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The Escondida Porphyry Copper Deposit, located in Chile's II Region 160 Km to the southeast of the city of Antofagasta, is currently owned by Minera Escondida Limitada, a company comprising The Broken Hill Proprietary (57.5%), Rio Tinto Zinc (30%) a group of Japanese companies represented by Mitsubishi Corporation (10%), and the International Financing Corporation of the World Bank (2.5%) (Fig.l)By 1983, most of the reconnaissance drilling was completed and prefeasibility studies were regularly updated as new drilling results were reported and project concepts re-evaluated (Fig.2). In October 1982 the project was transferred from Exploration Management to Operations. By the end of 1984 project pre-development activities, including inpit development drilling, geological exploration, water resource definition, an underground bulk sampling program and the initial project feasibility report, were completed.

Jan 1, 1990

By Downs M

The use of a cutting machine designed to allow simultaneous cutting and setting of roof supports has numerous advantages few development roads in coalmines. The use of such a machine with the added ability to cut a curved roof profile is of considerable interest for longwall development in thick coal.

Jan 1, 1998

The Airport Link Railway utilises innovative solutions to a number of issues associated with underground development and transport infrastructure planning. It is typical of the major change underway in the countryÆs rail and air transport industry. It involves the private sector providing transport facilities in competition with the public sector, a convergence of planning and transport imperatives, the use of the most technologically advanced engineering practices to minimise construction impacts on the community and a commercialised way of developing and maintaining railway infrastructure and services.

Jan 1, 1999

By D Williams

Recent advances in global positioning systems (GPS), machine guidance technology and telemetry allow an unprecedented level of control of surface mining operations. GPS technology can now locate the bucket of a shovel or the blade of a dozer within 50 mm. Some of the outcomes possible are: precise selective mining û even when the ore is visually indistinguishable from waste; tracking grade and tonnage of every ore parcel through the mine; real time productivity monitoring; detailed post accident safety analysis; and tracking the movements of every piece of equipment. This paper will consider the contribution that GPS based machine control systems can make to ensuring that surface mining projects deliver the outcomes promised in the feasibility studies. Case studies of installations are presented.

Jan 1, 2003

By Muir DM

In recent years, significant improvements have been made in the design and operation of carbon-in-pulp plants. Some of the major developments in plant operation and technology are reviewed together with an outline of the research being undertaken in Western Australia. The main problems facing operators include the understanding and control of carbon fouling and regeneration, and the recovery of gold from the carbon. It is shown that carbon fouling by a variety of agents, particularly cyanide, calcium carbonate and silica, cause a significant loss of kinetic activity which in turn leads to poor plant performance. The importance of acid washing and adequate thermal reactivation is discussed. Although the Anglo elution procedure is commonly used in South Africa its use in Australia in preference to the conventional Zadra elution procedure is likely to be re- stricted because of its demand for high quality water. Solvent elution by the recently developed Micron procedure using refluxing methanol, ethanol or acetonitrile vapours is an attractive alternative. This elutes gold in 4-6 hours and provides concentrated gold solutions suitable for simplified gold recovery steps.

Jan 1, 1984

Financial theory often takes some time to penetrate industry and when it does it can result in a paradigm shift in valuations and mental models. The Black Scholes option valuation was first published in 1973, although the authors were only awarded a Nobel Prize in 1997. The valuation of real options has been applied to the oil and gas industry for some time, however it has only recently been more widely applied to the non-oil, mineral resource sector. The use of real option valuation (ROV) for the valuation of marginal and short mine life resource projects is a more useful valuation tool than the conventional DCF, NPV valuation tool. The application of ROV has major implications for corporate strategy. It generally favours equity over debt funding and non-hedging over hedging. A retrospective assessment of the successful development of the Lennard Shelf Operations demonstrates the concepts of implementing real options and the value destruction of limiting operational flexibility through debt and hedging activities.

Jan 1, 2003

By Kidman B. E

The Fitzpatrick area is the deepest section of the North Mine, with the orebody located between 1450 and 1800 m below the surface and some 600 m NE of the main No. 3 Shaft orebody and separated from it by the intensely sheared Globe Vauxhall Shear Zone. Development towards the Fitzpatrick area commenced in 1977 after earlier initial exploration drive development. However, it was not until 1982 that mining in the Fitzpatrick area actually began with the silling out of No. 36 level at a depth of some 1600 in. Since that time mechanised cut and fill mining from an incline ramp system with connecting stope accesses has progressed some 25 m above No. 36 level. Initial sill development on No. 37 level at 1660 m depth also commenced in July 1987 to further develop the Fitzpatrick area.

Jan 1, 1988

By Staude W, Rosser A

Due primarily to the publication of the Fitzgerald Report the impact of taxation on the mining industry and the amount of taxes actual- ly paid by the industry have become items of intense debate. However, the discussion has been governed more by impassioned rhetoric than considered logic. It is equally as wasteful to the economy for the mining industry as a low cost efficient export earner to be punitively taxed, as it is for the industry to be given excessive taxation assistance. A comparison of the effect of five tax- ation policies on the cash flow of a capital intensive mining project is presented. The policies considered are Liberal 1969, Liberal 1976 with and without the coal levy, Labor 1975 and Labor 1976. The mining project used in the analysis is modelled on published estimates for the proposed Nebo coal project. The analysis is equally applicable to any large mining or petroleum development.

Jan 1, 1977

By E S. Bernard

Steel fibre reinforced shotcrete (SFRS) is increasingly being used as ground support in both civil and mining applications. In recent years, methods of assessing the performance of SFRS have been developed. These include the beam test such as that prescribed by ASTM C-1018 and the panel test prescribed in the EFNARC European Shotcreting Standard. The panel test has gained popularity in recent times due to the two-way action modelled in the test. However, some difficulties have been noticed. Shear failures sometimes occur and there appears to be a rather high degree of variability in the panel test results. A new method of testing panels has been proposed. A circular panel supported on three symmetrically arranged points has been assessed at the University of Western Sydney. This paper describes the new test which may be the basis of a new specification for the testing of toughness of SFRS and summarises research work which has been carried out to-date.

Jan 1, 1999

By Z Chang, S A. Mrozek, S Windle

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. It is important to understand skarn-porphyry transitions in order to use exposed skarns to look for associated and potentially larger porphyries. For such purposes, a good start is to understand the transition between porphyry and skarn in known deposits. In this contribution, we report the transition at Antamina, Peru, where skarns occur in and around a Miocene complex comprised of more than seven porphyritic intrusions. There are three types of skarn-porphyry relationships. The earliest intrusive phase, P1A, contains both endoskarn and porphyry-style quartz veins with secondary biotite halos. The porphyry quartz veins and endoskarns formed at the same time. Locally, the intrusion contains only endoskarn without porphyry quartz veins and is surrounded by exoskarns in carbonate wall rocks. In the third scenario, later porphyry (P2) intruding into P1A porphyry and skarns related to P1A contains abundant granular quartz veins and secondary biotite alteration but does not have significant endoskarn. The granular quartz veins also extend into earlier P1A skarns. The scarcity of endoskarn associated with P2 is related to the supply of Ca. The earliest P1A intrusion intruded into carbonates that supplied abundant Ca, therefore both endoskarns and exoskarns formed. In contrast, where the wall rocks of the later P2 intrusion are P1A or skarn related to P1A, there was little free Ca, therefore only porphyry-style quartz veins formed.CITATION:Chang, Z, Mrozek, S A, Meinert, L D and Windle, S, 2015. Skarn-porphyry transition – an example from the Antamina skarn, Peru, in Proceedings PACRIM 2015 Congress, pp 409–414 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The development of the Australian uraniumindustry over the last decade has been subjectto socio-political controversy, but the industryis now beginning to emerge onto the world scene.The socio-political controversies which haveexisted over developing Australian uranium arediscussed and suggestions put forward as topossible changes in the relationship of themining industry to the pplitical and socialstructure of Australian Society.The rate of growth in energy consumptionis considered and on the basis of a growth rateof 3% by the year 2000 the world will beconsuming twice the amount of energy that itdoes today. It is anticipated that the growthin generation of electrical power will begreater than the growth rate fQr energy.The dominant part played by coal and nuclearpower in the generation of electrical power isdiscussed. Nuclear power at present, contributesabout 4% of the world's electricityrequirements and by the turn of the centurythis could be nearer to 30%.

Jan 1, 1981

Hydrometallurgy has a history of over 300 years with copper leaching and cementation having been exploited in Spain as far back as 1670. Since then, hydrometallurgy has become an integral, expanding branch of extractive metallurgy. This paper reviews major developments in hydrometallurgy over the past century with emphasis on recent commercial developments and their impact on the mining and metals industries. The environment in which these developments has taken place has changed significantly in the past two decades and many factors, often non-technical, have emerged as constraints on the operation of existing plants and the expansion and development of new hydrometallurgical operations. Finally, a number of possible new developments that will shape the future of hydrometallurgy in the new millennium are discussed, particularly as they relate to the assimilation of technical advances in other areas of science and engineering. The impact of current trends in the education of hydrometallurgists and the provision of research in support of these future developments is also addressed.

Jan 1, 2000

Mineral sands make up only 3% of the value of mineral production in WA. However, the distribution of mining operations, close to the more highly populated south-west coastal areas, and the wide range of land-tenures and land-uses involved has resulted in the most complex range of regulatory procedures found anywhere in the State's mining industry.Mineral sands are mined on private agricultural and "minerals-to-owner" land, State forests, nature reserves, coastal reserves and vacant Crown land. Local Government authorities, State Government departments and private landholders can, depending on the land tenure, be involved in setting the environmental conditions for mining operations and supervising subsequent rehabilitation. In the past, rehabilitation was predominantly aimed at establishing an agricultural land-use after mining; however, it is now necessary for mining companies to rehabilitate mined areas to a much wider range of end land-uses.

Jan 1, 1986

Separation in magnetic fluids is one of the modern techniques that offer a unique approach to material manipulation in a broad spectrum of industries. Its wide-scale application has been restricted so far for a variety of reasons, including limited throughput, inefficient recovery of magnetic fluids and the cost of commercially available magnetic fluids. This situation has changed recently. Very selective separators, with automated density control, capable of treating a variety of materials in a wide spectrum of densities and particle sizes have been built by DebTech and applied in the diamond industry. Technology for the recovery of magnetic fluids has been developed and low-cost magnetic fluids, with high magnetisation and low viscosity are being produced on a production scale. Scale-up of the technology has been addressed and units capable of treating large tonnages of material have been designed. Such a development thus offers the minerals industry a technology that surpasses the existing technologies in selectivity, efficiency and versatility

Jan 1, 2000

By Balint F

The Izok massive sulphide deposits are located in the Northwest Territories of the remote western Canadian Arctic. Together they represent one of the highest grade undeveloped zinc-copper resources in North America. Metall Mining Corporation is presently engaged in a feasibility study on developing the Izok property as well as actively exploring for additional reserves. The Izok deposits are Archean-aged, volcanogenic massive sulphide (VMS) bodies hosted within and near the top of a thick sequence of predominantly felsic pyroclastic rocks. The hangingwall package includes additional felsic volcanoclastics, dacitic and basaltic flows, thin sulphide-rich iron formations, and turbiditic sediments. The felsic volcanics are intruded by syn- to late-hydrothermal dacitic dykes and sills and post-hydrothermal gabbroic dykes and sills. Both intrusives are interpreted to be volcanic feeders to overlying flows. All lithologies are cut by much later irregular granitic pegmatite dykes and regionally metamorphosed to pyroxene homfels grade. The deposits occur within a large kilometre-scale soda-depleted alteration zone. The immediate footwall and hangingwall rocks to the deposits are characterised by zones of muscovite-biotite (with or without sillimanite), lesser chlorite-biotite-cordierite (with or without anthophyllite), and locally intense silicificified and albitised zones. All lithologies have been affected by a later calcic metasomatic alteration. As currently defined, the Izok Zn-Cu-Pb-Ag deposits comprise a cluster of four complexly-zoned composite lenses: the Northwest, North, Central, and newly discovered Inukshuk deposits. The first three deposits are amenable to open pit mining while development of the Inukshuk deposit will require underground methods. The combined mineral inventory of the Northwest, North, Central and Inukshuk deposits at present totals 15.6 million tonnes with a grade of 2.4 per cent Cu, 13.8 per cent Zn, 1.4 per cent Pb, and 74.6 g/t Ag.

Jan 1, 1993

By E Werner, J J. Donovan, A J. Morris

Coal mining in the Pittsburgh coal seam, in the eastern United States, began in the late-1700s. Since that time numerous mining technologies have been used throughout the basin. Environmental concerns, particularly mine discharge quality, have only been considered since the early-1970s. During the last 20 years, many of the larger underground mines have closed and are now either flooding or already flooded. In order to understand the consequences and potential future effects of this flooding, mine mapping of the basin has been compiled utilising a geographic information system (GIS) with an emphasis on locating barrier pillars between mines. Mine flooding has been monitored at numerous sites utilising pressure transducers and data loggers. These data have been combined with historical data from mining companies and structure contour maps to yield chronological flooding maps of the basin from 1980 to present. Utilising these maps and the indicated flooding rates, future discharge locations have been identified along with estimates of when these discharges are likely to occur. Related work has identified barrier pillar hydraulic conductivities and vertical infiltration rates as a function of overburden thickness. All of this information has been integrated into a groundwater flow model that simulates mine flooding. This model is useful in defining mine to mine interactions as the various mines fill with water, and the testing of various flooding scenarios. The model will be used in evaluating mine discharge rates and evaluating the options for regional mine drainage treatment.

Jan 1, 2003

ALTHOUGH the mineral Stannite (Cu2S, FeS, SnS2 , also known as "bell 'metal" ore, tin pyrites, etc.) is found in various parts of the world, in only three iocalities has development proved it to exist in sufficient quantity to warrant the erection of treatment plants. Two of those mines are in New South Wales and one is an Tasmania. The writer will deal with the latter-the Conah mine, Zeehan, Tasmania, it being the most important and extensive occurrence so far worked. The Conah mine was first worked by a Tasmanian company for silver-Iead, and was fairly remunerative until the zone of secondary enrichment was passed through, when the lodes became too poor for further exploitation. During the time that the line was thus operated the stannite lode was discovered. It occurs in a graphitic slate, which, in common with the slates and spilites of the Zeehan field, is probably underlain by the stanniferous granite which outcrops two miles to the west. The Conah stannite lode is older than the galena lodes of the district, being faulted by one of the latter. Near the surface the lode was very rich.Shipments were sent out assaying 150 oz. of silver per ton, 20% copper, and 18% tin. An .apparently homogeneous sample of stannite, analyzed by the writer for the Tasmanian Geological survey, gave the following results:

Jan 1, 1915

For many years the mining industry at Broken Hill, New South Wales, Australia, was carried on with just sufficient attention to underground ventilation and hygiene conditions as to keep pace with necessity. However, the campaign against industrial diseases in other mining centres (notably South Africa) some years ago, brought the subject more prominently before local mining engineers.Throughout a period of several years, gradual improvement has been effected, and at the present time industrial hygiene is considered an essential part of the production operations of the various companies.In June, 1918, a move was first made by the Board of Trade advising an inquiry respecting the health of employees engaged in the metalliferous mining industry in the State of New South Wales. At the end of that year, a recommendation was made to the State Government by the Board of Trade that a Techni.cal Commission of Inquiry be appointed to examine and report upon the dust conditions of the metalliferous mines at Broken Hill. Following this a second report presented in 1919 made specific recommendations in respect to the scope of such a Commission. A Technical Commission of Inquiry was accordingly appointed and arrived in Broken Hill to inquire into the prevalence of miner's phthisis and pneumonoconiosis in the mines. Early in March, 1920, the examination of all mine employees commenced, and the work was completed in June, 1920. The full report of the activities of the Commission and the conclusions arrived at was officially published at a later date. Based on the recommendations...

Jan 1, 1940

In the Ora Banda area of the Eastern Gold- fields, the ultramafic rocks tend to be more deeply lateritized than most of the surrounding rock types, and lateritic nickel concentrations have been formed. Extensive drilling_has shown that, of the two intermixed suites be- neath the laterite - an extrusive peridotite- pyroxenite suite and an intrusive, highly magnetic dunite - the latter weathers to a more nickel enriched laterite. The top horizon I of the laterite consists of ferricrete. Horizon II consists mainly of bands of secondary silica in a clay matrix, formed in the reworking zone around the water table and stranded as the weathering profile migrated downwards. Horizon III ('ºaprolite") is composed of serpentinite, magnesite, iron oxides and silica, and grades dowil to the fresh bock composed variously of olivine, ser- pentine, talc, amphibole-chlorite and iron oxides. The main locus of nickel deposition is the zone containing the bottom of horizon II and the top of horizon III. The water table is also at this general level. .

Jan 1, 1973

Design of underground extraction layouts to protect surface improvements is an important area of subsidence research in the Coal Mining Engineering Branch of the Department of Mineral Resources, New South Wales, Australia. Some conventional partial extraction layout are important with reference to coal recovery and surface subsidence. The analysis ofsubsidence data collected from field surveys over longwall panels in the Southern Coalfield of New South Wales allows assessment of the effect of pillars left unmined between the longwall panels in reducing surface subsidence. The availability ofa wide variety of layouts with ranging degrees of surface movements affords considerable flexibility in designing layouts to suit a particular situation.Total extraction of coal should be the aim as far as possible. Partial extraction layouts should only be considered when surface subsidence movements caused by total extraction are not acceptable to the surface improvements.

Jan 1, 1985