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A simulation program has been developed tc predict the airflow distribution and thermal environment in multi-level narrow lode Cornish =n mines. Because of the approximate equality between fan power and natural ventilation _rergy a true thermodynamic mesh balance using mass flow rather than volume flow rate was required. Compressibility is allowed for by calculating mesh corrections on a mass flow of dry air basis. In this context, and within the confines of any steady state model, both the steady flow energy and pressure equations are satisfied with equal validity. The mesh balance includes natural ventilation energy, frictional losses, moisture lift work, water droplet energy and fan energy.

Jan 1, 1988

By Davey KJ

Complex sulphide ores are characterised by complex texture of the valuable minerals. Any assessment of the performance of differential flotation circuits treating such ore should include analysis of the effects of poor liberation of the valuable minerals. Selected samples were taken from balanced size by size surveys of the flotation section of a concentrator treating an ore body containing fine grained galena and sphalerite in a matrix of iron sulphides which is mostly pyrite. liberation measurements were made using the QEM*SEM system on four or seven size fractions. The measurements indicated that less than 40 per cent of the galena and less than 60 per cent of the sphalerite in the flotation feed was liberated. The final concentrates were largely composed of composites of valuable minerals and iron sulphide however there was a small but significant fraction of liberated iron sulphide. Using the sized mineral flows obtained from the original balances and the liberation measurements, a satisfactory liberation balance was obtained. This enabled the effect of liberation on the flotation performance to be examined; not only for the entire circuit but also in the rougher, scavenger and cleaning sections. In the zinc circuit the effect of a regrind mill could be assessed. Recovery of galena in the lead circuit was limited by the recovery of composite lead particles. Recovery of liberated galena exceeded 95 per cent in all size fractions while the recovery of composite galena exceeded 85 per cent below 38 ¦m but fell sharply above 38 ¦m. Examination of the behaviour of the liberated and composite galena in the various sections of the lead flotation circuit revealed high recoveries of both liberated and composite galena particles in the roughing and scavenging sections but very low recoveries in the final two cleaning stages. Similar trends to those observed in the lead circuit applied in the zinc circuit although the performance of the liberated sphalerite also fell off at sizes greater than 38 pm in this case. Thus the zinc recovery was limited by the flotation of both the liberated and the composite sphalerite. The effect of regrinding was to increase the recovery of sphalerite mainly by reducing the amounts of sphalerite in less liberated sizes rather than by increasing the liberation of the sphalerite within a given size Fraction.

Jan 1, 1993

By D Burgess

Since the days of mandatory high cost pilot plant testing in 6 ft + 2 ft SAG mills autogenous griding/semi-autogenous grinding (AG/SAG), mill specific energy is now calculated by various empirical formulae and pilot testing carried out in small laboratory mills. Barratt (1989) described a method using Bond Indices than adding a single factor of 1.25 to arrive at the AG/SAG specific energy. In 1991 the Canadians developed the SAGPower Index (SPI), test using 2 kg of material in a 300 mm diameter mill. This test has been further developed by Starkey, Hindstrom and Orser (2006). This test now includes a Bond Ball mill work index test.The Macpherson test is still being offered by some testing facilities. This dry test requires at least 180 kg of material.Morrell (2004) formulated an AG/SAG specific energy generator based on a drop weight index Value (DWi). This DWi value is related to the Ab parameter and the material specific gravity. Morrell reconfigured the BondÆs Third Theory formula to cause extra power requirements to be inputed. This technique incorporates the material specific gravity (SG). The AG/SAG specific energy values produced using this method are susceptible to higher values of crushing and rod mill work indices.This paper offered describes a more simple method to generate AG/SAG specific energies. This programme incorporates Bond work indices, the JKMRC parameter Ab measuring impact breakage and the parameter ta measuring the abrasion rate, then employs a series of efficiency values nominated for each transition size (AG/SAG T80). These efficiency values have been compiled over the years from actual operating plants and documented reports.CITATION:Burgess, D, 2012. A method of calculating autogenous/semi-autogenous grinding mill specific energies using a combination of bond work indices and Julius Kruttschnitt parameters, then applying efficiency factors, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 37-44 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By G Newling

Zinifex Rosebery Mine is a lead-zinc underground mining operation located at the base of Mount Black, on the West Coast of Tasmania. Mining activities at the Rosebery Mine have been undertaken for over 100 years, and it has been operating in its current form for over 60 years. A large surface and underground exploration drilling program over the last 18 months has increased the mineÆs expected mine life from five to 12 years, with expectations that over the next 18 months as the program continues this will swell to 20 plus years. Zinifex Ltd secured Rosebery Mine in April 2004 and commissioned a detailed life-of-mine (LOM) study on all aspects of the operation. One of the most detailed sections of this report was on the state of the current ventilation system. It was identified in this report that for mining at the current depth of approximately 1100 m to continue a minimum 30 per cent increase in ventilation quantity was essential, as well as a likely requirement for a refrigerant cooling plant for each of the two deepest panels, the K and P lenses. It was identified that Zinifex did not have personnel with the expertise in underground refrigeration to manage and implement a project of this nature. A second report was commissioned with Bluhm Burton Engineering (BBE), a South African firm specialising in both surface and underground large-scale refrigeration plants. BBE concluded that two refrigeration plants were required to provide the necessary cooling power in the lower sections of the mine. In 2005, with BBE as technical consultants, Zinifex Rosebery Mine embarked on a project to commission two underground refrigeration units capable of lowering the wet bulb temperature at the decline face by four degrees centigrade. This paper is intended to give the reader an overview of: Rosebery Mine operations,Rosebery underground refrigeration project,technical difficulties associated with implementing an underground refrigeration system, andkey learnings to date.

Jan 1, 2008

By A Kuras

Segmental tunnel linings are becoming more common in Australia. One current project employing a segmental lining is the City West Cable Tunnel (CWCT) in Sydney. The project has been commissioned by Energy Australia and is currently being constructed by Thiess Pty Ltd. The project includes 1.6 km of tunnel boring machine (TBM) driven, segmentally lined tunnel. The majority of the CWCT will be excavated through Hawkesbury Sandstone. The tunnel is required to carry a 132 kV electrical circuit under SydneyÆs central business district (CBD), between Haymarket and Energy AustraliaÆs City North Substation on Sussex Street. The segmental lining has been designed as a 3.2 m internal diameter, 200 mm thick universal ring with six trapezoidal segments. The design and detailing of this segmental lining presents some noteworthy challenges, including exposure to saline groundwater, and the exclusive use of steel fibres for flexural and tensile concrete reinforcement. This paper describes some of the key elements of the segmental lining design. These include:the case for choosing segmental linings over other forms of tunnel construction;the major design checks required of a segmental lining including ground loading, hydrostatic loading, joint bearing, joint rotation, ram loading and the early strength lifting case;the benefits of using steel fibres over conventional steel reinforcement;the design approach used for steel fibre reinforced concrete;the application of 3D computer modelling in the design;the provision for components including connector dowels and gaskets;the design for passive fire resistance; andthe design for durability of steel fibre reinforced concrete in a saline environment. Segmental lining design requires the application of specialist design approaches. Input is required by the construction team, as the methods of demoulding, handling, transportation and installation impact on the lining design. As the segmental lining is functioning as immediate ground support and also a permanent lining, high standards of manufacture and construction quality control are required to ensure that the 100-year design life is met. The requirement for a watertight tunnel means that detailing and installation of the EPDM gaskets is of importance.

Jan 1, 2008

By J R. Robinson

Prior to mine development, exploration drilling within the Luise Caldera on Niolam Island encountered gold mineralisation to the northwest of the main Minifie and Lienetz orebodies. This mineralisation was referred to as the Kapit orebody, and ten diamond drill holes were subsequently completed over the area to investigate its economic potential. Several significant mineralised intercepts were returned. These were interpreted using the orebody model developed for Lihir at that time which invoked a strong horizontal control to mineralisation. Additional consideration was given to the elevated geothermal temperatures encountered, the proximity of the mineralisation to the ocean, and its perceived depth below sea level, resulting in the Kapit area being given a low priority for follow up investigation. As a result, no further work was completed over Kapit until recently. The Kapit orebody was the target of an intense diamond drilling programme during 2002/2003. Data from this latest round of drilling has significantly improved understanding of the mineralisation and associated geology. The significant orebody now delineated at Kapit substantially differs from past interpretations, and the latest data has upgraded its economic potential. A resource estimate and other critical studies completed in 2003 enabled an updated reserve statement to be issued in February 2004 including the Kapit mineralisation for the first time. Total Probable Reserves at Kapit stand at 25.2 million tonnes (Mt) at 5.28 grams of gold per tonne (g Au/t), for a total of 4.3 million ounces (Moz) of contained gold.

Jan 1, 2004

By W R. Adamson

"Optimisation of drill and blast design and engineering can deliver a significant positive impact on the profitability of any mining operation; however, true engineering of the blasting process is less common than might be thought. The paper that follows explores this gap and suggests a process control-based approach to the challenge.The concept of applying modifications to drill and blast designs in order to achieve efficiency improvements in downstream mining processes is far from new. However, the author suggests that the practical application has become less than rigorous in a number of different sectors of the mining industry in a wide range of countries.There is a common tendency for the design process to become simplified to the point where the objective is merely the communication of instructions to field implementers (drillers, explosive suppliers, blasters, etc). In effect ‘design’ often degrades to ‘cut and paste’ with consequences that vary from mild to critical, with respect to the profitability of the business.Engineering of the drill and blast process involves the design function, not on a one-off basis but rather as a component of a more complete cyclical process that includes a statement of objectives, a design based on a suggested hypothesis, field measurement of results, comparison with the target ‘set point’ and the application of control measures followed by new measurement, including interpretation of the results in financial terms.When applied in this fashion, engineering provides practitioners with the means to optimise the drill and blast impact on the full spectrum business result of the mining activity.These concepts are discussed with reference to a surface gold mining operation applying run-of-mine heap leach extraction. Engineering optimisation by adapting process control and measurement techniques is demonstrated to be a key component of the solution set applied to generate enhanced operations productivity and stakeholder value. It is shown that a combination of rigorous measurement, model calibration and hands-on quality assurance/quality control facilitates the creation of a road map to profitability, stressing the need to consider economic trade-offs between operational expense (investment) and measurement of enhanced value (return on investment).The process, however, does not cease at this point. Implementation of true design practices, incorporating innovation and discipline in implementation or execution can drive the process to deliver demonstrable, technically validated outcomes. Furthermore, these technical results can be related to financially quantifiable impacts. However, this accomplishment does not guarantee that these gains or savings will reach the bottom line of those mining, quarrying and construction companies that begin the process with such high hopes.CITATION:Adamson, W R, 2015. Application of engineering discipline and a full-process optimisation focus – productivity to profitability without profuse pruning, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 3–12 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 24, 2015

By T P. Tafirenyika, K C. Corin, C T. O’Connor

There is a growing demand for copper driven by its applications in renewable energy and electric vehicles. Sulfide ores are an important source of copper. Flotation is a critical front-end process used to remove gangue minerals and concentrate the copper minerals. The electrochemical activity of sulfide minerals contributes to their overall activity in the flotation pulp. The mineral rest potential dictates how collectors interact with the mineral surface, and hence ultimately on the flotation response. Dissolved oxygen, (DO), pH, redox potential (Eh) and water composition and ionic strength are also significant in controlling flotation performance. The aim of this investigation was to determine the influence of the electrochemical environment both during milling and flotation on the flotation behaviour of bornite and chalcocite. For this investigation, the interactions of collector with bornite and chalcocite were studied using synthetic plant water (SPW1) and deionised water (DIW) at 5 different pH levels. Sodium isobutyl xanthate (SIBX) was used both in microflotation, collector adsorption and zeta potential tests.

Aug 24, 2022

By J H. Heo, J H. Park, M J. Lee

In this paper, the challenging points regarding the high temperature physical chemistry of slags to achieve the improved and stable electric arc furnace (EAF) or electric smelting furnace (ESF) technology on the way to green steel will be reviewed, and the recent experimental and modelling research will be discussed. For example, the initial melting phenomena of hot briquetted iron (HBI) and the slag formation behaviour was observed using a high-frequency induction furnace. Main component of gangue oxides in HBI was SiO2, Al2O3, and CaO in conjunction with unreduced iron oxide. To increase the dephosphorisation efficiency, the distribution ratio of phosphorus between metal and slag was calculated using FactSage™ software, version 8.2 (CRCT ThermFact, Inc., Montreal, Canada) and was compared to the measured results. The optimisation of slag chemistry is required not only for maximum dephosphorisation efficiency with good slag foamability but also for minimum slag volume with less refractory corrosion in EAF process. The slag chemistry is also one of key parameters affecting the operation efficiency in ESF in view of FeO reduction behaviour, viscosity, sulfide capacity, etc.

Jun 19, 2024

By P Revell, A Jenkin

This paper presents an analysis of significant Australian-based R&D programs focussed on the minerals industry, which was commissioned by CRC ORE. The landscape analysis may assist organisations with R&D management issues including program creation, program/partner selection, portfolio management, and public policy settings. The dataset was collated early in 2020, and contains programs being conducted by or with Australian-based ‘Research Service Providers’ (RSPs), most notably Universities and CSIRO. It does not include R&D being conducted in-house by mining and METS companies, or by them with other organisations that are not RSP’s. The dataset contains 65 R&D programs, with total annual cash funding of $229m (70% from industry and 30% from government). The total funding compares unfavourably with the combined R&D expenditure of Australian universities and CSIRO of over $12b, and minerals industry export revenues of over $200b. The R&D landscape is analysed by program numbers and funding, technical domain, geography, and funding source. Areas of relative strength are noted in ‘mineral processing’, CSIRO Minerals, and the CRC program. Areas of relative weakness are noted in ‘bulk materials handling and logistics’, ‘tailings and waste management’, and ‘social and community’. The field of preconcentration is noted as a current area of R&D strength, but it is under significant threat with the impending completion of CRC ORE. The overall R&D landscape is characterised by a majority of small-scale programs, low levels of industry coordination, a low focus on step-change innovation, and total funding lower than should be expected for such a large critical industry. It is hoped that key stakeholders in the Australian minerals industry, particularly governments, and mining and METS companies, reflect on the analysis and act to address holistic weaknesses.

Nov 10, 2020

By Mernagh T, Large R. R, Ryan C. G, Huston D. L

The Tennant Creek goldfield is one of the largest gold producing districts in Australia, and major deposits, including Gecko, Juno, Orlando, Peko, Warrego, Nobles Nob, Golden Forty, Argo, TC 8 and White Devil have produced more than four million ounces of gold over the past two decades. Gold-copper-bismuth mineralisation at Tennant Creek occurs in lenticular, ellipsoidal or pipe-like bodies of magnetite-hematite ironstones which are hosted in turbiditic sedimentary rocks of Proterozoic age (Large, 1975; Wedekind, Large and Williams, 1989; Le Messurier, Williams and Blake, 1990; Morrison, Donnellan and Hussey, 1992).

Jan 1, 1994

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high-speed photography to better understand the mechanisms of fracture and fragmentation.CITATION:Fourney, W L, 2015. The role of stress waves and fracture mechanics in fragmentation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 27–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By D Michaelsen, S Miller

The Grasberg Mine is a copper and gold open pit mine operated by PT Freeport Indonesia (PTFI) and located in the high equatorial mountains of the Indonesian province of Papua. The climate is alpine/subalpine with little seasonal variation in temperature or rainfall. The daily average temperature ranges from about 2¦C to 14¦C and the annual rainfall in the vicinity of the mine and overburden stockpiles is about 4000 mm to 5000 mm. Mining of the Grasberg open pit will continue until 2014 at which time approximately 2750 Mt of overburden will have been produced. Current overburden production rates are 200 Mt per annum. The current mill rate is 230 000 t/day from the Grasberg pit (190 000 t/day) and the underground operations (40 000 t/day). The acid rock drainage (ARD) issues associated with overburden from the Grasberg operations were identified early in the mining operation. Almost all overburden placed to date has been Potentially Acid Forming (PAF). Laboratory testing has identified four main overburden types: limestone and non-acid forming (Green waste), PAF low capacity (Blue waste) and PAF high capacity (Red waste), and Heavy Sulfide Zone (HSZ), which contains greater than 20 per cent pyrite. Waste type block modelling indicates that at least 30 per cent of the overburden production from 2003 to the end of Grasberg pit operations will be limestone. Strategies are being developed to maximise the beneficial use of limestone through strategic blending and placement for ARD mitigation and control.

Jan 1, 2003

By B Banerjee, H Masoumi, X Shen, S Raval, D Tannant

Structural mapping of pit walls can be performed using digital images and photogrammetry software, but the performance is limited by weather and environmental conditions including dust, rain and light. On the other hand, active sensors such as terrestrial laser scanners (TLS) and total stations (TS) suffer from vertical orientation bias and occlusions when persistent discontinuities dip at the same angle as the scanner line-ofsight. The recent development of the compact light detection and ranging (LiDAR) systems has made it possible to mount these sensors on unmanned aerial vehicles (UAVs) or drones which offer the potential to overcome limitations that are inherent in existing mapping systems. This study details the research involving integration and application of an advanced UAV-LiDAR system for structural mapping of a highwall. A state-of-the art laser scanner with an inertial measurement unit (IMU) and real-time kinematic global positioning system (GPS) was integrated on to a UAV. The system was first tested in a laboratory condition. Then the UAV-LiDAR system was employed to map a highwall of a coal mine. The planned flight trajectories tested the system at variable distances from the highwall face and at various speeds. The raw data collected from individual sensors were fused, filtered to remove noise, and segmented to produce a surface scan model. Finally, the point density and surface coverage were measured using the surface scan model of the highwall. The parameters were compared with equivalent measurements computed from a reference TLS data. The study demonstrates the capabilities of a UAV-LiDAR system to generate accurate and occlusion free data for mapping highwall geological structure with very quick and efficient flights in the field. CITATION:Raval, S, Banerjee, B, Shen, X, Masoumi, H and Tannant, D, 2018. Evaluation of a UAV-LiDAR system for mapping geological structures in an open pit highwall, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 496–503 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By T. Baker

The Eloise Cu-Au deposit is 60 km SE of Cloncurry in NW Queensland and has a current indicated reserve of 3.2 Mt @ 5.8 per cent Cu, 1.5gA Au and I9g/t Ag. It is hosted by metasediments and metabasic rocks that underwent amphibolite facies metamorphism at 550-600¦C and less than 3.5 kb. Peak metamorphism coincided with the regional D2 event which produced an S2 foliation with north-south strike and variable sub-vertical to steep east or west dip. The deposit is associated with several major shear zones parallel to the S2 foliation. The lodes form part of a large alteration system that is localised by the retrograde shear zones. Homblende-biotite-quartz with minor sulphides occur early in the alteration paragenesis which is overprinted by chlorite-muscovite-pyrrhotite-chalcopyrite ¦calcite+¦nagnetite. The later assemblage replaces the earlier Fe-K alteration as well as Fe-rich metamorphic assemblages such as homblende, biotite and staurolite indicating a post peak metamorphism timing for ore formation. Although replacive textures are the most common, the alteration can display open space infill and brecciation as well as durchbewegung and mylonite textures indicating that mineralisation occurred during ongoing ductile deformation. All these features are crosscut by a later brittle phase of calcite-chlorite-quartz¦pyrite alteration.

Jan 1, 1994

By A M. Myrvang, B Nøst, N Q. Trinh, I S. B Bergh

The iron ore producer Rana Gruber AS is situated in northern Norway just below the Arctic Circle, and has been producing hematite and magnetite concentrates for more than 60 years. Since the late 1990s, the major part of the production comes from a sublevel stoping underground operation after many years of open pit mining. Despite moderate mining depth, the operations have experienced considerable rock stress problems due to quite high tectonic, horizontal stresses. To manage the problems, comprehensive rock mechanics investigations have been carried out by SINTEF, a major contract research organisation. This has included in situ rock stress measurements, laboratory investigations and numerical modelling. Based on this and practical experience, satisfactory design of vertical and horizontal pillars was achieved. At depth, the ore width increases from 30–40?m to more than 100?m. This, together with a major planned increase in production, called for a change of the mining method. After thorough investigations and considerations, it was decided to change to sublevel caving, very much like the LKAB system. The development of the new system has been closely followed up by rock mechanics measures, including 3D numerical modelling and comprehensive monitoring of deformations and rock stress changes. To achieve a satisfactory caving of the hanging wall, all vertical and horizontal pillars in the sublevel stoping area had to be removed. This has been a challenging task, and the development of the caving has been slow until recently. However, now the caving develops satisfactorily.CITATION:Bergh, I S B, Trinh, N Q, Myrvang, A M and Nøst, B, 2014. From sublevel stoping to sublevel caving at Rana Gruber, Norway – rock mechanical aspects, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 323–330 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By A Lechner, T Baumgartl, S Arnold, P Audet

When revegetation is a part of a rehabilitation strategy at mine sites in arid and semi-arid environments, its success can be strongly affected by the availability of water prior or during the time of seed dormancy, germination and early growth of seedlings. The semi-arid and arid environments of northern Australia are characterised by highly variable and erratic rainfall and hence the actual weather conditions at and around the time of germination and seedling emergence play a critical role in determining the success of plant establishment and the type of plant community that may develop.Using available climate data, an analysis has been undertaken and a set of indices has been developed which describe the suitability of the climatic conditions for rehabilitation. In total, eight sites from Queensland and one site from New South Wales, Australia have been analysed. It could be determined that regular rainfall and relatively short periods of water-deficit are key characteristics of climate suitability. A comparison of the locations studied allowed the separation into suitable and susceptible locations in terms of the availability of water, amount of rain and duration of drought between rain events.In our experience, specific estimates of climate suitability are rarely incorporated into the design of mined land rehabilitation programs. We consider that the regional intensity, seasonality and extremity of climate represent an overarching component of landscape complexity, which in turn will influence the development of post-disturbance ecosystems in these regions. This paper presents the outcome of climate analyses paired with the development of suitability indices. A conceptual framework is presented explaining the suitability matrix and its incorporation as a prognosis tool to achieve greater certainty for success in rehabilitation development.CITATION:Baumgartl, T, Arnold, S, Audet, P and Lechner, A, 2014. Development of climate-based suitability indices for the improvement of success in rehabilitation, in Proceedings Life-of-Mine 2014 , pp 483–490 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By S S. Kanchibotla, S Morrell

In recent years there has been a growing recognition of the impact that mining practices have on the efficiency of mineral processing operations. Head grade, dilution, particle size distribution and their variability are known to have a significant effect on the throughput and recovery achieved in mineral processing plants. Improved process monitoring and modelling have provided the opportunity to identify and quantify some of these impacts and to define very significant incentives to optimise the overall operation from the mining face through subsequent comminution and processing. The Julius Kruttschnitt Mineral Research Centre has been undertaking research to optimise æMine to MillÆ performance through a major AMIRA research project and through individual research contracts with mining companies. This work has resulted in a broad range of field and laboratory experience in terms of both the challenges and the opportunities encountered when tailoring blasting operations to suit the overall æMine to MillÆ production chain. This paper describes the objectives of æMine to MillÆ blasting to optimise the system of rock breakage involved in the blasting, crushing and SAG milling of hard, brittle ores. The design of such blasts falls outside the conventional envelope of experience for most engineers and requires the consideration of some critical factors if the objectives of such blast are to be met and some of the potential problems are to be avoided. Experience to-date has also found that the quality of implementation is critical to the success of æMine to MillÆ blasts.

Jan 1, 1999

By I Manege, S M. Bennett

The PT Kaltim Prima Coal (KPC) operation is a large scale coalmine operating on the east coast of Kalimantan (Borneo), Indonesia. Originally developed under a coal contract of work (CCOW) with the Indonesian Government, new legislation has led to uncertainty as to the actual life of the mine, the size of the operating lease or mining area, the rehabilitation compliance requirements and other areas of concern. The actual life-of-mine (LOM) plan is therefore in a constant state of flux and must be updated and modified with every new piece of information.Under the CCOW system, the mine life ran from the first year of production (1992) for 30 years (2021), with the potential to extend for a further two ten-year periods. KPC has always intended to run until at least 2041. Under the new legislation, the potential term of the CCOW (to be replaced by a mining license) is open to interpretation, resulting in KPC having to prepare plans allowing for a LOM that may end in 2021, 2031, 2041 or a range of other possible periods of time.Uncertainty about legislation (and hence the mine life) possible production rates and available work areas; variable coal prices and costs; varying management contexts; the substantial reserves available; difficulty sourcing dump space; potential rehabilitation costs and the dependence of a community of over 100 000 people on a single operation sees the LOM and mine closure teams preparing dynamic yet thoroughly robust plans that are updated on multiple occasions per year.This paper will describe the procedure followed by KPC and the potentially show stopping issues that must be dealt with.CITATION:Bennett, S M and Manege, I, ?2014. Life-of-mine planning in a dynamic environment, in Proceedings Life-of-Mine 2014 , pp 379–388 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By D McB Martin, A Piechocka, M Jessell, M Lindsay, E Ramanaidou

The Hamersley Basin of Western Australia, approximately 500 km long by 200 km wide, is recognised globally for its rich endowment of iron ore resources. Two types of bedded iron ore mineralisation are recognised: the Proterozoic hypogene martite-microplaty hematite ores; and the more recent Cenozoic supergene martite-goethite ores. Exploration strategies depend on the style of mineralisation being targeted; however, stratigraphy and structure are fundamental controls on both ore types. Therefore, the ability to visualise the 3D geology of the entire basin is critical for the understanding of iron ore occurrences and their relationship to ore genesis of bedded iron ore mineralisation. However, due to the large size of the basin, generating a 3D geological model of the regional stratigraphy and structure has not been possible, or prioritised, primarily due to software limitations. Recent advances in implicit automated geological modelling presents an ideal opportunity to develop a 3D model of the entire Hamersley Basin. The innovative Loop software was used to model open source geological data (ie geological mapping, outcrop orientation data, and fault data) sourced from the Geological Survey of Western Australia. In addition to generating a 3D geological model, information such as stratigraphic thickness and fault offset information was extracted using the map2loop module and demonstrated its application to exploration targeting. This study demonstrates how a basin-wide 3D geological model was used to conduct a regional structural analysis of the Hamersley Basin. The results of this study provide opportunities for other prospective regions to be rapidly modelled in order to enhance the understanding of the geology and improve exploration targeting.

Nov 8, 2021