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By S H. Sie, R Seetharam, K Naito, T Takagi

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medicallhigh-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnS2), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

The gossan developed from the Whim Creek Cu-Zn-Pb-Ag sulphide deposit, in the Pilbara region of Western Australia, occurs near the top of a ridge in a dissected plateau 01 moderate relief. The gossan is characterized by the abundance of secondary ore minerals which indicates that it is relatively immature, due to climatic conditions and erosional stripping.The abundant presence of secondary carbonates indicates that the low pH generally resulting from sulphide oxidation has been neutralized, probably by the buffering effect of carbonatcs and silicates. Fe, Cu, Pb, 'Ag and Sn have been enriched in the gossan relative to the primary ore, and Mn, Ti, Co and Ni have been strongly depleted; other elements have remained substantially unchanged. The gossan has a strong gcochemical signature characterized by high Cu, Zn, Pb, As, Sb, Sn, Ag and Mo coutents. Boxwork textures are poorly developed, bu't the gossan has other diagnostic mineralogical features including sulphide inclusions in quartz and the presence of residual cassiterite.

Jan 1, 1982

By R Castroviejo, E Pirard, L PTrez-Barnuevo

Process mineralogy provides the mineralogical information required by geometallurgists to address the inherent variation of geological data. The successful beneficiation of ores mostly depends on the ability of mineral processing to be efficiently adapted to the ore characteristics, liberation being one of the most relevant mineralogical parameters. The liberation characteristics of ores are intimately related to mineral texture. Therefore, the characterisation of liberation necessarily requires the identification and quantification of those textural features with a major bearing on mineral liberation. From this point of view, grain size, bonding between mineral grains and intergrowth types are considered the most influential textural attributes. While the quantification of grain size is a usual output of automated current technologies, information about grain boundaries and intergrowth types is usually descriptive and difficult to quantify to be included in the geometallurgical model.Aiming at the systematic and quantitative analysis of the intergrowth type within mineral particles, a new methodology based on digital image analysis has been developed. In this work, the ability of this methodology to achieve a more complete characterisation of liberation is explored by the analysis of chalcopyrite in the rougher concentrate of the Kansanshi copper-gold mine (Zambia). Results obtained show that the method provides valuable textural information to achieve a better understanding of mineral behaviour during concentration processes. The potential of this method is enhanced by the fact that it provides data unavailable using current technologies. This opens up new perspectives to the quantitative analysis of mineral processing performance based on textural attributes.CITATION:PTrez-Barnuevo, L, Castroviejo, R and Pirard, E, 2013. New perspectives on quantitative textural analysis, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 191-198 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

By Ormsby W. R, Nicholson P. M

Woodcutters is a polymetallic vein-style deposit hosted by sediments of the Palacoproterozoic Whites Formation which forms part of the sedimentary sequence in the central Pine Creek Geosyncline. Past production and identified resources total over eight million tonnes at 5.5 per cent lead, 12.1 per cent zinc and 110 gA silver. The local geology is influenced by Archaean basement highs; the Rum Jungle and Waterhouse Complexes. Unconformably overlying basement are interbedded clastic and crystalline carbonate units (Batchelor Group) representing cyclic changes in the depositional environment. These exhibit onlapping features with the underlying rocks. Sediments of the overlying Frances Creek Group suggest a quiet period during subsidence and subsequent increase in water depth (the carbonaceous dolomitic shales and the interbedded dololutites of the Whites Formation) followed by proximal uplift resulting in the inundation of turbiditic flows (Acacia Gap Quartzite). All of the Palaeoproterozoic rocks show evidence of being affected by penecontemporaneous, basement circling faults with steep dips. The stress regime during the deposition of the Frances Creek Group was characterised by alternating episodes of thrusting and transpression. Periods of relaxation also occurred. The compression resulted in major NS strike-slip (transpressional) faulting, en-echelon NNE trending folds and NW-SE tensional cross faults. Thrusting produced N-S striking, steep dipping reverse faults and a possible decollement immediately above the Batchelor Group. Relaxation is evidenced by the intrusion of lamprophyre dykes and dolerite sills (Zamu Dolerite). Mineralisation at Woodcutters occurred in faults within the Whites Formation, probably synchronous with deformation and the deposition of the upper parts of the Frances Creek Group. Greenschist facies metamorphism occurred as the rocks were further buried. Several massive sulphide bodies occur at Woodcutters. A number of features influence the location and shape of these bodies. They are: ò the N-S transpressional faults and in particular associated dilation zones; ò intersection of the N-S transpressional faults with the axial plane of the NNE trending Woodcutters Anticline; ò intersection of the N-S transpressional faults with the NW-SE cross-faults; ò intersection of dololutite rich units with the NS transpressional faults where local replacement takes place; ò thickening of the lithological units in the vicinity of the anticlinal axis; and ò the anticline doubly plunging to both the north and south. The mineralisation exhibits vein-like features as well as epigenetic textures. Its boundaries are sharp, its thickness varies rapidly down dip and along strike, and no alteration halo exists though stringer veins of quartz-carbonate-pyrite ¦ sphalerite/galena occur in close proximity. A number of sulphide mineral assemblages have been recognised, each separated by periods of deformation and partially replacing the earlier assemblages. Vertically continuous zonation patterns highlight the presence of rich galena-sphalerite-silver in zones of maximum dilation and pyrite-arsenopyrite-gold concentrated at the along strike peripheries. The genetic model proposed has the mineralisation occurring whilst the transpressional regime was active. It was deposited from the same fluid that elsewhere in the Geosyncline formed the stratiform deposits higher in the sedimentary pile. Hydrocarbons sourced from the organic-rich Whites

Jan 1, 1994

Development of the Davcra flotation cell has continued over the past seven years. Preliminary testwork on single cells has now been extended to a com- plete Davcra flotation circuit, to cells ranging from 5 to 400 tons per hour capacity and to cells operating on a variety of materials. Operation of both test and production units has shown the Davcra cell to be competitive with conventional flotation machines. It offers a lower capital cost installation than conventional cells and in addition has a number of. operating advantages, particularly in its adaptability to automatic control.'

Jan 1, 1971

By Winrove G. S, Herdie G. J, McCarthy C. A

Production of hot metal from the Hlsmelt Research and Development Facility at Kwinana, Western Australia commenced in October 1993. The stand-alone facility is a unique, coal-based, integrated ironworks equipped to process iron ore fines to pig iron and simultaneously undertake a wide range of research tasks. The data generated will be used to verify the commercial potential of the technology and to set the design and operating parameters for a full-scale production plant. The design, construction, commissioning and initial operation of the HRDF has required many innovative and practical solutions to be developed and implemented by the international group of organisations contributing to the Hlsmelt Project. Initial operation has produced results which demonstrate the potential of the unique process technology associated with the core plant smelting unit. The recent achievement of post-combustion levels of 60 per cent with heat transfer efficiencies greater than 85 per cent demonstrates that the performance obtained with the Small Scale Pilot Plant in Maxhutte, Germany can be reproduced at a larger scale. The results presented in this paper support the thrust for further intensification and future commercialisation of the process.

Jan 1, 1995

By P Hayes, D Fadhlurrahman

Molten slags, fluxes and salts play key roles in a wide range of the high temperature industrial process applications, including metals production, refining and recycling, metal manufacturing processes, electrochemical metal production cells, batteries, and efficient heat transfer media. Recognising the importance and significance of fundamental scientific knowledge of these systems, the International MOLTEN Conference series was established to provide a forum to bring together leading academic researchers and industrial engineers to present and discuss the latest scientific ideas and findings, and their application in their respective fields. This article presents an analysis of the research carried out in this field over time in terms of the number of journal articles, fields and slag systems studied and geographical origin of the research.

Jun 19, 2024

By J Mukhopadhyay, J Gutzmer

Most world-class high-grade (60 - 67 wt per cent Fe) hematite iron ore deposits are the product of enrichment of Precambrian iron-formations but processes responsible for enrichment are still unclear. Different models, ranging from syngenetic and diagenetic (King, 1989), deep-seated hydrothermal (Powell et al, 1999; Barley et al, 1999; Taylor et al, 2001; Gutzmer et al, 2002) and ancient supergene (Morris, 1980; 1985; Van Schalkwyk and Beukes, 1986) to modern supergene (MacLeod, 1966) have been suggested. The high-grade hematite deposits stand in contrast to martiteûgoethite ores which are generally accepted to be the result of supergene enrichment of iron-formation because they are found along Cretaceous to Tertiary lateritic weathering profiles (Morris, 1980; Harmsworth et al, 1990). Uncertainties about the origin of the high-grade hematite ores appear largely due to the monomineralic composition of the ores. They are almost exclusively composed of hematite (as microcrystalline hematite and martite), a mineral with wide stability field and very simple chemical composition that reveals little about its origin. Second, many of the deposits have been overprinted by later deformation and chemical weathering obscuring primary ore characteristics and zonation (Taylor et al, 2001). Third, surprisingly few detailed geological studies have been undertaken on the deposits with the aim of unraveling ore genesis. Most studies focus on the present-day structure of orebodies and their general physical-chemical composition for mining and beneficiation purposes. A more thorough understanding of the origin of high-grade hematite iron ore deposits may be gained by combining available mining-orientated data with systematic petrographic-geochemical analyses of different ore generations and hematite phases. This paper presents a first summary of results of an ongoing study, started some two years ago, of high-grade iron ore deposits in South Africa, India and Brazil, including a comparison with the rather well studied deposits of the Hamersley Province in Australia.

Jan 1, 2002

By McDougall I, Claoue-Long J

A combination of high precision 40Ar/39Ar and U-Pb dating has been used to determine the age of hydrothermal minerals and host rocks in a number of Lachlan Fold Belt (LFB) gold deposits in New South Wales, Au4 ralii In particular, this investigation demonstrates that the UAr/ Ar technique of K-Ar dating can be used to determine the timing of mineralization in Palaeozoic systems.A close temporal link between mineralization and Late Ordovician to Early Silurian magmatism is indicated by the dating work. Hydrothermal sericite from the Goonumbla p8rph gy Cu deposit and Glendale Au prospect yieldsAt/ Ar step heating ages between 437.9 ¦ 1.1 and 441.2 ¦ 1.1 Ma (16), and4 minjrnum age of about 425 Ma has been obtained by Ar/ Ar dating of hydrothermal amphibole from the Browns Creek Au-Cu skarn deposit. Hydrothermal aluniI8 frog the Gidginbung epithermal Au deposit yields reset 44 Ar/ Ar ages of 401.0 ¦ 1.3 to 417.3 ¦ 1.3 Ma (16). U-Pb dating by ion microprobe on magmatic zircons from the vicinity of the Goonumbla and Gidginbung deposits gives ages of 438 ¦ 3.5 Ma (2 6), and 435 ¦ 2.5 Ma (2 (7) respectimly, W a minimum age of 435 Ma has been obtained by Ar/ Ar dating of magmatic phases from volcanic rocks adjacent to the Browns Creek skarn deposit. Magmatic episodes near the Sheahan-Grants gold skarnpost give ages of 479.2 ¦ 1.1 and 467.9 ¦ 4o1 by 'Ar/ 9Ar dating of magmatic amphibole. Most Ar/3yAr age spectra show the effects of partial Ar loss at between 360-420 Ma, probably due to heating caused by granitoid emplacement.The radiometric dating work in this paper suggests a restricted metallogenic epoch in the Late Ordovician-Early Silurian LFB, NSW, of similar duration to that found in the Andean margin and the western Pacific island arcs around the Pacific Rini.

Jan 1, 1990

By R Cox, S Pandey

The coal seam gas (CSG) industry is expanding rapidly in the Surat and Bowen basins. CSG production involves pumping water from the coal seams to release the gas adsorbed to coal particles. The reduction in water pressure in the coal seams will cause some reductions in water pressure in overlying and underlying aquifers because there will always be some interconnectivity between the formations. The Surat Basin is a sub-basin of the Great Artesian Basin, which contains aquifers of high economic, environmental and cultural value. The Condamine Alluvium is also an important water resource, which overlies parts of the eastern margin of the Surat Basin.Under the Queensland (Qld) regulatory framework, an area of intensive CSG development involving multiple CSG operators can be declared to be a cumulative management area. For such areas the Office of Groundwater Impact Assessment develops assessments of future impacts on aquifer water pressures and develops and manages arrangements. The results are published in underground water impact reports.The Surat underground water impact report (QWC, 2012) was approved in December 2012. This paper summarises the place of the report in the Queensland regulatory framework, the content of the report and progress in its implementation.CITATION:Cox, R and Pandey, S, 2013. Managing groundwater impacts in the Surat Basin, in Proceedings Water in Mining 2013 , pp 169-174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

At the beginning of the seventies pre- drainage of methane was introduced in West German coal mining in order to reduce the gas emission from the worked seam. After three pilot tests on the "Rheinland" Colliery (86 boreholes in seam "Prasident"), "Bergmannsgluck/ Westerholt" Colliery (23 boreholes in seam "Gustav") and "General Blumenthal" Colliery (27 boreholes in seam "Hugo" and 170 boreholes in seam "Karl") systematic large scale tests with extended investigations were carried out un the "Rheinland" Colliery (127 boreholes in the seams "Anna", "Blucher", Prasident"). During this time an analogous test was carried out on the "Consolidation" Colliery (21 bore- holes in seam "B"). In these studies and tests the technical feasibility, efficiency and economy could be proved, so that pre-drainage of methane starts spreading. On the "Rheinland" Colliery pre-drainage has become common practice in gassy seams. Mainly two points impede a faster spreading of method: 1. in many cases the necessary requirement, that one or both of the gate roads should ire driven 6 to 12 months before the face is worked, is missing. This is mainly due to the difficulty of retreat mining in passe seams.

Jan 1, 1982

By N Collins, A Woodley, A N. Danoucaras, C McCombe, N C. Kunz

Over the past decade, the mining industry has come to recognise the importance of water both to itself and to others. Water accounting is a formalisation of this importance that quantifies and communicates how water is used by individual sites and the industry as a whole. While there are a number of different accounting frameworks that could be used within the industry, the Minerals Council of AustraliaÆs (MCA) water accounting framework (WAF) is an industry-led approach that provides a consistent representation of mine site water interactions regardless of their operational, social or environmental context that allows for valid comparisons between sites and companies.The WAF contains definitions of off-site water sources and destinations and on-site water use, a methodology for applying the definitions, and a set of metrics to measure site performance. The WAF is comprised of two models: the input-output model, which represents the interactions between sites and their surrounding community, and the operational model, which represents on-site water interactions.Members of the MCA have recently adopted the WAFÆs input-output model to report on their external water interactions in their Australian operations, with some adopting it on a global basis. To support this adoption, there is a need for companies to better understand how to implement the WAF in their own operations. Developing a water account is non-trivial, particularly for sites unfamiliar with the WAF or for sites with the need to represent unusual features. This work describes how to build a water account for a given site using the input-output model, with an emphasis on how to represent challenging situations.CITATION:Woodley, A, Danoucaras, A N, McCombe, C, Kunz, N C and Collins, N, 2013. A robust methodological approach for mine site water accounting, in Proceedings Water in Mining 2013 , pp 335-342 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By J Karlovšek, M Hafner, M Žibert

The transport network in Europe is probably one of the most important systems for the European economy and society. Trans-national transport routes play a vital role in the traffic of goods and the supply of the population. In this respect, critical road infrastructures, like bridges, tunnels or control centres, can have a bottleneck function. Any disturbance of these structures could lead to negative consequences for the population and the economy as a whole.Project SecMan – Security Manual – is a simple four-step procedure for the identification of critical road infrastructures; assessment of these infrastructures regarding various man-made threats and the determination of effective protection measures was developed. These methodologies are summarised and combined into a comprehensive best-practice manual that allows for a trans-national structured and holistic security-risk-management approach for owners and operators of road infrastructures in Europe.Currently no common processes, methodologies or standards exist in Europe regarding the consideration of security relevant events for critical road transport infrastructures, eg tunnels, control centres and bridges. Attacks on the former can have severe short- and long-term effects with high media attention. A trans-national risk management approach would increase the possibilities for prevention as well as mitigation. A trans-national emergency response strategy would increase preparedness, as well as facilitating and accelerating the reaction in the case of an event.The main objective of the project is to develop a practical process for the identification of critical road infrastructures based on generally accepted security aspects. The assessment of these infrastructures would be carried out in a structured and traceable way regarding security relevant risks and the determination of effective protection measures for prevention and mitigation.The project is implemented by the German Federal Highway Research Institute (BASt) together with project partners from Austria (ILF) and Slovenia (DARS, ELEA iC).CITATION:Hafner, M, Karlovšek, J and Žibert, M, 2014. Road infrastructure security assessment and measures selection methodology using secman – tunnel example, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 69–82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By W Midgley, M Torok, I Canbulat, J Katupitiya, S Saydam, S Akdag

The green energy transition is expected to require a range of valuable minerals, which could be supplied through deep-sea polymetallic nodule mining. Deep-sea polymetallic nodules are mineral deposits with a composition well suited to produce lithium batteries, which are expected to be a necessary energy storage solution (Diouf and Pode, 2015; Paulikas et al, 2020) for the energy transition. By 2050 the annual demand for both cobalt and lithium is estimated to increase by around 450 per cent from 2018 levels (Hund et al, 2023), with the annual demand for nickel being greater than 2 million tons, and copper greater than 1 million tons. Polymetallic nodule mining is well positioned to provide these minerals in the near future. An intricate and comparatively unexplored ecosystem thrives within and surrounding the nodule fields (Smith et al, 2008). Deep-sea mining operations have the potential to disrupt and permanently damage this ecosystem through introduced pollution, artificial noise and light, and habitat destruction. Hence, there is a pressing need for new engineering and scientific endeavours to focus on developing new technologies to reduce any environmental impact from mining.

Sep 1, 2024

By D Giddings, S A. Silvester, S Pickerin

Underground fires represent a constant threat to the safety of underground personnel. Miners in the immediate vicinity may face intense heat, blinding smoke, toxic fumes, fall of ground and other direct effects of a fire. However, the vast majority of victims never actually see the fire, and are overcome either by deadly fumes in the ventilating current or by asphyxiation. The mine ventilation system, which maintains a sustainable atmosphere to the working places, can transport products of combustion with equal efficiency. Miners who are remotely situated from a fire may be forced to evacuate considerable distances, through dense smoke and fumes, or even become cut-off from escape. Additionally, miners may become confused by unfamiliar ventilation characteristics caused by fires. Conveyor belts are widely used for transporting minerals in mines as well as in many other industrial situations. Because they contain large amounts of polymeric materials their use in certain environments, especially coal mines, but also in steel works, power stations and other enclosed areas must be controlled to minimise the fire risk. Over last nine years there have been 60 fires in underground mines in the UK alone and that of these, half have been associated with conveyors. This paper summarises the results obtained from a recent research project that has developed a preliminary computational thermal and fluid dynamic model to represent the spread of flame along a typical conveyor belt used in UK deep coal mines. The results of these models have been calibrated against a series of experimental tests performed within a surface fire test gallery. An improved knowledge of the burn characteristics and rate of release of the products of combustion from conveyor belt fires will assist in the development of better fire detection and fire fighting techniques.

Jan 1, 2005

By A I M Ritchie

The pyrite oxidation rate is a process central to both the performance of bio-oxidation heaps, used in the pre-treatment of some refractory gold ores, and to the levels of pollution in acid rock drainage (ARD) from pyritic waste rock dumps. A goal in bio-oxidation heaps is to achieve high oxidation rates in the heap as a whole. In comparison, one way to mitigate the environment impact of ARD, is to reduce the overall oxidation rate in the waste rock dump since pyrite oxidation is the primary pollutant generation process. In both bio-oxidation heaps and waste rock dumps the overall oxidation rate of the pyritic material (the intrinsic oxidation rate) at these sites. Much research has been conducted over the last 40 years or so on the oxidation rate of pyritic material with particular emphasis on the catalytic role played by bacteria. More recently mathematical models and field measurements have clarified the extent to which oxygen transport rates are rate limiting, what the dominant oxygen transport mechanisms are and the physical properties of the heaps which have most impact on these transport rates and on the overall oxidation rate. How the performance of bio-oxidation heaps can be optimised and how the pollution load in drainage from waste rock dumps depends on gas transport mechanisms is briefly reviewed. The sensitive of the overall oxidation rate in bio-oxidation heaps and waste rock dumps to details of the intrinsic oxidation rate is quantified.

Jan 1, 1994

By Y Cao, J C. Tien

Occupational health and safety is essential in modern mining workplaces and in China it is often not given enough emphasis due to a lack of knowledge and/or appreciation. Although many health and safety regulations have been passed over the years, serious and relevant laws and regulations on mine health and safety are of recent history (since 2002), the level of stringent enforcement is still inconsistent and accurate field data are scant and not readily available. As of year-end 2006 there were 676 562 recorded cases of occupational diseases in China, of which 616 442 or 91 per cent were miners’ pneumoconiosis. Of these, 146 195 (23 per cent) have died, and an average of 10 000 new cases were added every year between 1991 and 2006. Another report shows that 93.18 per cent of miners have never had a contract with their companies, which means their cases were not even part of China’s official statistics. This study attempts to examine the prevalence of occupational diseases in the Chinese mining industry during 2000–2013, compiled from government annual reports and academic studies. The research will review the correlational analysis among occupational diseases, ventilation practices, protection devices and legislation.CITATION:Cao, Y and Tien, J C, 2015. Occupational diseases in China, with the emphasis on its occurrence in Chinese mine workers, in Proceedings The Australian Mine Ventilation Conference, pp 155–160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By Grader F. E

A linear motor properly wound can serve as a mechanism for separating paramagnetic sulphide minerals, like pyrrhotite, from other sulphides and associated gangue minerals. The effective- ness of separation depends on the energising current of the separator, the frequency of the a.c. cycle, and the particle size of the minerals. The speed of travel of the minerals over the surface of the separator is also a function of particle size, and appears to be constant. The movement of pyrrhotite, magnetite and iron filings of comparable size fraction (150um +74pm) on the linear motor surface has been observed using a cine camera. An attempt has been made to give a theoretical basis for the movement of the particles by calculating the minimum electrical energy required to move them. Further, the rate of decay of magnetic moment of the particles has been estimated for magnetite and it has been found that sufficient residual magnetism existed in the particles after they had been exposed to the first half of an a.c. cycle for them to have like polarity with the second half of the cycle. The particles are therefore repelled from the motor surface every second half of the cycle. This repulsion due to remanent magnetism is the probable cause of particle movement over the linear meter surf, e.

Jan 1, 1980

The Newmont Waihi Operations are centred on the Martha mine at Waihi, New Zealand. The mine has produced over 6.6 million ounces of gold from both openpit and underground sources since operations began in 1878. The current open pit operations commenced in 1988 and in the year to 30 June 2002 produced 129,790 ounces of gold at a cash cost of USD122 per ounce. This paper provides an overview of current operations and future directions.

Jan 1, 2002

By Kuganathan K, Potvin Y

Enterprise Mine at Mount Isa is to expand ore production from the current 1.4 to 3.5 mtpa by mining the 3500 Orebody, from which production is scheduled to start in February 1998 making this the deepest underground mine in Australia with its lowest mining horizon at nearly 1.6 km below surface. The following fill requirements were defined for the 3500 Orebody during the feasibility study: 1. a minimum filling rate of 250 ma/h, 2. a curing time of 28 days, and 3. minimum free fill water. This paper mainly describes the investigation of high density and paste fills for the 3500 Orebody. The investigation covered all the key issues relating to fill option selection, including design criteria, material supply and demand assessment, drainage modelling, tailing dewatering method, mix design and a pump loop test. Results of the investigation indicate that both high density fill and paste fill are technically feasible. The investigation has led to the selection of a blended tailing paste for the 3500 Orebody as the paste option has significant advantages over high density fill in stope filling rates and fill reticulation. The blended tailing for paste fill is finer than Isa deslimed tailing but coarser than full plant tailing. The paste fill selected has minimum binder and tailing dewatering requirements while a relatively high filling rate is achieved.

Jan 1, 1998