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Naturally occurring organic plastics have been in use for over 2,000 years. Plastics based on chemically modified organic polymers date back only about 100 years, and those based on synthetic polymers about 50 years. The development of ,these two latter groups up to the present day is outlined, and the basic techniques currently available for polymer-building and modi-fication (blending, copolymerisation, quantitative and qualitative struc-tural control, and'si de-group reactions)-are reviewed.

Jan 1, 1962

The Crown Minerals Act 1991 has introduced some significant changes to the New Zealand mining industry, not the least of which relate to the ability of miners to obtain access to land to conduct mining activities. This paper briefly reviews the relevant provisions of the Crown Minerals Act dealing with access arrangements, considers some typical features of access arrangements and examines a number of areas where problems may arise.

Jan 1, 1992

By Armstrong M

The Clermont Coal Mine will export steaming coal from the Wolfang Basin in Central Queensland, Australia. It is expected to be developed in the mid-1990s.The majority of the reserves lie in the 30 m thick Wolfang Seam. Overburden depth varies from 80 m at the subcrop line to 190 m in the centre of the basin.

Jan 1, 1992

By Boyling A

United Collieries Pty Limited is an Australian mining company operating one underground coal mine, United Colliery at Warkworth in the Hunter Valley district of New South Wales. Centrally positioned, United Colliery is adjoined by other coal mining operations and is located 80km north - west of Newcastle and 20 kilometres south - west of Singleton. (Fig. 1) High standard road and rail links provide ready access to customers and suppliers.

Jan 1, 1998

Optimisation of capital in the development process is critical to the profitability of any new mining venture. The process of optimisation should apply to all aspects, that is the financing, management, revenue, reporting and, of course, the development of the project. Unfortunately, too much emphasis has been placed on the optimisation of the financing or reporting aspects and too little on the project itself. This paper addresses the latter.

Jan 1, 1991

By Holly J

Mr. Champness: I wish to congratulate the authors on their paper, which covers a large variety of subjects. Not every mine is in the fortunate position to effect cost reductions by the sinking of a new shaft, but, as the authors have endeavoured to show in their paper, with improved techniques further reductions are possible. I would like to ask two questions. Can the authors give me an approximate idea...

Jan 1, 1956

The structure and tectonic setting has had a strong influence on gold mineralisation at the Porgera gold deposit. Here, the structural controls on the mineralisation at Porgera are discussed and placed in a regional tectonic context. The Porgera gold deposit is related to the emplacement of the Porgera Intrusive Complex. Prior to intrusive emplacement at Porgera, Papua New Guinea was affected by a major fold and thrust episode which occurred in response to arc-continent collision in the Late Miocene. After crustal shortening the region experienced a relaxation of compression which is expressed in the deformation accompanying mineralisation at Porgera. The first stage of mineralisation (stage I) is hosted by extension fractures, and is spatially associated with exposed intrusive stocks. A later episode of mineralisation (stage II) is hosted by the faults and fractures of the Roamane Fault Zone, which was active as a dip-slip normal fault during stage II mineralisation. Therefore a change in the tectonic environment from shortening to extensional tectonics can be seen at Porgera before and during mineralisation. Rapid fault-slip during stage II mineralisation may have aided high-grade gold mineralisation by subjecting hydrothermal fluids to changes in pressure, temperature, fluid-fluid and fluid-rock interaction. Uplift to form the highlands of Papua New Guinea occurred after mineralisation and was largely complete by 4.0 Ma.

Jan 1, 1995

The kinetics of the hydrogen reduction of iron oxides in granular calcined bauxite were studied at 550-1,050°C in a shallow bed reactor. The iron oxides behaved as a dispersion of particulate iron oxide in a porous alumina matrix in which the iron oxide particles were reduced independently. The observed rates of reaction were found to be virtually independent of the bauxite grain size. At 800,°C and above, the reduction was multistage, Le.1. Fe203 +2Al203 (matrix) ?2FeAl204, and2. FeAl204? Fe0 +Al203.Reaction 1 was very rapid. Reaction 2 was much slower, the latter stages being controlled, at least in part, by phYSIcal changes of the Fe0 and a-Al203 produced in the reaction. Owing to the observed nature of the material, the reaction rate controlling steps could not be determined.

Jan 1, 1972

By A McKay

The Great Artesian Basin (the Basin) is a large aquifer system underlying more than 20 per cent of continental Australia and most of Queensland. The aquifers of the Basin are an important water source for many industries, including the mining sector. The Queensland Great Artesian Basin Water Resource Plan (the Plan) was released in March 2006. The Plan provides a framework for the long- term holistic management of the aquifers in the Queensland Section of the Basin, in a manner that is consistent with the strategic management plan for the Basin as a whole. The paper describes the Basin and summarises trends in the demand for water in the Queensland section of the Basin. It describes the broad framework for management of the Basin by the individual Australian states, as well as the planning entitlement framework for water resource management in Queensland. The paper discusses the content of the Plan. This includes: the division of the aquifers into management areas and management units for management purposes, provision for protection of the flow of water to springs, limits on further allocating water, provision for a competitive process for access to new water and provision for water trading. Under the Queensland planning and entitlement system a resource operations plan is prepared to specify operational arrangements to implement a water resource plan. A resource operation plan for the basin is expected to be finalised before the end of 2006. The paper summarises the likely content of the plan.

Jan 1, 2006

During the life of a mining project in Papua New Guinea (PNG), the greatest impact is on the people of the project area and the most intense, day-to-day contact is between these people and the project's field staff. Yet formal structures at present emphasise contact between much higher levels of national government and company personnel. Whilst understandable, this is unfortunate particularly since, given the nature of PNG politics, villagers do have a powerful influence on project success, as recent dramatic events on Bougainville have indicated. A greater role for local views and greater attention to such views by other parties is clearly required. But to achieve a successful marriage between informal village politics and the formal structures of investment procedures will require considerable patience and adjustment. This should be reflected in the cost of project development and be regarded as being as of a significance equal to that currently accorded to the technical aspects of project development.

Jan 1, 1990

By R Ashworth, S J. Hall

During trials which began in May 2005, traditional steel dump bodies for transporting iron ore on 220-tonne haul trucks at a Labrador iron ore mine were compared to a novel rubber suspended dump body. Loads were measured and compared over some 93 700 loads, representing more than 20 Mt transported. Maintenance costs and downtime were also measured over the course of the trial, which lasted nearly one year. This paper outlines the parameters and results of the trials. Parameters measured included payload and production improvements, carry-back reduction, downtime due to body maintenance, and wear on the floor of the suspended dump body. These parameters were then compared to those for conventional steel dump bodies in use at the mine, and conclusions were drawn. The resulting comparisons were significantly positive in favour of the new suspended dump bodies, confirming that each truck could haul an additional 41 000 tonnes per year, that downtime hours could be considerably reduced, and that body availability and service life can be extended through use of the suspended dump body. There was also a high level of operator acceptance of the suspended dump bodies due to less loading shock and a smoother ride.

Jan 1, 2007

Hong Kong continues to display a remarkable enthusiasm for undertaking ambitious tunnelling schemes despite apparent recessions in the Asian economy. This paper provides an outline of tunnel projects currently under construction, those recently tendered and a glimpse of the extent of forthcoming projects which, according to Government sources, carry a price tag of HK$ 200B. Committed works will cost about HK$ 15B and involve a variety of TBM and drill and blast tunnels. These include the recently tendered works for KCRCÆs West Rail and MTRCÆs Tseung Kwan O railway extension, together with five no retendered TBM drives for the Strategic Sewage Disposal Scheme (SSDS) following forfeiture of the works by the Campenon Bernard-Maeda JV in mid-1997. The JV claimed unreasonable specifications leading to unacceptable levels of water inflow and dangerous working conditions. Key technical issues that are now arising in Hong Kong are:the general use of design and build contracts for bored tunnel contracts;a trend to accept TBM options for relatively short drives in urban areas;the use of æfixed-priceÆ contracts which in the current competitive market, can encourage tenderers to take contractors to take very high risks; andthe difficulty of predicting and managing water inflows in rock tunnels.This paper also includes a new empirical method of predicting water inflows in rock tunnels, and makes recommendations for managing these on-site.

Jan 1, 1999

By Streichfuss M, KeBler H-W, Burgwinkel P

This paper describes the design of an expert system used as a part of a diagnostic system for diesel hydraulic drives. A PC-based diagnostic system ruDi (KeBler and Burgwinkel, 1993) was developed to minimise the time for diagnosis and repair work of vehicles with diesel hydraulic drives used in the mining industry. One part of ruDi is an expert system that helps to locate errors in any of a vehicle's subsystems, and supports technicians in removing the cause of a malfunction. Apart from the standard knowledge of diesel engines and hydraulic transmissions, the expert system supports the interpretation of the data obtained during sophisticated engine analysis tests such as high-resolution speed analysis or high-pressure analysis of the diesel injection system. The expert system is designed to diagnose various vehicles of the same type. Data for each vehicle is stored separately allowing checks to be carried out individually for each machine. An additional feature of this system is a database interface to a Maintenance Planning and Control System (MPCS) that allows an automatic generation of work orders for the defects found during the expert system sessions.

Jan 1, 1995

By R C. Schodde

The future of any mining company depends on maintaining and growing its access to high-quality mineral resources. Often the true size of a given resource is not fully recognised until after mining has commenced. Also, the strong desire to increase production puts pressure to expand the resource base of the mine to get maximum value out of the capital employed. This, plus diminishing M&A opportunities and declining world-class greenfield discovery rates, makes brownfields exploration a high priority activity in any operating company. For the success and long-term survival of the company it is critical that this is done well. The primary aim of brownfields exploration is to find or acquire new deposits within economic transport distance of an existing mine that will add materially to shareholder value through: mine or capacity expansion, displacement of lower-margin ore from the mine plan, preserving and extending the mine life, and ensuring potential value is understood in order to maximise potential future mine development or exit. A number of strategic principles are important in any program designed to achieve these aims: understanding the life of mine (LOM) production profile and the related key drivers for exploration, understanding the dynamic nature of the brownfields search space, understanding and measuring depletion of the brownfields search space, understanding the potential of the near-mine region, investing in exploration technology to expand the search space, and investing in a basic geological understanding of the ore-environment. Examination of the LOM profile will highlight critical issues facing development plans for the mine including future grade and throughput issues, key technology requirements or innovations and scenarios for increased production. Exploration targets in the brownfields program should address these key issues. Often it is as æsimpleÆ as keeping mine development sufficiently far ahead of extraction to allow time for the various phases of exploration and resource assessment drilling. Because of the low additional capital costs required, expansion of the brownfields search space is strongly leveraged to: metal prices, development of new markets, incremental operating cost reductions, strategic changes in downstream requirements in integrated businesses, depletion of higher unit-value ores, and new technologies (both extraction and exploration). Therefore the brownfields search space is likely to incrementally expand through time and must be regularly reviewed. This is also important as any given search space will be progressively exhausted, resulting in smaller and higher cost discoveries. It is therefore important to monitor and critically review sustained trends of increasing brownfields discovery cost. The first wave of discoveries in any camp are usually empirically driven and do not need a strong geological understanding. However, an improved geological understanding is critical to making the next generation of hidden discoveries. To illustrate these points, a case study was carried out on the exploration and development history of the Kambalda nickel camp. Over a period of 40 years, more than 40 deposits were found containing over 1.7 million tonnes of nickel metal. Efficient mines need to maintain reserves for operating flexibility. Consequently, the company needs to clearly understand the global resource in order to maximise its full potential. In addition, understanding the full brownfields potential earlier in the development of a deposit rather than later, creates optionality through the flexibility that this understanding brings to future development choices. To ensure best practice in attaining this aim, the roles and responsibilities of the exploration team and the mine operation should be clearly understood. It is important for the explorers and the operators to have shared views about what needs to be done. Typically, mine operators would be accountable for identifying future resource requirements to support the life-of-mine production schedule whilst explorers would be accountable to ensure best-practice assessment of brownfields exploration opportunities. This would include an assessment of the global undiscovered endowment in the regional near-mine area. The balance between brownfield exploration drilling and resources to reserve conversion will need to be decided to ensure efficient operations are maintained. Both need to agree the optimum level of brownfields funding taking into account: urgency to replace or grow reserves, and quality of opportunities (relative to those elsewhere). The ultimate cost of ignoring the full brownfields potential of an operating asset can be significant, ranging from inefficient and poorly planned operations, lost opportunity cost and resultant value through under-utilised resources and, in the worst case, early exit from the asset at the bottom of the commodity cycle û leaving behind huge amounts of shareholder value.

Jan 1, 2006

By J Zeni

In 2001, the Springvale Coal Mine determined a requirement for a 360 m deep vertical airway to ventilate ongoing underground longwall mining operations. The project, referred to as the Springvale No 3 Ventilation Shaft, was completed in 2003 - 2004 by blind boring a 4.25 m diameter hole from the surface to the coal seam at 360 m depth. The shaft was completed with a 3.5 m inside diameter lining made from a continuous watertight steel and concrete composite pipe. Presented from both the clientÆs and the contractorÆs perspective, the following paper describes the process of constructing a blind bored ventilation shaft for this application. Beginning with the clientÆs definition of the requirements and specifications for the shaft, the paper describes the steps followed by Springvale Coal prior to awarding the contract. Springv aleÆs process involved a thorough site investigation including procurement of geotechnical data for prospective contractors and the management of issues relating to safety, quality and the environment. The clientÆs view is followed by a description of the planning and works performed by their nominated shaft drilling contractor, Ardent Underground Pty Ltd.The contractorÆs description of the works includes the details of the blind shaft drilling and lining construction process used for this application. The design of the shaft lining installed at Springvale Coal was the first of its type to be used in Australia. The successful installation of a watertight composite shaft lining and the safety of the method, which did not require any personnel to enter the shaft or the mine, were among the positive outcomes from the project.

Jan 1, 2005

By B Petrie, D J. MacKenzie

The Macraes mine is producing 175 000 ounces Au/year from a mesothermal deposit with total resource of at least five million ounces. The deposit is hosted in greenschist facies Otago Schist, a widespread Mesozoic metasedimentary sequence that forms the basement of the South Island of New Zealand. Mineralisation was controlled by a late metamorphic shear zone which had both brittle and ductile structures accompanying mineralisation. The shear zone dips shallowly (about 15¦), subparallel to the shallow-dipping regional foliation, and mineralization occurred during southwesterly-directed thrust motion. Mineralisation occurred under greenschist facies conditions (about 350¦C) during uplift of the Otago Schist in the late Jurassic. No syn- or late-metamorphic igneous bodies occur within the schist belt. The hosting shear zone is up to 120 m thick, and is traceable for more than 30 km along strike. The shear zone is truncated by an underlying low angle normal fault that juxtaposes mineralised lower greenschist facies rocks on to unmineralised upper greenschist facies rocks.

Jan 1, 2004

By Dickin FJ

Advances in the development and application of in situ imaging of mineral processing operations using electrical tomography techniques are reviewed and illustrated with case studies relating to pneumatic conveying, mixing and centrifugal separation processes. The potential for applying these methods to full three-dimensional visualisation of the dynamic behaviour of flow in pipelines and separators, and the resulting consequences for process-modelling strategies, are discussed.

Jan 1, 1993

By Cortes JP

In a dynamic environment such as the Star Mountains of Papua New Guinea Geotechnical Engineering for the Ok Tedi Project must be described as both interesting and challenging. To be effective a reasonable sized team of dedicated people is required with occasional supplementation by specialist consultants and an annual review process. Ok Tedi Mining Limited's (OTML) Geotechnical Section has a vision to be recognised as the leading mine-based geotechnical engineering section in PNG and to be world class by any international standards. This paper deals with the organisational and operational duties of the Geotechnical Section at the Ok Tedi Mine. One of our major roles is in the area of safety, and in particular in the early warning of natural and mining induced geological hazards that may affect safety and/or productivity. The major activities in- clude geotechnical inspections (pit, waste dumps, tunnels, re- gional), data collection activities and database management, geotechnical design and control work.

Jan 1, 1997

By Nowell SB, Cottrill DA

Host-rock - wallrock major and trace element geochemistry associated with epithermal gold mineralisation in the Hauraki Goldfield of New Zealand is poorly documented, even though rock geochemistry is a recognised tool in exploration. Such responses assist in recognition of the regional scale imprint of fossil hydrothermal activity, and indicate targets for detailed evaluation within these alteration zones.Recent investigation of gold deposits in the Waihi (Gladstone), Golden Cross (Empire), Thames (Waiotahi) and Coromandel (Tokatea) areas indicate enrichments of Au, As and Sb in the andesitic wallrocks hosting mineralisation. Of the other elements examined, Si, K and Rb are enriched, and Na, Ca, and Sr are depleted at all deposits. These trends are best developed in the vicinity of veining. In deposits with clay alteration dominating (Waiotahi and Tokatea) there is also depletion of Mg, Mn, Zn and Cu. Ba and Cr are variably enriched or depleted within different styles of alteration. Base-metal enrichment in the wallrocks is not a feature of Hauraki deposits.

Jan 1, 1990

By Pyrih R, House A, Shangraw J, Silva AJ

Sunbeam Mining -Corporation has the inten mine with heap leach gold recovery, near spent ore indicated a relatively high ar topographical configuration, the spent across a small drainage and a lake. Du permit for spent ore disposal from th agencies, concerns about the potential contamination by the arsenic were expres conducted extensive studies to addre contamination. These studies consiste( geochemical and geotechnical parameters underlying the proposed disposal si geotechnical investigations were also hydrologic characteristics were include with the use of an IBM PC computer. :ion of opening an open pit gold Stanley, Idaho. Testing of the ?enic content. Due to the local ore was planned to be disposed :ing the process of obtaining a federal and state regulatory for surface and ground water .ed. Sunbeam Mining Corporation is the potential for arsenic of laboratory testing of both of the spent ore, and the soils te. Field hydrogeologic and -onducted. Local climatic and 1 in the analysis of these data Conclusions of studies indicated that although the seepage through the spent ore disposal would contain an elevated dissolved arsenic content, the hydrologic and geochemical characteristics of the site would prevent arsenic migration into the local ground water system. The attenuation of arsenic on soils with high clay content, and dilution after reaching the ground water table would lower the arsenic content to acceptable Concentrations.

Jan 1, 1988