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Carbonation of reinforced concrete is a potential durability issue for vehicular tunnels. This is particularly the case where elevated carbon dioxide concentrations exist and when the design life is 100 years or more. The process of carbonation can result in loss of passive protection to embedded steel reinforcement and initiation of corrosion. Therefore, tunnel design needs to consider the potential for carbonation on internal surfaces and how design life can be achieved in severe environments. This paper examines methods for predicting carbonation and how deterioration can be mitigated through appropriate concrete mix design and construction practices.

Jan 1, 2008

By E House, V Lisitsin

Recent whole-rock geochemical data from nearly 900 fresh drill core and underground samples taken from seven central Victorian gold deposits confirm the presence of distinct and identifiable primary alteration haloes surrounding the deposits. Ferroan carbonate alteration extends for up to several hundred metres away from turbidite-hosted gold mineralisation outside of contact metamorphic aureoles. A less distinct phyllic alteration zone can be identified using geochemical molar ratios or short wave infrared analysis. It generally overlaps a sulfidic halo characterised by disseminated pyrite and in close proximity to mineralised structures, arsenopyrite. The extent of the sulfidic halo can be traced using low-level analysis of pathfinder elements such as S, Au, As and Sb. Recognition of these alteration features enlarges the target for exploration and provides a tool by which drilling can be directed towards mineralised structures. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Grace NC, Lightfoot BW

Small scale trials of the smelting of a copper concentrate in the Sirosmelt submerged lance reactor are described. Pellets of concentrate were dropped into the reactor while injecting air-rich mixtures of oil and air through a lance into a bath of matte overlain by slag. This produced a discardable slag and a matte which was converted in sequential stages in the same reactor to white metal and blister copper. Difficulties were encountered in determining the end points of the converting stages but control techniques were developed to allow successful operations producing blister copper. Deportments of minor constituents of the concentrate to slag, matte,metal and fume for the three stages are reported and possible applications are Discussed.

Jan 1, 1980

By S C. Dominy

The Minerals Education Australia program is offering a tertiary learning environment for the global mining industry. The Minerals Council of Australia has instigated this initiative, which is run by the Minerals Tertiary Education Council. The program is a pioneering partnership between the Australian minerals industry, Australian governments and key Australian universities. It is designed to deliver key undergraduate and postgraduate courses for tomorrowÆs minerals industry professionals in the fields of geoscience, mining and minerals engineering and metallurgy. The flagship course for geoscience professionals is the G3 Masters program. This is a coursework-based degree supported by the Minerals Tertiary Education Council, and a partnership between James Cook University, the University of Tasmania and the University of Western Australia. These partners represent the leading-edge providers of minerals geoscience education and R&D in Australia. The G3 program provides the full spectrum of post-graduate training skills in exploration, mining and economic geology topics.

Jan 1, 2003

By Mahoney M

For gas content analysis in recent years, it has been standard procedure to report results on a 'dry ash free' (daf) basis, under the assumption that gas only adsorbs onto coaly material. In order to test the relationship between ash and sas content, samples of various rock types were taken from two drillholes in the Newcastle Coalfield. The results of this study confirmed the correlation between gas content and ash, providing an accurate means of relating gas contents for all carbonaceous rock types.

Jan 1, 1995

Knelson concentrators are commonly used to recover fine liberated gold in gold processing plants. The decision to employ a gravity gold circuit consisting of centrifugal devices such as Knelsons is primarily taken on the results of GRG tests, among other considerations. While the GRG test is considered a material characterisation test, which is useful in the design stages, its use in evaluating the performance of an existing unit is questionable. The problem is exacerbated by the fact that it is time consuming and costly. This paper examines the validity of the GRG test for performance evaluation and discusses alternative test work that can be performed to evaluate the performance characteristics of an operating machine. Principles that are useful in selecting optimal operating parameters, such as optimal fluidising water flow rate for a given ore/machine combination, are also discussed and illustrated with laboratory and plant data.

Jan 1, 2007

By Hall T. P, Taylor R. N

Fluid flow in a 1:14 scale water model of the shaft and settler of the Kalgoorlie Nickel flash smelter has been investigated by flow visualisation and numerical modelling. Detailed flow fields through the reaction shaft, settling chamber and uptake are presented for flow rates up to 800 Vm and a number of burner configurations. The predicted flow fields were compared with experimental data obtained from streak photographs and video recordings. The effects of cessation of flow through individual burners and changes in shaft dimensions were also Investigated.

Jan 1, 1992

By R Lovel, P Fung, J Manuel, M OÆCo

The iron blast furnace is the most widely used and efficient producer of liquid iron. The integrated steel works is however under environmental pressure largely due to emissions from sintering and coking. The combustion of coke breeze during sintering contributes to greenhouse gases (eg carbon dioxide) and is the source of much of the emissions of SOx and NOx. Coke breeze, the fines produced during coking of coal, is also suffering supply issues as coke demand increases while coking capacity is constrained by environmental concerns.CSIRO Minerals has been investigating the use of wood biomass/char as a substitute for coke during sintering. Wood biomass, or char produced from it, is an attractive carbon source as carbon dioxide can be sequestered into growing biomass prior to combustion. It has great potential to reduce the emissions from integrated steelworks and improve their environmental acceptability. Harvested biomass/char is also a renewable and sustainable resource. Samples of pine wood flour, sawdust and red gum wood char were characterised and used in small-scale granulation and sintering tests. Red gum char granulated as well as coke and could be used to make acceptable sinter. Large-scale sinter pot test were conducted with char to produce sufficient sinter for ISO quality tests and calculate sintering performance parameters. Results showed that coke could be completely substituted by red gum char during sintering without loss of quality and with actual improvements in sintering performance. Furthermore, gas analyses made during sintering showed that there were significant reductions in SOx and NOx when char was substituted for coke. It is anticipated that the results reported here, although preliminary, will stimulate an increased effort into further research on the use of char in iron ore sintering.

Jan 1, 2004

Instantaneous outbursts have occurred at Metropolitan Colliery from the pick and shovel work of early days to the modern mining techniques of today. Developments have been the introduction of an emission index to measure the proneness of the coal to outbursts, drainage and destressing by large diameter holes, attempts at higher productivity by the introduction of pulsed infusion shotfiring and improvements in ventilation. The future plans and aims for the Colliery include prediction of outbursts, seam gas pre- drainage and longwall mining.

Jan 1, 1980

By E Werner, B R. Leavitt

The chemistry of acidic mine drainage discharging from flooded coal mines is commonly reported to improve with time after flooding. This investigation describes a 18-year dataset of post-flooding water chemistry for a below-drainage underground coal mine within the northern Pittsburgh coal basin (Pennsylvania, USA). The Montour mine is a 5650-hectare below-drainage coal mine of maximum 260 metres depth. Montour was closed in 1980 and flooded to within 38 metres of land surface within 4.8 years. Pumping averaging 210 L/s was then employed to maintain water levels at this elevation. The flooded proportion of the mine (by volume) at full flooding was 56 per cent. The shaft where water was pumped from Montour for water control is located about 70 per cent of the distance between the mine water table and the back of the mine ù that is, it is close to the back of the mine. The residence time (total water volume at flooding divided by pumping rate for control) is estimated at 5.6 years. Time series of chemical analyses show three phases of chemical behavior in post-flooding discharge. In Phase I (zero to two years after flooding), iron concentrations were high and reached their maximum (1100 mg/L). In Phase II (two to four years after flooding), a transition was begun to alkaline conditions, with decline in iron and other solutes. In Phase III (>4 years), net alkaline conditions began, with iron concentrations declining exponentially to 50 per cent of mined volume. This attainment of net alkalinity in this case may have also depended on abundant calcite in overburden extended up to 30 m above the mine floor.

Jan 1, 2003

By A Sellgren, M R. Carstens, R Visintainer

There is a wide variety of industrial pastes or non-settling slurries pumped in mining, dredging and reclamation projects as products, refuse and tails. The types and/or names of some of the common ones are alumina red mud, phosphate clays, tar sands mature fine tails, tar sands (CT) consolidated clays and fly ash. The pipeline performance or friction of these varies dramatically with the type, its concentration and the particulars of the actual slurry making it difficult to select pumping equipment and to design associated pipelines. The GIW Hydraulic Laboratory in Grovetown Georgia has tested a number of these slurries over the last 30 years for various mining customers. Where available in the public domain and/or where permission has been obtained, the results of those tests are presented in this paper in a form usable for pipeline and pump system designers and users.

Jan 1, 2005

The problem of spontaneous combustion has long exercised the minds of Mining Engineers. The idea of inertising an area with a non combustible gas has seemed to be an attractive way to overcome the problem. Various agents have been tried but nitrogen has particular attractions and advantages. Britain adopted the idea from the German industry and found that it was particularly suitable for the conditions in British Mines. Over 8 years much development work has been done and specialist equipment has been developed as the requirements came to be better identified with experience. There is a continuing programme of innovation and the technique can be further developed in the future as a means of protecting the very heavy investments which are being made in today's large capacity, heavily capitalised faces.

Jan 1, 1988

Geophysics is playing an increasingly important role in the exploration industry. In the soft rock scene the application of seismic techniques is basically mandatory prior to any drilling program. Simply, this is because, in a majority of situations, the seismic method is ideally suited to mapping accurately relatively flat lying strata and displaying structures that may host oil or gas. It is worth stressing that seismic methods do not delineate oil or gas but they map well in two or three dimensions. In the base metal arena, geophysical methods used are generally focussed on direct detection methods with the mapping application not often used except in potential fields (magnetics and gravity). The success rate in the last decade has not been good but this does not only apply to the application of geophysics; it really applies across the board of exploration techniques. Both geological and geochemical exploration have not had a success rate commensurate with the funds injected. Basically in the last ten years we have failed as explorers! As explorers we have been negligent in mapping. As geoscientists we have let the basic mapping and observation skills diminish û the old adage æboots on the groundÆ is still applicable but are we doing enough of it? The answer is clearly no. As explorers the huge burden of bureaucracy, eg Government Acts û local, state and federal, safety compliance, environmental compliance, etc has reduced the ægeologicalÆ time dramatically. This has culminated in an over-reliance on quick fix solutions, eg spot the bump geophysics or geochemistry. This obviously simplistic scenario is arguable but there is no doubt in the geoscientific areas we have failed in the last decade to provide adequate geoscientific maps to assist in exploration. This failure could partially be responsible for the current demise of the industry resulting in a reduction in exploration dollars and, hence, people. This trend is seen acutely in the geophysical area where the head count in comparison with the geological fraternity is low. Other trends during this downturn are inevitable as explorers maximise the use of the dollar in exploration and diminish spending on advances in geophysics. Improvements are being seen however in geophysical equipment, although it is considered that the main improvement will be in the interpretation of data. Specifically, the trend will be towards integrating geophysical data into geological, geochemical and spatial data sets producing quality interpretation and providing low risk drill targets. Examples of the current trends in hardware and future directions are discussed below. In interpretive schemes there are very few examples of integrated interpretation but the possible trends will be discussed with limited examples.

Jan 1, 2000

By Chia A. H

This paper presents an overview of the development and operation of the PT Adaro Indonesia coal mining project. This operation is an initial two million tonne per annum mine, located in South Kalimantan, Indonesia.The paper places emphasis on some of the more unique infrastructure development and operational challenges that exist in such a remote location environment.A brief summary is also given of the Indonesian coal industry, its direction and position as a significant coal producing competitor for Australia.

Jan 1, 1992

Most of the gold reef mined today in South Africa is approximately 1 m in width with slopes about 30 m long. To prevent production interruptions it is essential that the stopes should not be blasted in sections. The shortage of experienced labour and arduous working conditions at the face dictate the need for simple blasting techniques.Hence, a pyrotechnic blasting system of sequential firing is in use at present, although research work to improve this technique is in progress.

Jan 1, 1985

By Gardner CE

Uranium occurrences and the probable Australian reserves are discussed and the recovery and processing methods used in treatment plants at Radium Hill and Port Pirie, S.A., Rum Jungle and Moline, N.T., and Mary Kathleen, Qid. are reviewed. The broad aspects of the application of nuclear power in Australia are then considered, and those factors of greatest significance are highlighted. It is these factors that are most likely to dictate the future role of nuclear generation in Australia. In commenting on private industry applications, the paper emphasises that each case must be considered on its own merits, and a warning is given that general statements can be misleading. In the long-term situation nuclear power is considered to be capable of playing a leading role and the discussion covers desalination and high load industries although short term applications appear difficult to justify. In non-power applications for nuclear energy reference is made to isotopes and the uses of nuclear devices in mining and civil engineering with a pertinent comment on safety.

Jan 1, 1970

Engineering availability of the 120/200 tonne Wabco haulpak fleet at Mt. Whaleback was in the mid fifties and unstable. The project to achieve a reliable 66% during 1980 highlighted "plannable" maintenance, short cycle scheduling, condition monitoring, backlog control, and, above all, the importance of involving all affected people. It is not sufficient for consultants to design systems and make them work. The people who use the system must understand it, support it and "own" it. In this way, they will develop it and improve results after the outside help has been withdrawn INTRODUCTION In early 1979, PA proposed a programme to improve engineering availability of the Mt. Newman Mining fleet of 70 Wabco haulpak trucks of which 53 were 120 tonne and 17 were 200 tonne units. (Subsequently five 200 tonne trucks from Hamersley Iron were added to the fleet). The ore truck workshop was also responsible for 75 tonne trucks used as water trucks and general purpose vehicles. The need for action was clear. The fleet was achieving availability in the "mid fifties" with wide variations indicating that the fleet was becoming unreliable. Projected tonnages required a reliable 66% availability to be

Jan 1, 1982

The value of water is defined by its marginal utility. Challenges arise where the marginal utility is difficult to estimate. Therefore, when two or more interested parties wish to access water and they cannot use commensurate units for marginal utility; other means of value comparison must be sought. It is asserted here that sustainability principles can be used to guide this valuation if this is supported by a transparent decision framework. This paper proposes that the ICMM sustainable development principles provide appropriate guidance. In addition, a generic framework for decision making is suggested as a complement. Indicators of water management are recognised widely as an integral part of the accountability of minerals companies towards meeting sustainability goals. Less widely recognised are the ways in which sustainability principles can be used to guide decisions on water management which demonstrate growing awareness of its value. This paper illustrates the use of this logic in water issues associated with global sustainability challenges. It then goes on to demonstrate, using examples, that these links exist at all levels of the minerals industry and that indicators of this type are potentially as powerful as those currently being used. The reason for this is that the path from cause to effect is transparent and direct.

Jan 1, 2006

By Lindner E, Bosio M

South Australian coals are all low in rank and generally poor in quality, with difficult combustion characteristics. This circumstance makes the selection of a fuel source for future power generation difficult, requiring careful study and detailed analysis of the various alternatives. Combustion characteristics can have a significant effect on plant design and costs, and need early attention in any exploration and evaluation programme. The physical location of the deposits, often remote from established infrastructure and centres of population, is also a major factor in the ultimate cost of power at the poirl use.

Jan 1, 1977

By K Guilfoyle, A Robertson

In the mid-1970s, trucking ore from 400 m depth to the surface was perceived to be the practical and economic limit for metalliferous underground mines. Improvements in truck design and decline development resulted in the economic depth of haul exceeding 600 m by the mid-1990s. Today, mine operators and contractors are planning to use trucks for ore haulage from depths in excess of 1000 m. The authors of this paper estimate that there are in excess of 300 diesel-powered trucks operating in mines in Australia, and that by the year 2005 more than five per cent of these trucks will be æroad trainsÆ (ie trucks towing powered trailers or truck-trailer combinations). This paper examines the road train concept, presents cost and performance data and describes the advantages and disadvantages of the road train system as well as proposing the types of applications for use of road trains in Australian metalliferous underground mines. Truck performance is based on payload and average speed (expressed as tonnes x kilometres per engine hour (t km/h)). A road train with a powered trailer has a large payload capacity and two engines to provide a high ratio of power to gross weight. Thus it is possible to exceed 300 t km/h per cycle for an average haulage gradient of 1:9 compared to 250 t km/h for conventional articulated dump trucks (ADTs). It is likely that road trains in excess of 100 t capacity will have application for level ore haulage at large mines in Australia.

Jan 1, 2002