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The Olympic Dam deposit is located some 600 km north of Adelaide in South Australia. It was discovered in 1975 by Western Mining Corporation and in 1979 a joint venture was formed with British Petroleum for the evaluation and development of the project. Studies were completed and construction started in 1986 with the plant being commissioned progressively between April and August of 1988. In 1993 Western Mining acquired BP's interest and are now owners of the whole deposit. The scale of the initial development was 1.5 Mtpa of ore for the production of 45 000 tpa of copper cathode, 900 tpa of uranium oxide and some gold and silver. Two expansion programs have occurred in 1992 and 1995 and current performance is at the rate of 3 Mtpa of ore for the production of 84 000 tpa of copper cathode, 1500 tpa of uranium oxide, 24 000 oz per year of confined gold and 380 000 oz per year of confined silver (Table 1). An aerial view of the plant is shown in Figure 1. The benefit of diversifying into the production of more than one product is undoubted and the flexibility of being able to produce variable quantities of copper and uranium also allows advantage to be taken of a change in market conditions.

Jan 1, 1996

On 15 August 1998 the first section of the PUTRA LRT system was opened to the public as a free service prior to official commencement of revenue service on 1 September 1998. It is a remarkable achievement to open a highly advanced medium capacity urban railway scheme in four years after the outline concept began. Even more remarkable is the implementation of the next stage which is the underground section planned to be operational in mid-1999. The decision to build the first underground railway in any major urban centre is a technical challenge. The PUTRA LRT System can be likened to Hong Kong when the initial MTR system began in the 1970s and Singapore MRT in the 1980s. Prior to the PUTRA railway very little bored tunnelling had been undertaken in Kuala Lumpur. A few shallow sewer tunnels had been built but the main experience of tunnelling in Malaysia had been for water, hydroelectric and road tunnels usually through granite formations. The ground conditions in Kuala Lumpur were known mainly from experience of piled foundations and occasional deep excavations. The suitability and likely difficulties to be experienced during bored tunnelling could only be theoretically predicted. In both Hong Kong and Singapore, government owned corporations were set up to implement the scheme, but in Kuala Lumpur the whole project has been undertaken by a private company PUTRA, a wholly owned subsidiary of Renong Berhad.

Jan 1, 1999

By Wu Y, Qu Q

The Central Coal Mining Research Institute has developed the MAE acoustic emission monitoring system, the BD4-1 portable acoustic emission monitor and the MRB rock burst monitoring system. In the MAE system there is an IBM-PLAT, a receiver and 16 channels and the investigating range is 100 m. The main functions are detecting acoustic events from the working faces, periodically making statistics, prints, displays and storing of the results, and performing the off-line process such as drawing the curves of acoustic activity. The BD4-1 instrument has four channels, it works for more than 24 hours continuously, and keeps the data for more than 30 days after power tum-off. The BD4-1 is suited to the monitoring for a long or a short time as a fixed point where the system is invalid, especially to the monitoring of the acoustic activity promoted by the blasting. There is an IBM-PC/AT, a receiver and 16 channels spread 10 km in the system MRB. The system could on-line collect microseismic events throughout the whole mine, calculate the source location and the energy, and off-line draw the seismic activity draft of time-based or distribution in space. In practice, the forecasting is successful by using the acoustic emission and microseismic monitoring system and the portable instrument.

Jan 1, 1991

By O Aydan, K Sugiura, A Sakamoto

It is well known that some sinkholes or subsidence take place from time to time in the areas where abandoned room and pillar type mines exist. The authors have been involved with the stability of abandoned mines beneath urbanized residential areas in Tokai region and there is a great concern about the stability of these abandoned mines during large earthquakes as well as in long term. The 2003 Miyagi Hokubu and 2011 Great East Japan earthquakes caused great damage to abandoned mines and resulted in many collapses. Particularly the effect of the quality of backfilling of abandoned mine below the urbanized areas is very important under static and dynamic conditions. The authors present the effect of the quality of backfilling on the ground subsidence associated with abandoned lignite mines under static and dynamic conditions and discuss its implications on the urbanized areas above abandoned lignite mines in this study. CITATION:Aydan, O, Sugiura, K and Sakamoto, A, 2018. The quality of backfilling of abandoned lignite mines on ground settlement under static and dynamic conditions, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 134–141 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By G A. Davis, D G. Laughton

The great variability of mineral and energy prices has motivated some governments to incorporate a windfall profits tax into their mineral taxation regimes. Windfall profits taxes are a means for governments to capture additional mineral revenue when mineral prices are considered higher than some historic level. Governments need to be aware of the effects of such contingent taxes on the exploration, development and operating decisions of mining companies. Mining companies need to be able to calculate the full impact of windfall profits taxes on the economics of their projects. This paper examines the valuation of a multi-phase copper-gold project in the presence of a windfall profits tax. Real options Monte Carlo simulation is used to characterise the different exposures of the mine owner and of the government to the risky cash flow streams that they receive from the project. The results highlight that Monte Carlo simulation paired with the real option valuation method is able to account appropriately for the differing risk exposures, while the traditional discounted cash flow valuation model is not. Our key conclusion for governments and mining companies is that the impact of contingent tax and royalty terms can and should be assessed using advanced valuation techniques, and the results used to improve contract designs under the constraint of actual and perceived fiscal system stability.

Jan 1, 2007

High precision GPS systems for mining are accurate to within a few centimetres. Typical systems consist of one or more GPS antenna, GPS boards, sensors to detect the position of the blade or bucket of the machine radios to pick up correction signals, a computer to control the system and a display screen to give instructions and information to the operator. GPS systems offer two benefits û they give information to the operator to get his job done faster and more accurately and they can send information to management about how the job was done. On dozers, GPS systems allow the operator to accurately complete earthmoving jobs with no survey pegs. On hydraulic excavators the systems can be used to accurately locate the position of the bucket teeth for selective mining. On blasthole drills the systems can guide the operator to each hole and record accurate as-drilled plans. By reporting the position of the blade or bucket in three dimensions it is possible to continuously upgrade a mapfile of the excavation. From this file it is then possible to report productivity numbers in real time. High precision GPS works best with a minimum of five satellites visible. This may be difficult in a pit. Systems which also access the Russian GLONASSS satellites offer significantly better uptime. GPS systems will become indispensable for efficient mining operations in the future.

Jan 1, 2003

Coal mining in the Illawarra commenced in 1848. By the early twentieth century mining operations were spread over quite a distance along the coast centred on Wollongong. By this time there were already numerous tunnel mines and one shaft mine. Coal was first reported in Illawarra by Lieutenant Flinders on a voyage of exploration, southerly along the coast from Sydney in 1796. Because of the topography, particularly the escarpment and the narrowness of the coastal plain, access from Sydney was not easy by land and the normal access was by sea. It was not until some coastal areas had been developed for agricultural purposes that the mining of the seams on the South Coast commenced for the supp- ly of fuel. The most important mines in the early nineteenth century were Bulli and Osborne Wallsend. In general, coal was won from the tunnel mines and was transported directly, usually by tramway, to the nearest shipping point. Considerable hardship attended the earliest attempts at mining coal in regard to materials for mining and the way of life of the miners in the vicinity of the mines. With the growth of production and the installation of coke ovens at some mines the area, hitherto virgin bush- land, began to take on a more industrialised appearance. The mines were necessarily small,

Jan 1, 1976

By C P. Kramers

The need to provide a sufficient quality and quantity of backfill continues to increase in South Africa, particularly as related to the increasing depth of mining. More and more applications require well designed fill systems either as classified or cemented backfill, and in some applications even tailings/aggregate based backfills. The paper discusses developments in backfill technology in South Africa with special emphasis on reliable system designs and operations, particularly as related to the preparation and hydraulic transportation aspects. Approaches for the alleviation of previous problems associated with premature pipe failures in vertical shaft columns for the distribution of tailings based backfills are discussed. Resulting from CSIRÆs developmental work, reliable full-flow systems, which can operate at low system pressures, have become a common practice, provided that backfill flowrates and internal pipe sizes are well matched. This aspect is reviewed. With regard to the tailings/aggregate based backfills the paper reviews some of the results of comprehensive in situ monitoring and the development of such systems. It is shown that a thorough understanding of the effects of aggregate top size, fines content and slurry relative density is required in order to ensure the restartability of temporarily shut-down pipelines. Some innovative technologies for the comminution of development waste underground to yield aggregate products potentially suitable or hydraulic transportation and backfilling, are briefly discussed.

Jan 1, 1998

By M J. Pascoe

The performance of 460 stope surfaces at WMC ResourcesÆ Olympic Dam Operation (ODO) has been used to investigate the confidence that can be placed in the Stability Graph Method for design of stope dimensions. A detailed database of stope performance and ground condition information was established for each stope. The database contains all the required stability graph information as well as other factors thought to influence stability, such as discrete major structures, poor shape and exposure time. The performance of each stope surface was quantified by calculating Equivalent Linear Overbreak/Slough (ELOS). The performance of stope walls and crowns was plotted on the supported and unsupported case history stability graphs. Based on this information an ODO design limit of HR = 3.3 x NÆ0.33 has been suggested for stope walls. Walls that plotted above this line were 80 per cent stable, 20 per cent unstable and zero per cent failed. Below the line 60 per cent were stable, 30 per cent unstable and ten per cent failed. Supported crowns that are flat or arched in shape and are not within the influence of major structures can be designed in the stability graphÆs æstable zoneÆ with a strong likelihood of stability. The Stability Graph Method did not reliably predict the performance of unsupported crowns at ODO.

Jan 1, 2005

By J Lane, D J. Barker, B Pei

Queensland Alumina Limited (QAL) is the worldÆs largest producer of smelter grade alumina, located in Gladstone, Queensland, Australia. The plant employs evaporative cooling towers for waste heat rejection. Process water requirements include red mud residue disposal, steam venting to the atmosphere and Calcination feed moisture. Raw (untreated) water consumption in 2001 was 37 700 m3/d or 3.8 m3 per tonne of production. The Gladstone region experienced a water shortage in the period 2001 to 2003, resulting in progressive water restrictions. Industry operated under a ten per cent restriction from April 2002 and in November 2002 a 25 per cent restriction came in force. The maximum restriction level of 50 per cent was anticipated for the middle of 2003. Water restrictions of these magnitudes have the potential to result in significant production limitations, which would have major economic consequences for QALÆs owners, customers, suppliers and employees. Therefore it was imperative that measures be found to mitigate the impact of these restrictions. Furthermore, as one of the largest water users in the Gladstone region, QAL had an obligation to the community to minimise water usage as much as possible. A thorough analysis of water usage on site was conducted, focussing on all water streams leaving the plant. The philosophy used was that by minimising water outputs, the inputs would follow suit. Where possible, preference was given to solutions that provided lasting water savings. This occurs when the value of the water saving justifies the project cost, irrespective of water restrictions. By June 2002 an average water saving of 19 per cent was achieved, almost double the required saving. By end November 2002 further projects had increased the total water saving to 29 per cent, mainly through the re-use of GladstoneÆs municipal treated effluent as wash water. Further measures to reach the target of 50 per cent reduction were investigated. The evaporative cooling system was to be replaced with seawater cooling, using cooling towers to minimise the seawater pumping cost. Another benefit of this concept was the ability to dispose of the cooling tower bleed stream with the existing system for neutralised red mud disposal. This would avoid the need for an additional environmental outfall from the plant. In February 2003 the Gladstone region received over 500 mm of rain, which boosted water reserves to five years supply at forecast usage rates. This led to the lifting of all water restriction. As most of the implemented water savings measures are economically viable in the absence of water restrictions, raw water usage at QAL is still less than 75 per cent of pre-2002 levels.

Jan 1, 2003

This paper examines the broader implications of recent and ongoing changes in mineral resource managementå and reporting practices and the impact that these might have on mining companies. It is likely that an International Reporting Code will be developed in the near future, based on a number of National codes produced in recent years. However, this is only part of the reporting story, as an International Code brings with it a range of further issues to resolve. For the Code to be effective, there needs to be international recognition and perhaps licensing of Competent Persons and an expanded base of sponsoring professional bodies. Also, in an increasingly global business, shareholders, regulators and other interested parties need to know and understand the general processes involved in resource and reserve estimation and reporting in order to recognise companies that maintain the highest standards. There is a current trend towards greater scrutiny of company performance in a range of areas under the banner of corporate governance, and many changes are happening that will place greater disclosure burdens on all companies in the future. Good corporate governance means management of company assets for the benefit of the stakeholders. For a mining company, there is no greater asset than its mineral resources and reserves and directors are just as responsible for effective management of their mineral resources as they are for financial good practice. The paper looks at the relevance of corporate governance principles to mineral resource management and the changes that this could bring to the way that companies deal with regulators, shareholders, financiers and others. Finally, increased scrutiny and further regulation inevitably means greater effort by the industry and higher costs. Despite this the author believes that there are substantial offsetting benefits to be gained by companies prepared to take the initiative in improving resource management practices and communicating these improvements to shareholders. In order to achieve the benefits however, the industry needs to fully engage in the changes that are taking place û setting its own standards and working with the regulators rather than sitting back and being legislated against. Mineral resource reporting provides a good model of how this process can work and there will be other opportunities in the coming years as the industry seeks to develop best practice in mineral resource management. The author is an employee of Rio Tinto but wishes to point out that the views expressed in this paper are his own and not necessarily those of Rio Tinto.

Jan 1, 2002

Mineral exploration and development can have a significant impact on the environment and local communities, in some circumstances extending well beyond the mine site. Poor environmental performance and consequent social impacts by some companies have affected the reputation of the whole industry to the extent that the principal public concern about mining is its impact on the environment. This is consistent with public attitudes about other major natural resource sectors such as forestry and commercial fishing. Traditionally the community has relied on governments to set the benchmark for acceptable environmental and social performance through establishing and revising regulations governing the mining industry. This however assumes that regulations keep pace with community expectations. It also does not take into account those circumstances where governments can have conflicting roles as both watchdog and project partner. Government regulations and industry self-regulation are not in of themselves sufficient for the minerals sector to demonstrate that it has adequately addressed environmental and social issues associated with the sector. For the minerals sector to improve its reputation it must first improve its environmental and social performance. To do this requires the sector to operate to acceptable standards of environmental and social performance and for the sector to be able to credibly communicate this to its stakeholders such as investors, non-government organisations (NGOs), customers, staff, regulators and local communities. Independent third party certification of environmental and social performance (æcertificationÆ), already operational in forest and fisheries management, is proposed as a mechanism to enable the minerals sector to achieve this. World Wide Fund for Nature (WWF) and industry partners will be collaborating in a project to ascertain the applicability of æcertificationÆ to the minerals sector. A number of economic, social and environmental benefits are identified that could accrue should mining companies be able to differentiate themselves on the basis of environmental and social performance, an attribute evident in æcertificationÆ schemes. External audiences are seeking increasing levels of information and data on environmental and social performance of mining companies, be it local communities, investors, financial institutions or NGOs. Environmental and social reporting should be a key communications device that stakeholders can rely on as a reliable, credible source of information on environmental and social performance. WWFÆs contribution to the debate about environmental and social reporting has been to develop a process to assess the quality of environmental and social reports against reporting ingredients which WWF believe are important if a report is to be an accurate reflection of the reporting entitiesÆ environmental and social performance.

Jan 1, 2002

By C M. Côte, P Bolz, L Pagliero, M Edraki, M Shaygan, P Erskine

Mines in Queensland must now prepare a Progressive Rehabilitation and Closure (PRC) plan, with the requirement to justify the selection of the post-mining land use (PMLU) for each rehabilitation domain. Given that there are nearly 200 mines who must undertake a comprehensive PMLU assessment, there is a need to develop methods that will minimise the duplication of effort. As part of a broader initiative on innovative post-mining land use planning, this project undertook a regional analysis of the technical suitability of several PMLUs.

Aug 2, 2023

Mining of narrow vein mineralisation, invariably depending on the mining method selected, involves the extraction of both ore and waste rock. The level to which mining of waste rock can be minimised depends on numerous factors, but particularly the thickness and dip of the deposit. Resue mining is a method of mining that allows split face firing within stopes to allow waste and ore to be mined separately, allowing dilution to be minimised. This paper examines the technique of resue firing and its applicability to the mining of narrow vein deposits. Particular emphasis is placed on the conditions in which resue mining presents a suitable option for mining of narrow veins.

Jan 1, 2008

By Broome A

In a technologically oriented industry, it is important to understand and apply technology very consciously to create competitive advantage. Technology is not an activity which is simply restricted to CSIRO or the research and technology department. Technology improvement is a part of everyone's role. It is a way of life - the technology facet of continuous improvement. For this reason, The AusIMM has organised this Travelling Technology Forum - a series of presentations about automation in mining. To make the message more accessible, The AusIMM had originally planned to take the Forum to four regional mining centres: Mackay/Townsville, Singleton, Burnie and Kalgoorlie, but only one seminar was held, ie at Singleton in March 1997. Seminars at other locations were cancelled because of insufficient registrants. The presentation by Andrew Logan of BHP Cannington was not available for the Singleton forum. The aims of the forum were: ò to heighten awareness of the key technologies and their impact in the minerals industry in the medium term; ò to foster creative thinking; ò to encourage people to broaden their technical and commercial skills and develop individual networks and linkages based on an interest in these key technologies; ò to share information on the application of these technologies in the industry; ò to promote an enhanced appreciation of the need for an innovative culture; and ò to encourage staff to consider post graduate courses in technology management. The AusIMM wanted to not only raise awareness about `automation in mining' issues, but also to get technology in a more general sense back onto `centre stage'. The Forum was generously supported by CSIRO, Western Mining Corporation Ltd, BHP Coal Ltd, Aberfoyle Limited, Goldfields Ltd, Novacoal Australia Pty Ltd, Pasminco Ltd, and RGC Limited. The program was endorsed by the Centre for Mining Technology and Equipment (CMTE). Copies of the full papers are available from the authors, see `References'.

Jan 1, 1997

By D Mather

The Resources Boom of the 1960s in Australia provided a strong foundation for AustraliaÆs economic prosperity for the remainder of the twentieth century. In combination with sound economic management, our world-class minerals and energy sector has played a key role in the nationÆs competitiveness, and it has been the major source of our exports since the early 1970s. Even with the emergence since 1990 of major mineral provinces in Latin America and elsewhere, Australia has increased its percentage of world production of several minerals. Between 1990 and 2002, our share of iron ore production rose from 13 per cent to 20 per cent, nickel mine production from eight per cent to 17 per cent, copper mine production from four per cent to seven per cent and zinc mine production from 13 per cent to 17 per cent. Whether this situation will continue during the coming decades motivates the discussion of this reflective paper. The approach is to consider fundamental supply-side and demand-side issues in arriving at a view about the state of the world, the world minerals sector and the Australian resources sector in the coming decades. The argument draws from the experiences of other mature mineral producing countries such as Canada and the United States. In such nations, efficient producers have often sustained competitiveness for extended periods, despite falling grades and other challenging operating conditions. Yet several forces are changing the economic geography of the minerals industry in significant ways. These include the re-emergence of major global mining corporations, the revision of mineral policy in over 100 nations since 1985, the mobility of technology and more efficient transport both for mineral productions and mining professionals. Given these trends the paper argues that the Australian mining industry must continue to change and evolve significantly in the foreseeable future. Its leaders will need to be even more internationally focused if it is to maintain its strong competitive position.

Jan 1, 2006

By M P. Schwarz

In recent years, computational fluid dynamic (CFD) modelling of mechanically stirred flotation cells has been used to study the complexity of the flow within the cells. In CFD modelling, the flotation cell is discretised into individual finite volumes where local values of flow properties are calculated. The flotation effect is studied as three subprocesses including collision, attachment and detachment. In the present work, these subprocesses are modelled in a laboratory flotation cell. The flotation kinetics involving a population balance for particles in a semi-batch process has been developed. From turbulent collision models, the local rates of bubble-particle encounters have been estimated from the local turbulent velocities. The probabilities of collision, adhesion and stabilisation have been calculated at each location in the flotation cell. The net rate of attachment, after accounting for detachments, has been used in the kinetic model involving transient CFD simulations with removal of bubble-particle aggregates to the froth layer. Comparison of the predicted fraction of particles remaining in the cell and the fraction of free particles to the total number of particles remaining in the cell indicates that the particle recovery rate to the pulp-froth interface is much slower than the net attachment rates. For the case studied, the results indicate that the bubbles are loaded with particles quite quickly, and that the bubble surface area flux is the limiting factor in the recovery rate at the froth interface. This explains why the relationship between flotation rate and bubble surface area flux is generally used as a criterion for designing flotation cells. The predicted flotation rate constants also indicate that fine and large particles do not float as well as intermediate sized particles of 120 - 240 ¦m range. This is consistent with the flotation recovery generally observed in flotation practice. The magnitude of the flotation rate constants obtained by CFD modelling indicates that transport rates of the bubble-particle aggregates to the froth layer contribute quite significantly to the overall flotation rate and this is likely to be the case especially in plant-scale equipment.

Jan 1, 2005

By D L. Kennedy

It has always been a challenge to accelerate the underground development progress by increasing the advance rate of each development round. Surveys have shown that most of the development rounds have only been pulled 84 per cent to 94 per cent of the drilled length. Where bare detonators have been used as primers, less advance rate is expected. In order to obtain a good understanding of the influence of priming upon the advance rate in underground development, a series of high energy primer trials has been conducted by Orica Explosives in the goldfields using various types of Orica high energy Anzomex « primers. It has been shown that development face has been pulled an extra 140 mm to 420 mm by priming with Anzomex « K primers compared with conventional primers. From all the trials at different sites, we have seen that the face pulled using K primers was more square than that pulled using conventional primers. Virtually, no butts and toe were left on the face developed using K primers. Computer simulation has been conducted using either a conventional primer, a bare detonator or a K primer as initiator. The study compared the predicted crack patterns developed around the toe of the hole and it was deducted that a detonator-initiated hole would leave a butt some 200 mm longer than that from a conventional primer-initiated hole, and a K primer-initiated blasthole would give rise to stronger initial p-wave, promoting crack development around the toe and increasing the ability to pull close to the full depth.

Jan 1, 1999

By D Reid

Many of the relevant engineering behaviours of tailings are controlled to a large degree by the density of the material. For example, loose tailings are prone to brittle strength loss, while dense tailings are dilative (i.e. gain strength) at large shear strains. The critical state framework has been successfully developed over the past few decades to assess whether in situ conditions are contractive or dilative, and estimate relevant engineering parameters on that basis. Tailings comprising primarily silt-sized particles, when subaqueously deposited, often form a particularly loose state compared to subaerially deposited material of similar index properties. Such subaqueous deposition occurs in the decant pond area, where the tailings typically pluviate in quiescent conditions within a pond of standing water. Silt tailings deposited in such a manner have been observed to be extremely loose in a number of TSF investigations. Of particular concern, the deposited material in such cases appear to be significantly looser than can be reproduced in the laboratory - even using moist tamping, the sample preparation method which can usually produce the loosest samples possible in laboratory conditions. While the loose density of subaqueously deposited silt tailings is clear, in a well-managed upstream-raised TSF the decant pond is usually small and far from the perimeter embankments, however there are a number of examples where the engineering performance of such materials becomes relevant – for example, when historical deposition practices were poor, resulting in subaqueous deposition near the perimeter embankment. This paper outlines the geotechnical characterisation of a number of such subaqueously-deposited zones, compares the in situ state to that achievable in the laboratory, and discusses options for assessing the expected engineering performance of such materials when comparable laboratory tests are unavailable.

Jul 1, 2021

By B Tessier

Checking the quality of a blast may be considered as subjective. Checking this quality will require measuring objective parameters. One of them is the resulting fragmentation of the blasted product. Numerous fragmentation æmeasuringÆ systems have been developed and marketed, based on image-processing. This presentation of FragScan will illustrate advantages and difficulties when using such a system. FragScan is essentially defending a policy of large and representative sampling. The purpose is to show how fragmentation is discriminating both productivity and profit of quarry operations on a blast-by blast basis. The next step will then be to ædriveÆ the blasting process to reach a æbetterÆ fragmentation. Other applications require the fragmentation as an essential result: this is the case for large boulders used in structure-reinforcement. Several case-studies have shown that FragScan can be used for quality-control, checking size-distribution of the product according to the requirements of the end-user. Only clear thinking about the precise use of such a æmeasurementÆ will further the success of this task.

Jan 1, 2001