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Interest in the sampling of refined copper cathodes has heightened over the last ten years. This has followed the increasing importance of cathodes as the principle trading form for metallic copper. It has also been given impetus by recent trends for quality certification of manufacturing inputs, specifically the AS3900 and IS09000 series of standards.

Jan 1, 1976

By R H. Yoon, M Gupta, A Noble, K Huang

Froth flotation is the most commonly used separation technology in the mineral industries. Given the complexity of the pulp and froth phases as well as the multitude of operational parameters that influence flotation performance, purely fundamental models with strong predictive capacity are limited. As a result, accurately modelling modifications to an existing flotation circuit are challenging, particularly when using empirically-derived models from a different operating configuration. Despite these complexities, a recent publication by the authors (Huang et al, 2022) has shown that flotation rates can be accurately predicted from a first-principles model that incorporates hydrodynamic parameters (eg pulp density, superficial gas velocity, feed flow rates etc), surface chemistry parameters (eg contact angle, zeta potentials and surface tension), and size-by-class liberation data. Circuit simulations using this model were shown to be effective in predicting experimental graderecovery curves from the size-by-class mineral liberation matrix. Since the model is derived from fundamental characteristics of the flotation system, it can be used to simulate alternative circuit configurations with varying degrees of recycle. Conventional flotation circuits are operated in a closed-circuit configuration by routing the cleaner scavenger tails (CST) back to the rougher feed to provide an additional opportunity to recover the slow-floating particles. This widely-used flotation strategy has been under constant debate, and several researchers have provided evidence that open circuit configurations provide higher separation and better circuit control (Konigsman, 1985; Bulatovic et al, 1998; Thompson, 2016). Recently, Finch and Tan (2021), used linear circuit analysis to show that open circuit configurations have a fundamental advantage when stage recoveries are high. Given the limitations of these prior studies, the objective of the current work is to further evaluate the merits of the open circuit configuration through a detailed circuit analysis and simulation study incorporating the first principles model described above.

Aug 24, 2022

By V Ser, I Smit, C Robertson

Anglo American has been researching the potential benefits of inter-particle comminution techniques for several years. Inter-particle comminution has additional benefits in terms of milling circuit performance such as energy consumption and stability. This paper focuses on the flotation benefits. Inter-particle comminution leads to selective breakage, mineralogical analysis has shown that this leads to improved liberation of the valuable minerals. In addition to selective breakage, the relatively short residence time experienced in typical inter-particle comminution machines allows more efficient classification which contributes to a æsharperÆ product size distribution. The effect of particle size in flotation has been well documented in literature. In general, it is has been shown that there is an optimal particle size range for flotation, and that both above and below this range, flotation recovery is adversely affected. Results show that the narrow size distribution which results from inter-particle comminution improves flotation recovery. Furthermore, the absence of excessive fine gangue material which typically results from conventional fine (-75 ¦m) milling of talcaceous ores, can lead to 100 per cent savings in depressant consumption when such ores are subjected to inter-particle comminution. To-date, this technology has been evaluated on more than ten ores. This paper will focus on one set of results which demonstrates a number of common differences that exist between material that has been milled conventionally and using inter-particle comminution technologies, with emphasis on what the impact of these differences is on flotation performance. A pilot scale (200 kg/h) vertical roller mill (VRM) was used to produce the material, and the results shown will describe conventional laboratory batch, locked cycle and pilot plant flotation testwork.

Jan 1, 2005

By J Isles, S King, A Valenza, R Lawolo, J Evert

PT Nusa Halmahera Minerals (PT NHM) is an Indonesian joint venture company owned by a subsidiary of Newcrest Mining Limited (75 per cent) and PT Aneka Tambang (Persero) (25 per cent). PT NHM operates two underground gold mines, Kencana and Toguraci at the Gosowong mine site in North Halmahera District, North Maluku Province, Indonesia.The Toguraci underground mine development commenced in 2011 with ore production commencing in 2012. Water temperatures ranging from 50°C to 80°C were encountered in the Toguraci open pit associated with the structures containing the gold bearing veins and are believed to be fed from a relic volcanic system one to two kilometres below the mine. Underground development and production has continued to intersect these structures with the result that an integrated programme of geological, hydrogeological modelling and operational project work has been required to dewater the mine ahead of the descending stoping fronts.This paper will detail these programmes.CITATION:Lawolo, R, Isles, J, Evert, J, Valenza, A and King, S, 2017. Hot water management at PT Nusa Halmahera Minerals’ Toguraci Mine, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 191–198 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 16, 2017

The general theme of the paper is a resume of factors which induce management to explore for oil, gas, coal and uranium in Australia. It is non-technical in the sense that apart from brief references exploration techniques are not covered. The central theme is the interplay of such diverse factors as taxation, mining 'regu- lations, exploration costs, availability of competent personnel, potential markets within and outside Australia, projected prices of sources of energy and their distortion by governmental action including restrictions on international trade for economic or political reasons, the role of the so-called multi- national companies, extreme views by pressure groups on the preservation of the environment, the availability of funds for exploration and the possible returns to the providers of exploration monies.

Jan 1, 1974

Mere recognition of the need for technic- ally strong human resources in the'extractive metallurgical industries has not prevented the decline in the education base for broad spec- trum metallurgists. The ability of chemical engineers to perform very effectively in many extractive metallurgical positions does not remove from the need for a general metallurgic- al education system. The intrusion of chemical engineers into extractive metallurgy is only symptomatic of the problems facing the minerals industry and its educators. The prospect of a career in the minerals base industries is unattractive to potential students by virtue of perceived inadequacies in the professional basis of the industry and ignorance of its sig- nificance to Australia's future, as assisted by excessive secrecy and a low profile public Image.

Jan 1, 1987

By Quast K. B, Newell R, Caterford J. H

The most common reason for gold-bearing deposits being refractory is the presence of sulphides; in many cases these interfering minerals contain arsenic, antimony, or other environmentally-sensitive elements. A number of processes have been proposed or developed for pre-oxidation of interfering minerals. In most cases developers have focussed on gold recovery and capital costs, with relatively little data on the deportment or form of these potentially harmful elements. This paper surveys recent work connected with pressure pre-oxidation processes. Data from pilot plant treatment of refractory gold materials, using the nitric acid Redox process, is discussed along with the attendant flowsheet and engineering implications. Four refractory gold-bearing materials have also been tested at the University of South Australia for arsenic and antimony deportments.

Jan 1, 1991

After a very brief historical survey and overall assessment of traffic requirements, the invitation by the British and French Governments for private groups to make proposals for a "fixed link" is described, and the resulting plethora of proposals is reviewed. The three schemes which gave some promise of being adequately backed by private finance are described as follows:

Jan 1, 1987

The paper deals with the problems of grouting methods for fissured-porous rock. The paper describes design procedure, injection process patterns and hydrodynamic testing techni- que to plan grouting programs for fissured-porous aquifers. A number of case histories is given to illustrate the imp- lementation of developed methodology at various mining pro- jects.

Jan 1, 1988

Thank you for that introduction and especially thank you to the organisers for inviting me. I've had a considerable interest in this area and I've had the advantage of an education from Neil on the subject of offering documents as a result of our collaboration together on the Securities Information Review Committee.

Jan 1, 1989

By Riley S. J

Ranger Uranium Mine is located within the Alligator Rivers Region of the Northern Territory of Australia and surrounded by the World Heritage listed Kakadu National Park (Figure 1). The mining operation is currently producing about 1500 tonnes of uranium oxide annually, as well as considerable volumes of waste rock, low grade ore and tailings. The rehabilitation of the project should ensure that the radioactive mill tailings and other contaminants remain contained for at least 200 years, as required by the existing guidelines (Commonwealth of Australia, 1987). The present uranium mining operation is regulated by the Northern Territory Department of Mines and Energy who must refer to the Environmental Requirements when considering regulatory options. These Environmental Requirements were agreed by the

Jan 1, 1994

By O Aydan, K Sugiura, A Sakamoto

It is well known that some sinkholes or subsidence take place from time to time in the areas where abandoned room and pillar type mines exist. The authors have been involved with the stability of abandoned mines beneath urbanized residential areas in Tokai region and there is a great concern about the stability of these abandoned mines during large earthquakes as well as in long term. The 2003 Miyagi Hokubu and 2011 Great East Japan earthquakes caused great damage to abandoned mines and resulted in many collapses. Particularly the effect of the quality of backfilling of abandoned mine below the urbanized areas is very important under static and dynamic conditions. The authors present the effect of the quality of backfilling on the ground subsidence associated with abandoned lignite mines under static and dynamic conditions and discuss its implications on the urbanized areas above abandoned lignite mines in this study. CITATION:Aydan, O, Sugiura, K and Sakamoto, A, 2018. The quality of backfilling of abandoned lignite mines on ground settlement under static and dynamic conditions, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 134–141 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By M J. Saynor, J B. C Lowry

The Ranger Uranium Mine is located in the wet-dry monsoonal tropics approximately 250 km east of Darwin in the Northern Territory of Australia (Figure 1). Mining of open-cut ore bodies commenced in 1980 (Pit 1) and ceased in 2012 (Pit 3) and milling and production are scheduled to cease by 2021. At the conclusion of mining and milling operations, mine tailings will be returned to the mined out pits 1 and 3, which must then be physically isolated from the environment for at least 10,000 years (Australian Government 1999). The final landform also needs to have sufficient mitigation measures in place to ensure that areas downstream are not impacted by erosion products from the mine site. The proposed post-mining rehabilitated landform will cover approximately 847 hectares (8.5 km2) which represents an area that has the potential to supply sediment to catchments and streams downstream. One method of reducing runoff and associated sediment is the construction of rip lines along the contour to slow down the runoff velocity and to also trap fine sediment and nutrients in the depressions to assist vegetation growth.CITATION:Saynor, M J and Lowry, J B C, 2018. The impact of rip lines on erosion at the Ranger Mine Site, in Proceedings Life-of-Mine 2018, pp 150–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By B Godel, E R. Ramanaidou, M Verrall

Fortescue Metals Group Ltd Iron Bridge (IB) operation is a magnetite deposit located in the Pilbara region of Western Australia situated around 145 km south of Port Hedland. This Mesoarchean deposit belongs to the 3230 Ma Pincunah banded-iron formations (BIF), a member of the Kangaroo Caves Formation, Sulfur Springs Group (van Kranendonk, 2000).

Sep 18, 2023

By S W. Kingman, D Whit, I S. Lowndes

The use of compressive crushing equipment such as gyratory crushers within minerals processing plants can potentially generate large quantities of dust. Remedies to this problem include the retrofitting of shrouds, enclosures, local exhaust ventilation (LEV) systems and water suppression systems. The single or combined application of these systems must be optimised to ensure they operate efficiently. It is desirable that the future design planning of such facilities include integrated dust suppression and/or removal systems to ensure material delivery rates are maintained and the welfare of the workforce is protected. The characteristic release of dust and the disturbance to the surrounding ventilation airflow is investigated by the construction and solution of computational fluid dynamic (CFD) models validated by data obtained from scale experiments. A 3D computational model was constructed using the FluentTM CFD software to represent the background ventilation regime within an underground crushing installation. The falling ore is represented as a continuum granular fluid falling under gravity from the raised bed of the dump truck. Transient path lines are computed to simulate the updraft airflow generated by the tipping process and indicate the dispersion path of any entrained dust. The relationships between the falling ore material, the displaced air and the shear induced flow are determined by an analysis of the computed volume/mass flow rates predicted across the crusher opening. An analysis of the airflow patterns predicted by the CFD simulation models indicates strong shear flows induced between the tipped material and the surrounding airflow in the vicinity of the crusher during tipping, and a strong influence of the background ventilation regime on the path taken by this shear flow. Scale experimental studies were conducted to characterise the induced shear flow and visualise the potential entrainment and transport of dust. An analysis of these experiments is presented.

Jan 1, 2005

By E Taylor, F Lebbing

The $2.5 billion EastLink project is a 39 km tollway and includes twin three-lane, 1.5 km long, undrained driven tunnels with cross passages every 120 m. The hard rock tunnels are being built to avoid passing the motorway through the Mullum Mullum Valley and help preserve the unique flora and fauna in the area. The design of the permanent concrete lining and waterproofing system for the EastLink tunnels was both innovative and practical, to meet the demanding environmental and production constraints of AustraliaÆs largest road project. This paper describes several key aspects of the tunnel design and construction, including: design of fully tanked, permanent concrete tunnel linings for the main tunnels and cross passages to withstand 37 m head of water pressure in combination with potential rock loading in the future;optimisation of the tunnel shape to minimise the amount of reinforcement required and the design of special welded mesh which was developed within manufacturing constraints;100 year design life and durability considerations in every aspect and detail of the design including concrete mix design and stray current mitigation;development of a precast invert solution for the main tunnel permanent concrete lining to enable faster lining construction and to minimise risks to the tunnel membrane associated with fixing reinforcement and construction traffic;development of prefabricated reinforcement details for the junctions between the main tunnels and the cross passages to enable faster construction and minimise risks to the membrane associated with fixing reinforcement; andincorporating the tunnel drainage sump at the lowest cross passage in the alignment, resulting in deep excavation to satisfy the required storage volumes for drainage.

Jan 1, 2008

By G Billing a, D Gribble, E Hall, D Varga

The theoretical benefits of electronic detonators have been reasonably well documented. To support this, a practical comparison was made between the performance of the standard shock tube system, NONEL, and a high precision electronic system, HotShotÖ, at the Sunrise Dam Gold Mine. The expected benefits from electronic detonators to Sunrise Dam were identified prior to the trial. Based on these, a number of objectives were set to demonstrate the value of the HotShot system. These are an improvement in fragmentation leading to an increase in productivity, less oversize rehandling, increased throughput and more uniformity in muck pile movement. To maintain the integrity of the trial, the nominal timing of the shots was kept exactly the same, thereby restricting any performance improvements to the precision of the electronics. Accordingly, adjacent shots were chosen with consistent geology. Video footage was taken of the blasts and vibration monitoring was carried out by fixed geophones throughout the mine. Spot heights of the muck pile swell were taken immediately after the blast and heave profile graphs were generated for comparison. Video footage was taken for a period of three hours for both shots to analyse cycle times of the excavator and trucks. PITRAM data was also collected for analysis. As far as practicable, the ore was taken to the same finger on the run-of-mine (ROM) pad to assist in single sourcing for the crusher and to allow oversize to be separated out. From specific metrics taken during the trials, it was shown that the expected improvements due to the high precision timing of electronics were realised in all areas.

Jan 1, 2007

By D Macklin, R Hammond, T G. Blenkinsop

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Base metal sulfides at the Currawong volcanic-hosted massive sulfide deposit in the Lachlan fold belt of Victoria, south-east Australia, were formed in the late Silurian, but D2 deformation of the deposit in the Devonian Bindian orogeny was responsible for structural repetition that created the resource. The primary sulfide lenses were stacked by reverse-sense shear zones within a volcano-sedimentary sequence dominated by dacitic intrusions and turbidites. Shear zones were localised along lithological contacts, including the margins of the sulfide lenses. The competent dacitic intrusions did not fold during D2; folding was restricted to the packages of metasedimentary rocks. Overturning occurs within, but not between, the metasedimentary packages. The overall geometry of the deposit is that of a duplex, but the detailed shape does not conform to idealised duplex types, probably because of post-D2 deformation. A significant complicating factor for understanding the deposit, and for resource evaluation, is the dramatic variation in deposit geometry along strike, which may also be due to post-D2 deformation. The present day configuration of the deposit results from constructive thrust repetition of what may have been a single ore lens and destructive along-strike disruption controlled by rheology.CITATION:Blenkinsop, T G, Macklin, D and Hammond, R, 2015. Rheological controls on the geometry of the Currawong volcanic-hosted massive sulfide deposit, Lachlan fold belt, Victoria, south-east Australia, in Proceedings PACRIM 2015 Congress, pp 469–474 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By D L. Kennedy

It has always been a challenge to accelerate the underground development progress by increasing the advance rate of each development round. Surveys have shown that most of the development rounds have only been pulled 84 per cent to 94 per cent of the drilled length. Where bare detonators have been used as primers, less advance rate is expected. In order to obtain a good understanding of the influence of priming upon the advance rate in underground development, a series of high energy primer trials has been conducted by Orica Explosives in the goldfields using various types of Orica high energy Anzomex « primers. It has been shown that development face has been pulled an extra 140 mm to 420 mm by priming with Anzomex « K primers compared with conventional primers. From all the trials at different sites, we have seen that the face pulled using K primers was more square than that pulled using conventional primers. Virtually, no butts and toe were left on the face developed using K primers. Computer simulation has been conducted using either a conventional primer, a bare detonator or a K primer as initiator. The study compared the predicted crack patterns developed around the toe of the hole and it was deducted that a detonator-initiated hole would leave a butt some 200 mm longer than that from a conventional primer-initiated hole, and a K primer-initiated blasthole would give rise to stronger initial p-wave, promoting crack development around the toe and increasing the ability to pull close to the full depth.

Jan 1, 1999

By J Moncrieff, P Bellairs

The Black Star Open Cut is located immediately adjacent to the township of Mt Isa and is situated in the middle of extensive pre-existing infrastructure including two concentrators, two smelters, a wet fill plant and two shafts. At any one time there are in excess of 500 people working on the surface within an industry-accepted 600 m exclusion zone from Black Star blasts. Apart from the surface operations there are also the underground operations including the lead mine (closed in December 2005) and the Enterprise and X-41 mines that must clear for all Black Star blasts. The application of industry standard blasting exclusion zones (600 m) was risk assessed as imposing operationally prohibitive constraints which could cause significant business interruption due to the logistical challenges required to ensure that all personnel from surface plants were evacuated for each blast and potential for lost production whilst these personnel were not operating the plant. In was therefore an imperative for the blast exclusion zone to be reduced. This was achieved by the: use of a QA/QC team to ensure that relevant drill and blast implementation is within an acceptable tolerance (KPIs) from design; use of high-quality stemming material called HMR, which is a by- product of the concentrating process and is generally sized at -14 mm with very little fines; implementation of appropriate training and support to Black StarÆs own blast crews, reinforcing the need to achieve the designed amount of stemming in every hole; and provision of appropriate support from Black StarÆs management for additional resources to ensure that every blast achieves design within the KPIs but especially in high-risk areas. The blast exclusion zone was successfully reduced after monitoring the flyrock results from more than 176 blasts. Black Star Open Cut now maintains a minimum blast exclusion of 200 m in critical areas; however, general blasting currently uses a 250 m exclusion as this provides additional risk management whilst still minimising the logistics associated with clearing and securing the slightly increased area.

Jan 1, 2007