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By Mez W

the German ruining industry uses different residues for hackfilling and stowing. A hydraulic pipe conveying technology for these materials has shown advantages for the transportation into the mine. Pipeline conveying systems are able to bridge long distances, they save room within the underground workings and they save staff and costs. Absolutely necessary for successful use of the hydraulic conveying technology is the knowledge about the unusual non-Newtonian flow properties of solid/liquid mixtures like pastes and slurries. The flow resistance of these materials cannot be described easily by one viscosity. Owing to a yield point and a pseudo-plastic behaviour the viscosity changes with the shear rate and with the streaming velocity inside the pipe. Also these flow behaviours depend very sensitively on the liquid/solid-ratio, often so dramatically that gravimetric or volumetric dosing equipment is not in a position to control the production of backfill pastes. Quality changes of the solid raw materials (particle size distribution, density, mineralogical composition) lead to additional difficulties. The first experiences with hydraulic backfilling plants were troubled by plugged pipes. a bad backfill quality caused by unnecessarily high water content and high costs for chemical binders to solidify the backfill. The installation of viscosity controlled paste production leads to success with the hydraulic backfill technology. A development of the l)MT, a bypass pipe-viscometer, has been the key technology. The system is able to analyse on-line, difficult, sticky and abrasive substances and determine their non-Newtonian flow properties. Because the system measures real physical values it is in a position to pre-calculate process relevant parameters like the pressure drop of the backfilling paste in the conveying pipeline. Newer types of the viscometer system also measure the slurry density and calculate its composition. These systems have proven a success controlling backfill paste production plants. They offer it secure prevention of pipeline plugging and a production of high quality backfill pastes with a water content as low as possible.

Jan 1, 1998

By J Canterford

Although we have access to a wide range of sophisticated process design and improvement tools in combination with a significant range of case studies, the mineral resource industry still manages to be plagued by the negative publicity surrounding operating plant failures because they were neither smart nor safe, together with proposed projects that fail at the first or second hurdle. The general public and the finance industry are generally totally uniformed about projects that ramp-up to name plate capacity on time and on budget and even more so when ahead of schedule and under budget. As the saying goes, good news does not cut the mustard.The following is a summary of the author’s sometimes jaundiced view about why metallurgical plants do not live up to their technical and commercial expectations. In no way should the summary be construed as a negative reflection on the skills of the metallurgical profession. Rather, it is to be taken as a positive acknowledgement of those skills and is intended to highlight some of the major considerations that need to be assessed as a potential project transforms into a sustainable technical and commercial reality.While a considerable portion of the summary is directed at developing hydrometallurgical flowsheets, the general principles are equally important to all aspects of extractive metallurgy.For convenience, the summary covers the following five basic discussion points – project, people, process, patents and politicians.

Aug 8, 2011

Subsurface development requires some geotechnical conditions and challenges. Most of then are related to the compatibility between tunnelling system and surrounded ground conditions, and design criteria. Design criteria usually involve lining pressure and ground control of displacements. In order to fulfil these requirements, geotechnical parameters have to be obtained as well as construction aspects have to be taken into account for predicting the tunnel behaviour. The Brasilia Metro is presented as a case history illustrating the geotechnical conditions and challenges for its implementation. It is 42 km long, including tunnels excavated in collapsible porous soils by the New Austrian Tunnelling Method. The Brasilia porous clay presents some characteristics, which may lead to large deformations due to structural collapse. Empirical methods were calibrated for collapsible porous soils and then applied to predict tunnelling-induced settlements. Settlements due to soil structural collapse modify completely the expected settlement profile, increasing their values from the tunnel crown to the ground surface. Consequently, surface settlement trough volumes were also greater than the ground losses around the tunnel. In this case history, structural collapse of porous soils played an important role and must have been taken into account to predict correctly the settlement trough and profile. Numerical simulation has shown that settlement magnitudes due to structural collapse are strongly dependent on the soil stiffness reduction after collapse and the extent of the collapsible zone.

Jan 1, 1999

By Grady B. V, Ault A. R, Newman O. M G, Fraser R. J, Malcolm J. McPhersqn

In all electrolytic zinc plants cadmium is removed as an impurity prior to the zinc electrowinning stage of the process. Cadmium metal is the favoured form of this by-product and most plants use an electrolytic route for its production. The formation of dendrites in cadmium electrowinning processes is the major limitation to deposition rates. There is an economic incentive, therefore, to better understand the factors affecting their growth. A technique that has been used by others to examine fundamental aspects of dendrite growth has been applied to industrial strength electrolytes. It involves potentiostatic deposition in a cell containing the electrolyte of interest. The variation in the current with time at a given overpotential allows the determination of the dendritic growth induction time. A method was developed (the Locus method) from the investigation of a set of such potentiostatic curves, obtained over a range of applied overpotentials, that appears to give a measure of electrolyte quality with respect to dendritic growth in galvanostatic deposition. The Locus technique predicts that zinc at industrial concentrations in cadmium electrolytes should have a significant effect on morphology and that deterioration of morphology will occur as the zinc concentration in the electrolyte is increased. This effect is consistent with literature prediction and was shown to relate to a reduction of the diffusion limiting current density. Magnafloc R333 is used as an additive at Pasminco Metals-EZ to control the morphology of cadmium deposits and the Locus method was successful in predicting its dendrite inhibiting properties. A possible mechanism is discussed. This work has opened avenues for future research with respect to a technique that may have an industrial application in electrolyte characterisation and has pointed to a direction in which better understanding of galvanostatic dendritic growth may be found.

Jan 1, 1993

The major technological advances of the last 30 years have profoundly reshaped mining practices. Machines keep getting bigger while productivity continues to increase and manning levels drop. These trends will continue and the introduction of breakthrough technologies will continue to accelerate, driven by a continued focus on lowering the cost of production, improving the productivity of workers and machines, and ensuring safer working environments. At the same time, global consolidation of mining companies has impacted on technology development in a range of ways. There are many potential technologies being proposed, some already operating in Australian mines. The automation of underground load-haul-dump (LHD) trucks for example, continues the process of removing workers from the most dangerous operating environments. Global positioning systems fitted to draglines, fibre optic communication channels, and 400 tonne trucks are only some examples of what lies ahead. However, where we need to return focus is to the technology of management û which is also one of the two key interrelated themes of this keynote address. Have we, as an industry, adequately been able to keep up with technological advances? Are our management systems as competent as the machinery we employ? The other key theme is the processes of globalisation and consolidation. What are the impacts on our industry? What are the implications of these processes, particularly for the ways in which we manage our people? My paper is divided into several components:some comments on the coal industry and the dramatic restructuring we have seen in recent years; in the context of this restructuring, an overview of my company and its evolution; my views on the role of contractors; some comments on the consolidation also occurring in the mining machinery and equipment, technology and services sectors; some observations on two major areas of technology û drill and blast; and trucks, shovels and excavators; the implications of consolidation and new technology for our employees and management; and finally some comments on research programs.

Jan 1, 2001

By J Cortinez, P Vallejos, J Yianatos, M Rodriguez

Nowadays, one of the main problems in current flotation plants and new projects is the significant decrease in feed grades and changes in the mineral composition, which has an important effect on the mineral liberation and associations. Additionally, flotation plants usually operate with feed throughput higher than the original design, which has a significant impact on the feed particle size. All these conditions affect metallurgical performance, and must be evaluated and addressed, by improving control strategies for banks optimisation. For this purpose, the flotation of valuable minerals along the circuits requires better understanding, considering the compromise between performance and selectivity in flotation circuits. This paper presents a characterisation of the different minerals recovered along industrial flotation circuits. Plant sampling campaigns, performed in a copper industrial concentrator in Chile, provided the data for the study. Two rougher flotation banks consisting of cells of 130 m3 and 300 m3 were analysed. All the samples from the industrial surveys were analysed by screening and mineralogy, and the mineral recovery along the circuits was evaluated per particle size class, liberation class, type of associations, and others. Additionally, operating data on froth depth profiles complemented the evaluation of the mineral composition of concentrate streams, along the circuit. The results allowed for identifying and quantifying the main factors that affect the copper recovery and concentrate grade along the flotation banks. It was found that minerals with liberation lower than 50 per cent have a significant impact on the recovery. On the other hand, the decrease in the Cu grade in concentrates along the flotation circuits is mainly due to the relative increase of middling minerals (less liberated), non-valuable floatable minerals, such as free pyrite, and gangue entrainment. The characterisation of the gangue entrainment flow rate along the flotation banks showed a strong relationship with froth depth, which becomes more critical towards the last cells of the banks.

Aug 24, 2022

By E Jak, G Khartcyzov, M Shevchenko

The increasing complexity of ore resources and recycled materials in the feed of pyrometallurgical processes present a technical challenge to the metallurgical engineers working on maximising the recovery of the valuable elements and minimising the environmental impact of the processes. To address this challenge, the availability of computational tools that can predict the mass and energy balance in complex systems is required. Then the accurate description of phase equilibria in the complex multicomponent systems describing the chemistry of the pyrometallurgical processes becomes critical for the correct implementation of the indicated tools and facing the outlined industrial challenges. In the present study the distribution of selected elements (Pb, Zn, Fe, As, Sn, Sb, Bi and Ni) between oxide liquid and metal in the ‘CuO0.5’-CaO-AlO1.5 system in equilibrium with Cu metal at 1400°C (liquidus of CaAl2O4) was experimentally studied using the equilibration and quenching technique followed by the electron probe X-ray microanalysis of the resulted samples. The study covered a wide range of effective p(O2) over the system from 10-11 to 10-3.5 (corresponding to formation of immiscible CuO0.5-rich slag). To avoid loss of volatile elements (Pb, Zn, As, Sn, Sb and Bi), a correlation between ‘CuO0.5’ in oxide liquid and p(O2) in open system was obtained first, followed by studying the volatile elements distribution in closed conditions (Al2O3 crucible sealed in SiO2 ampoule), where ‘CuO0.5’ concentration was used as a marker to evaluate the effective p(O2) over the system. The experimental results were then used for the optimisation of the thermodynamic model parameters of the system as part of the integrated experimental and self-consisting thermodynamic modelling research program of phase equilibria in the Cu-Pb-Zn-Fe-Ca-Si-Al-Mg-O-S-(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co and Na) gas/oxide liquid/matte/speiss/metal/solids system.

Jun 19, 2024

By A R. Bonani, M P. Pe±a

The optimisation of slope angles, that is to say, increasing them, compared to the original design is always the subject of analysis of stability for geotechnical engineers and economic analysis for planning engineers. Questions to be answered include: What is the acceptable risk? What factor of safety? What probability of failure or reliability? The Rosario Open Pit has a history of failure, poor quality rocks and high pore pressures. It was decided to deepen the pit below the programmed design to test the practicality of different design approaches, which if successful, could be used to improve the economics of mining at Collahuasi. The revised slope design has factors of safety in the range of 1.0 to 1.2, probabilities of failure of ten to 38 per cent, and increased slope angles of between 3¦ and 5¦ with respect to the original design. The pit deepening with these design slopes will deliver an extra two million tonnes of ore which will have a significant positive impact on mining economics.

Jan 1, 2007

By A Roudnev, P Loderer

Mineral froth pumping utilising centrifugal slurry pumps is a major engineering challenge for both the end users and pump manufacturers. The traditional approach has been to oversize the pump for pumping mineral froth. New horizontal slurry froth pump designs offer opportunities to improve froth pumping capability of mineral froth with challenging (high) Froth Volume Factor while maintaining high efficiency, long wear life and stable pumping performance.CITATION:Loderer, P and Roudnev, A, 2018. A reliable solution for pumping mineral froth with challenging froth volume, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 291–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

The Division of Minerals and Geochemistry in collaboration with three mineral exploration companies, Mawson Pacific Ltd, Ramsgate Resources Ltd and Tectonic Systems Pty Ltd commenced a two year research project to investigate the application of remote sensing techniques to exploration for mineral deposits in access of the Yilgarn Block in Western Australia. The project utilizes satellite data such as day and night imagery from the NOAA-AVHRR (National Oceanic and Atmospheric Administration - Advanced Very High Resolution Radiometer) satellite. The recent research with the imagery in the Kalgoorlie, Southern Cross and Mt Magnet regions has highlighted the advantages of the mid infra-red and the two thermal response channels of NOAA-AVHRR for geological investigations. These three channels have the spectral resolution to distinguish stratigraphic units and younger intrusive bodies, and to delineate fracture zones and shear zones associated with Proterozoic dykes. But most important is the capacity to distinguish thermal signatures from geological structure, near-surface outcrop and palaeochannels which have been covered by unconsolidated sediments. The research project applies remote sensing methods including enhanced satellite imagery optimised to the Western Australian environment. It encompasses data from both space and airborne monitoring platforms that have obsreved a significant spectral response for the classification of alteration zone lithologies. It includes the collection of multiseasonal data from areas of interest which is essential both for the understanding of thermal characteristics of important lithologies and for the extrapolation from field work investigation to potential exploration areas. No comprehensive investigation of this type has been carried out within the Yilgarn goldfields.

Jan 1, 1987

By A B. Christie, R Barker

Recent studies carried out to support the development of a strategy for the New Zealand mineral industry by the NZ Minerals Industry Association have included investigations of mineral potential, and the development of scenarios for realising this countryÆs mineral potential by 2010. New economic research is applying a general equilibrium model to quantify the opportunity cost of this potential. The model analyses separately four categories of land (private land and three categories of Crown land) and identifies four distinct mineral classes û precious metals, industrial minerals, coal and aggregate. It investigates the economic effect of the increased availability of mineral resources on the mining industry itself, on other industry sectors and on the NZ economy generally, including its impact on unemployment, GDP and household welfare.The analyses suggest that increases in the level of GDP of between 1.9 per cent and 3.4 per cent may be obtained by utilising New ZealandÆs mineral wealth to varying degrees. The mineral industry sectors are significant beneficiaries under all scenarios; mineral output increases by between two and five times its current level. However, the flow-on effects to the rest of the economy, and to households, are also significant. The analyses show that household income, adjusted for changes in consumer prices, can be expected to increase by between 1.6 per cent and 2.7 per cent. This results largely from increased employment.

Jan 1, 2002

By G B. Smith, G M. Marshall, A Querzoli

The South Australian mining regulatory framework has adopted a performance based approach to the management of risk. This approach has been in place in South Australia for more than 10 years and is increasingly being implemented in mining jurisdictions in Australia and around the world. Performance based regulation focuses on setting appropriate environmental outcomes to be achieved based on an assessment of the potential impacts associated with the development, operation and closure of mining projects. Measurable compliance criteria, including completion criteria, are set to demonstrate achievement of the outcomes. It is the responsibility of the proponent to propose designs and strategies that will achieve the regulated environmental outcomes and to demonstrate the implementation of their designs and strategies will achieve the outcomes into the future. Tailings Storage Facilities (TSFs) are significant elements of many major mines and each is unique with site specific factors such a materials to be stored, design, size, location, climate, sensitive receptors, operating history of the facility (i.e. changes to design), site culture and company capability amongst a range of other factors. Consequently a fit-for purpose approach is a key principle of best practice regulation of tailings management as it takes the site specific factors into account in setting appropriate outcomes for mitigating the identified impacts associated with a proposed development. Achievement of those outcomes through fit-for purpose, well designed management strategies would ensure safe, stable and economic storage of tailings in a manner that complies with all legislative requirements and presents negligible public health and safety risks. Tailings storage must also have acceptably low social and environmental impacts, both on and off site, during operation and indefinitely post closure. Achievement of environmental outcomes during operations and at mine completion can then be demonstrated to the regulator and community through public reporting of compliance with measurement criteria which establish the appropriate level of impact for each individual operation. A number of new mining proposals including tailings storage facilities (TSF) have recently been assessed and approved in South Australia. The location, size, design, sensitive receptors, public interest and therefore risk profiles of these TSF’s have varied substantially between these new mining proposals. These considerations were reflected in the assessment of the TSFs and the resulting mining lease conditions of approval including the environmental outcomes to be achieved over the life of the facilities. This paper and the accompanying presentation will provide case studies of recently approved TSFs within South Australia and the regulatory framework for each case.CITATION:Smith, G B, Querzoli, A and Marshall, G M, 2018. Tailings regulation – a South Australian perspective, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 166–177 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By M D. Melville, B C. T Macdonald, T D. W

The surface waters in regions with acid sulfate soils (ASS) can contain high concentrations of acidity and dissolved metals. These soils cause problems for agriculture, construction and development. The water can be neutralised through many techniques, however a technique that is low in maintenance and low in cost is most desirable. Due to the vast spread of ASS along AustraliaÆs coastline an expensive and high maintenance solution would not be cost-effective. In this study, a passive treatment system that has been used to neutralise acid rock drainage has been applied to treat ASS water. This system is commonly referred to as an oxic limestone drain (OLD) or an anoxic limestone drain (ALD) depending on the waters dissolved oxygen concentration. The system that has been developed for ASS has a similar closed system to the OLD or ALD, that traps the carbon dioxide which forms when limestone reacts with acidic water. It has been called a closed tank reactor (CTR) and is constructed by placing limestone into an airtight tank. A common problem that will occur when acidic water with a high concentration of dissolved metals reacts with limestone is the formation of metal oxy-hydroxide precipitates. These precipitates can coat or armour the limestone and reduce its reactivity. To minimise the accumulation of precipitates in the CTR, perforated subdrains have been installed. It is anticipated that high water pressure and flow through the subdrains will remove some precipitates. A sump has also been installed at the base of the tank to collect precipitates that settle under gravity. The CTR has been tested for 70 days at a sugar cane farm located at McLeods Creek, NSW. Within this time the sump and subdrains have been used to flush the system. An orange solution was produced during flushing and it is believed to contain iron and aluminium precipitates. The initial performance of the CTR raised pH by at least one unit. Almost all dissolved aluminium was removed and more than half the dissolved iron. The total titratable acidity ranged from 17 - 92 mg/L CaCO3 in the initial month of monitoring. After passing through the CTR the acidity was reduced to zero. The performance of the CTR during the last few days of monitoring decreased. This is believed to be due to a pulse of water with higher acidity and dissolved metal content that lasted a week. In this pulse, the acidity reached 307 mg/L CaCO3 and the total dissolved aluminium reached a maximum of 24 mg/L. Higher concentrations of dissolved metals may have been the cause for lower performance due to increased precipitation and coating on the limestone.

Jan 1, 2003

It is well documented that drill and blast outcomes affect the downstream mining processes of loading, hauling, crushing and grinding but it can also significantly impact on mine profitability via dilution, recovery percentage, lump generation (iron ore), fines generation (coal, iron ore), coal loss and final wall stability. Drill and blast must therefore be optimised to improve the overall profitability via positively impacting on productivity and saleable product generation. It is however, difficult to achieve this because of the complexity of the number of parameters that must be integrated and managed across the entire mine value chain, ie the concept of æMine to MillÆ. This paper highlights, via a simple case study, the need to have a mineÆs drill and blast system both in control (so that it is predictable to a high degree) and with minimal variability (so the design actually makes it into the field). This type of management control is essential prior to optimisation work being undertaken. The æTeam ApproachÆ is discussed to illustrate the methodology of achieving drill and blast optimisation. A case study is presented to illustrate the potential benefits of this approach which in this mine represented a 27 per cent reduction in powder factor with the downstream functions achieving higher productivity with the same or reduced maintenance costs. It is essential for Australian mineÆs to implement the appropriate management strategies and experienced personnel placement to ensure that their mineÆs drill and blast system is correctly managed to facilitate the optimisation of profit. Without this, the Australian mining sector will become increasingly uncompetitive.

Jan 1, 1999

The Prominent Hill copper-gold deposit is located approximately 150 km north west of Olympic Dam, on the southern margin of the Mount Woods Inlier in South Australia. Its discovery in November 2001 resulted from the application of a geological model developed from geological, geophysical and petrophysical data pertaining to the Olympic Dam deposit. The discovery has dispelled the notion the Olympic Dam may be unique, and that another deposit like it is unlikely to be found. The Prominent Hill mineralisation is hosted by haematite-matrix hydrothermal breccias, which have suffered extensive iron-sericite-silica alteration and overprinting. Copper, gold, barium, fluorine, uranium, cerium and lanthanum are all intrinsically associated with the hydrothermal iron. Breccias intrude an east-west striking, fault-controlled sedimentary succession, which is flanked to both the south and north by volcanic complexes. Many similarities between Prominent Hill and Olympic Dam are documented including geological setting, mineralogy, breccia styles, and alteration. Differences relate largely to the nature of the immediate host rocks. The similarities and difference provide key data for improving exploration models for this style of iron oxide copper-gold deposit, both within the Gawler Craton as well as globally.

Jan 1, 2004

By A Gerson, S Miller, R Smart, J Thomas

Environmental Geochemistry International (EGi) and the Ian Wark Research Institute (IWRI) collaborated in a three-year Australian Minerals Industry Research Association (AMIRA) research project (Project Number P387A) focussed on the prediction and kinetic control of acid mine drainage. As part of this project, single addition, and sequential net acid generation (NAG) testing was carried out on sulfide mineral samples. The test samples comprised a range of synthetic waste materials prepared using a quartz bulk and controlled quantities of the commonly occurring sulfide minerals; pyrite (FeS2), pyrrhotite (Fe7S8), arsenopyrite (AsFeS), chalcopyrite (CuFeS2), chalcocite (Cu2S), covellite (CuS), bornite (Cu5FeS4), galena (PbS) and sphalerite (ZnS). NAG test results clearly show that there are significant differences between the acid forming potential of sulfide minerals. The NAG test results for each mineral were compared with theoretical acidity values (NAPP*). The NAPP* calculation was based on stoichiometric oxidation reactions assumed for each of the sulfide minerals. Sequential NAG values for pyrite corresponds closely to predicted NAPP* values, confirming the assumption that pyrite oxidation occurs according to the stoichiometry assumed. For the pyrite sample with 5 wt per cent S, two NAG stages were sufficient for all of the sulfur to be released to solution. Since sulfides in waste materials will generally be dominated by pyrite, results also confirm the validity of including NAG testing for ARD evaluation of most waste rock. NAG testing confirms that of the sulfide minerals examined, only pyrite, pyrrhotite, arsenopyrite and chalcopyrite are acid producing, ie able to produce leachate with a pH less than 4.5. In the case of sphalerite, galena, bornite, chalcocite and covellite the pH of the final NAG solution was greater than 4.5. The significant differences between the acid forming potential of different sulfide minerals could lead to overestimation of acid producing potentials based on NAPP values calculated from total per cent S alone, ie assuming all S is present as pyrite. The oxidation of galena during the NAG test resulted in the consumption of acid. The examination of the galena surface by X-ray photoelectron spectroscopy (XPS) after oxidation in peroxide solution indicated the presence of polysulfide. The reaction of sulfide to polysulfide is acid consuming, thus explaining the net acid consuming behaviour of galena in the NAG test. This reaction pathway may provide a possible explanation for the lower than expected acid production observed for some of the other sulfide minerals examined.

Jan 1, 2003

In the search for significant new economic base-metal resources within Australia during the early 1970s BHP's Exploration Department had observed that the majority of lead and zinc con- centrate production in Europe and the USA came from carbonate- hosted Mississippi-Valley-type (MVT) zinc-lead deposits, but Aus- tralia had no history of production from this class of deposit despite several very favourable geological environments, par- ticularly in the large Palaeozoic sedimentary basins. An exploration-research team was established in 1975 and the Lennard Shelf region, near Fitzroy Crossing, was selected as a most promising geological environment. Previous exploration for this class of deposit by other companies in Australia had largely used conventional exploration philosophies (geological mapping, geophysics and geochemistry to identify specific drill targets) but BHP sought specialist advice from a North American expert and adopted a grid-drilling philosophy, which involved wide spaced relatively deep diamond drill holes on a regular grid pattern, and statistical evaluation of the results. This technique resulted in the discovery of the Blendevale Deposit in 1978 in an area which had previously been explored by other companies using conventional methodologies. The deposit was delineated and a pre-feasibility study carried out in 1985 indicated that the resource of 20 Mt @ 8.3% Zn, 2.5% Pb was a marginal proposition.

Jan 1, 1988

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 B G. Lottermoser

Field and laboratory data combined with computational modelling have been used to predict the pit water quality for the Highway Reward mine. Open pit mining of the Highway Reward copper-gold deposit has produced a final mining void with a diameter of 600 m and a depth of 280 m. This void will be left to fill with ground and surface water once pumping of pit water ceases. Several leaching tables were constructed to simulate weathering reactions and surface water run-off in the major pit wall units during a 200-day leaching experiment. To date, about three-quarters through the experiment, combined run-off from these cells has reached a pH

Jan 1, 2003

By K Tungpalan, E Wightman, M Edraki, E Manlapig, L Keeney

The depletion of easily mined high-grade ore bodies resulted in the industry having to exploit lower grade, complex resources (Albanese and McGagh, 2011; Darling, 2011; Randolph, 2011). The trend is now towards mining and processing of low-grade and complex ores (Darling, 2011; Yingling, 1990). Variable geological and mineralogical characteristics, and complex mineralogy and texture can result in large variations in metallurgical response and also cause challenges in processing. (Carson, 1995; Lorenzen and Barnard, 2011; Yingling, 1990). Variability and the complex nature of ores are fundamental sources of risk that often cause the greatest economic impact (Dusci et al., 2007; Williams and Richardson, 2004). Hence it is important to effectively characterise these types of ore bodies and assess their processing performance (ie recovery, grade). To enable this, there is a need for the following: (i) characterisation of geological, mineralogical and metallurgical variability in the ore body; (ii) effective selection of drill core with characteristics that represent the range of ores in the entire ore body. CITATION: Tungpalan, K, Manlapig, E, Keeney, L, Wightman, E and Edraki, M, 2018. A systematic approach of sample selection to predict processing performance of an ore body, in Proceedings Complex Orebodies Conference 2018, pp 67–70 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018