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By D Mather

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

Jan 1, 2006

It is a commonplace of our industry that prices of most minerals have been historically weak during the 1980s. The International Monetary Fund's index of prices of metals fell 25 per cent between 1980 and 1982, rose slightly in 1983, and has since fallen further. In December last year it was 37 per cent below its 1980 average. The few temporary exceptions to the mineral industry's malaise highlight the excess capacity, which largely explains the weakness of prices. The industry has painfully come to recognise that more satisfactory prices will not be restored until supply capability and demand move back into better balance. Mine capacity was installed in the expectation of much faster growth of demand than has occurred. For a variety of reasons mine and plant closures have been insufficient to restore equilibrium to the market-place. The industry may, therefore, have to resign itself to continued weak prices for some years more, at least by the yardstick of the 1970s. Growth rates of demand have slackened off in line with economic activity, and in response to continuing substitution and technological improvements. To the extent that the recent weakness of oil prices stimulates the industrial countries' activity, demand for non-fuel minerals may grow faster than most forecasters now predict. It is, however, much too early to say how long the weaker oil prices will persist, and even more difficult to estimate their probable effects. In typical post-war business cycles the usual response to recession was to batten down the hatches, and ride out the storm. Sooner or later, and probably sooner, demand resumed its previous trend path, and prices recovered. The market, in effect, bailed mines out of trouble; the more efficient could make attractive pre-tax profits whilst even the poor to mediocre could earn a satisfactory living. Prices rose at least as fast as general inflation, and in the early 1970s much faster. In retrospect those price rises of the early 1970s were historically abnormal but they did not appear so in the prevailing inflationary climate of the time. When the market failed in the early 1980s many of the hardest hit companies looked for scapegoats.

Jan 1, 1986

By Boyle L. A

A positive displacement pump is being dev eloped for pipeline transportation of coking coal to a -50 mm export specification, at a con- centration and velocity which will allow trans- portation in the plug flow region, minimising degradation of the particle structure, and pipe= line friction losses which will be lower than with turbulent or laminar flow. Pump operation is by hydraulic powered free pistons in a rota- ting cylinder block, with cylinders overlapped by stationary inlet and discharge ports in a water lubricated and sealed rotary valve. Before this development coking coal was not considered suitable for transportation in slurry form, for the valves in the double act- ing duplex piston pumps used for slurry pipe- lines, cannot be divorced from the slurry and require that the solid material must be reduced to a fines'consistency before introduction into the pump suction. The hydraulic transportation of 10 million tonnes of -50 mm coking coal, 50 km from the Bargo area west of the escarpment to an offshore shiploader at Port Kembla is feasible. Study shows that economic factors alone would dictate that the development of a pumping system for long distance transportation of coking coal is necessary. The greatest impact from the slurry transportation of coking coal would be the

Jan 1, 1976

In order to meet the increasing demand for coal for their Newcastle Steel Works, the Broken Hill Pty. Co. Ltd., on June 5, 1937, approved of a scheme to sink a tunnel to the Victoria Seam at their Burwood Colliery. This seam was virgin at this locality and lay nominally horizontal at a depth of 320ft. vertical from the surface.For the purpose of despatch of the coal produced it was decided that the tunnel be equipped with a rubber belt conveyor system.This was a comparatively new departure in Australia, and, indeed, was one of the first installations of its kind in the world, designed to raise coal from considerable depth by this means. Later the tunnel was extended to the Borehole Seam, which lay nominally horizontal at a vertical depth of 600ft. from the surface. The whole installation is the subject of this paper.In planning a project of this kind, consideration had to be given to the following:-1. Location of tunnel with regard to existing surface railway sidings and shafts.2. Ultimate tonnage required.3. Width and construction of belt.4. Speed of belt.5. Inclination of belts.6. Number of belts and design of equipment.7. Cross-sectional area of tunnel.8. Inclination of tunnel.9. Surface drainage.10. Type of equipment for drifting the tunnel.11. Method of ventilating the tunnel during sinking.After the general layout and design of the scheme had been prepared it was decided that tunnel drifting would begin immediately and that the belt installation, together with the feeder plant, would be detailed and manufactured by the time the drift...

Jan 1, 1947

The inauguration of a geological department for the mines of North Broken Hill Limited necessitated the provision of accurate plans and sections upon which geological facts and projections might be plotted.Unfortunately, the basic data were very inadequate. For the British Section, sill survey plans were available, but no regular stope plans. Filling surveys had been preserved for many stopes, but on innumerable pieces of tracing linen, without heights of any kind, and not altogether reliable (as indicated by the finding of very inconsistent duplicates). For the bulk of the old stopes no plans exist at all. The expenditure of much time and patience has resulted in the co-ordination of most of the existing stope data, but the British Section must for the rest of its life continue to have surprises in store, as has been the case for many years past. Manufacture and preservation of stope records has, of course, been on a sound footing during recent years. No reliable cross-sections of the British Section were available.The Marsh, Junction, and Junction North Sections have for the most part very poor data. In the North Section, level plans were fairly reliable, and cross sections of the lode made for ore reserve purposes have been preserved for quite a few years. No floor plans of stopes were kept, however, until a couple of years ago.Diamond Drill records vary in quality. Practically none exist for the Junction and Junction North Sections. Logs have been kept for the British Section drill holes, but are...

Jan 1, 1940

By J Centofanti, D Conti, R Riske, C Morley, A Cook

Why is it so difficult? Why are there differences throughout the resources industry in how reconciliation factors are reported and calculated? Why is there no standard formula to use? These are common questions asked when mining companies try to compare reconciliation results across operations or attempt to undertake internal or corporate governance reporting processes. For many mining companies the calculation of reconciliation factors is often a very time and resource intensive part of mandatory reconciliation reporting. Some major mining companies, that move millions of tonnes of material per annum, dedicate full time resources to the calculation of reconciliation factors. The willingness of these companies to set aside resources demonstrates the value that operations place on good reconciliation reporting. Reconciliation is about measuring the variance between two like measures at different points along the mining sequence. It can be undertaken between predictive models, forecast plans and actual measured performance. Calculations are used to derive a variance between two sections within the mining sequence, with the result being commonly known in the resources industry as a æfactorÆ. Mining companies use the calculation of reconciliation factors as key performance indices (KPIs) to provide a æhealth checkÆ of their operation, with variances often pointing to issues either with the accuracy of the original estimate or the quality of the measurement being used in the comparison. There are many reconciliation factors that can be calculated and reported. This paper will set out, clarify and provide a recommended standard means of calculating each specific factor that, where adopted by a company, will ensure compliance with the international reporting codes, such as JORC. Using case studies from Rio Tinto Group (Rio Tinto) and BHP Billiton Mitsubishi Alliance (æBMAÆ), and the authors experience across a wide range of mine sites, the outline of a generic solution for tracking a parcel of material from the pit through to the port along with appropriate reconciliation factors is provided. The intention of proposing standardised reconciliation factor terminology and methodology is to provide the foundations of a system to enable communication and comparison across different commodities, companies and mines sites.

Jan 1, 2009

By R Pie, J Crusius, P Whittle, J J. McNee

The Main Zone and Waterline pit lakes at the Equity Silver Mine near Houston, BC (Canada) are the sites of an ongoing three-year government- and industry-funded research program. In order to assess the feasibility of various bio-remediation strategies, field-scale manipulations were conducted using enclosed mesocosms (limnocorrals). Two manipulation strategies were tested: addition of algal nutrients (phosphate and nitrate) to Main Zone Pit surface waters; and addition of algal nutrients (surface waters) and dissolved organic carbon (deep waters) to the Waterline Pit. Nutrient addition was conducted in order to stimulate algal production and enhance metal scavenging by biogenic particles, while dissolved organic carbon (ethanol) was added to increase oxygen demand and foster the development of sulfate reduction in pit bottom waters. Fertilisation resulted in rapid growth of natural phytoplankton populations in the surface waters of both pits. In the Main Zone Pit, the stimulation of algal growth resulted in the pronounced removal of both dissolved and total metals (Zn and Cu) from surface waters, with higher rates of metal removal being observed at higher nutrient additions. Metal removal could be attributed to the scavenging of dissolved metals by biogenic particles and subsequent particle settling. A similar pattern of removal from surface waters was observed in Waterline Pit (Zn and Cd). The addition of ethanol to deep waters in Waterline Pit was effective in promoting sulfate reduction in the lower layer. The development of reducing conditions resulted in near-quantitative removal of dissolved Zn and Cd, presumably as secondary metal sulfides. Iron, As and Ni profiles in Waterline Pit exhibited no evidence of removal from either surface waters or bottom waters. Collectively, the results demonstrate that the passive forms of bioremediation tested in these pit lakes may be effective for whole pit-lake remediation.

Jan 1, 2003

Solid Energy New Zealand Limited (æSolid EnergyÆ) is a state-owned coal mining company, producing 4.0 Mtpa from a number of opencast and underground mines in the Huntly, West Coast and Southland regions in New Zealand. The company currently exports 2.1 Mtpa of coking coal. Exports are expected to grow strongly over the next five year as the company expands production into new semi-soft and thermal coal reserves. Domestic coal demand is also expected to grow strongly, particularly in the North Island, as the Maui gas field reserves diminish, and thermal coal becomes more important for electricity generation and meeting the energy needs of forest processing and other industries. Solid Energy is expanding and developing its risk management practices across all areas of the business: strategic planning û extensive use of scenario analysis and probabilistic modelling over a 20 year period; investment decisions û development and application of a rigorous six stage æProject Assessment GuidelineÆ process for all new mine developments; geological and geotechnical risk assessment techniques û use of best practice techniques including seismic surveys; financial risk management û a dynamic approach to hedging based on effects based analysis of Cash Flow at Risk analysis against preset risk tolerances; risk financing û the use of a captive insurance subsidiary, and the experiences of a small coal company seeking to obtain insurance cover on a æhardÆ international insurance market; and integrated risk management û the challenges of trying to implement a broad integrated risk management approach across the company, that supports implementation of strategic objectives as well as meeting æcompliance or legislative basedÆ risk management requirements.

Jan 1, 2003

Blasting is at first sight a simple operation. Blastholes are drilled in a suitable pattern, primed, charged with explosives, stemmed and finally the blastholes are connected together to give the appro- priate initiation sequence. In practice the action of the explosive takes place in the interior of an opaque rock mass and only the external faces of the rock mass to be blasted can be easily observed. The mechanisms of blasting cannot be observed directly and must be inferred from observations of the free face and meas- urements of particle movement made by sensors grouted into holes in the rock. Explosives react very rapidly, in some microse- conds and any instrumentation of a blast must have an appro- priate response time. In many mines several rock types can be encountered during production. Several different methods of blasting may be necessary to cope with changes in rock types espe- cially if weak rocks are found in the final limits. This also makes it difficult to be sure of getting a large enough volume of rock to perform a series of reproducible experiments. While there appears to be agreement on the mechanism of blasting it is unlikely that a detailed understanding of how all the variables that can be encountered in practice affect blasting. The ease of assessment of the results of blasting depends on the criteria used. It is easy to isolate, measure and count over- size boulders. It is however difficult and costly to get a complete fragment size distribution. Methods used to assess blasting can vary significantly from site to site and the ways in which data are collected, presented and analysed will vary making compari- son of blasts at several locations very difficult. The definition of an optimum blast can also vary with the type of blasting. The muck-pile profile and fragmentation will be different for a dragline to that for a truck and shovel operation. In order to be able to assess blasting the mechanism has to be understood. Th rock and explosive properties considered rele- vant to blasting can then be determined. This paper discusses the generally accepted mechanism of blasting. The on-site observa- tions to assess blasting are-then listed. The mechanism of blast- ing can also be modelled and the use of modelling to optimize hlaetina ie thPn Aiernccarl

Jan 1, 1988

Mt Muro was a gold and silver mine in Central Kalimantan on the Island of Borneo, Indonesia. Aurora Gold through its Indonesian subsidiary Indo Muro Kencana owned the project. Processing commenced in November 1994, and ceased in June 2002. Mining, including prestripping, commenced in March 1994, and ceased in May 2002. Nominal throughput was 1.5 Mtpa, at average grades of 3.80 g/t Au and 99 g/t Ag. From the start of prestripping until the end of 1996, Drill Blast sampling was the main grade control method. After several studies into the viability of Reverse Circulation, including an assessment of costs and benefits, the switch from Drill Blast to Reverse Circulation was made in late-1996. From 1997 until the end of the project Reverse Circulation was the main grade control method. The mine-to-mill call factors û the reconciliation between predicted and actual tonnes and grades delivered to the mill û for the period from commencement of processing to December 1996 were 1.069 for tonnes, 0.949 for gold, and 0.969 for silver. The mine-to-mill call factors between January 1997 and June 2002 (excluding a period of significant illegal mining) are 1.086 for tonnes, 0.977 for gold and 1.025 for silver. At face value this indicates a 2.8 per cent absolute improvement for gold, and 5.6 per cent for silver. Using average grades for the project, an additional 5112 oz of gold, and 267 173 oz of silver were delivered annually to the mill using Reverse Circulation sampling instead of Drill Blast sampling. The additional recovered metal value is estimated at $US 2.87 M annually, significantly exceeding the cost of Reverse Circulation drilling. This paper discusses a number of issues that may affect the estimated benefits.

Jan 1, 2003

By W van der Westhuizen

Mining professionals recognise the need and application for reconciliation and value tracking. It is necessary however to examine our current reality, and evaluate the following. Do our reconciliations really balance correctly, and are we able to track value effectively throughout processes? If we are honest, in most operations the answer is a resounding no. This means that we are surrounded by fluctuation and deviations that we do not account for and do not understand. This is astounding, because given our level of scientific knowledge and the technological tools at our disposal we should have a good understanding of our environments and be able to manage them effectively. How do we manage effectively if we are surrounded by so much uncertainty? The purpose of this paper is to describe, at high level, the principles of reconciliation and value tracking, to highlight some areas where deviations are introduced into the mining process, and to propose a different approach to the apparent reconciliation and value tracking conundrum. The paper also poses several questions that need to be critically addressed at most operations. Instead of making the same mistakes each month in reconciliations, mining professionals need to acknowledge two facts. Firstly there will be uncertainty that we need to accept, since all our estimates are based on sampling, an orebody is not homogeneous and peopleÆs behaviour will influence the process, etc. Variability will always exist and lead to uncertainty. What is the current approach in the reconciliation process when a deviation occurs and how do we use reconciliation and value tracking to manage and improve our business? The second fact is that we need to stop using reconciliation and value tracking to only measure and report. We need to adopt a new approach to manage mining throughput, where reconciliation and value tracking are enablers to the success of the business. In most mining operations, significant effort goes into planning and measurement for the purposes of reconciliation and value tracking. The importance of accurate and effective reconciliation and value tracking should be to ensure the maximum utilisation of the resource, maximising throughput and enabling the business to deliver a product to its client, of the correct quality and in a timely manner.

Jan 1, 2002

Recent well-publicised problems with the start-up of new mining projects have continued to feed the perception that the mining business in general and Ore Reserves in particular are a poor risk. New mines commonly experience difficulties when the true variability of ore characteristics becomes apparent during commissioning. At this critical stage, the impact of lower metal recovery, reduced throughput or increased consumption of reagents and energy can have a catastrophic effect on economic returns, as illustrated by the premature closure of some operations. There appear to be several common reasons contributing to the poor performance of mining projects, of which three are examined here: lack of early risk assessment before feasibility studies are started, inadequate sampling for metallurgical test work and variability of the run-of-mine (ROM) ore. An underlying feature of these issues is the lack of effective interaction between geologists, mining engineers and metallurgists/ process engineers. Geologists need to be more aware of ore processing issues and the range of characteristics that need to be considered as part of the resource estimate. Metallurgists need a greater understanding of the variability of the run of mine ore in terms of all the characteristics that influence the design and operation of the plant. Mining engineers need to determine the short-term variability of the ore in the mine schedule, so that there is confidence that the quality of the run-of-mine ore will be within the design specifications of the plant. A substantial overlap between these disciplines and sharing of areas of responsibility is necessary if these and other technical problems are to be better understood, production estimates are to be improved and commercial risks are to be reduced. Although the JORC Code (1999) provides guidelines for reporting all the issues that are material to an Ore Reserve estimate, some issues are rarely fully addressed in Ore Reserve reports. In particular there is no formal requirement for a metallurgist to assure his or herself of the appropriateness of the Ore Reserve classification. Consequently the level of uncertainty related to recovered grade and ore processing characteristics may be understated. It is suggested that to meet the concerns of bodies funding new mineral developments a stronger multi-disciplinary approach to the analysis of mineral deposits and reporting of Ore Reserves is required. The culmination of this approach would be the formal requirement for a geologist, mining engineer and a metallurgist to co-sign Ore Reserve reports.

Jan 1, 2002

Industry has a very special request to make. Environmental issues must not be allowed to become a factor of competition so that nations or individual industries can gain economic advantages for themselves by encroaching unduly upon the environment. An international harmonisation of the demands imposed on specific industries and industrial plants where discharges are concerned is therefore essential. The same applies to any to any action contemplated against noxious products. An important step towards that goal is no doubt represented by the United Nations Conference on the Environment scheduled for 1972. Conclusions: Australia must recognise its responsibilities in an inter- national movement to control pollution. It must react on a national scale to a problem which is threatening our whole national environment. To gather, collate and coordinate the information needed to ensure policies which strike a balance between conservation and development, we must look towards the Commonwealth to coordinate the activities of its own instrumentalities and those State and independent bodies working in the area. Financial aid must be provided to stimulate research and later to ensure that environmental protection policies are observed. These policies will be founded on social economic theories which will be both practical and sound, The United Nations conference on the Environment is scheduled for 1972 and in this is the opportunity for international cooperation. Cooperation in the field of controlling legislation and the collection of much needed data. There is an imperative need to assemble facts for world use - an international know-how bank which acquires the most sophisticated technology of process design and waste purification. Arising out of this Conference, is it too much to expect that there could be established an international authority for environmental control, whose activities are governed on a multi-national basis? Such an organisation would have as its primary concern the collection and classification of official regulations, as well as the sheer collation of data to permit economic evaluation of the costs of conservation of the environment. There is an international scope with different factors involved, including industrial technology: in other words, the concrete measures taken against industrial pollutants ought to be more or less identical for similar industries irrespectives of the countries in which they operate. The assembling of an international common foundation of knowledge is imperative so as to acquire the most sophisticated technology of process design and waste purification available for all who are interested.

Jan 1, 1971

By A F. Idziak

The aim of the present study was an application of coal optical property measurements for analysis of paleostress field existing in fault zones of the Upper Silesian Coal Basin (USCB) during the coalification of organic matter. Measurements of vitrinite reflectance were carried out on coal samples taken near a hanging stope of the Klodnicki fault. Other samples had been taken in vicinity of the Krzyzowicki fault. The Klodnicki fault is one of the main tectonic discontinuities in the northern part of the USCB. It is postulated that its origin is related to the deep-rooted latitudinal discontinuity in crystalline basement of the basin. The Krzyzowicki fault is located in the western part of the USCB where fold tectonic style dominates. Vitrinite, one of the basic components of hard coal is generally considered as optically anisotropic material. Anisotropy of physical properties is induced mainly by stress, which arranges vitrinite structure. Vitrinite anisotropy can be described by an ellipsoidal model called reflectance indicating surface (RIS) which is a geometrical representation of the optical anisotropy tensor. The investigation of the RIS for vitrinite was carried out on coal samples. The apparent maximum and minimum reflectance values measured for a single vitrinite particle were plotted against corresponding bireflectance to construct the reflectance crossplot. Interpretation of this plot yielded the magnitudes of the RIS three principal axes. The data obtained point to differences in optical anisotropy of coal under the study. The coal samples taken from block tectonic zone near the Klodnicki fault had mean reflectance value of less than 0.80 per cent. Their anisotropy coefficients were about 0.1. Optical properties of coal changed from the biaxial positive in the western segment of the fault to the biaxial negative in its eastern part. It suggests that past tectonic stress was greater in the western part of the zone than in the eastern one. Coal originated from a fold tectonic zone at the vicinity of the Krzyzowicki fault has mean reflectance value much greater than from previous region (ÿ1.20 per cent). Its optical anisotropy coefficient is equal to about 0.07. It suggests that paleostress field was more isotropic. The presented study shows the usefulness of coal reflectance measurements in the analysis of paleostress field existing during coalification process.

Jan 1, 2003

By M Noy, P Hawkes

Improvements in the drill and blast process can impact on loader performance in a number of ways. The main effects being improved loading cycle times, less non-productive cycles such as oversize removal, clean-up and face raking and better bucket fill factors. The impact of improved loading cycle times on the overall cost and productivity of the load and haul cycle is very much dependent on the loader truck match and the management of the haul fleet. Previous work has shown that a 20 per cent improvement in dig cycle times may only lead to three per cent or less improvement in the overall productivity of the load and haul process. However, improving the mass loaded per pass by five per cent will lead to a five per cent improvement in productivity for any given haul fleet situation, assuming sufficient truck capacity. Work by Orica Explosives at Lab ChrysotileÆs Thetford Mine, Quebec, Canada showed a relationship between muckpile fragmentation and truck payload. With this in mind, work was carried out to determine the effect differing muckpile fragmentation distributions can have on excavator bucket fill factors. This work was performed in the laboratory to a 1:100 scale. Nine different distributions were used. These were characterised by the Rosin Rammler parameters, xc the characteristic size, and n, the uniformity index. The values of xc and n used were modelled on those previously measured at a Sydney quarry. For the range of distributions measured, it was found that the fill factors were lowest at a low characteristic size and a high uniformity index and highest at a high characteristic size and a low uniformity index. In other words the best fill factors were achieved with a more dispersed muckpile distribution with a larger characteristic size. The difference in fill factors was 16 per cent indicating that controlling the drill and blast process to produce a specific muckpile distribution can have a significant impact on the overall cost-efficiency and productivity of the load and haul process. Field measurement by Orica Explosives at a quarry in Canada supports this conclusion showing improvements of up to seven per cent in average bucket load by either increasing the characteristic size or decreasing the uniformity index of the muckpile.

Jan 1, 1999

By K Gilliland

The past decade has seen the widespread implementation of computerised real-time operational management systems in open pit mines. While these systems have made a significant impact on operational efficiency at a process level, surprisingly little work has gone into integrating these systems with other IT systems, including those used for tactical planning and enterprise resource planning. As a result of this gap in the information hierarchy, the goal of optimising an entire operation, or multiple operations, remains elusive. Implementation of computerised operational management systems in underground mines has been much slower. This is a significant, though often overlooked, reason why the productivity for underground mining is generally so much lower than for open pits. The historical reluctance to implement computerised operational management systems underground can in part be attributed to the underground environment, particularly the difficulty in establishing effective communications. Another factor retarding the implementation of systems underground has been the perception that the nature and scale of underground mining does not lend itself to computerised operational management. This perception can be challenged, not only by a process level examination of the underground mining, but also by a holistic examination of the entire industry. In recent years, the mining industry as a whole has destroyed rather than created wealth and underground mines are major culprits. The degree of value destruct has been more pronounced with underground mines, as the usual problem û low commodity prices û has been exacerbated by the harsh environment, low productivity and a æfog of warÆ no longer generally found in open pits. Faced with these realities, underground mines will have to adopt modern management tools or suffer extinction at the hands of an unsympathetic investment community. All is not gloom and doom, however. Technological advances have largely overcome the difficulties associated with the underground environment. As a result, there is a small, but growing, number of underground mines using computerised operational management systems to directly improve the bottom line. Much greater improvements can be realised if the industry takes advantage of the recent convergence in technology, to integrate process information with tactical and enterprise resource planning systems in order to provide a solid platform for all decision-making. This would result in the æeÆ mine. Given that the underground fraternity is essentially starting with a blank sheet, they have the opportunity to æsteal a marchÆ on open pit mines, who may be constrained by legacy systems. The benefits of the æeÆ mine are presented through a hypothetical case study that examines the shortfalls of the non-æeÆ mine. The paper ends by presenting a future vision for the æeÆ mine.

Jan 1, 2000

Fleet management systems have been adopted by many open pit mines throughout the world and the resulting improvement in truck cycle times has been one of the most significant contributors to mine efficiency. Ongoing enhancements to fleet management systems such as interfaces for vital signs monitoring have given incremental efficiency gains. Each incremental improvement is another step towards a grand vision of a totally automated mine. A relatively new fleet management system is being integrated with two other technologies to provide a highly reliable platform for a networked information system which monitors mine machinery and production. The paper reviews the integration project, the features of the new mine site information network platform and the contribution to productivity and safety. The new fleet management system has a predictive truck dispatch algorithm. It also has a distributed database that replicates rapidly so that each machine in the fleet has an identical database, thereby making each machine aware of other machinesÆ locations on the site. High precision systems for navigating and monitoring machinery such as drills, dozers, draglines and shovels provide individual machine operators with cockpit style real-time information to increase their operational efficiency. The integration of the new fleet management systems capabilities with the high precision systems that provide production information, machine vital signs data and operator information means that the mine operations and maintenance managers have real-time access to the whole mine siteÆs production data. Such a mine monitoring and reporting system is dependent on reliable wireless communications and reliable positions. Positions in fleet management and high precision systems for open pit mines are usually provided by global positioning system (GPS). Other global navigation satellite systems (GNSS) such as Glonass, and in the future Galileo, will provide additional satellite cover; however, some parts of open pit mines do not have enough sky visibility for reliable GNSS positioning and so a new centimetre level wireless positioning system called Locata is being integrated with the fleet and high precision systems to augment and backup the GNSS positions. The final integrated system will provide the highest levels of reliable position-based information to all stakeholders in a mineÆs operation, ensuring gains in productivity and safety.

Jan 1, 2008

By C J. Berry, P H. Briggs

Assessment of metal mobility, acid rock drainage production, and toxic effects from weathering of mineralised materials (ie mine-waste piles and outcropping alteration/ore zones) is key in evaluating and mitigating metal mining sites. Many metal- and acid-generating materials at these sites are sulfur minerals (sulfides to sulfates) with differing reactivities, weathering characteristics and metal contents. Our working hypothesis predicts that data on the types and quantities of sulfur minerals, coupled with comparison of their sulfur isotopic compositions to that of aqueous sulfate in the surrounding environment, can be used to evaluate primary pathways of weathering reactions at mining sites. We developed a sequential extraction scheme to separate the phases of sulfur in mineralised materials. Operationally defined phases, including monosulfides, disulfides, elemental sulfur, water-soluble sulfo-salts, acid-soluble sulfates, and resistant sulfate phases such as barite, are quantified gravimetrically and/or instrumentally. Several sets of experiments were designed to test the effectiveness of this extraction scheme. First, a variety of ore sulfides diluted in an inert matrix was analysed with the scheme. Results showed that molybdenite and arsenic-bearing sulfides do not behave as predicted from just their sulfur oxidation states, indicating that samples containing these minerals need special treatment for complete phase recovery. Second, a natural mine-waste composite standard was analysed by the scheme. The sum of the phases was equal to the total sulfur concentration analysed independently. Each phase had a similar, but distinct sulfur isotopic composition. The results were verified with a laboratory prepared æproxyÆ having the same mineralogical composition as the standard, but with each phase having a very different sulfur isotopic composition. The sulfur isotopic compositions of the recovered phases from the æproxyÆ showed that the scheme effectively separated the sulfur with only minor cross contamination of phases. The speciation and isotopic analyses were applied to both mine-waste piles and naturally occurring alteration zones at nine mine sites. A case study from one site comparing the sulfur isotopic composition of minerals in an alteration zone and dissolved sulfate in proximal streams is presented. This case study shows the application of our data to differentiating sources of sulfate in the surrounding environment.

Jan 1, 2003

By Derham DW, Newcombe LA

The operations of the Mount Morgan gold tailings retreatment plant were significantly improved in 1984 by the desliming of the CIP plant feed, which reduced cyanide consumption and increased percent gold dissolution. Subsequently, the development of slimes treatment, incorporating gold leaching from slimes solids by copper cyanide complexes in the process water, and gold adsorption on to carbon in an environment lacking free cyanide was successfully implemented. Mount Morgan was initially mined for gold commencing in 1882 on the auriferous ironstone cap to the sulphide ore body. During the history of mining and processing at Mount Morgan the operations have developed through numerous phases of gold and copper production, operating almost continuously through until the final closure in late 1990. The final phase of processing was the retreatment of tailings, predominantly flotation tailings accumulated since the 1930s, for the recovery of gold and minor silver. Tailings retreatment commenced in 1982 with the commissioning of a 10 000 tonnes per day CIP plant to treat some 40 million tonnes of tailings at an average grade of 1.08 g/t Au. The initial operations were hampered by high cyanide consumption and poor gold dissolution on the mixed siliceous/pyritic tailings. The successful development and implementation of the desliming of the CIP plant feed in 1984 (as described by Parsons and Hampshire, 1986) reduced cyanide consumption by 40 per cent, and raised gold extraction by 13 per cent points by virtue of significantly higher dissolved oxygen levels. The finer portion of the reclaimed tailings were deslimed by eighty 100 mm diameter AKW cyclones, with the desliming cyclone overflow thickened in a Warman 30 in diameter thickener for water recovery and slimes disposal. Operation of the desliming plant involved the discarding of a slime fraction representing about 15 per cent of the reclaimed feed. Although gold-bearing, the high content of cyanicides and oxygen consumers within the slime negated any conventional treatment of this stream with free cyanide for gold recovery. The natural lixiviant behaviour of the soluble copper cyanide complexes for gold, which was extremely evident at Mount Morgan, directed efforts in this area. Enhancement of gold leaching with a deficiency or near absence of detectable free cyanide, but with significant levels of copper cyanide complex from recycled process water were examined. Adsorption of this solubilised gold onto carbon in a similarly difficult environment required close examination.

Jan 1, 1993

It would be a good thing when reviewing the challenges to be faced by the Australian gold industry to set the backdrop and scene for them, by briefly examining the history of this vital and dynamic industry in the Australian context. Gold mining in Australia had its official beginnings in 1851 when John Lister and William Tom discovered gold at YorkyÆs Corner, later renamed Ophir by Edward Hargraves. From that first tentative beginning, the ensuing rush of prospectors into New South Wales and Victoria meant that the annual gold production in those early years surpassed that of the next 40 years. This early rate of production was only eclipsed when AustraliaÆs production was once again lifted by the discovery of gold on the other side of the continent, in Western Australia. (Figure 1). The years leading up to the First World War saw Australian production peaking once again at over 115 tonnes of gold, a production rate that would not be surpassed until 1988. This renaissance in production at the beginning of the 1980s was achieved by the application of technology. The advent of bigger trucks and shovels meant that earth-moving costs dropped dramatically. This, coupled with the highly effective and efficient carbon-in-pulp processing route, stimulated the Australian gold mining industry into a state of frenetic activity. These two innovations were the principal factors that enabled the economic exploitation of the lower grade haloes left by the æold-timersÆ around the deposits exploited at the beginning of the last century-no high finding costs here. AustraliaÆs production through the 1980s and the early part of the 1990s was largely supported by the exploitation of these haloes. As these were depleted, the aggressive exploration effort stimulated by the strong cashflows of these early oxide deposits resulted in new æblindÆ discoveries which are now emerging as the backbone of the Australian industry (Figure 2). Gold production is a major contributor to the Australian economy. In 1998/99 the Australian gold industry accounted for approximately 16 per cent of the value of all mineral exports, which in turn accounted for over 35 per cent of AustraliaÆs total exports. As such, the Australian gold industry, by itself, accounts for just under six per cent of AustraliaÆs total exports (Figure 3). Consequently, the industry is responsible for over one per cent of AustraliaÆs gross domestic product. These statistics are all the more compelling when we consider that, at the beginning of the 1980s, goldÆs contribution to exports and GDP was insignificant (Figure 4). Within the Australian resources industry, gold mines and associated infrastructure account for ten per cent of all capital expenditure (Figure 5). From an employment point of view, in 1997/1998 the industry directly employed (excluding contractors) about 7700 people, approximately 15 per cent of all those employed in the minerals industry. Just under nine per cent of the workforce in the minerals industry are female, whereas in the gold industry over 16 per cent are female.

Jan 1, 2000