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By D Craw, C E. Martin, C Smith, C Rufaut

Wangaloa Coal Mine opened in 1945, and by the time of its closure in 1989, had produced 750 000 tonnes of coal and disturbed an area of 75 ha. The original mining licence required land rehabilitation to exotic forestry, however the current owner, Solid Energy, has worked with Crown Minerals and local councils to write a new rehabilitation objective. The site is now being stabilised and replanted with native species, and may be available for public use before the coal mining licence expires in 2007. Site discharge permits expire in 2017, and by that time, it is anticipated that discharge water chemistry will be similar to background levels. MWH are currently contracted for management of the mine rehabilitation project. The Kaitangata coal unit mined at Wangaloa is sulfurous lignite with associated pyrite. Kaitangata coal contains 3.2 wt per cent sulfur, which is higher than most New Zealand coals. Initial analyses at Wangaloa indicate low pH (2.56.2) values in soil, groundwater and surface waters as a result of acid rock drainage (ARD) processes, leading to increased metal mobility and challenging conditions for vegetation. Pilot studies indicate pinus radiata needles contain up to 67 mg/kg boron, and elevated As, Cu and Zn concentrations in surface waters. The main lake at the site has a pH of approximately 4.9, despite lime dosage in 2002. There is a real need for a complete geochemical model of the Wangaloa coal mine. Such a model could be applied to similar restoration projects, and would assist by pinpointing geochemical processes and toxic metal relationships most harmful to the receiving environments. Using this model, rehabilitation in the future will be targeted and more efficient. This project is part of a larger scheme to characterise and model the Wangaloa mine site restoration, including waters, soil, vegetation, geology and invertebrates.

Jan 1, 2003

By C S. Szentesy, K Howie

The Rosia Montana gold deposit is located within the æGolden QuadrilateralÆ area in the Apuseni Mountains of Transylvania, Romania. The deposit is situated approximately 85 kilometres north of the regional centre of Deva, within the province of Alba, at elevations of up to 1100 metres above sea level. The Rosia Montana deposit contains a current resource of 344.07 million tonnes at an average grade of 1.3 grams per tonne (g/t) gold (Au) and 6.0 g/t silver (Ag) for a total (measured, indicated and inferred) contained resource of 14.29 million ounces of gold and 67.00 million ounces of silver. The resource was calculated using a 0.6g/t Au cut-off, a 10 x 10 x 10 metre block size and multiple indicator kriging. The low sulfidation style epithermal mineralisation at Rosia Montana is hosted within Tertiary age dacite intrusions and related vent breccias. Mineralisation is generally disseminated and associated with silica, adularia, illite, pyrite and carbonate alteration of host rocks, with minor late carbonate-base metal veins. Precipitation of precious metals is generally considered to have occurred as a result of over-pressurization, boiling and subsequent brecciation. The dacite intrusions are hosted in Cretaceous shallow marine and deltaic shales and slates, which overlie older Paleozoic sedimentary and metamorphic rocks within uplifted sections of oceanic sea floor.

Jan 1, 2002

By C Roche, G M. Mudd

The Morobe Province of central Papua New Guinea (PNG) has been mined for gold for nearly a century, although it is only in the past decade that large-scale modern mining commenced. The Hidden Valley gold-silver project began construction in mid-2006 and production by August 2009, and is located in the mountains above Wau in the headwaters of the Watut River. The mine is owned and operated by the Morobe Mining Joint Venture (MMJV), which also owns the Wafi-Golpu project, comprising the Wafi gold deposit and Golpu copper-gold deposit, situated in the Watut River Valley. Together they represent a potential mine of the scale of Ok Tedi or Bougainville or bigger. The MMJV is owned in equal shares by Newcrest Mining from Australia and Harmony Gold from South Africa. Although Hidden Valley was the first large-scale mine in PNG to engineer and build a tailings storage facility, poor environmental management during construction and early operations led to significant erosion of waste rock and sedimentation impacts throughout the ~200 km length of the Watut River. Since then, substantial efforts have been made to improve environmental management, especially waste rock placement and storage and water quality management. While the impacts from the Hidden Valley project appear to be reducing, the saga has heightened concerns by many along the Watut River and across PNG about ongoing impacts from mining.This paper presents the results of an ongoing project in the Morobe Province conducted by the Mineral Policy Institute examining the historical, current and future impacts of mining, including community views, social and environmental impacts and the monitoring and regulation of mining. Overall, there is a clear need to more fully integrate social and environmental issues into life-of-mine planning and go above and beyond regulatory requirements. In this way, some of the lessons learnt – by the community, MMJV and government – can be incorporated before, during and long after mining.CITATION:Mudd, G M and Roche, C, ?2014. Mining in Morobe, Papua New Guinea – impacts, assurance and self-determination, in Proceedings Life-of-Mine 2014 , pp 313–336 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D R. Cohen

As one of the four basic sciences, the study of geology is intrinsically worthy as a means of increasing fundamental knowledge of the behaviour and evolution of the universe. Geological knowledge can also be translated into practical outcomes for society such as resource discovery and protection of the environment. Australia has a long tradition of providing very high quality geoscience programs to prepare graduates for a range of occupations. We are, however, reaching a nexus in the way universities should or can deliver engaging programs. This has been triggered by the rapid evolution of the digital world (the Internet of Things), new technologies, unprecedented access to information, better understanding of the processes by which we learn and adapt our thinking, growing complexity in the problems we must face or opportunities to grasp, and university funding models. Designing education programs for the next generation of geologists extends far beyond tinkering with syllabuses. We must develop skills sets that will allow graduates to work in rapidly changing landscapes, but in doing so may have to sacrifice content to build capability in our graduates. Whereas universities must respond to changing demands on graduates by ensuring degree programs contain an appropriate balance of material and high quality of delivery, industry and government must also fulfil their responsibilities to provide additional training programs for graduates to assist their rapid transition into independent professionals. This paper examines various educational issues being considered in developing the new Decadal Plan for the Earth Sciences, and reflects on directions that education is heading in many of our universities.CITATION:Cohen, D R, 2017. Educating the next generation of geologists, in Proceedings Tenth International Mining Geology Conference 2017, pp 3–10 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Roasting of a Copper Sulfide Concentrate

Sep 13, 2010

Efficiency, Economics, Energy and Emissions - Emerging Criteria for Comminution Circuit Decision Making

Sep 13, 2010

By M Carr, K Williams, W Chen, J Plinke

The depletion of iron ore deposits at the face of the mine site dictates the necessity for the exploitation of formerly less attractive orebodies to meet the demand of the modern world. These orebodies will typically be found close to or even beneath the water table where an increasing clay and moisture content will result. Problematic iron ores, colloquially termed as ‘wet and sticky’ material (WSM), can have a significant impact in the material handling stream due to the expensive downtime of processing equipment, which is attributed to the inter-particle and boundary cohesion and adhesion forces of the bulk material.In order to gain a better understanding of the causes of poor handleability, experimental test methods to determine wall adhesion, and inter-particle adhesion within bulk materials were developed. Based on the combination of wall adhesion and inter-particle adhesion measurements, with traditional methods of assessing bulk material handleability, a new method to assess the potential of bulk materials to cause handling problems is proposed. This method reduces the multitude of factors leading to problematic behaviour to a handleability index (HI) [0,1], which is easily assessed and understood. The method is suitable for adhesive materials and applicable for a wide range of material flow, from gravity reclaim stockpiles to transfer chutes and carry back on conveyor belts.Additionally, this research presents an assessment of the HI derived by experimental testing of three iron ore samples. A clear understanding of the problematic behaviour of the iron ore samples is achieved with the use of dust extinction moisture (DEM) tests, which indicates the regions where problematic behaviour may be experienced on-site.CITATION:Carr, M, Plinke, J, Williams, K, Roberts, A and Chen, W, 2017. Determination of the handleability index of adhesive bulk materials, in Proceedings Iron Ore 2017, pp 503–510 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Mineral exploration and mining in New Zealand has had almost five years of new legislation. The requirement for different consents is a challenging, time consuming, expensive exercise but in most cases the new procedure is working, although the matter of obtaining access to land is still a major issue. Priority is critical. After lodgment of an application for a minerals permit there are many other matters to address such as identifying land owners, occupiers and administrators, preparation of access applications, consultation and preparation of various resource consent applications.

Jan 1, 1996

By L A. Martinez Tipe, J McKibben, S Barry

"Metal prices are central to a mineral investment decision and have a profound impact on the financial performance of companies in the mining industry. At its most basic level, metal prices are influenced by the disequilibrium between international metal volume supply and demand. That is, the commodity price is a regulator that equates international metal supply and demand where inventories act as a buffer between the emergence of this disequilibrium and its dissolution through a price change.From this viewpoint, mining companies are required to forecast metal and bulk commodity prices when evaluating minerals projects through discounted cash flow (DCF) analysis. While supply-demand models are instructive, many companies use historical prices, spot prices, futures/forward pricing and consensus opinion (or a combination of all of these) to develop price forecasts.This paper discusses the definition, fundamentals and differences between futures/forward and consensus pricing and the appropriateness of each in a DCF model for mine project economic evaluation.Our results demonstrate that great care is required when using either futures/forward or consensus pricing and that the decision to use one rather than the other requires consideration of other important elements in the DCF model (ie the risk-adjusted discount rate).CITATION:Martinez Tipe, L A, McKibben, J and Barry, S, 2016. Metal prices and the differences between forward and consensus pricing – which one is better for use in a discounted cash flow model?, in Proceedings Project Evaluation 2016, pp 149–158 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

The Clyde Power Project, and its Clutha Valley Development forerunner, has taken widespread investigations for various hydroelectric purposes both along the valley floors upstream from Alexandra and on the higher schist terrain. As part of this work the nature and extent of many of the alluvial deposits have been resolved and the ages established with varying precision. Gold values have been approximately appraised in some areas as an element of environmental assessment.

Jan 1, 1992

The area around Big Bell was actively explored and sporadically mined for gold from 1904 onwards. The lease was named Big Bell in 1913. The property became established as a major mining centre with the development of the Big Bell underground mine in 1936. Mining operations commenced in late 1937 and ceased in January 1955, after milling 5.56 million tonnes of ore and producing nearly 21 tonnes of gold. In 1969 Australian Consolidated Minerals Ltd (A.C.M.) acquired the deposit then explored it alone and in joint venture until the current joint venture agreement with a subsidiary of Placer Pacific Limited (PPL) was negotiated in 1984. Following exploration and evaluation of near surface mineralisation, and a reassessment of the remnant pillars underground, the concept of a large open pit in conjunction with an underground mine evolved. The feasibility study was completed in October 1987, and the decision to go ahead was formally announced on 2nd December 1987. Placer Dome Technical Services Ltd were contracted to be the Project Managers, commencing construction on site early in January 1988 and handing the plant over to the operators 13 months later. The capital cost of the project at handover was estimated to be $133 million. The operating team commenced pre-production stripping of the open pit on 1st May 1988. By 31st January 1989 almost 16.0 million tonnes had been stripped and 350,000 tonnes of ore stockpiled.

Jan 1, 1989

The fundamental features of the Cable Belt Conveyor are described. It consists of independent wire ropes which take the transmission load, and a special reinforced rubber belt which acts 'only as carrier of material. The first cable belt installation in Scotland is described briefly.A general description of this type of conveyor is followed by details of the rubber belt construction and the method of joining sections of belt. The drive unit, the tensioning arrangements and the power requirements are outlined.Applications of the cable belt conveyor are 'dealt with and its advantages summarized.INTRODUCTIONThe cable belt conveyor, as its name implies is a conveyor composed of steel wire ropes and a rubber belt, in which the ropes serve as transmission members, and the belt merely as a carrier of materials.Over the years it has been the ambition of engineers connected with the belt conveyor industry to develop a conveyor that would use the high tensile strength of wire ropes to transmit the stresses involved in the driving of large capacity belt conveyors. Different lines of approach have been adopted in the United States of America and in Britain. In the United States the method adopted was to introduce a large number of flexible steel cables into the rubber belt itself, in the form of a closely packed layer arranged across the full width of the belt. These small cables are packed in a nylon filled duck envelope which is incorporated in the rubber belt. This is commonly known as the steel corded conveyor belt. In Britain, a Scottish firm developed a rubber belt conveyor in which full advantage was taken of the high tensile features of wire rope, without embodying or moulding the wire rope into the rubber belt, so that the two wire ropes and the rubber...

Jan 1, 1957

Building the Unified Comminution Model The Unified Comminution Model (UCM) was formulated with the vision of bringing all comminution models onto a common base. The structure of the model relies on knowledge of the mechanical environment in the comminution devices to predict the modes and rates of collision in a device. A detailed understanding of the breakage modes and an ability to correctly test these modes for the ores in question is then required to feed into the UCM. A model structure has been developed that has the capability of dealing with multiple modes of breakage, such as low energy impact surface damage, chipping, sliding abrasion, cumulative impact body breakage and the transition of rock between modes. A critical review is presented on the shortcomings and limitations of utilising the discrete element method (DEM) to provide the mechanical environments. The assumptions and applicability of utilising DEM in milling models are presented and proposed routes to building a realistic mechanistic model are proposed. Based on this more realistic measures of collision energy have been derived from the DEM simulations, which better mimic the real breakage tests. Generic forms of the collision energy distributions have been observed and developed into functional forms for use in the simulation environment. The method of application of this model to a pilot SAG mill is presented.

Sep 13, 2010

By P O. Koons, R J. Norris, S C. Cox

 The Southern Alps is an active oblique collisional zone which has a characteristic wedge-shaped geometry above a low-angle ductile shear zone. The Main Divide region is a relatively low strain zone above this ductile shear zone, and is _deforming principally along steeply dipping strike-slip faults. Extensional fractures are common at a high angle to the regional structural trend. These steeply dipping structures act as conduits for gold-bearing fluids from depth, and small mesothermal gold deposits have formed at several structural levels including the near-surface region. Gold has also been deposited in a meteoricmetamorphic fluid mixing zone near a conductive thermal anomaly on the western slopes of the mountains. These various gold deposits and their well-constrained structural and tectonic settings can be used as analogues for larger, deeper-eroded mesothermal gold deposits in the Mesozoic Otago Schist belt. High level Miocene veins in NW Otago have formed beneath the main divide of the initiating Southern Alps. Late metamorphic gold-bearing veins formed as fluid escaped from the ductile-deforming crustal root beneath Mesozoic mountains.  

Jan 1, 1997

By F F. Pitard

The comparison between J Visman and C O Ingamells’ works with P M Gy’s works has been the object of intense debates in the past. Such negative debates inevitably resulted in a loss of many good opportunities. The author’s long experience in applying works of these three authors led to the pragmatic conclusion that it is relatively easy to integrate everything Visman and Ingamells created into the Theory of Sampling; therefore, it is suggested that the compatibility has been vastly overlooked, and a correction for such anomaly is recommended. It is important to emphasise that Visman and Ingamells works may be beneficial and provide relevant, harmonious additions in some areas, and ultimately offer attractive possibilities to sampling practitioners. Such additions may enhance our capabilities to predict sampling difficulties by using a stronger strategy and to design better sampling experiments that would allow us to further understand the heterogeneity of minor constituents, and especially trace constituents. Basically, the suggested integration is essential for sampling trace constituents in the environment, in food, in chemicals and in the pharmaceutical industries.CITATION:Pitard, F F, 2017. Integration of Visman and Ingamells’ works into the Theory of Sampling – a necessity to expand possibilities in sampling practices, in Proceedings Eighth World Conference on Sampling and Blending , pp 55–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

This paper focuses on two sites in the Mount Pleasant - McCormacks Bay area of Christchurch where residential development has taken place either within or immediately adjacent to former quarries for the extraction of volcanic rock. At the Quarry Road site less overburden was dumped on adjoining land around the turn of the century, and c.1980 dwelling and related construction took place on approximately 6 m of relatively loose fill material without the recognition of its presence or geotechnical characteristics. Subsequent settlements led to abandonment of a swimming pool and the underpinning of the 3-storey architect-designed house, whilst litigation brought by the owner resulted in findings of negligence against both the architects and engineers. At the Tramways Quarry site the Council approved subdivision of the former quarry area in the early 1980s without requiring any geotechnical evaluation of batter stability or related issues. During development it became apparent that significant blast damage had occurred to rock faces, necessitating a variety of remedial measures, and that waste materials had been dumped down faces without regard to long-term stability. Both case studies confirm the requirement for careful documentation of former quarry sites by territorial local authorities as part of their administrative function, and for detailed engineering geology and geotechnical evaluation of such areas prior to any residential use of the land.

Jan 1, 1998

The Hishikari gold deposit, discovered by the Metal Mining Agency of Japan, has become a giant class epithermal gold deposit with the highest grade of gold yet recorded in the world through detailed exploration and development by the Sumitomo Metal Mining Co Ltd. The exploration strategy involved a regional approach combining geological and gravity surveys over a 900 km2 area which had historically produced over 120 t of gold. These surveys were carried out to grasp the common geologic features of epithermal gold deposits in the survey area. A genetic model for epithermal gold deposits in the area under regional survey was also considered based on detailed research of the Kushikino epithermal gold deposit which was in operation at that time. This model was applied to the targeted areas, and important relationships between mineralisation, host lithology, intensive propylitic alteration and gravity highs became apparent. The Hishikari block was selected in this way and bonanza gold was discovered during drilling. Since the development of the Hishikari mine, information useful for further exploration for the same type of deposit has been accumulated.

Jan 1, 1995

Similarities and Dissimilarities in Florida Phosphate Ore Types - Surface and Bulk Property Analysis of the Flotation Feed, Concentrate and Tails

Sep 13, 2010

By P M. Ashley, M Muller

Massive sulphide ZnPbCuAg deposits in the Halls Peak district of north-eastern NSW are of the submarine volcanogenic type. They occur as a number of small lenses enclosed in shale and epiclastic rocks, in association with felsic volcanics of early Permian age. The deposits crop out in steep terrain near the eastern edge of the New England plateau. Local relief of 700 m and slopes up to 50¦, coupled with an average annual rainfall of about 1000 mm has led to local severe land sliding in previously mined areas. Mining from the 1890s to the 1960s has also resulted in unconstrained drainage of heavy metal-bearing acid waters and physical dispersion of finer grained metalliferous sediments into the Chandler River. Waters emanating from the main landslide area, from underground workings and draining scattered unconfined stockpiles of massive sulphide ore have pH values of 3 to 4 and contain elevated contents of Zn, Cu, Pb, Cd and Fe. Chemical mobility of heavy metals into streams occurs under low pH conditions with Zn exhibiting the greatest dispersion. Increasing pH conditions downstream cause precipitation of Fe phases and coprecipitation of heavy metals. Physical dispersion of secondary metal-bearing minerals into the surrounding creeks results in wt% levels of Cu, Pb and Zn in the stream sediments thereby exceeding the regional background values by one to three orders of magnitude. Areas disturbed by mining are characterised by lack of vegetation, biomagnification of heavy metals into algae and lower plants, and partial recolonisation by metal-tolerant grass species (Snow Grass, Poa sieberana; Blady Grass, Lomandra longifolia). Rehabilitation measures will have to include landslide stabilisation, impervious sealing or removal of sulphidic materials, import of topsoil and revegetation by metal-tolerant, slow-growing native grass and shrub species.

Jan 1, 1995

By R H. Sillitoe

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Geological concepts are employed routinely in porphyry copper exploration at the area selection, prospect appraisal and deposit definition stages. Regional, district-scale, deposit-scale and laboratory-based concepts can all play a role, with the resulting porphyry copper models providing templates for the integration of geochemical and geophysical responses and interpretations. Of the 19 concepts and parameters selected for brief discussion, those relating to subdivision of porphyry intrusions, understanding of diverse and commonly complex alteration-mineralisation patterns and lithocap characterisation are undoubtedly the most influential in exploration. Several of them are of particular importance because of their role in promoting grade development. Additional belt-, district- and deposit-scale features are currently little used but hold promise, whereas others have less practical value but help in underpinning the evolving porphyry copper genetic model.CITATION:Sillitoe, R H, 2015. Recent advances in porphyry copper geology and their exploration utility , in Proceedings PACRIM 2015 Congress, pp 35–44 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015