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By M Schaffer, T Kewe, N Moffatt

Porgera mine is 95 per cent owned by Barrick Gold Corporation. It is located at an altitude of 2200–2700 m above sea level in the Enga province of Papua New Guinea and produces approximately 460 000 oz per annum with a proven and probable reserve of 6.2 Moz. The refractory ore is ground in a conventional semi-autogenous grinding and ball mill circuit. After the gravity gold is recovered, the slurry is floated, oxidised in the autoclaves and then leached. This paper will focus on the flotation circuit and the recent upgrade of the control system. The five interdependent flotation circuits were challenging for operations to control as they dealt with variable grade, throughput and circulating loads, as well as the physical limitations of the equipment. With the installation of 18 Portage Froth Characterization® (PFC) cameras, the plant’s operation has been converted from a level-control based strategy that was focused on individual cells to one that targets grade and recovery control across the entire circuit. Variability in feed and the corresponding launder issues were addressed with a unique site initiative of deflector plates to indicate filling level. Non-linear closed loop control was implemented directly in the DeltaV Distributed Control System (DCS) using Portage Advantage Regulatory Control (PARC) algorithms and optimised with AwaRE advanced controllers. The most noticeable benefits achieved with the upgrade include improved flotation gold recovery, consistent flotation sulfur grade and autoclave performance. Correspondingly, there was a significant drop in boiler diesel fuel usage and launder overflow conditions.CITATION:Kewe, T, Moffatt, N and Schaffer, M, 2014. Porgera flotation circuit upgrade and expert system installation, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 345–356 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By D Weatherley, T Baumgartl, L Huang, Q Shao

The stabilities of rehabilitated landforms are often threatened by the altered surface hydrology, especially the excessive surface run-off, which may cause severe water erosion and associated pollutant transport to surrounding areas. These effects would lead to pollution in waterways and render the failure of newly established vegetation. An accurate quantitative evaluation of run-off problems are consequently essential for the proper rehabilitation designs which can help minimise these harmful consequences. For this purpose, in this study a novel run-off model, RunCA, was developed based on Cellular Automata (CA), integrating fundamental hydraulic principles. In this model, a series of rectangular cells were employed to cover the study area. Run-off production within each cell was simulated by determining the cell state (water surface elevation) that consists of both cell altitude and water depth. The distribution of water flow among cells was determined by applying CA transition rules based on the improved minimisation-of-difference algorithm and the calculated flow travelling time. RunCA was applied to various aspects in mined land rehabilitation planning, including landform designs for both hill-slopes and tailings dams, revegetation strategies and cover constructions. Simulation results showed that surface run-off increased with slope gradient and more run-off was produced on convex and straight slopes than on concave and S-shape slopes. Both mounds and rip lines constructed on the tailings dam surface could help reduce the water discharge. Vegetation planted in rows were more effective than those in columns or patches in controlling run-off. Increased cover thickness had the potential in reducing run-off rates, and the covers with an increasing thickness from top to bottom of the slope tended to be more efficient than those with a constant thickness. All these results have demonstrated the efficacy of RunCA as a simulation tool in assessing the hydrologic behaviours of different rehabilitation designs. Compared to the traditional hydrologic models, most of which were developed for the catchment scale studies, RunCA has the potential advantages in capturing the dynamic and spatially varied run-off behaviours at different spatial and temporal scales.CITATION:Shao, Q,?Baumgartl, T, Huang, L and Weatherley, D, 2014. A cellular automata-based run-off model and its application in mined land rehabilitation designs, in Proceedings Life-of-Mine 2014 , pp 81–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

I The South Platform of the Gippsland Basin is an extensive area of shallow basement covered by a relatively-thin Late Mesozoic-Cainozoic section. Although the sporadic exploration to-date has not resulted in any hydrocarbon discoveries, the area is under-explored and its taste potential has not yet been fully evaluated. The best potential appears to be in areas underlain by the Golden Beach Megasequence where structures are mainly related to basement fault blocks.

Jan 1, 1992

The Bureau of Mineral Resources has been engaged in regional geological and geophysical field work in the Alligator River and Cobourg Peninsula area since 1971, following the discovery of major uranium deposits. Geophysical work commenced with a regional airborne magnetic and radiometric survey which was followed up by some helicopter and ground work in August 1973. The interpretation of the earlier radiometric work is presented in conjunction with the results obtained from the follow-up work. Analyses of 100 outcrop and drill core samples collected have provided basic information on the physical properties and concentrations of uranium and thorium in various rock types. The uranium determinations were made by X-ray fluorescence and delayed neutron analysis, good agreement being obtained between the two methods. X-ray fluorescence was the main analytical technique used because of its ability to produce both uranium and thorium determinations.

Jan 1, 1975

The title of this paper suggests rather a comprehensive survey of the industry, but since it is not possible to do justice to this in a short paper, and, as the bulk of the Australian trade consists of buttwelded tube, the author proposes to deal only with this type.The buttweld process has been praetised for many years and, as the methods of manufacture are not widely known, a brief history of its development may be of interest. Few good reference books in the English language are available, and this reticence may possibly have retarded advancement in manufacture.The earliest method of making ferrous tubes consisted of bending a thin plate or strip to form a "skelp." The "skelp" was then raised to a welding heat and hammerwelded on an internal mandrel on a smith's anvil. Necessity, however, soon produced mechanical methods of making tubes, and, in 1812, an Englishman named Osborn patented machinery for "welding and making barrels of fire-arms and other cylindrical articles." The apparatus was arranged as shown in Fig. 1.The skelp was raised to a welding heat and placed in the swage block "A." A mandrel was then inserted and the tube lapwelded by the action of the tilt hammer.Various modifications of this apparatus quickly followed, to keep pace with the rapidly growing demand and the exigencies of war. These tubes were essentially of short length and mainly used for gun barrels. The advent of coal gas for lighting (patented by Murdoch) created a demand for small tubes of longer length, and necessity, as usual, produced a solution. In 1824 Jas. Russell, from *Works Manager, Stewarts & Lloyds (Australia) Pty. Ltd.

Jan 1, 1935

By K L. C Gontalves

In 1999, the Mineral Development Centre of CVRD (CDM) acquired a flotation device referred to as Mini Pilot Plant (MPP), which is able to run continuous flotation tests with drill core samples. Since then this equipment has been used to define the flotation circuit and process conditions during the pre-feasibility phase of CVRDÆs copper sulfide projects. Until now, the MPP results had not been validated for an industrial flotation operation. The present work consists of a comparison and correlation of the results from a flotation MPP and an industrial plant. In order to make this comparison, an industrial plant was completely sampled and the feed ore was tested on bench scale and on a MPP. The metallurgical and mass balances of each test were used for the comparison.

Jan 1, 2005

By M Ireland

Extensive use of diesel-powered mobile equipment in modern mines for materials handling, such as load-haul-dump machines, constitute a significant source of heat, exhaust gases and diesel particulate matter. Provision of sufficient quantities of fresh, cool air are required to remove such atmospheric contaminants from the environment for miners, particularly at depths where ventilation constraints and associated operating costs have an increasingly adverse impact. An alternative solution to diesel equipment to combat economic, environmental, social and health challenges, are battery electric vehicles (BEV), with the potential to expand production and substantially reduce ventilation and cooling demand, subsequently reducing operating costs. In this context, this paper focuses on the introduction of a battery electric loader to a diesel fleet at one of the deepest underground mines in Australia, the CSA Mine, a high-grade copper operation in Cobar, New South Wales. Analysis of a trial battery electric loader compared to existing diesel machines is performed with regards to infrastructure, technical and operational issues. Key benefits of battery electric vehicles over conventional diesel-powered vehicles are discussed, including lower energy consumption and greater efficiency, reduction of emissions and heat, reduced need for ventilation and lower operating costs. Challenges of introducing BEVs into an operation, along with the results from the comparative study are addressed under impacts to energy consumption, equipment selection, effects on ventilation and cooling, mine design and economic viability for future fleet implementation scenarios whilst meeting production targets.

Mar 29, 2023

By Kirkhouse C. B

Soon after the Broken Hill Limited started operations at their Iron and Steel Works at Newcastle, NSW, it was found necessary to install a mill for rolling small merchant bars, rounds, etc.An arrangement of the first mill laid down is shown on Plate 1., Fig. 1. This mill commenced operations on the 18th July, 1917.The feed for this mill was rolled in the existing 18-in. mill and sheared to the lengths required before being delivered to the billet storage yard. The billet storage yard is 90 ft. span, and is served by one 10-ton electric overhead travelling crane. Billets were placed on the billet bed preparatory to being charged into the heating furnace.The heating furnace was of the continuous recuperative with end discharge and had a hearth 40 ft. long by 10 ft. wide. The billets were pushed through the furnace by means of two hydraulic rams, which could either act together and push one row of billets, or act singly and push two rows of billets. This furnace was fired by producer gas from the producers shown on Plate I., Fig. l.The gas was conveyed to the furnace by means of a brick underground flue.

Jan 1, 1935

By Scoble M, Peck J

This paper reviews the instrumentation and monitoring of blasthole drills and electric mining shovels at a surface coal mine in western Canada. The drill monitoring component involved the development and implementation of microprocessor-based hardware on Bucyrus-Erie 45R and 60R drills. Over a two year period 3800 metres of blasthole drilling were monitored The drill data was subsequently correlated with core and geophysical logs towards identifying unique and reproducible ranges of performance parameter data for the different rock types penetrated. Using this technique, the geology of the study area benches was characterized in detail. Once these same benches had been blasted, the performance of a P&H 2800XP shovel was monitored as it worked through the blasted ground. In this regard, the influence of different digging conditions on shovel performance were identified in a range of blast and geological environments within the study area. The precise nature of these environments was confirmed by a correlation with the interpreted drill monitored data and muckpile size distributions obtained from a digital photo-analysis study. The excavation of 500 000 bcm of waste was thus monitored and a digging index derived which reflected variations in muckpile diggability. The paper concludes by proposing an integrated monitoring approach which, as a first step, uses interpreted drill data for explosive loading. This capability would permit greater accuracy in explosives loading ie. charge placement within higher strength lithologies, while avoiding weaker units. The performance of an instrumented shovel would then be monitored as it works through the resulting muckpile. Interpretation of the shovel performance data would determine the overall quality of the blast in terms of a digging index (DI), providing an indication of the relative digging effort and the effectiveness of the blast design.

Jan 1, 1990

By J M. Shekiro

In the chloride process to manufacture TiO2 pigment, feedstocks containing higher TiO2 contents (high-grade ores or HGOs) are favoured in order to minimise production of undesirable by-products. Most of today’s HGOs are produced through the smelting or reduction and leaching of ilmenite, processes which consume significant energy and/or produce large volumes of non-titanium materials that may have to be landfilled. In order to improve the economic and environmental sustainability of its TiO2 business, the DuPont Company, working with Kobe Steel Ltd, has developed an innovative process called TiRON for making HGO. Using a rotary hearth furnace, the process reduces ilmenite to a high TiO2 slag and metallic iron granules. The TiO2 slag is suitable for TiO2 pigment manufacture, and the iron is suitable for steel making. TiRON can process sand or rock ilmenite of varying compositions and particle sizes. Fossil fuel instead of electricity supplies the energy for the reduction. Dusts and off-spec materials are recycled. These process attributes, together with capital requirements estimated to be significantly lower, give TiRON substantial economic, environmental, and process flexibility advantages over conventional ilmenite upgrading processes. TiRON has been demonstrated at the semi-works scale, and preparations are being made to bring it to the pilot scale.

Oct 5, 2011

By H Turrer, M Badawi, R Belissont, Y Foucaud, E Kleiderer, L Southavy, J Mesquita, Y Basselin

The Mont Reed iron ore deposit, owned by ArcelorMittal, is situated approximately 140 km southwest of the Mont-Wright mine in the southern region of the Labrador Trough, Canada. Acquired by Québec Cartier Mining (QCM) in the 1960s, the Mont Reed mining property has remained unexploited due to the complex nature of the ore in the area. However, during the last years ArcelorMittal’s R&D team has been dedicated to developing a process to beneficiate the Mont Reed ore and produce high-quality pellet feed suitable for direct reduction furnaces. Extensive research revealed that achieving a good liberation degree of particles required grinding the material below 75 μm (P80 of 53 μm). To find the most effective technology for this task, a detailed comparison between ball mill and vertical stirred mill grinding was conducted. Both grinding technologies underwent detailed testing in bench-scale experiments. The ground products were comprehensively characterised, including size distribution analysis and chemical analysis per size fraction. Additionally, liberation analysis was performed using an automated scanning electron microscope (SEM). To determine the grinding specific energy, a method previously developed at Samarco (Brazil) for fine grinding of iron ores was employed. Furthermore, magnetic separation and flotation tests were conducted on the ground products. After a thorough evaluation of all the results, it was observed that both ball mill and vertical stirred mill grinding produced samples with similar physical characteristics. However, the vertical mill demonstrated higher efficiency in grinding the material. To conclude the study, an economic evaluation was conducted for both options considering various factors. Overall, ArcelorMittal’s R&D team’s dedicated efforts have brought them closer to unlocking the potential of the Mont Reed ore deposit and paving the way for its future utilisation to the production of high-quality pellet feed.

Sep 18, 2023

By T Bookless, J Pownell, D Meadows

The ever increasing trend of the gold price has meant that ore deposits that were previously considered too complex, or unattractive by virtue of their low gold grade, are now being investigated more closely. These ore deposits present a greater risk of failure than previously was the case. To ensure that the risk of project failure is reduced and the maximum value is derived from the deposit, its mineralogy, as well as other characteristics, should be well understood such that the optimum process can be designed.Quite often the flow sheet design is assembled using individual process components, from various sources, and without consideration of the complete system. Test work programs require careful planning and an open viewpoint in terms of comminution circuit design particularly with respect to ever increasing power costs across the globe. As an example, high pressure grinding roll (HPGR) technology in many cases offers better mineral liberation than the more traditional comminution devices and it does so at a reduced energy input, and yet HPGR test work is often restricted in its scope due to the perceived novelty of the technology and the resultant lack of generally agreed and accepted test work routes.In this paper the authors outline a typical HPGR test work process route driven by the needs of different ore types and illustrate that to optimise the project value, any test work program should start from the premise that thorough understanding of the ore is vital.CITATION:Bookless, T, Meadows, D and Pownell, J, 2013. Enhancing project value through a designed high pressure grinding roll test work program, in Proceedings World Gold 2013 , pp 291-300 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Coulter L. J

THE method of stope surveying as practised at the Mount Lyell Company's mines has been evolved out of the exigencies created by special conditions. It presents some novel features, and has proved effective for all requirements. All stope measurement work is brought under one complete system, to which office methods are standardized. Before proceeding to deal with the subject a brief description of the physical characteristics of the ore-bodies of each mine and the method of stoping will serve to show, cause ,for departure from ordinary survey practice.NORTH LYELL MINEThe ore-bodies of this mine occur on or near the conglomerate schist contact, and, being probably the result of replacements of both rocks, they rarely present any definite walls. It is usual for the payable material to merge into the respective countryrocks, and the limit of the occurrence is defined rather by assay value than by any distinct natural boundaries. The general configuration of these ore-bodies, therefore, is highly erratic both in horizontal and vertical section, so that, in order to obtain an accurate record of any occurrence, the measurement of the actual contour at short vertical intervals is essential.Stoping is carried out on a modification of the "rill." system, perhaps more properly described as "arched back" or "dome" stoping. Mullock rises are placed in as convenient positions as the erratic configuration of each ore-body will allow, and aroundthese rises the back is kept well arched, both longitudinally and transversely. The larger stopes are divided into arbitrary sections in which ore-breaking and mullocking are carried out in rotation, so that the whole of the excavation is seldom open for measuring at anyone particular time. Stacking or square-setting on the...

Jan 1, 1915

By S Morgan, L C Pagdalian, S Serdzeff, C Malaloy-on

It is widely accepted that mineral deposits are decreasing in metal grades. To remain profitable and meet market demand, mining companies are expanding their operations by increasing the tonnage treated. These expansions may include new concentrators with higher nameplate tonnages or upgrading the capacity of existing ‘brownfield’ operations. In many cases, the brownfield upgrade route is preferred as it is less capital intensive; however, brownfield upgrades are never straightforward and present many metallurgical and engineering challenges.For example, to increase feed throughput at a brownfield site, there will be a requirement to modify the mine development plan. This may result in the ore mineralogy varying beyond the current feed fluctuation range. To accommodate these ore variations, a combination of mineralogical analysis and small scale testwork can be used to develop a new process flow sheet to achieve the product recovery/concentrate grade requirements. In general, however, flow sheet development does not usually consider site specific layout constraints and equipment requirements. At sites where future expansions were never considered, taking this silo approach could lead to project delays and compromise the circuit design.Engaging an experienced technology partner ensures the nominated project team is involved throughout all stages and aspects of a given brownfield upgrade – from conceptual flow sheet development, through to detailed engineering, construction and commissioning. The recent Carmen Copper Corporation (Carmen Copper) circuit upgrade has been completed in technology partnership with Outotec. The circuit upgrade was extensive and included new equipment additions to the comminution, flotation and dewatering circuits. Carmen Copper’s intimate knowledge of the ore characteristics, in conjunction with a trusted, knowledgeable technology partner, facilitated a robust circuit design, and fast-tracked the project execution. This paper deals specifically with the flotation circuit upgrade and highlights the benefits to Carmen Copper of this holistic approach.CITATION:Morgan, S, Serdzeff, S, Malaloy-on, C and Pagdalian, L C, 2014. The benefits of technology partnerships during brownfield upgrades, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 471–476 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By S Padekar, C Tapia, D Likhachev, S Harlikar, D Sapkale

In the quest to access valuable critical minerals, humankind is expanding the frontier into extreme environments like space and deep-sea mining. These ambitious enterprises involve considerable costs and lengthy development cycles to ensure the robustness of mining systems in the face of the harshest conditions and unforeseen challenges. Unfortunately, obtaining information from these unexplored territories is complicated. Data is often scarce, incomplete or impossible to obtain until equipment is deployed, leaving engineers facing many uncertainties throughout the design, testing, production and preparation of such missions. Despite these challenges, these extreme environments operate under consistent physical and chemical principles that can be faithfully digitally replicated. However, unexplored areas and dynamic systems like weather and geology continue to carry uncertainties. While eliminating uncertainties remains elusive, Digital Twins offers a means of robust risk management tool. These virtual replicas can excel in simulating extreme conditions and unexpected events, helping optimise and validate mining system designs tailored for such hostile environments. This study takes inspiration from the Mars Science Laboratory (MSL) Curiosity Rover’s wheel damage rate to develop a Multiphysics Modelling and Virtual Motion Simulation (MMVMS) system. Using advanced Generative Design, this MMVMS system refines the MSL’s design, simulates component and system performance, and assesses the risk of premature damage while operating on Mars. Additionally, MMVMS integrates cutting-edge CAD design technologies from aerospace and manufacturing to realistically recreate the Martian environment and a detailed representation of MSL, allowing mobility verification and validation simulation to test different components in terms of materials, design, weight, power and, therefore, cost. The research highlights the precision of MMVMS in replicating extreme conditions, simulating and evaluating internal and external variables influencing the entire system (Rover) in real-time, and predicting movements, failures, and premature damage. This sophisticated Digital Twin technology, showcased in this research, holds promise not only for space missions but also to be adapted for terrestrial and deep-sea mining operations.

Sep 1, 2024

The hydraulic backfilling of mine tailings has proven very successful at the Homestake Mine in Lead, South Dakota. It allows greater versatility, selectivity and safety in mining. It has also minimized surface subsidence and underground rock movement. The tight filling also eliminates underground fires. This paper explains the hydraulic backfill method used and the problems encountered by so doing.

Jan 1, 1973

The Australian Constitution specifies certain powers of the Commonwealth Government to be used in its capacity as the national government. Certain of these broad powers result in the Com- monwealth having a facility to play an important part in the development of the mining industry. The State Governments, however, by virtue of their wide powers to regulate matters within the boundaries of a particular State, are more directly involved in the day to day administration and standards of activities of mining operations. In this respect the Common- wealth has something of a dual role because of its "State-like" responsibilities for the mainland Terri- tories. The components of the role that the Common- wealth Government discharges in relation to the mining industry are qualified to varying extents at particular times by the political persuasion of the Government. In absolute terms the components are as follows. 1. Economic management. The Commonwealth's fiscal and monetary policies have an important effect on industry as well as on State finances. In particular, the taxation regime employed by the Commonwealth Government is of direct importance to economic decision-makers in the mining industry. 2. International matters. International trade and commodity matters are, more and more, becoming an everyday part of the conduct of a nation's foreign affairs. 3. Exports. The Commonwealth Government, via the constitutional powers over overseas trade, have exercised varying degrees of control over mineral exports to achieve particular objectives. 4. Foreign capital and investment. Australia in general, and the mining industry in particular, is and will continue to be a net importer of capital. There appears to be bipartisan political agreement in Australia that foreign investment policy must be enunciated to ensure that investors. are in no doubt that Australia welcomes beneficial investment and technology from overseas. 5. Environment and Aborigines. Governments, both Commonwealth and State, have in recent years become more involved in these areas in response to their interpretations of community aspirations. 6. Energy. Access to assured supplies of energy is now viewed, by Governments worldwide, as a desirable asset to ensure the well-being of a nation's people and industries.

Jan 1, 1978

By A Giyose, V Malysiak, K Davey

Batch flotation tests were conducted on a haematite-bearing Sishen iron ore slimes sample from South Africa using reverse cationic flotation. The effect of grinding on flotation performance, the flotation response of various key impurities in the sample, and the feasibility of increasing metal recovery by refloating tailings in a scavenger flotation step were investigated. The test results indicate that reverse cationic flotation is effective in rejecting impurities from the iron ore sample tested. From a head grade assaying 6.4 per cent SiO2, 2.14 per cent Al2O3, 0.402 per cent K2O, 0.082 per cent P and 0.194 per cent TiO2, the levels of impurities were reduced to 1.83 per cent SiO2, 0.88 per cent Al2O3, 0.095 per cent K2O, 0.066 per cent P and 0.174 per cent TiO2 in the final concentrate at a Fe recovery of 74 per cent. The flotation response of SiO2, Al2O3 and K2O were found to be better than that of P and TiO2. The testwork demonstrated that grinding to 80 per cent passing about 49 microns is essential for upgrading the Sishen iron ore to produce >67 per cent Fe concentrate grade. This grind size corresponds to about 80 per cent liberation of haematite from the gangue minerals. Fe recoveries up to 76 per cent were obtained by refloating the rougher tailings in a scavenger stage, with little effect on the final concentrate grade. Size-by-size Fe recovery data obtained indicated that particles below ten microns were mostly lost in the desliming stage conducted prior to flotation whilst some reported to the froth by entrainment. Some of the coarser haematite-gangue composite particles reported to the froth product by genuine flotation.

Jan 1, 2009

By A L. Zawadski, B G. Putland

"This paper discusses a method to build a calibrated comminution circuit model, using historic operating data and blend information that is useful for forecasting and optimising plant performance, as well as evaluating expansion opportunities. A preferred method for building a calibrated power-based comminution model is discussed and justified based on two case studies, offering low-cost and effective strategies to utilise existing information for the maximum possible benefit.The first example is the Lefa Gold Mine located in Guinea, West Africa operating a semi-autogenous grinding (SAG) and ball milling circuit with recycle crushing (SABC). Daily blend information and operating data was utilised to build and calibrate a power-based model of the comminution circuit. The least squares regression method was used to solve the SAG mill specific energy requirement and the operating work index (Wio) for each individual ore type. The calibrated model was used to evaluate expansion strategies to sustain throughput at higher proportions of fresh ore based on the proposed life-of-mine schedule.The second example is the Ok Tedi Copper-Gold Mine in Papua New Guinea operating a SAG and ball milling circuit (SAB). The circuit limitation would often shift between the SAG mill and the ball mill due to variable ore characteristics and feed blend. Typical SAG mill relief strategies, such as recycle crushing or secondary crushing, required significant capital expenditure and the potential throughput benefit would vary depending on ore type, making economic justification difficult. Daily blend information and operating data was used to build and calibrate a power-based model of the comminution circuit to identify ore types that might benefit from higher blast intensities to increase fines content, thus relieving the SAG mill limitation and increasing overall throughput without a major capital investment.Citation:Zawadski, A L and Putland, B G, 2016. Calibrating Comminution Models Using Operating Data to Forecast and Optimise Plant Performance, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 17–26 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By G DeschOnes, M Fulton

The Eleonore property (James Bay district of Northern QuTbec), owned by Goldcorp, hosts gold within stockworks of quartz-tourmaline-arsenopyrite veins and veinlets contained within microcline (potassic alteration) and brown tourmaline replacement zones. The preliminary investigation to recover gold from drill core samples showed that flotation followed by ultra-fine grinding and cyanidation is the preferred option. Ultra-fine grinding is used to liberate gold finely disseminated in sulfides. The flotation concentrate used in the investigation had a P80 of 11 ¦ and contained 75.5 g/t Au, 5.0 g/t Ag, 10.3 per cent S, 0.07 per cent Cu and traces of antimony (0.03 per cent). The mineralogical characterisation showed the presence of 65 per cent gangue minerals, 23 per cent pyrrhotite (hexagonal), 9.6 per cent arsenopyrite, 2.2 per cent pyrite and 0.08 per cent chalcopyrite with trace amounts of galena (0.05 per cent) and sphalerite (0.03 per cent). Gold was in the form of native gold and electrum. A straight cyanidation conducted at pH 11.0, DO of 3 - 5 ppm, 2000 ppm NaCN, 20¦C and for 72 hours extracted 97.0 per cent Au and consumed 31.5 kg/t NaCN. The equilibrium was reached within 24 hours. Increasing the dissolved oxygen to 16 ppm reduced the consumption of cyanide to 22.0 kg/t with 96.7 per cent Au extraction. A 16-hour pretreatment with 2.0 kg/t lead nitrate, followed by a 24-hour cyanidation reduced the cyanide consumption to 6.0 kg/t with a gold extraction of 97.5 per cent. Increasing the lead nitrate addition to 6.0 kg/t reduced the cyanide consumption to 1.2 kg/t by passivating the surface of pyrrhotite. The gold extraction remained at 97.0 per cent. It was possible to decrease the concentration of cyanide to 800 ppm NaCN without compromising gold extraction. The associated cyanide consumption was 1.2 kg/t NaCN. The passivation of gold grains was an issue when the cyanide concentration was decreased to 550 ppm NaCN. The gold extraction decreased to 92.2 per cent. The average lime addition for all the tests was 7.4 kg/t and the average silver extraction was 80 per cent. Efficient cyanidation of an ultra-fine sulfide concentrate with only 800 ppm NaCN represents an advance in leaching of ultra-fine sulfide concentrates. The high addition of lead nitrate would certainly make cyanide destruction easier; consequently reducing the effluent treatment costs and making possible to meet the discharge regulations criteria.CITATION:DeschOnes, G and Fulton, M, 2013. Design of a leaching strategy to extract gold from Eleonore Mine ultra-fine sulfide concentrate, in Proceedings World Gold 2013 , pp 71-78 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013