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By E Drueppel, M Mistry, J Pateiro

As mining undoubtedly influences the natural environment future challenges of copper ore mining are minimisation of land use in area and duration, proper land rehabilitation as well as tailings management. One possible solution to avoid these negative impacts could be the application of underground mining with backfilling tailings compounds. This approach would definitely increase the production cost. Against this background the project analyses the influence of an æecologically satisfyingÆ copper ore mining on world market prize and demand as well as on the environment. In the project 261 copper ore mines accounting for 98 per cent of world copper production have been examined. After modelling a backfill plant, analyses of applied backfill techniques were conducted. Afterwards a method of cost estimation was developed and then the backfill plant model was applied in three case studies. The results were transferred into scenarios. The work closes with a short discussion and gives an outlook to forthcoming research. The results presented in this work have been generated within the Collaborative Research Center (CRC) 525 entitled æResource-orientated view of metallic raw material flowsÆ. This interdisciplinary project was established at Aachen University of Technology (Germany) in 1997 and is funded by the Deutsche Forschungsgemeinschaft (DFG). The long-term goal of this research program is the identification of options for the resource-sensitive supply and processing of metallic raw materials. In order to address the sustainable development challenges facing the metals and minerals industry an integrated resource management system is to be developed and tested for important metallic raw materials. Case studies for aluminium and copper are being conducted by the CRC 525 in order to provide useful and efficient tools for decision makers over the entire life cycle of these materials.

Jan 1, 2003

By G D. Price

The Golden Blocks Goldfield is located in the Slaty Creek area,North West Nelson, about 20 km west of Collingwood. Alluvial gold was discovered in Slaty Creek in 1861. Gold was mined from quartz veins up to 1.5 m thick at nine mines from the 1890s until the closure of the Aorangi Mine in 1911. Total production from the Golden Blocks Goldfield is estimated at 46 000 ounces of gold. The Aorangi Mine was the largest mine, with a recorded production of 27 978 ounces of gold at an average grade of 36 g/t. Quartz veins containing gold and sparse sulphide mineralisation occur in a slightly metamorphosed, complexly deformed over-turned sequence of Lower Ordovician sandstones and shales. Primary gold mineralisation is associated with intensely deformed zones that occur near or at carbonaceous shale and sandstone contacts. Some eighty-five percent of all gold production (39 000 ounces) came from four mines confined to the stratigraphically lowest, most widespread shale unit. The quartz veins exhibit textures consistent with a hydraulic fracturing mode of vein formation with fissure infill vein types predominating over replacement textures. Stylolites of carbonaceous material and recrystallization features within the veins suggest multiple phases of deformation. The lack of wall rock alteration, and low primary fluid inclusion temperatures of 200¦ - 265¦ indicate that the ore fluids were associated with a low temperature epithermal system. A model consistent with similar mineralisation styles observed in Ordovician sediments from Pacific Rim occurrences is presented. The high grades (up to 100 g/t) mined from the upper levels of several mines suggests supergene enrichment processes associated with the Upper Cretaceous weathering surface. The Golden Blocks Goldfield has had no modern exploration. The most recent exploration was undertaken in the early 1980s. There are known acid intrusives in the area, with potential for the application of new models of intrusive-related gold mineralisation.

Jan 1, 2004

Performance driver trees or KPI trees are reasonably well-known tools for analysing performance in mining operations. However, the tools are often not user friendly. They may be technically correct but they are often clunky. This means they donÆt promote simple management decision-making and donÆt encourage businesses to make them an integrated part of optimising their operations. This paper describes a simple but effective driver tree process and tool that has been successfully implemented and used to aid decision making across a number of mining and processing operations. The important aspects of employing driver trees to assist in management of operations are to ensure that the chosen solution:includes a reporting solution, provides the bottom line impact of the performance indicators, automatically gathers the necessary data that reconciles with existing reports, and is built around a review process that fits with existing management processes. An adequate solution enables operators to identify where there are performance gaps and to quickly prioritise the urgency for addressing these issues. Two case studies are chosen to illustrate the critical success factors of implementing a performance driver tree solution. The first is a large, complex open pit operation. The driver trees, reporting and management processes were initially established for the mining and processing aspects of the operations. Once the initial solution was bedded down, a follow-up project was carried out to establish the equivalent solution for the support areas of the business. The final solution covered stand alone performance driver trees for mining, processing, engineering, maintenance, health and safety, human resources and finance. These individual driver trees were integrated into a total solution that showed how all of the identified KPIÆs impact profit and quantified the dollar impact of all variations. The reporting solution that was put in place automatically creates prioritised lists of variances for the business to address. The second case study is a performance diagnostic project where driver trees were used to assess where gaps in performance were occurring, and then to evaluate the impacts of proposed initiatives.

Jan 1, 2007

By M W Kearns

The ERA - Ranger Mine ore processing operation consists of a sulphuric acid leach followed by counter current decantation and solvent extraction circuits. The most expensive unit processing operation at Ranger is the sulphuric acid leach. In 1992 and 1993 changes were made to the operation of the leach circuit. These changes have reduced power and reagent consumption in leach by 30 per cent and 20 per cent respectively with minimal effect on extraction efficiency. The first change was to operate the leach circuits at higher pHs than previously attempted. In addition a cap was placed on the amount of acid added to the leach circuit. Secondly, an on-line pH measurement system was installed and has reduced the variation with time of the leach circuit pHs. Finally, the number of leach vessels used was reduced from ten to seven. This action was undertaken after an examination of the uranium profile and the residence time in the leach circuit from previous years. This paper examines the above changes and assesses their effectiveness on plant performance and costs.

Jan 1, 1994

As the surrounding environment continues to change and evolve, mine managers face a changing climate of expectations. TodayÆs mine managers must juggle competing pressures to deliver sound social, environmental and economic results. Leadership is a fundamental tool for the effective mine manager. Whilst mine managers require solid technical and operational skills, importantly the manager must be able to engage a workforce, build and retain employees and seize opportunity for growth and development when presented. An important tool for engaging employees in the business at Rio Tinto Aluminium is the business improvement programme. At Rio Tinto AluminiumÆs Weipa mine, the business improvement methodology Six Sigma is used to deliver measurable, sustainable outcomes for the business. The next step in Rio Tinto AluminiumÆs improvement journey is to implement Lean Manufacturing at all managed operations. The operating environment for mine managers continuously evolves and effective mine managers must be flexible and adaptive to meet challenges. Governance and regulation constantly change in an environment of commodity cycles and finite resources. This increases pressure on the economic return achieved by the operation. As such, effective mine managers must be aware of and manage the operating environment û the broader, issues-based environment not just the immediate day-to-day responsibility of mine managing. This includes delivering on safety, community and environmental priorities. At Rio Tinto Aluminium, part of managing the business is via investment in the area of social partnerships to engage employees and the broader community in Rio Tinto AluminiumÆs commitment to sustainability. The Future Reef partnership entered with the Great Barrier Reef Research Foundation in 2005 forms an important part of Rio Tinto AluminiumÆs climate change strategy. This four-year, A$1 million investment funds programmes looking at the effect of ocean acidification on the Great Barrier Reef. The partnership is a unique example of industry and science working together on an area of mutual and national concern. Modern mine managers require a broad set of skills to effectively deliver outcomes. TodayÆs mine managers must make innovative and courageous responses to determine todayÆs strategy for tomorrowÆs future.

Jan 1, 2006

Prediction of large-scale underground opening stability in quite complex mining circumstances is being undertaken on a routine basis at The Zinc Corporation, Limited, (ZC) and New Broken Hill Consolidated Limited (NBHC) Broken Hill, Australia. A three- dimensional numerical modelling technique has been developed that gives good correspondence with the observed behaviour in many stopes. New insights into the rock mechanics of under- ground mining are flowing from this work. The modelling practice can be taught to engineers in a reasonable time-frame. In-house computing facilities including graphics workstations are needed. The RMS software is designed to be user-friendly and very robust.

Jan 1, 1983

By Marsham B, Baker D. C

The expansion of New Broken Hill Consolidated Limited (NBHC) concentrator necessitated the installation of hydrocyclone classifiers where rake classifiers had previously been used. Commissioning of the circuit and optimisation of circuit performance has highlighted problems related to classification of sulphide minerals. Testwork initiated to solve these problems has been used to develop cyclone models which have been incorporated in a ccnputer control strategy for the grinding circuit as a whole. The modifications to the circuit during the commissioning phase and the control philosophy are outlined.

Jan 1, 1983

Poorly designed sampling protocols generally result in high project risk by artificially increasing grade variability (ie the nugget effect). Sample collection, preparation and assay protocols that suit the ore type, together with QA/QC systems, will reduce this risk. All reporting codes (eg JORC, 2004) require the Competent Person to consider the quality and implication of sampling and assaying programs. High sampling errors beget higher project uncertainty; despite this fact, sampling does not receive the attention it deserves. The case studies presented show that many sampling issues frequently go unrecognised or unaddressed, resulting in poor project decisions during exploration through to feasibility and production. The overall conclusion is that correct sampling is critical to mining project success and that there is often a need for its optimisation.

Jan 1, 2007

The cement industry requires large quan- tities of limestone, its main raw material. It is the major consumer of this mineral. Limestone is widely distributed throughout Australia but location in relation to major markets, and transport considerations render most deposits of no economic value. Of those which are sufficiently close to the major me- tropolitan markets many are rejected as being unsuitable on grounds of quality, inadequate size for major development, or other reasons such as environmental considerations. Detailed geological investigations are necessary, not only to prove raw material sources prior to establishment of a cement works but also to permit planned extraction programmes and satisfactory grade control during subsequent development. Conventional field techniques have generally proved adequate for raw material exploration. Data assessment and reserves estimation also are by conventional methods although the specific requirements of the industry relating to raw material and cement quality, the type of manufacturing process and fuel used are relevant. A number of case studies from different geological environ- ments are examined and comparisons made bet- ween the predictions of the exploration stage and subsequent experience in quarrying prac- Tice.

Jan 1, 1979

A schematic overview of the variables which interact to determine ore reserves precedes consideration, in this context, of some recent views on the concept of a 'production cycle'. Political and governmental action, for whatever motives, is a greater obstacle to future mineral supply than technical problems.

Jan 1, 1979

Partnering has come to prominence in the Australian construction industry in a formal sense this decade. The high level of disputation in the building and civil construction industries in the 1980s drove its development in both Australia and North America. PartneringÆs use has been most prominent in the construction industry, particularly in the civil and construction sectors of the industry. It has found favour in some mining development projects, one of the most notable being BHP MineralÆs Cannington project in NW Queensland. This paper examines the requirements of successful partnering agreements and describes in detail the mine development partnering agreement at Cannington. In particular, the paper discusses the authorÆs experience and recommendations for partnering to avoid contractual problems and achieve win û win project outcomes for all parties to major mining projects.

Jan 1, 1999

The purpose of this paper is to outline the current status of financing in the Australian Gold Mining industry and to discuss a number of developments that have occurred during 1983/84.Recognising the importance of equity financing various equity issues, including project valuation, will be discussed against the backdrop of an industry experiencing both rapid growth and a changing structure.Nothwithstanding the current tax exempt status of the industry there is a trend towards more debt financing. A number of financing issues will be covered and it will be shown howvalue can be created through astute financing planning.

Jan 1, 1984

Future metal prices play a direct role in both the economic evaluation and short to medium planning of a mine scheduling sequence. It is difficult to predict with accuracy the future price of volatile metal commodities, however, it is possible to fix some future metal price, outside of long term contracts by the selling of futures contracts through a commodities exchange. The futures contract represents a fixed amount of a speci- fied quality of a commodity for future delivery at a predetermined price. Several different types of hedginc are possible, one in particular which is best suited for mining companies. There are relative advantages and disadvantages when trading in futures contracts and particular reference is made to gold contracts on the Sydney Futures Exchange.

Jan 1, 1980

There is little doubt that the vision (Spectre) of Voisey's Bay has completely spooked the Northern Hemisphere view on nickel to the exclusion of considering any other future nickel project. Voisey's Bay orebody is of world-class and will influence world nickel and cobalt supply for a very long time - but - has the world yet started to consider the enormous cost of acquisition and development of this find or the nickel price it will need to attract to cover these costs and its operating costs and keep its bankers and shareholders happy. That price will be the critical factor in determining Voisey's effect on world nickel and will be critical in ranking other new projects aimed at making up the nickel short fall created by the on-going demand for austenitic stainless steel. In my view, there is little doubt that some if not most of these `other' new projects will be developed in the South West Pacific from lateritic Resources.

Jan 1, 1996

By S Zaffron, O Loffredi

A critical concern of any mining company today is its relationship with the different stakeholder groups impacted by the operational activity û communities, unions, vendors, local partners and competitors, local and federal governments, interest groups and non-government organisations. What ten years ago would have gone unnoticed, now, and even more so in the future, can drastically impact the profitability and even existence of a mining operation. This paper describes the development and delivery of a new paradigm for creating effective external stakeholder relationships. We report on the actual measurable results of an integrated and highly complex initiative led by Lonmin Plc (Lonmin) and Landmark Education Business Development (LEBD) that significantly altered the nature of the relationship with the stakeholders. Given the nature of the long-term investment required in a mining operation, any breakdowns or surprises in its relationship with external stakeholders brings with it the potential for major loss. The transformation of executive and senior management and community leadership was required to enable them to be effective in managing this complex set of circumstances.

Jan 1, 2006

Natural gas was introduced to the Melbourne reticulation system in April 1969 and since that date sales to industrial consumers in the Gas & Fuel Corporation of Victoria area of supply, have increased by over 50% This increase has occurred despite the fact that the areas in which the new fuel is available have been dependent on the progress of the conversion operation from manufactured gas. The half way mark for conversion was reached in May 1970. The reason for the adoption of natural gas by industrial users is usually the result of objective financial analysis leading to the conclusion that the new fuel will give the lowest overall production cost. Many factors are involved in such an analysis of which the price of the fuel is only one. Amongst other important elements in the cost calculation are:- -ò òò -(1) The effect of fuel on product quality (2) Maintenance and handling costs for alternative fuel. In addition to economic gains for the individual user, the use of natural gas should benefit the whole community through its effect on such things as, air pollution and overseas balance of payments.

Jan 1, 1970

Optimising a mining or a quarrying operation about the overall cost is quite a challenge as there never is a situation where we have exactly the same conditions regarding rock properties, explosives' performance, mining equipment or evironmental restrictions. The amount of endless influencing parameters and variables make the evaluation process difficult. The enormous progress we have seen during the recent two decades in computing has however significantly increased our ability to evaluate and process the information gathered, and refine our existing prediction models. Refined models demand an increasing volume of good quality information to show reliable conformity with reality. There is a great need for co-operative work in the mining and quarrying society if we shall be able to screen all available data, systematically find the key-parameters influencing the results and to build robust scientific models. No organisations today have all the skilled people needed or can afford to hire the necessary specialists in all the overlapping branches. This paper highlights some on-going work where the Dyno Explosives Group is adding some new pieces to the giant jigsaw puzzle representing the ultimate model of the mining and quarrying operations we all of this society would like to see completed.

Jan 1, 1995

By E J. Gardiner, C M. Hogan

Acidic drainage has long been recognised as the largest environmental liability facing the mining industry, and to a lesser extent, the public, through abandoned mines. The Canadian Mine Environment Neutral Drainage (MEND) initiative was the first international multi-stakeholder program to develop scientifically based technologies to reduce the effect of acidic drainage. The original MEND Program extended over a nine-year time frame ending in 1997, with technology transfer activities continuing to the end of year 2000 under the MEND 2000 program. Both programs have contributed enormously to the understanding of acidic drainage and how to prevent it. MEND3, launched in 2001, intends to further this effort with a strong, research-driven program. The successes of the MEND initiative have come through the collaborative efforts of the partners, the sharing of experiences, the thorough evaluation of technologies and their incremental improvements. As a result, the knowledge base on acidic drainage has grown considerably. An international model of alliance between the various worldwide initiative involved in acidic drainage is being formalised at this conference. This global alliance will enhance technology transfer capabilities and will lead to improved environmental performance for the industry. It is through collaboration that we have achieved the most progress in environmental performance, and this formal relationship will further expand these benefits.

Jan 1, 2003

The classic description of Project Finance as "the reliance by lenders on the cashflow of a project, supported by the assets of the project with no recourse to the project sponsor's corporate balance sheet" has, like most other terms in the finance industry, evolved through recent usage. The area now under most scrutiny is the sharing of risks between parties either most able to take them or prepared to accept payment for them. Creativity in, and flexibility of financing structures have enabled project lending to continue under a dramatically different economic outlook. The diminishing competitiveness of the Australian producers in a global market place of uncertain commodity prices has discouraged the advancement of many large scale resource projects. The majority of new project financings has been designed to assist the relatively small company promote and develop its first projects. New trends- are emerging in four areas: sources of capital; borrowing structure; financing instruments (securitisation); and risk underpinning. As project financing becomes more widely used, the range of interested financiers grows. New initiatives contribute to its development and evolution with a view to increase effectiveness to the sponsor of any new venture.

Jan 1, 1987

This paper compares and evaluates the impact of income tax and value-added tax on the decision to explore for minerals or to develop a mine in four countries: Australia, Papua New Guinea, Argentina and Indonesia. Three aspects are considered in depth:- domestic tax rules applicable to mining projects;- taxation of foreign mining investment and foreign providers of expertise;- taxation of project finance (other than equity) from foreign sources.Specific tax issues discussed include tax deductibility of various costs, treatment of tax losses, special tax incentives, comparative treatment of various corporate structures, non-resident withholding taxes, and tax costs of various forms of project finance. The paper also illustrates the comparative impact of income tax on rates of return by means of a simulation of a mining project in each of the four countries. The simulation demonstrates why the highest rate of return may be obtained in Argentina and the lowest in Australia.Relevant features of the income tax systems in each country (at 15 February 1990) are summarized and compared in several tables annexed to the naner.

Jan 1, 1990