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By E P. Nelson, R Gutierrez, P W. Layer

The San JosT district in Patagonia comprises a number of epithermal precious metal quartz veins hosted by a Mesozoic volcanic sequence. New radiometric data indicates that upper Jurassic volcanism was closely followed by vein mineralisation in the lower Cretaceous. A structural model is discussed for the district at times of mineralization that may also apply on a regional scale and other mineralised districts in Patagonia. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By R Mackay, J Brereton

On 30 June 2020, the Mine Land Rehabilitation Authority (the Authority) superseded the Latrobe Valley Mine Rehabilitation Commissioner as the independent overseer of Victoria’s declared mine rehabilitation. Currently, only the Latrobe Valley’s three brown coalmines are declared, with each mine at a different stage of rehabilitation and closure planning: Hazelwood ceased mining in 2017, Yallourn is scheduled to end mining in 2028 and Loy Yang in 2035. The three declared mines are very large, close together (Figure 1) and present significant environmental risks that must be mitigated during rehabilitation and post closure. In addition to fire risks, the brown coalmines are inherently unstable and require continuous monitoring and management of ground movements and groundwater pressures. Since 2007 several damaging events have occurred, highlighting the difficulties of achieving long-term stability, even with good landform design and rigorous ground control management plans

Aug 2, 2023

By V Lickfold, A J. Crawford, A J. Wilson

A total of 12 alkalic porphyry centres of Late Ordovician age have been discovered in two mineral districts within NSW. The alkalic porphyry deposits are hosted within shoshonitic volcanic centres that formed where a major cross-arc basement structure (the Lachlan Transverse Zone) cut the Ordovician Macquarie Arc. The Macquarie Arc was amalgamated with the back-arc basin sediments of the Wagga Marginal Basin and with the proto-Pacific margin of Gondwanaland to form the Lachlan Fold Belt after the cessation of arc magmatism in the Late Ordovician. Within the Ordovician volcanic belts of NSW, the alkalic porphyries are the most significant mineral deposits economically. The combined resource of the Cadia district porphyries (729 Mt @ 0.79 g/t Au and 0.30 per cent Cu) makes Cadia the worldÆs seventh largest known porphyry gold system and the largest known gold resource in an alkalic porphyry system (574 t Au). Hydrothermal alteration in the alkalic porphyries comprises a complex sequence of potassic, calc-potassic, sodic, calc-sodic, propylitic and late-stage, typically fault-controlled phyllic assemblages. Hematite dusting is common in many of these alteration assemblages, giving the intrusions and the altered volcano-sedimentary host sequences a distinctive pink-orange colouration. Intensely developed hydrothermal alteration assemblages are localised to within a few hundred metres of the composite intrusions that sourced the mineralising fluids, making these deposits difficult exploration targets. Sulfides are typically zoned, with several of the deposits having bornite-rich cores, chalcopyrite-dominant annuluses and pyritic outer haloes. Gold is well correlated with bornite in most of the deposits, and with chalcopyrite at Cadia Hill.

Jan 1, 2002

By I Mason, M van de Werken, B Zhou, J Hargreaves, W Stasinowsky

A critical step in open cut coal mining is clean removal of the overburden. This is usually achieved by drilling, blasting and digging. A key part of this process being successful is to stop drilling at the correct blast ‘stand-off distance’. The stand-off distance is the distance between the base of the drilled blasthole and the top of the coal horizon to be mined. Having this correct provides a protective cap of rock above the coal horizon so that the blast will fracture all the overburden without damaging the coal horizon or mixing it with the overburden. Drilling beyond the correct stand-off distance causes the blast to continue into the coal horizon, damaging it and mixing it with the overburden, leading to significant losses of coal product. Conversely, drilling short of the correct stand-off distance results in additional work to remove the intact overburden.

Sep 1, 2024

By G Chitumbura

Raise boring is a critical aspect of mining at Xstrata Copper’s Mount Isa Copper Operations (MICO). MICO’s internal raise boring department regularly develops ventilation rises, orepasses and stope cut-off rises and reams approximately 2500 m per annum. Developed, trialled and implemented as standard practice over the past two years, procedural changes in constructing the raise bore machine’s foundations have significantly reduced operator exposure to raise boring’s inherent risks of working around open holes and manual handling. An additional cost benefit of this newly-adopted procedure is derived from reducing the likelihood of damaging the machine while de-rigging.When conforming to standard industry raise boring practices, exposure to an open hole begins when the reamer breaks through the concrete pad and ends when it is removed from the hole – a process which, depending on the size of the hole and the raise boring machine, can take up to three days to complete. Although wearing fall restraint equipment, operators working on and around the raise bore machine during de-rigging are continually exposed to the risk of falling from heights. In contrast, MICO’s newly-developed and successfully-implemented presink raise boring system reduces this exposure to a maximum of four hours, regardless of hole size. Exposure to manual handling hazards is also substantially reduced as the presink procedure eliminates manual placement of a 100 kg drill bit under the machine to commence pilot-hole drilling. Outcomes of implementing the presink System at MICO have been so beneficial that it is now standard procedure for all reaming in excess of 1 m diameters.

Mar 21, 2011

The Drake-Rivertree area lies in the far north east of the New England district of New South Wales. Drake is some 500 miles north of Sydney by road and 36 miles west of Lismore. Rivertree is situated 24 miles north of Drake.The Drake deposits were first worked in 1878 for gold which occurred in a very fine state in ferruginous gossan but at depth copper ore became more significant. The lodes at Rivertree, discovered in 1887, were worked for silver but mixed sulphides became more prominent in deeper levels.Several mines operated at each centre and each locality smelted its own ore.The mines at both centres were operated sporadically for many years though production was not particularly substantial.A number of the larger mining companies have shown a recent interest in this mining field with special emphasis on the Drake locality.GENERAL GEOLOGYThe two mining centres are situated to the north and south respectively of a belt of Permian marine sediments and volcanics similar to, and probably representing an easterly extension of, the rocks of the Emmaville district further west.E. C. Andrews (1907) recognized two stratigraphic units within what he called the Drake Series. The Lower Division consists of rhyolite flows, tuft's, breccias and agglomerates, followed by trachytic and andesitic tuft's containing cladochonns, thanmopora willcinsoni and other Permian forms.

Jan 1, 1962

By Gregg PEH, Stewart RB

Reclamation field trials commenced in 1985, two years before the granting of the Mining Licence. The level of pasture production on varying soil depths (0 cm, 5 cm, 15 cm and 25 cm) overlying both tailings and oxidised waste overburden was assessed. After seven years, the rate of increase of N, C, P and S, losses of S and P and pH changes were investigated on the plots where grass seed was sown into bare tailings. It was determined that on these plots it would take approximately 24 years to reach the original carbon and nitrogen levels at the mine site.

Jan 1, 1995

In the sixteenth century the Spanish Captain da Alvaro Soavedaro, on a search for the explorer Ferdinand Magellan, came across the main island of New Guinea which he named Isla del Oro (Island of Gold). Since that time exploration for, and mining of, gold has been pursued by many, culminating in . the development of major world-class projects in the latter part of the 20th century. Though various prospectors have panned for gold and small gold mining projects were undertaken through the seventeenth and eighteenth centuries, it was not until the 1880's when mining became a more concerted economic venture. Misima and Woodlark Islands in Milne Bay, Gura-Ackera and Yoada in Oro, and Lakekamu in Gulf Province and Keveri in Central Province were all gold producers by late nineteenth century. It was in the 1920's that corporations began mining in PNG and with the commencement of production at Panguna in Bougainville in 1972 a new era of mega-project mining began.' Today there are two large mining projects producing mainly gold and copper. The first, already mentioned, is Panguna on Bougainville Island. This project has provided Government with $US 475 million in taxes. ok Tedi is the second large mine development located in Western Province. It began production in 1984 with the extraction of the deposit's "gold Cap".

Jan 1, 1987

By ZáWang, F Hungerford, T Ren

Operations in an underground drill site have to co-exist within the mineÆs ventilation and operational system. The space requirements of a drilling operation have to be adapted to the limitations provided in available site space, which is usually defined by standard mining operations and geotechnical influences. These limitations affect borehole design, equipment positioning in the site layout and possible interactions with mining equipment and services such as water and power supply.The ventilation requirements for drill sites and the means employed vary with depth of the site, space and likely presence of gas. All drilling operations provide a particular service for the mine and in each case, drilling must operate in a manner which controls all gas, water and cuttings returning from the borehole. The various standpiping systems employed have evolved under differing influences and must cater for conditions during and after the drilling operations.The influences that gas content, pressure and flow, rib stability, cleat direction, borehole length, potential water pressure and flow have on a mineÆs operation and ventilation systems have to be considered in the design of standpipe length, diameter and fittings. Past history has a strong influence on common practice while worst case effects of a possible in-hole event should be catered for.This paper describes the early drilling systems and their limitations in ventilation and gas management. The drill site dimensions and set-up are discussed in the context of roadway conditions, equipment layout, ventilation and logistics. The use of standpiping to control all returns from the borehole is illustrated by referring to likely scenarios in a drilling site to achieve the most effective sealed depth to accommodate the worst case possibility of intersecting high pressure gas or water during the drilling operation. Practices to allow gas drainage in the return airway of a panel are described.CITATION:Hungerford, F, Ren, T and Wang, Z, 2013. operational management of underground in-seam drilling sites, in Proceedings The Australian Mine Ventilation Conference , pp 43-48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 1, 2013

The following is a discussion of a new approach to safety when developing or applying a new mining technology. In the form of an engineering process, the following approach had its inception in the military and aviation industries and is also very strongly evident in the chemical industry.The process has been developed and applied in the mining industry by the author. It is called 'Incremental Development and Management of New Technology'.The process is a composite of carefully selected System Safety Management, System Engineering and Financial techniques and methods. It consists of modules which can be modified to suit the requirements of a specific project. Modules provide an organised framework of activities to facilitate a gradual acquisition of pertinent knowledge and information and to enable progressive evaluation or verification of produced outcomes against specified requirements.

Jan 1, 1992

Strong markets for metals and energy over the past five years have supported equity and debt market funding to enable a new group of mining juniors to emerge in control of economic resources, some in regions with high investment risk. As companies drive these projects to development, production and positive operating cash flow, their Boards and CEOs are confronting important questions:Having achieved initial success, what is our longer term purpose as a company? Does the purpose originally described in the Initial Public Offering to raise equity remain wholly relevant? Given that purpose, how do we understand the available sets of opportunities and related risks? Should we be acquiring new assets or other companies, or developing the existing portfolio? What commodity sectors and geographies should we focus on? Or should we be conserving funds until asset prices or project costs provide greater assurance of value to shareholders? How do we translate that purpose into tangible goals that shape and direct the work of people in the organisation? How do we get the right work done in the face of high turnover and competition for capable staff? Drawing on the authorÆs career experience and on work undertaken by Heuris Partners, this paper provides a practical CEO framework for strategy development, organisation design and on planning the work of the business in the mining industry.

Jan 1, 2006

By J Bohm, B Csoke, I Tarjan

In process technology, especially in coal preparation, it is often necessary to have a continuous knowledge of the average density of granular material in order to achieve both quality control and process control. The paper presents a new method and means supported by laboratory measurements for the rapid, practically continuous, determination of the average density of continuously supplied granular material through frequent sampling.

Jan 1, 1993

By M Slight, H Lacy

In recent times, with the global mining industry’s focus on sustainable development there has been a significant focus on mine closure and rehabilitation performance and reporting through the development of the International Council on Mining Metals (ICMM), the Global Reporting Initiative and the Equator Principles. In addition, financial reporting obligations under International Financial Reporting Standards and the Sarbanes Oxley Act (2002) have also led to better understanding and improvements with industry closure performance, liability management and reporting.Under these sustainable development principles and financial reporting obligations, mining companies are required to consider mine closure planning and associated cost estimates across all life cycle phases of the mine. Internal processes have been developed within mining companies to better understand their closure liabilities and obligations and likely costs and cost estimating processes are generally developed for long-term life-of-mine (asset) planning and budgeting, financial reporting for corporate balance sheet provisioning purposes, and regulator reporting for environmental bonding and financial assurances.These days mining companies need to plan for, prepare and actually mine for closure right from the start of a project. This means that their closure and rehabilitation liabilities throughout each stage of the mine life cycle phases must be understood, planned for, managed and controlled.So how is the industry performing? Understanding of closure liabilities is improving and reflected in liability cost estimations that are recognising the likely issues to be faced at closure, but there is a way to go to ensure that the industry doesn’t add to the increasing legacy liabilities being passed onto the wider community.CITATION:Slight, M and Lacy, H, 2016. Closure liabilities – where are we at?, in Proceedings Life-of-Mine 2016 Conference , pp 28–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By Rashkovski GB

Until recently amalgamation has been the main process forextracting large gold particles from gravity concentrates obtainedduring the dressing of ores and placer gold deposits.Development of new technology for treating the gravityconcentrates was necessary because of the harmful effect ofmercury on subsequent production processes and theenvironment. The harmful effect of mercury is particularlyevident in the resin-in-pulp process that is widely applied inRussia.

Jan 1, 1993

By Saghafi A, Kelly M, Williams R. J

A two year program of research into the feasibility of long-hole drilling for improved gas emission control has been undertaken at Appin Colliery. State of the art equipment was employed involving cableless electronic surveying and down-hole motor drilling. The project involved the drilling of 1000 m long, in-seam boreholes in the Bulli seam and boreholes of similar length drilled cross measure and then in-seam along the underlying Balgownie seam. A new concept for gas drainage was defined, employing long-holes for both predrainage and post drainage.

Jan 1, 1988

By R Farana

The future challenges in mining instrumentation, mainly on future intelligent mines, are to continue providing instruments with the highest level of reliability at the lowest possible cost, and also to take advantage of technology existing in other industries and to adapt it to the mining context. New wireless instruments (smart sensors, smart actuators, smart controllers) would also be very useful, as well as instruments fully adapted to the monitoring of large movements that are observed, in both underground and open pit mines. Mining instrumentation is found to various degrees in most mines, both open pit and underground. Smart mining instruments present a certain number of aspects specific to the environment in which the instruments are installed. Namely, the instruments can be installed either for short-term or long-term purposes. The mining industry is always looking for useful instruments that can provide relevant information on ground behaviour adjacent to mining stopes or permanent infrastructure. The instruments must meet the various criteria, and must also evolve with the new mining technologies that are continuously being implemented. A strong collaboration between the mining industry, research organisations, and instrument manufacturers is the key to meeting these objectives. This contribution describes the current trends on smart sensors and smart instrumentation with Wireless LAN support.

Jan 1, 2003

Detailed cash flow forecasts have always been almost essential as a basis for judging the viability of proposed new mining projects. In recent years attempts have been made explicitly to take account, in such forecasts, of the uncertainties surrounding the assumptions upon which they are based. With the risk analysis approach, Monte Carlo simulation of the cash flows indicates in probability terms the combined effect of these uncertain basic assumptions. While the use of risk analysis has been widely discussed, few specific applications to real projects have been reported. The application of such an analysis in the feasibility study of the large new Deelkraal gold mine presently being established on the Far West Witwatersrand gold fields by the Gold Fields Group in South Africa is described in the paper. The paper also indicates how one of the major sources of uncertainty, namely the gold content of the ore, can be`quantified in objective probability terms. This feature distinguishes the application fran other published accounts in which only subjective probability assessments have been utilised.

Jan 1, 1977

Introduction The mine winder is an essential element in the mining of ore in deep level mines and therefore requires a high degree of reliability to avoid interruption of production. Failure of any component on a winder may also be dangerous and expensive to repair. The larger the failure the larger the stoppage. The failure of a winder drum is the ultimate catastrophe, not only because of the cost of replacement, but also because of the lead time in procuring a new drum. Today these types of failure are not as common but many failures have occurred in the past and even today many an old winder is con- sidered for a new and often more arduous duty. As far back as the turn of the century a lot of information had been gathered to try and clear up the complexities of the multi- layering effect of coiling rope under tension onto a drum. Before comparing results obtained by various researchers the nature of the pressure distribution between rope and drum due to multi-layering will be discussed briefly.

Jan 1, 1987

In Australia, current production of rare earth element (REE) minerals, monazite and xenotime, occurs as by-product from titanium-enriched placers and beach sands. Undeveloped REE resources are associated with carbonatites, alkaline igneous rocks, pegmatites, phosphorites, cemented fluvial sandstones, and uranium mineralisations. The REE are held within a range of minerals including silicates, phosphates, a1uminophosphates, carbonates, and oxides. The development of these REE resources may require new processing and extraction methods. The distribution of REE in the currently mined ore minerals, monazite and bastnaesite, does not match that requested by the market. Exploration for new REE resources should be focused on ores with more marketable REE distributions, particularly with heavy REE, neodymium, samarium, europium and yttrium enrichments. Such ores occur within alkaline igneous rocks, in laterites overlying carbonatites and alkaline igneous rocks, and in placers derived from low-grade regional and contact metamorphic sediments. Lateritic REE deposits may be easily and economically mined by shovel in open pits and are unlikely to require extensive crushing and milling. In addition, lateritic REE clay deposits may be processed by simple hydrometallurgicaltreatment mehtods.

Jan 1, 1991

By F Anthes, U Barow

Two tunnels are being bored using a æHydroshieldÆ in section 3.1 of the extension of the Underground railway line 5. At the end of the two tunnels, directly in front of the Hotel Adlon, the shields cannot be retrieved. The steel shell of the shield will be left in place within a sealed concrete block and the reusable components taken out through the completed tunnel. For the first time in Germany, an Underground tunnel is being lined solely by means of UNI rings. BerlinÆs Underground network is 165 km long and has 167 stations. Some 450 million passengers are transported annually. On account of the urban planning modifications that followed reunification, the network has to be adjusted, particularly in the city centre. The most significant project is the extension of the U5 from Alexanderplatz to the Lehrter Bahnhof. After completion, the U5 will be a continuous east-west traffic artery. It will provide a direct link with the new parliamentary and government district, open up new business districts and the cultural centre of the city.

Jan 1, 1999