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By H Mischo, G Barakos, J Gutzmer

The continuously growing demand for rare earth elements (REEs), in combination with the crisis of 2009 and the price spike of 2011, has initiated a treasure hunt for rare earth deposits all over the world in recent years. Since then, commodity prices have declined and are now quite stable, yet the world is still dependent on China’s dominance of the market and its export policies. Exploration is unremitting and numerous resources of potential interest have already been revealed in many countries; however, proceeding to mining operations is not that simple, especially when it comes to the exploitation of rare earth deposits. Evaluating the feasibility of a mining project is always a unique, sensitive and rather complex process that depends on multiple criteria.This paper focuses on clarifying the present and future global situation in the development of respective deposits and on identifying rare earth-specific criteria that influence the overall feasibility assessments of any potential (especially underground) mining projects. Environmental impacts, legislation issues and the presence of radioactive pollutants are some of the notable boundary conditions that govern rare earth mining operations and need to be taken into consideration. Furthermore, the balance problem between the supply and demand of the different REEs can determine decisively whether a deposit of specific REEs is economically exploitable. For this reason, evaluations are made regarding the future strategies to be enacted in order for the rest of the world to detach itself from this situation. The ultimate goal of these evaluations is for them to be incorporated in an overall assessment tool for rare earth underground mining procedures that will be implemented in real case studies to determine their sustainability.CITATION:Barakos, G, Mischo, H and Gutzmer, J, 2015. Status quo and future evaluations of global rare earth mining (with respect to special rare earth element-industry criteria), in Proceedings Third International Future Mining Conference, pp 21–30 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M I. Pownceby, S Hapugoda, H Han, E Donskoi, L Lu

Iron ore sinter mineralogy and its associated macro-/micro – structure has a strong impact on sinter quality. At a macroscopic scale, sinter ideally consists of a strong, porous matrix which bonds relict ore nuclei together. Microscopically, the sinter matrix (solidified from the melt part of the initial sinter mix) generally consists of complex calcium ferrites known as SFCA, secondary magnetite and hematite grains (precipitated from the primary sinter melt), glass and silicates. Depending on the conditions under which the sinter structure is formed, two major forms of SFCA with different morphologies are generally recognised, ie fine micro-platy SFCA (usually termed SFCA-I) and coarse columnar/prismatic SFCA. Detailed optical microscope observations of several pot grate and compact sinter samples revealed the presence of a variety of fine, coarse and dense forms of both types of SFCA. The controlled cooling tests revealed that cooling rate has an impact on the form and size of SFCA crystals. In this work, EPMA analysis of SFCA compositions from a variety of pot grate and compact sinter samples are presented. Results show that the SFCA types exhibit a broad range of complex compositions within the system Fe2O3/CaO/SiO2/Al2O3/MgO/TiO2/MnO2. Although SFCA-I and SFCA are known to be crystallographically distinct and with different, well-defined ranges in composition, there was considerable overlap in compositions of the experimental sinter samples. The development of SFCA textures depend on several parameters including the local chemistry and conditions including the maximum temperature attained and the cooling rate, within the sinter bed, thereby suggesting that SFCA identification based on morphology alone may be erroneous.

Nov 8, 2021

By R Knight

"In project evaluation there are two matters of keen interest to non-executive directors: the process by which an investment recommendation is reached, as well as the investment itself, as presented. It is sometimes mistakenly believed that Boards of directors are interested only in the result. That is not so. The process by which project evaluations are derived and socialised with the Board is as important as the result, sometimes more so.Setting aside the gloomy predictions of the doomsayers and looking through short-term volatility in supply and demand, the overall availability of mineral resources more often than not exceeds demand. There are in reality more development projects in prospect at any one time than are needed to meet the market. Only the fittest will prosper, although some others may survive.Optimism springs eternal in the mining industry and every project promoter, executive or entrepreneur has a convincing project development case. Some will create value for shareholders, but the historical evidence suggests that many will fail to meet the expectations set in their evaluation.Boards of directors make the final decision to invest, or not, in a new mine. Knowledge is power, and on that basis the balance of power favours management. Management has the facts (or in some cases, what passes for fact) and the passion to invest. The non-executives have the power of approval – yes or no – but before making a decision directors must demonstrate due diligence, the essential precursor to project approval.Management has a vital part to play in facilitating that due diligence process and in encouraging the independent thought processes of the Board. A closed approach by management fosters a negative, risk-averse attitude on the part of the Board. One that encourages an understanding of the rigour of the project evaluation process and the robustness of the result will allow directors to understand better the implications of their decision.CITATION:Knight, R, 2016. Project evaluation – a non-executive director’s perspective, in Proceedings Project Evaluation 2016, pp 11–19 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

By A Fyans, B Ghahreman-Nejad

This paper discusses the method and results of an options study into selection of the optimal form for a 130 m high tailings/water retaining dam, located in a region of high seismicity in central Iran. The proposed dam is part of a planned expansion project for Sarcheshmeh Copper Mine (SCM), which after construction will provide 550 million tonnes of additional tailings storage over the next 27 years. Geotechnical investigation at the proposed site indicated that adequate suitable low permeability materials (i.e. clay) were not available in the immediate vicinity of the dam site and would need to be imported from a distance of well over 10 km (direct). Given the magnitude of the estimated quantity of material and construction cost it was considered prudent to compare the cost of alternative dam design options for the proposed storage. A total of five dam design options are considered including a conventional rockfill embankment dam with an upstream sloping earth core (ECRD), a geomembrane face rockfill embankment dam (GFRD), a sloping asphalt core rockfill embankment dam (ACRD), a roller compacted concrete dam (RCCD), and a filter rockfill embankment dam for tailings storage together with a separate smaller earthfill core rockfill dam (ECRD) located downstream for storage of decant water. The risks, costing and design of all options are discussed in detail and the outcome of the study is presented.CITATION:Ghahreman-Nejad, B and Fyans, A, 2018. Optimum embankment design for a tailings dam, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 427–438 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By J Young, S Yu, P Moyo, M Powell, A Musunuri, B Bonfils, S Kanchibotla, P Yaroshak, V Jokovic

The appropriate design of liners continues to be an issue on many mills worldwide. Loss of milling capacity especially at liner change, uneven wear lives along the mill, substantial scrap on worn liners, excess mill down-time, undesirably short and unreliable wear lives are all common issues. This paper presents a designed approach to liner optimisation that follows a logical path of initial design and step-wise improvements based on liner wear monitoring. The target is to have a good liner design from start-up, then tune the profiles, heights and thicknesses based on wear monitoring. This is conducted as a team of liner specialist, site personnel and liner supplier. The application to the Pustynnoye SAG mill of JSC Altynalmas in Kazakhstan is presented. The increase in liner life by around 50% along with increased mill throughput of over 20% illustrate the huge benefit of the cooperative triumvirate approach through the gains that can be made in productivity and reduced liner costs.CITATION:Powell, M, Kanchibotla, S, Jokovic, V, Hilden, M, Bonfils, B, Musunuri, A, Moyo, P, Yu, S, Young, J, Yaroshak, P, Yalcin, E and Gorain, B, 2018. Advanced mine to mill application at the Barrick Cortez mine, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 177–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By W R. Adamson

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

Aug 24, 2015

By J Furtney, W Fu, D Nutakor, A Brose

Rock blasting outcomes are often a shared responsibility of both the mine operations group and the mine geotechnical group. From an operational logistics and planning perspective, blasting concerns include optimal fragmentation for subsequent crushing, ensuring the blast is energetic enough to allow easy digging, and understanding the effect of muck from a previous blast on the current blast. From a geotechnical perspective, wall damage and catch bench capacity are the primary concerns. Other concerns for both teams include damage to mine infrastructure by fly rock or blast-induced vibrations, and the stability of open stopes under the pit. This work presents two blast modelling applications (or ‘apps’). The basic app instantly gives fragmentation and wall damage predictions for a given generic blast design. The advanced app loads the current pit contours, reads the blast design from a spreadsheet, and calculates the expected vibration magnitude and peak frequency. The apps have been developed specifically for the Rio Tinto Borates and Lithium Mine in California and are used to support blast design between the operations group and geotechnical group. The basic app instantly gives fragmentation and vibration predictions given a blast design by combining the Kuz-Ram fragmentation model with the scaled distance model for vibrations. The advanced app uses the signature hole method. Blasting outcomes at the mine have improved since using the apps.

Jun 22, 2022

By M Svartsjaern, D Saiang and K Mäkitaavola

The Kiirunavaara mine is a large-scale (28 Mt/a) iron ore mine located in northern Sweden. The mine is owned and operated by Luossavaara-Kiirunavaara Aktiebolag (LKAB) using sublevel caving (SLC). The SLC area underlies an open pit decommissioned in the 1950s, the current main SLC haulage level is situated at an depth of 1100 m. The main orebody dips 60 degrees to the east with a distinct boundary defining the hanging wall to the east and footwall to the west. Since the 1980s damage has been observed both in the footwall rock mass as well as on the footwall crest of the open pit. Recent investigations indicate that the underground footwall damage is primarily controlled by large-scale slope failure mechanisms. Structurally controlled near-vertical planar shear failures in the upper footwall appear to be driven or facilitated by a step-path like curved shear failure situated in a zone starting ca 250 m, and intersecting the SLC about 100 m above the active mining level. To confirm this failure evolution a pilot underground measuring system has been designed and installed to monitor the expected rock mass displacements indicated by numerical models based on the above mechanisms. The systems consists of 50 m time domain reflectometry (TDR) coaxial cables installed in the footwall both across and away from an estimated damage extent boundary to monitor shear movements along natural joint surfaces. The TDR installation is combined with long extensometers to facilitate differentiation between diffuse shear and rock mass normal expansion. Additionally, a low-tech system of tape extensometer lines are installed in drifts and stopes running perpendicular to the ore strike to monitor horizontal displacements in the infrastructure as the footwall ‘slope’ loses confinement during mining advance when the mined out areas are replaced by caved rock from the hanging wall.CITATION:Svartsjaern, M, Saiang, D and Mäkitaavola, K, 2016. Underground footwall monitoring at the sublevel caving mine – Kiirunavaara, Sweden, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 773–780 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By DJ McKEE

Process control emerged in the mid-1960s as a new and exciting method of improving the performance of mineral processing operations. The early Australian developments, principally in Broken Hill and Mount Isa, were based on pioneering work in instrumentation, the availability of small digital computers and a particularly effective partnership between companies with technological foresight and University and CSIRO research groups. Initial progress was rapid and within ten years many plants were committed to process control. Process monitoring is now routine and most circuits have some level of control. However, few plants have comprehensive optimising control systems as the difficulty of developing control strategies which can cope with the wide variety of conditions encountered in most mineral plants has been fully appreciated. This paper summarises past experience and assesses the degree of application of different forms of process control in metallurgical plants. Barriers to the effective utilisation of opt rising control are identified and some suggestions for advancing the application of control are made.

Jan 1, 1992

By D Hatton, S Wilson, F Orrante, M Taghimohammadi, F van der Walt, N Arslan, M Westcott

"Cayeli Bakir Isletmeleri is an underground copper-zinc mine in turkey. The ore is highly variable with feed grades ranging from 1–4 per cent copper and 1–10 per cent zinc. Due to this variability, ore characterisation and blending strategies are crucial for performance optimisation.This paper presents a case study for a multidisciplinary approach to process optimisation, integrating Geometallurgical and advanced control methods to achieve optimised plant performance. The results from comprehensive metallurgical tests and surveys were used to develop a mathematical model utilising SGS’s Integrated Geometallurgical Simulator® (version number 2.5.24.0). The model was employed to determine the most appropriate operational settings required to ensure that optimised grades and recoveries are achieved for each ore type.SGS’s Modular Expert Technology (MET) expert system was then implemented to target these optimum operational ranges utilising online grade and froth velocity measurements. The successful conversion and deployment of the modelled process parameters into an expert system has resulted in significant improvements in overall recovery and circuit stability.Citation:Arslan, N, Westcott, M, van der Walt, F, Hatton, D, Taghimohammadi, M, Orrante, F and Wilson, S, 2016. A Multidisciplinary Approach to the Optimisation and Control of a Copper-zinc Grinding and Flotation Circuit, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 115–122 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By B Putland, I Lovatt, D Schwann, A Cervillin

The Mount Carlton project in Queensland's North East sits on a high-sulphidation epithermal style deposit rich in gold, copper and silver. Mt Carlton is an open pit mining operation with ore processed using a primary crusher, single stage SAG mill and flotation to produce a concentrate for sale. Orway Mineral Consultants (OMC) was involved in the original design of the comminution circuit and the project was commissioned in late 2012, with first concentrate shipped in March 2013. When Evolution sought to optimise the project in 2015, OMC was invited to assist by undertaking a circuit review to identify opportunities for the optimisation. During 2016, the Mt Carlton site team implemented the optimisation strategies developed in conjunction with OMC. These included reconfiguring the SAG mill discharge arrangement, reducing the average ball diameter and allowing the mill to operate at higher speed and under more autogenous conditions. Cyclone operation was changed to constant pressure and the vortex finder size was decreased. The combined strategies improved energy efficiency and allowed higher SAG mill power utilisation. The additional power has been used to increase throughput by 2.4 per cent while achieving a 27µm reduction in product size (P80) to gain downstream recovery improvements. The reduction in grind size has been achieved with only 6.8 per cent increase in specific energy consumption because of a 6.5 per cent increase in grinding efficiency. The circuit product size is also notably more consistent due to the improvements made to the cyclones, providing benefit to the downstream flotation circuit. A significant decrease in ball consumption was also gained, saving hundreds of thousands of dollars a year in operating cost.This paper will discuss the circuit design, start up and will detail the changes made during the optimisation and why these were successful.CITATION:Putland, B, Lovatt, I, Cervillin, A and Schwann, D, 2018. Mount Carlton comminution circuit design, start-up and optimisation, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 517–528 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By D J. Kilkenny, D A. O’Toole, P B. Hills, K L. Seah

An investigation was undertaken to critically analyse the use of fibre reinforced shotcrete (FRS) for a variety of applications in large diameter shafts. Those applications included the use of FRS with or without the addition of subsequent rock bolting in the temporary support cycle prior to the installation of a permanent lining, most likely cast in situ concrete or as the final lining medium.Numerous authors have considered the early re-entry and strength characteristics of FRS in recent years. The current study has investigated the practical application of the recommendations of many leading authors in an endeavour to establish practical and acceptable risk-assessed procedures for the use of FRS for rapid, safe, efficient and cost-effective shaft sinking.Shaft sinking is regarded as a specialist and potentially higher risk activity due to the confined work environment, exposure to ground conditions and a high degree of manual handling associated with getting materials to the sinking face. The use of robotically applied FRS as a primary lining in shaft sinking has significant safety advantages in reducing manual handing associated with mesh safety support and bolting, as well as reducing direct exposure to ground conditions.The study involved both field testing and a literature review. The study established an initial set of criteria for the use of FRS in the development of large diameter shafts and demonstrated a number of scenarios where the technique of robotically applied FRS provided significant safety and cycle time advantages. The opportunity for a fully sprayed single pass lining was also investigated as part of the project.CITATION:Hills, P B, O’Toole, D A, Kilkenny, D J and Seah, K L, 2014. Exploring the use of fibre reinforced shotcrete in large diameter shafts, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 295–306 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By A M. Avis

This paper presents an overview of recent developments in the Environmental Impact Assessment (EIA) process to provide the background for a more detailed analysis of environmental and social constraints that the Heavy Mineral Mining industry has encountered over the past decade. Four cases studies are reviewed to provide a context for further analysis and identification of cross cutting environmental and social issues that either resulted in the projects not proceeding, or in the Australian case study, places existing operations under significant pressure from anti-mining lobbyists. The Xolobeni project, from the Eastern Cape in South Africa, is presented as the primary case study because it is recent, topical, and accessible; and raised numerous issues related to mining in a sensitive environment. A proposal to mine an area adjacent to the Okefenokee swamps in 1997 was also met with strong opposition from various environmental groups in Georgia, USA. This case study is briefly reviewed to further understand what ultimately resulted in the project not proceeding. Opposition to mining at North Stradbroke Island is reviewed to identify current issues more applicable to a developed country. A further review of a strategic assessment undertaken at Wavecrest, Eastern Cape, South Africa is provided in support of possible solutions to the challenges identified in the case studies. Important common themes were identified, including in some cases unfortunate timing of the environmental studies, but in all cases opposition was due to ecological sensitivity, landscape quality and sense of place. In one case study limitations to the EIA process included inadequate detail in the specialist investigations and insufficient information on mitigation. In all cases public participation was a limitation. It was either insufficient; flawed through possible bias; too ‘top down’ and required engagement with mobilised, motivated lobbyists. There was also insufficient investigation of social impacts, particularly amongst rural communities directly affected by a project. Generally alternatives were inadequately considered, a recognised limitation of project level EIA. It is concluded that the EIA process should be started as early as possible (at prefeasibility), and that investigations should be expanded from a typical fatal flaw assessment to one that applies methodologies used in strategic assessment. In particular, opportunities and constraints of the natural and social environment should be assessed in the context of the mining option as well as other options, to allow for a more meaningful assessment of alternatives. Public participation must form an important part of this initial study, despite the potential risks associated with public engagement at an early stage in the project. The application of the IFC Performance Standards; and expanding the scope of the EIA into an environmental, social and health impact assessment will lead to a more rigorous procedure, and result in more defensible products which could successfully unlock the key to the resources in these sensitive areas.

Oct 5, 2011

By P Christen, D R. Ashley, G R. Power

The Ernest Henry Mine is currently a copper-gold open pit operation situated in north-west Queensland, Australia. It is owned and operated by Xstrata Copper with a current throughput of 11 million tonnes per annum; however, open pit operations are scheduled to cease in late 2011. The deposit dips at approximately 45¦ and extends for at least another 400 vertical metres below the final 530 m deep pit design. Resource drilling from 2002 until mid 2008 has enabled an Indicated Mineral Resource to be established to 1000 m below surface. Scoping and prefeasibility studies (PFS) have been completed toward determining if this resource is suitable for underground mining and a feasibility study is currently progressing with a sublevel caving (SLC) concept. This paper briefly describes the process by which the SLC method was selected, conclusions regarding the non-selected methods, and then discusses the optimisation process used to derive the mining plan. The key optimisation parameters include the production drive spacing, level spacing, draw strategy, cut-off grade and production rate. Key risks will then be assessed and economic sensitivities studied. Final sensitivities will use Monte Carlo simulations to improve the transparency of the projectÆs risk profile. The feasibility study (FS) began in March 2008 and this paper describes the main optimisation steps at the time of writing and outlines the plan for study completion through to March 2009.

Jan 1, 2009

By G Harbort

Traditional engineering design for flotation circuits use the “Rule of Thumb” approach. Typically this uses a nominated maximum head grade for design. A scale-up factor is applied to laboratory flotation tests for residence time. This scale-up factor is usually based on a designers experience at other flotation sites and may or may not be relevant to the circuit being designed, or the flotation equipment being used. A small number of locked cycle tests are assumed to represent the ore body and the results of these are often used for financial analysis, independent of changes in mine plan throughput and mineralogy.The engineering “Rule of Thumb” approach is only strictly accurate where there is very little variability in throughput, head grade and mineralogy. It may provide accurate design for mature established operations where a brownfield expansion is being considered but is unlikely to provide accurate design for a new, greenfield site.The use of geometallurgical modeling with floatability component simulation provides a design methodology with significantly less associated risk. The use of geological data for optimisation of operating plants has become a significant part of the modern process mindset. The underlying principle is to use spatial metallurgical information to drive production planning, mine planning, blast design, blending strategies and plant set-up. At a design stage the process designer can use geometallurgical information to evaluate bottle necks and potential design flaws and propose the best investment strategy for the project benefit.This paper details the geometallurgical characterisation of the Andash deposit and methodology used to review the project’s detail design and projected production.

Aug 8, 2011

By T Berryman, C Adams, L Griesel, C Buxton

The Kalgoorlie Consolidated Gold Mines (KCGM) schedule model is used for short- to medium-term planning and scheduling at the Fimiston Open Pit Mine (the Superpit). The model bridges the gap between grade control models, which are generated one to seven days prior to mining, and the annual Resource and Reserve model update that is used for budget and life-of-mine plans. The schedule model uses close-spaced grade control data (up to 20 000 m drilled each month) as well as resource definition drilling to estimate production volumes three to six months ahead of current mining. From this, a rolling 12 week mining and processing schedule is generated on a monthly basis. As the KCGM operation is mill and sulfur constrained, the schedule model needs to be an accurate predictor of ounces as well as tonnes, gold and sulfur grades. The process must also be time efficient in order to meet monthly planning and reporting deadlines. Due to the large amount of new data generated each month, model updates using conventional interpretation and estimation techniques have proven to be impractical and too time consuming. This paper will examine the evolution of the Superpit schedule model process over time, recent improvements and the effect of different model outcomes on short- and medium-term mine planning.CITATION:Griesel, L, Buxton, C, Adams, C and Berryman, T, 2014. The superpit schedule model – A time-efficient data-driven estimation for short- and medium-term planning, in Proceedings Ninth International Mining Geology Conference 2014 , pp 397–410 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 18, 2014

By J H. J Holtzhausen

Never has there been more focus on the health, safety, and well-being of our employees at the workplace. Ever evolving expectations of individuals, companies and clients are shaping regulatory reviews and advancing standards across the world in the drive to zero harm. The technology is advancing at a rapid pace, which is now allowing continuous real-time monitoring of contaminants to take place in the harshest of environments.

Oct 12, 2022

By H Thanasekaran, M J. Mankosa, J N. Kohmuench, G H. Luttrell

"Fluidised-bed flotation has been demonstrated over the last 16 years as an effective method for improving the flotation recovery of coarse particles. This technology has been successfully deployed into the industrial mineral sector with multiple installations within phosphate beneficiation plants and potash mills. Due to the minimal mineral surface expression required when utilising this technology, more recent studies have centred on the applicability of using this HydroFloat™ technology for the recovery of coarse sulfides and base metals. Multiple approaches have been investigated to determine the best means for implementing this novel coarse particle flotation system into both existing and new plant circuitry. These include the treatment of tailings to recover values that have been lost using conventional technologies and also the direct treatment of a coarse feed, either within the grinding circuit or by use of a separate split-feed flotation approach. Recent applications of the technology will be presented along with data generated from several test campaigns and ongoing research investigations. The benefits of properly applying this technology, such as reduced power consumption and increased mill capacity will be discussed.Citation:Kohmuench, J N, Thanasekaran, H, Mankosa, M J and Luttrell, G H, 2016. The Impact of Fluidised-bed Flotation for Treating Coarse Sulfides, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 105–112 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By L McCallum, G Dale, B Silverwood, T Roscoe, A Costin

The introduction of Progressive Closure and Rehabilitation Plans (PCRPs) in Queensland from 2019 places greater importance on planning and implementation of mine rehabilitation activities. The progress and outcomes of progressive rehabilitation activities is monitored and reported upon to demonstrate success in achieving progress towards the approved post-mining landform, and to inform corrective action where required. The requirements of PCRPs place additional emphasis on mine sites to quantify the risks of successfully achieving planned outcomes. This is particularly challenging given mined-land rehabilitation is a complex process involving decisions on multiple inter-acting management interventions, climatic conditions and spatially variable site characteristics.

Aug 2, 2023

By H Hy÷tyniemi

In this paper multivariate data analysis performed on a new multi-camera system implemented to zinc flotation circuit of PyhSsalmi mine is presented. Image-analysis-based system was developed to take advantage of the commonly known fact that the changes in the flotation process are reflected to the visual appearance of the froth surface. Most often the changes are seen first in the froth and later in other process measurements. The image variables are already utilised in closed loop control and considerable savings are achieved with the current setting, but the results coming from the separate cells are used individually. This is clearly not the optimal way to take advantage of the many measurements coming from different locations of the process. A better approach would be for example to use the measurements coming from the early stages of the process to predict the behaviour (or improve the quality of measurements) in the later stages. The methods described in this paper are aimed to improving the situation in this sense.

Jan 1, 2005