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Gold occurs at Mt. Charlotte associated with a stockwork of pyritised quartz veins in Unit 8 of the Golden Mile Dolerite. The ore- body is massive, 200m long and 40m wide and has been proved to over 600m below surface. Mining is by sublevel ring drill stoping with the ore recovered by diesel powered equipment. Ore reserves are based on traverses of diamond drill holes oriented to produce an equal intersection width on the two principal sets of quartz veins. Assay and geological boundaries are marked on each drill section and this boundary is transferred to mine plans and cross sections. Ring-drilling patterns are based on the cross sections and the resulting mining outline is transferred back to the drilling sections. The mine ore reserve is calculated from the mining outline.

Jan 1, 1979

By A S. Venkatesh, A Das

The Precambrian iron ore of Singhbhum-North Orissa region of eastern India occurs as part of the horseshoe-shaped broad synclinorium known as the Iron Ore Group (IOG) of rocks, which hosts the most important iron ore deposits in India. The Jilling-Langalota iron ore deposits are part of the IOG. Detailed mineralogical characterisation of different ore types has been carried out using transmitted and reflected light microscopy. Scanning electron microscope-energy dispersive spectroscopy (SEM- EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) have also been used with a view to test the amenability of these ore types for beneficiation requirements. It has been observed that haematite, martite and goethite are the main iron-bearing minerals. Kaolinite and quartz are the major gangue mineral phases. Considerable mineralogical, textural and compositional variations have been observed among the different ore types. Characterisation data reveals that the massive and hard-laminated ores are of higher grade with very few interlocking textures having haematite and martite as major mineral constitutents. The soft-laminated lateritic and friable ores are relatively low-grade varieties containing various proportions of impurities with complex interlocking textures. The soft-laminated and lateritic ores are porous in nature and contain friable oxide and hydroxides of iron along with kaolinite, gibbsite and quartz. The occurrence of kaolinite, gibbsite and hydrated oxides along the cavities and weaker mineral planes of haematite and martite has been observed. The friable nature and high alumina content of these ores are attributed to these secondary phases. The nature of these ores is responsible for producing large amounts of alumina-rich slime during mining and handling operations. Suitable beneficiation schemes have been recommended for each type based on detailed characterisation investigations on these ores.

Jan 1, 2007

The implementation, during recent years, of the concept of distributing chilled water to improve cooling at the working faces represents a very important innovation for the mining world. In a logical extension to that concept it has been recognized that distribution of the cooling water at high pressure would provide a potential source of energy for driving water powered hydraulic machinery such as rockdrills, water jets for moving rock, and support props, in the workings. With this in mind, the Research Organization of the Chamber of Mines of South Africa is pursuing the development of such a dual system that will provide cooling in a deep mine and, at the same time, drive hydraulic machinery. A comprehensive design of such a system has been completed and has shown the concept to be entirely feasible technically using technologies currently available. A pilot system is working in a mine shaft 2000 m deep giving a pressure of 20 MPa at the bottom of the shaft and distributing the cold water into the workings at a pressure of 17 MPa. The system shows considerable potential for improving existing mining methods and will open the way for the development of new mining methods for deep mining operations.

Jan 1, 1986

Three major and two minor uranium deposits 'have been worked by open out mining since the discovery of ,the Rum Jungle field in 1949. Total production has been about 9679000 tons of uranium ore at 7;39 lb U308/ton and 4029000 tons of copper-uranium ore at 6.27 lb U308/ton and 2.7% Cu, with significant tonnages of base'metal ores. The deposits occur in or near black pyritic slates of the Lower Proterozoic Golden Dyke Formation, near the contact with the under- lying Coomalie Dolomite. The mineralization is probably younger than the grahite complexes in the area, and a structural-stratigraphic control of ore deposition is used as a basis for uranium exploration.\

Jan 1, 1968

By McClarnon D. J

This paper aims to provide the reader with an insight into the field of computer graphics and Virtual Reality (VR), and show how both have been applied to the general area of Free Steered Vehicle (FSV) operations underground. It first explains this developing computer technology and explains its advantages over existing CAD based solutions. This paper deals with the graphical applications and implications of building models within a computer's memory. It then continues to describe the problems with Free Steered Vehicle operations. The work already carried out in the field of VR is explained, and the production of a VR system addressing the problems with fitting cameras to aid the driver's field of view is detailed. Another possible use of VR is also explained - the concept of risk regions, demonstrating its uses in the examination of proposed operational methods. Examples of possible uses are given, and its potential advantages over existing methods discussed. A case study of a computer-generated video involved with the safety of operations of FSVs is also presented. This addresses the precautions that pedestrians should take to ensure safe working in areas where FSVs are operating. This paper then concludes with possible further applications for computer graphics and VR, and the on-going research into these two technologies.

Jan 1, 1995

By Zhou A, Cadogan J. M

Direct reduction of iron ore (DR) is one of the promising technology emerging in the world's steel industry. Kinetics and Mossbauer studies of DR with hydrogen have been carried out at two temperatures of 600¦C and 800¦C in this investigation. The results show that different controlling steps govern the reduction rate at different temperatures. The mechanism was also found to vary during the reduction. The Mossbauer spectra of the samples reduced in various time intervals were studied to determine the phase changes during reduction.

Jan 1, 1997

By P Pelletier, J Tessier, C Duchesne

This paper summarises research into the study of the control of flotation processes based on froth images. A review of the froth flotation operation background and the relevance and role of the froth phase are presented. The use of numerical image analysis techniques for the extraction of significant patterns from industrial flotation froths is discussed. First, the froth was analysed by the use of the multivariate image analysis (MIA) method to extract the spectral variation contained in a RBG image. The partial least squares (PLS) method was applied to develop an empirical model for the prediction of froth grade. The results of this application are illustrated using an industrial case study. Second, the froth was also analysed by grey-level co-occurrence matrix (GLCM) and wavelet transform analysis (WTA) to extract features related more to morphological aspects. Since there is useful information hidden in froth texture, these methods are used as texture descriptor to classify different types of froths. They also provide qualitative information on the changes in the visual appearance of the froth. The pros and the cons of those methods are highlighted. Third, a control strategy based on a froth structure indicator was developed and implemented on an industrial zinc flotation circuit. The feedback controller uses the reagent flow-rate in order to maintain the froth structure at its set point. Process improvements obtained from the implemented control strategy are highlighted. Finally, the feasibility of implementing a hybrid control strategy consisting in a froth structure supervision controller based on the froth concentrate grade estimated by MIA and recovery inferred by image analysis is discussed.

Jan 1, 2005

By P A. Dowd

This paper describes an integrated approach to the evaluation of ore loss and ore dilution via geostatistical simulation of in situ geology and grade characteristics, simulation of blasting mechanisms and simulation of loading from a blast muck pile. The approach is demonstrated on a case study. The sequential Gaussian method is used to simulate in situ bench grades on the scale of the smallest selectable volume within a blast muck pile. The simulated grades of these component volumes are interpreted as the reality that would be available with exhaustive sampling. The simulated bench is subjected to a blast simulator, based on the SCRAMBLE model, which effectively moves each of the component model volumes to its final resting place in the blast muck pile. Ore/waste delineation and selective loading processes are applied to the simulated muck pile to determine the degree of selectivity that can be achieved by various sizes of loader and types of loading and to quantify ore dilution and ore loss. An in situ model representing the reality of knowing only the data and information that are available from specific grade control drilling and sampling grids is obtained by sampling the geostatistically simulated model on a specified grid. The volumes comprising the in situ model are then populated by estimates based only on the data and from the specified grade control drilling and sampling grids. Different drilling and sampling grids are used to generate different models, each reflecting the levels of data and information available. Selectivity is assessed as a function of the drilling and sampling grids as well as the size and type of loader. Performance is assessed against the ideal selectivity that could be achieved on the perfect knowledge model comprising the simulated values of each component volume. Costs, prices and financial criteria enable an optimal selection of the grade control drilling grid, size of loader, type of loading and blast design.

Jan 1, 2004

By N TassT, J Cyr

At the East Sullivan site, wood wastes covering the abandoned mine tailings impoundment prevent sulfide oxidation by creating an anoxic environment. The addition of coarse ligneous wastes and their high permeability favour infiltration, resulting in a water table rise that maintains most tailings under water saturation and thus provides an additional protection against sulfide oxidation. Moreover, high infiltration allows a more rapid flushing of acid prone groundwater generated prior to the cover placement, which could cause acid mine drainage over a long period of time. Finally, the pore-waters under the cover are characterised by a strong reducing potential, high alkalinity, and near neutral pHs. These conditions favour sulfate reduction and base metal precipitation as sulfides and as carbonates. Pore-water composition monitored from 1992 to 1998 showed a significant Fe2+ decrease, following cover placement. Thereafter, the restoration strategy capitalised on the alkaline and reductive properties of the waters underlying the wood-waste cover. An original treatment of acid effluents, based on the recirculation of water discharging around the impoundment through the organic cover, was implemented. In 2002, the recirculated water from May to October had a mean pumping rate of 240 m3/h, for a total volume of 800 000 m3. Data gathered near the dispersal zone from 2000 to 2002 show that despite the recirculation of acid water (pH ÿ3), the pH decreases by only one unit from 7 to 6, during the recirculation period, ie from May to November. However, alkalinity decreases from 800 to 100 mg/L-CaCO3. Despite this decrease, the alkalinity is back up to 800 mg/L-CaCO3 the following May, thanks to sulfate reduction. From 2000 to 2002, Fe2+ concentration in the pore waters near the dispersal zone is maintained below 2 mg/L. Evolution of surface water quality suggests that the contaminated groundwater flush is completed in the north and north-west area of the impoundment; the east sector is under recovery, while the south sector remains the most problematic. A wood-waste cover, besides limiting sulfide oxidation, can fill the role of alkaline reducing barrier for the treatment of these acidogenic waters, until a balance between acidity and alkalinity in the effluent is reached.

Jan 1, 2003

By Brent A. D, Olsen a. H, Mayfield P. L J, Grazier P. E

Concentrates produced from MnO2 and Fe203 ore fines have been targeted as potential feedstocks for direct metallurgical processing. Prereduction of pyrolusite-rich Mn02 sands to MnO has been investigated in batch and continuous experimental bubbling fluidised beds using CO-H2 reducing gas mixtures. This process has been found to produce a high grade feedstock suitable for smelting to ferroalloys or acid digestion for chemicals production. Similarly, production of highly metallised direct reduced iron (DRI) from hematite ore fines has also been investigated in batch bubbling bed reactors. Programs to characterise the reduction kinetics, fluidisation behaviour and defluidisation phenomena for both feedstocks are currently in progress to enable optimum process conditions to be determined.

Jan 1, 1995

By Jia X

Three-dimensional microscopic modelling techniques involving specific calculations based on direct computation of the Brownian, van der Waals, Born, electrical double layer repulsion, bulk, hydrodynamic and external forces (gravity, magnetic etc) acting on and between each particle in a mineral dispersion are now feasible using advanced computer processor architectures. This contribution surveys the hardware requirements, the advantages and limitations of the approach for enabling prediction of dispersion behaviour a priori. The notion of developing a generic particle simulator, akin to the use of molecular modelling in the area of drug design, based on inputting process-relevant data (solution chemistry, mineral solids properties, hydrodynamics etc) is discussed. The methodology is illustrated with application examples involving: predictions of coagulation of mineral fines; shape and size of magnetically-flocculated hematite; and the kinetics of fouling of membrane surfaces and walls.

Jan 1, 1993

By J Chen

Research conducted into backfill drainage at Mount Isa Mines since 1992 is described. Piping in draining backfilled stopes has been the primary cause of bulkhead failures and emphasis is placed on research into the piping mechanism. Laboratory and in situ tests aimed at understanding the piping mechanism have been conducted and the results are presented. A case history of piping in a draining bench stope fill mass is described and a technique for reducing the potential for bulkhead failures in bench stopes is presented. Hydraulic fill is produced by standard cycloning of tailings and the overflow (reject material) is sent to thickeners prior to placement in the tailings dams. Research into the partial introduction of thickener underflow into the backfill system and its influence on backfill drainage is also described.

Jan 1, 1998

By I H. Jung, W O. Choe

Gallium (Ga)-containing compounds such as Gallium Arsenide (GaAs) and Gallium Nitride (GaN) are widely used in electronic devices due to their superior electro-optical properties and their usages increase rapidly. For the sustainable supply of Ga to electronic industry, therefore, the recycling of Gallium becomes essential. Pyrometallurgical Ga recycling process involves the complex chemical reactions between slag, matte, liquid metal, gas, refractories, etc. Therefore, the accurate thermodynamic information and phase diagram data for the oxide system containing Ga2O3 is important. In the present study, new phase diagram experiments for binary SiO2-Ga2O3 and ternary CaO-SiO2-Ga2O3 system are carried out using Differential Thermal Analysis (DTA) and quenching experiments followed by Electron Probe Micro-Analyser (EPMA) and X-Ray Diffraction (XRD) phase analysis. Based on new phase diagram data and available literature data, the thermodynamic modelling of the entire CaO-SiO2-Ga2O3 system is performed for the first time.

Jun 19, 2024

By B McFadyen, Y Potvin, K Woodward

The Australian Centre for Geomechanics (ACG) held two workshops in 2019—one in Australia and one in Canada—to discuss processes and methods currently used in the mining industry for stope design and reconciliation. In practice, this work strives to optimise stope performance and aims to maximise ore recovery (minimise underbreak), while minimising dilution (overbreak). One of the key findings from the workshops was that current stope design practices, almost exclusively, rely on some versions of the empirical Stability Graph methods developed in 1980s. Although robust and useful at the feasibility study stage, there are a number of inherent shortcomings with this approach. The Stability Graph’s limitations first lie in that it cannot assess underbreak, which is a very important measure of performance. Furthermore, the method doesn’t consider a number of factors which often have a critical influence on stope stability, for example, drilling and blasting or the presence of faults. Given the current industry standard practice, there is a great opportunity to reinvent the stope design process to optimise performance. A finding of the workshops was that every mine quantifies stope performance in terms of volume reconciliation with a focus on dilution and ore losses, and reconciling metal tonnes recovered from the mill. Many mines further investigate stope performance by looking at individual stope faces and the causes for the deviations between the planned stope shape and the measured cavity. Recent research at the ACG has shown that investigating overbreak and underbreak at a higher resolution is a powerful way to identify the root causes of overbreak and underbreak. Finer scale assessment is achieved using an octree analyses, which effectively divides the relevant stope volume into cubes on the scale of a metre and produces many tens of thousands of data points. The octree data structure and subsequent analysis underpins a data-driven stope design methodology. The ACG is currently developing a design approach based on multivariate modelling methods that can account for the many variables that influence stope performance and forecast stope overbreak and underbreak results. Back-analysing stopes based on octree reconciliation results provides a rich database for training the model. Once the model can achieve reliable forecasting of overbreak and underbreak, an interactive drill-and-blast design will allow for the assessment of different firing strategies to optimise stope performance.

Mar 15, 2021

By A Yame, P J. Pollard, E Atase, J Garu, M Tangwari, D R. Hastings, R W. Smillie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Townsville prospect is situated approximately 4 km north of the Ok Tedi copper-gold mine in Western Province, Papua New Guinea. Drilling in the 1990s delineated a resource of >1 Moz of gold within shallow, skarn breccia-hosted mineralisation associated with quartz-carbonate infill, together with pyrite, chalcopyrite, pyrrhotite, sphalerite, galena, tennantite-tetrahedrite, arsenopyrite, marcasite, and a variety of Au-, Ag- and Bi-telluride minerals. The deepest of these historical holes (TVL034) also intersected copper-gold-silver mineralisation more than 100 m below the gold-rich zone that is associated with calc-silicate skarn breccia. Although copper-gold-silver mineralisation in DDHTVL034 is associated with clinopyroxene-rich skarn, it was also noted that garnet in the skarn breccia became progressively darker in colour with depth, ranging from green at shallow levels to dark red-brown at depth. This indicated that the skarn breccia is zoned, with more proximal garnet skarn at depth possibly indicating an association with porphyry-style copper-gold mineralisation.Based on this skarn zonation model, recent drilling at the Titan prospect, located approximately 500 m south of TVL034, was targeted at potential copper-gold silver mineralisation beneath shallow skarn breccia-hosted gold mineralisation. DDHTVL 081 intersected 46 m at 6.36 g/t Au from 68 m and 80.7 m and 1.67 per cent Cu, 1.27 g/t Au and 20.32 g/t Ag from 184 m. Exploration is now attempting to define the extent of copper-gold-silver mineralisation by defining structural controls on the skarn breccia together with paragenetic and mineral zoning data.CITATION:Smillie, R W, Pollard, P J, Hastings, D R, Yame, A, Tangwari, M, Garu, J and Atase, E, 2015. Exploration of the Townsville Cu-Au-Ag skarn, western province, Papua New Guinea – preliminary observations of paragenesis and zoning, in Proceedings PACRIM 2015 Congress, pp 593–600 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

The AJ Parker Cooperative Research Centre for Hydrometallurgy is the focus of a world-class effort in providing technical solutions to the minerals industry. The 85 FTE staff are drawn from the CentreÆs five joint venture research partners comprising universities (Curtin, Murdoch and Qld) and government research agencies (CSIRO and WA Dept of Industry and Resources). There are also 12 industry partners, representing most of the leading mining companies in the world. Around 45 postgraduate students, mainly PhDs, make a significant contribution to the research effort. Total annual expenditure on R&D is around $17 million.Hydrometallurgy activities encompass both fundamental and applied research across the alumina, gold and base metal sectors. The Centre is now growing its client base into overseas markets, particularly North America, South Africa and Europe. Quality, strategic R&D by the Parker Centre is seen by the industry as an attractive investment. A recent survey of the industry revealed an estimated ten-fold return based on direct costs of research to the client. In addition, the Parker Centre has a strong commitment to education of postgraduate students wishing to enter the mining industry as well as providing specialist courses for those technical professionals already employed in the industry. The wide range of employment opportunities in the mining industry is reflected in the diversity of the disciplines amongst the CentreÆs research team, eg extractive metallurgy, chemistry, biotechnology, physics, engineering, molecular modelling, microscopy, geology and computational fluid dynamics. How does an atomic force microscope and molecular modelling improve our ability to control gypsum scaling or understand crystallisation of alumina in a Bayer plant? Can a biologist contribute to the problem of the slow leaching of copper from chalcopyrite? Why are computational fluid dynamics and lasers the basis of understanding how to make thickeners work more efficiently. Can you combine a PhD or Honours degree with industry experience? What is crud and why is nickel stressed? These are typical examples of the CentreÆs research activities and demonstrate the contributions of its multi-disciplinary teams which keep the Australian mining industry at the cutting edge of advanced global technology.

Jan 1, 2003

Cominco Ltd's Polaris Mine in Canada's High Arctic has been successfully mining zinc ore in permafrost since 1981. Mining methods using frozen backfill have been the key to success. The mine is now producing about 60 per cent of the ore from pillars while maintaining high productivities. Annual ore production is just over one million tonnes providing more than 200 000 tonnes of zinc concentrate each year. Cominco Ltd has adapted management and operating practices to suit the harsh environment and the isolated site, and has shown that a profitable development can be carried out in the tough Arctic conditions, with minimum impact on the environment.

Jan 1, 1993

The mineral pulp as it passes through grinding-classification, flotation and solid-liquid separation is examined in the context of it being a particulate fluid. By focussing on the complex viscosity and yield stress of the fluid, new control strategies are discussed. The mineral-particulate fluid is dominatred by non-Newtonian rheology (ie shear thinning, shear thickening, shear yield stress and compressive yield strength). The control of this Theology is seen to be dependent on the fundamental practice-particle interaction forces and with adequate information, it is possible to use the complex shear properties to advantage. The advantages, in terms of final waste and concentrate management, to high weight per cent solids in the mineral particulate fluid, are explored and control strategies outlined.

Jan 1, 1993

The purpose of this work is to determine the equilibrium-state of the aqueous-solution which is produced by the leaching processes, including natural weathering of pyrite minerals. The latter can lead to acid-mine-drainage (AMD). The ferric iron species (Fe3+) resulting from bacteria-catalysed oxidation of ferrous iron (Fe2+), in the presence of water and air, is known to bring about steady-dissolution of minerals chalcopyrite (CuFeS2), sphalerite (ZnS), pyrite (FeS2), and so forth. Good-aeration, relatively high-porosity and sufficient bacterial activity tend to promote leaching in waste-rock-dumps. The composition of the aqueous-phase that accumulates in the pore-space (or in open-pits) is of practical interest as it would strongly influence the leaching of both sulfide and non-sulfide minerals. Since the reactions among the various ionic species occur relatively fast, the solution-phase may be regarded as approaching a state of virtual-equilibrium and it is possible to determine by computation the respective concentrations of the many dissolved species. For the Cu-Fe-H-O-S system, these species may include: H+, Fe2+, Fe3+, Cu2+, HSO4-, SO42-, OH-, CuSO4o, H2O, Fe(OH)+, Fe(OH)2+, Fe(OH)2+, Fe2(OH)24+, Fe(SO4)+, Fe(HSO4)+, Fe(HSO4)2+, and Fe(SO4)2-. The aqueous-system which may be constituted from appropriate mole-quantities of H2SO4, FeSO4, Fe2(SO4)3, and CuSO4 is in fact the result of various natural processes (reactions) and due respect must be accorded to the extents of these reactions. The present model computes the equilibrium molalities of the foregoing ionic and neutral aqueous species, using the iterative equilibrium constant method that ensures strict-adherence to charge-balance and elemental molar-balance constraints. The dissolving sulfide-minerals (FeS2, CuFeS2) consume Fe2(SO4)3, H2O, and O2 and yield FeSO4, H2SO4, and CuSO4 while the aqueous-phase tends to become progressively acidic (declining pH) reflecting the gradual increase in the extents of sulfide-dissolution reactions. The equilibrium-state of the solution-phase is computed for specific set of values for the extents of respective reactions. The temperature and pressure of the system are 25¦ C (298.15 K) and 101.325 kPa (1.0 atm), respectively. The mica-like minerals such as the biotite [H2K(Mg,Fe)3Al(SiO4)3] tend to consume much of the H2SO4(aq), with the extracted K+, Mg2+, Fe2+ and Al3+ ionic species accumulating in the solution. The precipitation of the jarosites (potassium, hydronium, or ammonium) contributes to the removal of ferric and ferrous species from the solution-phase. In the present work, the emphasis is on predicting the compositions of the aqueous- and condensed-phases with advancing time or increasing æextent of reactionÆ. The results of such calculations are compared to published data on raw AMD (acid-mine-drainage).

Jan 1, 2008

By Shrivastava P

The iron orebodies of the Pilbara region are formed by supergene enrichment of banded iron formation and rarely do such processes produce orebodies with uniform grade distrib- utions. The orebodies being mined or developed have to be worked to grade/quality constraints imposed by contractual agreement rather than natural characteristics. Hence it is imperative to use a non-biased ore reserve calculation method. The geostatistical study of a typical iron orebody is presented. Emphasised are the geological characteristics of the orebody manifested as a variable grade distribution of iron and impurities; the determination of variogram model; subsequent uses of the model for computation of ore reserves and kriged lock estimates; computation of dispersion variance and conditional simulation of orebody.

Jan 1, 1977