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The JORC Code contains a mandatory classification system for Mineral Resource and Ore Reserve estimates for public reporting. The classification is a statement of the Competent PersonÆs confidence in the estimate and an attempt to convey that confidence to the various users of the resource estimate. In general the classification process is either largely subjective, relying on the Competent PersonÆs experience, or relies on statistical measures derived from the estimation process, or is derived from an estimated level of confidence in the outcome. However, the statistical measures may not necessarily relate to the overall confidence in the resource or reserve which must take account of the confidence in the geological inputs to the estimation.In addition to the traditional deterministic interpretation and estimations adopted by geologists, semi-quantitative techniques are now available to improve the estimation of confidence while continuing to involve the Competent PersonÆs experience in the process. Methods for quantifying confidence in mineral resource estimates for advanced projects and operating mines have also been developed.Classification is undertaken primarily as a communication tool between the estimators and the other stakeholders in the process. A brief examination of the stakeholdersÆ requirements is included.

Sep 26, 2011

By S Tjerry, S Szylkarski, B Willis-Jones, I Dubinski

Achieving relinquishment of mining sites is becoming increasingly difficult, with a study by Byrne (2013) estimating that out of a set of 73 mining and metals sites around the world, less than ten per cent had achieved relinquishment over the last 50 years. The median forecast duration of time allocated for water management in the closure plans studied was approximately ten years, while the reality at the actual sites was a median duration of 22 years to date and growing.One of many challenges in mine closure planning is managing geomorphic stability of stream diversions. The challenge is to be able to demonstrate to regulators and the community that a proposed rehabilitation solution will be stable over the long term.During the mining operations, local watercourses and surface drainage can be diverted and managed using engineered channels and drainage structures. However, during the post-operations stage, the engineered channel and drainage may require modification to a more natural condition that will facilitate long-term environmental sustainability. Achieving geomorphic stability of a diverted watercourse is difficult, with the majority of stream diversions in Australia failing to meet expected design performance (White et al, 2013). Geomorphic stability is a complex process that is controlled by a combination of factors, including hydraulic flow conditions, geotechnical conditions and vegetation.This paper proposes that a fully dynamic and deterministic geomorphological model can be used to supplement the traditional empirical approaches to assess long-term geomorphic stability. The paper provides an overview of the geomorphological models and how they have been applied in engineering studies for forecasting future evolution of stream systems. The paper discusses the potential application of these models in the mining industry for forecasting and optimising surface water structures for the operations and post-operations stages of the mining cycle.CITATION:Szylkarski, S, Willis-Jones, B, Tjerry, S and Dubinski, I, 2016. Improving the reliability of stream diversion designs in mine closure plans using a morphological tool, in Proceedings Life-of-Mine 2016 Conference, pp 212–215 (The Australasian Institute of Mining and Metallurgy: Melbourne)

Jun 28, 2016

By W Mez

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

Jan 1, 1998

By M G. Hawtin

The Rocklands copper project is a multilode, iron oxide copper gold (IOCG) + cobalt mineralised system located in the Eastern Fold Belt of the Mt Isa Inlier. Rocklands orebodies cover a range of oxidation zones from oxide, to supergene and primary. Each zone contains different economic minerals of interest. The supergene zones contain significant amounts of native copper and the primary zones are dominated by chalcopyrite. The juxtaposition of these oxidation zones and minerals make it an interesting mineralisation system.Current mine production sampling collects a nominal 3 kg drill chip sample from a 1 m composite, RC drilled interval. A site specific sampling procedure was needed to quantify introduced sampling error when taking grade control samples. Due to oxidation and mineralogical variation in ore zones we needed to develop a practically achievable sampling methodology that ensures minimum sample mass and sample error requirements are achieved to ensure ‘representative’ samples for all ore types.These issues are planned to be resolved using an experimentally derived method using principles from the Theory of Sampling. This method uses an experimental calibration of parameters K and a for Gy’s fundamental sampling error formula using a modified 32-piece sampling tree experiment to compile sampling nomograms for the primary and supergene ores. This paper demonstrates the process undertaken to improve the quality and standard of existing mine production sampling procedures at the Rocklands operation.Results indicate a sample mass of 5 kg for RC drill chips is appropriate for both the primary and supergene ores to achieve a fundamental error below 0.01 or 10 per cent relative error, which is slightly higher than the existing sampling protocol of 3 kg. An additional experiment is recommended to compile sampling nomograms using the exact laboratory comminution and mass reduction stage information to assess the use of a 3 kg sample. The results also indicate no changes are required to existing sampling protocols when sampling RC drill chips in primary and supergene ore at Rocklands.Sampling nomogram results also provide a useful ‘rule of thumb’ reference guide to other mining and exploration companies to help understand minimum sample mass requirements and sampling error during exploration drilling, resource evaluation and mining production stages when targeting similar IOCG mineralised systems. A sample mass of 5 kg is recommended when RC drilling similarly IOCG mineralised prospects and deposits in the Cloncurry area. Future test work is recommended when additional open cuts become active as well as including resource drilling drill core to provide better three-dimensional sample representivity.CITATION:Hawtin, M G, 2017. Minimum sample mass from reverse circulation grade control drilling at Rocklands copper project, in Proceedings Tenth International Mining Geology Conference 2017, pp 337–346 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Geochemical data on Australian granites and pegmatites, and the mineral components of these rocks, are compared with that obtained in similar studies in the U.S.S.R. and elsewhere.The geochemical character of tin granites and the trace chemistry of their component minerals, particularly biotites, have some significance as ore guides in prospecting for tin.The primary geochemical dispersion of tin can be readily tested both in the laboratory and field by colourimetric methods, after volatilization with ammonium iodide, using modifications of the method described by Wood (1958).Secondary dispersions of tin in residual soils or alluvia can likewise be readly tested by rapid colourimetric methods in the field, but simple hydraulic methods, handling larger sample volumes, give reliable outlines of dispersion patterns.INTRODUCTIONThe search for tin ores, whether lode or placer in type, is usually directed on genetic grounds to country within or adjoining acid intrusives.A long established means of prospecting is to test samples for cassiterite by panning or other hydraulic separation.These methods can be used on crushed lode material or the natural materials from placers.With the advent of new techniques for extraction and for colourimetric analysis for tin (Wood, 1958 and Ross and White, 1961) a means is available for rapid analysis of materials not susceptible to quantitative testing by hydraulic methods because of the fine sizings of cassiterite or the occurrence of tin structurally held in minerals. The new methods thus opened up the field of tin prospecting by extending the search for ore guides to genetically associated rocks and minerals, wall ror-ks of veins and a wider range of superficial deposits.

Jan 1, 1963

The Greymouth Coal field is situated on the West Coast of New Zealand's South Island and has been mined for coal for more than 120 years. The area covered in this paper is within the Rapahoe Sector of this field and contains >200 million tonnes of low ash, low sulphur, bituminous rank coal. Paper No 6, presented to the 19th Annual Conference of the New Zealand Branch of The Australasian Institute of Mining and Metallurgy in Christchurch in August 1985 by R G Bowman, explained 'A Geologist's View' of the 'Economic Potential of the Greymouth Coalfield', and describes previous geological assessments of the Rapahoe Sector.

Jan 1, 1989

By Bowra N

Working capital is best described as money that must be supplied from a company's treasury to buy inventories for raw materials and finished products and to provide credit to customers who have not yet paid for delivered products. Working Capital requirements for resource projects are to a large extent, dependent on specific characteristics of the projects concerned. Important variables are the nature of the project and speed with which sales can be realised. The project's location is also important as this will influence inventory levels. Working capital requirements have a time profile, the present value of which can represent a significant portion of a projects overall capital needs. A significant component of a project's working capital is not readily recoverable or able to be reassigned should the project fail or be deferred.

Jan 1, 1986

Designing for early access to deep orebodies is an essential driver for improved project payback. Vertical shaft sinking techniques have been developed to allow concurrent mine level excavation while continuing to sink. Project cash flows can also be improved when simultaneously deepening existing shafts beneath operating hoisting systems. Further economic advantage has been realised through creative sinking sequencing in twin ventilation/service shaft projects. A fourth technique to reduce project schedules involves partial shaft barrel equipping allowing unrestricted access to construct stations and continue with level installations. This approach reduces interference with barrel sinking activities to insignificant proportions. This paper reviews how these approaches have added significant value to actual shaft sinking projects, as assessed from a contractorÆs perspective, and discusses some of the practical issues to be addressed when planning future projects. Designers need to take cognisance throughout all project engineering phases of the adage that you are only sinking when cleaning the face. Cleaning can only be sustained when there is sufficient hoisting capacity.

Jan 1, 2005

Properties of coal which are significant in relation to preparation for carbonization and conversion are reviewed, and existing coal preparation technology which has been used for production of cleaned coal of suitable ash content and petrographic composition for carbonisation, pyrolysis, hydrogenation and similar processes is described. Possibilities for application of this technology to some Australian coal seams is examined briefly. It is concluded that further survey work is required related to the optimization of selective crushing and concentrating operations, with the aim of maximizing production of quality products for carbonisation, etc mainly from Australian seams with only moderate coking characteristics.

Jan 1, 1980

Mine planning is difficult. Even for small operations, it involves reasoning with complex variables and the practical difficulties of mining. It is also about predicting and planning the future in an unpredictable physical and economic environment. Yet we rely on a handful of individuals and their spreadsheets to tell us how to do it û planning the business and activities of mining to hopefully produce results that will please stakeholders. Does it work? Not as well as it could. Planning affects everyone in the organisation. Company executives are demanding more reliability and stability in cost and revenue forecasts from their operations. Management want to explore ways of being more cost effective. Miners and contractors want more useful plans and realistic targets. And the planners have to describe the method that will translate business objectives into implementable plans. Even with the use of computer technology a lot of effort is expended to produce plans that are largely qualified by the level of knowledge and experience of individuals. Better use of information and the application of Intelligent Technologies can improve the quality and reliability of mine plans and schedules. By capturing the knowledge within the organisation and speeding up the planning process, Intelligent Technologies allow more options to be considered more rigorously. But it is not just about technology. It is about how technology is implemented and embodied in the way the business is managed for performance. When this happens, the real benefits of better planning start to flow.

Jan 1, 2003

By Mez W

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

Jan 1, 1998

By J Deraisme, P Epinoux, O Bertoli

"Société le Nickel exploits the Dôme lateritic nickel orebody at its Tiébaghi operations in New Caledonia. The site geology has an obvious bearing on recovery and metallurgical performance, with controls that are extremely complex at all scales, including lithology, oxydo-reduction conditions, mineralogy and multivariate geochemistry. In this context, establishing an adapted recoverable resource estimation method that is efficient and transparent proves an interesting challenge. The method must address the key notions of: support effect – the exploration data set can only warrant the estimation of large panels of 20 × 20 × 3 m3 that are much larger than the selective mining units (SMUs) of 5 × 5 × 3 m3 information effect – the selection at the production stage uses estimates based on information that is much denser than that available for mine planning.The problem is rendered more complex in this type of deposit by the fact that the additive variables used for the estimation (metal accumulation and ore tonnage) are not the ones used to establish the selection at the mining stage (ie the nickel grade of SMUs, which is the ratio of accumulation on tonnage). Eventually, the selection criteria not only involve Ni grades, but also other elements such as Al2O3, Fe2O3, MgO and SiO2.The solution presented in this paper is to construct an SMU multivariate simulation in the saprolitic horizon and construct an efficient post-processing aimed at producing multivariate recoverable resource estimates. The efficiency constraints imposed by the number of blocks to be simulated (1.5 million) lead to resorting to direct block simulations. The underlying multivariate discrete Gaussian model, which had its validity tested beforehand, is put to good use to mimic the selection process that happens at the mining stage by offering the ability to simulate a composite value located at random within each block.The paper also presents the application of a scenario reduction algorithm to pick a representative subset of a few simulations to help appraise the risk attached to the downstream (reserve optimisation and mine sequencing) phases of the project. The original version of the paper (see Deraisme, Bertoli and Epinoux, 2014) used an early version of the scenario reduction plug-in (named S2RM) built in Isatis® software, where measuring the distance between the initial set of scenarios and the reduced set was based on Ni only. The implementation presented here is for the second generation of S2RM, where measuring the distance between the initial and the reduced set of realisations is based on all study variables. The benefits of the measure adapted to the true multivariate nature of the problem are highlighted in this updated version of the paper.CITATION:Bertoli, O, Deraisme, J and Epinoux, P, 2014. Multivariate block simulations of a lateritic-type nickel deposit and post-processing of a representative subset, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 99–108 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By W Mackinnon

Coal mining operations require the expenditure of appreciable start up and working capital in order to produce saleable coal for domestic or export markets. The competitive nature of the coal business restricts margins, and so it is imperative that downside risks, in terms of production outcomes, are minimised. The major risks identified for a coal mining operation, aside from sales volumes and coal price, are generally thought to be confined to the geology of the deposit and the mining process. However, the impact of product quality and yield can be very significant. If product coal is inferior to projections, then it will need to be sold at a discounted price and this can dramatically impact on margins. Equally, if yield is five to ten per cent less than planned, then this will have a huge effect on profitability. This paper will look at issues relating to in situ moisture and density, resource quality evaluation, modelling of washability and dilution, and simulation techniques, and how best practice approaches can be incorporated into mine planning and feasibility studies. Risks are best modelled and understood by adopting a detailed approach that is fully documented and auditable. This is particularly needed for multi-seam and multi-product operations. Once a well defined systematic approach is established the potential risks can be evaluated by testing different scenarios, carrying out sensitivity analyses, variability modelling and examining extreme operating conditions. These have been discussed in the paper, along with some related issues such as the cost of quick fixes and the value of spending a little more in the coal preparation area.

Jan 1, 2003

By M Swart, H Ståhlbröst, P Toor

Development of SAG liners has always been a strong focus and interest in mineral processing as SAG liners significantly impact on plant performance (throughput and grind size), material costs and plant downtime. SAG shell relines typically determine the frequency and duration of plant shutdowns. Early SAG shell liner designs relied heavily on practical experiences and were limited in their size due to weight restrictions. Significant developments in Discrete Element Method (DEM) modelling, material and manufacturing technologies and larger reline machines have resulted in new and improved liner designs. This paper discusses the evolution of SAG shell liner design and its progression to the Skip Row design. Case studies have been provided for the Skip Row design in a variety of applications such as Single Stage SAG (SSS), SAG and Ball (SAB), SAG and Ball with Crushing (SABC) and Pre-Crush at a variety of mill diameters ranging from 24 foot to 34 foot. A detailed assessment has also been carried out comparing liner service life, ease of reline and performance (throughput, power and grind size) for a large 34 foot SAG mill when compared to the previous design.CITATION:Toor, P, Swart, M and Ståhlbröst, H, 2017. The evolution of SAG shell lining and introduction of the skip row design, in Proceedings MetPlant 2017, pp 158–184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By Norman TE

The design of composite materials for wear resistant service aims at com- bining two or more materials in such a way as to achieve unique and useful properties not generally available in any single homogeneous material. Properties and applications are presented of what might be described as a new generation of wear resistant materials, namely, metallic and part- metallic composites suitable for use in the high abrasion/moderate impact environment encountered in the crushing and screening of ore. Significant cost performance benefit can result from the use of such materials and several specific case histories are discussed. Some promising new developments, utilis- inn white iron and rubber, as yet in the field testing stage, are reviewed. Further comments are offered foreshadow- ing new composite developments, as yet untried but which appear to h,uve merit.

Jan 1, 1978

By G R. Hancock, S Grant, T Whiteside, J B. C Lowry, J Boyden, T J. Coulthard

Physically-based landform evolution models (LEM) provide a spatial framework to forecast the long-term geomorphic stability of post-mining landscapes. When used to test the relative stability of different landform designs, LEMs may assist with the development of optimal closure designs for rehabilitated mines. However, in order to reduce prediction error, factors controlling landscape evolution must also be accurately represented by models. This requires that the correct sets of processes are represented and that driving parameters used in LEMs are, if necessary, calibrated to the landscape of interest.Vegetation exerts strong controls on the hydrologic and geomorphic processes that drive landscape evolution. Hence, the spatial and temporal scales over which typical patterns in vegetation are represented in different landscapes are important considerations in LEM calibration. However, vegetation is rarely accounted for in LEMs and even when integrated is often represented simply, without representing spatial dynamics of vegetation cover that may impact landform development.This study focuses on characterising vegetation patterns to calibrate a new vegetation module of the The Cellular Automaton Evolutionary Slope and River (CAESAR)-Lisflood LEM to be applied to a conceptual rehabilitated landform of the Ranger uranium mine located in the Alligator Rivers Region (ARR) of northern Australia. In the ARR the spatial dynamics of vegetation over time are largely driven by monsoonal rains and topography. Extensive dry season fires are also common in the region, temporarily reducing vegetation cover where they occur. Hence, hydrology, topography and fire disturbance interact to shape a distinct, yet dynamic, mosaic of different vegetation types of varying cover density. As a basis for calibrating the new vegetation function, the distribution and dynamics of vegetation are characterised for this savannah landscape by remote sensing, in conjunction with ground data.CITATION:Boyden, J, Lowry, J, Coulthard, T, Whiteside, T, Hancock, G and Grant, S, 2016. Accounting for vegetation dynamics in landform evolution modelling, in Proceedings Life-of-Mine 2016 Conference , pp 63–66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

THOUGH the literature on the chamber process is considerable, it mostly refers to European conditions. Owing to the demand for acid for flotation and leaching at the mine, it may be necessary to work the process under other conditions. Consequently, some results obtained during the chlorination days at Mount Morgan, within the Tropic of Capricorn, may be useful for reference when working in a similar climate. Though the chambers must be protected against tropical storms, thorough ventilation should be provided, with plenty of space between the chambers, which are almost invariably crowded together. Not only does the space assist in the cooling of the chambers, but it is very desirable during repairs, when lead andtimber have to be hoisted up. The connecting flues between the chambers, which are fairly efficient mixers and condensers, should be round, supported from above, and with the least possible timber about them. Their position and arrangement deserve careful attention. Lattice work will be sufficient protection for the sides of the chambers, and the roof should be high and well ventilated. The Mount Morgan plant, crowded and not well situated, consisted of seven chambers (four over 50 ft. in length), one Glover tower 7 ft. 2 in sq. x 20 ft. high, one Gay Lussac 9 ft. sq. x 30 ft. higb, also one 5 ft. diam. x 25 ft. high. There was one pipe column 4: ft. sq. x 14 ft. 6 in. high. The chambers were run as one unit, and were much lower than those usually constructed in Europe-less than 15 ft. high. Provided that suitable timber can be obtained, 20 ft. is quite low enough. It should be quite satisfactory to use round poles for the studs, and so admit more air space between studs andlead.

Jan 1, 1920

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 G D. Richmond, J C. Chomley

Copper has been mined intermittently at Gunpowder, north of Mount Isa, since 1927. Most ventures have had some initial success but fluctuating copper prices, the small-scale of the operations and the remoteness of the site led to closures or sale. Processing routes have included direct sale of high grade ore, flotation of oxide and sulphide concentrate, and copper cement production from mine solutions. Copper cathode has been produced by heap and in-place leaching coupled with solvent extraction and electrowinning (SX/EW). Aberfoyle Limited recently purchased the Gunpowder operation and is expanding operations. An innovative high recovery tank leaching process, including a low temperature, low pressure autoclave, has been adopted. Copper cathode will be produced from an expanded solvent extraction/electrowinning plant at approximately 45 000 tonnes per year. The combination of expanded throughput and high metal recoveries will make Gunpowder a cost competitive producer.

Jan 1, 1998

By Madgwick J. C, Ralph B. J

A method for the determination of microgram quantities of uranium in leachates from low grade uranium ores is described. Solubilized manium is purified by transfer to an organic solvent by a selective solvent extractionprocedure using tributyl phosphate, iso-octane, and aluminium nitrate. The organic phase is mixed with scintillation fiuors in toluene and the radioactive decay determined in a liquid scintillation counter. The method is sensitive and reproducible in the range 3-30 µg uranium.

Jan 1, 1978