia, specifically underground coal mining. The safety advantages of TBM delivery when compared to New Austrian Tunnelling Method (NATM) delivery, or that of drill and blast, remains unrealised.With coal access drifts ranging between 1000?m and 3000?m in length, the construction of these facilities using TBMs could be done in a fraction of the time when compared to current practice. TBM world records currently stand at 435?m/week or 1600?m/month for the 7.0?m to 10.0?m range. Resource owners and developers should embrace the opportunity to deliver access to their orebodies in only a few months, excluding machine assembly and disassembly time.There are challenges in utilising TBMs for construction of Coal access drifts, such as; TBMs generally being bespoke design, maximising capital efficiency for drift development, and geotechnical variances between projects. This paper explores safer and more cost-effective options. This paper also provides detail of how the configuration within a completed drift could be optimised to ensure all site specific needs are met with regard to future use of the drift. The paper also includes descriptions of the engineering solutions that are available for physical and atmospheric challenges specific to coal drift applications and how the TBM manufactures are adapting to the regulatory requirements are also covered.Due to downward pressure on high cost bases and ever increasing safety requirements the popularity of TBMs in the Australian mining sector can be expected to increase and eventually become the default delivery method for coal drift construction, building them cheaper, faster and?safer.CITATION:Sibthorpe, D, 2014. Coal drift construction by tunnel boring machine, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 671–682 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

Safe, efficient production is a common objective for all large open pit mines. Despite comprehensive policies, procedures and regulations aimed at protecting workers, several people die each year in mining equipment-related collisions. The limited sightlines of heavy equipment operators coupled with difficult operating conditions are major contributing factors to the majority of mining equipment collisions. Off road haul trucks are the most common type of machinery involved in surface accidents. These vehicles represent the primary target for improving safety performance by mine operators. Although several commercial products have been introduced to address these issues, none have achieved significant market acceptance. The current collision avoidance solutions lack integration with onboard fleet management and equipment health systems. To achieve acceptance in industry, any collision avoidance system must offer high reliability, minimal false alarms, and value for money. With these criteria in mind, this paper will examine the pros and cons of the various technological approaches to collision avoidance in an open pit mining environment. The unique global positioning systems (GPS) and camera-based proximity detection solution on offer from Modular Mining Systems will be described. This solution uses intelligent filters to minimise false alarms. Tight integration with fleet management provides context information to enhance warnings and enable back-office near-miss analysis. Available today, this combination creates a practical solution to improve the situational awareness of heavy equipment operators, at a compelling price point. Future directions for maximising heavy equipment operator situational awareness will also be examined.

May 1, 2010

By M McGrory, A Rodolfo, J Paredes, L E. Manguba, K A Villaspir, G Webb, R Setiagani, H Cardenas

"OceanaGold’s Didipio operation has been in operation for three years. Integral to the flow sheet design is a flash flotation circuit treating a portion of cyclone underflow, consisting of an Outotec SK-500 flash rougher and an Outotec TC10 flash cleaner and a SB-2500 falcon treating flash rougher concentrate to recover fine free gold.Flash copper recovery has been holding steady at 60 per cent, while flash gold recovery at 50 per cent. Gold recovery from the gravity circuit is 22 per cent, bringing the overall flash plus gravity gold recovery to 72 per cent.Operation of the flash rougher is mainly by pulp level control. Control of copper grade in the flash cleaner is mainly controlled by air inflow and flash cleaner pulp level control drives copper recovery. Gold recovery around the circuit is mainly driven by gold head grade.SB-2500 concentrate is scalped with a 250 micron screen with the coarse fraction reporting to a SB-250 falcon, concentrate of which combines with the screen fine fraction to a Gemini table.Citation:Cardenas, H, McGrory, M, Webb, G, Paredes, J, Setiagani, R, Villaspir, K A, Manguba, L E and Rodolfo, A, 2016. Didipio Flash Flotation and Gravity Recovery Circuit, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 123–126 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By A Remes, A Dennis, M Talikka, T Kotiranta, S Horn

A mine project combines vast amounts of information from various disciplines including but not limited to geology, mining, metallurgy, technology, environment and economics. In many cases, all relevant information is not fully shared between all disciplines. Thus, project performance (technical, economical and sustainability) may be evaluated on basis of insufficient information resulting in non-optimal decisions, project execution and risk management. Advances in computing power and simulation software enable various data sets to be incorporated in a single digital platform enabling more efficient and transparent data sharing. In addition, linked data sets and simulation can support assessment and optimization of the project as a whole rather than focusing on optimization of individual events. CITATION:Horn, S, Remes, A, Kotiranta, T, Talikka, M and Dennis, A, 2018. Evaluation of sustainability of copper production value chain from ore to metal using advanced simulation, in Proceedings Life-of-Mine 2018, pp 87–89 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By J D. Bryant

The Ernest Henry Copper-Gold mine, the third largest copper deposit in Australia, is located 35 km NE of Cloncurry in the Mt Isa-Cloncurry mineral district of NW Queensland. Ernest Henry Mining Pty Ltd (EHM), a wholly owned subsidiary of Xstrata Copper Australia, operates the mine. Approximately 10.2 Mt of ore grading 1.12 per cent Cu and 0.56 g/t Au were processed during the 2001 - 2002 financial year. The Ernest Henry plant produces copper-gold concentrate, which is trucked to Mt Isa for smelting. The Ernest Henry deposit is a member of the diverse Fe-oxide-(Cu-Au) class of deposits. The orebody is hosted within a sequence of moderately SSE-dipping, intensely altered Paleoproterozoic intermediate metavolcanic and metasedimentary rocks. Copper (chalcopyrite)-gold mineralisation occurs mainly within the magnetite-biotite-calcite ¦ pyrite matrix of a 250 m + 300 m pipe-like breccia body. The breccia pipe comprises two anastomosing lenses separated by a lower grade, clast-supported breccia zone. Several anastomosing brittle faults affect the macro-geometry of the orebody. Copper grade is proportional to the degree of matrix support in the breccia. The July 2002 Ore Reserve was 88.7 Mt @ 1.0 per cent Cu and 0.5 g/t Au. Resource estimation at Ernest Henry is based on a large database of predominantly diamond drill hole information. Drill spacing is typically 50 m + 50 m. Ordinary kriging is used to estimate Cu, Au, SG and IST (oxidation indicator) into model parent cells of dimension 20 m E + 20 m N + 16 m RL. The block model is comprised of five geological-geochemical domains represented by 3D wireframe surfaces. Zonal control, where samples and blocks are assigned the same domain number, is used to control grade estimation. The geometry of the domains defines hard grade boundaries across strike and soft boundaries along strike A Deep Drilling Project was initiated in August 2002 with the initial aim of testing the down-plunge extension of the orebody to a vertical depth of over 1 km. The encouraging intersections to date have resulted in a significant increase in the mineÆs open pit Mineral Resource together with the identification of an underground Mineral Resource. Added benefits of the project included an expanded and updated geological legend and an improved understanding of the host geological sequence.

Jan 1, 2003

By B Small

CSA Mine, named after the nationalities of the mines first owners being Cornish, Scottish, Australian, is one of Australia’s deepest and highest-grade copper mines. A combination of the modified Avoca method and shrinking was a standard practice where production rings were fired against and bogged to waste fill. This method resulted in dilution and involved rehandling of waste material to refill the bogged stopes in the Western region and the QTS Central. The introduction of pre-charging blastholes using a wireless initiating system (WebGen™) has enabled CSA to design and fire stopes in reverse. This involves the use of a pre-charged Temporary Rib Pillar (TRP) against the waste fill material in a previously mined stope. The temporary pillar reduces dilution and improves conventional bogging as material is blasted towards the drawpoint rather than towards the waste fill material. Additional drill, prep and blast re-work is reduced or completely removed as rings can be charged prior to, in conjunction with, or after, charging of the slot. This is a safer practice as the charge crew spend no time working adjacent to a brow or open void. A TRP trial was conducted in the western orebody at CSA. The risk of exposure to a brow or open void while charging underground, and the bogger rehandling of waste material was successfully eliminated. Once reverse stoping was established in modified avoca stopes at CSA, two TRPs were implemented in challenging ground conditions in the QTS Central region. The TRPs were utilised in a retreating four-way intersection to extract a central diminishing pillar to close the level out. The ore recovered in this stope provided 5 per cent of CSA’s copper for the year. Without pre-charging with a wireless initiating system, two 5 m pillars totalling 6936 t of ore at 7 per cent either side of the stope would not have been recovered. CSA has implemented the practice of reverse stoping in modified avoca stopes using TRP for ten stopes since the successful trial. The development of additional blasting techniques enabled by precharging with wireless initiating systems is currently underway in the QTS North orebody at CSA Mine.

Mar 29, 2023