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By S Sabanov

Supplementary sampling of particulate mass concentration, the number concentration and the average particle diameter of nanoparticles using a TSI Dust-Trak DRX Aerosol Monitor, Naneos Partector 2 has been conducted. The aim of this study was to evaluate suitability of the instrument for long-term monitoring of diesel particulate matter (DPM) at conditions of polymetallic mines. Sampling was conducted in an area of the active ore heading, requiring the use of a diesel-powered face haul-age loader R1700 and a mine truck Caterpillar AD-45. The sampling was done for 126 minutes at a distance of 30 metres from the mine face. Results of this field work can be used to expand the sampling program to other mines. Expected outcomes of this study are to develop costeffective DPM control strategies, improve mine ventilation, and protect mineworkers’ health.

Oct 12, 2022

By P Christen

The Ernest Henry Copper gold mine situated in North West Queensland, Australia, is owned and operated by Xstrata Copper. Currently the open pit produces 11 Mtpa of ore. With open pit mining ceasing in mid 2011 development has begun on an underground sublevel cave mine to extend the life of the operation by another 12 years. When completed the open pit will be 530 m deep and 1.5 km in diameter. The orebody dips at approximately 45° and has been outlined a further 450 m below the base of the pit. This provides some challenges for the Ernest Henry underground mine which is designed to initially truck development and production ore from the end of the pit until a hoisting shaft is commissioned in 2013. Production will then increase to 5.0 Mtpa on its way to an ultimate rate of 6.0 Mtpa in 2016.This paper will focus on the capital development and infrastructure requirements for the underground mine. Areas covered include mine accesses, ore handling system, accommodations for the dip of the orebody, primary ventilation design, dewatering systems and selection of an underground workshop over surface only maintenance.Discussions include the complications arising due to the mine being located directly below a large open pit and the combination of first principle cost analysis and risk assessment which has been used to safely optimise the feasibility study designs.

Mar 21, 2011

By P Corbett, P Sheffield

Centennial Coal operates the Springvale longwall mining operation which extracts coal beneath the Newnes Plateau in the Western Coalfields of New South Wales. Springvale, and the neighbouring Angus Place mine, have a history of difficult geotechnical conditions where combinations of a relatively high stress regime and weak, laminated roof and extensive geological faulting has led to numerous roof failures throughout the mine’s life. Following development, the mines underground roadways can experience high levels of roof movement which may lead to roof falls. Multipoint wire extensometers are extensively used throughout the mine for roadway condition monitoring, and to reactively drive remedial strata support through trigger action response plans (TARPs).As a result of the use of high-density extensometer monitoring over a long period, the mines have an extensive archive of legacy data. Data processing has evolved over time in order to accommodate the increasing data volume, including direct data entry from the recently introduced hard-wired real-time monitoring instruments. It is likely that telemetric real-time instruments will be introduced in the future, which will cause another step change in data management requirements. This paper discusses the transition to and evolution of relational database management systems for extensometer and associated data.This paper also presents case studies of the use of a new software tool for reprocessing legacy data to enable time-scaled visualisation of monitoring data in the context of longwall and development face positions and installed strata support. The software can be used proactively in the identification of geotechnical risk factors and their interaction with the mining process to allow a more robust geotechnical hazard process. It interfaces directly with the widely used ExtoChart database software and can be presented with scale drawings of geological and geotechnical data to allow correlation of monitoring data results with risk factors.CITATION:Corbett, P and Sheffield, P, 2015. The use of high-intensity monitoring data to better characterise geotechnical properties of a non-homogeneous rock mass, in Proceedings Third International Future Mining Conference, pp 145–158 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M G. Shaw, M A. Rhamdhani, S P. Singh, A R. Duffy, B Eisenbart, A K. Shukla, G A. Brooks

The field of astrometallurgy is a growing area of study. Metal production on the Moon is likely to begin in less than a decade as major space agencies such as NASA (National Aeronautics and Space Administration) and CNSA (China National Space Administration) are preparing to construct permanent lunar bases. The utilisation of regolith to generate oxygen and metals is expected to be important in the development of a sustainable lunar habitat. This paper provides an overview of potential metallurgical processing methods for lunar conditions, emphasising the impact of lunar factors on slag chemistry. The interaction between regolith and the extracted metals, as well as their impact on slag composition and refractory performance, are critical considerations in metal production on the lunar surface. The initial research on lunar metallurgical technologies is focused on oxygen extraction and Fe-Si alloys are reported as the by-products of these processes. This paper delves into the fundamental thermodynamics associated with the carbothermic reduction of lunar regolith. Thermodynamic analysis using the FactSage™ ver 8.2 software package indicates that the Fe-Si alloy can be produced as a metallic product from the lunar regolith at temperatures ranging from 1400°C to 1600°C under terrestrial conditions. However, under ultra-high vacuum conditions (3 × 10-15 bar) on the Moon, the required operating temperature for producing ferrosilicon would be significantly reduced. Thermodynamic modelling results indicate that under lunar vacuum conditions, Fe-Si alloys only exist as solid phases at lower temperatures below 650°C. At higher temperatures, both Fe and Si are expected to be present in the gas phase. In this work, the carbothermic reduction of the Lunar Mare Simulant (LMS-1) is conducted under terrestrial conditions. The findings indicate that the process can readily yield Fe-Si alloys with 7–10 wt per cent Si at 1600°C. Additionally, energy dispersive spectroscopy (EDS) analysis of the resulting Fe-Si alloy indicates the presence of phosphorus up to 1 wt per cent.

Aug 21, 2024

By S Girard, L Rowland, V Lawson, Y Shields

Since 1948, ValeÆs Matte Separation Plant has been successfully using magnetic separation and froth flotation to separate the copper sulfide, nickel sulfide and Ni-Cu metallic alloy contained in Bessemer matte for downstream processing. Though some equipment upgrades have been performed over the years, the flow sheet has generally remained unchanged since the early 1970s. The need to improve metallurgical performance led to the trial of a scalping flotation column to produce a final copper concentrate ahead of the cleaner circuit feed to take advantage of a high degree of copper mineral liberation, reduce cleaner-recleaner circulating loads and decrease the associated loss of selectivity. Plant results indicated that 50 per cent of copper contained in the rougher concentrate could be recovered at final grade target. Results indicate that up to a 1.5 per cent increase in copper recovery to copper concentrate was achieved during the scalper trial due to a reduction in the generation of fine chalcocite which has historically been observed to report to flotation tailings due to surface contamination. Deficiencies are currently being addressed and a long-term trial is scheduled to confirm the benefits of copper scalping.CITATION:Girard, S, Rowland, L, Shields, Y and Lawson, V, 2012. Copper scalping at ValeÆs matte separation plant, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 299-308 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The 3.5 million tones per annum Enterprise mine is the newest underground copper mine at Mount Isa in northern Australia. At a depth of up to 2000 metres, it is the hottest and deepest mine in Australia. In situ rock temperatures sometimes exceed 60¦C requiring the installation of substantial amount of refrigeration to provide safe working conditions for mine workers. The latest refrigeration project at the mine, R67, required the design and installation of the worldÆs largest bulk air cooler and AustraliaÆs largest chilled water plant. The plant is mounted on the surface of the mine and provides 25 MW of refrigeration to cool some 580 kg/sec of ambient air to 11.4¦C. This is equivalent to the production of 6300 tonnes of ice per day. The plant was designed for high availability, as any downtime would result in substantial production losses to MIM, and also had the potential to quickly result in unsafe levels of heat stress within the underground workplaces. The bulk air cooler has been designed for a capacity of 34 MW(R), the expected ultimate carrying capacity of the 7 m vertical intake shaft. Being located well inside the tropics, technical issues such as control of thermal pulldown required special consideration. Also, the bulk air cooler had to be designed to handle whatever demand for fresh air was imposed by the mine below, with over 100 per cent variations in airflow expected, and without loss of thermal efficiency. A substantial program of risk assessment and HAZOP studies was used to protect underground miners from leaks of ammonia into the air or water circuits. Fully automatic control systems result in a totally unmanned plant that is supervised remotely. To improve efficiency, the plant is controlled by the outlet air temperature from the bulk air cooler û the first in the world to be controlled in this fashion. Engineering solutions to address environmental considerations were incorporated at the design stage through features such as the use of ammonia (a greenhouse-friendly gas) as the refrigerant, zero atmospheric discharge and a wastewater collection and re-use system.

Jan 1, 2002

By J Darbritz

"This paper details the events leading up to a slope failure that occurred at Kalgoorlie Consolidated Gold Mines (KCGM) and the remediation method executed using rope access specialists.n January 2016, KCGM Fimiston Pit experienced a double bench wall failure where approximately 80 000 t of material fell from the wall that blocked access to a ramp and caused minor damage to equipment.The event was triggered by heavy rainfall and occurred along unfavourable eastward dipping structures that lead into weaker shale/porphyry bands, which in turn left more material on the face. A remediation plan was formulated that would allow for the continuation of open pit operations while a full geotechnical assessment of the failure area could be conducted. This was accomplished by means of rope access specialists who abseiled down the wall and blasted off the remaining overhang using a portable drill rig and prepackaged explosives.This paper provides a brief overview of the KCGM operations, how the instability was identified and monitored, details of the failure event, outcomes of the geotechnical assessment and details on the remediation work.Citation:Graf, C and Sullivan, R, 2016. The Journey to Steepening the Pit Slope Angle - Advancing the Effectiveness of Wall Control, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 104–114 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By T C. Westerfield, G, M J. Mankosa

An innovative separator known as the HydroFloat cell has been developed specifically for the upgrading of coarse particles that are difficult to recover using conventional flotation cells. The novel characteristic of this separator is the formation of a hindered teeter-bed of fluidised solids into which small air bubbles are injected. The air bubbles selectively attach to hydrophobic particles and form particle/bubble agglomerates that segregate atop the teeter-bed due to their lower apparent specific gravity. The low-density agglomerates are eventually carried into the product overflow launder by the rising current of teeter water. Hydrophilic particles remain in the teeter-bed and are discharged to underflow as a high solids content tailing. Benefits of this hybrid flotation-density separator include enhanced bubble-particle contacting, increased particle residence time, and very low air demand. Test data indicate that significant improvements in the recovery of coarse particles can be achieved using this innovative technology. This article describes the theoretical basis for the development of the HydroFloat cell and provides an overview of recent pilot-scale tests conducted for the phosphate industry.

Jan 1, 2005

By B Beamish

"All underground coal mines in Australia are required to develop a Spontaneous CombustionManagement Plan (SCMP). The New South Wales Government has developed a guideline (MDG1006) to assist operations to comply with this requirement. A reference document is alsosupplied with the guideline that describes the type of information that is needed for input to theplan, including identifying possible tests that can be used for propensity assessment. However,there is no clear indication of what program of sampling and testing is suffi cient to provide adefi nitive assessment of spontaneous combustion propensity prior to and during mining. This paper reviews the existing methods available for quantifying spontaneous combustion propensity and discusses the sampling requirements that are needed from exploration to mining. A new, more defi nitive method of spontaneous combustion testing is also presented that benchmarks coal self-heating performance from mine ambient temperature to thermal runaway. Examples of the eff ectiveness of this new test method for identifying and quantifying reactive pyrite in coal as well as quantifying the diff erence between dry and wet season conditions are provided in the paper."

Jun 1, 2012

By B L. Dickson, E, M F. Lee, P A. Mikula

Computational techniques are needed to assist in the analysis and interpretation of the increasing amounts of geoscientific and mining related data and information that are routinely gathered at mine sites. New interpretation methods are needed to provide an integrated approach so as to establish relationships (cause and effect) or to be predictive about possible outcomes based on acquired data. Traditional multivariate statistical methods are often confused by variable relationships that are non-linear, data distributions that are non-normal, and by the data themselves that may contain missing values, text and both continuous and discontinuous numeric values. Modern data mining methods are available to understand the relationships within and between diverse data sets, and identify relationships or trends associated with processes, measurements and mine design parameters in mines. The self-organizing map (SOM) is a data mining approach with the advantage that all input data samples are represented as vectors in a data-space defined by the observations (variables). The SOM procedure is an exploratory analysis tool that highlights patterns and relationships. Results are internally derived, in an unsupervised fashion based on measures of vector similarity. Our SOM outputs are highly visual, which assists in understanding and illustrating the dataÆs structure and internal relationships. Two studies are presented. The first uses SOM to investigate the relationships between a range of measured and derived rock property parameters and their observed behaviours during mining. Our aim was to determine whether a SOM analysis would allow a better understanding of observed and predicted rock behaviours from their rock properties. The SOM analysis showed that there were indeed relationships between æbrittleÆ, æsugaryÆ, æslabbyÆ and æsqueezingÆ rock behaviours and a number of the input parameters. The computed SOM æstructureÆ was then used to assess the likely behaviour of unknown samples by assigning them into behavioural fields based on their measured and derived geotechnical responses. The second study was aimed at assessing whether a SOM analysis of microseismic data at the Kalgoorlie Consolidated Gold MineÆs (KCGM) Mt Charlotte mine can contribute towards understanding and potentially forecasting/minimising seismicity at the mine-design stage. The database comprised 40 sample æclustersÆ of microseismic parameters from the MS-RAP software package, which were derived from 2500 individual seismic events. The SOM analysis showed that some of the initial mining conditions are related to the seismic parameters. In each of the studies, the SOM procedures assisted in understanding the data and provided new insights. Because of its æordered vector quantisationÆ foundation, the SOM procedure is a substantial improvement over traditional statistical methods in three main areas:its ability to analyse data from disparate sources, including different data types; its ability to analyse sparse data sets with missing values; and its ability to analyse and visualise non-linear relationships within a data set.

Jan 1, 2006

By Shillabeer J

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By Grieveson P, Terry B. S

Carbothermic reduction of sulphide minerals for achieving a selective separation of metallic species from complex minerals has been discussed by considering the prevailing oxygen potential during the course of reaction. Construction of univariant plots for the reduction of sulphides with carbon monoxide gas or carbon and in the presence of either lime or anhydrous calcium sulphate is the key feature of this work. The theoretical calculations for univariants in the Cu-Fe-S-O system indicated a preferential separation of metallic copper and iron by imposing a chemical potential. This is evident from a logarithmic plot of sulphur dioxide partial pressure against reciprocal temperature. The results are compared with empirical data for the reduction equilibrium. The reduction behaviour of the constituent sulphides are also discussed together with the experimental results and theoretically predicted phase stability diagrams.

Jan 1, 1992

By Y K. Leong

Iron ore tailings typically containing 40 to 50 per cent Fe can be beneficiated to iron ore products containing 54 to 60 per cent Fe. The impurities are comprised of clay, quartz, cristabolite and TiO2. Goethite and hematite are also present. At high concentrations of 55–60 wt% solids, the tailings displayed high yield stress and viscosity and cannot be pumped over long distances. Composite additives comprising of NaOH, phosphate-based additives and sodium metasilicate are found to reduce the viscosity and yield stress very significantly by a few orders of magnitude. The yield stress of 100 Pa can be reduced to almost zero. At this state, dilution of the tailings with its process water to 40 per cent solids causes the coarse and high-density iron ore particles to separate from the colloidal fractions located in the supernatant after a few minutes of sedimentation. Separation by decantation produces a sediment with an Fe content of 54 per cent from tailings with 47 per cent Fe. Another tailings sample with 48 per cent Fe was beneficiated to greater than 57 per cent Fe using NaOH-metasilicate-polyphosphate additives and employing an additional washing step. The use of other composite additives, NaOH and polyphosphates, increased beneficiated product Fe content to greater than 60 per cent from the same tailings. With the current iron ore spot price of more than US$180 per tonne, the cost of this treatment process even including a desalination step, if necessary, is relatively insignificant. This study has given tailings an economic value that should be exploited as soon as possible.

Nov 8, 2021

By G DeschOnes, M Fulton

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

Sep 26, 2013

By T Angerer, N H. Maund, S Hagemann, D R. Cowan

Cliffs Natural Resources Pty Ltd - Asia Pacific Iron Ore's (formerly Portman Iron Ore Limited) K deposit (Dowd's Hill), at its Koolyanobbing operation in Western Australia, hosts enriched magnetite mineralisation below the presently mined haematite-goethite ore zone. Two distinct northwest-southeast elongated, highly magnetic anomalous bodies that dip to the north-east appear to be sourced by this deeper mineralisation. Magnetic modelling indicates significant remanent magnetisation with Qratios around 1.5, directed shallow down. The north-west anomaly is overlain by a ridge of uneconomic banded iron formation (BIF) and the present waste dump, whereas the south-east body was partly exposed during ongoing mining of overlying haematite-goethite ore. Sections of the magnetite mineralisation in this south-east anomaly were intersected previously by diamond drill holes. Review of the historic cores identified potential magnetite enrichment, with grades and mineralogy that might be amenable to beneficiation. A first-phase reverse circulation drilling program was designed to further delineate the trend and extent of the two anomalies. The following magnetite mineralisation assemblages are recognised from cores, reverse circulation (RC) drill cuttings and pit mapping of the south-east magnetic body: higher-grade magnetite-haematite ¦ goethite and magnetite ¦ pyrite and lower-grade, recrystallised magnetite-quartz (BIF), magnetite-carbonate, magnetite-talc and minor magnetite-bearing mafic schist. Disseminated specularite is locally present in theassemblages. Talc-schist and massive pyrite occur along the footwall contact. Magnetic susceptibility measured from drill chips within the magnetite-enriched zones reveals an apparent susceptibility values range of 0.2 to 1.3 SI. Preliminary results from Satmagan and Davis tube recovery analysis shows that the magnetite content in these mineralised zones correlate well with existing geophysical data and magnetic susceptibility measurements.

Jan 1, 2009

By M D. Sussman

A large number of countries in the world now have some regulation for labelling the presence of genetically modified organisms (GMO) in food. For the last ten years, ISO/TC 34/SC 16 has been providing methods, guidelines and requirements concerning the evaluation of molecular biomarkers including GMOs. This activity makes sure that stakeholders on all sides of commercial transactions are satisfied and their marketing or regulatory needs are met. Developing and maintaining a transparent, science-based environment for users of horizontal methods for molecular biomarker analysis is a high priority. Sampling and analysis of molecular biomarkers has become critically important for food and agricultural organisations developing, producing, distributing and selling genetically engineered, non-genetically engineered, identity preserved and/or organic crops and their derived products and preventing their respective destructive diseases. To aid in international harmonisation, a new work item proposal to develop an ISO type A management system standard (MSS) for organisations including laboratories using molecular biomarker analysis and sampling has been submitted to ISO/TC 34/SC 16. The purpose of this MSS is ensuring that determination of the presence, absence or quantification of a particular biomarker with a relationship to a product quality determinant, a marketing claim, a regulation or a plant pathogen is carried out under a suitable quality assurance / quality control system. This MSS will provide an overarching system to apply and manage molecular biomarker analysis and sampling for any organisation large, medium or small in a private, government or academic setting.CITATION:Sussman, M D, 2017. ISO/TC 34/SC 16 horizontal methods for molecular biomarker analysis – molecular biomarker analysis and sampling management system, in Proceedings Eighth World Conference on Sampling and Blending , pp 295–302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By T N. Little

The aim of any rock breaking activity is to achieve success by developing designs that are blasting objective-specific and geology-specific, and then implementing such designs. This paper targets mining geologists with the aim of extending their knowledge of the rock fragmentation processes and providing insights to the significant relationships between geology and blasting. There are two main relationships, and if mining geologists appreciate both these relationships, then they can play a key role in optimising production. The business risk continuum is introduced to support this understanding. The first relationship is between geology and potential blasting hazards, and the operational complexity required to manage those risks. The risks associated with eight different ground types are discussed in terms of ground conditions, hazards and controls. These types are: reactive ground, hot ground, geothermal ground, fibrous ground, cavernous ground, combustible ground, pyritic ground and conductive ground.The second relationship is between the bench geology and blasting results. The blasting results discussed include: muckpile characteristics, remaining rock faces and blasting emissions. In this regard, some detailed insights and graphical examples are given for the influence of geology on blasting emissions, in particular, vibration, airblast and flyrock.A detailed description of the geological materials themselves can convey much useful information for blasting operators provided they are able to utilise this knowledge. Geologists are ideally suited to provide this description more effectively if they are familiar with the blasting process and the rock mass properties that influence blasting hazards and blasting results. It is also important to have clear statements of blasting objectives and associated operational targets, and this will maximise the likelihood of achieving the desired outcomes. The main aim of the paper is to highlight that geology is currently not fully utilised in the blasting process. In this regard, geologists are often not entirely aware of the blasting process and how they can contribute. The two significant relationships discussed above are integral parts of this process, and thus they are discussed as separate issues in the main body of this investigation.

Aug 22, 2011

By D Kahler

Modern gold production from the Gympie Goldfield commenced in 1995 with the first production from the Monkland Mine. The primary ore target was the 2.5 m wide Inglewood Fault ore zone, which was initially mined using traditional narrow-vein shrink stoping. This manuallyintensive mining method allowed the mine to re-open with minimal capital cost, however the trade off was low productivity and high operating costs. As the mine has developed, access through 100-year-old, timber-lined, small shafts, and the high cost of delineating reserves, has restricted modernisation of the operations. In early-2000 a stockwork lode was discovered adjacent to the existing workings with an economic width of 40 m. In order to maximise the benefit of such an orebody, mining needed to be approached in a new way. This paper summarises the many changes implemented at the Monkland Mine, including the necessary cultural change, implementing long-hole stoping, de-bottlenecking and the application of mechanisation. The result has been a significant improvement in safety performance, higher productivity and a more secure future for all those involved in the project.

Jan 1, 2002

By R Klepper

Separation of leach residue suspended solids from pregnant liquor solution is an important step in hydrometallurgy flowsheets. Alternative flowsheet options are counter-current decantation (CCD) thickeners or counter current washing (CCW) horizontal belt vacuum filters. Extensive sedimentation and vacuum filtration simulations have been completed by FLSmidth on leach discharge slurries to indentify equipment capacity and performance. These data were used to compare Capex and Opex for CCD versus CCW alternatives. In addition, Capex and Opex for large horizontal belt vacuum filters with filtration areas greater than 250m2 are compared to current state of the art sizes of 150m2. This paper presents this information and discusses various advantages and disadvantages.

Aug 8, 2011