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By J Fewings, T McCredden, S Seet, C Fitzmaurice

"Flotation of nickel sulfide ores are generally constrained by nickel grade and impurity concentrations (notably magnesium and arsenic) in the product delivered to smelters. Being a physical separation process, flotation recoveries and grades are limited by the grade recovery curve of a particular operation, where increasing product grades are invariably associated with lower recoveries. Impurities put further pressure on this relationship, as removal of impurities from the final concentrate is almost always associated with nickel losses.Western Areas Ltd are developing a proposed expansion to its Cosmic Boy concentrator to treat an impurity stream, that is high in nickel and would otherwise report to tails. Through the use of BioHeap® technology Western Areas aims to recover the nickel and discard the arsenic to tailings. This expansion will consist of a biohydrometallurgical plant that leaches the nickel arsenic minerals, removing the arsenic as a stable iron/arsenic hydroxide, while recovering the nickel as a high-grade nickel sulfide product (at approximately 50 per cent nickel). This can then be blended with final concentrate to improve nickel grades and recoveries, while simultaneously reducing impurity levels or used to produce high value products like nickel sulfate.The introduction of a small microbial leach plant may be beneficial to base metal concentrators constrained by impurities or grade.Citation:Fewings, J, Seet, S, McCredden, T and Fitzmaurice, C, 2016. BioHeap® - Breaking the Grade/Recovery Curve for Nickel Concentrators, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 361–368 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By A Harburg, A Dendys, G Green

Dugald River Mine (DRM) is located approximately 85 km north-east of Mount Isa, and 65 km northwest of Cloncurry, in the north-west Queensland Minerals Province of Australia. DRM is an underground operation and includes an above ground processing area, a 200 ha tailings facility, two waste rock dumps and associated infrastructure. The mining method is conventional underground longhole open stoping and downhole benching of a lead/zinc deposit within a black slate environment. The deposit is estimated to contain ~53 Mt of zinc and lead, which will be mined over a 30-year period. During operations, waste rock is segregated into either Potentially Acid Forming (PAF) or Non-Acid Forming (NAF) based primarily on the sulfide concentration of the rock. In particular, the NAF waste rock is an asset and is used for various small construction projects during operation; however, its primary use is for rehabilitation work at closure. Since beginning operations in 2017, DRM has generated more NAF than was originally anticipated. Whilst this is an excellent asset to DRM, it did pose a logistical problem of where to store the additional NAF for the life-of-mine and how to manage the run-off. DRM experiences distinct wet and dry seasons with hot conditions and periods of rainfall between November to April, and relatively dry and mild conditions between May to October. Majority of rainfall is received between January and February with an annual average rainfall of 501.1 mm. Short and intense rainfall events are common. DRM’s above ground infrastructure is land-locked between two large ephemeral watercourses, making the significant expansion of any assets challenging from a permitting/regulation and cost perspective. MMG is also a member of the International Council on Mining and Metals (ICMM) and is committed to adapting to a changing climate through operations and closure. Following extensive studies DRM opted to store the additional NAF material into the adjoining NAF Dam and concurrently upgrade a previously minor sediment basin into a highly engineered sediment basin which relies on automatic flocculant dosing to meet the required discharge quality limits. This basin is climate-resilient in that the dosing system can be adjusted to counter high intensity extended rainfall events which produce highly variable inflow water quality. This abstract broadly describes how DRM designed and implemented an engineering innovation to enable the site to meet the changing climatic challenges. The abstract then describes the process to design the sediment basin and how the dosing rate was established and validated. Finally, the abstract comments on the effectiveness of the sediment basin and how it has revolutionised DRM’s approach to water treatment and management; all whilst minimising the disturbance footprint of the operation

Aug 2, 2023

By B Zhao

Gas and coal dust, as potential harmful elements (PHEs) produced during mining, are considered two serious threats to the safe mining and the health of miners because of its explosive and pathogenic properties. To solve this problem, compound reagents enhanced water spraying technology was used to control the gas and coal dust in excavation working face in this study, and spray testing platform and wind tunnel were used to investigated the suppression effect for gas and coal dust. In addition, sink test, and agglomeration experiments were also used to analyse its suppression mechanism. Testing results show that the dust reduction efficiencies of compound reagents enhanced water spraying technology for four different particle sizes were 80 per cent, 91.43 per cent, 94.74 per cent and 94.46 per cent, and improved by 14 per cent, 10.86 per cent, 8.42 per cent and 4.25 per cent compared to water spraying. Moreover, the gas suppression efficiency also can be increased more than 20 per cent. Sink test, and agglomeration experiments results show that compound reagent improves the spreading efficiency of the liquid on the surface of the coal by changing its wettability, and this process can not only slow down the desorption rate of gas by forming a water-sealing effect in the coal surface indicated, but also promote the agglomeration of fine-grained coal dust.

Oct 12, 2022

There is an established need for an inflow of foreign capital if New Zealand is to meet projected growth rates. The Government recognises this and encourages capital inflows especially where there are allied economic benefits such as the access to specialised know-how or export markets. The Government has promulgated certain Regulations which are administered by the Reserve Bank. Under the Capital Issues (Overseas) Regulations 1965, consent is required before any company incorporated overseas can commence business in New Zealand or before an overseas person can borrow or raise any money in New Zealand. A New Zealand company is deemed to be an overseas person if more than 25% of the voting power is held by non-residents. In terms of current policy, overseas companies are permitted to borrow in New Zealand only a limited amount of working capital and some longer term capital calculated on the ratio that their New Zealand owned equity capital bears to their overseas owned equity capital. Wholly owned overseas companies are expected to bring all of their Fixed term capital from overseas.

Jan 1, 1971

By M Brewster

Goldfields Abosso Goldfields Limited (AGL) is a Ghanaian registered company that owns and operates the Damang Gold Mine. Gold Fields Ghana Holdings Limited holds a 71.1 per cent interest in AGL. The Damang concession held by Gold Fields Ghana Holdings Limited covers a total area of 271 km2 located 40 km north of the town of Tarkwa in the south-western part of Ghana. Gold Fields as a company registered on the New York Stock Exchange is legally obliged to be SOX (Sarbanes-Oxley). Sarbanes-Oxley Section 404 (SOX404) is on management assessment of internal controls. The Mineral Resource Management (MRM) function of AGL manages three Prospecting Licenses and two mining licences. At least ten pits/prospects are scattered along the two limbs of the Damang Anticline and have two main types of mineralisation notably Paleoplacer and Hydrothermal. Thus SOX404 procedures are put in place to treat each mineralisation type in the best way for reliable resource outputs and estimates. Generating auditable resources for AGL is a prime but most important function of MRM. Thus important checks are built and designed to ensure that all relevant geological and geostatistical inputs conform to procedures outlined under SOX404 requirements. More importantly sign offs are designed to ensure that technical personnel involved in all aspects of resource and reserve generation are satisfied and can be held accountable.

Jan 1, 2007

By Lean P. J

The present The Zinc ODrporation, Limited and New Broken Hill Consolidated Limited (ZC/NBHC) tailing dam (Site C) is expected to reach its terminal capacity late in 1985. Planning and design of new facilities for disposal of tailing after 1985 which includes new tailing dams (Site D) commenced during 1980. This paper briefly describes planning guidelines and specifications, location considerations, environmental aspects, operating strategy, engineering specifications, envirormental aspects and scheduling of works.

Jan 1, 1983

At the beginning of this year it was my pleasure and responsibility to take over the Presidency of our Institute from Mr A. A. Parish who, as did his predecessors, filled the office with distinction. It is a great privilege to address you as President and it is an occasion for my wife and family, and I am most grateful for your inviting them to the buffet dinner. Our Secretary (Miss Jacka), who processes all Presidents, has told me that there are neither questions nor discussions on Presidential Addresses, and that being so, I felt free to select a controversial topic. The address I have prepared is not strictly true to label; because I intend to include also the effect on agricultural production in Australia if Britain joins the European Economic Community (i.e. the Common Market).Three points of view are1. the European, which is one of equanimity deriving from the initial brilliant success of their scheme,2. the British, which is one of anxiety not to miss the bus, coupled with a commendable wish not to inimically affect existing Commonwealth arrangements,and3. the Australian, which is one of alarm.In England all are drawing their own conclusions on the subject and views range from the extreme desirability, to the extreme undesirability, of the United Kingdom joining.No one in Britain wants Australia, or New Zealand, to...

Jan 1, 1962

By A Jewbali, R Perry, R Inglis, L Allen

"The use of conditional simulation to characterise mine plan uncertainty is increasing for the assessment of risk in mining projects. While the development of grade uncertainty profiles is relatively straightforward and can be validated using standard geostatistical techniques, the addition of geological uncertainty to evaluate total risk remains problematic. Some of the problems associated with geological uncertainty methods include the clustering of data in favourable geologic units, difficulty in training image definition and the inability to address change of support issues for categorical variables. Despite these obstacles, the importance of geological uncertainty as a contributor to total uncertainty has prompted Newmont to explore and evaluate the use of various techniques (and combinations of techniques) on different deposit types.Two orogenic deposits of different geological complexity were selected for the study: Subika, a shear zone-hosted deposit, and Merian, a deposit containing gold mineralisation associated with quartz vein zones and stockwork within which are found higher-grade quartz breccia zones. Newmont trialled various categorical simulation approaches to determine the applicability of these methods for each deposit type and the effect of parameter choice on the width of the uncertainty interval. Some of the techniques that were trialled include multiple point statistics methods, sequential indicator simulation using local probabilities as well as variations of these methodologies.The goals of this study included: gaining an understanding of which techniques may work best in which deposit types gaining an understanding of the intricacies of each method gaining an understanding of the effect that each method has on total uncertainty analysis.This paper presents a comparison of the various techniques and makes recommendations for their use in uncertainty analysis.CITATION:Jewbali, A, Perry, R, Allen, L and Inglis, R, 2014. Applicability of categorical simulation methods for assessment of mine plan risk, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 85–98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By Mowat BA, Leach TM

The Morobe Goldfield in Papua New Guinea has produced in excess of 120 tonnes of gold from predominantly alluvial sources. Hardrock gold has been mined historically at Wau (23t) and Edie Creek (40 and geological resources have been established at Hidden Valley (780, Kerimenge (360 and Hamata (30t). Numerous prospects have also been identified within the goldfield. Primary gold mineralisation is related to intrusion of dacitic to andesitic Edie Porphyry (2.4 to 3.8 Ma), often with associated diatremes, which have intruded along major regional structures. A full spectrum of deposit styles from proximal (mesothermal) to distal (epithermal) to the porphyry source is recognised. The transition between the proximal and distal styles is recognised both between deposits and within an individual deposit. The deposit styles should be termed porphyry related gold mineralisation rather than given the generic epithermal and mesothermal labels.

Jan 1, 1995

The emergence of a new range of database communication standards and software has provided the impetus for the development of a new approach to exploration and mining data management. The acQuire software produced by acQuire Software Pty

Jan 1, 1998

By I Basson, J A. Miller, M Becker, F C. de Beer, L C. Bam

"Geometallurgy brings together geologists, mine planners and process engineers to extract meaningful mineralogical and textural information from an orebody, with a view to predicting its metallurgical response. Preferably, automated analytical techniques, which provide mineralogical and textural information, should process a large number of samples quickly, relatively inexpensively and reliably. Microfocus X-ray computed tomography (µXCT) is capable of producing 3D volumetric information on texture and mineralogy that satisfies some of these criteria. µXCT has been used extensively to study the porosity and internal pore structure of iron ore pellets as part of downstream processing. It has not been widely applied to earlier mineralogical and textural analysis of unprocessed ore, due to the limited ability of X-rays to penetrate high-density samples. In this contribution, we propose scanning methods to overcome this limitation, thereby facilitating a broader application of µXCT to iron ore resource management.CITATION:Bam, L C, Miller, J A, Becker, M, De Beer, F C and Basson, I, 2016. X-ray Computed Tomography – Determination of Rapid Scanning Parameters for Geometallurgical Analysis of Iron Ore, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 209–220 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

The Bowen Basin of Queensland and the Hunter Valley of New South Wales are the two largest black coal producing areas in Australia. Mining activities require the availability of large on-lease storages for water and tailings. The legislative framework for the regulation of large dams is slightly different between the states. The paper provides a broad outline of the regulatory framework in each state, with particular reference to Queensland and New South Wales. In New South Wales, water storages and tailings dams are treated similarly by the regulator. Under the Queensland Water Act 2000, now proclaimed, referable dams are restricted to water supply dams the failure of which involves population at risk downstream. Tailings dams are excluded, being deemed hazardous waste dams regulated under the Environment Protection Act 1994. These storage facilities are required to include a ædesign storage allowanceÆ so that the possibility of spillway discharges is minimised. New South Wales is moving toward this requirement. A curious anomaly is emerging in Queensland: the legislative definition of hazardous waste û material resulting from the processing of minerals û does not extend to coal tailings since coal is not included in the definition of a mineral. The paper explores this and other ramifications for mining operations of the new legislation as well as general trends in criteria affecting the cost of providing water and tailings storages.

Jan 1, 2003

Good morning and thank you for the opportunity to address this yearÆs New Zealand Minerals Conference.   As you have already heard from the Associate Minister of Energy, the Government believes that the minerals industry is an important part of our economy. In particular, our coal and lignite resources have the potential to play an important role in New ZealandÆs energy sector as both a primary fuel and as a means to produce electricity.   The Government has taken a keen interest in the primary fuel sector given the declining reserves of natural gas sector. The energy sector is a key driver of economic growth and it is therefore critical that we have a reliable supply of primary fuel as part of the energy mix.   In a global sense, New Zealand is like many other countries regarding the need to secure energy for the future. Natural gas will be a key bridging fuel in the transition from an energy market based on fossil fuels to one based on renewables over the next century.   However, natural gas as a solution to this energy transition has some pragmatic limitations for New Zealand. There is uncertainty as to when new domestic reserves of gas can be discovered and developed. And the alternative of imported LNG poses a number of costs and risks to the economy.   New ZealandÆs coal resources are vast-estimated to be enough to last hundreds of years at the current rate of extraction. The main question is can extraction be increased and sustained to meet the demand of domestic power producers and at the same time meet commitments to lucrative international markets?   At this point it is appropriate for me to place coal into context with Governments overarching policy objectives for energy. The Government has stated objectives for the energy sector emphasising energy efficiency and an increased focus of renewable energy, while still ensuring security of supply and certainty as to energy costs and risk. Coal certainly can make a contribution to these objectives going forward.

Jan 1, 2005

By D J. Williams

Tailings management is typically constrained by many factors that are taken as given. These include the tailings production rate that must be accommodated, the desire to deliver the tailings cheaply and easily as a slurry using centrifugal pumps, and a tailings footprint limited by the desire to minimise capital costs leading to a rapid tailings rate of rise and a low settled density. Other constraints include wall raises being delayed due to limited capital, inadequate tailings water and rainfall run-off management, and the net present value (NPV) approach to capital expenditure that puts off expenditure at the expense of performance. All of these constraints result in the tailings occupying much more volume than is necessary, being difficult to rehabilitate, and not being capable of supporting a beneficial post-mining land use or function. Ultimately, such constrained tailings storage facilities will assume very large dimensions, but each will typically be developed as a series of smaller storages that are filled rapidly and added to progressively. The optimal stage to efficiently recover process water is in the process plant, but this is limited by the desire to use centrifugal pumps rather than the more costly positive displacement pumps, which also require greater management of tailings deposition. Process water can also be recovered from the tailings storage facility (TSF) decant. Tailings water that is not recovered from the plant or the decant will be lost to entrainment within the tailings, seepage to the foundation or through the wall, or evaporation. However, tailings water is not always suitable for reuse in the plant, particularly when it becomes contaminated by the processing, and it may simply be stored on the TSF. This will exacerbate the seepage of contaminated water to the environment, and will limit the densification of the tailings that would otherwise occur due to desiccation of the tailings on exposure. If a larger tailings footprint were developed early, cycling of tailings deposition in thin lifts between a number of cells could occur, maintaining the dormant cells dry to enhance desiccation and densification, and ultimate rehabilitation. The end result would be a much reduced stored volume of tailings, the potential for upstream raising, and ease of rehabilitation to a high level. The higher initial capital cost would be overtaken by reduced ongoing capital, operating and closure costs.CITATION:Williams, D J, ?2014. An alternative whole-of-life approach to tailings management, in Proceedings Life-of-Mine 2014 , pp 285–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By E Villaescusa, A Kusui, R Talebi, R Hassell, C Arcaro

Northern Star Resources (NSR) operates several seismically active mines as part of its Kalgoorlie Operations. In order to successfully continue mining at depth in increasing stress conditions, strategies need to be developed to reduce, control and manage the impact of seismicity causing damage to the rock mass. Consequently, a research partnership was developed with the WA School of Mines (WASM) through Mining3. The main aim of the project was to develop appropriate ground support standards that could withstand the expected dynamic response with minimal to no rehabilitation required for the life of that excavation. The project utilised a design methodology for determining the required energy demand based on detailed geotechnical mapping, probabilistic analysis of wedge formation and an estimate of rock ejection velocity based on uniaxial compressive strength of the intact rock (Villaescusa et al. 2016). The ground support scheme consists of high tensile chain link mesh, resin encapsulated de-coupled posimix bolts and plain strand cable bolts, in one, or multiple passes together with plain shotcrete. Implementation of the design posed several challenges including how to install the chain link mesh, maintaining the required productivity, ensuring quality control, and understanding the interaction of the several ground support components within the scheme. The implementation of the system within a trial area was successful from development mining to open stope extraction. The most significant field verification of the system occurred with near field M+1.9 seismic occurring in proximity to an operating long-hole drill. Despite large displacements exceeding 0.5m in places, there was no significant ejection of rock or failure of the ground support system. Following the successful trial, the ground support design methodology and standards have been implemented across several NSR sites. The system forms the basis for the successful extraction of resources in future high seismic risk areas.

Mar 15, 2021

By G Munro

he Melbourne City Link project will complete a missing link between two existing major freeways in the Melbourne road network, providing a much needed bypass of the Central Business District for through traffic. The project, which is being financed under a BOOT arrangement with the Victorian State Government, involves the upgrading of significant stretches of existing freeway and the construction of new sections involving viaducts and tunnels. The tunnel sections, which are the focus of this paper, are beneath residential and business areas, the Yarra River, the Royal Botanic Gardens and significant sporting facilities where surface construction would be either impossible or unacceptable (reference Figure 1). The shorter, 1.62 km west bound Domain tunnel comprises two cut and cover sections through Olympic Park then the Yarra River, the driven section of 0.68 km length and exits through a common cut and cover section with the east bound tunnel under St Kilda Road and Sturt Street. The longer 3.76 km east bound tunnel commences at the common portal, through cut and cover under St Kilda Road then 2.86 km of driven section before exiting at a cut and cover section at Burnley. The longer Burnley tunnel has an access and ventilation shaft at approximately its mid point.

Jan 1, 1999

By Player WP

The legislative operating environment, or the mineral regime, that a country has to offer is one of the key determinants that a company wanting to invest in an area takes into account in formulating its investment decision. The New Zealand Government recognises this and the importance of getting the regime right in order to provide for continuing investment in mineral exploration and mining in New Zealand. In recent years, the Government has given considerable attention to developing legislation which provides for investment to take place; for those making the investments to have a stable, fair and open investment environment with government intervention only when considered absolutely necessary because other approaches are not working; and for the people of New Zealand to know that investment must meet acceptable health and safety standards and have acceptable impact on the environment. Also of key importance is having a clearly defined mining regime which includes rules on how to obtain a permit and rules in respect of ongoing permit compliance, rights to develop a mineral resource and permit conditions (in particular, the royalty regime). In New Zealand, these matters will all be addressed in what are referred to as "minerals programmes".

Jan 1, 1995

A new national-scale geochemical survey is under way inAustralia with the aim to provide energy and mineral explorers with state-of-the-art precompetitive data and information about the continentÆs potential resources. This low-density geochemical survey will provide a national geochemical data layer using consistent sampling medium and sampling, preparation and analytical methods. Large-scale geochemical patterns thus revealed are expected to point to new areas of exploration potential. The project is funded under the Onshore Energy Security Program. It is hoped that this new national geoscience dataset will help make Australia a more attractive destination for energy and mineral exploration investments. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By R Klepper

Separation of leach residue suspended solids from pregnant liquor solution is an important step in hydrometallurgy flowsheets. Alternative flowsheet options are counter-current decantation (CCD) thickeners or counter current washing (CCW) horizontal belt vacuum filters. Extensive sedimentation and vacuum filtration simulations have been completed by FLSmidth on leach discharge slurries to indentify equipment capacity and performance. These data were used to compare Capex and Opex for CCD versus CCW alternatives. In addition, Capex and Opex for large horizontal belt vacuum filters with filtration areas greater than 250m2 are compared to current state of the art sizes of 150m2. This paper presents this information and discusses various advantages and disadvantages.

Aug 8, 2011

Until early-1997, Mount Isa Mines Limited (MIM) generated electrical power for most of north-west Queensland. The discoveries of many new orebodies in the region meant the inevitable increase in power generation requirements for the new mines. In addition, the expansion at Mount Isa itself meant that MIM had to invest in new generating capacity or utilise the existing generating plant more effectively. Using its generating plant more effectively required MIM to undertake rigorous energy management within its own operations. A personal computer based system with a wide area network was installed as the basis for energy management. The result was that energy consumption was reduced, the need for additional generating plant was curtailed, and capital outlay for the generating plant that was required was delayed. As a direct result of energy management, carbon dioxide emissions were reduced substantially.

Jan 1, 1998