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By N R. Johnson

The overland conveyor at the Los Pelambres mine in Chile is designed to move 8700 t/h of material over 12 km at a speed of 6 m/s while descending 1400 m. The conveyor, which is divided into three segments, is equipped with a braking system that must bring it to rest without producing excessive stresses in the conveyor belt. Retardation and gently stopping a mass of 250 t requires retardation times in the order of 60 seconds. Brakes that can provide this performance require sophisticated controls as well as very high heat absorption capacity. This paper describes the thermal analysis of the braking system, which required the use of novel materials to meet the arduous duties imposed on the callipers and discs.

Jan 1, 2005

By Carrucan M. J

Costain Resources Limited operates two open cut coal mines in the Hunter Valley coalfields of New South Wales, Ravensworth Mine and Warkworth Mine. The location of the Ravensworth operation is shown in Figure 1. In the case of the Ravensworth Mine, Costain Australia is essentially a contract miner and is contracted to supply coal to Pacific Power (previously The Electricity Commission of New South Wales), on contracts won through a tender system. Due to the existing infrastructure and the lease area that associated with the contract, the mining strips at Ravensworth South have a maximum strike length of 1500 metres. This paper deals with the methods of scheduling used to overcome the challenge of mining the short strike length, multi-seam deposit at Ravensworth South.

Jan 1, 1992

The necessity for agreed project outcomes, which are in accordance with client needs, and the subsequent requirement for a unique approach to managing project implementation is discussed. Reasons for appointing a separate project team to manage a project are established. The selection of a project manager, based on the services they can provide and on their characteristics, skills and management style, is discussed. The consequences of selecting the wrong project manager are explored. A broad overview of the requirements for the project team is provided. Criteria for the selection of team members, and the role played by the project manager in this selection, are discussed. The levers that drive `on-time and on-budget' projects are discussed in terms of the project's vision, goals, controls, and incentives.

Jan 1, 1997

By K H. Esbensen

The critical role of representative sampling is featured and illustrated by selected examples from the geosciences and beyond. As there already are many demonstrations of the potential (and potentially large) economic consequences of ignoring proper standards with respect to representativity, eg for mining and minerals processing companies, which æstand to lose millions of dollars by failing to optimise exploitation of their mineral resourcesÆ, such need no further iteration here.This keynote lecture, rather, takes a point of departure from the opposite perspective: what is to be gained by a scrupulous stand for representativity? Honesty, reputation, credibility, market advantage - is what!CITATION:Esbensen, K H, 2012. The critical role of representative sampling, in Proceedings Sampling 2012 , pp 9-12 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

By Worner H. K

The paper briefly summarises the work of the Titanium Research Section in the Metallurgy Department of the University of Melbourne and mentions the development of a new electrolytic process for titanium production. This process utilises the "hot-spot" cathode technique and titanium carbide anodes. An introduction is given to three further papers on titanium metallurgy to be presented to the Institute.INTRODUCTIONThe unique combination of strength, lightness and corrosion resistance possessed :by titanium and its, alloy has made them of great interest to engineers. However, high cost, difficulties of production and limited knowledge of techniques of application restrict their usage at present almost exclusively to high priority armaments.The cost of the metal is divided between extraction and processing and much research has been carried out to devise new and cheaper methods for winning the metal from its ores. Processing costs will be reduced when production volume increases.Extraction research is proceeding rapidly overseas and Kellogg (1955, p. 72) reports that 'at least seventeen companies in the U.S.A. are interested in titanium production. Of these, two are producing the metal by a modified Kroll process, three are building Kroll plants and the remainder are in various stages of research activity. The Horizons Corporation alone is contemplating electrolytic extraction and is building a pilot plant. Steinberg et aI. (1955, p. 252, p. 332) have reported the early work done by the HorizonsCorporation on electrolysis of potassium fluotitanate and titanium monoxide in fused salt electrolytes. Of these two, the former appears to be the more attractive process.

Jan 1, 1956

By B Leyland

The media in Australia is currently rife with articles and pronouncements on global warming as the most significant crisis of our time, which may æthreaten the future of civilisation as we know itÆ. This has been recently reinforced by release of Al GoreÆs film æAn Inconvenient TruthÆ, and one would be led to believe that the science of global warming is settled. And yet there is a strong body of literature disputing this apparent consensus which suggests that care should be exercised in introducing radical policies to solve a crisis which may not be real. Such policies would have a major impact on those in professions such as engineering (project approvals and design to minimise greenhouse gas emissions), accounting (carbon tax issues) and the law (corporate disputes on greenhouse gas issues are already in train in the USA). This paper addresses the hysteria apparent in the climate change debate by presenting factual evidence relating to climate change and the current phase of mild global warming. Some of the more extreme statements on future impacts are repudiated with published data, and alternatives to the purported role of fossil fuels in temperature change are offered. The potential impact of political decisions on professional activity is discussed, as are the implications of a possible future reversal of the scientific consensus, as has occurred in the past. The paper concludes with a call for the professions to exercise their Learned Society role to ensure that a rational and public debate is held on the broad issue of climate change.

Jan 1, 2007

By U Berg, T Neumann, Y Song

Eutrophication of water bodies is one of the most severe environmental problems worldwide. It is well known that the availability of phosphate, as the limiting nutrient, is crucial for increased primary production and eutrophication. Calcite exhibits positive surface charge in most natural waters and can therefore be used for phosphate immobilisation. In this study, sorption experiments were performed in order to test different calcite materials regarding their suitability for use in restoration of eutrophic lakes. These short-term experiments were performed under different hydrochemical conditions (pH, SICC, initial dissolved P concentration) and with varying calcite properties (specific surface area and amount) in order to predict the long-term stability of the Ca-P-bonds. Peculiar shapes of isotherms that could not be explained only by adsorption processes were detected in the individual experiments. Depending on the residual P-concentration in solution, the isotherms can be divided into three sections indicating different processes responsible for the P-fixation on calcite surfaces. Adsorption prevails in equilibrium with lowest residual P-concentrations. The inflection of the isotherm at moderate residual P-concentrations suggests that precipitation and transformation of a Ca-P compound becomes dominant. This is supported by characteristic Ca/P-ratios for different Ca-P-compounds (b-tri- calcium-phosphate, octa-calcium-phosphate). On the new surface, phosphate ions again are fixed by adsorption. The observed transformation of P-bonding is crucial for sustainable phosphate immobilisation on calcite surfaces. While pure adsorption processes are reversible, the development of a thermodynamically stable Ca-P-phase, like hydroxylapatite, will lead to a lasting immobilisation of phosphate.

Jan 1, 2008

Downstream value-adding is a strategic issue for a country like Australia, which has a resources-driven sector of a scale that has significant impact on the national economy. The question of why producers are not doing more to ævalue-addÆ is often asked. In Australia this debate takes place within the context of: an era of unprecedented growth in demand for resources driven by the rapid urbanisation of China, India and others;impending legislation and uncertainty around carbon pricing;rapidly rising energy costs;significant supply-side shortages including infrastructure, skills and manufacturing capacity; andsignificant industry consolidation of primary resource producers with commensurate improvements in market power.There are several examples of resource-based industries which have developed their business along the complete value-chain; for example large oil and gas producers successfully span upstream and downstream operations including refining and petro-chemicals as well as retail distribution of fuel and other products. Relevant frameworks that provide insight and understanding into the strategic issues around value-adding are reviewed and examples of the application of these frameworks to companies and industries which have successfully adopted a strategy of integrating along the value-chain, as well as those players who have focused on parts of the value-chain are presented. The issues around value-adding in Australia are then reviewed with reference to these frameworks and it is concluded that the issue is a conflict between the objective companies who wish to maximise financial value versus the desire of governments to increase economic benefits. An approach to aligning these objectives is proposed.

Jan 1, 2008

I start with some lines from "Pleasures of Hope" by the poet Campbell, published in 1798, which sets the flavour of what I am going to say. They blissful omens bid my spirit see The boundless fields of rapture yet to be; I watch the wheels of Nature's mazy plan, And learn the future by the past of man. I hope to echo the poet's optimistic view of what is yet to come. I am not sure I can find all the omens blissful but we all have some experience of what the wheels of Nature's mazy plan get up to. His advice to learn the future by the past of man seemed sensible to follow, so on the principle that the past of several men would be better than one alone I invited Alan Attwood, Maurice Cahalan, Gavin Moncrieff, Derek Temple, and Peter Wright to help me prepare this address; I am most grateful to them for their contributions. Of the technologies covered in this sequence of keynote addresses, metallurgy is the one which is closest to our consumers. On the age-old principle, which I do not expect to see changed in the 21st Century, that production is about providing the customer with what he wants, when he wants it, where he wants it, and at a price he can afford, I think we should start by trying to see how the market place is likely to develop, and to work back from there to review what technology we need to meet these demands.

Jan 1, 1986

Outsourcing of mining operations and services is done for various reasons and there is no single model which fits all situations. Experienced contractors and mine owners have also developed, more often than not, jointly, numerous commercial arrangements and project delivery methods to suit their particular project. It is often the case that some mine owners who have not considered outsourcing to contractors do so because of a simple lack of understanding of the potential benefits. This paper will highlight the potential benefits and perceived disadvantages of outsourcing for mine owners and demonstrate how these issues have been addressed by the mining contracting community over recent times as well as demonstrate the evolution of current commercial arrangements in engaging mining contractors.

Jan 1, 2006

This is a philosophical paper. it discusses some of the concepts underlying the estimation of geological reserves and the determination of cut-off grades. It explores how they interrelate and how they merge eventually with mine design and mining reserves. The main intent is clarification, particularly in certain areas where misconceptions are common.

Jan 1, 1990

By U Dzharlkaganov, B Bekmurzayevand M

The principle conception is presented of timely planning of winning operations in complex-structural blocks and faces in week-24-hourly regime. For adequate description of complex interconnections of open cast operation in space and in time and solving of optimisation problems in timely regime it is necessary using of complex logical and calculation procedures.

Jan 1, 2003

The correct assessment and understanding of geotechnical conditions is fundamental to mine design and, hence, successful (safe and efficient) mine planning, design and operations. However, this assessment and understanding is simply not possible unless there is a sound appreciation of the geology of the project. This paper addresses geological uncertainty in mine engineering and its communication, and shows that a mining project that does not take geology properly into account in the engineering phase is fraught. Uncertainty levels become excessive, which leads to hazards and consequential risks in design and operations in terms of both safety and efficiency. Several examples, both positive and negative, are provided to make the point. The paper concludes that mining geologists must become more overtly cognisant of the influence of geology on mine engineering. Equally importantly, mining (and geotechnical) engineers must communicate better with their geological colleagues to ensure that they (the engineers) have a clear understating of the geological issues affecting their operations. The engineers must know how to ask the right questions of the geologists. Engineers who do not understand and take account of geology in their designs and operations are failing the expectations of stakeholders.

Jan 1, 2006

By L D. Meinert

Skarns typically are zoned and the deposit- or district-scale zonation pattern is an important tool in exploration for skarn deposits. Zonation in individual deposits has been described in many publications, and the general zoning patterns have been summarised by Einaudi, Meinert and Newberry (1981), Meinert (1997), and Meinert, Dipple and Nicolescu (2005). Although zonation is present in most skarns as the result of a basic process of transferring heat and fluids from magmas to wall rocks, the specific zoning pattern in each skarn may vary greatly. For example some zones may be missing entirely or multiple zones may be telescoped. Such variations can be caused by several factors including depth of formation, magma composition, timing of the exsolution of magmatic aqueous fluids, redox state of the magma and redox state of the wall rocks. To use zonation as a predictive tool in skarn exploration, all the controlling factors have to be considered. In this study, we discuss some of the factors that may affect the zoning patterns in Ca skarns. Magnesium skarn has dramatically different mineralogy and is not discussed here. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Breen AM, Phelan JM, Doherty RJ

Early in 1990, Pancontinental Resources (Base Metals) Pty Ltd commenced flotation treatment of ore from the complex copper-lead-zinc sulphide orebody at Thalanga, 65 km west of Charters Towers in North Queensland. The orebody consists mainly of primary sulphide ore but also contains a substantial proportion of supergene ores which are being processed during the first year of operations. The supergene ores are of three main types, designated as A, B, and C. Supergene A ores are essentially copper ores, containing little lead and zinc, while B and C ores are copper-lead-zinc ores with different degrees of alteration of the original chalcopyrite and different ratios of copper to zinc content. Copper is present in the supergene ores mainly as chalcocite, digenite and covellite. Lead and zinc occur mainly as galena and sphalerite respectively. This paper describes the development of flotation plant practice, aided by laboratory testing, to process the supergene ores. The major challenge in treating these ores is that a varying proportion of the sphalerite is naturally activated and is not easily depressed in flotation by the conventional zinc depressants.

Jan 1, 1991

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

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

Curragh Queensland Mining Limited, a co-venture of Australian and overseas interests, operates a large multi-seam strip coal mine in Central Queensland. Coal uncovery is by four large walking draglines.Mine planning is an essential and strong component of the Curragh operations so that informed short- and long-term management and operational decisions are made.

Jan 1, 1992

By McBride N

Location The Boddington Gold Mine (BGM) is located approximately 120 km south east of Perth, Western Australia. (Figure 1). Located within the picturesque Darling Ranges, the land was previously used for forestry activities prior to mining commencing in mid-1987. Mineralisation is hosted within deeply weathered felsic and intermediate intrusions and volcanic rocks of the Saddleback Greenstone Belt.

Jan 1, 1995

Gold recovery by catalytic copper ammonium thiosulphate solution has been studied. Such a process strategy is very attractive for leaching certain difficult-to-treat ores and presents lessened lixiviant toxicity compared to cyanide. Newmont Gold Company has evaluated the ammonium thiosulphate heap leach process for gold recovery from low-grade carbonaceous sulphidic refractory ores following biooxidation. The ammonium thiosulphate leach process has been studied in laboratory, pilot plant and demonstration scale. Satisfactory test results support the continuation of process development. However, the thiosulphate leach chemistry was found to be very complex. Maximum control of the stability of the leaching system is a key factor for success, especially for the heap leach process. Important solution chemistry is discussed in this paper.

Jan 1, 1997