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The results expected from a longwall face can best be estimated from the ideal production rate, determined by the capacity of the equipment and the conditions in which it is installed, the effective operating hours, and the utilisation.The effective operating hours are determined by a number of scheduling factors which include the proportion of manned time to calendar time, the effective shift factor (effective time to manned time) and the move times.Analysis of the results achieved on the last 121 completed longwall panels in Australia (1984 onwards) shows a significant trend between 'actual tonnes/manned hour' and 'ideal production rate' (the measure of the capacity of the installation).Using 1982 'state of the art' longwall equipment, (the average in use in the seven year period), it should be possible to produce around 2.7M tonne/year ROM from a mine with one longwall. Few mines are achieving this.A review of production scheduling factors and general natural hazards affecting some mines suggests three things.1. Whilst some increase in average effective hours has followed the CIT decision, further improvement is possible at many installations.2. Many mines subject to general natural hazards, such as high gas make and high general stress, have found effective solutions and achieve the same utilisation as the overall average.3. A small number of faces within such mines have been severely affected, some less so. The most severe effects of natural hazards appear to be very site specific. This emphasises the need for detailed investigation of the causes, and development of means of predicting their presence. Only then can either satisfactory technical solutions be found to overcome the problems or prior decisions be chosen not to mine badly affected panels.

Jan 1, 1991

By T Goswami, M Edmondson

Henry Walker Eltin (HWE) are the mining contractors for Gloucester Coal at Stratford mine, which is in an environmentally sensitive area in the Avon Valley, NSW, Australia. Normal blasting at Stratford is done in a æstand upÆ or æbox cutÆ mode to suit the truck and shovel operations. Recently an opportunity of doing a throw blast became available when part of a ramp had to be blasted to accommodate changes to the pit design while not damaging the remainder of the ramp. The objective was to maximise throw into the void in order to minimise excavation costs by reducing the amount of overburden to be moved by the excavation fleet. It was necessary that the best result be achieved while staying within the vibration and airblast limits at a neighbouring property and nearby township. Both objectives were achieved through the application of OricaÆs knowledge of blast design, modelling and i-konTM electronic detonators. The i-kon system was used because of its known benefits in cast blasting and environmental control. The i-kon system provides the blaster with much greater accuracy, control and the flexibility to tailor blast designs. It has been found previously to enhance blast throw and provide cleaner high walls (Brent, 2002). The blast was a success, producing a muckpile with a high degree of looseness and consistent fragmentation, with an average throw to final spoil position of 37.5 per cent. This was achieved without any environmental exceedance. In addition, high speed filming showed that the coal edge had remained largely in place, indicating minimal coal loss. The results exceeded the expectations of HWE Stratford and the overall cost savings to HWE Stratford from this blast were recognised to be substantial. Further throw blasting opportunities at Stratford have been followed using the i-kon system to maximise benefits.

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

More than in any other way, the community judges the minerals industry by its environmental performance. Minerals Council of Australia web site www.minerals.org.au/media/code Time is overtaking us. What was good enough yesterday is not good enough today. What may be acceptable today wonÆt be tomorrow. So we need to leap forward. We need to begin to move towards sustainability. Dick Zandee, Managing Director, Placer Dome Asia Pacific The competition for access to exploration and mining opportunities is intense. So is competition for the best people, capital and community support. Poor environmental performance damages a companyÆs ability to attract these. Quite simply, good environmental management is good business. Hugh M Morgan AO,Chief Executive Officer,WMC Limited. Decisions made by private industry and international corporations are increasingly determining the fate of the environment. ...Nothing could be more shortsighted than for todayÆs conservationists to neglect cooperation with business and industry as a means of moving company philosophy and public accountability ahead in favour of the environment. Dr Claude Martin,Director General,WWF International The four quotes above well illustrate the challenges faced by companies and conservationists in attempting to achieve the societal goal of sustainable development. That this aspirational goal itself is far from clearly defined, although it has been widely accepted and endorsed by governments, business and civil society, exacerbates the challenges. Sustainable development has as its central thesis the integration of environmental, social and economic policy. Its attainment by business has been described John Elkington (1998) as the pursuit of the ætriple bottom lineÆ - the achievement of social and environmental targets, in addition to the traditional economic bottom line. It is self-evident that business is both competent and comfortable defining and measuring economic performance and reporting that performance to internal and external audiences. As long as information has been prepared according to the established standards of measurement and reporting of economic performance, all audiences can have confidence in its accuracy. Business does not enjoy the same competence and comfort with regard to social and environmental performance. This is no startling condemnation of business, any more than it is a criticism of governments, non-government organisations (NGOs) or academia. It is a statement of fact that the tools to allow for credible definition and reporting against the other two components of the ætriple bottom lineÆ have yet to be fully developed and are, therefore, far from being widely accepted. Crucial to achieving sustainability is the ability to measure progress toward the goal. The task is to develop means to define appropriate performance standards and to credibly measure and report company environmental and social performance against those standards.

Jan 1, 2000

Risk Management has been applied relatively slowly in the mining industry. Except for the risk concept application in financial considerations, the application of Risk Management in safety management has been far from satisfactory. When applied it was treated in a global occupational safety and health sense. Regardless of how much the mining industry has progressed over the years it is still, in many respects, `state-of-the-art' business. The safety aspects of mining are well known and yet little understood by the public. Regardless of what has been achieved so far and how much effort has been put into it, mining is regarded as an unsafe and somehow rude business. Safety records of the mining industry vary from State-to-State. Latest mining related disasters in PNG and Queensland and some other fatal accidents support this public perception. They purport a need for change in managing safety in the mining industry. The latest mining fatalities have raised the issue: What must be done to improve safety standards? Duty of care, risk management and system engineering concepts can provide some answers. Risk Management principles which have been advocated for some time provide many answers and explanations and can make safety management more constructive and workable. What has been missing so far is that this concept has neither been applied nor has been modified for its practical application and purpose on a larger scale. A risk management approach to the management of safety and health in the mining industry is addressed, herein. This approach does not attempt to provide the solution. It does, however, provide a basic understanding of what Risk and Risk Management are all about. Rational management of risk is addressed in the life cycle and system contexts. A system of continuous improvement is applied. There is always a chain of events, outcome, exposure, consequence(s), and consequence(s) value(s). It means that development of an event takes place in time and space. Dynamic circumstances have been created in or within the system. It is a decision-making process designed to provide a methodology which is directed not toward a mathematical model but toward easy use and application in dynamic working environment, by decision-makers who can be anybody from either a risk taker or a risk creator. The emphasis is placed not only on arriving at the best practical, possible and fair decision but also on structured and systematic acquisition of knowledge about the system, its hazards and associated risks, hence increasing the decision maker's ability to manage the decision-making process related to the management of risk.

Jan 1, 1995

For the last decade Australia has been the leading exporter of both steam and coking coal. In the ten-year period 1989 - 1998 steam coal exports increased by 93 per cent and metallurgical coal exports increased by 50 per cent. However, profitability of the steam coal sector has been disappointing. The coking coal sector, especially the hard coking coal segment, has fared better but its profitability was more because of its ability to maintain relatively high prices rather than its inherent productivity. Until quite recently the Australian coking coal sector was widely expected to be able to maintain this comfortable state without undue effort for the three major æpartnersÆ; the companies, the State Government and the unions. But coking coal could now be heading down the path followed by steam coal that ends with long-term over-supply and, despite steady improvements in productivity, poor profitability. Steam coal entered the ænewÆ era of long-term over-supply some years ago. Over-supply was due to the rapid increase in production in Indonesia, often from new mines and Australia. AustraliaÆs production rise was underlain by the apparent belief that the best way to lower costs was to increase production. In the first couple of years costs didnÆt fall much but the additional tonnage was sold at lower and lower prices into the spot market. By mid-1998 the difference between the contract price set with Japanese utilities and spot sales was often in excess of $US12 per tonne. Japanese contract prices and tonnages have since fallen significantly. Steam coal has moved from being a product to being a commodity. Any profits are due more to the low Australian dollar rather than inherent mine productivity. Seaborne coking coal trade has been dominated by Australia, Canada and the USA, with the USA becoming less competitive. Unfortunately, when the Queensland capacity expansion was well down the pipeline, the Asian financial crisis occurred and the Japanese economy entered what appears to be a long-term recession. Contract prices fell 18 per cent, tonnages decreased and some mines have been reclassified as supplying lower priced coking coal. The paper analyses past and expected future trends in labour and mine productivity, rail freight and FOB export port cash and total costs of the Australian steam coal and coking coal sectors and discusses the market outlook for Australia. The future economic viability of the industry is analysed and discussed in the light of the rapidly changing global environment.

Jan 1, 2000

By Paley N, Cameron A, Townson P

Although blasthole deviation is a problem which can seriously affect blasting operations, there is little practical emphasis on controlling this deviation and no practical emphasis on understanding its practical behaviour. The most common way of dealing with it involves tight control over drill set up and surveying hole paths. The surveying might involve simple collar location and inclination measurement to estimate the hole's actual path. At best, some operations routinely survey hole paths after all holes in a stope have been drilled. In addition, although there is an expectation that holes will deviate, there is no planning for this behaviour in order to reduce its impact on the blast. Design decisions are invariably made with the assumption that holes are straight. If and when surveys reveal problems it is possible only to adjust charging and initiation to 'work around them'. In extreme cases the drill might be recalled to fill in gaps. The lack of planning and the lack of understanding are doubtlessly linked.A model is presented that will predict the expected path of a drill hole. By knowing how a selected few holes deviated it is possible to make a good estimate of the deviation of other holes in the same rock mass. After minimal calibration the model can be used to increase the amount of information for a given amount of surveying or the amount of surveying can be reduced while maintaining the same level of knowledge of blasthole deviation. Equally important is the ability to plan for the deviation in future drilling through altering the initial collar angles or drilling from different locations. It is the authors' hope that planning for hole deviation becomes as much a part of the design process as planning for detonator delay scatter and explosive performance variation.

Jan 1, 1992

An Environmental Impact Statement (EIS) for a major mining development typically has to address various aspects of surface water management, including some which generally tend to be the more contentious: the diversion of rivers and creeks from areas disturbed by mining, and their rehabilitation; the effective management of disturbed area run-off via the collection, containment and treatment of contaminated water on site in sedimentation dams; the collection, containment and treatment of mine pit water; the decommissioning of surface water storages; final void water quality; and water discharge criteria. Environmental Impact Assessment processes for proposed mining developments in Australia at the state and commonwealth level usually involve a form of Initial Advice Statement (or Notice of Intent), Terms of Reference, an EIS, and a Supplementary Report (or similar) which responds to agency and public comment on the EIS. The EIS is used by approval agencies to decide the acceptability of the Project, and to set the conditions of approval. The conditions are often in the form of a state-issued æOperational LicenceÆ or similar. With mining, the initial approval at the EIS stage is often just a pre-cursor to various other planning related approvals, including obtaining a mining lease. Afterwards, mine plans and plans of operations must be submitted to government at various stages of the mineÆs life, ostensibly to provide the detailed mine planning over periods of one û five years. Despite all this additional planning and documentation beyond the submission of the EIS, government approval agencies are increasingly not satisfied with conceptual water management designs and commitments to an outcome (such as meeting a specified water quality standard) in the EIS. Agencies are also requiring sufficient water management design information to be convinced that the outcomes are achievable. To assist proponents of major mining developments, the Queensland Government has published Technical Guidelines for water management, and Environment Australia has published a æBest Practice Environmental Management in MiningÆ booklet on water management. In addition, the Australian and New Zealand Environment and Conservation Council (ANZECC. 2000) has published Water Quality Guidelines which provide an approach to water management, and provide receiving water investigation trigger criteria. So, what are the water management issues that are likely to be the subject of comment, debate and negotiation prior to the EIS being approved? and what commitments may a mining proponent have to make in order to convince the approval agencies that sufficient investigation and design has been provided? This paper provides some answers to this question, by reference to recent major mining proposals which the author has managed through state and commonwealth Environmental Impact Assessment processes.

Jan 1, 2003

In the introduction to a recent paper dealing with, the relationships of magnetite and hematite in the banded iron formations or "jasper bars" of the Western Australian pre-Cambrian(17)t the author made a brief mention of these interesting rocks, of the principal series in which they occur and of a few of the rock and mineral types to be found within them.He drew attention to the essential shnilarity of these Western Australian banded iron formations to those of the pre-Cambrian of such other countries as the United States Lake Superior region, Sweden, South Russia, India, South Africa and Brazil, and gave a brief summary of his views as to the origin of the formations in Western Australia. Furthermore he stated that the banded iron formations have proved of considerable direct economic importance in the goldfields and other' regions of Western Australia, and he referred to the assistance they have provided the field geologist in geological mapping and the determination of geological structures.It is in elaboration of this last statement that the present paper has been written. In the following pages will be found some examples of the use to which the jasper bars have been put in the determination of the geological structure of critical areas in the goldfields of the State.Firstly, however, it may be as well to recapitulate the features of interest in these rocks. The true jasper bars or banded iron formations including the types jaspilite, banded hematite quartzite and banded magnetite quartzite or chert, together with their higher grade metamorphic derivatives such as banded magnetite-gruneri~ quartzites, magnetitegrunerite schists, fayalite ,and hedenbergite bearing handed magnetitegrunerite quartz rocks and' to 'a lesser extent magnetite-hypersthene grunerite quartz rocks, are abundant in the older series of the Western Australian pre-Cambrian. They are best developed in the older Greenstone or Kalgoorlie series of the goldfields districts, interbedded with metamorphosed basic lavas, tuffs and sediments. The mineralogy andpetrology of these rocks, the history of their metamorphism and their origin have been discusseq elsewhere in some detail by the author(19), (20). In one of the papers(20) it was clearly demonstrated that in the light of the true facts the old silicified shear zone theory of the origin of the jasper bars is quite untenable and that the formations undoubtedly represent sedimentary horizons as was recently pointed out by McKinstry(14).It has also been shown that banded ferruginous cherts, quartzites and cherty carbonate rocks of much lower metamorphic grade are well developed...

Jan 1, 1943

By A Purchase, C Stacey

The procedure for operation of deluge systems installed in road tunnels is still a subject of debate. The work undertaken in this paper assists in the understanding of the effects of deluge in road tunnels, and thus aims to help inform the development of operational policy. Analysis was undertaken using computational fluid dynamics (CFD) simulations to help explore the deluge interaction with the tunnel ventilation (including smoke exhaust) and combustion products. It was found, for the scenarios considered, that: Deluge activation can decrease the required critical velocity for smoke backlayering, and this in turn can improve the effectiveness of a smoke exhaust system.The dominant parameter for deluge effectiveness is the vehicle configuration, with shielded scenarios (such as a fire in the passenger compartment) showing almost no water reaching the fire. The water delivery rate (5 mm/min versus 10 mm/min) has only a minor effect on the smoke duct damper inlet temperatures and downstream smoke temperatures for small fires (5 MW). For large fires (50 MW) the higher water delivery rate gives slightly improved performance (lower damper inlet temperatures and lower downstream smoke temperatures). A one-dimensional transient tunnel model incorporating different operational and deluge response policies (ie deluge activation times) was developed. It was used to examine the influence of different operational parameters on life safety risk and tunnel damage risk. It was found, for the scenarios considered, that: The life safety risk for different scenarios has a sensitivity to deluge activation policy with the case of delaying the deluge activation for a long time giving the worst outcomes. However, the most critical parameters for life safety risk are operator response time (for all response activities, not just deluge) and the type of fire (configuration, size and growth rate).There is a reduction in risk of tunnel damage when the deluge is activated earlier, although the fire configuration (ie whether or not the seat of the fire can be reached) has the greatest influence on the outcome. It is concluded that the deluge activation policy should be case-dependent. It will depend on the tunnel, the safety systems provided, and most particularly the vehicles involved. The current policy in Australian tunnels is for manual activation of the deluge by the tunnel operator as soon as practical after the fire is confirmed (see also PIARC, 2007). This is a good policy. However, future work may be helpful to improve the skills of operators to make the best judgement as to when deluge should be activated, balancing all risks. This work could include research to further the understanding of deluge and fire in road tunnels, training programs and consideration of historical fire events.

Jan 1, 2008

By N Weatherstone

A consistent and reliable international approach to public reporting of a mining companyÆs main assets, its Mineral Resources and Mineral Reserves, has become of increasing importance in recent years with the rapid globalisation of the mining industry. Through the efforts of the Committee for Mineral Reserves International Reporting Standards (CRIRSCO), a committee representing national resource/reserve reporting committees in Australia, South Africa, UK/Ireland/Western Europe, Canada, USA and Chile, the reporting standards in most æwesternÆ countries use almost identical resource and reserve definitions and are generally around 90 - 95 per cent compatible. New codes based on the CRIRSCO model are being developed or considered in other countries, including Peru and the Philippines. This unified approach has provided the mining industry, regulators and investors with a common framework to report and interpret mineral resource and reserve estimates, thereby facilitating funding to the mining industry through improved investor understanding and confidence. The common reporting standards are reflected in the CRIRSCO International Template, available on CRIRSCOÆs web site, a document that is kept æliveÆ by reflecting the best of the most recently published CRIRSCO-type national standards. In a significant exception to this unified industry approach, the USA Securities and Exchange Commission (SEC) requires adherence to its own standard, only partly compatible with CRIRSCO-type standards, with adverse and costly implications for companies listed in the USA. A major industry submission was presented to SEC in April 2005 which, if accepted, would bring about considerable compatibility of CRIRSCO and SEC standards. The UN Economic Commission for Europe (UN-ECE) has, since 1992, been developing its Framework Classification (UNFC) as a single global system for harmonising all existing national and international resource/reserve reporting systems, covering both government and industry requirements and both the hydrocarbon and solid minerals sectors. While few mining companies report their resources and reserves using the UNFC, the system is accepted or is being examined as a basis for reporting by some governments, including those of Russia, China and India. The UN-ECE agreed in 1999 to incorporate CRIRSCO definitions into the UNFC for those categories of resources and reserves used for market-related reporting, but a more recent edition of the UNFC removed or changed the definitions, requiring re-engagement by CRIRSCO to ensure compatibility. Since 2005, CRIRSCO and the Society of Petroleum Engineers (SPE) have been involved in discussions with the International Accounting Standards Board (IASB), which plans to develop a new Accounting Standard for the Extractive Industries as part of its International Financial Reporting Standards. At the request of the IASB, CRIRSCO and SPE have been examining any potential for convergence of resource/reserve definitions between the mining and hydrocarbon industries. Each of these systems is described in this paper and high level comparisons made.

Jan 1, 2006

There are many different challenges when sampling mineral commodities. Sampling is part of many decision-making processes, from control of the number of drops of a reagent to all aspects involved in determining how much to pay for a mineral consignment. However, if all decisions must be supported by correct assumptions, or at least agreed terms, how can this be guaranteed? The main approach is to emphasise the importance of continuous surveying of sampling practices. If they are based on non-recommended protocols, this raises concerns. In addition, safety failures and lack of appropriate behaviour from the technical perspective can lead to disasters, both from the human and business perspectives. Impacts on safety and health are clearly unacceptable. It should be noted that imperfect safety and health practices in sampling operations have a strange correlation with incorrect sampling techniques. The commercial interface can also be affected. Companies have studied extensively the various aspects of measuring quality parameters for mineral commodities to understand the risks for investors and owners, and they take decisions that fundamentally respect the interests of parties in contracts and not result in losses. Every result should be obtained in defensible ways, and neither losses nor profits taken in indefensible ways. Most of such situations are related to bias; a significant systematic difference between a measured value and a reference value for a contractual quality parameter. Bias is always undesirable, because it always implies an incorrect advantage for one party and without doubt an undesired disadvantage for the other party. These situations are solved financially through a third-party arbitrator becoming involved in delicate situations, such as a commercial claim, but the outcome is always tangibly or intangibly bad for one of the parties. Another possibility is a permanent or temporary loss of precision. Poor precision, due its nature, generates reasonably balanced losses and profits, but it may hide out-of-control situations, generate instability and induce financial losses due to actions taken towards clearing commercial disputes involving interlaboratory programs, sample exchanges and duplicated sampling and sample preparation procedures, in the end wasting time and resources and creating a permanent source of commercial tension. While bias situations demand immediate adjustments for correctness, poor precision has to be understood as something that cannot be just calibrated out and is a situation that demands investment of time and effort. Precision optimisation has to take into account best practice for obtaining the required precision as well as cost/benefit analysis studies. Purchasers, engineers, salesmen and all personnel need to recognise that sampling is a major area to understand when taking decisions. The aim is to spread concepts that can really help, such as simple in-house actions to improve productivity and completion of surveys on commercial sampling operations, in order to ensure correct results are obtained and assertively take corrective actions, thereby establishing a healthy relationship with investors, suppliers and purchasers and in the process optimising the business.

Jan 1, 2008

Evidence abounds for sea-level change having occurred throughout geological and recent time. Driven by climatic changes, by cycles of glaciation and deglaciations, and by tectonics the position of sea-level relative to the crust has been going up and down since oceans first formed. Rates of these differential movements have been as high as 10 mm/year during the last major deglaciation as sea-level rose by about 150 m in about 15000 years. Tectonic processes can also produce change in sea-level relative to the crust of several mm/year as in, for example, the uplift of the Huon Peninsula in Papua New Guinea. To understand what is happening to sea-level today and what may be happening in the future it is necessary to understand the geological and climatic processes that have caused sea-level to change in the past and the best laboratory for the study of these processes is the geological and geomorphological record. Evidence for observations of sea-level change throughout Late Pleistocene and Holocene time is plentiful in the Australian region. Temporal variability is characterized by a low-stand, at more than 100 m below the present level, at about 20 000-18 000 years ago followed by a rapid rise and transgression of the continental margin up to about 6000 years ago. After this time sea-levels remained within a few metres of their present value but the patterns of change are not everywhere the same. The depth of the low stand at about 18 000 years ago does not appear to have been the same everywhere. Nor does the time at which sea-level first reached its present value appear to have been everywhere the same. The fluctuations about present sea-level during the past 6000 years appear to have been different in different localities. As yet there has not been a wholly satisfactory quantitative explanation for this spatial variability. How much, if any, is indicative of vertical tectonics? How much is the result of the Earth's response to the changing surface loads as mass is exchanged between ice sheets and the oceans? Can any of it be attributed to past changes in global climate? Or are the observations just wrong?

Jan 1, 1990

The geographical region of South East Asia is variously defined, but generally agreed to include the Asean group - Philippines, Malaysia, Thailand, Singapore and Indonesia. Other regional countries, such as Vietnam, Laos, Burma, Kampuchea etc. are of course geographically part of the region, however in economic terms, they play a minor role. It is the Asean group that dominates present economic activity and provides the overwhelming opportunity for commercial development. My experience in South East Asia has been gleaned over 15 years of regular travel in the region. More recently, we have established company offices in Malaysia, Singapore and Indonesia to extend and deepen contacts with major customers. This progressive development is an integral part of a planned growth pattern and will be discussed in more detail shortly. South East Asia is a rapidly developing economic growth centre, a fact which is clearly recognised and accepted by most commentators. An important question is then to be asked: Why has the region been relatively neglected by Australian, U.S. and European industrial supply companies? I will attempt to address this question in the context of industrial minerals and propose some ideas as to how effective sales programs could be developed. Firstly, let's consider the market potential provided by countries within the region. It is reasonable to suggest that industrial growth in S.E. Asia over the past 20 years has been generally steady and in some cases, explosive. Until recently, this growth has predominantly been driven by development of internal (regional) demand. Population growth and rising living standards have ensured that basic industries have enjoyed a solid uptrend in sales and production. The industries which most benefitted from regional economic development over this period were, interestingly, those which we understand to be major users of industrial minerals - glass, ceramics, paper, surface coatings, cement, refractories, rubber and plastics. Each of these industrial sectors has been influenced by different growth stimulii over a 20 year period. Nevertheless, they also enjoy a common feature which ensured an above average performance. All sectors are fundamental to an environment enjoying rising living standards and rapid growth in general prosperity. More recently, internal growth factors have been overtaken by a recognition that manufactured products from the region are competitive in export markets. This comparatively recent development provides the most interesting possibilities for higher value industrial mineral raw materials. Let me explain: For 20 years, industrial growth in South Asia has essentially been focused on satisfying domestic demand. Finished quality of manufactured items was orientated to a developing market more interested in cost than aesthetics or long life. This was reflected in raw material specifications, which often did not exist and at the best were undemanding.

Jan 1, 1989

By T Gibbons, M Korte, C Brent, K Runge

The Barrick Osborne concentrator has gone through a number of upgrades since commissioning and steadily increased production from the original 119 t/h design capacity to 265 t/h milling throughput in 2008. This was achieved incrementally over several years, by maximising operating efficiencies, in order to minimise capital expenditure, and take advantages of economies of scale; but more importantly it was reached with no measurable loss of recovery. Osborne currently processes a blend of under- ground with open pit material from the nearby Trekelano deposit. Following primary/secondary crushing, the material is processed through a rod/ball mill grinding circuit ahead of rougher/scavenger flotation that produces a copper concentrate.Osborne was seeking a further increase in plant throughput of the order of 15 per cent, but at more sustainable levels of secondary crusher plant utilisation. In early 2008, Osborne contracted Metso Minerals Process Technology Asia-Pacific and South America (MMPT) to review the entire process from run-of-mine feed to final copper concentrate. This review would be done concurrently, with surveys of both the crushing/ grinding and flotation circuits being performed at the same time. The outcome would be a steady-state model of the complete flow sheet allowing the crushing/grinding model to interact with the flotation circuit model such that overall process optimisation was possible. Two key outcomes for the operation are exploration of the operating limits of the currently installed plant, and projection of the logical next stage of potential capital plant expansions. This paper covers Part B or the flotation component of the project. A separate paper discussing Part A or crushing and grinding is also being presented at this conference. Surveys of the Osborne flotation circuit were performed along with a comprehensive review of the cell characteristics including measurements of the gas and froth phases of individual flotation cells. These data resulted in a size-by-size floatability component model of the complete circuit. This circuit model was then used to perform steady-state simulat- ions to evaluate options to improve both overall circuit and individual cell performance. The grinding circuit model discussed in a separate paper or Part A of this project was then used interactively with the flotation circuit model to recommend the best operating regime to maximise overall efficiency. For example, the balance between increased crushing and grinding costs versus higher copper recovery and final concentrate grade. Due to changes in market conditions in the fourth quarter of 2008, the focus was shifted to prioritising operational changes rather than capital expansion modifications, in order to improve circuit performance.

Jan 1, 2009

By D L. Richardson, B Tiedt, C D. Morgan

Following residentsÆ concerns that the ongoing operations of Collinsville Coal (CCP) mine may be resulting in the release of contaminants, including products of acid mine drainage (AMD), into downstream environments, the Queensland Environmental Protection Agency (QEPA) issued CCP with a Notice to Conduct or Commission an Environmental Evaluation at Three Mile Creek. A key objective of the Environmental Evaluation was to assess the extent and magnitude of impacts to aquatic communities and their habitats. A multidisciplinary investigation examined a suite of physical, chemical and biological indicators to meet this objective. The study also aimed to identify contaminants of concern and the location of potential pollutant sources. Potential indicators of AMD, including elevated dissolved solids concentrations and low pH, were evident within the mine lease. However, significant differences in concentration of these indicators upstream and downstream of the confluence with Three Mile Creek were not observed. Although only proxy indicators of AMD contamination, these results suggest that the extent of impacts downstream is minimal. For the purpose of this study, physio-chemical indicators were selected on the basis of those best likely to provide an understanding of the likelihood of contamination, within the constraints of readily available long-term monitoring data. Ecosystem health indicators were adopted to supplement the existing data set and provide a more æroundedÆ perspective of water quality attributes within the system, generally unattainable by standard physio-chemical assessments. In contrast to AMD products, sediments were considered more likely to have a widespread impact on aquatic ecosystems. Waterways throughout the study region, including those unaffected by mining, have been affected by broad-scale sedimentation and were typically highly turbid. Due to the many diffuse sources of sediment potentially liberated within the catchment, the contribution of the mine compared to other land uses on total sediment loads entering streams is difficult to determine. This is clearly a major management issue for mines throughout the Bowen Basin. Streams of the central Queensland region display enormous variability in water flows and physio-chemical characteristics over a range of spatial and temporal scales. This variability presents major difficulties in distinguishing anthropogenic impacts from natural variability (noise). Despite this variability, impact monitoring by mines in the central Queensland district has tended to focus almost entirely upon physio-chemical indicators. The results of the present study indicate that a multiple indicator approach to environmental assessment is more useful for separating mine related impacts from natural ænoiseÆ and impacts from other land uses. In the absence of such information, by adopting the precautionary principle of Ecologically Sustainable Development (ESD), there is potential for an environmental impact to be incorrectly attributed to mining when other activities in the catchment may be contributing to changes in stream æhealthÆ.

Jan 1, 2003

Gold was discovered in the Bendigo area of Victoria in 1851 (Willman and Wilkinson, 1993), and all the early gold mining of any note involved washing (puddling) the gold out of the regolith or alluvium. The waste material from this process was a semi-fluid mixture of rock debris, soil and water, referred to as `sludge'. Puddling machines were gradually introduced to speed up the puddling process (Cole, 1994), and by 1855 an estimated 2000 machines were in the district (Anderson, 1978). In 1859 it was estimated that approximately 2 293 000 m3 of material was puddled annually by the machines on the eastern side of the goldfield, whose waste drained into Bendigo Creek and its tributary gullies. It was also estimated that after the gold was removed, approximately one-quarter of the residue/sludge consisted of the heavier, coarse-grained material which settled out fairly quickly, while the remainder, approximately 1 720 000 m3, was the fine-grained material which flowed downstream for some distance (VPP, 1859 - 60). From these figures it can be assumed that for the ten years during which this volume of puddling was maintained (1854 - 1864) over 5 700 000 m3 of gravels and sands and 17 200 000 m3 of fine-grained sludge had been discharged into and around Bendigo Creek. This was enough to cover an area of over 400 km2 to a depth of 5 cm. By 1859 the problems associated with the sheer volume of sludge being discharged were such that a Royal Commission was appointed to `Enquire into the Best Method of Removing the Sludge from the Gold Fields' (VPP, 1859 - 60). The goldfields referred to were those in the Bendigo area around the township of Sandhurst (now known as Bendigo). The Report of the Commission (VPP, 1859 - 60) stated that: `... inspection of the country bordering upon the course of the Bendigo Creek, to a distance of about fifty miles from Sandhurst . . . ' had revealed that the sludge had ' . . . filled up watercourses and flooded pasture lands . . . '. It also noted that ' . . . even on the plains, thirty or forty miles away from Sandhurst, where the sludge flows thin, and is relieved from its heavier particles, we found it baked into a perfect concrete, and in thicknesses varying up to two feet or more . . . '. The italics were used for emphasis in the original text. As it was considered unlikely that the physical evidence for such widespread inundation would have disappeared completely over the intervening 130 or so years, a project was initiated to locate any evidence of the inundation in the current landscape. If such evidence were to be found, then an estimate could be made of both its extent and its effects on the topography, drainage, and land-use of the inundated area. Extensive field work has determined that over 700 km2 to the north of Bendigo was inundated by the sludge. The area has not been uniformly covered, but has occasional `inliers' which have obviously escaped inundation by being slightly higher than the surrounding areas. Today the sludge is readily identified as a very fine-grained, hard-setting, concrete-like `capping' overlying a well-developed, well-structured, pedal horizon, or in some instances, the gravels and sands of a creek bed. The thickness of the sludge capping varies between a few centimetres and three metres (Peterson, 1996). The buried topography was gently undulating, in direct contrast with the almost unnatural flatness of

Jan 1, 1997

By T Muri

The drying operation of materials from particulate solids, through slurries and suspensions, to continuous sheets represents an important part of several processes in the chemical and mineral industries. The increasing demand of high productivity at low cost and minimal environmental impact makes it complex to evaluate and choose the best available drying technology for each industrial application. The drying technologies are mainly characterised on the basis of how the wet product is related to the drying medium, namely: direct and indirect drying. In the direct drying method (convection drying), the product is brought into direct contact with the drying medium, which may be hot gas or air. Large quantities of gas are necessary for transfer of the required energy. A special case of the direct dryer is the fluid bed dryer, in which the product floats on a cushion of air or gas. The process air is supplied to the bed through a perforated distributor plate and flows through the bed of solids at a velocity sufficient to support the weight of particles. Very high heat and mass transfer values are obtained as a result of the intimate contact with the solids and the relative velocities between individual particles and the fluidising gas. In the indirect drying method (conduction or contact drying), the wet product is separated from the drying medium. The drying unit can consist of a rotor forming the indirect contact heating surface mounted in a stationary or rotating shell. The indirect method uses saturated or superheated steam resulting in low energy consumption and minimal environmental impact. In this paper, a review is given of the technologies available on the market based on different drying methods. The advantages and the disadvantages are summarised with respect to issues such as investment and operating cost, maintenance, product capacity, product handling and environmental impact.

Jan 1, 2006

By Fullagar P. K

In resource definition and mine development, major capital expenditures are committed on the basis of sparse information and even in production surprises such as bad ground are not uncommon. Drill holes constitute the principal source of information about the orebody and its environment and optimisation of drilling implies maximising the yield of useful information per dollar expended. Geophysical borehole logging provides new flexibility for optimising the drilling budget. Economic benefits can flow from geophysical logging at all stages of the mining cycle. The most commonly cited benefit is substitution of diamond delineation drilling with cheaper percussion or reverse circulation drilling in cases where geophysical logs can substitute for core. This approach can deliver an attractive direct saving in drilling costs (and time) if drill meterage is unchanged, or a potentially greater indirect benefit from better ore control if more holes are drilled within the original drilling budget. More ore contact intercepts per dollar can translate into lower dilution and enhanced ore recovery, thereby increasing revenue as well as reducing mining costs. Substitution of diamond drilling with percussion drilling is not always feasible. However, geophysical logging of diamond holes is often highly advantageous in its own right, both for geotechnical characterisation as well as ore delineation. Operational advantages of logging include data objectivity, speed of interpretation and reduced core handling and analysis costs. Geophysical logging assists mining engineers by providing a continuous measure of in situ rock strength, even over intervals with poor core recovery. The additional expense of geophysical logging in blast holes can be justified in terms of more accurate ore boundary delineation and rock strength evaluation. Precise ore boundary delineation permits refinement of charge placement, to minimise dilution and maximise recovery. Detailed knowledge of rock strength can enable optimisation of blast design. Rock strength can be evaluated in real-time via analysis of drill performance data recorded with measurement-while-drilling (MWD) technology. To successfully apply geophysical logging in mines, its technical, operational and economic viability must all be established. This entails verification of the existence of appropriate physical property contrasts, investigation of the best way to integrate the geophysical results with the mining method and an objective assessment of the value of the resulting mine performance benefit. Geophysical logging is already well established in many mining operations. The greatest impediments to its wider utilisation at mines are: lack of appreciation of geophysics by most mine geologists, engineers and managers; limited interpretational aids; and the necessity to re-enter completed drill holes. In this paper we endeavour to address these issues by informing mine geologists about potential applications of geophysics, by illustrating automated interpretation of geophysical logs and by highlighting the importance of emerging MWD and logging- while-drilling (LWD) technology.

Jan 1, 1997

Batterham and Algie began their paper on: `The role of technology in the minerals industry' (1995) by noting that while: it is often stated that innovation is central to the economic survival of mining and minerals processing in the face of global competition, .. . technology is often far from a core strategy in our industry. This point is correct. Throughout the world, as a broad generalisation, mining companies do not value technology development as a principal means of gaining competitive advantage. It is important to understand why this is the case. Batterham and Algie address this question by making distinctions between innovation, technology and research. They note that while: all successful (mining) companies are good at innovation . . . that innovation can proceed without any research and development and that it is innovation that generates the competitive advantage, not research and development per se. In this paper we accept these arguments. However, our focus is somewhat different. Whereas Batterham and Algie took a mining company's perspective on the technologies of mining and processing, we take a broader view of the opportunities for technology development for company Australia but, in order to focus the argument, we restrict our discussion to the area of mining (rather than processing); we focus particularly on mining systems and mining equipment. We begin by looking at the motivation of companies operating in any industrial sector to invest in research and development. Figure 1 recognises four levels of industrial maturity. For companies in the embryonic and growth stages R&D often is essential to initiating and developing the business. Mining, on the other hand, is a mature industry. In mature industries the conventional roles for R&D are to reduce costs, to extend product differentiation, or to develop new technology with the aim of rejuvenating the business. Next we ask whether these general-industry arguments apply to the mining industry. If they do then the mining industry should value R&D more highly; after all cost reductions and business rejuvenation are goals that are worth achieving. On the other hand if, for whatever reason, these general arguments do not apply to mining then this may lead the mining industry to invest only modestly, or not at all, in R&D. In this event, while this may be a rational decision for the mining industry, it may not be in the best interest of a nation like Australia where revenues from the sale of mineral products represent an important part of the country's economy.

Jan 1, 1997