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By Kuganathan K, Potvin Y

Enterprise Mine at Mount Isa is to expand ore production from the current 1.4 to 3.5 mtpa by mining the 3500 Orebody, from which production is scheduled to start in February 1998 making this the deepest underground mine in Australia with its lowest mining horizon at nearly 1.6 km below surface. The following fill requirements were defined for the 3500 Orebody during the feasibility study: 1. a minimum filling rate of 250 ma/h, 2. a curing time of 28 days, and 3. minimum free fill water. This paper mainly describes the investigation of high density and paste fills for the 3500 Orebody. The investigation covered all the key issues relating to fill option selection, including design criteria, material supply and demand assessment, drainage modelling, tailing dewatering method, mix design and a pump loop test. Results of the investigation indicate that both high density fill and paste fill are technically feasible. The investigation has led to the selection of a blended tailing paste for the 3500 Orebody as the paste option has significant advantages over high density fill in stope filling rates and fill reticulation. The blended tailing for paste fill is finer than Isa deslimed tailing but coarser than full plant tailing. The paste fill selected has minimum binder and tailing dewatering requirements while a relatively high filling rate is achieved.

Jan 1, 1998

By A Valero, G M. Mudd

There is active debate and research around the most suitable indicators to assess the sustainability of mining. The most common approach is to report a range of data for a given mine site (or less preferably, a company total), such as inputs, outputs, benefits and potential costs. The most popular protocol in use (and growing rapidly) is the Global Reporting Initiative (GRI). However, these measures are numerous and still do not allow a single over-arching indicator to be developed. Other measures, such as known mineral resources over time, do not account for critical challenges such as declining ore grades, increasing wastes and poorer quality ores or more difficult mineralogy. By adopting a thermodynamic approach to sustainability, through the concept of æexergyÆ, it is possible to incorporate into a single measure the effective quality of mineral resources. Exergy involves the assessment of the minimum energy costs involved in producing a mineral resource with a specific chemical composition and concentration from common materials in the environment. The exergy of a mineral resource is evaluated from mineralogic composition, concentration (or ore grade) and, of course, quantity, by multiplying the unit exergies with the tonnes of the resource produced (or consumed). Since exergy is a thermodynamic quantity (ie energy or joules), it is additive across different minerals, such as iron ore to gold to copper or even oil and gas or coal û making it an ideal indicator to assess mineral resource sustainability at the industry scale rather than the individual mine scale. This paper briefly outlines the theoretical basis for exergy, and then presents a range of commodity case studies showing the application of exergy to the Australian mining industry. Overall, the usefulness of exergy is clearly demonstrated for use as a broad indicator of the sustainability of mineral resources at the national or even global scale.

Jan 1, 2009

By G Hancock, A Kemp, I Taylor

The mine site is situated south east of Port Hedland in the Pilbara region of Western Australia. A detailed engineering design was undertaken for six irregularly shaped waste rock dumps at the site. The design was undertaken to ensure long-term stability of the dumps and optimise material movements for closure construction. The Watershed Erosion Prediction Program (WEPP) and SIBERIA landscape evolution modelling was undertaken for the landforms using regional and site-specific material characteristics to provide an indication of the maximum allowable slopes and corresponding slope lengths for long-term stability.The majority of the waste materials present in the waste rock dumps are considered likely to be subgrade banded iron formation (BIF) and chert, which is generally competent material. The presence of a large number of dolerite dyke swarms indicates appreciable volumes of dolerite were produced as waste from the pits. Geological records also indicate that the dolerite is logged as being heavily kaolinised in the geological logging, hence kaolinite is very likely to be present within the waste dumps on-site. This material has an elevated risk of being highly erodible/dispersive. Clays and shales are also likely to be present in the dumps and are considered to be less competent material (relative to the BIF/chert).The final design configuration of the largest existing ‘unplanned’ waste rock stockpile is compared to a hypothetical continuous ten degree outer embankment alternative. This paper will present a brief description of the alternatives for closure of three waste dumps in close proximity to each other and how the detailed design based on site-specific materials and conditions compare to an alternative approach blankly assuming that most materials will be erosionally stable at less than ten degrees.CITATION:Kemp, A, Taylor, I?and Hancock,?G,?2014. Landform design for Pilbara mine site – why plan and design waste rock dumps for closure based on site-specific conditions?, in Proceedings Life-of-Mine 2014 , pp 47–54 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

The Manto Verde mine is found in the coastal ranges of the Atacama desert, 1000 km north of Santiago, Chile . The deposit is a fault-breccia specularite-oxide copper mineralisation hosted by the Jurassic andesites of La Negra Formation. It is located in a tensional fault that joins twoparallel arms of the Atacama Fault. The mine is in feasibility study: reserves are of the order of 60 Mt at 0.9 wt per cent soluble copper; mining will be undertaken at a rate of 11 000 tpd utilising an open pit and the ore will be heap-leached with acidified sea water, with copper recovery and by SX/EW.

Jan 1, 1992

By N Meadows, M Rodriguez

A 200 000 tpa heap leach demonstration plant was approved by the Murrin Murrin Joint Venture (MMJV) in December 2005 and engineering commenced in January 2006. The demonstration plant will utilise stockpiled ore reject material (æscatsÆ) and extract nickel and cobalt. Limited production from the demonstration plant is expected by the end of 2006. The demonstration plant will enable the company to fully investigate and understand all associated technical issues over the next 12 to 18 months, including the potential to expand the heap leaching operation to a commercial scale. In parallel, the MMJV will continue a research and development program to improve and expand the application of its heap leaching technology.

Jan 1, 2006

By D Horacek, I K. Sheppard

Ok Tedi is in a period of transition. By 2008 mill feed will consist of higher levels of high-grade but metallurgically challenging skarn ores. Additionally, the Taranaki pit will start production in 2008 along with the start-up of a new pyrite concentrator. Taranaki ores are very high in sulfur. Sulfur is captured in a pyrite concentrate prior to tailing entering the Ok Tedi River. These and other complex scheduling issues will need to be resolved over a critical three-year period. With these requirements in mind, Ok Tedi contracted AMC Consultants to develop a custom version of the Life of Business Optimisation System (LOBOS¬) to assist medium-term production scheduling at Ok Tedi. LOBOS utilities enable Ok Tedi planning engineers to:import polygon-based reserve data (Blast Masters) from MineSightÆs Interactive Planning Tools (IP Tools); graphically construct block sequencing and material flow constraints; edit constraints defining standard scheduling, processing and financial relationships; define dump and stockpile attributes; and assign capacities to production systems, plants, dumps and stockpiles. LOBOS converts Ok TediÆs production scenario into a mixed integer program (MIP) and submits the resulting model to IlogÆs Cplex MIP Solver. The Solver seeks an optimal production schedule that maximises net revenue per mill hour while meeting all constraints. This paper introduces Ok Tedi and its production requirements and relates these requirements to the facilities developed for an Ok Tedi version of LOBOS.

Jan 1, 2007

By D Reid, J McKibben, M Noppe

International mineral disclosure standards and guidelines aligned with the CRIRSCO (Committee for Mineral Reserves International Reporting Standards) template were developed to inform stakeholders about the relative accuracy and confidence levels of publicly reported information and to support investment decisions, particularly when advancing projects through different development stages. The traditional stages range from early to advanced exploration, through pre-development (with Mineral Resources and pre-feasibility and/or feasibility levels of study) before the final development stages, where a decision to proceed with construction or production (or both) is made. The traditional definition of Mineral Resource and Ore/Mineral Reserve classification categories and techno-economic study levels (including Preliminary Economic Assessment (PEA), Scoping Study (SS), Pre-Feasibility Study (PFS) and Feasibility Study (FS)) were defined with pre-development project assessment in mind. As such, these definitions are not necessarily well aligned to the reporting structures required by operating mines which need to consider a range of timelines spanning short to long-term operating conditions. However, the same terminology and definitions are used, or expected to be used, by both project developers and mine operators when reporting resources, reserves and techno-economic study outcomes. This paper discusses how various stakeholders in the minerals industry (including competent/qualified persons, mining company leaders, investors, lenders and regulators), generally interpret the definitions of Mineral Resource and Ore Reserve categories in terms of the relative accuracy of the estimates, their link to techno-economic study levels and their contribution to life-of-mine (LOM) schedules. The paper examines the degree to which mining companies recognise, and apply, enhanced operational knowledge to reflect short-term views of the relative accuracy and confidence levels associated with publicly reported Mineral Resource and Ore Reserve estimates and forecasts. Furthermore, this paper explores how this knowledge is applied to support ongoing Mineral Resource, and particularly Ore Reserve, generation and reporting. This paper is informed by public data and responses to an internal survey prepared by the authors and completed in 2021 by several mining companies.

Mar 22, 2022

By Lynch A. J

Comminution within rod mills has been investigated by use of a matrix analysis of breakage processes. A parameter, the number of breakage stages, has been introduced and comminution within all rod mills has been expressed in terms of the number of grinding stages and a function which describes the feed rate, mill diameter, and mill speed. The effect of variation in feed rate, feed sizing analysis and mill speed on the number of breakage stages is discussed, but no general relation is proposed because more study is needed.INTRODUCTIONRod mills are normally used as the first unit of multi-unit systems for the grinding of metalliferous ores and the cost of operating rod mills may be considerable. For both economic and metallurgical reasons, it is therefore necessary that the mills should be operated efficiently and that a knowledge of the mechanism of the size reduction process within rod mills should be as complete as possible. While a qualitative assessment of the process may be of some value, a quantitative assessment gained by describing the process in mathematical terms can be of much greater use because it may also be used for design and control purposes.In this paper, an empirical mathematical model is postulated to describe the size reduction process within rod mills and it is used to analyse the effects of variations in both rates and size distributions of the feed to the mills.GRINDING CHARACTERISTICS OF ROD MILLSMyers (1953) discussed the grinding characteristics of rod mills and suggested that a pronounced screening effect, resulting in the preferential grinding of the coarser particles, occurs within the mills. This is illustrated in...

Jan 1, 1964

By M Begbie, R J. Norris, D J. MacKenzie

The Otago Schist is crossed by numerous deformation zones that formed in the latter stages of metamorphism and uplift of the metamorphic belt. These deformation zones are long (tens of km) linear features at the regional scale, and are generally narrow (km scale or less). Many of these structural zones separate schist domains with different rock types and structural/metamorphic histories. The Hyde-Macraes Shear Zone is one such deformation zone, and this zone hosts the active Macraes gold mine. The Rise & Shine Shear Zone, 80 km NW of Macraes, is also enriched in gold and has been mined historically. Mineralisation in both these shear zones occurred during the transition from ductile to brittle deformation as the schist belt was uplifted from greenschist facies metamorphic conditions. Recrystallisation of quartz and micas in the early stages was overprinted by cataclasis, with sulfide and gold precipitation throughout. Many of the other late metamorphic deformation zones formed under similar greenschist to sub-greenschist facies conditions, with similar overprinting of recrystallisation textures and folds by more brittle textures such as breccias. Under these conditions, originally regionally pervasive deformation at the highest metamorphic grades was evolving towards more focussed high strain zones at lower temperatures and pressures. Shear zones initially focussed fluid flow along microshears and mineral grain boundaries, resulting in 1 to 100 m scale alteration and replacement in the host schist, with only local development of quartz veins. Fluid flow was not controlled by open fractures, and the rate of fluid movement was probably slow and pervasive. After uplift into the brittle regime, the schist belt underwent tectonic extension. Extension was accompanied by development of swarms of steeply dipping veins, with localised mineralised normal faults. Hydrothermal fluid flow throughout this uplift history was a normal consequence of late stage devolatilisation of the metamorphic belt. Hence, all late metamorphic deformation zones should be considered prospective for gold accumulation.

Jan 1, 2005

By S C. Dominy

Current and proposed methods of resource classification relate to the geological, economic and technical confidence in the estimated resource. Geological confidence is, however, only vaguely defined. It is largely related to the level of drilling and sampling, to the geologistÆs perceived level of confidence in his/her work and on the continuity of the mineralisation. Rarely has any real attempt been made to assess how well a deposit has been explored, sampled and evaluated and how accurate or realistic the geological model is for the deposit. This contribution reviews the impact of two of the potential sources of error, ie sample recovery and quality. The first of these parameters is measured during logging and assaying, but is often forgotten during grade and tonnage estimation, and resource classification. Preliminary studies have shown that modelling of this parameter is a valid exercise, which should accompany the evaluation of grade and other economic parameters. The sample recovery factor for an ore block can then be used to reassess the confidence in the block. It could, for example, downgrade the status of a Measured Resource to an Indicated Resource even though standard methods might indicate that the higher classification is applicable. A method is proposed by which this recovery factor could be incorporated into current resource classifications producing a more sophisticated and comprehensive measure of sample quality. A review of the sources of error naturally leads to the assignment of scores to each stage of the evaluation process, depending on the methods used and assumptions made. Sample recovery is one important factor, which is likely to appear at several stages. These scores can then be weighted and combined in a manner resembling that used in the CSIR Rock Mass Classification. This score will then allow the resource estimate to be rated on a scale from 0 to 100 per cent to produce a Quality Control Index (QCI). However, this index must then be modified using an Evaluation Difficulty Index (EDI), which reflects the difficulty of a particular style of mineralisation to accurate resource estimation. This results in the production of a Resource Reliability Rating (RRR), which can then be linked to international classifications, such as the 1999 JORC; 2000 CIM; and 2001 EURO codes. This will permit a more precise definition of geological confidence levels or, combined with estimation error, produce a classification system in its own right. This same rating can also be used as the basis for technical audits of mineral projects.

Jan 1, 2002

By I Zh Bunin, V A. Chanturia, V G. Minenko, M V. Ryazantseva, A L. Samusev

A promising source for the extraction of rare metals and REEs in Russia is the eudialyte ores of the Lovozero deposit, which do not contain active uranium components. The eudialyte ore reserves of the Lovozero Massif are considered virtually unlimited and therefore have the potential to become a primary source of a number of rare and rare earth metals. The goal of this study was to comprehensively examine the effect of the parameters of high-power nanosecond electromagnetic pulses (HPEMP) and dielectric barrier discharge (DBD) on the leaching performance of eudialyte concentrate and the selective separation of zirconium and REEs from productive solutions. Using scanning electron microscopy and infrared spectroscopy, the mechanism behind the intensification of acidic dissolution of eudialyte as a result of pretreatment with energy impacts was described. During the HPEMP treatment, weakening and destruction of the eudialyte surface was observed, which at the substructural level is expressed in the deformation and local destruction of Si10O27, Si9MO30 resulting in formation of microcracks. During the DBD treatment, the formation of characteristic defects was observed in the form of imprints of dielectric breakdown microchannels and individual mineral fragments. Pretreatment of eudialyte concentrate using HPEMP made it possible to increase the recovery of zirconium into the pregnant solution of leaching by 3.4–4.3 per cent (from 86.6 per cent to 90.9 per cent) and by 4.1 per cent (from 86.6 per cent to 90.6 per cent) when using DBD. The increase in the total recovery of REEs was 1.2–1.8 per cent (from 87.7 per cent to 89.2 per cent). The effect of pH values, solution temperature, initial concentrations of valuable components on the successive recovery performance of zirconium and REEs from the pregnant solutions nitric from the acid leaching of eudialyte concentrate by chemical precipitation was examined. The possibility of selective separation of the zirconium product and rare earth elements with a zirconium recovery of 99.95 per cent and a REE recovery of 87.5 per cent was established. REE loss with the zirconium product was 8.0 per cent and 4.5 per cent with the spent pregnant solution.

Aug 24, 2022

By P Dowd, A Adeli, C Xu, X Emery

Geometallurgical modelling is increasingly being incorporated into mineral resource modelling and estimation as a means of increasing efficiency, decreasing operating costs and reducing risk in mining operations. Traditional geostatistical workflows for geometallurgical modelling face several difficulties, in particular, related to the non-additivity of process response variables, to highly heterotopic data sets and/or to preferential sampling designs, all of which may explain why most attempts to estimate geometallurgical response variables from assay data and mineralogy are still based on statistics and machine learning. The aim of the work presented here is to demonstrate the applicability of geostatistics to estimate copper recovery from copper sulfide ores at the Prominent Hill Iron Oxide Copper-Gold (IOCG) deposit in Australia. As recovery is non-additive, the preferred workflow is the joint estimation of the masses of metal in the feed and in the concentrate, both of which are additive variables. While the mass of metal in the feed can be estimated from abundant online assay analyses, the mass of metal in the concentrate can only be estimated from a very limited number of laboratory-scale batch flotation tests. Traditional approaches to estimating the masses of metal in the feed and in the concentrate, such as simple and ordinary co-kriging, are described and discussed. A modified version of co-kriging is introduced, which incorporates linear relationships between the mean values of the input variables, in addition to a spatial correlation model. Co-kriging with related means is shown to outperform traditional simple and ordinary co-kriging in terms of precision, accuracy and consistency of the estimates, and offers a practical and efficient tool to deal with highly heterotopic and preferential sampling designs.

May 24, 2023

By A Sainoki, D Fukuda, K Shioya, C Zhang, M Sharifzadeh, T Yamaguchi, S Saydam, J Kodama, C A. Amagu, Y Fuji

In an open pit mining, ensuring stability of rock slope has been one of the major challenges. As the instability of rock slopes can results in slope failures; consequently, endanger the lives of workers, affect mining operations, and often lead to economic losses. Therefore, it is practical important to study the stability of rock slopes to ensure safe, smooth, and effective mining. The stability of rock slope of about 130 m height at Higashi-shikagoe limestone quarry, which has experienced slope failures four times since 1996, was assessed. The rock mass at the quarry is consists of mainly limestone, schalstein and slate rocks intersected by clay seams of about 70 m thick at footwall of the rock slope. Previously, the effects of limestone excavation at the foot of the rock slope and shear failure due to rainfall infiltration have been investigated. Although clay is widely known to plays a vital role in the stability of slopes in engineering projects including mines, but its impacts on slope deformation at the study quarry are not adequately examined. Therefore, the present study addressed the impact of presence of clay on slope deformation at Higashi-shikagoe limestone quarry by employing both field displacement measurements and numerical simulation. Firstly, surface displacements measured by automated polar system (APS) for over eight years were analysed to understand the overall characteristics of the slope deformation. The measured results show that the displacement gradually decreases with time. The maximum displacement of about 100 mm was observed at middle of the rock slope. Secondly, the effect of deterioration and plastic behaviour of the thick clay layer were simulated using two-dimensional finite element method (2D FEM). The simulated results reveal that the clay exhibited deterioration by water contact and plastic behaviour arising from mining activities at the footwall of the clay zone. Based on the characteristics of the measured and simulated results, it was found that the displacement induced by the effect of deterioration of clay is more noticeable at the north side of the quarry whereas displacement induced by excavation is quite significant at the south side of the quarry if clay behaves as an elasto-plastic material.

Nov 29, 2022

Mechanism Responsible for Flocculation in Poly (N-Isopropylacrylamide) Temperature Responsive Dewatering - Attractive Interaction Forces Induced by Surface Hydrophobicity

Sep 13, 2010

Courses in chemical engineering and metallurgical engineering at the University of Queensland were compared and the main difference was found to be the greater emphasis on the application of chemical engineering fundamentals, particularly chemical thermodynamics, to specific processes in the metallurgy course. This reflects the distinctive features of extractive metallurgical processes which are not common in other chemical engineering processes and which justify the study of extractive metallurgy in its own right. B.Sc. courses in metallurgy provide one way in which the specialist knowledge of extractive metallurgy can be taught. General metallurgy courses are considered to be preferable to those restricted solely to extractive metallurgy since graduates of a general course have a wider choice of employment, while excessive emphasis on extractive metallurgical applications in chemical engineering courses could reduce the non-specific nature of these courses. Postgraduate diploma and higher degree programmes are avenues for non- metallurgists to acquire knowledge of the discipline.

Jan 1, 1984

By D J. Williams, A K. Kho, A Shokouhi, N Tucker

The disposal of dewatered coalmine tailings and coarse reject within spoil piles is gaining popularity as a means of eliminating separate surface tailings storage facilities or dams. The contrasting characteristics of coalmine spoil, coarse reject and tailings are somewhat complimentary, making the co-disposal of dewatered tailings within spoil piles geotechnically feasible and environmentally attractive. However, the impacts of mixing plant rejects within spoil piles are not well understood; in particular, the effects of water draining from the mixed plant rejects on the moisture content of the surrounding spoil. Changes in moisture content can cause additional collapse and degradation settlements of the spoil pile. A series of laboratory tests has been undertaken on mixtures of dewatered coalmine tailings, coarse reject and spoil. The results of these tests have been incorporated into a spreadsheet-based settlement prediction tool to investigate the effects of incorporating mixed plant rejects on total spoil pile settlements. This paper presents the laboratory tests undertaken, the incorporation of the test data into the settlement prediction tool, and settlement estimates for the various mixtures at different stages of construction.CITATION:Kho, A K, Tucker, N, Williams, D J and Shokouhi, A, 2015. Impact of co-disposing mixed plant rejects on spoil pile settlements, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 51–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By T Walton, C Perring, M Pepper, G Gerber

The Yandicoogina Channel Iron Deposit (CID) is an accumulation of iron pisolites cemented by a goethite-rich matrix. The Yandicoogina CID’s are found in a palaeochannel that meanders within a broad structural basin of the Yandicoogina Syncline in Pilbara region of Western Australia. RTIO Yandicoogina Mine Geology team contributed to a number of strategies maximising the iron ore reserves mined by Rio Tinto. Two strategies are discussed: the replacement of the Batter-Berm final pit walls by contour dozing; and upgrading the lower grade material to crusher feed. 1. Contour dozing – traditional Batter-Berm pit final wall configuration left kilometre long wedges of ore sterilised around bench margins. Contour dozing final walls (ie dozing of ore down the ore-waste contact) as internally defined by RTIO Yandicoogina Mine Geology (Mine Geology), enabled recovery of additional crusher feed. 2. Upgrade of lower grade material – the lower ore domain (GVL) within the Yandicoogina orebody contains numerous clay pods. Contaminant Al2O3 inherent within clay pods can result in CID material outside of crusher feed grade specifications, causing it to be flagged as ‘internal waste’ in mining models and permanently lost to waste dumps. In 2011, after multiple tests, Mine Geology demonstrated that this material could be upgraded to crusher feed via wet processing. With the support of the RTIO Metallurgical Development team new grade specifications were defined. The resulting material has been used to supplement higher grade ore. While increasing the mining ore output, these ongoing value-adding strategies also promote more sustainable mining via better use of the non-renewable iron ore commodity. The initiatives extend mine life, reduce waste movement, improve strip ratio and increase productivity

Mar 22, 2022

By E Shilov, R Dixon, L Tovey

BHP Western Australian Iron Ore (WAIO) operations use a suite of slope monitoring systems which are deployed to operational areas based on the ground control risk. Slope Radars are one system used within WAIO, having recently deployed and integrated a network of 22 radar systems across the operations. The integration required the development of supporting network architecture, infrastructure, virtualised hosting, security protocols and a technology support model. This has enabled data transfer between the physical radar systems located in open pits, to on-site offices, a vendor supported remote control room in Indonesia and the WAIO Integrated Remote Operations Centre for data analysis and monitoring of system and displacement alarms 24/7. The typical technical skillset of a Geotechnical Engineer does not include the knowledge and capability to understand and develop the supporting IT infrastructure required for establishing an integrated radar monitoring network. This paper will provide a discussion of the technology considerations for integrating radar systems and highlight the importance of the developed partnerships between internal geotechnical and technology teams and the external vendor team to ensure a reliable, robust and scalable slope monitoring solution.

Nov 29, 2022

By B Yang, L Wang, C Y. Ng

Flotation process intensification is often achieved through changing chemical reagent scheme or flotation machine or both, which likely brings a hefty burden to the flotation plants in terms of capital or operating expenditure. A novel approach to flotation process intensification is the use of acoustic sound, which has been demonstrated to be effective in improving the flotation of various mineral systems with different type of flotation cells. This approach was based on the dynamic stabilisation effect of acoustic sound on the flotation froth. The present work aims to understand the influence of various experimental conditions on the effectiveness of the approach. First, the effects of sound frequency and amplitude were studied with column flotation of silica particles. Results showed that the flotation performance was improved only within a certain range of frequencies and above certain amplitude. The study was then extended to the mechanical flotation of quartz particles with various size ranges and at two solids concentrations. With sound, the recoveries of different size fractions within the range of 20–212 μm were all increased. In particular, the recovery of 150–212 µm particles was increased from 0 per cent to approximately 25 per cent, demonstrating the potential for extending the upper limit of particle size in flotation by using acoustic sound. Furthermore, mechanical flotation of chalcopyrite particles at various collector dosages (50–150 g/t) was carried out with and without sound. Results showed that the increment of the final flotation recovery was increased with sound at different collector dosages. Overall, acoustic sound has the potential to be used as an effective and versatile method for flotation process intensification.

Aug 24, 2022

By M Darvall

Magnetite ore blending has yielded signifi cant performance improvements in OneSteel’s magnetite concentrator. The magnetite concentrator beneficiates magnetite ore from the Iron Magnet Deposit and produces concentrate, which is pelletised, then fed to the OneSteel Whyalla blast furnace. Concentrator feed variability severely detracts from the concentrator’s performance, affecting both concentrate yield and grade, which impacts on all downstream processing costs.A coordinated approach has integrated mine planning, geological modelling and grade control, to minimise concentrator feed variability, through effective ore blending throughout the mining and stockpiling process.Mine planning personnel design shots that extend the full width of the orebody and hence across the stratigraphic profi le. Based on geological information contained in block-outs and in consultation with Geology, the Grade Control team allocates material to each primary stockpile, potentially from every stratigraphic domane in the orebody. This ensures primary stockpiles are designed with maximum practical homogeneity and consistency.Using only primary movement, the allocated ore is stockpiled in a layer-cake fashion. The ore is pimple dumped across the width of the stockpile footprint and on completion of a layer, it is dozed flat with an access ramp that allows dumping to commence on the next lift. The primary stockpiles are reclaimed normal to build direction and the magnetite is crushed, all in, to a concentrator feed stockpile.The ore is sampled at the crusher from a falling stream cut. These assay data, are used for benchmarking and control charting the grade and variability of concentrator feed stockpiles. The concentrator feed stockpiles have demonstrated a statistically signifi cant reduction of within pile variation, between pile variation and pile to pile variation, primarily attributable to the development of ore blending. The concentrator has seen sustained, improved performance as a direct result, which translates into lower concentrate cost per tonne and improved yield and quality.

Jul 11, 2011