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By Elford H. S

Australia has many potentially important tin deposits, particularly on the eastern shore of the continent and in Tasmania. A number of these have been worked on a meagre scale, while some of them, because of metallurgical, transport, and other difficulties, have not as yet been developed.Believing that the full development of the tin fields of the Commonwealth of Australia is in part dependent upon the adoption of the most efficient methods of milling and smelting, the Development and Migration Oommission arranged for the first-mentioned author to visit the mining fields of Cornwall, one of the oldest tin-producing districts of the world, and prepare a report for the information of the Commission.This paper, now presented to the Australasian Institute of Mining and Metallurgy with the hope that it will assist the full development of tin mining in Australia, is the joint work of both authors.For over two thousand years tin has been produced from the Cornish mines. Even the ancient Greek historians made mention of tin mining in Cornwall, and it is probable that during the earliest periods the mining was alluvial. As early as 1602 a stamp battery working in Cornwall was described, and in 1671 calcination and buddling was a recognised scheme of treating pyritic ore. In the first half of the 16th century the output of tin from Cornwall was 700 tons per annum, and, from then on, production increased to the maximum in 1914 of 6500 tons. At present (Oct., 1929) the Cambourne-Redruth area produces over 95% of the Cornish tin output. This area includes such mines as the South Crofty, East Pool, Dolcoath, Parkanchy, Polhigey, and Wheal Kitty. The remaining 5% is largely supplied by the Levant and Geevor mines at Pendeen, St. Just area, near Land's End.

Jan 1, 1930

By B Wentzinger, Y Keulemans

This paper presents the results of a field study designed to assess the impact of vane rotation speed on the estimated undrained strength for two Australian bauxite tailings storage facilities. The vane test results are assessed against cone penetration and dissipation tests results to identify if partial drainage may be an issue. An innovative tool capable of measuring pore pressures during vane shear testing, the Piezovane™, is introduced as an improvement over the standard field vane to assess drainage conditions in real-time.

Jul 1, 2021

By J M. Santini, I C. A Streimann

Arsenic is a naturally occurring element in the environment and is toxic to biological systems. Arsenic can exist in the environment in the following redox states, arsenite (+3), arsenate (+5), arsine (-3) and elemental (0) (Oremland and Stolz, 2003). Arsenic is released into the environment by natural and anthropogenic activities such as rock weathering and ore mining, respectively. Such activities result in the release of the soluble inorganic arsenic oxyanions, arsenite and arsenate. The redox state of arsenic in the environment is influenced by a number of factors including, redox potential, pH and microorganisms (Irgolic et al, 1977; Genc-Fuhrman, Tjell and McConchie, 2004). Recently, the ability of microorganisms to influence the cycling of arsenic in the environment has attracted much attention. Microorganisms that can oxidise arsenite and reduce arsenate have been isolated and the mechanisms of arsenic metabolism are currently being investigated. The differences between arsenic resistance and arsenic metabolism are being revealed. The role of microorganisms in the release of arsenic into the environment is of particular importance with arsenic contamination of waters causing the death of millions of people worldwide, due to the consumption of contaminated water (Vasken Aposhian et al, 2003; Islam et al, 2004).

Jan 1, 2004

By D S Wallis

Northern Australia leads in world-class mineral deposits' is a bold statement. First there must be a starting point. Land north of the Tropic of Capricorn (23¦ 26' 5") will be regarded as Northern Australia covering nearly 40 per cent of the land surface of Australia. As opposed to land south of the Tropic of Capricorn, it should be regarded as Tropical Northern Australia and for the sake of brevity, (TNA) Refer Figure 1. Apart from the tyranny of distance from centres of power and population in the temperate zone, it suffered in the past from the belief that the tropics are unsuited for European workers and from the lack of infrastructure. Outstanding mineral deposits of iron, base metals, gold and diamonds, discovered and developed in the past three decades, provided the substance for the title. There are many world-class mines producing and there are mineral deposits neutralised through Government policy. TNA can maintain its lead in world-class mineral deposits provided Government policy will stop partitioning the land and decreasing that available for exploration. Let's look at what we have that is world-class. In Western TNA iron ore deposits at Paraburdoo, Mt Tom Price, Marandoo, gold at Telfer, diamonds at Argyle. In central TNA uranium at Ranger and Jabiluka, lead-zinc-silver at McArthur River, gold at the Tanami, manganese at Groote Eylandt and bauxite at Gove. In eastern TNA Mt Isa, Hilton, Century zinc-lead, bauxite at Weipa, gold at Kidston, Mt Leyshon, magnesite at Yamba and coal mines in the Bowen Basin. Those mines or deposits stand out yet are only an indication of the numerous lesser mines and of mineral deposits depending for development on market demand and/or changes in Government policy, eg 'The Three Mines' policy. Very large areas of mineral rich structures in the western, central and eastern parts of TNA are concealed below flat lying comparatively young unmineralised sediments. The Great Artisan basin sediments in eastern TNA can and do host oil shale and non metallic minerals. Nearly 40 per cent of western TNA is covered by the Great Sandy Desert. The Canning Track, with a series of 54 wells, was constructed by surveyor Alfred Canning in 1908 - 1910 with great difficulty. It extends 1700 kilometres from Halls Creek in the north to the gold town of Wiluna in the south, through the Great and Little Sandy Deserts. Gold explorers are following favourable structures extending to the north east below the sediments and sand hills covering the track. Half of central TNA's mineral structures are concealed by the Tanami desert and the Cretaceous sediments covering the pastoral regions of the Barkly Tableland and the Daly Waters to Top Springs pastoral areas. The Georgina Basin in the south eastern section is part of the concealment.

Jan 1, 1994

By J Addai-Mensah, W Skinner, C Kelsey, J R. Kelly, E Baawuah

Comminution continues to be the most capital-intensive unit operation in mineral processing. The fundamental purpose of comminution is to liberate the valuable minerals so that they can be economically concentrated into saleable products. Declining ore quality characterised by lower grade and increased complexity requires significant energy consumption for comminution. Low-grade magnetite ores are typically fine-grained and require fine to ultra-fine grinding (P80 ~ 30 - 40 µm) to enhance its liberation from the typically siliceous gangue matrix. Historically, this has been achieved using multi-stage crushing and grinding technologies, which require high energy consumption with low energy efficiency. This motivated innovations in energy efficient technologies for comminution. Such technology has been developed in the IMPTEC super-fine crusher. It is an innovative, dry (with the potential to be operated wet), media-free, energy efficient crusher that can to reduce 10 mm feed particles to 19 – 30 µm with very low recycle loads. In this study, the mineralogical and physicochemical characteristics of crushed magnetite ore using the IMPTEC super-fine crusher have been investigated in comparison with those of rod milling. The super-fine crusher generated higher liberated magnetite minerals in the – 300 + 212 µm and < 45 µm size fractions compared to rod mill. Both comminution devices generated large low-grade hematite and goethite middlings. However, the rod mill produced higher locked/unliberated hematite and goethite compared to that of the super-fine crusher. Quartz mineral had the highest liberation irrespective of the comminution device used. The super-fine crusher generated higher entrapment of other minerals within the silica matrix compared to the rod mill. The breakage mechanism of the super-fine crusher which is predominantly through high compression with shear, generated improved mineral liberation in the coarse size fractions compared to the predominant abrasion and attrition breakage mechanisms of rod milling. The higher mineral liberation generated by the rod mill is potentially due to the prolonged batch milling of the ore compared to the single-pass open circuit of the super-fine crusher.CITATION:Baawuah, E, Kelsey, C, Kelly, J R, Addai-Mensah, J and Skinner, W, 2018. Mineral liberation studies of IMPTEC super-fine crusher – 130 crushed product, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 313–326 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

Level measurement of underground orepasses is important. Orepasses are not only utilised to funnel ore to the shaft skip loading station but also as silos for storing of ore in order to smooth out ore flow in a shaft system. Safety and operational efficiency are also improved as proper orepass level measurement could prevent overfilling of tipping areas. A study was therefore commenced to determine alternative technologies available as well as identifying practical installations across the Anglo American plc Group. From an instrumentation perspective an orepass system is an extremely difficult environment to take measurements in. Factors like dust, vapour, interference, bridging, wear and physical installation have to be taken into account. The study discusses time-of-flight (ultrasonics, radar and laser) measurement techniques followed by other possible solutions. These solutions included strain gauge measurement, the æjumping monkeyÆ technique, radiotomography, fibre optics and very long baseline interferometry (VLBI). Finally, various South African suppliers have been approached in order to determine instrumentation that is available for orepass level measurement in the marketplace. These recommendations were verified, where possible, by visiting the claimed installations.

Jan 1, 2005

By Lang SC

The Broken River Province, in the northern part of the Tasman Orogen, is divided into the Camel Creek and Graveyard Creek Subprovinces. In the Late Cambrian to Early Ordovician, and again in the Late Ordovician, the northern part of the Tasman Orogen was probably a convergent margin with calc-alkaline volcanism. These episodes may have been separated by a passive phase in which quartz-rich flysch and tholeiitic volcanic rocks were deposited. Subsequently, in the Silurian, the region underwent extension forming a large turbidite basin which included the Camel Creek Subprovince and the Hodgkinson Province to the north. Melange is pervasive in the Camel Creek Subprovince which was folded twice in the Devonian. The melange may be related to thrusting accompanying D1. No rocks younger than Early Devonian have been recognised whereas, in the Hodgkinson Province, deposition continued until the latest Devonian. The Graveyard Creek Subprovince formed adjacent to the Camel Creek Subprovince, probably as a pull-apart basin on stable crust. The deformation history of the Graveyard Creek Subprovince contrasts markedly with that of both the Hodgkinson Province and Camel Creek Subprovince. In the Graveyard Creek Subprovince, melange is only present in Early Ordovician rocks. No major angular unconformities have been recognised in the overlying marine to non-marine sequence, which ranges from Early Silurian to Early Carboniferous. Several hiatuses and a slight angular unconformity, all within the Devonian, may be related to the major events in the Camel Creek Subprovince. A major deformation in the Graveyard Creek Subprovince in the Early Carboniferous had only slight effects in the Camel Creek Subprovince. Movement on the Clarke River Fault was probably an important influence on sedimentation and deformation in the Broken River Province.

Jan 1, 1990

By G M. Zhomin, A S. Arkhipin, A Kondratiev

Viscosity of multicomponent slags is one of the crucial physicochemical properties for many industrial processes and technologies. While the viscosity-temperature relationship of completely molten slags can well be described by an Arrhenian-type law, the compositional dependence of viscosity is still not fully understood, especially in compositional regions with the lack of experimental data (eg at the glass-former concentration of 90 molar per cent or higher). In the present work major compositional relationships of the activation energy of viscous flow have been revised for numerous binary and ternary slag systems on the basis of experimental data collected and stored in the viscosity database OxiVis. For example, it has been found that the activation energy relevant to the polymerisation effect in binary systems of the MO-GFO type, where MO is the modifier oxide (ie monovalent K2O, Na2O, Li2O and bivalent CaO, MgO, BaO, MnO, PbO etc) and GFO is the glass-forming oxide (SiO2 or B2O3) is not always proportional to the third power of XGFO (contrary to the Urbain formalism) and can vary significantly dependent on the slag system. Also, the activation energy of the charge compensation effect has been revised for ternary systems of the AO-MO-GFO and AO-MO type, where AO is the amphoteric oxide (Al2O3, Fe2O3 or other). A simple polynomial model has been proposed on the basis of the carried-out analysis for estimation of viscosities of multicomponent slag systems. The model has been optimised against the experimental viscosities in the selected binary, ternary, and higher-order oxide systems and has been shown reasonable agreement with the experimental data.

Aug 21, 2024

The amount of land subjected to coal surface mining in the United States has been reported at 1, 302, 000 acres (1). Latest National Coal Association estimates (1968) show that about 65, 000 acres are affected annually in the production of 186, 000, 000 tons of coal. Peabody Coal Company affects approximately 9500 acres annually in the ten States in which we are presently operating. Surface mining at Moura, Australia was begun in February 1961. In Marcy 1963, the Marion 7900 dragline with 35 cubic yard bucket went into operation and in 1967 the Marion 8900 dragline with a bucket capacity of 130 cubic yards was put into operation. In addition a third dragline, a 480W was added in 1969. It carries a 15 cubic yard bucket and is used to work areas that are too small to justify movement of the larger machines, In 1969 the Moura surface mine produced 3, 002, 774 short tons, and in 1970 3, 418, 933 short tons.

Jan 1, 1971

By W N. Qin, B Zhang, W Z. Huang, X S Mo

Mengzi Mining and Metallurgy Co, Ltd (MMMC) polymetallic ore contains recoverable amounts of tin, lead, zinc, pyrite and other valuable minerals. With the change in orebody, the run-of-mine (ROM) ore changed from lead zinc rich ore to tin rich ore, where the current ROM ore contains 0.45–1.25 per cent tin, 20–25 per cent sulfur, and 0.20–0.35 per cent copper. The previous processing flow sheet was designed to recover lead zinc rich ore and it is clearly not suitable for recovery of the current tin rich ore, where the tin was already overground and tin recovery was only 50.19 per cent. The Mengzi Mining Company has recently modified the concentrator circuit by incorporating rod mill and high efficient Derrick fine screen. As a result of the improved classification efficiency, the overgrinding of the tin ore was minimised and the recovery of tin was improved by 20.71 per cent, ie from 50.19–70.90 per cent. An additional $10 M revenue per annum can be achieved as a result of the modification.CITATION:Qin, W N, Huang, W Z, Mo, X S, Zhang, B and Wheeler, J, 2014. Application of high efficient fine screen to improve the recovery of tin concentrate, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 487–492 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By P J. Howard

Atlas Iron Limited’s McCamey’s North project lies at the eastern end of the Hamersley Basin, approximately 50 km east of Newman, Western Australia, and 3 km northeast of BHP Billiton’s Jimblebar Mine. The presence of significant surface iron mineralisation identified during field reconnaissance, has subsequently been further defined by detailed mapping and RC drilling.The project area is dominated by outcrops of moderate to steeply north and south dipping banded iron formation, cherts and shales of the Boolgeeda Iron Formation overlying rhyolites and rhyodacites of the Woongarra Volcanics. In lower lying areas recent colluvium and alluvium mask the Archaean geology. Drilling and downhole geophysics has allowed a composite stratigraphic section to be compiled through almost the entire Boolgeeda Iron Formation.Surface orientations and subsurface stratigraphic correlations using natural gamma logs indicate large scale open folding about east-west trending fold axes across the project area; while small scale tight to isoclinal folding with similar fold axis orientations are visible at the outcrop scale. These folds are cut by a number of moderate to steeply south-dipping normal faults defining a series of north-dipping fault blocks which repeat the stratigraphy across the project area.Bedded iron mineralisation consists mainly of haematite-martite and goethite ores with best results of 78 m @ 60.5 per cent Fe. Vitreous goethite is observed at the surface of the mineralised horizons. The mineralisation exhibits a strong stratigraphic control and extend down-dip up to 120 m below surface. The strike extent of the mineralisation is still to be determined. An inferred resource of 39 Mt at 58 per cent Fe has been defi ned to date (ASX: AGO 3 February 2011).The fi ndings at McCamey’s North indicate that there is potential for economic iron mineralisation to exist in other areas of Boolgeeda Iron Formation within the Hamersley Basin.

Jul 11, 2011

By A Horn

Mineral processing is characterised by a constant adaptation to changing raw materials and market conditions. It is the link between the mined raw material and a marketable product. As a lot of high-grade reserves are exploited, a steady deterioration of raw material quality can be observed. At the same time, the customer’s requirement for product purity and consistent quality increases.Over recent years beneficiation techniques for iron ore fines have become more important in order to achieve a maximised utilisation of ore resources and to produce competitive products according to international standards.Many high capacity iron ore beneficiation plants that target the production of fines focus on gravity separation processes using fluidised bed classifiers and spirals or wet high intensity magnetic separators as an alternative. This paper demonstrates the suitability of utilising the allflux® two-stage fluidised bed classifiers to treat iron ore particles up to 2 mm in size as well as showing how the high capacity gaustec® wet high intensity magnetic separation (WHIMS) technology offers several advantages compared to other WHIMS technology.The combination of the allflux® and gaustec® technologies offer the following benefits:The two-stage fluidised bed classification extracts a significant amount of concentrate from the feed. This in turn reduces the feed capacity required for the gaustec® WHIMS located downstream.The second classification stage produces a -0.5 + 0.1 mm product and a -0.1 mm product. The efficiency of the magnetic separation on these classifi ed products is high due to optimised settings for each size fraction.

Jul 11, 2011

By D Craw, P V. Angus

Gold mineralisation at Macraes occurs as late quartz-carbonate veins within a body of sheared and hydrothermally altered Otago Schist, the Intrashear Schist. The alteration is characterised by the presence of rutile and the absence of epidote and titanite, indicative of an alteration fluid containing >10 mol per cent CO2. In areas of high strain, a fabric of black microshears develops, gradational to mylonitic cataclasite in the high strain zone adjacent to the hanging wall of the duplex shear zone. The microshears contain hydrothermal graphite, inferred to have been deposited from a methane-rich fluid. The mylonitic cataclasite is characterised by abundant pyrite, the absence of albite and extreme grain size reduction. Gold recovery in the CIL processing plant at Macraes can drop to 50 per cent or lower for some unfavourable ore types. Preg-robbing by a component in the ore, possibly graphite, was suspected as the cause. Mylonitic cataclasite was identified as the lithology responsible for the poor recoveries, with the capacity to bind about 30 ppm of gold in the leach tanks. A program of detailed geochemistry and quantitative grain-size measurement using Coulter analysis was undertaken to identify specific mineralogical factors associated with preg-robbing. The results indicate that pyrite, graphite, and extreme grain-size reduction are the factors associated with highly preg-robbing ores at Macraes. The evolution of the mylonitic cataclasite is accompanied by strong potassium enrichment, as muscovite, and depletion in sodium as albite is removed. This suggests that a simple powder XRD ratio of the albite to illite peaks would suffice to distinguish the preg-robbing ore for grade-control purposes.

Jan 1, 1999

By G E. Smith, G N. Lye

Wall control blasting practices are necessary to reduce the impact of blasting on mine faces but can also have a significant negative impact on mine productivity and operating costs. The conventional practice in deep open pit mines is to use so-called trim blasts adjacent to pit walls. To provide burden relief these trim blasts have fewer rows than full production blasts and are fired to a cleared free-face; hence they are termed æunchokedÆ. This practice leads to scheduling constraints on the pit operations and can cause ore dilution due to excessive muckpile movement. The use of such trim blasts stems from the perception that increased wall damage results from æchokedÆ blasts. These concerns are based on the unproven assumptions that blast vibration levels and explosive gas penetration increase with increased blast burden and face confinement. This paper describes work undertaken as part of a major investigation into wall control blasting at the KCGM Fimiston Mine, Kalgoorlie, Western Australia. It details a study to assess damage effects due to blast burden. Borehole air pressure measurements and borehole video camera inspections were done behind a series of single blastholes drilled with varying burden distances, as well as behind a dedicated trim blast and a full production blast. It was found that the measured damage effects, including visible rock cracking, dilation, and the limited extent of gas penetration behind the blastholes, did not vary significantly with burden or blast type for the cases tested. This result was in complete agreement with detailed vibration measurements conducted by Blair and Armstrong (2001) during the study, which found that vibration was independent of blast burden. As a result of these investigations, changes to the blasting practices at the mine were implemented. Dedicated trim blasts and free-face blasting have been replaced by modified production blasts and the practice of æchokingÆ blasts has been introduced. This has resulted in a significant improvement in productivity and cost savings without compromising pit wall integrity.

Jan 1, 2001

By C M. Stewart

Lithium battery electric powered vehicles and machines (BEVs) continue to gain traction inunderground mining use, with predictions they will dominate the underground light and heavy vehicle fleets for some mines within the next decade. There are clear advantages for ventilation systems through reduced heat output and the elimination of harmful exhaust gases and diesel particulates. However, the risks and effects of BEV fire emergencies for underground personnel and ventilationsystems are still largely in the early stages of analysis and understanding. This paper conducts an industry review of a selection of lithium battery fire incidents and research.A research paper review on lihthium fire behaviour, intensity and toxicity will be analysed and comparisons made with equivalent diesel machinery fires for context. Guidelines for mine firemodelling parameters will be offered to assist in predicting the behaviour, heat and emissions from BEV fires, and recommendations and conclusions will be drawn on the specific hazards of lithium battery fires compared to conventional diesel powered machines.

Oct 12, 2022

Banks' focus in using cash flow methods can differ markedly from that of equity investors. This paper attempts to explain and describe bankers' approach by: ò outlining the fundamental difference between banks' and investors' risk / return profiles. ò describing lenders' consequent use of cash flow methods in mineral valuation. areas. explaining lenders' specific treatment of key risk Fundamental to understanding banks' appraisal of mineral projects is the appreciation that lenders have a basically different risk profile and outlook from those familiar to equity investors. Lenders do not normally participate in any project upside. The economics of lending dictate that banks can only accommodate a low probability of loan default and consequently banks' principal focus in mineral ""valuation"" is ensuring an acceptably comfortable probability of debt repayment. A simple conceptual explanation of lenders' risk / return position is outlined.

Jan 1, 1994

By D Readett

The most critical variable in the successful establishment of the Murrin Murrin Heap Leach plant was the effective agglomeration of the Ni laterite ore. This paper describes the test work undertaken to establish the key agglomeration parameters including state of the art testing and analysis procedures. These parameters were then utilised to establish the key design and operational concepts for the world’s first commercial scale Ni laterite heap leach. Following the technical and economic success of the operation, the actual operational data is compared back to the original test work data.

Aug 8, 2011

By G B. Douglas

Lime-based neutralisation has long been the remediation treatment of choice for acidic mine pit waters. While suited to the attenuation of acidity, lime-based neutralisation may be difficult to implement efficiently due to variation in quality and the partial loss of neutralisation efficiency due to armouring. Large volumes of gypsum-bearing sludge may also require mechanical dewatering and transfer to final voids prior to resumption of in-pit mining or closure. Thus, operational costs may be substantially higher than primary neutralisation alone. Lime production also results in large greenhouse gas (CO2) emissions.Hydrotalcites (HT) are a class of Mg-Al layered double hydroxide minerals with the composition Mg6Al2(CO3 )(OH)16.4H2O. A range of other divalent and trivalent cations may also readily substitute for Mg (eg Cu, Ni, Pb, Zn), Al (eg Fe, La, Ce) and metalloids/oxyanions (SeO42-, AsO43 -/CrO42 -, MnO4-) for CO3 into the hydrotalcite structure. A common feature of acid mine pit waters, often overlooked in assessment of potential remediation options, is the frequent predominance of divalent and trivalent cations as a consequence of partial decomposition of both ore and gangue minerals during in-pit wall rock leaching. Thus, given the presence of substantial divalent and trivalent cations in acidic mine pit waters, an opportunity exists to exploit and in effect work harmoniously with the prevailing pit water composition to form a polymetallic hydrotalcite.The utility of hydrotalcites in the remediation of acidic mine pit waters lies in their ability to incorporate a wide range of contaminants; instantaneous formation, often in a single step; simple post-treatment solute composition; rapid settling; low sludge volume; and the potential to form ore-grade precipitates potentially amendable to reprocessing to (partially) recover remediation costs. Examples of hydrotalcite formation as a method to remediate contaminated acidic mine pit waters at laboratory-scale to full-scale will be presented.CITATION:Douglas, G B, 2015. Whither lime? In situ hydrotalcite precipitation as a method of remediation for acidic mine lakes, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 97–104 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By G Brewster

The Eagle on the Hill tunnels form part of an upgrade of Mt Barker Road, 15 km to the southeast of Adelaide. The upgrade significantly improves safety and reduces delays on this major road, which winds steeply through mountainous terrain. The twin tunnels each spanning 15 metres run in parallel for a length of 480 metres. The tunnels are excavated in slightly weathered high strength slates and very high strength quartzites of the Saddleworth Formation on the western margin of the Mount Lofty Ranges. Steeply dipping slate cleavages and the high fracture ratio result in many slope stability problems in the project area. The level of geotechnical investigation undertaken prior to the calling of tenders for the project was extensive. This included the excavation of a pilot tunnel along one of the tunnel alignments, which allowed accurate mapping and rating of the rock, resulting in an increased level of confidence during the tender process. One of the features of the winning alternative tender design was the use of canopy tubes, flexible steel ribs and shotcrete to replace up to 40 metres of deep portal cuts in unstable rock with driven tunnels. Slope stability issues were overcome with the use of rock dowels and shotcrete. The support concept allowed the safe driving of the tunnel portals with as little as two metres of overburden. The design incorporated lining drainage and criteria for fireproofing based on European experience to ensure the ability of the tunnels to remain stable in the case of a severe fire incident. The support design allowed for maximum flexibility with a range of support types able to deal with the varying ground conditions. Design development and support refinement continued throughout the tunnel construction phase with close liaison between the designer and the constructor. Monitoring and review of feedback from the construction site by the Sydney based design team was easily achieved by means of electronic transfer of photographic and survey information, telephone and fax communication and regular site visits. The contractor for this project is Macmahon Concrete Constructions Joint Venture (MCCJV) and the designer is Connell Wagner. Excavation commenced in January 1998 with tunnel breakthrough having been achieved in early-August 1998 and mid-September 1998 respectively. Concrete lining construction is scheduled for completion in April 1999.

Jan 1, 1999

The purpose of this paper is to list by tabulation and flow sheet, the operating equipment and installations in use at Rosebery, and to refer to particular items which may be of interest for purposes of comparison, or because they possess some unusual feature. The general perspective has been taken from the viewpoint of operating and maintenance experience.The sequence begins with ore breaking and transport and proceeds through milling operations. The paper is in two sections, first, mechanical equipment, second, electrical equipment. A brief outline of a scheme for using gravel wash for stope filling, which is in course of installation, has also been given.

Jan 1, 1949