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ABSTRACTMechanised cut and fill stoping in the Racecourse orebodies between II and 9 levels was started in 1964.Five stopes are in progress over the two level interval, extracting the full strike length (600-2,000 ft) of each orebody without transverse pillars.Each stope is served by a central 10 ft by 12 ft service intake ventilation raise and an 8 ft by 8 ft return air raise at each end of the stope. Each stope is divided into two sections for drilling. firing. mucking, and fillingto maintain steady production. All equipment is kept in the stope for one level lift stoping. Gardner-Denver 2 boom jumbos are used for uphole drilling and Wagner ST 5 Scooptrams for loading and transport to ore passes located in the footwall of the orebody. A Wagner PTIO is used for materials handling and scaling of the stope backs.Mill tailings, after one stage of cycloning are used to fill the stope, one section at a time. About 80 per cent of the water is removed by decantation while the remainder percolates through hessian-covered pipes and boxes.The ore is passed to 11 level where it is hauled by the 3 ft 6 in. gauge train to the tipple at the shaft area. The ore is crushed underground before hoisting to the surface.A performance of about 100 ton/manshift is achieved by the drilling, blasting, and mucking crews in the stopes.

Jan 1, 1968

By S C. Dominy

The grade of ore at Marvel Loch mine is directly related to the presence or absence of shear zones and quartz-sulfide-rich hornblende (¦ diopside) veining within areas of plagioclase alteration. An experienced geologist can identify these features in hand specimen. Practical rules have been developed to assist this visual identification. The structural sites and styles of alteration and veining most conducive to gold mineralisation have also been determined. The work has enabled a better understanding of the geological controls on mineralisation at Marvel Loch, and has clarified geological understanding for optimisation of grade control modeling, ore block mark-ups, and minimisation of ore loss and dilution during excavation. In addition to this, it has enabled a detailed understanding of mine scale structural controls, geometry and relative grade relationships.

Jan 1, 2003

Several glacial episodes have been distinguished in the Shotover Valley. These produced fluvioglacial aggradational deposits downvalley from the terminii, commonly with well-preserved terrace treads, as exemplified near Skippers. Chronological links can be determined between the Shotover tills and sediments and assessed equivalent deposits in the Wakatipu Basin/Kawarau Valley region through axial valley profiling. Constructed relationships suggest older Shotover events were probably large and left little detrital deposits within the valley. In contrast, the younger advances were smaller and valley-constrained. They are modelled as being wholly of Waimea or Otira Glaciation age, advances from the latter period producing the visually distinctive flights of terraceremnants. Both the terraces and the inner gorge, now occupied by the Shotover River, have been extensively worked for alluvial gold. Enrichments in the former environment have predominantly been as bottom or intermediate lags produced during degradation phases of catchment erosion. Surface lags have been locally targeted. Placer mining in terrace areas involved both tunnelling and sluicing techniques. In the modem river the greatest concentrations were on the schist or false bottoms, although flood gold has always contributed to the returns. Placer mining techniques here were highly variable.

Jan 1, 1998

To secure a sustainable competitive advantage some smelters may need strategies based on flexibility in feed and product ranges depending on immediate future projections of profitability. This paper explores the technical requirements for strategic diversity in smelting, leaving procurement, marketing and contractual considerations aside. The days when a smelting operation is tied specifically to say only processing zinc concentrates are perhaps drawing to a close. While internationally traded mineral concentrates are available, attractive business opportunities must exist for fully diversified custom smelters. Certain new and emerging technologies have inherent characteristics that are evaluated in this context. The paper identifies the basic building blocks that will permit such a scenario and assesses the technical feasibility. The ability to respond flexibly to environmental pressures is highlighted as being of paramount importance.

Jan 1, 1996

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high-speed photography to better understand the mechanisms of fracture and fragmentation.CITATION:Fourney, W L, 2015. The role of stress waves and fracture mechanics in fragmentation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 27–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Eri G

Ok ledi Mining Limited underwent a major transition from radio based truck dispatching to computerized dispatching for its equip- ment fleet in October, 1996. Modular Mining's Computerized Dispatch System was selected based on reputation and superior customer support. Modular's dispatch system is a fleet management system that uses computer, data communication and global positioning sys- tem technology to produce automatic, optimized haul truck as- signments. Optimization is achieved by equally distributing trucks to shovels so that truck queuing and shovel idling times are mini- mized. Computer illiterate mine operations personnel had to overcome a rather steep learning curve to use the high technology equipment. fortunately the system was able to be configured to use bitmap

Jan 1, 1997

By S A. Ravishankar

An overview of flotation reagents used in sulfide and non-sulfide separations, from an industrial perspective, is given in this presentation to highlight the current applications knowledge. The historical and theoretical aspects, which are well documented in numerous books and reviews, will only be highlighted, when necessary, to support the theme of this paper, viz critical analysis of reagent research, design, selection and optimisation with an emphasis on relevance to plant needs and practice. The three types of flotation reagents; viz collectors, frothers and modifiers, used currently in the industry are briefly reviewed; pitfalls and gaps, arising from somewhat arbitrary and reductionistic practice in reagent applications, are identified; and the impact of environmental regulations on current and future reagent development is discussed. The importance of frothers and modifiers, which have received less overall attention than collectors, is highlighted. The need for a rational, holistic (or ætotal systemÆ, ætop-downÆ) approach for reagent design, selection and optimisation is discussed with a view to provide remedies for pitfalls and a platform for filling gaps in reagent chemistry and applications, and to develop reagent technology that can deliver robust solutions to plant needs. Flotation Matrix 100TM, a comprehensive package designed at Cytec to incorporate all the elements of the holistic approach û viz definition of mineralogy and plant needs, rule-based expert system rational reagent selection, and laboratory and plant best practices û will also be described.No paper available for this abstract

Jan 1, 2005

Close spatial relationships between the deposits of the Etheridge Goldfield (23 000 kg of bullion) and various regional geological and geophysical features suggest that genesis of the ore deposits was a multi-stage process that started with magmatic and metamorphic stages in the mid-Proterozoic, climaxed with structural and hydrothermal stages in the late Palaeozoic and terminated with an oxidation enrichment stage in the Cainozoic. Acceptance of this hypothesis permits classification of the Georgetown region into areas likely to contain deposits of the Etheridge type and those unlikely to do so. Consequently there is little scope for the discovery of extensions of this field. However, the stratigraphic interval between the source rocks of the Etheridge field and stratigraphically bigger host rocks of the Croydon field may contain disseminated replacement gold deposits of the Carlin type. The potential host (pyritic carbonaceous and locally dolomitic siltstone of the Candlow Formation) is locally faulted and cut by granitoids and the extension of a mineralised, long-standing zone of structural weakness.

Jan 1, 1980

By R Zhou, B J. Monaghan, S J Chew, R J. Longbottom, D J. Pinson, H Li, P Zulli, G Zhang, L Lu

Steelmakers are increasingly motivated to use iron ore resources with a wider range of grades and mineral types that were previously considered unsuitable or uneconomical for sintering. In this respect, specific issues, which now require further investigation and understanding, include the sintering of ore types with:- overall higher gangue content- elements that cause problems in the steel manufacturing operations- distinctive sintering performance compared with traditional hematite-rich iron ores. Laboratory-based investigations of the sintering performance and the behaviour of gangue impurities during sintering is an important step towards the successful utilisation of these resources in steelmaking.In terms of laboratory-based sintering investigations, there are two generally accepted experimental scales utilised prior to undertaking industrial-scale trials, which include: bench-scale tablet (compact) testing and pilot-scale pot testing. The former has the advantages of flexibility and more precise control of sintering conditions; but it is difficult to simulate the heterogeneity of a sinter bed. The latter, which is carried out in pots with diameters between 150–500 mm, simulate the commercial sintering process and conditions quite well, but is time-consuming and labour-intensive due to operational complexity. It is therefore desirable to establish a smaller scale pot testing facility that avoids the disadvantages of the normal sintering pot but can provide comparable information.To explore the feasibility of small-scale pot testing, a ‘millipot’ facility was established to examine the sintering performance of iron ores and other non-traditional ferrous materials. The millipot has a diameter of 53 mm and height of 400 mm. The facility has the capability to monitor the sintering temperature at a number of locations (axial, radial) within the sinter bed and to adjust the suction (‘windbox’) pressure. This paper describes the development of the millipot facility and operational procedures, together with initial tests undertaken in order to match its performance with industrial sintering performance.CITATION:Li, H, Zhou, R, Pinson, D J, Zulli, P, Lu, L, Longbottom, R J, Chew, S J, Monaghan, B J and Zhang, G, 2017. A millipot set-up for sintering investigation of iron ores, in Proceedings Iron Ore 2017, pp 85–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

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

By A Prinsloo, R Tewu

Automatic control of semi-autogenous grinding (SAG) mills has often been considered complex. Recent experiences at Century Zinc (worldÆs second largest open pit zinc mine) refute this. Together with operating knowledge and appropriate control techniques high quality control is achievable. In this application model-based, constraint, and multiple output control were employed. The control was implemented using standard blocks in the plant DCS. The resulting overall control strategy fulfils the operating objectives and controls the mill with minimal operator involvement over 95 per cent of the time. Previous campaigns using expert systems and complex DCS based control have lacked durability. Their fall into disuse is briefly discussed.

Jan 1, 2009

By M Dickie

During the 1980s and early 1990s low cost gold treatment plants were at the forefront of the Australian engineering and mineral processing business. This opportunity was the result of a high gold price and innovative design by emerging engineering companies in an expanding market. The low cost approach to gold plant design and project execution resulted in smaller and shorter life projects becoming viable and the multiplicity and fast track approach of the projects resulted in sharp learning curves. From the mid 1990s to the early 2000s the relatively low commodity prices and resultant reduction in minerals opportunities also resulted in innovative design in both small and large plants, albeit on a reduced scale. The innovation was associated with alleviating capital cost pressures for large capacity low-grade (eg NewcrestÆs Cadia) or small-scale (eg JubileeÆs Cosmos) projects to either improve NPV or to enable the project to be won and profitable in the competitive lump sum environment. Between 2004 and 2008 the engineering market became less competitive from an engineerÆs perspective due to the high demand for engineering services in a high price commodity market. The need for innovation remained but was driven overtly by shortages in water, power and personnel and long equipment lead times. This paper discusses some of the factors that contribute to the capital cost of a project and the scope for improving the likelihood of financing and increasing the project net present value (NPV). Case studies with recent large copper concentrator projects will be used to demonstrate how a value driven approach to project and plant layout can result in significant improvement in NPV.

Jan 1, 2009

By S Moradi

The aim of this study was to investigate the possibility of leaching zinc from the tailing (-2 mm) of Angouran flotation plant using sulphuric acid. The tails were first calcined at 800¦C for one hour. The effect of factors such as stirring rate, temperature, initial acid concentration and solid/liquid ratio, on zinc extraction were studied. The results obtained show that at the best conditions, about 91 per cent of zinc were leached using a stirring rate of 800 rpm, a reaction temperature of 50¦C, a 30 minute reaction time, a 100 g/L initial sulphuric acid concentration and solid:liquid ratio 1:6 g/ml. The P85 of the feed material was about 150 ¦m and acid consumption was 600 kg/t.

Jan 1, 2002

By Holly J

The period following World War II has seen many changes in stoping techniques at The Great Boulder Gold Mine. The new methods resulted in improved unit production figures, and have given some relief from the rising worldwide cost spiral in the post war years.Significant production figures are shown graphically in...

Jan 1, 1956

This paper gives a description of the methods of mining employed at North Broken Hill Limited, Broken Hill, N.S.W.GEOLOGICAL NOTESThe main Broken Hill lode occurs as a replacement of tightly folded pre-Cambrian sediments. Replacement has followed certain stratigraphical horizons and the main bulk of the ore is found where these have been packed into the noses of anticlinal and synclinal folds.Throughout the mine the ore-bearing folds pitch north fairly consistently at 45 degrees, as a result of which two favourable horizons in the same fold appear in plan as separate orebodies and these are referred to as the "Southern Orebody" and the "Northern Orebody" respectively.The general dip of the orebodies to the west is about 60 degrees. A typical sill is shown in the plan of the 1,400-ft level (Fig. 1).Both the hanging wall and footwall rocks throughout the mine are weak and, as a result, it is necessary that the hanging wall must be well supported after ore extraction, to prevent subsidence. The weakness in the footwall is confined to a narrow zone, approximately 60 feet in width. This weaknes.q is a source of trouble in the development headings which pass through it, It is sufficiently crushed to transmit weight from the overlying wall to the gangways below.Another feature causing ground instability is the presence of many faults. Although their effect on the shape and character of the orebody is relatively small their...

Jan 1, 1940

By Parker A. J, Giles D. E

Solutions of copper(II) sulphate in acidified aqueous acetonitrile leach copper from copper-lead matte derived from the drossing of lead with sulphur to produce solutions of copper(I) sulphate. The reactivity of the matte constituents towards copper(II) sulphate is Cu2S> PbS > CuS > > Pb. According to the leach conditions, part or ,all of the copper may be leached 'leaving a residue of CuS/PbS, or S/CuS/PbS04, or S/PbS04, to be recycled to the lead smelter. Complete extraction of the copper requires leaching with oxygen which occurs under mild conditions in the presence of acetonitrile and sulphuric acid in water. Copper is selectively recovered as a pure product by electrochemical or thermal disproportionation of copper(I) sulphate solutions. A notional process is proposed.

Jan 1, 1979

Vein swarms in metamorphic terranes such as the Otago Schist Belt, New Zealand provide evidence of past hydrothermal flow systems leading to fault initiation and reactivation. A major episode of hydrofracturing and fluid redistribution occurred during early Cretaceous exhumation of the schist belt. As a result, presently exposed lower greenschist facies greyschists in NW Otago are pervaded by abundant quartz-filled hydraulic extension fractures with associated normal faults hosting quartz¦scheelite¦gold mineralisation. Once the effects of Cenozoic folding have been removed, a regional subhorizontal schist foliation contains an aligned array of subvertical hydrofractures striking NNW, striking parallel to a set of low-slip conjugate normal faults; the array extends over an area >1500 km2 and over a depth interval >5 km. The hydrofracture array comprises a mesh of interlinked extensional-shear and pure extension veins. These veins show mutually cross-cutting relations. Extensional hydrofracturing apparently preceded the development of major throughgoing normal faults. Low-displacement normal faults are infilled with laminated quartz (¦ scheelite) veins (

Jan 1, 2002

THE millng methods employed in the Mount Lyell Mining and Railway Company's mines are, perhaps, less known to the milling world than those of other important districts, due to the geographical remoteness and isolation of the Mount Lyell field,but they present many features which are unusual, and should be of interest to the mining engineer. Typical mining is carried out on an open-stope system, details of which are the result of local experience and evolution, and of which the outstanding feature is that the ground is so worked as to be largely self-supporting by virtue of domical form given to the stope roofs. It is locally termed "rill" stoping,' but differs widely from what is generally understood by that designation, chiefly in that the "rill" or slope is developed in every direction from a central focus, and not merely in directions followllig the strike of a lode or ore-body whose longitudinal dimensions are very much greater than its width. Such terms as "donie stoping" or "arched-back stoping" would be more appropriate and descriptive.The company's active operations' at the present time extend to the Mount Lyell and North Lyell mines, and, though the fundamental principles of stoping methods are the same in each, the dissimilarity of the ore-bodies, both in nature and mode ofoccurrence, necessitates considerable variation as to details to meet the respective conditions. The Mount Lyell pyritic body lends itself to the adoption of the .system in its simplest and almost ideal form, and a description of stoping in this mine willserve best to illustrate it, while later reference to details of practice in the North Lyell mine will indicate how it may be varied to meet more difficult circumstances.

Jan 1, 1915

The smelting of the Broken Hill lead concentrates at the Broken Hill Asso,ciated Smelters produced, among other products, approximately 4,900 ounces of gold and 8,800,000 ounces of silver during the year ending June 30th, 1938. The following table shows the actual amounts of gold per ton of lead concentrate produced during this period at the important mines. The total gold in the period is calculated from the number of tons of lead concentrates produced, and by comparison with the production' of silver, shows thatthere is no constant relation between the amounts of gold and silver.The fact that no gold is seen during milling, even when gravity concentrating tables are employed, signifies that the gold does not occur as occasional coarse particles.Further, as the values increase considerably in the flotation slime, it can be inferred that the gold occurs as minute inclusions in one or more of the minerals in the lead concentrates.The four most abundant minerals in the lead concentrate are galena, zinc blende, chalcopyrite, and...

Jan 1, 1940

By I Thin, L Morizzi, C Seymour, G Mungur

Olympic Dam has been investigating mine design options for the South Mine Area (SMA), which will continue using the existing sublevel open stoping (SLOS) method. The SMA is an undeveloped mining area, located south of the existing underground mining areas currently in production at Olympic Dam. The SMA study reached the stage where geotechnical inputs were required for stope design, infrastructure location and ground support forecasts. A large database of geotechnical data was collected to inform open pit designs for the ODX (Olympic Dam expansion) project (resulting from 659 drill holes). This geotechnical data has since been reprocessed to align with design inputs required for the SLOS mining method. The result has been the construction of a preliminary three-dimensional mining rock mass model (MRMM) that has been incorporated into preliminary stope mine design and infrastructure layout assessments, which have taken into account the predicted prevailing ground conditions.As with any model, it is necessary to improve the confidence in its predictability; therefore the model must be calibrated. The preliminary SMA MRMM was no exception. First pass calibration was possible with results from underground geotechnical window mapping from exposed rock mass conditions in the lateral development and surface geotechnical holes for ventilation shafts.The SMA project continues to advance and has started a program of resource drilling. Selected holes have been identified that target data limited areas. This will ensure that the data gaps are infilled in order to maintain the required data density required to improve the model confidence. In addition, further underground window mapping in the SMA will provide ‘mine scale drill hole’ data that can be used to either update the MRMM or as part of planned future calibration. Stope performance data from stopes will provide further valuable data for calibration purposes.The proposed paper will present the process and findings that have been followed in order to establish a well calibrated geotechnical model that can be used with an acceptable level of confidence in the ongoing refinements of the mine design and planning process for the SMA.CITATION:Thin, I, Morizzi, L, Mungur, G and Seymour, C, 2016. Building and calibration of a geotechnical model for sublevel open stope design at Olympic Dam, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 523–532 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016