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The region we call the West Coast is acknowledged as one of the richest and most diverse mineral provinces in the world. It's the most rugged part of Tasmania and our island is one of the most rugged parts of Australia, so that speaks for itself. A hostile land of razorback mountains, deep ravines, dangerous rivers, almost impenetrable rainforests and a climate that can change from mild to freezing in a matter of hours.

Jan 1, 1993

By M Lee, J F. Carswell, G Reitsema

"The increased costs of underground mining have continually challenged engineers to identify opportunities for alternatives to common approaches to underground development. Considerations to the design of horizontal and vertical development at the Dugald River mine targeted inclined raise boring to reduce horizontal development, not only to reduce cost, but to allow development activities to focus on other areas of the mine.The mine plan consists of 50 raise bored ventilation shafts, of which 17 have been mined to date with diameters ranging from 3.1 m to 5 m and lengths from 30 m to 200 m. The expected performance and stability of these shafts has been determined using methodologies proposed by McCracken and Stacey (1989) and further refined by Peck, Coombes and Lee (2011). Actual raise performances have been collated and compared to a database of raise bore performances across Australia as presented by Coombes, Lee and Peck (2011), and form a database of raise bore performance specific to Dugald River.Opportunities to further optimise the mine plan and reduce costs have seen the introduction of large diameter-inclined raise bored ventilation shafts to minimise the required lateral development to connect the ventilation circuits. Large diameter inclined shafts ranging between 3.1 m and 4.5 m in diameter have been successfully mined with dips down to 70°, reducing the cost of lateral development by more than $1 million over the next two years.Both technical and operational challenges were overcome in the mining of large diameter-inclined raise bores, including modification of: existing methodologies of assessing shaft wall stability for inclined raises. These included variations of the McCracken and Stacey method and the utilisation of the modified stability number (N’) previously developed for stope performance (Potvin, 1988). both the collar and toe development profiles, including the general set-up of the raise bore drill rig to reduce the operational risks associated with angled raises.Due to their success, inclined raises have been designed for subsequent stages of the life-of-mine ventilation system at Dugald River. This has resulted in significant capital cost savings for the mine.CITATION:Carswell, J F, Reitsema, G and Lee, M, 2017. Vertical and inclined raise bore performance at Dugald River mine, in Proceedings 13th AusIMM Underground Operators’ Conference 2017, pp 313–320 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 16, 2017

By D Cliff, K Bailey

Traditionally occupational health and safety (OH&S) has been managed for the direct benefits of reducing injury and illness to workers on mine sites. In the current skill shortage climate it is important to recognise the value that OH&S management can have in assisting mines in minimising their exposure to this issue. In times of skills shortage turnover is high as mines poach personnel from each other. This leads to loss of corporate knowledge and loss in productivity through the need to train new personnel in mine-specific operating procedures. In addition absenteeism can significantly disrupt production as there may be no ready replacements available for key jobs. Pressure will be placed upon workers to remain at work even though they are not completely fit for work, leading to presenteeism and consequently loss in productivity. In addition to the threats to routine operation, the loss of management and professional staff can significantly increase catastrophic risk through loss of experience and corporate knowledge. There is increased pressure to focus on events that occur regularly in the here and the now and underestimate the rare, or unlikely, events.The theme of this paper is that by properly addressing OH&S management at mine sites, companies can minimise their exposure to these problems. Put simplistically, a safe and healthy mine is a sustainable and productive mine. Case studies and relevant literature will be used to support this premise.CITATION:Cliff, D and Bailey, K, 2012. Health, safety and sustainability, in Proceedings International Mine Management 2012, pp 53-58 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 20, 2012

By M Recabarren, A Echeverria, J Ronda, J I. Guzman, R Dodds, G Juarez, E Vila-Echague

A strategic mine plan is a fundamental part of any mining operation. It must provide a realistic and operative extraction and processing schedule, and yield the highest value for the business. For open pit mines, the problem can be modelled as a set of blocks representing the deposit, for each of which we need to decide if it is going to be mined, if so, when and where it will be sent (process, stock or dump).This problem can be proven to be of NP-Hard complexity. The traditional approach used by mining engineers to tackle this complexity is to separate the problem into more tractable components, solving each separately. The first step is to use the Lerchs-Grossman (LG) algorithm to obtain the final pit limit, as well as a set of optimised pit shells (nested pits), using different input prices. Then, using this input, operational phases are designed. Third, the set of phases can be used as an input for a phase-bench style optimisation, usually using a mathematical programming-based algorithm.There are, however, several problems with this approach. First, dividing the problem into simpler parts has the consequence that any compromises made at early stages limit the potential value left for the following steps. Second, LG is a static algorithm, with no concept of the time-value of money, capacity limits, opportunity costs, etc. Phase design is essentially a manual step, for which nested pits provide insufficient information in practice, and therefore the quality of the result in terms of potential net present value (NPV) depends strongly on the experience and expertise of the designer. This means that key input data such as commodity prices, different processes capacities and mine movement limits, are considered only at scheduling, when there is little room for optimisation. This sequential approach limits the potential value in each step, where a simplified problem is addressed, instead of addressing the real, and more complex problem, which is dynamic and should be solved as a whole.We present in this paper an algorithm, and its commercial software implementation, that addresses the dynamic problem as a whole, simultaneously and automatically creating a high-value strategic mine plan that adheres to basic operational constraints, determining dynamic cut-off grades and delivering a set of phases which can serve as a much stronger guide than nested pits for the final design. We discuss some of the key elements of the algorithm and propose a new methodology for strategic mine planning, where phase design dynamically responds to mining strategy definition. Results using different mining and operational parameters on a fictitious copper deposit are used as a demonstrative example.CITATION:Juarez, G, Dodds, R, Echeverria, A, Guzman, J I, Recabarren, M, Ronda, J and Vila-Echague, E, 2014. Open pit strategic mine planning with automatic phase generation, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 147–154 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

There is no good news! The market environment for raising capital for resource projects is getting tougher. The regulatory and accounting environment is fast becoming more difficult and the hurdles to successfully raising debt, lease, equity or hybrid finance are now considerably higher. As ever, well structured companies and capital issues can and will survive, if not thrive. An outline of the market and regulatory environment for successful issues is set out below, followed by some comparison of stockmarket values of resource assets compared to more technical appraisals.

Jan 1, 1990

By S Lehane, S Pearce

The characterisation and assessment of waste rock has been the subject of considerable research, and many guidance documents have been published both internationally and within Australia. While these documents provide detailed information on how to characterise waste rock, there is not a great amount of detail on how to determine the optimal waste management options from an operational viewpoint. For example, typical questions that a mine operator would seek answers to include: What placement method should be used (eg end tipping versus paddock dumping)? What is an optimal tip head height for waste placement in a storage facility? How should sulfide grade control be carried out?Defining the contributing factors to waste management and waste material placement and assessing the contribution of each variable directs these assessments towards a semi-qualitative and quantitative methodology. Quantitative methodologies show an increase in the confidence of these assessments by providing logical, measureable assessments.As part of a strategic assessment for waste management at an active mine site, a detailed risk-based investigation of the influence of variables common to waste placement was completed. These variables included placement method, placement height, sulfur grade and material conditioning (eg compaction) on the associated risks of waste material storage. The assessed risks include temperature assessments (potential for thermal take-off as a result of spontaneous combustion), toxic gas production and flow and acid production potential. Applying a numerical modelling approach to the assessment of the different waste material placement strategies allows for the variation in risk to be graphically presented and communicated through risk matrices and histograms.CITATION:Pearce, S and Lehane, S, 2015. Quantitative risk assessment tools to assist with waste management and placement guidelines, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 353–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By M Kim, J Park, I-K Suh, E Kim, J Lee

One of the key technologies in developing hydrogen-enriched ironmaking operations is the control of the carburisation, melting, and dripping behaviour of the iron ore burden materials. When a hot compacted iron (HCI) is charged in the blast furnace or the FINEX Melter-Gasifier, iron oxide reduction, the reduced iron’s carburisation, and the melting of iron and slag occur successively. This study investigated the reduction, carburisation, melting and dripping behaviour of HCI under a COH2 gas mixture using the high-temperature X-ray radiographic technique. Under 100 per cent CO gas atmosphere, the dripping temperature was 1410°C. When 5 per cent H2 was introduced, the dripping temperature slightly decreased to 1400°C. Furthermore, the dripping temperature gradually increased as the H2 gas composition increased. As 30 per cent H2 was introduced, the dripping temperature reached 1414°C. The carbon concentration in the drained metal samples gradually increased with increasing H2 composition. It is considered that H2 decreased FeO content in the slag, yielding the increased melting temperature and viscosity of the slag. On the other hand, H2 accelerated the carburisation of the reduced iron by CO gas, enabling the homogenisation of the oxide materials to form a liquid phase. Therefore, it is considered that introducing H2 in the reactor is helpful to increase productivity and energy efficiency by accelerating the liquid phase’s formation.

Aug 21, 2024

By T Raynlyn, R J. Holmes, J R. Manuel, A Poliakov, L Lu

The prediction of sintering performance of iron ore fines and the possibility of targeted optimisation of specific sinter properties are very important for both the iron ore industry and related research organisations. Physical pilot-scale sinter runs require large amounts of raw materials and are expensive, so it is critical to target large test work programs with many different sintering parameters effectively. To predict values for sintering performance parameters such as tumble index (TI), low temperature reduction disintegration index (RDI) and productivity, a comprehensive database of pilot-scale sintering experimental results has been established and empirical modeling conducted. Similarly to earlier work, physical, chemical and mineralogical characteristics of the iron ores have been considered. However, in contrast to the previous work where only one textural parameter was taken into account, namely the proportion of dense haematite ore texture, the current model includes the abundances of several different textures which were combined into different textural factors corresponding to different sinter properties. Coefficients for the variables within specific regression equations can provide a better understanding of the effect of the variables on the corresponding sintering performance. The modelling results have also been used for predicting the sintering performance of mixtures that were not part of the database used for establishing the models. Comparison of experimental and modeling results for the verification test data is also reported in this paper.

Jan 1, 2009

By H Kurth

High specification Prompt Gamma Neutron Activation Analysis (PGNAA) has been successfully applied to conveyed flows at iron ore operations since 2002 to representatively measure ore quality for improved quality management and process control. While the PGNAA technique has changed little since that time, significant improvements have been made in measurement capability. Elements previously unable to be measured well or at all using this technique are now measurable and one of these is phosphorus. Aluminium and magnesium are also key elements in addition to calcium and silicon in determining sinter basicity in ironmaking. Other elements measured routinely in iron ores include iron, carbon, potassium, sulfur and manganese. The benefits of representative measurement cannot be overstated as iron ore mining operations in South Africa, Europe, Australia, Asia and the Americas have discovered. The technology is applicable to any conveyed flow where elemental analysis in real time assists with quality management, from raw materials in ironmaking through to scrap steel in steelmaking and coal quality for coke-making. Major benefits are realised when raw material processing is optimised and this often includes diversion of material meeting a required quality so it can bypass unnecessary processing. This includes waste rock which can be diverted from a plant feed stream in 30 sec increments or ore that meets product quality being diverted to bypass beneficiation. Analysers are successfully utilised to identify ore types that assist with upgrade optimisation in jig plants; measuring feed, product and discard flows to also account for metal content. Product flows to stockpiles help manage production flows and stockpile qualities for different products and assist in blending ores into trains or ships to confirm specification compliance. Technologies can be used in magnetite processing but are predominantly used in hematite and goethite ore processing operations. The paper details examples of the above applications at various operational sites providing estimates of economic benefit as well as operational improvements.

Sep 18, 2023

By J Lyons, M Hasan, D Pepper, C Vadeikis

Processing of large volumes of ultrafine ores has long challenged mineral processing operators because of lower recoveries and increased tailings. This has led to many deposits, or parts of existing deposits, being viewed as uneconomic. As the mining industry can no longer afford to overlook resources that require finer sizes to achieve liberation or result in high tailings losses, the need for technologies to address these issues has increased. Mineral Technologies (MT) worked with a prominent Australian iron ore producer over five years to implement an innovative gravity separation technology for the beneficiation of ultrafine magnetite. The magnetite mineralisation requires a liberation size of <40 μm and selective rejection of ultrafine silica prior to magnetic separation. Through collaboration with the client, MT applied their Lyons Feed Control Unit (LFCU) technology for the beneficiation of finely grained magnetite. LFCUs are widely used in the mineral sands and iron ore gravity plants, and in tailings applications, to recover water and provide constant high density process streams. This project was an extension of knowledge gained from these applications. Test work was conducted on-site, using 1 t/h pilot and 300 kg/hr laboratory scale units. This test work showed that the LFCUs could reject 20 per cent of feed mass to tails whilst recovering >94 per cent of Fe to product. This upgraded the feed from 53.7 per cent Fe and 19.7 per cent SiO2 to 63.8 per cent Fe and 8.8 per cent SiO2. Recovery by size data showed a minimum 88 per cent Fe recovery to product for <8 μm material and up to 98 per cent Fe recovery for the -38+25 μm fraction. The LFCU rejected 70 per cent of <25 μm SiO2. The information obtained from the test work was utilised in the design of the full-scale units which are due for installation at the project site in 2021. This paper outlines the results of this laboratory and pilot scale test work and how the data obtained was used to design the full-sized units.

Nov 8, 2021

By B McFadzean, N P. Lima, D A. Deglon

The reverse flotation of Itabirite iron ore is typically performed after a desliming step in which most of the sub-10 µm particles are removed. This is done to limit processing problems such as poor flotation recovery of SiO2 due to slime coatings and increased slurry viscosities, unmanageable froths and increased losses of hematite particles due to entrainment. However, the rejection of ultrafine particles contributes to large losses in iron recovery and may contribute to the instability of tailings dams. The aim of this study is to decouple the effects of ultrafine particles in the pulp and froth phases to better understand the processing capabilities of the fines fraction. The flotation test work was performed in a special-purpose continuously operated laboratory flotation cell that has a deep froth section to simulate plant-scale froth conditions. Five conditions of fines addition were investigated at three different froth heights and a solids concentration of 50 per cent. The behaviour of the pulp and the froth were decoupled using froth stability and froth recovery tests. This showed that, even though there is an exponential increase in froth stability at increasing fines quantities, the performance of the pulp has the overriding effect on the overall SiO2 recovery. Pulp zone, froth zone and overall SiO2 recoveries showed that overall recoveries increased by about 3.6 per cent for every 1 per cent decrease in fines content. This meant a large increase of 20 per cent in SiO2 recovery when going from undeslimed to deslimed feed. This was driven largely by increases in the pulp zone recoveries, which were about 4 per cent for every 1 per cent decrease in fines content. The froth recoveries, on the other hand, decreased by between 0.75 per cent and 2.5 per cent for every 1 per cent decrease in fines content, depending on froth height. This paper explores further insights into iron ore flotation processing at different slimes concentrations.

Aug 24, 2022

Sublevel open stoping (S.L.O.S.) was introduced at Rosebery in 1972 in the wider ore blocks below 14 level, largely replacing cut and fill methods which had been in use up till that time. During 1973/74 the method produced 10% of primary stoping tonnes, and by 1981/82 it increased to 65%. Because of the increasing reliance placed on sublevel open stoping for primary stoping production, every effort was made in both planning and operating to: - maximise ore recovery and reduce dilution - increase productivity - reduce costs.

Jan 1, 1982

By M Saghaeian, V Sheikhzadeh, R Hejazi

Mining dilution is one of the most important factors affecting the economy of mining projects. Instead of quantifying dilution in mining studies, it is common to assume a general dilution such as 5 per cent for massive deposits. Dilution increases the operating costs in the plant by increasing the tonnage of material to be milled. It prolongs the mine life by reducing plant’s effective capacity. It also reduces the feed grade. In most cases, lower feed grade means lower plant recovery. Dilution also increases the cut-off grade, which in turn reduces the overall ore utilisation of a mine. In this study has been investigated applying pre-concentration by dry magnetic separation for decreasing of dilution impact on reserve estimation and open pit design in low-grade iron ore mine. Based on the preliminary open pit design and assumption 3 per cent as dilution factor, the mineable ore in life-of-mine (measured + indicated) has been estimated with Fe = 25 per cent, SiO2 = 49.7 per cent. Based on the experimental test work on the ore, by dry low intensity magnetic separation of dry HPGR product grinding circuit, it is possible to remove diluted waste material and liberated gangue before concentrate plant, so that around 34 per cent rejected and Fe grade increase from 25 per cent to 33 per cent and by weight recovery 66 per cent. The results of the test work showed that this methodology could decrease largely the impact of dilution in the feed to the plant. It also slightly effect on the reducing of dilution factor impact for open pit design and optimisation and leads to increase the mineable tonnage in the low-grade magnetite iron ore mine.

Aug 24, 2022

By P Walker, I Crnkovic, D Bennett

The Phu Kham deposit represents a copper-gold porphyry system, with mineralisation present in skarn, stockwork and disseminated styles. Significant folding and alteration events have created a complex heterogeneous mineralogy horizon. Weathering and water table contact have created a leached zone, overlying transition zones with supergene chalcocite- dominant secondary copper mineralisation and clay-rich gangue. Primary ore copper mineralisation is mainly chalcopyrite with minor bornite. The major challenges to the copper-gold flotation process are a wide size distribution of chalcopyrite mineralisation and poor primary grind liberation, a high pyrite content in skarn ore requiring aggressive pyrite depression conditions, clay-rich gangue and non-sulfide copper mineralisation in weathered zones, and a significant association of gold with pyrite.The Phu Kham concentrator has been developed as a conventional semi-autogenous grinding (SAG) and ball milling circuit followed by selective rougher flotation, regrinding and cleaner flotation to produce a copper concentrate containing payable gold and silver values. The concentrator flow sheet design offered a capital efficient compromise between high copper recovery bulk sulfide flotation with large cleaning capacity, and lower recovery copper selective rougher flotation to ensure concentrate specification of 24 per cent copper grade could be achieved. This paper will examine and discuss concentrator flow sheet development, including projects implemented since commissioning to improve copper recovery, and future projects designed to maintain and enhance copper in concentrate production with decreasing copper grade and increasing pyrite content of ore feed, and increasing hardness of primary ore.CITATION:Bennett, D, Crnkovic, I and Walker, P, 2012. Recent process developments at the Phu Kham Copper-Gold Concentrator, Laos, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 257-272 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By D Hillier, A Giblett, K Parker, V Ramsell

Kalgoorlie Consolidation Gold Mines (KCGM) operates the Kalgoorlie Super Pit open cut, Mt Charlotte underground mine, Fimiston process plant and Gidji Roaster facility for joint venture partners Newmont Mining Corporation and Barrick Gold. In 2004, the Fimiston plant was upgraded by the addition of gravity concentration to the Fimiston and Mt Charlotte grinding circuits, including the installation of a central intensive cyanidation reactor to process the gravity concentrates. The gravity project was justified after detailed analysis demonstrating an expected increase in overall gold recovery of approximately one per cent, in addition to reduced elution costs and reduced gold inventory in flotation concentrate stockpiles. The gravity circuits were commissioned in August 2004, and have since consistently recovered 10 to 20 per cent of the gold present in the KCGM ore, delivering a reduction in coarse gold losses equivalent to 0.45 per cent additional metal recovery and contributing to improved metal accountability.CITATION:Giblett, A, Hillier, D, Parker, K and Ramsell, V, 2012. The impact of gravity gold recovery at Kalgoorlie Consolidated Gold Mines, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 199-206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Nicol SK, Engel MD

Ion flotation involves the adsorption of ionic species, in association with surfactant molecules, at the surface of rising gas bubbles, for the purpose of recovering and concentrating those ions. The objective of this study was to optimise the ion flotation process using a heap-leach liquor, containing gold cyanide, and the surfactant cetyl trimethyl ammonium bromide (CTAB). The aim was to minimise the surfactant reagent dose, maximise the throughput of feed liquor in the process, and satisfy the dual constraints of a high gold recovery and a high volume reduction factor. Development of a first order model of the ion flotation process formed the theoretical basis for the test program procedure and the interpretation of the results. Batch tests were used in order to determine the ultimate recovery curve for the heap leach liquor-CTAB surfactant system. The results indicated that a surfactant dose of about 0.083 g/l would be necessary in order to achieve a satisfactory gold recovery. Continuous tests were then performed on a small-scale pilot plant at the Newcastle Laboratories. The optimum result achieved was a gold recovery of 85 per cent, a volume reduction factor of ten, and a feed throughput of 2.3 m3/m2-h. Recent work also indicates that very much higher volume reductions can be achieved using a larger diameter vessel. The improvement may be a consequence of a reduction in wall effects and hence an improvement in foam drainage.

Jan 1, 1993

By A N. Parry, G van Wyk

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

Oct 10, 2016

By H Thanasekaran, M J. Mankosa, J N. Kohmuench, G H. Luttrell

"Fluidised-bed flotation has been demonstrated over the last 16 years as an effective method for improving the flotation recovery of coarse particles. This technology has been successfully deployed into the industrial mineral sector with multiple installations within phosphate beneficiation plants and potash mills. Due to the minimal mineral surface expression required when utilising this technology, more recent studies have centred on the applicability of using this HydroFloat&#8482; technology for the recovery of coarse sulfides and base metals. Multiple approaches have been investigated to determine the best means for implementing this novel coarse particle flotation system into both existing and new plant circuitry. These include the treatment of tailings to recover values that have been lost using conventional technologies and also the direct treatment of a coarse feed, either within the grinding circuit or by use of a separate split-feed flotation approach. Recent applications of the technology will be presented along with data generated from several test campaigns and ongoing research investigations. The benefits of properly applying this technology, such as reduced power consumption and increased mill capacity will be discussed.Citation:Kohmuench, J N, Thanasekaran, H, Mankosa, M J and Luttrell, G H, 2016. The Impact of Fluidised-bed Flotation for Treating Coarse Sulfides, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 105&ndash;112 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By J Herrmann, J Richards, B Hutchison

An extensive trial of laser-based survey and monitoring systems at Hillgrove Resources Kanmantoo Copper Mine in the Adelaide Hills, South Australia, has proved the capabilities of the system in monitoring rock movements on open pit walls. Initially, the trial involved deploying a Maptek I-Site 8820 laser scanner and the proof-of-concept Maptek Sentry software in the Nugent Pit to monitor ductile rock movements located up to 260 m away. The system was proven to be capable of monitoring various rock movements from 1.5 tonne rockfalls up to a 40 m high toppling wall failure. Data collected from smaller rockfalls was used to help build a database for Hillgrove’s rockfall management program. As part of the trial, the laser scanner was deployed to monitor a ramp movement event, as well as the toppling failure, adjacent to an IBIS slope stability radar. Both devices monitored the slump and the slowly developing toppling movements, with similar results. Although the radar was used as the successful ‘critical alarm’ device for the toppling failure, post-failure analysis showed the laser-based system to be capable of performing a similar role in the ductile rock regime; albeit over much shorter distances than the radar capability. A second laser scanner was deployed to monitor Kanmantoo’s Emily Pit in early December 2014, where it successfully provided critical alarm warnings for a block topple event. Sentry software, which takes advantage of Maptek I-Site 3D spatial imaging technology, was first released in November 2014 to meet industry demand for a cost effective, flexible system to detect movement. Sentry has now been re-launched as a fully transportable monitoring system. Deployed in a custom trailer, the system offers a power and communications module, cellular and Wi-Fi networking and a stable bollard for the I-Site laser scanner and Sentry software. This paper will present rock wall movement data from the Sentry trial and a subsequent two years of monitoring of the open pit walls at the Kanmantoo Copper Mine, at distances out to 750m. In addition, examples of remote geological mapping and small rockfall detection, using the laser scans, will be described. The Sentry system has proven to be beneficial for the continual improvement of slope monitoring and risk management at hard rock mines. CITATION:Hutchison, B, Richards, J, Richards, J and Herrmann, J, 2018. Mine rockfall and rock wall failures – proven digital laser-based approach for monitoring slopes at the Kanmantoo Copper Mine, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 463–472 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By P M. Hetherington, M P. Murphy, K E. Crook, F Pym

Resource characterisation is critical for informed decisions in both strategic and operational space. The sources of information for resource characterisation are limited by: direct measurement of resource attributes, such as grades, rock-types, mineralogy, and are available only from sparse locations, ie drill holes; or indirect geophysical measurements such as seismic, gravity or electro[1]magnetic survey. Data collection tools, methods, and processing technologies are constantly improving providing a broad spectrum of options for data collection strategies. The cost of each data survey varies from thousands to millions of dollars with the value of each additional data having diminishing return for a particular business decision. The value of information analysis provides the optimal decision on data collection strategy within a limited available budget. This work presents an example of value of information analysis for new Blast Hole Assay Tool (BHAT) and Reverse Circulation Grade Control (RCGC) data used in addition to the wider spaced exploration data. The value of information is quantified in terms of reduction of grade uncertainty, ore loss and dilution by comparing different combinations of data collection methods. Four different strategies were considered: exploration samples in addition to 50 per cent of blastholes surveyed with BHAT, exploration samples in addition to 33 per cent of blastholes surveyed with BHAT, exploration with wide-spaced RCGC data, and exploration without additional grade control. For each strategy the observed values have been simulated using advanced multivariate geostatistical simulations and compared with simulated ground truth models. The calculated uncertainty, ore loss and dilution informed the optimal data collection strategy. Opportunity to reduce sample density from the nominal 50 per cent of drill holes was evaluated.

Mar 22, 2022