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By V Srinivasan, P Knights, C T. Farrelly

By 2025, with the widespread industry adoption of remote operation centres and advanced analytics, mining companies will find themselves making better, more informed decisions across the value chain. Process automation will drive significant business integration and reorganisation. Better collaboration between functions will make cross value chain optimisation a reality. Wherever possible decisions will be automated, based on analytical models and embedded in an enterprise decision management (EDM) architecture. This will take care of many of the minor day-to-day or the minute-to-minute decisions that consume operators and managers today. More flexible information technologies and architectures derived from the extensions to Web 2.0 and service oriented architecture (SOA) will solve many of the integration issues of today. The ongoing business imperatives for doing more with less people will make true collaboration with partners such as mining contractors, equipment vendors, transport providers, suppliers and maintenance contractors commonplace throughout the industry. All these organisations will be linked in and share common goals and objectives in real-time while providing visibility of internal constraints and available capability, allowing optimised decisions to be made across the extended enterprise. Humans will increasingly move to a more supervisory role and will use advanced collaboration to quickly solve complex abnormal issues that span the value chain out to the extended enterprise. The open collaboration and communication models instilled in the workforce through the widespread use of social networking technologies will drive thought leadership far beyond current æbest practiceÆ thinking. This will encourage the mining industry to extract the business value from rapidly converging fields of study such as environmental sciences, neuroscience, psychology, engineering, information technology and business finance. The future of mining will see a more uniform distribution of data savvy workers between the ages of 20 - 40, forcing a change in current operations. This group will drive the adoption of ubiquitous computing, augmented reality, presence and digital labelling. The enterprise will shift from a relatively static disparate set of functions to a digitally aware, integrated and interactive environment with information available, in context and just in time, to those who need it. The networked virtual enterprise will therefore be a reality.

Jan 1, 2008

By B Snook, G Rollinson, R Fairhurst, R Herrington

Nickel laterites constitute a significant proportion of the worldÆs Ni reserves and are considered environmentally friendly alternatives to traditional sulfide resources. Subsequently they are of increasing significance for exploration and production. To be successfully exploited, however, they require an understanding of the relations between mineralogy, texture, grade and recovery. The development of automated quantitative mineralogy can aid in the characterisation of the ores to help improve extraction and processing methods. Recent developments in hydrometallurgy have resulted in relatively straightforward recovery of Ni in silicate (saprolite and smectite) ores. However, the extraction of Ni from limonitic ores is more complex. It requires a detailed understanding of the iron-hydroxide species and other, potentially interfering, oxide and hydroxide compounds. Particularly the relations between the Ni-bearing goethite and Mn, Al and Cr may adversely affect the economic prospects of an ore. Manganese can adversely affect the selective recovery of Ni and Co from solutions but has also been highlighted as a significant potential by-product (cf, Zhang and Cheng, 2007). Aluminium hydroxides can be significant acid consumers leading to an increased expense of extraction (Johnson, Cashmore and Hockridge, 2005). Chromite is resistant to acid attack, but chromium in goethite may adversely affect the dissolution leading to a retention of Ni (McDonald and Whittington, 2008). This study presents an investigation of oxide and hydroxide species in laterites using QEMSCAN« EDS/SEM-based automated quantitative mineralogy. Samples were collected from Turkey (¦aldag), Albania and the Philippines. Particular emphasis has been placed on the development of a quantification for Ni-poor and Ni-rich goethite.

Jan 1, 2008

By P Waters, P Hollings, M Baker, D R. Cooke

Over the last three million years, porphyry and epithermal mineralisation in the Baguio Mineral District has been driven by calc-alkaline magmatism associated with the subduction of the South China Sea plate and the Scarborough seamounts beneath northern Luzon, Philippines. Coupled with extreme uplift and exhumation rates, mineralisation in the Baguio District has been responsible for the emplacement of over 922 million grams of gold. As one of the oldest intrusive bodies associated with the Baguio District, the Black Mountain Cu-Au deposit consists of at least five intrusive phases overprinted by potassic and propylitic alteration and sulfide mineralisation. Gold ore grades are low and molybdenum grades high with respect to other porphyry Cu-Au deposits in the Baguio Mineral District. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By A H. Hofstra, G P. Landis, P Emsbo, A G. Hunt

Models of the evolution of the hydrothermal systems that form porphyry Cu (Mo-Au) deposits are compromised because aqueous magma-derived fluids in the ore zones of most deposits have changed from their original magmatic compositions as a result of cooling, depressurising, mineral precipitation, brine-vapour unmixing and fluid-rock reactions. However, in deep quartz-rich, sulfide-poor veins from numerous porphyry type deposits, we have identified parental fluids trapped in inclusions at near magmatic temperatures and pressures above the brine-vapour unmixing solvus. We have analysed these inclusions for bulk salinity, density, solute chemistry, helium isotopic ratios and elemental composition. These parental inclusions contain 35 - 70 volume per cent bubble, are low to moderate salinity, contain up to ten mol per cent CO2, and commonly contain a chalcopyrite daughter crystal. Our results indicate that these Cu-rich fluids transport Cu from a plutonic complex below upward into a hydrothermal system, where decompression, cooling, unmixing and water-rock reaction drive ore-mineral precipitation. Na/Cl ratios greater than one indicate that in addition to chlorine, sulfur and/or carbonate must play a key role in Cu transportation. Helium isotope ratios indicate that between ~15 and 100 per cent of helium in these fluids is mantle-derived. We suggest that in addition to He, volatiles from mafic magmas in the mantle are also likely to supply CO2, Cu and S to the fluids that form porphyry copper deposits. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Same-batch and non-blind as well as blind pulp duplicates are often submitted as quality assurance/quality control (QA/QC) control samples to a routine laboratory along with routine assays (and other control samples such as reference material samples). The current ways of interpreting the results of duplicate assays to derive QA/QC conclusions and decisions, however, has not yet been formalised in a scientific manner. The current, prevailing approach and its limitations are reviewed and a new method is proposed as a substitute tool. This new tool should allow for operational error detection on a batch per batch basis (ie batch rejection) as well as laboratory performance assessment with time on reproducibility.

Jan 1, 2008

By S R. Pecover

AustraliaÆs opal and sapphire mining industry has fallen from its peak in the 1980s and 1990s into a significant low today. This is not due to exhaustion of the resource, but instead an over-reliance of the Australian miner on achieving a fair price for the gemstone product from offshore middlemen dealers. Gemstone and geological research is also at a low as Federal higher education expenditure has fallen with research institutions relying increasingly on private funding in an environment of restricted autonomy and flexibility for researchers. What little remaining research skills the universities have is being bled into the private sector as a result of the mining boom and encouraged by lower than average academic salaries. Nevertheless, some highly innovative research has been taking place, often by self-funded individuals and retired academics simply with a desire to advance the understanding of the particular branch of science in which they are interested. New models for the formation of sapphire and opal are now beginning to be applied to the exploration for these gemstone commodities. This research, together with well thought out plans for managing the gemstone product through its value-adding steps to the jewellery retail level, has the potential to bring about a resurgence in the Australian gemstone industry.

Jan 1, 2008

By J Johansson

The aim of this paper is to discuss how to form work and organisations in the mines of the future. The Kiruna underground iron ore mine in the far north of Sweden is used as an example on how technical development affects organisational issues like skills, work identity and gender. Over a period of 50 years one can see a transformation of work from manual underground work to automation and remote control from surface level. What characterised the old underground workface was the close relation between man and the hard rock and with arduous physical work under dangerous conditions. Today, the face miners are located on the seventh level of an office building close to the mine. There is also an emerging, and in many aspects already evident, knowledge transformation û from the old and obsolete physical and tacit knowledge and skills (for example the ability to æread the rockÆ) to something new, which can be described as abstract æhigh-techÆ knowledge and skills. The modern technology has created a new type of work û new in terms of competencies and knowledge as well as workload and organisation. At the same time the mining company are recruiting more women and promoting the former pure male work as attractive workplaces for both women and men. All this has effects on how individuals and company create and recreate skills, identity and gender. To some extent the technological development predestines these changes, but there are some choices to be done when forming good work and organisations for the mines of the future. The traditional mining workplace culture and behaviours and the old type of masculinity, the æmachoÆ style, will be challenged by the new æhigh-techÆ work and new competency demands. The changes risk meeting restoring responses, which can have negative impact on the performance of the organisation, for example making it inflexible and perhaps ælaggingÆ behind the technological development. These questions need to be handled when planning future mining.

Jan 1, 2008

Sixty years after its inception, after an alternation of periods of admiration and rejection by the industry, Sampling Theory can now be seen as going through its golden age. A brief history of its successive transformations and progresses achieved by its author, Pierre Gy, and his followers, reveals the theoretical as well as practical difficulties that had to be vanquished to reach this point. Its current level of acceptance and corresponding trends are discussed and illustrated, with an insight on its increasing real role in the industry and future prospects for its further development.

Jan 1, 2008

Research cruises dedicated to seafloor hydrothermal activity along the Kermadec arc first began with the Sonne-135 expedition in 1998. This was followed by the worldÆs first systematic survey for venting along an arc during the 1999 NZAPLUME I expedition. Since then, cruises dedicated to mapping plumes along the Kermadec arc include NZAPLUME II (2002), NZAPLUME III (2004) and ROVARK (2007). In addition, the manned submersible cruises SWEEP Vents (2004) and NZASRoF (2005) utilised the Shinaki 6500 and Pisces V, respectively, to sample in detail select hydrothermalsystems for mineralised samples, rocks and vent fluids. The ROVARK (2007) cruise was the first to deploy an autonomous underwater vehicle (ABE) along the arc which surveyed Brothers volcano at a far greater resolution than had been done previously by ships on the sea surface. While these expeditions have largely been led by GNS Science, together with its collaborators from National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory (NOAA/PMEL), significant contributions have been made by other groups from various nations, exemplifying the global interest in seafloor hydrothermal activity associated with intraoceanic arcs. This is an ASTRACT only. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Two years ago I was sitting in a big lecture theatre at the School of Mines in Kalgoorlie at the annual New LeadersÆ Conference listening to a guy tell us all how much he loved his job, travelling the country ælegallyÆ blowing stuff up à and getting paid to do it. I would have paid to see and do the things he spoke of à now IÆm that guy. From finishing a mining engineering degree at the University of Ballarat, through the job hunt, to firing environmental blasts in Tassie and designing and implementing construction blasts in the middle of the Gold Coast. My name is Rohan Stevens and IÆm a blast-o-holic. While the æjob huntÆ we all embark on toward the end of our degrees is a stressful time, itÆs also very exciting in the current climate. There are a number of things I have learnt through both my hunt for the job that best suited me and working for the worldÆs largest explosives manufacturer. If at least you donÆt benefit from my learnings IÆm certain you will enjoy hearing about (and viewing) some of the work I have had the opportunity to be involved with over the last 18 months with Orica Mining Services.

Jan 1, 2008

The Ernest Henry Mine is an open pit copper-gold mining operation located in north-west Queensland, Australia. It is owned and operated by Xstrata Copper with a current concentrator throughput of approximately ten million tonnes per annum. The pit will cease mining towards the end of 2010. Extensive surface diamond drilling has confirmed an extension of the orebody to depths of 1000 m below surface. A prefeasibility study was commissioned in late 2006 to investigate underground mining options with the preferred mining method being an inclined sublevel cave. In February 2008 mining of a decline commenced in conjunction with a feasibility study to further investigate the project. Work from the prefeasibility study indicates that an underground crusher, conveyor and hoisting shaft could be utilised to crush and transport broken ore from the sublevel cave workings to the concentrator. The study suggests that a production rate of five million tonnes per annum could be achieved and sustained for up to ten years. Ventilation designs and requirements will form a large section of the feasibility study. This paper will detail investigations of preliminary ventilation network designs of the proposed sublevel cave. Work has been completed using both Ventsim and VumA ventilation simulation packages. Ventsim was used to provide preliminary estimations and suggest alternatives for: surface fan duties;airflow characteristics (direction, velocity, pressure and quantity); andventilation network design in key mine areas. With mining activities reaching depths in excess of 1000 m below surface an analysis of heat conditions should be conducted. The VumA software package was used to model the thermal properties of the ventilation system. This model will provide a basis for the preliminary decisions on refrigeration requirements for the mine.

Jan 1, 2008

By G W. Scott, H M. Lukey

The Lake Superior Region has been a producer of iron ore for over 150 years. Early mining operations concentrated on direct shipping ores, which are the result of post-depositional upgrading principally by deep weathering. As direct shipping ore reserves became depleted, the focus changed to the production of iron ore pellets from taconite. The post-depositional processes responsible for upgrading taconite are regional metamorphism, contact metamorphism and hydrothermal processes (Clout and Simonson, 2005). While these processes are important in iron ore genesis they can also contribute to liberation problems and in some instances reduced pellet quality (Han, 2004). Low-grade metamorphic mineral assemblages can negatively impact liberation and pellet quality. Low-grade iron formation may contain a suite of carbonate minerals including ankerite, dolomite, kutnohorite, siderite and magnesiosiderite. Variation in the distribution and composition of siderite and magnesiosiderite makes controlling the MgO content of pellets difficult. Carbonate minerals also require calcination in the pellet induration process, which requires additional heat to be added to the system, slowing down the induration process and reducing throughput. Prediction of carbonate mineralogy and carbonate mineral chemistry is an important goal of ore characterisation for pelletising properties. Contact metamorphism causes changes in mineralogy and grain size (Klein, 1973; Gunderson and Schwartz, 1962). Increasing the grain size of magnetite should improve its liberation characteristics. However, plant grinding targets may not allow the coarse-grained, more easily liberating magnetite ores to increase throughput and can actually result in decreased throughput due to recirculation. While magnetite and martite ores are well understood (Lukey, Johnson and Scott, 2007) late open-space filling microplaty haematite ores are not. These ores, while composed of similar minerals, have a unique genesis that results in fine grain size and complex textures that present liberation challenges and often make interpreting laboratory metallurgical test results more difficult.

Jan 1, 2007

By C Aldrich

In this paper, the use of topology preserving projections (Sammon maps) and neural networks are considered as a basis for the construction of multivariate statistical process control charts for a semi-autogenous grinding circuit on a gold plant. Comminution circuits are often operated in a quasi-steady state mode, where the mills tend to move rapidly from one state to another. This makes them difficult to monitor by conventional means designed for continuous steady state processes. As a first step, process data reflecting normal operating conditions are mapped with SammonÆs algorithm. Only one feature is extracted at a time and each mapping is captured by a neural network model to allow online application. Reverse neural network models are used to reconstruct the data prior to the extraction of subsequent features from the data residuals. The ensemble of neural network models can then be used for both fault detection and identification. The approach compared favourable with both linear and non-linear principal component models. It was able to detect two simulated fault conditions both with a reliability of 100 per cent, as opposed to 57.8 per cent and 95.2 per cent detected by an approach based on the use of linear principal component analysis and 84.1 per cent and 98.0 per cent detected by an approach based on non-linear principal components extracted with auto-associative neural networks.

Jan 1, 2007

By D H. Bell

Slab-buckle failures in coal sequences involve thin slab deformation in strata dipping parallel to the footwall, and are a consequence of both unloading and the weak nature of the thinly bedded rock mass. Methods of modelling and predicting such occurrences include: +        a conceptual model using a base friction table, +        a mathematical model using the Euler solution for column and beam bending (after Goodman, 1980), and +        computer analysis techniques such as UDEC (Universal Distinct Element Code after Cundall and Hart, 1993).   Slab-buckle failures have the potential to seriously disrupt production because of their volume and rapidity, and to endanger both equipment and personnel working on the pit floor.   In July 2004 a large slab-buckle failure occurred overnight after a new batter and bench had been formed at the Malvern Hills Opencast Mine in inland Canterbury. This involved the entire length of the pit (85m along strike) when a 2m thick intact slab with a total volume of ~3500m3 translated down dip 6.2m on the base of a thin coal seam to form a pronounced buckle at the toe. The coal measures consist of finely laminated mudrocks with multiple coal seams of varying thickness dipping ~45¦ to the southeast, and the opencast mine had been designed with footwall batters formed parallel to bedding with a vertical bench separation of 15m.   Back analysis of the Malvern Hills failure was necessary to investigate the controls on footwall instability, and for future mine design. An engineering geological model was created and samples of the slab material and failure surface were collected and tested to establish the required parameters for use in the Euler solution for column and beam bending. Back analysis using the Euler solution provided unrealistic results that overestimated the overall length of a stable slope by more than 10 times.   No further large scale slab-buckle failures have developed at the mine site, in part because of the slow rate of coal extraction, but precautionary drainage of the footwall slopes has been undertaken to improve overall batter stability. The location of the slab-buckle failure on a critically positioned pre-sheared thin coal seam with full hydrostatic head is considered the most probable cause of the July 2004 failure, rather than inherent instability of the generic bench and batter arrangement adopted. The use of a precedent-based engineering geology approach to future mine design is considered the most appropriate solution in the circumstances.

Jan 1, 2007

The link between exploration success and new ideas from research and development (R&D), although often assumed, is rarely well explained or well illustrated. One issue is understanding the role of innovative ideas in the exploration process, and another is determining the relative contributing factors to an exploration success. A useful measure of gold exploration success over an extended time period and geographic area is discovery rate (θ): Discovery rate θ = gold discovered/exploration expenditure (usefully expressed as tonnes of gold per $1 million). The total gold discovered is strongly leveraged to discovery rate, as any increase in θ typically has a positive effect on exploration expenditure. Hence, improving the discovery rate is a key driver for a sustainable mineral industry, especially for gold. There are very few ways to influence θ beyond innovative R&D ideas and breakthroughs, and well-motivated and trained staff. The Australian gold industry has experienced exceptional exploration success with 9956 tonnes of gold discovered from 1979 to 2003, inclusive. This equates to: Discovery rate θ = 0.9 t/A$1 M Two-thirds of this gold has been found in the Yilgarn craton of Western Australia (6265 tonnes Au). Without this exploration success, there would have been no platform on which to build the current gold industry and to take advantage of elevated gold prices and advances in mining and processing. Several causes of the Western Australian gold success have been proposed, and more than one may be correct. Gold price, and mining and processing advances have all had influence; but exploration success and discovery of gold were essential to add to the miniscule resource base of 1979. A comparison of the exploration methods used to search for gold in the Yilgarn craton in 1979, and 1990, highlights a small number of breakthrough ideas introduced to the industry during the 1980s, and in most cases emanating directly from local R&D. By the 1990s, these ideas were being used in most gold exploration programs in the Yilgarn craton, and are still used today. These six breakthroughs are: epigenetic timing of gold deposit formation (ie after formation of rock sequence), chemical and mechanical role of host rocks, relevance of carbonate alteration haloes, gold dispersion in the regolith, optimal sampling media, and appreciation of landforms in exploration program design. Interestingly, gold exploration science in Western Australia entered the 1980s period without rigid paradigms in place regarding gold deposit formation; there was a balance between descriptive and genetic models, there was scope to research gold deposits from microscopic to global scales and there were highly effective industry research uptake processes in place: it is suggested here that these favourable conditions contributed to the exploration success and industry growth.

Jan 1, 2007

By J B. Holman, P A. Weber, P Lindsay

Underground and opencast coal mining has occurred since 1896 on the Stockton Plateau, West Coast, New Zealand. Acid Rock Drainage (ARD) from historic and current mine workings has had an adverse environmental impact on the surrounding aquatic environment. The two main catchments affected by ARD from historic and current mine workings are the Mangatini and St Patrick Stream catchments. Solid Energy New Zealand Ltd (SENZ) is using active (e.g. alkali dosing) and passive (e.g. engineered cover) technologies to mitigate the adverse environmental effects associated with ARD contaminated waterways. This paper discusses the passive technologies. Principal strategies include the capping of high capacity potentially acid-forming volumes of overburden. The mudstones were found to generally have the highest sulphur levels compared to other overburden lithologies. Areas with high mudstone volumes are prioritised to be encapsulated and 390 Ha is planned to be capped in the Mangatini catchment in the near future.   Monitoring beneath granite, cement kiln dust and coal combustion product covers show oxygen can be reduced to less than 10% of atmospheric levels. Laboratory column leach tests that were subjected to oxygen flux rates of 10 % showed reducing oxygen ingress into acid-forming material can result in significant acid load reductions.   The oxygen content below the cement kiln dust cover was generally lower than 5% and water quality measured in lysimeters beneath this cover improved after 50 weeks of emplacement. Column leach tests containing saturated samples were undertaken to determine the most appropriate water medium in preventing pyrite oxidation. The sample saturated with ARD (pH ~ 3) had a negligible acid production rate and leached very minor Al concentrations although Al is soluble at low pH. This indicated saturating waste rock dumps with ARD can be an effective method in mitigating ARD formation.

Jan 1, 2007

By A R. Bye, T R. Stacey

Anglo PlatinumÆs Potgietersrust Platinums (PPRust) operates three open pits and plans to excavate 90 Mt of rock in 2007. With pit slopes expected to reach a height of 400 m, the geotechnical department has a key role to play. Over the last four years PPRust has successfully implemented new geotechnical strategies and tactics to reduce risk, improve safety and maximise profitability. A large database of core logging, face mapping and rock testing data has been assembled and used for failure analysis, geotechnical zoning and rock mass ratings. The data has also been used for optimising blast designs on a daily basis through the use of a geotechnical block model. This greatly improves blast fragmentation and therefore loading and milling efficiencies. The slope design process involves limit equilibrium analysis, numerical modelling, rock fall analysis and block modelling. Slope management includes comprehensive limit blasting and visual inspections, and state-of-the-art slope monitoring equipment, namely the GroundProbe radar, Riegl lasers and GeoMoS automated prism monitoring. The risk-consequence approach has been used in slope optimisation, where all the slope analyses, operational controls, costs of failure, economic analyses of various slope designs and fault tree analyses are used to determine the ideal slope designs. These activities added over $25 million of value to the operation and also ensured compliance with Anglo AmericanÆs acceptable risk level. The successful mining of the optimised slopes is to due to the greatly improved geotechnical knowledge and slope management. PPRustÆs geotechnical work is used as a benchmark for Anglo American open pit operations. The focus of the paper will be on the value added to the operation by all aspects associated with slope management.

Jan 1, 2007

By K Paki, K Parker, J F. Dupont

The Mount Charlotte grinding circuit at KCGMÆs Fimiston mill was recently equipped with three 650 mm CAVEX cyclones in order to improve the overflow P80, reduce the fines bypass to the underflow and improve the underflow density/recovery of water to the overflow. After the first two sets of surveys were conducted air core boosters (ACBs) were installed on the 650 mm CAVEX cyclones in an attempt to further increase their performance. JKTech was approached to assist with the examination of the data obtained from the surveys; this data was intensively modelled to determine, to a high degree of confidence, the impact the changes to the cyclones had on the classification and the benefits to the plant. This paper outlines the outcomes of the trial and the methods used to determine those outcomes.

Jan 1, 2007

By T Hughes

Upward pressure on all mining operations is coming from the triple bottom line. To some extent this is being offset by the rise in mineral prices, but this may or may not continue. The other serious issue facing all companies is the replacement of economic reserves as exploration levels over the past decade continued to decline in line with falling mineral prices. In order to underpin the sustainability of the mining industry it is necessary to continue to reduce cost, reduce the mine environmental footprint, whilst increasing community benefit. At the same time it is imperative that we increase the economic reserves. The highest risk is in adding new mineral discoveries as the strike rate for economic discovery decreases. Gekko Systems Pty Ltd recognises that the most simple and risk averse route to increasing economic reserves is to reduce cut-off grade in the mine, thereby bringing formerly uneconomic reserves into the economic category. We have been developing a new process flow sheet which embodies the triple bottom line and the issue of economic replacement of reserves. This paper describes this flow sheet and presents four examples where this concept is/can be applied to bring about triple bottom line benefits. Sustainability can only be assured if we are the ones in control of our environment, costs and reserves.

Jan 1, 2007

In general the iron ore industry has been slow to adopt the Whittle Pit optimising software in the evaluation of iron ore deposits. The reasons for this are two-fold:the iron ore industry has developed techniques, usually bespoke software residing in the corporate offices of the respective iron ore companies, to establish their final pit limits; and the fact that the Whittle software doesnÆt easily lend itself to estimating a sales product of constant quality without maximising grade (metal content). The Whittle software is based on the work done by Lerch and Grossman (in the early 1970s), which proposed that graph theory be used to establish an optimal surface that maximises the revenue from a deposit. The maximised surface created in the pit optimiser is translated into a proposed optimal final pit shape that can be used by the mine design engineers as a target outline to lay out the final practical pit. By treating a geological and ore resources model that was created for an iron ore deposit as a subset of the recoverable resources estimation (RRE) type of geological models, the evaluation of an iron ore deposit and establishing the final pit is greatly simplified in the Whittle 4-X optimiser. Instead of trying to optimise the iron content of the deposit, the emphasis swings to maximising the extraction of a finished and saleable iron ore product. This is achieved by treating the finished saleable iron ore as an element in the multi-element Whittle optimiser. The quality of the finished sales product is represented, and the material that cannot be used in the blended product is also shown. Proposals for enhancing the functionality in the Whittle 4-X optimiser to make the evaluation of iron (and coal) deposits easier includes the creation of a new reporting function that will allow the user to specify which field(s) can be used as the divisor(s) for the reporting of the element grades in the model.

Jan 1, 2007