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Cyanide-extractable gold is far more meaningful in the definition of ore, and control of extraction, than fire- assayable or aqua regia digestible gold. The use of cyanide- extractable gold addresses the significant problems of over- as well as under-assaying by fire and aqua regia digests. The problems of conventional control or diagnostic cyanidation extractions: lengthy extraction, and masking by pregrobbing in cyanidation extractions for assay purposes; are surmounted with a novel activator - Leach WELL. Full extraction of liberated gold, insignificantly affected by preg-robbers, can now be achieved within 30 minutes. This can assist in reducing common gold losses presently often hidden by inappropriate mine call factors, and/or high grade cut values. This paper includes a discussion of fundamental mechanisms of cyanidation, preg- and assay-robbing, which underlie the phenomena Involved.

Jan 1, 1992

In order to understand the technique, basic theoretical principles of radiation emission and in- strumentation theory are reviewed. Methods of surveying, reduction of data and interpretation are outlined. Other applications of the technique (e.g. in airborne geological mapping), as well as its specific use in uranium exploration, are discussed. By means of case history-type examples the successful applicant of gamma-ray spectrometry, as a tool in Australian mineral search, is demonstrated.

Jan 1, 1969

By Khosrowshahi S

The objectives of grade control remain unchanged but new methods are being developed to attain them. Since the early-1990s, an improvement in the power of mine site computers has made the geostatistical tools of conditional simulation more accessible. Optimisation of the grade control process on mine sites now involves two stages: optimisation of the sampling regime and optimisation of the interpretation of ore and waste boundaries. Optimisation of the sampling regime first requires an understanding of the nature of the mineralisation and in particular the impact of particle size on the sampling precision. This relationship, termed the Fundamental Error of sampling, enables an optimum subsampling protocol to be defined for the sample preparation and assaying. However, the actual sample collection method, whether drilling or trenching, must be correctly selected and the sampling grid should be optimised. The relative costs and benefits of various alternative sampling methods and grids can be determined using the method discussed. The use of the grade control data can also be optimised. In the past ore and waste boundaries were often defined using a linear interpolation algorithm that smoothed the data (such as polygonal, sectional, inverse distance squared or even kriging methods). Frequently the relative impact of ore loss and dilution could not be estimated. Conditional simulation to generate equiprobable alternative maps (realisations) can now be adopted to address these issues. A transfer function is then used to evaluate the similarities and differences between the maps. The Ore Block Optimisation (OBO¬) process is a transfer function that produces a three-dimensional model of the optimal ore block outlines. This provides a clear guide for the mining geologist to refine and mine. The nature of the transfer function and the inputs and outputs are discussed. In the past, reconciliation has been the `acid test' for any grade control system. Any ore blocking method based on conditional simulation can make use of the exhaustive data set to ensure that reconciliation between prediction and production will improve significantly. The OBO¬ method provides a guide to the mining geologist to ensure that the best ore blocks are mined. Misclassification between ore and waste is reduced, ore loss and dilution are minimised (and are measurable) and ore is optimally assigned to stockpiles of various cut-off grades. These advantages significantly enhance mine profitability and control of the mined grade.

Jan 1, 1997

By R S. Sing, M D. Yadav, G Udaybhanu

This paper presents the results of the first part of a research project to study the effect of various inhibitors to reduce the spontaneous heating susceptibility of some highly susceptible Indian coal seams. In this investigation 11 inhibitors were chosen and applied at three, five and ten per cent of their concentrations in an aqueous solution for four coal samples collected from four different seams. The susceptibility of coal samples, before and after application of these inhibitors, was determined by carrying out crossing point temperature (CPT) analysis. The findings of this study have indicated that it is possible to retard the tendency of spontaneous heating of Indian coals to a considerable extent by the application of six of the inhibitors studied. Further, these inhibitors were tested in 1:1 combination to study their synergistic effect. Finally the economics of the application of these inhibitors has been analysed and four inhibitors are recommended for field use. These results have direct application to control fire and improve productivity and safety in coal mines.

Jan 1, 2005

By T Hausler

The pitfalls, pleasures and management issues associated with international and remote projects are diverse.However, no problem is insurmountable and if an engineering team chooses (by luck or good planning) to push through the difficulties, success can mean an extremely satisfying experience for individuals and a significant, positive result for an organisation.International projects are not for the faint hearted or inflexible. Working in foreign lands with people who may or may not speak English and who may not initially respect you can become mentally and physically tiring.Sometimes the challenges are not fully explained to individuals in advance. Individuals then often learn about the challenges ù and discover solutions ù on the job. While this initially puts great pressure on individuals, matters improve eventually, especially when the locals come to understand that you are on site to make a positive difference.This paper will discuss aspects of a recent international project including meeting international clientsÆ expectations, dealing with cultural differences, social reckoning, environmental issues, and personal challenges. Specifically, it will cover aspects of working within a Russian cultural setting and overcoming social barriers.The paper also presents coping strategies for long periods of time spent away from home in remote places with extremes in weather beyond the normal experience of most Australians. For example, dealing with the effects of the spring thaw and coping with temperature ranges of -45 to +45¦C.Lastly, and possibly most importantly, there will be a focus on the role of translators. They have the power to make an engineer everyoneÆs best friend or, on your behalf, to order cold chicken liver and heart salad for lunch. If an engineering team can establish a working relationship with translators, they can become an invaluable asset and both on and off site.CITATION:Hausler, T, 2013. Achieving success in large-scale, remote area metallurgical plant projects, in Proceedings MetPlant 2013 , pp 539-552 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By M Yahyaei, P Knights, M S. Kizil, J Qu

Digital Twins (DTs) are transforming business operations across many industries through their accurate representations of physical entities enabled by IoT technologies.

Sep 1, 2024

By Sutherland R. A, Rawling K. R

The Nanisivik Mine is located 750 km north of the Arctic Circle at the north end of Baffin Island in the Canadian High Arctic, and has been in production since 1976. The paper describes the regional and local geology and the current mining and mineral processing operations, including recent innovations in each area. The Nanisivik zinc-lead deposits comprise Mississippi Valley type sulphides in a block-faulted sediment sequence of Proterozoic age. The deposits formed in two mineralizing stages by replacement of the carbonate host rock. Exploration techniques adapted to the permafrost environment include high frequency EM and ground probing radar. Core drilling is done with calcium chloride brine but trials with heated flushing water indicate potential for cost reduction. The predominant mining method at Nanisivik is room and pillar. Cut and fill is used in some satellites to the main zone. Due to the permafrost, dry drilling is employed in the underground mining. The permafrost enhances ground stability, permitting large underground openings and, as a result, the use of relatively large scale mining equipment. For power conservation, a remote control system for the ventilation fans has reduced mine power costs. The milling of the simple coarse-grained ore in an arctic environment requires special techniques in the design and operation of the plant for materials handling, utilisation of waste heat, reagent selection and tailings disposal. Regulated heavy metal contents in effluents discharged to the sensitive environment are achieved by natural processes. A recent change from sub-aqueous disposal of tailings to beach type deposition within a cell in the tailings area is reviewed. Planning closure of the property presents special problems and an opportunity for innovative techniques. Approximately 25 per cent of the employees at Nanisivik are drawn from the Inuit population of the Canadian Arctic. As the first permanent industrial activity in the High Arctic some innovative approaches to employee relations were required which have resulted in a very stable, culturally mixed community in a remote location.

Jan 1, 1993

The Elura Orebody consists of a number of parallel, vertically oriented pipe-like structures of pyrite-sphalerite-galena mineralization located at the core of a structural dome. Concentric zoning of the mineralization into an outer Siliceous, intermediate Pyritic and inner Pyrrhotitic Zone has been previously recognized and is used in routine geologic modelling of the lead, zinc and silver grades.Statistical analysis of the metal grade distribution in the orebody has confirmed the importance of the mineralogical zones in the understanding of grade trends. The gradational nature of intra-zone boundaries, especially those related to the subjective definition of the Siliceous Zone, are apparent in the statistics.

Jan 1, 1990

By D Reid

Many of the relevant engineering behaviours of tailings are controlled to a large degree by the density of the material. For example, loose tailings are prone to brittle strength loss, while dense tailings are dilative (i.e. gain strength) at large shear strains. The critical state framework has been successfully developed over the past few decades to assess whether in situ conditions are contractive or dilative, and estimate relevant engineering parameters on that basis. Tailings comprising primarily silt-sized particles, when subaqueously deposited, often form a particularly loose state compared to subaerially deposited material of similar index properties. Such subaqueous deposition occurs in the decant pond area, where the tailings typically pluviate in quiescent conditions within a pond of standing water. Silt tailings deposited in such a manner have been observed to be extremely loose in a number of TSF investigations. Of particular concern, the deposited material in such cases appear to be significantly looser than can be reproduced in the laboratory - even using moist tamping, the sample preparation method which can usually produce the loosest samples possible in laboratory conditions. While the loose density of subaqueously deposited silt tailings is clear, in a well-managed upstream-raised TSF the decant pond is usually small and far from the perimeter embankments, however there are a number of examples where the engineering performance of such materials becomes relevant – for example, when historical deposition practices were poor, resulting in subaqueous deposition near the perimeter embankment. This paper outlines the geotechnical characterisation of a number of such subaqueously-deposited zones, compares the in situ state to that achievable in the laboratory, and discusses options for assessing the expected engineering performance of such materials when comparable laboratory tests are unavailable.

Jul 1, 2021

By C McInnes

The key to successful flotation plant design, production planning and mine/mill optimisation is a solid understanding of the resource to be processed. As advocated by the authors of this paper, the main components of geometallurgical modelling of an orebody and its associated flotation plant are: an ore sampling program and subsequent laboratory testing of these samples in order to extract process model parameters; geostatistical distribution throughout the resource model of the process parameters; calibration of the plant via benchmarking (for existing operations); and plant simulation using a system of process models and the distributed metallurgical parameters (from step two) as the data set.It is important that the grinding and flotation models are linked. For example, a laboratory test conducted on a drill core sample, intended to represent a portion of the orebody, is conducted at a specific grind (represented by a P80). However, when that ore is actually processed through the plant it may well be (and in many cases most likely will be) at another P80. Additionally, the flotation plant residence time will often be determined solely by the grinding circuit capacity and feed slurry density. In the case of SAG mill û ball mill circuits, the fluctuations in tonnage and grind are known to be high. The modelling approach described in this paper allows for changes in the measured flotation kinetic parameters in order to reflect the expected grind as determined by the comminution process.

Jan 1, 2005

By D Cliff

"It has been 17 years since the mine disaster at Moura No 2 Mine in Queensland. Recent disasters in the USA and New Zealand prompt the question what has changed since 1994. This paper att emptsto answer this question and identify areas that need improvement."

Jun 1, 2012

Since the earliest recorded prospecting of the 1860's mineral exploration and mining in Fiordland has been discouraged by the formidable physical difficulties presented by its isolation, extremely rugged relief, treacherous coastal waters and generally unfavourable weather conditions. Government assistance was often sought by the miners and prospectors but little, if any, support or encouragement was received after the initial period. During the 1840's decorative marble was quarried at Caswell and Dusky Sounds. A prospector discovered and attempted to mine copper sulphides to the north of Dusky Sound (Parks Mineral Beds) and near Mt Solitary. A small Pb, Zn, Cu, Ag, Au bearing quartz reef was discovered and driven on in the granite coast line of Preservation Inlet (Bradshaws Reef) and the ore roasted on site. Alluvial and quartz lode gold was discovered at Preservation Inlet in the 1890's and led to the recorded recovery of 11 000 oz of mainly lode gold. Falloff in grades with depth, thinning and splitting of the reefs and the high mining costs at this location led to a virtual abandonment of the field by 1906. In the late 1950's and early 1960's the geology of Fiordland was mapped by the Geological Survey at 1:250 000 scale, but field work was largely confined to the shore lines of the coast and fiords. In view of the physical difficulties it is not surprising that mineral exploration and mining up to 1970 was limited to the scant attention outlined above.

Jan 1, 1977

By Y Tsukurimichi, D Asahina, T Endo, T Takemura

Scientific knowledge of Mars’ surface morphology and internal geological structure has been accumulated through satellite imagery and numerical topographic data using remote sensing technology, as well as seismic surveys by the on-site lander. Recent studies show that Marsquakes could be caused by the release of strain energy generated by the contraction of Mars. In particular, Marsquakes occur around the graben where many faults are existed and formed regularly spaced patterns. This implies that Marsquakes occur when the stress field of the Martian crust is an extension condition, and normal faults appear on the surface. We focus on the linear relationship between the fault spacing and the thickness of the mechanical layer as an approach to studying the internal structure from satellite images. Mechanical layer is a layer that composes of the same mechanical properties and is mainly bounded by lithology (Narr, 1991; Gross, 1993). The linear relationship between the thickness of the mechanical layer and the joint spacing has been studied and its slope is called the Fracture-Spacing Index (FSI) (Narr and Suppe, 1991). Soliva, Benedicto and Maerten (2006) showed that the stress drop zone (stress shadow) due to the fault activities affects the fault spacing. Figure 1 shows the approach used to estimate the thickness of the mechanical layer from the fault spacing on Mars. This paper aims to better understand the internal mechanical structure of Mars estimated by the geometrical pattern of faults on the Martian surface. We report the initial studies of this work. The lab-scale physical experiments and numerical experiments were presented to demonstrate the relationship between the thickness of the mechanical layer and the geometric pattern of fractures

Nov 29, 2022

By Holmes RJ, Sowerby BD, Watt JS

Major improvements have taken place in mineral and coal processing in the last decade. The development of nuclear on-line sensors that continuously analyse the material being processed has led to better control of metalliferous mineral processing and increased recovery of valuable minerals. The recent development of on-line techniques for analysis of coal is expected to be of similar Importance. Australian developments in on-line nuclear gauges are reviewed. These include systems for in-stream analysis of mineral slurries with comments on plant operating experience; on-line determination of ash in coal using low energy Y-ray transmission and pair production techniques; in-stream determination of solids weight fraction and ash content of coal in slurries with variable voidage; and on-line determination of moisture in coal, iron in high grade iron ores and sulphur in lead sinter.

Jan 1, 1986

Nine case studies are presented to illustrate how risks can be, minimised or quantified during pit optimisation, utilising Whittle Four-D software. Each case study covers a specific problem that has been encountered from a wide variety of pit optimisations. Case A: Maximising profits when the tenement owner is paid a royalty on tonnes processed. Case B: Allocating product prices, rather than a single commodity price during optimisation. Case C: Quantifying processing costs that are affected by penalty elements in the ore. Case D: Exploration expenditures below current pits can be quantified through the use of simulation techniques. Case E: Alternative strategies can be quantified when pits are restricted by tenement boundaries. Case F: Relocation of mine infrastructure that requires large capital expenditures, can be simulated by allocating costs to an area during optimisation. Case G: Evaluating alternative corporate strategies during pit optimisation. Case H: Sensitivity analysis for price, processing cost and mining cost. Case I: Quantifying the advantages of using additional mining capacity during the early periods of mining.

Jan 1, 1994

By Davies H, Pigram C, Sunata W, Falvey D, Loxton C, Giddings J, Rogerson R

PALAEOMAGNETIC CONSTRAINTS ON TERRANE TECTONICS IN NEW GUINEA Chris Klootwijkl), John Giddingsl), Wahyu Sunata2), Chris Pigraml), Charles Loxton3), Hugh Daviesl), Rick Rogerson3) and David Falveyl) 1) Bureau of Mineral Resources, Canberra, Australia 2) Geological Research and Development Centre, Bandung, Indonesia 3) Geological Survey of Papua New Guinea, Port Moresby, Papua New Guinea

Jan 1, 1987

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 A Grace, C Sennersten, A Davie, R Lyu, C A. Lindley, O Goldstein, T Thomas, L De Macedo Camargo

Block modelling is a well-established method for modelling ore reserves as a basis for strategic mine planning and mine development. Off-Earth mining, particularly of asteroids, can benefit from block models; however, the significantly different characteristics of asteroids and their methods of mining require reconsideration of the geometry and annotations of block models. Terrestrial block models consist of rectangular prisms within Euclidean coordinate systems. Their labels and parameters typically include location within a mine-specific coordinate system, x, y and z dimensions, specific gravity, hardness, grades of metals of interest and so on.These data provide an input to mine design and strategic mine planning. Mining asteroids may require different coordinate systems (eg spherical, elliptical or cylindrical, rather that Euclidean) and attributes that vary from Earth-based block models. These include: variable gravitational vectors throughout the block modelrotational moment or accelerationrotation rates. Materials within asteroids may show different isotopic compositions. Asteroid mining has the unique characteristic of a mine being identical with an asteroid. The position of the asteroid/mine in space and its full orbital elements provide critical inputs to mission design and costing. Hence, the block model concept needs to be extended with this metadata. The orbital position and behaviour of the Earth must be included for active mine planning, and increasing automation of mine planning and operations needs to consider terrestrial weather and telecommunications infrastructure. Financial planning requires analysis of the net present value of extraterrestrial mining compared with terrestrial alternatives, so a fully automated mining enterprise should integrate terrestrial and extraterrestrial block models at different scales and resolutions. Blocks can be indexed via octrees, allowing for hierarchical scales that support analytics for deriving new knowledge and correlating features across different scales.CITATION:Lindley, C A, Sennersten, C, Davie, A, Goldstein, O, Lyu, R, Grace, A, Evans, B, Pentecost, D, Thomas, T, De Macedo Camargo, L, Craig, J, Salomao, G N, Hellicar, A, Biggins, D, Timms, G, Coombe, M, Shahriar, M S, Smith, G and Rahman, A, 2015. A multilayer 3D index tool for recursive block models supporting terrestrial and extraterrestrial mine planning, in Proceedings Third International Future Mining Conference, pp 289–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M W. N Buxton, M S. Shishvan, J Benndorf

The flow of information, and consequently the decision-making along the chain of mining from exploration to beneficiation, typically occurs in a discontinuous fashion over long timespans. In addition, due to the uncertain nature of the knowledge about deposits and the inherent spatial distribution of material characteristics, actual production performance in terms of produced ore grades and quantity and extraction process efficiency often deviate from expectations. Reconciliation exercises to adjust mineral reserve models and planning assumptions are performed with timely lags of weeks, months or even years.With the development of modern information and communication technology over the last decade, a flood of data about different aspects of the production process is available in a real-time manner. For example, sensor technology enables online characterisation of geochemical, mineralogical and physical material characteristics on conveyor belts or at working faces. The ability to utilise this additional information and feed it back into reserve block models and planning assumptions opens up new opportunities to continuously control the decisions made in production planning to increase resource recovery and process efficiency. This leads to a change in paradigm from a discontinuous method to near real-time reserve reconciliation and model updating, which calls for suitable modelling and optimisation methodologies to quantify prior knowledge in the reserve model, process and integrate information from different sensor sources, back propagate the gain in information into reserve models and efficiently optimise operational decisions in real-time.This paper introduces the concept of an integrated closed-loop framework for real-time reserve management, incorporating sensor-based material characterisation, geostatistical modelling under uncertainty, modern data assimilation methods for sequential model updating and mining system simulation and optimisation. The effectiveness of the framework and the value added will be demonstrated in an illustrative case study.CITATION:Benndorf, J, Buxton, M W N and Shishvan, M S, 2014. Sensor-based real-time resource model reconciliation for improved mine production control – a conceptual framework, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 223–234 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By B Ellis

Brunswick Mine is one of the largest underground zinc/lead mines in Canada, producing 3.4 million tones of ore annually. As mining activities advance to deeper levels, ground pressure also becomes greater. To cope with the highly stressed ground, the mine has taken some strategic measures to ensure the targeted production level. Such measures include the implementation of a pastefill system and transferring the mining method from primary/secondary stoping to pillarless pyramid stoping. With the pillarless mining method, stope sizes become smaller and the number of active stopes is also less than before. In addition, mining sequence and cycle time have to be strictly followed according to production schedule. The blasting project described in this paper tackles one of the steps in the mining cycle aimed at shortening the blasting cycle time in a stope. Furthermore, this project was conducted and managed with the Six Sigma initiative in Noranda which was implemented in the fall of 1999. Like a typical process review, the blasting operation was examined by breaking it down into many steps that can be quantified and measured. Each activity was then correlated with different factors associated with blast design as well as blast operations underground. It was found that the utilisation of voids plays a key role in the blasting cycle time. With improved void utilisation ratio, blasting cycle time has been reduced from an average of 12 shifts to ten shifts per stope. This improvement translates into approximately 180 000 tonnes of ore being blasted without any increase in manpower. This paper presents the technical aspects of the study, as well as some operational issues and improvements made during the project.

Jan 1, 2001