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The relationships between Aboriginal Traditional Owners and mining companies have often been mired in dispute, particularly since the High Court Mabo decision and the Native Title Act of 1993. In the Pilbara region, Rio Tinto Iron Ore (RTIO) impacts the traditional country of 12 Aboriginal Traditional Owner/language groups. Over the past 12 years the company and the Traditional Owners have negotiated and settled several significant land use agreements including the Yandi Land Use Agreement over the Yandicoogina mine in 1997, between Hamersley Iron (now Rio Tinto Iron Ore) and three language groups û the Bunjima, Nyapaili and Innawonga people and the Eastern Guruma Indigenous Land Use Agreement (ILUA) of 2006. These substantive agreements are now being followed by a new generation of region wide ILUAs which are close to conclusion. Arising from these regional agreements is a new framework for engagement which has been informed by the implementation of the previous agreements in the Pilbara and across the Rio Tinto group of companies. They are driven by both a company desire to have a consistent approach to engaging with Traditional Owners and the Traditional Owners wanting to have a similarly transparent and consistent standard of performance by the company in implementing the agreements which can deliver improved employment, cultural heritage engagement and direct and indirect benefits for the life of mining by the company. During the past three years the growth in the Pilbara, Western Australia brought new opportunities with people flocking to the region for employment flowing from the mining boom. Housing was at a premium and FIFO (fly-in, fly-out employment arrangements) was developed as a method to manage the general growth and demand for skills. Despite the recent down turn in the world economy since September 2008, which has reduced demand for minerals, the Pilbara continues to enjoy high levels of employment and as a result there is still significant pressure on housing and services provision. Although there has been vast economic growth in the Pilbara not only by mining companies but also oil and gas companies, the 2006 census data indicated that the direct benefits of improved employment, business development and engagement in the mainstream economy continued to exclude Aboriginal people. Indigenous people constitute a significant proportion of the population in the Pilbara region, some 6000 people û currently 14 per cent of the population rising to 18 per cent by 2015 û yet they remain at the bottom of the socioeconomic scale. More than 40 years of mining has returned relatively little to this group of people who are the permanent residents of the region and are connected through their traditional culture to this country (Taylor and Scambary, 2005). Ensuring local Aboriginal participation in the mainstream economy has been a challenge for resource companies, Traditional Owners and local residents in the Pilbara. The case study explores the relationship between a mining company û Rio Tinto Iron Ore and the Traditional Owners of the Pilbara. It examines two projects that have been developed to engage Indigenous people in the development of their region and through regional representation and business development to build a sustainable future for themselves and their future generations and at the same time ensure social cohesion to support social licence to operate. The case study also examines the process that was followed by Rio Tinto Iron Ore and its operations in undertaking a regional agreement for land access, participation and the integration of local Indigenous people into their business and the local economy.

Jan 1, 2009

By L Dubron

This study details a mineralogical and textural characterisation of West African iron ores with an emphasis on their behaviour during mineral processing. By means of both qualitative and quantitative characterisation, a simulation of the beneficiation process applied to these iron ores is performed. A series of different analytical tools are used, including:X-Ray Diffraction (XRD) for qualitative mineralogical analysis;• qualitative optical microscopy (phase identifi cation, description of micro-textures) and (semi)• quantitative optical microscopy (counting of particles, phases and textural types); and• chemical analysis.All the information provided by these analytical methods are combined into a quantitative mineralogical and textural analysis, here called ‘modal analysis’, which enables us to simulate the capability of West African iron ores to be benefi ciated by magnetic and gravimetric separation techniques.On one hand, both qualitative XRD and optical microscopy have revealed the presence of the following mineralogical phases: magnetite, haematite, goethite and quartz. On the other hand, the chemical analyses provide us with quantitative inputs expressed as oxides. We have converted the oxides into mineralogical contents expressed as magnetite, haematite, goethite and quartz. In this way, we build a simple quantitative mineralogical analysis.Beside this, the semi-quantitative approach of the characterisation by optical microscopy also provides us with a liberation study, enabling us to split the gangue-bearing content between two types of particles:1. liberated gangue-bearing particles, and2. composite particles composed by both iron (oxhydr) oxides and gangue-bearing minerals.We have assumed that we could anticipate the behaviour of these two kinds of particles through a mineral process, by simulating the removal of at least the liberated particles of gangue. Optical microscopy also revealed a trend in the weathering profi le of the Tokadeh ore horizon with a decrease from bottom to top of magnetite and an increase of both goethite and martite showing a higher level of oxidation and hydration in the upper ore horizon.We have applied this removal extent upon the quartz content of the mineralogical quantitative analysis and we have re-calculated the quantitative mineralogical analysis considering the expected decrease in the quartz content. Finally, by converting the re-calculated (oxhydr) oxides contents into iron grades and summing them, we do obtain a fi nal simulated iron grade for the upgraded products.

Jul 11, 2011

By A R. Penney

Safety management, both personal and that associated with catastrophic hazard, helps to define the success of mining companies. Personal safety management, often categorised by slips, trips and falls, has been widely addressed, with numerous approaches successfully adopted. Catastrophic hazard can lead to a single accident (eg ground collapse, underground fires etc) causing multiple fatalities. Catastrophic hazard management in mining is an emerging discipline, and as such there are various pitfalls to demonstrate its effectiveness and success; it is much more than simply meeting regulatory requirements. Various standards, guidelines, and leading practices are available for reporting key performance indicators. While measuring and reporting safety related key performance indicators (KPIs) such as Total Recordable Injury Frequency Rate (TRIFR), Lost Time Injury Frequency Rate (LTIFR), are important, they often lack detail, and give little insight into the effectiveness of catastrophic hazard management strategies and controls. Catastrophic hazards are low likelihood, high consequence events, and as such demand a different management approach. Companies cannot use the suite of personal safety metrics to help demonstrate management of catastrophic hazards. In-field verifications have revealed that senior management commitment to safety is often clear, well organised, and resourced. However, there are often some inconsistencies between what management promotes and plan, to what the operational teams understand and implement. Communication and clear understanding of expectations were the common themes identified to help empower supervisors to reinforce requirements of catastrophic hazard management. A lack of specific, measurable, and time-sensitive goals and objectives for the short- or medium-term, making it challenging to track progress was another key observation. Development of an integrated, multi-disciplinary auditing process executed by an experienced team of technical subject matter experts, provided an in-depth understanding of the requirements of catastrophic hazard management. Areas such as underground fire prevention, explosive storage, electrical safety, mobile vehicle interactions, ground control, inrush, and shafts and winders management have substantial overlap and intertwined processes, and similar strategies for emergency responses. Auditing of catastrophic hazards and safety management systems compliance is only the first step in safety assurance. Completing operational performance audits in technical areas and benchmarking the site verification of safety management documents and verifications forms a critical part to clearly demonstrate industry leading safety practices. No longer is it the external inspection or regular hazard management plan review requirements that dominate, but rather the culture of continual hazard identification, management, controls verification, underpinned by improvement and follow-up verifications of the corrective actions.

Mar 29, 2023

By L Kormos, V Lawson, G Hill, G Marrs

"In sulfide nickel deposits throughout the world, pentlandite and pyrrhotite are commonly found together along with varying amounts of chalcopyrite and platinum group minerals (PGMs). The mafic or ultramafic host silicates associated with the sulfide mineralisation commonly exhibit a complex assemblage of magnesium bearing silicates, many of which themselves contain significant nickel. Four types of ore are proposed, each presenting their own processing challenges. These are: economic grades of Ni, Cu and PGE (platinum group element) in a pyrrhotite-bearing sulfide deposit, with low pyrrhotite to pentlandite ratios  economic grades of Ni, Cu and PGE in a pyrrhotite-bearing sulfide deposit, with moderate to high pyrrhotite to pentlandite ratios uneconomic high pyrrhotite: low tenor deposits low-grade low sulfide, high MgO ± PGE deposits that can sometimes be economically mined and processed.The grades and recoveries of nickel concentrates produced from sulfide ores can be significantly impacted by the ore mineral texture, the nickel tenor of the sulfides, and the polytype of pyrrhotite which may be either hexagonal (non-magnetic) or monoclinic (magnetic). The mineralogy of the silicates is also of great importance, especially the magnesium silicates and those which tend to produce particles which are asbestiform or which affect slurry viscosity. Other magnesium silicates such as serpentine carry nickel in solid solution, limiting the recovery entitlement of nickel by flotation because serpentine is not amenable to sulfide flotation mechanisms. Differences in plant flow sheets and reagent assemblages are required to effectively separate these minerals.Experience from a variety of plant operations and from extensive flow sheet development programs are discussed. Examples are given of where significant improvements in nickel circuit performance can be made by adjusting plant physical processing conditions or process chemistry to compensate for measurable ore properties and characteristics.CITATION:Lawson, V, Hill, G, Kormos, L and Marrs, G, 2014. The separation of pentlandite from chalcopyrite, pyrrhotite and gangue in nickel projects throughout the world, in Proceedings 12th AusIMM Mill Operators’ Conference 2014, pp 153–162 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 1, 2014

By A Simmons, J Chan, A Li, Q Gu, D M. Brett

The paper presents an example of field density achievements using thin layer deposition and solar drying and compares this with compaction data from laboratory testing and field trials of mechanical densification processes.

Jul 1, 2021

By ALAN J. HARGRAVES

It is normal that Shepherd and Rixon, in their contributed discussion (this issue) see differences with Hargraves (1983), as it exemplifies the present uncertain situation worldwide, a situation expected to remain until better understanding and wider agreement lead to the real goal of the prevention of instantaneous outbursts of coal and gas.

Jan 1, 1983

At the beginning of the seventies pre- drainage of methane was introduced in West German coal mining in order to reduce the gas emission from the worked seam. After three pilot tests on the "Rheinland" Colliery (86 boreholes in seam "Prasident"), "Bergmannsgluck/ Westerholt" Colliery (23 boreholes in seam "Gustav") and "General Blumenthal" Colliery (27 boreholes in seam "Hugo" and 170 boreholes in seam "Karl") systematic large scale tests with extended investigations were carried out un the "Rheinland" Colliery (127 boreholes in the seams "Anna", "Blucher", Prasident"). During this time an analogous test was carried out on the "Consolidation" Colliery (21 bore- holes in seam "B"). In these studies and tests the technical feasibility, efficiency and economy could be proved, so that pre-drainage of methane starts spreading. On the "Rheinland" Colliery pre-drainage has become common practice in gassy seams. Mainly two points impede a faster spreading of method: 1. in many cases the necessary requirement, that one or both of the gate roads should ire driven 6 to 12 months before the face is worked, is missing. This is mainly due to the difficulty of retreat mining in passe seams.

Jan 1, 1982

By K Aikawa, M Ito, K Mitsuhashi, Y Ebisu, J V. Satur, I Park, N Hiroyoshi, T Suto

Copper concentration using flotation is becoming more difficult, because of an increase in ore complexity accompanied by smaller grain sizes of copper minerals than usual, requiring finer grinding in order to liberate them. Project Arqueros, located at the mid northern part of Chile, is a copper mine project with an orebody consisting of various sulfides such as chalcopyrite, chalcocite, and bornite. Some of the copper minerals in Arqueros show low floatability mainly because of their fine grain size and resulted fine grinding size, and also because of the complex mineralogical composition. For example, chalcopyrite in Arqueros floats less than the other copper sulfide minerals. In this study we carried out some kinetic flotation tests with the Arqueros ore using a laboratory-scale forced air type flotation machine by varying the regrinding size. The products were assayed and mineralogically analysed to compare the minerals in their flotation behaviour with respect to size classes and liberation classes. The results were compared with a model calculation according to bubble size measurement. From the flotation testing and mineralogical analysis, it was found that copper minerals of the same size and liberation class floated at the same rate even with different regrinding size. At the same time the comparison between experiment and calculation showed that the fine particles of less than 5 µm size floated faster in actual than in the model applied. These results suggested that interactions among minerals of different species and of different sizes had positive impacts on the flotation rate of the fine particles. It indicates that this phenomenon can be applied to improve copper recovery in the project.

Aug 24, 2022

By M K. C Roberts, M G. Magwaza, J W. L Hanekom, P Piper, R Lousteau

Due to the perceived potential to extract the second economic manganese seam at its Black Rock Operations in the Northern Cape Province, South Africa, Assmang commissioned an investigation with respect to mining method and sequencing of the two orebodies in 2007. Based on this initial study into multiseam potential, conditions and impacts, the rock engineering aspect was expanded to determine conceptual rules to govern the extraction of both manganese seams using the normal bord-and-pillar layout implemented at this operation. This work included the theoretical analysis using basic pillar design practices and numerical modelling, including the use of Map3D, UDEC and Phase2 codes.In 2013, Assmang launched a large-scale investigation into the potential to increase mine output from all possible manganese sources at the operation. Included in this investigation was the requirement to confirm or modify the conceptual multiseam extraction rules to implementation. As part of this confirmation process, stress measurements, borehole camera audits and additional numerical modelling were performed at a particular site on the operation where a limited extraction of both seams had been undertaken. The results obtained from this process provided confidence in the conceptual extraction rules and allowed the derivation of final extraction rules that will be implemented at the operation as the multiseam mining process becomes more widespread.CITATION:Hanekom, J W L, Roberts, M K C, Magwaza, M G, Lousteau, R and Piper, P, 2014. Confirmation of multiseam extraction rules for Black Rock Manganese Operations, Assmang, Northern Cape, South Africa, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 107–116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

During underground mining, rock mass changes can occur as a function of the mining sequence and excavation processes. Mining-induced rock mass damage can occur due to redistribution of static stresses and the application of dynamic stresses from blasting and seismic activity. These rock mass changes can result in a degradation of strength of the bulk rock mass and the remaining rock surrounding existing excavations. Rock mass damage near existing excavations which lead to excavation-scale instabilities such as rock fall, excavation closure, or visible rock mass fracturing can detrimentally affect the safety and profitability of mining operations.The focus of the current work was the prediction and assessment of damage to mine infrastructure occurring in relation to the blasting of a sublevel open stope. The study case involved a 60kt stope located in a highly-competent rock mass at a large Australian sublevel open stoping mine. The mine infrastructure of interest for investigation included local stope access development, critical access and haulage development crossing a regional-scale fault, an explosives storage magazine and a ventilation return air raise. The methods used to predict or assess the blast-induced damage to each infrastructure element in response to stope extraction were:- intact rock strength testing,- discontinuity mapping,- linear-elastic static stress modelling,- blast-damage mapping,- near-field blast vibration monitoring and analysis,- geophysical assessment using inferred stiffness and wave velocity methods, and- post-extraction void assessment.The results of the detailed blast damage prediction and assessment program at the mine site have been discussed by the primary author elsewhere (Fleetwood, 2010). The current work will address blast-induced damage to mine infrastructure as a result of extraneous blasting vibrations from stope production blasting. A method for predicting the amplification of excavation surface motions from reflecting body waves will be discussed as well as the results of damage mapping around the study stope. The results of the damage mapping program identified blast-induced damage that occurred to the surface of the explosives storage magazine and local stope access development. No damage was observed at the main fault crossing or return air raise where higher vibration amplitudes were measured or predicted.

Dec 6, 2010

By D François-Bongarçon

The link between geostatistics and Theory of Sampling (TOS) is examined again in view of new findings made while trying to compare predicted sampling variances and estimated grades (using geostatistics) on the same material, and this provides an important consistency requirement whenever calculations are made that involve both theories in a comparative way. It also briefly explores the relationship to De Wijs fractal model of mineralisation and eventually provides new support for the use of consistency theory for calibrating TOS variance formulas.CITATION:François-Bongarçon, D, 2017. Theory of Sampling and geostatistics – the ultimate link, in Proceedings Eighth World Conference on Sampling and Blending , pp 391–394 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By P Holtham, R Dunne, D Stoll

Flash flotation is a process designed to remove coarse, liberated, fast floating minerals from hydrocyclone underflow. Irrespective of liberation, coarse particles would normally remain in a grinding circuit until they are reground fine enough to report to the hydrocyclone overflow. Additionally, minerals of high density also report to hydrocyclone underflow despite being fine in size and/or liberated because hydrocyclones separate on the characteristics of both particle size and density. Dense particles continually reporting to the hydrocyclone underflow can lead to over-grinding and the production of ultra fine particles. These particles exhibit slow flotation kinetics and thus are difficult to float in conventional flotation circuits. Therefore, removing coarse, liberated particles from the hydrocylcone underflow by flash flotation has the potential to improve recovery and can improve dewatering unit operations and reduce grinding costs.The impact on the overall performance of the flotation circuit by removing coarse, fast floating minerals prior to conventional flotation is not well understood. Ultimately, predicting the overall recovery improvement provides the justification for the installation of a flash flotation cell within the milling circuit. This paper will describe attempts to estimate flash flotation recovery improvements to the overall circuit using kinetic data from simplified batch cell flotation tests combined with limn-based modelling techniques.CITATION:Stoll, D, Dunne, R and Holtham, P, 2012. Modelling the impact of flash flotation from batch cell flotation tests using limn, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 179-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Duniam P

Sequencing of large underground firings is a critical aspect of blast performance. Using theory developed in open cut operations, where blast results are easier to quantify, a new technique for sequencing underground mass blasts has been developed. The basis for the technique is to identify timing regimes to control fragmentation and relief then apply non-electrics to fit these criteria. The use of computer software to graphically interpret delay statistics enables the evaluation of designs in a realistic manner.

Jan 1, 1995

By V Glenn, P McKenna, H Vickers, P Audet, M J. Gillespie, A Gravina, D R. Mulligan

A requisite corollary of mineral sand mining on North Stradbroake Island (Queensland (Qld), Australia) has been the progressive rehabilitation of post-mined lands for the revegetation of native subtropical Eucalypt communities. Since 2005, rigorous environmental monitoring has been undertaken to verify the annual development of post-rehabilitated sites. From these long-term analyses, a chronosequence of land revegetation (ranging from three to 26 years postrehabilitation) was developed to examine the rehabilitation trajectories of various post-mined sites in relation to proximal undisturbed locations. Here, we identified that some sites may be deviating from the intended natural analogues as evidenced by the opportunistic colonisationand otherwise æinvasiveÆ behaviour of a regionally native species (Black Sheoak - Allocasuarina littoralis), which appear to be displacing the intended Eucalypt varieties. Although it is recognised that the broader data trends correspond to distinct periods of adaptive modifications to the implementation of rehabilitation (ie pre- and post-1995), this analysis focuses on further identifying potential above- and belowground feedback mechanisms underlying these divergent ecological outcomes.CITATION:Audet, P, Gravina, A, Glenn, V, McKenna, P, Vickers, H, Gillespie, M J and Mulligan, D R, 2012. Above/belowground feedback may facilitate and sustain mono-dominance on rehabilitated North Stradbroke Island, in Proceedings Life-of-Mine 2012 , pp 15-24 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By J Coombes

Within the mining industry there is a growing trend of placing inexperienced technical people into positions of responsibility beyond their readiness. Their responsibilities often include providing the fundamental basis for decision-making: the resource model or even the daily grade control estimates. Whilst software continues to make the processes more accessible, the thinking and rationale for selecting parameters still requires control rather than auto-piloting. Operators run these systems in virtual isolation, and have limited immediate access to experts. Beyond the stress of the professional burden are the increased risks to the mining operations and overall project success.While many experienced experts recall being thrown in the deep end, the relative isolation from experts coupled with the gravity of professional burden before readiness, is less familiar. Many recall in intimate detail the experts who gave them direction, assisted them along the way and even helped them claw out of inadvertent mistakes. Experienced professionals all have a responsibility to enable capability across the generations, to ease the burden and to mitigate the risks.This paper provides an outline of how mentoring as an on-the-job professional development process can be structured to more fully enable success of a mentoring program. Three examples complement the principles presented.CITATION:Coombes, J, 2012. Structuring meaningful mentoring, in Proceedings International Mine Management 2012, pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By S Maryati

Surface mining activities disturb large areas, produce great sediment loads and tend to be a source of water pollution if they are not managed properly. Coal mining in Indonesia has a very high risk of soil erosion because the coal mining areas are generally located in tropical areas with a high average of rainfall (4000 - 6000 mm/year) and use surface mining methods. The main factors affecting erosion risk are climate, soil type, topography, vegetation cover and management factors. Thus, the monitoring of erosion risk in mining areas is very important due to the characteristics of coal mining in Indonesia. The objective of this research is to determine the ability of satellite images (remote sensing data) and geographic information systems (GIS) to provide an accurate and up to date spatial database for the monitoring of erosion risk in surface coal mining areas using the Universal Soil Loss Equation (USLE) method.The erosion risk analysis and spatial data processing are generated by the ArcGIS 9.3 software and need several data, namely: an erosivity map, erodibility map, a slope map, vegetation index map and land management or land cover map. The erosivity map is derived from the rainfall data, whereas the erodibility map is derived from the soil map. The slope map is derived from the SRTM-DEM (Shuttle Radar Topography Mission-Digital Elevation Model) and processed using 3D analyst tools. Furthermore, the vegetation index map and land cover map are derived from a satellite image using digital image processing techniques.This preliminary study produced results that show soil erosion monitoring, which is integrated with remote sensing and GIS technologies, has great potential for producing accurate, advance, and low cost erosion risk maps in coal mining areas. This map is very important for getting spatial distributions of the erosion and useful for developing erosion management plans.

Nov 22, 2011

By C Smith, R I. Maczkowiack, P D. Erskine

Open cut coal-mining has been conducted in the Bowen Basin region of central Queensland for almost five decades, and has disturbed an estimated area of 140 000 ha of agricultural land until 2011. Approximately one-third of the area disturbed by mining has been rehabilitated to pastures or bushland. However, none of the rehabilitated land has yet been assigned a specific end-use. This research project develops an approach for assessing end-use risks for the regionÆs mined land, and develops risk assessment models for selected end-uses. First, a web-based survey of stakeholders was used to identify risks to be assessed. The risks identified were surface erosion, subsurface erosion, bushfires, weeds and feral animals. The survey also identified possible end-uses of bushland and grazing. Second, conceptual risk models were developed based on the risk assessment concepts of likelihood and consequence specified in the Australian and New Zealand risk assessment standards. Likelihood was modelled using site characteristics and management factors that influence the occurrence probability of risks (eg surface erosion), while consequence was modelled using a set of site condition indicators and condition thresholds (changes in root-zone water-holding capacity, soil erodibility, vegetation ground cover and soil organic matter and transition probability to a non-preferred ecosystem type).The factors influencing likelihood and consequence for each risk have been integrated using Bayesian networks. The next step in model development is to parameterise the Bayesian networks using existing equations, empirical datasets, or expert opinion where data are not available. The parameterised models will be used to assess grazing and bushland end-uses against erosion, bushfire, weed and feral animal risks for rehabilitated mined land sites, with the purpose of identifying the relative risks associated with each end-use, and the landform design specifications and land management practices under which end-use risks are minimised.CITATION:Maczkowiack, R I, Smith, C and Erskine, P D, 2012. Risk assessment models for post-mining land use, in Proceedings Life-of-Mine 2012, pp 33-42 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By Offler R, Lau J, Lea J. F

The stratiform and vein-type pyritic silver-Iead-zinc-copper sulphide deposits of Sunny Corner, NSW are hosted by acid volcanic and clastic sedimentary rocks of Middle Silurian to Early Devonian age. The rocks have been subjected to low-grade regional metamorphism (prehnite-pumpellyite facies) and three phases of folding and four faulting events are recognised. Pyrite is intensely fractured, indicating brittle deformation. Chalcopyrite and galena exhibit deformation twins and slip planes indicating ductile deformation; sphalerite and chalcopyrite show straight and curved grain boundaries and dihedral angles of 120° as evidence of annealing recryslallisation. Sulphur isotope ratios for 22 samples from five deposits range from 1.7 to 10.7 per mil and average 7.4 per mil. Sulphur isotope data are similar to those from other stratiform sulphide deposits in acid volcanic rocks of Late Silurian age in the eastern Lachlan Fold Belt, especially Woodlawn and Captains Flat and together with other features of the mineralisation, suggest a volcanic exhalative origin for the Sunny Corner deposits.

Jan 1, 1984

By D R. Seaman, Y Peng, F Burns, D J. Bradshaw

Telfer Gold Mine is a gold-copper mine in the eastern Pilbara of Western Australia, owned and operated by Newcrest Mining Limited. TelferÆs ores are processed by a dual train, 21 Mt/a, concentrator where gold is primarily recovered by gravity concentration and the flotation of a gold-bearing copper concentrate. A minor portion of TelferÆs gold is also recovered to a pyrite concentrate that undergoes treatment via carbon-in-leach (CIL) cyanidation. The gold recovery of the CIL circuit is below the industry standard and operates with a high reagent consumption rate.With a new fine-grinding facility, the Telfer process plant will have the ability to liberate copper and gold from the pyrite concentrate and recover these by flotation prior to the existing leaching circuit. This process will improve overall gold and copper extraction, while reducing reagent consumption in the CIL circuit.This article is an overview of the development of this methodology. Size-by-size analysis and mineralogical studies of monthly composites identified factors limiting the CIL gold recovery and the causes of high reagent consumption. Laboratory studies confirmed a relationship between the regrind product size and gold leach recovery. The addition of an intermediate flotation stage ensured that the regrind circuit will improve overall recovery while at the same time reducing operating costs. Without the addition of a flotation stage, the additional reagent consumption from regrinding alone would be prohibitive towards increasing recovery. Pilot scale studies confirmed the conditions required to selectively recover gold and copper from the pyrite concentrate as well as establishing the full scale regrinding energy requirements. Construction of this facility at Telfer is currently underway.CITATION:Burns, F, Seaman, D R, Peng, Y and Bradshaw, D J, 2012. Development of a pyrite regrind circuit at Telfer Gold Mine, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 45-52 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By J Harmse

This paper deals with the modernisation of the brakes on an electrically coupled Blair multi-rope hoist and covers the removal of the old calliper brakes and hydraulic control system, and its replacement with brake discs, disc braking units and hydraulic control systems. The paper covers the braking requirements of the hoist, which is made up of two electrically coupled single-drum hoists, together with the theory behind the choice of brakes and control systems supplied. The paper also covers the project logistics that were required in order to install and commission the new brakes and control systems with the minimum disruption to production on the only rock hoist on a major production shaft. Items covered include the modifications to civil works, pre-installation of bearing lubrication systems, brake discs and hydraulics and the interfacing of the new hydraulic control system to the existing electric control system. It had to be designed to be compatible to a new electric drive and control system due for installation at the end of 2005.

Jan 1, 2005