Search Documents

The Pongkor Gold Mine employs 678 staff. The mine is owned by the Indonesian state company PT Antam Tbk and is located 100 kilometres south west of Jakarta, in Java, Indonesia. Mine and infrastructure development started in 1992 following intensive geological exploration over 15 years. First gold production was in June 1994. The mine comprises three main orebodies: Ciguha, which is nearly mined out, dips at 75¦ from surface to 150 m. Kubang Cicau, dipping at 80¦ from surface to 230 m, and averages 3.5 metres thick at a grade of 10 g/t Au and 128 g/t Ag; and Ciurug, dipping at 60¦ from surface to 300 m and averages eight metres thick at a grade of 14 g/t Au and 172 g/t Ag. Present global ore reserves are 4.6 million tons at a grade of 12.3 g/t Au and 133.6 g/t Ag. Exploration is continuing for new veins. Initial mining was by manual cut and hydraulic fill at Ciguha, followed by Kubang Cicau. In 1996, it was proposed to convert Ciurug to a mechanised cut and fill operation. Two single boom jumbos and three load-haul-dumps (LHDs) were purchased with the assistance of a gold loan from NM Rothschild and Sons. Implementation of this upgrade was delayed by both a national economic crisis and an invasion of the concession by illegal miners. It was not until May 1999 that raise bore vent rises and access drift infrastructure commenced. Major underground development started in 2000 and is continuing. Production cut and waste fill stoping started in July 2001. The change from manual to mechanised methods has required a total change in work practices and attitudes. However, the process has resulted in a production increase from 600 tpd to 1200 tpd. A three-month compliance test (a condition of the financing loan) was successfully completed, from July to September 2001, with an average production of 700 tpd at Ciurug and 500 tpd from Kubang Cicau.

Jan 1, 2002

The Beverley uranium mine û now in production in the remote north of South Australia at1000 tonnes per annum û was established to meet a projected, but little-recognised shortfallin primary supply of uranium for the nuclear industry in the early part of the 21 st century. Inthe context of AustraliaÆs lack of bi-partisan support for uranium mining and the nuclearindustry, a four to five year window of opportunity existed from 1996 to establish the mine.During this period, Beverley achieved a number of firsts including: the first ISL mine inAustralia; the largest ISL mine in the world and the first to produce more than 500 tonnes ofuranium in its first year; the first to be established under a new Native Title regime in SouthAustralia; and the first to be established under a revised South Australian Mining Act.Beverley was brought into production against the background of: hostile opposition fromanti-nuclear activists; a suspicious and at-times hostile media; a regulatory and politicalcommunity that was unfamiliar with ISL mining; commercially unsophisticated Aboriginalgroups; an inexperienced engineering industry; and the vagaries of development in a remote,semi-arid location with neither population nor infrastructure. The lessons that can be learnedfrom Beverley showed that û like much in life û flexibility and timing are crucial.

Jan 1, 2002

By R H. Knight

Uncertainty in prediction and modelling of geological (physical) ore continuity in geometrically complex ore deposits is a key risk factor in mining. Reducing geometric uncertainty of hard-boundary ore/waste contacts and related geological features improves the efficiency of local mineral resource estimation and reserve calculation, mine/stope planning, ore control and in-mine exploration. Detailed underground mapping of serial-level drives provides a continuous record of the characteristics and contact configuration of ore, as well as crucial ore-related geological features that are required to resolve geometrical variability when closely spaced drilling proves inadequate or is cost-prohibitive. The mapping-based approach described in this paper re-establishes the focus on the geology of the orebody by incorporating high-value, detailed geologic mine mapping information. Mapped ore-related configurations and relationships, recorded on a succession of faces or on a series of levels, provide the basis for 3D interpolation and extrapolation of the local geologic continuity of an orebody. Correlative points representing locations of key ore-related geologic features on each face or level are linked by 3D polylines or trajectories forming a coherent geometrical framework. The coherent progression of geometric changes mapped by these trajectories reveals the overall ‘dynamic’ of the geometrical framework, as well as the spatial tendencies of its geological constituents. Distinct sets of ore control trajectories are selected from within the framework and are used in the construction of alternative geological ore continuity models. As mining proceeds, alternative models are evaluated, and are then either refined or rejected. The geometrical framework is used to evaluate theoretical models and practical heuristics, focus exploration targeting and inform and guide all aspects of mine geology in active mines. This approach also lends itself to analysis of global ore continuity in the re-evaluation of mature or abandoned mines. Its use is particularly effective in geometrically complex orebodies such as the West Branch orebody and the orebodies of No 2 mine of the Balmat-Edwards-Pierrepont zinc district, which are used to illustrate the method. CITATION:Knight, R H, 2014. A mapping-based approach to geological continuity prediction using examples from the Balmat-Edwards-Pierrepont Zinc District, St Lawrence County, New York, USA, in Proceedings Ninth International Mining Geology Conference 2014 , pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By M Scamardella

The CSA Mine is located at Cobar, New South Wales, where it was in continuous operation from 1966 to the time it went into receivership on 29 January 1998. When it closed it was under the ownership of Golden Shamrock. Glencore International, in conjunction with Mt Lyell Mining, undertook a due diligence study to determine the feasibility to re-open the mine. This envisaged operating CSA Mine as a low-cost, copper concentrate producer under the direction of Cobar Management Pty Ltd (CMPL). The new workforce would consist of contractor trades people in operating functions under the co-ordination of CMPL staff, both on the surface and underground. This was the key to establishing the new culture in the workforce. The orebodies at CSA Mine are steeply dipping with copper-lead-zinc mineralisation in zones of strong alterations in a fine-grained siltstone host sequence. The predominant economic minerals are chalcopyrite, sphalerite and galena. The major gauge minerals are pyrrhotite, pyrite, chlorite, sericite and quartz. Ore for the project is being developed and mined from two high grade copper lenses within the QTS North system. Chalcopyrite occurs in two forms. The first consists of coarse chalcopyrite grains in association with pyrrhotite or pyrite. The second form consists of chalcopyrite grains intergrown with pyrrhotite grains. This form of chalcopyrite is quite rare. It allows electrochemical interactions between grains, resulting in rapid oxidation of the chalcopyrite surface. Physically this ore looks like, and has been mistaken for æpeacock oreÆ, ie bornite, but is infact oxidised chalcopyrite.

Jan 1, 2000

By R W. Henley, L Knuefing, M Turner, Y Zhang, M Saadatfar, A Limaye, R Cruikshank, M A. Knackstedt, A Kingston, L Beeching, N Francois

A better understanding of ore fragmentation and the textural features of ore is a key to the energy efficient extraction of targeted minerals from low-grade ore deposits. In this study, X-ray microcomputed tomography (micro-CT) is employed to study mineral liberation during the tensile failure and onset of fragmentation of a copper ore. Our results show that X-ray micro-CT could inform new studies of ore micromechanics and fragmentation at the laboratory scale and may offer new avenues to address current challenges in the design of efficient comminution processes. We present the results of experiments based on a high-pressure apparatus enabling micromechanical studies to be carried out in situ (inside a micro-CT scanner). This platform produces high-quality 3D images of the evolution of a sample of porphyry copper ore during an in situ fragmentation test. A sequence of tomographic images enables mapping in 3D of both the deformation of mineral phases and the fragmentation process. The fragmentation occurs quasistatically through multiple stages starting with an initial tensile fracture splitting the ore diametrically, followed by tensile-activated nucleation and growth of multiple fractures producing a complex fracture network. Coupling breakage with microstructural information enables quantitative determination of the impact of ore texture heterogeneity on fracture patterns and mineral liberation. This microstructural information can be compared to key measurements of the ore mechanical behaviour such as the global deformation energy, strain deformation field and the stress relaxation response. The latter allows one to identify interesting precursor signals of the tensile failure. The copper liberation, fragment size distribution and breakage patterns are statistically characterised and related to comminution mechanisms which are clearly identified in the sequence of tomographic images. The two dominant mechanisms are rock-rock friction/compression induced by fracture closing and compression-driven fragmentation at rock-crusher contact points.

Aug 24, 2022

By S Norman

The Water Delivery Alliance (WDA) was established to design, construct and commission the pump station and desalinated water delivery pipeline to link the desalination plant on the Kurnell Peninsula (constructed by others) with the existing distribution network at Erskineville, Sydney, Australia. The WDA consisted of McConnell Dowell Corporation Ltd (Macdow), Bovis Lend Lease Pty Ltd (BLL), Kellogg Brown and Root Pty Ltd (KBR), Worleyparsons Ltd (WOR), Environmental Resources Management Group Inc (ERM) and Sydney Water Corporation (SWC).Sydney’s Desalination Project is one of the initiatives to secure Sydney’s water supply against the effects of climate change, population growth and drought. The desalination plant, 100 per cent powered by renewable energy, can supply up to 250 million litres of water per day (mld), which is up to 15 per cent of Sydney’s water needs. The project involved the construction of an 18 km pipeline with an ultimate capacity of 500 mld to accommodate any future increase in the output of the desalination plant.The Alliance procured three full-face tunnel boring machines (TBM) from Herrenknecht AG to construct the 6.5 km of tunnel that would provide a conduit for the DN1800 welded mild steel cement mortar lined (MSCL) pipeline at a number of locations along the route. Nineteen shafts and 16 tunnels were required to complete this work.Crucially one of the TBM drives involved construction of a tunnel into Botany Bay under protected marine life habitats; enabling the connection of the MSCL water carrier pipeline into the dredged section of pipeline underwater, approximately 800 m off-shore in Botany Bay.This paper details the retrieval of the 17.4 m long TBM from the ocean floor upon completion of the Botany Bay tunnel allowing for subsequent use on the Project. Elements covered in the paper include the 835 m tunnel, design and construction techniques for the tunnel and recovery, and details of the methods used to install the DN1800 water carrier pipeline.

Mar 8, 2011

By J Pan, C M. Tang, D Q. Zhu, C C. Yang, S W. Li, Z Q. Guo

The short process of electric furnace steelmaking with direct reduction iron (DRI) as raw material is an important process for smelting high-quality and special steels. In order to prepare high-quality DRI, the pellets with basicity of natural basicity and 0.4 were prepared from magnetite concentrate (MR=0.09, MR=0.4) and hematite concentrate (HR=0.02, HR=0.4). Based on the HYL method, the gas-based direct reduction experiments were conducted under the condition of rich hydrogen (H2/CO = 2.6). The reduction index (RI), reduction swelling (RSI), cold compressive strength (CCS), and phase changes of the pellets were systematically studied. The results show that the RI of four kinds of pellets is greater than four in the temperature range of 800~950°C. For the magnetite pellets, at a fixed reduction temperature, the RSI increases and then gradually decreases, reaching a peak between 50 per cent and 80 per cent. Moreover, the RSI enhances with the increase of the reduction temperature. In general, the RI, RSI, and reduced CCS of the MR=0.09 pellets are better than those of the MR=0.4 pellets. For the hematite pellets, the maximum RSI decreases from 23 per cent to 17 per cent during hydrogen-rich reduction, while the compressive strength increases from 500 to 1070 Nꞏpellet-1. The main reason is that the glass phase generated by the increase of basicity adheres to the surface of hematite grains, hindering the contact between reducing gas and particles. As a result, the apparent activation energy is reduced, which is not conducive to the reduction process. In addition, the glassy phase attached to the hematite reduces the migration rate of Fe2+/Fe3+, resulting in a difference in the reduction expansion rate of hematite in the inner and outer layers of the pellet. Thus, concentric cracks are formed inside the pellets, the RSI increases and reduced CCS decreases.

Sep 18, 2023

By H Bruyn, K Ehrig, V Liebezeit, A Robertson, M Smith, D Grant

"The Olympic Dam geometallurgy program has generated a large quantity of data that has been used to create a geometallurgically enabled block model. An ongoing challenge is to convert data into usable information and embed geometallurgical practices into resource model development and mine planning to assist with the identification of opportunities to maximise value.This paper will discuss the methods used to disseminate geometallurgical information throughout the planning life cycle including data extraction methods from the geometallurgy acQuire database, and the inclusion of a geometallurgy module in the Olympic Dam Stope Reserves database. The use of geometallurgical information in short-, medium- and long-term mine design and scheduling, including its use in grade descriptor development and stope value assessment tools will also be presented. The detail of development of specific geometallurgical models is outside the scope of this paper.At Olympic Dam, the incorporation of geometallurgical capability within the long-term planning team, traditionally the domain of mining engineers, has proved essential in broadening the base of geometallurgical knowledge as well as focusing geometallurgy resources on value-adding areas while providing a holistic risk based long-term plan.CITATION:Liebezeit, V, Ehrig, K, Robertson, A, Grant, D, Smith, M and Bruyn, H, 2016. Embedding Geometallurgy into Mine Planning Practices – Practical Examples at Olympic Dam, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 135–144 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By D Connelly

Magnetite ores can be used to produce very high-grade concentrates that are suitable feed for the direct reduction process route but the high sulfur content of some concentrates can cause substantial environmental issues. Processing of high sulfur magnetite ore is therefore increasingly problematic for the industry. Generally, the industry demands a concentrate with <0.05 per cent sulfur and <2 per cent silica. This paper reports the outcomes of a study to produce a concentrate with the requisite low sulfur content from a sulfur-rich magnetite ore. The main findings may be summarised as follows: if the sulfur is present in magnetite as nonmagnetic pyrrhotite or pyrite, it can be beneficiated using magnetic separation and hence, monoclinic pyrrhotite is magnetic and is magnetically recovered with magnetite leading to a concentrate that is too high in sulfur. X-ray diffraction and QEMSCAN analyses revealed that the magnetite concentrate was liberated at P80 30 microns and was associated with maghemite, pyrrhotite (magnetic), carbonates and hematite with very low amounts of chalcopyrite, sphalerite and arsenopyrite. Sulfur removal using flotation was the first stage of investigation and this required flash flotation in the grinding stage followed by column flotation of the initial concentrate to generate the final concentrate. At the same time, it was observed that oxidation of the pyrrhotite had a negative effect on its flotation requiring copper sulfate to activate it. Bioleaching and concentrate leaching were also considered and achieved over 90 per cent sulfur removal but were deemed unsuitable owing to the production of highly reactive wastes and high CAPEX. Reference is made to a number of operating magnetite producers and how they manage the sulfur in feed.

Sep 18, 2023

By S Marshall, A Fowler

The Augusta underground mine at Costerfield in Central Victoria has been in operation since mid 2006; however, AGD Operations Pty Ltd have explored and undertaken open pit operations in the area for over 20 years. The high-grade, narrow gold-antimony orebody is being mined using both mechanised and hand-held methods, to produce up to 70 000 tonnes per annum at ten grams per tonne gold and six per cent stibnite. AGD Operations Pty Ltd processes the ore on site using gravity and flotation to produce two products; a concentrate which is sold to Chinese smelters and a gravity concentrate which is refined off-site. The circuit achieves up to 30 per cent recovery of gold from gravity methods. There are many challenges in the underground mine, including an orebody with an average width of 300 mm, very poor rock mass conditions in the host rock and variable dips in the ore along strike, between 45¦ and 90¦. The upper levels of the mine have been developed ready for stoping; however, their depths range from 20 m to 70 m below surface in both oxide and transitional material. A major fault structure consisting of mud has been encountered underground and is associated with the orebody causing very poor ground conditions, water inflow and requiring additional reinforcement. The northern limit of the mine is defined by the proximity of historical workings in the South Costerfield mine, which is being continuously dewatered.

Jan 1, 2008

The region we call the West Coast is acknowledged as one of the richest and most diverse mineral provinces in the world. It&apos;s the most rugged part of Tasmania and our island is one of the most rugged parts of Australia, so that speaks for itself. A hostile land of razorback mountains, deep ravines, dangerous rivers, almost impenetrable rainforests and a climate that can change from mild to freezing in a matter of hours.

Jan 1, 1993

By C Mark

Coal bursts involve the sudden, violent ejection of coal or rock into the mine workings. They are a particular hazard because they typically occur without warning. During the past two years, three US coal miners were killed in two coal bursts, following a six-year period during which there were zero burst fatalities.This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major longwall mining coalfields that have struggled with bursts for decades. The Utah experience displays many of the ‘classic’ burst characteristics, including deep cover, strong roof and floor rock, and a direct association between bursts and mining activity. In Colorado, the longwalls of the North Fork Valley (NFV) also work at great depth, but their roof and floor strengths are moderate, and most bursts have occurred during entry development or in headgates, bleeders or other outbye locations. The NFV bursts also are more likely to be associated with geologic structures and large magnitude seismic events. The paper closes with a brief discussion of how US longwalls have managed the burst risk.CITATION:Mark, C, 2014. Coal bursts in the deep longwall mines of the United States, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 33–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By Y Peng, D Wannas

In the fine particle flotation technologies being developed today the fine hydrophilic (gangue) particles are usually well dispersed. These highly dispersed fine particles can be recovered into the flotation froth product by mechanical entrainment. Flocculation of hydrophilic particles caused by polymer depressants could potentially reduce the mechanical entrainment of these particles. This paper reports testwork completed on fine particles of several solids, iron oxide, hydroxylapatite, galena and sphalerite, as well as on a relatively coarse quartz sample (-75+38 ¦m). Dodecylamine was used as a collector for the quartz, and several dispersants and polymer depressants, including sodium silicate, sodium metaphosphate, zinc sulfate, potassium dichromate, corn starch, corn dextrin and carboxymethyl celluloses (with molecular weights of both 700 000 and 80 000) were used as flotation modifiers. The major part of the testwork involved flotation tests in a 200 ml flotation column. Both water and solid recoveries were recorded. The degree of flocculation and dispersion was determined by settling tests in 250 ml graduated cylinders. It was observed that flocculation of the fine hydrophilic particles significantly reduced their mechanical entrainment, while dispersion severely aggravated it. Thus, in the flotation separation of artificial mixtures of the -75+38 ¦m quartz and fine iron oxide or hydroxylapatite, polymer depressants that caused flocculation were found to perform better than the ones that did not cause flocculation.

Jan 1, 2005

By G Phillips

The Merlin project is situated 130 km south of Cloncurry in North West Queensland, Australia. It is located within the Pre-Cambrian Mt Isa Inlier and is grouped within the Eastern Fold Belt. The host rocks are metasedimentary rocks of the Proterozoic Kuridala and Staveley Formations adjacent to the Mount Dore Granite.Merlin zone represents part of the Mount Dore polymetallic deposit containing copper, zinc, silver, gold, lead, cobalt and most recently has been found to host molybdenum mineralisation. This is intimately associated with economic grades of rhenium, a naturally occurring metal that is an important component of high temperature aircraft engines. The host rock sequence is a 200 m thick zone of metasediments sandwiched between competent granite in the hanging wall and brittle quartzite in the foot wall. A distinct shear marks the contact between the granite and metasediments. The host rocks are comprised of three main rock types: black shale, phyllite and altered banded calc-silicate.Mineralisation dips to the east at approximately 45&#176; in a package of fine grained pelites and banded calc-silicates. The top 150 m of the sequence is typified by black shale and phyllite. The lower 50 m is typified by pink banded calc-silicate. The main molybdenite zone is located at and parallel to the pelite-calc-silicate contact. Down dip, the zone splits into two or three veins hosted by the calc-silicate rock suite and haloed by thin, steep dipping, stylolitic molybdenite veinlets.The deposit was discovered in 2008 by routine infill reverse circulation sampling conducted for the Mount Dore copper deposit. One hole penetrated below the main target Cu horizon and intersected visible molybdenite. During 2009 and 2010 a 50 &#215; 50 m diamond drill pattern delineated a total mineral resource of 6.7 Mt @ 1.3 per cent Mo, 23g/t Re, 0.3 per cent Cu (mostly Indicated Mineral Resource with minor Inferred Mineral Resource). The resource has been estimated using ordinary kriging within grade domains. Access to the deposit has commenced via a decline and production through the nearby Osborne flotation concentrator (70 km south) is expected in 2012. All facilities and resources are fully owned and operated by Ivanhoe Australia Limited, a public listed company on the Australian and Toronto stock exchanges.

Aug 22, 2011

By A Tsang, D La Rosa, L Julian, W Hunt, R Pratama

Mineral extraction is facing the twin challenges of finite resources and increasing environmental and economic costs. Society’s growth is matched by an increase in demand for the earth’s resources. It is incumbent on us as contemporary mining professionals to promote and facilitate ethical and efficient practices. Technological developments have and will continue to allow a decrease in viable cut-off grades, creating new economic opportunities from deposits that were previously uneconomic. Mining low-grade deposits however, even with perfect recoveries, will have a significant environmental cost for the metal won. The greatest opportunity to increase metal with the least environmental cost is to increase the metal yield from existing mines. The determination of mining polygons is a critical juncture where rock is typically subjected to the binary grading of either ore or waste. This is undertaken using a number of factors, such as the mining equipment being used and the recovery in the processing plant. Traditionally, mining polygons were generated on the in situ grade control model. This ignores the complex differential blast dynamics that occur during blasting. Two opportunities exist to improve metal yields: optimise the blast design to achieve the post-blast muck pile that will support the greatest outcome; and generate optimised polygons on the post-blast muck pile. A data set from a Canadian Gold deposit is used to demonstrate the potential benefit of iterative blast movement modelling and grade control polygon optimisation on metal yield. The impact of blasting on the total recoverable metal is presented, highlighting blast design as a critical process in the mining value chain.

Sep 1, 2024

By G Corbett

Epithermal Au-Ag deposits form in the upper 1 km of the crust and are therefore best preserved in the less eroded Pacific rim arcs, although also recognised elsewhere. Two profoundly different ore fluid types give rise to low and high-sulfidation styles apparent as variations in ore and gangue mineralogy as well as characteristic zoned wall rock alteration. Low sulfidation epithermal Au deposits are derived from near neutral composite magmatic-meteoric fluids and divided into a group with a stronger intrusion association within arcs grading in time and space from: quartz-sulfide Au + Cu, to carbonate-base metal Au, and the epithermal quartz Au + Ag, whereas in strongly extensional settings the influx of meteoric waters promotes the development of chalcedony-ginguro banded Au-Ag epithermal veins. In the presence of continental crust particularly in Latin America polymetallic Ag-Au veins represent a Ag-rich equivalent of carbonate-base metal Au and passes upwards to chalcedony-ginguro Au-Ag style. By contrast high-sulfidation epithermal deposits are deposited from an acidic magmatic fluid which provided characteristic hydrothermal alteration by reaction with wall rocks grading outwards as mineral assemblages dominated by: vughy silica, alunite, pyrophyllite-diaspore, dickite-kaolin and then illite-smectite neutral clays. Au mineralisation is commonly refractory with enargite deposited dominantly later within the silica zone.Exploration for epithermal Au deposits benefits from an understanding of the controls to mineralisation which commonly give rise to the development of ore shoots with widest and highest Au grade ore zones. In low-sulfidation systems a combination of competent host rocks, dilatant structures, higher grade styles of mineralisation and efficient mechanism of Au deposition, contribute towards ore shoot formation. High-sulfidation epithermal Au systems occur in permeable volcanic and breccia host rocks which are linked by major structures to the magmatic source.CITATION:Corbett, G, 2013. Pacific Rim epithermal Au-Ag, in Proceedings World Gold 2013 , pp 5-14 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By U König, N Norberg

Traditionally, quality control of iron sinter has relied on time-consuming wet chemistry. However, the mineralogical composition that defines the physical properties, such as strength or reducibility, is not monitored.X-ray diffraction (XRD) analysis in combination with Rietveld quantification and statistical data evaluation using partial least squares regression (PLSR) has been successfully trialled to determine the mineralogical composition and process parameters such as the FeO (Fe2+) content and basicity of iron sinter within an analysis time of less than eight minutes per sample. The results were compared with wet chemistry data.PLSR does not require pure phases, crystal structures or complex modelling of peak shapes. The analysis is therefore easy to set up and ideal if only one property needs to be analysed. PLSR results show an accuracy for the FeO content of &#177;0.3 per cent for the samples analysed in this case study.Both the PLSR and Rietveld methods take the full XRD pattern into account and can be simultaneously applied on the same measurement. PLSR was found to be the more robust method if only FeO and basicity results are required. The Rietveld method helps to predict other parameters, such as the compression strength of the sinter, by monitoring all existing phases (eg larnite C2S or silico-ferrite of calcium and aluminium phases).CITATION:K&#246;nig, U and Norberg, N, 2015. Iron sinter process control using x-ray diffraction, in Proceedings Iron Ore 2015, pp 53–60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Carter A. J, Miller D. M, Holder N. H M, Van Aswegen P C

The Harbour Lights Mine situated at Leonora in Western Australia, mines a refractory sulphidic gold ore. The main sulphide minerals are pyrite and arsenopyrite. Due to the association of gold with the pyrite and arsenopyrite, gold recovery is not amenable to the normal cyanidation process.A pyrite/arsenopyrite flotation concentrate is produced at Harbour Lights. This concentrate has been stockpiled for the past two years.A bio-oxidation process (BIOX«)* to treat refractory gold flotation concentrates has been developed by GENMIN in South Africa. Harbour Lights acquired the technology from CRL BIOX« Pty Limited in Brisbane, to treat the refractory gold concentrates.

Jan 1, 1992

By M P. Murphy, C M. D Barton

When developing a new underground mine, the geological interpretation that guides the mineral resource is crucial to the preparation of a reliable ore reserve. In preparing a robust geological model to underpin a resource estimate, practitioners must weigh the comparative risk of accepting a relatively wide-spaced drill hole pattern, versus a more close-spaced pattern that ensures a high local geological confidence for mine planning but may have an exponentially increased time and monetary cost. This paper details the authors’ investigations into the geological uncertainty of IGO’s Odysseus Deposit, which is approximately 645 km north-east of Perth, Western Australia. At Odysseus, the komatiitic nickel sulfide mineralisation is irregularly cross-cut by nickel-barren pegmatites that have intruded and offset its thick ultramafic orebodies. These pegmatites generate significant uncertainty in the precision of Odysseus’ resource volume and tonnage estimates, as well as the subsequent quantification of pegmatite mining dilution in its ore reserve. To quantify the geological uncertainty in the pegmatite interpretations, IGO’s mineral resource practitioners prepared several geological risk studies over the Odysseus North lode, which is the lode most affected by the pegmatites. These studies included categorical conditional simulation of the pegmatites, preparing implicit geological models with alternative algorithms, trialling a machine learning application to prepare a maximum likelihood geological model, and finally assessing the early results of the pre-production close-spaced drilling to these different models. To assess the precision of the different single-outcome models, the authors’ compared the estimated pegmatite content of each model to the range of possibilities modelled by categorical conditional simulation within the planned stopes at Odysseus North. An estimation confidence score for each modelling method was then prepared for each alternative single-outcome modelling method. From these studies IGO concluded that a close-spaced drill pattern is essential at Odysseus, supporting the view of the Competent Person in 2017 who proposed a 25 m drill spacing in areas affected by pegmatite which had been partially classified as Inferred.

May 24, 2023

By N Bianco, D Drinkwater

The professional skills shortage is intensifying, and commentators are predicting a shortfall in supply of qualified professionals for the mining industry, ranging from thousands to tens-of-thousands by 2020 (Tuckwell, 2011; Scoble, 2011; Laurence and Hebblewhite, 2011). Human resources are already stretched, and university graduates arriving in the workplace are often moved rapidly into management positions where there is limited scope to develop their engineering proficiency. This process may well be developing excellent young managers, but our industry is producing fewer excellent young engineers (Munro and Tilyard, 2009). Many believe that it is engineering excellence that is likely to be the key to our industryÆs success in the decade to come. An innovative in-house graduate development program has been created by specialists at the JK Centre in partnership with two mining companies. This program, known as MetSkill«, has been running throughout 2012. Groups of graduates have had to identify a process plant optimisation opportunity and embark on a structured program of data collection and analysis, facilitated by a æteaching teamÆ of researchers and consultants from the Julius Kruttschnitt Mineral Research Centre (JKMRC) and JKTech. This group project culminates in a report-back session to senior company officials. Along the way, a series of short workshops and other activities provide opportunities to work on specialist skills, and support is also offered by senior technical specialists from the companies involved.This paper outlines key features of the MetSkill« program, along with a report-card on progress in 2012 and plans for further program development in 2013.CITATION:Drinkwater, D and Bianco, N, 2012. Developing minerals industry leaders by encouraging metallurgical excellence, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 287-290 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012