Search Documents

By S Porter

The Melbourne City Link Project is a privately funded road infrastructure project linking three significant existing freeways in the vicinity of the Central Business District. The State Government, through the Melbourne City Link Authority, has contracted Transurban to build, own and operate City Link for a concession period of 34 years before the road network is transferred to the State. Transurban has a contract with Transfield Obayashi Joint Venture (TOJV) to design and construct the works. The project is divided into the southern and western sections and the tunnel works comprised the significant component of the Southern Link. Outside of the cut and cover tunnels at the portals, the driven tunnels component was constructed by TOJV direct labour. TOJV subcontracted all design work to a joint venture of Hyder Consulting and CMPS&F (Hyder/CMP). The geology in the tunnel corridor and generally below the city of Melbourne is highly variable and constantly changing. The tunnels were driven, for the most part, in siltstone and sandstone of the Silurian age, but also intersected overlying basalts and clays. The Silurian bedrock is a fractured aquifer that is connected to overlying alluvial aquifers. Consequently, the construction of the tunnels was a complex engineering task. This paper details the operational relationships and procedures developed to deliver a design that was aligned to the construction constraints and delivered an end product that met all technical, quality, cost and program goals.

Jan 1, 1999

Coal washing practice can be improved not only by critical examination of the plant being operated but also by studying plants operated in other areas. The developments at the Australian Iron & Steel Pty. Ltd. plants are discussed in relation to experiences there as well as developments which have taken place in Queensland in recent years. Early A.I.S. problems involved small coal cleaning in heavy medium cyclones and flotation. A proposed future plant flowsheet for A.I.S. is considered in the light of these experiences. Reference is made to plants operated by the Thiess, Peabody, Mitsui Coal Company Pty. Ltd. at Moura and the Utah Development Company's plants at Blackwater and Goonyella in the development of coal washing prac- tice in Australia.

Jan 1, 1975

By N Van Buc, E Coroiu

The rapid socio-economic growth of Hanoi City coincides with a corresponding growth of the transport demand. Today, the transport in Hanoi is completely dependent on private modes of transport. Because of the lack of an efficient public transport system and the expected rapid increase in traffic volumes, the movement of people and goods in the urban areas of Hanoi will cause congestion in the present city transport network. The solution of the construction of new roads, or the widening of the existing streets, is very expensive in urban areas and usually causes many social problems due to the resettlement of people. From the point of view of the number of inhabitants, Hanoi City is now over one million. Above this number the international experience shows that the public transportation must be a mass transport system with large capacity, commercial speed and also independent as much as possible from the street network. According to the Hanoi Master Plan for 2020, the Hanoi urban population will be over 3.5 million persons. Also, in the next 15 years, the distances between centre-destination points will be doubled by comparison to 1995.

Jan 1, 1999

By KenGemar P, Perembo R. C B, Winn R. D

The New Guinea orogen comprises terranes that have accreted to the northern margin of the Australian craton. The history of the accretion of terranes begins earlier (in the Late Cretaceous) and is more complex than has been suggested previously. There was a collision in the central highlands in the Late Paleocene or Early Eocene, and a Finisterre collision that precedes and is distinct from the later (Pliocene) Bismarck volcanic arc collision.

Jan 1, 1997

By Delahey G, Dunne R

At New Celebration Gold Mine the advent of treating primary sulphide ores resulted in decreased gold recoveries of four to ten per cent. The grind coarsened due to an increase in ore hardness and gold in the residue was found to be associated with pyrite. Finer grinding improved recoveries but was impractical as production rates would have decreased to unacceptable levels. An alternative approach that has proved to be viable combines both gravity separation, to recover the coarse gold bearing sulphides, and then regrinding the concentrate in a tower mill prior to releaching in the cyanide leach circuit. The tailings treatment plant was commissioned in December 1990 and details of the first 18 months' operations are Provided.

Jan 1, 1993

It is generally known that Charters Towers was discovered by Mosman, Clarke and Fraser in 1871. However, the time was ripe, and these three were barely in front of others. There is one account that prospectors from Ravenswood visited the area months before but decided it was too far from water, and that one of them had told Mosman and party of the find. There is another account that Joe Larkins found the discoverers before they had registered any ground - this may explain Mosman's quick departure for Ravenswood.When the news spread, the rush was rapid, and there was soon a sizeable population: probably too many, as within twelve months the infant settlement was under considerable stress. First, the presiding Gold Commissioners had adopted "unusual and arbitary" interpretations of the Regulations, and many of the miners were aggrieved; Charters, the senior Commissioner, was accused of favouring moneyed interests, and of retiring ill whenever a brawl or confrontation occured. As a result, the law of the field soon became "the survival of the strong". Second, the settlers were, divided on where the main town should be: Millchester, near the water, or Charters Towers near the mines. Third, the discovery of gold at the Millchester Deep Lead in August, 1872 was followed by highly exaggerated accoants in_' the southern papers, apparently fabricated by local business speculators. The resulting rush resulted in hundreds of unlucky prospectors having to return or seek other fields. In that period two men were killed in squabbles over ground. To make matters worse, by October 1872 a drought had set in, water cost three pence a bucket, fodder was scarce, cartage expensive, and the price of crushing ore rose to thirty shillings per ton.

Jan 1, 1986

Nine case studies are presented to illustrate how risks can be, minimised or quantified during pit optimisation, utilising Whittle Four-D software. Each case study covers a specific problem that has been encountered from a wide variety of pit optimisations. Case A: Maximising profits when the tenement owner is paid a royalty on tonnes processed. Case B: Allocating product prices, rather than a single commodity price during optimisation. Case C: Quantifying processing costs that are affected by penalty elements in the ore. Case D: Exploration expenditures below current pits can be quantified through the use of simulation techniques. Case E: Alternative strategies can be quantified when pits are restricted by tenement boundaries. Case F: Relocation of mine infrastructure that requires large capital expenditures, can be simulated by allocating costs to an area during optimisation. Case G: Evaluating alternative corporate strategies during pit optimisation. Case H: Sensitivity analysis for price, processing cost and mining cost. Case I: Quantifying the advantages of using additional mining capacity during the early periods of mining.

Jan 1, 1994

The lignites of Otago and Southland offer a potentially viable future feedstock for electricity production and possible conversion to petrochemicals or liquid fuels. The deposits, when combined, represent New ZealandÆs largest energy inventory; equivalent to about 74 000 petajoules û or approximately 35 times current natural gas reserves. Too often dismissed as irrelevant to New ZealandÆs energy future because of adverse perceptions of the value of low rank coals, the strategic value of this resource is in fact huge.   Investigations of the lignites extend back over more than 50 years (LFTB various, CRL Energy Ltd). Whilst it is not the intention of this paper to review this work, these investigations have confirmed the suitability of the resource as a feedstock for thermochemical conversion. Current estimates of South Island lignite mining costs are NZ$1.0 - 3.0/GJ (Natusch 2005), making these resources amongst the most competitively-priced energy sources available world-wide.   This value, however, will only be captured if we as a country begin to envisage a world-scale, long-life, integrated and multi-faceted development sized to supply world markets for chemicals or fuels. Recent CAE studies (Hooper and Riddolls, 2005) have emphasised the vital importance of ensuring that any exploitation of this resource maximises their value to New Zealand. The question that thus must be applied is how might large-scale utilisation of the resource fit with New ZealandÆs primary energy supply, and its potential for the export of high-value commodities.   From the broader perspective of New ZealandÆs total energy supply equation we need to examine other supply options beyond just the generation of electricity. We face in this country a situation wherein almost all our liquid fuels feedstock has to be imported with projections for an increasing dependence on imported oil. In addition NZ has a natural gas reserves-to-production ratio of less than ten years, and dwindling supply from local production. Without further natural gas discoveries, New Zealand has only a window of approximately five years before we will need to commit to imported LNG or some other thermal fuels option.   In other words, New Zealand is facing an uncertain future unless we can restore energy inventories to cover an adequate strategic reserve capacity as well as enable long-term investment in alternative sources. Within this context the South Island lignite resources are thus deserving of more attention. The extent of the resource is well known, its suitability for conversion reasonably assessed, and its magnitude such that there is little doubt that lignite conversion could adequately meet NZÆs future energy needs for many years out.   This paper reviews coal gasification technology, its application to lignite and the possibilities for future development of the lignite resources. It is argued that the strategic imperative for this country is to secure the lignite resources as a primary energy source for this country well into the latter half of this century.

Jan 1, 2005

By P Breuer, X Dai, A Bergamin, D Hewitt

"Copper-ammonia-thiosulfate?leaching of gold has been researched for several decades as a potential alternative to cyanidation. However, this technology has not yet been applied commercially due to many challenges such as complex solution chemistry, reagent degradation and losses, system instability with losses of precious metals and difficulties in gold recovery from the leachate. Progress has been made at CSIRO in tackling some of these challenges including:better understanding and control of the leach conditions to minimise reagent losses whilst maximising gold recovery use of strong base ion exchange resins to recover the gold strategies to deal with polythionates that adsorb competitively with gold on ion exchange resins development and evaluation of process flow sheets.As a result there has been increased interest from the gold industry and renewed activities to develop thiosulfate based processes for gold recovery. One application area, which has been developed to the point of piloting, is the treatment of gravity gold concentrates using a copper-ammonia-thiosulfate leach with ion exchange recovery of the gold thiosulfate. This paper describes some of the advancements in the development of a potential process flow sheet for this application.CITATION:Dai, X, Breuer, P, Hewitt, D and Bergamin, A, 2013. Thiosulfate process for treating gold concentrates, in Proceedings World Gold 2013, pp 61-70 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 26, 2013

This paper describes the new iron and steelmaking process recently commissioned at NZ Steel. Ironsand mined and concentrated at Waikato North head is slurry pumped 18 km to the company's Glenbrook works. Ironmaking includes the direct reduction process pioneered at Glenbrook in the 1970s and a new continuous electric melter. The molten, high carbon pig iron produced is then fed to a vanadium recovery unit and on to the KOBM oxygen steelmaking vessel. Steel is cast into billets or slabs. The new plant, which is the first stage of a fully integrated works at Glenbrook, raises New Zealand Steel's production capacity from 150 000 t/y to 750 000 t/y.

Jan 1, 1986

By M J. Gillespie, P D. Erskine

Mine site rehabilitation generally includes the re-shaping of overburden to create a final landform, manipulation of substrates and subsequent revegetation. Due to the wide range of environmental variables that influence rehabilitation progression, having clearly-stated final land-use goals and ongoing significant contributions to the planning process, from prefeasibility through to mine closure, is essential for achieving stable landforms and sustainable rehabilitated communities. Two examples of rehabilitation processes in the phosphate rich region of North West Queensland are used to illustrate some of the possible benefits of early planning and communication of rehabilitation requirements.Approximately 160 km south of Mount Isa, Incitec Pivot Limited operates a 35 year old open cut mine at Phosphate Hill. Monitoring of rehabilitation areas and selected analogue sites is undertaken annually, but the initial landform design, substrate management and species selection has created a difficult environment for revegetated areas to successfully establish. Constant management input (such as weed management, erosion control, supplementary seeding, etc) will, therefore, be required over a long time frame.The second example uses exploratory drilling and historic costean pits at Legend International HoldingÆs Paradise South site, 135 km north of Mount Isa, to determine the success of natural vegetation colonisation on waste rock and compacted soils, and the effects of cattle grazing on recolonisation. This information can be used by planners of the mine life to inform possible end-land use decisions and proposed completion criteria.In a semi-arid environment such as North West Queensland, the creation of a post-mine landscape suitable for nature conservation and/or grazing can be an arduous task. The input from environmental personnel at all stages of the mining process will positively impact upon the quality of the resulting rehabilitation and ensure undesirable legacy issues are minimised.CITATION:Gillespie, M J and Erskine, P D, 2012. Importance of early rehabilitation planning - Case studies from North West Queensland, in Proceedings Life-of-Mine 2012 , pp 187-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

In order to fully understand why Amax Coal puts such extreme emphasis on the drilling and blasting programs at each of our mines, we must review the past. This paper will discuss the drilling and blasting techniques we used in the 1970s and their evolution to current practices. As time progressed, major changes influenced the surface mining of coal through new more restrictive governmental controls and local communities organising into groups with two goals in mind, one to shut down the mines and the second to try and get rich by making false and unjust damage suits against the mines. In virtually all of our midwest surface operations we have at one time or presently are facing litigation that has reached into the millions of dollars. Amax Coal has worked in co-operation with the United States Bureau of Mines in the areas of blast vibration, shot design, highwall safety, blast casting studies and many more. Today we are continuing to work with Dr David Siskind and his expert staff seeking answers to old and new problems addressing the blasting of overburden and parting seams.

Jan 1, 1995

By Davies H, Pigram C, Sunata W, Falvey D, Loxton C, Giddings J, Rogerson R

PALAEOMAGNETIC CONSTRAINTS ON TERRANE TECTONICS IN NEW GUINEA Chris Klootwijkl), John Giddingsl), Wahyu Sunata2), Chris Pigraml), Charles Loxton3), Hugh Daviesl), Rick Rogerson3) and David Falveyl) 1) Bureau of Mineral Resources, Canberra, Australia 2) Geological Research and Development Centre, Bandung, Indonesia 3) Geological Survey of Papua New Guinea, Port Moresby, Papua New Guinea

Jan 1, 1987

By D I. Cliff, K Johnstone, N LaBranche

The resurgence of silicosis and coal worker’s pneumoconiosis (CWP) in mining and the recent ban of engineered stone products underscore the need to comprehensively address mineral dust exposures and the associated health hazards. Worker exposure to particulate matter, remains a pressing concern demanding nuanced exploration as all dusts are not created equal. The established link between silica and respiratory diseases necessitates a more detailed understanding of the characterisation of particulates and their health impacts. While current monitoring relies on total mass, it is increasingly evident that the size, shape, mineralogy and agglomeration of particles play a crucial role in determining health impacts. This has been evident in the engineered stone industry with workers not only facing a greater risk of silicosis, but also seeing a faster progression of the disease and a higher likelihood of dying from it. Simultaneously, the surging demand for critical minerals, integral to low-carbon economies, has seen government and industry fast tracking the exploration, mining and processing of these commodities. Critical minerals, crucial in technologies like lithium-ion batteries and high-performance alloys, are central to achieving global environmental goals. Significant funding is currently being allocated to advance the development and processing of these materials, however there remains a considerable gap in understanding potential health risks, urging comprehensive health risk assessments. To tackle these challenges, the University of Queensland has developed innovative dust characterisation methodologies, including the use of the Mineral Liberation Analyser (MLA), a scanning electron microscope, to characterise respirable and inhalable dust samples. This advanced technique, initially applied in coal and metals mining, is expanding to critical minerals mining, unravelling diverse mineralogical components and particle size distributions. This conference presentation will showcase the latest research, emphasising the use of advanced analytical techniques to deepen our understanding of the size, shape and mineralogical composition of particulate matter. By synergising insights from coalmines, metals mines, smelters, engineered stone and critical minerals assessments, we aim to proactively manage health risks, contributing to safer workplaces and responsible production practices in the mining sector.

Apr 16, 2024

Lithocaps are potentially voluminous zones of advanced argillic and associated argillic alteration located above the subvolcanic intrusive environment. They constitute exploration objectives for epithermal and porphyry-type deposits. High-sulphidation epithermal deposits may be sought within lithocaps, whereas low-sulphidation deposits may exist on their edges. Porphyry Cu-Au/Au deposits may be accessible beneath lithocaps if systems are telescoped sufficiently. Oxidation of the basal, pyritic parts of lithocaps may promote supergene sulphide enrichment under appropriate tectonic and climatic conditions.

Jan 1, 1995

By Nixon TR

The Australian Coal Industry Research Laboratories Ltd. (A.C.I.R.L.) MINVENT computer program can be used to simulate existing and projected colliery ventilation requirements. New collieries can be planned using a database of ventilation parameters which were ascertain- ed by A.C.I.R.L. surveys at selected collieries in N.S.W. and Queensland. Several techniques are used in both the formulation of the database and in the evaluat- ion of a ventilation system, prior to analysis by the MINVENT program. The analysis of a ventilation system requires the measurement of air quantities, pressures and hence airway resistances. All resistances are calculated at standard air density of 1.205 kg/m3. Air densities are derived from barometric pressure and wet and dry bulb temperature readings. Airway frictional and shock losses, leakage through stoppings and overcasts, flow of air through regulators, face resistance and resistance of anomalous ventilation features are related to the typical Australian measured data presented.

Jan 1, 1983

By Offler R, Lau J, Lea J. F

The stratiform and vein-type pyritic silver-Iead-zinc-copper sulphide deposits of Sunny Corner, NSW are hosted by acid volcanic and clastic sedimentary rocks of Middle Silurian to Early Devonian age. The rocks have been subjected to low-grade regional metamorphism (prehnite-pumpellyite facies) and three phases of folding and four faulting events are recognised. Pyrite is intensely fractured, indicating brittle deformation. Chalcopyrite and galena exhibit deformation twins and slip planes indicating ductile deformation; sphalerite and chalcopyrite show straight and curved grain boundaries and dihedral angles of 120° as evidence of annealing recryslallisation. Sulphur isotope ratios for 22 samples from five deposits range from 1.7 to 10.7 per mil and average 7.4 per mil. Sulphur isotope data are similar to those from other stratiform sulphide deposits in acid volcanic rocks of Late Silurian age in the eastern Lachlan Fold Belt, especially Woodlawn and Captains Flat and together with other features of the mineralisation, suggest a volcanic exhalative origin for the Sunny Corner deposits.

Jan 1, 1984

By S T. L Harrison, J-P Franzidis, M Becker, N Dyantyi, J L. Broadhurst

Gold mining is a major contributor to the South African economy, but is associated with several environmental issues such as acid rock drainage (ARD). ARD is due to the oxidation of sulfides in gold tailings and is characterised by low pH, high sulfate content and elevated concentrations of heavy metals that contaminates scarce water resources and subsequently limits the use of such waters without treatment. Treatment strategies can only be implemented if the acid-generating potential of mine wastes is effectively predicted using common static and kinetic acid prediction tests. The choice of test performed is usually a trade-off between the number of samples, speed of the test, cost of the analysis and level of information obtained. Often the results of these various tests are not consistent with one another. This study uses mineralogy to analyse biokinetic test results of a Witwatersrand gold sample in order to improve the understanding of behaviour of mine wastes under different ARD prediction test conditions.All ARD prediction testing methods investigated in this study showed that the gold sample is considered to be potentially acid forming with net acid generation (NAG) pH of 2.5 and net acid producing potential (NAPP) of 36 kg H2SO4/t. Results of biokinetic test showed that ANC was consumed within four days confirming acid producing potential of the sample with low neutralising potential as observed from acid base accounting (ABA) (4.7 kg H2SO4/t) and mineralogy (4.9 kg H2SO4/t). Results generated in this study demonstrated importance of mineralogy in both understanding the controlling reaction mechanisms playing key role in ARD formation and its capability as a prediction technique. Future work will focus on the application of mineralogy in interpreting the behaviour of mine waste under different static test conditions with a view to assessing their applicability and reliability in estimating potential acid generating characteristics of gold tailings.CITATION:Dyantyi, N, Becker, M, Broadhurst, J L, Harrison, S T L and Franzidis, J-P, 2013. Use of mineralogy to interpret laboratory-scale acid rock drainage prediction tests - a gold case study, in Proceedings World Gold 2013, pp 519-526 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By S Doyle

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Macraes gold mine in Otago, New Zealand, is developed along the central portion of the Hyde-Macraes Shear Zone (HMSZ), which dips gently to the NE, and is traceable over 30 km of strike, before disappearing under tertiary cover. Mineralisation is most intensely developed along the hanging wall shear, which defines the upper limit of the shear zone, although significant packages of quartz vein arrays and mineralised shears occur sporadically beneath the hanging wall shear.The Macraes gold mine is now in its 25th year of operation, well beyond the projected mine life at the time of commissioning in 1990, and currently contains over triple the measured and indicated resource inventory that was defined at start up. The extended mine life and resource growth has been driven by exploration and resource development success, efficient low-cost mining and processing, improving gold price, as well as an ethos of continuous improvement.The emphasis of Oceanagold’s exploration and resource development has shifted over time; from hanging-wall-focused mapping, soil sampling and step-out drilling, through exploitation of previously drilled stockwork mineralisation, to the pursuit of blind, higher-grade underground targets.Mineralisation within the HMSZ remains open at depth, and the regional potential has not been fully tested. Given the relatively low-grade of gold mineralisation at Macraes, the consideration of tungsten as a supplementary co-product provides an exciting opportunity.CITATION:Moore, J and Doyle, S, 2015. Resource definition in the world-class Macraes gold mine, New Zealand, in Proceedings PACRIM 2015 Congress, pp 557–564 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By G Chen

Magnesite and dolomite are two salt-type minerals. The surface characteristics of these two minerals are almost the same. It is very difficult to remove dolomite from magnesite ores by flotation process. The present study was performed to develop a new collector and a better flotation scheme for magnesite from dolomite. The flotation tests show that there exists a significant difference in flotability between magnesite and dolomite when dodecyl phosphate synthesised with dodecanol, phosphorus oxychloride and other chemicals is used as collector. Sodium silicate was used as the modifier to improve flotation selectivity. It was found that sodium silicate selectively depressed magnesite at pH 4.5 - 7.5. The separation of magnesite from dolomite was achieved in a reverse flotation which resulted in a 76.1 per cent yield of magnesite with a grade of 47.3 per cent at 100 ppm dodecyl phosphate and 75 ppm sodium silicate. The flotation mechanism was investigated by characterising surface electrical properties and measuring the adsorption density of the reagents on magnesite and dolomite.

Jan 1, 2005