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Results of investigations on adsorption and desorption of CO M CH and a mixture of the two gases are described.4 Results showed that even when the equilibrium conditions contains 50% Co and 50% CH4, the gas emission in the initia' stages will contain as much as 80% CH . 4 The temperature has a small effect and so also particle size for 1.4-11.2mm. The ratio of CO2/CH gases adsorbed in coal samples depends upon t4he equilibrium pressure and this ratio decreases with pressure. Results of field tests support laboratory studies.

Jan 1, 1988

By M McCarthy

Over the last six years Mandalay Resources has increased production rates and improved safety outcomes at its Costerfield mine in Victoria, Australia. This mine is an underground operation utilising narrow mining techniques to extract vertical veins, and produces up to 80 000 equivalent ounces of gold per annum, in both gold and antimony value.The operational challenges of narrow vein mining include controlling overbreak when veins being mined are only 300 mm wide. The mine has developed methods and modified equipment to suit extraction of these veins. Productivity improvements over the period have involved development of a stoping method and equipment to suit 1.8 m wide development drives. Over the last five years and during a skills shortage, recruitment, training and retention of personnel has been key to keeping corporate knowledge and skills to execute a careful efficient mining technique to minimise overbreak.Managing an underground operation close to nearby residents has unique challenges. Historically Victorian residents had family members work as underground miners; however, in the current day with few underground operations in this jurisdiction, community knowledge of mining has decreased. The Costerfield Operations are only 100 m from the nearest residence and the company values community engagement, partnership and investment with local Heathcote organisations.The mine has invested substantially in executive coaching of its leadership team early, which has paid dividends in problem solving potential of that team and ensuring the operation delivers on its promises to all stakeholders. The operation has become safer and employees are now more aware of their individual contribution in producing safe, efficient gold and antimony that benefit the whole operation, community and the region.CITATION:McCarthy, M, 2016. Costerfield – a narrow vein case study, in Proceedings International Mine Management Conference, pp 331-338 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By M Field

Kimberlite pipes, as opposed to dykes, sill and secondary deposits, are the primary target for diamond exploration companies because they have simple geometries and can contain large volumes of potentially diamond-bearing ore. Once discovered, important decisions have to be made regarding the sampling of these geological entities to establish the total volume of ore present, and to define the internal geology, which can be complex in nature and controls the distribution of diamond grade. It is essential that as part of this process the uncertainty in constructed geological models are assessed. In this paper the Orapa AK1 kimberlite pipe in Botswana is used as a case study to explore a potential methodology for defining this uncertainty. The uncertainty of the rock volumes of different types can be characterised by a geostatistical approach. Geostatistical simulations, based upon a plausible representation of the geological bodies, provide different possible images of the orebody that can be considered as different realities. By testing different borehole layouts and drilling the orebody virtually on the computer, many different, but equi-probable realisations of the pipes can be produced. It is then possible to estimate the rocksÆ volumes and compare them with the actual ones. A statistical analysis of the relationship between estimation error and the number of boreholes can then be used to optimise the next sampling campaign. The rock volumes are obtained from a two-step simulation process. Firstly, the pipe geometry is simulated by means of introducing variations around the geological block model, by an original method called centre point simulation (CPS), which has been developed for this purpose. Secondly, the internal geology is then simulated within the pipe. The methodology for simulating the internal geological zones has to be adapted to the level of information and to the geological structure itself. The upper portion at Orapa AK1 is filled with sedimentary crater facies. Here plurigaussian simulation techniques can be applied that are adapted to the simulation of sedimentary facies. The central zones of the pipe are typically subvertically-oriented massive volcaniclastic deposits and breccias and the lower regions comprise a complex root zone. CPS is appropriate for these zones.

Jan 1, 2006

By A N. Parry, G van Wyk

"Sensor based automatic ore sorting technologies are used in the minerals industries to efficiently remove waste and submarginal grade material from crushed and screened run-of-mine (ROM) ore, producing a coarse (typically >10 mm) upgraded preconcentrate at an early stage in the mineral processing circuit. This avoids additional energy intensive downstream processing of this rejected component of the ROM feed, leading to lower unit operating costs and reduced tailings disposal volumes.Test work on bulk low-grade gold ore stockpile samples from Central Norseman Gold Proprietary Limited has been conducted, indicating high gold recoveries as well as high material rejection rates. A financial model, based on these results, evaluates grade sensitivity and identifies a minimum stockpile grade for adequate financial returns. The base case modelling estimates that the ex-stockpile grade (including the fines bypassed fraction) can be more than doubled through ore sorting and that the project will be highly viable with strong cash flow generation at stockpile grades as low as 0.7 g/t gold. The modelling will enable the company to benchmark ore sorting options against stockpile reclaim and screening operations currently employed. Citation:Parry, A N and van Wyk, G, 2016. Upgrading Low-grade Gold Ore Stockpiles by Preconcentration Using Ore Sorting - an Assessment of the Economic Impact and Viability, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 179–190 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Thirumalai K, Peluso R. G

The United States has more than 45 billion tons of economic coal reserves in seams above 10 feet thick and current underground production from thick seams represent less than three per cent of the total production. A tripling of underground production from thick seams is necessary within the next 10 years to meet U.S. coal production demands. An analysis of underground accident and production data is presented in the paper. A study of accident and injury distribution in different coal seam heights in the eastern and western part of the United States in seams ranging in thicknesses from 5 to 15 feet indicates that the seam thicknesses do not produce adverse impact on underground injury incidence. Accidents associated with roof falls and haulage account for about 70 per cent of underground mining injuries.

Jan 1, 1976

By Cocks T

The 15-year long debate between the industry, Government and Aboriginal people about the rights and wrongs of Land Rights, the right of Aboriginal people to control development on their land and the relationship between the parties, has been long and often bitter. It has so far been a war of words and often the truth has been the first casualty. This paper looks at the debate and presents the perspective of Aboriginal people, as well as looking at how the industry and Aboriginal people can work together for everyone's benefit. It addresses such matters as: ò why Aboriginal people believe they have the right to control development on their land; ò the perception that Aboriginal people are anti-development; ò the perception that Aboriginal land is 'locked-up'; and ò how companies can negotiate with Aboriginal people.

Jan 1, 1994

By L Clarke, R N. Campbell, F Bourke, J Anderson

Lithological units have been classified geotechnically with mechanical tests and discontinuity measurements from the GRD Macraes Limited, Macraes Gold Project and Rotowaro coal mine open pits, New Zealand. Using these measurements slope stability probability classifications (SSPC) have been quantified based on an adaption of Hack's (1998) SSPC system which places less influence on rock quality designation and unconfined compressive strength than previous slope/rock mass rating systems. The Hack weathering susceptibility rating has been modified by using the chemical index of alteration values from XRF major element analysis. Slaking and weathering is an important parameter in slope stability in the Waikato Coal Measures and Otago schist lithologies and hence a non-subjective method of assessing slaking/weathering in relation to the chemical index of alteration has been introduced. Other major components of this adapted SSPC system are the inclusion of rock moisture content and rock strength anisotropy effects on slope stability. This paper explains the systematic approach of using the adapted SSPC system to classify slope stability probability. The main modifications of Hack's SSPC system are the introduction of rock intact strength derived from Mohr-Coulomb failure criteria which has been adapted for varying moisture content, weathering state and confining pressure. It is suggested that the subjectivity in assessing intact rock strength within broad bands in the initial SSPC system is a major weakness of the initial system. Initial comparison of rock mass friction angles, cohesion and strengths derived from the adapted SSPC are compared with results derived from modified Hoek-Brown criteria, MRMR and SMR classification systems. The advantage of the modified SSPC system is that slope stability probability, maximum batter and overall slope height and overall slope angle for open pit walls can be predicted in addition to orientation dependent and orientation independent stability. Examples are provided, using the modified SSPC system to predict initial optimum pit slope designs in proposed greenfield mine sites.

Jan 1, 2000

By M D. Urbani

HiTec Energy Ltd has been conducting research since 1996 into novel process routes for the treatment of low-grade and waste manganese sources for the production of high value and high quality electrolytic manganese dioxide (EMD) for the alkaline battery market. HiTecÆs approach is to treat previously unsaleable manganese deposits and mine site tailings using a novel sulfur dioxide leach route, followed by purification and electrowinning to generate the sought-after EMD product by an environmentally superior processing route to those presently practiced throughout the world today.HiTec Energy Ltd expects to be in commercial production with its Stage 1 facility in Kalgoorlie in the last quarter of 2004 for the production of 12 500 tpa EMD. With this production facility being adjacent to a laterite nickel producer with available waste manganese units, the opportunity arose for HiTec to combine its existing technologies with processes (that will be discussed in this paper) to turn two waste by-products into products that are used for high-tech purposes.HiTec Energy Ltd and the Parker Centre have had a collaborative research relationship for a number of years in areas involving EMD and battery related technologies. Meanwhile the solvent extraction (SX) group of the Parker Centre (CSIRO Minerals) has developed SX processes to separate manganese from nickel and cobalt. A project was initiated by HiTec Energy to recover manganese from waste laterite leach solutions using SX technology. Batch tests were conducted to select a suitable organic system for the extraction of manganese in terms of selectivity and extraction and stripping kinetics.A total of eight organic systems were tested by determining pH isotherms of metals using a laterite nickel process waste stream. Two organic systems, the Versatic 10 and Versatic 10/synergist systems, were chosen for further test work with Shellsol D70 chosen as the diluent for both systems.The Versatic 10/synergist system would be advantageous over the pure Versatic 10 system because fewer SX stages are required, resulting in a smaller organic inventory and lower capital costs. The risk of gypsum formation is also significantly lower with the synergistic system.

Jan 1, 2004

Developed and built in 1982 for simultaneous bathy-metric and reflectivity mapping of the deep ocean by the Hawaii Institute of Geophysics, SeaMARC II was a breakthrough in sea-floor mapping technology. The design was developed cooperatively by industry and academia, and the system has served as a prototype for a new generation of mapping tools for operation in both shallow and deep water.Research programs using the SeaMARC II system have focussed on basic research into the geophysical evo-lution of the Pacific, ranging from intra-atoll mapping to surveys of the deep-sea trenches. During the past few years most work has been concentrated on detailed investigations of the morphology of mid-ocean spread-ing centers, seamounts, and the subduction zones which surround the Pacific. The detail provided by the high resolution, 10-km wide side-scan sonar images of fault and fold structures, combined with the swath of bathy-metric information obtained simultaneously, allow previ-ously unattainable analysis of seafloor morphology and are leading to development of detailed models for ocean crust genesis and deformation.

Jan 1, 1990

By A L. Wills

Cliffs Natural Resources Pty Ltd (Cliffs) operates iron ore mines in the Koolyanobbing region of Western Australia. Ore is mined from three separate hubs and trucked to Koolyanobbing. There it is crushed and screened to lump and fines finished products and railed to Esperance port for export to Asian customers. Cliffs is renowned in the marketplace for its consistent product quality. In 2010, 9 Mt of ore was exported to Asia.Over the last three years, Cliffs has systematically refurbished its product quality system (PQS), to improve efficiency of production while maintaining its high standard of product quality. Particular attention has been given to reducing inventory, which has required significant modifications to the production process design.In redesigning the production process, emphasis was placed on maximising the application of the inherent blending in each of the production process steps and dedicated blending was only introduced where essential. Simulation modelling and statistical analysis of process capabilities were utilised to develop a system that optimises inventory, minimises rehandle, eliminates several decision-making steps and maintains a pull focus throughout the value chain.The new planning functions are now fully integrated and effectively control long-term grade variability rather than relying on long-term stockpiling. The production process design and the daily crusher blend plan are used to control short-term grade variability. With the upgrading of the planning processes the accuracy and consistency of algorithms for lump per cent and lump and fi nes grades became more important and an increased geometallurgical function has been added to the company.The continuous stockpile management system was upgraded to increase the effectiveness of the daily crusher blend planning process and is now the sole intervention point in the production process for grade-based decisions. Grade control systems were modified to utilise advances in software and geostatistics to deliver accurate short range planning models. The reconciliation and sampling systems have also been refurbished with an emphasis on practical application and feedback loops.Accountability and transparency are provided by management reports that are generated from a centralised data warehouse and the introduction of a corrective action system. Standardised reports are available to all stakeholders and a quarterly KPI scorecard assists the management review process.The successful rejuvenation of the PQS has culminated in operational efficiency through the implementation of an integrated end-to-end process flow. Shareholder value is maximised through maximising recovery of the resource and minimising costs. Customer focus is maintained by reliably delivering product with acceptable and low grade variability.

Jul 11, 2011

By E P. O’Dwyer

Segment and gasket lining in tunnel boring machine (TBM) tunnels; and sheet membrane lining systems in driven tunnels are robust waterproofing systems each with a proven history of performance in Australia and further afield. Where an interface between these two systems occurs, the potential for costly failures is vastly increased and additional attention to detail is required in design, planning and construction. TBM cross-passages represent the most common occurrence of this interface, with steel compression flanges and neoprene gaskets being the typical means of connecting the waterproofing systems. There is a large variance in both detailing these flanges and associated outcomes, which makes this an area where there is room for improvement within the industry.The paper will look to tease out the various issues associated with this interface and how they can be dealt with efficiently with appropriate design measures, robust planning and carefully controlled construction methods.The paper will also look to review the new technologies and systems currently being put forward as potential alternatives, including an epoxy tape system, which has recently been successfully trialled on a project in Europe under high-pressure head.CITATION:O’Dwyer, E P, 2014. The challenge of waterproofing cross passages in segmentally lined tunnel boring machine tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 315–322 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By R Wynn, R A. Pax, S Mann, B Cornish

The semi-autogenous grinding (SAG) mill at the MMG Century operation has failing load cells that are essential to the control strategy used to stabilise the mill. Currently, mill-bearing pressure is used as a proxy for the load cells, but it has been found to be a noisy signal and lacking in useful sensitivity. It is also prone to variations and drift due to temperature. After consideration of a number of options, a non-contact acoustic array has been installed around the SAG mill to provide a more stable proxy load signal as well as other information about the internal operation of the?mill.The installation consists of 12 microphones to provide some detail into the operational differences that occur during normal operations at the MMG Century SAG mill. This acoustic approach acknowledges that operational grinding mills emit significant acoustic emissions that are a consequence of the dynamic environment prevailing inside them.Previous studies have attributed the acoustic noise to a range of events that occur inside these mills (Pax, 2011; 2012). Consequently, non-contact acoustic determinations of in-mill behaviour can provide powerful insights into the operation of the primary comminution tumbling mills. By measuring key microphone signal attributes at different positions around a mill, a holistic picture of mill internal operation can be developed.This paper will describe the installation of the 12 microphones and discuss the use of the acoustic load signals as a proxy for failing load cells. It will also present data from new observations of internal mill dynamics and the results of implementation of control using these acoustic signals. Key to the control approach has been the development of a logically coherent picture of the processes inside the mill.CITATION:Pax, R A, Wynn, R, Mann, S and Cornish, B, 2014. Implementation of acoustic arrays for semi-autogenous grinding mill?operation, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 273–282 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By E Villaescusa, C Drover

The stability of access tunnels is one of the main engineering challenges in deep underground mine construction. Many underground hard rock mining operations are now reaching depths where the induced stresses are such that sudden and violent failure of the excavations can occur very soon after construction. The loading conditions on the installed ground support schemes are often underestimated by conventional engineering design methods. Therefore, the actual loading conditions often exceed the installed ground support capacity. This can result in failure of the excavations and, in extreme cases, potentially closure of mining operations amounting to hundreds of millions of dollars in lost production. More frequently, violent excavation instability at great depth causes operational delays, costly and unplanned rehabilitation, as well as risks to worker safety. In order to address this challenge, this paper briefly summarises a modern, innovative approach to the design and construction of mine development at great depth. The process follows seven main steps. The first step is to characterise the rock mass strength, structure and stress. The second step is a stability assessment, which identifies the plausible modes of excavation failure, based on the rock mass characterisation. The third step is the definition of an excavation geometry which is harmonic to the high stress conditions. The fourth step is to prepare a site-specific face destressing drill and blast design which will reduce the potential for rock mass instability during the development construction cycle. The fifth step is to accurately quantify the expected loading conditions on the installed ground support. The method of doing so is uniquely analytical and probabilistic. It is based on the natural mechanical relationships between rock strength, structure, induced stress and the physical characteristics of the instability, including its mass and ejection velocity. The sixth step of the design process is to specify a ground support scheme arrangement with sufficient strength and displacement capacity to exceed the rock mass demand by a safe margin. The final stage is to install the complete ground support scheme using mechanised technologies which minimise the exposure of the equipment operators to unsupported ground at the tunnel face.

Nov 29, 2022

By L O. Filippov, I V. Filippova

Subsea massive sulfide deposits have particular mineralogical compositions and textural features differentiating them from onshore ore. When extracted from salty water and exposed to the air, massive sulfide samples strongly oxidise and soon become covered by thin layers of iron, copper and zinc-rich sulfates and oxides, as well as elemental sulfur. The textural properties vary according to the degree of maturity and the sample position within the hydrothermal deposit. Because of the variation of secondary mineralisation and porosity level, sea floor massive sulfides respond differently from terrestrial ore to processing methods. Froth flotation, commonly applied to separate all types of sulfides from the gangue minerals, is one possible treatment technique to process sea floor ore. Sulfide recovery rate is, in most cases, excellent (>90 per cent). However, separation of the various mineral phases is difficult to obtain even when applying known methods used for onshore ore. Moreover, the flotation behaviour decreases dramatically with time of conservation, even when the samples were stored in a confined environment. High pH range, which is a good way to depress pyrite and therefore to favour the flotation of copper and zinc sulfides, does not have the same effect on subsea ore. Consequently, careful flotation procedure should be elaborated to obtain efficient mineral separation for this specific marine ore.CITATION:Filippov, L O and Filippova, I V, 2015. Processing of subsea massive sulfide ores by flotation – similarity and features with terrestrial ores, in Proceedings Third International Future Mining Conference, pp 239–244 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M E. Watson

Minimising dilution and ore loss is an important part of ensuring profitability of a gold mining operation. White Foil open pit gold deposit is a low-grade deposit and therefore managing ore quality is a high priority. Ground movement through blasting can displace ore and waste boundaries up to 10 m from their in situ location and therefore requires stringent ore movement monitoring and adjustment. There are currently only two options for monitoring blast movement – utilising visual targets (commonly lengths of polypipe) but this has widely been replaced by electronic blast movement monitors (or BMM). Regardless of the technology used, the basic principle is to compare the pre- and post-blast locations of the targets to determine the movement of the rock mass during blasting, which is then used to determine the final location of ore and waste boundaries.The Blast Movement Technologies (BMT) BMM system has been used at White Foil since June 2014. The system has been effective and reliable during that time; however, the annual cost of using the BMM system is greater than other monitoring alternatives. As such, the open pit geology team conducted a study comparing the BMM system against the conventional polypipe technique. The objective was to quantify the profit and loss that would occur based on the ore block transformations from both methods. Eight blasts were selected where polypipes were installed in additional holes adjacent to the BMM monitoring holes. The resulting movement vectors from the respective methods were used to create post-blast ore blocks by transforming the in situ ore blocks. While polypipe is a cheaper alternative, the BMM system tracks ore and waste boundaries more effectively resulting in better quality control, enhanced ability to minimise dilution and ore loss thus maximising profit. For these eight blasts, it is calculated that the BMM system resulted in A$664 978 extra profit through a reduction of ore loss. The total cost of a yearly BMM package was recovered in the first two blasts of this study. The primary reason for the difference is that polypipe had a poor recovery rate of 32 per cent compared with 92 per cent for BMM at White Foil. Therefore, the data used to transform the ore blocks was less representative, resulting in inaccurate post-blast ore block boundaries when using polypipe.CITATION:Watson, M E, 2017. Blast movement monitors or polypipe? A study into cost-effective blast movement monitoring at White Foil gold mine, Western Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 433–440 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By Q Zhuo, P C. Pistorius, M N. Al-Harbi

A likely increasingly important pathway for future low-carbon ironmaking and steelmaking is the combination of gas-based direct reduction with electric furnace steelmaking (DRI-EAF route), or with electric smelting (DRI-ESF route). In the DRI-EAF route, the gangue that is present in the iron ore is fluxed and removed as slag in the melting (steelmaking) step. This is in contrast with integrated steelmaking, in which the gangue is removed as part of blast furnace ironmaking. For DRI-EAF steelmaking, the amount and composition of slag depend on the iron ore composition, flux additions and iron yield. Slag volume and composition affect phosphorus removal, foaming behaviour and the process energy requirements. In this work, heat data from a year of DRI-EAF production was analysed to test whether the expected relationship between slag volume and electricity consumption for EAF steelmaking was observed. The data include slag analyses (one sample per shift), and heatlevel information on all inputs, final steel temperature and dissolved oxygen concentration, electricity consumption, tapped steel mass and tap-to-tap time. In analysing the data, the slag volume was estimated from the assayed slag CaO concentration and CaO inputs to the EAF. The expected effect of slag volume on steelmaking energy consumption was calculated with a mass and energy balance, considering the heat of mixing of the slag. The calculated energy requirement of slag formation is in line with previous estimates reported in the literature.

Aug 21, 2024

Drilling underground can be a hazardous undertaking in many circumstances. Raiseboring and boxhole boring underground could form an integral part of the block caving production methodology and getting the right mix of technical capability, ergonomics and economical viability has been the goal of many machine manufacturers. With the introduction of the Terratec Universal Boring Machine concept, flexibility of raiseboring, downreaming and boxholing has been enhanced by the introduction of a single machine that will perform all three processes. In addition to its technical flexibility, additional safety features have been introduced that will eliminate many sources of injury by mechanising most of the operational procedures. Together with the one-man remote operation, this machine design addresses and solves many of the safety issues. This paper outlines the machine concept, details its safety features and shows the techno-economic advantages for use in the block caving environment. Block caving is a distinct caving method applied mostly to large massive orebodies because of the inherent low costs and high production capabilities. Areas of sufficient size are mined by undercutting so that the mass above will cave naturally. Extraction of the caved ore at the bottom of the ore column causes the caving action to continue upward until all of the ore above the undercut level is broken into sizes suitable for handling (Figure 1).

Jan 1, 2000

By Noller B. N, McGill R. A

The Alligator Rivers Region has been the scene of one of Australia's most intensive environmental monitoring efforts since the current generation of uranium mining was mooted in the 1970s. Prior to mining, the local environment and the nature of potential impacts were not well known. The initial monitoring programs therefore included large baseline characterisation and research components. After some 15 years, water, soil and sediment monitoring programs have been reduced to a fraction of their early size, as the mining and natural systems became better known and characterised, and the actual nature of the environmental impacts were established. Modem techniques allow much more rapid and thorough identification of chemical species and elements of concern, allowing much more focused monitoring programs to be designed. In the 1980s data collection was emphasised at the expense of interpretation, and monitoring programs were maintained at much higher levels than were in fact required. It is now clear that investigations are important and should be distinguished from monitoring programs, and that the timely interpretation of investigations and implementation of recommendations can greatly reduce the effort and expense that can be involved in a monitoring program. Monitoring programs based on a sound understanding of potential environmental impact may then be efficient and cost-effective, yet provide sufficient information to assess the environmental impact of mining, guide further environmental protection measures when problems are detected, and demonstrate compliance with regulatory requirements.

Jan 1, 1994

By J Boshoff, D Reid

It has been recognised worldwide that the liquefaction risk of unconstrained tailings stacks or cyclone underflow embankments requires careful consideration. The stability of a tailings deposit where the perimeter embankments are made up of hydraulic fill is often governed by post-liquefaction stability.Cyclones are frequently used around the world to classify tailings into a coarse underflow for building a tailings impoundment wall and a finer fraction that is disposed of into the basin. The shear strength of the tailings that form the outer embankment of a tailings storage facility (TSF) and the location of the phreatic surface are the two most significant factors influencing the structural integrity of the facility. The coarse underflow is placed in such a way as to contain the overflow, which is finer, has low strength and is often poorly consolidated.A cyclone field trial was undertaken at a gold mine in Western Australia to assess the feasibility of using the cyclone deposition method to optimise and increase the capacity of an existing tailings cell. The aim of the cyclone trial was to collect information to demonstrate to the client and the regulators that cyclone deposition was a feasible option for raising TSF embankments. The cyclone trial provided an opportunity to assess the cyclone under field conditions and the quantity and quality of the underflow fraction produced on-site. A variety of methods were used to assess the flow liquefaction susceptibility of the tailings underflow sample produced during the cyclone field trial.The field trial, laboratory testing and analysis will be discussed in this paper.CITATION:Boshoff, J and Reid, D, 2015. The resistance of cyclone underflow material to flow liquefaction, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 151–156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

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

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

Aug 24, 2022